title: An Exploration of the Cognitive and Behavioural Dimensions of Law Students' Online Legal Research Processes

contributor:
Beach, Pamela
Education

subject:
Legal Research
Law Students
Cognitive Processes
Think-Aloud Method
Information Seeking Behaviour
Online Research Behaviour

abstract:
Legal research is an essential skill for lawyers and a fundamental part of Canadian law school curricula. In recent years, legal research has shifted from a print-based activity to an online one. Legal research educators have argued that this transition requires law students to learn a new set of research behaviours and cognitive skills (Callister, 2010; Harker, 2013; Wheeler, 2011). However, this literature is largely conceptual in nature, and very little is known empirically about the experiences of law students as they conduct legal research online. The current study addresses this gap by examining the cognitive processes and online research behaviours that occur when law students conduct online legal research.
Five second-year law students from an Ontario university performed an online legal research task that was recorded. After completing the task, participants did a virtual revisit think-aloud (Beach & Willows, 2017), in which they verbalized their thoughts while viewing the screen recording of their research session. Participants also completed a demographic questionnaire and a semi-structured interview after the session. The data was analyzed using qualitative methods to gain an in-depth understanding of the participants’ experiences conducting online legal research. The analysis resulted in a taxonomy of cognitive processes during online legal research that closely resembles the cognitive processes and knowledge types described in Bloom’s Revised Taxonomy of Learning Objectives (Anderson & Krathwohl, 2001). In addition, empirical evidence was found for key cognitive processes previously identified in the legal research literature, namely, evaluating and selecting relevant legal information; creating a research plan and reflecting on research processes; and the application of metacognitive skills. With respect to online legal research behaviours, this study found three broad categories of research behaviour that were prevalent throughout the participants’ research sessions: (1) Information-seeking behaviour, (2) Reading, and (3) Notetaking. The study findings provide insights into the cognitive processes and research behaviours in which law students engage when conducting online legal research. These findings can inform the ongoing development of instruction, learning outcomes, support tools, and prompts to help students conduct online legal research more effectively.

abstract: M.Ed.


title: The Influence of Movement Costs on Search Behaviour

contributor:
Flanagan, J. Randall
Neuroscience Studies

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

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

rights: Intellectual Property Guidelines at Queen's University

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

subject:
visual search
motor costs
decision making

abstract: Humans regularly search their environment for an object to grasp through movements of the eye, head, and body. While search behaviour in humans has been well-studied, there has been little work which has investigated if the movement costs associated with searching influence where we search. While it has been shown that people attempt to minimize movement costs in other sensorimotor tasks, it is unclear to what extent people minimize these costs when making decisions of where to search for a target object. This thesis investigated whether people attempt to minimize both the biomechanical effort and time associated with searching for, and reaching to, target objects. The three studies contained in this thesis had participants search an environment for a target among distractors through either movements of the hand or eye. We manipulated the costs associated with searching, or reaching, by increasing the effort or time it took to search or reach to particular locations of the search environment. In the first study, we conducted a series of experiments to test the influence of movement effort and time on both visual and manual search. We found that visual search was influenced by time, but not effort associated with searching, with manual search being influenced by both time and effort costs. In the second study, we showed that participants are more influenced by movement time and effort costs during visual search when the costs are specified by visual information present in the search space. In the third study, we showed that participants are capable of minimizing movement effort during manual search after learning to associate the effort involved in search to visual features of potential target objects. Together, these studies are the first to directly reveal the influence of movement costs on search behaviour, reinforcing the view of search as a complex sensorimotor behaviour.

abstract: PhD


title: Laboratory Characterization of Turbulent Hyporheic and Free Surface Flows Associated with Bars in Gravel Streams and Related Efforts to Improve Measurement Techniques

contributor:
da Silva, Ana Maria Ferreira
Civil Engineering

subject:
Hyporheic flow
Gravel bar
Nortek Vectrino Profiler
Saw-tooth pattern
Interference region
Gravel stream
Seepage ratio
Suction and injection

abstract:
Bars and pool-riffle sequences are common occurrences in gravel streams, and a major driving force affecting the exchange of groundwater and free surface water in upper river reaches. Such topographic features induce downwelling and upwelling hyporheic flows, essential to the preservation of the river ecosystem.
The primary goal of this work is to address the lack of data on hyporheic flows induced by bars and their effect on the streamflow. An extensive laboratory study detailing both the hyporheic and free surface flows is presented. The work is limited to the study of a two-dimensional axisymmetric bar, 1.6 m long and 0.06 m high, over a substrate of finite thickness and subjected to a 0.18 m streamflow depth.
It is found that over the upstream side of the bar, the hyporheic flow abstracts a significant amount (10.1%) of water from the free surface flow. Through the combined effect of suction and injection, a pronounced shear layer forms 0.01 - 0.015 m away from the bed surface, leading to intense turbulence activity on the downstream side of the bar. In particular, the region around the location where the hyporheic flow divide line meets the bed surface appears as a preferential region for the generation of eddies, that ultimately grow considerably as they are conveyed downstream, before dissipating.
This study is also used as an opportunity to investigate means of acquiring more accurate measurements of streamflow instantaneous velocities using the Nortek Vectrino Profiler. For this purpose, two additional experimental studies are presented. These deal with the minimization or elimination of the saw-tooth pattern in vertical profiles of pertinent quantities (velocities and turbulence stresses), and ways to minimize the instrument's interference region near the bed.

abstract: PhD


title: Supersonic Combustion Wave Propagation in an Obstructed Volume of Hydrogen

contributor:
Ciccarelli, Gaby
Mechanical and Materials Engineering

subject:
detonation
deflagration-to-detonation transition
supersonic combustion
explosion safety
detonation propagation
soot foil
quasi-detonation
obstructed channel

abstract: As the use of hydrogen as an energy carrier becomes more prevalent, deep knowledge of its combustion characteristics are required to protect personnel and property in the vicinity of its use. This knowledge is also important for new and novel applications of this carbon-free fuel in the transportation, home energy, grid storage, and gas generation markets. An atmospheric release of gas, even in small quantities due to its wide flammability range, can be ignited by a low energy source. Acceleration of the flame in the presence of obstructions can lead to supersonic combustion and transition to detonation. This work, consisting of six related studies presented in manuscript format, focuses on the combustion wave propagation characteristics of hydrogen in obstructed environments, such as those typically encountered in accidental release scenarios. Specific focus is directed to four areas linked to supersonic combustion: the role of shock reflections, the development of an unobtrusive low-cost diagnostic for detonations, leveraging simultaneous and multi-axis diagnostic techniques, and the role of three-dimensional behaviour. The cyclic nature of quasi-detonation propagation in an obstructed channel, consisting of gas transition from deflagration to detonation and back, is investigated using high-speed schlieren photography and a simultaneous soot-foil technique to couple the physical record of the combustion wave with the temporal record. This allows for the identification of key shock reflection processes, and how they couple to each other in the propagation mechanism. The impact of channel width on wave behaviour revealed a new continuous detonation mechanism supported by obstructions but not involving more common shock ignition. Numerical investigation of the prevalent shock reflection ignition at an obstacle was used to determine the critical incident condition required for direct detonation (strong) ignition at typical quasi-detonation conditions.

abstract: PhD


title: DESIGN AND COMPUTATIONAL VALIDATION METHODS OF A COMPOSITE PASSENGER AIRCRAFT SEAT WITH ADVANCED MATERIAL MODELING TECHNIQUE

contributor:
Kim, Il Yong
Mechanical and Materials Engineering

subject:
Composite Materials
Finite Element Analysis
Explicit Dynamic Analysis

abstract: As industry has adopted the use of carbon fiber reinforced plastics (CFRPs) at an increasing rate, the need for specially developed design and analysis methods increase likewise. Specifically, through development of new low-cost CFRP materials, a broadening range of industries are intent on adopting the benefits of CFRPs at attainable costs. With the invention of new composite materials and material configurations, arises the need for new modeling techniques and practices to give users more capabilities in the design process. This thesis is presented to provide further insight into computational design processes and validation methods associated with a newly developed CFRP material. A laminate optimization process for CFRPs is compared with traditional topology optimization (TO) processes as conceptual design tools for a passenger aircraft seat concept, showing potential of 8% performance gain over traditional materials and methods. Additional work is presented into the development of an advanced material modeling technique specifically tuned and correlated for a new CFRP material system, denoted as long fiber prepreg sheet (LFPS). This LFPS modeling technique has been developed within LS-DYNA software to have the capability to model the progression of intralaminar and interlaminar failure. This technique has been correlated to experimental results through explicit dynamic analysis of three experimental testing procedures, producing maximum load results within 1%, 10%, and 2% of each tensile, short-beam, and shear scenarios, respectively. The LFPS modeling technique also showed matching failure mechanisms to each testing scenario. This modeling technique has been developed with the intent to give future users the capability to model LFPS structures with confidence and to provide insight for other users to develop material modeling techniques for similar materials. Further work has been presented which begins to evaluate the efficacy and performance of the developed LFPS modeling technique on large-scale practical problems. The culmination of the work presented in this thesis leaves a strong foundation of design and validation methods for improving capabilities in modeling the LFPS material and can act as a framework for other techniques to be developed for similar materials.

abstract: M.A.Sc.


title: Essays in Firm-level Productivity, Mortgage Policy Reform, and Intellectual Property Protection

contributor:
Clark, Robert
Economics

subject:
firm-level productivity
mortgage policy reform
intellectual property protection

abstract:
This dissertation investigates policy-relevant questions concerning firm-level productivity, mortgage interest deduction, and intellectual property protection. The first essay explores the effects of debt and equity financing on firm-level productivity and productivity growth using a state-of-the-art production function estimation approach that addresses the transmission bias. I find that equity financing has a positive effect on productivity and productivity growth. In contrast, debt financing has a negative effect on productivity and productivity growth. I also find the productivity effects of financing to be heterogeneous across sectors within the manufacturing industry.

The second essay studies the impact of a Dutch mortgage policy reform that eliminated mortgage interest deduction for interest-only and deferred amortization mortgages on January 1, 2013. The econometric challenge addressed in this study is the fact that households choose mortgage products based on observable and unobserved characteristics, which results in a selection bias. I ameliorate this concern by combining kernel matching with a difference-in-difference estimator to make predictions about the effects of the policy reform. I find that the reform led to higher mortgage interest rates for treated households. Moreover, I find that the policy compelled the treated mortgagors to reduce their mortgage debt by opting for cheaper and smaller homes.

The third essay examines the role of external cooperation and  practices of competitors in the informal sector in influencing adoption of IP protection in East Africa. I find that firm size, access to a skilled labour force, use of retained earnings, and being an exporter have positive associations with IP protection. I also find that adoption of IP protection has a positive correlation with access to external research and/or software consultants and external R&D. In contrast, use of foreign technology is associated with lower probability of IP protection as it crowds out in-house innovation. Competition from informal firms has no correlation with the probability of adopting IP protection if a firm appraises it to be a minor obstacle. However, firms that perceive practices of the informal competitors as a moderate obstacle or a major obstacle or a very severe obstacle are more likely to embrace IP protection.

abstract: PhD


title: EVALUATION OF PHASE ANGLE AS A PRACTICAL PARAMETER FOR LOW TEMPERATURE SPECIFICATION GRADING OF ASPHALT BINDERS

contributor:
Hesp, Simon
Chemistry

subject:
phase angle
low temperature specification grading
BBR
specification grading
thermal cracking
Extended BBR

abstract:
The importance of road and highway systems in the development of a nation’s economy cannot be overemphasized.  Over the years, concerted efforts have been made by researchers to develop and design test methods with high accuracy, repeatability, and reproducibility. The goal is to reduce pavement failures and the high cost of road construction and rehabilitation. Current low temperature performance tests such as the bending beam rheometer (BBR) and extended BBR (EBBR) tests are not without limitations. They could be time-consuming and require more sample quantity even though they are rigorous and accurate. Hence, this study aims to examine the viability of limiting phase angle measurement as a credible alternative to the laborious extended BBR (EBBR) procedure.
In this study, a total of 239 samples were tested from various agencies and are grouped into tank samples, core samples and loose mix samples. Agency A and Agency B were carefully examined to ensure climatic and traffic requirements are met. High temperature performance grade (HTPG), intermediate temperature performance grade (ITPG), regular bending beam rheometer (BBR), extended bending beam rheometer (EBBR) tests were carried out on the samples. In addition to this, the data obtained from each test were correlated with limiting phase angle temperature [T(30°), T(45°)].
From the study, Agency B largely met the climatic and traffic requirements when compared with Agency A, due to a much more effective approach adopted by the agency. Furthermore, correlation studies involving ITPG, BBR, and EBBR with limiting phase angle temperature showed that core samples have the highest correlation followed by loose mix samples and tank samples. From the large data set used in this study, it is more evident that the limiting phase angle measurement is a viable alternative to evaluate the thermal cracking performance of binders because of its higher sensitivity, easier experimental procedure, and smaller sample quantity requirement.

abstract: M.Sc.


title: THE QUANTIFICATION OF NEUROCOGNITIVE IMPAIRMENT ACROSS THE SPECTRUM OF KIDNEY DISEASE

contributor:
Boyd, J. Gordon
Neuroscience Studies

subject: Chronic Kidney Disease (CKD)

subject: Acute Kidney Injury (AKI)

subject: Kinarm

subject: Neurocognitive Impairment

subject: Regional Saturation of Cerebral Oxygenation (rSO2)

subject: The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)

subject: Cognitive Impairment

abstract:
Over the last decade, it has become evident that patients with chronic kidney disease (CKD) are at high risk of developing neurocognitive impairment, which may influence medication/dietary adherence and quality of life. I therefore initiated a program of research that used cutting-edge robotic technology (Kinarm) to precisely and objectively quantify neurocognitive impairments in patients with CKD. To contextualize my work, a systematic review and meta-analysis was performed. Of the one-hundred and forty-eight studies identified, the vast majority used dementia screening tools to identify impairments in patients with CKD. It also demonstrated that patients who were pre-dialysis and dialysis-dependent CKD performed significantly worse than non-CKD controls.

I then performed a prospective observational study that quantified neurocognitive impairment in a cohort of patients with CKD. Forty-nine patients were recruited and assessed with the Kinarm and a traditional neurocognitive screening tool. Although, little impairment was detected by the neurocognitive screening tool, Kinarm detected impairments in up to ~50% of the cohort (task dependent). Additionally, this is the first study to demonstrate that perceptual-motor impairments are common in patients with CKD in addition to attention and executive function impairments.

Next, I characterized neurocognitive impairment in an understudied cohort: patients who experience acute kidney injury (AKI). Twenty-one patients with AKI were compared to healthy controls, and 21 active control patients matched for cardiovascular risk factors. Patients with AKI performed worse than healthy controls on attention, visuomotor, and executive function tasks. Additionally, patients with AKI performed significantly worse on attention and visuomotor domains when compared to active controls. This was the first study to prospectively investigate neurocognitive impairments after AKI.

Finally, to investigate a potential mechanism of accelerated neurocognitive impairment in patients with end-stage renal disease, I used near-infrared spectroscopy to serially measure cerebral oxygenation during hemodialysis sessions for 1 year. Ultimately, low recruitment rates deemed the study unfeasible, but interesting relationships between cerebral oxygenation, mean arterial pressure, and fluid removal rates were observed. In summary, neurocognitive impairments are common in patients with kidney disease, particularly in perceptual-motor, attention, and executive function domains. Future studies will need to address how these impairments affect quality of life.

abstract: PhD


title: USE ATYPICAL ASPHALT BINDERS FROM ALBERTA OILSAND SOURCES FOR THE EFFECTIVE RECYCLING OF ASPHALT PAVEMENT

subject:
Reclaimed Asphalt Pavement
Virgin asphalt binder
Rheological properties
I-FIT

abstract:
Utilization of Reclaimed Asphalt Pavement (RAP) and Reclaimed Asphalt Shingles (RAS) optimizes the use of natural resources by saving the cost for virgin asphalt binders and therefore reducing their environmental footprint.  This thesis presents experimental results of using RAP and RAS with virgin asphalt binders from Alberta oil sands deposits.
Virgin asphalt binder A from the Athabasca deposit and virgin asphalt binder C from the Cold Lake deposit were modified at two different RAP weight percentages (20 % and 40 % by weight of the total binder). Each blend was tested under four different aging conditions (Unaged, Rolling Thin Film Oven-aged (RTFO), Pressure Aging Vessel-aged (PAV) for 20 h (PAV-20) and 40 h (PAV-40)). The RAP sources used in this study came from rehabilitation contracts on Highway 7 and Highway 403, while tear-off shingles were used as a source of RAS binder. Fourier Transform Infrared (FTIR) spectrometry was used to monitor the degree of oxidation when binders were modified with RAP and RAS and subsequently aged in RTFO and PAV. Rheological properties of the modified binders after different aging protocols were assessed using a Dynamic Shear Rheometer (DSR). Hot Mixed Asphalt (HMA) tests were conducted for neat asphalt binders, 20 % RAP-modified binders and Polyethylene Terephthalate (PET)-modified binders using the Illinois Flexibility Index Test (I-FIT) at two different temperatures (room temperature and -10 °C).
	Rheological results showed that virgin binder A is the softer one and therefore accommodates more RAP than C. The results also reveal that 20 % RAP added to A can be used as a lower cost alternative for virgin C, as the two materials possess nearly the same rheological grade. According to the I-FIT results, using neat A with 20 % RAP gives higher flexibility than using neat C for HMA. Finally, using PET fibers with virgin binders drastically increases the flexibility of the HMA in the semi-circular bending test.

abstract: M.Sc.


title: The role of interference versus exploitative competition in shaping life histories of the smaller tea tortrix

contributor:
Nelson, William A
Biology

subject:
Intraspecific competition
Life history
Population dynamics
Insect pest
Insecticide

abstract:
Intraspecific competition is ubiquitous in nature and can fundamentally shape the individual life history. Competition occurs, and consequently influences life-history traits, through the direct effects of interference and indirect effects of exploitation. Importantly, it is the relative contribution of these two pathways that determines the overall impact of competition on life history. Since life history scales up to explain population dynamics, understanding the competitive mechanisms is required when predicting the impact of intraspecific competition on dynamics. However, current methods to identify the relative importance of each pathway are exclusive to a few taxa which limits our understanding of the consequences of competition.

In this thesis, I designed an approach to disentangling the role of interference versus exploitation in shaping life-history traits. The approach complements lab experiments and mathematical modeling that are applicable to a broad range of taxa. I demonstrated the approach with the smaller tea tortrix (Adoxophyes honmai), a pest moth for which competition is suggested to govern its recurrent population cycles in the field and in the lab. I found that competition in the moth is best characterized by a high level of interference that results in mortality, suggesting aggressive interactions. Next, I investigated whether temperature changes competition. Using the same approach across a temperature range, I found that temperature has no major effect on the competitive mechanisms. Then, to understand why the moth competes aggressively, I explored its cannibalistic behavior. Using a lab experiment, I showed that individuals tend to cannibalize at a low rate which improves their fitness. Finally, I asked whether insecticides alter the interference competition. Using lab experiments, I found that aggressive interactions increase with sublethal doses of insecticide.

Overall, I showed how competition shapes the moth life history and how this can change with environmental factors. These findings are essential for the proper embedding of competition into population models to accurately predict the pest cycles. They also imply that insecticides, by altering competition, can have substantial effects on dynamics. Lastly, the approach I developed to characterize the competitive mechanisms can help other biological systems to predict the impact of competition on population dynamics.

abstract: PhD


title: BUILDING RESILIENCE TO HIGH WINDS USING FRAGILITY ANALYSIS

contributor:
Genikomsou, Aikaterini
Civil Engineering

subject:
Tornado
Structures
FEA
Roofs
Fragility Analysis
Reconnaissance

abstract:
North America gets hit with approximately 1,100 recorded tornadoes annually.  In Ontario, Canada, more than 12 tornadoes are recorded between the months of May and September annually. Two major tornadoes hit Ottawa, Canada on September 21, 2018. Ottawa, Ontario suffered an Enhanced Fujita (EF 3and EF2) tornado in Dunrobin and Arlington Woods, respectively. These severe events destroyed numerous buildings, and thus, a field investigation was conducted to observe the damages in the structures. Damage-assessment data was recorded with a focus on damage failure modes and functionality of the buildings during the field investigation. According to the data collected, the damage was characterized based on different levels and discussion was formulated surrounding the way residential buildings should be built to assure resilience against tornadoes. Based on the site investigation, it was found that roofs are the most vulnerable component of a residential house and are often left with rafter, sheathing and shingle damages when exposed to high wind pressures.
Fragility analysis can be used to estimate the probability of failure of a roof when constructed with specified nails and sheathing sizes. Specific type of nails, roof to wall connection details and sheathing sizes based on the damaged roofs that were previously assessed in the Dunrobin area in Ottawa,Ontario. Empirical fragility analysis considers eight different scenarios, including different sheathing and nail sizes. These baseline structures were used to analyze how different variables in a wooden roof could affect the fragility analysis results. The considered variables included the nail type, panel size, wind load and dead load.
Finally, Finite element analysis (FEA) was conducted using the ABAQUS software to model and determine the structural responses of typical residential roofs. The wood-framed roof models permitted visualtion of the structural behaviour under wind pressures such as excessive stresses. The FEA model results were then compared to the results  from a field investigation in Dunrobin, Ontario. This methodology will allow for a more accurate prediction of tornadic wind-induced damage on residential roofs to be used for better design and construction practices.
The performance of the examined buildings from the field investigation, the fragility models and the initial ABAQUS models, suggests a need for more resilient design and retrofit methods to strengthen buildings envelopes.

abstract: M.A.Sc.


title: ENERGY DISSIPATION FROM INTERNAL SOLITARY WAVES SHOALING ON FLAT AND MILDLY SLOPING BEDS

contributor:
Boegman, Leon
Civil Engineering

subject:
internal solitary wave
wave energy dissipation
dissipation length scale
bolus
flat and sloping bed

abstract:
Abstract
Boundary layer separation-driven near-bed instability beneath internal solitary waves (ISWs) of depression may be a significant source of wave-energy dissipation and drive localized mixing and resuspension in coastal regions. In chapter 2, the details of estimates of energy flux by internal waves to quantify the dissipation of ISWs as they propagate over a flat bottom. Wave flume experiments were carried out to measure the dissipation of turbulent kinetic energy in the boundary layer beneath shoaling ISWs. Wave dissipative length scale of O(100) wavelengths for unstable waves; which is in agreement with limited field observations. Stable waves propagated significantly further (>1000 wavelengths). Internal solitary wave energetics were used to model wave dissipation lengthscales in terms of the wavelength and momentum thickness Reynolds number L^*=100λ+2.5×10^10 λ〖Re〗_ISW^(-3.7). In chapter 3, laboratory experiments were performed to measure dissipation within the turbulent bottom boundary layer beneath an ISW. Velocity vector maps were measured using Particle Image Velocimetry. Different methods of estimating dissipation from spatial gradients of the vector maps were compared, based on measured components of the dissipation tensor. Estimates based on assumptions of isotropy are typically larger than those based on methods using available velocity gradients with least number of assumptions (e.g., direct method). All the methods reproduce the same order-of-magnitude estimates for the dissipation rate (ε~10^(-7)-10^(-6)  W kg^(-1)) but the differences varied from 5% to 80% than the corresponding direct estimates. Chapter 4 describes an experimental investigation on the dissipative phase of ISWs as they propagate over uniformly sloping topography (S = 0.04) in a 20 m flume. Velocity profiles were recorded with three acoustic Doppler velocimeters. As each wave propagated up the slope, the wave of depression steepened and developed into an elevation-like wave before finally dissipating through forming a discrete vortex of dense fluid (bolus) which propagated for some distance up the slope. The dissipation length scale was parameterized in terms of the internal Iribarren number (ξ=S⁄√(a⁄λ)) as L^*=(302.7×ξ-10.4)×a and requires only a knowledge of incident ISW amplitude a and wavelength λ.

abstract: PhD


title: Aerial Captures: Extractivism and the Logistical Media of Air Travel in Postwar Canada

contributor:
Lord, Susan
Cultural Studies

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
maps
extractivism
logistical media
mobilities
air travel

abstract: The rapid development of technologies for air travel since the Second World War has contributed to significant changes in how space is perceived, conceived and imagined in Canada. From the extensive mapping conducted by Canadian air survey companies across the world between the late 1940s to the 1970s, to the networks for air travel that carved commercial corridors between urban centres and remote parts of Canada, air travel helped standardize emergent ways of seeing land as transparent, quantifiable and ready for resource extraction. The distanced and calculative view afforded by air travel has helped a small sector of the population to measure, standardize and reify relationships on land, thereby integrating representations of natural resources into transnational systems of circulation. In this portfolio thesis, I examine the media produced through and for air travel in Canada, including air surveys, maps, surveillance systems, and artworks. Postwar developments in air travel, combined with changing border control policies and technologies, also meant the proliferation of extractive ways of seeing the body through biometrics and other imaging technologies in the security theatre of airports. I therefore examine Canada’s three busiest airports, examining their cultural displays and security apparatuses, in order to critically consider visual regimes of governmentality. In this thesis, I outline how extractivism entails the negation of place-based relationality, and its replacement with the relationality of logistics and the world-system. This portfolio thesis takes the form of standalone chapters framed by an introduction and a conclusion, and accompanied by a web-based research-creation project (miningmaps.net). This project includes artistic data visualizations examining the widespread use of “fly-in/fly-out” operations in Canada’s gold mining industry, and their wide-ranging environmental, social and cultural implications.

abstract: PhD


title: Digital Rockfall Databases: Developing Best Practices for Semi-Automatic Extraction of Rockfall from LiDAR

contributor: Geological Sciences and Geological Engineering

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Geohazards
Rockfall
Remote Sensing
Laser Scanning
Point Clouds
Quantitative Risk Analysis
Magnitude-Frequency
Change Detection
Surface Reconstruction
Computational Geometry

abstract:
In the digital age, the ability to collect and store information of phenomena in our world has become ever more useful, considering the vast improvements of predictive models and simulations. Geohazards are no different; acquiring data in order to characterize, forecast, and simulate geohazards requires the monitoring and documentation of their occurrences, with as much accuracy and detail as possible. Over the previous decade, advancements in remote sensing has resulted in platforms for capturing detailed 3-Dimensional surficial information of our surrounding world, providing opportunities to monitor geohazards with high levels of detail. Systems with oblique views are able to capture near vertical surfaces of rock cliffs, allowing for the monitoring and characterization of rockfall. Much research has thus focused on characterizing and understanding the failure mechanisms of rock slopes, by developing and applying tools for extracting information key to the rockfall phenomenon.

Observing rockfall allows for an understanding of its magnitude-frequency distribution, its spatial distribution, its geological and environmental triggering factors, as well as its chaotic interaction with the terrain. The potential power of digital rockfall databases is therefore limited by our ability to extract rockfall from our data – this is the focus of this thesis. Over the past 8 years, semi-automated methods have been developed and improved for extracting rockfall from laser scanning data. Although it is simple in theory, many sequential subprocesses are required, and thus, any errors introduced are capable of propagating, significantly impacting a rockfall database. In this thesis, I aim to build some best practices considering the common tools that have become utilized across different examples of semi-automated rockfall extraction methodologies.

I cover my variation of a semi-automatic method for assembling rockfall databases, and refer to its useful application in the domain of quantitative hazard and risk analyses. I discuss a heavily utilized change detection algorithm (multiscale model-to-model cloud comparison, or M3C2) used for isolating changing features in sequential spatial datasets, and discuss its spatial averaging component that has a substantial effect of rockfall extraction. I provide detailed insight into the estimation of rockfall point cloud volumes in 3D using computational geometry-based surface reconstruction methods. I recommend a hybrid surface reconstruction methodology comprised of two methods, the Alpha Solid, and the Power Crust. Together, the hybrid methodology is robust in achieving the correct topology of the rockfalls, while optimally considering prominent concave geometrical features and detailed surficial information. I finish my thesis by discussing the applications of digital rockfall databases into modern quantitative hazard and risk analyses, and I provide recommendations for future work.

abstract: M.A.Sc.


title: Veteran Teachers’ Perceptions of School Principals’ Leadership Influence on School Culture within the Secondary School Setting

contributor:
Butler, Alana
Education

subject:
Veteran Teachers
School Principal
Principal
Leadership
School Culture
Effective Leadership
Ineffective Leadership
Transformational Leadership
Authentic Leadership
Irresponsible Leadership

abstract: Educational researchers have noted that school leadership and culture can play an influential role in student success and academic achievement, which is widely considered the ultimate goal of education. This influence is attributed primarily to school culture and only indirectly due to the impact of the principal’s practice. There exists a significant gap in the literature regarding the perspectives of veteran teachers on the functioning and impact of this phenomenon. The purpose of this study was to explore veteran teachers’ perceptions of school principals’ leadership influence on school culture within the secondary school setting. Eight retired teachers, each with over 20 years of teaching experience, were recruited to participate in this study due to their in-depth personal experiences with leadership and school culture throughout their careers. Two rounds of open-ended, semi-structured, individual interviews were completed to elicit participants’ experiences, observations, and opinions with respect to the phenomenon being studied. A system of Pattern coding was used to analyze responses and establish themes. Three main themes emerged from the analysis of the data: a) effective school leadership, which aligned with authentic and transformational leadership models; b) ineffective school leadership, consistent with models of irresponsible leadership; and c) factors mitigating the influence of school leadership on school culture. Practically speaking, positive leadership practices were perceived to be more influential than negative practices, teachers viewed themselves as the gatekeepers of school culture, and reduced autonomy rendered a principal’s potential influence on school culture nearly negligible. By understanding how veteran teachers perceive the leadership practices observed in past principals, future principals can be more effectively recruited and trained to lead, enact positive change in their schools, and improve student success.

abstract: M.Ed.


title: Comprehensive Study on Modulation of a Dual Active Bridge Converter

contributor:
Jain, Praveen
Bakhshai, Alireza
Electrical and Computer Engineering

subject: Optimization, Dual Active Bridge converter, Electric Vehicle, DC-DC converter, Optimal Modulation

abstract:
In recent years, the single-phase Dual Active Bridge (DAB) converter has gained significant importance as it has simple power circuit, bi-directional power flow, and zero voltage switching (ZVS) operation. Although, numerous researchers have worked on this converter and proposed many modulation techniques, a thorough mathematical treatment of this converter has been missing from the literature.
This thesis presents a thorough mathematical treatment of the DAB converter. All the possible theoretical modulation patterns for the DAB converter are derived from the mathematical analysis. It is mathematically proven that there are up to 140 distinct switching patterns that can be applied to the converter. It is shown in the thesis that there are only two modulation patterns those result in the optimal performance of the converter in terms of minimum rms current and guaranteed zero-voltage-switching under wide range of operating conditions.
An analytical solution is developed and a step-by-step algorithm to obtain optimal time ratios for the two selected modulation patterns (denoted by Pattern (z) and Pattern (q) in this thesis) is given. The concept of idle time interval is introduced in this thesis. Then it is shown that the optimal modulation is based on pattern (z) with no idle time interval and pattern (q) with idle time interval. An optimal pattern modulation technique based on variable frequency has been introduced. It has been shown that a frequency variation of about 50% around the optimal power level corresponding to the maximum pattern efficiency can further reduce the conduction losses by 10%.
It is also shown how the optimal modulation can be extended to the scenario with reverse power flow as well as with an inverse ratio of voltages. The modulation pattern presented here is the optimal solution for every DAB converter with arbitrary parameters.

abstract: PhD


title: Thermal Ecology and Plasticity in the Burying Beetle, Nicrophorus orbicollis: An Observational Field Study

contributor:
Bonier, Frances
Biology

subject:
Life History
Phenotypic Plasticity
Burying Beetles
Nicrophorus orbicollis
Temperature
Thermal Ecology

abstract: Environmental temperatures are among the most significant factors affecting the ecology, behaviour, and evolution of organisms across all levels of biological organization. As such, understanding the impacts that natural thermal regimes have on organisms is central to the study of thermal ecology. Too often we, as ecologists, find ourselves drawing conclusions regarding interactions between temperature and organisms from laboratory studies using presumed optimal temperatures in studies of long-standing captive populations. Here, we used an observational field study to 1) describe the thermal ecology of a species of burying beetle, Nicrophorus orbicollis, 2) document natural associations between temperature and reproductive behaviours, and 3) document natural associations between temperature and traits related to fitness. We found that 1) the realized thermal regime inside brood chambers differed from both non-use subterranean sites and the soil surface, as well as from the temperatures commonly used in captive studies, 2) beetles buried carrion deeper when air temperatures were warmer, and 3) temperature inside the brood chamber predicted life-history traits: mean larval mass was lower when temperature variation increased and, contrary to previous findings of captive studies in our lab, overall brood size increased with mean temperatures. Our findings suggest that we should use caution when interpreting results from past captive work on N. orbicollis, as the conditions used in these studies may not reflect those seen in nature, leading to results with limited biological relevance. However, by producing a detailed description of the thermal ecology of N. orbicollis and supplying correlative evidence linking fitness components to temperature, our work aims to provide a more ecologically relevant context for future work on this species and burying beetles more generally, with the added benefit of being able to better predict how climate change may impact this and other similar species in the future.

abstract: M.Sc.


title: Development and Initial Testing of a Brief Mindfulness Meditation  Training Intervention for Preoperative Patients: An Application of the ORBIT Model

contributor:
Tripp, Dean
Psychology

subject:
Preoperative Anxiety
Preoperative Distress
Program Development and Evaluation
Psychology
Surgery
Knowledge Translation

abstract: Over 1,500,000 surgical procedures occur in Canada every year. Although medical and technological advances have greatly improved outcomes, surgery is not risk free: for instance, 3-16% of patients receiving general anesthesia will experience a perioperative complication; and approximately 30% of arthroplasty patients report an adverse event. Biomedical, social, and psychological factors have all been associated with poor surgical outcomes and perioperative complications. One such factor is preoperative distress, an acute stress reaction experienced by a patient in response to impending surgery. Individuals with higher preoperative distress experience more adverse events, like delayed wound healing and mortality. The psychological technique of mindfulness meditation is associated with improved health and well-being, and is suggested as a potential tool for mitigating preoperative distress. Informed by the mindfulness mediation literature, Social Cognitive Theory, and the ORBIT Model of Developing Behavioural Treatments for Chronic Disease, this dissertation aimed to develop and test a mindfulness meditation protocol for patients undergoing elective surgery. Research took place in three parts, corresponding with Phases IA, IB, and IIA of the ORBIT Model. Study One utilized a theory-guided, mixed-methods design, in which surgical wait-list patients (N = 31) and health care providers (N = 20) provided feedback regarding their perceptions of and preferences concerning preoperative mindfulness meditation. In Study Two, Study One findings were integrated with the results of a literature review to develop a theory-grounded and evidence-based mindfulness meditation intervention. The intervention was reviewed by both health professionals (N = 16) and surgical wait-list patients (N = 14), who reported that it was both acceptable and beneficial. Lastly, Study Three was a proof-of-concept study in which the mindfulness meditation intervention was tested via randomized controlled trial. Surgical wait-list patients (N = 66) received either standard care or standard care plus mindfulness meditation. Results indicated small but consistent pre-post meditation improvements in health/wellness perceptions, suggestive that a brief, online meditation bestows an acute benefit. Between-group differences in perioperative health, mental health, and functioning variables were primarily non-significant and small. Together, the three studies suggest that a brief, online mindfulness meditation program is feasible and may produce acute changes in patient health. However, many questions remain regarding the role of mindfulness meditation during the perioperative window. Namely: Is there something unique within the perioperative environment that renders (brief, online) mindfulness meditation non-effective? Do patients require a greater “dose” of mindfulness meditation to see an effect? (And, if so, are these higher-dose interventions feasible?) What surgical- or patient-level factors might moderate effects?

abstract: PhD


title: Psychological Mechanisms of Desired Attitudes

contributor:
Fabrigar, Leandre
Psychology

rights: Attribution-NonCommercial 3.0 United States

subject:
attitudes
motivated reasoning
values
attitude functions
desired attitudes

abstract: Attitudes are people’s evaluations of specific objects as being good or bad. Sometimes people wish that they held attitudes other than the ones they actually do (desired attitudes). Previous work has demonstrated that desired attitudes are felt to be aversive when they differ from actual attitudes, and that people are motivated to collect information to eliminate these discrepancies. However, minimal work examines the antecedents of desired attitudes, and no previous work has shown desired attitudes predicting actual attitude change. Nor does existing scholarship empirically demonstrate the psychological mechanisms that lead people to create and pursue desired attitudes. In the present five experiments, I explored how identity-related concerns can prompt people to form desired attitudes distinct from their actual attitudes, as part of a larger framework in which attitude functions are posited as the root of desired attitudes (the functional hypothesis). For example, when people learned that a painting they formed an opinion of was made by an immoral (moral) painter, they were influenced towards negative (positive) desired attitudes. Several unique desired attitude constructs (structural evidence of desired attitudes; subjective experiences of desired/actual attitude discrepancies) arose from these identity-related pressures. Also, consistent with the functional hypothesis, when people were exposed to identity-related pressures but were prevented from forming appropriate desired attitudes, they experienced disruptions in moral clarity, implying that people sometimes form desired attitudes to maintain their moral identity. Furthermore, desired attitudes played an important role in guiding subsequent attitude change – even in contexts where participants had no access to new information that they could use to facilitate attitude change (the signpost hypothesis).

abstract: PhD


title: Defending defined: Exploring how youth defending against peer victimization

contributor:
Craig, Wendy
Psychology

subject:
bullying
peer victimization
peer intervention
defending
adolescence

abstract: The current dissertation comprises three research studies that examined how youth defend their peers from victimization, as well as the social-emotional correlates of these defending behaviors. Theories of prosocial behavior, social-information processing, and adolescent socialization were applied to understand the multidimensional nature of peer defending behaviors across studies. Study 1 focused on the development and validation of the Defending Behaviors Scale (DBS) in a sample of early adolescents (n = 572). Results supported a four-factor model consisting of comforting, reporting, solution-focused, and aggressive defending. Most youth reporting using a variety of defending behaviors, with girls being more likely to use comforting and reporting and boys being more likely to use aggressive defending. Studies 2 and 3 used the DBS to examine the social-emotional predictors and outcomes of these defending behaviors. Study 2 (n = 120) employed a novel virtual-reality paradigm to examine defending behaviors as they unfold in real- time. The central finding from this study indicated that both anger and empathy interact to predict different defending behaviors. Lastly, study 3 (n = 334) used a longitudinal social network design to examine the social risks and rewards of defending behaviors in the peer group. Results demonstrated peer socialization effects for comforting, reporting, and solution-focused defending behaviors. Each defending behavior was reinforced in gender-normative ways by the peer group in terms of subsequent changes in victimization and popularity. Through the integration of theoretical perspectives and application of novel research methods, this dissertation describes the intrapersonal and interpersonal factors that influence how youth defend against peer victimization. Findings from this research can inform the development of bullying prevention and intervention efforts that aim to increase peer defending among early adolescents.

abstract: PhD


title: Understanding the Complexity and Nuance of Social Identity in Youth Sport Using a Novel Ecological Momentary Assessment Method

contributor:
Martin, Luc
Bruner, Mark
Kinesiology and Health Studies

subject:
ecological momentary assessment
behavioral observation
social identity
youth sport
leadership
daily diaries
multilevel modelling

abstract:
The social environments in sport play an important role in determining whether participants realize the various individual and group outcomes associated with sport participation (Eys et al., 2019). Indeed, sport researchers have increasingly turned to the social identity approach (SIA; Tajfel & Turner, 1979; Turner et al., 1987) for theoretical explanations pertaining to how intragroup and intergroup factors contribute to optimal team environments (e.g., Rees et al., 2015). Two important limitations pertaining to the body of literature are that it has (a) been largely limited to athletes’ perceptions (e.g., an absence of behavioural measures and/or perceptions from social agents such as coaches and parents/guardians) and (b) primarily involved the exploration of perceptions as they relate to the immediate sport activity. This dissertation aims to address these gaps in three studies that introduce the Electronically Activated Recorder (EAR; Mehl et al., 2001) and a sport adapted EAR methodology that enables the exploration of intragroup and intergroup interactions in the sports’ broader social environments (e.g., in the locker room, on the car ride to/from sport, at the dinner table).
	Study 1 provided a comprehensive overview of traditional and innovative approaches to examining sports’ broader social environments before introducing a sport-adapted EAR methodology as a novel approach to assessing intragroup and intergroup behaviours. Study 2 applied these methodological advancements to explore the interactions between members of youth ice hockey teams during a three-day competitive tournament. The findings showed that youth athletes were more likely to engage in behaviours indicative of ingroup affect and cognitive centrality on days when they received more of the same behaviours from teammates, coaches, and parents. Study 3 investigated identity leadership in the daily interactions and behaviours of competitive youth coaches during the three-day tournament. Coaches’ observed interactions were found to be representative of the four dimensions of identity leadership (i.e., identity prototypicality, advancement, entrepreneurship, and impresarioship), which were used in both positive and negative ways. Overall, the dissertation advanced the sport-adapted EAR methodology as an innovative approach for investigating social identification processes in the everyday interactions between members of youth sport teams.

abstract: PhD


title: The Bilayer Polymer Light-Emitting Electrochemical Cells

contributor: Physics, Engineering Physics and Astronomy

subject:
doping
light-emitting electrochemical cell
polymer interface
solid polymer electrolyte
ion transport
electroluminescence
p-n junction

abstract: Polymer light-emitting electrochemical cells (LECs) are solid-state polymer devices that form light-emitting p-n junctions in situ from electrochemical doping, which occurs under an applied voltage or current bias. LECs typically consist of a combination of a luminescent polymer, an electrolyte polymer, and a salt. This creates a mixed ionic/electronic conductor. When comparing the LECs to other polymer/organic light-emitting devices, the LEC is advantageous as it is not dependent on the electrode's work functions. However, a key LEC limitation is the phase separation among the luminescent polymer and the electrolyte-salt complex. One solution to the phase separation issue is to separate the LEC into two layers: the luminescent polymer layer and the electrolyte layer, creating a bilayer LEC. In my thesis, multiple studies were conducted to explore whether the thickness of the luminescent polymer layer changes the performance of the bilayer LEC, the development of a blue bilayer LEC, and examining a different bilayer LEC configuration of a luminescent polymer layer on top of a LEC layer. In the varying CP thickness study, the thinner CP layer allowed the ions to penetrate the total depth of the CP layer and commence uniform doping propagation. Meanwhile, in the thicker CP layer, the ions do not fully penetrate the CP layer which leads to a broadened light-emitting junction formation. The bilayer LECs have faster turn-on times than the single-layer LECs. In addition, the current and doping propagations in bilayer LECs demonstrated a linear dependence with varying operating voltages and an Arrhenius dependence with varying operating temperatures. These faster doping speeds imply that the long-range ion transport in the CP layer or crossing the CP/SPE interfacial energy barrier has a minimal effect to doping speed; rather, the limiting factor to the doping speed is the SPE bulk-resistance. These studies are important to understand the fundamental of bilayer LECs and potentially be the gateway to high-performances LECs, and other organic devices.

abstract: M.A.Sc.


title: Development of Material Extrusion Infill Optimization Approaches for Various-Resource Entities

contributor:
Kim, Il Yong
Mechanical and Materials Engineering

subject:
Topology Optimization
Infill
Additive Manufacturing

abstract: Additive manufacturing (AM) is an expanding research field, proportional to the increased adoption the industry is experiencing.  With AM machines targeted towards industry level clients and hobbyists alike, the diversity in customers has become quite large.  Given the benefit of AM being specialized at producing prototypes or parts in the mass customization categories, small scale producers can remain competitive with larger industries if they are able to compete on the design frontier.  As the specialized software suites commonly used today in the new accelerated design cycle are quite expensive and require an advanced technical comprehension, beginner users are not able to benefit as greatly from them compared to the larger entities.  To alleviate this disparity, this work targets the furtherment of optimization algorithms and methodologies applicable to all levels of an AM user’s ability.  The introduction of an engineering-centric AM evaluation tree will allow non-technical managerial level users to evaluate the applicability of 3D printing for their applications.  The design of a practical methodology that can be leveraged by any material extrusion (MEX) user will provide a foundation from which all parts with appreciable infill can be optimized.  An expansion of this work will be subsequently provided that allows more technically advanced users to generate custom infill, improving on the structural performance available through commercial infill patterns.  Lastly, the incorporation of manufacturing specific constraints into a topology optimization code will combine optimal topology results with practical manufacturing constraints for infill design, alleviating the need for substantial design reinterpretation.  The culmination of the presented work provides an optimization framework for the hobbyist level users that have not historically seen many tools available to them, while simultaneously furthering the realism of constraints found in optimization algorithms, producing more manufacturable final results.  Overall, advances in the research are presented at all levels of AM ability which stand to further the industry as a whole.

abstract: PhD


title: ON THE (IM)POSSIBILITY OF TRANS PHILOSOPHY: TRANSITIONING TEXTS AND GENRE REASSIGNMENT

contributor:
Davies, Jacqueline
Philosophy

subject:
trans philosophy
trans poetics

abstract: This thesis consists of two parts: the first is an academic article that puts forward three arguments—phenomenological, affective, and ambiguous—for the use of trans poetics as a form of trans philosophy. The second is a collection of poems serving as an example of how one might do trans philosophy through trans poetics, as well as a user’s guide for interpreting the poems.

abstract: M.A.


title: Use of phase angle in lieu of critical crack tip opening displacement for asphalt binder specification

contributor:
Hesp, Simon
Chemistry

subject:
materials chemistry
asphalt binder specification
polymer chemistry
asphalt binder
specification grading
limiting phase angle temperature
Crack Tip Opening Displacement (CTOD)

abstract:
The road pavement sector in countries with cold climates such as Canada currently faces a significant problem with the construction of asphalts demonstrating less than optimal long-term performance. Therefore, attention should be paid to the asphalt binder acceptance criteria used. This study considers how phase angle specification limits can be used in lieu of Critical Crack Tip Opening Displacement (CTOD) as a more practical asphalt binder acceptance property.
Two sets of binders were tested using the Dynamic Shear Rheometer to determine the resistance to fatigue cracking, permanent deformation, performance at high, intermediate and low temperatures. The Double-Edge-Notched Tension (DENT) test was performed to measure the ductile strain tolerance in the presence of critical tensile stresses. Subsequently, DENT parameters of binders were compared with limiting temperatures where the phase angle reached either 30° or 45° to check for a possible correlation. The results showed promising ability of 30° phase angle temperature  to evaluate the strain tolerance of asphalt binder.
These results showed that 30° phase angle temperature  is slightly more useful than 45° phase angle temperature  to evaluate the strain tolerance of asphalt binder as well as the high temperature performance grade is very sensitive to additives and is more informative for asphalt long-term behavior prediction than intermediate and low temperature performance grades.

abstract: M.Sc.


title: Manufacturing Redemption: An analysis of brand responses to the killing of George Floyd.

subject:
Racial Capitalism
Branding
Advertising
Wokewashing
Black Lives Matter
Social Media

abstract: On May 25 2020, George Floyd, a Black 46-year-old father of five from Houston, Texas, was killed by Derek Chauvin, a white police officer arresting Floyd for allegedly using a counterfeit $20 bill at a grocery store. His death was met with disgust and unrest, with protests happening on the streets and online. As has become expected in the past several years with any dominant online conversation, the social media accounts of major brands started to take part and comment. These companies’ expressions of corporate grief and reflection were swift, well-packaged, and on-brand. But as major corporate brands often benefit from economic stratification - including racial-economic hierarchies - these brands' substantive actions often belied their slickly-produced expressions of solidarity with Black Lives Matter. This project examines the brand statements that appeared on social media - and continue to appear on social media - in the wake of Floyd’s killing, probing how these statements operate to produce meaning. How do they function as brand messages that continue to sell? How are they structured and consumed? How do they allow brands to have a voice in an ongoing fight for racial justice while allowing those same brands to benefit from racial capitalism and injustice? In their words and actions, brands have demonstrated an economic imperative to express alignment with Black Lives Matter and those who speak out against anti-Black racism. And yet those words and actions mainly serve to mask their misdeeds. Through close readings of brand statements, analysis of the brands behind the statements, and an examination of the advertising tropes and trends that inform the creation of the statements, this project examines how these brand actions function to misdirect consumer attention from real world conditions and mask and deflect from the brands’ roles in perpetuating racial capitalism.

abstract: M.A.


title: EFFECT OF OXIDATION ON RHEOLOGICAL PROPERTIES OF ASPHALT BINDERS

subject: Asphalt Oxidation Aging Rheology

abstract:
Understanding the oxidation pathway of asphalt and its effect on its chemical, physical and rheological properties cannot be overemphasized. In sustaining and ensuring long-lasting asphalt pavements in road constructions, the mechanism of oxidation needs to be known so as to reduce its rate of oxidation during its service life. Asphalts behave differently due to their difference in chemical composition which differ from one source to another. A common observation in the oxidation of asphalt is the production of carbonyl group. Unfortunately, no tangible reaction mechanism of asphalt is known due to its complex structure.
The effect of oxidation on the rheological properties of asphalt was studied under this research. Asphalt binders of different sources and different physical properties were obtained for this work and studies. Also, the thickness was varied for the pressure aged binders at 20 hours. Service life aging was simulated using the Pressure Aging Vessel (PAV) and the extent of oxidation before and after aging were considered using the Fourier Transform Infrared Spectrometer (FTIR). Rheological properties before and after aging were also carried out using the Dynamic Shear Rheometer (DSR) while the Fraass Breaking Point (FBP) instrument was used to simulate the fatigue resistance in asphalt binders by determining the temperature at which cracks initiate.
An increase in the carbonyl index of the binders were noticed with increase in aging hours. Also, the stiffness of the binders increased with a decrease in the phase angle as aging took place. Differences in rheological properties were noticed with different sources. It was also observed that the binder thickness of 1 mm of pressure aged binders at 20 hours showed close characteristics with that of 3.2 mm aged at 40 hours.

abstract: M.Sc.


title: TRANSLATIONAL CHARACTERIZATION OF ACUTE PHOSPHATE DISPOSITION AS IT RELATES TO BONE AND MINERAL HOMEOSTASIS AND CHRONIC KIDNEY DISEASE

contributor:
Adams, Michael A
Holden, Rachel M
Biomedical and Molecular Sciences

subject:
Chronic Kidney Disease
phosphate
CKD-MBD

abstract: Elevated serum phosphate is an independent risk factor for cardiovascular disease (CVD) in the general population, and this elevated risk is most prominent in the setting of chronic kidney disease (CKD). Dysregulation of mineral homeostasis is a hallmark of progressing CKD, however serum phosphate elevates very late in disease progression. This thesis describes a series of translational experiments that address a largely overlooked aspect of phosphate homeostasis, acute phosphate regulation. The overall objective of the research was to characterize the role of acute phosphate homeostasis within long-term homeostasis and it’s importance in pathophysiological settings. This work introduces a clinical tool, termed an oral phosphate tolerance test (OPTT), whereby the acute circulating, hormonal and excretory responses are assessed following the consumption of a phosphate-containing drink. This response was characterized in the setting of both healthy and impaired kidney function in humans, addressing the roles of age, sex and prevailing dietary phosphate. The acute response to an oral phosphate load was also characterized in the context of a rat model of CKD and in a pharmacologically induced model of vascular calcification to assess distribution and acute tissue accrual via phosphate radioisotope tracking. The major findings are: (i) impaired acute phosphate excretion is present in kidney disease prior to chronic elevations in serum phosphate, (ii) calcifying vasculature has a significant role in acute non-renal phosphate clearance following a phosphate challenge such that there is a blunted rise in serum phosphate following acute oral phosphate, (iii) chronic consumption of high dietary phosphate attenuates the hormonal response to an oral load of phosphate, but does not impact the excretion efficiency, and (iv) the OPTT responses differed according to sex, but not age, whereby females excreted more phosphate and calcium in the time period immediately after delivery. The acute non-renal phosphate clearance mediated by calcifying vasculature likely contribute to the initiation and progression of VC. These findings point to the importance of targeting diet-induced phosphate spikes therapeutically to reduce the morbidity linked to the progression of vascular calcification, and other phosphate-driven diseases. The OPTT has potential as a clinical tool for the early identification of impaired phosphate tolerance in populations at risk for CVD.

abstract: PhD


title: Characterizing Neurodegenerative Disease Biomarkers in Cerebrospinal Fluid of Non-human Primates

contributor:
Munoz, Douglas
Boehnke, Susan
Neuroscience Studies

subject:
Cerebrospinal Fluid
Non-human Primate
Rhesus macaque
Cynomolgus macaque
Amyloid-beta
Tau
Neurofilament Light
Alzheimer's disease
biomarkers

abstract:
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by several pathological changes including amyloid plaques, neurofibrillary tangles, synaptic loss, and neuroinflammation. There are currently no disease modifying therapeutics that have translated from preclinical animal models to human clinical trials. One solution to bridge this translational gap is to use non-human primate (NHP) models, which are phylogenetically similar to humans. However, a key issue with developing new preclinical models is the need to validate their disease progression and therapeutic outcomes.
Using similar methods to diagnosing human neurodegenerative disease patients, current NHP models of neurodegeneration have used identification of biomarkers in cerebrospinal fluid (CSF) and blood (e.g., amyloid-beta (Aβ), tau proteins, neurofilament light (NFL)). Despite these emerging NHP models, little is known about the properties of CSF neurodegenerative disease biomarkers in healthy, experimentally naïve NHPs, or what factors might influence their concentrations. Thus, it is difficult to interpret pathological CSF changes in animal models if baseline measures have not yet been adequately established.
Here, we collected lumbar CSF from a colony of healthy, experimentally naïve male and female cynomolgus and rhesus macaques (n=82). In a subset of these animals (n=16), cisterna CSF was also obtained. We analyzed Aβ40, Aβ42, tTau, pTau and NFL to assess if there were species, sex, age, and location effects. Aβ40 and Aβ42 were significantly higher in rhesus macaques, and female rhesus were higher than male rhesus. NFL and tTau were higher in males, and NFL was higher in rhesus macaques. pTau was not affected by species or sex. Sample acquisition site only affected NFL, which was higher in CSF from lumbar puncture compared with cisterna magna puncture. These values can be used as a reference guide for researchers developing NHP models of neurological diseases. Additionally, we analyzed the effect of performing repeated lumbar punctures on these biomarkers. Performing lumbar punctures in NHPs elevated NFL for up to 100 days but not other neurodegeneration biomarkers. Should these results translate to human clinical work, this has important implications for researchers when designing CSF sampling time points so that disease progression and treatment outcomes are not confounded.

abstract: M.Sc.


title: Ediacaran Fronds from South Australia and Newfoundland

subject: Ediacaran Paleontology Geology Fronds

abstract:
The Ediacara biota (575-539 Ma) represents a seminal event in the evolution of life, the first abundant appearance of large, architecturally complex, soft-bodied organisms after three billion years of mostly microbial evolution. Fronds occupied all tiers of the Ediacaran ecosystem and were the first animals with a construction allowing them to partition the water column macroscopically resulting in a tiering ecosystem similar to Phanerozoic marine ecosystems in structure.
	Elongate fronds were a rarity in the Ediacaran, one in particular, formally named Rangea longa, was defined in 1966 but has not been studied in detail since. The specimens of this elongate frond are disparate in appearance, which have resulted in their exclusion from global syntheses and  assigned to five different genera since its formal designation. The specimens of the Mincham-Flounders collection constitute one species with four taphonomic variants that illustrate the 3D structure of this frond. Akrophyllas longa is an elongate rangeomorph bifoliate frond attached to a bulbous holdfast either directly or with a short stem. The primary branches consistently appear sigmoidal in shape with rectangular secondary branches oriented perpendicular to the primaries. These fronds can be assigned to the Rangeomorpha, an extinct clade near the base of animal evolution, but exhibit an architecture and a construction that differs significantly from all other rangeomorph genera yet described and are herein formally designated as a new genus.
	Frond dusters, small fronds never reaching more than 8 cm in height as adults, occur commonly in the Ediacaran of Avalonian Newfoundland but have not been extensively described. A new frond duster is described and named here that displays unique architecture, otherwise unknown from the Ediacaran biota and easily distinguished from all Ediacaran macrofossils, justifying its erection as a new genus and species. This frond is a spatulate, feather-like frond with primary branches emerging from a single point at the base of the petalodium, complete with a bulbous holdfast with filamentous connections. Convergent evolution has resulted in numerous frond dusters sharing a similar body plan. We are slowly uncovering the diversity of fronds occupying the lowest tier of the Ediacaran ecosystem.

abstract: M.Sc.


title: Assessing the biotic and abiotic factors influencing the distribution and intensity of cyanobacterial harmful algal blooms in Dog Lake, South Frontenac using UAV imaging and eDNA

contributor:
Wang, Yuxiang
Lefebvre, Daniel
Biology

subject:
Cyanobacteria
Limnology
Harmful Algal Blooms
Algal Blooms
UAV
Remote Sensing
eDNA
Environmental DNA
Microcystis

abstract: Cyanobacterial harmful algal blooms (CHABs) deteriorate water quality and cause widespread economic and ecological damage to aquatic ecosystems. Efforts in mitigating and monitoring CHABs face challenges from their complex predictors, dynamic spatial and temporal distributions, and scope. Traditional monitoring techniques do not have the resolution, coverage, or frequency to characterize small scale CHABs. Novel approaches with unmanned aerial vehicles (UAV) surveillance and environmental DNA (eDNA) sampling allow us to examine CHAB distribution, intensity, and potential toxicity. We conducted in situ field experiments in Dog Lake, South Frontenac, Ontario, Canada. In February and March of 2019, we collected lacustrine eDNA samples from the top 0.5 m and bottom 0.5 m of sites with lakebed depths ranging from 1-19 m, as well as from ice cover. We used qPCR to quantify the concentration of the Microcystis aeruginosa mcyE and 16S rRNA genes. Our results indicated overwintering M. aeruginosa showed depth preference, with high concentrations at lake surface in deeper areas of the lake. Shallow areas of the lake had higher eDNA concentrations overall. Ice cover was a potential source of spring inoculum. In May to October, we conducted UAV surveys and collected localized weather data, water variables, eDNA, and toxin samples from Milburn Bay, Dog Lake. We used a cyanobacterial signal enhancement algorithm to quantify the area and distribution of CHABs. We created a multiple linear regression model, with CHAB coverage as the independent variable, and various topographic, weather, and biotic variables as predictors after model selection for the strongest predictor time periods with best subsets selection. Wind reduced CHAB particle size and coverage. 16S rRNA eDNA concentration correlated with microcystin concentrations. Overall, we concluded that the timing and duration of weather variables had a notable impact on the predictive value of environmental variables on CHABs at a local scale. UAV surveys had a cost of approximately $50 per mission, while eDNA sampling had a cost of approximately $5 per sample. We demonstrated that RGB-UAV surveying in tandem with eDNA sampling are a powerful, novel approach to CHAB monitoring.

abstract: M.Sc.


title: Turbulent and Non-Turbulent Interfaces in Low Mach Number Airfoil Flows

contributor:
Wu, Xiaohua
Mechanical and Materials Engineering

subject:
Turbulent and Non-Turbulent Interfaces
compressible airfoil flow
flow topology

abstract:
This thesis reports the first successful identification and investigation of turbulent/non-turbulent interface (TNTI) in airfoil flows – all the previous TNTI studies were confined to canonical flows such as wakes, jets or flat-plate boundary layers.

In the present study, airfoil TNTIs were detected by the Fuzzy Cluster Method and confirmed to be physical a posteriori by the distinctive quasi-step jump behaviour in conditionally-averaged statistics along traverses normal to the TNTIs.

To investigate the kinematics of airfoil TNTIs, the NACA-0012 airfoil flow at 2-deg angle of attack (AoA), chord-based Reynolds number Re_c=100,000 and Mach number Ma=0.5 was simulated. We compared the TNTI statistics in four flow regions: transitional and turbulent boundary layers, upper and lower wakes. Airfoil curvature parameters are noticeably affected by the transitional state of the flow; there are only minor differences between the turbulent-boundary-layer TNTI and the turbulent-wake TNTI. Downstream of transition, local entrainment is more pronounced on relatively flat TNTI surfaces.

To investigate the dynamics of airfoil TNTIs, three DNS cases were considered: the cylinder flow at diameter-based Reynolds number Re_D=10,000 and Ma=0.2 with a symmetric wake and strong vortex shedding, the NACA-0012 flow at 2-deg AoA with a slightly asymmetric wake and weak vortex shedding, and the NACA-0012 flow at 10-deg AoA, Re_c=60,000 and Ma=0.3 featuring a highly asymmetric wake and strong vortex shedding. We investigated four subzones of the instantaneous TNTIs: leading edge (LE), trailing edge (TE), bulge and trough. The zonal conditionally-sampled invariants of the velocity gradient tensor, enstrophy production and orientation of local structures suggest that wake TNTI properties depend more heavily on the degree of vortex shedding and relatively less on the degree of wake asymmetry. Random relative orientation between the vorticity vector and the TNTI normal is observed in the trough, which casts doubts on the notion of vortex structure confinement across the entire TNTI. The turbulent flow near the TE is found to be effective in enstrophy production, whereas the turbulent flow near the LE is the least effective.

Overall, the present work expanded the TNTI research field into the domain of aeronautical flow.

abstract: PhD


title: Investigation of the processing of proprioception and vision for motor actions at the behavioural and neural levels

contributor:
Scott, Stephen
Neuroscience Studies

subject:
motor cortex
optimal feedback control
proprioception
vision
population dynamics
multi-sensory integration

abstract:
Moving in a complex and dynamic environment requires continuous processing of different sources of information.  Optimal feedback control (OFC) is a theory of motor control that predicts how information updated by sensory feedback should be integrated into motor commands for voluntary actions. This theory emphasizes that sensory feedback is critical for motor actions and should be flexibly used in accordance with the behavioural goal. In this thesis we tested several key predictions from OFC about how sensory feedback should be integrated.
Our first study (Chapter 2) examined how corrective actions to visual feedback of the limb (cursor) were impacted by properties of goal and the environment.  Our results indicate that the motor system processes visual feedback using two processes, an early process starting 90ms after a disturbance reflecting spatial redundancies of the goal, and a later process starting 120ms after a disturbance reflecting environmental obstacles.
Our second study (Chapter 3) examined if goal shape influences how monkeys correct for sensory errors.  We found goal shape influenced corrective responses to mechanical and visual disturbances of the limb starting 70ms and 90ms after the disturbance, respectively.
Our third study (Chapter 4) examined the organization of different sources of sensory feedback to primary motor cortex (M1), an area involved with performing feedback control. Vision typically provides the only source of sensory input about behavioural goals whereas proprioception and vision provide sensory inputs about the limb.  As predicted from OFC we found limb and goal feedback targeted virtually the same neurons in M1 and generated similar patterns of activity.
Our fourth study (Chapter 5) tried to unify two competing views about M1.  OFC views M1 as a feedback controller relying heavily on sensory feedback for control. In contrast, a recent theory suggests M1 behaves like an autonomous dynamical system with little influence from sensory input based on observations of rotational dynamics in M1. We show that rotational dynamics are present in feedback control networks indicating  rotational dynamics are not unique to autonomous dynamical systems.
Collectively, these studies provide insight into how the motor system integrates sensory feedback at the behavioural and neural circuit levels.

abstract: PhD


title: Electrochemical Deposition of Nanostructures on a Microelectrode Platform for Surface Enhanced Raman Scattering Applications

contributor:
Raveendran, Joshua
Chemical Engineering

subject:
Surface enhanced Raman Scattering
AC Electrochemical Deposition
Chemometrics

abstract: The demand for point-of-use sensors continues to increase as the dangers to human health and wellbeing from new bio-chemical hazards, illicit drugs and toxicants continue to rise. To allow for early, cost-effective and decentralized chemical analysis, the next generation of sensors need to be portable, rapid, affordable and user-friendly. Surface-enhanced Raman scattering (SERS) is a water compatible, non-destructive, label-free sensing mechanism that can identify and quantify different chemical compounds in liquid and solid samples. Microelectrodes have previously been shown to produce SERS substrates, albeit with very poor surface coverage and limited to laboratory testing. The objective of this thesis is to study a novel approach for combining microelectrodes and electrochemical deposition, in order to form extensive SERS active structures devoid of said limitations. In this work, we establish that an alternating electrical current can successfully be used to reduce silver ions to form SERS active dendritic nanostructures without damaging the microelectrodes or oxidizing the reduced metal. The nanostructures form in a distinctive manner to standard deposition processes. Here the nanostructures grow along the insulating substrate from all edges of the electrodes, capable of reaching lateral lengths near 300 μm with nm features. The role(s) that electrical parameters, surface interactions and solution composition play in the deposition process are studied to identify the parameters and conditions needed to promote the two-dimensional growth and maximize the SERS enhancement of the nanostructures. Furthermore, it is demonstrated that the formed nanostructures could act as concentration amplification devices, accelerating and localizing analyte adsorption from solution, a unique feature for SERS substrates. The SERS substrates are compatible with a handheld Raman spectrometer, therefore amenable for point-of- need sensing. Finally, it is shown that these SERS substrates can serve as scaffolds for forming Ag/Au bimetallic nanostructures with enhanced chemical stability using a galvanic reaction. The synergy between SERS and chemometrics was explored as the nanostructures were used to identify and quantify toxicants in food and water. The combination of SERS, microelectrodes and chemometrics offers a great deal of promise for point-of-need testing as the nanostructures can be used alone or further augmented to improve compatibility with complex samples.

abstract: PhD


title: PROTON IRRADIATION SAMPLE HOLDER II (PISH II)

contributor:
Daymond, Mark
Mechanical and Materials Engineering

subject:
PROTON IRRADIATION SAMPLE HOLDER
Accelerator
Nuclear Material

abstract:
In recent years, the Canadian and international nuclear industries have been bustling with activity in reactor refurbishments and research in new reactors. The Reactor Material Testing Laboratory (RMTL) at Queen’s University plays a significant role in material research that has applications in extending the lifetime of existing reactors, as well as the evolution of new nuclear reactors. The tandem accelerator in RMTL is used to simulate the radiation damage and changes to materials occurring in a nuclear reactor. Previously, it used the sample holder known as PISH I to hold samples during proton or alpha particle irradiation. The sample holder controls the temperature of the sample along with monitoring the beam current during experiments.
This thesis explores the design and implementation of a new sample holder named PISH II. It improves upon the accuracy of temperature and beam current measurements by adding a thermal camera and secondary electron suppression plate to the system. PISH II includes a complete redesign of the edge detector that allows easy adjustment of beam size, as well as a universal sample stage that provides the capability to mount various sample shapes such as a bulk plate, thin foils, narrow strips and C-shape samples.
Additionally, a foil testing apparatus was developed as an add-on system to PISH II to test the aluminum foils that could potentially be used in RMTL’s Proton Irradiation Tensile Rig (PITR). A 75 μm aluminum foil was irradiated on the foil testing apparatus by a 6 MeV and 10-20 μA proton beam while under pressure. At a current of 20 μA, the foil ruptured and failed due to material weakening secondary to thermal effects and potential irradiation damage.

abstract: M.A.Sc.


title: Early Mobility After Fragility Hip Fracture

contributor:
DePaul, Vincent
Woo, Kevin
Aging and Health

subject:
Aging
Older adult
Hip fracture
Fragility hip fracture
Mobility
Mixed methods
embedded case study
tdf
com-b
Acute care
Knowledge translation

abstract:
Older adults who experience a fragility hip fracture are at risk of significant loss of functional limitation – up to 60% never regain their baseline level of mobility. Research has shown that in the first days following hip fracture surgery, older adults spend an average of 23 hours of each day, either lying or sitting in bed. Daily prolonged periods of bedrest place this older adult population at risk for serious complications. Evidenced based provincial quality standards do recommend that older adults participate in early mobility activities every day after hip fracture surgery. The primary aim within this research was to develop an understanding of factors that may influence an older adult’s participation in mobility activities after experiencing a fragility hip fracture and while still in the acute care hospital setting.
Two separate studies were conducted examining older adults' participation in mobility activities after hip fracture surgery. The studies focused on one hospital postoperative unit within a large tertiary care centre. In Study I, a retrospective chart review, it was shown that although healthcare providers demonstrated utilization of the evidence within provincial recommendations, older adults exhibited limited participation in early mobility activities. The chart review did not identify factors on the unit which may have contributed to the low rates of participation in early mobility activities. In Study II, a convergent design mixed methods approach was utilized to comprehensively describe activities undertaken by this older adult population after surgery. Interviews with healthcare providers and patients offered a detailed description of the barriers and enablers influencing mobility activities' facilitation and participation.
Findings from this thesis will help in the development and integration of meaningful and locally specific interventions to encourage an older increased participation in early mobility activities after hip fracture surgery.

abstract: PhD


title: Handing Over The Keys: Intergenerational Legacies of Carceral Policy in Canada, Australia, and New Zealand

contributor:
Little, Margaret
Political Studies

subject:
Canada
New Zealand
Australia
Intergenerational
Imprisonment
Indigenous
Critical Policy Analysis
Intersectionality
Carceral policy
Colonialism

abstract:
The impacts of criminalisation and imprisonment are felt throughout generations. Indigenous communities experience confinement on a hyper scale in countries that continue to grapple with colonial legacies, including Canada, Australia, and New Zealand. Policy changes have not been mitigating this reality and in many cases exacerbate experiences of harm. Different forms of confinement including imprisonment in prisons have been experienced intergenerationally (within and across generations) by some families and communities. With a goal of transformative change, this dissertation asks: how should Canada, Australia, and New Zealand reconfigure policy approaches to address hyper imprisonment and intergenerational imprisonment in partnership with Indigenous communities?

To answer the research question, this dissertation uses Intersectionality-Based Policy Analysis (IBPA), a twelve-question framework that was developed by Olena Hankivsky et al. (2012) to aid policy analysts and researchers in using an intersectional lens to examine policy issues. My application of IBPA to this issue draws on literature and policy material and is grounded in 106 qualitative interviews with 124 Indigenous and non-Indigenous people in policy, frontline services, academia, and with those who have experienced imprisonment personally or as a family member of a prisoner. Participants report significant impacts of imprisonment on families and communities, which greatly impact Indigenous people over generations. Participants identified a diverse range of changes needed to address intergenerational imprisonment of Indigenous people. The policy priorities and societal objectives identified in the interviews guide my analysis of paths forward.

I recommend “placing the keys” in community hands and adopting policy-making approaches that focus on the long-term effects of decisions made today. Placing the keys in community hands means acknowledging, resourcing, and supporting local initiatives to interrupt intergenerational imprisonment. It also means breaking down structures that criminalise people, and building up structures that keep people well and whole. An intergenerational, ripple-effect approach focuses on centring the long-term impacts of policy choices on individuals, families, and communities now, and mitigating harmful impacts on future generations to come.

abstract: PhD


title: Modelling and Parameter Estimation of a PO3G Polyether Process

contributor:
McAuley, Kimberly
Chemical Engineering

abstract:
This thesis focuses on developing advanced fundamental models for production of polytrimethylene ether glycol (PO3G) from bio-based 1,3 propanediol. These models describe the time-varying concentrations of monomer, oligomers, end-groups and by-products (i.e.,  unsaturated ends, water, and propanal) during PO3G production in a batch reactor system with an overhead condenser. A comprehensive dataset from industrial sponsor, E. I. du Pont Canada, is used to support parameter estimation and model validation. Using model predictions and the available data, the current research provides a better understanding about the influences of process operating conditions on PO3G production rate and product properties.
Novel probability factors are developed to permit simplification of model equations when accounting for the complex influence of super-acid catalyst on the polycondensation rate. The model is extended through multiple steps to account for: i) the dynamic behaviour of the condenser, ii) the inhibitory influence of water on polycondensation kinetics, iii) formation, consumption, and evaporation of cyclic oligomers, and iv) the effects of temperature. Model parameters are ranked from most-estimable to least-estimable using orthogonalization-based parameter-ranking techniques, and a mean-squared-error criterion is used to determine which parameters are estimable. Parameter estimation is performed using industrial data obtained from eight batch-reactor runs at temperatures ranging from 160 to 180 ̊C and using super-acid catalyst levels from 0.10 to 0.25 wt%.
The resulting PO3G models and parameter estimates provide good predictions of industrial data and will be useful for selecting operating conditions for commercial PO3G production. The PO3G models (along with the current parameter estimates) can also be used to select the operation settings for future experimental runs, which will produce more reliable parameter estimates and consequently, more accurate model predictions. The author recommends using a sequential Bayesian model-based design of experiment (MBDOE) approach when designing new PO3G experiments. This method is recommended because Monte-Carlo simulations results reveal that new parameter estimates obtained using the designed experiment will be more accurate, on average, compared to parameter estimates obtained using new experiments selected from among the corners of the permissible design space.

abstract: PhD


title: Marrying a Redcoat: Women's Experiences of Marriage in the British Garrison of Quebec City, 1763-1820

contributor:
Errington, Jane
History

subject:
marriage
women
Quebec City
military/civilian relationships
British Army
garrison

abstract:
In 1763, following the Treaty of Paris, Quebec City officially became a major British garrison. As a result, there was a constant and substantial presence of Anglophone and Protestant young men, the majority of them single, in a city with a civilian population mostly French and Catholic. Over 600 of these military men married during their time in the city. However, previous historiography of the garrison of Quebec City has overlooked the women who became army wives.
Looking at the period 1763-1820, this study examines women’s experiences of marriage in the British garrison of Quebec City with particular considerations of the social divisions between officers and soldiers’ wives. Marriage in the British garrison of Quebec happened in a specific colonial context, in which military, religious and political factors played out on marriages. Focusing on the women who married British soldiers or officers reveals that the garrison remained a distinct entity in Quebec City with a dominant British culture; at the same time, it was a porous entity that mirrored the cultural and social diversity of the city. The close proximity in which the military and the civilian populations lived in the urban space resulted in a significant degree of integration between the two populations through marriage. This study thus aims to demonstrate that although army wives were a minority of the military population, they were an integral part of the garrison and contributed to shaping Quebec City’s social dynamic throughout the British regime.

abstract: M.A.


title: Biophysical and Synthetic Studies of Guanine Quadruplex Binders

contributor:
Petitjean, Anne
Chemistry

subject:
Cancer
Organic Synthesis
Binding Affinity

abstract: Cancer is a group of diseases prevalent in Canada and around the world, and depending on the type of cancer, can be associated with a high death rate. Cancer is considered a genetic disease that results from mutations to normal genes called ‘proto-oncogenes’. Mutations to these proto-oncogenes result in ‘oncogenes’, whose gene expression leads to uncontrolled cell growth and proliferation. The RET oncogene codes for a defective overactive receptor protein located on the cell membrane, which upregulates intracellular growth and proliferation pathways, leading to the progression of various cancers, especially thyroid cancer. Likewise, the c-MYC oncogene is involved with the progression of colon, breast, prostate, cervical, and lung carcinomas. Genome-based regulation of RET and c-MYC has been explored as a potential cancer therapeutic. Normally, genomic deoxyribonucleic acid (DNA) exists in the double-helical structure, but in certain cases, DNA can self-assemble into higher-order architectures called guanine quadruplexes (G4s). By folding in the region that controls gene expression (‘promoter’ region), the G4 has the ability to stall gene expression, thus expanding research has been dedicated to the development of small molecules that can stabilize G4s within the promoter regions of oncogenes. In recent years, the Petitjean Group has made an exciting discovery of a small platinum-based molecule (L) that can bind various G4s with high affinity, and exhibits high quadruplex over duplex selectivity. In the first part of this work, biophysical studies to analyze the binding affinity and stoichiometry of L to G4s are described. Specifically, results from ultraviolet-visible spectroscopy suggest tight binding of L with a telomeric G4 and a 2:1 binder to G4 stoichiometry. Analysis and fitting of fluorescence indicator displacement (FID) assay data suggests similar tight binding between L and the c-MYC-G4. These are detailed in Chapter 2. The tight binding and thus strong stabilization of G4s offered by L is highly promising for future development as an anti-cancer agent. However, a challenge that remains is to specifically target one G4 among the thousands of G4s that can fold in the genome to prevent off-target effects as a potential drug candidate. In the second part of this work, the development of small molecules that can specifically recognize and target the RET oncogene promoter G4 is described. To achieve this specificity, an aminonaphthyridine functionality was incorporated into the design of these small molecules, with the goal for the aminonaphthyridine to interact with structural features unique to the RET-G4, thus enhancing specificity for the RET-G4. Two independent synthesis pathways, the isocyanate and the di-succinimidyl carbonate (DSC) pathway were explored to synthesize dimeric and monomeric targeting molecules, respectively, which are detailed in Chapter 3.

abstract: M.Sc.