title: Fibrocytes in Chronic Lung Disease

contributor:
Kolb, Martin
Gauldie, Jack
Xing, Zhou
Health Sciences

subject:
Chronic Lung Disease
Translational Medicine
Biomarker
Fibrocyte
Injury model
Medical Sciences
Medical Sciences

abstract:
The focus of this thesis was the role of fibrocytes in chronic lung disease. These bone marrow derived cells have been identified in the lung and the circulation in patient samples and animal models of lung injury. However, the precise mechanistic role of the fibrocyte is still to be elucidated.

Live assessment of lung changes in animal models of chronic lung disease allows for real time observation of changes, and gives a readout which can be translated to humans who undergo similar tests. In this thesis, we adapted an existing model of lung injury, and delivered a discrete treatment to a single lung lobe while monitoring its successful delivery.

I also developed a robust system to examine the relationship between fibrocyte response, and cytokine expression previously identified in chronic lung disease. We found a connection between cytokine expression and fibrocyte mobilisation. Our model showed that fibrocyte mobilisation in the presence of existing lung injury does not improve and rather can worsen existing lung injury. This was a significant finding as it confirms the role of the fibrocyte as a participator or conductor in fibrogenesis and it suggests that this cell may play a role in the development of chronic lung diseases.

Finally, we contributed to the ongoing characterisation of the fibrocyte as a prospective biomarker. We confirmed the cell’s identity by characterising it by its known markers and biological characteristics. We also identified the presence of this cell in chronic lung disease and linked its presence to disease progression.

abstract: Doctor of Philosophy (Medical Science)


title: Reconsidering Paurs Use of Creation Language in Romans 8: Employing a Corpus-Driven Model of Systemic Functional Monosemy

contributor:
Porter, Stanley E.
Christian Studies

subject: Christianity Religion Christianity

abstract: A majority of modem scholars understand Paul's use of creation language (κτίσιϛ) in Rom 8: 18-23 as part of a commentary on the state of sub-human creation. or nature-an understanding that is still disputed in some quarters. This position serves as a point of departure for an inquiry into the state of lexical study in New Testament scholarship. In light of contemporary approaches. this thesis articulates a theory of monosemy--a minimalistic semantic theory cast in the framework of Systemic Functional Linguistics. This theory is fundamentally corpus-driven with a special focus upon metaphorical extension. The model is applied to Paul's use of creation-language through a robust corpus analysis and an investigation into κτίσιϛ's role in textual and ideational functions within the paragraph. I argue that κτίσιϛ plays a role in the cohesive structure of Rom 8:18-23 and-contra the majority of interpreters-functions as a nominalized ideational metaphor for the human body.

abstract: Master of Arts (MA)


title: Dislocating AOP: An Analysis of Anti-Oppressive Practice's Subject Positions

subject:
Anti-Oppressive Practice
social work educators
social justice
Social and Behavioral Sciences
Social Work
Social and Behavioral Sciences

abstract:
Anti-Oppressive Practice (AOP) has become one of the most influential approaches to contemporary social work practice. Despite its widespread significance it seems that there is confusion, and a lack of consensus, regarding what AOP actually is. This research, therefore, examines how social work educators understand AOP in order to determine what AOP looks like and whether it has since acquired a fixed and defined identity. Data gathered from eleven qualitative interviews with social work educators at three Canadian universities revealed that AOP is understood as having nine core tenets; and yet, AOP is also understood as being a highly fluid and ambiguous epistemology. The research also showed that AOP's fluidity and ambiguity are not weaknesses to be resolved, but rather are intentional and purposeful as they enable it to resist and dismantle dominance, and pursue social justice.

AOP's fluidity and ambiguity was theorized as mirroring the fluidity and ambiguity of human identities and identity categories-both resist being fixed and reified, as they are more than the sum total of these parts. In this regard, it is proposed that AOP can be understood as occupying multiple subject positions. Analysis of AOP's subject positions revealed that when AOP tends toward becoming fixed and fully known it becomes co-opted and compromised by structures of dominance and is used as a tool of oppression. In other words, when AOP is definitively located it ceases to be anti-oppressive. It seems, therefore, that we must constantly dislocate AOP through critical dialogue in order to ensure that it is a means of dismantling dominant structures of power and pursuing social justice.

abstract: Master of Social Work (MSW)


title: The Function of Mythic Figures in the Tirumantiram

contributor:
Sivaraman, Krishna
Younger, Paul
Religious Studies

subject:
Tirumantiram
Tamil manual
mythic
facets of Śavism
Arts and Humanities
Religion
Arts and Humanities

abstract:
The Tirumantiram is a three thousand verse Tamil manual of Āgamic Śaivism composed about the seventh century A.D. by a yogī sage known as Tirumūlar. This work I was accepted into the canonical collection of Śaiva devotional works known as the Tirumuṟai, and can be shown to have significantly influenced the writers of the later canonical collection of Śaiva philosophical texts. Still, the Tirumantiram remains little known outside of South India and even less understood. Both Indian and Western scholars have tended to ignore this work which they commonly characterize as being obscure, opaque and esoteric. While acknowledging the presence of obscure verses and coded portions of the text dealing with advanced yogic instruction, it is my intention to show (a) that the Tirumantiram was composed for a wide-ranging audience of householders and rulers as well as learned Brahmins and trained yogis, and (b) that the aim was to reconcile tensions existing between various Southern Śaiva sects. I will also argue that Tirumūlar sought to accomplish this task by creatively explicating the metaphysical, moral and mystical aspects of Āgamic Śaivism with the aid of mythic figures in order to communicate his insights on a more popular level.

The mythic references incorporated into the text lend themselves to being studied under three general exegetical headings. That is, they can be distinguished as having an apologetic, tropological or anagogical thrust corresponding to the three facets of Śaivism mentioned above. In the process of analyzing the mythic imagery and indicating how it was skillfully employed to develop major themes which are reiterated on a more advanced level in other portions of the text, it should become clear that, on the whole, the Tirumantiram was a unified composition and not a mere compilation of solitary verses as has been suggested by K. Zvelebil and others. To my knowledge, this is the most protracted study of the Tirumantiram in English since A. Visvanatha Pillai produced his translation and commentary on several hundred selected verses in the mid 1960's.

The numbering of Tirumantiram verses cited or quoted in this study follows that found in G. Varadarajan's Edition. The latter was chosen because it is both reliable and more readily available than other responsible editions. For words I have followed the form of transliteration adopted by standard works on Indology. As for the transliteration of Tamil, several systems are currently in use. Here I will follow that set forth in the Madras Tamil Lexicon.

abstract: Doctor of Philosophy (PhD)


title: The organizational cultures of Ontario Schools of Nursing: A grounded theory study to explain the adoption and incorporation of simulation

contributor:
Jack, Susan
Pamela Baxter, Kevin Eva, Lynn Martin
Nursing

subject: Simulation

subject: organizational culture

subject: nursing

subject: nursing leaders

subject: Schein

subject: Rogers

subject: innovation

subject: grounded theory

subject: Educational Assessment, Evaluation, and Research

subject: Educational Leadership

subject: Higher Education Administration

subject: Nursing Administration

abstract:
Background: Internationally, simulation has been widely used as a teaching strategy in nursing programs. In Ontario, Canada, simulation has gained increasing acceptance and use in nursing education and has been met with a parallel investment of resources. Current literature offers insights into individual-level factors that contribute to the adoption and incorporation of simulation but there is a lack of understanding of how organizational factors shape this this educational strategy.

Objective: The purpose of this grounded theory study was to create a mid-range explanatory theory that describes how the organizational cultures of undergraduate nursing programs shape the adoption and incorporation of mid- to high-level simulation as a teaching and learning strategy.

Methods: Constructivist grounded theory was used to guide this research.

Results: A seven-phase process related to adopting and incorporating simulation into nursing curricula was uncovered. Sites that moved through the phases of the process and integrated simulation into all levels of the curriculum were classified as high-uptake. The level of uptake of simulation by nursing programs influenced the potential outcomes. From the findings, a theory was developed: the Organizational Elements that Shape Simulation in Nursing (OESSN) that includes five key organizational elements that shape the adoption and incorporation of simulation in nursing curricula.

Conclusion: This theory provides nursing programs with insight about the core organizational concepts that influence the adoption and incorporation of simulation within their curricula. The OESSN highlights the organizational elements to be cognizant of when adopting and incorporating simulation and perhaps other technological innovations within nursing curricula.

abstract: Doctor of Philosophy (PhD)


title: Multilevel Method for Turbulence Energy Spectrum Estimation by Compressive Sampling

contributor:
Kevlahan, Nicholas
Computational Engineering and Science

subject:
compressive sampling
turbulence
energy spectrum
wavelets
optimization
Computational Engineering
Computational Engineering

abstract: Recent developments in signal processing called Compressive Sampling (CS) show that the measurement and reconstruction of sparse signals often requires fewer samples than is estimated by the sampling theorem. CS is a combination of a linear sampling scheme and a reconstruction method and, typically, the signal is assumed to be sparse, compressible, or having a prior distribution, with the reconstruction error measured in the \ell^2 norm. This thesis investigates the application of CS to turbulence signals, particularly for estimating some statistics or nonlinear functions of the signals. The main original research result of the thesis is a proposed method, Spectrum Estimation by Sparse Optimization (SpESO), which uses a priori information about isotropic homogeneous turbulent flows and the multilevel structure of wavelet transforms to reconstruct energy spectra from compressive measurements, with errors measured on a logarithmic scale. The method is tested numerically on a variety of 1D and 2D turbulence signals, and is able to approximate energy spectra with an order of magnitude fewer samples than with traditional fixed rate sampling. The results demonstrate that SpESO performs much better than Lumped Orthogonal Matching Pursuit (LOMP), and as well or better than wavelet-based best M-term methods in many cases, even though these methods require complete sampling of the signal before compression.

abstract: Master of Science (MSc)


title: Completing the New Periodicity Lemma

contributor:
Smyth, W.F.
Computing and Software

abstract: The “Three Squares Lemma” (Crochemore and Rytter 1995) famously explored the consequences of supposing that three squares occur at the same position in a string. Essentially, it showed that this phenomenon could not occur unless the longest of the three squares was at least the sum of the lengths of the other two. More recently, several papers (Fan et al. 2006; Franek, Fuller, et al. 2012; Kopylova and Smyth 2012; Simpson 2007) have greatly extended this result to a “New Periodicity Lemma” (NPL) by supposing that only two of the squares occur at the same position, with a third occurring in a neighbourhood to the right. The proof of the NPL involves fourteen subcases, twelve of which have been proven over the last seven years. In this thesis, we prove the final two remaining.

abstract: Master of Science (MSc)


title: Data-driven approaches for sustainable operation and defensible results in a long-term, multi-site ecosystem flux measurement program

contributor:
Arain, M. Altaf
Geography and Earth Sciences

subject:
Biometeorology
Eddy Covariance
Carbon Exchange
Ecosystem Flux
Turkey Point
Data Management
Environmental Monitoring
Environmental Monitoring

abstract:
Modern advances in biometeorological monitoring technology have improved the capacity for measuring ecosystem exchanges of mass, energy and scalars (such as CO2). Translating these measurements into robust and accurate scientific information (and ultimately, understanding) requires careful assessment of operations throughout the biometeorological data life cycle. In response, this research analyzed and optimized aspects of data collection, management and filtering for an ecosystem exchange measurement program over an age-sequence of temperate white pine forests.

A comprehensive data workflow and management system (DWMS) was developed and implemented to support the entire data life cycle for all past, present and future measurement operations in our research group, and meet the needs of a collaborative, student-led data management environment. Best practices for biometeorological data management were introduced and used as standards to assess system performance.

Roving eddy covariance (rEC) systems were examined as a means of producing reliable time-integrated carbon exchange estimates at multiple sites, by rotating an EC system in a resource-mindful approach. When used with an optimal gap-filling model and rEC rotation schedule (2 sites with 15-day rotations), the results suggested its viability, as annual NEE estimate uncertainties ranged between 35 and 63% of the annual NEE flux magnitude at our study sites – even though approximately 70% of half-hours were filled.

Lastly, a data-driven approach was used to investigate the effects of different friction velocity and footprint filtering methods on time-integrated carbon exchange estimates at our fetch-limited forests. Though predicted flux source areas varied considerably between footprint models, our objective analyses identified the model (Kljun et al., 2004) and within-fetch requirement (80%) that optimized reliability and representativeness of carbon exchange estimates. Applying this footprint model decreased annual NEE by 31 to 129% (59 to 207 g C m-2 y-1) relative to no footprint application, and highlighted the importance of objective analyses of EC flux filtering methods.

abstract: Doctor of Philosophy (PhD)


title: MALDI MASS SPECTROMETRY BASED ASSAYS FOR SCREENING AMINOGLYCOSIDE KINASES

contributor:
Brennan, John D.
Capretta, Alfredo
Magarvey, N.
Chemistry and Chemical Biology

subject: small molecule screening

subject: aminoglycoside phosphotransferase

subject: sodium silicate

subject: sol-gel process

subject: automated screening

subject: Analytical Chemistry

subject: Materials Chemistry

subject: Analytical Chemistry

abstract: Aminoglycoside antibiotics are commonly used to treat bacterial infections but are highly susceptible to chemical modification, leading to resistance. Chemical modification can be hindered through the use of small molecule inhibitors that target bacterial enzymes involved in resistance, most notably kinases. Current methods for the discovery of small molecule inhibitors of kinases and related “kinase-like” enzymes are limited in throughput and utilize slow, tedious, and expensive assays. This thesis is focused on the development of highly versatile and scaleable kinase and “kinase-like” screening platforms for the discovery of small molecule inhibitors of these drug targets. The work begins with the validation of a matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS) platform utilizing phosphorylation of kanamycin, an aminoglycoside antibiotic, by aminoglycoside phosphotransferase 3ʹIIIa (APH 3ʹIIIa) as a model system. Using a product-to-substrate signal ratio as an internal standard, the assay was used to functionally screen over 200 compounds, combined into mixtures to enhance assay throughput. Moreover, the assay was used to determine inhibitory dissocation constants for newly discovered modulators. Throughput was further increased to a novel dual-kinase assay targeting a bacterial enzyme, APH 3ʹIIIa and a human kinase, protein kinase A (PKA), which was validated using the previous small molecule library. Alternative assay development platforms were also studied using imaging mass spectrometry of reaction microarrays and the fabrication of sol-gel derived bioaffinity chromatography columns. The MS-based kinase assays developed herein are highly amenable to high throughput screening, and have the potential to be extended to other important therapeutic targets.

abstract: Doctor of Philosophy (PhD)


title: Social Networks, Research Evidence, and Innovation in Health Policymaking in Burkina Faso

contributor:
Lavis, John N.
Abelson, Julia
Dion, Michelle
Health Policy

subject:
Health policy
social network analysis
knowledge translation
evidence-informed health policy
low-income country
policy network
Health Policy
Health Policy

abstract: This thesis was successfully defended on January 15, 2014 at McMaster University.

abstract: Understanding why policies change is an important pursuit for researchers and policy-makers alike. Research evidence is one of many possible factors that encourage or constrain policy change, as is the role of ‘networks’ of policy actors. Despite extensive empirical literature on each of evidence-informed health policy and policy networks, the two have rarely been studied together, particularly in low-income country policy environments. This thesis explores both of these variables in a broader structural context of institutions, interests and ideas. Concepts and approaches from social network analysis are applied to three distinct research questions and chapters with the objective to: 1) develop and test a conceptual framework for the integration of networks, institutions, interests and ideas as major variables explaining policy change; 2) test the relationship between policy network structure (closure and heterogeneity) on the use of research evidence and innovation across the three cases; and 3) model the factors that influence the formation of an evidence exchange relationship between policy actors, and the effect of those exchanges on actor-level use of research evidence. Taken together, the findings of this dissertation present persuasive support for adopting a network lens to study evidence-informed health policy and policy change.

abstract: Doctor of Philosophy (PhD)


title: Long-term Effects of Impoundment on Ecosystem Functions of Coastal Wetlands in Georgian Bay

contributor:
Chow-Fraser, Patricia
Waddington, James Michael
Biology

subject:
Laurentian Great Lakes
impounded coastal wetlands
Georgian Bay
aquatic macrophytes
fish
water levels
Biology
Environmental Health and Protection
Hydrology
Biology

abstract: Seasonal and annual water-level fluctuation is a primary mechanism that maintains high aquatic biodiversity in coastal marshes of the Laurentian Great Lakes by preventing formation of dense mono-cultures of emergent or submergent plants. The past 14 years of sustained low water levels in Georgian Bay (Lake Huron) have prompted proposals to impound coastal wetlands as a way to mitigate against desiccation. We hypothesize that a loss of hydrological connection with the Great Lakes would lead to altered water chemistry and an expansion of emergent vegetation at the expense of aquatic habitat. This could result in a fish community with reduced diversity which may positively impact the larval amphibian community. On the other hand, bird communities may respond with only short-term gains, and may not demonstrate long-term benefits without active management. We investigate how long-term severance of hydrological connection between coastal marshes and Georgian Bay affect ecosystem functions. We compare food web components of a chain of three coastal wetlands in Tadenac Bay that were sequentially impounded by beaver activities over the past 5 decades. We also surveyed the food web of Wye Marsh, which was impounded over 80 years ago, and compare it with that of Matchedash Bay, which had never been impounded. In both cases, there were negative impacts of impoundment on water chemistry, vegetation and fish communities. Bird communities showed no significant differences but larval amphibian diversity was greater in the beaver impoundments than in the hydrologically connected coastal wetland. Based on our results, we do not recommend impounding Georgian Bay wetlands as a means to restore and maintain water levels.

abstract: Master of Science (MSc)


title: Consumer Identity Theft Prevention And Identity Fraud Detection Behaviours: An Application Of The Theories Of Planned Behaviour And Protection Motivation

contributor:
Archer, Norman P.
Bontis, Nick
Detlor, Brian
Business

subject:
indentity theft
identity fraud
consumer behaviour
Management Information Systems
Management Information Systems

abstract: Consumer behaviour has and may increasingly have a vital role to play in protecting personal data. Understanding the behaviours of consumers in preventing identity theft and detecting identity fraud is therefore key to creating programs that minimize exposure and potential loss. In this study, based on the Theory of Planned Behaviour (TPB) and Protection Motivation Theory (PMT), an exploratory study elicited salient beliefs about identity theft prevention and detection behaviours. These beliefs were then used to create a survey to measure the strength of the salient beliefs, attitudes, intentions and behaviours, which was administered online and produced 351 valid responses. Statistical analysis was performed on eight behavioural groups, based primarily on principal component analysis of twelve behaviours. The groups were: using physical security, practicing password security, monitoring bank accounts and credit cards, getting a credit report, checking the land registry, using 'remember my password', clicking on a link in an e-mail, and giving out personal information over the phone. Results showed that beliefs with a significant influence on consumer intentions for a given behavioural group were a mix of beliefs about identity theft in general and beliefs about the behaviours in that group. While attitudes towards behaviours of consumers in any specific group had a significant influence on the intent to perform behaviours peculiar to that group, they had virtually no impact on the intent to perform behaviours in other groups. The intent to perform identity theft prevention and identity fraud detection behaviours uniformly had a statistically significant influence on actual reported behaviour, but much of the variance in behaviour was unexplained. An analysis of qualitative responses showed that gender, language and age all had significant impacts on respondents' likelihood of mentioning specific vulnerabilities, and prevention and detection measures.

abstract: Doctor of Philosophy (PhD)


title: Enhanced Ductility of Masonry Shear Walls Using Laterally Confined (Self-Reinforced) Concrete Block

contributor:
Tait, M.J.
Drysdale, R.G.
Civil Engineering

subject:
Concrete Block
Confinement
Ductility
Self-Reinforced
Shear Wall
Masonry
Civil Engineering
Structural Engineering
Civil Engineering

abstract: The aim of the study presented in this dissertation was to investigate a new method of improving the ductility of masonry shear walls by means of confinement. This proprietary method, referred to as Self-Reinforced Concrete Block (SR Block) employs a previously untried technique of molding lateral confining devices into concrete block. This internal reinforcement provides lateral confinement to the enclosed volume of block and grout material. The resulting triaxial state of compressive stress under axial load allows the confined material to maintain high compressive capacity while undergoing high axial compressive strains. The results from a proof-of-concept program indicated improved plasticity due to the presence of the confining devices within the block. Despite spalling of the unconfined portions of the block at high strains, the SR Block specimens retained load carrying capacities in excess of the peak capacity of similar unreinforced/unconfined block prisms at strains beyond 2% with no visible damage to the confining devices or to the confined material. Further to this proof-of-concept study, an experimental program was undertaken involving additional prism tests as well as testing of shear walls constructed with the SR Block. This program proved the efficacy of a second confining device design in enabling prisms to retain compressive load capacity to strains over six times larger than that of standard grouted masonry. Additionally, the results of the shear wall program indicated that these desirable characteristics were effective in a wall configuration and led to significant increases in the displacement ductility of the walls when compared to similar, unconfined walls. The data presented is expected to serve as a basis for future testing and acceptance of SR Block as a method of increasing the compressive strain capacity of reinforced masonry in order to improve the ductility of masonry shear walls as a lateral force resisting system.

abstract: Master of Applied Science (MASc)


title: Response of Two-Way Reinforced Masonry Infill Walls under Blast Loading

contributor:
Tait, M.J.
El-Dakhakhni, W.W.
Civil Engineering

subject:
Blast
Infill
Reinforced Masonry
Out-of-plane
SDOF
Two-Way
Civil Engineering
Structural Engineering
Civil Engineering

abstract: The increased public safety concerns to the consequences of deliberate and accidental explosions have led to the development of the Canadian (CSA S850- 12) and American (ASCE 59-11) blast standards. There is an urgent need to investigate and quantify the response of structural components under such extreme loading conditions. This is especially important for masonry components, where research has been limited due to the misconception that masonry (both reinforced and unreinforced) is an inadequate material for blast hardening applications. The standards allow the use of experimental testing or dynamic analysis in order to determine peak responses and evaluate them in terms of the code prescribed performance limits and accompanying levels of damage. The current study investigates the response of non-integral and non-participating infill walls designed to undergo two-way out-of-plane response and detailed to fail in flexure under static loading conditions. Through experimental blast testing and dynamic model validation of reduced-scale walls under a range of design-basis threat (DBT) levels, this study shows that reinforced masonry is a viable alternative for blast protection. However, the current flexural-based code requirements, thought to be conservative, may be inadequate at loads of higher impulse where shear damage is prevalent. This study also shows the influence that changing the boundary configuration and level of reinforcement has on the peak response, where the performance limits of the current codes makes no provisions for these parameters.

abstract: Master of Applied Science (MASc)


title: ACOUSTIC COMMUNICATION IN THE JOINT-NESTING SMOOTH-BILLED ANI, CROTOPHAGA ANI

contributor:
Quinn, James S.
Sigal Balshine, Ben Evans
Biology

subject:
aggressive signals
alarm signals
communication
cooperative breeding
Crotophaga ani
repertoire
Behavior and Ethology
Behavior and Ethology

abstract: I studied acoustic and visual communication in the Smooth-billed Ani, a joint-nesting, cooperatively breeding cuckoo. I describe vocal repertoire of this species using both qualitative and quantitative methods. In this first, formal description of the species’ repertoire, I provide verbal descriptions of each call type, the contexts in which each call is produced, spectrograms, and acoustic measurements for each call type. I used multivariate statistics to show that call types can be correctly classified based on acoustic measurements alone. Smooth-billed Anis are capable of complex communication, including the use of functionally referential alarms and signals of aggression that reliably predict attack. Functionally referential signals are produced in response to a specific set of stimuli and elicit predictable, appropriate responses in signal receivers, even in the absence of any other cues. I show that anis produce two distinct signal types, chlurps and ahnee alarms, in response to two different predator classes, aerial and terrestrial, respectively. I also show that receiver responses to playback of these alarm signals are distinct and appropriate to evade predation from aerial and terrestrial attackers. Aggressive signals should increase in aggressive contexts, predict subsequent aggression and elicit responses from signal receivers. I show that hoots, an acoustic signal, and throat inflation, a visual signal, both increase in aggressive contexts and reliably predict aggressive escalation in the form of direct attacks on a mount. The receiver response to hoots and throat inflation remains to be tested. In the synthesis, I provide suggestions for future research.

abstract: Master of Science (MSc)


title: Developing a model for intestinal ammonia handling in rainbow trout

contributor:
Wood, Chris M.
Biology

subject:
ammonia
intestine
sodium
NKCC
ammonia transport
fish
Biology
Cellular and Molecular Physiology
Comparative and Evolutionary Physiology
Systems and Integrative Physiology
Biology

abstract:
Ammonia is the primary nitrogenous waste product in teleost fish, which is produced primarily through protein metabolism. Fish experience natural elevations in internal ammonia loads, including during digestion where luminal ammonia concentrations in the intestine rise substantially. Furthermore, the intestine may absorb a portion of this ammonia, despite it being toxic to the fish. Based on this, in vitro techniques were employed in order to develop a model for teleost intestinal ammonia handling.

Ammonia absorption and endogenous ammonia production occur along the entire length of the intestine. However, section-specific differences exist in terms of both endogenously produced ammonia and ammonia flux rates, with the highest rates in the anterior and mid intestine. Feeding stimulated an increase in production rates in all intestinal sections. Overall, ammonia originating from the gut may account for up to 42% of post-prandial whole-fish ammonia excretion. This could partly be attributed to the increased activity of the ammonia-producing enzyme glutamate dehydrogenase, and decreased activity of the ammonia-fixing glutamine synthetase. Furthermore, gut tissue ammonia concentrations surpassed typical chyme concentrations and were well regulated independent of high luminal ammonia, suggesting active transport across the intestinal epithelium.

Seawater (60%) acclimation caused no substantial changes in the ammonia handling properties of the intestine. Ammonia transport in the intestine of both freshwater and seawater trout appears to occur via active means, coupled to Na+/K+ ATPase activity. Specifically, this involves Na+ linked transport through substitution of NH4+ for K+ on the apical Na+/K+/2Cl- co-transporter occurring predominantly in the anterior and mid intestine, and solvent drag through fluid transport (osmotically driven by active NaCl absorption) in all sections. Additionally, Rhesus glycoprotein mediated ammonia transport likely occurs through basolateral Rhbg1, supporting previous molecular evidence. Overall this thesis illuminates the quantitative importance and mechanisms of gut ammonia transport in fish, and highlights future research avenues.

abstract: Master of Science (MSc)


title: Generating Learning Algorithms: Hidden Markov Models as a Case Study

contributor:
Carette, Jacques
Software Engineering

subject:
code generation
hidden markov models
domain specific languages
machine learning
bayesian statistics
Other Engineering
Other Engineering

abstract:
This thesis presents the design and implementation of a source code generator for dealing with Bayesian statistics. The specific focus of this case study is to produce usable source code for handling Hidden Markov Models (HMMs) from a Domain Specific Language (DSL).

Domain specific languages are used to allow domain experts to design their source code from the perspective of the problem domain. The goal of designing in such a way is to increase the development productivity without requiring extensive programming knowledge.

abstract: Master of Applied Science (MASc)


title: Molecular dynamics (MD) simulation study of low angle grain boundary (LAGB) mobility in pure Al and Al-Mg alloys

contributor:
Hoyt, Jeffrey J.
Zurob, Hatem S.
Purdy, Gary R.
Materials Science and Engineering

subject: Pure Aluminum

subject: Solute pinning

subject: Al-Mg alloys

subject: Dislocation pinning

subject: Grain boundary motion

subject: Molecular dynamics (MD) simulation

subject: Artificial driving force (ADF) technique

subject: Recovery kinetics

subject: Microstructure-property relationship

subject: Materials Science and Engineering

subject: Materials Science and Engineering

abstract:
Low angle grain boundary (LAGB) mobility is an essential parameter for developing the analytical models that describe the kinetics of recovery and predict the nucleation of recrystallized grains. The thesis is aimed at the molecular dynamics (MD) simulations study of LAGB mobility determination in pure Al and Al-Mg alloys. All the previous experimental studies reported that the presence of several defects, such as solutes and dislocations, retard the boundary motion and provide lower mobility. However, very few studies have been conducted in MD simulation to capture the interactions of those defects with the migrating grain boundary. This thesis is focused on providing complete understanding of LAGB determination along with a comprehensive explanation of solute and dislocation retarding effects on boundary motion.

The LAGB mobility in pure Al was computed from two different MD techniques as a function of temperature and misorientation. Within numerical uncertainties, both techniques provide the same magnitude of mobility at 300K for 7.785o boundary and at 700K for 23.07o boundary. It was observed that ADF method is not applicable to determine LAGB mobility at high temperature due to failure of order parameter computation. The MD derived activation energy is found to be approximately ten times lower than the experimental observations.

A strong solute pinning effect on boundary motion was observed at all misorientations and solute concentrations studied in Al-Mg alloys. An approximate linear relationship is found between the restraining force and the solute concentration in a distributed solute approach. In addition, the extrinsic dislocations are found to completely pin both 7.785o and 23.07o boundary motion at low driving forces in pure Al at 300K. The MD results do not reveal significant qualitative differences of the pinned boundary structure for the low and high angle boundaries and will be discussed in terms of the previous experimental observations.

abstract: Doctor of Philosophy (PhD)


title: Effects of the Physical Environment During Maturation on Subsequent Reactivity to Visual Stimulation in Mongolian Gerbils (Meriones unguiculatus)

contributor:
Galef, B. G.
Psychology

subject: Psychology Psychology

abstract:
Mongolian gerbils (Meriones unguiculatus) living in their natural habitat flee to their burrows and footthump in response to the appearance of humans, while conspecific individuals reared in open-laboratory cages approach and investigate humans attempting to handle them. The present series of investigations was undertaken to determine the role of the differences in the physical rearing environment of laboratory- and wild-born gerbils in the development of their response to the visual stimuli provided by humans.

A testing procedure was developed to quantify the response of gerbils to the sudden presentation of a human-like visual stimulus and the behaviour of gerbils reared under a variety of conditions assessed in this test situation. It was found that gerbils reared in the laboratory, in gerbil-constructed tunnel systems, responded to the sudden presentation of human-like visual stimulus by fleeing to shelter, footthumping and remaining concealed for long periods, while many gerbils reared in open-cages responded to presentation of the stimulus by approaching and visually fixating it.

Analysis of the features of the tunnel environment responsible for the potentiation of the flight and concealment response in tunnel-reared animals revealed that the critical factor in tunnel-rearing was the provision of shelter during maturation. Neither the isolation from illumination nor the isolation from stimuli associated with human handlers, resulting from rearing in a tunnel, was responsible for the observed effects of tunnel-rearing. The experience of moving in and out of cover, provided by rearing in environments having shelter available, appeared to potentiate the flight and concealment response.

Observation of behaviour in a second situation measuring reactivity, that is willingness to descend from the centerboard of a visual-cliff, revealed that the effects of rearing with shelter available were not restricted to situations involving flight to shelter in response to sudden visual stimulation. Willingness to descend from the centerboard was markedly increased by rearing in environments providing shelter.

It was further found that even a relatively brief exposure to an environment providing opportunity for flight and concealment was sufficient to potentiate the entire behavioural syndrome in open-reared gerbils. Gerbils reared in normal laboratory cages would exhibit the pattern of flight and concealment in response to sudden stimulation, normally observed in tunnel-reared gerbils, if they were places in a tunnel system for 24 hours. However, behaviour of tunnel-reared gerbils was not affected by 24-hour exposure in an open-cage.

Taken together, the results of the present experiments suggest that the syndrome of reactive behaviour exhibited by wild, as compared with laboratory-reared, gerbils is the result of differences in the physical environment in which they are reared. Experience of a sheltered area early in life, for either brief or extended periods, is sufficient to potentiate reactive behaviour in gerbils at maturity.

abstract: Doctor of Philosophy (PhD)


title: GPU-based Parallel Computing for Nonlinear Finite Element Deformation Analysis

contributor:
Sirouspour, Shahin
Electrical and Computer Engineering

subject: Parallel Computing

subject: total Lagrangian

subject: Nonlinear Finite Element

subject: Real-time

subject: Surgical Simulation

subject: GPGPU

subject: Biomedical

subject: Numerical Analysis and Scientific Computing

subject: Biomedical

abstract:
Computer-based surgical simulation and non-rigid medical image registration in image-guided interventions are examples of applications that would benefit from real-time deformation simulation of soft tissues. The physics of deformation for biological soft-tissue is best described by nonlinear continuum mechanics-based models which then can be discretized by the Finite Element Method (FEM) for a numerical solution. Computational complexity of nonlinear FEM-based models has limited their use in real-time applications. The data-parallel nature and intense arithmetic operations in nonlinear FEM models are suitable for massive parallelization of the computations, in order to meet the response time requirements in such applications.

This thesis is concerned with computational aspects of complex nonlinear deformation analysis problems with an emphasis on the speed of response using a parallel computing philosophy. It proposes a fast, accurate and scalable Graphic Processing Unit (GPU)-based implementation of the total Lagrangian FEM using implicit time integration for dynamic nonlinear deformation analysis. This is a general formulation valid for large deformations and strains and can account for material nonlinearities. A penalty method is used to satisfy the physical boundary constraints due to contact between deformable objects. The proposed set of optimized GPU kernels for computing the FEM matrices achieves more than 100 GFLOPS on a GTX 470 GPU device. The use of a novel vector assembly kernel and memory optimization strategies result in a performance gain of up to 25 GFLOPS in the PCG computations.

abstract: Doctor of Philosophy (PhD)


title: Statistical Phylogenetic Models for the Inference of Functionally Important Regions in Proteins

contributor:
Golding, Brian G.
Evans, Ben J.
Xu, Jianping
Biology

subject:
Phylogenetics
Bayesian Model
Protein Function
Statistics
Bioinformatics
Bioinformatics

abstract: An important question in biology is the identification of functionally important sites and regions in proteins. A variety of statistical phylogenetic models have been developed to predict functionally important protein sites, e.g. ligand binding sites or protein-protein interaction interfaces, by comparing sequences from different species. However, most of the existing methods ignore the spatial clustering of functionally important sites in protein tertiary/primary structures, which significantly reduces their power to identify functionally important regions in proteins. In this thesis, we present several new statistical phylogenetic models for inferring functionally important protein regions in which Gaussian processes or hidden Markov models are used as prior distributions to model the spatial correlation of evolutionary patterns in protein tertiary/ primary structures. Both simulation studies and empirical data analyses suggest that these new models outperform classic phylogenetic models. Therefore, these new models may be useful tools for extracting functional insights from protein sequences and for guiding mutagenesis experiments. Furthermore, the new methodologies developed in these models may also be used in the development of new statistical models to answer other important questions in phylogenetics and molecular evolution.

abstract: Doctor of Philosophy (PhD)


title: Understanding The Blogging Practices Of Women Undergoing In Vitro Fertilization For Treatment Of Infertility

contributor:
Jack, Susan
Sword, Wendy
Nursing

subject:
In Vitro Fertilization
Infertility
Blogs
Blogging Practices
Discourse Analysis
Nursing
Nursing

abstract: The experience of infertility and its associated treatments, including in vitro fertilization (IVF), can have a profound impact on the emotional health and well-being of women desiring to become mothers. While researchers have measured the impact of infertility or described the experience and processes related to infertility and its treatment, what remained to be explored was a virtually pre-packaged collection of rich descriptions of the IVF experience as captured in women’s blogs. This discourse analysis sought to describe the blogging practices of women undergoing IVF for treatment of infertility, exploring both the content and function of the IVF blog discourse. Data were collected from the text of seven women’s blogs and resulted in four main functions of the discourse: creation of and connection to a community, emotional support, blogging as therapy, and creation of an IVF resource. Findings suggest that blogging can have a positive impact on the psychosocial consequences experienced by women in fertility treatment. Findings of this study also have methodological implications for researchers considering blogs as a data source in qualitative research.

abstract: Master of Science in Nursing (MSN)


title: Life Goes On: An Exploration into the Experience of Community Reintegration for Working-aged Persons Post-Stroke

contributor:
Richardson, Julie
Wilkins, Seanne
Letts, Lori
Rehabilitation Science

subject:
Stroke
Community Reintegration
Working-aged
Qualitative
Rehabilitation and Therapy
Rehabilitation and Therapy

abstract:
Since 2004, there has been a 12% relative increase in stroke prevalence in the working-aged (18–65 years) population of Ontario. Studies have shown that successful community reintegration is an important indicator of perceived quality of life post-stroke.

The purpose of this interpretive phenomenological study was to explore the lived experience of community reintegration for working-aged persons post-stroke in order to inform the development of appropriate and effective strategies to support their community reintegration and continued stroke recovery.

The essence of the phenomenon of community reintegration for working-aged persons post-stroke emerged as: “Life Goes On: The journey of surviving a stroke in the prime of your life”. Six themes emerged to support this journey of community reintegration after stroke: 1) processing the shock, 2) starting the road to recovery, 3) living with stroke, 4) who am I? 5) carrying-on and 6) transcending the stroke. While participants experienced their personal journey to community reintegration in a unique way, their journey led them to realize that in order to successfully reintegrate back into their community, they needed to adjust, adapt and reach some level of acceptance in order to move on and essentially transcend their stroke

There needs to be a call to action for the delivery of client-centered stroke care. A client centered approach to stroke care will ensure that the voices of working-aged persons post-stroke are heard and given priority in their rehabilitation and community reintegration planning.

abstract: Master of Science Rehabilitation Science (MSc)


title: Mammoth phylogeography south of the ice: large-scale sequencing of degraded DNA from temperate deposits

contributor:
Poinar, Hendrik
Biology

subject:
Mammoths
ancient DNA
high-throughput sequencing
targeted enrichment
Biological and Physical Anthropology
Biology
Biological and Physical Anthropology

abstract: Mammoths (Mammuthus) have been studied extensively at the genetic level. However due to both taphonomic and technological limitations, only one of several late Pleistocene mammoth species, the woolly mammoth (M. primigenius), has been investigated. This limits our impression of mammoth population history to the the northern latitudes, just one of several environments in which mammoths lived and went extinct. It also obscures their evolutionary chronology, which prevents proper climatic and biogeographic contextualization of their history. Fortunately recent technological advances in high-throughput sequencing and targeted enrichment promise to expand Pleistocene faunal population phylogeography to non-permafrost, non-cave burial contexts. However the capacity and behavior of these combined technologies for characterizing ancient DNA is largely unexplored, preventing efficient and routine use for population-level studies. In this thesis I test and apply these technologies to remains of mammoth species from throughout North America. I first demonstrate their potential for poorly-preserved DNA, and then I evaluate their efficient application to large sample sets, as well as for capturing complete nuclear genomes. I then use these technologies to sequence dozens of mitochondrial genomes from Columbian (M. columbi) and other non-woolly mammoths, reconstructing their matrilineal phylogeography south of the ice. The revealed patterns not only imply a deep chronology for mammoth matrilineal diversity, but also that North American mammoth evolution was occurred via separate episodes of interbreeding between resident and invading populations, and between ecotypes. Overall the biological and methodological discoveries afforded by this body of work outline future research avenues on mammoth evolution, behavior, and extinction.

abstract: Doctor of Philosophy (PhD)


title: Thermal habitat utilization by northern pike (Esox lucius) in Tadenac Bay, Georgian Bay, Ontario, Canada

contributor:
Chow-Fraser, Patricia
Biology

abstract:
The northern pike (Esox lucius) is a recreationally and ecologically important top predator fish in the Laurentian Great Lakes, where there are still naturally reproducing populations, especially in the relatively undisturbed eastern arm of Lake Huron, Georgian Bay. I conducted a two-year study in a relatively pristine embayment, Tadenac Bay, located in eastern Georgian Bay to determine 1) how thermal habitat suitability changes both seasonally and annually and 2) how radio-tagged northern pike utilize different thermal habitats. During May and June in both years, water temperatures throughout the water column were favourable (13-21°C) for growth of northern pike adults, but during July and August, the surface to 5m was often above favourable temperatures. Yet in both years, during the middle of July (week 30), individual fish were tracked to areas with temperatures >27°C. During the warmer year (2011), the larger females used significantly deeper habitat (2.89±0.46m SE, n=9) than the smaller males (1.93±0.17m, SE, n=27) (one tailed t-test, t(45)=-2.00, p=0.035). During the cooler year (2012), females used deeper habitat (3.60±0.84m SE, n= 8) compared to males (2.45±0.32m, SE, n= 15) but the means were not statistically significant.

A comparison of mean annual water levels of Georgian Bay with variation in global mean surface temperature show that the warmest years to date coincided with sustained low water levels in Georgian Bay since 1999. Global circulation models predict that these warming trends will continue and will lead to further reductions in water levels. Based on a bathymetric model for Tadenac Bay, a drop in water level of 1 m from current levels (2012) would result in 18% loss of existing habitat. The approach used in this study can be applied to other regions of Georgian Bay to quantify current and projected thermal habitat for northern pike.

abstract: Master of Science (MSc)


title: CHARACTERIZATION OF INHERENT AND INDUCED ANISOTROPY IN GRANULAR MATERIALS

contributor:
Pietruszczak, S.
Razaqpur, G. A.
Civil Engineering

subject:
Granular materials
Constitutive model
Microstructure
Evolution law
Discrete Elements
Geotechnical Engineering
Geotechnical Engineering

abstract:
The main aim of this PhD dissertation is to investigate the inherent and induced anisotropy in granular materials. The study includes both the experimental and theoretical aspects and provides a methodology for characterizing the mechanical response of granular materials that display anisotropy.

The content of this thesis is divided into two main parts. The first part is focused on investigating the mechanical properties of materials with inherent anisotropy. In particular, an experimental program designed to investigate the mechanical properties of Ottawa standard sand (C109), with inherent anisotropy that is generated by the initial densification process, is described. The program involves a series of direct shear as well as triaxial axial tests. Its primary objective is to demonstrate that anisotropy may occur in sands that have nearly spherical particles (i.e. are typically considered as isotropic) provided the distribution of pore space has a preferred orientation due to the initial densification process. Following the experimental part, the mathematical formulation based on the Critical Plane Approach (CPA) is presented for describing anisotropic mechanical behavior of the material. The procedure for identification of parameters embedded in the constitutive model is outlined and an extensive numerical analysis is conducted simulating the experimental tests.

The second part of this thesis deals with induced anisotropy and its focus is on developing an evolution law for the fabric of particulate materials as a function of continuing deformation. The microstructure descriptors are based on lineal intercept measurements and include the areal porosity and the mean intercept length distribution. The methodology involves performing a series of Discrete Element simulations for a granular assembly under evolving directions of the principal stress/strain and defining a correlation with the evolution of material axes. It is demonstrated that granular materials with spherical particles may become anisotropic due to the initial compaction process and that the induced anisotropy is characterized by the coaxiality between the microstructure and the total strain tensors. The proposed evolution law is incorporated into the constitutive framework for anisotropic materials, as discussed in the first part, and some numerical simulations are conducted. It is demonstrated that the proposed approach can describe, at least in a qualitative manner, several manifestations of induced anisotropy in granular materials.

abstract: Doctor of Philosophy (PhD)


title: Downlink Trafﬁc Scheduling in Green Vehicular Roadside Infrastructure

contributor:
Todd, Terence D.
Dongmei Zhao, Ted Szymanksi
Electrical and Computer Engineering

subject:
ITS
VANET
Vehicular
Green
Scheduling
RSU
Electrical and Electronics
Power and Energy
Systems and Communications
Electrical and Electronics

abstract: This thesis proposes different scheduling algorithm to be implemented on the Roadside Units in ITS environment. Both variable and constant bit rate cases are considered.

abstract:
Vehicular Ad-hoc Networks (VANETs) will be an integral part of future Intelligent Trans- portation Systems (ITS). In highway settings where electrical power connections may not be available, road-side infrastructure will often be powered by renewable energy sources, such as solar power. For this reason, energy efficient designs are desirable.

This thesis considers the problem of energy efficient downlink scheduling for road- side infrastructure. In the ﬁrst part of the thesis, the constant bit rate (CBR) air interface case is investigated. Packet-based and timeslot-based scheduling models for the theoretical minimum energy bound are considered. Timeslot-based scheduling is then formulated as a Mixed Integer Linear Program (MILP). Following this, three energy efficient online scheduling algorithms with varying complexity are introduced. Results from a variety of experiments show that the proposed scheduling algorithms perform well when compared to the energy lower bounds.

In the second part of the thesis, the variable bit rate (VBR) air interface option is considered. Ofﬂine scheduling formulations are derived that provide lower bounds on the energy required to fufill vehicle requests. An integer linear program (ILP) is introduced which can be solved to ﬁnd optimal ofﬂine VBR schedules. Two ﬂow graph based models are then introduced. The ﬁrst uses Generalized Flow (GF) graphs and the second uses time expanded graphs (TEGs) to model the scheduling problem. Four online scheduling algorithms with varying energy efficiency, fairness and computational complexities are developed. The proposed algorithms’ performance is examined under different traffic scenarios and they are found to perform well compared to the lower bound.

abstract: Doctor of Philosophy (PhD)


title: Study of the Regulation of Nitrite reductase in Neurospora crassa.

contributor:
Sorger, G.J.
Biology

subject: Biology Biology

abstract:
Two nitrite reductase activities were identified in crude extracts of wild type Neurospora exposed to nitrate ions: a first one catalyzes the stoichiometric reduction of nitrate to ammonia (AP); a second causes the disappearance of nitrite to something other than ammonia (ND). The second activity (ND) which is present in all strains under all conditions, was isolated by ultra-filtration through a collodion membrane or by precipitation with 50% acetone. This activity could account for the difference between the nitrite reduction and ammonia production catalyzed by crude extracts of fully induced wild type mycelia. The properties of the ND component were studied by examining the effect of organic solvents, proteases, sulfhydryl reagents, metal-complexing agents and temperature on its activity. The AP activity which is inducible by nitrate or nitrite and is present only in nitrite-utilizing strains, was deduced from a comparison of nitrite non-utilizing mutants and the wild type strain to be the assimilatory enzyme.

Nitrate was found to induce the assimilatory nitrite reductase directly. Four different approaches were employed to show this: a study of the kinetics of induction of nitrate - and nitrate reductase; an examination of the induction of nitrate reductase by nitrate in the presence of tungstate or in the presence of ammonium ions; a comparison of the induction of nitrite reductase by nitrate in nitrate reductaseless mutants and in the Wild type strain. Active nitrate reductase does not appear to be necessary for the induction of nitrite reductase by nitrate as suggested by Cove and Pateman (7). The nitrite reductase apoprotein, on the other hand, seems to be involved in the induction of the assimilatory nitrite reductase.

Ammonium ions repressed the induction of the assimilatory nitrite reductase by nitrate. This repressive effect was an indirect one; ammonium ions had to be metabolized first in order to repress nitrate reductase. This was shown by the lack of repression in strain am-la, a glutamate dehydrogenaseless strain.

A model is proposed to describe the possible mechanism of induction and repression of nitrite reductase in Neurospora crassa.

abstract: Doctor of Philosophy (PhD)


title: COMPARISON OF METHODS FOR DETECTION OF ARSENIC IN SKIN USING XRF

contributor:
McNeill, Fiona
Fleming, David
Chettle, David
Medical Physics

subject:
X-Ray Fluorescence
arsenic
skin
dosimetry
handheld XRF
x-ray spectrometry
Other Physics
Other Physics

abstract:
Arsenic (As) is an element that is well known for its toxic capabilities. It is odorless and colorless and is known to contaminate the drinking water of populations in several parts of the world. Routine monitoring of arsenic exposure is usually performed with urine, hair or nail, where samples are collected for laboratory analysis. Arsenic’s strong affinity to keratin rich tissues make skin another possible measurement site, in addition to the latter two tissues mentioned above. In some cases, skin samples are extracted for analysis. This is painful and invasive and is not ideal for in vivo monitoring of arsenic. The ability to quantify elemental concentration non-destructively is the major calling card of x-ray fluorescence (XRF). To that end, work was started on development of XRF detection systems for arsenic. The technique has shown promise for other elements and dramatic improvements in As detection capabilities were previously found when going from a radioisotope-based x-ray source to an x-ray tube based approach.

This thesis documents the comparison of three x-ray tube based detection systems intended for the measurement of arsenic in skin. Two benchtop systems were used, with a) extended development of the previously assembled system and b) the first use of a separate detection system. Two handheld x-ray analyzers (portable detection systems) were also investigated in stand mode, where they were attached to a purpose-built mounting stand, provided by the manufacturer, during all analysis. Polyester resin phantoms were used to model arsenic in skin and a nylon backing was used to represent as bulk tissue behind skin. During the course of the work, modifications were made to the laboratory setup associated with the benchtop approaches.

A benchtop polychromatic Mo anode x-ray tube based x-ray fluorescence (XRF) detection system was the first system used in this work. Through modifications to the existing design of the system, the lowest minimum detection limit (MDL) achievable was found to be (0.611±0.001) ppm normalized to gross scatter, where ppm is ug of arsenic per gram of dry weight (resin). The measurement time was ~1800 seconds real time. The equivalent (skin) and whole body effective doses delivered were (19±3) uSv and (163±47) uSv respectively. The corresponding direct (un-normalized) MDL was (0.499±0.002) ppm, in agreement with that found previously. Modifications to the system allowed a reduction in the localized effective dose delivered, to achieve this MDL, from (0.64±0.03) uSv previously to (0.14±0.04) uSv here.

Next, the current work investigated two handheld x-ray analyzers provided by InnovX. A PiN diode detector based Alpha 4000S model unit (W anode x-ray tube) and a Silicon Drift Detector (SDD) based Delta model (Au anode x-ray tube). Both units were operated in benchtop mode: they were mounted in a stand and a phantom was placed on a kapton exit window. The lowest gross-scatter normalized and direct detection limit with the Alpha 4000S unit was (1.649±0.002) ppm and (1.651±0.002) ppm respectively. The equivalent and whole body effective doses delivered were found to be (9.4±2.2) mSv and (94±22) uSv respectively. The localized effective dose was (6.4±1.5) X 10-3 uSv. By comparison, the Delta unit produced a gross-scatter and direct normalized detection limit of (0.570±0.002) ppm and (0.558±0.002) ppm respectively. The equivalent dose delivered was found to be (19.0±9.0) mSv. The corresponding localized and whole body effective doses delivered were (9.7±4.6) X 10-3 uSv and (190±90) uSv respectively.

The last system used in the current research was a monochromatic Ag anode x-ray tube based XRF setup. A doubly curved crystal (DCC) was used to select the Ag K-alpha line and focused the beam to a spot size of mm2 at the focal length. The phantoms were placed at a farther distance where the beam had expanded to a larger area. The lowest Compton scatter normalized detection limit with the Si(Li) detector was found to be (0.696±0.002) ppm. After characterizing its performance in a range of energies, a silicon drift detector was also used on this system. It had the benefit of higher throughput capabilities and superior resolution. The housing of the detector was sufficiently small that it could be placed closer to the phantom surface than the Si(Li) detector. The lowest Compton-scatter normalized detection limit with the SDD was (0.441±0.003) ppm in 1800 seconds real time. The equivalent dose was found to be (11±2) mSv and the localized and whole body effective doses were found to be (3.92±0.87) X 10-3 uSv and (110±23) uSv respectively. A significantly lower system dead time was observed with the SDD. Finally, Monte Carlo simulations of the system were performed to evaluate the performance of three ratios when their phantom measurement values were compared against simulations of skin. Results were found to be in agreement to withinin vivo concentration of arsenic in skin (ICRP).

Finally, EDXRF measurements were performed on bulk cores of skin, ex vivo. While it was not possible to detect arsenic in the samples, due to the samples being collected from members of the public as opposed to an exposed population, a depth profile of numerous skin samples, starting from the surface and running straight down, was obtained for calcium, iron and copper.

abstract: Doctor of Philosophy (PhD)


title: Truth and Non-Existence in Aristotle

contributor:
Johnstone, Mark
Hitchcock, David
W., Richard T.
Philosophy

subject: Aristotle; Metaphysics; Language; Logic; Mind

subject: History of Philosophy

subject: History of Philosophy

abstract: This work critically examines Aristotle’s statements regarding truth in relation to what does not exist, and defends a cohesive interpretation of Aristotle on truth and non-existence against contemporary commentators. Aristotle speaks of what does not exist in various contexts within his works, and questions about things that don’t exist arise at every level of the structure of reality Aristotle lays down in Chapter One of De Interpretatione. Aristotle refers to things, affections of the soul, and statements as truth-bearing. However, the ways in which each is said to be true or false suggests that Aristotle applied the notion of “truth” more strictly at some times than at others. In the following chapters I examine what Aristotle conceives of as non-existent; how it is possible to speak about these things; the apparent contradiction between the Categories and De Interpretatione regarding what is true to say of what does not exist; how fictional entities are conceived and to what exactly it is that words that signify the fictional refer; Aristotle’s correspondence theory of truth with regard to what does not exist; the definition of truth as applied to non-standard truth-bearers (objects, perceptions and phantasia); and how Aristotle avoids the contemporary problem of “empty” terms. This work, as a whole, finds a great amount of complexity in Aristotle’s concept of truth, evidenced by his accounting for what does not exist. What does not exist does not in fact cause much trouble for Aristotle, either with respect to how they are objects of thought, or with respect to the utterances that can be made about them, or with respect to the truth of those utterances.

abstract: Doctor of Philosophy (PhD)


title: Stuck in the Impasse: Cynicism as Neoliberal Affect

contributor:
O`Brien, Susie
O`Connor, Mary
York, Lorraine
English and Cultural Studies

subject:
affect
agency
subjectivity
American Dream
cruel optimism
ugly feelings
American Popular Culture
Critical and Cultural Studies
Film and Media Studies
Literature in English, North America
American Popular Culture

abstract: Recent work in affect theory has addressed the category of what Sianne Ngai terms “ugly” feelings (Ngai 2007, Edelman 2004, Halberstam 2011) and the costs associated with the premium placed on so-called positive modes of thinking and feeling (Berlant 2011, Ahmed 2010, Love 2007), yet cynicism persists in many accounts as the feature of an undesirable political subjectivity. Likewise in popular and political discourse, cynicism is denounced as the mark of an ineffectual subject who chooses to opt out, rather than reach for supposedly obvious markers of (capitalist) achievement. This dissertation refuses these characterizations, instead considering cynicism as an affect bound up in neoliberal sociopolitical shifts. I argue that cynicism describes a feeling of living under structural conditions that curtail—in ways that are often effaced—the kinds of self-determining subjectivities that have been taken for granted as a feature of Western, liberal democracies and remain foundational to imagined modes of dissent. Exploring this situation in the context of three cultural frames—politics and governance, modes of labour in capitalist economies, and a structure of feeling premised on the pursuit of happiness—I examine cynical subjectivities in fiction, film, and American political discourse so as to 1) develop an inquiry into affect as situated between subject and structure; 2) acknowledge the commonality of a feeling of impasse and dominant cultural narratives that mask this frustration of agency; and 3) consider inertia and passivity as sensible orientations in a cultural moment in which the costs of momentum are becoming increasingly visible.

abstract: Doctor of Philosophy (PhD)


title: Modeling particle-particle and particle-wall interactions in liquid-particle flows in complex geometries

contributor:
Hrymak, Andrew N.
Michael Thompson, Maryline Lightstone
Chemical Engineering

subject:
coupled particle fluid flows
numerical simulation
discrete element method
particle-fluid interactions
complex geometries
free surface flows
Other Chemical Engineering
Other Chemical Engineering

abstract:
Many practical fluid flows involve liquid-particle systems and so there is a need to better understand the mechanism of particle deposition, adhesion, and agglomeration in suspensions, especially in complex geometries with moving boundaries and free surfaces. In this thesis, the nature of the particle-solid interactions and particle-fluid interactions is studied where the above complexities are present, taking into account particle collision, colloidal, and hydrodynamic forces, and two way coupling between the fluid flow and particles. The research is motivated by the industrial examples of: flow of dross particles near the sink roll surface in a galvanizing bath (moving surface), and the flow of particles in slot coating dies (free and moving surfaces). Particle motion and agglomeration play important roles in the example systems chosen for this fundamental 3-D study. Numerical studies of flow of dispersed suspensions makes it possible to understand the effects of flow conditions, particle characteristics, and flow geometry specifications that lead to agglomeration of particles in complex systems, especially where experimental studies are difficult to perform. Often the effects of these conditions are discovered due to process or product failures, rather than through insight into the processing steps.

The modeling methodology used in this work is that micron sized spherical particles are tracked in the fluid phase by solution of Newton`s second law of motion for each particle. Fluid phase applies hydrodynamic forces on particles (drag, lift). Body forces, (soft sphere) particle-particle collisions and particle-wall collisions are considered. Particle concentrations are in the dilute regime between 0.01-5%vol. Flow of particles with the fluid phase is a fully coupled formulation in systems with particle concentrations > 1%vol.

The thesis is organized around three example problems taken from industry that pose challenging modeling issues. The first involves particle collisions with a moving wall (dross particles in a zinc bath). The second problem includes particle-particle and particle-wall collisions in a turning flow geometry. The third problem, particle dispersion flows in a slot coating die, has the most complexity and includes particle-particle, particle-wall and free surfaces.

Dross particle build up on the sink roll inside the zinc bath is an industrial problem that causes significant down time, and where an experimental study of the molten zinc in a bath running at C is difficult to perform. With the aid of computational fluid dynamics, turbulent flow of molten zinc in galvanizing bath is simulated, compared with previous cold model experiments, and coupled with the motion of dross particles around the sink roll. The presence of fixed position hardware and moving sink roll and guide rolls in a bath with dimensions in the orders of meters, and micron sized (20-100 ) dross particles makes this case a complex study. Drag, buoyancy, lift force and soft sphere nonlinear collision is considered in solution of Newton`s law of motion for each particle. Turbulent flow is simulated using a standard model. Simulations show regions on the sink roll where particles are dragged toward the surface of sink roll and have long residence times. These regions have been reported to experience large particle build-ups in the hot-dip galvanizing process.

In another study, formation and breakage of agglomerates in a turning flow is studied. Neutrally buoyant particles with concentration of 5%vol are tracked in a fully coupled flow. Particles form agglomerates at the corner, where drag and lift force from the fluid breaks a number of agglomerates. The presence of a moving wall in the turning flow shifts the suspended particle formations toward the inside of channel. Location of particles agglomerates shifts toward the free surface with the presence of free surface at the turning flow.

Motion of micron sized spherical particles with 1-4%vol through a slot die coating system is elucidated in a separate study. The system is complex with presence of moving web and free surface. Discrete element method (DEM) for motion of dispersed phase and volume of fluid (VOF) method for solution of continuous phase are integrated in a simulation study. Particles are 2-4 and the flow dimensions of the system are in the order of 100 . Particles experience collision, colloidal and hydrodynamic forces. Coupling between flow of particles and fluid phase is conducted. The results of this study show particle positions on the coating film can be predefined and depends on their initial positions within the feed slot. Particles agglomerate in recirculating regions of the coating gap and follow the streamlines of flow on the moving web. Regions in the coating gap where particles have high residence times (inside the die and near the feed slot edges) have particle agglomerations in the slot die coating system.

abstract: Doctor of Philosophy (PhD)


title: A Study of Integrated Structural Control Systems for Multi-Hazard Response Mitigation

contributor:
Tait, Michael J.
Civil Engineering

abstract: Dynamic Vibration Absorbers (DVA), including Tuned Mass Dampers (TLD) and Tuned Liquid Dampers (TLD) have been successfully employed to reduce excessive wind-induced resonant vibration motions in flexible structures. A limited number of studies have focused on utilizing TMDs in base isolated structures to reduce resonant motions resulting from multi-hazards (both wind and seismic excitation). A recent study has investigated the wind-induced response of a base isolated (BI) structure with a TLD under wind loading, however, its response under seismic excitation was not considered. The focus of this research was on the behaviour of coupled passive structural control base isolation systems under base excitation with particular attention on a BI-building-TLD. A series of shake table tests were conducted on a base isolated scale-model building with a TLD system mounted on its roof. The isolation system comprised of stable unbonded-fiber reinforced elastomeric isolators (SU-FREI). Tests, with and without liquid in the TLD system, were carried out to evaluate the influence of the TLD under both harmonic base excitation and earthquake excitation at various excitation amplitude levels. An existing BI-structure-DVA numerical model was modified to incorporate a multi-parameter isolator model (Backbone Curve model) to simulate the behaviour of a SU-FREI isolation system and was evaluated using results from the shake table study. The BI-structure-DVA numerical model was used to carry out a preliminary investigation on different combinations of linear and nonlinear base isolators with linear and nonlinear DVA under harmonic excitation. An iterative updating scheme was added to the numerical model to simulate the amplitude dependent behaviour of SU-FREI under earthquake excitation and this updated model was then used to investigate the performance of the BI-building-TLD and a linear BI-building-TLD under different earthquake ground motions.

abstract: Master of Applied Science (MASc)


title: FUNCTIONAL FOODS AND WOMEN'S HIGH CHOLESTEROL

contributor: Josee Johnston; Tina Moffat; James Gillett

subject: Functional Foods

subject: High Cholesterol

subject: Women

subject: Health

subject: Sociology of Diagnosis

subject: Class

subject: Cardiovascular Diseases

subject: Inequality and Stratification

subject: Knowledge Translation

subject: Medical Nutrition

subject: Medicine and Health

subject: Public Health Education and Promotion

subject: Quantitative, Qualitative, Comparative, and Historical Methodologies

subject: Sociology

subject: Women's Health

subject: Cardiovascular Diseases

abstract:
This dissertation takes the format of a "three paper model" (i.e. Sandwich Thesis), and all three articles have been submitted for publication.

Article 1 (Chapter 4) - appears in Food, Culture & Society (2014).

Article 2 (Chapter 5) - appears in Social Science & Medicine (2014).

Article 3 (Chapter 6) - Revise & Resubmit from Sociology of Health & Illness

abstract:
Food and the various aspects surrounding what we eat, what we should eat, and concerns about how to remain healthy and ward off disease and illness is escalating while our choices are endless. In this competitive food market a new type has emerged: the functional food. Functional foods are those that have an added health benefit beyond the basic nutritional content and display physiological benefits in reducing chronic diseases. A popular category of functional foods are those that purport to lower one's cholesterol. In particular, high cholesterol is marketed as a "disease" rather than a risk factor for various cardiovascular diseases, such as heart disease. Little is known about the sociological diagnosis of high cholesterol and the marketing of functional foods, in particular with women. This dissertation address this gap by asking: (1) How is high cholesterol (HC) identified and marketed as a disease rather than a risk factor for cardiovascular diseases in functional food advertising - specifically addressing the Becel® pro.activ® margarine campaign? (2) How do women understand the issue and causes of high cholesterol; and (3) What do women understand the solution to high cholesterol to be and how do they view Becel's® high cholesterol solution? --The findings center on 4 key issues:

The construction and marketing of high cholesterol as a disease (i.e. via the sociology of diagnosis), rather than a risk factor for heart disease;

The causes of high cholesterol and attribution of blame are placed on women's poor lifestyle choices and seen as an individual responsibility;

There are class differences regarding women's knowledge and awareness of the social determinants of health (SDOH); and

The solution to high cholesterol is individualized via the 'proactive myopia' repertoire.

abstract: Doctor of Philosophy (PhD)


title: Semidefinite Relaxation-Based Soft MIMO Demodulation via Efficient Dual Scaling

contributor:
Davidson, T. N.
Electrical and Computer Engineering

subject: MIMO soft demodulation; BICM-IDD; semidefinite relaxation; dual scaling

subject: Systems and Communications

subject: Systems and Communications

abstract:
Soft multiple-input multiple-output (MIMO) demodulators are a core component of iterative receivers for MIMO communication systems that employ bit-interleaved coded modulation (BICM). The role of these demodulators is to extract a good approximation of the posterior likelihood of each bit transmitted at each channel use. The main challenge in designing a soft MIMO demodulator is to achieve the desired level of performance at a reasonable computational cost. This is important because in the case of a memoryless MIMO channel, the computational cost of the exact soft demodulator increases exponentially with the number of bits transmitted per channel use, and the cost grows faster in the case of the channels with memory.

Several approximate low-complexity soft demodulators for memoryless channels have been proposed in the literature. In this thesis, we develop a low-complexity soft MIMO demodulator that is based on semidefinite relaxation (SDR) and uses the max-log approximation to reduce the cost of the demodulation. In particular, we develop a customized dual-scaling algorithm to solve the semidefinite program that constitutes the core computational task of the SDR-based soft demodulator. The computational cost per iteration of the customized dual algorithm is about half that of the existing customized primal-dual algorithm, and this leads to a reduction in the overall computational cost. We apply the customized dual-scaling algorithm to two different list-based soft demodulators, the list-SDR and single-SDR demodulators, and compare the performance, computational cost, and EXIT chart characteristics of these demodulators with other existing methods. This comparison shows that the developed demodulator provides a desirable trade-off between performance and complexity.

abstract: Master of Applied Science (MASc)


title: CHARACTER AS A SOCIOLOGICAL PHENOMENON: AN INTERACTIONIST ANALYSIS OF SEMINARY LIFE

contributor:
Shaffir, William
Pawluch, Dorothy
Miall, Charlene
Sociology

subject:
Character
ethnography
symbolic interaction
seminary
Sociology
Sociology

abstract:
In the social sciences, the dominant approach to the study of character—people’s

essential interactional dispositions, especially of a moral and durable nature—has been to

treat it as a set of objective dispositions lodged within the individual. This dissertation

challenges the objectivist orthodoxy in the study of character by examining it from a

symbolic interactionist perspective (Mead 1934; Blumer 1969; Strauss 1993). Drawing on

14 months of ethnographic research in two Protestant Christian seminaries as an

empirical case, I find that character is ultimately a matter of audience definition, a selfother

dispositional designation achieved in social interaction. Three empirical papers

examine specific aspects of the character-making process. The first paper considers

character as a contingency influencing people’s trajectories of involvement in group life.

The second paper examines how ministry students define and experience character

formation in the seminary. The third paper analyzes how character problems are

identified and responded to in the seminary.

abstract: Doctor of Philosophy (PhD)


title: Optical Velocimeters

contributor:
Ballik, E.A.
Physics

subject: Physics Physics

abstract:
Three types of optical velocimeters are investigated in this thesis. The first, which employs a laser source, is the differential heterodyne laser Doppler velocimeter (DLDV). The second, which employs a conventional light source, is what we refer to as the white light fringe image velocimeter (WFIV). The third, which employs a laser source. we refer to as Fourier image velocimeter (FIV). The latter two techniques are new and were developed during the course of this work.

The systems parameters for all three velocimeters are investigated both theoretically and experimentally. The main objective was to determine optimum operating conditions for achieving a high signal-to-noise ratio (SNR) and good spectral quality.

In the cases of the DLDV and WFIV the research included extensive investigations of the effects of receiver aperture size, particle number density (n), and detection angle, on the SNR. Theoretical derivations of the SNR, based on optical heterodyning and the Mie scattering theory for the WFIV, are found to have good agreement with carefully conducted experiments.

In particular it was observed that with the WFIV the SNR is proportional to n for n values corresponding to less than one particle in the probe volume. The SNR remains constant for large n values. In the case of the DLDV, the SNR was always found to be proportional to n when the coherent condition was satisfied. Consequently, it is concluded that the DLDV signal results almost entirely from coherent scattering, even when the number of particles in the probe volume is as low as 0.02 ( the lower limit of the measurements).

The FIV is designed to provide a large probe depth. A derivation of the self-imaging property of Fourier images is presented in Chapter 8. Fourier images are a result of Fresnel diffraction from a periodic object, and have the properties of reproducing the intensity distribution of the object. There is excellent agreement between theory and experiment on the functional form of the diffraction patterns at and near the Fourier image. The phenomenon of repair of errors in the object is also observed.

Preliminary applications of the two new techniques (WFIV and FIV) to the measurement of particle velocities have been carried out using a range of particle sizes, both on rotating disks and in fluid flow. In addition, velocity profile measurements of water flow in a square duct were carried out employing the WFIV. In all cases, comparable measurements were carried out employing a DLDV. It is found that under certain conditions the techniques are comparable both in accuracy and sensitivity.

abstract: Doctor of Philosophy (PhD)


title: Reactive Magnetron Sputtering as a Growth Alternative for Gallium Nitride Nanowires

contributor:
LaPierre, Ray
Kitai, Adrian
Kleiman, Rafael
Engineering Physics

subject: gallium nitride

subject: nanowires

subject: sputtering

subject: Electronic Devices and Semiconductor Manufacturing

subject: Nanoscience and Nanotechnology

subject: Nanotechnology fabrication

abstract:
Gallium nitride (GaN) nanowires are high-performance materials with wide, direct bandgaps and superior electronic properties. Although their properties make them of great interest for next-generation technologies, widespread adoption has been limited by expensive production processes. Here, the results of growing GaN nanowires via DC magnetron sputtering at different temperatures and using different metal catalysts are reported.

A new substrate heater was designed to minimize contamination from the heater filament and increase the substrate temperature window to in excess of 800°C. Sixteen-mm2 (111) silicon samples had one-to-four nm of a metal catalyst deposited on them using evaporation. This metal catalyst layer (gold, platinum, or nickel) was employed to induce catalyst-assisted vapor-liquid-solid nanowire growth. GaN was deposited via a reactive nitrogen DC magnetron sputtering system. Surface morphology and composition were analyzed using both scanning and transmission electron microscopy. Energy-dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy were used to measure the presence of gallium and nitrogen in the resulting nanowires, respectively.

This furnace significantly reduced tungsten contamination to below the detectable levels of EDS. GaN nanowires were present on gold-catalyzed samples only in the gold-covered region of the silicon substrate exposed to a gallium flux. Nanowire morphology improved as temperature was elevated, but it did so at the cost of lower areal density. Conversely, platinum-coated samples yielded fewer nanowires than their gold-coated counterparts. Samples that had nickel deposited on them displayed the best GaN nanowire growths. They had the best surface morphologies, had negligible oxygen concentrations, and were single crystalline.

abstract: Master of Applied Science (MASc)


title: Design of Silicon Photonics External Cavity Laser

contributor:
Knights, A. P.
Cassidy, D.T.
LaPierre, R.R.
Engineering Physics

subject:
Silicon Photonics
External cavity laser
Data Centre
Traveling wave modeling
Electromagnetics and photonics
Electromagnetics and photonics

abstract:
The development of silicon photonics, driven by the increasing demand for bandwidth from data centre applications, is receiving growing attention. As a result of the indirect bandgap of Si material, it is more practical to heterogeneously incorporate the laser source than fabricate directly on Si. Of all the approaches, an external cavity laser (ECL) approach which consists of III-V gain material and Si photonic integrated circuit (SiPIC), is a flexible and cost effective solution. This thesis captures theoretical and experimental work on the design of SiPIC ECLs. In addition, a four wavelength laser source using an SiPIC ECL scheme is proposed and studied.

The theoretical tool is first introduced on the traveling wave model (TWM) and it is numerically solved with FDTD in Matlab. A digital filter approach is used to describe the feedback from an SiPIC external cavity, where the phase delay of the digital filter is investigated and utilized to set the cavity length.

The III-V gain chip and SiPIC are then examined separately for their characterization, along with the coupling and feedback requirements in an ECL design.

Lastly, experiments are conducted to demonstrate the feasibility of four wavelength ECLs and SiPIC ECLs.

abstract: Master of Applied Science (MASc)


title: STATISTICAL AND METHODOLOGICAL ISSUES IN EVALUATION OF INTEGRATED CARE PROGRAMS

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
Biostatistics
Clinical Epidemiology
Clinical Trials
Integrated care
Statistical Methodology
Health Research Methodology
Applied Statistics
Biostatistics
Clinical Epidemiology
Clinical Trials
Health Services Research
Statistical Methodology
Statistical Models
Applied Statistics

abstract:
Background

Integrated care programs are collaborations to improve health services delivery for patients with multiple conditions.

Objectives

This thesis investigated three issues in evaluation of integrated care programs: (1) quantifying integration for integrated care programs, (2) analyzing integrated care programs with substantial non-compliance, and (3) assessing bias when evaluating integrated care programs under different non-compliant scenarios.

Methods

Project 1: We developed a method to quantity integration through service providers’ perception and expectation. For each provider, four integration scores were calculated. The properties of the scores were assessed.

Project 2: A randomized controlled trial (RCT) compared the Children’s Treatment Network (CTN) with usual care on managing the children with complex conditions. To handle non-compliance, we employed the intention-to-treat (ITT), as-treated (AT), per-protocol (PP), and instrumental variable (IV) analyses. We also investigated propensity score (PS) methods to control for potential confounding.

Project 3: Based on the CTN study, we simulated trials of different non-compliant scenarios. We then compared the ITT, AT, PP, IV, and complier average casual effect methods in analyzing the data. The results were compared by the bias of the estimate, mean square error, and 95% coverage.

Results and conclusions

Project 1: We demonstrated the proposed method in measuring integration and some of its properties. By bootstrapping analyses, we showed that the global integration score was robust. Our method has extended existing measures of integration and possesses a good extent of validity.

Project 2: The CTN intervention was not significantly different from usual care on improving patients’ outcomes. The study highlighted some methodological challenges in evaluating integrated care programs in a RCT setting.

Project 3: When an intervention had a moderate or large effect, the ITT analysis was considerably biased under non-compliance and alternative analyses could provide unbiased results. To minimize the bias, we make some recommendations for the choice of analyses under different scenarios.

abstract: Doctor of Philosophy (PhD)


title: VARIATIONS IN SENSE OF PLACE ACROSS IMMIGRANT STATUS AND GENDER: RELATIONSHIP TO AIR QUALITY PERCEPTIONS AMONGST WOMEN IN HAMILTON, ONTARIO, CANADA

contributor:
Williams, Allison
Geography and Earth Sciences

subject: Sense of Place; Environmental Perceptions; Immigrants; Hamilton; Canada; Women

subject: Human Geography

subject: Human Geography

abstract:
In the first paper, sense of place (SoP) is used to evaluate immigrant experiences in three small to medium-sized Canadian cites: Hamilton, ON; Saskatoon, SK; and, Charlottetown, PEI. First, quantitative analysis is used to compare SoP amongst immigrant and Canadian-born respondents in the three cities. Ordered logistic regression determined four significant predictors of SoP: income; age; neighbourhood length of residence and, city of residence. Despite an observed difference in evaluations of SoP between immigrants and Canadian-born individuals, regression analysis did not identify immigrant status as a significant predictor of SoP.

The second paper employs a mixed-methods strategy to examine individual perceptions of air quality and sense of place amongst Canadian-born and immigrant women in Northeast Hamilton. Furthermore, the study aims to determine the influence of sense of place on local environmental perceptions. Qualitative focus group discussions suggest that Canadian-born women may be more aware, knowledgeable and concerned about large-scale air quality issues; however, the tension between economic and environmental needs hinders their sense of control. Quantitative survey results suggest that Canadian-born residents have a higher absolute value of sense of place than immigrants. Bringing together the qualitative and quantitative data suggests that sense of place may inform environmental perceptions.

abstract: Master of Arts (MA)


title: High-resolution near-shore geophysical survey using an Autonomous Underwater Vehicle (AUV) with integrated magnetometer and side-scan sonar

contributor:
Boyce, Joe
Earth Sciences

subject:
Autonomous underwater vehicle (AUV)
Overhauser magnetometer
magnetic survey
side-scan sonar
ferrometallic target detection
Geology
Geophysics and Seismology
Ocean Engineering
Robotics
Geology

abstract:
Small, low cost Autonomous underwater vehicles (AUVs) provide ideal platforms for shallow water survey, as they are capable of unmanned navigation and can be programmed to acquire data at constant depth, or constant altitude above the seabed. AUVs can be deployed under most sea states and are unaffected by vessel motions that often degrade sonar and magnetometer data quality. The integration of sonar and magnetometer sensors on AUV’s is challenging, however, due to limited payload and strong magnetic fields produced by the vehicle motor.

In this study, a Marine Magnetics Explorer Overhauser magnetometer was mated to a portable AUV (OceanServer Iver2) creating the first practical AUV- deployed magnetic survey system. To eliminate magnetic interference from the AUV, the magnetometer was tethered to the AUV with a 5 m tow cable, as determined by static and dynamic instrument testing. The results of the magnetic tests are presented, along with field data from a shallow water test area in Lake Ontario near Toronto, Canada. AUV-acquired magnetic survey data were compared directly with a conventional boat-towed magnetic survey of the same area. The AUV magnetic data were of superior quality despite being collected in rough weather conditions that would have made conventional survey impossible. The resulting high-resolution total magnetic intensity and analytic signal maps clearly identify several buried and surface ferrometallic targets that were verified in 500-kHz side- scan sonar imaging and visual inspection by divers.

abstract: Master of Science (MSc)


title: Portfolio Optimization under Value at Risk, Average Value at Risk and Limited Expected Loss Constraints

contributor:
Pirvu, Traian A
David Lozinski, Tom Hurd
Mathematics and Statistics

subject:
Portfolio Optimization
Average Value at Risk
Risk Management
Value at Risk
Geometric Brownian Motion
Mean-Reverting Model
Finance and Financial Management
Other Applied Mathematics
Portfolio and Security Analysis
Finance and Financial Management

abstract: In this thesis we investigate portfolio optimization under Value at Risk, Average Value at Risk and Limited expected loss constraints in a framework, where stocks follow a geometric Brownian motion. We solve the problem of minimizing Value at Risk and Average Value at Risk, and the problem of finding maximal expected wealth with Value at Risk, Average Value at Risk, Limited expected loss and Variance constraints. Furthermore, in a model where the stocks follow an exponential Ornstein-Uhlenbeck process, we examine portfolio selection under Value at Risk and Average Value at Risk constraints. In both geometric Brownian motion (GBM) and exponential Ornstein-Uhlenbeck (O.U) models, the risk-reward criterion is employed and the optimal strategy is found. Secondly, the Value at Risk, Average Value at Risk and Variance is minimized subject to an expected return constraint. By running numerical experiments we illustrate the effect of Value at Risk, Average Value at Risk, Limited expected loss and Variance on the optimal portfolios. Furthermore, in the exponential O.U model we study the effect of mean-reversion on the optimal strategies. Lastly we compare the leverage in a portfolio where the stocks follow a GBM model to that of a portfolio where the stocks follow the exponential O.U model.

abstract: Master of Science (MSc)