title: Traffic Estimation, Prediction and Provisioning in IP Networks

contributor:
Szymanski, Ted. H.
Nicola Nicolici, Hubert deBruin
Electrical and Computer Engineering

subject:
IP Networks
Traffic Prediction
Traffic Provisioning
ARIMA Filter
Systems and Communications
Systems and Communications

abstract:
The study of Internet traffic behavior in a real IP network is the subject of this thesis. Traffic Matrix of a telecommunication network represents the exchanged traffic volume between the source and destination nodes in the network and is a critical input for network studies. However, in most cases, traffic matrices are not readily available. Existing network management protocols such as the ‘Simple Network Management Protocol’ (SNMP) have been used to gather other observable measures, such as link load observations. The first part of this thesis reviews famous methods and approaches that try to infer and estimate the source-destination traffic matrix from the observable link loads.

Another important subject in networks is to predict bandwidth requirements in the future. The second part of this thesis reviews some existing methods and approaches of traffic prediction. Recently a traffic prediction method which uses multiple Time-Series analysis, each operating on a different time-scale, has been proposed. This method uses multiple ‘AutoRegressive Integrated Moving Average’ (ARIMA) filters to predict the future bandwidth requirements. Each ARIMA filter operates on a different time scale, i.e., quarter-hour, hour, day, and week. The proposed method associates a weight with each ARIMA filter, and adjusts the weights according to which filter is currently the most accurate predictor. A review of this newly proposed method is presented. Extensive experimental results have been gathered to test the robustness of the method. The filter coefficients of each ARIMA filter have been varied, and the accuracy of the predicted traffic has been measured. Extensive experimental measurements indicate that the model is very robust, and that large changes to each filter's coefficients have only a small effect on the accuracy. In all cases we evaluated, the method is very robust, predicting short-term future traffic demands with typically ≈95% success rates.

abstract: Master of Applied Science (MASc)


title: Economic Analysis of Different Coronary Syndrome Treatment Strategies in a Prehospital Setting

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
STEMI
prehospital
12-lead ECG
cost-effectiveness
economics
Health Economics
Health Economics

abstract:
BACKGROUND

For ST-segment elevation myocardial infarction (STEMI) patients received by emergency medical services (EMS), prehospital identification with 12-lead electrocardiogram/cardiography (ECG) and advanced notification of the receiving centre may increase access to primary reperfusion and reduce mortality, compared to standard cardiac monitoring. The lifetime benefits and costs of upgrading to a 12-lead ECG system are uncertain.

OBJECTIVE

To determine the cost-effectiveness of prehospital identification with 12-lead ECG and advanced notification vs. no prehospital identification and no advanced notification.

METHODS

A probabilistic Markov model was designed from a government payer perspective. Outcomes were lifetime incremental quality-adjusted life-years (QALYs) and healthcare costs. Type of primary reperfusion, 30-day and one-year mortality were from a cohort study conducted in Ontario. Reinfarction, stroke and revascularization rates were derived from the literature. Inpatient costs and professional fees came from the Ontario government; follow-up costs from published literature. The analysis was stratified by eligibility to bypass to a percutaneous coronary intervention (PCI) centre.

RESULTS

In bypass eligible settings, prehospital identification and advanced notification led to an average 0.23 additional QALYs and $1,501 additional costs over no prehospital identification and no advanced notification. In bypass ineligible settings, it led to an average 0.15 fewer QALYs and $130 additional costs. It was a cost-effective strategy 87% and 40% of the time in bypass eligible and ineligible settings, respectively, at a willingness-to-pay of $50,000/QALY.

CONCLUSIONS

In bypass eligible settings, prehospital identification with 12-lead ECG and advanced notification is a cost-effective intervention. In bypass ineligible settings, there is no evidence of cost-effectiveness.

abstract: Master of Science (MSc)


title: Boring and Cavity - Dwelling Algae: Effects on Cementation and Diagenesis in Marine Carbonates

contributor:
Risk, Michael J.
Geology

subject: Geology Geology

abstract:
Endolithic (boring) and chasmolithic (cavity-dwelling) marine filamentous algae are important erosive and diagenetic agents in modern carbonate environments. The rates at which endolithic algae bore into crystals of Iceland spar calcite and other substrates are geologically very rapid. Within 213 days the surface of Iceland spar monitored in the sea in Discovery Bay Jamaica is found completely infested by the algae. The curve of infestation versus time is similar to a normal population growth curve.

Variations in environmental conditions, notably light and agitation of the substrate, are important controls on rate of infestation, though agitation may not be quite as important as previously thought. The amount and composition of light available to the algae affects their activity, to the point where the algae apparently will not bore in the absence of light (this includes at depth within the sediment). This indicates that most endolithic algal infestation occurs at, or very close to, the sediment surface; as a result endolithic algae may be of value in the determination of paleophotic zones in ancient carbonate sequences.

Substrate crystallography exercises strong control over filament orientation during initial infestation; this control breaks down as infestation of the substrate proceeds.

Several processes of micritization are observed on the Iceland spar crystals, including partial boring infilling, residue micritization, and exteriour micrite envelope formation. The micrite envelopes form on the surface of the crystal by the coalescence of cemented (calcified) exposed endolithic or chasmolithic filaments. The low Mg calcite precipitated on the filaments is deposited only on dead algae and is found as early as 65 to 95 days after the crystals are placed in the sea. The broken filaments are a significant source of micrite and peloidal sediment in the reef and nearby environments. "Constructive" micrite envelopes and calcified algal filaments are found throughout the Phanerozoic as far as the Ordovician.

Constructive micrite envelopes will not likely develop in highly agitated environments where grains are constantly moved about, unless periods of quiescence in the order of weeks or months occur. During quiet water periods endolithic algae growing out of grains or micrite envelopes, or chasmolithic algae, may become calcified in intergranular pores by precipitated calcite. These intergranular calcified filaments, found as far back as the Ordovician, stabilize the sediment and may prevent remobilization. This may allow further filament calcification, micrite envelope formation, and complete to partial infilling of intergranular pores by calcified filaments and associated micrite and microspar cement.

abstract: Doctor of Philosophy (PhD)


title: PREDICTING RISK FOR ADVERSE OUTCOMES FOLLOWING DISTAL RADIUS FRACTURE

contributor:
MacDermid, Joy
Richardson, Julie
MacIntyre, Norma
Rehabilitation Science

subject:
Distal radius fracture
adverse outcomes
fall risk
chronic pain
rehabilitation

abstract:
Some individuals remain at risk for adverse outcomes such as chronic wrist/hand pain, falls, and fall-related osteoporotic fractures after distal radius fracture (DRF) remain. This thesis includes five studies that were conducted to establish prediction rules for assessing the risk of these adverse outcomes following DRF.

The first manuscript outlines a theoretical framework (RACE - Reducing pain, Activating, Cognitive reshaping, Empowering) for managing the risk of adverse outcomes, mainly chronic pain, in individuals with DRF. The RACE is one of the first frameworks to suggest a risk-based management approach for individuals with DRF.

The Patient-Rated Wrist Evaluation (PRWE) is a condition-specific measure for DRF used in research as well as clinical practice to measure pain and functions in individuals with different wrist/hand injuries. The second manuscript contributes to the literature by providing the first systematic literature review that synthesizes the evidence regarding the psychometric properties of the PRWE. The review determined that the PRWE has excellent reliability, construct validity, and responsiveness in individuals with DRF.

The third manuscript indicates that the baseline pain intensity is an independent predictor of chronic pain in individuals with DRF. The results also suggest that the individuals who score ≥35/50 on the pain scale of the PRWE at baseline have 8 times greater risk for developing chronic wrist/hand pain compared to those who score < 35/50.

The fourth and fifth manuscripts describe results of a two step study. The fourth manuscript is a structured literature synthesis that identified suitable measures for predicting the risk of falls and fall-related osteoporotic fractures following DRF. The fifth manuscript summarizes the results of preliminary analysis of psychometric properties of selected fall risk measures identified in the fourth manuscript. The fifth manuscript also provides feasibility and sample size requirements for conducting a fall prevention trial in individuals with DRF.

abstract: Doctor of Philosophy (PhD)


title: Liberalism, Hermeneutics, and the Other

contributor:
Allen, Barry
Madison, Gary
Enns, Diane
Philosophy

subject:
Liberalism
Hermeneutics
Other
Post-modern
Universality
Continental Philosophy
Ethics and Political Philosophy
Continental Philosophy

abstract:
For hermeneutics, liberal universality—the belief that rights for being humans as such are universally true—is a sort of subjective universality. Subjectivity is just another way of saying that universality is historically situated, and whoever claims universality cannot objectify herself from her own history; accordingly, universality is not universality-as-the-thing-is (a sort of “objective” universality), but universality-for-person P -in-her-historical-situation, even if the claimer is totally unaware of the restrictions imposed by her own tradition and historicity.

Subjective universality reveals the fact that the content of universality is affected by the personal dimension of its claimer. That is, the claimer’s personal background, including culture, language, tradition, education, social-economical aspects, even gender and race, are reflected, consciously or unconsciously, explicitly or implicitly, directly or indirectly, in her view of what universality ought to be.

How to treat the other— a political and metaphysical category of existence that is radically different from oneself—reveals the subjective nature of liberal universality. In history, this subjectivity worked negatively, for liberals, to select and exclude some groups e.g. women, the propertyless, and the colonized subjects. But in light of our contemporary understanding of what is truly free and equal, this subjectivity can function positively to assure respect for the other and avoid producing new types of alienated other. The advocated liberal approach is a hermeneutic approach, which asserts the practices of being humble, dialogical, non-violent, and voluntarily self-dislocated, in dealing with the other.

abstract: Master of Philosophy (MA)


title: LITHIUM MAS NMR STUDIES OF LITHIUM ION ENVIRONMENT AND ION DYNAMIC PROCESS IN LITHIUM IRON AND MAGNESIUM PYROPHOSPHATE AS NEW SERIES OF CATHODE MATERIALS FOR LITHIUM ION BATTERIES

contributor:
Goward, G.R.
Peter Kruse; Yurij Mozharivskyj
Chemistry

subject:
Cathode material
Lithium ion battery
Solid-State NMR
Materials Chemistry
Materials Chemistry

abstract:
Lithium-ion batteries provide a more cost-effective and non-toxic source of reusable energy compare to other energy sources. Several research studies have lead to production of some more promising cathode components for lithium ion batteries. Recently, a new series of pyrophosphate-based composition Li2FeP2O7 and Li2MnP2O7 has been reported as cathode materials. They have shown a 3D framework structure and the two Lithium-ions in the three-dimensional tunnel structure make it possible that more than one lithium ion be extracted during cycling. Lithium solid state nuclear magnetic resonance (NMR) is an effective technique to study this cathode material, not only for analyzing local structure, but also for investigation of the microscopic processes that take place in the battery.

In this work, Li2FeP2O7 and Li2MnP2O7 have been synthesized. The lithium environment of these materials is studied using 1D 6,7Li NMR. Assignment of Li2MnP2O7 spectrum has been made based on Fermi-contact interaction and crystal structure. Both variable temperature experiment and 1D selective inversion NMR are used to establish Li-ion pathways as well as Li hopping rates for Li2MnP2O7. Also, 7Li MAS NMR measurements are used to characterize Li environments in LixFeP2O7 after being electrochemically cycled to different points, and preliminary results regard to changes to ion mobility in LixFeP2O7 at different electrochemical cycled points are presents here, solid-solution (de)lithetiation process is confirmed for this material.

abstract: Master of Science (MSc)


title: The role of Xin in skeletal muscle regeneration

contributor:
Hawke, Thomas
Medical Sciences

subject:
skeletal muscle regeneration
satellite cell
Xin
muscular dystrophy

abstract:
Adult skeletal muscle has the remarkable capacity of regenerating in response to stressors, such as overuse, injury, or myopathic conditions. A fundamental contributor to the regenerative process is satellite cells, which are the primary stem cells of skeletal muscle. Uncovering factors involved in satellite cell function will greatly improve their therapeutic potential, especially for patients suffering from myopathic diseases.

The protein Xin was previously identified as being highly upregulated in damaged skeletal muscle and localized to the satellite cell population, however its purpose there has not been elucidated. Therefore the overall goal of this study was to determine the role of Xin during skeletal muscle regeneration and within its resident stem cell population. This was approached using Xin knockdown (Xin shRNA) and knockout (Xin-/- mice) models, whereby any deficits or changes in the regenerative process can be attributed to the lack/absence of Xin. The results of the following studies reveal that when Xin expression is reduced or absent, muscle regeneration is impaired, satellite cell activation is altered, and muscle fiber morphology moves towards a myopathic state.

Furthermore, since Xin has been shown to be upregulated during regeneration, it was interesting to study the expression of Xin in human myopathic muscle which is in a constant state of regeneration. It was observed that Xin expression correlates with degree of damage in myopathic muscle, regardless of disease diagnosis. Therefore, these data have improved our understanding of muscle regeneration, satellite cell function, and suggest a clinical marker for defining muscle damage severity.

abstract: Master of Science (MSc)


title: ADAPTIVE EVENTS IN THE TUMOR LIMIT THE SUCCESS OF CANCER IMMUNOTHERAPY

contributor:
Bramson, Jonathan
Medical Sciences

subject:
T cell
Vaccine
Immune Suppression
Tumor microenvironment
Cancer Immunotherapy
Allergy and Immunology
Allergy and Immunology

abstract: Pre-clinical and clinical data strongly support the use of immunotherapies for cancer treatment. Cancer vaccines offer a promising approach, however, the outcomes of clinical vaccine trials have been largely disappointing, prompting a need for further investigation. Using the B16F10 murine melanoma, we have investigated the local events within growing tumors following recombinant adenovirus immunization. In chapter 2, we investigated the ability of a pre-clinical vaccine to elicit only transient tumor growth suppression. We observed that tumors were initially infiltrated by a small number of highly functional tumor-specific CD8+ T cells following vaccination that instigated a rapid adaptive response in the tumor that suppressed local immune activity. In chapter 3, we questioned whether increasing the rate and magnitude of early immune attack would result in more robust tumor attack prior to tumor adaptation. Increasing the rate of tumor-specific CD8+ T cell expansion following vaccination resulted in tumor regression and durable cures in approximately 65% of treated mice. Further analysis revealed that tumor regression correlated with an early burst in immune attack that outpaced tumor adaptation. In chapter 4, we explored whether the same vaccine could be improved when combined with immunomodulatory antibodies. Vaccination combined with anti 4-1BB and anti PD-1 resulted in complete tumor regression and durable cure of >70% of treated animals and was associated with increased local immune activity. Gene expression profiling revealed a unique gene signature associated with the curative treatment, which was also associated with positive outcome in human melanoma patients. The described research sheds new light on mechanisms that limit the efficacy of therapeutic cancer vaccines. Namely, rapid tumor adaptation, triggered by early vaccine-induced CD8+ T cells, acts to suppress the local immune response prior to maximal immune attack. Strategies to overcome these adaptive processes should therefore be considered in future vaccine design.

abstract: Doctor of Philosophy (Medical Science)


title: The Assessment of Structural and Material Bone Qualities in Adults with Type 2 Diabetes

contributor:
Papaioannou, Alexandra
Medical Sciences

subject: osteoporosis

subject: type 2 diabetes

subject: bone

subject: mineralization

subject: trabecular bone microarchitecture

subject: magnetic resonance imaging

subject: bone quality

subject: fracture

subject: Endocrine System Diseases

subject: Geriatrics

subject: Musculoskeletal Diseases

subject: Nutritional and Metabolic Diseases

subject: Endocrine System Diseases

abstract: The risk of fracture is higher in adults with type 2 diabetes compared to controls without type 2 diabetes, despite normal or higher than normal bone mineral density (BMD). In addition to BMD, bone strength depends on other factors such as structural and material bone qualities, which are not accounted for in BMD measurements. The objective was to determine whether structural and material bone qualities are different in adults with type 2 diabetes compared to controls without type 2 diabetes. First, a cross-sectional study was undertaken using MRI to investigate distal radius trabecular bone microarchitecture, a structural bone quality. In women with type 2 diabetes, trabecular bone holes were larger compared to controls, which is important because greater trabecular bone hole size is related to reduced bone strength. Next, a two year prospective study was conducted with the participants involved in the cross-sectional study to determine whether changes in trabecular bone microarchitecture are different in women with type 2 diabetes compared to controls. There was a greater increase in the number of trabecular bone holes in women with type 2 diabetes compared to controls, which provides early evidence of trabecularization of cortical bone in women with type 2 diabetes. In the third study, quantitative backscattered electron imaging (qBEI) was used to derive bone mineralization density distribution (BMDD) outcomes for bone samples from adults with and without type 2 diabetes to compare material bone quality. There was evidence of elevated bone calcium concentration and reduced mineralization heterogeneity in bone samples from adults with type 2 diabetes compared to controls, which may contribute to bone brittleness. In summary, differences in structural and material bone qualities identified in this body of work provide explanations for elevated fracture risk in adults with type 2 diabetes.

abstract: Doctor of Science  (PhD)


title: Highly Shear-Thinning Mucoadhesive Hydrogels for Ophthalmic Applications

contributor:
Hoare, Todd
Chemical Engineering

subject:
Shear thinning polymers
hydrophobic-associative polymers
poly vinylpyrrolidone
mucoadhesion
Chemical Engineering
Chemical Engineering

abstract:
Highly shear-thinning polymers that can easily flow upon the application of shear but form gels at rest have multiple potential applications in the eye. In the front of the eye, a formulation that can easily be administered via a conventional eye dropper but form a gel within the tear film once applied would be beneficial for prolonging drug release at the front of the eye, either alone or as a medium for entrapping nanoparticles or nano-objects loaded with drugs. In the back of the eye, vitreous substitutes that can be administered through a narrow gauge needle (and, ideally, removed via the same) may be beneficial for retinal surgeries.

The overall objective of the proposed research is to chemically modify PVP through grafting strategies to improve its viscometric and mucoadhesive properties while maintaining the beneficial properties, which make it useful in ophthalmic applications.

N-vinylpyrrolidone is copolymerized with N-vinylformamide to produce a functionalized grafting platform P(VP-co-VF), which is then grafted with low concentrations of short hydrophobic grafts to introduce non-Newtonian flow profile to the precursor.

For applications at the back of the eye, the hydrophobic grafted PVP can be injected into the vitreous cavity of the eye in a liquid form to form subsequently a gel-like substance and function as a substitute for the vitreous humour. For application at the front of the eye, the shear thinning properties of hydrophobic-grafted PVP is combined with the mucoadhesive properties of phenylboronic acids (PBA) to improve the bioavailability of the drugs delivered to the front of the eye with eye drops.

Rheological characterization of the solutions has shown the potential to form gel-like materials via hydrophobic associations without sacrificing the facile injectability of the material. Targeted gelation and mucoadhesion properties can be obtained by the synthesis of polymers with desired PBA and hydrophobic graft contents.

abstract: Master of Applied Science (MASc)


title: Galactose Modified Polyvinylamine, a New Class of Water Soluble Polymers

contributor:
Pelton, Robert H.
Chemical Engineering

subject: Polyvinylamine

subject: Galactose

subject: Glycopolymer

subject: RCA Lectin

subject: Protein

subject: Quartz Crystal Microbalance with Dissipation (QCM-D)

subject: Polyelectrolyte complex

subject: Chemical Engineering

subject: Polymer Science

subject: Chemical Engineering

abstract:
Synthetic carbohydrate carrying polymers have gained substantial attention recently due to their biocompatibility and their wide range of applications such as targeted drug delivery systems, gene therapy and cell-specific biomedical materials. The overall objective of this research is to develop novel carbohydrate bearing polymers through modification of polyvinylamine (PVAm) backbone with galactose groups and to discover potential applications for this new category of glycopolymers.

PVAm-g-galactose (PVAm-GAL) with various molecular weights and grafting extents were prepared and characterized by nuclear magnetic resonance (NMR) and potentiometric and conductometric titration. Bonding of PVAm-GAL with phenylboronic acid modified PVAm (PVAm-PBA) and phenylboronate modified surfaces were studied on a quartz crystal microbalance with dissipation (QCM-D). Multilayer assembly of alternating layers of PVAm-GAL and PVA-PBA was formed on the silica sensor.

Interaction of PVAm-GAL with RCA120 lectin, a galactose specific protein, was studied on a silica sensor using QCM-D. Galactose binding proteins are overexpressed in hepatocyte and have been widely exploited for targeting the liver tissue with the help of galactosylated polymeric carriers. RCA120 lectin shows spontaneous adsorption on galactose rich surfaces obtained by the adsorption of PVAm-GAL on silica sensors. Association constant of the interaction was calculated . Effect of pretreatment with bovine serum albumin (BSA) was also examined.

Cationic polymers can form polyelectrolyte complexes (PECs) with negatively charged DNA, resulting in formation of nano-sized complexes for gene delivery purposes. PECs based on PVAm-GAL and different DNA samples were prepared and their physicochemical properties were investigated using dynamic light scattering (DLS) and electrophoretic mobility measurements. Furthermore, PVAm-GAL was studied as coating for Ca-alginate beads which are widely used for cell encapsulation purposes. PVAm-GAL can strengthen the capsule’s surface and increase the physicochemical stability of the beads against chemical degradations. PVAm-GAL coated alginate beads successfully survived treatment with sodium citrate and high ionic strength solutions.

abstract: Master of Applied Science (MASc)


title: The Use of Process and Simulation Modeling to Inform the Design of Electronic Prescribing Systems

contributor:
Holbrook, Anne
McKibbon, Ann
Bowen, James
eHealth

subject:
electronic prescribing
computerized provider order entry
simulation model
process model
workflow model
workflow diagram
Health Services Research
Health Services Research

abstract:
Objectives: (1) to assess whether computer simulation modeling or process modeling have improved medication management systems, including informing the design of e-prescribing systems for Canada, and (2) to build and validate a workflow diagram of the handwritten medication management process in the community setting for Canada and use it to obtain feedback from stakeholders.

Methods: A systematic review was conducted to assess whether the modeling techniques have improved medication management systems. A workflow diagram was developed and used to obtain feedback from stakeholders as to where problems exist in the current paper-based process and where information technology might be of help. Analyses were descriptive and qualitative.

Results: The systematic review identified 13,376 citations, 8 of which were included in the full data extraction. The review revealed that simulation models of e-prescribing systems have been developed, but their accuracy and usefulness has not been established. One process model had been used to analyze a Canadian medication management system, but no evidence was found that process models had any positive impact on e-prescribing development in Canada.

Fifteen stakeholders, including 5 physicians, 5 pharmacists, and 5 members of the public provided feedback using the workflow diagram. All stakeholders agreed that the diagram was a realistic representation of the actual handwritten medication management process, suggesting face validity. The majority of stakeholders identified the most problematic processes as generating the prescription by the physician (9/15 (60.0%)) and drug checking by the physician (6/15 (40.0%)).

Conclusions: There is a lack of published evidence on simulation models and process models, and the studies that exist do not suggest any benefit in informing e-prescribing design. We developed and established face validity for a workflow diagram of the paper-based medication management cascade. Stakeholders believed that generating the prescription and drug checking by the physician could be improved by e-prescribing.

abstract: Master of Science (MSc)


title: Global Optimization of Dynamic Process Systems using Complete Search Methods

contributor:
Chachuat, Benoit
Mhaskar, Prashant
Chemical Engineering

subject: Dynamic Optimization

subject: Global optimization

subject: Branch and bound

subject: Interval analysis

subject: Taylor models

subject: Convex relaxations

subject: McCormick relaxations

subject: Polyhedral relaxations

subject: Verified numerical methods

subject: Ordinary differential equations.

subject: Chemical Engineering

subject: Dynamic Systems

subject: Non-linear Dynamics

subject: Operational Research

subject: Ordinary Differential Equations and Applied Dynamics

subject: Process Control and Systems

subject: Chemical Engineering

abstract: Efficient global dynamic optimization (GDO) using spatial branch-and-bound (SBB) requires the ability to construct tight bounds for the dynamic model. This thesis works toward efficient GDO by developing effective convex relaxation techniques for models with ordinary differential equations (ODEs). In particular, a novel algorithm, based upon a verified interval ODE method and the McCormick relaxation technique, is developed for constructing convex and concave relaxations of solutions of nonlinear parametric ODEs. In addition to better convergence properties, the relaxations so obtained are guaranteed to be no looser than their underlying interval bounds, and are typically tighter in practice. Moreover, they are rigorous in the sense of accounting for truncation errors. Nonetheless, the tightness of the relaxations is affected by the overestimation from the dependency problem of interval arithmetic that is not addressed systematically in the underlying interval ODE method. To handle this issue, the relaxation algorithm is extended to a Taylor model ODE method, which can provide generally tighter enclosures with better convergence properties than the interval ODE method. This way, an improved version of the algorithm is achieved where the relaxations are generally tighter than those computed with the interval ODE method, and offer better convergence. Moreover, they are guaranteed to be no looser than the interval bounds obtained from Taylor models, and are usually tighter in practice. However, the nonlinearity and (potentially) nonsmoothness of the relaxations impedes their fast and reliable solution. Therefore, the algorithm is finally modified by incorporating polyhedral relaxations in order to generate relatively tight and computationally cheap linear relaxations for the dynamic model. The resulting relaxation algorithm along with a SBB procedure is implemented in the MC++ software package. GDO utilizing the proposed relaxation algorithm is demonstrated to have significantly reduced computational expense, up to orders of magnitude, compared to existing GDO methods.

abstract: Doctor of Philosophy (PhD)


title: The Analysis of the Volatile Components in Canadian Wine

contributor:
Tomlinson, R. H.
Chemistry

subject: Chemistry Chemistry

abstract: A new technique for the rapid and quantitative analysis of the volatile components in wine has been developed. This technique includes a new design of solvent extractor which is more efficient than any previously described designs and a low-temperature, vacuum concentrator. This technique was applied to the study of the patterns of formation of the volatile components in Concord and Blue Hybrid wines as a function of the fermentation progress. The effect of fermentation temperature on these patterns was also investigated. Identification of a number of volatile components was achieved using both qas chromatographic retention time and mass spectrometric techniques.

abstract: Doctor of Philosophy (PhD)


title: Using PLFA to constrain microbial distribution related to S-cycling in oil-sands composite tailings during reclamation

contributor:
Slater, Greg
Earth and Environmental Sciences

subject:
oil sands
plfa
hydrogen sulfide
cell density
syncrude
Geochemistry
Geochemistry

abstract:
Microorganisms are the most abundant living things on the planet and they drive many important environmental processes. They can do this by coupling reduction – oxidation (redox) reactions. In such reactions, the oxidation of reduced organic matter is coupled with the reduction of another compound, which serves as the electron acceptor. All microbes contain lipids in their cells; phospholipids are the main components of the cell membrane where they make up a consistent component of cell mass. Therefore, in situations where direct cell count is unrealistic, lipid analysis can be used to provide information on microbial communities. Because they hydrolyze shortly after cell death,PLFAs indicate only viable cell biomass, and PLFA analysis provides valuable insight on cell density distribution across a site. One application of PLFA analysis is within this thesis, where it was used to investigate the microbial community at Mildred Lake, Syncrude’s primary tailings settling basin. At Mildred Lake, Syncrude is constructing a freshwater fen over the deposited composite tailings (CT) as part of their reclamation process. Understanding the microbial biogeochemical cycling associated with these reclamation activities is an important component for management decisions affecting the site and thus, inform future reclamation activities.

PLFA analysis on samples from the site showed variable concentrations equivalent to estimated cell densities on the order of 107 decreasing to 106 in the CT.These cell density ranges are expected for oligotrophic systems. Phospholipids can also be biomarkers if they are indicative of a specific group of microbes. The study at Mildred Lake identified biomarkers for sulfate reducing bacteria (SRBs). The presence of these biomarkers provided a basis for the hypothesis that sulfide detected at the site was potentially from SRBs.

This thesis provides information on the fundamental concepts of lipids and the application of lipid analysis on the environmental samples from the Mildred Lake site to understand its microbial community and cycling of sulfur to prevent potential environmental issues associated with the generation of sulfide.

abstract: Master of Science (MSc)


title: A Current Source for Electrical Impedance Tomography

contributor:
Moran, Gerald R.
Medical Physics

subject:
Medical Physics
Physics
Physics

abstract:
The first prototype version of the current source for electrical impedance tomography was studied. Based upon its performance, a second version of the current source was built, including various improvements designed to address the issues of this first version.

The frequency range was extended from 1kHz to 125kHz up to 1kHz to 1 MHz, and additionally the new design allow the production of either sine, triangular or square waves.

The DC offset from the DDS output voltage signal was removed and the voltage signal was amplified to ±10V (peak to peak) from ±325mV (peak to peak) in two stages. A fixed gain of 5 was implemented in the first stage and a variable gain (from 0 to 6) was implemented in the second stage to provide more control of the injected current.

The single-ended voltage signal from the variable gain stage was translated into double-ended signals by implementing two unity gain buffer operational amplifiers, one inverting and the other non-inverting. This double-ended voltage signal then was applied to the voltage control current source.

Three voltage control current source circuits; current pump, improved Howland and Bi-polar were implemented on a PCB and a wire board.

The following five quality indicators were used to assess the performance of both versions of the current source: (1) The stability, (2) the balance of the current injection, (3) the output impedance, (4) the variation in the output current due to changes in the impedance at a fixed frequency and (5) the variation in the output current due to changes in frequency at a fixed load.

All three circuits in the second version were stable; however, the first version was not stable. Only in the second version - the improved Howland voltage control current source was the current injection balanced over the full range of frequencies.

The output impedances of the second version current source circuits were 25KΩ (bi-polar), 256KΩ (Howland) and 7KΩ (current pump) at 100 KHz as compared to the first version 8KΩ at 62.5 KHz. The output impedance for the second version Howland circuit was much higher than the other circuits.

The maximum variations in the output current were 6.35% (bi-polar), 22.44% (current pump) and 0.77% (Howland) due to variations in the load (150Ω - 2150Ω) at a fixed frequency (100 KHz). This is in comparison to the first version, which was 10.55% due changes in load (480Ω -1180Ω) at a fixed frequency (62.5 KHz). Clearly the improved Howland circuit demonstrates the lowest current variation as a function of the load.

The maximum variations of the output current due to changes in frequency (1kHz to 300kHz) was about 37% (bi-polar), 55% (Howland) and 89.83% (current pump) at a fixed maximum load 2150Ω for this second version of the McMaster EIT current source. This compares to the first version of the current source which was about 8.47% due changes in frequency range from 1 kHz to 62.5 kHz at maximum load of 1180Ω. In this case the bipolar current source demonstrated the lowest variation in output current with frequency.

However based upon all of the test results, the improved Howland current source version II outperforms the other circuits and the first version.

abstract: Master of Science (MS)


title: HOPX EXPRESSION IN IMMUNE REGULATORY B CELL REGULATE INTESTINAL INFLAMMATION

contributor:
Yang, Pingchang
Tang, Damu
Forsythe, Paul
Medical Sciences

subject:
Hopx
IBD
Colitis
Bregs
B cell
Probiotics
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
Inflammatory bowel disease (IBD) is chronic, relapsing, intestinal inflammation characterized by periods of remission and exacerbation. Pathogenesis of IBD is a complex process and the exact aetiology is unclear yet. Studies have provided evidences that IBD is a result of a genetic predisposition that leads to a mucosal immune regulatory cell defect, barrier defects, and susceptibility to environmental triggers like luminal bacteria and specific antigens. Innate and adaptive immune responses to commensal bacteria are balanced by the multiple regulatory cells like T regs and B regs. Monoclonal-antibody-based therapies have been identified for the treatment of IBD but, they have side effects and the efficacy is not stable. Hence, great expectations lie towards finding a successful cure for IBD.

Recent studies have proved the involvement of several different genes in the pathogenesis of IBD and there expressions were highly reduced in IBD. Homeodomain only protein- Hopx is a nuclear protein required to modulate heart growth and function. Expression of Hopx has been reported in various types of normal tissues but not in malignant tissues. Recent study on Hopx revealed that Hopx is needed for the function of regulatory T cells induced by DCs. However the correlation between Hopx gene and IBD remains unanswered. In this study, we examined the role of Hopx expressing regulatory B cell in IBD.

The aim of this study is to investigate whether the expression of Hopx in regulatory B cell play a key role in suppressing colitis in murine model.

The expression of Hopx was studied using cellular and molecular techniques including flowcytometry, immunohistochemistry, western blotting and real time RT-PCR.

As a first step, we investigated the Hopx expression in colitis and control murine model. After we found the possible involvement of Hopx gene in regulating intestinal inflammation, we further our study to investigate whether Hopx is expressed by regulatory B cell and function together to inhibit intestinal inflammation. After establishing Hopx and B regs association, we used probiotics to modulate Hopx expression in regulatory B cells in order to prevent/reduce intestinal inflammation. Finally we elucidate the importance of Hopx expression by injecting neutralizing anti-Hopx antibody to block Hopx.

Together, studies on human intestinal tissue and murine model revealed that Hopx expression is suppressed during inflammation condition. Probiotic administration helps to increase Hopx expressing Breg cell thereby, prevent IBD. Hopx deficient group expressed high frequency of proinflammatory cytokines and reduced immune regulatory cells. This particular study proposes that the down regulation of Hopx contributes to the development of intestinal inflammation.

abstract: Master of Health Sciences (MSc)


title: Cell Death Mechanisms at the Endoplasmic Reticulum

contributor:
Andrews, David W.
Leber, Brian
Doble, Brad
Biochemistry

subject:
Endoplasmic reticulum
Cell death
Bcl-2
E-cadherin
Modification
O-glycosylation
Cancer Biology
Cell and Developmental Biology
Cell Biology
Life Sciences
Cancer Biology

abstract: In the recent years considerable progress has been made to understand how the protein Bcl-2 regulates apoptosis at the mitochondria. By comparison, the cell death mechanisms at the endoplasmic reticulum remain unclear. In response to the agents that cause endoplasmic reticulum stress in breast cancer cells, the cell-cell adhesion molecule E-cadherin is modified by two independent modifications comprising pro-region retention and O-glycosylation. Both the modifications on E-cadherin inhibit its cell surface transport and the resultant loss of E-cadherin on the plasma membrane sensitizes cells to apoptosis. During this process binding of E-cadherin to type I gamma phosphatidylinositol phosphate kinase (PIPKIγ), a protein required for E-cadherin trafficking to the plasma membrane is prevented by O-glycosylation. E-cadherin deletion mutants that cannot be O-GlcNAcylated continue to bind PIPKIγ, traffick to the cell surface and delay apoptosis, confirming the biological significance of the modifications and PIPKIγ binding in the cell death regulation. These results also led me to determine whether there is a cell death pathway in which commitment to cell death is mediated by proteins primarily located at the endoplasmic reticulum. The studies show that the growth of estrogen receptor-positive breast cancer cells in charcoal stripped bovine serum leads to a form of programmed cell death which is protected by Bcl-2 exclusively localized at the endoplasmic reticulum instead of the mitochondria. Interestingly, the BH3 mimetic ABT-737 can abolish the protection mediated by Bcl-2 localized at the endoplasmic reticulum. Taken together, these studies suggest the novel role of the endoplasmic reticulum in programmed cell death through the identification and elucidation of the mechanisms that regulate the cell death pathway at this organelle.

abstract: Doctor of Philosophy (PhD)


title: Particle subgrid scale modeling in large-eddy simulation of particle-laden turbulence

contributor:
Tullis, S.
Lightstone, M.
Mechanical Engineering

subject:
large-eddy simulation
particle-laden turbulence
particle subgrid scale modeling
approximate deconvolution method
stochastic modeling
computational fluid dynamics
Fluid Dynamics
Mechanical Engineering
Fluid Dynamics

abstract: This thesis is concerned with particle subgrid scale (SGS) modeling in large-eddy simulation (LES) of particle-laden turbulence. Although most particle-laden LES studies have neglected the effect of the subgrid scales on the particles, several particle SGS models have been proposed in the literature. In this research, the approximate deconvolution method (ADM), and the stochastic models of Fukagata et al. (2004), Shotorban and Mashayek (2006) and Berrouk et al. (2007) are analyzed. The particle SGS models are assessed by conducting both a priori and a posteriori tests of a periodic box of decaying, homogeneous and isotropic turbulence with an initial Reynolds number of Re=74. The model results are compared with particle statistics from a direct numerical simulation (DNS). Particles with a large range of Stokes numbers are tested using various filter sizes and stochastic model constant values. Simulations with and without gravity are performed to evaluate the ability of the models to account for the crossing trajectory and continuity effects. The results show that ADM improves results but is only capable of recovering a portion of the SGS turbulent kinetic energy. Conversely, the stochastic models are able to recover sufficient energy, but show a large range of results dependent on Stokes number and filter size. The stochastic models generally perform best at small Stokes numbers. Due to the random component, the stochastic models are unable to predict preferential concentration.

abstract: Master of Applied Science (MASc)


title: In Search of a Culture of Fear: Understanding the Gap Between the Perception and Reality of School Dangers

contributor:
Davies, Scott
Budros, Art
Vaillancourt, Tracy
Sociology

subject: School Crime; School Violence; Culture of Fear; Institutional Theory; Confirmatory Bias

subject: Educational Sociology

subject: Educational Sociology

abstract: Over the past few decades, issues of school violence and crime have received international attention. High profile events, such as the Columbine or Virginia Tech school shootings, have led schools and boards of education world-wide to create and implement numerous policies and procedures in an attempt to keep students safe. However, data on school violence trends demonstrate a far more equivocal situation. School violence trends demonstrate stability over time at low levels of actual violence. In this dissertation, I attempt to account for the gap between the high number of school responses and the relatively low and stable trends in the prevalence of school crime and violence. Three main hypotheses, stemming from the culture of fear, institutional theory, and confirmatory bias, account for this gap. The culture of fear hypotheses suggests that the gap has been created by widespread fear that is pervasive, decoupled from the ecology of school crime and violence, and generated widely by the mass media. Although this is a cultural theory, institutional theory takes an organizational approach to account for this gap. Institutional theory suggests that the gap has been created by institutional processes of schools seeking legitimacy and reflecting how centralized hierarchies respond to the institutional environment, where fear takes a more loosely coupled form, and can be sensitive to the ecological variation of school crime and violence. The third hypothesis is a cognitive one, and suggests that confirmatory bias processes are the mechanisms by which scattered and sporadic acts of school violence receive large scale exposure, and therefore not only are able to generate cultures of fear, but also serve to legitimate policy. These three hypotheses are tested using a mixed-methods approach, including 66 interviews with key-players associated with schools (students, teachers, administrators, and parents), descriptive analyses of existing survey data (e.g., National statistics; Safe Schools Survey), and a content analysis of the media’s presentation of issues surrounding school crime and violence. This mixed methods approach provides a unique and holistic approach to test these hypotheses, asking several different research questions of various levels of analysis (from the individual to the community). Explaining the gap between school violence trends and school responses provides a unique contribution to the literature: it furthers our understanding of the complexities associated with school safety; it operationalizes and tests the culture of fear theory which, to date, has not been accomplished, and; it utilizes institutional theory and confirmatory bias in new ways, by applying them to issues of school safety.

abstract: Doctor of Philosophy (PhD)


title: A COMPARISON OF RESEARCH UTILIZATION AMONG RURAL AND URBAN NURSES WORKING IN ACUTE CARE SETTINGS

contributor:
Ciliska, Donna
Maureen Dobbins, Noori Akhtar-Danesh
Nursing

subject:
rural nurses
acute care
research utilization
comparison
descriptive study
Nursing
Nursing

abstract:
The purposes of this study are to compare the differences in research utilization among rural and urban nurses working in acute care hospitals and to examine the individual and contextual factors that may be associated with the differences. A quantitative research designed was used to compare the responses of 220 nurses (109 rural and 111 urban) working in a Local Health Integrated Network in South West Ontario, Canada. Data were collected using a modified version of Estabrooks’ (1997) self-report, mail-in, Research Utilization Survey. Results from the data analysis are discussed. Rural and urban nurses reported similar conceptual, instrumental, and persuasive research utilization (RU), with conceptual RU being the most commonly used form. However, rural nurses reported using overall RU significantly less than their urban counterparts did.

Rural nurses reported having less access to organizational champions and resources, such as library research journals and computers, than nurses in urban practice had. An analysis of the association between the individual and contextual variables and overall RU indicates that approximately 26% of variance in nurses’ overall RU scores can be predicted from the variance in scores of the following variables: (a) positive RU attitude, (b) organizational relationships supportive of RU, (c) level of competence, and (d) location of nurses. The findings support a multi-dimensional conceptualization of RU and the merits of exploring individual factors as well as organizational and environmental context in future research, theory development, and implementation of strategies to promote RU among nurses.

abstract: Doctor of Philosophy (PhD)


title: SYNTHESIS OF NARROWLY DISTRIBUTED LOW MOLECULAR WEIGHT POLYETHYLENE AND POLYETHYLENE MIMICS WITH CONTROLLED STRUCTURES AND FUNCTIONALITIES

contributor:
Zhu, Shiping
Faucher, Santiago
Hwee Ng, Todd Hoare
Chemical Engineering

subject:
living polymerization
polyethylene
ring opening metathesis polymerization
low molecular weight
modeling
Polymer Science
Polymer Science

abstract:
The controlled synthesis of functional low molecular weight polyethylene and polyethylene mimics is important in tuning polymer properties and is of great industrial interests. Living polymerization is a method that allows for precise control in polymer structure. Although high molecular weight polymers with controlled structures can be efficiently produced via living polymerization, the production of low molecular weight polymers faces the challenges of the use of large amounts of expensive catalyst and the broadening of polydispersity.

The synthesis of well-defined functional low molecular weight polyethylene and polyethylene mimics is studied. Promising polymerization systems, including living ring opening metathesis polymerization (ROMP), living coordination polymerization, coordinative chain transfer polymerization (CCTP), and living C1 polymerization, are identified and are analyzed based on product properties, efficiency, cost, and safety.

Within the identified systems, living ROMP is selected for study due to the industrial relevance of ROMP polymers, the availability of raw materials, and the ease of reaction setup. The efficiency of ROMP is challenged by polydispersity broadening resulting from slow initiation and poor reactor volume efficiency due to its implementation as a solution polymerization process. The challenges are addressed by the use of excess phosphine and the realization of ROMP as a bulk polymerization process.

Experimental results demonstrate that bulk ROMP with and without phosphines yield product with similar or enhanced molecular weight distribution control as solution ROMP. Kinetic studies confirm living polymerization behaviour of bulk ROMP. A mathematical model is developed for the first time using method of moments to describe the kinetics and development of molecular weight distribution of ROMP. The model is a useful tool in preliminary research and commercialization of ROMP. The success of bulk ROMP and the development of a representative model yield ROMP as a promising method for the production of low molecular weight polymers with controlled architecture.

abstract: Master of Applied Science (MASc)


title: Stress, Slack, and Hopkins' Terrible Sonnets

contributor:
O`Connor, Mary
English

subject:
English
English Language and Literature
English Language and Literature

abstract:
The main contention of this thesis is that considerable insight into Gerard Manley Hopkins' Terrible Sonnets may be gained through a consideration of Hopkins' term, slack. Much critical attention has been given to Hopkins' idiosyncratic vocabulary of stress, instress, scape and inscape, but little has been given to slack.I argue that the concept of slack, an antonym to the well-known Hopkinsian term, stress, is fundamental to the man's thought, his way of seeing, and his poetry.

I begin by examining the incarnational vision which Hopkins began to develop at Oxford, and which depended upon his capacity to perceive a just proportion in the mixture between Being and Not-being, or between stress and slack. However, the dynamic apprehension of unity in diversity depends on the perception of the observer. Hopkins' metaphysic broke down when he was spiritually and physically unable to perceive the incarnate word embodied in created forms. It is in this condition of slack, in which he felt himself to be devoid of the sensations of both God's stress and of his own answering instress that the Terrible Sonnets were written.

The experience of slack in the Terrible Sonnets is distinct from the experience of stress, which is the generative impulse at the heart of mot of Hopkins' poetry, and especially his Nature Sonnets. The distinguishing features of the Terrible Sonnets are revealed by an examination of the imagery, metrical patterning, and structure of these six poems. In each area, the experience of slack is manifest in the thought and expression of the poetry. I conclude by noting that slack is a temporary condition, and that the possibility for returning to stress, and for re-establishing a dynamic relationship with God, was always present for Hopkins.

abstract: Master of Arts (MA)


title: Kant's Metaphysical Deduction

contributor:
Noxon, James
Philosophy

subject: Philosophy Philosophy

abstract:
The thesis is, (a), that there is an important and coherently argued stage (designated 'the metaphysical deduction') in the Critique of Pure Reason which concerns certain features of the pure understanding, and (b), that this stage does not invoke Kant's doctrines of sensibility, nor does it requie support from the arguments of the Transcendental Deduction. The thesis is argued in the attempt to reconstruct the essential framework of the metaphysical deduction.

An examination of the logical forms of judgments, a brief review of how these are conceived to relate to the pure concepts of the understanding, and an examination of the pure concepts themselves form the content of the first three Chapters. It is then argued that the pure concepts are unschematised, that is, have no sensible significance (Chapter Four). There follows a reconstruction of the argument of Kant's deduction of the pure concepts from the forms of judgments (Chapter Five). Finally, the idealist implications of the conclusions of the argument of the metaphysical deduction are exposed (Chapter Six).

abstract: Master of Arts (MA)


title: Sedimentology and Regional Implications of Deep-water Sandstones of the Tourelle Formation, Ordovician, Quebec

contributor:
Middleton, G. V.
Geology

subject: Geology Geology

abstract:
Coarse sandstones of the allochthonous Lower Ordovician Tourelle Formation occur in spectacular exposures along the south shore of the St. Lawrence River. The formation is characterized by thick-bedded, coarse, massive sandstones. Individual graded beds may be tens of metres thick, and may contain slabs of shale, siltstone, or bedded chert up to 16 m in length. Cross-stratification and unusual near-horizontal stratification are the only internal depositional structures. Fluid-escape pillars indicate post-depositional liquefaction. Associated facies are thick shale units, rippled siltstones, slurry sandstones, classical turbidites, slump sheets, and clastic injections.

The Tourelle Formation was deposited on the channelized mid-fan of a submarine-fan complex. Several major channels (to 13 m deep) contain sandstone fills which thin upward. Most asymmetric megasequences thin upward, and are also interpreted as channel fills. These cycles average 20 m thick. A model for the filling of submarine fan channels is presented. Well-defined thinning or thickening upward trends are not common, although thinning upward cycles dominate sequence (Markov) analysis.

At some outcrop localities, packets of coarse sandstone alternate with thick shale horizons, interpreted as mud blankets over abandoned mid-fan lobes. Rippled siltstones are interpreted as overbank deposits adjacent to distributary channels.

Thick sandstones can be divided into stratified or massive layers, which may be capped by normal tractional structures. Inverse-graded stratification bands (to 10 cm thick) are based by a near-horizontal scour surface. Several such "bands" form a division of stratification. Stratified layers are well graded (distribution grading), and have a strong and consistent a-axis fabric, with long axis parallel to flow. Upcurrent imbrication exceeds 20°. These layers were deposited beneath supercritical turbidity currents. Stratification bands formed by progressive "freezing" of a flowing grain layer at the base of the current.

Massive layers may be well graded, poorly graded, inverse-to-normally graded, or ungraded. a-axis grain orientation is most strongly developed at the base and top of layers. The middle parts of individual units may have bimodal or isotropic fabrics, with both upcurrent and downcurrent imbrications. Most massive layers, or divisions, were deposited rapidly from dense, supercritical turbulent suspensions as a result of decreasing current capacity at velocities on the order of 10 m sˉ¹. Unusually thick layers containing enormous blocks were probably transported by laminar debris flows on slopes of 0.02 to 0.05.

The average composition of Tourelle sandstones is 45.6% quartz, 8.2% feldspar, 13.4% rock fragments, 16.1% chloritic matrix, and 15.3% calcite "cement". These sands contained 10 to 15% primary detrital matrix. The most distinctive rock fragments are radiolarian chert, and mafic to felsic volcanic detritus. The heavy mineral suite contains rounded ultrastable zircon and tourmaline, abundant epidote group minerals and garnet, unstable prismatic hornblende and pyroxene, and 18% transluscent cherry-red chromite.

Tourelle detritus was derived by erosion of rising cordillera and obducted ophiolites in the interior of the nascent Taconic orogenic belt, and represents the first influx of detritus from a southeastern source. Previous sediments were eroded directly from the Grenville shield and its fringing carbonate bank. These sediments were recycled to form Tourelle sands.

A plate tectonic model is proposed which involves closing of a marginal ocean basin along a southeastward-dipping subduction zone, collision of the ancient continental margin of North America with a volcanic are situated on a micro-continent of crystalline Grenville basement, and obduction of a large sheet of ophiolite. Previously published models do not provide a source area for the Tourelle Formation, and must be considered inadequate.

The Tourelle dispersal system consisted of a series of small, closely-spaced and coalescing submarine fans which were consistently deflected to the west along a sloping, elongate depositional trough.

abstract: Doctor of Philosophy (PhD)


title: Key Aspects of the Operation of Immersion Programmes

contributor:
Najm, S.M.
Lepicq, D.
French

subject: French

subject: French and Francophone Language and Literature

abstract: The existing types of French Immersion programmes1 have been extensively examined, tested and analysed with respect to the linguistic and scholastic progress of the participating students. Such factually based findings would suffice for evaluating results achieved by most educationally innovative programmes. However, French Immersion is a programme that seeks to promote in the student not only a measurable linguistic mastery of the target language, but also the acquisition of knowledge of the second culture and, as well, the development of those attitudes and predispositions which favour acceptance and appreciation of the French language, French-Canadian culture and francophones generally. The goals of the programme are, therefore, not purely academic, but also cultural, psychological, emotional and social. Such a far-reaching enterprise inevitably entails profound changes in the structure of the traditional curriculum and risks influencing the attitudes of the various people involved (teachers, parents, administrators, students) toward the learning process and may affect their mutual relationships. The programme's impact on these members of the Immersion community has been important, and it has induced great changes in the traditional relationships among these groups. Yet there has been little attempt to analyse these spin-off effects inherent to the programme, to understand them or come to grips with the problems they produce. Issues as fundamental as setting out clear, measurable goals and procedures for the Immersion programme, teacher training, curriculum, working conditions, effects on the Regular-stream (English) component of the school, public relations and accountability have been largely ignored. Having been an Immersion teacher for four years, I am very aware of the need to further this type of investigation of academic and para-academic components of the programme and also to establish new ground rules for interaction in the altered Immersion community. It is for this reason that I decided to analyse the programme's structure, operation and relationship with the community in the light of recent research in such areas as the psychology of language learning, second language pedagogy, organization and public perception of Immersion programmes "in other locations,2 my own experience and observations and so on. A questionnaire I devised and distributed to educators involved with the Immersion programme provided a wealth of personal reactions, criticisms and suggestions to help deepen and illustrate my findings. In this project, my exposition of different organizational and interactional problems (Chapter II), leads to a series of practical recommendations (Chapter III), offering strategies and detailing resources appropriate for dealing with the major types of problems arising in this particularly demanding and controversial programme. This research project should add significantly to knowledge on hitherto neglected pedagogical aspects of one French Immersion programme and on human interactions within the school itself (teachers, principals, students, Regular-stream and Immersion), and relations between school representatives and the surrounding community (parents, politicians, school boards, public opinion, media, etc.). It should constitute a useful source of information for a critical revision of self-examination of attitudes and behaviours of teachers, administrators and parents involved in the Immersion programme and eventually help to suggest necessary adjustments and changes in the future policies and strategies of those above mentioned both on a pedagogical and interactional level. By providing information and recommendations, my aim is to contribute to a more efficient and harmonious learning and teaching environment for all those involved in an innovative and worthwhile educational enterprise.

abstract: Master of Arts (MA)


title: "Fierce warres and faithfull loues" Edmund Spenser's Pictorialism: Motifs of Mars and Venus in The Faerie Queene and Renaissance Visual Art

contributor:
Roebuck, W.G.
English

abstract: This thesis involves an exploration of the relationship between the pictorial nature of Spenser's The Faerie Queene and the visual arts. The doctrine of ut pictura poesis indicates that the affinity between the sister arts of painting and poetry was of fundamental concern in the Renaissance. The extent of Spenser's awareness of and familiarity with the visual arts is a contentious point, but there are indications of possible connections. There are many possible visual influences by which Spenser could have been acquainted with traditional modes of representation. Spenser's pictorial technique involves a pattern of painting a picture rich in emblematic detail and then withdrawing from description to comment on this easily visualized depiction. He thus sets up a system of clarification and doubt that requires a wary and alert reader. In discussing Spenser's pictorialism, the myth of Mars and Venus provides a good example, especially as the theme of love and war is common throughout the poem. Through the repetition of certain key elements together in one picture, a motif is set up so that the reader eventually recognizes this image as having meaning and significance in itself. Some of the individual features are also present in visual depictions of the lovers, showing a shared tradition of the way in which a subject or figure was frequently portrayed. The negative aspects of the Mars and Venus story are demonstrated well by this motif. Each time it appears there are subtle differences that should alert the reader. There are also positive and humorous sides to the myth of Mars and Venus and just as there are characters who illustrate the negative side, so, too, are there those that are types demonstrating these other two aspects. Thus through an examination of the relationship between painting (and the other visual arts) and The Faerie Queene, added dimensions of meaning can be enjoyed by the reader.

abstract: Master of Arts (MA)


title: Electrodeposition of Co-Mn and Cu-Mn based Spinels onto Solid Oxide Fuel Cell Interconnects

contributor:
Petric, Anthony
Materials Science and Engineering

subject:
Spinel
Solid Oxide Fuel Cell
Coating
Other Materials Science and Engineering
Other Materials Science and Engineering

abstract: Solid oxide fuel cells are an efficient method of converting hydrocarbon fuels to electrical power. However, due to some problems with poisoning, these have made no headway in the energy market. The evaporation of chromium oxides from metallic current collectors causes rapid degradation of the cells on the cathode side. It has been shown that spinel coatings reduce the effects of chromium oxide evaporation. In this thesis, two spinel systems are explored for potential application. Cobalt-manganese spinel is a stable spinel which have a wide range of composition, while remaining sufficiently conductive. Copper-manganese spinel, which is much more conductive than cobalt-manganese, is slightly less stable, but nonetheless a candidate. All components of the spinels explored can be electrodeposited from aqueous solutions, at room temperature. By controlling the concentrations of metallic ions, and other additives, coatings can be deposited on interconnecting plates with reproducible results. The newly coated interconnects can be oxidized in-situ. For characterization, the samples for this thesis were oxidized at 800°C. Two substrate materials were used, ferritic stainless steel and a chromium-iron alloy. Stainless steel substrates showed good coating adhesion, but high concentrations of iron were found in the spinel structure. Chromium alloy substrates were better protected by spinel coatings. However, nitride formation at the substrate interface caused localized delamination of the coating. It was shown that plating operations can be scaled up to 10 cm by 10 cm plates, with little modification of the processes used.

abstract: Master of Applied Science (MASc)


title: Analytical and Biomedical Applications of Porous Membranes

contributor:
Ghosh, R.
Chemical Engineering

subject:
Membrane
microgel
analytical
pattern
Membrane Science
Membrane Science

abstract:
Membrane filtration is widely used to biomedical and analytical applications. Compared to other techniques available membrane filtration provides fast processing time, easy availability, robust performance and relatively low cost. These advantages make ultrafiltration and microfiltration well integrated into bioseparation, purification of biomedical materials and downstream polishing. Apart from the advatanges, there are certain drawbacks with microfiltration and ultrafiltration. While perceived negative in many scenarios, the effects does not necessarily counteract the purpose of the process and could find some useful applications if treated from a different perspective.

By the virtue of fast processing of membrane filtrations, applications were made in processing biomedical materials and developing analytical methods. Poly(N-isopropylacrylamide) microgels are of potential in many biomedical applications. Microfiltration and ultrafiltration of such microgels for fast purification were explored. Meanwhile, the environmental responsive behaviours of such microgels bring about opportunity and challenge. Investigations were made on the salt-responsive transmission behaviours of microgels in microfiltrations. A hypothesis was raised and verified. Implications of applications in vivo were drawn based on experimental results. Many techniques for analysis of protein-drug binding have been under development. A new alternative utilizing pulsed tangential flow ultrafiltration was developed in this study and used to obtain binding data between aspirin and BSA under different conditions. The performance of the systems was assessed under different parameter settings. Possibility of further automation was discussed. On account of the fouling and concentration polarization, a new perspective was taken with the effort of developing such effects into potential applications. Patterned fouling was introduced and the fouled membrane was used to filter coloured feed to reveal the patterns transferred. Concentration polarization in ultrafiltrations with different levels of fixation of membranes was visualized by dyed particles. The possible flow modes under these conditions were suggested. A hypothesis was attempted from a fluidics point of view.

abstract: Master of Applied Science (MASc)


title: The Substitutability and Separability of Monetary

contributor:
Robb, A.L.
Leach, J.
Economics

subject: Economics Economics

abstract:
In this thesis, I have three objectives: (1) to estimate the substitutability/ complementarity relationship between monetary assets; (2) to systematically test the empirical significance of the separability (aggregation) assumptions implicit in broad definitions of money, and (3) to compare the use of simple-sum and Divisia monetary quantity indices as data in an empirical demand system.

The theoretical part of the thesis consists of deriving a system of monetary asset demand equations from an individual model of utility maximizing behaviour. This model takes advantage of a number of important advances in the theory of models of utility maximization in this context, such as: the duality between direct and indirect utility functions; and the theory of two-stage optimization.

For our empirical work, we use a demand system which is derived from a flexible functional form interpretation of the indirect translog utility function. The use of such an approximate demand system enables us to impose theoretical restrictions through explicit side constraints on the parameters, thus permitting statistical tests of their validity. Moreover, as Denny and Fuss (1977) have shown, the approximate trans log model permits a less restrictive test of separability than the Berndt-Christensen exact translog framework.

The model was applied to quarterly Canadian data for the period 1968I-1982IV, and was estimated using Barten's (1969) F.I.M.L. method for estimating singular systems.

The results obtained from the study lead to a number of important conclusions and are also of value as indicators of potential future research.

abstract: Doctor of Philosophy (PhD)


title: PREDICTION OF CUTTING COEFFICIENTS DURING ORTHOGONAL METAL CUTTING PROCESS USING FEA APPROACH

contributor:
Ng, Eu-Gene
Elbestawi, Mohamed
Veldhuis, Stephen
Mechanical Engineering

subject:
Finite element analysis
Metal cutting process
Arbitrary Lagrangian Eulerian
Manufacturing
Manufacturing

abstract: Finite element analysis (FEA) employs a science-based approach in which the complete machining process can be simulated and optimized before resorting to costly and time-consuming experimental trials. In this work, cutting coefficient of AISI 1045 steel will be estimated using finite element modelling using Arbitrary Lagrangian Eulerian formulation (ALE). The estimated values are then experimentally validated. A parametric study is carried out after in order to investigate how some cutting parameters can affect the cutting coefficients. The process parameters to be varied include feed rate, cutting speed, and cutting edge radius.

abstract: Master of Applied Science (MASc)


title: Exploring the built environment and physical activity in rural Ontario health units

contributor:
Valaitis, Ruta
Donna Ciliska, John Eyles
Nursing

subject:
built environment
physical activity
rural
public health
obesity
chronic disease prevention
Environmental Public Health
Public Health and Community Nursing
Public Health Education and Promotion
Environmental Public Health

abstract:
The purpose of this thesis was to explore how health units servicing large rural populations in Ontario are integrating the built environment into public health interventions related to physical activity for the purpose of fostering healthy and sustainable communities. Additionally, this research sought to identify barriers and/or enabling structures that rural health units face in addressing the built environment within physical activity programming.

This exploratory research study employed a descriptive qualitative approach. Semi-structured interviews were conducted with a purposeful sample of public health practitioners and managers identified by participating health units (n=12) as those most knowledgeable about program planning, implementation, and policy development in relation to physical activity and the built environment. Key themes were identified using qualitative content analysis and an inductive approach.

The types of interventions were: engagement with policy work at a county or municipal level; building and working with community partners; gathering and providing evidence; hosting knowledge sharing opportunities; program development and implementation; social marketing, information sharing and awareness raising; and resource development and dissemination. Barriers and enabling processes and structures were identified at an organizational, community, and systemic level. Specific rural contextual enablers and barriers were also identified.

This was the first study to the researchers’ knowledge that has examined current practices of Ontario’s rural health units related to built environment initiatives. In-depth perspectives elicited from public health practitioners and managers address gaps in the literature and contributes to new knowledge regarding built environment interventions to enhance physical activity in rural settings.

abstract: Master of Science (MSc)


title: Curvature Analysis of Aeromagnetic Data

contributor:
Morris, William A.
School of Geography and Geology

subject:
Geophysics
Statistics
Aeromagnetics
Digital Signal Processing
Mineral Exploration
Quality Control
Geophysics and Seismology
Geophysics and Seismology

abstract: Fundamentally the amplitude, sign, and frequency of a magnetic signal are inherently linked to curvature. This thesis employs curvature analysis as a semi-automated tool for source signal extraction from a magnetic field surface represented by a grid. The first step is to compute the full, profile, and plan curvatures from the magnetic grid. These values are used in two approaches to curvature analysis: statistical and lineament. The descriptive statistics mean, standard deviation, kurtosis, and skew are computed for quantitative analysis. Mean is used in conjunction with kurtosis and skew to assess frequency content of the signal, magnetization and source dip. Standard deviation characterizes low, moderate, and extreme curvatures. A rapid technique to statistical analysis is applied using a graphical approach with histograms and scatterplots. Histograms display frequency distribution and scatterplots display the relationship between different curvatures. Curvature in the maximum dip direction is used to systematically identify surficial lineaments characterized as continuous troughs or ridges. These lineaments may represent geological sources or remanent acquisition artefacts. Lineaments representing faults and dykes are used in conjunction with a priori knowledge to determine mineralization vectors since many ore deposits are structurally controlled. Quality control of the aeromagnetic grid levelling application may be assessed using spatial correlation of flight lines and magnetic lineaments. In this work curvature analysis is applied to simple synthetic models and two Canadian aeromagnetic data sets. Curvature analysis was applied to magnetic data from the Wopmay Orogen to identify bedrock contacts, fault configurations, and dyke swarms. The data was also used to show lineaments displayed as rose diagrams may be used as an alternative to standard Fourier power spectrums for assessment of levelling. Magnetic survey data from Southern Ontario was used to show a statistical approach to identify regional dip, dominant magnetization, and interference in anomalies.

abstract: Doctor of Philosophy (PhD)


title: Alterations in Skeletal Muscle Strength and Mitochondrial Function Induced by Aging and Exercise

contributor:
Tarnopolsky, Mark
Kinesiology

subject:
oxidative stress
sarcopenia
muscle atrophy
inactivity
fatigue
Exercise Science
Musculoskeletal Diseases
Exercise Science

abstract: Introduction: Mitochondria are important organelles for skeletal muscle function. Mitochondria are susceptible to many forms of stress that alters their morphology, energy generation and reactive oxygen species (ROS) production, which collectively promote degeneration and dysfunction in skeletal muscle. These processes are implicated in many health disorders, particularly in the aging process itself. Exercise is well established to increase muscle mitochondrial content and thus may attenuate several aspects of mitochondrial deterioration. Methods: Both human and animal models of mitochondrial stress (aging, ROS) were utilized in order to determine their effects on mitochondrial and muscle function. Additionally, exercise training was used in order to assess its therapeutic potential in ameliorating defects in oxidative capacity, muscle atrophy and metabolic adaptation in skeletal muscle. Results: Aging resulted in reduced strength, aerobic capacity, larger intramyocelluar lipid droplets and fewer mitochondria in skeletal muscle. These changes were related to suppressed lipid metabolism, mitochondrial dynamics and organelle turnover. Habitual aerobic exercise partially attenuated the age-related loss of muscle strength and aerobic capacity, presumably due in part to improved mitochondrial function. Persistent mitochondrial oxidative stress prevented mitochondrial adaptations to exercise training in mice, a phenomenon that may explain why exercise cannot fully counteract the effects of aging in skeletal muscle. Conclusions and significance: This work furthers our knowledge of the mitochondrial consequences of aging and the therapeutic potential of aerobic exercise within skeletal muscle. These results can be applied to other differentiated tissues that are severely affected by aging (brain, heart) and the effects described here are likely relevant to other conditions that result in muscle atrophy and energetic insufficiency.

abstract: Doctor of Philosophy (PhD)


title: Towards a Perspective on the Perpetuation of the Canadian Federal System: Federal-Ontario Relations in University Education , 1945-1970

contributor:
Aster, H.
Political Science

subject:
Political Science
Political Science

abstract:
The literatures on federalism, integration, and political development all tend to present the progressive centralization of popular allegiance and political power over time as the normal and expected pattern of the historical experience of federations and other states. Canada is an ongoing federation which does not conform to this model. Canada's internal fragmentations seem at least as compelling as ever, even after more than a century of federal union. Yet the federation has managed to endure while maintaining its divisions. In recent years certain Canadian provinces have become increasingly assertive and persuasive advocates of full autonomy in fields of provincial jurisdiction. They have also sought the fiscal capacity to implement this authority. For a number of reasons some provices have induced the federal government to abandon its practice of unilaterally making policy in fields of provincial jurisdiction. Because the federal government retains an interest in these services (which include health, welfare, and education), and because some other fields of mutual concern (notably natural resources) are under joint supervision, direct negotiation between executives of federal and provincial governments has become a familiar characteristic of the federal system since the middle 1960's. This new development in federal-provincial relations is often called executive federalism.

The study comprises a case study analysis of the evolution of the federal-provincial relationship in one jurisdiction, between the federal government and one province, over a specified time period. Federal and Ontario government files, and interviews with civil servants, supply most of the research material. The immediate objective is a preliminary assessment of how and how well the two sets of government executives have accommodated their conflicting interests in the university field. Ultimately, such a finding suggests some generalizations about how the Canadian federal system is evolving and is being perpetuated in a period when disagreement between federal and provincial governments is the most intense in Canada's history. A set of terms is introduced as analytic tools to assist in a discussion of the dynamic social environment in which federal systems operate. Such as exercise facilitates the attainment of a new perspective on the relative status of the two levels of government in Canada at this time, and helps to promote an appreciation of the proper strategy for managing intergovernmental conflict. These tools may prove useful in future comparative studies of intergovernmental public policy making in federal states.

It is concluded that executive federalism is inevitable and workable in the present federal-provincial climate. In any case, no practical alternative now exists or is likely to appear soon. Although both federal and provincial governments have sacrificed their interests to some degree in executive federalism, only the federal government had surrendered fiscal and jurisdictional manoeuvrability. It is suggested that the federal government consider bringing the provinces into the making of policy in federal fields of provincial concern. Such as alteration of executive federalism might weaken provincial government resistance to continued federal involvement in provincial jurisdictions, and thereby lessen conflict in federal-provincial relations and safeguard the federal government's remaining leverage in provincial fields.

abstract: Doctor of Philosophy (PhD)


title: Towards Healthier Aboriginal Health Policies? Navigating the Labyrinth for Answers

contributor:
Coleman, William
Political Science

subject: Aboriginal health policy; Health Transfer; Community-based research; Self-determination; Health governance

abstract:
The purpose of this dissertation is to discuss and evaluate processes and institutional structures that influence relationships between Aboriginal communities and government in the development, implementation, and evaluation of health policy. It explores the changing nature of Aboriginal health policy and politics in Canada and examines the shift to self-determination that has transpired in Canada’s Aboriginal health policies focusing on their application to Aboriginal peoples. This dissertation examines two Aboriginal health policies in Canada: the federal health transfer policy and Ontario’s Aboriginal Healing and Wellness Strategy. Both policies are intended to improve health at the community level by supporting the development of community-based and culturally appropriate health programs. Thus, using community-based research methods, this dissertation maps some of the key political stakeholders in Aboriginal health policy, from local level community members and health representatives to peak provincial and federal Aboriginal organizations, to the offices of ministers in Canadian parliament. I reflect upon the processes and institutional structures that shape relationships between the Aboriginal community-controlled health sector and government.

I examine several First Nations communities in northern Ontario involving both federal and provincially supported initiatives to illustrate the strengths, weaknesses and paradoxes that surface from the implementation of locally controlled health programs. I contrast these efforts with a second First Nations community in Manitoba that operates solely under the federal health transfer policy. I juxtapose these two communities to assess whether additional layers of community-controlled initiatives make tangible differences to community wellness; particularly for Aboriginal peoples living off reserve. This dissertation is being written under the theoretical assumption that governance and community wellness are intrinsically linked. Arguably, there is a definitive correlation between self-determination and community well-being; self-determination may be a determining factor in improving conditions for Aboriginal peoples and understanding resiliency.

This dissertation is about a long lasting colonial legacy of social inequalities in Aboriginal health but also about the incredible successes in Aboriginal health. It is also about the many challenges of Aboriginal representation and self-determination in the context of contemporary Canadian society.

abstract: Doctor of Philosophy (PhD)


title: An Experimental Analysis of Response Differentiation

contributor:
Platt, J. R.
Psychology

subject:
Other Psychiatry and Psychology
Other Psychiatry and Psychology

abstract:
Four experiments were undertaken to identify properties of differential reinforcement relevant to response differentiation. Differential reinforcement was given for the length of "runs" of pigeons' key pecks, the length of a run being defined as the number of responses on a key preceding a spatially different terminal response.

In Experiment I, a criterion run-length was assigned each subject and each subject was reinforced only following emission of a run-length which exceeded its criterion. Criterion run-lengths of 5, 10 and 20 responses were assigned to different groups. Mean run-lengths (N) were related to criteria (n) by a power function:N = 2.63 n^0.69. The fractional exponent of this function implies that the proportion of responses exceeding criterion was lower for higher criterion values. Because reinforced response values were confined to an extreme of the dis tribution, a lower proportion of reinforced response values indicated a greater difference between the distribution of values of the response emitted by a subject and the distribution of values reinforced. Since higher criterion values produced higher asymptotic mean run-lengths, the differential between emitted and reinforced run-lengths was also related to asymptotic run-length.

A similar relationship between mean run-length and the proportion of responses exceeding a criterion was obtained in Experiments II and III. These experiments used a differential reinforcement paradigm in which thecriterion was continuously adjusted for each subject so that a constant proportion of its distribution of run-lengths exceeded its criterion. In Experiment II, the proportion of the distribution exceeding the criterion was set at 15%, 30% or 45%, for different groups. However, only a random half of the run-lengths exceeding the criterion for animals in the 30% group, and one-third of those for the 45% group were actually reinforced, so that the overall probability of reinforcement was constant at 0.15 for all groups. Increases in the mean length of runs were obtained for all groups, with the 15% group exhibiting a more rapid change and a higher asymptotic mean run-length than the 30% group, which in turn exceeded the 45% group.

In Experiment III, pigeons were reinforced only for run-lengths in the most extreme 30% of their run-length distributions. One group received reinforcement for a random half of these run-lengths, while others received reinforcement for all of the run-lengths in this range. The relative extremeness of run-lengths selected for reinforcement was therefore constant (30%) 'vhile the overall probability of reinforcement was either 0.30 or 0.15. Increases in mean run-length were obtained, but no differences in the rate of change or asymptotic mean run-length were found between groups.

The results of Experiments II and III suggest that the relative extremeness of run-lengths selected for reinforcement, that is the differential between emitted and reinforced run-lengths, determines the rate and extent of changes in values of a response. The relationship between the relative extremeness of reinforced response values and the rate and extent of changes in emitted response values was further

demonstrated in Experiment IV. Reinforcement was provided for a fixed area of the distribution of run-lengths closest to a specified target value. For one group, the area of the distribution reinforced was 15%, while another group was reinforced for a random half of run-lengths in the closest 30% to the target. Reinforcement probability was thus held constant at 0.15. Mean run-lengths changed in the direction of the target at a rate dependent on the difference between the mean run-length and the target run-length. An asymptote was reached (rate of change = 0) when mean run-length approached the target value (differential = 0). The relationship between asymptotic mean run-length and target run-length was nearly linear for both 15% and 30% groups.

The results of this series of experiments were discussed in terms of a hypotnetical differentiation process emphasizing the differential between the central tendencies of the distributions of emitted and reinforced response values, expressed in percentage units. When a differential exists, a change in the distribution of response values occurs in a direction which tends to reduce the differential, and at a rate proportional to the magnitude of the differential. When no differential exists, no change occurs. Since change in many dynamic response properties is resisted in a way which suggests an opponent process (e.g.iLaw of Least Effort), the asymptote reached after differential reinforcement represents an equilibrium between differential reinforcement and its opponent process. The increased effectiveness of differential reinforcement when relatively more extreme response values are reinforced would thus not only result in greater rates of change, but would also overcome the resistance of the opponent process to a greater extent,shifting the equilibrium point to a higher value.

abstract: Doctor of Philosophy (PhD)


title: A DRUG DELIVERY APPROACH TO OVERCOMING FIBROUS TISSUE GROWTH ON POROUS POLY(LACTIC-CO-GLYCOLIC ACID) DISCS AND STUDY OF SCAVENGER RECEPTOR MEDIATED RESPONSES TO BIOMEDICAL MATERIALS

contributor:
Jones, Kim S.
Margetts, Peter J
Brash, J.L.
Biomedical Engineering

subject:
Biomaterials
Scavenger Receptors
Foreign Body Response
Medical Devices
Immune Response
Biomedical Engineering
Biomaterials
Biomaterials

abstract: A compatible interface between a biomedical material and host tissue is paramount to the continual function and life-span of medical devices that reside in the body. However, the unfavourable host response that ensues when foreign materials inhabit the body must be overcome for sophisticated medical devices, such as artificial organs and real-time biosensors, to be used clinically. My thesis research commenced with a search to find a pharmaceutical compound that could be incorporated into a medical device to suppress the accumulation of fibrous tissue. A prolyl hydroxylase inhibitor, a drug developed to inhibit collagen synthesis, was found to be effective at inhibiting collagen deposition within and on the outer surface of a poly(lactic-glycolic acid) disc, and also limited connective tissue ingrowth. Furthermore, the drug suppressed Scavenger Receptor A (SRA) expression on a macrophage-like cell culture, a receptor known to contain a collagenous domain. The latter finding prompted a review of the literature, upon which it was discovered that SRA mediates leukocyte adhesion and binding to an assortment of materials, such as silica, modified polystyrene, titanium, and iron(III) oxide. As a result, a series of studies were initiated to investigate whether leukocytes use SRA to detect a range of different biomedical materials. Consequently, we found that SRA contributes very little to leukocyte binding of two common medical polymers, polystyrene and poly(lactic-co-glycolic acid), but may interact with the materials to affect the cytokine profile in the local environment. In a subsequent study, SRA was found to be crucial to the leukocyte binding of polyanionic hydrogels. In summary, we have identified a unique pharmaceutical strategy for suppressing the accumulation of fibrous tissue on medical devices in vivo, and uncovered a mechanism of leukocyte stimulation in response to incubation with biomedical materials that the material science research community was not previously aware of.

abstract: Doctor of Philosophy (PhD)


title: Monitoring, Diagnosing and Enhancing the Performance of Linear Closed-Loop Real-Time Optimization Systems

contributor:
Marlin, Thomas E.
Chemical Engineering

subject:
Chemical Engineering
Chemical Engineering

abstract:
Linear Programming (LP) has a wide range of industrial applications, including closed-loop systems such as real-time optimization and the steady-state economic optimization at each execution of Model Predictive Controllers. This thesis presents new metrics for monitoring the performance of linear closed-loop real-time optimization systems, as well as new methods for improving their performance when necessary. A novel diagnostic method for ranking parameter importance with respect to the objective function is also presented.

Many standard methods are available for estimating the effects of parameter uncertainty on the objective function without a basis change, and more powerful existing methods require enumeration or sampling. This work introduces new sensitivity methods in LP problems with uncertain coefficients that can be correlated, appear in equality and inequality constraints, and have uncertainties with large enough magnitudes to lead to basis changes.

The new monitoring approach measures the uncertainty effect as the range between the maximum and minimum profit in the plant under closed-loop optimization, termed the Profit Gap, and both its maximum and expected values can be determined.

If the monitoring indicates a substantial Profit Gap could exist, the improvement step designs experiments to reduce parametric uncertainty. The unique experimental design maximizes the total profit during and after the experiment to the end of a production run.

Both the monitoring and improvement methods involve the solution of bilevel optimization problems, which include complementarity constraints. Results of application to a closed-loop gasoline-blending problem demonstrate the power of the methods. The studies include typical uncertainties and measurement noise and show the economic benefits possible through the application of real-time monitoring and improvement.

abstract: Doctor of Philosophy (PhD)


title: Item Concreteness and Spatial Location as Sources of Conflict Between Recall and Concurrent Visual Perception

contributor:
Brooks, L. R.
Psychology

subject: Psychology Psychology

abstract:
The relative contributions of spatial organization and item concreteness or picturability to recall processes was investigated by attempting to induce modality-specific interference between recall and response. Subjects learned lists of items which were varied in physical or referential visual characteristics. They later signalled information about them either vocally or via a visually-guided response.

Some ways of presenting lists for learning which are traditionally regarded as increasing reliance on mediating visual imagery were effective in generating conflict between recall and the visually-guided response; this effectiveness was limited to presentation conditions and list types which introduced spatial organization into the stimulus material. The concreteness of individual items was not useful in predicting visual conflict. Recall-response interference was eliminated by providing the subject with a response sheet which was spatially compatible with the stimulus array used during the learning phase.

The results are interpreted in the following ways: There are circumstances under which verbal mechanisms alone cannot account for recall processes when the to-be-recalled material is a list of concrete nouns. To account for these results one needs to postulate a mechanism which shares execution and/or control capacity with the visual system. The fact that spatial organization rather than item concreteness predicts visual conflict indicates a need to distinguish between these two factors in the study of internal visual representation. In subjects' attempts to recall information, spatial location is much more easily interfered with than the internal representation of formal characteristics of single items.

The distinction drawn between the internal representation of location and form in the thesis parallels a similar distinction that has been made with respect to visual perception in studies with humans and other vertebrate species. The results are also discussed in relation to attempts to distinguish semantic and imaginary mediators of learning on the basis of modality-specific interference.

abstract: Doctor of Philosophy (PhD)