title: IN-PIXEL TIME DIGITAL CONVERTER FOR TIME-OF-FLIGHT PET IMAGING

contributor:
Deen, Jamal M.
Peng, Hao
Nicolici, Nicola
Electrical and Computer Engineering

subject:
Biomedical
Electrical and Electronics
Biomedical

abstract:
In the past decades, great advances in biomedical imaging towards using less invasive and more sensitive imaging modalities have enabled early detection of diseases through timely diagnosis of patients. Positron emission tomography (PET) imaging, as one of the recent imaging technologies, provides imaging from cellular-level metabolic changes in tissues. This gives PET imaging a substantial lead in detecting disease in their very early stages. PET imaging provides high sensitivity and chemical specificity. However, it suffers from low resolution compared to other imaging methods. Time of Flight (ToF) PET imaging, one of the derivations of the PET, improves the imaging by exactly determining the position of the annihilation event using a time digital converter (TDC). By achieving the timing information of the incident anti-parallel photons coming from an event in ToF PET scanner, the TDC helps to determine the exact location of the event. So, it increases the resolution of the PET scanner.

A ToF PET custom-designed TDC has been proposed in this work. The designed TDC offers relatively high resolution and dynamic range (DR) to satisfy some PET imaging specifications. To increase the sensitivity and reduce the noise and latency, in-pixel design of TDC is desired. Therefore, a time digital converter that is specifically designed for ToF PET should follow a strict set of criteria in its design procedure. A three-staged hierarchical TDC was designed and implemented in 0.13μm standard CMOS technology to reduce the total number of delay elements for this area limitation issue. Also, a novel half-CLK period interpolation idea was proposed to reduce the total size of the TDC even more. A counter and half-CLK counter construct the coarse stage of the TDC. A delay locked loop (DLL) works as the first fine interpolator, while, the Vernier delay line (VDL) acts as the second fine interpolation stage.

A high resolution of 39ps was achieved with a relatively high DR of 1.28μs and the measured DNL and INL of 0.2TLSB and 0.4TLSB. Due to all area reduction techniques used, the final designed TDC measures for 0.11 mm2, which is much smaller than other similar TDCs with the same resolution and DR. As the amount of delay in the delay elements in the TDC are susceptible to any change in the environmental changes, a delay locking method was used to compensate for process, voltage and temperature (PVT) variations.


title: INCLUSION CONTROL MODEL IN THE LADLE METALLURGY FURNACE

contributor:
Irons, Gordon
Coley, Ken
Petric, Tony
Materials Science and Engineering

subject:
model
inclusion
ladle metallurgy furnace
bubbling
slag
steel
Metallurgy
Metallurgy

abstract:
The inclusions are harmful to the steel cleanliness; process parameters such as stirring and steel and slag oxidation must be controlled to obtain a final number of inclusions in the steel whose size is smaller than the critical size for each steel product.

A simple mathematical model was developed to analyze the impact of bubbling, slag and initial oxidation level on inclusion distribution control (quantity and size of them) during the process in a Ladle Metallurgy Furnace (LMF).

The initial inclusion size distribution is calculated and adjusted with the samples analyzed by SEM-EDAX, this initial distribution decreases by removal mechanisms such as bubbling and slag and they can increases by reoxidation.

The model allows predicting the inclusion removal by bubbling mechanism as a function of gas flow rate and inclusion size and it proves which a softer stirring is better for removal inclusion than stronger one. An interesting point analyzed is the effect of stirring level on small and large inclusions.

According to the inclusion number removal by slag, it is possible to appreciate like larger inclusions are removed easier than smaller ones. This mechanism is the most important to remove inclusions calculated by this model.

abstract: Master of Science (MSc)


title: EFFECT OF DRYING INDUCED AFFORESTATION ON PEATLAND ECOHYDROLOGY: IMPLICATIONS FOR WILDFIRE VULNERABILITY

contributor:
Waddington, J.M.
Carey, Sean
Earth and Environmental Sciences

subject: Peatland Wildfire Drought Ecohydrology Hydrology Hydrology

abstract:
Peatlands cover 170 million hectares of Canada's land and are long thought to be resistant to consumption by wildfire. However, boreal peatlands are likely to become increasingly vulnerable to wildfire as climate change lowers water tables and exposes deeper peat to burning. Currently, the Canadian Forest Fire Weather Index (FWI) System is used to assess vulnerability of peat to ignition and consumption, despite being developed for upland soils. Given the need to assess wildfire risk in peatlands, this study investigated the range and variability of key variables relevant to wildfire hydrology of the subsurface and canopy across five peatlands. Road impacted and drained peatlands were included to examine the influence of drying on afforestation (a surrogate for a future drier climate) and extend the range of parameterizations for peatlands.

Increased drying led to significant increases in canopy fuel loads coupled with increased interception (upwards of 97%) and canopy storage, highlighting failures of the current FWI rainfall routine. Increased drying led to enhanced transpiration across impacted (≈ 2.8 mm d-1) compared to pristine sites (≈ 0.68 mm d-1). However, increases in above ground vulnerability were somewhat offset by ecohydrological feedbacks serving to increase peat moisture retention in the drier sites. But the most severely impacted peatland displayed the poorest moisture retention qualities of all peatlands perhaps indicating the existence of a threshold response to drying induced afforestation on peat moisture retention properties.

Our findings suggest that modified FWI components are suitable for predicting the general moisture status and fire danger in boreal peatlands, highlighting key areas in the parameter to be improved.

abstract: Master of Science (MSc)


title: Telecommuting Travel Behavior: Examining the Influence of Work Status on Distance and Mode Choice in the National Capital Region

contributor:
Scott, Darren M.
Kanaroglou, Pavlos
Geography and Earth Sciences

subject:
Travel Behaviour
telework
telecommute
impact
TDM
travel demand management
transportation demand management
travel distance
mode choice
Geographic Information Sciences
Human Geography
Other Geography
Geographic Information Sciences

abstract: This study explores telecommuter travel behaviour by examining discretionary travel distance and mode choice. The study utilizes data obtained from the 2005 origin-destination survey conducted by TRANS, a joint transportation planning committee serving the National Capital Region of Canada. The study compares and explains the discretionary travel behavior of teleworkers relative to other population groups and identifies that the average teleworker travels 3 times farther than regular workers and 1.7 times farther than non-workers for discretionary purposes. Regression indicates that dependent children, vehicle accessibility, housing type, residential distance to the urban core, land-use mix, residence within a Greenbelt region and day of the week all positively affect travel distance. Conversely, age, proximity to shopping centers and inclement weather demonstrate significant negative effects. Then, through binary logistic regression, the study confirms that work status significantly influences mode choice. Similarly, the following predictor variables demonstrate a significant positive effect towards active mode choice: teleworker work status, larger household size, greater income, warmer temperature, closer proximity to shopping centers, apartment housing type, trips for recreational and restaurant purposes, taking subsequent trips in a day, and travel between 8:00 A.M. and 4:00 P.M. On the contrary, increased entropy, trips within the Greenbelt region, dependent children under 16 years old, increased vehicle accessibility and trips for transporting someone or for shopping purposes all reduce the probability of active travel mode choice.

abstract: Master of Arts (MA)


title: CHARACTERIZATION OF ANTIVIRAL PROPERTIES OF TRAPPIN-2 AND ELAFIN AGAINST HIV-1 AND HSV-2 IN THE FEMALE GENITAL MUCOSA

contributor: Molecular Immunology, Virology and Inflammation

subject: trappin-2

subject: elafin; sexually-transmitted infections; HIV-1; HSV-2; polyI:C; inflammation; innate; antiviral

subject: Medical Immunology

subject: Medical Microbiology

subject: Reproductive and Urinary Physiology

subject: Viruses

subject: Medical Immunology

abstract: Sexually transmitted infections (STIs), especially HIV/AIDS and HSV-2, continue to be a devastating burden on societies around the world. The close link between HSV-2 and HIV-1, the role of inflammation in driving these infections, and the limited success and availability of prophylactic and therapeutic measures underscore the need for continued search of alternative means of protection. Characterization of endogenous antimicrobials, especially those local to the female genital tract and actively regulating inflammatory and antiviral responses, could be beneficial for microbicidal trials. Although regulators of mucosal immunity, such as serine antiproteases, trappin-2 and elafin (Tr/E), have been associated with resistance to HIV-1, their antiviral activity remains poorly understood. Thus, the research presented in this thesis centers on characterization of antiviral properties of Tr and E individually and their potential mechanisms in defense against HSV-2 and HIV-1 in the female genital mucosa. Chapter 2 examines Tr/E contribution to antiviral host defense responses elicited by a synthetic mimic of viral dsRNA, polyI:C. Chapter 3 documents the presence and characteristics, including potential mechanisms, of antiviral activity of Tr/E against in vitro and in vivo HSV-2 infection. Chapters 4 and 5 determine the contribution of Tr/E to the natural anti-HIV-1 protection of CVL and structural characteristics, mode(s) of action, and cellular distribution/localization of antiviral Tr/E proteins. Therein, we present novel properties of each Tr/E by demonstrating their inhibitory and multiple effects against both HSV-2 and HIV-1. These effects appear to be mediated either through virus or cells and be associated with altered viral attachment/entry, transcytosis and infection, innate viral recognition, modulated inflammation and increased antiviral protection of cells. Reported antiviral activity of Tr/E was also contextual and exerted, at least in HEC-1A cells, via autocrine/paracrine mode and depended on elafin’s nuclear localization and its unmodified N-terminus. Tr/E may represent viable candidates for further studies in the field of STIs.

abstract: Doctor of Philosophy (PhD)


title: PREVALENCE OF POSTOPERATIVE CHRONIC PAIN AFTER TOTAL HIP OR KNEE ARTHROPLASTY

contributor:
MacDermid, Joy C
Woodhouse, Linda
Stratford, Paul
Rehabilitation Science

subject:
chronic pain
post-operative pain
total hip arthroplasty (THA)
total knee arthroplasty (TKA)
prevalence
neuropathic pain scales
Other Rehabilitation and Therapy
Other Rehabilitation and Therapy

abstract:
Background: Total joint arthroplasty (TJA) is considered the treatment of choice to alleviate pain and improve function of patients with osteoarthritis. However,recent evidence suggests that a significant proportion of patients continue to report pain, or worsening of their symptoms well after their joint replacement. We call this chronic pain “phantom joint pain” as it persists despite the fact hat the affected joint has been replaced.

Chronic pain of neuropathic origin may be a consequence of surgery or in patients with osteoarthritis (OA); there may be a combination of nociceptive and neuropathic pain (NP) mechanisms. As there are no definitive physiological indicators for NP or gold standards for diagnosis, Guidelines on Neuropathic Pain Assessment advocate the use of screening tools to evaluate the patient’s pain experiences and potentially characterize various pain features.

Despite suggestions that phantom joint pain post TJA is a common problem there is limited information about its prevalence among Canadians. To date there are no studies that have characterized neuropathic vs. non- neuropathic chronic pain features in a TJA population.

Purpose: The purpose of this work was to determine the prevalence of chronic pain following total hip (THA) or knee (TKA) arthroplasty, and to identify the proportion of the cohort with chronic pain whose symptoms suggested the pain was of neuropathic origin. In addition we evaluated the ability of the NP Subscale of the McGill pain questionnaire [NP-MPQ (SF-2)] to identify individuals with NP vs. Non NP in the TJA population.

Methods: A retrospective cohort study (2-4 years post joint replacement) of 148 participants with primary unilateral TJAidentified from a large joint arthroplasty database (n=1143). Chronic pain was defined as post surgical pain reported 6-12 months following surgery to be 3 or higher (out of 5) on the Oxford Hip/Knee Scores, and that pain was the same or worse than reported preoperatively. A postal survey was used to administer the NP-MPQ (SF-2)and the Self-Administered Leeds Assessment of Neuropathic Signs and Symptoms (S–LANSS) (1.5-3.5 years post TJA). S-LANSS was the “non reference standard” for classification of neuropathic pain. Human research ethics approvals from Sunnybrook Health Sciences Centre and McMaster University/Hamilton Health Sciences were obtained prior to the study.

Results: The response rate to the postal survey to identify those with chronic pain of neuropathic origin was 53%. Thirteen percent of individuals experienced chronic pain; among individuals with chronic pain, neuropathic subtype was found in 28% (S-LANSS ≥ 12) - 43% [NP-MPQ (SF-2) ≥ 0.91]. Receiver Operating Characteristic (ROC) analysis for NP-MPQ (SF-2) yielded an area under the curve of 0.89 (95% CI: 0.82, 0.97). A cut off score of 0.91 NP-MPQ (SF-2), maximized sensitivity (89.5%) and specificity (75.0%). Our results revealed moderate correlation (r=0.56; 95% CI: 0.40, 0.68) between the S-LANSS and NP-MPQ (SF-2)scores in patients with NP post TJA.

Conclusion: Based on our results, a considerable percentage of individuals (13%) experience chronic pain following TKA and THA. Moreover, among individuals with chronic pain symptoms, a significant proportion (28-43%) of those experience pain that appears to have a neuropathic component, even 1.5 to 3.5 years following surgery.Overall prevalence of NP in TJA was 3.3 to 4.5%. The NP-MPQ (SF-2)subscale demonstrated “good” discriminatory ability, thus it might be useful in identifying patients with NP following TJA. Moderate association exists between the scales and this could affect prevalence rates in studies; or diagnosis of NP of individual patients based on the criterion used.

abstract: Master of Science (MSc)


title: The Cultural Politics of Youth, Health and Lifestyle in the Aftermath of the Childhood Obesity “Epidemic”

contributor:
O`Brien, Susie
Brophy, Sarah
Moffat, Tina
English and Cultural Studies

subject:
obesity
childhood
health
lifestyle
representation
Feminist Philosophy
Public Health
Visual Studies
Feminist Philosophy

abstract:
In this dissertation I argue that the currency of the childhood obesity “epidemic” as a health crisis is derived largely from processes of representation and reproduction through which fatness has been re-calibrated as something pathogenic. I develop the position that the “childhood obesity epidemic”—influenced as it is by neoliberal notions of what constitutes a healthy individual and a vital body politic—risks exacerbating, rather than mitigating, the vulnerability of children.

The methodology of this project uses the example of lifestyle to illustrate how consensus about the presence of an “obesity epidemic” has been built, the concept of lifestyle being read as representative of how particular constellations of anxiety regulate what counts as true in the developing body of social knowledge concerning childhood obesity. I contend that the problem of lifestyle captures the complexities of the “childhood obesity epidemic” because children are presupposed, in obesity discourses, to be more vulnerable to the sweeping set of social trends brought under the rubric of the “obesity epidemic” than adults.

In what follows, I investigate the rationale for anti-obesity through an investigation of a series of analogous clusters, cases of persuasive ideas borne out of the moral panics subtending childhood obesity. I ask what it means that the child’s diminished capacity for autonomous decision-making is considered to be especially critical in the face of popular culture’s media “bombardment.” More broadly, I focus on the delimiting effect that anti-obesity’s politicization of lifestyle has had on recent attempts to think through the articulation of health, consumerism, environment, and the government of risk.

abstract: Doctor of Philosophy (PhD)


title: CHARACTERIZATION OF CHLAMYDIA PNEUMONIAE CDSD AND ITS ROLE IN THE BASAL BODY OF THE TYPE III SECRETION APPARATUS

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
Chlamydia pneumoniae
type III secretion
CdsD
Medical Microbiology
Medical Microbiology

abstract: Chlamydia pneumoniae is a Gram-negative, obligate intracellular bacterium which shares its unique biphasic developmental cycle, genus-specific lipopolysaccharide, and complement fixation antigen with the other Chlamydia species. Intracellular bacteria, like Chlamydia, require strategies to invade host cells, evade host detection, commandeer host processes, and absorb nutrients in order to support their developmental cycle and survive. The type III secretion (T3S) system meets these needs by transporting bacterial effector proteins across the bacterial membrane and through the host cell membrane. The T3S system in C. pneumoniae is composed of approximately twenty different proteins, whose encoding genes are dispersed throughout ten operons in the Chlamydia genome. CdsD (Cpn0712), a basal body protein component of the T3S apparatus, is suggested to localize to the inner membrane and anchor other T3S structural components of the inner membrane ring. However, the cytoplasmic N-terminal domain contains two putative forkhead-associated (FHA) domains which may play an additional functional role in cellular signalling. This large hypothetical inner-membrane protein is poorly characterized in C. pneumoniae and the role of the predicted phospho-threonine binding, N-terminal FHA domains has yet to be elucidated. Herein, we provide evidence that CdsD has a high affinity for five cytoplasmic (CdsQ, CdsL, CdsN, PknD and SycH) and one periplasmic (CdsF) T3S-associated proteins. We also provide the first evidence that the phosphorylation of CdsD may permit the phosphorylation-dependent oligomerization or interaction with other phosphorylated components of the T3S apparatus. Future research will clarify the role of phosphate signalling in the T3S virulence mechanism. Ultimately, this may lead to a greater understanding of signalling mechanisms that regulate the secretion of bacterial effectors into host eukaryotic cells.

abstract: Master of Science (MSc)


title: A CRITICAL COMPARISON OF WORKERS’ COMPENSATION IN SOUTH KOREA AND CANADA: DIFFERENT ROUTES TO THE SAME DESTINATION?

contributor:
Zhou, Rachel Y.
Social Work

subject:
Workers' Compensation
Citizenship
Welfare State
Social Work
Social Work

abstract:
Since the historic compromise between employers and workers in Germany in the late 1880s, whereby workers gave up their right to sue their employers in return for an administrative system that would compensate them for medical fees and income losses, Workers’ Compensation (WC) has been part of workers' protection against occupational hazards. Neo-liberal globalization, on both the domestic and global levels, with the accompanying the drives to increase productivity and reinforce international competitiveness are, however, undermining WC's effective functioning.
The worldwide vulnerability of WC is apparent, and South Korea and Canada are no exceptions. Despite the very different origins and developmental processes of WC in these two countries, in the context of neo-liberal globalization they seem similarly directed. The research aims to develop a comparative and contextualized analysis of the development of WC in these two countries, and to develop a critical analysis of the erosion of welfare through the recent changes in WC in them. Two research questions are thus explored: a) How has WC in South Korea and Canada developed since its adoption?; and b) How have the recent changes in WC in these two countries eroded the notions of the “welfare state” and “citizenship”, which are key to WC’s original purposes?
Using comparative policy analysis based on documents review, this research suggests that the advent of WC in Canada was a spontaneous response to social circumstances that demanded an institution to deal with the increase in occupational accidents that accompanied industrialization in the early 1900s. Conversely, WC in South Korea was established through the government imperative for economic growth and its other political purposes, which are typical features of the developmental welfare models.
The initial development of WC in Canada was thus radically different from its counterpart in South Korea; but recent reforms in the two countries demonstrate how neo-liberal ideology and managerialism have both led WC in the same direction. For instance, the employers' financial incentive of the experience rating system prevents the compensation of injured workers, and eventually renders WC ineffective as a social safety net. Early return-to-work programs are consistent with the “welfare-to-work” model for injured workers, and amount to a method of shifting costs from employers to public tax payers. The WC reforms in question, in both countries, reflect a very narrow and restricted conception – a neo-liberal conception – of citizenship.
These “anti-labour” elements of social insurance for injured workers are mainly products of neo-liberal globalization, which emphasizes efficiency and competitiveness above all else. In the context of neo-liberal managerialism, a number of workers in developed countries who are, mostly, non-regular and migrant workers are precluded from the protection of WC. While workers in the North are implicitly marginalized, their counterparts in the South are explicitly ignored by social security systems.

abstract: Master of Social Work (MSW)


title: The Effects of Sensory Deprivation on Sleep and Other Regulatory Processes in Adult Cat

contributor:
Heron, W.
Psychology

subject: Psychology Psychology

abstract:
It is known that human subjects deprived of meaningful visual, auditory and somatosensory stimulation (sensory deprivation), spend a larger portion of their time asleep (increased Stage I & II) than when in a normal environment. Furthermore, that phase of sleep which is characterized by the presence of rapid eye movements (REM sleep) is altered under these conditions, with REM density (number of rapid eye movements per minute) being greatly increased. However, little progress was being made toward understanding the conditions needed to obtain these effects, or the neural mechanism underlying them. Therefore, the effects of sensory deprivation on sleep of adult cat were studied, since if the results from the human experiments could be duplicated, various experimental, manipulations could be performed to elucidate the mechanisms.

It was found that adult cat responded to sensory deprivation in a manner analagous to human subjects since both REM density and the amount of time spent in the light phases of sleep increased during deprivation. The increase in REM density was not due to a change in the frequency with which the neural generator of REMs initiated eye movements since PGO wave density remained constant across conditions. Rather, it appeared to be due to the fact that the proportion of large amplitude, high velocity REMs increased during deprivation concomitantly with the change in REM density. In agreement with this, a positive correlation between REM density and average EOG amplitude was found under normal conditions and during sensory deprivation. The increase in sleep time during deprivation was found to be most similar to that described by others following sensory deafferentation. Thus, neither the proportion of deep SWS nor REM sleep was altered, while that of light SWS was greatly increased. The minimum condition needed to obtain these effects was found to be the lid suture procedure used to prevent vision during deprivation. Thus, lid suture alone and lid suture coupled with total light deprivation had equivalent effects while light deprivation alone caused only marginal changes. These results were contrasted to the human experiments where large sleep effects were obtained by requiring the subject to wear a translucent mask.

Finally, a preliminary account of the effects of sensory deprivation on other regulatory mechanisms was given. It was found that for some animals, food consumption and body weight increased and body core temperature decreased during deprivation.

abstract: Doctor of Philosophy (PhD)


title: Functional studies of the interstrand cross-link repair protein, SNM1A and its beta-CASP domain

contributor:
Junop, Murray
Russell Bishop, William Sheffield
Biochemistry

subject:
SNM1A
interstrand crosslink repair
beta-CASP
inclusion body protein refolding
nuclease
cisplatin
Biochemistry
Biochemistry

abstract: Interstrand cross-linking (ICL) damage to DNA is cytotoxic as it blocks replication and transcription. This cytotoxicity is exploited in anti-cancer therapies, but increased ICL repair limits the efficacy of these chemotherapies. SNM1A (sensitive to nitrogen mustard 1A), of the beta-CASP family of nucleases, has been shown to participate in the initiation of one of the ICL repair processes. Biochemical studies of SNM1A have been limited due to insolubility and instability of SNM1A in bacteria and insect cell lines and toxicity in human cell lines. Work reported in this thesis describes a novel and efficient method of generating active protein from inclusion body expression of the beta-CASP domain of SNM1A. This refolded beta-CASP domain shows 5’ exonuclease activity on single stranded and double stranded DNA in vitro. Nevertheless, this domain alone is unable to complement pso2 null ICL repair defects in S. cerevisiae after exposure to ICL agents. These functional studies of the beta-CASP domain of SNM1A will be helpful in directing future research on its role in ICL repair. Additionally, this will aid future structural and inhibitor studies of this essential interstrand cross-link repair protein, SNM1A.

abstract: Master of Science (MSc)


title: Gastrointestinal-Sparing Effects of Novel NSAIDs in Rats with Compromised Mucosal Defence

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject:
NSAIDs
Gastrointestinal
Co-morbidity
Mucosa
Rats
Ulceration
Digestive, Oral, and Skin Physiology
Disease Modeling
Medical Pharmacology
Pharmaceutics and Drug Design
Digestive, Oral, and Skin Physiology

abstract: Nonsteroidal anti-inflammatory drugs are among the most commonly used prescription and over-the-counter medications, but they often produce significant gastrointestinal ulceration and bleeding, particularly in elderly patients and patients with certain co-morbidities. Novel anti-inflammatory drugs are seldom tested in animal models that mimic the high-risk human users, leading to an underestimate of the true toxicity of these drugs. In the present study we examined the effects of two novel NSAIDs and two commonly used NSAIDs in models in which mucosal defence was expected to be impaired. Naproxen, celecoxib, ATB-346 (a hydrogen sulfide- and naproxen-releasing compound) and NCX 429 (a nitric oxide- and naproxen-releasing compound) were evaluated in healthy, arthritic, obese, hypertensive rats, and in rats of advanced age (19 months) and rats co-administered low-dose aspirin and/or omeprazole. In all models except hypertension, greater gastric and/or intestinal damage was observed when naproxen was administered in these models than in healthy rats. Celecoxib-induced damage was significantly increased when co-administered with low-dose aspirin and/or omeprazole. In contrast, ATB-346 and NCX 429, when tested at doses that were as effective as naproxen and celecoxib in reducing inflammation and inhibiting cyclooxygenase activity, did not produce significant gastric or intestinal damage in any of the models. These results demonstrate that animal models of human co-morbidities display the same increased susceptibility to NSAID-induced gastrointestinal damage as observed in humans. Moreover, two novel NSAIDs that release mediators of mucosal defence (hydrogen sulfide and nitric oxide) do not induce significant gastrointestinal damage in these models of impaired mucosal defence.

abstract: Master of Science (MSc)


title: Body mapping with geriatric inpatients receiving daily haemodialysis therapy for end-stage renal disease at Toronto Rehabilitation Institute: A qualitative study

contributor:
Sinding, Christina
Grenier, Amanda
Gillett, James
Health and Aging

subject: Body mapping

subject: haemodialysis

subject: hemodialysis

subject: nephrology

subject: health communication

subject: geriatric medicine

subject: Art Practice

subject: Body Regions

subject: Health Communication

subject: Knowledge Translation

subject: Medical Anatomy

subject: Medical Physiology

subject: Movement and Mind-Body Therapies

subject: Nephrology

subject: Other Medical Specialties

subject: Other Mental and Social Health

subject: Preventative Medicine

subject: Somatic Bodywork and Related Therapeutic Practices

subject: Therapeutics

subject: Art Practice

abstract: All images in this document may not be produced without the expressed written consent of the author.

abstract:
The innovative research method of “body mapping” was used in this study with geriatric inpatients receiving daily hæmodialysis therapy for end-stage renal disease at Toronto Rehabilitation Institute.

Five people took part in this study; three participants completed all study phases. They created three body maps each and took part in one follow up, semi-structured interview to share their experiences of body mapping. Two themes were drawn from the data: (1) body mapping gives patients a voice to communicate their experiences in the dialysis unit; and (2) body mapping makes visible participants’ illness adjustment patterns, and levels of connection, or disconnection in the dialysis unit.

Based on the ways body mapping benefitted participants in this study, it is reasonable to suggest that this visual communication tool could be useful in other research settings, and as a clinical tool to support patients’ attention to their bodies and their interactions with healthcare providers.

abstract: Master of Arts (MA)


title: KANT ON FREEDOM, PROPERTY RIGHTS AND ENVIRONMENTAL PROTECTION

contributor:
Sciaraffa, Stefan
Igneski, Violetta
Waluchow, Wil
Philosophy

subject:
Kant
Freedom
Law
Politics
Environmental Protection
Ethics and Political Philosophy
History of Philosophy
Other Philosophy
Ethics and Political Philosophy

abstract: This thesis aims to develop a principled rationale for coercible environmental protectionist duties, based on Kant’s Metaphysics of Morals, specifically, the Doctrine of Right. The claim of the thesis is not that such a rationale can be directly extracted from Kant’s arguments in that work, but rather that it can be reasonably extrapolated based on Kant’s framework. For Kant, politico-juridical authority, and its exercise via coercion, can be justified only in terms of the requirements of a system of freedom. Accordingly, the only legitimate rationale for coercively inhibiting environmentally destructive activities would be that such activities are, in one way or another, contrary to freedom, or incompatible with a system of Right based on freedom. The Kantian perspective on law and politics, as applied to environmental issues, demands that we ask: in what way do acts of environmental destruction constitute a hindrance, obstruction, or diminishment, of freedom; or, in what way are such acts a defective and transgressive exercise of freedom? The basic aim of this thesis is to answer these questions, and, more specifically, to establish that owners of finite natural resources (especially land) owe duties of forbearance with respect to their holdings, i.e., duties not to destroy or dissipate (or use non-sustainably) such resources. A primary challenge is that, from a Kantian perspective, any such analysis has to be based exclusively on the idea of freedom – as opposed to notions of “harm”, “welfare”, the “public good” or the “intrinsic value of nature”. Kant’s “Juridical Postulate of Practical Reason” furnishes the key to our response: environmentally destructive activity is a hindrance to freedom, and thus transgressive, because it renders usable natural resources unavailable for further use, whereas the postulate actually demands that ostensibly usable objects remain available for use in perpetuity. Further, the permissibility of environmental destruction ultimately entails the permissibility of the annihilation of the material preconditions of any possible exercise of freedom. As such, environmentally destructive acts must be intolerable within a system of Right, and environmental preservation is an imperative of Right.

abstract: Master of Arts (MA)


title: INTERSECTION STATE VISUALIZATION FOR REALTIME SIMULATIONS

contributor:
Mohrenschildt, Martin v.
Sekerinski, Emil
Nedialkov, Ned
Computing and Software

subject: simulation

subject: real-time

subject: presagis

subject: traffic light

subject: Other Computer Engineering

subject: Other Electrical and Computer Engineering

subject: Other Engineering

subject: Other Computer Engineering

abstract: Driving simulators have existed since the beginning of the $20th century. From its roots, it has been a technology used primarily to train drivers, test and prototype new technology, and improve the safety of automobile users. As technology has progressed, so has the quality of the driving simulation, and along side it, the complexity of experiments performed. The McMaster motion simulation system combines the latest software with state of the art psychology techniques, to analyze the driving experience in new and unique ways. To accommodate the wide range of plausible experiments, a robust software system was developed that allows for custom driving scenarios. The software system is comprised of several sub-components including content generation, scenario management, visualization and artificial intelligence. This thesis details the development of a traffic light system and its incorporation into the existing simulation system. A variety of challenges were encountered including real-time constraints, adapting flight software to driving simulation, inter-system communication, and interoperability of multiple APIs. A secondary objective was to document, this thesis records the methodology used to overcome these challenges in an attempt to facilitate future work in this field.

abstract: Master of Applied Science (MASc)


title: Residuals in the growth curve model with applications to the analysis of longitudinal data

contributor:
Hamid, J.
N. Balakrishnan; J. Beyene
Statistics

subject:
Decomposition of linear spaces
growth curve model
residuals
decomposed residuals
Statistical Methodology
Statistical Methodology

abstract: Statistical models often rely on several assumptions including distributional assumptions on outcome variables and relational assumptions where we model the relationship between outcomes and independent variables. Further assumptions are also made depending on the complexity of the data and the model being used. Model diagnostics is, therefore, a crucial component of any model fitting problem. Residuals play important roles in model diagnostics. Residuals are not only used to check adequacy of model fit, but they also are excellent tools to validate model assumptions as well as identify outliers and influential observations. Residuals in univariate models are studied extensively and are routinely used for model diagnostics. In multivariate models residuals are not commonly used to assess model fit, although a few approaches have been proposed to check multivariate normality. However, in the analysis of longitudinal data, the resulting residuals are correlated and are not normally distributed. It is, therefore, not clear as to how ordinary residuals can be used for model diagnostics. Under sufficiently large sample size, a transformation of ordinary residuals are proposed to check the normality assumption. The transformation is based solely on removing correlation among the residuals. However, we show that these transformed residuals fail in the presence of model mis-specification. In this thesis, we investigate residuals in the analysis of longitudinal data. We consider ordinary residuals, Fitzmaurice’s transformed (uncorrelated) residuals as well as von Rosen’s decomposed residuals. Using simulation studies, we show how the residuals behave under multivariate normality and when this assumption is violated. We also investigate their properties under correct fitting as well as wrongly fitted models. Finally, we propose new residuals by transforming von Rosen’s decomposed residuals. We show that these residuals perform better than Fitzmourice’s transformed residuals in the presence of model mis-specification. We illustrate our approach using two real data sets.

abstract: Master of Science (MSc)


title: DESIGNING A PROTOTYPE TO PROVIDE SECURE COMMUNICATION BETWEEN PHYSICIANS: A SURVEY TO EXAMINE ACCEPTABILITY AMONG USERS

contributor:
McKibbon, Ann
Archer, Norman P.
Mondal, Tapas
eHealth

subject:
Secure Communication
Email Exchange
Physician-Physician Communication
Provider Communication
Internet Security
Technology and Innovation
Technology and Innovation

abstract:
OBJECTIVE: The aim of this study was to explore an alternative method of secure data exchange of patient information among physicians using their existing email.

METHODS: A four-step framework was designed to effectively conduct the research. It involved designing a prototype of a web-based system called ST-SecRx to simulate secure communication between physicians while exchanging sensitive patient data through email. The simulation achieved through the system was meant to determine and measure response of physicians to the use of secure email or similar communication tools for exchanging patient data. Physicians were invited to use ST-SecRx and subsequently participate in a survey to determine its acceptability and their perceptions about the usefulness of the software. Finally, the data collected from the survey were analyzed.

RESULTS: Data were collected from 22 physicians from various healthcare facilities in the province of Ontario, Canada. Eliminating questionnaires with no response resulted in 19 valid responses. Results revealed that 57.9% used email support provided by their organization for exchanging patient data. Over 70% acknowledged that factors such as: ease of use, not having to use an email different from the one provided by their employer, not having to create and remember new password every three to six months, and data transfer complying with privacy regulations would facilitate their use of ST-SecRx. More than 50% of the physicians felt that the simulated system as demonstrated to them was more secure and easier to use when compared to previously used methods of patient data exchange through email. The majority of the physicians (from 57.9% to 73.7%) agreed with all the six questions on behavioral intention to use ST-SecRx. Overall 42% were willing to pay between $5 and $20 per month for ST-SecRx. Additional analysis of data by age, sex and discipline did not reveal any substantial differences in their enthusiasm to use the system.

CONCLUSION: The current research was successful providing data on what is important to clinicians who want to exchange data on patients with other clinicians. Use of systems similar to the prototype ST-SecRx could be an improvement over conventional email, provided that they would ensure security using encrypted technology under public key infrastructure methods and systems. Overall the physicians were satisfied with ST-SexRx and found it simple, fast, easy to use, and secure, and they indicated that they intended to use it if it were made available and it conformed to privacy and security standards. Also, such a secure system would have the potential to reduce the overall cost of healthcare by reducing duplication of diagnostic tests and making patient- specific information exchange faster. More research needs to be conducted with a larger sample size to validate the findings of this study. The limitations, dissatisfaction, and concerns expressed by the physicians who used ST-SecRx could direct future research. Future studies could include other healthcare professionals in the exchange of sensitive clinical data.

abstract: Master of Science (MSc)


title: Temperature-Dependent Dielectric Properties of Tissue Phantoms and Tissue Samples at Microwave Frequencies

contributor:
Nikolova, Natalia
Noseworthy, Michael
Fang, Qiyin
Electrical and Computer Engineering

subject:
Tissue Properties
Dielectric Properties
Microwave Imaging
Breast Imaging
Temperature Dependence
Cole-Cole Model
Biomedical
Biomedical

abstract:
Accurate knowledge of the frequency- and temperature-dependent dielectric properties of biological tissues is crucial in the development of ultra-wideband diagnostic and therapeutic technologies such as microwave breast cancer detection and hyperthermia treatments. This work examines the temperature dependence of the dielectric properties of the five tissue phantom-types developed by our group as well as porcine fat, muscle and liver tissues for the frequency range from 3 GHz to 10 GHz and for the temperature range from 5 °C to 45 °C. A systematic and simple measurement procedure is developed to measure the continuous temperature dependence of the dielectric properties of the various phantom and tissue types. The temperature trends of the dielectric properties of the different phantoms and tissues are investigated.

Linear temperature coefficients at discrete frequencies are impractical and insufficient in ultra-wideband applications when realistic, non-linear numerical models of the dielectric properties are required. Therefore, a compact one-pole Cole-Cole model is used to model the frequency dependence of the dielectric properties of the measured samples at every temperature point. A second- or third-order polynomial is used to model the temperature dependence of the Cole-Cole parameters. The final model is a one-pole Cole-Cole model whose parameters are polynomial functions of temperature. This model enables the estimation of the relative permittivity and the conductivity of the measured phantom and tissue types at any temperature and frequency.

abstract: Master of Applied Science (MASc)


title: DESIGN OPTIMIZATION AND MODELING OF PLASMONIC STRUCTURES

contributor:
Bakr, Mohamed H.
Electrical and Computer Engineering

subject:
Plasmonics
Surface Plasmons
Optimization
Multilevel
3-D chips
Slit array
Rotator
Electromagnetics and photonics
Optics
Electromagnetics and photonics

abstract: In this thesis, we discuss the study and realization of surface plasmon polaritons (SPPs) and their devices. Plasmonics is the emerging field that will help technologies advance further into the nano-scale without the concern for delays or size limitations. SPPs are a more advanced field of photonics as they use metals instead of the semiconductors or insulators used in optics. They operate at frequencies in the light and near infrared spectrum, as this range produces their unique characteristics. Plasmonics possess the miniaturization of electronics and the speed of photonics. They do not suffer from both the delays in nano-electronics, and the size limitations faced in optics. In this thesis, we present the optimization of plasmonic slit arrays by designing the parabolic phase profile of the array. Moreover, we present a novel multilevel plasmonic coupler that will aid in the realization of 3-D plasmonic chips, as well as quadrature modulation. The theory, procedures, and results are all presented and discussed.

abstract: Master of Applied Science (MASc)


title: Summarizing the theoretical foundation for hospital communication research: A scoping review of interdisciplinary literature.

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
Hospital Communication
Nuclear Power Generation
Communication theory
Communication Model
Knowledge Translation
Knowledge Translation

abstract: Hospitals are complex socio-technical systems where health professionals from varied backgrounds interact with each other and technology for the wellbeing of patients. Effective communication among the members of the care team is vital for optimal care; poor communication can result in suboptimal care and in many cases, lead to adverse events (AEs) and even death. More than a decade after the US Institute of Medicine report which catalyzed patient safety improvement measures, patient safety remains a major concern. Two-thirds of AEs in hospitals are still linked to communication errors. Hospitals are trying to improve communication by introducing new communication devices like smart phones and tablet computers for professional use. However, they are being deployed without adequate study of the mechanics of communication in hospitals or their use affects inter-professional communication. High risk organizations such as nuclear power plants, aviation and the military have achieved better safety records than healthcare. This is likely because they have studied their communication challenges and based their assessments on a firm theoretical foundation before implementing customized solutions. This approach in healthcare is lacking. Therefore a scoping review was conducted to collect communication theories, models, frameworks, and methods applicable to new information and communication technology used in hospitals. Literature from basic and applied science domains such as cognitive psychology, human factors engineering, organizational behavior, sociology, communication sciences and from high risk organizations like aviation, nuclear power generation and defense was reviewed. 14 theories, 12 models and 12 communication analysis methods were identified. One of the selected methods was employed to conduct a case study of a case of faulty communication reported in the AHRQ web M&M. It is not known how well those theories, models and analysis methods can be adapted to medicine. Future research may be able to address the issue and adopt theories and models to hospital communication research, modifying existing theories and models to suit the unique requirements of hospitals or by developing a strategy to design them de-novo.

abstract: Master of Science (MSc)


title: The Contribution of Edward Augustus Freeman to Victorian Historiography

contributor:
McCready, H. W.
Rempel, Richard A.
History

subject: History History

abstract:
In recent years, detailed studies have been made of a number of major figures in Victorian historiography, such as Thomas Arnold, James Anthony Froude, John Richard Green, and others. Edward Augustus Freeman (1823-1892), British historian and controversialist, was regarded during his lifetime as one of Britain's most skilled and formidable historical authorities, yet he has not had his work examined thoroughly and justly by contemporary historians. Freeman's contributions to historical writing and thinking, while admittedly limited, were influential and valuable, yet they have been largely ignored in this century or presented in exaggerated caricature.

This thesis deals with several aspects of the life and work of E. A. Freeman. It does not pretend to be a definite biographical examination of Freeman's rich and active career. Rather, it is directed toward his historical thought and the influences on the formation and development of that thought. The work is divided into ten chapters, opened by a short review of biographical and bibliographical details of Freeman's career.

Three chapters which follow examine Freeman's historical methodology; how he thought history should be written and how he actually went about executing his own historical design. One chapter reveals Freeman as a crusader for broadening the number of approaches to historical material, including the employment of information and techniques developed in auxiliary sciences such as geography, philology, and numismatics. A second re-evaluates Freeman's devotion to and skill at source criticism, adopting a position somewhat less adulatory that that of his contemporaries and less unsympathetic than most critics of this century. Finally, attention is given to Freeman's own halting attempts to make use of comparative method in his history and to his influence in promoting comparison to younger scholars.

A second section is devoted to analysis of the major features of Freeman's philosophy of history. While Freeman himself often boasted that he had no historical philosophy, his work reveals a relatively coherent body of thinking about history which is here explored. Freeman is shown in the three chapters of this section to believe strongly in the scientific character of historical study, but this apparent streak of positivism was mitigated by his belief that history was capable of achieving only a limited degree of certainty. History, however, was ultimately only slightly more uncertain than the vaunted physical sciences, themselves far from unerringly certain. Freeman also made a significant contribution to the continuing debate over the place of moral judgments in historical writing. It is clear that while he, with many other historians of his day, made moral and character judgments an important part of his narrative, those judgments were almost always tempered by a profound historical sense and thoughtful personal empathy. Finally, the examination of Freeman's historical philosophy undertakes to clarify this historian's very poorly understood vision of the unity of history. Both the grandeur and limitations of this "magnificent, but appalling doctrine" are explored; and attention is given to the way in which this theory influenced Freeman's own writing and the ways in which it came to influence the work of later historians.

The study takes up the question of Freeman's place in a trans-Atlantic school of "Teutonists." In this examination of Freeman's conception of and work in national history, it becomes clear, for example, that he held dearly a number of suspect theories regarding the origins and character of the English people, especially before 1066. Yet this analysis of Freeman's serious historical work on the subject indicates that he was neither the blind racist nor the uncritical nationalist that he is often portrayed as being. Indeed, while Freeman's work was a powerful impetus to the study of national history and the search for national origins in both England and the United States, no evidence can be found to indicate that Freeman consciously or seriously distorted history in the service of his cherished vision of the early English people.

Finally, some of the key principles of Freeman's political philosophy are examined. The historian who today is most widely known for his provocative remark that "History is past politics and politics present history" did to some degree permit his political views to give direction to his history. In most contemporary studies, Freeman's complex and unusual political philosophy is only poorly understood and improperly labeled. Furthermore, it was most often the case that Freeman's politics stemmed directly from his historical study and the information and attitudes developed thereby. In fact, it is only by considering Freeman's political stances as the fruit of his historical research that one can find a real coherence in what might seem to be a superficial political faith that ranges across the spectrum from radical to reactionary.

The study attempts not only to analyze Freeman's history but to place it in the wider context of British and nineteenth-century historiography. A transitional figure, Freeman, by training and temperament a visionary, universal historian of the mold of Niebuhr and Arnold, became an advocate of a more detailed, scientific, and professional type of history-writing. The marriage of the two was not always happy in Freeman's own writing, but he strove to impart a loftier vision and more sober and scholarly methodology of history to both historians and the general public.

abstract: Doctor of Philosophy (PhD)


title: Sustaining Palliative Care Teams That Provide Home-Based Care In A Shared Care Model

contributor:
Williams, Allison
Health Geography

subject:
Integrated Care
Home Care
Palliative Care Teams
Primary Care
Shared Care
Qualitative Research
Health and Medical Administration
Human Geography
Other Geography
Primary Care
Health and Medical Administration

abstract: This research examined the barriers and facilitators involved in the development and sustainability of palliative care teams using a shared care model. Shared care is established when interdisciplinary specialist palliative care teams (usually comprised of a palliative care physician, an advanced practice nurse, a psychosocial spiritual advisor, a bereavement counselor, a case manager and an administrator) form partnerships with primary care providers (usually frontline family physicians and home care nurses) to support the complex needs of terminally-ill patients and their family members in the home setting. Palliative care teams overcome gaps in the current health care system, such as: lack of palliative care specialists; poor coordination and integration of care, and; a health care workforce with insufficient training in palliative care. This type of service delivery model is common in medical specialties such as mental health and obstetrics, and various forms of palliative shared care have been implemented in other countries such as the US, Australia, UK, Italy and Spain, where it has been shown to be cost-effective. There are few palliative care teams working in a shared care model in Canada; this provided the impetus to investigate the process of how this integrated approach is developed and sustained within the context of specific populations and geographies. A longitudinal case study in a Local Health Integration Network (LHIN) area in Southern Ontario, comprised of urban and rural communities, was conducted in order to evaluate barriers and facilitators in using a shared care model from the perspective of team members, key-informants and stakeholders. The evaluation of barriers and facilitators informed recommendations to guide the sustainability of palliative care teams working in a shared care model.

abstract: Doctor of Philosophy (PhD)


title: Development and Underdevelopment in the Third World: Theoretical Approaches

contributor:
Goldstein, Marshall
Political Science

subject:
Political Science
Political Science

abstract:
The aim of this thesis is to show that dependency theory, put forward by its proponents as a theoretical framework adequate to the problem of examining the dynamic of the process of development in the countries of the third world, while an advance on bourgeois formulations that preceeded it, remains problematical on the most fundamental of levels.

The thesis argues, in fact, that dependency theory must be rejected as an analytical framework for the reason that it locates the crucial determinant of uneven levels of development in the realms of circulation and of exchange, and not at the level of production.

It is my submission that dependency theory has been superceeded with the development of a perspective that has come to be known as the modes of production approach. Unlike dependency, the modes of production approach situates the problem of uneven development at the level of production, and not in the realm of circulation.

The modes of production approach, the thesis argues, which theorizes the questions of deveiopment and underdevelopment, not in terms of the 'development of underdevelopment', a la dependency, but rather in terms of the articulation of the capitalist mode of production with non-, and primitive capitalist modes of production, thus remains an adequate theoretical perspective with which to address the question of the uneven levels of development which prevail on a world scale.

abstract: Master of Arts (MA)


title: Characterization of Erythromycin Esterases: A Genomic Enzymology Approach to Macrolide Resistance

contributor:
Wright, G.D.
Biochemistry

subject: Biochemistry Biochemistry

abstract: Enzymatic inactivation of antibiotics is a successful strategy employed by antibiotic resistant clinical pathogens. Genes coding for the antibiotic inactivating enzyme erythromycin esterase, or Ere, have been found in a variety of bacterial species, from clinical isolates to environmental soil-dwelling organisms. In order to better understand this family of proteins and this mode of macrolide resistance, four erythromycin esterases (EreA from Providencia stuartii, EreB from E. coli, and two putative Ere's from Saccharopolyspora erythraea and Bacillus cereus) were purified and characterized using a genomic enzymology approach. A robust quantitative enzyme assay was developed, and kinetic parameters for these different enzymes were compared. In the absence of a crystal structure for EreA or EreB, a model for EreB was developed based on the existing structure of the putative esterase from B. cereus. The importance of some conserved and potentially catalytic residues was examined using site-directed mutagenesis. Combined with mutagenesis, inhibitors, pH studies and solvent isotope effects were used to investigate potential enzyme mechanisms and two potential mechanisms were proposed for this family of proteins. A greater understanding of the function and mechanisms of antibiotic resistance elements such as the erythromycin esterases may provide valuable insights to aid in the ongoing struggle against resistant organisms in clinical settings.

abstract: Master of Science (MSc)


title: An Ecological Philosophy of Self and World: What Ecocentric Morality Demands of the Universe

contributor:
Allen, Barry
Enns, Diane
Doubleday, Nancy
Philosophy

subject:
Ethics
Ecology
Environmentalism
Biology
Selfhood
Activism
Biodiversity
Continental Philosophy
Ethics and Political Philosophy
Other Ecology and Evolutionary Biology
Other Psychology
Political Theory
Biodiversity

abstract: When environmental philosophy began as a political movement, one of its original goals was to transform people's lifestyles. This required appeals to everyday intuitions and emotional writing evoking the intrinsic value of nature. This style exists in institutional environmental philosophy today, but sits uneasy with academic pressure toward rigor and careful analysis. The first half of my thesis criticizes various problems in environmental philosophy regarding these issues and arguments for other moral principles that displace intrinsic value. I attempt to return the concept of intrinsic value to a prominent place in environmental philosophy, not as a popular intuition, but as an answer to one central philosophical question: the point of human existence. Engaging with particular topics in ecology, biology, phenomenology, ethology, complexity theory, and the assemblage theory of Deleuze and Guattari, the second half of my thesis builds a concept of selfhood that I hope is adequate to answer that question of why humanity should bother ensuring its survival.

abstract: Doctor of Philosophy (PhD)


title: A BRAIN MODEL FOR THE STUDY OF MR SUSCEPTIBILITY INDUCED PHASE BEHAVIOR

contributor:
Haacke, Mark E.
Noseworthy, Michael
Biomedical Engineering

subject:
Brain Model
Phase MRI
Susceptibility Weighted Imaging
susceptibility mapping
T2* mapping.
Bioimaging and biomedical optics
Bioimaging and biomedical optics

abstract:
MR phase images contain essential information about local magnetic susceptibility sources in the brain, creating a new type of contrast in magnetic resonance imaging (MRI). The goal of this thesis is to demonstrate with a model of the brain how accurately the transformation of phase to susceptibility takes place.

A 3D brain model uses the Forward process to calculate magnetic field perturbations caused by susceptibility properties of the tissues in the model. Homodyne High Pass (HP) filter and SHARP algorithm are used to process the simulated phase images. Similarly, MR magnitude data are simulated using tissue properties such as T1, T2* relaxation times and spin density.

The halo ring around red nucleus in the real phase data is believed to be an indicator of a capsule around red nucleus. Similar effect is seen in the simulated phase images without including the capsule of red nucleus in the model, this comparison explains that the halo effect may just be entirely or a part of the phase behavior around red nucleus. A negative susceptibility in the internal capsule region, seen in both simulated and real susceptibility maps, is discussed as a possible artifact caused by the processing techniques after comparing the simulated susceptibility maps produced from unprocessed and processed phase data. The brain model is used to determine the optimum echo time of the initial gradient echo sequence in order to produce a high quality susceptibility map with reasonably low error and better time efficiency.

abstract: Master of Applied Science (MASc)


title: Nonlinear propagation of incoherent white light in a photopolymerisable medium: From single self-trapped beams to 2-D and 3-D lattices

contributor:
Saravanamuttu, Kalaichelvi
John S. Preston, William J. Leigh
Chemistry and Chemical Biology

subject: organosiloxane

subject: photopolymer

subject: optical self-trapping

subject: optochemical self-organization

subject: black and grey incoherent soliton

subject: Atomic, Molecular and Optical Physics

subject: Electromagnetics and photonics

subject: Materials Chemistry

subject: Optics

subject: Polymer and Organic Materials

subject: Polymer Chemistry

subject: Semiconductor and Optical Materials

subject: Atomic, Molecular and Optical Physics

abstract:
Optical beams that travel through a material without undergoing divergence are known as self-trapped beams. Self-trapping occurs when a beam induces a suitable index gradient in the medium that is capable of guiding the original beam. An incoherent light consists of femtosecond scale speckles, due to random phase fluctuations and were not thought to self-trap until recently. In 1997, Mitchell et al., showed that white light can self-trap, provided the medium cannot respond fast enough to form index gradients to these speckles individually. However, detailed studies have been hampered by a lack of suitable materials and strategies for enabling such a response. In 2006, our group showed that a photopolymer is suitable for incoherent self-trapping, since the index change is governed by an inherently slow rate of polymerization (of the order of milliseconds). This has enabled further studies of various phenomena with white light self-trapping.

The studies here show (i) the first direct experimental evidence of interactions of two incoherent white light self-trapped beams, as well as fission, fusion and repulsion. Existence of dark self-trapping beams with incoherent white light was also shown, counter intuitively in a positive nonlinear medium. (iii) Lattices were formed with multiple ordered bright as well as dark self-trapping filaments using optochemical self-organization. (iv) Woodpile-like 3D lattices with bright and dark beams were also demonstrated and simulations showed theoretical band gaps. (v) Self-trapping of a co-axial beam of incoherent white light was also shown experimentally and through simulations.

abstract: Doctor of Philosophy (PhD)


title: Individual differences in the local or global processing styles within individuals with Autism: an evidence against the Weak Central Coherence and the Enhanced Perceptual Processing theories.

contributor:
Bennett, Patrick J.
Rutherford, Mel
Sekuler, Allison
Psychology

subject:
autism
biological motion
navon tasks
local-global processing
cognition.

abstract: Previous studies have reported inconsistent results for people with Autism Spectrum Disorders (ASD) in both biological motion and Navon tasks. Each of these tasks require both local and global processing and were used in this study to compare processing styles of both ASD and typical groups. In the biological motion study, the ASD and the typical groups completed an emotion and a direction-discrimination experiment with happy and angry point-light walkers, which were presented in four different stimulus conditions: upright, inverted, scrambled and random. Overall, the ASD group had higher reaction times and lower accuracy, but the effect of condition did not differ between groups. Both groups performed worse in terms of accuracy and reaction times in the scrambled (i.e., local information only) conditions, therefore revealing a global bias in the processing of biological motion information. In the Navon task study with the same participants, typical individuals exhibited a global precedence effect, manifested as lower reaction times for global stimuli as well as global interference in “look for only local digits” task. However, individuals in the ASD group did not, on average, show a local or a global bias. In a subsequent analysis, the ASD group was divided into locally-biased and globally-biased sub-groups. Now, when a three way analysis between typical and the two ASD groups was performed, the globally-biased group’s performance was not distinguishable from that of the typical group, while no global bias was observed for the locally-biased group. When these two groups were compared on the Biological Motion study, the locally-biased group had no reaction time difference across conditions including both biological motion and Navon tasks, unlike the globally-biased group, who displayed higher reaction times for the scrambled condition, just like the typical group did. Therefore, it is possible that the inconsistencies in the local-global processing literature of individuals with ASD may have resulted because the studies did not account for individual differences in processing styles within the ASD groups that may be variable, unlike typical individuals who have a global bias for most tasks.

abstract: Master of Science (MSc)


title: Nonlinear light propagation and self-inscription processes in a photopolymer doped with Ag nanoparticles

contributor:
Saravanamuttu, Kalaichelvi
Harald D. H. Stöver, Adam P. Hitchcock
Chemistry and Chemical Biology

subject:
Nonlinear optics
self-action effects
three-dimensional lithography
polymer waveguide
metallodielectric microstructures
metal nanoparticles
Physical Chemistry
Physical Chemistry

abstract:
The resonance of surface plasmons on metal nanoparticles can be excited at visible wavelengths. The extraordinary enhancement of a variety of optical phenomena in the vicinity of metal nanoparticles has been attributed to the strong fields generated under resonance conditions. As a result, extensive research has been carried out to incorporate the extraordinary optical properties of metal nanoparticles into optical devices and applications, ranging from spectroscopy (e.g, surface enhanced Raman, IR and Fluorescence), optical sensing and imaging, to photovoltaic cells, photonic crystals and optical switches. Particular effort has been directed towards producing stable dispersion of metal nanoparticles within soft dielectric matrices and their subsequent construction into different device geometries.

This thesis describes a method to photolytically generate Ag nanoparticles within organosiloxane sols, which can subsequently be photopolymerized in the presence of photoinitiators and therefore, be patterned through a variety of photo-inscription processes. The mechanism of Ag nanoparticle growth and evolution is described in detail followed by the fabrication of periodic metallodielectric gratings through photomask and laser interference lithography. Studies also showed that three different forms of nonlinear light propagation, optical self-trapping, modulation instability and spatial self-phase modulation could be elicited in the Ag nanoparticle-doped systems. Detailed experimental examination of these phenomena elucidated significant differences in their dynamics in the metallodielectric systems compared to non-doped samples. These included variations in the dynamics of self-trapped beams such as the excitation of optical modes, critical thresholds for modulation instability and self-phase modulation. The potential of these nonlinear processes for the self-inscription of 3-D metallodielectric structures including cylindrical multimode waveguides and waveguide lattices has also been studied.

abstract: Doctor of Philosophy (PhD)


title: A two step mechanism for activation of actinorhodin export and resistance in Streptomyces coelicolor

contributor:
Nodwell, Justin
Gerry Wright, Marie Elliot
Biochemistry

subject: Actinorhdin Streptomyces Resistance Export

subject: Biochemistry, Biophysics, and Structural Biology

subject: Life Sciences

abstract: Antibiotic producing organisms often bear cognate export and/or resistance mechanism encoded in the same cluster of antibiotic biosynthetic genes, but how expression of these protective genes associated with the cognate biosynthetic machinery was poorly understood. This work focuses on elucidating the mechanism by which the antibiotic producing bacteria initiate and sustain self-resistance in individual cells and across the colonies. Actinorhodin is a blue pigmented antibiotic produced by Streptomyces coelicolor. Within its biosynthetic gene cluster, an actAB operon encodes two putative efflux pumps and is regulated by the transcriptional regulator ActR. This work (1) identified that normal yields of actinorhodin require actAB expression and both actinorhodin and its 3-ring pathway intermediate (e.g. DHK) could relieve actAB expression from ActR repression in vivo; (2) created an ActR mutant that interacts productively with a 3-ring intermediate (e.g. (S)-DNPA) but not actinorhodin and responds to actinorhodin biosynthetic pathway with induction of actAB and normal actinorhodin production; (3) demonstrated that actinorhodin producing cells could induce actAB expression in non-producing cells and actinorhodin is the intercellular signal in this case; (4) showed actAB expression in “intermediate only” ActR mutant is short lived and in the absence of the actinorhodin-mediated signaling step the culture experiences widespread cell death. Based on these results, we proposed a two-step model for actinorhodin export and resistance where intermediates trigger initial expression for export from producing cells and actinorhodin then triggers sustained export gene expression that confers culture-wide resistance.

abstract: Doctor of Philosophy (PhD)


title: Atmospheric and Surface Control on Evapotranspiration during Soybean Maturation

contributor:
Davies, J. A.
Geography

subject: Geography Geography

abstract:
Procedures to calculate hourly and daily evapotraspiration from vegetated surfaces in the absence of lysimetric or micrometeorological measurements are few. A new for physically-based evapotranspiration models to account for atmospheric and surface control on the process is recognized. The micrometeorological investigation described in this study is a response to this need.

During the growing season of 1974, a measurement program was conducted to study atmospheric and surface control on hourly and daytime evapotranspiration. Data collected include net radiation and soil heat flux densities; vertical profiles of temperature, vapour pressure and windspeed; soil moisture; and leaf stomatal resistance.

The combination model which combines equations dealing with the energetics of evapotranspiration and turbulent transfer was employed in the study of hourly evaporative relationships. In the variant of the model used, atmospheric and surface controls on the process are explicitly considered through the deployment of an aerodynamic resistance to water vapour exchange and a surface resistance to water vapour efflux. Hourly estimates of aerodynamic resistance to water vapour exchange were computed from wind profile data. The combination model was insensitive to aerodynamic resistance errors. Hence, simple parameterization of surface roughness and zero plane displacement could be used with single level windspeed measurements to evaluate aerodynamic resistance. Also stability correction could be ignored for practical applications.

Bulk stomatal resistance was evaluated by residual from the combination model on an hourly basis. Comparison was made with independent estimates developed from stomatal resistance and leaf area index measurements. After canopy development was sufficient to dominate surface energetics, the agreement between the estimations was good. Leaf stomatal and bulk stomatal resistances were found to vary in response to irradiance, soil moisture availability and the vapour pressure deficit of the air. However, the relationship found for the latter is not well defined.

For days when canopy development was sufficient to dominate surface energetics, daytime evapotranspiration totals normalized by equilibrium evapotranspiration are linearly related to soil moisture availability when volumetric soil moisture is below 0.12 mm³ H₂O/mm³ soil. With soil moisture above this threshold limit, evapotranspiration proceeds at a potential rate. These results may prove useful in computing daytime evapotranspiration from cropped surfaces.

abstract: Doctor of Philosophy (PhD)


title: Cutting Edge Microgeometry, Modeling and EE-Honing

contributor:
Koshy, Philip
Ng, E.
Mechanical Engineering

subject:
Cutting Edge
Honing
EDM
Preparation
Manufacturing
Mechanical Engineering
Manufacturing

abstract: This thesis presents the proof-of-concept of electro-erosion edge (EE) honing as a novel edge preparation process that is based on micro-shaping of the cutting edges of metal cutting tools by electro discharge machining (EDM). This process in its simplest form is first applied to straight edge high speed steel cutting tools which results in a four-fold enhancement in the lives of these tools as compared to the sharp unprepared ones. In the next step the EE-honing application is expanded to hone carbide tools of a complex geometry through the innovative idea of using foil counterfaces. Foil counterface ensures the uniform processing of the entire edge length irrespective of macrogeometric complexities such as curvilinear cutting edges and nose radii. By employing this technique, cutting tools of a complex geometry can be prepared with only 13% edge radius variation which is significantly lower than 40% variation reported for conventional edge preparation processes. ED-machining of cemented carbides necessitates the systematic identification of optimal process parameters to preserve process stability and surface integrity. It is shown that by the application of optimal EE-honing process parameters, EE-honed tools achieved the same life of conventionally prepared ones with the same radii. The advent of advanced edge preparation techniques like EE-honing process has led to the emergence of engineered cutting edge microgeometries most of which cannot be represented by a single edge radius value. In this regard, a novel idea of using parametric quadratic curves for comprehensive cutting edge characterization is presented in the next part of this thesis. The free-knot B-spline approximation enables the unique identification of cutting edge separation points from the clearance and rake faces. Subsequent to the edge identification, quadratic parametric polynomials are employed to characterize the cutting edge by four characterization parameters. These parameters are contour-based and easy to visualize. As the final part of the thesis, the EE-honing process is simulated numerically to gain a better insight into the process. Simulation can model the generation of symmetrical and asymmetrical edges and predict edge geometry with the maximum of 14% error.

abstract: Doctor of Philosophy (PhD)


title: Physical activity in a multi ethnic Canadian population: The association of physical activity with cardiovascular risk factors and exploration of physical activity patterns

subject:
Clinical Epidimeology
Biostatistics
Biostatistics

abstract:
Obesity has become a global epidemic in children and adults and a decline in physical activity (P A) has contributed to this phenomenon. Low P A has been identified as a risk factor for various diseases, including cardiovascular disease. Past literature has identified variations in P A by sex, ethnicity and socioeconomic status (SES), but the majority of studies have been restricted to American populations. This thesis explored trends in total, work related and leisure time PAin a multiethnic Canadian population.

Analyses were conducted using data from the SHARE, SHARE-AP and SHAREAP Action studies. The reliability and validity of physical activity questionnaires (P AQs) were assessed using Pearson and Spearman's rank correlation. Risk factors by PA level were compared using analysis of variance (ANOVA) for continuous variables and chisquare tests for categorical variables. Fisher's exact test was used to determine whether risk factor clustering by P A level was more evident when using P AQs or the RT3 accelerometer (RT3), and Cohen's Kappa coefficient was used to determine the agreement between the PAQs and the RT3 in classifying participants. The Chi-square goodness of fit test was used to determine differences in P A trends and multiple binary logistic regression was performed to determine variable association with low total P A.

Reliability coefficients of all PAQs ranged from 0.06 to 0.80 while validity assessments ranged from -0.07 to -0.17 against systolic blood pressure for the modified ARIClBaecke Questionnaire and -0.10 to -0.30 for the PAQs used in SHARE-AP Action. Greater risk factor clustering was seen in low P A groups compared to high PAin SHARE and SHARE-AP data. However, no such association was seen in SHARE-AP Action and there was poor agreement in PA level classification between the PAQs and the RT3. Differences by sex, ethnicity and SES were apparent in different contexts ofPA. As well, low P A was associated with South Asian and Chinese ethnicity, increasing age, low SES and Aboriginals in the low SES category. These findings show that differences in P A exist between different groups. Identifying populations prone to inactivity can assist in the development of health promotion strategies that target individuals susceptible to low PA.

abstract: Master of Science (MSc)


title: MULTI-MODELLING of ABRASIVE WATERJET MACHINING

contributor:
Ng, Eu-Gene
Mechanical Engineering

subject:
Abrasive Waterjet Machining
CFD
Erosion Model
Mechanical Engineering
Mechanical Engineering

abstract:
Abrasive waterjet (AWJ) machining is a complex, non-conventional machining process involving numerous input parameters including hydraulic, abrasive, mixing and cutting that must be accurately manipulated to guarantee precise cutting and quality. Currently, available models are empirical or require continuous calibration, or extensive experimental work. To reduce the calibration and experimental time required for accurate prediction of AWJ cutting, computational fluid dynamics (CFD) is being utilized to model the nozzle flow interaction; high pressure water is pushed through the orifice into the mixing chamber, pulling the abrasive into the flow and cohering in the focus tube. Initial research worked towards understanding the effect that input parameters - such as pressure, particle size and shape, focus tube length and volume fraction of air in fluid mixture - have on the velocity profile through the nozzle and upon exit to the atmosphere. Once understood, the CFD model can be utilized to vary mass-inlet, mixing head, orifice and focus tube dimensions to optimize velocity profile of abrasive material including magnitude and jet coherency. Primarily focused on pump pressure, which is limited by technology - an optimized AWJ nozzle will increase material removal rate and/or enhance cut quality without making changes to any other AWJM components.

Utilizing the velocity output information from the CFD model, a depth of penetration erosion prediction model was generated. Based on methodology from Finnie, and modified by Hashish and ElTobgy, a multi-particle erosion model of an impacted work piece is developed. With an updated formulation for the specific cutting resistance of a work piece, dependent on particle velocity and nozzle traverse speed, the erosion prediction over the sixty-five different setups modelled and tested experimentally, reduced error on average 41.8%. Moreover, the development of this model created multi-layered surface plots, illustrating for quick reference, the erosion of a work piece for a given set of parameters albeit mass flow rate, pump pressure and traverse rate.

Further, a database of quick reference guides, including variable input settings, nozzle types, garnet types and work piece materials can easily be developed. Finally, a new methodology for the leading edge of the waterjet is described and can be incorporated into the erosion simulation by making use of the ``top-hat`` profile generated in the CFD model. This would reduce reliance on model constants to account for secondary cutting, or when particles do not contribute to cutting but are simply entrained in the fluid flow.

Both models demonstrated good correlation with experiments or literature. The use of these models will increase understanding of the complex abrasive waterjet process and reduce the need for costly experiments moving forward.

abstract: Master of Applied Science (MASc)


title: An Equivariant Main Conjecture in Iwasawa Theory and the Coates-Sinnott Conjecture

contributor:
Kolster, Manfred
Mathematics

subject:
Number Theory
Number Theory

abstract:
The classical Main Conjecture (MC) in Iwasawa Theory relates values of p-adic L-function associated to 1-dimensional Artin characters over a totally real number field F to values of characteristic polynomials attached to certain Iwasawa modules. Wiles [47] proved the MC for odd primes p over arbitrary totally real base fields F and for the prime 2 over abelian totally real fields F.

An equivariant version of the MC, which combines the information for all characters of the Galois group of a relative abelian extension E/F of number fields with F totally real, was formulated and proven for odd primes p by Ritter and Weiss in [33] under the assumption that the corresponding Iwasawa module is finitely generated over ℤp ("µ=0"). This assumption is satisfied for abelian fields and conjectured to be true in general.

In this thesis we formulate an Equivariant Main Conjecture (EMC) for all prime numbers p, which coincides with the version of Ritter and Weiss for odd p, and we provide a unified proof of the EMC for all primes p under the assumptions µ=0 and the validity of the 2-adic MC. The proof combines the approach of Ritter and Weiss with ideas and techniques used recently by Greither and Popescu [13] to give a proof of a slightly different formulation of an EMC under the same assumptions (p odd and µ=0) as in [33].

As an application of the EMC we prove the Coates-Sinnott Conjecture, again assuming µ=0. We also show that the p-adic version of the Coates-Sinnott Conjecture holds without the assumption µ=0 for abelian Galois extensions E/F of degree prime to p. These generalize previous results for odd primes due to Nguyen Quang Do in [27], Greither-Popescu [13], and Popescu in [30].

abstract: Doctor of Philosophy (PhD)


title: UNDERSTANDING FUNDAMENTAL SECONDARY RULES AND THE INCLUSIVE/EXCLUSIVE LEGAL POSITIVISM DEBATE

contributor:
Waluchow, Wilfrid
Sciaraffa, Stefan
Giudice, Michael
Philosophy

subject:
Rule of Recognition
Rules of Change
Rules of Adjudication
Directed Powers
Legal Positivism
General Jurisprudence
Jurisprudence
Jurisprudence

abstract: Within legal positivism, the theory which holds that there is no necessary connection between legal validity and morality, there is dissensus about whether there can be a contingent connection. Inclusive legal positivists suggest that it is possible for morality to play a role in determining a norm’s legal validity while exclusive legal positivists argue for the opposite. This dissertation examines this debate between inclusive legal positivism and exclusive legal positivism focusing on how paying attention to all of the fundamental secondary rules in a legal system can affect arguments about the coherence of either theory. The fundamental secondary rules being the rules which identify other rules, identify authority and authorize changes. I will be demonstrating that three exclusive legal positivist arguments against inclusive legal positivism are unconvincing because of the role that fundamental secondary rules play in our legal systems. Shapiro and Raz offer arguments against inclusive legal positivism based on different important features that they believe the law possesses. However, given their commitment to a particular type of fundamental secondary rule, specifically a directed power, exclusive legal positivism is unable to better capture these important features. Himma suggests that inclusive legal positivism cannot explain how a court can have final authority to determine constitutional cases involving moral criteria. Again, however, we examine what fundamental rules an inclusive legal positivist could employ to explain the phenomenon, we find that exclusive legal positivism is in no better position. At the end of the dissertation, I will suggest why I think continuing with these types of arguments will continue to be fruitless and briefly examine how similar inclusive and exclusive legal positivism are through investigating how one might determine whether a given legal system had an inclusive rule of recognition or exclusive one.

abstract: Doctor of Philosophy (PhD)


title: FORMATION OF SILICON NANOCRYSTALS IN SiO2 BY SILICON IMPLANTATION AND SUBSEQUENT ANNEALING

contributor:
Knights, A. P.
Y. Haddara and Dr. L. Soleymani
Engineering Physics

subject:
PL Intensities
Thickness Effect
Semiconductor and Optical Materials
Semiconductor and Optical Materials

abstract: Since the first description of Si nanocrystals, research in this field has gone through raid progress and potential applications of Si nanocrystals have been established. There are several methods applicable to the fabrication of Si nanocrystals with one of the most used being ion implantation followed by thermal annealing. Two types of thermal annealing are available for use: furnace annealing (FA) for several hours, normally in an N2 atmosphere; and rapid thermal annealing (RTA) for a short time (less than a few minutes), again in an inert atmosphere such as N2. The formation of the nanocrystals then proceeds with decomposition, segregation, diffusion, nucleation, aggregation, growth and crystallization. This formation requires temperatures in excess of 1000o C such that noticeable photoluminescence may be observed. This thesis explores the fabrication of Si nanocrystals using the McMaster ion implanter and subsequent RTA. The implantation conditions required to form luminescent nanocrystals are determined. For example, for an implantation energy of 10 KeV a minimum dose of 1.5 1016 ions cm-2 is required. The relationship between luminescent intensity and post-implantation annealing is also explored. An optimum annealing temperature of 1100oC is found. For the first time to the author’s knowledge, a study of the effects of thin film thickness on luminescent intensity is conducted. The major conclusions of this thesis are i) a specific thickness of oxide layer has the maximum PL for a fixed implantation energy and implantation dose, ii) PL intensity is inversely proportional with measuring temperature., iii) the type of oxidation process has a large effect on PL intensity.

abstract: Master of Applied Science (MASc)


title: Effects of Acute and Chronic Low-Volume High-Intensity Interval Exercise on Cardiovascular Health in Patients with Coronary Artery Disease

contributor:
MacDonald, Maureen J.
Kinesiology

subject:
flow-mediated dilation
endurance exercise
cardiorespiratory fitness
heart rate
blood pressure
intima-media thickness
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
The merits of low-volume high-intensity interval exercise (HIT) have been established in healthy populations; however, no studies have examined this exercise prescription in patients with coronary artery disease (CAD). The present thesis examined the acute and chronic effects of HIT in patients with CAD.

The first study demonstrated transient improvements in brachial artery endothelial-dependent function, assessed using flow-mediated dilation (FMD), 60-minutes following a single bout of either HIT or moderate-intensity endurance exercise (END) in habitually active patients. The second study demonstrated no effects of training status on the acute endothelial responses to exercise; following 12-weeks of either HIT or END training. However, there was a significant reduction in endothelial-independent function immediately post-exercise, at both pre- and post-training, which requires further examination. The third study demonstrated comparable increases in fitness and resting FMD following 12-weeks of END and HIT, lending support to the notion that favorable adaptations are obtainable with a smaller volume of exercise. Lastly, the fourth study demonstrated no change in heart rate recovery following 12-weeks of END and HIT. However, pre-training heart rate recovery values reported by our sample were in a low risk range, which suggests training induced improvements may only be achievable in populations with attenuated pre-training values.

The results of this thesis provide preliminary evidence supporting the use of HIT in patients with CAD. The findings of favorable transient and chronic improvements following HIT are notable, especially given the HIT protocol involves less time and work than END, which was modeled after the current exercise prescription in cardiac rehabilitation. Further investigations are necessary, including the assessment of additional physiological indices, the feasibility and adherence to HIT, the inclusion of CAD populations with co-morbidities including heart failure and diabetes, as well as other forms of HIT training including HIT combined with resistance training.

abstract: Doctor of Philosophy (PhD)


title: Professor Murphy on Legal Defectiveness

contributor:
Waluchow, W.J.
Sciaraffa, Stefan
Igneski, Violetta
Philosophy

subject:
defectiveness
natural law
weak natural law
functional argument
illocutionary argument
Jurisprudence
Philosophy
Public Law and Legal Theory
Jurisprudence

abstract: This thesis is mainly a critical examination of Professor Mark C. Murphy’s theory of defectiveness. In his view, being backed by decisive reasons for action is a standard internal to legality, to the property of being law, such that a law or a legal system that is not backed by decisive reasons for action fails to measure up and thus, is defective qua law or legal system. Following a short introduction, I will devote chapter I to presenting Professor Murphy’s theory of defectiveness in the context of his defence of the natural law tradition. In the remaining two chapters, I shall state and assess two types of argument in support of this main thesis. Chapter II is concerned with the functional argument, which holds that law’s characteristic activity, thus law’s function, is to provide dictates backed by decisive reasons for action. I criticize Murphy’s account claiming that his explanation is bereft of a causal mechanism that links certain characteristic activities with certain effects, which is the main element of non-agentive functional explanations. The different type of argument that attempts to present the presence of decisive reasons as a non-defectiveness condition of illocutionary acts in general, and thus for legal illocutionary acts, is considered in chapter III. Here, I argue that Murphy’s position is not supported by the orthodox theory of illocutionary acts. From this I conclude that we have reason to doubt Professor Murphy’s success in providing an appropriate theory of legal defectiveness.

abstract: Master of Arts (MA)


title: Applying Machine Learning to Speech Processing in Hearing Aids

contributor:
Bruce, Ian C.
Electrical Engineering

subject:
Electrical and Computer Engineering
Electrical and Computer Engineering

abstract:
The neurophysiological basis of sensorineural hearing loss is thought to be hair cell damage or stria vascularis atrophy in the cochlea. The normal cochlea is responsible for a very complex, dynamic, nonlinear analysis and coding of acoustic signals, which is distorted by cochlear impairment. To overcome hearing loss, a typical hearing aid provides linear gain or some simple form of dynamic compression. However, such simple processing cannot fully compensate for the effects of cochlear impairment. In this thesis, machine learning is used to investigate more optimal speech processing schemes for hearing aids.

A model of the auditory periphery is utilized to develop a set of neural predictors of human speech intelligibility. These are shown to have similar accuracy to acoustic predictors of intelligibility such as the articulation index. The neural predictors are then used as error metrics in a machine learning framework to train simple linear and compressive hearing aid algorithms. The results are consistent with empirically derived prescriptions for hearing linear gain and compression.

It thus appears that to develop speech processing algorithms that provide greater benefits than those currently available in hearing aids, it is necessary understand more fully the distortions that are occurring in the cochlea due to hearing loss and to develop processing algorithms that specifically target compensation of these distortions. An analysis of the differences in compression, suppression and adaptation in the normal and impaired cochlea is performed using the model of the auditory periphery, and specific distortions are quantified. From this analysis, several speech processing algorithms are proposed that may more fully compensate for the effects of cochlear impairment on the neural representation of speech.

abstract: PhD Otolaryngology (PhDOtol)


title: liTo Clip Elysium": Desire, Structure, and the Meaning of Misprision in Shakespeare's Venus and Adonis.

contributor:
Silcox, Mary
English

subject:
English Language and Literature
English Language and Literature

abstract: This thesis begins by examining the ways in which Shakespeare's Venus and Adonis anticipates its own criticism. For insofar as the critical history of Venus and Adonis attempts to enclose or explain "what" the poem means, rather than "how" the poem means, it tends to repeat the dramatic and lexical motions of the poem itself By exploring the most pronounced discrepancies in the critical discussion around the poem, I show that interpretations of Shakespeare's epyllion which strive to locate a definitive center for the text--be it allegorical, psychological, or historical...tend to reveal the ways in which a reader's desire inhabits the text. Indeed, the poem's lack of a satisfying resolution has led a number of critics to ascribe a sense of closure for the poem's conclusion, just as its representation of ambiguous and aggressive female sexuality has lead to a series of incomplete readings, which repeat the actions of poem. The second section of the thesis then attempts to explain "how" the poem's structure imagery, and intertexuality evoke a sense of frustration in its readers. The poem's structure, I argue, is base. on a series of repeated patterns that moves from pursuit and opposition to ostensible but unrealized union. Although the poem's imagery and narrative structure appears to move towards a moment of synthesis in which Venus and Adonis unite, the poem never actually reaches such a point. The narrative an imagistic structure of Shakespeare's epyllion thus tantalizes the reader's hope for resolution, without ever fulfilling such a desire.

abstract: Master of Arts (MA)