title: The Effects of Hydroquinone and Benzoquinone on the Transcription Factors PU.1, AML-1, C/EBP, C-MYB AND GATA-2 IN HL-60 CELLS

contributor:
Winn, Louise M.
Biomedical and Molecular Sciences

subject:
Benzene
HL-60
Hydroquinone
Benzoquinone
Transcription factor
DNA binding

abstract:
Benzene, a common chemical solvent and component of cigarette smoke, is a ubiquitous environmental pollutant that most Canadians are routinely exposed to by inhalation. Benzene is classified as a group 1A carcinogen by the International Agency for Research on Cancer (IARC) and exposure to benzene is linked to both myeloid leukemia and aplastic anemia in humans. Benzene is metabolized to toxic reactive metabolites by CYP2E1 enzymes in the body and many studies have concluded that benzoquinone and hydroquinone are the most toxic of benzene metabolites. There are several transcription factors that play a significant role in hematopoietic differentiation. Of these transcription factors, PU.1, AML-1, C/EBP-a, c-Myb, and GATA-2 are considered the most crucial to differentiation. PU.1, AML-1, C/EBP-a, c-Myb, and GATA-2 are specific to cells in the hematopoietic system and play a critical role in hematopoietic differentiation as knockout mice deficient in any of these transcription factors possess impaired hematopoietic cells, eventually resulting in death of the animal. To test the hypothesis, that exposure of HL-60 cells to hydroquinone and benzoquinone will result in altered DNA binding activity and relative protein expression of PU.1, AML-1, C/EBP-a, c-Myb and GATA-2, HL-60 cells were plated at 5.0 x105 cells/ml in 10 ml plates and exposed to either phosphate buffered saline, or equal parts hydroquinone or benzoquinone totaling 5, 10, 15, or 25 µM parts for 20 hours. Following exposure, cells were harvested and nuclear fractions were isolated and then used in a filter plate assay to determine DNA binding of the transcription factor.
Western blotting was also performed on nuclear extract samples in order to confirm protein presence. Filter plate assays revealed no significant differences in DNA binding amongst the different treatment groups when assaying for PU.1, AML-1 and C/EBP-a iiDNA binding. However, c-Myb and GATA-2 DNA binding assays revealed a decrease in DNA binding when the 25 µM benzoquinone and hydroquinone treatment group was compared to the vehicle control. Western blotting performed on the nuclear extracts demonstrated the presence of PU.1, AML-1, C/EBP-a, c-Myb and GATA-2 with no observable difference in relative protein expression. This data suggests that altered DNA binding of c-Myb and GATA-2 may play a role in benzene-mediated toxicity.

abstract: M.Sc.


title: The Role of Social Media in Financial Markets

contributor:
Johnson, Lewis
Riordan, Ryan
Business

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:
Finance
Social Media

abstract:
This three-essay thesis examines the role of social media in financial markets from multiple perspectives. Chapter 2 explores the economic consequences of the Securities and Exchange Commission’s (SEC’s) regulation of corporate use of social media. Following the April 2nd, 2013 SEC regulation allowing firms to use social media to communicate financial information to investors, corporate tweeting becomes informative: meaning that a firm’s stock price responds to its own tweeting. This was not the case prior to the regulation.
Chapter 3 examines whether firms that use social media have a lower cost of equity capital. To the extent that the use of Twitter can lower information asymmetry between firms and investors, firms’ cost of capital is expected to be reduced. The two findings of chapter 3 are that 1) the use of Twitter corresponds to a lower cost of equity capital, and 2) firms that face the greatest information asymmetries – namely smaller firms, firms that are covered by the least number of analysts, and firms with the least proportion of institutional ownership, benefit particularly from tweeting financial information about their firm.
Chapter 4 turns to investors’ use of Twitter. Harnessing the wisdom of the crowd, Twitter daily sentiment about stocks corresponds to daily stock prices. Specifically, positive Twitter sentiment corresponds to higher returns and negative sentiment corresponds to lower returns. Furthermore, firms whose stock exhibits the greatest dispersion of analyst forecasts are tweeted about more often. This suggests that social media provides an outlet where investors provide opinion and discussions about stocks, especially in the absence of analysts’ (professional) consensus.

abstract: PhD


title: CMOS-Integrated Array Transducers For High-Frequency Ultrasonic Imaging

contributor: Physics, Engineering Physics and Astronomy

subject:
Ultrasound
Transducers
CMOS
ASIC
High-Frequency
PZT
Linear Array
Annular Array
Integrated

abstract:
One of the challenges in the fabrication of array transducers suitable for high-frequency ultrasonic imaging is providing electrical connections between the array elements and external systems such as pulser and beamforming circuits. Element connectivity is difficult due to the fine element pitch, as well as strict limitations on the physical size of the probe required for some high-frequency imaging applications such as intravascular ultrasound (IVUS) imaging. Previously, channel reduction has been demonstrated through single-element or partially-sampled array transducers that are mechanically translated during image acquisition. These systems offer ease of fabrication and connectivity due to their low channel count, however, the reliance on mechanical scanning is undesirable.

This thesis presents the proof-of-concept of a new type of high-frequency array transducer that maintains the low system complexity associated with a reduced channel count, while at the same time offers the ability to electronically scan an active array pattern. A unique feature of this design is the presence of a custom scanning application-specific integrated circuit (ASIC), which is fully integrated into transducer stack. The ASIC reduces the number cables required by multiplexing a collection of array elements into a small number of channels. To allow for simplified methods of fabrication, two novel substrate bonding techniques are demonstrated that allow full integration of the scanning ASIC into the acoustic stack while not relying on the precise alignment of the two substrates. The integration schemes were demonstrated using a 68 element linear array that includes a custom scanning ASIC in the acoustic stack. The concept is extended to show the feasibility of an electronically-scanned, 50 MHz annular array, which would be suitable for catheter based IVUS imaging for the management of vascular disease. Feasibility has been shown through simulation and experiment, demonstrating that satisfactory transducer performance can be achieved when incorporating a combination of unique materials and structures into the integrated transducer.

abstract: PhD


title: Sialylation of cell surface glycoproteins facilitates formation of 3D multicellular prostate cancer spheroids

contributor:
Szewczuk, Myron R.
Biomedical and Molecular Sciences

subject:
Sialic acids
Spheroids
Prostate cancer

abstract:
Prostate cancer spheroid based three-dimensional culture models (referred to as prostaspheres) have provided insight into prostate cancer biology by highlighting the importance of cell–cell interactions and the extracellular matrix in the tumor microenvironment. The prostasphere model have particular advantages over 2D monolayer culture models in terms of 3D structure and having cell-cell and cell-ECM adhesion instead of cell-culture plate adhesion. The cyclo-RGDfK(TPP) peptide-based biochemical method is a simple, reproducible and cost-effective method of spheroid formation. The cyclo-RGDfK(TPP) peptide method of spheroid formation depends on the cell surface glycoproteins, integrins and cadherins. The terminal monosaccharide of these glycoproteins is sialic acid. Using human metastatic androgen independent prostate carcinoma PC3 and DU145 cell lines and their respective gemcitabine resistant (GemR) variants, prostaspheres were generated by using cyclic Arg-Gly-Asp-D-Phe-Lys peptide modified with 4-carboxybutyl-triphenylphosphonium bromide (cyclo-RGDfK(TPP)). By using cyclo-RGDfK(TPP) peptide in a dose- and time-dependent manner, both DU145 and DU145GemR cells formed prostaspheres. In contrast, PC3 and PC3GemR cells formed irregular cell aggregates at all concentrations of cyclo-RGDfK(TPP) peptide. The formation of prostaspheres was not dependent on the level of E-cadherin expression by the prostate cancer cell lines. Using lectin cytochemistry and flow cytometry, it was found that DU145 and PC3 cells and their drug resistant variants expressed different levels of α2,3 sialic acid (SA) and α2,6 SA residues on the cell surface which correlated with the ability to form prostaspheres. Prostasphere volume was dose-dependently reduced following pretreatment with
α2,6 SA specific neuraminidase (Vibrio Cholerae). Oseltamivir phosphate (OP), a neuraminidase1 inhibitor, did not have any effect on the level of sialic acid and therefore in the formation of spheroids. These results suggest that the relative levels of specific sialoglycan structures on the cell surface glycoproteins correlate with the ability of prostate cancer cells to form prostaspheres.

abstract: M.Sc.


title: There’s No Space Like Home: Examining the Cultural Complexity of Creating the Space of Home

contributor:
Handelman, Jay
Business

subject:
Consumer Culture
Space
Space of Home
Home Renovations

abstract: The home is a bedrock of Western culture, society and economics. Consumer research draws attention to the home as a space laden with meaning and of ubiquitous importance in consumers’ lives. However, this literature also reveals inherent misalignments in how we understand the home. The home is a site for self-expression, but also a site of conformity to taste, aesthetics and expectations of market value. The home is a site for family practices, which may conflict with social norms of tidiness that manifest in the home. The ubiquity of the home masks its cultural complexity. The purpose of this work is to examine how consumers navigate these cultural misalignments, multi-level forces, and overall work of creating and recreating the space we call “home.” I draw upon Henri Lefebvre’s (1974) model of the production of space as a theoretical lens to examine how consumers negotiate the creation of the space of home. Through 21 in-depth interviews with consumers engaged in home renovations, four interviews with service providers and a purposeful observation of home exhibitions shows, marketing and media, my study reveals four major findings which contribute to consumer research and broader theories of space. First, I find that part of the reason home renovations are stressful for consumers is that in the process, consumers configure the home as a reflection of their personal identity. An outdated home reflects an outdated identity. Second, I find that consumers are fearful of an ever-present market-based anonymous gaze in their home regulating the enactment of their identity. Third, I introduce the importance of the role of harmony, as opposed to resistance, in the creation of space. Lastly, I introduce a new role in the market, that of a Space Orchestrator. Space Orchestrators are deeply embedded in understanding the consumer and the market, which therefore positions them to guide consumers to configure their homes in ways that represent both their identity and the demands of the market, thus helping to create the home as a space of cultural alignment.

abstract: PhD


title: Secular World: Victorian Secularism as a Global Ideology in its Imperial Context, 1840-1880

contributor:
den Otter, Sandra M.
Jainchill, Andrew
History

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Victorian Secularism
British Empire
Race and Racism
Comparative Religion
Social Ethics
Secularization
George Jacob Holyoake
Charles Bradlaugh
Charles Southwell
Religion and Political Thought
Working-Class Radical Thought

abstract:
This thesis examines the development of British secularist ideas of morality and social ethics, and how those ideas informed secularist views of non-Europeans and the imperial civilizing mission. I investigate the relationship between secularism as an ideology and the development of secularity as one of the defining characteristics of modernity. Secularism was founded by G. J. Holyoake, a whitesmith and Owenite lecturer, in 1851. The movement served as a vital link between a pre-1848 artisan radical tradition and the socialism of the final decades of the nineteenth century.
I investigate how imperial knowledge creation informed the development of secularist ethical and political ideas, and the impact of those ideas upon secularist interventions into imperial debates, particularly regarding the European civilizing mission. Previous historians of the secularist movement have neglected to demonstrate how the religious pluralism of empire and its attendant political and administrative challenges shaped secularism as a strain of liberal thought. Concomitantly, research into Britain’s uneasy negotiation of the religious diversity of its empire has not sufficiently incorporated the dynamics of domestic freethought. Secularism promoted belief in a rational, utilitarian morality that would unleash humanity’s innate capacity for moral and intellectual progress. My research contributes to scholarship on the impact of empire and globalization on European modernity and secularity. Faith in universal human progress was and remains a defining characteristic of secularism. I am interested in how ideas of progress have been both informed and challenged by difference and the implications of power.

abstract: PhD


title: Remote Sensing of the Canadian Arctic: Modelling Biophysical Variables

contributor:
Treitz, Paul
Geography and Planning

subject:
Remote sensing
Arctic
Percent vegetation cover
fAPAR
Vegetation

abstract: It is anticipated that Arctic vegetation will respond in a variety of ways to altered temperature and precipitation patterns expected with climate change, including changes in phenology, productivity, biomass, cover and net ecosystem exchange. Remote sensing provides data and data processing methodologies for monitoring and assessing Arctic vegetation over large areas. The goal of this research was to explore the potential of hyperspectral and high spatial resolution multispectral remote sensing data for modelling two important Arctic biophysical variables: Percent Vegetation Cover (PVC) and the fraction of Absorbed Photosynthetically Active Radiation (fAPAR). A series of field experiments were conducted to collect PVC and fAPAR at three Canadian Arctic sites: (1) Sabine Peninsula, Melville Island, NU; (2) Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, NU; and (3) Apex River Watershed (ARW), Baffin Island, NU. Linear relationships between biophysical variables and Vegetation Indices (VIs) were examined at different spatial scales using field spectra (for the Sabine Peninsula site) and high spatial resolution satellite data (for the CBAWO and ARW sites). At the Sabine Peninsula site, hyperspectral VIs exhibited a better performance for modelling PVC than multispectral VIs due to their capacity for sampling fine spectral features. The optimal hyperspectral bands were located at important spectral features observed in Arctic vegetation spectra, including leaf pigment absorption in the red wavelengths and at the red-edge, leaf water absorption in the near infrared, and leaf cellulose and lignin absorption in the shortwave infrared. At the CBAWO and ARW sites, field PVC and fAPAR exhibited strong correlations (R2 > 0.70) with the NDVI (Normalized Difference Vegetation Index) derived from high-resolution WorldView-2 data. Similarly, high spatial resolution satellite-derived fAPAR was correlated to MODIS fAPAR (R2 = 0.68), with a systematic overestimation of 0.08, which was attributed to PAR absorption by soil that could not be excluded from the fAPAR calculation. This research clearly demonstrates that high spectral and spatial resolution remote sensing VIs can be used to successfully model Arctic biophysical variables. The methods and results presented in this research provided a guide for future studies aiming to model other Arctic biophysical variables through remote sensing data.

abstract: PhD


title: Drag, Demons, and Dirt: Centering Indigenous Thought in Critiques of Prairie Queer Settler Colonialism

contributor:
Morgensen, Scott Lauria
Gender Studies

subject:
Indigenous Studies
Settler Colonialism
Queer
Prairie

abstract: My thesis takes as its central question ongoing colonialism in white queer settler affective and discursive relationships to the prairies and to “home.” I engage with the works of queer and feminist Indigenous theorists, poets, and arts by the likes of Gregory Scofield, Adrian Stimson, Erica Violet Lee, Zoe Todd, Billy-Ray Belcourt in order to fully articulate my critique of queer settler colonialism. I observe how white queer settlers experience their queerness as an obstacle to full and immediate participation in the settler colonial project, which hinges on cis and heteronormativity, and then recuperate their belonging through queer articulations of colonial claims to home on occupied Indigenous lands. Over the course of this project, I also notice how whiteness mobilizes both anti-Black racism and Indigenous dispossession. In order to investigate these white queer affective attachments to home, I work closely with cultural production made by white queer settlers from Edmonton and Calgary, specifically works by Darrin Hagen, Trevor Anderson, and Rae Spoon. I find it necessary to take these books, films, and music seriously as they are located within and reproduce larger systems of settler colonialism.

abstract: M.A.


title: Exploring Students' Motivation to Engage in Sustainable Engineering Practice

contributor:
Strong, David S.
Mechanical and Materials Engineering

subject: Engineering Education for Sustainable Development

subject: Engineering education

subject: Sustainable engineering practice

subject: Sustainable development

subject: Motivation

subject: Value

subject: Engineering Discipline

subject: Impact of Engineering

abstract:
This study used a quantitative approach to explore Canadian undergraduate students’ motivation to engage in sustainable engineering practice. Engineering is considered to be a key profession for sustainable development, which requires engineers and engineering students to be motivated. An ex-post facto design was used to measure students’ stereotypes of and previous experiences with, self-concept of abilities of, and relative value of sustainable engineering practice. These elements were used to investigate and compare students’ motivation levels across gender, year of study, and engineering discipline. A survey instrument was developed specifically for this study and was tested in a mixed method pilot study with a sample of graduate engineering students. After the pilot study, the improved survey instrument was distributed to undergraduate students at eight engineering institutions across Canada.
	The results from the survey instrument suggested that students’ have high value for but limited experiences with sustainable engineering practice. As a result, the the results suggested that students are not necessarily motivated to engage in sustainable engineering practice. Male students were found to have slightly higher self-concepts of some of their abilities and no differences were found among year of study. Most differences occurred among the engineering disciplines in the Stereotypes and Previous Experiences factors. Students in the ECE and Science, and Mechanical- Based disciplines had less positive and more limited experiences than students in the Chemical- and Environmental-Based disciplines. There were some differences between the ECE and Science and the Environmental-Based disciplines in students’ relative value. Generally, students valued sustainable engineering practice more for utility than intrinsic reasons. In all disciplines, students were biased towards the environmental element of sustainable engineering practice and incorporated only simplistic considerations.
	A universal definition and understanding of sustainable engineering practice should be adopted to provide a foundation for practice. Generally, students require more experiences with sustainable engineering practice in their engineering programs. To address the differences among the disciplines, discipline-specific interventions should be developed to address the application and integration of the social, economic, environmental, and multidimensional elements of sustainable engineering practice.

abstract: M.A.Sc.


title: Exploring Academic Acculturation Experiences of Chinese International Students with Low Oral English Proficiency: A Musically Enhanced Narrative Inquiry

contributor:
Bolden, Benjamin
Education

subject:
Academic acculturation
Chinese international students
Oral English proficiency
International education
Musically Enhanced Narrative Inquiry

abstract: Situated within an increasing trend of globalization and internationalization, 97 percent of Canadian universities offer international experiences to students. Chinese international students are the biggest international student group in Canada, and they are also the group with the lowest spoken English scores. Studies have demonstrated that oral English capacity significantly influences international students’ academic acculturation. However, little is known about the lived academic acculturation experiences of Chinese international students with limited spoken English. To address this literature gap, this study aimed to understand the academic acculturation experiences of Chinese international students with limited spoken English currently studying at a Canadian university. A musically enhanced narrative inquiry approach was employed, building on traditional forms of narrative inquiry by utilizing sound and music. Data were collected through art-informed interviews with six Chinese international students, and were analyzed through both narrative and musical re-storying, resulting in the creation of both literary and musical narrative representations. Expectancy-Value Theory served as a theoretical framework that informed the study design and the interpretation of results. The narratives from all six Chinese students demonstrated high levels of psychological stress during their academic acculturation and that their motivation for spoken English learning was drastically improved in relation to their academic acculturation experiences. By exploring the experiences of Chinese international students with limited spoken English capacity through a musically enhanced narrative inquiry, this study contributes to the existing understanding of international students’ academic acculturation, and has uncovered implications for various associated stakeholders including Chinese students, parents, and teachers, and host country educators and support service personnel who work with international students.

abstract: M.Ed.


title: The Role of Endocytic Adaptor Endophilin A2 in Human Breast Cancer Signaling, Metastasis, and Targeted Therapy

contributor:
Craig, Andrew W.
Biomedical and Molecular Sciences

subject:
Breast cancer
Metastasis
Endophilin
Endocytosis
HER2
Triple-Negative
Trastuzumab

abstract: The leading cause of death in breast cancer is metastatic burden. Classification of breast cancer cases by molecular subtype reveals that those categorized as triple-negative (TNBC) and human epidermal growth factor receptor 2 overexpressing (HER2+) exhibit more invasive phenotypes, higher rates of metastasis, and worse survival. Tumour progression requires signaling via receptor tyrosine kinases epidermal growth factor receptor (EGFR) and HER2, as well as invasion through the extracellular matrix (ECM) directed by membrane-type 1 matrix metalloprotease (MT1-MMP). Coordinated endocytosis of these receptors is essential for their cellular functions. Endophilin A2 (Endo II) is a Bin/Amphiphysin/Rvs (BAR) domain protein involved in endocytosis. Studies have identified Endo II as a substrate of Src kinase involved in establishing and maintaining a tumorigenic and metastatic phenotype in mice. However, the specific role of Endo II in human breast cancer progression remains unclear. This thesis investigated the role of Endo II in human TNBC and HER2+ cancer models. High Endo II expression was detected in TNBC and HER2+ subtypes, and was correlated with poor prognosis in human breast tumours. Stable knock-down (KD) of Endo II in several human TNBC and HER2+ cell lines resulted in defects in internalization and signaling by EGFR and HER2 in TNBC and HER2+ models, respectively. Cell migration and invasion in vitro were also reduced upon Endo II KD. In TNBC cells, Endo II KD suppressed ECM degradation by invadopodia, despite higher levels of MT1-MMP on the cell surface. Endo II KD also limited tumour growth and metastasis in mammary orthotopic tumor xenograft models. Lastly, HER2 internalization and the cytotoxicity of Trastuzumab and Trastuzumab Emtansine (T-DM1) were suppressed in Endo II KD HER2+ cells. These results identify Endo II as a positive regulator of both breast cancer metastasis, as well as the cytotoxic response to antibody-based therapy. Overall, this thesis provides a foundation for refined approaches to alter Endo II expression and function in high-risk patients, as a means to increase sensitivity and mitigate resistance to targeted therapies.

abstract: PhD


title: A laboratory study of the effectiveness of thermal remediation on creosote impacted soil

contributor:
Mumford, Kevin G.
Kueper, Bernard H.
Civil Engineering

subject:
Thermal Remediation
Creosote
Groundwater
Contamination

abstract:
Groundwater can be impacted by many types of contaminants, some of which are difficult to remediate, such as dense non-aqueous phase liquids (DNAPLs). DNAPLs can exist for long periods of time in the subsurface and may result in decreased groundwater quality, decreased land value and an increased risk of indoor air quality impacts to nearby infrastructure. In situ thermal remediation has been proposed and implemented at sites impacted by volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), though additional information is required to elucidate fundamental mechanisms and establish performance expectations.

Preliminary laboratory studies were conducted to determine the effectiveness of heating at moderate temperatures on soil impacted to various degrees with creosote, a multi-component SVOC DNAPL. Co-boiling temperatures observed during heating were near the boiling point of water due to the low volatility of the creosote. Though VOC removal from soil occurred quickly during co-boiling, polycyclic aromatic hydrocarbon (PAH) concentrations in soil appeared unchanged, indicating that higher temperatures or longer heating durations are necessary to achieve typical regulatory standards.  Subsequent laboratory tests were conducted to determine the effectiveness of heating at moderate, elevated and highly elevated temperatures on soil impacted with creosote. PAH concentrations in soil decreased the most during co-boiling for all heating tests, and continued to decrease during extended heating periods of up to 10 days at highly elevated temperatures (320 °C). However, PAH concentrations in soil remained above Ontario’s regulatory standards after completion of all tests. Dissolution tests designed to simulate groundwater flow through treated sites post-heating revealed continuing PAH dissolution into water.

The results from these two studies indicate that in situ thermal remediation of multi-component SVOC DNAPLs, at least to the temperatures tested in this study, does not result in soil PAH concentrations below applicable regulatory limits. Furthermore, remaining PAHs in treated soil continue to partition into the aqueous phase. Additional research into higher temperature thermal applications and the effects of pumping during heating are recommended to fully determine whether in situ thermal remediation is a viable option for SVOC DNAPL impacted sites.

abstract: M.A.Sc.


title: Body Segment Inertial Parameters of Toddlers

contributor:
Dumas, Geneviève A.
Mechanical and Materials Engineering

subject:
Body Segment Inertial Parameters
Anthropometrics
Toddler
Body Segment Parameters
Photogrammetric

abstract:
Body segment inertial parameters (BSIPs) are required to study human kinetics and to model the human form. The purpose of this study was to determine the BSIPs in toddlers using the photogrammetric method. Twelve male and twelve female toddlers (1.5-3years) were photographed in two planes, front and side, with reflective markers placed at the joint centres. The subjects were also weighed and had their height measured. Jensen’s elliptical model was used to segment the images and zone the segments in 3mm thick slices. The segment masses, centre of mass (COM) locations and radii of gyration (ROGs) about the three principal axes were calculated and normalized in a percent form.
Segment mass proportion of the head was found to decrease as the child ages while the mass proportion of the thigh increases. The trunk’s mass proportion increased with body mass index. These trends follow those found in the literature. The COM locations of segments were compared to the literature. The COM location of the head moves distally as the child ages. The COMs of the thigh and shank move proximally as muscle mass is developed. ROGs were highly variable due to posture variability from a population who found the photogrammetric protocol difficult to follow. To minimize positional errors, all subjects were analyzed together. The arm, forearm, thigh and shank were found to be similar to the literature while the hand and foot differed due to protocol difficulties. The ROGs of the head, neck and trunk could not be compared to the literature due to segmenting differences. The estimated total body mass was compared to the measured mass using a scale. The average error was 1.7% (SD=2.9%).
Despite some challenges and limitations of working with toddlers, the study was able to collect BSIPs of toddlers and provide data for a frequently overlooked population. The results of this study provide important data for those studying the biomechanics of toddlers or developing models of toddlers.

abstract: M.A.Sc.


title: The Genetic Structure of Species' Geographic Ranges: An Evaluation Using the Coastal Dune Endemic  Camissoniopsis  Cheiranthifolia (Onagraceae)

contributor:
Eckert, Christopher G.
Biology

subject: Genetic Structure of Species' Ranges

abstract:
The development of molecular techniques has spurred thousands of population genetic studies on a wide variety of plant and animal species. Particularly important, but still relatively rare, are studies that properly test for geographic variation in genetic structure across species’ ranges. This thesis investigates the effects of population density, mating system variation, distance between populations and hybridization on the genetic diversity, differentiation and structure across the range of Camissoniopsis cheiranthifolia (Onagraceae). By combining a transplant experiment with microsatellites, I also provide an empirical test of one of the most poorly resolved questions in evolutionary biology: Why do species exhibit limits to their distributions?
I developed 24 species-specific nuclear microsatellites loci (nSSR) and used 13 of these and six variable chloroplast microsatellites (cpSSR) to investigate the genetic consequences of the transition from outcrossing to selfing in C. cheiranthifolia. As predicted, small-flowered, selfing populations had lower nSSR diversity (but not cpSSR) than large-flowered, outcrossing populations but they were not more differentiated. The reduction in diversity was greater than the expected from selfing alone, but could not be accounted for by indirect effects of selfing on population density. Five parapatric nSSR clusters and three groups of cpSSR haplotypes usually (but not always) differed in mating system, suggesting that selfing may often initiate ecogeographic isolation. However, lineage-wide diversity failed to support that selection for reproductive assurance initiated selfing in this species.
I also investigated if hybridization with C. bistorta has influenced the genetic structure of C. cheiranthifolia in areas of closest parapatry. I confirmed that closet parapatry was associated with extensive genetic continuity between self-incompatible C. cheiranthifolia and C. bistorta and these were indistinguishable genetically within the broader context of geographic variation in C. cheiranthifolia, suggesting that C. bistorta could be an inland ecotype of C. cheiranthifolia
Finally, fitness increased toward and beyond the northern range limit of C. cheiranthifolia but edge individuals were not best suited to conditions beyond the range. Despite strong genetic differentiation and very low, nondirectional gene flow, there was no evidence of local adaptation, except at the coarsest spatial scale, suggesting range limitation via constraints to dispersal.

abstract: PhD


title: Wing Kinematics and Flexibility for Optimal Manoeuvring and Escape

contributor:
Rival, David E.
Mechanical and Materials Engineering

rights: Attribution-NonCommercial 3.0 United States

subject:
Biological swimming
Biological flying
Vortex dynamics
Leading-edge vortex
Flow separation
Particle Tracking Velocimetry

abstract: Understanding how animals control the dynamic stall vortices in their wake is critical to developing micro-aerial vehicles and autonomous underwater vehicles, not to mention wind turbines, delta wings, and rotor craft that undergo similar dynamic stall processes. Applying this knowledge to biomimetic engineering problems requires progress in three areas: (i) understanding the flow physics of natural swimmers and flyers; (ii) developing flow measurement techniques to resolve this physics; and (iii) deriving low-cost models suitable for studying the vast parameter space observed in nature. This body of work, which consists of five research chapters, focuses on the leading-edge vortex (LEV) that forms on profiles undergoing rapid manoeuvres, delta wings, and similar devices. Lagrangian particle tracking is used throughout this thesis to track the mass and circulation transport in the LEV on manoeuvring profiles. The growth and development of the LEV is studied in relation to: flapping and plunging profile kinematics; spanwise flow from profile sweep and spanwise profile bending; and varying the angle-of-attack gradient along the profile span. Finally, scaling relationships derived from the observations above are used to develop a low-cost model for LEV growth, that is validated on a flat-plate delta wing. Together these results contribute to each of the three topics identified above, as a step towards developing robust, agile biomimetic swimmers and flyers.

abstract: PhD


title: Using Deep Learning to predict the mortality of Leukemia patients

contributor:
Skillicorn, B. David
Cordy, James R.
Computing

subject:
Deep Learning
H2O
Leukemia
Cancer
Acute Lymphoblastic Leukemia
ALL

abstract:
“If it were not for the great variability among individuals, medicine might as well be a science, not an art.”  Sir William Osler, Canadian physician and McGill alumnus, quoted in 1892.

       Personalized medicine is the approach that tailors the treatment of patients based on their unique genetic makeup and genetic environment.  When equipped with details of individual variation, physicians can separate patients into subgroups to predict which patients must be treated aggressively and which patients would respond to one drug rather than another. Personalized medicine is now being applied towards the prediction of mortality in childhood Acute Lymphoblastic Leukemia (ALL) patients. This is because individual children differ in the sensitivity of their leukemic cells and in their response to treatment-related toxicity. Currently, mortality prediction for childhood ALL is based on risk-stratification performed by expert doctors. The genotypic (actual set of genes), phenotypic (expression of those genes in observable traits) and clinical information is used to stratify children into various risk categories. The information collected by doctors for risk-stratification include response to certain drugs, clinical factors such as age and gender and biological measurements such as white blood cell count.
       The goal of this thesis is to automate the prediction of childhood ALL mortality using genotypic and phenotypic information of patients. We intend to achieve this using the Deep Learning algorithm, which is known to analyze non-linear and complex information, such as cell-interactions, effectively. We conduct this thesis using the Big Data software called H2O, using R. We first experimented with the standard Deep Learning parameters, and later adjusted the size and shape of the general network by optimizing the depth and retention factor of hidden neurons. We improved the accuracy by using the techniques of Out-of-Bag Sampling, Bagging and Voting. We later tuned H2O’s platform-specific network parameters. Later, the number of votes needed to obtain the highest accuracy of predictions, is also tuned.  We built confusion matrices for each of our Deep Learning models to evaluate how well our models perform. Our results are promising as they are corroborated by the clinical dataset and they perform better than the physicians’ predictions.

abstract: M.Sc.


title: Regulation of the mexAB-oprM efflux operon of Pseudomonas aeruginosa

contributor:
Poole, R. Keith
Microbiology and Immunology

subject:
Pseudomonas aeruginosa
MexAB-oprM
Efflux
Multidrug
Resistance-Nodulation-Division
Antimicrobial Resistance
Regulation

abstract: Multidrug efflux systems are important determinants of antimicrobial resistance in the human pathogen Pseudomonas aeruginosa where they compromise anti-pseudomonal chemotherapy. The major multidrug efflux system in P. aeruginosa is encoded by the mexAB-oprM operon, expression of which is regulated by a MexR repressor whose activity is negatively modulated by the anti-repressor protein, ArmR. armR occurs as part of a two-gene operon, PA3720-armR, that is regulated by the product of the divergently-transcribed nalC repressor gene, with nalC mutants showing elevated PA3720-armR expression and, so, elevated mexAB-oprM expression and multidrug resistance. The function of the PA3720 protein is unknown. We show here that PA3720 functions as a non-specific RNA binding protein that binds to and destabilizes the adjacent armR-bearing mRNA. Expression of armR is also shown to be translationally coupled to PA3720. In an earlier study, aminoglycosides were shown to induce expression of PA3720-armR, suggesting that these drugs may also promote mexAB-oprM expression dependent on ArmR. Consistent with this, aminoglycosides promoted expression of mexAB-oprM; however, this was independent of ArmR. Instead, the aminoglycoside-responsive AmgRS two-component system mediated aminoglycoside induction of this efflux system. Consistent with this, mutational activation of the AmgS sensor kinase yielded elevated levels of mexAB-oprM expression, and purified AmgR bound specifically to the mexAB-oprM promoter region. Screening of P. aeruginosa strain PAO1 transposon mutants for increased sensitivity to carbenicillin- carbenicillin is a MexAB-OprM substrate and carbenicillin sensitivity is a surrogate for loss of mexAB-oprM expression - led to the identification of several genes with probable roles in mexAB-oprM expression or activity. The gene disrupted in one of these mutants, bamB, encodes for a component of the outer membrane β-barrel protein assembly machinery and was assessed for its role in facilitating the assembly of OprM, a β-barrel outer membrane protein. Western immunoblotting revealed that BamB is not required for OprM insertion into the outer membrane. These studies provide additional insights into the regulation of mexAB-oprM expression in P. aeruginosa.

abstract: PhD


title: The Mapkey: Preliminary Design, Construction and Testing of a Novel UAV Platform for Cavity Surveying

contributor:
Marshall, Joshua A.
Mining Engineering

subject:
Unmanned Aerial Vehicle
Autorotation
3D Surveying
Underground

abstract:
This thesis presents research related to the preliminary design, construction and testing of a novel autorotating unmanned aerial vehicle (UAV) for gathering 3D maps of underground cavities. The novel UAV is called "The Mapkey". Current underground cavity surveying is conducted by using a stationary light detection and ranging (LiDAR) sensor extended into a void to collect a 3D point cloud. This method is costly and takes a significant amount of time. An autorotating UAV equipped with a LiDAR payload was constructed to collect a 3D point cloud as it flies along the vertical extent of an underground cavity. The potential benefits of this novel surveying method include: cost reduction, increased survey accuracy and reduced survey times.

Autorotation is the state of flight where the main rotor rotates due to the flow of air upwards through the rotor. The constructed autorotating UAV passively falls through the cavity and rotates as it falls. A single-beam LiDAR payload attached to the UAV collects range data from the surrounding environment and monitors the relative position and orientation of the UAV as it falls. The vertical descent and rotation of the LiDAR payload maps the surrounding environment by way of a 3D helical scan pattern. Data is retrieved and post processed to create a 3D map of the cavity.  Applications for the acquired data could be to estimate the volume of the cavity or to identify interesting features such as overhangs. This device was tested in a laboratory environment and results show that the UAV is capable of recreating a 3D point cloud of its surrounding environment. Future work includes testing in a more representative underground environment and further processing of the collected point cloud to determine the volume of an underground cavity.

abstract: M.A.Sc.


title: Dynamic Modelling of Gear Transmission Systems With and Without Localized Tooth Defects

contributor:
Mechefske, Chris K.
Timusk, Markus
Mechanical and Materials Engineering

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
Gear Mesh Stiffness
Gear Dynamic Model
Secondary Effects
Localized Tooth Defects
Cylindrical Gear

abstract:
Gear transmission systems are widely used in many industry applications. Increased demand for higher-speed, improved performance and longer-lived machinery, makes the prediction and control of gear vibration and noise, as well as the early detection and diagnosis of gear defects important considerations. Many researchers use dynamic modelling of gear vibration to increase knowledge about the vibration generating mechanisms in gear transmission systems and the dynamic behaviour of gear transmission systems in the presence of some kinds of localized tooth defects.

This project aims to advance the current understanding of gear dynamics by introducing more accurate and realistic gear dynamic modelling strategies for cylindrical gear (spur gear and helical gear) transmission systems with and without localized tooth defects (tooth fillet crack and spalling defect). A series of studies have been conducted to reflect different aspects of gear dynamics. The main conclusions can be as summarized below:

1. Corner contact effect should not be neglected in the gear dynamic analysis if no or an insufficient amount of tooth profile modification is applied when the gears are working under heavy load.

2. The dynamic coupling behaviour is obvious in the direction of off-line of action when a gear pair with gear eccentricities is running at relatively low-speed range where the resonances of gear torsional vibration are most likely to be excited.

3. The addendum modification can affect gear dynamics through the back-side mesh stiffness, especially when the gears are working under light load or idling conditions.

4. Special attention should be paid to the tooth inclination deformations for the early detection of the initial crack damage. Besides, the spatial crack with non-uniform crack depth will lead to unevenness of the dynamic load distribution on the cracked tooth flank. Tilting motions can therefore be excited whenever the cracked tooth comes into the mesh.

5. The nonlinear elliptical contact patterns do affect the excitations due to spalls especially for spalls with small size and gear pairs running under heavy load. The proposed model considering the effect of the nonlinear elliptical contact patterns by introducing modification coefficients can yield more realistic and accurate results.

abstract: PhD


title: Reds in Beds: The Communist Party of Canada and the Politics of Reproduction, 1920-1970

contributor:
Duffin, Jacalyn
History

subject:
Canada
Sex
Socialism
State Medicine
Birth Control
Abortion
Eugenics
Population Control
Juvenile Delinquency
Venereal Disease
Reproduction
Communist Party of Canada
Left History
Communism
Medicine
Toronto
Newspaper

abstract: In the early twentieth-century, the Communist Party of Canada (CPC) initially hesitated to discuss the politics of reproduction as a means of easing material inequity for women and men of the working class. Nevertheless, over five decades, this topic appeared often in the CPCs official and unofficial publications, illustrating a sustained interest in the taboo subject. My thesis draws upon archival materials, communist and mainstream newspapers, and medical periodicals to survey contemporary opinions of birth control, abortion, eugenics, juvenile delinquency, venereal disease, and state medicine. Using the lens of left-politics, these topics are contextualized with reference to the extant literature on the histories of politics, sex, reproduction, labour, and medicine in Canada and beyond. Far from being confined to a few secretive individuals, the militant left engaged a dense network of activists who took stock of the social as well as physical reproduction of the nation. Often their interests appeared indistinguishable from the mainstream, and occasionally overlapped with those of their right-leaning opponents. The CPC unfailingly argued for an understanding of sex and reproduction that reflected its Marxist worldview. Some multi-generational discussions were so durable that they would outlast and outgrow the militant left to emerge within the rhetoric of a multitude of Canadian liberation groups by the late sixties and early seventies. I argue that investigation of the politics underwriting the ideas of the CPC and its ideology of a healthy, socialized body politic, elucidates complexities in the formation of mainstream Canadian approaches to sex, reproduction, and health.

abstract: PhD


title: Radioreduction and Radiopurity of Acrylic in the DEAP-3600 Dark Matter Experiment

contributor: Physics, Engineering Physics and Astronomy

subject: DEAP

subject: Lead-210

subject: Radon-222

subject: Acrylic

subject: Resurfacer

abstract: The DEAP-3600 experiment is a single-phase liquid argon dark matter detector employing pulse discrimination to mitigate background-like events and isolate WIMP-like events. The vessel that holds 3600~kg of target, and the flowguide that guides convective flow, are made of ultrapure acrylic plastic. Diffusion of radioactive radon and radon progeny within air into the acrylic post-fabrication result in a surface layer that is orders of magnitude more radioactive than the bulk material. The robotic sanding of the vessel and the manual sanding of the flowguides, to reduce surface contamination to that of the bulk, are discussed: the Resurfacer removed 360 ± 30 μm of acrylic from the vessel surface as a rate of 10.5 ± 2.3 g/hr, and a minimum of 37 μm was manually removed from the argon-exposed flowguide surfaces. The empirical assay of acrylic bulk contamination is also discussed: a content of (2 ± 2) × 10^-19 grams of Pb-210 per gram of acrylic was measured, with a procedural Pb-210 recovery efficiency of 47 ± 13%.

abstract: M.Sc.


title: Essays in International Capital Flows and Capital Controls

contributor:
Lloyd-Ellis, Huw
Lapham, Beverly
Head, Allen
Economics

subject:
Capital Flow
Capital Control
Business Cycles
Open Economy Macroeconomics
Foreign Direct Investment
Monetary Policy
Emerging Market
Exchange Rate
Interest Rate

abstract:
In this dissertation, I first explore the effects of categories of capital inflows on output volatility and output growth in developing countries and propose a welfare-improving capital control policy. I provide empirical evidence and theoretical support for capital control targeted at foreign portfolio liabilities and examine its quantitative welfare implications. I then examine the dynamic effects of global monetary policy as well as emerging economies’ domestic monetary and exchange rate shocks on the categories of capital inflows.

In Chapter 2, I first analyze the effects of financial account openness on output volatility and output growth in developing countries. I then study the effects of the categories of capital inflows on output volatility and output growth. I use panel cross-country ordinary least square regressions and panel instrumental variable regressions, and estimate the effects of financial account openness and categories of capital inflows on output volatility and output growth.

In Chapter 3, I develop and analyze a stochastic, small open economy, real business cycle model. The model incorporates two categories of capital inflows, endogenous collateral constraints, interest rate premia above the world interest rate and adjustment costs which are increasing and convex in each capital inflow type. Investments financed by foreign direct liabilities increase production more than those financed by foreign portfolio liabilities as foreign direct liabilities increase productivity via technology transfer. A capital control taxis imposed on foreign portfolio liability interest payments. Model simulations indicate that an increase in the tax rate on foreign portfolio liability interest payment results in a welfare improvement.

Chapter 4 analyzes the effects of the U.S. monetary policy shocks on gross foreign direct and portfolio investment inflows to emerging markets and compares them to those associated with domestic monetary policy and exchange rate shocks. It uses panel and country-specific structural vector auto-regressions to analyze and compare the dynamics, magnitude, and differential impacts of the shocks on each inflow category. The response of foreign direct investment inflows to policy shocks is weak while that of foreign portfolio investment is stronger and immediate. I also provide clearer comparison of “push" and “pull" factors on financial flows via forecast error variance decomposition.

abstract: PhD


title: Effects of age and environment on locomotor performance in adult Drosophila melanogaster

contributor:
Robertson, Mel
Biology

subject:
locomotor performance
Drosophila
age
pulsed light stimulation
hypoxia
CNGL channel
electrophysiology

abstract: Drosophila melanogaster has been an attractive animal model for more than 100 years. Our laboratory has established a high-throughput assay for fly locomotion in a circular arena. Fly locomotor activity involves the interaction between the environment and internal physiological characteristics, including age. Behaviors such as walking, feeding and resting are age-specific, however, how age affects the fly locomotion and whether such changes are strain specific is unclear. Environmental effects such as variation in temperature and humidity also affect locomotor performance. However, the effects on locomotion of long-term environmental change such as the pulsed light stimulation, or the short-term environmental change such as acute hypoxia, are unknown. For my thesis, I investigated the effect of age on locomotor performance by examining boundary preference, path length per minute and 0.2 s path increment during locomotion in small circular arenas, and the speed of locomotor recovery from anoxia. My results show that locomotor performance depended on age, and such age-dependent changes differed between fly strains. I also studied the effect of pulsed light stimulation on locomotor activity and extracellular electrical activity in the brain. This stimulus increased boundary preference and the distance travelled in a circular arena, as well as the periodicity of episodic motor activity. In addition, I examined locomotor responses to hypoxia and the role of CNGL channel in these responses. Hypoxia and re-oxygenation modulated locomotor performance, and flies with down-regulation of CNGL showed reduced locomotion under normoxia, reduced recovery from hypoxia, and reduced basal level of CNS extracellular K+ concentrations. In response to hypoxia, down-regulation of CNGL increased extracellular K+ concentration change, reduced time to reach the K+ concentration peak, and delayed time to recover from hypoxia. Upregulation of cGMP partially compensated for the changes in locomotor activity and electrophysiological alterations in response to hypoxia. Taken together, age and environmental stimuli affect fly locomotor performance, and CNGL channels are involved in modulating locomotion and CNS function in response to hypoxia in adult Drosophila.

abstract: PhD


title: Essays on Commodity Price Shocks,  Bank Risk and Market Volatility Forecasting

contributor:
Milne, Frank
Economics

subject:
Commodity Price Shocks
Bank Risk
Macro- finance Linkages
Factor Models
VARs
Volatility Forecasting
Heterogeneous Autoregression
OLS Post-Lasso
OLHAR
Model Selection
Tail Risk
Quantile projections
Density forecasts

abstract: My dissertation has three main chapters. Chapter 2 develops a structural dynamic factor model that estimates the effects of commodity price shocks on the Canadian macroeconomy, bank lending and bank risk. Unlike most literature treating commodity price changes as exogenous, I identify global structural shocks driving real commodity prices and find that global demand and commodity market–specific shocks are crucial. These two shocks are shown to have quite different implications for bank lending and risk, which confirms the importance of disentangling shocks driving commodity price changes. I also discover that on average, the total loan growth and the noninterest income ratio of large Canadian banks are more responsive to the above two commodity price shocks than those of small Canadian banks. Chapter 3, coauthored with Tian Xie, studies how to better forecast the daily market volatility (VIX) index. We propose utilizing the ordinary least square post–least absolute shrinkage and selection operator (OLS post–Lasso) from Belloni and Chernozhukov (2013) to select the predictors and estimate the coefficients for a heterogeneous autoregressive (HAR) model (Corsi, 2009). In an out–of–sample analysis with the VIX data, our proposed OLS post–Lasso HAR (OLHAR) model generates a different combination of predictors from those ex ante imposed by the standard HAR model. Moreover, the OLHAR model shows its dominance over the standard HAR and other competitor models at forecasting the VIX either weekly, biweekly, or monthly ahead. Chapter 4 develops a tail risk forecasting system tailored to Canada and provides a set of one–quarter ahead forecasts of tail real and financial risk by factor–based conditional quantile projections. My model forecasts the steepest decline in GDP–Oil at 2009Q2, and the peaks of the nonperforming loan (NPL) ratios of Bank of Montreal (BMO) and Canadian Imperial Bank of Commerce (CIBC) at 2010Q2 and 2010Q3, respectively. For BMO and CIBC, the banking factors contribute the most to the peaks of the Value at Risk (VaR) forecasts of the NPL ratios. The commodity price factors also compose a prominent portion of the total contribution from the global factors.

abstract: PhD


title: Needs of Families of Children with Cerebral Palsy in Bangladesh

contributor:
Aldersey, Heather
Rehabilitation Science

subject:
Bangladesh
Children With Cerebral Palsy
Family Needs
Support

abstract:
Background: A child with disabilities (CWD) can have a significant impact on the entire family unit. Families with a CWD are more likely to experience poverty and inequitable access to important resources, particularly in low resource countries like Bangladesh due to stigmatization and discrimination. Over the last few decades, an increased number of studies on family needs had been conducted in high-income countries, but family needs are under-studied in low-income countries. Therefore, the aims of this study were to: (a) explore the needs of families of children with cerebral palsy (CP) in Bangladesh; (b) investigate how some of the family needs have been met, and (c) identify the sources of supports that might help families to meet their needs in the future.
Methods: Face to face, semi-structured, in-depth interviews were conducted with 20 family members (12 mothers, 4 fathers, 1 sister, 2 grandmothers, and 1 aunt) who visited the Centre for the Rehabilitation of the Paralysed (CRP), Bangladesh between June and August 2016 to receive services for a child with CP. A constant comparison method of the grounded theory approach within the broader spectrum of qualitative inquiry was used to analyze the data.
Results: Participants identified five categories related to needs: (a) financial needs, (b) access to disability-related services, (c) family and community cohesion, (d) informational needs, and (e) emotional needs. Participants overwhelmingly reported that financial need is their greatest family need. Participants highlighted that some of their needs have been met through non-governmental organizations, extended family and community members. Participants reported that they receive little to no support from the government. However, participants identified the government as the key source who can play vital role in meeting their unmet needs.
Conclusions: Further studies on needs of families of children with conditions other than CP and those who do not have access to rehabilitation services at CRP may provide greater insights into the needs of families impacted by disability in Bangladesh. Additionally, an in-depth analysis of existing disability related policies is required to determine the extent to which consideration of and accommodation for family needs is embedded within existing policies.

abstract: M.Sc.


title: A Protocol-Specific Constraint-Based Intrusion Detection System

contributor:
Dean, Thomas R.
Zulkernine, Mohammad
Computing

rights: Attribution-ShareAlike 3.0 United States

subject:
Constraint
Intrusion Detection System
Network Protocol
Domain Specific Language

abstract:
With the advancement of new technologies, the frequency of malicious attacks is also growing rapidly. Even networks without external connections cannot hide from these attacks. Constant monitoring of a network is vital for an organization's security system. Among numerous monitoring techniques, network behavior analysis has become popular. Normal traffic patterns of a network can be modeled as network constraints. The violation of these constraints indicates the possibility that an intrusion has occurred.

Expressing network vulnerabilities is not an easy task. Sometimes, it is more complicated than recognizing an intruder's attack pattern. Currently, network administrators use Intrusion Detection System (IDS) rules to define security concerns regarding their networks. An IDS rule finds it difficult to detect sophisticated multi-packet intrusions. Constraints compared to IDS rules possess better expressiveness to describe a network behavior for defending the network against different attacks.

Evaluating constraints in an efficient manner is a key to achieving a better IDS. Numerous constraint checking techniques provide good performance in solving constraints. However, they are not always effective in checking constraints with dynamic information.

In this thesis, we propose a protocol specific constraint-based IDS to detect intrusions in a network. We investigate two protocols used in the Data Distribution Service (DDS) and identify their vulnerabilities. These two protocols are Internet Group Management Protocol (IGMP) and Real-Time Publisher Subscriber Protocol (RTPS). We develop constraints to protect a network against attacks that may exploit these vulnerabilities. For checking these constraints, a naive tree-based technique along with an optimized version is presented. Both techniques have the adaptability to cope with a continuous update of relevant network behavior information from a network traffic. The structure and life cycle of the constraint trees are explained in detail. A Domain Specific Language (DSL) is designed to express these constraints. An experimental private network is built which simulates network traffic similar to an Air Traffic Control System (ATC). Finally, we present how this IDS evaluates network constraints against the traffic generated from the experimental network and prevents attacks.

abstract: M.Sc.


title: Teacher Educators' Approaches to Assessment

contributor:
DeLuca, Christopher
DeLuca, Christopher
Education

subject:
Classroom Assessment
Teacher Educators
Approaches to Assessment
Assessment Literacy
Teacher Education
Assessment Education

abstract:
Teacher educators have the potential to wield tremendous influence in shaping educational reform through the education of teacher candidates. Brookhart, a leading assessment researcher, argues that a primary influence on teacher candidates’ assessment capability involves teacher educators’ approaches to assessment: “teacher candidates’ repertoire of effective teaching practices depends on the beliefs about learning and the approach to assessment espoused by the respective teacher educator” (2016, p. 17). This study examines Canadian teacher educators’ approaches to assessment, with particular attention to the relationship between instructional focus (e.g., assessment, curriculum, professional studies) or assessment education model on teacher educators’ approaches to assessment.
	A quantitative design was used to examine teacher educators’ approaches to classroom assessment. Through completion of the Approaches to Classroom Assessment Inventory, teacher educators from nine provinces shared their approaches to assessment in relation to five classroom assessment scenarios. They also reported the degree to which assessment content was integrated into the teacher education courses they instructed.
	Results of this study showed that teacher educators’ approaches to assessment within discrete themes (i.e., Assessment Purpose, Assessment Process, Assessment Fairness, Measurement Theory), were highly consistent. However, when considering teacher educators’ approaches to assessment across Assessment Themes, there was a high degree of variability. Differences in how assessment and curriculum/professional studies educators integrated assessment content into the teacher education courses they instructed were also noted.
	Findings from this research serves to inform the development and delivery of teacher assessment education. As this study provides the first examination of Canadian teacher educators’ assessment literacy, teacher educators are provided the opportunity to compare their assessment literacy to that of K-12 classroom teachers and teacher candidates. Findings from this study begin to lay the foundation for future studies into the impact of Canadian teacher educators’ assessment literacy on teacher education.

abstract: M.Ed.


title: Understanding the Role and Nature of Intuition in Philosophical Inquiry

contributor:
Bakhurst, David
Bakhurst, David
Philosophy

subject:
Intuition
Tacit Knowledge
Education
Philosophy

abstract: This thesis explores the role and nature of intuition in philosophical inquiry. Appeals to intuition have either been used as evidence for or against philosophical theories or as constitutive features of judgement. I attempt to understand our uses of intuition by appealing to tacit knowledge. The hope is to elicit a picture of intuition as being practical and explanatory. Our reliance on intuition is warranted if we understand it as an expression of tacit knowledge.

abstract: M.A.


title: Marie: A disenfrancised First Nation woman from Kipawa

contributor:
Luce-Kapler, Rebecca
Morcom, Lindsay
Luce-Kapler, Rebecca
Morcom, Lindsay
Education

subject: First Nation women of Canada

subject: Indian Act of Canada

subject: Disenfrancisement

subject: Bill C-31

subject: Section 12(1)(b) Indian Act of Indian Act

subject: Poverty

subject: Racism

subject: Native Education

subject: Teacher Education

abstract:
Abstract
The Indian Act of Canada specifically targeting First Nation women has been blatantly discriminatory. In 1951 section 12(1) (b) was successfully passed and dealt specifically with First Nation women, effectively disinheriting them when they married non-status men. Conversely, Native status was not only retained for their brothers, but also passed on to their non-Native wives. It remained that way until 1981 when the United Nations, an international body, deemed it sexually discriminatory. Though challenged by Native women across Canada, there was little effort from the courts, band councils and Native advocacy groups to correct this injustice. It wasn’t until 1985, when Bill C-31 was introduced to deal with this injustice. This thesis followed Marie’s experience as she was disenfranchised. Disenfranchised women were forced to make do in urbanized communities where opportunities were few and poverty the trend. In Marie’s case poverty, loss of identity, lack of education, abuse and dislocation from her community affected her greatly. She could neither belong in the Western world, nor return to her community. Such Women fell under the full effect of colonization. Their communities crossed them off their membership lists and they were rejected not only from their communities, but often from within their own families. Section 12(1) (b), as it dealt with First Nation women had the deleterious effect of dividing communities and families from within. Though she eventually regained her status, Marie shared reflections about her journey back and acknowledged that her healing came from giving back and serving others. It is what made her resilient. Marie was interviewed over the summer of 2016 and her experiences written as narratives and collected by Catherine Davis, her daughter and author of this study. As the stories of mother and daughter intertwine in the writing of this thesis, it became an autoethnography where personal experiences intersect with the public domain. This study has implications for any Canadian teacher who interacts with First Nation people. Experiences, like Marie’s, offer balance iii and is the first step in the Truth and Reconciliation process. Stories have the power to heal and telling the truth is where we start.

abstract: PhD


title: The Impact of Noisy Vestibular Stimulation on Self-motion Phenomena

contributor:
Troje, Nikolaus F.
Troje, Nikolaus F.
Psychology

subject:
Multisensory integration
Vection
Simulator Sickness
Virtual reality
Self-motion
Vestibular
Vision
Bayesian inference
Sensory conflict
Sensory reweighting

abstract:
Low immersion and sickness experienced in virtual reality (VR) are two important barriers that inhibit the widespread adoption of VR technology. Both are thought to relate to visual-vestibular mismatch. Recoupling multisensory cues can generate more convincing illusory self-motion (vection) and reduce sickness, but current methods rely on expensive or invasive techniques to simulate expected cues. According to a Bayesian framework of sensory integration, adding sensory noise may also reduce mismatch by changing sensory weights. This thesis explores this idea and proposes that ‘noisy’ vestibular stimulation presents an attractive solution to the above problems.
I investigated the potential for improving VR experiences using two techniques that generate noise in the vestibular system. Rather than recoupling the senses, I aimed to encourage discounting of vestibular cues that are inconsistent with vision. In Chapter 2 I assessed the potential for improving immersion by measuring the effect of noisy vestibular stimulation (either bone-conducted vibration, BCV; or galvanic vestibular stimulation, GVS) on vection onset latency. I found a large reduction in vection latency when transient BCV or GVS were used at visual motion onset. The evidence suggests that a more compelling sensation of self-motion is achieved when sensory mismatch is reduced.
In a second study I examined the extent to which sickness is reduced when BCV is applied during path navigation in a high-end VR display (Chapter 3). Results revealed lower sickness when transient noisy stimulation was applied. In a replication of this experiment I found that BCV reduced sickness to a similar extent when observers used a commercial head-mounted display.
The results of Chapter 2 and 3 offer evidence that BCV reduces multisensory mismatch by down-weighting vestibular information according to Bayesian cue combination models. Given this context I also expected BCV to reduce self-motion sensitivity in a real-world movement discrimination task (Chapter 4). The results of a third study did not support my predictions, suggesting that the effects of noisy stimulation on self-motion may be more complex than previously considered.
Together the findings give rise to a variety of opportunities for further testing of the technique, which are discussed in Chapter 5.

abstract: PhD


title: Democratizing Energy in a Marketized World: The Cases of Costa Rica and Nicaragua

contributor:
McDonald, David A.
McDonald, David A.
Global Development Studies

subject:
Energy Democracy
Privatization
Energy Transition
Renewable Energy
Post Carbon
Participatory Democracy
Energy Development

abstract: This thesis explores the experiences, motivations and the imaginary of people who seek to democratize access to energy. Through a survey of the energy democracy movement in Europe and North America and a case study of two participatory and democratically oriented electricity providers in Central America, this thesis examines the differences and similarities between democratizing energy in the Global North and Global South in the context of marketization and the global push to transition to renewable energy. The forces of an expanding global energy economy are increasingly influencing the way that we can access and consume energy in our lives. Local interactions cannot be understood by an isolated analysis without considering the larger structural conditions that implicate them. Today, we are witnessing a global push to transition our energy resources from fossil fuels to renewables due to the emergency of climate change. For the most part, this transition preoccupies itself with changing the technological instruments that source us the energy. Yet few changes are targeting transition from growth focused market-based economic models. Energy Democracy is one new imaginary that people are rallying around to help realize alternatives to drive more equitable and sustainable post-carbon futures. This thesis finds that there are unfounded normative assumptions being made about groups organizing around energy democracy that is causing scatter in the movement. There is an aggressive strand of energy democracy that readily accepts for-profit schemes and risks turning energy democracy into just another space for capital accumulation in the energy sector. This thesis presents two important suggestions for reconciling these problems. Firstly, to look beyond moving the term itself and prioritize connecting on the basis of the underlying principles that define the term. This will ultimately create more meaningful solidarity in the future, and a more grounded and unified movement. Secondly, to increase focus on exploring the experiences and motivations of like-minded groups in the Global South who are heavily implicated by this global energy transition and, necessarily, by any movement that seeks an alternative to it.

abstract: M.A.


title: Investigating the Dopaminergic and Glucocorticoid Systems as Underlying Mechanisms of Anhedonia

contributor:
Olmstead, Mary
Olmstead, Mary C.
Psychology

subject:
Anhedonia
Reward Responsiveness
Dopamine
Glucocorticoid
Stress

abstract: Anhedonia, a severe deficit in reward processing, is an endophenotype of several neuropsychiatric disorders (APA, 2000) and increases susceptibility to depression (Atherton et al., 2015), substance abuse (Hatzigiakoumis et al., 2011), and suicidality (Winer et al., 2016). Recent literature suggests that anhedonia reflects a maladaptive interaction between reward circuitry and stress, the former being mediated by the mesolimbic dopamine (DA) system and the latter by the glucocorticoid system (Vrieze et al., 2013). The role of the DA system in the development and maintenance of anhedonia has been studied extensively, but little is known about the contribution of the glucocorticoid system to this process. The goal of the current study was to investigate the dopaminergic and glucocorticoid systems as underlying mechanisms of anhedonia using a validated rat test of anhedonia, the probabilistic reward task (PRT). In this task, rats learned to discriminate between two ambiguous tones for a sucrose reward. During testing, one lever was programmed to produce three times more reward than the other lever. Similar to healthy humans, rats develop a response bias toward the more frequently reinforced stimulus, regardless of which tone is presented. Consistent with prior literature, the response bias was enhanced following amphetamine- (AMPH) induced DA activation, and reduced following pramipexole- (PRAMI) induced DA inhibition. Additionally, a 21-day chronic mild stress (CMS) regimen attenuated the response bias in a subpopulation of animals relative to no stress controls. Finally, the glucocorticoid antagonist, mifepristone (MIFE), had no effect on the response bias relative to saline (SAL); however, the glucocorticoid agonist, dexamethasone (DEX), attenuated the response bias relative to both SAL and MIFE. These results confirm a role of DA in reward processing, and highlight an additional contribution of the glucocorticoid system in the mediation of this effect. Thus, it is plausible that chronic stress directly interferes with normal mesolimbic DA functioning, which leads to an overall impairment in reward responsiveness. These findings underscore the importance of treatment directed toward the DA and glucocorticoid systems, rather than the current SSRI treatment. Future studies on the etiology of anhedonia should carefully investigate the interaction of these systems in reward processing.

abstract: M.Sc.


title: Primary/Junior Pre-Service Teachers’ Knowledge, Attitudes, and Perceptions of Including Students with ADHD in General Education Classrooms: A Mixed-Method Study

contributor:
Berg, Derek
Berg, Derek
Education

subject:
Pre-Service Teachers
ADHD
ADHD Knowledge
Pre-service Teacher Attitudes
Pre-service Teacher Knowledge
Pre-Service Teacher Perceptions of ADHD
Pre-Service Attitudes Towards ADHD
Pre-Service Teacher Knowledge of ADHD
ADHD in general education classrooms

abstract: Negative attitudes towards students with Attention Deficit Hyperactivity Disorder (ADHD) are a lingering challenge in the education system. It is important to examine pre-service teachers’ perceptions of ADHD in an educational setting due to the influential roles of teachers on students. Pre-service teachers’ knowledge and attitudes, as well as their perceptions of ADHD, have powerful influences on the ways in which teachers' pedagogical decisions affect their interactions and relationships with students. The purpose of the study was to explore pre-service teachers’ knowledge of ADHD and their attitudes and perceptions towards including ADHD in the general classroom. The purpose of this study was informed by two research questions: Do coursework and practicum experience influence pre-service teachers’ knowledge, attitudes, and perceptions of including students with ADHD in the general education classroom? What underlies a change in pre-service teachers’ knowledge, attitudes, and perceptions of including students with ADHD in the general education classroom? A mixed-method study was conducted using a sequential explanatory design, examining 28 primary/junior pre-service teachers from a university, in a city in Ontario. Pre-test and post-test data were collected through questionnaires, responses to vignettes, and in-depth individual interviews. Questionnaire analysis indicated four significant differences from time 1 to time 2. Three individual interviews were conducted; overall pre-service teachers had positive attitudes towards students with ADHD, but lacked content knowledge and felt there were weaknesses in their knowledge due to their teacher education program design. This study provides an in-depth understanding of pre-service teachers’ knowledge, attitudes (what they think or feel) and perceptions (their understanding or interpretation) of students with ADHD. Findings of this study could be of interest to Ontario curriculum developers, policy makers, teacher educators, and practicing teachers.

abstract: M.Ed.


title: Surveillance Gone Too Far? Individual Reactions to the Use of Drones in Urban Areas.

contributor:
Murakami-Wood, David
Sociology

subject: Surveillance UAV Drone Space Privacy Visibility Exposure

abstract: Unmanned Aerial Vehicles (UAVs), popularly referred to as ‘drones’, have increased in popularity over the past two decades. Various concerns have been raised about their implementation, primarily focusing on their surveillance capabilities. Through an intervention explanatory sequential design 80 participants (50F/30M) in South Eastern Ontario, Canada, were either exposed to a UAV (Experimental = 40) or not (Control = 40) and were given a word association task. From these participants, a subsample of 16 (F=7, M=9) respondents (8 from both groups) was taken for semi-structured interviews. The findings from the word association task indicate that the control group associated UAVs with more military applications and less positive admirations while the experimental group had the exact opposite results. Additionally, both conditions and genders found surveillance associations to be related to UAVs. Results from the semi-structured interviews indicate that individuals are influenced by previous knowledge surrounding UAVs and are primarily concerned about the surveillance implications for the following reasons: exposures to privacy, chilling/conforming behaviours, feelings of unease, signifies ‘Big Brother’, mobile cameras, gendered notions of surveillance and operation, and influences crime control and perception. Further qualitative analysis revealed that even though both genders found surveillance of UAVs to be an issue, they do so for different reasoning. Females were more likely to indicate the UAV being used to observe their body while males were more concerned with general uses of voyeurism. Overall, UAVs have the potential to evoke a sense of ‘surveillance gone too far’ depending on the context in which they are used. It is speculated that this aversion arises out of the power-space-visuality relationship UAVs hold, causing reactions to become more visceral.

abstract: M.A.


title: Direct Numerical Simulation of Fluid Flow and Mass Transfer in Spacer Filled Channels

contributor:
Pharoah, Jon G.
Pollard, Andrew
Beale, Steven B.
Mechanical and Materials Engineering

subject:
CFD
Fluid Dynamics
Mass Transfer
OpenFOAM

abstract:
Reverse osmosis separation processes are often performed using spiral wound mem- brane modules. Spacer meshes are placed between adjacent membrane layers to prevent them from coming into contact. Spacers promote mixing and increase mass transfer by disrupting fluid flow in the channel, and can reduce the chance of concen- tration polarization in the membrane. In this thesis a simplified membrane module configuration consisting of a straight channel with an array of centred cylindrical spacers is analyzed using direct numerical simulation. The purpose of the study is to gain a better understanding of the fluid flow and mass transfer in the channel, and to determine if any phenomena are periodic.
Solutes with Schmidt numbers of 1, 3, and 5 are examined for Reynolds numbers of 100, 300, and 500 (based on the cylinder diameter and bulk velocity when there is no blockage). Flow and concentration fields were analyzed for their impact on effects such as the vortex shedding, velocity spectra, pressure drop, shear rate, and mass transfer. Vortices are shed along the top and bottom of the cylinders, and their convection downstream has significant impacts on the local shear stress at the wall. As the Reynolds number increases, the local peak of the shear rate fluctuates, indicating that the flow is not periodic.
The concentration field becomes more dilute with an increase in both Reynolds i
and Schmidt numbers. The location of the local maxima and minima is dependent on the nature of vortex shedding. Mass transfer enhancement is strongly related to shear stresses and improved with increasing Reynolds number and Schmidt num- ber. The spatial distribution of the Sherwood number does not indicate a periodic concentration field for a Reynolds number above 100.
The scope of the work was limited by a need for computing resources in excess of what was available. Future work should include gaining additional data points for the proposed correlations by varying the Reynolds and Schmidt numbers. Additional configurations should be considered, such as an array of cylinders with an off-centre location, and an array of cylinders that follow a ”zig-zag” pattern.

abstract: M.A.Sc.


title: Elucidating the Biosynthesis of Nucleocidin, a Fluorinated Natural Product Produced by Streptomyces Calvus

contributor:
Zechel, L. David
Chemistry

subject: Nucleocidin

abstract: The formation of carbon-fluorine (C-F) bonds represents a very rare form of enzyme catalysis relative to other organohalogens. Instead of an oxidative mechanism, desolvation and nucleophilic incorporation of fluoride is required. Nucleocidin, produced by Streptomyces calvus, is a novel fluorinated analog of adenosine. The fluorine at the 4’-carbon of nucleocidin demands an unusual sequence of cleavage of the 4’C-H bond of the ribose ring and stereospecific glycosylation of fluoride. The nucleocidin biosynthetic gene cluster has recently been identified in Streptomyces calvus. This provides an opportunity to elucidate the functions of the encoded enzymes. To determine the minimal set of genes required to synthesize nucleocidin, a strategy was developed to clone the gene cluster using transformation associated recombination (TAR) in yeast, followed by heterologous expression in another Streptomyces strain. In parallel, CRISPR/Cas9 was used to inactivate selected biosynthetic genes. Plasmids encoding CRISPR/Cas9 that were designed to inactivate orf171, nucG, and nucK were conjugated into S. calvus. Additionally, the biosynthesis of a chlorinated derivative of nucleocidin was attempted by incorporating the putative ascamycin halogenase genes acmX and acmY into S. calvus Spore 4. Integration of acmX into the chromosome of S. calvus Spore 4 was successful as confirmed by PCR, while integration of acmY could not be confirmed.The presence of nucleocidin in the extracts of S. calvus Spore 4 att::[acmX, aac(3)IV] and S. calvus Spore 4 was confirmed by 19FNMR spectroscopy. A new signal was observed in the S. calvus Spore 4 att::[acmY,aac(3)IV] extract that was not observed in the S. calvus Spore 4 extract. This could correspond to a chlorinated derivative, or a new nucleocidin biosynthetic or shunt intermediate. AcmX was successfully heterologously expressed in E. coli and purified. Further studies can focus on assaying AcmX to confirm its function as a variant B FADH2-dependent chlorinase. A putative purine nucleoside phosphorylase (orf206) present in the nucleocidin cluster was heterologously expressed as inclusion bodies in E. coli, setting the stage for purification under denaturing conditions. Finally, enhanced production of nucleocidin was not observed after orf191 encoding a predicted streptomycin-like regulatory gene was integrated onto the chromosome of S. calvus Spore 4. Overall, this work sets the stage for investigating the functions of nucleocidin biosynthetic genes and generating new nucleocidin derivatives.

abstract: M.Sc.


title: Mental Health and Physical Activity in Canadian Adolescents with Attention Deficit Hyperactivity Disorder

contributor:
Pickett, William
Public Health Sciences

subject: Mental health

subject: Physical activity

subject: Epidemiology

abstract:
Background: Adolescents with attention deficit hyperactivity disorder (ADHD) are at a heightened risk for poor mental health. Limitations of medication use for the treatment of ADHD include non-response and adverse side effects. Physical activity has shown promise for such treatments through the alleviation of the direct symptoms of ADHD, as well as the fostering of positive mental health. However, the contexts in which physical activity occurs in youth with ADHD and impacts upon their mental health have not been thoroughly explored.

Objectives: The objectives of this thesis are to: 1) describe the prevalence of positive and negative mental health indicators in Canadian youth with ADHD and compare the prevalence of these indicators to Canadian youth without ADHD, 2) estimate the strength and statistical significance of associations between different types of physical activity and mental health indicators in adolescents with ADHD, and; 3) examine the potential influence of biological sex and age in these relationships.

Methods: Data from the 7th cycle of the Health Behaviour in School-aged Children (HBSC) study was used. Prevalence estimates were calculated for each mental health indicator by ADHD status. Rao-Scott chi-square tests were conducted to examine group differences. Multi-level log binomial regression models were developed to explore the associations of interest.

Results: Canadian adolescents with ADHD reported poorer mental health than Canadian adolescents without ADHD. Within the ADHD population, females reported a higher prevalence of negative mental health indicators than males. Inconsistent patterns were found between engagement in different types of physical activities and mental health in youth with ADHD. The main potential etiological finding was that engagement in physical activity in certain contexts was associated with high prosocial behaviour in adolescents with ADHD.

Conclusions: Identification of different mental health patterns in males and females in the ADHD population suggests the possibility of differential diagnoses of ADHD by biological sex. Physical activity in different contexts may have differential effects on the mental health of young people with ADHD. Understanding of these relationships could help inform public health to develop physical activity interventions that are the most effective in this subpopulation of youth.

abstract: M.Sc.


title: Unconventional Lives with Conventional Dreams: An Examination of the Formal and Informal Work Intersect Among Homeless Ottawa Youth

contributor:
Baron, Stephen
Baron, Stephen W.
Sociology

subject:
Criminology
Sociology
Crime
Homeless Youth
Street Youth
At-Risk Populations
Labour Experiences
Employment
Ottawa
Attitudes
Motivations
Informal Labour
Formal Labour

abstract:
The goal of this research is to understand how work (both formal and informal) is situated within the lives of homeless youth and how this intersect is affected by peer networks and relationships developed on the streets. This research aims to increase understanding on whether homelessness and formal work are compatible through highlighting the everyday challenges that affect homeless youth in their struggles to successfully transition off the streets and into adulthood. Through 30 semi-structured in-depth interviews with a sample of homeless youth recruited from Ottawa, Ontario, this research investigates how peer networks affect a street youth’s ability towards taking conventional or alternative pathways to money- making pathways. Further, it examines why some homeless youth choose the types of informal money- making strategies they are engaged in and why they stray away from conventional working aspirations.

Results reveal that despite maintaining conventional goals and aspirations regarding rejoining conventional streams of society, youths turned to informal work due to their lack of viable options in the formal economy. Engagement in the informal economy was cited as necessary in order to satisfy addictions and generate a quick income to alleviate economic instability. Informal working involvements were met with numerous impeding risks and barriers including being subject to victimization, harsh weather conditions, mental and physical health issues and demographic barriers. Cumulative disadvantages were seen to impede youths’ abilities to successfully navigate their informal behaviours on the streets as well as maintain an attachment to family, friends, and school. Further, in most cases youth tended to lack significant formal employment experiences. Even when attaining formal employment, youths turned to illegal activities to supplement their incomes. Severe barriers challenged youths’ abilities to maintain employment as well as balance an attachment to family, friends, and school. These included challenges inherent to living without stable shelter, a lack of viable transportation and struggles with addiction. The results also suggest how social networks influenced youths’ navigations on the streets in respect to employment (both formal and informal) by facilitating criminal engagement through direct and indirect exposures and being embedded in criminal networks. Formal employment facilitation was nearly non-existent through means of peer network influences and youths’ motives and attitudes regarding conventional lifestyle aspirations did not reflect that of their peer networks. The findings in this research are discussed in light of Agnew’s (2006) General Strain Theory and McCarthy et al.’s (2002) Social Capital Theory. Suggestions are offered for future research directions and implications for policy.

abstract: M.A.


title: "It's a Practice, Not a Performance": Unraveling the Atomized Self and Becoming Nomadic Through Ashtanga Yoga

contributor:
Day, Richard
Cultural Studies

subject:
Yoga
Philosophical Nomadism
Melancholia
Psychoanalysis
Subjectivity
Decolonization
Embodiment

abstract: Modern forms of yoga practice are increasingly focused on the body, emphasizing the physical benefits of the practice while positioning the body as an effective tool for accessing and working with the mind. Holding patterns in the body are often interpreted in relation to psychological or emotional tendencies and certain postures are seen as manifestations of fears or anxieties encountered in daily life. In this way, the yoga mat can be interpreted as an intensely psychological space, one that mobilizes the body in the project of self-transformation and healing and lends itself to the creation of therapeutic communities and relationships. This work explores the links between the embodied nature of yoga, specifically ashtanga yoga, and the cultivation of more relational and nomadic forms of subjectivity. Through participant observation and individual interviews conducted with ashtanga teachers and practitioners at a specific yoga studio in Western Canada, I explore the contexts in which the practice of ashtanga yoga can unsettle bounded or atomized understandings of self. I focus explicitly on how, when practiced in an intersubjective environment that emphasizes healing over transcendence or enlightenment, the practice can provide an effective medium for identifying across and between difference, challenging conceptions of what a body is and does in ways that can open up the possibility for a more affirmative relation with alterity. By encouraging practitioners to understand the body as intimately connected to them yet exceeding their ability to fully know or control it, a sustained engagement with the ashtanga practice can introduce a quality of Otherness into practitioners’ understandings of self and can help relinquish some of the need for ownership and control characteristic of settler subjectivities. I examine the factors that render practice more accessible to certain segments of the population, namely the middle-class, and emphasize the need to continually investigate ways of keeping practice communities open and flexible.

abstract: M.A.


title: Investigating Catalyst Coated Membrane Equilibration Time For Polymer Electrolyte Membrane Fuel Cell Manufacturing

contributor:
Pharoah, Jon
Mechanical and Materials Engineering

subject:
PEM
Fuel Cell
Catalyst Coated Membrane
Catalyst Layer
Equilibration

abstract: Mercedes-Benz Canada Inc., Fuel Cell Division, manufactures polymer electrolyte membrane fuel cell stacks for use in vehicles. The manufacturing line is being optimized for efficiency and quality control, in order to uphold the high standards of Mercedes-Benz Inc. vehicles. In an operating polymer electrolyte membrane fuel cell, the catalyst coated membrane facilitates the electrochemical reaction that generates electricity. This research examines the equilibration of catalyst coated membrane rolls to controlled temperature and humidity conditions, before they are used in the manufacturing of polymer electrolyte membrane fuel cells. Equilibration involves allowing the water content in the catalyst coated membrane to stabilize at the controlled conditions, in order to reduce mechanical stress in the material for better manufacturability. Initial equilibration measurements were conducted on discrete catalyst coated membrane samples using novel electronic conductivity measurements of the catalyst layer, and compared to ionic conductivity measurements of the membrane. Electronic conductivity measurements are easier to implement in the manufacturing environment than the more complex ionic conductivity measurements. When testing discrete catalyst coated membrane samples in an environmental chamber, the equilibration trends for the measured ionic and electronic conductivity signals were similar enough to permit us to adapt the electronic conductivity measurements for catalyst coated membrane in roll form. Equilibration measurements of catalyst coated membrane rolls were optimized to achieve a robust and repeatable procedure which could be used in the manufacturing environment at Mercedes-Benz Canada Inc., Fuel Cell Division.

abstract: M.A.Sc.


title: Identification and Reduction of the Alpha Background, From 238U and 232Th Decay Chains, in the DEAP-3600 Experiment.

contributor: Physics, Engineering Physics and Astronomy

subject:
Physics
Dark Matter
Alpha Background

abstract:
Different cosmological and astronomical observations from the past century indicate that non-baryonic matter, commonly referred to as dark matter, dominates the composition of the universe. Discovering the nature and properties of dark matter has been one of the most pursued goals of modern physics.
The DEAP collaboration developed a single-phase 3600 kg liquid argon experiment, DEAP-3600, to measure possible nuclear recoils generated by the interactions between the target nuclei and WIMP particles from the surrounding galactic dark matter halo. DEAP-3600 utilizes the powerful pulse-shape discrimination method to distinguish between the aforementioned interaction and its different types of background.
The work presented in this thesis focuses on the identification and reduction of the background from alpha particle decays, from the $^{238}$U and $^{232}$Th decay chains. This was first undertaken with the development and deployment of a custom designed sanding robot, aimed at reducing radiogenic surface contamination, which removed 506$\pm$50 $\mu$m of acrylic from the inner-most portion of the detector surface. Furthermore, different analysis tools were developed and used during different phases of the experiment to measure the remaining radiogenic activities carefully. Said analysis estimated a liquid argon bulk activity of 0.540$\pm$0.0016 mBq for the $^{222}$Rn chain and 0.0127$\pm$0.0022 mBq for the $^{220}$Rn chain, as well as an overall surface activity of 3.87$\pm$0.41 mBq. This thesis also reports on the first WIMP analysis performed with the DEAP-3600 experiment. With a total fiducial exposure of 14226$\pm$1384 kg-days, no WIMP candidate events were identified in the dataset allowing to set an upper limit on the WIMP-nucleon cross-section of $1.77\times10^{-44}$ cm$^{2}$, at a WIMP mass of 100 GeV.

abstract: PhD