title: Regulation of electrical transmission by protein kinase C in Aplysia bag cell neurons

contributor:
Magoski, Neil S.
Biomedical and Molecular Sciences

subject:
bag cell neurons
PKC
gap junction
electrical transmission modulation
PMA

abstract: Electrical synapses are composed of gap junctions, made from paired hemi-channels that allow for the transfer of current from one neuron to another. Gap junctions mediate electrical transmission in neurons, where they synchronize spiking and promote rapid transmission, thereby influencing the coordination, pattern, and frequency of firing.  In the marine snail, Aplysia calfornica, two clusters of neuroendocrine bag cell neurons use electrical synapses to synchronize a 30-min burst of action potentials, known as the afterdischarge, which releases egg-laying hormone and induces reproduction. In culture, paired bag cell neurons present a junctional conductance that is non-rectifying and largely voltage-independent. During the afterdischarge, PKC is activated, which is known to increase voltage-gated Ca2+ current; yet, little is understood as to how this pathway impacts electrical transmission. The transfer of presynaptic spike-like waveforms (generated in voltage-clamp) to the postsynaptic cell (measured in current-clamp) was monitored with or without PKC activation. It was found that pretreatment with the PKC activator, phorbol-12-myristate-13-acetate (PMA), enhanced junctional conductance between bag cell neurons. Furthermore, in control, presynaptic action potential waveforms mainly evoked postsynaptic electrotonic potentials at both -60 and -40 mV. However, with PKC activation the presynaptic stimulus consistently elicited postsynaptic action potentials from resting potentials of -40 mV, and would occasionally result in firing from repetitive input at -60 mV. Moreover, to assess whether this enhanced electrical transmission genuinely reflects a greater junctional conductance or a change in postsynaptic responsiveness, a fast-phase junctional-like current was applied to single bag cell neurons. Neurons in PMA always fired action potentials in response to current injection as opposed to control, which were less likely to spike. This outcome did not change when the junctional-like current was artificially enhanced in control conditions. Also, in response to fast- and slow-phase electrotonic potential (ETP) waveforms, Ca2+ current was markedly larger in single PMA-treated neurons. These findings suggest that PKC activation may contribute to afterdischarge fidelity by recruiting postsynaptic Ca2+ current to promote synchronous network firing. Finally, Aplysia gap junction genes (innexins) were transfected into mouse N2A cells and characterized. This revealed a biophysical and pharmacological profile similar to native gap junctions.

abstract: M.Sc.


title: From Genes to Genomes: Local Adaptation and Adaptive Potential in Two Arctic Seabirds

contributor:
Friesen, Vicki L.
Biology

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.

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Arctic
Genomics
Local Adaptation
Murres
Uria Aalge
Uria Lomvia

abstract:
By investigating the mechanisms underlying the evolution and the maintenance of local adaptations we can help predict how species will adapt to future environmental change. In this thesis I investigate local adaptation and adaptive potential in thick-billed and common murres (Uria lomvia and U. aalge), two arctic seabirds of international conservation concern. Thanks to the recent development of new genomic methods, I address three major themes that are relevant for both the development of evolutionary theory and conservation: 1) the role of gene flow in the origin and maintenance of adaptation; 2) levels and distribution of standing genetic variation, and their contribution to adaptive potential; and 3) the genomic mechanisms maintaining an adaptive dimorphism within a single interbreeding population.
First, I review the literature on genomics of local adaptation with gene flow and find that adaptation can be maintained despite gene flow, that gene flow itself can promote adaptation, and that genetic architecture is important in the origin and maintenance of local adaptations.
Second, I genotype genome-wide markers and toll-like receptor genes (TLRs) to investigate local adaptation and adaptive potential in thick-billed murres. Thick-billed murres do not show signatures of local adaptation to their breeding grounds, but outlier loci group birds according to their non-breeding distributions, suggesting that selection and/or demographic connectivity in the winter may explain patterns of differentiation in this species. Genetic variation at TLRs does not decrease with increasing latitude as predicted, but tests of selection and measures of genetic diversity suggest differences in local selective regimes at most genes. Thick-billed murres show high levels of standing genetic variation and their adaptive potential will mostly depend on rate and magnitude of environmental change.
Finally, I improve and annotate the assembly of the highly heterozygous genome of the thick-billed murre. Using this assembly as a reference, I perform whole genome analyses to investigate the genomic basis of an adaptive dimorphism in Atlantic common murres. I show for the first time that a 60 kb complex copy number variant in a non-coding region maintains differences in plumage and cold adaptation despite high gene flow.

abstract: PhD


title: Landscape Patterns of Permafrost Disturbance and Degradation in the Canadian High Arctic

contributor:
Lamoureux, Scott F.
Geography and Planning

subject:
Permafrost Degradation
Permafrost Disturbance
Canadian High Arctic
Susceptibility Modelling
Remote Sensing
Interferometry

abstract: Intensification of permafrost disturbances such as active layer detachments (ALDs) and retrogressive thaw slumps (RTS) have been observed across the circumpolar Arctic. These features are indicators of unstable conditions stemming from recent climate warming and permafrost degradation. In order to understand the processes interacting to give rise to these features, a multidisciplinary approach is required; i.e., interactions between geomorphology, hydrology, vegetation and ground thermal conditions. The goal of this research is to detect and map permafrost disturbance, predict landscape controls over disturbance and determine approaches for monitoring disturbance, all with the goal of contributing to the mitigation of permafrost hazards. Permafrost disturbance inventories were created by applying semi-automatic change detection techniques to IKONOS satellite imagery collected at the Cape Bounty Arctic Watershed Observatory (CBAWO). These methods provide a means to estimate the spatial distribution of permafrost disturbances for a given area for use as an input in susceptibility modelling. Permafrost disturbance susceptibility models were then developed using generalized additive and generalized linear models (GAM, GLM) fitted to disturbed and undisturbed locations and relevant GIS-derived predictor variables (slope, potential solar radiation, elevation). These models successfully delineated areas across the landscape that were susceptible to disturbances locally and regionally when transferred to an independent validation location. Permafrost disturbance susceptibility models are a first-order assessment of landscape susceptibility and are promising for designing land management strategies for remote permafrost regions. Additionally, geomorphic patterns associated with higher susceptibility provide important knowledge about processes associated with the initiation of disturbances. Permafrost degradation was analyzed at the CBAWO using differential interferometric synthetic aperture radar (DInSAR). Active-layer dynamics were interpreted using inter-seasonal and intra-seasonal displacement measurements and highlight the importance of hydroclimatic factors on active layer change.  Collectively, these research approaches contribute to permafrost monitoring and the assessment of landscape-scale vulnerability in order to develop permafrost disturbance mitigation strategies.

abstract: PhD


title: Cold Acclimation of Chill Coma Mechanisms in the Locust CNS

contributor:
Robertson, Mel
Biology

subject:
Locust
Insect
Chill Coma
CNS
Potassium
Neurophysiology
Cold Acclimation
Rapid Cold Hardening
RCH

abstract: Temperature has profound effects on the neural function and behaviour of insects. When exposed to low temperature, migratory locusts (Locusta migratoria) enter chill coma (neuromuscular paralysis) and can resume normal body functions after returning to normal temperature. Our laboratory has studied phenomena underlying environmental stress-induced comas in locusts and found that they are associated with a sudden loss of K+ homeostasis and also a temporary electrical silence in the central nervous system (CNS). However, the mechanisms underlying chill coma entry and recovery are not well understood, particularly the role of the CNS has not been determined. Here, I investigated neural function during chill coma in the locust by measuring electrical activity in the CNS. As pre-exposure to moderately low temperatures, either chronically (cold acclimation) or acutely (rapid cold hardening; RCH), has been found to improve the insect’s cold tolerance, I also determined cold acclimation and RCH protocols that will improve the locust's cold tolerance and whether these protocols affect neural shutdown during chill coma in the locust. With an implanted thermocouple in the thorax, I determined the temperature associated with a loss of responsiveness (CTmin) in intact male adult locusts. In parallel experiments, I recorded field potential (FP) in the metathoracic ganglion (MTG) in semi-intact preparations to determine the temperature that would induce neural shutdown. I found that acclimation at 10 ˚C and RCH at 4 ˚C reduced chill coma recovery time (CCRT) in intact animal preparations and RCH at 4 ˚C for 4 hours reduced the temperature at neural shutdown in semi-intact preparations. These results suggest that pre-exposure to cold can improve the locust's resistance to chill coma and support the notion that the CNS has a role in determining entry into and exit from chill coma in locusts.

abstract: M.Sc.


title: Role of the Frontal Eye Field, Superior Colliculus, and Basal Ganglia in Flexible Saccade Behavior

contributor:
Munoz, Douglas P.
Neuroscience Studies

subject:
Frontal Eye Field
Superior Colliculus
Subthalamic Nucleus
Caudate Nucleus
Substantia nigra pars reticulata
Saccade Initiation
Pro-saccade
Anti-saccade
Free Viewing
Basal ganglia
Saccade Threshold
Saccade

abstract: A distributed network of cortical and subcortical brain regions mediates the control of voluntary behavior, but it is unclear how this complex system may flexibly shift between different behavioral events. This thesis describes the neurophysiological changes in several key nuclei across the brain during flexible behavior, using saccadic eye movements in rhesus macaque monkeys. We examined five nuclei critical for saccade initiation and modulation: the frontal eye field (FEF) in the cerebral cortex, the subthalamic nucleus (STN), caudate nucleus (CD), and substantia nigra pars reticulata (SNr) in the basal ganglia (BG), and the superior colliculus (SC) in the midbrain. The first study tested whether a ‘threshold’ theory of how neuronal activity cues saccade initiation is consistent with the flexible control of behavior. The theory suggests there is a fixed level of FEF and SC neuronal activation at which saccades are initiated. Our results provide strong evidence against a fixed saccade threshold in either structure during flexible behavior, and indicate that threshold variability might depend on the level of inhibitory signals applied to the FEF or SC. The next two studies investigated the BG network as a likely candidate to modulate a saccade initiation mechanism, based on strong inhibitory output signals from the BG to the FEF and SC. We investigated the STN and CD (BG input), and the SNr (BG oculomotor output) to examine changes across the BG network. This revealed robust task-contingent shifts in BG signaling (Chapter 3), which uniquely impacted saccade initiation according to behavioral condition (Chapters 3 and 4). The thesis concludes with a published short review of the mechanistic effects of BG deep brain stimulation (Chapter 5), and a general discussion including proof of concept saccade behavioral changes in an MPTP-induced Parkinsonian model (Chapter 6). The studies presented here demonstrate that the conditions for saccade initiation by the FEF and SC vary according to behavioral condition, while simultaneously, large-scale task dependent shifts occur in BG signaling consistent with the observed modulation of FEF and SC activity. Taken together, these describe a mechanistic framework by which the cortico-BG loop may contribute to the flexible control of behavior.

abstract: PhD


title: Exploring the Experience of Teachers Working with Exceptional Learners

contributor:
Berg, Derek
Education

subject:
Teachers
Exceptionalities
Thriving
Burnout
Compassion Fatigue

abstract:
Regular classroom teachers, who often report that they lack adequate training and resources, increasingly find themselves supporting students with special education needs (Connelly & Graham, 2009). Teachers working in challenging environments can thrive in their role and continue to experience professional growth and passion about their work with students with exceptionalities (Perry, Brenner, Collie, & Hofer, 2015). Thriving is one framework of psychological wellness that can provide insight into the experiences of teachers working with exceptional learners (Spreitzer & Porath, 2014). Chronic stress from occupational demands such as heavy workload and insufficient resources can negatively affect the wellbeing of teachers and lead to poor mental health (Desrumaux et al., 2015). Burnout and compassion fatigue are two constructs of poor mental health that can inform our understanding of teachers’ social and emotional experiences.
The purpose of this study was to explore the social and emotional experiences of teachers working with exceptional learners in regular classrooms. The objective of this study was to describe the elements within teachers’ professional roles that they report contribute to their social and emotional experiences understood through the lenses of thriving, burnout, and compassion fatigue. Interviews were conducted with five teachers: one full-time in-service teacher and four teachers who are pursuing graduate studies in education. The theme of thriving emerged as a significant component of the interview with all five participants. All five participants described experiences of vitality and learning as essential to their workplace satisfaction and overall thriving. Although the data from this study did not suggest that participants were experiencing burnout or compassion fatigue, elements of the two constructs did emerge as relevant to the social-emotional experiences of the teachers.

abstract: M.Ed.


title: Proline-Based Chiral Stationary Phases: Insights Into the Mechanism of Chiral Selectivity

contributor:
Horton, J. Hugh
Chemistry

subject:
Chiral Stationary Phases
Chemical Force Spectrometry
Chemical Force Titration
Chiral Selectivity
XPS
AFM

abstract:
Proline (Pro) is a unique amino acid that has been examined previously as a potential chiral selector for high-performance liquid chromatography. In recent years, a new class of promising Pro based enantioselective stationary phases has been studied and the longer peptides were found to be competitive with commercial chiral stationary phases (CSPs).
Here, we aim to perform a comprehensive examination of a t-butoxycarbonyl- (t-Boc-) terminated monoproline selector. This selector was grafted through an amide linkage to an aminopropyl siloxane-terminated Si (111) wafer and to a silicon atomic force microscopy tip. To ensure a flat, homogeneous overlayer of selectors suitable for force spectrometric measurements, the prepared surfaces were characterized using XPS, AFM and contact angle measurements.
Chemical force spectrometry (CFS) has been used to examine the chiral discrimination in our monoproline CSP by measuring the interaction forces between two D- or L-monoproline monolayers in water and in the presence of a series of amino acids in solution to explore the degree to which binding of amino acids impacts self-selectivity.
Chemical force titration (CFT) has been used to observe the influence of variations in pH on the binding interaction of proline modified chiral surfaces. Here we aim to explore the connection between side-chain hydrophobicity and differences in the nature of the binding between different ionic forms of amino acids and the t-Boc-Pro interface, and thereby to gain insight into the mechanism of chiral selectivity.
The CFS results show several trends for different proline selector/amino acid combinations and indicate that the binding characteristics of amino acid to the proline surface is strongly dependent on the amino acid side chain where hydrophilic side chain amino acids exhibit a selectivity opposite to that seen for those with hydrophobic side chains.
The CFT studies also provide valuable insights into interactions between the proline selector and the amino acids under a wide range of pH conditions, indicating that protonated amine groups of alanine and serine are closely involved in the binding mechanism to proline surfaces. On the other hand, the presence of the second carboxylic group in aspartic acid plays an important role while interacting with proline.

abstract: PhD


title: Investigative Comparison of Tank and Recovered Asphalt Samples Through Physical Performance Testing and Chemical Analysis

contributor:
Hesp, Simon
Chemistry

subject:
Comparison
Tank
Recovered
Asphalt Binder
Performance Testing
Chemical Analysis

abstract:
Despite the development of improved performance test protocols by renowned researchers, there are still road networks which experience premature cracking and failure. One area of major concern in asphalt science and technology, especially in cold regions in Canada is thermal (low temperature) cracking. Usually right after winter periods, severe cracks are seen on poorly designed road networks. Quality assurance tests based on improved asphalt performance protocols have been implemented by government agencies to ensure that roads being constructed are at the required standard but asphalt binders that pass these quality assurance tests still crack prematurely. While it would be easy to question the competence of the quality assurance test protocols, it should be noted that performance tests which are being used and were repeated in this study, namely the extended bending beam rheometer (EBBR) test, double edge-notched tension test (DENT), dynamic shear rheometer (DSR) test and X-ray fluorescence (XRF) analysis have all been verified and proven to successfully predict asphalt pavement behaviour in the field. Hence this study looked to probe and test the quality and authenticity of the asphalt binders being used for road paving. This study covered thermal cracking and physical hardening phenomenon by comparing results from testing asphalt binder samples obtained from the storage ‘tank’ prior to paving (tank samples) and recovered samples for the same contracts with aim of explaining why asphalt binders that have passed quality assurance tests are still prone to fail prematurely.
The study also attempted to find out if the short testing time and automated procedure of torsion bar experiments can replace the established but tedious procedure of the EBBR.
In the end, it was discovered that significant differences in performance and composition exist between tank and recovered samples for the same contracts. Torsion bar experimental data also indicated some promise in predicting physical hardening.

abstract: M.Sc.


title: Clashes in Confinement: Men's Gendered Experiences with Conflict in Canadian Prisons

contributor:
Sacco, Vincent F.
Sociology

subject:
Prison
Masculinities
Qualitative Interviewing
Gender
Conflict
Violence
Sociology
Criminology
Pain of Imprisonment
Snowball Sampling
Research Ethics

abstract: This dissertation presents the results of in-depth qualitative interviews with twenty-three formerly imprisoned men regarding their lived experience with prison conflict and the pain of incarceration. The results suggest that prison is a gendered ‘total institution’ (Goffman 1961). The pains that men experience in prison are uniquely gendered in that the deprivations imposed by incarceration– deprivation of autonomy, liberty, goods and services, heterosexual sex, and security (Sykes 1958) – in the reverse, define idealized masculinity as it is currently socially constructed: self-reliance, independence, toughness or invulnerability, material and economic success, and heterosexual prowess. From these shared deprivations emerges a gendered code of conduct that perpetuates a hierarchy among incarcerated men by constructing violent masculinity as a subcultural norm. The results suggest that the gender code in prison represents a set of rules that create opportunities for men to police each other’s gender performance and make claims to masculine statuses. Because status is inextricably tied to survival in this context, many men feel pressured to perform violent masculinities in prison despite privately subscribing to a non-violent sense of self-concept. The results suggest that violence is an expressive and instrumental resource for men in prison. A gender theory of prison violence, methodological findings, theoretical implications, ethical considerations and the short and long term aftermath of violent prison conflict are discussed.

abstract: PhD


title: Classifying And Predicting Software Security Vulnerabilities based on Reproducibility

contributor:
Zulkernine, Mohammad
Computing

subject:
Vulnerability
Security Failure
Hard to Reproduce Vulnerability
Vulnerability Classification
Software Metrics
Vulnerability Prediction
Machine Learning

abstract:
Security defects are common in large software systems because of their size and complexity. Although efficient development processes, testing, and maintenance policies are applied to software systems, there are still a large number of vulnerabilities that can remain, despite these measures.

Some vulnerabilities stay in a system from one release to the next one because they cannot be easily reproduced through testing. These vulnerabilities endanger the security of the systems.
We propose vulnerability classification and prediction frameworks based on vulnerability reproducibility. The frameworks are effective to identify the types and locations of vulnerabilities in the earlier stage, and improve the security of software in the next versions (referred to as releases).

We expand an existing concept of software bug classification to vulnerability classification (easily reproducible and hard to reproduce) to develop a classification framework for differentiating between these vulnerabilities based on code fixes and textual reports. We then investigate the potential correlations between the vulnerability categories and the classical software metrics and some other runtime environmental factors of reproducibility to develop a vulnerability prediction framework.

The classification and prediction frameworks help developers adopt corresponding mitigation or elimination actions and develop appropriate test cases. Also, the vulnerability prediction framework is of great help for security experts focus their effort on the top-ranked vulnerability-prone files. As a result, the frameworks decrease the number of attacks that exploit security vulnerabilities in the next versions of the software.

To build the classification and prediction frameworks, different machine learning techniques (C4.5 Decision Tree, Random Forest, Logistic Regression, and Naive Bayes) are employed. The effectiveness of the proposed frameworks is assessed based on collected software security defects of Mozilla Firefox.

abstract: M.Sc.


title: Study of the Electrochemical, Physical and Morphological Characteristics of Anode Catalysts for Perfluorosulfonic Acid (PFSA) Membrane Water Electrolysers

contributor:
Peppley, Brant A.
Chemical Engineering

subject: Iridium Based Electrocatalyst

subject: PEM Water Electrolysis

subject: Oxygen Evolution Reaction Electrocatalyst

subject: Polyol Synthesis

subject: Support Materials OER electrocatalyst

abstract:
A number of supported and un-supported Oxygen Evolution Reaction (OER) iridium based electrocatalysts for Polymer Electrolyte Membrane Water Electrolysis (PEMWE) were synthesized using a polyol method. The electrocatalysts and the supports were characterized using a wide range of physical and electrochemical characterization methods.  The effect of morphological characteristics of the OER electrocatalyst and the support on the OER activity was studied. The results of this thesis contribute to the existing research to reduce the cost of PEMWE by enhancing the utilization of precious metal for OER electrocatalysis.
Iridium electrocatalysts supported on antimony tin oxide (Ir/ATO) were synthesized using the polyol method with two different heating techniques: conventional and microwave-irradiation. It was shown that the physical morphology and electrochemical properties of Ir/ATO synthesized with the two heating methods were comparable. However, the microwave irradiation method was extremely faster than the conventional heating method.
Additionally, the effect of heat treatment (calcination temperature) on the morphology and OER activity of Ir/ATO synthesized electrocatalyst with the conventional polyol method. It was found that the iridium electrocatalyst synthesized with the polyol method, consisted of 1-5 nm particles, possessed an amorphous structure, and contained iridium with an average oxidation state of less than +4. Calcining the catalyst at temperatures more than 400 ºC and less than 700ºC: 1) increased the size of the iridium particles to 30 nm, 2) changed the structure of iridium particles from amorphous to crystalline, 3) increased the iridium oxidation state to +4 (IrO2), 4) reduced the electrochemically active surface area by approximately 50%, and 5) reduced the OER activity by approximately 25%; however, it had no significant effect on the physical and chemical morphology of the ATO support.
Moreover, potential support metal carbides and oxides including: Tantalum Carbide (TaC), Niobium Oxide (Nb2O5), Niobium Carbide (NbC), Titanium Carbide (TiC), Tungsten Carbide (WC) and Antimony-doped Tin Oxide (ATO, Sb2O5-SnO2), were characterized, and used as support for the iridium OER electrocatalysts. TaC was found to be a promising support, and increasing its surface area by 4% improved the OER performance of the final supported catalyst by approximately 50%.

abstract: PhD


title: Successful Aging with Illness

contributor:
Beamish, Rob
Sociology

subject:
Social Determinants of Health
Resilience
Engagement
Gender

abstract:
In twenty years almost one in four Canadians will be over the age of 65. How successfully these people age will influence their quality of life and contribute to their physical health. Illness and disease are frequent components of aging; however, ‘successful aging’ research normally excludes people with illness. Older people living with illness, even life threatening illness, often self-report a good quality of life and continue to experience psychological well-being and a significant engagement in social life. This dissertation uses a three manuscript approach to examine successful aging among people with illness.
The first manuscript employed a scoping review to examine the models used in recent successful aging research, compiling the most frequently used constructs which included: engagement, optimism and/or positive attitude, resilience, spirituality and/or religiosity, self-efficacy and/or self-esteem, and gerotranscendence.
The second manuscript utilized data gathered via interviews (online or in person) with people over the age of 65 years living with illness. The majority of these participants reported success in aging; only resilience was predictive in the binomial regression analysis.
The third manuscript examined the role of social determinants of health on successful aging. The analysis revealed that disengagement from community-activities showed a significant association with higher self-reported successful aging. The best fitting model for predicting rate of successful aging with illness was a linear combination of participants’ ageism score and community activity score, while controlling for gender and age.
When considered together, the results from these three manuscripts suggest that successful aging can be experienced by older adults aging with illness. And that, among these older adults, resilience, community interaction and ageism may all play a part in determining the extent to which aging is experienced as successful. Recommendations include the suggestion that we embrace the idea that people with illness can self-define as successful agers. Further, since some of the associated constructs (e.g. resilience) can be fostered, successful aging could be bolstered by education or programs to build skills along with the usual treatment modalities for the illnesses that co-exist.

abstract: PhD


title: Expanding our Constitutional Horizons: A Comprehensive Study of Quasi-Constitutionality in Canada

contributor:
Walters, Mark D.
Law

subject:
Quasi-Constitutionality
Quasi-Constitutional Law
Administrative Law
Constitutional Theory
Statutory Interpretation
Constitutional Interpretation
Human Rights
Access to Information
Privacy Legislation
Language Rights
Judicial Review
Legislative Supremacy
Parliamentary Supremacy
Parliamentary Sovereignty
Fundamental Law
Manner and Form
Primacy Provisions
Declarations of Inoperability
Inoperable

abstract:
A number of laws in Canada which uphold rights are referred to as quasi-constitutional by the courts in recognition of their special importance. Quasi-constitutional statutes are enacted through the regular legislative process, although they are being interpreted and applied in a fashion which has become remarkably similar to constitutional law, and are therefore having an important affect over other legislation. Quasi-constitutionality has surprisingly received limited scholarly attention, and very few serious attempts at explaining its significance have been made. This dissertation undertakes a comprehensive study of quasi-constitutionality which considers its theoretical basis, its interpretation and legal significance, as well as its similarities to comparable forms of law in other Commonwealth jurisdictions.

Part I examines the theoretical basis of quasi-constitutionality and its relationship to the Constitution. As a statutory and common law form of fundamental law, quasi-constitutionality is shown to signify an association with the Canadian Constitution and the foundational principles that underpin it. Part II proceeds to consider the special rules of interpretation applied to quasi-constitutional legislation, the basis of this interpretative approach, and the connection between the interpretation of similar provisions in quasi-constitutional legislation and the Constitution. As a statutory form of fundamental law, quasi-constitutional legislation is given a broad, liberal and purposive interpretation which significantly expands the rights which they protect. The theoretical basis of this approach is found in both the fundamental nature of the rights upheld by quasi-constitutional legislation as well as legislative intent. Part III explores how quasi-constitutional statutes affect the interpretation of regular legislation and how they are used for the purposes of judicial review. Quasi-constitutional legislation has a significant influence over regular statutes in the interpretative exercise, which in some instances results in conflicting statutes being declared inoperable. The basis of this form of judicial review is demonstrated to be rooted in statutory interpretation, and as such it provides an interesting model of rights protection and judicial review that is not conflated to constitutional and judicial supremacy.

abstract: PhD


title: Retro-Neoliberalism: Elite Counter-Protest in Latin America, 1940-1975

contributor:
Lovell, W. George
Geography and Planning

subject:
neoliberalism
Latin America
Mont Pèlerin Society
think-tanks

abstract: This research challenges the origin story of neoliberalism in Latin America. Drawing on archival data from the Mont Pèlerin Society and the personal archives of leading but neglected figures in the post-war push to rebuild economic liberalism, I present a historical geography of elite counter-protest that both predates and broadens the generally accepted “birth” of neoliberalism in 1970s Chile. Beginning in the 1940s, Latin American elites found common cause with key figures from economic liberalism’s most radical wing: the Austrian School. While existing literature links the onset of neoliberalism in Chile to the Austrian School, particularly with respect to the School’s influence on the early Mont Pèlerin Society, this dissertation is the first comprehensive inquiry to place the Austrian tradition in the ideational and organizational landscape of Latin America. Embracing a new mission that promised to save the soul of Western civilization, Latin America’s retro-neoliberal leaders collaborated with transnational actors to build a network of Austrian-inspired think-tanks and institutes of higher learning in the region. These organizations, in turn, served as recruiting mechanisms to found the Hispanic quarter of the Mont Pèlerin Society, which was dominated not (as might be assumed) by Chileans, but rather by retro-neoliberal elites from Mexico, Argentina, Guatemala, and Venezuela. By 1975, when scholars began analyzing how a run-of-the-mill economics department had been transformed into a bastion of free-market thinking in Chile, an entire neoliberal university was up and running in Guatemala, exposing all students, regardless of discipline, to the Austrian tradition – the crowning achievement of Latin America’s retro-neoliberal network. Investigating, and accounting for, the development and impact of this initiative sheds new light on the neoliberal landscape in Latin America, and raises important questions for the study of neoliberalism more broadly.

abstract: PhD


title: The "Write" Way: Creative Writing as a School-based Approach to Treat Childhood and Adolescent Anxiety

subject:
child
adolescent
anxiety
creative writing
school-based
treatment
teacher resource
mental health
intervention

abstract: This project identifies the need for school-based mental health interventions that address the emotional, psychological, and social challenges that accompany childhood and adolescent anxiety. A review of the literature demonstrated that, despite the existence of “what works” criteria established through years of research, school-based mental health initiatives aimed at addressing disorders like anxiety are falling short of desired outcomes. Given the evidence that creative writing interventions such as bibliotherapy, expressive writing, and therapeutic stories can have a significant impact on anxiety disorders and related issues, this project endeavoured to synthesize the evidence and give practical use recommendations for these techniques in a comprehensive teacher resource booklet. Future recommendations involve the need for educators and mental health professionals to consider schools as viable alternatives to traditional treatment delivery settings. Additionally, universal, preventative, evidence-based approaches that follow the established criteria of “what works” should be implemented to ensure program and intervention effectiveness.


title: Fish Distributions in Lake Ontario's Eastern Basin and the Upper St. Lawrence River: An Analysis Using GIS and Occupancy Modelling Techniques

contributor:
Tufts, Bruce L.
Biology

subject:
Fisheries
Ecology
Lake Ontario
St. Lawrence River
Round Goby
Yellow Perch
Sunfish
Occupancy modelling
Biology
Conservation

abstract: Predictive models of species distributions are important tools for fisheries management. Unfortunately, these predictive models can be difficult to perform on large waterbodies where fish are difficult to detect and exhaustive sampling is not possible. In recent years the development of Geographic Information Systems (GIS) and new occupancy modelling techniques has improved our ability to predict distributions across landscapes as well as account for imperfect detection.  I surveyed the nearshore fish community at 105 sites between Kingston, Ontario and Rockport, Ontario with the objective of modelling geographic and environmental characteristics associated with littoral fish distributions. Occupancy modelling was performed on Round Goby, Yellow perch, and Lepomis spp. Modelling with geographic and environmental covariates revealed the effect of shoreline exposure on nearshore habitat characteristics and the occupancy of Round Goby. Yellow Perch, and Lepomis spp. occupancy was most strongly associated negatively with distance to a wetland. These results are consistent with past research on large lake systems indicate the importance of wetlands and shoreline exposure in determining the fish community of the littoral zone.  By examining 3 species with varying rates of occupancy and detection, this study was also able to demonstrate the variable utility of occupancy modelling.

abstract: M.Sc.


title: WIPO and the Reinforcement of the Nagoya Protocol: Towards Effective Implementation of an Access and Benefit Sharing Regime for the Protection of Traditional Knowledge Associated with Genetic Resources

contributor:
Amani, Bita
Law

subject: Traditional Knowledge associated with Genetic Resources

subject: Nagoya Protocol

subject: Intellectual Property

subject: Biopiracy

subject: International Regimes

subject: Regime Complex

subject: Access and Benefit Sharing

subject: Traditional Knowledge

subject: Intergovernmental Committee on Intellectual Property and Genetic Resources, Traditional Knowledge and Folklore

subject: Indigenous Peoples

subject: Third World Approach to International Law

abstract: Traditional knowledge associated with genetic resources (TKaGRs) is acknowledged as a valuable resource. Its value draws from economic, social, cultural, and innovative uses. This value places TK at the heart of competing interests as between indigenous peoples who hold it and depend on it for their survival, and profitable industries which seek to exploit it in the global market space.  The latter group seek, inter alia, to advance and maintain their global competitiveness by exploiting TKaGRs leads in their research and development activities connected with modern innovation.  Biopiracy remains an issue of central concern to the developing world and has emerged in this context as a label for the inequity arising from the misappropriation of TKaGRs located in the South by commercial interests usually located in the North.  Significant attention and resources are being channeled at global efforts to design and implement effective protection mechanisms for TKaGRs against the incidence of biopiracy. The emergence and recent entry into force of the Nagoya Protocol offers the latest example of a concluded multilateral effort in this regard. The Nagoya Protocol, adopted on the platform of the Convention on Biological Diversity (CBD), establishes an open-ended international access and benefit sharing (ABS) regime which is comprised of the Protocol as well as several complementary instruments.  By focusing on the trans-regime nature of biopiracy, this thesis argues that the intellectual property (IP) system forms a central part of the problem of biopiracy, and so too to the very efforts to implement solutions, including through the Nagoya Protocol.  The ongoing related work within the World Intellectual Property Organization (WIPO), aimed at developing an international instrument (or a series of instruments) to address the effective protection of TK, constitutes an essential complementary process to the Nagoya Protocol, and, as such, forms a fundamental element within the Nagoya Protocol’s evolving ABS regime-complex.  By adopting a third world approach to international law, this thesis draws central significance from its reconceptualization of biopiracy as a trans-regime concept.  By construing the instrument(s) being negotiated within WIPO as forming a central component part of the Nagoya Protocol, this dissertation’s analysis highlights the importance of third world efforts to secure an IP-based reinforcement to the Protocol for the effective eradication of biopiracy.

abstract: PhD


title: Toxicity of polychlorinated biphenyls and N-phenyl-1-naphthylamine in the juvenile turtle, Chelydra serpentina

contributor:
Langlois, Valerie S.
Environmental Studies

subject:
polychlorinated biphenyls
N-phenyl-1-naphthylamine
snapping turtle
toxicity
gene expression
detoxification

abstract:
Polychlorinated biphenyls (PCBs) and substituted phenylamine antioxidants (SPAs) are two chemical groups that have been used in multiple Canadian industrial processes. Despite the production ban of PCBs in North America in 1977, they are still ubiquitous in the environment and in wildlife tissues. Previous studies of fish, amphibians, birds, and mammals have shown that PCBs are toxic and act as endocrine disruptors. In contrast, SPAs, specifically N-phenyl-1-naphthylamine (PANA), have received very little attention despite their current use in Canada and their expected environmental releases. The effects of PCB and PANA exposures in reptiles remain unknown thus, juvenile Chelydra serpentina were used in this thesis as a model vertebrate to fill in missing toxicity research gaps due to their importance as an environmental indicator.
First, food pellets were spiked at an environmentally relevant concentration of the PCB mixture Aroclor 1254 (A1254) to model hepatic bioaccumulation (0.45 μg/g A1254 for 31 days) and depuration (clean food for 50 days) of PCBs in turtles. No significant differences in PCB concentrations were observed between the control and treated animals, suggesting that juvenile turtles exposed to environmentally relevant concentrations of PCBs can likely detoxify low concentrations of PCBs. Additionally, two dose-response experiments were performed using A1254 or PANA spiked food (0-12.7 μg/g and 0-3,446 μg/g, respectively) to determine hepatic toxicity and bioaccumulation in juvenile C. serpentina. An increase in hepatic cyp1a was observed when exposed to the highest dose of both chemicals: 1) for A1254, induction correlated to the significant increase in hepatic PCB congeners that are known to be metabolized by CYP1A; and 2) for PANA, induction suggested that CYP1A has a potential role in its detoxification. PCBs are known endocrine disruptors, but no significant changes were observed for both thyroid receptors (alpha and beta) or by estrogen and androgen receptors. This lack of response, also noted in the PANA exposure, suggests that C. serpentina is less sensitive to endocrine disruption than other vertebrates. Furthermore, the expression of genes involved in cellular stress was not altered in PCB and PANA exposed animals, supporting the resilience of turtles to oxidative stress. This is the first study to demonstrate the toxicity of PCBs and PANA in C. serpentina, demonstrating the turtle’s high tolerance to contamination.

abstract: M.E.S.


title: Efficient algorithms for beacon routing in polygons

contributor:
Rappaport, David
Computing

subject:
Beacon attraction
Beacon Kernel
Beacon watchtower
Efficient algorithms
Computational geometry

abstract:
In a paper by Biro et al. [7], a novel twist on guarding in art galleries is introduced.
A beacon is a fixed point with an attraction pull that can move points within the polygon. Points move greedily to monotonically decrease their Euclidean distance to the beacon by moving straight towards the beacon or sliding on the edges of the polygon. The beacon attracts a point if the point eventually reaches the beacon. Unlike most variations of the art gallery problem, the beacon attraction has the intriguing property of being asymmetric, leading to separate definitions of attraction region and inverse attraction region. The attraction region of a beacon is the set of points that it attracts. For a given point in the polygon, the inverse attraction region is the set of beacon locations that can attract the point. We first study the characteristics of beacon attraction. We consider the quality of a "successful" beacon attraction and provide an upper bound of $\sqrt{2}$ on the ratio between the length of the beacon trajectory and the length of the geodesic distance in a simple polygon. In addition, we provide an example of a polygon with holes in which this ratio is unbounded. Next we consider the problem of computing the shortest beacon watchtower in a polygonal terrain and present an $O(n \log n)$ time  algorithm to solve this problem. In doing this, we introduce $O(n \log n)$ time algorithms to compute the beacon kernel and the inverse beacon kernel in a monotone polygon. We also prove that  $\Omega(n \log n)$ time is a lower bound for computing the beacon kernel of a monotone polygon. Finally, we study the inverse attraction region of a point in a simple polygon. We present algorithms to efficiently compute the inverse attraction region of a point for simple, monotone, and terrain polygons with respective time complexities $O(n^2)$,  $O(n \log n)$ and $O(n)$. We show that the inverse attraction region of a point in a simple polygon has linear complexity and the problem of computing the inverse attraction region has a lower bound of $\Omega(n \log n)$ in monotone polygons and consequently in simple polygons.

abstract: PhD


title: The Influence of Healed Intrablock Rockmass Structure on the Behaviour of Deep Excavations in Complex Rockmasses

contributor: Geological Sciences and Geological Engineering

subject:
Geological Engineering
Rockmass Characterization
Rockmass Behaviour
Numerical Modelling
Direct Shear Laboratory Testing
Complex Rockmasses
Healed Intrablock Structure
Underground Excavations

abstract:
Conventional rockmass characterization and analysis methods for geotechnical assessment in mining, civil tunnelling, and other excavations consider only the intact rock properties and the discrete fractures that are present and form blocks within rockmasses. Field logging and classification protocols are based on historically useful but highly simplified design techniques, including direct empirical design and empirical strength assessment for simplified ground reaction and support analysis. As modern underground excavations go deeper and enter into more high stress environments with complex excavation geometries and associated stress paths, healed structures within initially intact rock blocks such as sedimentary nodule boundaries and hydrothermal veins, veinlets and stockwork (termed intrablock structure) are having an increasing influence on rockmass behaviour and should be included in modern geotechnical design. Due to the reliance on geotechnical classification methods which predate computer aided analysis, these complexities are ignored in conventional design. Given the comparatively complex, sophisticated and powerful numerical simulation and analysis techniques now practically available to the geotechnical engineer, this research is driven by the need for enhanced characterization of intrablock structure for application to numerical methods. Intrablock structure governs stress-driven behaviour at depth, gravity driven disintegration for large shallow spans, and controls ultimate fragmentation.
	This research addresses the characterization of intrablock structure and the understanding of its behaviour at laboratory testing and excavation scales, and presents new methodologies and tools to incorporate intrablock structure into geotechnical design practice. A new field characterization tool, the Composite Geological Strength Index, is used for outcrop or excavation face evaluation and provides direct input to continuum numerical models with implicit rockmass structure. A brittle overbreak estimation tool for complex rockmasses is developed using field observations. New methods to evaluate geometrical and mechanical properties of intrablock structure are developed. Finally, laboratory direct shear testing protocols for interblock structure are critically evaluated and extended to intrablock structure for the purpose of determining input parameters for numerical models with explicit structure.

abstract: PhD


title: Strategic Diplomacies: Indigenous Governance, International Politics, and Natural Resources in Canada

contributor:
Nossal, Kim Richard
Political Studies

subject:
International Relations
Canadian Foreign Policy
Indigenous
Resource Extraction
Diplomacy
Mining
Canada

abstract: International Relations theory would predict that central governments, with their considerable material resources, would be unlikely to face a challenge from a substate government. However, substate governments, and particularly Indigenous governments, are pushing back against central government control in both domestic and international spheres. Indigenous governments are leveraging their local mining sectors to realize their interests and express local identities—interests and identities that may not be congruent with those of the central government. Applying the case study of the resource extraction sector in Canada, this thesis asks: under what conditions are substate governments able to challenge the authority of central governments in the international arena? Canada’s reliance on the global extractive resource sector is a major driver of its international policy preferences, but the increased engagement of Indigenous governments in the sector challenges the control of the federal government. Focusing on the resource extraction sectors in British Columbia, Saskatchewan, and Ontario, this thesis argues that there is a mutually reinforcing relationship between Indigenous governments’ international engagement and their domestic autonomy; both challenge the parameters of state authority. Both force the state to respond to claims of control from multiple sites and to clarify convoluted policy environments. A confluence of factors—including increased Indigenous connections to the globalized economy, new Canadian regulatory frameworks, and recent Supreme Court of Canada cases regarding Indigenous lands—have all altered the space in which Indigenous governments in Canada participate in the resource extraction sector and produce overlapping or multilevel governance structures. This thesis demonstrates that Indigenous international engagement entrenches the authority and political legitimacy manifest in Indigenous governments’ insistence on equitable and horizontal negotiations in Canada’s lucrative resource extraction sector. A cumulative process occurs in which domestic and international expressions of political autonomy reinforce each other, produce further opportunities to express authority in both environments, and trouble the state’s capacity to fully realize its international policy preferences.

abstract: PhD


title: Node-wide Asynchronous Message Progression for Efficient & Scalable Communication in  High Performance Computing

contributor:
Afsahi, Ahmad
Electrical and Computer Engineering

rights: An error occurred getting the license - uri.

subject:
HPC
MPI
Communication/Computation Overlap
Asynchronous message progression
RDMA

abstract:
High Performance Computing (HPC) has served as the enabler for several scientific and engineering accomplishments. Consequently, there has been an ever-increasing demand to create larger and faster high performance systems. To efficiently utilize the HPC resources, parallel applications rely on software that abstract the cluster hardware. Currently, the most prominent software abstraction standard in HPC is the Message Passing Interface (MPI). Parallel applications entail communications to synchronize and to share intermediate results. To minimize the duration of application executions, it is crucial to overlap such communications with the computations.
The MPI standard specifies three messaging semantics, namely, point-to-point communication, one-sided communication and collectives. In point-to-point communication, the overlap of large payloads has been a problem and there have been several proposals to address this. Among these approaches, asynchronous message progression is more adoptable because of its ability to deal with a wider range of inefficiencies and its non-reliance on specialized hardware. Traditional asynchronous message progression approaches have relied on either polling or interrupt based threads. The polling based approach is more responsive but is resource-intensive. On the other hand, the interrupt based approach is resource-efficient but is associated with overheads. This thesis proposes a node-wide asynchronous message progression technique that offers the advantages of both polling and interrupt based approaches, while minimizing or eliminating their adverse effects. This approach was found to be scalable, incur negligible overheads, induce the ideal amount of overlap in most scenarios of point-to-point communications and cast a small memory footprint. This technique was found to improve the overlap of certain collectives as well.
One-sided MPI communication offers the ability to transfer messages with few or no synchronizations, regardless of the payload size. This scheme promotes overlaps but there are several overlap inhibiting scenarios. This thesis proposes a similar asynchronous message progression technique to address such scenarios. The one-sided implementation was able to achieve overlap in the different inefficient scenarios, with negligible overheads and a small addition to the memory footprint.

abstract: M.A.Sc.


title: Design of an Experimental Rig to Characterize the Gust Response of Small Wind Turbines and Autorotating Seeds

contributor:
Rival, David E.
Mechanical and Materials Engineering

subject:
Unsteady aerodynamics of wind turbines
Samara seed aerodynamics
Experimental fluid dynamics

abstract: This thesis investigates the rotational behavior of abstracted small-wind-turbine rotors exposed to a sudden increase in oncoming flow velocity, i.e. a gust. These rotors consisted of blades with aspect ratios characteristic of samara seeds, which are known for their ability to maintain autorotation in unsteady wind. The models were tested in a towing tank using a custom-built experimental rig. The setup was designed and constructed to allow for the measurement of instantaneous angular velocity of a rotor model towed at a prescribed kinematic profile along the tank. The conclusions presented in this thesis are based on the observed trends in effective angle-of-attack distribution, tip speed ratio, angular velocity, and time delay in the rotational response for each of rotors over prescribed gust cases. It was found that the blades with the higher aspect ratio had higher tip speed ratios and responded faster than the blades with a lower aspect ratio. The decrease in instantaneous tip speed ratio during the onset of a prescribed gust correlated with the time delay in each rotor model's rotational response. The time delays were found to increase nonlinearly with decreasing durations over which the simulated gusts occurred.

abstract: M.A.Sc.


title: Keeping Variables within Bounds: Using Information between Observations

contributor:
Nielsen, Morten Ørregaard
Economics

subject:
Bounded Variables
Limited Processes
Regulated Brownian Motion
Diffusion Models
Zero Lower Bound

abstract:
This research develops an econometric framework to analyze time series processes with bounds. The framework is general enough that it can incorporate several different kinds of bounding information that constrain continuous-time stochastic processes between discretely-sampled observations. It applies to situations in which the process is known to remain within an interval between observations, by way of either a known constraint or through the observation of extreme realizations of the process. The main statistical technique employs the theory of maximum likelihood estimation. This approach leads to the development of the asymptotic distribution theory for the estimation of the parameters in bounded diffusion models.

The results of this analysis present several implications for empirical research. The advantages are realized in the form of efficiency gains, bias reduction and in the flexibility of model specification. A bias arises in the presence of bounding information that is ignored, while it is mitigated within this framework. An efficiency gain arises, in the sense that the statistical methods make use of conditioning information, as revealed by the bounds. Further, the specification of an econometric model can be uncoupled from the restriction to the bounds, leaving the researcher free to model the process near the bound in a way that avoids bias from misspecification.

One byproduct of the improvements in model specification is that the more precise model estimation exposes other sources of misspecification. Some processes reveal themselves to be unlikely candidates for a given diffusion model, once the observations are analyzed in combination with the bounding information. A closer inspection of the theoretical foundation behind diffusion models leads to a more general specification of the model. This approach is used to produce a set of algorithms to make the model computationally feasible and more widely applicable.

Finally, the modeling framework is applied to a series of interest rates, which, for several years, have been constrained by the lower bound of zero. The estimates from a series of diffusion models suggest a substantial difference in estimation results between models that ignore bounds and the framework that takes bounding information into consideration.

abstract: PhD


title: Sucrose Bingeing Reduces the Reward Value of Sucrose

contributor:
Olmstead, Mary C.
Neuroscience Studies

subject:
Sucrose bingeing
conditioned place preference
binge eating disorder
eating disorder

abstract: Binge eating occurs primarily on highly palatable food (PF) suggesting that the reward value of food has an important role in this behaviour.  Bingeing also leads to reward dysfunction in rats and humans.  The rewarding effect of binge eating may involve opioid mechanisms as opioid antagonists reduce PF consumption in animals that binge eat and binge eating produces neuroadaptations of opioid receptors in rodents.  We tested this hypothesis by using the conditioned place preference (CPP) paradigm.  First we established a sucrose CPP in male and female Long-Evans rats (n=8 for each group) using 1%, 5%, 15%, or 30% sucrose solution.  Next, rats underwent the sucrose bingeing model in which separate groups of rats (n=8 for each group) received 12hr and 24hr access to 10% sucrose solution and chow, 12hr access to 0.1% saccharin solution and chow, or 12hr access to chow only every day for 28 days.  Immediately following these sessions, rats were conditioned and tested in the CPP paradigm using a 15% sucrose solution.  Finally, we examined whether the sucrose bingeing model altered morphine reward in female rats.  Rats (n=8 for each group) received 12hr and 24hr access to 10% sucrose solution and chow every day for 28 days. Immediately following this access period, rats were conditioned to morphine (6mL/kg) or saline solution in the CPP paradigm and tested for a CPP.  In all experiments, rats drank more sucrose solution than water during conditioning sessions. Male rats did not develop a CPP to any concentration of sucrose solution and females developed a CPP to 15% sucrose solution only.  Following the sucrose bingeing protocol, sucrose CPP was attenuated in male rats that binged on sucrose and in all female rats. Sucrose bingeing in females did not affect the development of a CPP to morphine. These results suggest that sucrose consumption and sucrose CPP are measures of different psychological components of reward.  Furthermore, sucrose bingeing reduces the rewarding effect of sucrose, but not morphine, suggesting that opioid reward is still intact.

abstract: M.Sc.


title: Vortex evolution in the wake of accelerating low-aspect-ratio plates and three-dimensional bodies of revolution

subject:
vortex dynamics
flow separation
added-mass

abstract: To find examples of effecient locomotion and manoeuvrability, one need only turn to the elegant solutions natural flyers and swimmers have converged upon. This dissertation is specifically motivated by processes of evolutionary convergence, which have led to the propulsors and body shapes in nature that exhibit strong geometric collapse over diverse scales. These body features are abstracted in the studies presented herein using low-aspect-ratio at plates and a three-dimensional body of revolution (a sphere). The highly-separated vortical wakes that develop during accelerations are systematically characterized as a function of planform shape, aspect ratio, Reynolds number, and initial boundary conditions. To this end, force measurements and time-resolved (planar) particle image velocimetry have been used throughout to quantify the instantaneous forces and vortex evolution in the wake of the bluff  bodies. During rectilinear motions, the wake development for the flat plates is primarily dependent on plate aspect ratio, with edge discontinuities and curvature playing only a secondary role. Furthermore, the axisymmetric case, i.e. the circular plate, shows strong sensitivity to Reynolds number, while this sensitivity quickly diminishes with increasing aspect ratio. For rotational motions, global insensitivity to plate aspect ratio has been observed. For the sphere, it has been shown that accelerations play an important role in the mitigation of flow separation. These results - expounded upon in this dissertation - have begun to shed light on the specific vortex dynamics that may be coopted by flying and swimming species of all shapes and sizes towards efficient locomotion.

abstract: PhD


title: Roles of the Immune Cytokine Environment on Clonal Growth of Murine and Human Tet2 Mutant Bone Marrow Progenitors: Implications for Myelodysplastic Syndromes

contributor:
Rauh, Michael
Pathology and Molecular Medicine

subject:
Immune Cytokines
TNF-alpha
IFN-gamma
Myelodysplastic Syndromes
Tet2 Mutation

abstract: TET2 is a tumor suppressor gene that has been implicated in the epigenetic regulation of gene expression. Inactivating TET2 mutations are common in MDS. These mutations may contribute to early clonal dominance and myeloid transformation, although the exact mechanisms remain to be elucidated. Common to the environment of MDS are elevations in cytokines, such as TNFα and IFN-γ.  It was hypothesized that inflammatory cytokines TNF-α and IFN-γ may promote clonal expansion of TET2 mutant progenitors. Adult (10-14 weeks-old) Tet2 wild type (+/+) and Tet2 mutant (-/-) C57BL/6 mice strains were chosen as a model system.  Lineage negative cells (Lin-), enriched for hematopoietic stem and progenitor cells, were isolated from Tet2 +/+ and -/- bone marrow and cultured in the absence or presence of varying concentrations of TNFα or IFN-γ in methylcellulose colony formation assays and long term cell culture assays, over a period of 12 and 30 days respectively, and their colony growth, cell count, immunophenotype and resistance to apoptosis were examined. Where indicated, serial re-plating was performed. Expression of apoptotic regulators was assessed by qRT-PCR. In the triplicate experiments, starting with equal densities of Tet2 +/+ and -/- Lin- cells, Tet2 -/- Lin- cells displayed increased resistance to cytokine-induced growth suppression and superior colony forming ability over +/+ in the serial re-plating assays under stress of increasing TNFα or IFN γ. Tet2 -/- progenitors also displayed a lower apoptotic index compared to +/+ under stress of increasing TNFα, suggesting increased resistance to TNFα induced apoptosis. Transcriptional data showed low expression of Tnfr1, Fas  and caspase 8, as well as a high expression of Bcl-2 and Iap1 in Tet2 -/-  compared to +/+ under stress of TNFα.  Tet2-/- also showed increased basal expression of endogenous TNFα mRNA compared to +/+. In the human colony growth assay, the clonal growth of TET2 mutant CFU-GM progenitors was enhanced at low TNFα concentrations. Conclusion: Mutations that promote resistance to environmental stem cell stressors are a known mechanism of clonal selection in aplastic anaemia and JAK2-mutant MPN and our findings suggest that this mechanism may be critical to clonal selection and dominance in MDS.

abstract: M.Sc.


title: Salmonella Enterica serovar Typhimurium Infection in Mouse Pregnancy

contributor:
Croy, B. Anne
Biomedical and Molecular Sciences

subject:
Placenta
Foodborne Pathogens
Infection
Pregnancy

abstract:
Salmonella are Gram-negative, intracellular food-borne pathogens that cause pregnancy
complications. In pregnant mice, Salmonella enterica serovar Typhimurium (S.Tm) infection results in
placental bacterial replication, inflammation, necrosis, and fetal loss by unknown mechanisms.
Necroptosis, or programmed necrosis mediated by RIPK3 (receptor-interacting protein kinase 3), an
inflammatory cell death pathway, is implicated in the pathogenesis of S.Tm in non-pregnant mice. This
goal of this thesis was to investigate the role of necroptosis in the pathogenesis of S.Tm infection during
mouse pregnancy. I hypothesized that elimination of the key necroptotic cell death protein RIPK3 would
decrease placental inflammation and trophoblast cell death, and increase conceptus survival compared to
controls.
Mice expressing a functional Slc11a1 (encodes the natural resistance-associated macrophage
protein 1, NRAMP1) gene with or without RIPK3 function (Ripk3-/-Slc11a1+/+ compared to Slc11a1+/+)
were infected with 103 S.Tm by tail vein injection on gestational day (GD) 12. Mice were euthanized on
GD 14 (48h post-infection) or GD 15 (72h post-infection) and implantation sites (IS) and maternal serum
were harvested for analyses.
In nearly all challenged mice (except one outlier), S.Tm were detected in most IS within a litter
but there was limited immune cell infiltration, placental damage or cell death in Slc11a1 competent mice
regardless of Ripk3 gene deletion. Maternal serum cytokine analyses confirmed lack of maternal immune
responses to S.Tm infection. IS amongst the litter of a single dam (Ripk3-/-Slc11a1+/+ at 72h postinfection)
displayed heavy but not universal placental S.Tm infection of decidual tissues and
spongiotrophoblast, associated with elevated maternal serum pro-inflammatory cytokines. S.Tm infection
of the fetal yolk sac (YS) was observed in 54.5% of IS from this dam. YS infection was confirmed in
archival samples in mice expressing Ripk3 with intact Slc11a1 and in mice lacking functional Slc11a1. In
Slc11a1 incompetent mice, S.Tm were detected in placental labyrinthine trophoblast. Based on the
available data, this thesis suggests that Ripk3 and necroptosis have no significant roles in either promotion
or prevention of progressive Salmonella infection during mouse pregnancy. It also provides pilot data that
NRAMP1 controls placental localization and lethality due to YS infection.

abstract: M.Sc.


title: Weight Loss in the Chiropractic Profession

contributor:
French, Simon
Public Health Sciences

subject:
Chiropractic
Chiropractor
Health Care
Healthcare Professional
Weight Loss
Weight Management

abstract:
Background: Excess weight places a significant burden on health. Clinical practice guidelines advise healthcare professionals to provide weight management interventions to patients with overweight and obesity. Chiropractic practice may provide a unique opportunity to deliver weight management interventions to those with overweight and obesity. However, little has been done to address overweight and obesity within the chiropractic profession. Identifying the extent of this evidence-practice gap in chiropractic practice is the first step in addressing this issue.

Objectives: This thesis was to assess the clinical practices of weight loss provided by chiropractors. The primary objectives were to 1) determine the prevalence of overweight and obesity in the adult patient population that sought chiropractic care, 2) describe the frequency and distribution of chiropractor directed weight management intervention, 3) identify associations between chiropractor directed weight management interventions and specific patient-level and chiropractor-level variables, and 4) examine the interaction between patient weight and comorbid conditions and whether chiropractors offered weight management interventions.

Methods: Data from the Ontario Chiropractic Observational and Analysis Study was used (N = 42 chiropractors, N = 3523 patient encounters). Multilevel logistic regression was performed. Patient-level as well as chiropractor-level variables were investigated and associations with weight management provided by chiropractors were identified.

Results: The majority of patients who sought chiropractic were overweight or obese (61.2%). Weight loss was provided to only 5.4% of patients. Chiropractors who graduated between 1995 and 2005 (OR: 0.02, 95% CI: 0.00 - 0.13) or prior to 1995 (OR: 0.08, 95% CI: 0.01 - 0.42) provided weight management significantly less than chiropractors who graduated between 2005 and 2014. No significant interaction was observed between patient adiposity and comorbid conditions with chiropractors directed weight loss.

Conclusion: The majority of patients who seek chiropractic care are overweight and obese. Chiropractors are in a unique position to help improve patient health through offering weight management. However, this opportunity has not been fully realized by the chiropractic profession.

abstract: M.Sc.


title: Investigating the mesh dependency and upscaling of 3D grain-based models for the simulation of brittle fracture processes in low-porosity crystalline rock

subject:
Numerical Modelling
Rock Mechanics
Distinct Element Method

abstract: The application of 3D grain-based modelling techniques is investigated in both small and large scale 3DEC models, in order to simulate brittle fracture processes in low-porosity crystalline rock. Mesh dependency in 3D grain-based models (GBMs) is examined through a number of cases to compare Voronoi and tetrahedral grain assemblages. Various methods are used in the generation of tessellations, each with a number of issues and advantages. A number of comparative UCS test simulations capture the distinct failure mechanisms, strength profiles, and progressive damage development using various Voronoi and tetrahedral GBMs. Relative calibration requirements are outlined to generate similar macro-strength and damage profiles for all the models. The results confirmed a number of inherent model behaviors that arise due to mesh dependency. In Voronoi models, inherent tensile failure mechanisms are produced by internal wedging and rotation of Voronoi grains. This results in a combined dependence on frictional and cohesive strength. In tetrahedral models, increased kinematic freedom of grains and an abundance of straight, connected failure pathways causes a preference for shear failure. This results in an inability to develop significant normal stresses causing cohesional strength dependence. In general, Voronoi models require high relative contact tensile strength values, with lower contact stiffness and contact cohesional strength compared to tetrahedral tessellations. Upscaling of 3D GBMs is investigated for both Voronoi and tetrahedral tessellations using a case study from the AECL’s Mine-by-Experiment at the Underground Research Laboratory. An upscaled tetrahedral model was able to reasonably simulate damage development in the roof forming a notch geometry by adjusting the cohesive strength. An upscaled Voronoi model underestimated the damage development in the roof and floor, and overestimated the damage in the side-walls. This was attributed to the discretization resolution limitations.

abstract: M.A.Sc.


title: Analysis of Non-Stationary Flows Using Eulerian and Lagrangian Frameworks

contributor:
Rosi, Giuseppe Antonio
Mechanical and Materials Engineering

subject:
Experimental Fluid Mechanics
Atmospheric Surface Layers
Shear Layers
Entrainment

abstract: Recent developments have made researchers to reconsider Lagrangian measurement techniques as an alternative to their Eulerian counterpart when investigating non-stationary flows. This thesis advances the state-of-the-art of Lagrangian measurement techniques by pursuing three different objectives: (i) developing new Lagrangian measurement techniques for difficult-to-measure, in situ flow environments; (ii) developing new post-processing strategies designed for unstructured Lagrangian data, as well as providing guidelines towards their use; and (iii) presenting the advantages that the Lagrangian framework has over their Eulerian counterpart in various non-stationary flow problems. Towards the first objective, a large-scale particle tracking velocimetry apparatus is designed for atmospheric surface layer measurements. Towards the second objective, two techniques, one for identifying Lagrangian Coherent Structures (LCS) and the other for characterizing entrainment directly from unstructured Lagrangian data, are developed. Finally, towards the third objective, the advantages of Lagrangian-based measurements are showcased in two unsteady flow problems: the atmospheric surface layer, and entrainment in a non-stationary turbulent flow. Through developing new experimental and post-processing strategies for Lagrangian data, and through showcasing the advantages of Lagrangian data in various non-stationary flows, the thesis works to help investigators to more easily adopt Lagrangian-based measurement techniques.

abstract: PhD


title: Protein-triggered Sustained Drug Release Controlled by Aptamers Bound to Oligomer-crosslinked Alginate

contributor:
Wells, Laura
Chemical Engineering

rights: This publication is made available by the authority of the copyright owner and may not be copied or reproduced except as permitted by the Copyright Act or with permission from the copyright owner.

subject:
Drug delivery
Aptamers
Biomaterials
Protein therapeutics
Bio-responsive drug delivery
Sustained drug delivery

abstract:
Sustained drug release systems provide many advantages over traditional delivery methods such as extending the time in which the drug is found to be within an effective concentration within the therapeutic window, which decreases the frequency of administration of the drug, and increases patient compliance. Research using polyacrylamide crosslinked by oligomers containing an aptamer sequence, has demonstrated a pulsatile release over 50 minutes triggered by a 2 mM target adenosine concentration. This thesis aims to build off this concept by designing a system that delivers in a sustained manner when triggered by micromolar target concentrations reflective of disease in vivo, using macromolecular targets.  For example, the disease wet age related macular degeneration (wet AMD) is associated with increased concentrations of the protein vascular endothelial growth factor (VEGF-A) – a macromolecule. Patients with wet AMD would benefit from the implantation of devices or microspheres that release drugs in a sustained manner in response to local VEGF concentrations.

	In this thesis, we hypothesize that the protein lysozyme, used to demonstrate proof-of-concept, could trigger the increased release of drugs from oligomer-crosslinked alginate. The objectives are to (i) demonstrate sustained release from alginate, (ii) design oligomer crosslinked alginate that degrades in response to lysozyme, and then (iii) use these systems to control the release of FITC-dextran with and without lysozyme.

	A series of control experiments and analyses were used to optimize the crosslinking of alginate by annealed oligomers. The cumulative release of FITC-dextran (MW 20,000) from oligomer crosslinked alginate increased by 3.4 μg when lysozyme (3 μM) was introduced at 48 hours, as opposed to controls which released only 0.2 μg. FITC-loaded alginate microspheres coated by oligomer-crosslinked alginate released 15% more FITC-dextran over 120 hours when placed into 3 μM of lysozyme than without lysozyme. Controls of alginate crosslinked with PEG or control oligomers (without a lysozyme aptamer sequence) had no changes in release with lysozyme.

	The incorporation of a lysozyme aptamer onto oligomers used to crosslink alginate disks or alginate coatings on microspheres resulted in different diffusion and release of FITC-dextran into PBS with or without lysozyme.  This approach could be adapted for the delivery of drugs to diseases with specific protein profiles such as wet AMD.

abstract: M.A.Sc.


title: A New DC UPS for DC Power Distribution System in Data Center

contributor:
Jain, Praveen K.
Electrical and Computer Engineering

subject:
Data center
DC Distribution System
DC UPS
Three-level AC-DC Converter
Power Electronics

abstract:
In recent years, the 380V DC and 48V DC distribution systems have been extensively studied for the latest data centers. It is widely believed that the 380V DC system is a very promising candidate because of its lower cable cost compared to the 48V DC system. However, previous studies have not adequately addressed the low reliability issue with the 380V DC systems due to large amount of series connected batteries. In this thesis, a quantitative comparison for the two systems has been presented in terms of efficiency, reliability and cost. A new multi-port DC UPS with both high voltage output and low voltage output is proposed. When utility ac is available, it delivers power to the load through its high voltage output and charges the battery through its low voltage output. When utility ac is off, it boosts the low battery voltage and delivers power to the load form the battery. Thus, the advantages of both systems are combined and the disadvantages of them are avoided. High efficiency is also achieved as only one converter is working in either situation. Details about the design and analysis of the new UPS are presented.
For the main AC-DC part of the new UPS, a novel bridgeless three-level single-stage AC-DC converter is proposed. It eliminates the auxiliary circuit for balancing the capacitor voltages and the two bridge rectifier diodes in previous topology. Zero voltage switching, high power factor, and low component stresses are achieved with this topology. Compared to previous topologies, the proposed converter has a lower cost, higher reliability, and higher efficiency. The steady state operation of the converter is analyzed and a decoupled model is proposed for the converter.
For the battery side converter as a part of the new UPS, a ZVS bidirectional DC-DC converter based on self-sustained oscillation control is proposed. Frequency control is used to ensure the ZVS operation of all four switches and phase shift control is employed to regulate the converter output power. Detailed analysis of the steady state operation and design of the converter are presented.
Theoretical, simulation, and experimental results are presented to verify the effectiveness of the proposed concepts.

abstract: M.Sc.


title: Examination of the Effect of Time Delay on Fragmentation

contributor:
Katsabanis, Panagiotis (Takis) D.
Mining Engineering

subject:
fragmentation
blasting delay
blasting fragmentation
blasting
time delay

abstract:
The main objective of blasting is to produce optimum fragmentation for downstream processing. Fragmentation is usually considered optimum when the average fragment size is minimum and the fragmentation distribution as uniform as possible. One of the parameters affecting blasting fragmentation is believed to be time delay between holes of the same row. Although one can find a significant number of studies in the literature, which examine the relationship between time delay and fragmentation, their results have been often controversial. The purpose of this work is to increase the level of understanding of how time delay between holes of the same row affects fragmentation.
Two series of experiments were conducted for this purpose. The first series involved tests on small scale grout and granite blocks to determine the moment of burden detachment. The instrumentation used for these experiments consisted mainly of strain gauges and piezoelectric sensors. Some experiments were also recorded with a high speed camera. It was concluded that the time of detachment for this specific setup is between 300 and 600 μs.
The second series of experiments involved blasting of a 2 meter high granite bench and its purpose was the determination of the hole-to-hole delay that provides optimum fragmentation. The fragmentation results were assessed with image analysis software. Moreover, vibration was measured close to the blast and the experiments were recorded with high speed cameras. The results suggest that fragmentation was optimum when delays between 4 and 6 ms were used for this specific setup. Also, it was found that the moment at which gases first appear to be venting from the face was consistently around 6 ms after detonation.

abstract: M.A.Sc.


title: Computational Study Using Tensile Force and Torque to Manipulate Axial Chirality in Biaryl Molecules

contributor:
Mosey, Nicholas
Chemistry

subject: Chemistry Mechanochemistry Chirality Computational

abstract: Biaryl molecules are widely studied systems that have applications in a broad selection of fields including pharmaceuticals, environmental protection, liquid crystal synthesis, and metal organic framework synthesis. Extra care is required in consideration of the axial chirality they often exhibit. Careful control of axial chirality in biaryl molecules is a blossoming area of study which remains open to fresh interpretation. This study, employing quantum chemical calculations and first principles molecular dynamics simulations, has demonstrated that a mechanochemical scheme may be employed wherein mechanical work introduced by the application of tensile forces and torques can be used to promote enantiomeric excess in a number of axially chiral substituted biaryl molecules. Furthermore, quantitative control over the timescales of biphenyl rotation and chiral purification is offered. Subsequently, a system incorporating Taylor series approximations has been employed to approximate the effects of mechanical work on the potential energy surface, reducing the number of quantum chemical calculations required in order to identify a suitable range of tensile forces and torques in order to achieve enantiomeric excess.

abstract: M.Sc.


title: Development of a Feedstock-to-Product Chain Model for Densified Biomass Pellets

contributor:
Pollard, Andrew
Strong, David S.
Mechanical and Materials Engineering

subject:
techno-economics
life cycle analysis
biomass
wood pellets

abstract:
The Q’Pellet is a spherical, torrefied biomass pellet currently under development. It aims to improve on the shortcomings of commercially available cylindrical white and torrefied pellets. A spreadsheet-based model was developed to allow for techno-economic analysis and simplified life cycle analysis of Q’Pellets, torrefied pellets and white pellets. A case study was developed to compare the production of white, torrefied and Q’Pellet production based on their internal rates of return and life cycle greenhouse gas emissions. The case study was based on a commercial scale plant built in Williams Lake BC with product delivery in Rotterdam, Netherlands.
Q’Pellets had the highest modelled internal rate of return, at 12.7%, with white pellets at 11.1% and torrefied pellets at 8.0%. The simplified life cycle analysis showed that Q’Pellets had the lowest life cycle greenhouse gas emissions of the three products, 6.96 kgCO2eq/GJ, compared to 21.50 kgCO2eq/GJ for white pellets and 10.08 kgCO2eq/GJ for torrefied pellets. At these levels of life cycle greenhouse gas emissions, white pellets are above the maximum life cycle emissions to be considered sustainable under EU regulations.
Sensitivity analysis was performed on the model by modifying input variables, and showed that white pellets are more sensitive to uncontrollable market variables, especially pellet sale prices, raw biomass prices and transportation costs. Monte Carlo analysis was also performed, which showed that white pellet production is less predictable and more likely to lead to a negative internal rate of return compared to Q’Pellet production.

abstract: M.A.Sc.


title: New metrics for finite automaton complexity and subregular language hierarchies

contributor:
Salomaa, Kai Jr
Computing

rights: Attribution-NonCommercial 3.0 United States

subject:
Finite Automata
Ambiguity
Tree Width
Paths
String Path Width
Depth Path Width
Acyclic
Nearly Acyclic
Regular
Subregular
Languages

abstract:
The degree of ambiguity of nondeterministic finite automata (NFA) has been studied significantly since at least the 1980s.
Roughly speaking, the degree of ambiguity counts the number of accepting computations of an NFA.

To get a more comprehensive understanding of the branching complexity of NFAs, we introduce and study the string path width and depth path width measures.
The string path width on a string w counts the number of all accepting and non-accepting computations on w, and the depth path width on an integer l counts the number of all accepting and non-accepting computations of a length l.
We focus on cases where these measures are finite, that is, there is some input which has maximal string or depth path width.
We give algorithms to decide the finiteness of the string and depth path width of an NFA.
The latter algorithm relies on structural properties that characterize NFAs with finite depth path width, and the former is based on existing algorithms to compute the degree of ambiguity.
We give upper bounds for the finite string and depth path width of an NFA or a DFA (deterministic finite automaton).

It is well known that acyclic NFAs define exactly the class of finite languages.
We consider less restrictive conditions that define the class of nearly acyclic NFAs.
An NFA is nearly acyclic if it does not have two cycles where one can be reached from the other.
It is shown that the nearly acyclic NFAs are exactly the NFAs with finite depth path width.

We study and introduce variants of existing subregular language families.
We establish (non)-inclusion relationships for these new classes, relative to each other and their existing counterparts.
Additionally we show that an infinite hierarchy exists within the most powerful new family, generalized word-definite languages.

We examine the structural limitations and give maximal examples of nearly acyclic NFAs.
We also show that nearly acyclic NFAs recognize the class of generalized word-definite languages.
For nearly acyclic DFAs, we establish a stronger correspondence: they recognize all generalized word-definite languages, and any DFA recognizing a generalized word-definite language must be nearly acyclic.

abstract: M.Sc.


title: Regulation of HC11 Mouse Mammary Epithelial Cell Differentiation by the Rac/Stat3 axis

contributor:
Raptis, Leda
Pathology and Molecular Medicine

subject:
Stat3
Cadherins
Differentiation
Breast cancer
Rac1
Mammary Epithelium

abstract:
Studying cellular differentiation can reveal valuable information underlying the mechanisms that mediate cell fate. The HC11 mouse mammary epithelial cell line has long been used as a model to study lactogenic differentiation in vitro. Differentiation of HC11 cells requires the addition of hydrocortisone, insulin, and prolactin, added at confluence. Recently, our lab demonstrated that engagement of E-cadherin in HC11 cells, which is favoured under conditions of confluence, triggers a dramatic increase in the activity of the cRac1, small GTPase, which, in turn, activates Stat3 (Signal Transducer and Activator of Transcription-3). Therefore, we hypothesized that the E-cadherin/Rac/Stat3 axis may play a role in HC11 cell differentiation.

My results demonstrate that this pathway positively regulates HC11 mammary epithelial cell differentiation and that it is a key mediator of cell fate. Particularly, the strength of the Rac signal is key for the outcome of the differentiation process; cRac is critically required for differentiation, and at low levels, mutationally activated RacV12 is able to increase differentiation, presumably by reinforcing the E-cadherin/Rac differentiative signal.  However, high RacV12 expression blocked differentiation while inducing neoplastic transformation. On the other hand, despite the fact that Stat3 was also required for differentiation, constitutively active Stat3 expression was found to block differentiation at all levels.

In conclusion, hyperactive RacV12 may have opposing functions, depending upon its level of expression.  As a result, a complete Rac inhibition may not be necessary in order to reverse a Rac-driven, neoplastic phenotype in a clinical setting, since the residual, low levels of Rac may be actually promoting cellular differentiation, a finding which could have important therapeutic implications.

abstract: M.Sc.


title: Achieving Bright Blue Phosphorescent Platinum(II) Compounds with Cyclometallating Phenyl-1,2,3-Triazole Ligands

contributor:
Wang, Suning
Chemistry

subject:
Blue Emitters
Platinum Compounds
OLED

abstract:
Although tremendous progress has been made in the research and commercialization of organic light emitting diodes (OLEDs), the development of efficient and stable deep blue OLEDs remains one of the greatest challenges. This thesis describes our approach to achieve highly efficient deep-blue phosphorescent emitters based on cyclometalated Pt(II) compounds bearing 1,2,3-triazole moieties. The influence of different ancillary ligands and the impact of various substituent groups and ligand denticity on phosphorescent emission color, phosphorescent quantum efficiency, excimer emission, thermal and UV stability of these molecules were carefully examined. Their performance in OLED devices has also been evaluated.

A series of dimesitylboron(BMes2)-functionalized Pt(II) complexes based on N∧C-chelate phenyl-1,2,3-triazolyl backbones and acetylacetonate, picolinate or pyridyl-1,2,4-triazolyl ancillary ligands have been synthesized and their use as emitters in efficient greenish-blue and white phosphorescent OLED devices were demonstrated. This was the first example of using phenyl-1,2,3-triazoles as the cyclometallating ligand in Pt(II) complexes and revealed that this was a viable approach to achieve bright blue phosphorescent Pt(II) compounds.

We then synthesized a class of brightly phosphorescent Pt(II) compounds that contain an NC-chelate phenyl-1,2,3-triazolyl ligand (ptrz) and an NC-chelate pyridyl-1,2,4-triazolyl ligand (pytrz) with different substituent groups.  When the bulky trityl group (Ph3C) was introduced, the thermal stability of the molecule was improved and the excimer emission was reduced. Efficient greenish-blue phosphorescent OLED devices with no excimer emission were successfully fabricated using the Ph3C-contining compounds.

Finally, by using tetradentate or macrocyclic cyclometallating ligands, the photostability of the corresponding Pt(II) complexes was greatly enhanced as they undergo less structural distortion at the excited state. Bright and efficient deep blue OLEDs with high color purity were successfully fabricated using the macrocyclic Pt(II) complex, demonstrating a new route to stable and highly luminescent deep blue Pt(II) emitters.

abstract: PhD


title: Thermal Properties of the Cobourg Limestone

contributor: Geological Sciences and Geological Engineering

subject:
Thermal properties
THM coupling
Nuclear Waste Storage
Cobourg Limestone

abstract:
The underground storage of used nuclear fuel in Deep Geologic Repositories (DGRs) has been a subject of research in Canada for decades. One important technical aspect of repository design is the accommodation of the mechanical impacts of thermal inputs (heating) from the fuel as it goes through the remainder of its life cycle. Placement room spacing, a major factor in project cost, will be determined by the ability of the host rock to dissipate heat. The thermal conductivity and linear thermal expansion will determine the evolution of the temperature and thermally-induced stress fields. Thermal processes must be well understood to design a successful DGR.

This thesis examines the thermal properties of rocks, how they are influenced by factors such as temperature, pressure, mineralogy, porosity, and saturation; and common methods for calculating and/or measuring these properties. A brief overview of thermal and thermally-coupled processes in the context of DGRs demonstrates the degree to which they would impact design, construction, and operation of these critical structures. Several case histories of major in situ heating experiments are reviewed to determine how the lessons learned could be applied to a Canadian Underground Demonstration Facility (UDF).

A mineralogy investigation using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) examines samples of the Cobourg Limestone from the Bowmanville and Bruce sites, and demonstrates geographical variability within the Cobourg Formation. The thermal properties of samples from the Bowmanville site are determined. A divided bar apparatus was constructed and used to measure thermal conductivity. The temperature measurement component of the divided bar apparatus was used to measure linear thermal expansion. Finally, the past investigations into the thermal impact of a DGR are reviewed, and the implications of the laboratory testing results on similar analyses are discussed.

abstract: M.A.Sc.


title: The Impact of a Severe Psychiatric Illness on a Cancer Diagnosis, Treatment, and Survival

contributor:
Groome, Patti A.
Public Health Sciences

subject:
Severe Psychiatric Illness
Colorectal Cancer
Healthcare Disparity
Survival

abstract:
Background: Individuals with a severe psychiatric illness (SPI) are vulnerable to cancer care disparities. The contributions of cancer-related mortality to lower life-expectancy in individuals with an SPI have been understudied.
Methods: This thesis investigated the association between an SPI history and colorectal cancer (CRC) outcomes in a cohort of patients diagnosed in Ontario between 01/04/2007-31/12/2012 using provincial healthcare data. SPI history was determined using hospitalization, emergency department, and psychiatrist visit data and categorized as ‘no history of mental illness, ‘outpatient SPI history’, and ‘inpatient SPI history’. The thesis was organized around a causal framework, highlighting the complexity of the relationship between an SPI and worse cancer outcomes. The thesis investigated the SPI effect on an unknown cancer stage, non-receipt of surgical resection, non-receipt of adjuvant treatment, and on overall and CRC-specific survival. Multiple log-binomial, logistic, and modified Poisson regression were used to study dichotomous outcomes. Multiple Cox-Proportional hazards, Aalen additive hazards and Fine & Gray sub-distribution hazards regression were used to study time-to-event outcomes.
Results: CRC patients with an inpatient SPI history had 1.45 (95% CI: 1.31-1.84) times the risk of an unknown stage cancer at diagnosis, 2.15 times the risk of not receiving surgical resection (95% CI: 1.07-4.33), and 2.07 times the risk of not receiving adjuvant treatment (95% CI: 1.72-2.50), compared to those with no history of mental illness. The outpatient SPI effect was smaller in magnitude and often non-significant. The hazard ratio (HR) of death from any cause was 1.91 times higher for individuals with an inpatient SPI (95% CI: 1.63-2.25) and 1.40 times higher for individuals with an outpatient SPI history (95% CI: 1.22-1.59); the HR of death from CRC was slightly lower and the HR of non-cancer death was higher, than the overall estimates. Some significant effect modification by age, sex and stage at diagnosis was noted; however, the study was not adequately powered to detect interaction.
Conclusions: These three studies tell a consistent, cohesive story of cancer outcome inequalities for patients with an SPI across the cancer care trajectory. Future work to understand why these inequalities exist and how to best intervene are necessary.

abstract: PhD