title: Experimental and Numerical Study on the Extreme Behaviors of Sliding Isolation Bearings

contributor:
Becker, Tracy
Civil Engineering

subject:
Double friction pendulum bearing
Shake table test
Extreme events
Numerical modeling
Base isolation
Collapse risk
Restraining Rim

abstract:
Sliding isolation bearings are used widely around the world to minimize damage to structures and their contents during earthquakes. Past studies have typically focused on the behavior of sliding isolation bearing under design conditions; however, as the performance-based earthquake engineering advances, it is necessary and critical to understand the ultimate or even failure behavior, of structural systems under extreme conditions. Using a double friction pendulum bearing with non-articulated slider as an example, this thesis comprehensively investigates the extreme behavior of the sliding bearing components as well as steel frame buildings isolated using these bearings.
This thesis is comprised of two major parts. The first includes numerical and experimental studies of double friction pendulum bearings at the component-level. Finite element investigation shows that depending on the superstructure mass there are two major failure modes for the double friction pendulum bearings. When the superstructure mass is sufficiently large, the failure mode is dominated by the restraining rim yielding; however, when the mass is relatively small, its failure mode shifts to bearing uplift. A simplified analytical model which can directly simulate the impact and uplift behavior of double friction pendulum bearing is also implemented, comparing well to the finite element analysis. Then, to validate the ability of the models to predict extreme behavior as well as to investigate the effect of the restraining rim design, which varies around the world, an experimental study was carried out. Uplift behavior and significant rim yielding were observed during the shake table tests. Moreover, other response parameters, including uplift and shear forces, are evaluated and compared among different rim designs. It is found the restraining rim design has a substantial influence on the bearing’s extreme behavior.
The second part of the thesis investigates the system-level behavior of steel frame buildings isolated with double friction pendulum bearings. It is found that the stiffness of the superstructure largely dictates the system-level failure modes and collapse probability. Initially, bearings with rigid restraining rims are investigated. For flexible moment-resisting frames, the system-level failure modes are mixed: both the bearing uplift and superstructure yielding contribute; also, using current code-minimum design results in acceptably low probability of collapse. However, for stiff concentrically-braced frames, the impact force can impose large ductility demands on the superstructure regardless of its strength. As a result, the system-level failure comes exclusively from superstructure yielding, and only by increasing bearing’s displacement capacity beyond the minimum code allowed can the design meet as acceptably low collapse probability. When flat rims are used instead for the bearing design, the failure modes for both building types are exclusively bearing failure. Furthermore, while it is more apparent for concentrically-braced frames, using flat rims for the bearings can reduce the collapse probability compared to using rigid rims.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Data analysis of rainfall event characteristics and derivation of flood frequency distribution equations for urban stormwater management purposes

contributor:
Guo, Yiping
Civil Engineering

subject:
rainfall data analysis
flood frequency
analytical models
probabilistic models
stormwater management
goodness of fit
rainfall events
hydrograph shapes
Poisson test
saturation-excess runoff
infiltration-excess runoff
hydrological models
design storm approach
event-based approach

abstract: further development of the simple and promising analytical probabilistic approach

abstract: Urban stormwater management aims at mitigating the adverse impacts of urbanization. Hydrological models are used in support of stormwater management planning and design. There are three main approaches that can be applied for this modeling purpose: (1) continuous simulation approach which is accurate but time-consuming; (2) design storm approach, which is widely used and its accuracy highly depends on the selected antecedent moisture conditions and temporal distribution of design storms; and (3) the analytical probabilistic approach which is recently developed and still not used in practice. Although it is time-effective and it can produce results as accurate as the other two approaches; the analytical probabilistic approach requires further developments in order to make it more reliable and accurate. For this purpose, three subtopics are investigated in this thesis. (1) Rainfall data analysis as required by the analytical probabilistic approach with emphasis on testing the exponentiality of rainfall event duration, volume and interevent time (i.e., time separating it from its preceding rainfall event). A goodness-of-fit testing procedure that is suitable for this kind of data analysis was proposed. (2) Derivation of new analytical probabilistic models for peak discharge rate incorporating trapezoidal and triangular hydrograph shapes in order to include all possible catchment’s responses. And (3) the infiltration process is assumed to continue until the end of the rainfall event; however, the soil may get saturated earlier and the excess amount would contribute to the runoff volume which may have adverse impact if not taken into consideration. Thus, in addition to the infiltration process, the saturation excess runoff is also included and new models for flood frequencies are developed. All the models developed in this thesis are tested and compared to methods used in practice, reasonable results were obtained.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Urban stormwater management aims at mitigating the adverse impacts of urbanization. Hydrological models are used in support of stormwater management planning and design. The analytical probabilistic stormwater management model (APSWM) is a promising tool for planning and design analysis. The purpose of this thesis is to further develop APSWM in order to make it more reliable and accurate. First, a clear procedure for rainfall data analysis as required by APSWM is provided.  Second, a new APSWM is derived incorporating other runoff temporal-distribution patterns. Finally, the possibility of soil layer saturation while it is still raining is added to the model. All the models developed in this thesis are tested and compared to methods used in engineering practice, reasonable results were obtained.


title: The air-drying of Escherichia coli reporters in natural polymers and incorporation into simple bioassays

contributor:
Brennan, John
Chemical Biology

subject:
microbial biosensor
paper-based
air-drying
natural polymers
acacia gum
pullulan

abstract: Microbial biosensor systems (MBS) are useful for analyte detection owing to their low cost, sensitivity, and selectivity for bioavailable analytes. Due to typically poor shelf-life and sensitivity to external conditions, there are few reports of MBS technology applied to simple analytical devices. The effectiveness of air-drying MBS in natural polymers was investigated as a novel preservation technique. Two colorimetric Escherichia coli MBS, a tetracycline-inducible reporter and an arsenate-inducible reporter, were dried on various substrates yielding novel MBS platforms. In proof-of-concept experiments performed in 96-well microplates, both systems demonstrated responsivity after air-drying in low concentrations of pullulan.  However, the MBS were unresponsive following brief storage of 1 week. To improve the preservation of MBS, sensing strips were created by air-drying concentrated acacia gum-based MBS suspensions onto paper. Cells dried on these strips demonstrated responsivity upon solubilization in various tube-based assays. MBS sensing strip responsivity was demonstrated following storage for 6 weeks at 4 °C. Tetracycline-responsive sensing strips also performed well in assays using spiked lake water samples. Air-drying in natural polymers was an effective MBS preservation technique, and allowed for the creation of “mix and read” style assays which were simple, equipment-free and ready-to-use.

abstract: Thesis

abstract: Master of Science (MSc)


title: Inflammation, infections and the microbiome of children with short bowel syndrome

contributor: Medical Sciences (Division of Physiology/Pharmacology)

abstract:
Children with short bowel syndrome have reduced gastrointestinal mass due to surgical resection in the neonatal period.   This multi-pronged health translational study investigated the previous infectious history, microbiome, and inflammation of twelve children with this disease.  We sought to further understand how dysbiosis, bacterial products such as butyrate, and intestinal permeability may link with the type and frequency of bloodstream infections and systemic inflammation.
The most frequent pathogens identified in bloodstream infections were coagulase-negative Staphylococcus, Enterococcus species, Klebsiella species and Candida species.  Sixty-one percent of cultured microbes could be considered enteric with a gastrointestinal origin.
With high-thoroughput 16S rRNA fecal analysis, children with intestinal failure demonstrated the most significant dysbiosis with the lowest Shannon diversity and an abundance of the Escherichia genus seemingly attributable to the pro-inflammatory species E. coli.   Commensal anaerobes known to produce SCFA including Ruminococcaceae and Lachnospiraceae were significantly reduced in those with IF.  Similarly, measured butyric acid was significantly reduced in children with IF compared to controls (median 0.37nmol/mg vs 10.92nmol/mg; p<0.0001).
Serum analysis of intestinal permeability markers including circulating bacterial products lipopolysaccharide and muramyl dipeptide (MDP) were similar between children with SBS and controls.   Furthermore, no differences were detected in gene expression of pro- or anti- inflammatory transcription factors, cytokine concentration, or fecal calprotectin.
Children with SBS exhibit dysbiosis, a reduction in SCFA-producing microbes and reduction in butyrate concentration.  Fecal analysis has identified a significant abundance of likely E. coli however it remains the sixth most common microbe cultured in bloodstream infections.  The microbial community is significantly altered in children with intestinal failure with implications on complications of this disease including feed advancement, bacterial overgrowth, gastrointestinal motility and infection.  Further research will be needed to investigate if manipulation of the microbiome can influence important clinical outcomes and alter bacterial translocation and infection.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Short bowel syndrome is a condition caused by surgical removal of a large portion of the intestine.  This research identified the most common bacteria which cause serious bloodstream infections and characterized the bacterial composition, known as the microbiome, in their intestine.  The microbiome, in this population, exhibited a lower number and variety of bacteria, fewer ‘good’ bacteria and an overgrowth of specific bacteria usually in very low abundance in the intestine of healthy children.    Children with short bowel syndrome had less bacteria by-products, which help maintain a healthy digestive tract.  We did not identify differences in the permeability of the intestine or evidence of inflammation.   These results are important to understand the interactions between bacteria of the intestine, the digestive complications of short bowel syndrome, and to establish a link between the microbiome, bloodstream infections and inflammation, which in the future can help advance future treatments for this serious disease.


title: Calcium Regulation in Drosophila Melanogaster and Mechanisms of Malpighian Tubule Calcium Transport

title: Calcium Regulation and Transport Mechanisms in Drosophila

contributor:
O'Donnell, M. J.
Biology

subject:
drosophila melanogaster
calcium regulation

abstract:
Most studies of insect Malpighian tubules (MTs) have examined transport of monovalent ions (K^+, Na^+, Cl^-). Isolated Drosophila melanogaster MTs also transport Ca^2+ from bath to lumen and transport is stimulated by cAMP. The lower segment of the MTs transports Ca^2+ at a higher rate per unit length than does the main segment known to produce the primary urine. This study examines both whole animal calcium regulation in larvae, pupae and adults and the mechanisms of Ca^2+ transport by isolated MTs. Drosophila melanogaster appears to regulate its calcium content and haemolymph calcium level. Calcium content of the whole fly only increased 10% with a 6.2-fold increase in dietary calcium. Anterior MTs can contain as much as 50% of the whole animal calcium content. The difference in MTs accumulation is due primarily to the enlarged initial segment of the anterior MTs. This segment, absent from the posterior MT, contains calcium-containing concretions. Whole fly calcium content does not increase continuously with the age implying that calcium is eventually being excreted.
Haemolymph calcium concentrations do not change in response to changes in dietary calcium, suggesting that calcium concentration is regulated either by the rate of absorption or by the rate of excretion. The midgut and the enlarged initial segment of the anterior MTs may play important roles in haemolymph calcium regulation. Isolated MTs show sensitivity to both Ca^2+ channel blockers and Ca^2+ -ATPAse inhibitors on the basolateral and apical membranes respectively. Voltage-gated calcium channels appear to mediate calcium movement from bath to cell. A ruthenium red sensitive Ca^2+ -ATPAse may be used to transport calcium against the electrochemical gradient from cell to lumen. Lastly, the dissolution of luminal concretions plays a large role in net calcium secretion.

abstract: Thesis

abstract: Master of Science (MSc)


title: THE METABOLIC AND INFLAMMATORY EFFECTS OF NUCLEOTIDE OLIGOMERIZATION DOMAIN (NOD) PROTEIN SIGNALING DURING OBESITY AND BACTERIAL STRESS

contributor:
Schertzer, Jonathan
Biochemistry and Biomedical Sciences

abstract: Intestinal dysbiosis contributes to obesity and insulin resistance, but intervening with antibiotics, prebiotics, or probiotics can be limited by specificity or sustained changes in microbial composition. Postbiotics include bacterial components such as lipopolysaccharides, which have been shown to promote insulin resistance during metabolic endotoxemia. The data presented in this thesis demonstrates that bacterial cell wall-derived muramyl dipeptide (MDP) is an insulin-sensitizing postbiotic that requires the nucleotide oligomerization domain 2 (NOD2) protein. Injecting MDP lowered adipose inflammation and reduced glucose intolerance in obese mice without causing weight loss. MDP reduced hepatic insulin resistance during obesity and low-level endotoxemia. NOD1-activating peptidoglycan worsened glucose tolerance. The transcription factor interferon regulatory factor 4 (IRF4) distinguished opposing glycemic responses to different types of peptidoglycan. IRF4 was dispensable for exacerbated glucose intolerance via NOD1, but was required for MDP/NOD2-induced insulin sensitization and lower metabolic tissue inflammation during obesity and endotoxemia.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Obesity is associated with insulin resistance, which is the primary predictor of type 2 diabetes. This research aims to understand the relationship between obesity, insulin, and diabetes by investigating the immune system. Inflammation contributes to insulin resistance during obesity. Inflammation is controlled by the immune system, which normally protects the body against disease. Good bacteria living inside the gut are beneficial because they aid digestion and increase nutrient absorption. Studying how bacteria interact with the immune system is important because microbes activate inflammatory responses. Therefore, different bacteria might be critical in preventing or promoting insulin resistance and diabetes during obesity. This research investigates the therapeutic effects of small compounds found in certain types of bacteria that interact with the immune system. These compounds activate specific immune responses and might be used as a new type of drug based on a "probiotic" health strategy. Bacterial compounds may reduce the amount of inflammation during obesity, thereby reducing the rates of type 2 diabetes.


title: Effect of Thermal Ageing on the Corrosion and Stress Corrosion Cracking of Type 310S Stainless Steel in Supercritical Water

contributor:
Kish, Joseph
Zheng, Wenyue
Materials Science and Engineering

abstract:
This thesis documents a multi-faceted investigation of the effects of thermal ageing-induced microstructure instability on the corrosion/oxidation and stress corrosion cracking (SCC) susceptibility of Type 310S stainless steel in supercritical water (SCW). The motivation for this study is the exiting knowledge gap associated with these two material performance aspects, which are considered essential to help guide the selection of a fuel cladding material for application in the Canadian Gen IV Supercritical Water-Cooled Reactor (SCWR) design concept. The focus was placed on the pressurized light water coolant outlet conditions (25 MPa SCW at 500-550 °C) considering that the likelihood for corrosion and SCC in combination with microstructure instability resulting from thermal ageing is presumed to be relatively high. The working hypotheses being that (i) Cr-rich intermetallic precipitate formation would serve to bind alloyed Cr, thus preventing the formation of protective Cr-rich oxide scales required for suitable corrosion/oxidation performance and (ii) Cr-rich grain boundary precipitate formation would serve to enhance SCC susceptibility by either sensitizing (chemical factor) or embrittling (mechanical factor) grain boundaries.
Two limiting thermal ageing treatments were evaluated. The ‘S’ treatment, designed to ‘sensitize’ the microstructure, induced significant Cr-rich M23C6 carbide precipitation on the grain boundaries concomitant with the development of adjacent
Ph. D. Thesis, Yinan Jiao McMaster University, Materials Science and Engineering
III
Cr-depleted zones. This limiting case represented a short-term exposure condition for the fuel cladding. The ‘TT’ treatment, designed to ‘mechanically embrittle’ the microstructure, induced significant Cr-rich sigma (σ)-phase precipitate formation on the grain boundaries and within the grains. This limiting case represented a long-term exposure condition for the fuel cladding. The ‘SA’ treatment, designed to solution anneal the microstructure, served as the baseline microstructure exhibiting a low extent of microstructure instability.
Long term thermal ageing of Type 310S austenitic stainless steel at the maximum expected fuel cladding temperature operation temperature range of Canadian-SCWR concept to produce the TT material induced significant σ phase precipitate formation within the grains and on grain boundaries, all without the concomitant adjacent Cr-depleted zone formation. Such microstructure instability did not have a major effect on the general corrosion/oxidation susceptibility since the thermally-aged material exhibited a similar weight gain and oxide scale structure after exposure in 25 MPa SCW at 550 °C as the solution annealed material, albeit after relative short exposure time (500 h). The likely reason for this was the discontinuous nature of the σ phase precipitate formation.
The remaining research conducted was aimed towards investigating the effect of thermal ageing on the intergranular SCC susceptibility of Type 310S stainless steel in SCW. A ‘first approximation’ attempt to isolate and assess the potential contribution of
Ph. D. Thesis, Yinan Jiao McMaster University, Materials Science and Engineering
IV
the likely chemical factor (sensitization) and mechanical factor (embrittlement) to the overall cracking mechanism. The overall ranking in terms of an increasing degree of sensitization, as determined by Double Loop – Electrochemical Potentiokinetic Reactivation (DL-EPR) testing, of three heat-treated materials studied is: SA ~ TT << S. The ranking reflects the controlling role played by Cr-depleted zones, which were only observed in the S material. The absence of a Cr-depleted zone accompanying the σ phase grain boundary precipitates in the TT material indicates that the treatment time of a 1000 h was sufficient to “self-heal” the Cr-depleted zone, which was expected to have formed during the early stages of the treatment at 800 °C.
Bulk uniaxial tensile measurements revealed both the S and TT material were embrittled relative to the SA material. The associated fractography revealed that the grain boundaries in the S material were sufficiently embrittled to cause intergranular fracture, whereas the grain boundaries in the TT material were not sufficiently embrittled to cause intergranular fracture. Classic micro-void formation involving a M23C6/matrix decohesion process occurs on the S material grain boundaries. Intergranular facture occurs as these micro-voids coalesce on the grain boundaries. In contrast, micro-void formation involving cracking of the large hard σ phase precipitates occurs on the TT material grain boundaries. Transgranular ductile fracture of the softer austenite matrix occurs as these micro-voids coalesce across the grains as the softer grains need to accommodate the stress after fracture of hard σ phase
Ph. D. Thesis, Yinan Jiao McMaster University, Materials Science and Engineering
V
precipitates.
The effect of thermal ageing on the SCC susceptibility of Type 310S in SCW was evaluated using the Slow Strain Rate Test (SSRT) technique, straining samples to 10% in 25 MPa SCW at 500 °C. The results were interpreted in light of the likely contributions of the chemical (sensitization) and mechanical (embrittlement) factors as revealed by the above mentioned research. The sensitized material exhibited well-developed intergranular SCC after straining to 10% (about 7.5% plastic strain). The TT material exhibited neither intergranular nor transgranular SCC susceptibility under the same exposure conditions. The localized deformation model for SCC initiation was combined with a void-assisted film-cleavage model for SCC propagation to explain the SCC susceptibility of thermally-aged Type 310S stainless steel in SCW.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Identifying Factors Associated with the Development of Tamoxifen Resistance in Breast Cancer

contributor:
Tang, Damu
Medical Sciences

abstract:
Breast cancer (BC) is the most common female malignancy. It is estimated that an average of 72 Canadian women will be diagnosed with BC each day. Although significant advances in BC screening and treatment has resulted in a steady decline in mortality rates, BC remains the second most common cause of cancer related deaths in women. Tamoxifen (TAM) is the most widely used treatment among women with estrogen receptor (ER) positive (ER+) BC, the major type of BC consisting of approximately 70% of cases. Although approximately 50% of patients with advanced ER+ BC initially respond to treatment, approximately 1/3 of patients treated with TAM develop resistance and recurrence. TAM resistance is thus a major challenge in BC treatment, largely owing to our limited understanding of the underlying mechanisms. In our effort to investigate these mechanisms, we have examined a number of candidates for their contributions to BC progression and the development of TAM resistance.
Sharpin is a newly emerged oncogenic protein. It associates with the PTEN tumor suppressor and inactivates PTEN-derived phosphatidylinositol (3,4,5)-trisphosphate (PIP3) phosphate activity. Sharpin is also a component of the linear ubiquitin chain assembly complex (LUBAC) which plays a key role in NFB activation. In accordance with this knowledge, we have constructed three Sharpin gene amplification-derived signatures using the Metabric dataset (n=2059) within the cBioPortal database. These signatures are significantly associated with declines in overall survival (OS) in BC patients and are independent risk factors of BC death after adjusting for known clinical factors. Additionally, we demonstrated that Sharpin sustains ER+ BC cells survival of TAM-derived cytotoxicity, which is in part through activation of AKT and NFB signaling.
The development of TAM resistance is a complex process, and is regulated by complex mechanisms or factors. Indeed, my research also revealed BMI1 being important in conferring resistance to TAM in ER+ BC. BMI1 is a well-known oncogenic protein in various human cancers; it demonstrates oncogenic functions in part through sustaining cancer stem cells and repression of tumor suppressors, p16INK4A and p14ARF. While evidence reveals BMI1 promoting breast cancer stem cells, whether BMI1 promotes resistance to TAM remains unknown. By using comprehensive approaches, we demonstrated that BMI1 confers ER+ BC cell resistance to TAM in vitro and in vivo. In patients, BMI1 expression is associated with ER+ BC, and contributes to resistance to endocrine therapy. Furthermore, BMI1 promotes TAM resistance in part through upregulation of pathways and factors that play important roles in TAM resistance, including ER signaling, MUC1, and androgen receptor (AR). AR contributes to TAM resistance through conversion of TAM from an ER antagonist to an agonist. Likewise, in BMI1 overexpressing MCF7 cell-derived xenograft tumors, TAM stimulates tumor growth, suggesting BMI1 enhancing the agonist activity of TAM.
Besides Sharpin and BMI1-derived oncogenic functions, our research suggests CYB5D2 providing tumor suppressor function towards BC and the development of TAM resistance. CYB5D2 was originally identified for its role in promoting neurogenesis. Recently, it has also been acknowledged as a tumor suppressor in cervical cancer.  We demonstrate CYB5D2 downregulation in primary breast tissues and following the development of TAM resistance in vitro and in vivo. Furthermore, downregulation of CYB5D2 is significantly associated with a reduction in OS in patients with BC.
Taken together, this thesis demonstrates three novel factors, including both oncogenic and a potential tumor suppressing factors, which contribute to TAM resistance. These findings improve on our knowledge of BC progression as well as the development of TAM resistance in ER+ BC. The knowledge uncovered here will have applications in improving management for patients with BC.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Fingerprints for Indoor Localization

contributor:
Zheng, Rong
Computing and Software

subject:
indoor localization
fingerprint
mobile crowdsensing
active learning

abstract:
Location-based services have experienced substantial growth in the last decade. However, despite extensive research efforts, sub-meter location accuracy with low-cost infrastructure continues to be elusive. Comparing with infrastructure-based solutions, infrastructure-free indoor localization has the major advantage of avoiding extra cost for infrastructure deployment. There are two typical types of infrastructure-free indoor localization solutions, i.e., Pedestrian Dead Reckoning (PDR)-based and fingerprint-based. PDR-based solutions rely on inertial measurement units to estimate the user's relative location. Despite the effort, many issues still remain in PDR systems. For example, any deployed smartphone-based PDR system needs to cope with the changing orientation of smartphone that the phone might be putting in a pocket, or being taken out to use, etc. In addition, the outputs of Micro Electro-Mechanical Systems (MEMS) sensors on smart devices vary over time which results in rapidly accumulated localization errors without external references. Fingerprint-based solutions utilize different types of location dependent parameters to estimate user's absolute location. Although fingerprint-based solutions are usually more practical than PDR-based, they suffer from laborious site survey process. In this dissertation, we aim to mitigate these challenges.

First of all, illumination intensity is introduced as a new type of fingerprints to provide location references for PDR-based indoor localization. We propose IDyLL -- an indoor localization system using inertial measurement units (IMU) and photodiode sensors on smartphones. Using a novel illumination peak detection algorithm, IDyLL augments IMU-based pedestrian dead reckoning with location fixes. Moreover, we devise a burned-out detection algorithm for simultaneous luminary-assisted IPS and burned-out luminary detection. Experimental study using data collected from smartphones shows that IDyLL is able to achieve high localization accuracy at low costs.

As for fingerprint collection, several frameworks are proposed to ease the laborious site survey process, without compromising fingerprint quality. We propose TuRF, a path-based fingerprint collection mechanism for site survey. MobiBee, a treasure hunt game, is further designed to take advantage of gamification and incentive models for fast fingerprint collection. Motivated by applying mobile crowdsensing for fingerprint collection, we propose ALSense, a distributed active learning framework, for budgeted mobile crowdsensing applications. Novel stream-based active learning strategies are developed to orchestrate queries of annotation data and the upload of unlabeled data from mobile devices. Extensive experiments demonstrate that ALSense can indeed achieve higher classification accuracy given fixed data acquisition budgets.

Facing malicious behaviors, three types of location-related attacks and their corresponding detection algorithms are investigated. Experiments on both crowdsensed and emulated dataset show that the proposed algorithms can detect all three types of attacks with high accuracy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The relationship between gender or sex and mobility in middle and older aged community-dwelling adults with chronic conditions

contributor:
Richardson, Julie
Rehabilitation Science

subject:
gender
sex
age
mobility
chronic conditions
systematic review
secondary data-analysis

abstract: The purpose of this thesis was to determine the relationships between gender or sex with mobility in middle aged and older community-dwelling adults with chronic conditions. Study one was a systematic review of published literature on whether gender or sex predict mobility in middle aged and older adults with chronic conditions in community-dwelling setting. Study two was a secondary analysis study (data from a randomized controlled trial where there were no statistically significant differences between rehabilitation intervention group and control group) to determine whether age and sex predict self-reported and performance-based mobility-related outcomes in community-dwelling middle and older aged adults with chronic conditions. This relationship was also examined in the context of sociodemographic and comorbidity variables. The information gained from these studies could be used to inform and guide future research and prevention intervention programs for people with risk of mobility limitation.

abstract: Thesis

abstract: Master of Science (MSc)


title: Examining distributed change-detection processes through concurrent measurement of subcortical and cortical components of the auditory-evoked potential

contributor:
Trainor, Laurel, J.
Psychology

subject:
Electroencephalography
Human audition
Auditory-evoked potential
Change-detection
Development
Sound localization

abstract: Study of the mammalian auditory system suggests that processes once thought exclusive to cortical structures also operate subcortically. Recently, this observation has extended to the detection of acoustic change. This thesis uses methods designed for the concurrent capture of auditory-evoked potential (AEP) components attributed to different subcortical and cortical sources. Using such an approach, Chapter 2 shows that 2-month-old infants respond to infrequent changes in sound source location with neural activity implicating both subcortically- and cortically-driven mechanisms of change-detection. Chapter 3 describes the development of a new stimulation protocol and presents normative data from adult listeners showing that the morphologies of several well-known subcortical and cortical AEP components are related. Finally, Chapter 4 uses the new methods developed in Chapter 3 to demonstrate that stimulus regularity not only affects neural activity at both subcortical and cortical structures, but that the activity localized to these structures is linked. Together, the studies presented in this thesis emphasize the potential for existing technologies to study the interaction of subcortical and cortical processing in human listeners. Moreover, the results of Chapters 2 through 4 lend support to models wherein change-detection is considered a distributed, and perhaps fundamental, attribute of the auditory hierarchy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Diversity and Evolution of Antibiotic Resistomes

contributor:
Wright, Gerard
Biochemistry and Biomedical Sciences

subject:
Antibiotics
Antibiotic resistance
Microbial evolution

abstract:
The relentless evolution of antibiotic resistance in pathogens is one of the most pressing medical concerns of the 21st century. Antibiotic resistance and antibiotic drugs originated in environmental bacteria, where they have been integral to their evolution for millions of years. The application of antibiotics in medicine and agriculture has selected for mobilization and dissemination of resistance genes in pathogens. Understanding their evolution here will aid in combating their evolution in pathogens.
This work expands the known mechanistic, functional, and genetic diversity of resistance (i.e. resistomes) in environmental bacteria. I systematically parse the extensively drug-resistant resistome of Paenibacillus sp. LC231, which was sampled from an underground ecosystem spatiotemporally isolated from the surface for over 4 Myr. Paenibacillus sp. LC231 was resistant to 26 of 40 drugs tested. Informatic annotation of resistance genes and functional genomes revealed 18 new resistance elements including five determinants without characterized homologs and three mechanisms not previously known to confer resistance.
I investigated the resistome of Brevibacillus brevis VM4 to study the relationship between species diversity and resistance diversity in the Paenibacillaceae family, which includes Paenibacillus sp. LC231. I found that resistome diversity does not correlate with species diversity, consistent with horizontal transfer of resistance genes.
In each of Paenibacillus sp. LC231 (MphI) and B. brevis VM4 (MphJ), I identified Mphs with unique substrate specifies. I identified the molecular determinants of substrate discrimination in MphI and in doing so, I developed a general strategy for understanding and predicting the functional evolution of resistance enzymes. Together, this work expands the known diversity of resistance that will enable better detection of resistance in pathogens.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Infections caused by antibiotic resistant bacteria are a significant medical problem. Bacteria will always become resistant to antibiotic drugs. Understanding how resistance evolves is essential for increasing the effective lifetime of these drugs. Antibiotics have been naturally produced by bacteria for millions of years, which caused the spread of resistance in environmental bacteria. Medical and agricultural antibiotic use by humans caused resistance in environmental bacteria to transfer to pathogenic bacteria. My work expands the known causes of resistance in environmental bacteria so that we can better detect the causes of resistance in pathogens. In doing so, I demonstrate that multi-drug resistance is over 4 million years old and that environmental bacteria naturally transfer resistance genes. Furthermore, I develop a way to predict the evolution of new resistance functions by inferring their evolutionary histories.


title: IDENTIFICATION AND FUNCTIONAL CHARACTERIZATION OF CONSERVED RESIDUES AND DOMAINS IN THE MACROPHAGE SCAVENGER RECEPTOR MARCO

contributor:
Bowdish, Dawn
Medical Sciences

subject:
MARCO
Macrophage
Scavenger Receptor
Phagocytosis

abstract:
Host defense against pathogenic organisms represents one of the most important and highly-conserved biological processes across the evolutionary timescale. The ability to detect, engulf and destroy particulates for either nutrition or host defense is conserved from single-celled protists to complex multicellular organisms. A central component of host defense is the recognition of invariant, conserved patterns on pathogenic organisms through the use of pattern recognition receptors (PRRs), such as macrophage receptor with collagenous structure (MARCO). MARCO modulates binding and phagocytosis of unopsonized microorganisms and particulates, tethers ligands to signalling complexes and enhances cellular adhesion. Current literature suggests these functions are mediated via the C-terminal scavenger receptor cysteine rich (SRCR) domain. The relative importance of this domain remains unclear, as other, closely-related scavenger receptors function independently of the SRCR domain via a shared lysine-rich motif.
In chapter 3.1, we discovered and cloned a naturally-occurring transcript variant of MARCO which lacks the SRCR domain, termed MARCOII. We demonstrated that the SRCR domain is required for ligand binding and internalization and that MARCOII can form heteromeric complexes with MARCO and reduce receptor function. Furthermore, the SRCR domain enhanced TLR2/CD14-mediated pro-inflammatory responses to Streptococcus pneumoniae. Finally, it was demonstrated that the SRCR domain modulates MARCO-mediated cellular adhesion.

In chapter 3.2, we used comparative phylogenetics to identify human specific mutations and residues undergoing positive selection in human MARCO. We demonstrated that humans possess a unique phenylalanine residue at position 282 that is polymorphic, with some humans encoding an ancestral serine residue. We also demonstrated that glutamine at position 452 is found in Denisovans, Neanderthals, and extant humans, but all other non-primate, terrestrial, and aquatic mammals possess an aspartic acid residue. We cloned the ancestral residues and loss-of-function mutations and demonstrated that these residues enhance ligand association and phagocytosis of Escherichia coli.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Some of the most ancient mechanisms of host defense rely on invariant recognition of pathogens through the use of pattern recognition receptors, such as the macrophage receptor with collagenous structure (MARCO). MARCO plays an integral role to allow for specialized subsets of white blood cells to bind pathogens, activate signalling complexes and to bring pathogens inside the white blood cell for destruction. Current literature suggests the C-terminal Scavenger Receptor Cysteine Rich (SRCR) domain of MARCO is required for these processes. This remains under scrutiny, as other closely-related receptors have been shown to operate independently of the SRCR domain. Herein, we utilized a variant of MARCO which lacks the SRCR domain and patterns of evolution to confirm both that the SRCR domain is critical for receptor function and to discover novel sites within the human MARCO protein that play indirect, but important roles in receptor function.


title: High-Fidelity Simulation Model of a Dual FIFO CAN Stack

contributor:
Lawford, Mark
Wassyng, Alan
Computing and Software

subject:
Controller Area Network
simulation
timing analysis
CAN
modeling
SimEvents

abstract:
This thesis presents a simulation model for a Control Area Network (CAN) software stack, the Dual FIFO CAN (DFC) stack, and a method for identifying and incorporating the details of the host environment (hardware setup, operating system, etc.) into the implementation of the simulation model in order to achieve a high level of fidelity. The method enable the simulation model to produce more realistic simulation results that are close to real-life experiments of the target system compared to existing commercial and academic simulation tools, which mostly ignore the system details

The simulation model is implemented based on the specification documents of the DFC stack as well as knowledge gained from real-life experiments about the DFC stack and its host environment, a dual-core Electric Control Unit (ECU) hardware test bench that runs a Real-Time Operating System (RTOS). Like the actual DFC stack, the simulation model offers features such as dual non-preemptive FIFO transmit queues and TX buffers, and reserved slots in the queues for higher-priority messages. By using the method introduced in this research, the simulation model also offers options, once enabled and configured with proper parameters, for simulating a host environment that has effects on the behaviors of the modeled CAN stack. And these features are not fully available in existing commercial and academic simulation tools.

The model provides internal calibration values of the DFC stack as configurable parameters to the user, making it easy to customize the simulation.
Configurable calibration values includes the total number of slots in the transmit FIFO queues, number of reserved slots in the queues, transmit-rate thresholds that decide to which transmit queue a message is routed and whether a message is eligible to enter the reserved slots of the queues, and together they determine the queuing behaviors of the DFC stack. The options for simulating a host environment (an ECU on a CAN network in a modern vehicle, for instance) is capable of recreating the timing effects (delays, jitters or other effects due to the processing load, physical limitation and internal implementation) of the target host environment on the simulation results. Both deterministic (constant values, etc.) and/or statistical (probability distributions, etc.) models can be used to configure each single timing effect from the simulated host environment.

The simulation model is also automated to transmit a set of customized transmit message (configurable message ID, DLC, period and internal transmission priority) and process simulation results according to the purpose of the simulation (statistical analysis, plots of data, etc). These features make it possible for the simulation model to be used not only to simulate various customized simulation scenarios, but also for different purposes in various stages of the development process, for instance, a pre-experiment simulation run before a test bench experiment to test the correctness of the calibrations and predict the possible outcomes of the experiment, or, simulations for confirmation purposes in order validate the test bench data after the test experiment. The model is compatible with typical modeling, simulation and development environments as it is implemented in MATLAB SimEvents environment, which works with third-party CAN development tools such as Vector CANoe. It is also designed to work with the high-fidelity model of the Vector CAN protocol stack from Whinton (2016).

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Identités Mouvantes dans la littérature migrante québécoise contemporaine

contributor:
Papillon, Joëlle
French

subject: Québécois migrant literature, postcolonial theory, irony, humour, oral tradition, transnational identity

abstract:
This thesis, consisting of four chapters, examines the shifting identities in contemporary québécois migrant literature, as well as the way the Other is represented by the authors in our study. The first chapter is devoted to the methodology and the theoretical framework for our research, which, in terms of postcolonial critique, is based on Homi Bhabha’s concept of « third space » as a creative literary space and fertile ground for the exploration of identity. Our study also explores concepts pertaining to specific traits of migrant literature, such as oral tradition, irony and humour, and transcultural identity, from theorists such as Janet Paterson, Linda Hutcheon and Lise Gauvin. The second chapter focuses on the writing of Marie-Célie Agnant and Abla Farhoud, both of whom use the notions of home and of oral tradition to gather the generations and to establish family histories. These two authors portray the image of a grandmother, exiled in Québec, and represent these women as the backbone of their respective families. The third chapter takes a very different approach to the question of Otherness, examining the use of irony and humour as tools for social critique in the work of Dany Laferrière and Pan Bouyoucas, two authors who use humour to mask the serious nature of their subject matter. Their critique of modern society is developed by exploiting the concept of «Otherness». The fourth and final chapter is dedicated to a more contemporary expression of the experience of migration, as portrayed in the work of Kim Thúy and Ying Chen, whose writing signals a significant departure from the themes of the earliest literature classified as « migrant », in the sense that they both adopt a neutrality of tone and create a literary production mostly absent of spatiotemporal reference. For Thúy and
!
vi
Chen, writing represents an apprenticeship of the French language and of cultural integration. Today’s Québécois migrant literature questions the pluralisation of identities, as well as the concepts of individual identity and collective identity. As such, the developing pluralistic nature of Québécois society is better represented within its literary scene. Within the framework of our study, what interests us the most is the changing face of the migrant identity over the course of the past fifty years, as well as the trajectory of its representation in this body of literature.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis examines the evolution in the representation of migrant identity and the experience of migration at the heart of contemporary Québécois literature. This research questions the pragmatic aspect of literature, specifically the establishment of new identities in twentieth and twenty-first century Québec and Canada. Our corpus explores the literary representation of life on the margins of a host society. By applying the postcolonial research on Otherness and Identity of theorists such as Homi Bhabha, Lise Gauvin and Janet Paterson, we are able to analyse the distinct characteristics of the literary production on memory and history, and on displacement, that originate from what Bhabha calls the gap between cultures.


title: Corrosion Fatigue of Friction Stir Welded Magnesium Alloy AZ31B: A Comparative Study

contributor:
McDermid, Joseph R.
Kish, Joseph R.
Materials Science and Engineering

subject:
Magnesium
Corrosion
Fatigue
Friction Stir Welding

abstract: Load controlled cyclic fatigue testing was conducted on base metal (BM) and friction stir welded (FSW) magnesium (Mg) alloy AZ31B compact tension (CT) specimens in laboratory air and a 0.05 wt. % NaCl fog environment in efforts to delineate the effects of salt fog and stir welding on fatigue performance under tension-tension loading conditions. FSW beads were produced on single piece AZ31B sheet product, simulating a pristine friction stir butt weld. Optical and electron microscopy, as well as X-ray diffraction was employed to observe the features and characteristics of fracture surfaces. The resulting stress vs. number of cycles to failure (S-N) curves demonstrated a reduction in fatigue life in a salt fog environment and an increase in fatigue life for FSW specimens compared to equivalently loaded BM specimens. Tensile frame displacement data indicated that the salt fog environment had an immediate effect on the BM samples, with an increased displacement required to meet the load control criteria. Fatigue cracks that propagated in CT samples that were notched in the direction of FSW tool travel consistently propagated towards the retreating side (RS) of the stir zone.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: EXPLORING BRANCHED SILICONE POLYMERS TO TAILOR THE PROPERTIES OF GELS

contributor:
Brook, Michael A.
Chemistry and Chemical Biology

subject: Silicone Polymers

abstract:
Silicones are useful in a variety of applications due to their diverse properties. The materials gain additional value when the basic constituents, oils and elastomers, are combined to create silicone gels. These materials possess excellent tunable properties such as moldability, tack, and adhesion, which are useful in certain circumstances. Only linear oils are currently used to make commercial silicone gels. While the materials initially possess desirable properties, over time the linear silicone oil can bleed out, and naturally, this is problematic for a variety of reasons. Among other things, the physical properties of the gel change and the oil that leaches out can be problematic. We test in this thesis the hypothesis that the use of branched silicone oils, as opposed to linear materials, in a gel could lead to lower levels of bleed (or slower release). There is currently very little research in the literature on the effect of adding branches to linear silicone polymers.
This thesis explores the synthesis of branched structures (dendrons) synthesized using the Piers Rubinsztajn reaction. These compounds were subsequently grafted onto linear SiH bearing silicone polymers at different frequencies through a hydrosilylation reaction. The branched silicones were characterized by NMR and the viscosity of the various oils was measured; the latter property correlated with the frequency of branching. The viscosity increased in a linear fashion until a maximum viscosity was observed, at which point further branching led to a slight decrease in viscosity; this trend was observed with silicone backbones at three molecular weights.
The branched silicone oils, capped with vinylpentamethyldisiloxane to remove remaining SiH sites, were then incorporated into gels. The Young’s modulus was measured and bleed measurements were collected twice over a ten-day period. Both measurements demonstrated that branching silicone polymers influenced the properties relative to linear silicone oils of comparable molecular weight. We discuss the possible origins of these differences.

abstract: Thesis

abstract: Master of Science (MSc)


title: Polymer-embedded AC-driven Light-emitting Diode (LED) Assembly

contributor:
Kitai, Adrian
Materials Science and Engineering

abstract: The traditional framework of LED assembly can only work with direct current(DC) source, and requires soldering/wire bonding, limiting the flexibility and further improvement of display resolution. In this thesis, an innovative small-size AC-driven LED assembly has been successfully developed, in which LEDs get their power through insulating dielectric layers without wire bonding when using high-frequency AC source. This novel package method of an AC powered flexible dual-LED unit is built up with two reverse-parallel-connected LED chip, namely dual-LEDs. The dual-LEDs preparation process is involved with the surface and interface modification, dielectric composites and combined transparent electrode layer processing. The key parameters of preparing the polymer-embedded LED platelet are obtained and the properties of combined transparent electrodes of Indium Tin Oxide(ITO)/silver nanowires(AgNWs) have been investigated. The luminous properties of the AC-driven assembly are explicitly evaluated based on the Sawyer-Tower method and the luminous intensity and luminous efficiency in variation of input AC voltage are presented.  The package shows a good flexibility and is much smaller in size compared with traditional LED package, as well as eliminates the need of wire-bonding to be powered on. The method of assembly is very promising in the future low cost printed assembly of large numbers of dual LED platelets in a sheet or strip.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Four Essays in Inequality

contributor:
Grignon, Michel
Economics

subject:
Inequality
Health
Family
Social Assistance
Applied Econometrics

abstract:
This thesis contributes new knowledge to discussions of inequality in three
arenas and two methodological syntheses that might inform future statistical
analyses. Methodologically, the application of unconditional quantile
regression in a two-stage model is used to determine whether response bias
plays any role in the patterns observed in survey responses (Chapter 2), and,
a recent development in the program evaluation literature (the synthetic
control method) is combined with flexible parametric survival models to
identify treatment effects where stratification is perfectly correlated with
treatment (albeit under restrictive assumptions). The analyses undertaken
herein have discovered: that self-assessed unmet need for healthcare has an
empirical basis for application as reporting behaviour statistically predicts
decline in health, that the likelihood of reporting unmet need conditional on
health and healthcare utilization is correlated with the dimensions along
which social scientists might map inequality, that government programs
intended to provide a minimum level of utility are unresponsive to regional
poverty-relief efforts, and that household bargaining outcomes regarding
number of children can be predicted by exposure to a parental divorce. The
implications of these findings are manifold. First, while self-assessment of
healthcare access is a valid metric on average to overcome limitations of
needs-adjusted utilization, its use in cross-sectional analysis as it is currently
obtained in survey across many different jurisdictions is suspect. Second, the
patterns of fertility conditional on parents’ divorce suggest that household
bargaining in Canada does not likely belong to several different theoretical
frameworks. Specifically, bargaining most likely exists in an environment
where women still bear the cost of children in the event of a divorce, or
bargaining exists without commitment. Finally, while the theoretical
literature makes compelling claims about interactions between different levels
of government policy, in practice this may not be the case even if
policy-wordings seem to suggest this would be particularly relevant.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
This thesis explores three separate dimensions of inequality. First, a method
of improving measurement of inequity in healthcare is demonstrated in a
world of heterogeneous preferences where traditional methods exploiting
observed utilization are shown to be inadequate. Potential issues resulting
from response bias in the metric used in the method from chapter 1 are
investigated in chapter 2. Next, the experience of a parents’ divorce as a child
is correlated with adult fertility showing that the intergenerational
transmission of marital instability may influence decisions on family size as
an adult, specifically, only women show a change in fertility outcomes after
the exposure to their parents’ divorce. Finally, the effect of a regional
transfer intended to improve living standards for the poor is examined for its
effect on the workfare program in Ontario. The transfer is found to increase
the duration of welfare benefit receipt by two months, representing a welfare
improvement for eligible recipients.


title: Towards Agricultural Application of Wood Pulp Fibres

contributor:
Pelton, Robert
Chemical Engineering

subject: wood pulp fibre, agricultural mulching, biodegradable mulch, paper making, foam forming, hydroponics, cellulose fibre, surface modification

abstract:
Sustainable agriculture is a crucial factor to be considered in order to meet the growing demand for food production. The need for low cost and highly functional materials to provide the most efficient cultivation process has led the agriculture industry to consume petrochemical and mineral based material in an enormous amount. Thus, disposal of the used mulch materials has become a serious environmental issue. In this work, the possibility of using wood pulp fibre in two distinct applications in agriculture is investigated. First, agricultural mulching is the subject of the study and second, we focus on using wood pulp fibre as growing medium in greenhouses.
Mulching in agriculture is an essential practice in order to have high crop yield, healthy products, and more efficient cultivation process. Over the years, agricultural mulch has been made out of a variety of materials. The most common of all is plastic mulch due to its low price and high functionality. However, the problems associated with applying and removing the enormous load of plastic and their disposal have made it an option far from ideal. Therefore, there is a need to develop mulches based on biodegradable materials. Paper-based mulch is one of the candidates, In the first chapter of this work, with a review of previous works in this area, we attempt to develop a new spray-able mulch based on wood pulp fibre. A novel foam forming method is utilised to deposit wood pulp fibres in combination with other chemicals as an evenly distributed fibre network on a porous bed. Currently available paper based-mulch is of a very high basis weight. In first part of this work, application of a foam formed low basis weight paper-based mulch is investigated. Whereas, in the second chapter, the use of wood pulp fibres in a similar function as “rockwool” in soilless greenhouse farming is investigated.
Rockwool is named after fibres made of melted minerals at temperatures as high as 2000°C. Rockwool is used as blocks for seeds growth and propagation and as an alternative for soil in greenhouses. The feasibility of microenvironment control of the rockwool blocks in crop production plus its low cost have made is popular. However, their disposal has always been an environmental issue. The biodegradability of wood pulp fibres is a great advantage over mineral fibres used in rockwool. In the second chapter of current work, we study the possibility of using wood pulp fibres as carriers for agriculturally beneficial chemicals. Specifically, we focus on binding and release properties of small organic molecules from wood pulp fibres. The goal is to achieve an understanding of the capability of wood pulp fibres to be used in building biodegradable growing medium blocks in greenhouses.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: CONTROLLING SILICONE-SACCHARIDE INTERFACES THROUGH BORONIC ACID MODIFICATION OF SILICONE POLYMERS

contributor:
Brook, Michael
Chemistry

abstract:
Silicone elastomers, which are normally crosslinked using metal catalysts, are traditionally reinforced with mineral fillers to achieve desired mechanical properties. When alternate, hydrophilic materials are used as fillers the silicone must be modified using amphiphilic moieties to mitigate phase separation.  Herein it is reported that renewable saccharides can be used to both crosslink and reinforce silicones. The grafting of boronic acids, which bind to saccharides, to silicone polymers gives materials that, when added to aqueous solutions of mono- or polysaccharides, without catalysts, generated elastomers via the boronic acid interaction with saccharides. The efficiency of crosslinking, as shown by Young’s moduli, depended strongly on the specific saccharide and the density of boronic acid groups on the silicone. Simple silicones normally phase separate in water saccharide mixtures. However, pretreatment of silicone boronates with the saccharide phytoglycogen, followed by exposure to water, led to stable aqueous phytoglycogen/silicone dispersions (pastes). The different outcomes arising from the order of addition are attributed to better dispersion of the silicone and saccharide in the latter case. Rheological studies of the pastes showed that, unlike the elastomers, viscosities depended more on the fraction of silicone in saccharide; number of boronic acid contact points between the silicone and saccharide was only a minor contributor. The equilibrium concentration of sugar/boronate contacts, which stabilize the water/oil interfaces, remains high even at high concentrations of water and even when the specific binding constant for an individual saccharide is low.
Additionally, the ability of the surfaces of these modified silicones to adsorb saccharides was investigated. Silicone boronic acids (SiBA) with and without permanent (non-hydrolyzable links), were prepared by hydrosilyation of a tartrate-protected styrylboronate. Hydrolysis led to free boronic acids at the interface to which the saccharides sorbitol, pullulan, casein and phytoglycogen, and the glycosylated protein, mucin, chemisorbed. Surface active proteins like albumin and casein adsorbed on such surfaces too, but only on the SiBA surfaces would (poly)saccharides and the glycosylated proteins adsorb; HSA was an exception.  It was not possible to exchange polysaccharides like phytoglycogen from the surface, even when using sorbitol, a monosaccharide with a better binding constant to boronic acid. The behaviors of these surfaces are reported.

abstract: Thesis

abstract: Master of Science (MSc)


title: Robust Discriminant Analysis With Asymmetric Classes

contributor:
McNicholas, Paul
Mathematics and Statistics

subject:
Discriminant analysis
mixture discriminant analysis

abstract: Discriminant analysis uses labelled observations to infer the labels of unlabelled observations in a population. Despite many advances in unsupervised and, to a lesser extent, semi-supervised learning over the past decade, discriminant analysis is often employed using approaches that date back to very well-known work of Fisher in the 1930s. One notable exception is mixture discriminant analysis, where the labels are estimated using parametric finite mixture models, commonly the Gaussian mixture model. The supposed advantage with mixture discriminant analysis is that   multiple Gaussian components can be used for each class, hence providing a work around when a class is not Gaussian. This thesis makes several contributions to ``modern" discriminant analysis. Three robust discriminant analysis methods are introduced using mixtures of multivariate t-distributions, mixtures of multivariate power exponential distributions, and mixtures of contaminated Gaussian distributions, respectively. This provides an appealing framework for handling varying tail-weights and peakedness in the classes that may also contain mild outliers. To facilitate the modelling of asymmetric classes, we also explore robust discriminant analysis via finite mixtures of generalized hyperbolic distributions and mixtures of multivariate skew-t distributions. These approaches are tailored towards skewed classes but also have the added advantage of modelling symmetric classes where necessary. Finally, we introduce an approach that combines support vector machines with mixture discriminant analysis. This approach defines class boundaries in the labelled observations and, in some sense, improves mixture discriminant analysis performance. Crucially, in all of our mixture modelling work, we consider the case where the number of components per class is one. The utility of the approaches introduced is demonstrated on simulated and real data sets.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The interrelationships among motor competence, physical activity and health-related fitness in the early years

title: Motor competence, physical activity and fitness in childhood

contributor:
Cairney, John
Kinesiology

subject:
Developmental Coordination Disorder
preschool
accelerometry
musculoskeletal fitness
aerobic fitness
physical activity
children
motor competence

abstract: Motor competence is positively associated with physical activity and health-related fitness (HRF) across childhood and adolescence. Owing to their motor difficulties, children with Developmental Coordination Disorder (DCD) are found to have poorer HRF and lower activity levels compared to typically developing (TD) children. It is thought that children with DCD are less physically fit due in part to hypoactivity; however, it is still unclear how young these deficits emerge, or if physical activity explains these HRF differences. This thesis aims to fill these gaps by examining physical activity and HRF in preschool children with and without DCD, and testing mediation models linking motor competence to HRF through physical activity engagement, both cross-sectionally and over time from preschool to school age. The first and second studies demonstrated that preschool children with DCD exhibit poorer musculoskeletal and aerobic fitness compared to TD children, however physical activity engagement was similar and did not explain these fitness deficits. The third study found that the relationship between motor competence and physical activity was not significant at preschool age, but emerged over time as children reached school age. Additionally, motor competence was a significant positive predictor of musculoskeletal fitness across the early years, again largely independent of physical activity levels. This thesis represents the first comprehensive series of studies that examines objectively-measured motor competence, physical activity and HRF in large samples of preschool-age children both with and without DCD. These studies highlight that poor motor competence is a risk factor for poor physical fitness, irrespective of physical activity in the early childhood period. Early motor interventions may positively influence physical fitness and may help to prevent the declines in physical activity observed as children with DCD reach middle childhood and adolescence.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Children with motor coordination difficulties are more likely to be unfit and inactive compared to typically developing (TD) children. However, it is still not understood when these problems emerge, or if inactivity explains why children with motor difficulties are less physically fit. This thesis examines the links between motor competence, physical activity, and fitness in two large cohorts of preschool-age children. Results show that young children with motor difficulties are less physically fit, but are not less active than TD children. In addition, children with better motor skills become more active as they get older. Despite similar physical activity levels at preschool age, these findings highlight that poor motor abilities in early childhood are a risk factor for poor physical fitness and future inactivity. Interventions targeting motor skills in the early years may help children stay active and healthy as they age.


title: Structure-Switching Signaling Aptamers in Nanomaterials: From Understanding to Applications

contributor:
Brennan, John
Chemical Biology

subject:
sol-gel
DNA/RNA aptamers
graphene oxide
paper-based sensor

abstract:
Functional nucleic acids (FNAs), which include both DNA/RNA aptamers and DNA enzymes, have emerged as promising biological recognition elements for biosensors.  These species typically require immobilization on or within a solid support, which is usually interfaced to some kind of signal transducer and readout system when use in biosensor.  Our group has successfully immobilized several functional nucleic acids in the past, including fluorescence-signalling DNA enzymes, DNA aptamers and RNA aptamers by entrapping them into porous silica or organosilica materials prepared by the sol-gel method using percursors such as sodium silicate (SS), diglyceryl silane (DGS), tetrametylorthosilicate (TMOS) and trimethoxymethysilane (MTMS).
While the earlier work established the ability of entrapped FNAs to retain binding and catalytic activity, only limited information was obtained on how different factors affect the performance of immobilized FNAs, and no information was obtained on the effects of aging and storage conditions on FNA performance. The initial objective of this thesis was to employ advanced fluorescence methods to better understand the nature of immobilized DNA and RNA aptamers, and in particular how entrapment in different sol-gel based materials affected FNA performance for detection of small molecule analytes. It was found that the ability of the entrapped aptamer reporters to remain fully hybridized was the most important factor in terms of signalling capability for both DNA and RNA aptamer reporters. It was also observed that more polar materials derived from SS were optimal for both types of aptamer reporters, since these allowed the entrapped aptamers to remain hydridized to their complementary strands and still retain the dynamic motion needed to undergo structure switching, while providing a minimum degree of leaching.
The second objective of my research was to develop a paper-based biosensing device incorporating immobilized DNA and RNA aptamers that could be used in the fields of point-of-care diagnostics to further expand the utility of structure-switching aptamer reporters to real world application. A dual response (fluorescence / colorimetric) paper-based sensor utilized printed graphene oxide to immobilize both a RNA and a DNA aptamer in a recognition zone.  Upon target addition, the aptamer desorbed and eluted to an amplification zone where rolling circle amplification was used to generate a colorimetric output.  This sensor could function with clinical samples such as serum and stool, and allowed detection of key bacterial markers (ATP and glutamate dehydrogenase) at clinically relevant levels.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Design and Analysis of Dynamic Real-time Optimization Systems

contributor:
Swartz, Christopher L.E.
Chemical Engineering

subject:
Dynamic Real-time Optimization
Economic Model Predictive Control
MPC
Process Automation Architecture
Control Performance

abstract:
Process economic improvement subject to safety, operational and environmental constraints is an ultimate goal of using on-line process optimization and control techniques. The dynamic nature of present-day market conditions motivates the consideration of process dynamics within the economic optimization calculation. Two key paradigms for implementing real-time dynamic economic optimization are a dynamic real-time optimization (DRTO) and regulatory MPC two-layer architecture, and a single-level economic model predictive control (EMPC) con figuration. In the two-layer architecture, the economically optimal set-point trajectories computed in an upper DRTO layer are provided to the MPC layer, while in the
single-layer EMPC con figuration the economics are incorporated within the MPC objective function. There are limited studies on a systematic performance comparison between these two approaches. Furthermore, these studies do not simultaneously consider the economic, disturbance rejection and computational performance criteria. Thus, it may not be clear under what conditions one particular method is preferable over the other. These reasons motivate a more comprehensive comparison between the two paradigms, with both open and closed-loop predictions considered in the DRTO calculations. In order to conduct this comparison, we utilize two process case studies for the economic analysis and performance comparison of on-line optimization systems. The first case study is a process involving two stirred-tank reactors in-series with an intermediate mixing point, and the second case study is a linear multi-input single-output (MISO) system. These processes are represented using a fi rst principles model in the form of differential-algebraic equations (DAEs) system for the  first case study and a simplified linear model of a polymerization reactor for the second case study problem. Both of the case study processes include constraints associated with input variables, safety considerations, and output quality. In these case study problems, the objective of optimal process operation is net profit improvement.

The following performance evaluation criteria are considered in this study: (I) optimal value of the economic objective function, (II) average run time (ART) over a same operating time interval, (III) cumulative output constraint violation (COCV) for each constraint. The update time of the single-layer approach is selected to be equal to that of the control layer in the two-layer formulations, while the update time of the economic layer in the two-layer formulation is bigger than that of the single-layer approach. The nonlinear programing (NLP) problems which result in the single-layer and two-layer formulations and the quadratic programing problem which corresponds to the MPC formulation are solved using the fmincon and quadprog optimization solvers in MATLAB. Performance assessment of the single-layer and two-layer formulations is evaluated in the presence of a variety of unknown disturbance scenarios for the  first case study problem. The effect of a dynamic transition in the product quality is considered in the performance comparison of the single-layer and two-layer methods in the second case-study problem.

The  first case study problem results show that for all unknown disturbance scenarios, the economic performance of the single-layer approach is slightly higher than that of the two layer formulations. However, the average computation times for the DRTO-MPC two-layer formulations are at least one order of magnitude lower than that of the EMPC formulation.
Also, comparison results of the COCV for the EMPC formulation for different sizes of update time intervals could justify the necessity of the MPC control layer to reduce the COCV for the economic optimization problems with update times larger than that of the MPC control layer. A similar computational advantage of the OL- and CL-DRTO-MPC over the EMPC is observed for the second case study problem. In particular, it is shown that increasing the economic horizon length in the EMPC formulation to a sufficiently large value may result a higher economic improvement. However, the increase in economic optimization horizon would increase the resulting NLP problem size. The computational burden could limit the use of the EMPC formulation with larger economic optimization horizons in real-time applications. The ART of the dual-layer methods is at least two orders of magnitude lower than that of the EMPC methods with an appropriate horizon length. The CL-DRTO-MPC economic performance is slightly less than that of the EMPC formulation with the same economic optimization horizon.

In conclusion, the performance comparison on the basis of multiple criteria in this study demonstrates that the economic performance criterion is not necessarily the only important metric, and the operational constraint limitations and the optimization problem solution time could have an important impact on the selection of the most suitable real-time optimization approach.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Effective Properties of Li-ion Batteries Using a Homogenization Method With Focus on Electrical Conductivity

contributor:
Srinivasan, Seshasai
Mechanical Engineering

subject:
Lithium ion
Additive-free cathodes
Bruggeman
Homogenization

abstract: Additives used in the cathode of a Lithium-ion (Li-ion) battery to improve electrical conductivity can negatively impact the ionic conductivity and specific capacity. Therefore, recent focus on the design of Li-ion battery is on the additive-free cathodes. This research work aims to provide a simple rule for the design of cathode microstructure using extensive study of the effect of particle size and volume fraction on effective electrical conductivity. Most design methods used to model the effective transport properties of lithium ion battery electrodes utilize the approximations based on Bruggeman’s formula. However, this formula does not consider the microstructure geometry and hence cannot accurately predict the effective transport properties of complicated microstructure like those of Li-ion battery electrodes. In this thesis, based on the principles of mathematical homogenization, an extensive analysis of randomly generated two-phase microstructures idealized for li-ion battery cells is carried out to obtain more accurate estimates of the effective electrical conductivity. To this end, a wide range of values of particle size, volume fraction and conductivity ratios are considered to evaluate the effective conductivity values. From these results, an explicit formulation based on these three parameters to predict the effective conductivity is provided to establish a framework for a simple design rule for additive-free cathode microstructures. Finally, the significance of the microstructural information is highlighted by studying the discharge characteristics of a battery for a theoretical battery model using the Brugemman’s formulation as well as the proposed formulation based on the mathematical homogenization technique.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: ARABIS: an Asynchronous Acoustic Indoor Positioning System for Mobile Devices

contributor:
Zheng, Rong
Zhao, Dongmei
Electrical and Computer Engineering

abstract:
Acoustic ranging based indoor positioning solutions have the advantage of higher ranging
accuracy and better compatibility with commercial-off-the-self consumer devices.
However, similar to other time-domain based approaches using Time-of-Arrival (ToA)
and Time-Difference-of-Arrival (TDoA), they suffer from performance degradation in
the presence of multi-path propagation and low received signal-to-noise ratio (SNR)
in indoor environments. In this thesis, we present ARABIS, a robust and low-cost
acoustic indoor positioning system (IPS) for mobile devices using an asynchronous
TDoA-based solution. We develop a low-cost acoustic board custom-designed to support
large operational ranges and extensibility. To mitigate the effects of low SNR
and multi-path propagation, we devise robust algorithms that iteratively remove possible
outliers by taking advantage of redundant TDoA estimates. Experiments have
been carried out in two testbeds of sizes 10.67m × 7.76m and 15m × 15m, one in
an academic building and one in a convention center. The proposed system achieves
average and 95% quantile localization errors of 7.4cm and 16.0cm in the first testbed
with 8 anchor nodes and average and 95% quantile localization errors of 20.4cm and
40.0cm in the second testbed with 4 anchor nodes only.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Time Consistent Behaviour and Discount Rates

contributor:
Pirvu, Traian
Mathematics and Statistics

subject: time consistent, portfolio, optimization, discount rates

abstract:
Decisions such as saving, investing, policymaking, have consequences in multiple time
periods and are called intertemporal. These choices require decision-makers to trade-off costs and benefits at different points in time. Time preference is the preference
for immediate gratification or utility over delayed gratification. The discount rate is
a tool used to measure this psychological phenomenon.
This thesis considers the problem of an individual maximizing his utility from
consumption and final wealth when his discount rate is not constant. The question
we answer is the following: if we allow the individual to update his decisions, will he
stick to his original strategy or will he switch?
We show that there are cases in which the individual's strategy keeps changing
thus his behaviour becomes time inconsistent. In Chapter 1, we introduce two notions
to solve this inconsistency problem: The agent can pre commit i.e. he does not
change his original optimal strategy. The agent can also plan for his future changes of
strategy and adopt time consistent strategies also known as subgame perfect strategies.
We also review the existing literature on time discounting and time consistency.
Chapter 2 considers the time consistency in the expected utility maximization
problem. The risk preference is of the Constant Relative Risk Aversion (CRRA) type,
the time preference is specified by a non constant discount rate and we allow the volatility of the stock price to be stochastic. We show that the determination of one
quantity: the utility weighted discount rate completely characterizes the individual's
subgame perfect strategies.
Chapter 3 is about equilibrium pricing in a model populated by several economic
agents in a complete financial market. These agents are investing, saving
and consuming and want to maximize their expected utility of consumption and
final wealth. We allow the economic agents to differ in their risk preferences, beliefs
about the future of the economy and in their time preferences (non constant discount
rates). Since the optimal strategies are time inconsistent, the equilibrium is
computed by using the time 0 optimal ( precommitment) strategies for the market
clearing conditions.
Chapter 4 considers the same model as chapter 2. We solve the equilibrium
problem when time consistent strategies are used for the market clearing conditions.
We limit the study to two economic agents. The subgame perfect equilibrium is
compared to the optimal equilibrium of Chapter 3.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: An Investigation into News Driven Business Cycles of Small Open Economies

contributor:
Letendre, Marc-Andre
Economics

abstract:
In this thesis we examine the news driven business cycle hypothesis which posits that business cycles might arise purely on the basis of expectations of future changes. Although the news shocks literature often concentrates on news about future technological changes, we on the other hand, study news about a country interest rate and a monetary policy interest rate in the context of small open economies (SOEs). Country interest rate news shocks refer to the anticipated changes in the rate at which the SOE borrows/lends in the international financial markets. Monetary policy news on the other hand refers to the anticipated changes of the policy rate usually transmitted to the public through `forward guidance'. We argue that such pieces of news about interest rates change the expectations of economic agents and influence current economic activity without any actual change ever occurring. Further, we extend our SOE framework to study an optimal monetary policy rule for Canada.

In Chapter 2, we examine how anticipated changes in future country interest rates influence the business cycles of emerging SOEs like Argentina and Mexico. To this end, we introduce country interest rate news shocks in a SOE model.  We use annual Argentine data from 1900-2005 to estimate our model using Bayesian methods.  We find that anticipated shocks to country interest rates explain a good deal of variations in the growth rate of investment and trade balance-output ratio of Argentina. The model also generates business cycles statistics that are consistent with those of Argentina. We find similar results for Mexico as well.

In Chapter 3, we extend our SOE framework of Chapter 2 to a New Keynesian SOE model in order to explore the role of monetary policy news shocks in Canadian business cycles. Once again, we perform a Bayesian estimation of the model with Canadian and US data from 1981Q3-2012Q4. The novel feature of the monetary policy rule employed in this study is the inclusion of US interest rate deviations in the Canadian monetary policy rule motivated by the highly correlated US and Canadian short term nominal interest rates over the above mentioned time period. Our estimation results show that the response coefficient of Canadian monetary policy to US interest rate deviations is indeed positive. Moreover, both the unconditional and conditional variance decomposition of variables in the model reveal that although monetary policy news shocks explain some of the variation in the growth rate of output and consumption, overall they are not a major source of Canadian business cycles. However, they explain a good portion of the variation in money supply growth and inflation in Canada.

Chapter 4 builds on the New Keynesian Dynamic Stochastic General Equilibrium (DSGE) framework developed in Chapter 3. In this chapter, we ask the following question: does reacting to US interest rate changes help the central bank achieve its mandate? To this end, we represent the mandate of the central bank by a loss function which is a linear combination of the variances of inflation, output gap and  nominal interest rate changes which the central bank seeks to minimize. The weights attached to each of the three terms of the loss function represent different policy regimes. We assess the performance of the estimated interest rate rule of Chapter 3 with and without reaction to US interest rate deviations in achieving the central bank's mandate under different policy regimes. We find that under the estimated rule, reacting to US interest rate deviations neither helps nor hurts the central bank to achieve its mandate. Next, we ask the following questions: what values of the policy coefficients would minimize the loss function and  would the optimal simple rule include US interest rate deviations in it? We find that the optimal rule has a positive coefficient on US interest rate deviations (larger than its Bayesian estimate) for all the policy regimes. It also has a large coefficient on inflation. Therefore, our analysis suggests that the central bank should include US interest rate deviations in its reaction function and should react even more aggressively to US interest rate changes and inflation than it did based on our Bayesian estimates.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: CARBAMAZEPINE & GEMFIBROZIL AFFECT ZEBRAFISH REPRODUCTION

title: LONG TERM ADVERSE EFFECTS OF CARBAMAZEPINE AND GEMFIBROZIL ON MALE ZEBRAFISH (Danio rerio) REPRODUCTION

contributor:
Wilson, Joanna
Biology

subject: Carbamazepine Gemfibrozil Zebrafish Reproduction

abstract: Pharmaceuticals are emerging surface water contaminants, and are manufactured, used, and released into environment in considerable amounts. Concerns have been raised due to the inherent potency and bioactivity of these molecules, which makes effects at low concentrations more likely. The ubiquitous presence and stability of pharmaceuticals brings up concerns about the frequency and length of exposures. However, the distribution and fate of these compounds in surface water bodies is not clear. There is limited information about the potential effects in non-target, especially aquatic, species vulnerable to cumulative or lifelong exposures. Carbamazepine (CBZ) and gemfibrozil (GEM) are two of the most frequently detected pharmaceuticals in surface water. This thesis examined sub-lethal adverse reproductive effects of chronic direct exposure of CBZ and GEM to F0 zebrafish and several generations of unexposed offspring; the effects of exposure on testicular steroidogenesis were also examined. Chronic exposure of zebrafish to CBZ and GEM reduced ex vivo production of 11KT in testes. In vivo, CBZ decreased reproductive output, 11-ketotestosterone (11KT), male courtship and aggression behaviours, and sperm morphology in F0 parents. The F1, F2 and F3 offspring of CBZ exposed males had lower reproductive output, altered courtship, aggression, sperm morphology and lower 11KT compared to fish from the unexposed lineage. The adverse effects persisted into the F3 generation which suggested transgenerational paternal effects. GEM decreased reproductive output in F0 parents and a reduction in 11KT, altered male courtship, aggression and sperm morphology. Unexposed F1 male offspring, but not other generations, had sub-lethal toxic effects from parental exposure.  We therefore suggest that CBZ and GEM act as endocrine disruptors in fish and that chronic exposure may reduce male reproductive fitness.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Human pharmaceuticals reach aquatic environments through municipal wastewater. The bioactivity of pharmaceuticals at low concentrations has raised concerns about undesired effects in aquatic species like fish, which can experience chronic exposures. This thesis examined adverse reproductive effects of direct chronic exposure of carbamazepine and gemfibrozil to parental zebrafish and their un-exposed offspring for multiple generations. Exposure to both compounds reduced androgens and reproduction and altered behaviour, and sperm quality in males. Effects persisted in the unexposed offspring. Parental carbamazepine exposure impacted multiple generations. We suggest that carbamazepine and gemfibrozil may reduce male reproductive fitness by reducing male sex steroids.


title: Skeletal evidence for vitamin D deficiency and chronic respiratory infections across the life course at two Roman period sites

contributor:
Brickley, Megan
Anthropology

subject: Paleopathology; Bioarchaeology; Vitamin D deficiency; Chronic respiratory infection; Life course; Roman archaeology

abstract: This research contributes to understandings of the occurrence of and associations between skeletal evidence of vitamin D deficiency and chronic respiratory infections across the life course based on human skeletal material from the Roman period sites of Isola Sacra in Italy (1st - 3rd centuries AD) and Ancaster in the United Kingdom (3rd - 4th centuries AD). Modern clinical data demonstrate a positive association between these two conditions that affects the ways in which they are experienced today, and may extend into the past. Macroscopic, radiographic, and histological evidence for skeletal manifestations of vitamin D deficiency and chronic respiratory infections were considered in the context of archaeological and historical evidence available for the Roman period in order to elucidate patterns in disease occurrence that reflect the unique local biologies of these two assemblages. Differing prevalence values for active and healed lesions caused by both conditions, as well as variation in age at death distributions and the relationship of lesions associated with vitamin D deficiency and chronic respiratory infections with one another and with age at death, provide information on the experience of both conditions and the potential interactions between them. Skeletal lesions caused by both conditions are present in individuals throughout the life course at Ancaster and Isola Sacra, with particular implications for disease experiences during infancy, adolescence, and pregnancy in the Roman period. These results point to a picture of morbidity and mortality at Ancaster that involves longer term survival of and more efficient immune responses to chronic disease processes, with higher levels of skeletal lesions indicating the presence of more "survivors" at this site. The combination of lower frequencies of skeletal lesions and higher mortality at Isola Sacra, on the other hand, suggests that fewer individuals may have survived to the point where they were able to mount a skeletal response to disease.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Hydrogels with Dynamic Biochemical Environment for 3D Cell Culture

contributor:
Wylie, Ryan G.
Chemical Biology

subject:
Hydrogels
Biomaterial
Tissue Engineering
3D Cell Culture
Dynamic
Extracellular Matrix

abstract:
The in vivo 3D extracellular matrix provides a temporal regulatory environment
of chemical cues. Understanding this dynamic environment will be crucial for efficient
drug screening, diseases mechanism elucidation, and tissue engineering. Therefore, in
vitro 3D cell culture systems with reversible chemical environments are required. To this
end, we developed a non-cytotoxic agarose-desthiobiotin hydrogel to sequester
streptavidin biomolecule conjugates (KD 10-11 M), which can then be displaced by the
addition of biotin (KD 10-15 M). Streptavidin biomolecule conjugates were simultaneously
and sequentially immobilized by changing media components. The time required for
biochemical environment exchange was minimized by increasing the surface area to
volume ratios and pore size of the hydrogels. We temporally controlled the cell adhesive
properties of hydrogels with RGD modified streptavidin to influence endothelial cell tube
formation.

abstract: Thesis

abstract: Master of Science (MSc)


title: Slight of Home: Queer Theory, Joseph Losey, and the Architecture of Desire

contributor:
Attewell, Nadine
English and Cultural Studies

abstract:
This thesis aims to bring the notion of slightness to bear on a reading of domestic space in the films of the American-born, British film-maker Joseph Losey. By drawing on psychoanalysis, queer theory and cultural materialist frameworks, I examine the material traces, patterns, and forms of house and home, which cannot be folded into logics of identity. Rather than parsing a form of domesticity that is queer because of the nature of the intimacy or sexuality that it houses, I argue that the queerness of domesticity can be found in the forms, patterns and details of home which are too subtle to rise to the discursive level at which home becomes a disciplinary category.

Although the theoretical frame of this project is largely informed by psychoanalytic and specifically Lacanian-orientated queer theory, its focus on slightness marks a departure from the emphasis on negativity that has qualified this branch of the field. Examining in detail the Losey’s films The Servant (1963), Eve (1962), Secret Ceremony (1968), and The Go-Between (1971), and drawing on materialist, semiotic and architectural points of reference, I explore the ambiguities of desire that inhere in the forms and detail of domestic space. I interpret these not as a deficit or withholding that either stands to be corrected or that insists on its own lack, but rather as a texture or quality already realized in its insignificance. In this way, the thesis offers a way to reframe the negativity associated with Lacanian psychoanalytic queer theory and to think of the queerness of domesticity as a kind of slightness that can be read in the forms domesticity takes.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)