title: Environmental Values Education in School Curricula

contributor:
Beattie, Catherine
Taylor, S. M.
Geography

subject: Geography Geography

abstract:
Environmental education is ultimately concerned with changing the behaviour of learners so that decisions that they make throughout life are made after consideration of the effects of acting on these decisions. This report offers a conceptual model adapted from Ajzen and Fishbein (1980), and Hungerford and Volk (1990). This model attempts to explain behaviour and shows that the values that an individual holds are one of the variables that influence behaviour. This project describes the reforms that are taking place in education in Ontario and the potential they have to marginalize environmental education, and specifically environmental values education (EVE), in the curriculum of our schools.

As a means of resisting this, the project describes tools that were developed for assessing changes in values that have an influence on the development of positive environmental behaviours. The hypothesis central to this effort is that if environmental educators can show that EVE programs are necessary and effective, then a place for EVE programs may be assured. To do this, environmental educators will need to develop quantitative assessment tools since these are perceived by the public to be more valid and reliable than qualitative assessment.

An analysis of a trial of the assessment tools developed by the author revealed no statistically significant changes in the values espoused by students, either as members of a group, or as individuals. However, this points to defects in the expectations and administration of the assessment rather than in the tools themselves. These findings were the basis for recommendations made by the author. In response to the defects that were uncovered in the analysis, modifications to the assessment tools and their administration are recommended. Along with this are recommendations regarding both pre-service and in-service teacher education.

abstract: Master of Science (Teaching)


title: Nuclear Structure Studies of ¹⁴²Praseodyium

contributor:
Summers-Gill, R.G.
Physics

subject: Physics Physics

abstract: [missing page 64]

abstract:
The independent quasi particle model of nuclear excited states has successfully been applied by previous authors to the N = 83 nuclei 140La and 142Pr. In both these nuclei configuration mixing between the(π1°g7/2ν2f7/2) and (π2°g5/2ν2f7/2) configurations is expected to produce 14 negative parity states with spins 0,1,1,2,2,3,3,4,4,5,5,6,6,7. In the case of 140La all fourteen states have been identified among the low lying excitations (below 600 Kev). In 142Pr previous research had placed 10 of the expected low lying states, and all of these were located below 200 kev.

In our research, using data from 139La (α,n) gamma-gamma coincidence, from 141Pr (d,p), and 144Nd (d,q), we were able to suggest the locations of three new nuclear levels in 142Pr , two of which we believe to be the 6- cind 7- spin states not seen by previous investigators. The results are encouraging because these two levels are found at approximately the same excitation energy as the corresponding states in 140La , and one hopes, therefore, that the similarity in level structure between these two nuclei can be explained by a neutron-proton interaction common to both nuclei. The three new states which we are suggesting are, [refer to the table in the pdf].

abstract: Master of Science (MS)


title: Oxidation of o-xylene in an integral packed bed reactor

contributor:
Hoffman, T. W.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract:
The oxidation of o-xylene was investigated in an integral packed bed reactor using a K2SO4 promoted vanadium pentoxide catalyst on a TiO2 support.

Reaction products consisting of nine chemical components were analyzed by a new temperature-programmed gas chromatographic technique using three different columns to effect separation.

A kinetic model based on the REDOX (catalyst reduction and oxidation) mechanism was employed. The statistical method of experimental design for parameter estimation based on M.J. Box's modification [116] of the Draper and Hunter method [47] was used. Statistical analysis based on the eigenvalue-eigenvector method of Box et al. [45] indicated correlation among the responses and this method was used to transform the multiple response data for use in estimating the parameters in the kinetic model.

Since parameter estimates in the model were available from Wainwright's previous work [26], the method of Hoffman and Reilly [124] which is based on Bayes' theorem, was used to transfer this prior infonnation on the parameters to the present experimental system.

The kinetic data obtained from using the new chromatographic technique developed in this study were found to be consistent. The kinetic model of Wainwright [26] for this reaction system was fitted to the multiple response data obtained from this study. The adequacy of this model in representing the. data was also tested. The use of the statistical teclmiques in experimental programs to develop kinetic models was found to be extremely effective. Some of the difficulties in using them are outlined.

abstract: Master of Engineering (ME)


title: The Development of Perceptions of Facial Attractiveness

contributor:
Maurer, Daphne
David Feinberg, Laurel Trainor
Psychology

subject:
face perception
attractiveness
averageness
symmetry
experience
development
Child Psychology
Cognition and Perception
Child Psychology

abstract: There is strong agreement among adults both within and across cultures as to which faces are attractive (Langlois et al., 2000), and these perceptions can affect social interactions via the ‘beauty is good’ stereotype (Dion, Berscheid, & Walster, 1972). Adults perceive faces that are symmetrical to be more attractive than faces that are less symmetrical (Perrett et al., 1999), and faces that approximate the population average to be more attractive than most other faces (Langlois & Roggman, 1990). I examined the development of the influence of symmetry and averageness on children’s judgments of facial attractiveness in the faces of children and adults. In the work presented in chapters 2 and 3, I presented children and adults with pairs of faces that had been transformed to be more symmetrical and less symmetrical (chapter 2) or closer and farther from their group average (chapter 3). On each trial, participants selected which face was more attractive from the pair. I found that symmetry did not influence 5-year-olds’ judgments of attractiveness, but it did influence 9-year-olds’ judgments of attractiveness although to a lesser extent than those of adults. I additionally found that averageness strongly influenced 5-yearolds’ attractiveness judgments, and the strength of the preference increased from age 5 to 9, and from age 9 to adulthood. These findings are the first demonstrations that symmetry and averageness influence attractiveness judgments prior to adolescence, and that they influence attractiveness judgments in children’s faces. To assess whether natural differences in face experience can affect how strongly averageness is preferred in different face categories, I tested children attending single-sex schools and expected averageness to influence attractiveness judgments more strongly in same-sex than opposite-sex faces of their own age (chapter 4). I did not find that pattern of results. Averageness might influence attractiveness judgments regardless of the age and sex of face because a minimum level of face experience could be adequate for attractiveness judgments based on a prototype and/or because of similarities among averages of different ages and sexes. Together, the findings of this thesis demonstrate that children assess facial attractiveness based on some of the same dimensions as do adults, but that children are more tolerant of deviations from averageness and symmetry. Developmental changes might reflect the refinement of a face prototype as experience with faces increase, increased visual sensitivity as the visual system develops, and/or increased salience of cues for mate choice after puberty.

abstract: Doctor of Science  (PhD)


title: AN EVALUATION OF MEASUREMENT OF ADHERENCE AND PATIENT RECRUITMENT METHODS IN PATIENT ADHERENCE TO MEDICATION RESEARCH

contributor:
Haynes, Brian R.
Lauren Griffith, Anne Holbrook
Health Research Methodology

subject:
Adherence
Measurement
Quality
Methodology
Patient Recruitment
Systematic Review
Clinical Epidemiology
Clinical Epidemiology

abstract:
Objective: To provide an overview of the state of trial methodology concerning measurement of patient adherence and patient recruitment, and explore how the quality of these methods impact the adherence results found in trials.

Data sources: Major bibliographic sources, reference lists, and clinicaltrials.gov were searched for relevant trials up to January 2013.

Study selection: Approximately 150 trials were included in the full systematic review, from which 50 trials were selected to represent several methods of measuring adherence.

Results: There were a variety of different measures of adherence with qualities ranging from valid and unobtrusive, to unreliable and subjective. The median overall quality of adherence measures was 5 (IQR 3, maximum score 9, higher is better). The overall correlation of the quality of the measures of adherence and the coefficient of variation (CV) or proportion adherence suggested that adherence measures rated as higher quality were associated with a higher CV but not associated with a lower proportion adherence. The median overall quality of patient recruitment methods was 2 (IQR 1, maximum score 6, higher is better). The correlation of the power of a trial and the quality of the patient recruitment methods, was slightly positively correlated for both binary and continuous data.

Conclusions: The quality of methods employed in adherence trials varies considerably and affects at least some findings of these trials. The importance of these differences in quality merits further study, but it is clear that better standards of adherence measurement are needed to support adherence research.

abstract: Master of Science (MSc)


title: A DOCUMENT DRIVEN APPROACH TO CERTIFYING SCIENTIFIC COMPUTING SOFTWARE

contributor:
Smith, Spencer
Alan Wassyng, Ned Nedialkov
Computing and Software

subject:
scientific software
nuclear physics
documentation
literate programming
SRS
FP
Software Engineering
Software Engineering

abstract:
With the general engineering practices being followed for the development of scientific software, scientists are seemingly able to simulate real world problems successfully and generate accurate numerical results. However, scientific software is rarely presented in such a way that an external reviewer would feel comfortable in certifying that the software is fit for its intended use. The documentation of the software development - Requirements, Design and Implementation, is not being given the importance it deserves. Often, the requirements are improperly and insufficiently recorded, which make the design decisions difficult. Similarly, incomplete documentation of design decisions and numerical algorithms make the implementation difficult. Lack of traceability between the requirements, design and the code leads to problems with building confidence in the results.

To study the problems faced during certification, a case study was performed on a legacy software used by a nuclear power generating company in the 1980's for safety analysis in a nuclear reactor. Unlike many other scientific codes of that time, the nuclear power generating company included a full theory manual with their code. Although the theory manual was very helpful, the documentation and development approach still needed significant updating. During the case study, 27 issues were found with the documentation of the theory manual, 2 opportunities to update the design and 6 programming style issues were found in the original FORTRAN code. This shows room for improvement in the documentation techniques in the development of scientific software based on a physical model.

This thesis provides a solution to the certification problem, by introducing software engineering methodologies in the documentation of the scientific software. This work proposes a new template for the Software Requirements Specification (SRS) to clearly and sufficiently state the functional and the non-functional requirements, while satisfying the desired qualities for a good SRS. Furthermore, the proposed template acts as a checklist and helps in systematically and adequately developing the requirements document. For developing the design and implementation, this thesis introduces Literate Programming (LP) as an alternative to traditional structured programming. Literate Programming documents the numerical algorithms, logic behind the development and the code together in the same document, the Literate Programmer's Manual (LPM). The LPM is developed in connection with the SRS. The explicit traceability between the theory, numerical algorithms and implementation (code), simplifies the process of verification and the associated certification.

abstract: Master of Applied Science (MASc)


title: Evaluation of Active Balancing Algorithms and an Improved Method for a Deployed Active Battery Balancer as Well as Physical Implementation

contributor:
Kirubarajan, T.
T. Doyle (Chairman), N. Schofield
Electrical and Computer Engineering

subject: Battery Management System

subject: Controls and Control Theory

subject: Electrical and Electronics

subject: Other Electrical and Computer Engineering

subject: Power and Energy

subject: Controls and Control Theory

abstract:
Abstract

 Lithium-ion cells have been the workhorse for customer products including laptop computers, cell phones and battery energy storage systems that can store energy from renewable energy sources. The internal resistance of them is very low, resulting in a low amount of wasted energy. Performance of Li-Ion cells is wonderful if they treated well. For this reason, an efficient battery management system (BMS) is essential in order to maximize the battery's capacity, battery means a collection of cells wired in series providing a higher voltage. So by using a BMS, SOC (State Of Charge) levels of cells get closer to each other resulting increased life and capacity of a battery. There are active and passive battery balancers. The energy which is extracted from those cells with higher SOC using passive balancer is wasted in heat, so it is not so efficient in terms of wasted energy in comparison with active balancing algorithms. There are different types of active balancing techniques. Cell to cell technique, cell to battery and battery to cell. Among the above mentioned, cell to battery performs well. However, when push-pull converters (which have high performance) are used, flux imbalance phenomenon ( which is resulted in a asymmetric hysteresis loop of a magnetic core) is unavoidable. In order to prevent this phenomenon, current mode topology is used. Hence, the transistors won't burn out due to this effect. In this thesis I simulated current mode algorithms with push-pull converters with MATLAB SIMULINK. I also physically designed push-pull converters and built it with help of chips ( current mode controllers, optocouplers, transistors, fast recovery diodes, linear and shunt regulators). I did simulate two active balancing methods ( Cell to cell and cell to battery) and compared the results. The results that came from cell to battery indicated a better performance in terms of balancing speed. For three cells balancing time reduced from 3570 seconds in cell to cell method to 518 seconds in cell to battery method.

abstract: Master of Science in Electrical and Computer Engineering (MSECE)


title: CHARACTERIZATION OF FERRONIOBIUM AND THE THERMODYNAMICS AND KINETICS OF DISSOLUTION OF NIOBIUM COMPOUNDS IN LIQUID IRON

contributor:
Malakhov, Dmitri V.
Irons, Gordon A.
Materials Engineering

subject:
ferroniobium
dissolution
HSLA steel
microstructure
thermodynamics
modeling
Metallurgy
Metallurgy

abstract:
Solidification of Nb-microalloyed HSLA steels may result in the precipitation of niobium carbonitrides, which is hardly surprising in view of their extreme thermodynamic stability. Recently, it was proposed in literature that coarse Nb-rich particles found along the centerline of continuously cast HSLA steels originated from ferroniobium additions during ladle metallurgy. In particular, it was hypothesized that thermally stable phases formed during manufacturing of ferroniobium were released into the melt once the ferroniobium had partially fused. In this contribution, Scheil–Gulliver formalism is employed to predict the phase portrait of ferroniobium in an attempt to simulate the manufacturing process of ferroniobium.

To corroborate the predictions, the microstructure of ferroniobium is characterized to determine if thermally stable particles exist in ferroniobium. Further, a model is developed to predict the dissolution rate of thermally stable phases that were observed in ferroniobium as well as in the centerline region of as-cast HSLA steel. Finally, a sample near the centreline region of a Nb-microalloyed HSLA steel is characterized and centreline compositions are measured. Based on experimental evidences, an alternative explanation to the origin of thermally stable particles found near the centreline of HSLA steels is proposed.

abstract: Master of Materials Science and Engineering (MMatSE)


title: Elastic Properties and Line Tension of Self-Assembled Bilayer Membranes

contributor:
Shi, An-Chang
Physics and Astronomy

subject:
Bilayer
SCFT
Soft Matter
Polymer
Helfrich
Membrane
Biological and Chemical Physics
Condensed Matter Physics
Statistical Models
Biological and Chemical Physics

abstract: The bending moduli and line tension of bilayer membranes self-assembled from diblock copolymers was calculated using the self-consistent field theory. The limitation of the linear elasticity theory (Helfrich model) was evaluated by calculating fourth- order curvature moduli in high curvature systems. It was found that in highly curved membranes, the fourth-order contributions to the bending energy becomes comparable to the low-order terms. The line tension (γL) of membrane pores was also investigated for mixtures of structurally different diblock copolymers. The line ten- sion was found to depend sensitively on the diblock chain topology. Addition of short hydrophobic copolymers was found to reduce the line tensions to negative values, showing that lipid mixtures may be used as pore stabilizers.

abstract: Master of Science (MSc)


title: A Hyrdoinformatic Approach to Basin/Coastal Water Management

contributor:
Tsanis, Ioannis K.
Civil Engineering

subject:
Civil Engineering
Civil Engineering

abstract:
A geographical information system has been creatively utilized to assist in the study and better understanding of the spatial variation and distribution of certain processes in water resources and coastal engineering. Hydroinformatics is the contemporary term that best describes the interactive knowledge-based non-expert decision support systems (DSSs) developed in this study in the form of GIS-based algorithms.

The spatial distribution of the annual orographic rainfall on the island of Crete (Greece) was modelled by using the multiple linear regression (MLR) method. The MLR models, developed and applied through the GIS interface, provided better estimates/predictions of rainfall at un-gauged locations than the conventional spatial interpolation techniques. This, in turn, resulted in more realistic spatial distribution of rainfall. A new DSS was developed that was applied to the island of Crete and Switzerland to asses rain gauge worth within an established network. This system provided the tools needed to reduce the number of gauges, if necessary, in an existing network, which means eliminating redundant gauges while maintaining an efficient network. Another tool was also developed to provide a ranking system that is based on performance evaluation of a number of spatial interpolation techniques in large and small rain gauge networks. Recommending the usage of certain techniques over others for a certain set-up of gauges and their records should improve the gridded precipitation input to distributed hydrological models. The same procedure may be followed for any other spatial variable (hydrological, meteorological, etc). Switzerland and the municipality of Hamilton-Wentworth (Ontario, Canada) were used as test cases for system evaluation.

A new GIS module was developed to estimate reference evapotranspiration based on the Penman-Monteith and Class A Pan Evaporation methods and using the station- and grid-based approaches. Although the combination of the grid-based approach and the Penman-Monteith method is recommended, the collection of significant amount of meteorological data from a relatively dense meteorological network is required for better results.

GIS was also used to facilitate the estimation of irrigation water requirements for different scales. Zooming in from large-scale (in the island of Crete) with limited number of meteorological stations to smaller scales with more "representative" stations provided support for the usage of the grid-based approach for calculating irrigation requirements.

For coastal engineering, a GIS pre-processor was developed for pollutant transport modelling in coastal areas. It provides accurate input to the models in the form of user-specified well-descritized bathymetry and shoreline, which are also used for post-processing purposes (i.e. graphical display). In addition to saving time in generating input files, this GIS pre-processor provides higher spatial accuracy, since all themes are geographically-referenced, which eliminates the possibility of overlapping or misplacing. It also shows great flexibility in generating grids of different cell sizes, interpolation techniques, and spatial extent. Transferability of the project between users and terminals makes it more accessible and convenient.

abstract: Doctor of Philosophy (PhD)


title: The Evolution and Ecology of Learning and Social Behaviour in Insects

contributor:
Dukas, Reuven
Psychology

subject:
Learning
Social Learning
Fruit Flies
Insects
Social Information
Social Behaviour
Behavior and Ethology
Behavior and Ethology

abstract: Animals utilize information about their environments in order to adaptively modify behaviour. Such information may come from individual experience or from social sources, both of which have costs and benefits to the animal. Here I first show benefits of individual learning with respect to foraging performance, a good proxy of fitness, in bumblebees in a naturalistic setting. Second, I show that despite fitness costs associated with learning, fruit flies do not modify their investment in learning ability due to environmental complexity of larval foraging environment. Third, I show that fruit fly larvae utilize social information in their foraging decisions, including social learning, despite increased competition costs. Fourth, I show that adult fruit flies also use the presence of larvae as a source of social information to find suitable food patches. Finally, I show that larvae spontaneously form small foraging aggregations, one benefit of which may be an improved ability to dig and burrow into the surface of the food. I discuss the costs and benefits of both individual and social learning, as well as the potential for insect model systems in future studies of sociality and learning.

abstract: Doctor of Philosophy (PhD)


title: Solid solution strengthening and texture evolution in Mg-Y alloys

contributor:
Niewczas, Marek
Materials Science and Engineering

subject:
Magnesium alloys
solid solution strengthening
texture
strain rate sensitivity
fracture surface
Structural Materials
Structural Materials

abstract: Tension and compression experiments have been carried out on a series of Mg-Y alloys with Y content up to 1.3 at.%, in a range of temperatures between 4.2K and 298K, to study the effect of Yttrium on mechanical properties and strain hardening. The alloys show strong difference in the hardening behavior under tension and compression attributed to the effect of texture. The yield strength scales with concentration of the solute as cn, where c is the concentration of the solute in atomic percent and n~2/3. The results suggest that in addition to the atomic size and modulus misfit effects, the valence may be responsible for the enhanced strengthening of Y in Mg. Strain rate sensitivity measurements carried out under tension and compression reveal that Mg-Y alloys show decreasing SRS with increasing Y content at 298K and exhibit a negative SRS in highly concentrated alloys. At low temperatures the alloys show positive SRS increased with Y content. Texture measurements suggest that increasing Y content in alloys decreases the amount of basal component and enhances non-basal orientations. The reduced yield asymmetry between tension and compression observed in higher Y content alloys is being attributed to the weakening of the basal texture.

abstract: Master of Applied Science (MASc)


title: ROLES OF MALIC ENZYMES OF RHIZOBIUM

contributor:
Finan, Turlough M.
Biology

subject: Symbiotic

subject: Host-dependent phenotype

subject: malic enzyme

subject: metabolism

subject: rhizobia

subject: nodule

subject: Biology

subject: Environmental Microbiology and Microbial Ecology

subject: Microbial Physiology

subject: Biology

abstract:
C4-dicarboxylic acids appear to be metabolized via the TCA cycle in N2-fixing bacteria (bacteroids) within legume nodules. In Sinorhizobium meliloti bacteroids from alfalfa, NAD+-malic enzyme (DME) is required for symbiotic N2-fixation and this activity is thought to be required for the anaplerotic synthesis of pyruvate. In contrast, in the pea symbiont Rhizobium leguminosarum pyruvate synthesis can occur via either the DME pathway or a pathway catalyzed by phosphoenolpyruvate carboxykinase (PCK), pyruvate kinase (PYK), and pyruvate dehydrogenase. Here we report that dme mutants of Sinorhizobium sp. NGR234 formed root nodules on a broad range of plants and that the level of N2-fixation varied from 90% to 20% of wild type depending on the host plants inoculated. NGR234 bacteroids had significant PCK activity and while single pckA and single dme mutants fixed N2 on Macroptilium atropurpureum and Leucaena leucocephala (albeit at a reduced rate), a pckA dme double mutant had no N2-fixing activity (Fix-). Thus, NGR234 bacteroids appear to synthesize pyruvate from TCA cycle intermediates via DME or PCK pathways. These NGR234 data, together with other reports, suggested that the completely Fix- phenotype of S. meliloti dme mutants may be specific to the alfalfa-S. meliloti symbiosis. We therefore examined the ME-like genes azc3656 and azc0119 from Azorhizobium caulinodans, as azc3656 mutants were previously shown to form Fix- nodules on the tropical legume Sesbania rostrata. We found that purified AZC3656 protein is an NAD (P) +-malic enzyme whose activity is inhibited by acetyl-coenzyme A (acetyl-CoA) and stimulated by succinate and fumarate. Thus, whereas DME is required for symbiotic N2 fixation in A. caulinodans and S. meliloti, in other rhizobia this activity can be bypassed via another pathway(s).

In S. meliloti both malic enzymes DME and TME share similar apparent Kms for substrate and cofactors, but differ in their responses to TCA cycle intermediates, with DME activity inhibited by acetyl-CoA and induced by succinate and fumarate. Previous results in our laboratory indicated that DME is essential for symbiotic N2 fixation, while TME fails to functionally replace DME. One possible reason for it is that a high ratio of NADPH/NADP+ in S. meliloti bacteroids prevents TME from functioning in nodules. We sought to lower the NADPH/NADP+ ratio by overexpressing a soluble pyridine nucleotide transhydrogenase (STH). However, metabolite measurements indicated that overproducing STH failed to lower the ratio of NADPH/NADP+ in S. meliloti.

Previous studies assumed that DME and TME might play different roles in central carbon metabolism. To gain insight of their physiological functions, genome-wide microarray analysis was conducted in S. meliloti single dme and tme mutants grown on glucose or succinate. The most striking changes of gene expression were observed in S. meliloti dme mutants grown on succinate. The functions of upregulated genes suggested that DME might play an important role in regulating TCA cycle intermediates, important for the maintenance of metabolic flux through TCA cycle during C4-dicarboxylate oxidation. However, changes of gene expression found in tme mutants were not significant enough to predict the physiological functions of TME protein in central carbon metabolism.

abstract: Doctor of Philosophy (PhD)


title: Influence of Primary Somatosensory Cortex on Interhemispheric Inhibition

contributor:
Nelson, Aimee J.
Kinesiology

subject:
Primary somatosensory cortex
SI
interhemispheric inhibition
IHI
cTBS
peripheral somatosensory input
Motor Control
Motor Control

abstract: The control of unimanual and bimanual tasks is a highly orchestrated process in which primary motor cortex (M1) and primary somatosensory cortex (SI) play key roles. While somatic cortices are known to aid in the control of hand movements, the neural mechanisms by which they act remain largely unknown. One mechanism which is thought to mediate the control of hand movements between bilateral M1s is called interhemispheric inhibition (IHI), a neurophysiological mechanism by which one M1 is able to inhibit the contralateral M1, reducing the occurrence of unwanted movements, or enabling the performance of two differing tasks. Previous research suggests that IHI may be one mechanism by which SI aids in the control of hand movements and this thesis further examined this relationship. Two experiments were performed to investigate the influence of SI on IHI. Experiment 1 investigated the effects of direct modulation of SI cortical excitability on IHI. Experiment 2 investigated the effects of peripheral somatosensory inputs on IHI. The collective results of Experiments 1 and 2 suggest that SI can indeed modulate IHI from either the cortical or peripheral level, with increases in IHI seen following either intervention. Further, it was found that SI selectively modulates only the short latency phase of IHI (SIHI) as well as that mixed afferent inputs were most effective in altering SIHI. The novel findings of this thesis suggest that SI is indeed capable of aiding in the control of motor outputs and thus may be a possible target in future rehabilitative strategies.

abstract: Master of Science in Kinesiology


title: Analytical Modelling of Isotype Heterojunctions

contributor:
Kleiman, R. N.
Engineering Physics

subject:
heterojunctions
isotype heterojunctions
metal-semiconductor contacts
Engineering Physics
Engineering Physics

abstract: An isotype heterojunction is a junction between two layers of dissimilar semiconductors both of which are doped either n-type or p-type. These semiconductor structures are found in a variety of optoelectronic devices, such as solar cells, semiconductor lasers, and detectors. Motivated by the structure of third generation inorganic solar cells, this thesis concentrates on the analytical modelling of isotype heterojunctions and its application to the design optimization of these devices. The main development of this work is the introduction of an analytical expression for the current density across an isotype heterojunction valid for arbitrary doping concentration ratios. This result generalizes the standard expression found in the literature, which is limited by the assumption that the doping concentration ratio between the two sides of the heterojunction is equal to one. The generalization is developed by employing the Lambert W function in the solution of the electrostatic boundary condition associated with the heterojunction interface. As done in the derivation of the standard expression found in the literature, the generalization only considers thermionic emission, but the same method can readily be applied for other transport mechanisms. A key feature of this generalized result is that it mathematically contains the expression for the current density across a metal-semiconductor Schottky contact as a limiting case, thereby unifying the treatment of these two heterointerfaces into a single general analytical description. This latter find is particularly significant from a theoretical perspective, considering that the two heterointerfaces are traditionally described as separate topics in the presentation of semiconductor device theory.

abstract: Master of Applied Science (MASc)


title: DISCRETE-TIME POISSON CHANNEL: CAPACITY AND SIGNALLING DESIGN

contributor:
Hranilovic, Steve
Chen, Jun
Electrical and Computer Engineering

subject: Discrete-time Poisson

subject: Channel Capacity

subject: Signalling desing

subject: intersatellite optical communication

subject: capacity-achieving distribution

subject: multiple access channel

abstract:
The discrete-time Poisson (DTP) channel models a wide range of optical communication channels. The channel capacity and capacity-achieving distributions are generally unknown. This thesis addresses system design of DTP channels and presents novel contributions to the capacity of DTP channel, properties and closed-form expression of the capacity-achieving distribution under peak and average constraints, signalling design, and sum-capacity-achieving distributions of DTP multiple access channel (MAC) with peak amplitude constraints.

Two algorithms are developed to compute the channel capacity of DTP channel as well as the capacity-achieving distribution with average and peak amplitude constraints. Tight lower bounds based on input distributions with simple forms are presented. Non-uniform signalling algorithms to achieve the channel capacity are also demonstrated. Fundamental properties of capacity-achieving distributions for DTP channels are established. Furthermore, necessary and sufficient conditions on the optimality of binary distributions are presented. Analytical expressions for the capacity-achieving distributions of the DTP channel are derived when there is no dark current and when the dark current is large enough. A two-user DTP multiple access channel model is proposed and it is shown that the sum-capacity-achieving distributions under peak amplitude constraints are discrete with a finite number of mass points.

abstract: Doctor of Philosophy (PhD)


title: The Investigation of Theta-burst Stimulation over Primary Somatosensory Cortex on Tactile Temporal Order Judgment

contributor:
Nelson, Aimee
Jim Lyons, Richard Staines
Kinesiology

subject:
Temporal Order judgment
Transcranial Magnetic Stimulation
Primary Somatosensory Cortex
Behavioral Neurobiology
Motor Control
Other Kinesiology
Systems Neuroscience
Behavioral Neurobiology

abstract: Temporal order judgment (TOJ) refers to one’s ability to successively report the temporal order of two tactile stimuli delivered to independent skin sites. The brain regions involved in processing TOJ remain unclear. Research has shown that TOJ performance can be impaired with a conditioning background stimuli and this phenomenon, known as TOJ synchronization (TOJ-S), is suggested to be mediated by inhibitory neural mechanisms within the primary somatosensory cortex (SI) that create perceptual binding across the two skin sites. Continuous theta-burst stimulation (cTBS) over SI impairs tactile spatial and temporal acuity. This dissertation examines the effects of cTBS on TOJ and TOJ-S performance on the hand. In Experiment 1, TOJ and TOJ-S were measured from the right hand before and for up to 34 minutes following 50 Hz cTBS over SI. In Experiment 2, same measurements were obtained bilaterally for up to 42 minutes following 30 Hz cTBS over SI. Compared to pre-cTBS values, TOJ was impaired for up to 42 minutes on the right hand following 30 Hz cTBS. TOJ-S performance was improved for up to 18 minutes on the right hand following 50 Hz cTBS. These experiments reveal two major findings. First, cTBS act upon different inhibitory circuits that are suggested to mediate TOJ and TOJ-S. Second, cTBS parameters may dictate cTBS effects over SI excitability. The findings of this work not only emphasize the significant contributions of SI on tactile temporal perception, it provides novel insight of the underlying neural mechanisms of cTBS effects on SI cortical excitability.

abstract: Master of Science in Kinesiology


title: Immediate expansions by valuation of fields

contributor:
Haskell, Deirdre
Bradd Hart, Patrick Speissegger
Mathematics and Statistics

subject:
valuation
definable
immediate expansions
separably closed valued fields
valued o-minimal fields
algebraically closed valued fields
intermediate structures
Algebra
Algebraic Geometry
Logic and Foundations
Algebra

abstract:
The main subject of investigation is the so-called "immediate expansion''
phenomenon in various first-order valued-field structures over the
corresponding underlying field structures. In particular, certain "valued
o-minimal fields'', certain Henselian valued fields with non-divisible valued
groups, and certain separably closed valued fields of finite imperfection degree, are
shown to have this property.

abstract: Doctor of Philosophy (PhD)


title: Role of Ingestion in Aversion Learning

contributor:
Siegel, S.
Psychology

subject: Psychology Psychology

abstract: The role of ingestion in taste and odor aversion learning is usually considered to be limited to bringing subjects in contact with the gustatory and olfactory conditioned stimuli. Results of the present series of experiments indicate that ingestion not only facilitates contact with certain cues, but under certain circumstances, also facilitates the conditioned aversion behavior. Rats that drink a novel-flavored substance prior to toxicosis evidence stronger learned aversions to the taste in subsequent drinking preference tests than subjects that experience the novel flavored substance in the absence of ingestive behaviors during conditioning. Similarly, ingestion during odor-aversion learning results in stronger aversion behavior, provided subjects drink the same solution during postconditioning tests as had been ingested during conditioning. Control groups demonstrated that the facilitory effect of ingestion on odor-toxicosis learning is not a result of acquired aversions to the flavor of the solution ingested. Rather, the results are consistent with the hypothesis that subjects drinking during odor-toxicosis conditioning acquire aversion not only to the CS odor and the flavor of the ingested solution. Additional evidence suggests that this interaction probably occurs in the central nervous system and not at the level of the receptors.

abstract: Doctor of Philosophy (PhD)


title: Peopling the Pre-Dorset Past: A Multi-Scalar Study of Early Arctic Lithic Technology and Seasonal Land Use Patterns on Southern Baffin Island

contributor:
Cannon, Aubrey
Anthropology

subject: Anthropology Anthropology

abstract: This dissertation aims to identify and understand the seasonal, subsistence, and social contexts of lithic tool production, use, and discard amongst the Pre-Dorset peoples inhabiting southern Baffin Island. Lithic artifact assemblages from four coastal and three inland site components are examined for patterns of variability that can be used to address two interrelated research problems. The first focuses on understanding functional differences between Pre-Dorset inland and coastal sites. While Arctic archaeologists generally believe the Pre-Dorset followed a season round structured by inland and coastal activities, comparative analyses to explore how sites in these locales were used and when they were occupied have not been conducted. The second problem seeks to study variability as though "people mattered." Current analyses of Pre-Dorset culture focus largely on culture historical issues, thus there is a little sense of who these people were. Over 24,000 lithic artifacts are analyzed using a combined methodological approach. Isolated patterns of variability are interpreted using two theoretical frameworks: the organization of technology, and agency theory. Because the stated research problems have different spatial and temporal dimensions, a multi-scalar framework is used to organize separate scales of analysis. The results of this study indicate the Pre-Dorset people occupying southern Baffin Island did follow a seasonal round structured by inland and coastal activities. However, the primary incentive drawing people inland was the availability of lithic raw materials. Using a direct procurement strategy, specially organized task groups traveled to the interior during the warm season to renew their toolstone supplies and interact with other distant groups. Those individuals who did not travel inland remained at sites in the coastal uplands. At the end of summer, there groups reunited in the coastal uplands where Arctic char and caribou are abundant. The Pre-Dorset then organized their lithic and organic toolkits in preparation for the journey to their winter camps in the outer coastal regions.

abstract: Doctor of Philosophy (PhD)


title: A Riemannian Distance For Robust Downlink Beamforming

contributor:
Wong, Kon Max
Electrical and Computer Engineering

subject:
Robust beamforming
Riemannian distance
Signal Processing
Signal Processing

abstract: We examine the robust downlink beamforming design from the point of outage probability constraint. We further reason that since the estimated downlink channel correlation (DCC) matrices form a manifold in the signal space, the estimation error should be measured in terms of Riemannian distance (RD) instead of the commonly used Euclidean distance (ED). Applying this concept of measure to our design constraint, we establish approximated outage probability constraints using multidimensional ball set and multidimensional cube set. We transform the design problem into a convex optimization problem which can be solved efficiently by standard methods. Our proposed methods apply to both Gaussian distribution assumption and uniform distribution assumption. Simulation results show that the performance of our design is superior to those of other robust beamformers recently developed.

abstract: Master of Applied Science (MASc)


title: SOCIAL PERCEPTIONS OF VOCAL AND FACIAL SEXUAL DIMORPHISM IN RELATION TO MATE CHOICE: ATTRACTIVENESS, FITNESS RISKS & INTRASEXUAL COMPETITION

contributor:
Feinberg, David R.
Psychology

subject: voice; face; fundamental frequency; mate preferences; evolutionary psychology

subject: Other Psychology

subject: Other Psychology

abstract: Previous research indicates that vocal and facial masculinity and femininity influence perceptions of attractiveness. Men generally perceive women with feminine traits as more attractive than less feminine women. This may be because women who possess more feminine traits are likely to be healthier and more fertile mates than are less feminine women. Masculine male traits also influence women’s perceptions of attractiveness. Although women do not always prefer masculine male traits, preferences for masculinity are observed under circumstances where women may gain the fitness benefits of heritable health and dominance. Masculine traits in men and feminine traits in women are further associated with the potential fitness risks of infidelity and reduced investment in mates. Here I address three previously unanswered questions concerning the influence of masculinity and femininity on social perceptions. First, how do male vocal and facial masculinity influence perceptions of attractiveness when these two traits are presented simultaneously? Second, does vocal masculinity influence perceptions of the potential fitness risks of infidelity and reduced relationship investment in mates? Third, do male masculinity and female femininity influence perceptions of potential same-sex rivals? In this dissertation I demonstrate that simultaneously presented male vocal and facial masculinity influence women’s perceptions of men’s attractiveness, that perceivers are somewhat aware of the potential fitness risks associated with preferring high quality mates, and that vocal and facial masculinity influence mate choice and intrasexual competition in similar ways. Overall, these studies demonstrate the pervasive influence of masculinity and femininity on mate-choice relevant social perceptions.

abstract: Doctor of Philosophy (PhD)


title: THE DYNAMICAL SYSTEMS APPROACH TO MACROECONOMICS

contributor:
Grasselli, Matheus
Pirvu, Traian
Deaves, Richard
Mathematics and Statistics

subject:
stochastic dynamical systems
macroeconomics
post-keynesian
Dynamic Systems
Macroeconomics
Dynamic Systems

abstract:
The aim of this thesis is to provide mathematical tools for an alternative to the mainstream study of macroeconomics with a focus on debt-driven dynamics.

We start with a survey of the literature on formalizations of Minsky's Financial Instability Hypothesis in the context of stock-flow consistent models.

We then study a family of macro-economical models that date back to the Goodwin model. In particular, we propose a stochastic extension where noise is introduced in the productivity. Besides proving existence and uniqueness of solutions, we show that orbits must loop around a specific point indefinitely.

Subsequently, we analyze the Keen model, where private debt is introduced. We demonstrate that there are two key equilibrium points, intuitively denoted good and bad equilibria. Analytical stability analysis is followed by numerical study of the basin of attraction of the good equilibrium.

Assuming low interest rate levels, we derive an approximate solution through perturbation techniques, which can be solved analytically. The zero order solution, in particular, is shown to converge to a limit cycle. The first order solution, on the other hand, is shown to explode, rendering its use dubious for long term assessments.

Alternatively, we propose an extension of the Keen model that addresses the immediate completion time of investment projects. Using distributed time delays, we verify the existence of the key equilibrium points, good and bad, followed by their stability analysis. Through bifurcation theory, we verify the existence of limit cycles for certain mean completion times, which are absent in the original Keen model.

Finally, we examine the Keen model under government intervention, where we introduce a general form for the government policy. Besides performing stability analysis, we prove several results concerning the persistence of both profits and employment. In economical terms, we demonstrate that when the government is responsive enough, total economic meltdowns are avoidable.

abstract: Doctor of Philosophy (PhD)


title: THE CARBON ISOTOPE SYSTEMATICS AND PHOSPHOLIPID FATTY ACID PROFILES OF MICROBIALITE-ASSOCIATED COMMUNITIES

contributor:
Slater, Greg F.
Geography and Earth Sciences

subject:
microbialite
biosignature
PLFA
Kelly Lake
Biogeochemistry
Environmental Chemistry
Organic Chemistry
Biogeochemistry

abstract:
Modern microbialites provide the opportunity to explore the influences of biology on microbialite formation and understand how biosignatures can be preserved in these structures. In this study, we used the isotopic compositions (δ13C) of phospholipid fatty acids (PLFAs) and their structurally-defined profiles, in conjunction with calcium carbonate isotopic compositions and imaging to evaluate microbial autotrophic and heterotrophic processes associated with freshwater microbialites from Kelly Lake, British Columbia. This was done to determine what types of metabolism may have been influencing microbialite growth and whether a biosignature of this process was preserved. In addition, PLFA profiles from a microbialite-derived pure culture were analyzed under various growth conditions to assess environmental influences on microbial PLFA composition.

Although the majority of the δ13C values of Kelly Lake microbialite surface carbonates fell within the range predicted for equilibrium precipitation, samples collected from 26 m were found to have enriched δ13Ccarb values and are likely a biosignature of autotrophy at this depth. PLFA profiles and δ13CPLFA values also supported the predominance of autotrophy, however, they indicated that heterotrophic organisms were also present. This data suggests that autotrophic metabolisms have influenced the local geochemistry in the past, at least at 26 m, and are likely substantial contributors to microbialite growth.

Changes in temperature, pH, NaCl concentrations, and cell densities were found to induce variations in the PLFA profiles of the Exiguobacterium strain RW2. The degree of PLFA unsaturation changed in each of the different culture conditions, and was predominantly adjusted through alterations in the branched monoenoic PLFAs, particularly i-17:1Δ5. These results highlight the difficulties associated with applying PLFA profiles as evidence for shifts in a microbial community composition, since altered growth conditions can induce intra-specific PLFA changes.

abstract: Master of Science (MSc)


title: CHARACTERIZATION OF THE HOST RESPONSE TO CLINICAL ISOLATES BELONGING TO THE STREPTOCOCCUS MILLERI GROUP

contributor:
Surette, Michael
Biochemistry and Biomedical Sciences

subject:
Immunity
Immunology of Infectious Disease
Pathogenic Microbiology
Immunity

abstract:
The Streptococcus Milleri Group (SMG) asymptomatically colonize the gastrointestinal, female urogenital, and upper respiratory tract in the healthy population, and are therefore traditionally considered commensals. The SMG, however, are also pathogens that cause pyogenic and pulmonary infections. The factors that differentiate pathogenic from non-pathogenic isolates have proven difficult to identify, and consequently the determinants of SMG pathogenicity remain unknown. Characterization of the immune response to the SMG is important towards advancing the understanding of SMG pathogenicity, however there are limited studies that have done so.

Herein, we sought to investigate the cytokine profiles produced by human peripheral blood mononuclear cells in response to 35 clinical isolates of the SMG. Cytokine profiles varied across isolates resulting in a spectrum of responses that separated into three subgroups including a high, intermediate, and low response group. The responses were consistent across three individuals with the exception of several differences, which are discussed and warrant further studies on host susceptibility to SMG infections. The high and intermediate response groups were enriched with clinical isolates from invasive infections, which were found to induce significantly higher cytokine production than airway isolates. Cytokine induction was independent of TLR2 activation, suggesting that other pattern recognition receptors are involved in the recognition of and response to the SMG. Phenotypic characteristics, which are used in the clinical identification of the SMG, did not correlate with cytokine induction; therefore phenotypic tests are not sufficient to identify immunostimulatory isolates. The host response to the SMG characterized in this study provides foundational knowledge for future studies to investigate the mechanism of recognition as well as the function of downstream effector responses in the control of colonization and infection.

abstract: Master of Science (MSc)


title: Bergsonian Metaphysical Undercurrents in Rorty's Liberal Gradualism

contributor:
Allen, Barry
Philosophy

subject:
Henri Bergson
Richard Rorty
Charles Dickens
Vladamir Nabokov
Liberalism
The Open Society
Utopia

abstract: The central thesis of Bergsonian Metaphysical Undercurrents in Rorty’s Liberal Gradualism is that those who take the greatest risks for social reformations are always motivated by the feeling of being part of something indefinitely greater than themselves and their own moral communities (however capacious these may be): progress just is this vague sense of indefinite movement, or becoming. In works such as Matter and Memory, Creative Evolution, and The Two Sources of Morality and Religion, Henri Bergson identified this sense of movement with time, the evolution of life, and the emotion of love respectively. Though he would probably laud Bergson’s insistence that philosophy should be partisan, Richard Rorty would be less hasty in making Bergson’s identifications, for Rorty thinks social progress is best served by gradual increases in our local sense of “us” effected by imaginary identification with others through literary exposures, not a mystical sense of oneness with all creation. Improvising on a Bergsonian note, I hold that one must already be an aspiring mystic, or moral hero, for one to get an expanded sense of “us” from reading literature. But such a lifestyle is incredibly difficult to maintain, requiring superhuman courage and moral reflection. It is only in the inspiring, active presence of a genuine moral hero that a readership will be able to make such efforts, and reliably take to literature the way Rorty would like in order to form his goal of a maximally capacious liberal utopia. Mystics act out of the metaphysical or religious conviction, whether real or imagined, that they are instruments of a great force of love. Rorty’s own utopian project would then be dependent on (and, perhaps, even an unknowing product of) these spiritual, metaphysical undercurrents of social progress.


title: VIRTUAL FLUOROSCOPY SYSTEM FOR ARTHROSCOPIC SURGICAL TRAINING

contributor:
Wohl, Gregory
Shirani, Shahram
Biomedical Engineering

subject:
Virtual Fluoroscopy
Arthroscopic Surgery
Tracking
Image Registration
Biomedical
Biomedical devices and instrumentation
Systems and integrative engineering
Biomedical

abstract:
Minimally invasive operations have gained popularity over open surgical procedures in the recent years. These procedures, require the surgeon to perform highly specialized tasks including manipulation of tools through small incisions on the surface of the skin while looking at the images that are displayed on a screen. Therefore, effective training is required for the surgeons prior to performing such procedures on patients.

In this thesis I explored a novel idea for creating a training system for arthroscopic surgery. Previously obtained CT images of a patient model and the surgical tools are manipulated to create a library of fluoroscopy images. The surgical tools are tracked (a mechanical tracker and an electromagnetic tracker used in each iterations) in order to generate a spacial relationship between the patient model and the surgical tools. The position and orientation information from the tracking system is translated into the image coordinate frame. These homologous points in the two images (of surgical tools and the patient model), are used to co-register and overlay the two images and create a virtual fluoroscopy image.

The output image and the system performance was found to be very good and quite similar to that of a fluoroscopy system. The registration accuracy was evaluated using Root Mean Square Target Registration Error (RMS TRE). The RMS TRE for the system setup with the mechanical tracker was evaluated at 2:0 mm, 2:1 mm, and 2:5 mm, for 4, 5, and 6 control points, respectively. In the system setup with the electromagnetic tracking system the RMS TRE was evaluated at 7:6 mm, 12:4 mm, and 11:3 mm, for 5, 7, and 9 control points, respectively. The acceptable range of error for arthroscopy procedures has been proposed to be 1-2 mm.

It was concluded that by using a tracking system, which is not prone to interference and allows for a wide range of motion this system can be completed to the point of manufacturing and use in training new surgeons.

abstract: Master of Applied Science (MASc)


title: CULTURING AIRWAY POLYMICROBIAL COMMUNITIES UNDER CONTINUOUS FLOW CONDITIONS

contributor:
Surette, Michael G.
Biochemistry and Biomedical Sciences

subject: Bacteriology

subject: Bacteriology

abstract: Microbes are ubiquitous in the biosphere and play important roles in natural ecosystems. They are typically present as diverse, complex communities, and in humans these communities are present on all exposed surfaces and mucosal tissues. The human upper respiratory tract harbors a complex microbiome and the composition includes what are traditionally considered commensal organisms, including a significant proportion of anaerobic bacteria. It is generally assumed that most of the bacteria from any particular environment cannot be readily cultivated, including the human microbiome. Some in vitro microfluidic and in vivo models are available to study the airway microbial communities, however these methods are expensive, limited and are not practical for experiments manipulating the community. A robust culture-based approach that can propagate these polymicrobial communities has been developed in this study to investigate spatial-temporal changes in bacterial populations in vitro. Matrix embedded synthetic bacterial communities, comprised of aerobes and anaerobes, were cultivated in continuous flow cell systems. The structure of communities propagated in these systems was compared to those in static and shaken batch cultures. The data shows that reproducible stable bacterial communities can be propagated with these culture methods, however the community composition varies considerably with the approach used. Only matrix embedded communities, cultured under continuous flow conditions, could successfully retain obligate anaerobes when flow cell systems were operated in an aerobic environment. This optimized method was used for culturing complex and diverse natural communities from clinical samples (sputum). The majority of bacteria present in the original sample were recovered in flow cell cultures and the methodology was consistent. This study provides an experimental system that can be used for examining microbial community dynamics and community structure-function relationship.

abstract: Master of Science (MSc)


title: MOLECULAR EVENTS UNDERPINNING CHANGES IN TISSUE METABOLISM WITH WHEY AND SOY PROTEIN INGESTION IN ENERGY RESTRICTION IN OVERWEIGHT/OBESE ADULTS

contributor:
Phillips, Stuart
Gibala, Martin
Parise, Gianni
Kinesiology

subject:
Higher protein diet
skeletal muscle
energy restriction
Exercise Science
Other Nutrition
Exercise Science

abstract: Energy restriction-induced weight loss results in the loss of both fat mass (FM) and fat free mass (FFM). Declines in FFM, comprised mostly of skeletal muscle, have the potential to impair metabolic health. A recent meta-analysis demonstrated higher protein hypo-energetic diets (≥ 1.25 g/kg/d) can help retain FFM (Weinheimer, Sands, & Campbell, 2010). This effect is attributed to protein ingestion induced stimulation of muscle protein synthesis (MPS), which is dependent on protein source (Tang, Moore, Kujbida, Tarnopolsky, & Phillips, 2009). However, protein source on modulating FFM preservation during ER remains understudied. In a double blind investigation, 40 adults (BMI 28-40) undertook a moderate 14 day hypo-energetic diet. Subjects were randomized to be supplemented twice daily with whey (WHEY) or soy (SOY) protein, or a carbohydrate (CHO) powder as part of their ER diet. Preliminary and post diet intervention testing included skeletal muscle biopsies, blood samples and DXA measures. Absolute changes in body mass (-2.3 ± 0.18 kg), FM (-1.2 ± 0.16 kg) and FFM (-0.8 ± 0.24 kg) did not significantly differ between groups. Basal serum cortisol was unchanged in WHEY but increased significantly in SOY and CHO (p

abstract: Master of Science in Kinesiology


title: Mechanisms of Filler Flocculation with PEO/Cofactor Dual-component Flocculants

contributor:
Pelton, Robert H.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract:
High molecular weight poly(ethylene oxide) (PEO) is used in papermaking as a flocculant to incorporate fines and fillers into papers. PEO flocculation is more effective in the presence of cofactors, which are phenolic polymers capable of forming aqueous complexes with PEO. In this work, two types of model cofactors were developed to study the PEO/cofactor flocculation mechanism. The first type of cofactors were latex particles with polystyrene-core poly(vinyl phenol)-shell (PS-PVPh) prepared by the surfactant-free emulsion polymerization. It was found that PS-PVPh particles enhanced the ability of PEO to flocculate polystyrene latex. When composite particles were added after PEO, they bridged together PEO-coated particles and aggregates. When composite particles were added after PEO, they bridged together PEO-coated particles and aggregates. When composite particles were added before PEO, they acted as bridging agents and adsorb PEO in an extended configuration ideal for flocculation.

The second type of cofactors developed were water soluble tyrosine-containing polypeptides (TCP). TCP cofactors had well-defined structures and were optically active. Therefore, many analytical techniques, such as NMR, light scattering, isothermal titration calorimetry, and circular dichroism, were able to be applied to study the PEO/TCP complex formation mechanism. By taking into account the complex formation mechanism, the complex bridging flocculation mechanism of Xiao et al. was extended to explain many flocculation mechanisms. According to the extended mecahnism, PEO/TCP complexes function as bridges to couple filler particles. Meanwhile, the complexes undergo deactivation - this is a new concept developed in this work. The deactivated complexes lose the ability to couple fillers, preventing the flocculation from reaching completion. It was proposed that the deactivation was induced by the encapsulation of TCP phenolic groups by PEO.

abstract: Doctor of Philosophy (PhD)


title: Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia

contributor:
Mishra, Ram K.
Hoare, Todd
Selvaganapathy, Ravi P.
Neuroscience

subject:
nanoparticle
microgel
antipsychotic
allosteric modulator
PAOPA
Amino Acids, Peptides, and Proteins
Biochemistry
Biomaterials
Cell Biology
Medicinal Chemistry and Pharmaceutics
Molecular and Cellular Neuroscience
Molecular Biology
Nanomedicine
Nervous System Diseases
Pharmaceutics and Drug Design
Polymer Science
Psychiatric and Mental Health
Toxicology
Amino Acids, Peptides, and Proteins

abstract: Lectin-functionalized, Poly [oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) loaded with 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA) and poly(ethylene glycol)–block-poly(D,L-lactic-co-glycolic acid) (PEG-PLGA) nanoparticles loaded with haloperidol were prepared with narrow size distributions and sizes < 135 nm. The microgels and nanoparticles exhibited high Solanum tuberosum lectin (STL) conjugation efficiencies, encapsulation efficiencies, and drug loading capacities. The in vitro release of PAOPA and haloperidol was slow in physiological conditions over 96 hours, demonstrating minimal drug leakage and the potential for efficient drug transport to the targeted brain tissue. POAPA, POEGMA and the STL-functionalized POEGMA microgels were found to be non-toxic in both cell lines, indicating that they would not be toxic when administered intranasally or when they reach the brain. The nasal epithelial cell uptake of rhodamine-labelled microgels was higher in cells when the STL-functionalization was present. All haloperidol-loaded nanoparticle formulations were found to be highly effective at inducing catalepsy, while intranasal administration of STL-functionalized nanoparticles using the intranasal spray device increased the brain tissue haloperidol concentrations by 2-3.5 fold compared to STL-functionalized particles administered intranasally with a pipette. For the first time, brain tissue concentrations of rhodamine-labelled microgels confirmed that microgels are capable of passing the blood-brain barrier and that this uptake is size dependent. These formulations demonstrate promise in the reduction of the drug dose necessary to produce a therapeutic effect with antipsychotic drugs for the treatment of schizophrenia using a non-invasive route of administration.

abstract: Master of Science (MSc)


title: Politics and its Double: Deleuze and Political Ontology

contributor:
Allen, Barry
Lampert, Jay
Gedge, Elisabeth
Philosophy

subject:
Deleuze
Political Ontology
Politics
Duns Scotus
Spinoza
Univocity
Continental Philosophy
Metaphysics
Continental Philosophy

abstract: The objective of this thesis is to intervene into the ongoing dispute surrounding the political import of Gilles Deleuze’s single-authored work, specifically Difference and Repetition and The Logic of Sense. This thesis presents an alternative explanation to the question of whether or not Deleuze’s philosophy is political. By situating the debate surrounding Deleuze’s political implications in the contemporary ontological turn in political theory, this thesis argues that Deleuze’s works can be considered to be political in the non-conventional sense of the term, that is, insofar as a conceptual distinction is made between politics and the political. I further argue that Deleuze’s univocal ontology influences a concept of the political that is immanent to his thought, and in this respect he can be said to present a political ontology. The reading of Deleuze’s political ontology addresses not only the common critiques of his philosophy as posed by thinkers such as Alain Badiou, Peter Hallward, and Slavoj Žižek, but also sheds light on the problematic relationship between philosophy and politics.

abstract: Master of Arts (MA)


title: Polar Codes for Multiple Descriptions

contributor:
Chen, Jun
D. Zhao and S. Dumitrescu
Electrical and Computer Engineering

subject: polar codes multiple description rate splitting

subject: Electrical and Computer Engineering

subject: Electrical and Computer Engineering

abstract: Two coding schemes based on polar codes are proposed for the multiple description (MD) problem. The first scheme is an adaptation of the one developed by \c{S}a\c{s}o\u{g}lu {\em et al.} for the multiple access channel to the MD setting. Specifically, it is shown that the scheme is able to achieve certain rate pairs on the dominant line of the achievable rate region determined by El Gamal and Cover (EGC) when the associated auxiliary random variables have different prime alphabet sizes. Different from polar coding for the multiple access channel considered by \c{S}a\c{s}o\u{g}lu {\em et al.}, the auxiliary random variables in the MD problem can be dependent, and their alphabet sizes play an unexpected important role in the construction. The second scheme is based on the idea of rate splitting. We show that it can achieve the entire EGC rate region. The effectiveness of the proposed polar coding schemes is verified by the experimental results.

abstract: Master of Applied Science (MASc)


title: 'Securing' the Homeland? A Comparison of Canadian and American Homeland Security Policy in the Post-9/11 Period

contributor: Political Science - International Relations

subject:
Homeland Security
Securitization Theory
Copenhagen School
9/11
Canada
United States
International Relations
International Relations

abstract:
In the post-9/11 period, the United States can be seen to have securitized its approach to homeland security policy. Canada did not follow suit. Instead, the Canadian state sought to respond to American securitization initiatives in order to protect its own state interests. An in-depth examination of securitization theory demonstrates that this theoretical construct has been re-interpreted by scholars and adapted to various research agendas. This dissertation differentiates amongst three variants of securitization theory: philosophical, sociological, and post-structural. Common to these competing variants of securitization theory was the finding that the role of the audience had remained vague, hindering the use of this theoretical model for examining the policy creation process. Focusing on the philosophical variant of securitization theory, as originally articulated by the Copenhagen School, this dissertation re-evaluates the role of the audience while examining the ways in which the American approach to homeland security was securitized in the new security environment that emerged following 9/11, as well as Canada’s response to this securitization.

This project divides the audience into two separate groups, made up of three components. The elite audience, which is comprised of members of the state policy elite, and the media first determine whether or not an issue poses an existential threat to the security of the state. The populist audience - the state’s public - then determines for itself whether or not it accepts the existential nature of the threat. This division of the audience into two separate groups allows for a clearer understanding of whether or not a given issue has been successfully securitized.

In the post-9/11 period, the American audience groups willingly accepted that the threat of terrorism posed an existential threat to the state. The Canadian audience groups, prompted by their own authorized speakers of security, did not recognize terrorism as posing an existential threat to the Canadian states. Ultimately, an examination of the audience groups in these two states demonstrates the utility of the philosophical variant of securitization theory for evaluating states’ responses to security threats.

abstract: Doctor of Philosophy (PhD)


title: THE SENSORIMOTOR CONTROL OF SEQUENTIAL FORCES: INVESTIGATIONS INTO VISUAL-SOMATOSENSORY FEEDBACK MODALITIES AND MODELS OF FORCE-TIMING INTERACTIONS

contributor:
Lyons, James
Kinesiology

subject:
Force production
Motor timing
Visual feedback
Somatosensation
Auditory feedback
Sensory reafference
Motor Control
Motor Control

abstract: Many daily motor tasks involve the precise control of both force level and motor timing. The neural mechanisms concurrently managing these movement parameters remain unclear, as the dominant focus of previous literature has been to examine each in isolation. As a result, little is understood regarding the contribution of various sensory modalities to force output and interval production in sequential motor tasks. This thesis uses a sequential force production task to investigate the roles of visual and somatosensory feedback in the timed control of force. In Chapter 2 we find that removal of visual force feedback resulted in specific force output errors, but leaves motor timing behavior relatively unaffected according to predictions of the two-level timing model by Wing and Kristofferson (1973). In Chapter 3, we show that force output errors exhibited in the absence of a visual reference may be related to the processing of reafferent somatosensation from self-generated force pulses. The results of Chapter 4 reveal evidence that force errors exhibited following visual feedback removal are consistent with a shift in the perceived magnitude of force output and that the direction of error may be determined by prior task constraints. In Chapter 5 we find evidence of effector-specificity in the processing of and compensation for reafferent somatosensation. Lastly, in Chapter 6 we find that the interplay between audition and somatosensation in the control of sound level by the vocal effectors resembles that which is observed between vision and somatosensation in the control of force by the distal effectors.

abstract: Doctor of Philosophy (PhD)


title: Sensing dictionary construction for orthogonal matching pursuit algorithm in compressive sensing

contributor:
Kirubarajian, Thia.
Electrical and Computer Engineering

subject:
compressive sensing
orthogonal matching pursuit
sensing dictionary
measurement dictionary
mutual coherence
restricted isometry constant
Signal Processing
Signal Processing

abstract: In compressive sensing, the fundamental problem is to reconstruct sparse signal from its nonadaptive insufficient linear measurement. Besides sparse signal reconstruction algorithms, measurement matrix or measurement dictionary plays an important part in sparse signal recovery. Orthogonal Matching Pursuit (OMP) algorithm, which is widely used in compressive sensing, is especially affected by measurement dictionary. Measurement dictionary with small restricted isometry constant or coherence could improve the performance of OMP algorithm. Based on measurement dictionary, sensing dictionary can be constructed and can be incorporated into OMP algorithm. In this thesis, two methods are proposed to design sensing dictionary. In the first method, sensing dictionary design problem is formulated as a linear programming problem. The solution is unique and can be obtained by standard linear programming method such as primal-dual interior point method. The major drawback of linear programming based method is its high computational complexity. The second method is termed sensing dictionary designing algorithm. In this algorithm, each atom of sensing dictionary is designed independently to reduce the maximal magnitude of its inner product with measurement dictionary. Compared with linear programming based method, the proposed sensing dictionary design algorithm is of low computational complexity and the performance is similar. Simulation results indicate that both of linear programming based method and the proposed sensing dictionary designing algorithm can design sensing dictionary with small mutual coherence and cumulative coherence. When the designed sensing dictionary is applied to OMP algorithm, the performance of OMP algorithm improves.

abstract: Master of Science in Electrical and Computer Engineering (MSECE)


title: YOU ARE NOT WHAT YOU EAT DURING STRESS: AN ISOTOPIC EVALUATION OF HUMAN HAIR FROM BELLEVILLE, ONTARIO

contributor:
Prowse, Tracy
Brickley, Megan
Schwarcz, Henry
Anthropology

subject:
Stable isotopes
human hair
diet
physiological stress
Biological and Physical Anthropology
Biological and Physical Anthropology

abstract: Carbon and nitrogen isotope values in sequential segments of human hair keratin provide an archive of temporal fluctuations in isotopic composition close to the time of an individual’s death. By combining stable isotope analysis with a microscopic examination of hair, this thesis explores health status prior to the death of early settlers from St. Thomas’ Anglican Church cemetery in Belleville, Ontario (1821-1874). The purpose of this thesis is to determine if there is a consistent difference in carbon and nitrogen isotopic signatures along sequentially segmented hair in individuals who have observable pathological conditions versus individuals who display no osteological evidence of pathology. Elevated nitrogen values can be associated with physiological stressors such as chronic illness, infection, or injury that affect an individual’s metabolic state. Elevated nitrogen values represent a recycling of nitrogen derived from the breakdown of existing proteins in the body and subsequent tissue repair. Results from 10 individuals indicate that δ15N values increase greater than 1‰ if an individual was suffering from a pathological condition (e.g., periostitis) or decrease by 1‰ if an individual was possibly pregnant, while δ13C values remained relatively constant. The variability in nitrogen values over 1‰, coinciding with less change in δ13C values, may be indicative of physiological stress. These results suggest that δ15N values are not only useful for studying diet, but may also be used as indicators of physiological stress.

abstract: Master of Arts (MA)


title: RESIDENTS' PERCEPTIONS AND UNDERSTANDINGS OF SUBURBS IN HAMILTON, ONTARIO

contributor:
Harris, Richard
Geography and Earth Sciences

subject:
Environmental Design
Human Geography
Place and Environment
Public Policy
Transportation
Urban, Community and Regional Planning
Urban Studies
Urban Studies and Planning
Environmental Design

abstract: The literature on the topic of suburbia is vast. Most studies however, have been written from the point of view of suburban outsiders. Very few scholars have asked suburbanites what they think about the neighbourhoods in which they live. This gap is significant because of our growing awareness of various problems associated with the suburbs, notably those connected to the environment and human health. Focusing on Hamilton, Ontario, this thesis addresses this gap, looking at what suburbanites think about the suburbs in general, as well as their own neighbourhoods. Semi-structured interviews were conducted with 30 residents of single-family, detached dwellings in three neighbourhoods in Hamilton that on most criteria would be considered suburban. Most notably, it was found that suburban residents have difficulty conceptualizing suburbia when asked to define it abstractly, but have less difficulty completing this same task when asked to consider a real-world example instead. As well, it appears that most suburban residents have heard very few positive comments about the suburbs from outside sources. Other findings relate to where suburban residents consider the suburbs to be located in Hamilton, what they think about the negative complaints that have been directed at the suburbs by critics, and what advantages and disadvantages they associate with living in a suburban neighbourhood. These results may have important implications for future research on how suburbanites perceive the suburbs, and for policies aimed at reshaping the suburbs to reduce social, environmental, and economic costs of the suburban lifestyle.

abstract: Master of Arts (MA)


title: Interface and Energy Efficiency of Organic Photovoltaics

contributor:
Xu, Gu
Adrian Kitai and Joey Kish
Materials Science and Engineering

subject:
Interface
Energy Efficiency
Organic Photovoltaics
Polymer and Organic Materials
Semiconductor and Optical Materials
Polymer and Organic Materials

abstract:
As a promising new technology, organic photovoltaics (OPVs) have been widely studied recently. To improve the device efficiency for commercial use of 10%, a number of attempts have been made in my research. The ultra-low frequency AC field was first employed, to align p/n polymers during fabrication. The resulting devices showed 15% increase in device efficiency, attributed to the optimized morphology and enlarged p/n interface. During the improvement process, dual nanostructures of the polymers were found, the highly oriented layer and the randomly distributed part, which provided a better understanding of the OPVs under the AC field alignment.

The OPV stability was then studied by impedance measurements, to track multi-interface degradation without breaking the device. It was found the degradation of p/n junction was attributed to the deteriorated morphology and oxidized polymers, whereas the semiconductor/metal interface changed by producing metal oxides as degradation products.

The dramatic contrast between the bilayer and bulk heterojunctions (BHJ) was at last investigated by capacitance measurements in vacuum. The existing models of the BHJs had difficulty explaining the higher overall capacitance, compared with that from the bilayer devices. The resulting puzzling charge density was clarified by separating the measured capacitance into two parallel components, one from the space charge of the proposed Schottky junction, and the other from the dark dipoles presumably formed spontaneously across the donor/acceptor interface.

abstract: Doctor of Philosophy (PhD)


title: Lower Bajocian (Jurassic) Ammonoid Faunas of the Western Americas

contributor:
Westermann, G. E.
Geology

subject: Geology Geology

abstract:
The Lower Bajocian (Jurassic) ammonoid faunas from the lower parts of the Yakoun Formation along Skidegate Inlet (Queen Charlotte Islands) belong to three distinct faunules, probably of different ages: the Zemistephanus richardsoni faunule at MacKenzie Bay (upper Sauzei Zone or lowermost Humphriesianum Zone), the Stephanoceras skidegatense - Chondroceras defontii faunule at Richardson Bay (Humphriesianum Zone) and the Stephanoceras itinsae - Chondroceras oblatum faunule on South Balch Island (upper Humphriesianum Zone).

Taxonomic and stratigraphic comparisons with other ammonoid faunas from the western margins of both North and South American show that close affinities exist with southern Alaska, mainland British Columbia, western Alberta and eastern Oregon, and lesser ones with western interior United States, Chile and Argentina. Larger samples led to a number of taxonomic revisions by establishing the range of variation of species.

The following dimorphic species are recognised: Stephanoceras ilinsae (McLearn) ♀ & ♂[=Stephanoceras yakounense. McLearn ♀ - Itinsaites itinsae McLearn ♂], Stephanoceras skidegatense (Whiteaves) ♀ & ♂ [microconch new], Zemistephanus richardsoni (Whiteaves) ♀ & ♂ [microconch new], Chondroceras oblatum (Whiteaves) ♀ & ♂ [microconch new] and Chondroceras defontii (McLearn) ♀ & ♂ [microconch new]. As a consequence of these dimorphic pairings the microconch genus Itinsailes McLearn, 1927 is regarded as a junior subjective synonym of Stephanoceras Waagen, 1869, and Kanastephanus McLearn, 1927 as a subjective synonym of Zemistephanus McLearn, 1927. The new species Zemistephanus alaskensis ♀ is described.

abstract: Doctor of Philosophy (PhD)


title: CATECHOLAMINE REGULATED PROTEIN 40 (CRP40): CLINICAL IMPLICATIONS IN PARKINSON’S DISEASE

contributor:
Gabriele, Joe
Mishra, Ram
Neuroscience

subject: Analytical, Diagnostic and Therapeutic Techniques and Equipment

subject: Behavioral Neurobiology

abstract:
Parkinson’s disease (PD) is characterized by progressive cell death of the dopaminergic neurons of nigrostriatal pathway. Several causes have been implicated for PD via neurochemical research including mitochondrial dysfunction, oxidative stress, and protein misfolding, to list a few. The novel Catecholamine Regulated Protein 40 (CRP40) has certain dopaminergic and neuroprotective features that implicate its importance for PD research. Recent studies using post-mortem brain tissue of patients with PD found MOT-2/CRP40 depletion in the frontal cortex and substantia nigra. MOT-2/CRP40 reduction is also observed in striatal brain tissue samples from a hemi-lesioned preclinical animal model of PD. Most recently, work done at the University of Laval in collaboration McMaster University suggests that levels of CRP40 mRNA are in deficit in blood platelet samples from a primate model of PD.

The studies presented in this thesis suggest that the CRP40 protein has a dual function with regards to PD. The full-length CRP40 binds dopamine and, upon injection at the striatum of 6-hydroxydopamine hemi-lesioned rats, alleviates behavioural symptoms for up to 7 days. On the other hand, a 7kDA fragment of CRP40 does not bind dopamine, but does confer the same alleviatory effect upon intra-striatal injection in 6-hydroxydopamine hemi-lesioned rats. Not only has a protein now been identified with novel potential as a therapeutic agent for PD, but also the approximate region of the CRP40 protein responsible for behavioural effects.

The later studies of this thesis show that CRP40 is found dysregulated in platelets of PD patients and lymphocytes of SCZ patients. This evidence has revealed CRP40 as a novel PD biomarker, for which on going studies are now in place to explore the potential of CRP40 as a diagnostic for PD.

abstract: Doctor of Philosophy (PhD)


title: An Investigation of Attentional Bias to Threat Using the Dot Probe Task: Relation to Social Anxiety and Psychometric Characteristics

contributor:
Schmidt, Louis A.
Psychology

subject:
attentional bias
threat
social anxiety
psychometrics
dot probe
Psychology
Psychology

abstract:
Research utilizing the dot probe task to examine attentional bias to threat in social anxiety has yielded inconsistent findings. Many manipulations have been included across dot probe studies, perhaps contributing to the discrepant results. Alternatively, the psychometrics of the dot probe may play a role. Two studies that have examined the psychometric properties of the task found the task to be unreliable (Schmuckle, 2005; Staugaard, 2009).

Prompted by the mixed findings, the present study had two overarching goals. The first was to replicate and extend the extant literature by incorporating a number of manipulations into the dot probe task and examining individual differences in social anxiety, and personality types associated with social avoidance and social approach, or shyness and sociability, respectively. The second goal was to investigate the psychometrics of the dot probe task by assessing its test-retest reliability and internal consistency. To address these goals, participants completed a dot probe task that involved manipulations of emotional valence (happy, angry), intensity (moderate, strong), and exposure time (100ms, 500ms) of facial stimuli on two occasions, separated approximately by a month. Additionally, participants were parsed into high and low groups of social anxiety, shyness, and sociability by way of median splits on two personality measures.

Using attentional bias scores, a group difference was observed only in the sociability grouping at Time 1. In the low sociability group, a marginal (p=0.049) interaction between valence and intensity was found. This interaction, however, was not observed at Time 2. Additionally, poor test-retest reliability and internal consistency of the task were observed.

These findings bring into question the nature of attentional bias in social anxiety, shyness, and sociability, and the psychometric soundness of the dot probe task. Conceptual and psychometric issues are discussed pertaining to the present study’s results and the extant dot probe literature.

abstract: Master of Science (MSc)


title: AN EXPLORATION OF THE BURDEN OF PAIN AND HEALTH-RELATED QUALITY OF LIFE OF LONG-TERM SURVIVORS OF BRAIN TUMOURS IN CHILDHOOD

contributor:
Barr, Ronald D.
Health Research Methodology

subject:
child
brain tumour
health-related quality of life
pain
survivor
health utilities index
Epidemiology
Oncology
Pediatrics
Epidemiology

abstract:
Background: Health-related quality of life (HRQL) studies have inconsistently identified a burden of pain in survivors of brain tumours in childhood, with limited exploration of this morbidity.

Objective: To explore the HRQL, with a focus on pain, in survivors greater than 10 years from diagnosis of a primary brain tumour in childhood or adolescence.

Methods: A cross-sectional study was undertaken using Health Utilities Index (HUI) questionnaires. Location of pain was queried using a homunculus and a colour-analog scale facilitated the reporting of severity. Single-attribute HRQL scores for participants with and without pain were compared. Stability of pain over a decade was established using available HUI2/3 data from the same cohort with imputation for missing variables.

Results: Twelve males and 13 females out of 37 eligible subjects participated in this study. Participants (mean time from diagnosis of 19.7 years) had mean multi-attribute HRQL scores of 0.79 (SD of 0.23) for HUI2 and 0.69 (SD of 0.29) for HUI3. Thirteen (52%) participants reported pain, with ranges in severity and location of the discomfort. Participants with pain had considerably greater burdens of morbidity in sensation and emotion than those without pain. Pain also increased from the initial interview (10 years prior) to the final interview.

Conclusion: As a group, long-term survivors of brain tumours in childhood have diminished overall HRQL. However there is variability between subjects. Pain appeared to be a persistent and significant burden in a subset of individuals, with those experiencing pain reporting greater severity of morbidities in other attributes.

abstract: Master of Science (MSc)


title: Performance optimization of a PET insert for simultaneous breast PET/MR imaging

contributor:
Peng, Hao
Troy Farncombe, Michael Patterson
Medical Physics

subject:
PET
Monte Carlo simulation
image reconstruction
resolution modeling
performance optimization
Biological Engineering
Other Physics
Biological Engineering

abstract: Our group aims to develop a dedicated PET/MR system for breast cancer imaging. In order to evaluate and optimize the performance of the PET component, Monte Carlo simulation was made to help us choose the configuration parameters for hardware design. A resolution modeling method was also proposed and implemented on the GPU device to not only improve the spatial resolution of the reconstructed images but also accelerate the reconstruction speed. The PET component is configured with a ring shape composed of LYSO+SiPM detectors. Such design is compatible to MRI, and feasible for time of flight PET. Several aspects are included to be investigated in the simulation which are geometry configuration, counting performance and image quality. From the simulation result, the system configured using 2x2x20mm3 LYSO crystal with two DOI layers and 3 detector rings results in 6.2% photon sensitivity. The Noise equivalent count rate is improved with better time resolution, the peak NEC is found to be 7886 cps with 250 ps time resolution. The system is able to achieve 2.0 mm spatial resolution which is found to be more uniform with the addition of DOI layers. With the help of TOF, the lesion is visualizable with shorter scan time than the non-TOF system. The resolution modeling method is based on the coincidence detection response function modeling and multiray projection. It is found to improve the spatial resolution uniformity and contrast recovery. At the same time it reduces the position offset and background noise. The speed and accuracy improvement for this model is also discussed.

abstract: Master of Science (MSc)


title: FATTY ACIDS IN NUTRITION SOURCES FOR PRETERM INFANTS

contributor:
Fusch, Christoph
Sandeep Raha, Salhab el Helou
Medical Sciences

subject:
premature infant/VLBW
lipid emulsion
breast milk
fatty acid
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
Of the three components of parenteral macronutrient classes (protein, carbohydrate and lipid), the lipid class is the least understood and the fatty acid distribution in lipid emulsion products has the potential to play a critical role in the development of infant morbidities. Breast milk has long been considered the gold standard for infant nutrition, but when infants cannot tolerate enteral feeds, the use of lipid emulsions cannot be avoided despite their adverse side effects.

In this study, fatty acid profiles from five commercially available lipid emulsion products were compared to the profile of breast milk. As well, resulting serum on each of these nutrition sources were compared to the profile of either lipid emulsion (Intralipid) or breast milk. Fatty acid profiles for matched pairs of breast milk from mother and resulting serum from infants were compared as well as the profile of normotriglyceridemic serum samples to hypertriglyceridemic ones. Results indicate that not one lipid emulsion product is like another, nor do their profiles closely resemble breast milk even though they are intended to replace the fat portion of the infant’s natural source of nutrition. Serum was not found to directly reflect the fatty acid profile of the nutrition source administered, as was expected based on literature, highlighting that there is a complex web of pathways between nutrition administration and appearance of fatty acids in the serum. Further research is necessary to define the effect of fatty acid chain length and degree of saturation on these metabolic pathways, as the very essence of interrelations such as these can complicate interpretations of results.

abstract: Master of Science in Medical Sciences (MSMS)


title: On Complete Non-compact Ricci-flat Cohomogeneity One Manifolds

contributor:
K., McKenzie Y.
Mathematics

subject:
Ricci-flat
cohomogeneity one
asymptotically conical
Lyapunov function
Geometry and Topology
Geometry and Topology

abstract: We present an alternative proof of the existence theorem of B\"ohm using ideas from the study of gradient Ricci solitons on the multiple warped product cohomogeneity one manifolds by Dancer and Wang. We conclude that the complete Ricci-flat metric converges to a Ricci-flat cone. Also, starting from a $4n$-dimensional $\mathbb{H}P^{n}$ base space, we construct numerical Ricci-flat metrics of cohomogeneity one in ($4n+3$) dimensions whose level surfaces are $\mathbb{C}P^{2n+1}$. We show the local Ricci-flat solution is unique (up to homothety). The numerical results suggest that they all converge to Ricci-flat Ziller cone metrics even if $n=2$.

abstract: Master of Science (MSc)


title: DIAGONALIZATION AND LOGICAL PARADOXES

contributor:
W., Richard T.
Griffin, Nicholas
Hitchcock, David
Philosophy

subject: Diagonalization; Logical Paradoxes; Semantic Paradoxes; Set-theoretic Paradoxes; The Liar Paradox; The Revenge of the Liar; The Heterological Paradox; Berry's Paradox; Definability; Representational Predicates; Truth-gap Theory; Deflationary Theory of Truth

subject: Logic and foundations of mathematics

subject: Philosophy of Language

subject: Logic and foundations of mathematics

abstract: The purpose of this dissertation is to provide a proper treatment for two groups of logical paradoxes: semantic paradoxes and set-theoretic paradoxes. My main thesis is that the two different groups of paradoxes need different kinds of solution. Based on the analysis of the diagonal method and truth-gap theory, I propose a functional-deflationary interpretation for semantic notions such as ‘heterological’, ‘true’, ‘denote’, and ‘define’, and argue that the contradictions in semantic paradoxes are due to a misunderstanding of the non-representational nature of these semantic notions. Thus, they all can be solved by clarifying the relevant confusion: the liar sentence and the heterological sentence do not have truth values, and phrases generating paradoxes of definability (such as that in Berry’s paradox) do not denote an object. I also argue against three other leading approaches to the semantic paradoxes: the Tarskian hierarchy, contextualism, and the paraconsistent approach. I show that they fail to meet one or more criteria for a satisfactory solution to the semantic paradoxes. For the set-theoretic paradoxes, I argue that the criterion for a successful solution in the realm of set theory is mathematical usefulness. Since the standard solution, i.e. the axiomatic solution, meets this requirement, it should be accepted as a successful solution to the set-theoretic paradoxes.

abstract: Doctor of Philosophy (PhD)


title: 2D/3D Registration Algorithm for Lung Brachytherapy

contributor:
Farrell, Tom
Hunter, Robert
Wierzbicki, Marcin
Medical Physics

subject:
2D/3D registration
lung brachytherapy
computed tomography
Physics
Physics

abstract:
The typical High Dose Rate (HDR) lung brachytherapy procedure involves inserting treatment catheters into the bronchi next to the tumour location using a bronchoscope. The anterior-posterior and lateral fluoroscopy images are acquired in order to localize the catheters prior to treatment. Although, these images enable accurate reconstruction of the catheter location, they do not allow for the visualization of the tumour or organs-at-risk due to poor soft tissue contrast. Although CT images offer an improved soft tissue contrast, moving the patient with catheters in place prior to each treatment is impractical.

An alternative option is to use prior diagnostic or external beam radiation treatment planning CT images. These images cannot be used for treatment planning directly because of the variation in patient positioning between the CT and orthogonal images acquisition. In order to account for positioning differences, a 2D/3D registration algorithm that registers the orthogonal images with a previously acquired CT data was developed. The algorithm utilizes a rigid registration model based on a pixel/voxel intensity matching approach. A similarity measure combining normalized mutual information (NMI), image gradient, and intensity difference was developed. Evaluation of the algorithm was performed using tissue equivalent phantoms, and, in the clinical setting using data from six patients. The mean registration error was 2.1 mm and 3.2 mm for phantoms and patients respectively.

External objects such as the treatment table and ECG leads are often in CT images, affecting the above mentioned 2D/3D registration. To address this, an algorithm for automatic removal of external objects from CT images was developed. This was applied to automatic contouring and removal of the fiducial markers in CT images used for external beam radiation therapy treatment planning for breast cancer. The algorithm was further modified to compute the girth of patients as part of a diagnostic radiology clinical trial.

abstract: Doctor of Philosophy (PhD)


title: SOLUTIONS OF A TWO-COMPONENT GINZBURG-LANDAU SYSTEM

contributor:
Alama, Stanley
Bronsard, Lia
Pelinovsky, Dmitry
Mathematics and Statistics

subject:
Calculus of variations
Elliptic equations and systems
Superconductivity
Vortices
Mathematics
Mathematics

abstract: We study Ginzburg–Landau equations for a complex vector order parameter to a two-component system. We discuss the existence, uniqueness, asymptotics, monotonicity and stability of solutions by extending Alama-Bronsard-Mironescu's results in a more general case.

abstract: Doctor of Philosophy (PhD)