VictorJuiz/thesis huggingface dataset:
Chromium and Neodymium Complexes of bis-Phosphinimine Pincer Ligands and Their Behaviour in 1,3-Butadiene Polymerization

Polybutadiene, the homopolymer of 1,3-butadiene, is a synthetic rubber especially important in the production of tires. Industrially, it is polymerized using multi-site catalysts that do not offer significant control over molecular weight distribution resulting in polymers with poor mechanical properties. Single-site polymerization of 1,3-butadiene results in narrow molecular weight distribution and thus increased impact resistance and durability. Complexes of chromium and neodymium bearing bis-phosphinimine pincer ligands have been synthesized and studied for their behavior in 1,3-butadiene polymerization in combination with methylaluminoxane. The complexes that were active produced highly cis-1,4-polybutadiene with high molecular weight and narrow polydispersities. The co-polymerization of acrylonitrile and 1,3-butadiene with the bis-phosphinimine chromium (III) complexes and methylaluminoxane to produce nitrile-butadiene rubber was also explored. The insertion of 1,3-butadiene into nickel-methyl and nickel-hydride complexes bearing the bis-phosphinimine pincer ligands was examined using nuclear magnetic resonance spectroscopy and will also be discussed.

Keywords: polybutadiene
chromium
neodymium
phosphinimine
pincer ligand
1,3-butadiene
Advisor: Stephan, Douglas
The Attorney General’s Obligation to Report Breaches of Rights in Proposed Legislation: How the Canadian and New Zealand Reporting Cultures Differ

This paper examines the Attorney General’s obligation, in Canada and New Zealand, to report on inconsistencies in proposed legislation with the Canadian Charter of Rights and Freedoms and the New Zealand Bill of Rights Act 1990. Although the obligations are similar, the Canadian and New Zealand Attorneys General have developed very different reporting cultures. The Canadian Attorney General has never issued a report; the New Zealand Attorney General has issued many. This paper’s thesis is that the different reporting cultures are attributable to the different constitutional structure in each jurisdiction and different understandings of the independence of the Attorney General. Under this analysis, the usefulness of comparative analysis between the two jurisdictions is limited: constitutional differences cannot be ignored. The paper evaluates proposed changes to the reporting obligation in each jurisdiction in light of this analysis.

Keywords: Canadian Charter of Rights and Freedoms
New Zealand Bill of Rights Act 1990
Attorney General
Human Rights
Legislation
Parliament
Constitutional law
Bill of rights
Advisor: Roach, Kent
3D Printing: Convergences, Frictions, Fluidity

The emergence of desktop ‘3D printing’ is not only a technological development, but equally a social and economic phenomenon that actively (and often contentiously) co-produces the material and ideological infrastructures it occupies. Reflecting wider momentum toward digital-material convergence, the current “revolution” in desktop digital fabrication is fundamentally attributable to the efforts of decentralized Maker and DIY communities who, connected through digital networks, practice citizen-led technological experimentation and occupy novel spaces for innovation and entrepreneurship. Employing hybrid qualitative methods that include Critical Making, this research explores the following themes: rhetoric versus reality, the divisive notion of ‘digital craft’, perceptions of authenticity, as well as cultural momentum manifested in decentralization, convergence, stratification, and iteration. An overarching theme emerges: 3D printing is a fluid phenomenon – in literal, metaphorical, technological and cultural ways.

Keywords: 3D printing
digital culture
material culture
design
craft
Makers
DIY
Critical Making
Advisor: Ratto, Matthew
Access to Justice and the Institutional Limits of Independent Courts

Canadian citizens’ inability to access courts has been a subject of controversy for decades. Despite widespread evidence that Canada’s legal aid system is faltering, governments continue to be unwilling to commit the resources necessary to remedy the problem. In this thesis, the author argues that people’s inability to access courts and obtain legal representation not only has implications for their rights and interests, but may also undermine judicial independence. Judicial independence, the author claims, is best understood as a variable bundle of rights, guarantees and powers conferred on courts and judges that preserves and enhances their abilities to adjudicate impartially, maintain a constitutional distribution of powers and uphold the rule of law. Since people’s inability to access courts can impair the judiciary’s ability to preserve these values, judicial independence is undermined. The author claims that it is possible to correct problems of inaccessibility by appointing state-funded counsel in appropriate circumstances.

Keywords: judicial independence
access to justice
Advisor: Dyzenhaus, David
On the Flow Characteristics behind a Backward-facing Step and the Design of a New Axisymmetric Model for their Study

An extensive review was made to study the wake characteristics of a backward-facing step. Experimental and numerical studies of the backward-facing step suggest that the wake of a separated shear layer to be dependent on parameters such as: expansion ratio, aspect ratio, free stream turbulence intensity, boundary layer state and thickness at separation. The individual and combined effects of these parameters on the reattachment length are investigated and discussed in detail in this thesis. A new scaling parameter, sum of step height and boundary layer thickness at separation is proposed, which yields significant collapse of the available data. Based on the literature review, an axisymmetric model is designed for further investigating the dynamics of the flow independent of aforementioned parameters. Additionally, porous suction strips are incorporated to study the step wake characteristics independent of Reynolds number. This model has been built and will be tested extensively at UTIAS.

Keywords: separated shear flows
backward-facing step
Advisor: Lavoie, Philippe
Understanding Cognitive Function In Older Adults With Type 2 Diabetes Mellitus via Environmental Stress in the Functional Magnetic Resonance Imaging Environment and Metabolic Stress Associated with Glucose Ingestion

The objectives were to explore cognitive function in older adults with Type 2 Diabetes Mellitus (T2DM) through two studies: 1) a pilot study involving the metabolic stress of glucose ingestion and the environmental stress of a functional magnetic resonance imaging (fMRI) environment and 2) an fMRI study exploring the neural mechanisms through hippocampal and prefrontal functional imaging during memory and executive functioning tasks. In T2DM subjects, environmental stress produced greater impairment in memory performance and metabolic stress produced overestimation of memory performance, with similar executive functioning, relative to healthy subjects (pilot study). T2DM subjects also sowed reduced hippocampal and greater prefrontal activation compared to healthy subjects (fMRI study). Moreover, the metabolic stress caused greater hippocampal and prefrontal activation in healthy subjects relative to placebo (fMRI study). These results indicate plausible neural mechanisms behind T2DM- and stress-associated cognitive impairments that can be used for future improvements in cognitive retention and rehabilitation.

Keywords: Nutrition
Neuropsychology
Cognition
Imaging
Advisor: Greenwood, Carol
Shear & Extensional Effects in Internal Flows of Dilute Polymer Solutions

Shear and extensional flows of dilute polymer solutions were studied experimentally in an attempt to understand the mechanism of polymer-induced drag reduction. A flowcell capable of simulating the dynamics of a turbulent boundary layer, involving the motion of counter-rotating vortices, was designed and fabricated. The pressure drop across the flowcell was measured for different flow arrangements, first with a Newtonian fluid and then with drag reducing, dilute polymer solutions. The pressure drop in excess of the Newtonian baseline, after accounting for viscous effects, was used as a measure of elastic effects. With the dilute polymer solutions, elastic effects were observed both in shear, extensional, as well as presheared extensional flows. These effects can be attributed to additional normal stresses generated by shearing. For extensional flows, the observed effects were independent of elongation rates, indicating that a conclusion regarding the mechanism of drag reduction cannot be made from the flowfield investigated.

Keywords: elastic effects, polymer solutions, shear, extension, boger fluids
Advisor: James, David F.
Effects of Cannabis Dependence on Cognitive Function in Males with Schizophrenia

Background: Cognitive impairment and cannabis use are common among patients with schizophrenia. However, the moderating role of cannabis on cognition remains unclear. Aim: We sought to examine cognition and symptomatology as a function of cannabis use patterns in schizophrenia. Methodology: Cognition was assessed in male outpatients with current cannabis dependence (n=18), historical cannabis dependence (n=21) and patients with no lifetime use (n=8). In addition, we explored the relationship between cumulative cannabis exposure and cognition among lifetime users. Results: Lifetime cannabis users demonstrated better processing speed than patients with no lifetime use. Notably, patients with current dependence exhibited robust relationships between cumulative cannabis exposure and cognition; associations were absent in former users. Conclusions: Cannabis status has minimal effects on cognition in schizophrenia. However, cumulative cannabis exposure significantly impairs cognition in current, but not former users, suggesting that the state dependent negative effects of cannabis may be reversed with sustained abstinence.

Keywords: schizophrenia
addiction
Advisor: George, Tony Peter
Generation of Planar Cell Polarity (PCP) in vitro for Epithelium Tissue Engineering

Engineering epithelium with correct structure is essential for generating functional tissue. During tissue development, cells organize in defined patterns through cellular signalling. Artificial generation of the signalling that organizes cells within the tissue offers a novel approach for engineering tissues with appropriate structure. Planar cell polarity (PCP) is a cellular signalling pathway involved in the organization of epithelial cells. Our goal is to study the effect that co-culturing genetically distinct populations of epithelial cells, with variable levels of one of the core PCP proteins, has in epithelial cell sheet organization. MDCK cells transduced with a tagged PCP core protein (GFP-Vangl2) and wild type MDCK cells were co-cultured side-by-side. The effect of tight junction and cilia formation, and localization of the GFP-Vangl2 protein were evaluated. The results suggest that tight junction and cilia formation are not affected. On the other hand, the GFP-Vangl2 protein seems to be affected at some level.

Keywords: Epithelium Tissue Engineering
Planar Cell Polarity
Advisor: McGuigan, Alison P.
Indications of Stress Corrosion Cracking Resistance in Alloy 82 Dissimilar Metal Welds in Simulated Primary Water Environments

Joints between carbon steel and Alloy 600, containing Alloy 82 weld metal, were exposed to two steam-hydrogen environments considered to simulate exposure to primary water conditions in a Pressurized Water Reactor (PWR) or Canada Deuterium Uranium (CANDU) reactor. The welds were found to have elevated and variable iron contents due to dilution by carbon steel during welding. This gave the Alloy 82 weld, near the inner surface of the component, an iron content approaching that of Alloy 800. A potentially protective external iron oxide film formed on the inner surface of the weld. However, the chromium content throughout the weld is below that which would form an external chromium oxide. The results indicate that low chromium content causes internal oxidation throughout the weld and potentially below the external iron oxide which could lead to Primary Water Stress Corrosion Cracking (PWSCC).

Keywords: Internal Oxidation
Stress Corrosion Cracking
Oxidation
Alloy 82
Alloy 800
Alloy 600
Cracking
Corrosion
Nuclear
Primary Water
Advisor: Newman, Roger C.
Improving Credit Card Fraud Detection using a Meta-learning Strategy

One of the issues facing credit card fraud detection systems is that a significant percentage of transactions labeled as fraudulent are in fact legitimate. These “false alarms” delay the detection of fraudulent transactions. Analysis of 11 months of credit card transaction data from a major Canadian bank was conducted to determine savings improvements that can be achieved by identifying truly fraudulent transactions. A meta-classifier model was used in this research. This model consists of 3 base classifiers constructed using the k-nearest neighbour, decision tree, and naïve Bayesian algorithms. The naïve Bayesian algorithm was also used as the meta-level algorithm to combine the base classifier predictions to produce the final classifier. Results from this research show that when a meta-classifier was deployed in series with the Bank’s existing fraud detection algorithm a 24% to 34% performance improvement was achieved resulting in $1.8 to $2.6 million cost savings per year.

Keywords: data mining
credit card
meta-learning
artificial intelligence
algorithms
fraud detection
Advisor: Lawryshyn, Yuri Andrew
In and Out of Consciousness: Sustained Electrophysiological Activity Reflects Individual Differences in Perceptual Awareness

Examining the neural correlates associated with the moment a stimulus enters or exits conscious awareness is one way to potentially identify the neural mechanisms that give rise to consciousness. In the present study, we examined neural activity using electroencephalogram (EEG) recordings while participants observed a bilateral shape-from-motion (SFM) display. While the display is in motion, the observer perceives an object that is immediately segregated from a noisy background. After the motion stops, the observer’s experience of the object remains momentarily in awareness, before it eventually fades out of consciousness back into the noisy background. Consistent with subjective reports of perceptual experience, we observed a prominent sustained posterior contralateral negativity (SPCN), but only in conditions associated with sustained awareness. Importantly, the amplitude of the SPCN was correlated with individual differences in visual awareness, suggesting that this activity plays a significant role in the maintenance of objects in consciousness.

Keywords: Visual Awareness
Visual Working Memory
Perception
Consciousness
Advisor: Ferber, Susanne
Identification and Characterization of the Interaction between VPS33B and SNAREs

VPS33B is a Sec1/Munc18 protein required for the biogenesis of α-granules in megakaryocytes, which give rise to platelets. Mutations in VPS33B cause arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome. Platelets from ARC patients completely lack α-granules, causing a bleeding disorder. VPS33B plays a role in vesicular fusion events through its interaction with the SNARE proteins, though no such interactions have been identified. Here, it is shown that VPS33B interacts with STX6, a member of the syntaxin subfamily of SNAREs. The introduction of ARC mutations into VPS33B completely abrogated binding to STX6. Confocal microscopy studies revealed STX6 co-localizes well with markers of the α-granule biogenesis pathway. This implies a role for the interaction of VPS33B with STX6 in α-granule biogenesis. Based on the known structure of STX6 and that predicted of VPS33B, suggests a novel and unique mode of binding between VPS33B and STX6 compared to other identified SM-STX pairs.

Keywords: SNAREs
Sec1/Munc18
VPS33B
syntaxin-6
megakaryocyte
platelet
Advisor: Kahr, Walter
Multispectral Detection of European Frog-bit in the South Nation River using Quickbird Imagery

This thesis investigated multispectral detection of the invasive floating macrophyte, European Frog-bit, using Quickbird imagery and fuzzy image classification. To determine if the spectral signature of European Frog-bit were separable from other wetland vegetation, a species level land cover classification was conducted on a 6km section of the South Nation River in Ontario, Canada. Supervised and unsupervised imagery classification approaches were evaluated using the fuzzy classifiers, Fuzzy Segmentation for Object Based Image Classification (FS) and Fuzzy C-Means (FCM). Both approaches were sufficiently robust to detect European Frog-bit. User’s and producer’s accuracies for the European Frog-bit class were 81.0% and 77.9% for the FS classifier and 63.5% and 73.0% for the FCM classifier. These accuracies indicated that the spectral signature of EFB was sufficiently different to permit detection and separation from other wetland vegetation and fuzzy image classifiers were capable of detecting EFB in Quickbird imagery.

Keywords: Fuzzy Classification
European Frog-bit
Multispectral Detection
Quickbird
Advisor: Robinson, Vincent
He, Yuhong
The Effect of Zoledronate Pretreatment on BMP Induced Bone Formation in Mice

Recombinant human bone morphogenetic proteins (rhBMPs) are increasingly used for reconstructing bony defects, fracture non-unions, and augmenting existing bone volumes. For the numerous patients taking bisphosphonates, the impact of prior bisphosphonate treatment on rhBMP bone induction is not well understood. Objective: to evaluate the effect of the prior treatment with zoledronate on rhBMP induced bone formation in mice. Methods: 42 mice were pre-treated with 0, 2, and 20 µg of zoledronate/mouse. The osteoinductive activity of a bioimplant, containing rhBMP-2, was assessed using the mouse muscle pouch assay, and analyzed with micro CT and histology. Results: micro CT demonstrated that BMP bioimplants placed in mice pretreated with 20 µg of zoledronate, formed bony ossicles of greater volume but reduced bone density compared to controls. Histologically, the heterotopic ossicles from the 20 µg group consisted of more immature bone than those from the other groups. Conclusion: bone induced by rhBMP-2 in mice pre-treated with a high concentration of zoledronate was immature as evidenced by radiographic and histologic appearance.

Keywords: zoledronate
BMP
bone morphogenetic proteins
bisphosphonates
bone graft
Advisor: Peel, Sean
Analysis and Implementation of Fine-grained Distributed Maximum Power Point Tracking in Photovoltaic Systems

This thesis deals with quantifying the merits of Distributed Maximum Power Point Tracking (DMPPT), as well as providing solutions to achieve DMPPT in PV systems. A general method based on 3D modeling is developed to determine the energy yield of PV installations exploiting different levels of DMPPT granularity. Sub-string-level DMPPT is shown to have up to 30% more annual energy yield than panel-level DMPPT. A Multi-Input-Single-Output (MISO) dc-dc converter is proposed to achieve DMPPT in parallel-connected applications. A digital current-mode controller is used to operate the MISO converter in pseudo-CCM mode. For series-connected applications, the virtualparallel concept is introduced to utilize the robustness of the parallel connection. This concept is demonstrated on a three-phase boost converter. The topology offers reduced output voltage ripple under shading which increases the life-time of the output capacitor. The prototypes yield output power benefits of up to 46% and 20% for the tested shading conditions.

Keywords: Photovoltaic
solar energy
distributed maximum power point tracking
partial shading
dc-dc converter
performance analysis
3D modeling
solar forecasting
Advisor: Trescases, Olivier
Patient-centered Perspectives of Communication and Handover between the Emergency Department and General Internal Medicine

Effective communication among clinicians is critical for patient safety. This multi-site observational study analyzes inter-clinician communication and interaction with information technology, with a focus on the critical process of patient transfer from the Emergency Department to General Internal Medicine. The study provides insight into clinician workflow, evaluates current hospital communication systems, and identifies key issues affecting communication. It suggests opportunities for improvement: • extending the role of the electronic patient record, • rendering it available on a mobile platform, • developing an improved paging system. It also identifies design trade-offs to be negotiated: • synchronous communication vs. reducing interruptions, • notification of patient status vs. reducing interruptions, • portability vs. screen size of mobile devices, • speed vs. quality of handovers, • information privacy vs. accessibility. The results inform the potential development of an intervention meeting seven principles: interconnectivity, context awareness, accessibility, redundancy, user customization, security, and intuitive user interfaces.

Keywords: communication
handover
hospital
information technology
emergency department
general internal medicine
transfer
pager
Advisor: Cafazzo, Joseph
Design and Evaluation of Pressure-based Sensors for Mechanomyography: an Investigation of Chamber Geometry and Motion Artifact

Mechanomyography (MMG) has been proposed as a control modality for alternative access technologies for individuals with disabilities. However, MMG recordings are highly susceptible to contamination from limb movements. Pressure-based transducers are touted to be the most robust to external movement although there is some debate about their optimal chamber geometry, in terms of low frequency gain and spectral flatness. To investigate the question of preferred geometry, transducers with varying chamber shapes were designed, manufactured and tested. The best performance was achieved with a transducer consisting of a low-frequency MEMS microphone, a 4 micron thick aluminized mylar membrane and a rigid conical chamber 7 mm in diameter and 5 mm in height. Furthermore, microphone-derived MMG spectra were found to be less influenced by motion artifact than corresponding accelerometer-derived spectra. However, artifact harmonics were present in both spectra, suggesting that bandpass filtering may not remove artifact influences permeating into MMG frequency bands.

Keywords: microphone
mechanomyography
access technology
acoustics
membrane vibration
muscle vibration
physiological measurement
physiological signal
mechanomyogram
MMG
intensification
amplification
rehabilitation engineering
motion artifact
artefact
signal contamination
SNR
SNSR
Advisor: Chau, Tom
Canada’s Patented Medicines (Notice of Compliance) Regulations: Removing Inefficiencies to Encourage Generic Competition

Canada’s Patented Medicines (Notice Of Compliance) Regulations fail to achieve the intended purpose of balancing innovation with timely generic market entry. An examination of the inefficiencies created by the Canadian regulations reveals that key features of U.S. pharmaceutical law should be adopted to improve the disjointed regulatory system that impedes generic competition. Specifically, the regulations should be amended to consolidate multiple proceedings into one cause of action that evaluates patent validity. An economic incentive to challenge weak patents should also be introduced in Canada. These features encourage competition without deterring pharmaceutical research and development because only patents that are not truly inventive will be invalidated after a full inquiry. As such, the intellectual property laws will continue to satisfy Canada’s international intellectual property obligations and protect innovative medicines and allow recovery of costs and monopoly profits to new and useful pharmaceutical products.

Keywords: patent
pharmaceutical
Notice of Compliance
Hatch Waxman
generic pharmaceutical
Advisor: Fadel, Mohammad