title: Childhood Parental Invalidation and Young Adult Non-Suicidal Self-Injury

contributor:
Holden, Ronald R.
Psychology

subject:
non-suicidal self-injury
invalidation
emotion regulation
impulsivity
self-criticism
depression

abstract: Non-suicidal self-injury (NSSI) is a prevalent behaviour that serves many functions, but is associated with increased distress, impairment, and risk of death by suicide (Andover, Morris, Wren, & Bruzzese, 2012; Burke, Hamilton, Cohen, Stange, & Alloy, 2016). The overall goal of the current project was to make meaningful theoretical and applied contributions for our current understanding and treatment of NSSI. The present research first investigated potential causal mechanisms by which parental invalidation, a potential familial risk factor for NSSI, may lead to engagement in this maladaptive behaviour. Results of Study 1 supported the existence of two serial mediation mechanisms whereby childhood emotional invalidation by parents leads to increased engagement in NSSI: (a) through increased difficulties in emotion regulation and negative urgency impulsivity, and (b) through increased self-criticism and depressive symptoms. Study 2 aimed to validate the retrospective, self-report measure of parental invalidation used in Study 1 (the Invalidating Childhood Environment Scale) by examining its test-retest reliability, and concurrently gathering retrospective sibling-report data. Results supported the reliability and validity of this measure, and thus its use in the current and future research. The goal of Study 3 was to investigate the effectiveness of two interventions designed to help individuals resist their self-critical thoughts, and thereby interrupt the second NSSI mechanism identified in Study 1. It was hypothesized that these interventions would lead to reduced NSSI engagement and associated depressive symptoms. The interventions were not found to be effective in this case, as individuals in both the control and intervention conditions showed significant reductions in both NSSI engagement and depressive symptoms across the study interval. Theoretical implications, practical applications, limitations, and future directions are discussed.

abstract: PhD


title: Exploiting the Unique Plasmonic Phenomenon of Metallic Nanostructures for Sensing and Biosensing Applications

contributor:
Escobedo, Carlos
Chemical Engineering

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:
surface plasmon resonance
biosensor
surface relief gratings
nanohole arrays
bacteria detection
crossed surface relief gratings

abstract: Real-time, accurate sensing promoted by analytical sensors is extremely important for advances in drug discovery, disease diagnosis and for studying biological systems. In particular, label-free surface plasmon resonance (SPR)-based sensing, promoted by metallic nanostructures which can couple incident light with free electrons in the metal layer, have been widely used commercially. However, current commercial SPR systems suffer from high cost, low-throughput and have a high footprint making them unusable for point-of care applications. In this dissertation, a new SPR biosensor based on plasmonic crossed surface relief gratings (CSRGs) is demonstrated. Miniaturized optical biosensing platforms based on CSRGs and nanohole arrays (NHAs) are employed for sensing of molecular interactions in a quantitative manner. The CSRGs- and NHAs- based SPR devices measure the transmission of the normally incident light with the help of a collinear optical setup consisting of off-the-shelf electronics and optical components. The devices allow for the nanomolar detection limit of molecules in analyte-analyte binding kinetic assays and allow for the detection of pathogenic bacteria in complex biological matrices, in clinically relevant concentrations. Additionally, newly developed nanofabrication method involving template-stripping of CSRGs enable the production of large-area metallic nanogratings in an inexpensive and high-throughput fashion, allowing for chemical sensing of contaminant via surface enhanced Raman spectroscopy. The work presented in this dissertation can give rise to novel miniaturized and portable sensing and biosensing platform with improved performance and multi-disciplinary applications.

abstract: PhD


title: Control of nonholonomic mechanical systems using virtual surfaces

contributor:
Gharesifard, Bahman
Lewis, Andrew
Mathematics and Statistics

subject:
Geometric control
Control theory
Control design
Mechanical systems
Nonholonomic systems
Dynamics

abstract:
In this report we study the modelling of simple mechanical systems evolving on trivial principal bundles, specifically \emph{locomotion} systems with nonholonomic constraints.

We show how we can model motion via group actions on configuration manifolds and assess the relationship between the constraints (and constrained variables) and the variables that physically induce motion on the vehicle by studying principal bundles.

With knowledge of the controllability (using the Lie algebra rank condition) of this formulation of a constrained simple mechanical system, we proceed to outlining a methodology to design a universal control algorithm for constrained mechanical systems using the method of virtual surfaces (or potential functions).

Lastly, we design a set of virtual surfaces to make a rolling disk (arguably the simplest practical nonholonomic system) stabilise to a point, track a path, and avoid a sequence of obstacles in the plane.

abstract: M.A.Sc.


title: Whose Government and What Law? A Political Sociological Investigation of Corruption in Lebanon and its Effect on Government, Legality, and the People

contributor:
Murakami-Wood, David
Sociology

subject:
Corruption
Politics
Law
socio-legal
political sociology
Lebanon
Middle East
legality

abstract:
Levels of corruption in Lebanon are at an all-time high. According to the Transparency International Index, Lebanon ranks 143rd out of 180 in level of corruption (with 180 being the worst). The citizens are also disenchanted with the high levels of political corruption. A survey by Transparency International found that 67% of individuals though that “most” or “all” individuals working in the public sector are corrupt. Clearly, corruption is a pervasive problem in Lebanon. This thesis is about political corruption and how it undermines the structure of government, the rule of law, and the socio-cultural landscape in the Republic of Lebanon. Detailed research on how the rule of law is undermined by corruption is lacking, particularly in the literature about Lebanon.
Through nine in-depth interviews with members of the political elite, as well as high-ranking legal and government-related figures, I aim to understand how corruption undermines the societal institutions such as government and law in Lebanon and how, in turn, this impacts citizen interaction with these institutions. The results can be divided into two sections. The first result section addresses how the political elites use their position to engage in corruption and weaken the institution of government. This chapter also addresses how corruption influences citizens’ relationships with government. There are six key themes in this chapter: political self-interest, nepotism, clientelism, sectarianism, transparency, and distrust of government. The second result section analyses how the legal system is manipulated by the political elites to engage in corrupt behaviours, and how this manipulation renders legal institutions weak and inefficient. This chapter addresses how corruption undermines the rule of law, particularly in the eyes of the population. Finally, the thesis ends with a discussion of how all these themes intersect across politics and law.

abstract: M.A.


title: Formation of a Normative Comparison Base by Physiological Factors, Personality Dimensions and Neural Correlates

contributor:
Milev, Roumen
Neuroscience Studies

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
MRI
Early Life Stress
Resting-State Functional Connectivity
Sleep
Personality
Preeclampsia
Resting-State Networks

abstract:
Introduction: There is variance in a healthy population, but it is poorly characterized and understood. Variations can come from common factors like demographics, experience of early life stress (ELS), physiological factors and personality dimensions. Characterizing the heterogeneity in a non-clinical sample is important to (1) understand what “normal” is; (2) better understand the differences between healthy and pathology and; (3) identify biomarkers of vulnerability and resilience.
Methods: 253 healthy controls from three CAN-BIND cohorts were assessed. Demographic data, sleep quality, personality dimensions and resting-state functional connectivity (rs-FC) were collected and analyzed.
Results: Those who experienced ELS had significantly different sleep duration, quality and efficiency compared to those who did not experience ELS. Those who experienced emotional neglect were more likely to score higher on the neurotic dimension. Lastly, females are more likely to be neurotic and agreeable compared to males. Our meta-analysis found that rs-FC of the default mode network (DMN) follows an inverse U-shape where it is strongest in adulthood and weakest in children and elderly. Cognitive function is positively correlated with DMN rs-FC. Females exhibit stronger intra-network connectivity compared to males. In the CAN-BIND cohorts, we found that there are sex and age differences with seeds in all six resting-state networks of interest. All five personality dimensions exhibited sex differences in rs-FC with seeds in the DMN, fronto-parietal, salience, meso-paralimbic networks. The presence of ELS impacted rs-FC in all personality dimensions and measures of sleep quality with seeds in all six of the resting-state networks. Lastly, children born from gestations complicated from preeclampsia exhibit altered rs-FC with the bilateral amygdalae and medial prefrontal cortex – offering evidence that in utero ELS also impact neural correlates.
Conclusion: The impact of our results is as follows: (1) there is natural variance in a “normal” population; (2) to parse out true clinical findings, researchers must control for our results and cannot assume that healthy controls are homogeneous and; (3) identification of vulnerability and resilient biomarkers.

abstract: PhD


title: Integration of GNSS Precise Point Positioning and Inertial Technologies for Land Vehicle Navigation

contributor:
Noureldin, Aboelmagd
Korenberg, Michael
Electrical and Computer Engineering

subject:
GNSS
PPP
vehicle navigation
PPP/INS integration
reduced INS
lane-level positioning

abstract:
The last decade has witnessed a growing demand for precise positioning in many applications such as autonomous car navigation and precision agriculture. Precise positioning can be obtained from the global navigation satellite systems (GNSS) through either differential techniques or precise point positioning (PPP). PPP is currently favored over differential GNSS because it provides a global solution without the need for local reference stations. Nevertheless, PPP must address the error sources that are canceled in differential GNSS, and hence, it requires a longer time to converge. Therefore, employing PPP for land vehicles would be challenging due to frequent signal degradation and blockage. Integrating PPP with an inertial navigation system (INS) can solve the solution continuity issue; however, the INS solution drifts over time which can result in losing the desired accuracy. The implementation of a reliable PPP/INS system that can preserve the required accuracy is not a trivial task, especially with financial and computational cost constraints.
In this work, two PPP/INS systems were developed. The first system integrates the single-frequency (SF) PPP measurements from a low-cost GNSS receiver with low-cost micro-electro-mechanical systems (MEMS) inertial sensors. The purpose of this system is to provide a reliable, low-cost navigation solution for land vehicles with sub-meter level accuracy. The system was evaluated through two road tests where it could maintain sub-meter position accuracy with short GNSS outages and reliable performance with long-term outages. The second system integrates the dual- frequency (DF) PPP with the Reduced Inertial Sensor System (RISS) for car lane-level navigation. The high-precision needed in lane-level positioning can be achieved by integrating DF-PPP with high-end INS. Since high-end INS are expensive, this work proposed the use of RISS instead of the traditional INS. RISS uses only one gyroscope and two accelerometers which can contribute to saving more than half the cost of a high-end INS. The proposed DF-PPP/RISS system was tested through three road tests that included highway driving under several overpasses, and the system was able to maintain horizontal position errors less than 50 cm. The developed PPP/INS systems are expected to play an essential role in the different applications of land vehicle navigation.

abstract: PhD


title: Creating a Map for Surgeons: Direct Blotting Assisted Stamping of Tissue for MALDI Imaging Mass Spectrometry

contributor:
Oleschuk, Richard
Chemistry

subject:
MALDI-IMS
MALDI
Tissue imaging
Stamping
Direct contact blotting

abstract: MALDI imaging mass spectrometry is an attractive technique for the discovery of disease biomarkers from surgically removed tissue sections.  It can provide spatial resolution and relative abundance of a wide range of biomolecules across the tissue surface.  While the technology has advanced considerably in the past decade it suffers from several drawbacks including a limited percentage of biomolecules that can be imaged, complex sample handing steps lead to loss of/or distortion of analytes, and the significant amount of time between sample harvest and analysis.  To address the shortcomings of cumbersome sample preparation associated with tissue analysis, not limited to sectioning of the tissue, embedding samples, and storage we explore the development of patterned surfaces able to obtain a chemical profile of tissue via direct contact imprinting. This can yield spatial chemical information about imprinted tissue histopathology without the need for embedding, sectioning, or storage. Multiple patterned surfaces have been explored, including: C-18 and poly-lysine functionalized, laser micromachined surface energy traps (SETs), micro-biopsy needle arrays and micro-solvent extraction arrays. Micro-solvent extraction arrays have been shown to successfully image tissue surrogates and preliminary results show the ability to extract prognostic tissue material and provide accurate molecular mapping of tissue samples. Solvent micro-extraction arrays are fabricated using oleophobic coatings with SETs, also known as micro-patches, arrayed by plasma etching allowing for droplets of analytes to be confined in spatially resolved patches. Based on these findings, surface stamping and MALDI analysis can be implemented as a powerful tool for determining spatial distribution of biomarkers in vivo. This may greatly reduce analysis time and the loss/distortion of potential biomarkers.

abstract: M.Sc.


title: Field monitoring of pile walls designed to selectively stabilize slow moving landslides in Peace River, Alberta

contributor:
Take, W. Andy
Civil Engineering

subject:
Landslide
Monitoring
Pile wall
Selective stabilization

abstract: The Peace River region of Alberta, Canada is a highly active landslide area characterized by creeping landslides in weak lacustrine clays and silts.  Much of the infrastructure for the region is built upon historical landslides and marginally stable slopes.  Case studies of two landslides being selectively stabilized by pile walls in the Peace River region were conducted to investigate the relationship between the continued deformation of the downslope landslide material and the structural response of the pile walls.  Two remote camera configurations were implemented, a photogrammetry technique at the first site and a two-dimensional digital image correlation (DIC) technique at the second site, to investigate the ability to use image based monitoring as a method of measuring large scale deformations downslope of these pile walls.  The first study investigates a site that initially consisted of a cantilevered spaced pile wall that no longer sufficiently stabilized the landslide feature impacting a highway.  A new, significantly larger tied-back tangent pile wall was constructed to address the ongoing landslide activity.  Two years of post-construction monitoring have indicated excellent performance of the wall, and negligible deformations of landslide material.  Due to the limited landslide movement, it was not possible to verify the photogrammetry monitoring technique.  The second study examines a different landslide feature impacting a highway that was selectively stabilized with a pile wall.  Three years of monitoring at this site indicates pile wall deformations up to 30 mm, and increases in ground anchor tie-back load of approximately 10%.  Downslope landslide movements were measured with a high temporal resolution two-dimensional DIC technique using remote camera images.  Deformation measurements ranging from 300 mm at a distance of 25 m downslope of the wall up to 1600 mm at a distance of 50 m downslope of the wall were recorded.  Continued long term monitoring of these of selective stabilization walls will be important in assessing the service life of current pile walls and guiding efficient design of future pile walls.

abstract: M.A.Sc.


title: Implications of Fiber Nonlinearities on Coherent Optical Fiber Communications

contributor:
Cartledge, John C.
Electrical and Computer Engineering

subject:
Fiber Optic Communication
Kerr Fiber Nonlinearities

abstract:
A primary objective of optical system design is to satisfy the ever-increasing capacity demand for communication services. Fulfilling this target by increasing the cardinality of modulation formats is at the expense of a reduced system tolerance to transmission impairments with the capacity ultimately limited by Kerr fiber nonlinearities. The research presented in this thesis focuses on exploring solutions to fulfill the demand for increased capacity and studying advanced techniques for modelling and characterizing systems, predicting performance, and estimating critical parameters.
The thesis investigates the quantification of the impact of fiber nonlinearities on the spectral broadening denoted as the spectral edge power (SEP) (Chapter 2). The implications of intra- and inter-channel nonlinearities for 224 Gb/s single-channel and 256 Gb/s 9-channel dual polarization 16-ary quadrature amplitude modulation (DP 16-QAM) systems are quantified in terms of SEP. The experimental results demonstrate that the launch power that minimizes the bit error ratio and SEP coincides.
The research utilizes spectral and power efficient multi-dimensional modulation formats, which provide the capability to fine-tune the spectral efficiency (Chapter 3). The performance of the four-dimensional set-partitioning (SP) 128-QAM is experimentally investigated. The results demonstrate improvements of 5.3% and 8.2% in the information rates for the 256 Gb/s SP 128-QAM compared to the DP 16-QAM at the same bit rate and for transmission over 2100 km and 2700 km, respectively.
The thesis studies the estimation of the nonlinear signal-to-noise ratio (SNRnl) using artificial neural networks (Chapter 4). The accuracy of the estimation procedure is verified for a 34.5 Gbaud DP 16-QAM signal with a maximum normalized root-mean-square error of 0.37% for estimating SNRnl in simulation, and less than 0.25 dB deviation from the true SNRnl for estimates obtained with varying fiber length and launch power in experiments.
The research explores the identification of the shaping distribution of rate-adaptive transmission systems using the estimates of SNRnl and taking advantage of the unique properties of nonlinear interference noise (Chapter 5). The identification results exhibit success rates of higher than 96% and 79% for two groups of five shaping distributions corresponding to bit rate granularities of 25 Gb/s and 12.5 Gb/s, respectively.

abstract: PhD


title: Collective Memory in Transition: Macdonald, Cornwallis and Statue Removal in Canada

contributor:
Hoeniger, Cathleen
Art History

subject:
Collective Memory
Statue
Monument
Canadian History
General Edward Cornwallis
Sir John A. Macdonald
Halifax
Victoria, British Columbia
Residential Schools
Truth and Reconciliation
Indigenous
Polling
Heritage
Maurice Halbwachs
Pierre Nora
lieu de mémoire
Mi'kmaq

abstract:
This thesis documents the 2018 removals of the John A. Macdonald statue in Victoria, British Columbia and the Edward Cornwallis statue in Halifax, Nova Scotia. Writings on memory by Maurice Halbwachs and Pierre Nora form the central theoretical basis of the thesis. These authors have examined memory as a group-based phenomenon, as well as the connection between collective memory and physical objects such as statues. They have also addressed the issue of presentism, how our interpretation of the past is shaped by present concerns. The destruction of cultural sites in times of social change, which results in the vulnerability of memory tied to these sites, is also explored. Portraits are examined as a category of art that is especially vulnerable to targeted destruction. The Balkan Conflicts of the 1990s, the end of communism in Eastern Europe, and the Spanish colonization of the Americas provide examples of cultural destruction where collective memory has been targeted, contested or lost.
	This thesis argues that the Macdonald and Cornwallis statue removals are connected to a shift in Canadian collective memories towards acknowledging the perspectives of Indigenous peoples. Macdonald and Cornwallis traditionally have been remembered favourably as founders of Canada and Halifax, respectively. In contrast, many Indigenous people view Macdonald primarily as an architect of residential schools, and see Cornwallis in the context of his scalping proclamations against the Mi’kmaq during his governorship of Nova Scotia. The historical basis for the conflicting memories of each man, and the history of each statue’s commission, raising, and more recent removal are examined. Further insight into the Canadian public’s perspectives regarding the commemoration of these figures, and the removal of their statues, is provided by a review of public opinion polling.

abstract: M.A.


title: Reading Attitude as a Predictor of Reading Proficiency for Senior High School English Learners in China

contributor:
Beach, Pamela
Education

subject: L2 reading attitude

subject: L2 reading proficiency

subject: senior high school English learners in China

subject: English reading teaching

abstract:
As the concept of key competencies is highlighted as the emphasis and guideline: the pursuit of education should be combined with knowledge, skills, emotional attitude, cultural awareness, and morality, etc., students’ affective domain in Chinese English literacy education starts to gain increasing attention.
Research on first language (L1) reading reveals that reading attitude influences reading skills (Morgan & Fuchs, 2007) and strongly affects reading proficiency (McKenna & Kear, 1990). However, most of the current views of reading attitude are shaped by the research on L1 learners, leaving the field of  Second Language (L2) reading attitude an unexplored area (Kim, 2016; Lee & Schallert, 2014). Hence, the present study investigated English language learners’ English reading attitude and its relation to English reading proficiency within the context of Chinese senior high schools.
Three hundred and ninety-eight Chinese 11th grade students from three senior high schools in Guangzhou completed an English reading attitude questionnaire. Scores from their English reading comprehension test were collected to indicate their English reading proficiency. Data was quantitatively analyzed using descriptive statistics, exploratory factor analysis, correlation, multiple regression, and t-test.
Results showed that while students had strong beliefs concerning the values and usefulness from English reading, they also had strong negative emotions towards English reading. Of the six factors displayed to measure L2 reading attitude in this study, Negative Affect and Self-assessment significantly contributed to L2 reading proficiency (p < .05). With regard to the differences in how students perceive English reading between high-achievers and low-achievers, significant differences were found in Cognitive Attitude, Negative Affect, Conative Attitude and Self-assessment. Several contributing factors were confirmed to predict English reading attitude, including Reading Frequency, Teachers’ Encouragement, Parents’ Encouragement, and Gender. More specifically, how often students read English books for pleasure was a strong predictor of L2 reading attitude.
 This study adds to the rapidly expanding field of the affective components of L2 reading development in China, and contributes to existing knowledge of L2 reading attitude and its relation to L2 reading proficiency by addressing the research gap with high school participants in mainland Chinese educational context.

abstract: M.Ed.


title: Investigating the Initiation of Spreading Depolarizations

contributor:
Andrew, R. David
Neuroscience Studies

subject:
spreading depolarization
stroke

abstract:
Ischemic stroke is one of the most prevalent, devastating and therapeutically challenging medical conditions. Following brain ischemia, failure of the Na+/K+ ATPase is linked with a massive cationic influx through an unidentified channel that drives spreading depolarization (SD). With focal stroke, SD can devastate neurons in the ischemic core as well as recur and expand the affected area for hours and even days after the initial incident. Despite the critical role of SD in ischemic brain pathophysiology, the link between Na+/K+ ATPase failure and the opening of the channel that drives SD onset is unclear.
This study proposes that an SD activator (SDa) is released by metabolically stressed gray matter and drives SD genesis. We hypothesize that an unidentified SDa can be identified, is likely not glutamate and may originate from microglia. The role of glutamate in inducing SD was evaluated to determine if glutamate could be the SDa. Oxygen glucose deprivation (OGD)-induced SD in live brain slices was shown to persist treatment with glutamate receptor antagonists kynurenate and MK-801, although a delay in SD onset was observed. Glutamate application to live brain slices also showed that it did not initiate SD, but in some slices, glutamate promoted a slower localized signal spread surrounding the weight securing the slice. Microglia were also investigated as a source of the SDa; however, blockade of the channel KCa3.1 with TRAM-34, as well as blockade of M1 microglial activation with minocycline did not significantly affect SD initiation. Finally, high pressure liquid chromatography (HPLC) was utilized to characterize superfusate from brain slices that had undergone SD, while matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS) was used to analyze SD-related compounds in fresh frozen brain slices. Size exclusion HPLC identified a ~2 kDa peak that was associated with SD and may contain an SDa. MALDI-IMS analysis of brain slices exposed to OGD revealed three compounds (m/z 593, m/z 610 and m/z 620) that are associated with SD genesis and propagation. Further characterization may yield a novel therapeutic target to mitigate neural damage during acute brain ischemia.

abstract: M.Sc.


title: Syntactic Priming of Ditransitive and Dative Constructions within and across Languages in High School English Learners

subject:
syntactic priming
high school English learners
bilingual syntactic representation

abstract:
Syntactic priming refers to the phenomenon in which people tend to produce a sentence structure that they have previously encountered. Syntactic priming research, taken as a useful tool for probing into bilingual syntactic representations and processes, has become a focus of psycholinguistics since the 21st century. However, there is insufficient research on second language learners who speak distant languages and there are no peer-reviewed studies comparing English-English syntactic priming with Chinese-English priming. Also, only a few syntactic priming studies target the high-school population. To address these gaps, this study investigated within-language (English-English) and between-languages (Chinese-English) syntactic priming on high school students. The primary aims are to understand Chinese high school English learners’ bilingual representation, and shed light on syntactic priming research in terms of how different factors influence the occurrence of priming effects. Additionally, this study provides implications for second language acquisition from the perspective of psycholinguistics. Specifically, this study examines whether priming occurs on the high-school population and how it is affected by priming languages and language proficiency. The research design adopted a typical paradigm for syntactic priming research — the Sentence Completion Task (Pickering & Branigan, 1998). Sixty high school students participated in the experiment. Half of the students were considered low English proficient and half were considered high. Participants were asked to complete a sentence completion task and a questionnaire about their background information. The data analysis involved mixed ANOVA and t-tests.
The results indicated that the types of priming structures, L2 proficiency, and priming languages interactively influenced the magnitude of syntactic priming effects. Both double objects and prepositional objects showed priming effects. Overall, the effects in the high proficiency group were larger than those in the low proficiency group; the within-language effects were also larger than the between-languages ones.
    The results indicated that the low proficiency participants remained at the stage of item-specific representation in L2; L2 representation of the high proficiency participants has become abstract but still separate from L1. The findings provide some evidence in support of the developmental view of the syntactic representation. Findings also have implications for theory and practice.

abstract: M.Ed.


title: Whose Knowledge, Whose Water, Whose Life: A case study of water governance and mining in Sekhukhune, South Africa

contributor:
Goebel, Allison
Environmental Studies

subject:
Water Governance
Mining
South Africa

abstract:
Since news about Day Zero in Cape Town captured public attention, water scarcity in South Africa has become a widely known problem. However, the country has been impacted by similar issues for decades. This is especially true for the Sekhukhune District Municipality, where the prominence of mining and poor water governance have negatively impacted waterscapes, limiting the availability and quality of water for local communities. In this study, political ecology is applied as a framework to observe the power dynamics among water governance stakeholders. Methods used include document analysis, semi-structured interviews and field observations.
This research explores the evolution and implementation of water policies in South Africa before assessing the role of stakeholders in Sekhukhune’s water governance structures. It continues by discussing bulk water infrastructure and the provision of water services to local communities where the significant influence of mining companies is uncovered. Indeed, through major investments to infrastructure projects, mining companies secure continued access to water resources for their operations. Despite this, it becomes clear that many local communities, from those living next to large infrastructure projects to those living near mining operations, have not benefited from these investments and are currently contesting the lack of water services.
This study also addresses how host communities around mining operations have been directly impacted by relocations, migrations and the loss of livelihoods, and the link this has had to the availability and quality of water. There have been significant obstacles for communities who have attempted to express their grievances in various ways. Specifically, there is some evidence to suggest there is collusion or corruption between government representatives, traditional leaders and mining companies that negatively affects communities.
Ultimately, it is evident that the role of communities as stakeholders in water governance structures is undervalued. Despite this, some interesting success stories are highlighted that demonstrate how communities have developed synergies and strategies of their own to apply pressure, resulting in notable shifts in power structures.

abstract: M.E.S.


title: What is a wearable? A query

contributor:
Sismondo, Sergio
Sociology

subject:
wearable technology
ethnomethodology
phenomenology
white papers
quaternions
motion sensors
wearables
problem solving
duality of design
quiring
hype cycle
sociology of expectations
reflexive ethnography

abstract:
Designers go through much trial and error and troubleshooting with stubborn materials and conceptual structures just to get to a working prototype. Eventually, these efforts converge around uncovering successful use-cases and positive narratives aimed at rousing investment and culminate in the creation of an ecosystem supporting other complimentary devices. From the micro-shaping efforts of the R&D lab, to the macro-shaping forces of technology summits, expos, and conferences where these narratives are fashioned, user-and-device are caught in between and co-configured. Over time, designs and documentation are continually adjusted with varying user needs and requirements, exerting upward pressure on design efforts, fueling the insight that no clear distinction between using and designing a technology can be made. A recent technology has the potential to make this reciprocal relation more unambiguous than ever before. Wearable technologies are devices that use sensors to measure and record different kinds of user actions – and how people are using (and not using) the device is crucial for its ongoing development and the next iteration.
With a combination of ethnography, (post)phenomenology, SCOT and ANT, this dissertation explores three moments shaping what wearables are/are for: a problem-solving episode in the development of a wearable device, the building of wearable constituencies, and the work of distilling both those efforts into a stable, communicable and marketable message. In doing so, I aim to bring renewed attention to what has been called “the double movement of ontological design” – the idea that we design our world and the world designs us back. I introduce what I call the duality of design to reflect these ever-present co-constitutive forces. The term also calls for reflexive attention to the role of the observer-participant in this relation, and along the way, I uncover a pattern common to all the constitutive activities being described, what I term quiring. Adding reflexive and ethnomethodological components to analyzing the building of sociotechnical frames offers important opportunities for reconceptualizing our relationship with the technologies we use, design and study.

abstract: PhD


title: Tracking the fate of nickel during transformation of nesquehonite to dypingite at 35°C

abstract:
The weathering of ultramafic rocks facilitates the formation of hydrated Mg- carbonate minerals. Carbon mineralization allows CO2 to be stored within solid, stable carbonates, by reacting CO2 with alkaline, earth metal-bearing hydroxide and silicate minerals. Engineered storage of CO2 in magnesium carbonate minerals is one method of offsetting greenhouse gas emissions. This method is favourable because carbonate minerals persist at Earth’s surface for thousands of years, and are considered permanent over geologic time. However, ultramafic rocks commonly contain transition metals that can be released during enhanced dissolution and are therefore of concern for accelerated carbon mineralization processes. Optimization of engineered Co2 requires knowledge of the fate of transition metals during the hydrated Mg-carbonate phases. In this study, we track the fate of Ni during the transformation of nesquehonite (MgCO3 · 3H2O), which can be
used to store CO2, to dypingite (Mg5(CO3)4(OH)2·5H2O), a more stable carbonate. The transformation of nesquehonite to dypingite is temperature dependent, and was completed over 30 days at a temperature of 35°C. Transformation occurs through dissolution – repreciptation mechanisms. Our results demonstrate that nesquehonite readily sequestered Ni present in solution. Ni was immobilized, likely by substitution for Mg, or trapping, however it was partially released during the transformation to dypingite.
These metals may be sequestered and stored rather than released during accelerated carbon mineralization, and may therefore not pose a risk to the environment.


title: Durability of Natural Fibre-Reinforced Polymer Composites

contributor:
Fam, Amir
Civil Engineering

subject:
fibre
FRP
flax
durability
fatigue
environmental degradation
sandwich panels
cold climate

abstract: Fibre-reinforced polymers (FRP) are a composite system which may be able to meet the demands of both new and existing infrastructures. Due to its constituents’ environmental impact, natural alternatives are becoming increasingly popular; however, their longevity still needs to be assessed prior to its use in civil infrastructure. In this thesis, the long-term performance and durability of natural fibres (flax) and resins (epoxidized pine oil (EPO) and furfuryl alcohol (FA)) were investigated, using 729 tension coupons and 36 structural insulated panels (SIP). Four phenomena were studied: wet-dry cycling, freeze-thaw cycling, cold temperature testing and mechanical fatigue testing. Flax-FRP (FFRP) exposed to 12 wet-dry cycles experienced maximum reductions of 12% and 19% in tensile strength and modulus, respectively, due to delamination at the fibre-resin interface. FFRP exposed to 300 freeze-thaw cycles experienced maximum reductions of 8% and 10% in tensile strength and modulus, respectively, due to delamination at the fibre-resin interface and damage within the fibres. In both cases, conventional epoxy and EPO underwent hydrolysis, and exhibited a decreased and increased glass transition temperature, respectively. To mitigate damage, flax was treated to reduce moisture absorption and improve fibre-resin bond, although similar deterioration was observed post-conditioning. Conversely, conventional glass-FRP showed no deterioration. Furthermore, FFRP tested at cold temperatures resulted in a 20% increase in stiffness, specifically the slope of the second linear phase of its bi-linear stress-strain response. FFRP-skinned SIPs tested at cold temperatures showed a 28% increase in capacity under flexural load; however, there was no impact on the load-deflection response within serviceability limits. Finally, FA-based carbon-FRP (CFRP) was tested in tension-tension fatigue. Based on a 2,000,000 fatigue life, the ASTM model predicted an allowable stress amplitude of 59% and the Whitworth model predicted a modulus retention of 65%. Conventional epoxy-CFRP had a predicted modulus retention of 80%. Through this study, it is clear that FFRP with a higher FVF will be more resilient against cyclic environmental exposure than those with fibre treatment; and, its performance will improve in cold climates. Furthermore, FA-CFRP’s fatigue performance is worst than epoxy-CFRP; however, this trade-off may be beneficial for its chemical resistance.

abstract: PhD


title: Predicted Position Error Triggers Catch-Up Saccades During Sustained Smooth Pursuit

contributor:
Blohm, Gunnar
Khan, Aarlenne Z
Neuroscience Studies

subject:
Saccades
Smooth-Pursuit
Eye-movement
Prediction
Motor control
Uncertainty

abstract: Humans are largely visual animals and require that images of objects of interest must be held steadily on the fovea, a region on the retina that allows for high visual acuity. In order to maintain gaze on objects in the environments, humans must move their eyes to keep the object centered on the fovea using saccades, rapid eye movements that redirect the line of sight to a peripheral target, and smooth pursuit, which allow for tracking of low-velocity objects moving within the environment. When objects are fast or unpredictable, the brain coordinates the execution of both pursuit and saccades to catch-up to the target. Deciding to trigger a catch-up saccade during pursuit influences the quality of visual input. This unconscious decision is a trade-off between tolerating being off target when no saccade is triggered or a transient loss of vision during the saccade as the eye moves rapidly. Although catch-up saccades have been extensively investigated, it remains unclear how the trigger decision is made by the brain. de Brouwer et al (2002) demonstrated that catch-up saccades were less likely to occur when the expected time to contact a target using pursuit alone is between 40 and 180ms into the future, referred to as the smooth zone. More recently, we proposed a model (Coutinho et al., 2018) that relies on a probabilistic estimation of predicted future position error (PEpred). Informed by model predictions, we hypothesized that saccade trigger time length and variability will increase when pre-saccadic predicted errors are small or visual uncertainty is high (using a blurred target). Data collected from human participants performing a double step-ramp task showed that large pre-saccadic PEpred (>10deg) produced fast reacting saccades regardless of the level of uncertainty while saccade trigger times preceded by small PEpred (<10deg) were significantly modulated by high uncertainty. The data supports our hypothesized role of PEpred in deciding when to trigger a catch-up saccade during smooth pursuit and indicates a common predictive decision process that governs motor coordination of eye movements.

abstract: M.Sc.


title: All the World's a Stage: Local, National, and Transnational Histories of the Stratford Festival

contributor:
Brison, Jeffrey
History

subject: Canadian history

abstract: This dissertation examines the history of the Stratford Festival, a theatre festival founded in Stratford, Ontario, Canada, in 1953, at local, national, and transnational levels.  Through the case study of the festival, this dissertation investigates the intersection of and negotiation between culture and commerce in postwar Canada.  This dissertation analyzes nationalism and tourism as concurrent and symbiotic processes in order to understand how identity and economics are negotiated in Canadian cultural industries.  Echoing Vera Zolberg’s expression on the appeal of American museums, this dissertation argues that historically the Stratford Festival has attempted to function as “an elite experience for everyone.”  The theatre’s negotiation of a mass culture of nationalism, on the one hand, and its elite cultural status on the other, has been integral to the festival’s commercial success and attraction of tourists since its founding.  In studying the Stratford Festival in this context of local, national, and transnational influences and tensions, this dissertation contributes to an understanding of Canadian cultural nationalism and tourism, and engages with an emerging literature that addresses the nature of Canadian culture and the resilience of Britishness as a factor in Canadian identity.  This work challenges the cultural categorization of the festival by positioning it as both an elite institution and one striving for mass appeal, and thus complicates hierarchies of culture.  This dissertation is structured around thematic explorations of the theatre’s history: its founding, nationalist controversies over hiring British talent, the performance of Stratford as a tourist destination, public and private funding of the festival, and its national and international touring activities beyond Stratford.  Ultimately this dissertation argues that the Stratford Festival’s success comes from balancing its seemingly divergent identities, but its difficulties also emerged as it operated within the liminal space between classical/commercial, national/transnational, and Canadian/Britishness.

abstract: PhD


title: Examining the Influence of Waist Circumference in Cardiovascular Disease Risk Prediction Modeling

contributor:
Ross, Robert
Kinesiology and Health Studies

subject:
Waist Circumference
Cardiovascular Disease
All-Cause Mortality
Risk Prediction

abstract:
Cardiovascular disease (CVD) is the leading cause of non-communicable disease and pre-mature death worldwide. Waist circumference (WC) is a measure of abdominal adiposity that is strongly related to both CVD and all-cause mortality. However, WC is not routinely measured in clinical practice.

Predicting which individuals will develop disease is a fundamental aspect to modern healthcare. To date, there is limited research examining whether adding WC to current risk prediction models will improve how well the model identifies individuals at risk for future disease. Therefore, the purpose of this thesis is to investigate whether the addition of WC improves CVD and all-cause mortality risk prediction compared to current models.

We analyzed data from 34,377 men and 9,477 women who completed a baseline examination at the Cooper Clinic (Dallas, TX) during 1977 – 2003 and enrolled in the Aerobics Center Longitudinal Study (ACLS). Participants were followed until mortality or December 31st, 2003. WC was measured at the level of the umbilicus and other health risk factors including blood pressure, blood lipids, smoking, and diabetes were collected using standardized methods.

Our primary finding was that the addition of WC does not improve risk prediction for fatal CVD, non-fatal CVD and all-cause mortality. This observation remained consistent across several statistical strategies to assess model performance. However, WC was significantly associated with the outcomes beyond common clinical risk factors.

The findings of this thesis demonstrate that although WC is significantly associated with pre-mature death, adding WC to established risk prediction models does not improve how well the model is able to identify which individuals are at increased risk for future disease.

abstract: M.Sc.


title: Electrokinetic Assembly of Nanoparticles for Surface-Enhanced Raman Scattering-Based (Bio)Chemical Sensing

contributor:
Docoslis, Aristides
Escobedo, Carlos
Chemical Engineering

subject: electrokinetics microelectrodes sensors nanotechnology

abstract:
Surface-enhanced Raman scattering (SERS) enables sensitive detection of (bio)chemical analytes. However, the need for nanostructured noble metal substrates poses a major obstacle to its application. In this thesis, we present a novel metallic nanostructured SERS substrate that is also produced in a nanofabrication-free manner. The substrates are formed through the electrokinetic assembly of silver nanoparticles, which results in extended dendritic structures. A unique feature of these nanostructures is their ability to function as concentration amplification devices, thereby enhancing their analyte detection efficiency. Moreover, the used SERS-active dendrites can be removed and replaced in a few minutes.
In this work, we demonstrate the detection of illicit drugs in both aqueous samples and saliva using our SERS substrates. Identification and quantification of illicit drugs is accomplished via Principal Component Analysis coupled with a Support Vector Machine. We demonstrate 100% accuracy in the detection of four illicit drugs (cocaine, heroin, THC, and oxycodone), and 98.3% accuracy in the quantification of cocaine across four orders of magnitude. Finally, we demonstrate a method for the detection of cocaine in saliva to a limit of detection of 100 ppb. We also establish a microfabrication-free “SERS-from-scratch” technique to produce our SERS substrates from a wide range of materials, including commercially available glass slides pre-coated with indium tin oxide. Our SERS substrates also have applications in the detection of toxic contaminants in food products. We apply our chips for: (1) the detection of thiram, a toxic pesticide, in apple juice, to a limit of detection of 115 ppb, with no sample preprocessing; and (2) the detection of melamine, a toxic food additive, to a limit of detection of 1.5 ppm in milk and 100 ppb in infant formula.
Finally, we extend our method to enable SERS-active gold nanostructures via the electrokinetic assembly of gold nanoparticles. We explore the effects of conductivity on the growth of these nanostructures, and demonstrate the sensing capabilities of these gold nanostructures via: (1) the chemical detection of rhodamine 6G and thiram; and (2) a specific bioassay to detect streptavidin on biotin-modified gold nanostructures.

abstract: PhD


title: Genomic and Metabolic Guided Discovery of Bacterial Natural Products

contributor:
Ross, Avena
Chemistry

subject:
bioinformatics
machine learning
natural products
biosynthesis

abstract: Natural products from bacteria have long been the source of inspiration of new pharmaceutical compounds spanning from immunosuppressants to antimicrobials. Rapid discovery of bacterial natural products is hampered by several roadblocks in identification, dereplication, and activation. The goal of my thesis was to explore these roadblocks and identify novel solutions to streamline natural product discovery. The first chapter provides background on natural product discovery and biosynthesis. It gives insight into how several genomic and metabolic tools work in order to dereplicate and guide the isolation of novel natural products. Throughout the thesis, the need for a genomic mining tool capable of finding natural product analogues is highlighted and used to explore medicinal space. Chapter two introduces the concept of scaffold guided genomic mining and propose how we can use it to identify novel therapeutic analogues with different drug-like properties. To overcome current challenges in biosynthetic gene cluster comparison needed for scaffold guided genomic mining a new method for defining gene clusters based on natural language processing algorithms was created. I then built the analogous cluster comparison information tool to streamline identification and dereplication of analogous gene clusters. Chapter 3 demonstrates the utility of the tool to identify a prodigiosin analogue BE-18591 in Streptomyces. The tambjamine like molecule BE-18591 had previously been isolated but no known biosynthetic gene cluster was known to produce it. The compound was isolated and the gene cluster architecture was compared to other known analogues to identify its biosynthetic origin. Chapter 4 provides personal outlook on how the tool described herein will be used in the future and what the landscape of natural product discovery will look like in the coming years.

abstract: M.Sc.


title: Altering Compliance of a Load Carriage Structure in the Medial-Lateral Direction

contributor:
Li, Qingguo
Mechanical and Materials Engineering

subject:
Gait
Load Carriage
Metabolic Power
Oscillating Load Carriage
Medial
Lateral

abstract: For work or recreation, many individuals transport heavy loads within a backpack. Carrying substantial weight while walking typically causes an increase in muscle activity, metabolic energy expenditure, and increases likelihood of injury. Understanding different modes in which a carried load can interact with a user could help inform design decisions of smart load carriage devices that minimize the burden of carrying weight. We explore this concept in this thesis by investigating a novel mode of load carriage: allowing carried weight within a backpack to oscillate in the medial-lateral direction. To date, our understanding of oscillating load carriage dynamics are constrained to the sagittal plane. Previous studies have explored vertically oscillating carried weight and have observed reductions in peak load carriage forces experienced by the user and reductions of the metabolic cost of walking. We seek to expand this understanding by investigating medial-lateral oscillating load carriage and its effects on gait. We created a novel load carriage device, and through device modelling, chose device parameters that resulted in out-of-phase mass oscillations with respect to trunk medial-lateral excursions. We found that peak load carriage forces were significantly reduced when walking with an oscillating mass, compared to a fixed mass. However, contrary to peak load carriage forces, the metabolic power of walking significantly increased. We identified an increase in the frontal plane interaction moment experienced by the user during oscillating conditions that increased with mass oscillation amplitude. This suggested that perhaps reducing the amplitude of mass oscillations may improve the metabolic response of users. The second objective of this thesis was to generate electricity from the oscillations of the carried mass. We developed an energy harvesting module that generated 0.22 W of electricity while carrying 9 kg of weight. The energy harvesting module also acted as a system damper reducing the amplitude of mass oscillations. We found that with reduced mass oscillations, the metabolic power required to walk with the device was not significantly different than walking with the mass rigidly fixed. The knowledge garnered through this exploration of medial-lateral load carriage will help inform future decisions on smart load carriage device design.

abstract: PhD


title: Blockade of the Human Ether A-Go-Go-Related Gene (hERG) Potassium Channel by Fentanyl

contributor:
Zhang, Shetuan
Biomedical and Molecular Sciences

subject:
hERG
potassium channel
cardiac action potential
sudden death
voltage clamp
fentanyl
electrophysiology

abstract: Fentanyl poses a serious health concern, with abuse and death rates rising over recent years. Despite the high number of overdose deaths attributed to fentanyl, the complete molecular mechanisms of such deaths have not been well-defined. Although activation of opioid receptors in the brainstem causes respiratory depression, in most cases of drug-induced sudden death cardiac arrhythmias are implicated. Therefore, we posited that disruption of cardiac electrophysiology may contribute to fentanyl-induced death. The human ether-a-go-go-related gene (hERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel (IKr). Drug-mediated disruption of hERG function is the primary cause of acquired long QT syndrome, which predisposes affected individuals to ventricular arrhythmias and sudden death. Therefore, we investigated the effects of fentanyl on hERG channels. The effects of norfentanyl, the main metabolite, and naloxone, an antidote used in fentanyl overdose, were also examined. Currents of hERG channels stably expressed in HEK293 cells were recorded using whole-cell voltage-clamp. When hERG tail currents upon −50 mV repolarization after a 50 mV depolarization were analyzed, fentanyl and naloxone blocked hERG current (IhERG) with IC50 values of 0.9 and 74.3 μM, respectively, whereas norfentanyl did not block. The reduction of IhERG by fentanyl was not antagonized by naloxone, indicating that the reduction was not through activation of opioid receptors. An interesting finding is that fentanyl-mediated block of IhERG was voltage-dependent. Consequently, when a human ventricular action potential waveform voltage protocol was used, fentanyl blocked IhERG with an IC50 of 0.3 μM, which is within the range of blood concentrations after overdose deaths in humans. Furthermore, fentanyl (0.5 μM) blocked IKr and prolonged action potential duration in ventricular myocytes isolated from neonatal rats. The concentrations of fentanyl used in this project were higher than seen with clinical use but overlap with post-mortem overdose concentrations. Further, co-expressed long and short isoforms of hERG, proposed to mimic native channels, displayed an increased sensitivity to fentanyl. Although mechanisms of fentanyl-related sudden death need further investigation, blockade of hERG channels may contribute to death for individuals with high-concentration overdose or compromised cardiac repolarization.

abstract: M.Sc.


title: Social Control and Public Water in Cochabamba, Bolivia

contributor:
McDonald, David
Geography and Planning

subject: social control; participation; water governance; remunicipalization; Cochabamba; Bolivia

abstract: During the Water War in 2000, residents of Cochabamba, Bolivia, famously mobilized against water privatization, and gained back public control of the city’s water utility. Nearly two decades later, the water movement’s vision of democratic water provision remains largely unfulfilled. The city suffers from a prolonged water crisis of chronic water shortages and uneven distribution, with most of the peri-urban areas not connected to the municipal water operator. Drawing on 18 months of fieldwork, including participant observation and in-depth interviews with water users, community leaders, policymakers, water utility representatives, government officials, scholars, and activists, this thesis explores the daily struggles for better public water services in Cochabamba. As a starting point, I return to the Water War of 2000, where mobilized citizens demanded the democratization of governance structures through ‘social control,’ a local form of public participation. I argue that the inequitable water services in Cochabamba, stratified among classed, racial, and gendered lines, are linked to weak mechanisms of public participation, which can be traced to fundamental divides amongst actors over the meaning of participation. In order to analyze how participatory mechanisms have developed, I build a typology of different kinds of participation according to their conceptualizations, intended outcomes, tools, and practices. Applying this framework to the water and sanitation sector in Cochabamba uncovers whose interests are served, and which groups are included or excluded from access to water and decision-making. It further illustrates how, in their implementation, participatory practices are not linear and can be distorted or appropriated towards different ends. Competing perspectives of ‘social control’ and participation, weak participatory mechanisms, institutional inertia and persistent neoliberal logic have impeded transformative participation from taking hold within the municipal service provider in Cochabamba. Understanding what leads to mixed results of remunicipalization is crucial to strengthening public alternatives.

abstract: PhD


title: No Man is an Island: Interdependent Conceptions of Selfhood in Wyatt, Donne, and Milton

contributor:
Hanson, Elizabeth
English Language and Literature

subject: Wyatt, Thomas, Sir, 1503?-1542

subject: Donne, John, 1572-1631

subject: Milton, John, 1608-1674

subject: subjectivity

subject: selfhood

subject: poetics of the self

subject: interdependency

subject: English poetry -- 16th century -- History and criticism

subject: English poetry -- 17th century -- History and criticism

abstract: This doctoral dissertation examines interdependent conceptions of selfhood in the works of Sir Thomas Wyatt (1503-1542), John Donne (1572-1631), and John Milton (1608-1674). While previous studies of selfhood in the Renaissance have been dominated largely by conceptions of the self based on autonomy, nascent individuality, and agency – or the lack thereof – the present dissertation argues that these three Renaissance writers conceived of the self in interdependent terms, emphasizing instead the value of the community and interpersonal relationships in the experience of selfhood in their poetry. Through a close analysis of each writer as a case study involving conceptions of the self in dialogue with particular discourses (such as Stoicism, Anglican irenicism, and Italianate Republicanism), this dissertation argues that it is only through examining Renaissance selfhood in terms of interdependency that we can begin to accurately understand how the self was conceived of and experienced in the period.

abstract: PhD


title: Interleukin-27 Modulates Monocyte and Macrophage Toll-Like Receptor Responses to Bacterial and Viral Components

contributor:
Gee, Katrina
Biomedical and Molecular Sciences

subject: TLR

subject: Toll-like receptor

subject: LPS

subject: monocyte

subject: macrophage

subject: IL-27

subject: cytokine

subject: TLR4

subject: TLR5

subject: TLR7

subject: TLR8

subject: cytokine

subject: immunology

abstract: Interleukin (IL)-27 is a heterodimeric cytokine with pleiotropic functions across both innate and adaptive immunity. Composed of subunits IL-27p28 and EBI3, IL-27 signals via a heterodimeric receptor of gp130 and WSX-1 to activate STAT1 and STAT3 homo- and heterodimers. As a cytokine produced in response to Toll-like receptor (TLR) signaling, IL-27 plays a role in modulating immune cell function during infection. TLRs are a class of pattern recognition receptors involved in the detection of pathogen associated molecular patterns (PAMPs) and corresponding induction of proinflammatory immune responses. Although IL-27 was originally identified as a mediator of helper T cell function, new functions of IL-27 on innate immune cells have come to light on myeloid cells, including enhancing antigen presentation as well as anti-microbial properties. Several anti-viral functions of IL-27 have been identified and it has been established that IL-27 can amplify responsiveness to lipopolysaccharide (LPS). The specific role of IL-27 during these anti-microbial responses is still largely unknown. While these new properties of IL-27 have been identified, how IL-27 modulates innate immune receptors such as TLRs that are involved in microbial recognition has not been investigated. In this thesis, how IL-27 impacts the expression and function of anti-bacterial TLRs, TLR4 and TLR5 and anti-viral endosomal TLRs, TLR7 and TLR8, is investigated using a model of human monocytes and macrophages. Upon stimulation with IL-27, monocytes and macrophages displayed enhanced TLR4, TLR5 and TLR7 expression, but expression of TLR8 was unaffected. TLR4 and TLR5 signaling, and TLR4-mediated cytokine production, was amplified by IL-27 in response to ligand stimulation. However, dissimilar to the anti-bacterial TLRs, the enhanced TLR7 expression did not result in amplified cytokines responses. Instead, TLR8 activity was amplified by IL-27 stimulation, even though its expression remained constant. Additionally, inhibition of TLR8 activity was shown to be inhibited by activation of TLR7 in monocytes and macrophages. Altogether, this work identifies novel functions of IL-27 in modulating innate immune responsiveness and provides insight into the potential mechanisms behind the anti-microbial promoting properties of this cytokine.

abstract: M.Sc.


title: RET Activation by Glial Cell Line-Derived Neurotrophic Factor Protects Myenteric Neurons Against Selectively Lethal Challenge by Inflammation

contributor:
Blennerhassett, Michael
Neuroscience Studies

subject: Myenteric plexus

subject: Neuroprotection

subject: Glial cell line-derived neurotrophic factor

subject: Inflammation

abstract:
Intestinal functions are predominantly controlled by the enteric nervous system (ENS), which is comprised of the inner submucosal and outer myenteric plexuses. The myenteric plexus innervates the intestinal smooth muscle layers to coordinate intestinal motility. Alterations in the structure of the myenteric plexus can result in dysmotility, which is seen in severe intestinal inflammation, such as the transmural inflammation of Crohn’s disease, one of the two major types of Inflammatory Bowel Disease (IBD). As well, animal models of IBD have displayed sustained and seemingly irreversible myenteric neuron loss.

GDNF, the neurotrophin responsible for development of the ENS, displays neuroprotective effects in adult systems, but this has not been studied in the post-natal ENS. We proposed that GDNF could protect myenteric neurons from inflammatory damage and tested this in a co-culture model system as well as in the TNBS-induced model of colitis in rats. Two distinct neurotoxic challenges that are present in intestinal inflammation are metabolic inhibition and high levels of nitric oxide, and these were modelled in vitro using chemical agents. Quantification of neuronal structure using immunocytochemistry and image analysis showed that either exogenous or cell-mediated GDNF delivery were equally successful in preventing myenteric neuron loss from these challenges.

Since only the mature isoform of GDNF has been shown to influence myenteric neurons, the processing of GDNF in the intestine during physiological and inflammatory states was investigated. The matrix metalloproteinase MMP-9 was shown to be an essential protease in GDNF processing to yield the mature isoform as well as functional outcomes. Both MMP-9 and GDNF were expressed in intestinal smooth muscle cells, and these showed parallel upregulation with pro-inflammatory stimuli. We conclude that exogenous or cell-mediated GDNF delivery is effective in preserving myenteric neurons during inflammatory challenge.

abstract: M.Sc.


title: Using Deep Models to Predict Sudden Episodes of Hypotension in Critically Ill Patients

contributor:
Mousavi, Parvin
Maslove, David
Computing

subject:
Deep Learning
Precision Medicine
Hypotension
ICU
Machine Learning

abstract:
The vast quantities of data generated and collected in the Intensive Care Unit (ICU) have given rise to large retrospective datasets that are frequently used for observational studies. The temporal nature and fine granularity of much of the data collected in the ICU enable the pursuit of predictive modeling. In particular, forecasting acute hypotensive episodes (AHE) in intensive care patients has been of recent interest to researchers in the healthcare domain. Advance warning of an impending AHE may give care providers additional information to help mitigate the negative clinical impact or prompt a search for an evolving disease process. However, the currently accepted definition of AHE is restrictive and does not account for inter-patient variability.

In this thesis, a novel definition of an AHE based on patient-specific features of blood pressure recordings is proposed. Next, deep learning methods are explored to predict the onset of patient-specific episodes of hypotension at variable event horizons and amounts of observational data.

An initial study on a single institutional cohort is conducted before extending the use of deep models to an external validation cohort. Using a single-institutional cohort of 538 patients, an initial deep model was able to successfully predict the onset of an episode of hypotension with an area under the receiver operating characteristic curve (AUROC) up to 0.87. When extending the use of deep models to an institutionally external cohort of 223 patients, a refined model was able to successfully predict the onset of an episode of hypotension in the internal dataset with an AUROC up to 0.86 and the external cohort with AUROC up to 0.87. Deep models are shown to outperform a baseline logistic regression approach inspired by the current state-of-the-art on both internal and external test data. The outcome of this work presents a generalizable definition of a patient-specific event and a complimentary deep model that can successfully predict the onset of an episode of hypotension across care centers.

abstract: M.Sc.


title: Nonlinear Response of Monolayer Graphene to THz Frequency Radiation

contributor: Physics, Engineering Physics and Astronomy

subject:
Graphene
Nonlinearity of Graphene
THz Radiation
Nonlinear Response of Graphene

abstract:
Graphene, as a zero-bandgap two-dimensional semiconductor with a linear electron band dispersion near the Dirac points, has potential to exhibit very interesting nonlinear optical properties. In particular, third harmonic generation of terahertz (THz) radiation should
occur both due to the nonlinear relationship between the crystal momentum and the current density, and due to the interaction between interband and intraband parts of the current densities due to the vanishing bandgap. This thesis examines the nonlinear response of graphene to THz radiation. The THz response of graphene is investigated by developing density matrix equations employing the length gauge. It is possible to produce higher-frequency THz radiation through the generation of harmonics. Several experimental works have examined the harmonic generation in graphene with the radiation normally incident upon the graphene sheet. In this thesis, a configuration is considered where the graphene sheet is located inside a parallel-plate waveguide and the THz radiation is incident parallel to the sheet. This new configuration is found to increase the power efficiency by more than a factor of 100 relative to the normal-incidence configuration. The pump depletion, self-phase, and cross-phase modulation are also included in modelling the response of this system.  In addition, an optimized waveguide system is designed with two dielectric layers with different indices of refraction to overcome the phase mismatch between the pump field and third-harmonic field at high input fields. Because typical scattering times in graphene are only a few tens of femtoseconds and the period of THz light is on the order of a picosecond, scattering cannot be ignored in modelling the THz response of graphene. Later in the thesis, the linear and nonlinear THz response of graphene is investigated using the velocity gauge to explore the differences between the results obtained in the length and velocity gauges when phenomenological scattering is included. Finally, the nonlinear THz response of graphene is calculated in the length gauge with microscopic scattering. Different scattering mechanisms including neutral impurity scattering and optical phonon scattering are included in our microscopic model. We find that the nonlinear response is much more sensitive to the strength and type of scattering than is the linear response, indicating that any accurate model of harmonic generation in graphene should include microscopic scattering.

abstract: PhD


title: Efficient Deep Blue Pt(II) Emitters for OLEDs and Push-Pull Boron Functionalized Isomers

contributor:
Wang, Suning Jr
Chemistry

subject: deep blue phosphorescent Pt(II) emitters

subject: 1,3-dipolar cycloaddition

abstract: This thesis describes the development of two distinct types of luminescent materials and the exploration of their photophysical properties. The first part of the thesis focuses on the synthesis of four new deep-blue phosphorescent Pt(II) compounds by introducing side alkyl chains of different length to two reported Pt(II) compounds with tetradentate and macrocyclic chelate ligands, respectively. The employment of a new synthetic pathway leads to higher yield of the products and shorter reaction time. The modified Pt(II) compounds possess improved solubility in organic solvents, similar photophysical properties, and better performance as the deep-blue electrophosphorescent emitters of OLEDs, compared to the corresponding original Pt(II) compounds. In second part of the thesis, a series of fluorescent indolizino[6,5,4,3-def]phenanthridine derivatives were produced by 1,3-dipolar cycloaddition reactions between a new azomethine ylide and eight selected alkynes. All the BPhMes2-functionalized compounds are found to exhibit charge-transfer (CT) fluorescence, while the others exhibit π to π* transitions. Among them, the three pairs of push-pull regioisomers that are formed by reactions with BPhMes2-functionalized asymmetrical internal alkynes are worthy of most attention. They possess distinct electronic and photophysical properties and some of which show rare and interesting temperature “turn-on” fluorescence.

abstract: M.Sc.


title: Conflictual Justice: The Probationary Supervision of Indigenous Offenders in Northeastern Ontario

contributor:
Srivastava, Sarita
Sociology

subject:
Criminal Justice
Post-Colonial Theory
Decolonization

abstract: This thesis explores the probationary supervision of Indigenous offenders in Northeastern Ontario through semi-structured interviews with four recently retired probation officers, and one Institutional Elder. Thematic analyses revealed three interlocking findings. First, probationary work requires foresight and situational awareness to balance competing conceptions of criminal justice that foreground policy, namely a balance between enforcement and offender rehabilitation. Second, establishing trust with Indigenous offenders is particularly challenging given a lengthy history of colonial assimilation, cultural destruction, and social marginalization - often situated within racial and cultural prejudices evident within Canada's criminal justice system. Probation officer's work with Indigenous offenders situates within a broader socio-political environment that attempts to contextualize the unique circumstances of Indigenous offenders that is suggestive of a turn towards reconciliation through a recognition of the hardships of Indigenous peoples. Lastly, these efforts fall short, as the Canadian state's appeal to reconciliation is ambivalent in the sense that it bounds Indigeneity within the settler-state's system of rules. Within this process, probation officers in Northeastern Ontario - despite their noble intentions - are limited by a lack of Ministry services, and community resources. Within this location, Indigenous and non-Indigenous offenders alike do not receive the resources they need for rehabilitation in areas such as substance abuse, and ultimately is contributing to a cycle of criminality, particular within Indigenous populations, that exposes the ambivalence of the state. The results of this thesis suggest that perhaps an insurmountable cultural incongruity exists within the probationary process, and by extension the criminal justice system, wherein the needs of Indigenous offenders are not met within a colonial system that appears alien and repressive.

abstract: M.A.


title: Investigating the Role of Neutrophils in Endometriosis Pathophysiology

contributor:
Tayade, Chandrakant
Biomedical and Molecular Sciences

subject: Endometriosis Neutrophils Inflammation Angiogenesis

abstract: Endometriosis is a debilitating gynecological disease characterized by the presence of endometrial-like tissue lesions outside of the uterus. Chronic inflammation is a hallmark feature of endometriosis, which has been observed in the form of elevated cytokines, chemokines, and immune cell populations such as neutrophils within the systemic circulation and peritoneal fluid of endometriosis patients. However, whether and how neutrophils actively contribute to endometriosis pathophysiology have remained poorly understood. With emerging roles for neutrophils in chronic and sterile inflammatory processes, we sought to provide in-depth characterization of neutrophil involvement in endometriosis using patient specimens and an established mouse model. We demonstrated that neutrophils reside within patient ovarian endometriotic lesions and that patient lesions possess elevated expression of various factors known to influence neutrophil recruitment and function. We also provided first evidence that systemic circulating neutrophils from endometriosis patients display unique transcriptomic differences compared to healthy control neutrophils. Through extensive time-course characterization of our syngeneic, immunocompetent mouse model of endometriosis, we revealed that neutrophils are rapidly recruited to the peritoneal environment early after surgical endometriotic lesion establishment and remain present in murine lesions long term. Furthermore, neutrophil recruitment was associated with elevated peritoneal fluid and systemic chemokines, inflammatory cytokines, and pro-angiogenic mediators. In vivo neutrophil depletion altered the peritoneal and systemic immune microenvironment of endometriosis mice as demonstrated by alterations in inflammatory cytokines and a reduction in the pro-angiogenic vascular endothelial growth factor. Taken together, these findings highlight a novel dimension for neutrophils in early events such as modulation of the local inflammatory environment and angiogenesis associated with development of endometriotic lesions.

abstract: M.Sc.


title: Impact of Androgen Deprivation Therapy on the Gastrointestinal Microbiota of Prostate Cancer Patients

contributor:
Sheth, Prameet
Pathology and Molecular Medicine

subject:
Androgen Deprivation Therapy
Metabolic Syndrome
Gastrointestinal Microbiota
Prostate Cancer
Next Generation Sequencing

abstract: Background: Prostate Cancer (PCa) is one of the leading causes of cancer in men. Androgen deprivation therapy (ADT), the standard of care for advanced PCa, has been associated with developing the metabolic syndrome. The gastrointestinal microbiota (GIM) plays a central role in governing host metabolic processes. We aimed to prospectively investigate the short and long-term impact of ADT on the GIM of PCa patients. We hypothesized that there will be a reduction in gastrointestinal bacteria associated with promoting human health (Clostridiaceae and Bifidobacteriaceae families) and an enrichment of bacteria associated with human pathologies (Bacteroidaceae and Enterobacteriaceae families) in men following ADT initiation. Methods: Men with PCa prior to ADT initiation or those on a watchful waiting protocol (WWP) were enrolled by the Centre of Applied Urological Research. Stool, blood, urine and saliva specimens were collected from men at baseline (prior to ADT initiation) and then prospectively 3, 6, 9 and 12 months following enrolment. Participants were asked to complete a questionnaire about food habits, basic demographics, medication use and history of gastrointestinal inflammatory disorders. DNA isolated from stool samples was sequenced on an Illumina MiSeq 2000 and analyzed on MicrobiomeAnalyst and Prism 8, using alpha and beta diversity metrics for community level analysis, and nonparametric Friedman tests with Dunn’s multiple comparisons, for bacterial level analysis. Results: Fifteen PCa ADT-naïve men were enrolled; 11/15 initiated ADT, while 4/15 were on a WWP. The median age of both cohorts was 76, while mean weight, body-mass index, and waist circumference was significantly different between the two groups at baseline (p = 0.001, p = 0.018, p = 0.050, respectively). Sequencing analysis revealed no significant differences in community diversity between the two cohorts at baseline. ADT initiation was associated with no significant changes after 3 months, however 6 months of ADT was associated with a complete loss in Bifidobacteriaceae family (p = 0.04). Conclusions: The reduction of the family Bifidobacteriaceae may be linked to the metabolic changes associated with ADT initiation. Our study is the first to provide a prospective analysis on the impact of ADT on the GIM of PCa patients.

abstract: M.Sc.


title: Passage Dependence of Multiple-Choice Items in Reading Comprehension Component of English Academic Test of Guangdong Province

contributor:
Timmons, Kristy
Education

subject:
English Academic Test
Reading Comprehension
Passage Dependence
Multiple-Choice Items

abstract:
With the deepening of the reform in examination and enrollment system in China, the English Academic Test plays an increasingly important role in selecting the secondary school graduates for institutions of higher vocational education. Therefore, it is of great significance to ensure the quality of the test. A substantial body of research has shown that test takers are able to correctly respond to reading comprehension (RC) multiple-choice (MC) items without reading or comprehending the accompanying passage (Hannon & Daneman, 2001; Katz, Blackburn, &Lautenschlager, 1991; Lifson, Scruggs, & Bennion, 1984), confirming that the passage dependence issue does exist in the testing of RC. The term passage dependence refers to the extent to which students can correctly answer the RC questions depending on whether they have read the accompanying passage. This study seeks to determine the extent to which the RC MC items in the English Academic Test is passage-dependent from the perspective of passage types and item types.
            A quantitative analysis (descriptive statistics, Independent-Samples T Test, One-Sample T Test, Chi-Square Test) of performance in RC component of the English Academic Test 2017 and 2018 were conducted on 343Grade 11 students in two senior secondary schools in Guangzhou, China. The results of the present study are as follows：
 (1) Participants’ scores of the items for both narrative and expository passages under the with-passage condition were significantly higher than the scores obtained under the without- passage condition. Furthermore, the items associated with narrative passages were more passage-dependent than the items associated with expository passages. (2) Factual item type was more dependent on the passage than the inferential item type. (3) There was a significant relationship between item types and Passage Dependence Index.  In addition, the main idea item type and vocabulary-in-context item type were the least passage-dependent item types.
            The result of passage types indicates that the RC component of the English Academic Test was with relatively high validity regarding passage dependence. Students and teachers are advised to be aware of the fact that it is impossible to gain success in the RC test simply by applying test-wise strategies. Emphasis should be made on the development of students’ RC ability. Meanwhile, the result of item types provides empirical evidence for the test designers for improving the quality of the test.

abstract: M.Ed.


title: Characterizing the Effects of Sub-Concussive Head Impacts on Brain Biomarkers: a Multi-Modal Approach Toward Developing Safer Practices on the Football Field

contributor:
Cook, Douglas J.
Neuroscience Studies

subject: dual-calibrated magnetic resonance imaging

subject: cerebrovascular physiology

subject: cerebral metabolism

subject: functional connectivity

subject: helmet accelerometers

subject: sub-concussive impacts

subject: cerebral blood flow

subject: TEDx

subject: behavioural intervention

subject: sport-injury prevention

subject: sport safety

subject: football

subject: knowledge translation

abstract:
Growing literature has raised concerns that repeated sub-concussive impacts to the head may induce changes in both structural and functional brain biomarkers. Despite these findings however, evidence from neuroimaging using the blood oxygenation level dependent (BOLD) contrast has limited our understanding for the effects of repetitive head impacts on physiological parameters such as cerebral blood flow (CBF), cerebrovascular reactivity (CVR) and cerebral metabolic rate of oxygen consumption (CMRO2).

In this project, we combined novel calibrated magnetic resonance imaging methods with helmet accelerometers to gather insight about the effects of sub-concussive collisions on brain hemodynamics and explore the relationship between head impacts and changes in brain biomarkers. Dual-echo BOLD and arterial spin labelling (ASL) contrasts modulated via precise gas breathing manipulations (i.e., hypercapnia and hyperoxia) were used to study changes in the brain of collegiate football players, while accounting for time-varying fluctuations in cerebrovascular physiology. Increases in default-mode network functional connectivity, as well as changes in resting CBF and CMRO2, were all documented following exposure to head impacts, suggesting that brain physiological parameters may be sensitive to repeated mechanical loading from sub-concussive events during the season.

Using these findings as a basis for actions toward reducing head impacts in football, we leveraged TEDx Montréal as a social platform to introduce the NeuroProtection Project - a novel approach designed to re-focus coaching practices toward improving how athletes are thought to engage in contact on the football field. Finally, the effectiveness of the NeuroProtection project was tested in high- school football players using a combination of video analyses, helmet accelerometers and customized training paradigms. Significant improvements in blocking and tackling techniques were observed following introduction of the data-informed intervention, as well as a ~30% decrease in the frequency of head impacts sustained during practice. These findings suggest that targeted behavioral interventions may
be used to improve coaching practices and promote safer play.

Altogether, it is hoped that these findings will motivate the integration of multi-modal imaging designs to deepen our knowledge for the effects of sub-concussive impacts, while inspiring the expansion of community-based initiatives like the NeuroProtection project to prioritize safety in contact sports.

abstract: PhD


title: Development of a Computational Treatment Planning System for Radiofrequency Ablation of Vertebral Metastases

contributor:
Fichtinger, Gabor
Computing

subject:
Computational
Treatment Planning
Radiofrequency Ablation

abstract:
Introduction: Vertebral metastases affect around 61,000 Americans annually. The presence of vertebral metastases may lead to skeletal related events which can include pain, fracture, and neurologic compromise, all of which can negatively impact a patient’s mobility and quality of life. Radiofrequency (RF) ablation is a minimally invasive thermal therapy used to palliatively treat vertebral metastases. Current treatment practices incorporate little to no treatment planning and utilize two-dimensional imaging to localize the vertebra of interest. This may lead to inadequate treatment dose or delivering dose to healthy tissues. To address the need for better planning and delivery of RF ablation in spine procedures, this work aims to design and develop a computational treatment planning system (TPS) capable of generating patient specific treatment plans. The system was validated using functionality and usability testing.
Methods: System requirements were determined based on input from clinicians and researchers. Using these requirements, a TPS that could interact with an external dose engine was developed using the open source platform, 3D Slicer. Patient imaging was obtained to perform functionality testing of the designed TPS. Testing was performed using a simplified prescribed dose function. The calculation of damage volumes was done on voxel-based meshes and compared to a ground truth. Usability testing was also performed with data captured from questionnaires given to clinicians after interacting with the system.
Results: 14 patient CT scans were used to generate RF ablation treatment plans. In all cases the TPS was able to perform all necessary functionality. The voxel-based meshes produced thermal damage volumes larger than the ground truth. Usability testing indicated that clinicians were supportive of this TPS being adopted for RF ablation of vertebral metastases. The most likely clinical uptake for this system would come through radiation oncology, with treatment plans provided to orthopaedic surgeons and interventional radiologists.
Conclusion: A computational treatment planning system could be a feasible and beneficial addition to the clinical workflow for RF ablation of vertebral metastases.

abstract: M.Sc.


title: Formative Evaluation And Pilot-Testing Of A Communication Program For People With Parkinson's Disease

contributor:
Ghahari, Setareh
Rehabilitation Science

subject:
Parkinson's Disease
Self-management Program
Pilot Study
Formative Evaluation
Health Communication

abstract:
Health professionals and people with Parkinson’s disease both agree that lapses in communication interfere with efficient and effective health care. The Talk4HealthCare program was developed with the aim of helping people with Parkinson's disease to have a collaborative healthcare journey by improving their knowledge, self-efficacy, health communication, and health service navigation.
The aim of this thesis was to assess the potential of the program for further development and investment in terms of fit with literature, expert opinion, feasibility, and effect.  This aim was achieved through three studies: scoping review, formative evaluation and pilot testing.
A scoping review was conducted that provided theoretical justification for the program and helped in the refinement of the program.  We found person-level and system-level barriers prevent people with Parkinson’s disease from accessing healthcare. Communication barriers may arise at both levels.
A formative evaluation was conducted by contacting fifteen Parkinson’s disease experts (people with Parkinson’s n=5, healthcare professionals n=4, educators n=4, family members n=2).  These experts took part in semi-structured focus group or individual interviews and indicated that the program covered essential and significant topics to promote communication skills through a well-designed format. They recommended changes to adapt the program to the physical needs of people with Parkinson’s disease. The program was thus refined and prepared for the pilot test.
A pilot test, using a multiple-methods study design, tested feasibility and achievement of outcomes, and a qualitative study was aimed to obtain feedback from the participants.  Eight people with Parkinson’s disease (median age 72 years; male: female = 3:5) were recruited from Parkinson Canada. Data collection took place by administering questionnaires and telephone interviews.  The pilot study showed a large effect size for knowledge (0.59) and communication skills (0.51), and moderate effect size for self-efficacy (0.25).  The participants of the pilot study found that the program well organized with appropriate content and format.
Overall, the program was found to be consistent with the literature; acceptable to Parkinson’s Disease experts, feasible to implement, and effective in improving the communication skills. The efficacy of the program should be tested in a further study with larger sample size.

abstract: M.Sc.


title: Atmospheric Dependence of Fractoluminescence and Phononic Emissions in Inorganic Scintillator Fractures

subject:
Scintillator
Fracture
Fractoluminescence
Dark Matter Detection
Acoustics
Humidity

abstract:
Background signals in particle detectors can originate from several categories of sources, including radioactivity found in the detector or its housing and cosmic radiations. High energy physics relies heavily on the use of particle detectors that are capable of identifying the desired particles while ruling out backgrounds. Fractures in the detectors create a background that makes it difficult to anticipate the timing of their occurrence. Given that typical rare-event search experiments last months or longer, it would be advantageous to find a way to identify when fractures occur and how to discriminate against them. The Double Cleavage Drilled Compression (DCDC) geometry allows creating fracture-inducing stresses in the material in a reliable manner. Given the brittle nature of Bismuth Germanate (Bi3 Ge4 O12 or BGO) single-crystal scintillators and their negligible afterglow, this thesis investigates backgrounds due to fractures in BGO crystals in the DCDC geometry. A series of experiments were conducted where both photonic and phononic emissions were recorded along with the crack propagation to study the fractoluminescence and acoustic signals generated, and how they would interfere with particle detection. Fractoluminescence in global fracture was confirmed in BGO over many conditions. Acoustic emissions due to fractures were correlated to the crack growth, and significant acoustic events were measured during subcritical fracture. The subcritical fracture was measured using image analysis of the crack, and the crack growth model was identified using evolutionary algorithms.

The thesis also discusses the design of micro-fabricated chips to test the effects of cryogenic temperatures on the rate of crack growth, and to study the possibility of quantum effects dominating the subcritical fracture mechanism.

abstract: M.A.Sc.


title: Development of a solid-phase extraction method for the separation of algal lipid classes

contributor:
Champagne, Pascale
Jessop, Philip
Chemical Engineering

subject:
biodiesel
algae
lipids
microalgae
Scenedesmus sp.
solid-phase extraction
triglycerides
phospholipids
glycolipids
fatty acids
lipid classification
algal lipid classification
useful lipids for biodiesel production

abstract:
Algal oils have been extensively used as feedstocks for the production of biodiesel. These can be obtained using one of several extraction techniques, such as Soxhlet extraction. A critical issue is the presence of compounds in the crude extract that lead to lower yields and low-quality biodiesel produced, i.e. phospholipids (PLs). Solid-phase extraction (SPE) is commonly used for the analytical and sample preparation of compounds due to its rapidity, low cost and simplicity; including lipid analysis. The literature presents validated SPE methods for the fractionation of lipids in complex mixtures (i. e. human sources). However, SPE methods applied to algal lipid classification have yet to be fully developed and validated in the literature.
The objective of this project is thus to provide the user with a rapid, efficient and reliable standardized analytical method for the determination of useful lipids, triglycerides (TGs) and fatty acids (FAs) from algal biomass to produce biodiesel.
Firstly, critical factors affecting the performance of the SPE procedure using NH2-Si were identified and evaluated, namely active phase, loading mass, precondition step and elutions. The results indicated that there is a cross-contamination between lipid classes, especially PLs, which were prone to be prematurely eluted when high quantities are present in the algal biomass (>15 mg). SPE conditions (active phase, loading mass, precondition step and elutions) were modified and tested in order to decrease the cross-contamination. The modified SPE method solved the PL elution issue. However, the elution of other type of lipids of interest was negatively affected (i. e. underestimation of fatty acids).
Secondly, current SPE procedures using -Si and NH2-Si to quantify algal lipids were tested and standardized, and the results were then compared to the composition of standard mixtures of lipids used to perform the SPEs.
An accurate reference to determine the total useful lipid content for biofuel production and other applications, using SPE procedures, is recommended in this thesis. SPEs using -Si and NH2-Si columns can be performed consecutively to quantify, firstly, neutral lipids (TGs, and FAs), GLs and PLs; and secondly, TGs and FAs; respectively.

abstract: M.A.Sc.


title: Decolonizing Public Places and Public Memory: Kingston Ontario

contributor:
Godlewska, Anne
Geography and Planning

subject:
Indigenous heritage
reconciliation
decolonization
commemoration
settler-ignorance
public memory
municipal heritage
places of public memory
Kingston
heritage landscapes

abstract: Since the release of the final report of the Truth and Reconciliation Commission, municipalities are increasingly addressing reconciliation in their practice, including new engagement with Indigenous heritage and public memory. Municipal perspectives of heritage are frequently colonial and result in Euro-Canadian commemorative landscapes that reinforce official national narratives of history and identity. These landscapes limit the expression of Indigenous heritage and reinforce settler-ignorance. If the goal of creating reconciliatory spaces is to foster dialogue, interaction, and opportunities for conciliation, current municipal heritage practices are insufficient. This research uses Kingston, Ontario as an opportunity to explore municipal heritage practice in the context of reconciliation, and learns from Indigenous peoples what new places of public memory might look like when created from decolonial perspectives. It indicates that there is a need not only for the modification of current colonial commemorative landscapes, but also for the creation of new places of Indigenous public memory that are dynamic, emphasize dialogue and community, and that might create opportunities for conciliation. Decolonizing municipal heritage practice will require a willingness to experience discomfort and vulnerability, the redress of settler-ignorance, and a commitment to creating new relationships with Indigenous peoples.

abstract: M.A.