title: The effect of obesity on cognition in adults with and without a mood disorder

contributor:
Taylor, Valerie
Neuroscience

subject:
Obesity
Cognition
Major Depressive Disorder
Bipolar Disorder

abstract: Obesity is a common medical illness that is known to confer risk for a large number of medical illnesses, such as Type II Diabetes, hypertension, cancer, and late-life dementia. More recently, the relation between obesity and decline in cognitive performance, independent of other comorbid medical conditions, has begun to be examined. Individuals with mood disorders (Bipolar Disorder [BD] or Major Depressive Disorder [MDD]) display an increased prevalence of both obesity and risk factors for cardiovascular disease. Moreover, BD and MDD are associated with impairment in cognitive functioning across multiple domains. The contribution of obesity to cognitive decline in this population has not been explored. This thesis begins with a systematic review of the literature examining the impact of obesity on cognition, providing a thorough background of this relation. The following chapter introduces a prospective cohort study designed to comprehensively explore the relation between obesity and cognition in individuals both with, or without, a mood disorder. The first of set of results from this study are presented in the remaining chapters. The neuropsychological study findings indicate that MDD and obesity may have an additive effect on cognition, resulting in significant cognitive decline in obese adults with MDD. Moreover, we show that different neural activation patterns are seen during a cognitive magnetic resonance imaging (MRI) task in obese versus obese MDD patients. Collectively, this provides strong evidence that populations already at risk for cognitive impairment, such as mood disorder populations, are susceptible to further cognitive changes due to increased weight.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: AN EXPERIMENTAL STUDY OF THE EFFECTS OF SURFACE ROUGHNESS AND SURFACTANT ON POOL BOILING OF NANOFLUIDS

contributor:
Hamed, Mohamed
Mechanical Engineering

subject:
Pool Boiling
Nanofluids
Surface Roughness
Surfactant
Nucleate Boiling
HTC
Deposition
Dispersant
SDBS
Stability
Nucleation Frequency
Bubble Size
Isolated Bubbles

abstract:
The use of nanofluids as heat transfer fluids has received a lot of attention from the heat transfer research community. Due to the increased thermal conductivity of nanofluids over their base fluids, the number of nanofluids scientific publications increased significantly in the past decade. The effects of the heated surface roughness, nanoparticles and surfactant concentrations on pool boiling of nanofluids have been thoroughly investigated. However, contradicting findings have been observed under what appeared to similar test conditions.
In this experimental investigation, two boiling surfaces have been prepared with an average surface roughness of 6 and 60 nm using high precision machining. Alumina Oxide-Water based nanofluids have been used in this investigation. The initial nanoparticle size reported by the manufacturer is 10 nm. The nanoparticles concentration has been kept at 0.05 wt. %. A Sodium Dodecylbenzenesulfonate (SDBS) surfactant has been added to the nanofluids in order to improve its stability. Results showed that the nanofluids boiling performance depended on the boiling surface roughness. The heat transfer coefficient (HTC) obtained in the case of the smooth, mirror finished surface showed an enhancement of 205% with respect to pure water. This trend was reversed in the case of the rough surface which is believed to be due to significant nanoparticles deposition. The HTC obtained with the rough surface was 12% lower than that of pure water. The effect of the surfactant concentration on nanoparticles deposition has been investigated by changing the surfactant concentration from 0.1 to 1.0 wt. %. In the case of the rough surface, the increase of surfactant concentration was found to reduce the formation of the nanoparticles deposition layer. The HTC obtained with the higher surfactant concentration was increased by 46 %.
The effect of nanoparticles concentration on the smooth surface shows an unexpected trend of 20 % reduction of the transfer rate of the nanofluids coupled with the increase of the nanoparticle concentration from 0.05 to 0.1 wt. %. However all concentrations showed heat transfer enhancement with respect to pure water. The minimum heat transfer coefficient ratio enhancement was 11 % using 0.1 wt. % nanofluids with respect to pure water.
Since nanoparticles deposition has been observed and attributed to micro-layer evaporation, an investigation has been carried out to examine the nucleation process during the pure water and nanofluids pool boiling. The bubble growth rate in both cases was analyzed at different wall degrees of superheat ranging from 104.3 to 105.9 ºC. In addition, the bubble departure diameter and frequency have been measured and compared for both cases. The nanofluid bubble size was about 80 % smaller than that of pure water. The nanofluid bubble departure had almost constant frequency of 500 Hz over the range of wall superheats whereas the maximum bubble frequency in the case of pure water was 22.72 Hz.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: PREVENTION OF CLOSTRIDIUM DIFFICILE INFECTION

title: Prevention of Clostridium difficile infection: a systematic review and critical appraisal of clinical practice guidelines and an independent participant data meta-analysis on probiotics for prophylaxis in adults and children administered antibiotics

contributor:
Johnston, Bradley C
Mertz, Dominik
Health Research Methodology

subject: Clostridium difficile

subject: Individual participant data meta-analysis

subject: Clinical practice guideline

subject: Probiotics

abstract:
Clostridium difficile infection (CDI) prevention is of high priority. We reviewed clinical practice guidelines (CPGs), and conducted an individual participant data meta-analysis (IPMDA) of randomized controlled trials (RCTs) to assess effectiveness and safety of probiotic prophylaxis.
For CPGs, we rated quality, summarized recommendations with their strength and author-reported evidence, then re-evaluated evidence. For the IPDMA, we pooled RCTs investigating probiotics versus control for CDI prevention among antibiotic consumers, using generalized linear mixed models. Our outcomes were CDI and serious adverse events (SAEs). We adjusted for age, sex, hospitalization status, and exposure to high risk antibiotics. We assessed study risk of bias and confidence in estimates of effect.
Five international guidelines were evaluated, and all scored poorly for applicability, stakeholder involvement, and rigor of development. Recommendations were not always linked to evidence, and guideline authors were not transparent about how evidence limitations impacted their decisions. None of the guidelines recommended probiotics.
Fourteen studies contributed data, with one pending. Probiotics reduced CDI among all studies and the adjusted model. No covariates were significantly associated with CDI. Subgroups suggested that high incidence did not affect probiotic effectiveness, and high-dose, multi-strain probiotics were more beneficial. Our estimate was robust to sensitivity analyses. Probiotics did not significantly affect SAE odds among all studies and the adjusted model. Increasing age was a significantly associated with SAEs. No SAEs were reportedly probiotics-related. For both outcomes, estimates were similar from data of obtained and not obtained studies. Confidence in estimates was moderate for both outcomes, due to low event rates.
Current guidelines on CDI prevention did not adhere well to validated standards for development and reporting, most notably due to insufficient links between recommendations and supporting evidence. Our preliminary analysis suggests that probiotic prophylaxis is useful and safe for CDI prevention.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Clostridium difficile infection (CDI) is a common hospital-associated infection, and prevention is of high priority. We reviewed clinical practice guidelines on CDI prevention to summarize their recommendations, and assess the quality of guideline development and reporting. Furthermore, we analysed patient data from randomized clinical trials to obtain an overall estimate (meta-analysis) of whether using a novel strategy, probiotic prophylaxis, is effective and safe. The guidelines had several limitations, importantly that authors were not transparent about how recommendation were developed, and recommendations were not always linked to evidence. Although no guideline recommended using probiotics to prevent CDI, our advanced analysis of previously conducted trials suggested that it was an effective intervention, reducing infections by approximately 76%, and was not associated with differences in serious adverse events compared to participants not receiving probiotics. In summary, guidelines on CDI prevention should be improved, and probiotics may be considered as an additional strategy.


title: BLAST DAMAGE MITIGATION IN SUBMERGED SYSTEMS. PHASE I: INTERNAL EXPLOSION

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

subject:
Cold-formed steel
Blast
Damage Mitigation
Sacrificial Cladding

abstract:
This thesis is focused on quantifying the dynamic performance of lightweight metal sandwich systems under confined explosions, where this effort represents the first of a multi-phase comprehensive research program that is focused on developing blast damage mitigation techniques in submerged structures. A confined explosion occurrence inside such facilities may lead to paralyzing all operations depending on the functions of the affected sections. Subsequently, using sacrificial cladding placed as a physical barrier over critical components that might be vulnerable to a potential explosion is considered to be an effective blast damage mitigation technique. Furthermore, sandwich panels can be an ideal system to be used as sacrificial cladding, as it can be manufactured to possess high stiffness-to-weight ratio and superior energy absorption capabilities. Consequently, an experimental program was performed to investigate the performance of lightweight cold-formed steel sandwich panels under both quasi-static loads and confined explosions, where a total of fifty-seven sandwich panels were tested, considering various core configurations, different core sheet thickness, and different blast load intensity levels.
The American ASCE/SEI 59-11 and The Canadian CSA/ S850-12 blast design standards predict the dynamic response of a structure component based on the static resistance function by applying dynamic increase factors. Subsequently, the static resistance functions for the proposed panel configurations were investigated experimentally and compared with the introduced analytical model, in order to quantify accurately the inelastic panel response. The quasi-static test program was performed in two stages, where the first included eighteen single layer core sandwich panels, which represented longitudinal and transverse corrugated core configurations. The results of the first stage configurations demonstrated an efficient strength and stiffness, but showed a lack in energy absorption capabilities and ductility capacity. Therefore, in the second stage, different core configurations were developed, including twenty-one panels representing Bi-directional and X-core double layered core configurations and its counterpart Uni-directional single layer core configuration. The results of the second stage demonstrated an enhancement in the ductility and energy absorption capabilities compared to the configurations tested in the first stage. The residual deformations and failure modes demonstrated were assessed and discussed in details, where web crippling, local buckling and global buckling induced by shear or flexurewere determined. In general the static resistance functions for each tested panel were used to quantify the panels’ yield loads, ultimate capacities, and corresponding displacement levels. Moreover, the influences of both the core configuration and the core sheet thickness on the panels’ stiffness, ductility levels and energy absorption were quantified.
Based on the conclusions of the static testing and considering the ductility, capability of energy absorption, and the behavior beyond the elastic zone, two different core configurations were chosen to be tested under confined explosions. Eighteen panels were tested in a cylindrical shape blast chamber representing a typical submerged structure under different scaled distances ranged from 2.82 to 1.09 m/kg1/3, in order to demonstrate different damage state levels in accordance with the blast design standards (ASCE/SEI 59-11, CSA/ S850-12). In the blast testing results, the incident and reflected pressure time histories of the blast wave were measured, while the modified Friedlander equation was used to fit the first positive phase of the reflected pressure histories. In addition, the displacement response histories of the back face of the tested panels were recorded. The measured values of peak incident pressure, peak reflected pressure, incident impulse and the reflected impulse were compared to the predicted values using ConWep (Hyde 1990) considering the spherical explosion, and have shown a good agreement. Furthermore, the failure modes and the post blast damage were determined and compared to the static observations.
In order to complement the experimental program, a nonlinear inelastic single degree of freedom model was developed in order to predict the dynamic response of the sandwich panels. The model used the recorded blast load and the static resistance while applying the dynamic increase factors recommended by the standards (ASCE/SEI 59-11, CSA/ S850-12). The model results were in a good agreement with the experimental data. Furthermore, the different ductility and support rotation values obtained experimentally and predicted analytically were related to the different damage levels specified by blast standards. Finally, the influence of sandwich panel core configuration on the dynamic blast response of the tested sandwich panels was discussed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Study of the Distributed RC Low-Pass and Notch Filters as Feedback Networks in Active Circuit Design

contributor:
Campbell, C. K.
Electrical Engineering

subject:
feedback
circuit
RC network
distributed RC structure
frequency selective feedback
notch filter

abstract: The application of uniformly distributed RC networks as feedback elements in the design of active circuits has been investigated. Distributed RC structures were fabricated using Mylar Film, Teledeltos resistance paper and metallic foil, and used to experimentally verify the predicted responses of particular active and passive configurations. By exploiting the frequency selective feedback provided by a distributed notch filter it was possible to construct an active band-pass filter operating at 1 MHz which achieved a Q of 50 without the use of inductance. For the design it was important that the notch parameter was deliberately chosen to be less than optimum (i.e., a< 17.78) so that the feedback circuit did not apply positive feedback in the region of the notch frequency. Application of positive feedback (a> 17.78) and sufficient amplifier gain would convert the active filter into a feedback oscillator. As predicted, the band-pass filter response was strongly influenced by the amplifier gain and phase characteristic, while amplifier impedance exerted only minor effects.

abstract: Thesis

abstract: Master of Engineering (ME)


title: ASSESSING THE SPATIOTEMPORAL DYNAMICS OF CROP YIELDS AND EXPLORING THE FACTORS AFFECTING YIELD SYNCHRONY

contributor:
Kolasa, Jurek
Biology

subject: ecology

abstract: Variation in crop yields has significant impacts on food supply in many developing nations and on global food prices. I applied a recently quantified link between spatial and temporal variation to gain general insights on the dynamics of food production, as well as to test whether a prediction that relies on space-for-time substitution applies for crop yields, and at which spatial scale. I analyzed patterns of variation on global yield for 77 crops recorded in 212 countries over 22 years (1990 – 2012). I found that if we know how crop yields vary in space, we could predict variation in crop yields over time at various scales. Specifically, spatial variation can substitute for temporal variation in predicting the variability of yield of certain staple crops when synchrony and persistence (persistence = consistent differences in mean yield values among locations or regions) are taken into account. This space-time substitutability has potential to forecast temporal stability of food production from its spatial data alone, which should allow countries and various agencies to improve agricultural policies and production forecasts to ensure stability in local and global food supply. I also found that a crop’s preferred climatic conditions were strong predictors of synchrony between countries at the continental scale. This provided insights on the type of crops that are good candidates for effective use of spatial variability to predict their regional temporal variability in yields. These include crops that have high preferred-germination-soil temperature, low minimum crop water needs, and low minimum growing period. Lastly, as global warming increases crop yield synchrony, the total variability of global food supply increases, which results in lower stability in global food supply and exacerbates food insecurity. Combined with the predicted higher frequencies of climate extremes, the findings in this study reinforce the current view that climate change will have negative consequences on the global food supply.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Fluctuation in crop yields has significant impacts on food supply in many developing nations and on global food prices. I analyzed patterns of variation on global yield of 77 crops recorded in 212 countries over 22 years. I found that if we know how crop yields vary in space, we could predict fluctuation in crop yields over time at various scales. Since crop yields are the most important aspect in raising global food supplies, the ability to accurately forecast how much they will fluctuate would aid governing bodies in dealing with uncertainties and make informed decisions to ensure stability in local and global food supply. I also found that a crop’s preferred climatic conditions were strong predictors of its simultaneous drop (or rise) in adjacent countries. This helps to decide which crops are good candidates to use spatial variability in predicting their regional temporal variability in yields.


title: ASSESSMENT OF THE CLUMPED ISOTOPE COMPOSITION OF CALCITE FOR PALEOTHERMOMETERY

contributor:
Kim, Sang-Tae
Geography and Earth Sciences

subject:
clumped isotopes
calcite
geochemistry
paleothermometer

abstract:
Clumped isotope paleothermometry defines carbonate formation temperature based upon the relative abundance of the 13C18O16O isotopologue within CO2 (Δ47) formed through phosphoric acid digestion of carbonates. When precipitated in equilibrium, resultant Δ47 values are inversely-proportional to growth temperature, where 13C18O16O is more abundant at lower temperatures. To precisely define Δ47 values, a rigorous analytical protocol is required to: (1) minimize CO2-H2O isotope exchange during acid digestion; (2) purify CO2 to remove contaminants; (3) quantify the raw Δ47 value using a mass spectrometer configured for m/z 44 – 49; and (4) normalize the raw Δ47 value to account for machine-specific isotopic scrambling and Δ47 vs. δ47 non-linearity. Amongst laboratories with well-established analytical protocols, substantial disagreement still exists between proposed clumped isotope calibrations at low temperatures. To investigate the source of this discrepancy, calcite was precipitated between 15 – 40 °C from a HCO3-(aq)-dominated solution using an upgraded constant addition technique. This technique is the first to provide simultaneous control of δ18OH2O and δ13CDIC values of parent solution. Observed oxygen isotope fractionation between calcite and water is in agreement with Kim and O’Neil (1997), providing robust evidence of calcite precipitation in oxygen isotope equilibrium. Δ47 values were determined using McMaster’s clumped isotope facility, yielding the following calibration:

Δ47-RF = 0.0351 (± 0.0021) × 106/T2 + 0.2982 (± 0.0233)

This calibration observes a similar temperature dependency to theoretical models as well as ‘shallow’ slope experimental studies. To provide context to experimental calibrations with ‘steep’ slopes, we consider the non-equilibrium isotope effects of CO2 hydration/hydroxylation and HCO3- dehydration/dehydroxylation reactions on precipitating calcite. We propose that low temperature calcites primarily responsible for the ‘steep’ slopes of certain calibrations have partially inherited the disequilibrium isotope composition of DIC due to significant non-equilibrium isotope effects associated with the aforementioned CO2 hydration/hydroxylation and HCO3- dehydration/dehydroxylation reactions.

abstract: Thesis

abstract: Master of Science (MSc)


title: Preparation and Characterization of Cation Selective Permeable Membrane

contributor:
Dickson, Sarah
Kim, Younggy
Civil Engineering

subject: Selective membrane preparation and characterization

abstract:
Abstract
Heavy metals are used in many industrial processes and their cations are either valuable or environmentally harmful to discharge in wastewater. Thus, it is necessary to separate heavy metals in wastewater treatment. Amongst several technical methods of separation, use of permeable membranes is an important one. For separation processes, membranes can be selective towards a target heavy metal cation either against mono-valent common cations or against other similar heavy metal cations.

Synthesis of selective permeable membranes for separation purposes is an area of continuous research to meet specific needs in different applications. One of the common applications of selective separation by a permeable membrane is cation/anion separation processes using cation exchange and anion exchange membranes. Another application of selective permeable membranes is the separation of mono-valent cations from other higher valence cations.

Some researchers have focused on specific selective separation of heavy metal cation from other heavy metal cations having the same valent charge. Some use chelating particulates dispersed in a neutral polymeric membrane matrix and others applied a thin chelating film on the surface of a commercial cation exchange membrane.

In this work, the synthesis of novel permeable selective membranes and their use for selective separation between two di-valent heavy metal cations is presented. Three different sets of membranes were prepared in non-imprinted and imprinted forms. The ion imprinted membranes form is prepared by pre-reacting the target metal ion with the selective chelating monomer before applying in situ polymerization step, and in the non-imprinted membranes form this step is not considered. Their morphological and chemical structures were determined and their separation performances were investigated using a diffusion dialysis technique.

The first membrane (non-imprinted polyvinylidene fluoride-divinylbenzyl-triethylenetetramine (PVDF/diVB-TETA) and Cu-imprinted PVDF/diVB-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer divinylbenzyl-triethylenetetramine diVB-TETA (or diVB-TETA-Cu) within a PVDF substrate, using a divinylbenzene cross-linker. Fourier transform infrared FT-IR spectroscopy showed the successful in situ polymerization of the chelating monomer within the PVDF texture. The permeation study showed that the ion-imprinted membrane has a Cu2+ selectivity factor of 3.78, while the non-imprinted membrane has a Cu2+ selectivity factor of 1.65. In addition the Cu2+ permeation flux in the imprinted membrane is 3.9 time that in the non-imprinted membrane

For the second membrane, the synthesis is similar to the first membrane for both non-imprinted and imprinted forms (polyvinylidene fluoride-divinylbenzyl-triethylenetetramine-N,N'-methylenebis(acrylamide)   (PVDF/diVB-TETA-N) and PVDF/diVB-TETA-N-Cu respectively), except that the used cross-linker was N,N'-methylenebis(acrylamide). In addition, sodium 4-vinylbenzyl sulfonate was added in selected percentages, (5-15% mol), to enhance the permeation flux. FT-IR spectroscopy analysis of the prepared membranes confirmed the chemical structure of diVB-TETA-N and sulfonate group into PVDF. Permeation and selective separation studies for the prepared membranes showed that the ion-imprinted membrane has a higher selectivity for copper permeation over the non-imprinted membrane. However imprinted membrane showed a lower flux for the permeated cations than that of the non-imprinted membranes The addition of the sulfonate groups to the prepared membranes enhanced the flux of the permeated cations, but the copper selective permeation decreased for both types (non-imprinted and ion-imprinted). Moreover, the ion-imprinted membrane PVDF/diVB-TETA-N-Cu showed a lower flux for the permeated cations than that of the non-imprinted membranes PVDF/diVB-TETA-N. Selective separation factors decreased to unity when the content of the sulfonate groups increased to 15% mol. Ion imprinted membrane prepared with 10% of sulfonate group showed optimum copper selectivity factor (α = 30304) and permeation flux for copper (0.4949 μmol cm‒2 h‒1)

The third membrane (non-imprinted Selemion TM cation exchange membrane-divinylbenzyl-triethylenetetramine (CMV-S/diVB-TETA) and ion-imprinted CMV-S/diVb-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer, diVB-TETA (or diVB-TETA-Cu), on the surface of the commercial cation exchange membrane, Selemion, using divinylbenzene as cross-linker. FT-IR spectroscopy confirmed the chemical structure of the chelating polymer on the CMV-S membrane surface. Permeation study showed that ion-imprinted CMV-S/diVB-TETA-Cu membrane reached high separation factor (α = 17), yet the flux is low (0.0391 μmol cm‒2 h‒1). Non-imprinted CMV-S/diVB-TETA membrane of thickness (0.115±0.005 mm) using cross-linker (10% DVB) showed reasonable copper selectivity factor (α = 2.723) and permeation flux (0.433 μmol cm‒2 h‒1)

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Power of Spectacle: Shakespeare's Tempest in the Restoration

contributor:
Walmsley, Peter
Silcox, Mary
English

subject:
Restoration
The Tempest
Dryden
Davenant
The Enchanted Island
Shadwell

abstract: This thesis examines the complex relationship between drama and royalist politics during the English Restoration, and how power is translated through language and space. I focus primarily on Dryden and Davenant's adaptation of Shakespeare's Tempest, re-titled The Enchanted Island (1667), but also draw connections to Thomas Shadwell's operatic version of 1674 and Thomas Duffet's Mock Tempest of 1675. I argue that the new adaptations reinforced the superiority of a monarchical rule over an English commonwealth and republic and subverted radical political movements that had arisen during the English Civil War. I do so by applying Guy Debord’s theory of spectacle to the Restoration stage.  He defines spectacle is a "diplomatic representation of hierarchic society to itself, where all other forms of expression are banned" (Debord 23). Ultimately, conservative powers co-opted and appropriated subversive ideas and used the stage as direct access to public discourse.  By separately examining the low and high plot I will show how spectacle functions through language and images and works to reinforce Prospero as the ultimate vision of a 'father-king'. By drawing from Debord,  I will attempt to draw connections between modern day power structures, such as mass-media, and the Restoration stage. I argue that the means by which power is translated through mass media is analogous to how playwrights of the Restoration captured the attention of their audiences.

abstract: Thesis

abstract: Master of English


title: Spontaneous  Oscillations in a Gas-Fluidized-Bed

contributor:
Baird, M. H. I.
Chemical Engineering

subject: spontaneous, oscillations, fluidized, pressure

abstract:
 The spontaneous oscillations of a fluidized bed with a variable volume below the bed support are investigated.

 The pressure vs. time dependence of the fixed bed is determined for glassbeads of 3 size ranges and for hematite.

 For each case several different bed masses were employed. For the oscillating bed the influence on the frequency of the oscillations of the materials fluidized, the size of the particles, the chamber volume and the superficial gas velocity are studied.

 Models of five different authors have been reviewed and a model to describe the relationship between the frequency and various parameters such as chamber volume, bed mass, gas velocity and the pressure drop characteristic (Δp vs. μ) is derived. The latter together with three other models have been evaluated by means of the experimental data.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: NORTH KOREA DOES NOT EXIST: HUMAN RIGHTS IN ASYMMETRY

contributor:
Wylie, Lana
Political Science

subject:
North Korea
human rights

abstract:
The first three chapters of this dissertation critique the findings and recommendations of the February 2014 report of the United Nations Human Rights Council Commission of Inquiry on human rights in the Democratic People’s Republic of Korea (DPRK, North Korea).  They contend the report is grounded in hyperreal representational practices and functions as an instrument of securitization.  It thereby reifies the asymmetrical state of war that is a root cause of DPRK human rights violations.  These three chapters then function as a vehicle for the final two chapters that locate the primary origins of the Western understanding of North Korea within American/Western liberal ideology.  North Korea’s ideological position makes appropriate the framing of DPRK human rights violations as extraordinary by contrast to other comparable countries.
The Introduction asserts the relevance of the asymmetrical conflict between the DPRK and its adversaries and introduces the theories of Thierry Balzacq, Pierre Bourdieu, and Jean Baudrillard.  Chapter One critiques the selectivity and methodology of the report, particularly the de-temporalization, de-localization and extrapolation of allegations as representative of the experiences of ordinary North Koreans.  Chapter Two demonstrates the indeterminacy and hyperreal representational practices of the report’s findings of extraordinary crimes against humanity against hostile, starving and ‘abducted’ populations.  Chapter Three challenges the lack of DPRK objectivity in the report’s presentation of historical and geopolitical context, particularly the neglect of the consequences of the asymmetrical state of war.  Chapter Four introduces the philosophy of Slavoj Žižek and asserts its relevance to identifying North Korea as an abjected, gendered and racialized fantasy-space of American/Western liberalism (objet petit a).  Chapter Five considers the consequences of ideology for empirical critique and DPRK agency, advocating unconditional normalization and investment as the most ethical American DPRK policy.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: The Biology of Regulatory T Cells in Human Allergen-Induced Asthma

title: Regulatory T Cells in Allergic Asthma

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject:
allergic asthma
regulatory T cells
allergen challenge
Foxp3

abstract:
Regulatory T cells (Treg) are essential for the induction and maintenance of immunological tolerance to self and foreign antigens.  The development of allergic asthma is mediated by T helper cell type-2 (Th2) inflammatory mechanisms and may also involve, based on murine and human studies of allergic asthma, compromised Treg immune regulation.  Our overall objective was to more thoroughly elucidate the biology of Treg in allergic asthma, and to better understand their potential as a treatment for the disease.
	Initially, we characterized three different Treg phenotypes based on frequency and functional capacity.  We showed both quantitative and functional heterogeneity in circulating Treg.  Quantitative variability was also observed in circulating, but not airway, Treg when comparisons were made between healthy controls and asthmatic subjects.  These findings emphasize the need for clear definitions of Treg phenotypes, and that interpretation of their frequency and function in health and disease needs to be phenotype-specific.
	Next, we assessed the Treg response in mild allergic asthmatic isolated early responders and dual responders after allergen inhalation challenge.  We observed a reduced frequency of airway Treg after allergen challenge in DR, but not IER, associated with a smaller ratio of Treg to CD4+ cells. These data suggest that Treg to T effector cell (Teff) balance is important in the regulation of late asthmatic responses.
	Lastly, we evaluated the effects of two novel monoclonal anti-asthma therapies on circulating Treg after allergen inhalation challenge.  We demonstrated that neither anti-OX40L nor anti-TSLP therapy altered circulating Treg frequency, while anti-TSLP, but not anti-OX40L, was effective in attenuating allergen-induced airway responses. These observations demonstrate the need for further investigation into the effects of anti-asthma therapies on Treg as well as the development of novel therapies aimed at manipulating Treg in order to better control immune responses.
	The findings of this thesis enhance our understanding of Treg in allergic asthma.  Treg, utilized as stand-alone or adjunct therapy, may provide a novel therapy in the treatment of allergic asthma.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: X-Ray Crystal Structure Investigation of [Re(C5H5N)4 O2]Cl.2H20

contributor:
Lock, C. J. L.
Chemistry

subject: crystal, structure, x-ray, diffraction, bonds

abstract: The crystal structure of dioxotetrapyridine-rhenium(V) chloride dihydrate has been determined by single crystal x-ray diffraction methods. The structure has been found to belong to the trans-dioxo- group of compounds. The Re=O bond in the structure has been shown to have a bond-order of about 2, with the average Re=O bond length of 1.76(J) A. The probable structures of the monohydrate and anhydrous dioxotetrapyridine-rhenium(V) chloride have been discussed on the basis of the observed pseudo-symmetric structure for the dihydrate with a non-centrosymmetric space group. The nature and strength of the hydrogen bonds in the structure have also been discussed.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Moral Consequences of Context: An Analysis of Bradshaw and Colleagues' Model of Moral Distress for Military Healthcare Professionals

contributor:
Schwartz, Lisa
Global Health

subject: Moral Distress

subject: Moral Dilemma

subject: Military Healthcare Professionals

subject: Ethical Dilemma

subject: Moral Context

subject: Healthcare Professionals

subject: Ego Depletion

subject: Moral Injury

subject: Moral Luck

subject: Moral Distress Model

subject: Qualitative Research

subject: Moral Distress Resolution

subject: Contextual Controllability

subject: Moral Stress

subject: EMMRG

abstract: This paper provides an analysis of Bradshaw and Colleagues' model of military healthcare professionals' moral distress experiences. Using novel interview data collected from Canadian Forces healthcare professionals, the steps of the model are validated or potential refinements are suggested.

abstract: Military healthcare professionals (HCPs) may experience moral distress during international deployment. Moral distress is experienced when a HCP faces a moral dilemma, e.g., knows the morally correct course of action but is blocked from taking it, or where all available courses of action require something of moral significance be given up. While the literature indicates that moral distress often negatively impacts the mental health of the individual and the effectiveness of the organization, limited research has examined moral distress amongst military HCP. Many similar stressors and psychological health problems are present for both civilian and military HCP; however, the unique context of deployment necessitates further examination. This thesis explores the military HCP experience with moral distress by using Bradshaw and colleague’s model of progression from the encounter with a moral dilemma to the impact on individuals and organizations. Through the analysis of novel interviews collected by the Ethics in Military Medicine Research Group (EMMRG), Bradshaw and colleague’s model of military moral distress is compared to participant’s experiences and qualitatively analysed, with the results outlining where the model is supported and where refinement is recommended. These challenges were then supported by a literature review from the disciplines of virtue and feminist ethics, moral psychology, bioethics, and civilian HCP moral distress research. Two novel and significant revisions to the model are suggested: representing and integrating the cumulative experience of moral distress, and re-conceptualizing the resolution process based on the consideration of contextual controllability on moral responsibility.

abstract: Thesis

abstract: Master of Science (MS)

abstract: This thesis examines the experience of moral distress in military healthcare professionals (HCPs) while working abroad, where a HCP faces a moral dilemma, e.g., knows the morally correct course of action but is blocked from taking it or it requires something of moral significance be given up. This thesis analyses the most recent model of military HCP moral distress (Bradshaw, et al., 2010) by comparing it to the experiences described by participants in the Ethics in Military Medicine Research Group (EMMRG) study. The results outline support for the model as well as novel suggestions for revision, which are supported by literature from a variety of disciplines. Two adjustments to Bradshaw and colleague’s model are suggested: clearer representation of the cumulative nature of moral distress as well as a reconceptualization of the resolution process to consider the influence of the immediate and extended environment on moral responsibility.


title: Securing Borders in West Africa: Transnational Actors, Practices, and Knowledges

contributor: Political Science - International Relations

subject:
security
borders
Senegal
Mauritania
habitus
assemblage
migration
biometrics
West Africa
Sahel

abstract:
This dissertation examines border security practices in West Africa, with emphasis on the effects of practices of international intervention. The dissertation advances an understanding of borders as institutional spaces, eschewing a view of borders as geographical features alone. It leverages this view of borders to examine the everyday practices of border control, focusing in particular on the security professionals who cooperate and compete over the meaning and enactment of border security. The dissertation draws from ethnographic fieldwork in Senegal and Mauritania to advance three case studies. First, it examines Spanish police cooperation with Senegal and Mauritania on the prevention of irregular migration by sea and land routes. Second, it analyzes Mauritania’s construction of new border posts in response to migration and terrorism. Third, it looks into the adoption of biometric identification at airports and in official documents in Senegal and Mauritania. In each of these cases, the dissertation argues, everyday border security practices are framed in terms of capacity, with border control taking on the practical characteristics of statebuilding.

This dissertation makes three key contributions to knowledge. First, by focusing on the quotidian social and technical aspects of borders, it provides a view into the concrete knowledge practices and organizational politics that drive border control, even if they are of complex causality. Second, this dissertation contributes to security studies a theorization of the movement of security practices and understandings between global contexts. Third, by relying on fieldwork in closed and rarely accessible contexts, it provides a view into the functioning and social relations of West African fields of security.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation examines efforts to boost border security in Senegal and Mauritania—two states on the Atlantic coast of West Africa—with emphasis on the international cooperation and knowledge transmission that emerges as part of these efforts. The dissertation argues that borders are not only lines on a map, but institutions in which security professionals compete and cooperate over questions such as who should carry out border control and how. It also argues that with security framed as a question of development and state capacity, securing borders becomes a question of statebuilding. To show this, the dissertation draws on data from interviews in law enforcement and national security agencies, embassies, and international organizations to provide a mapping of actors in the field of border security and their relations. Its empirical cases focus on joint migration patrols, border post construction, and the use of biometric identification


title: Multiple Ingredient Dietary Supplement and Protective Effects in Gamma Irradiated Mice

contributor:
Rollo, C. David
Boreham, Douglas
Biology

subject:
MDS
Radiation
Diet Supplement
Gamma
Protect
Mitigate
Olfaction
Behaviour
Novel Object Recognition
Novel Placement Recognition
Cytokines
DNA oxidation
Radiation Damage
Multiple Ingredient Dietary Supplement
Mice
C57Bl
Chemofog
Cognition

abstract: Cognitive impairment, “Chemofog”, has been well established as a negative outcome of otherwise successful medical radiation treatments. Mitigation of this negative feature would dramatically increase quality of life for those recovering from cancer treatment. There is currently no known intervention to protect or restore cognitive function of patients undergoing radiation treatments. Development of a multiple ingredient dietary supplement (MDS) is meant to offer a non-invasive therapy to help mitigate risk and decrease damage to individuals. The MDS was originally designed to off-set 5 key mechanisms associated with aging including oxidative damage, inflammation, impaired glucose metabolism, mitochondrial dysfunction and membrane deterioration. Radiation damage shares many of the same deficiencies that develop with age and supplementation with MDS would impact many of the same pathways. Changes in cytokine profile (inflammation markers), and biomarkers of behavioural functions, sensory functions, and oxidative damage provide preliminary evidence of MDS impacts.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Adult Phenotypic Plasticity in Thermogenesis: An Interpopulation Study using High and Low Altitude Deer Mice

contributor:
McClelland, Grant B.
Biology

subject:
Phenotypic Plasticity
Maximal Aerobic Capacity
Nonshivering Thermogenesis
High Altitude
Basal Metabolic Rate
Cold & Hypoxia

abstract:
High altitude is one of the most extreme environments experienced by terrestrial mammals due to both low ambient temperatures and oxygen availability. Deer mice native to high altitude have a greater thermogenic capacity in hypoxia compared to a lowland population, likely as a consequence of both genetic adaptations and phenotypic plasticity. To understand the adaptive variation in phenotypic plasticity, F1 generation lab-reared mice were acclimated to chronic warm-hypoxia, cold-normoxia, and cold-hypoxia.

Acclimation led to equal increases in thermogenic capacity in hypoxia for all stressors in high altitude deer mice. Low altitude mice also increased their thermogenic capacity after acclimation, with a distinct increase after acclimation to cold-hypoxia. The thermogenic capabilities of the high and low altitude mice tested in hypoxia were equal, suggesting that both populations of mice had reached a “metabolic ceiling”. Basal metabolic rate increased after acclimation to cold and cold-hypoxia. Nonshivering thermogenesis was not affected by acclimation or altitude ancestry. Shivering thermogenesis contributed 70 to 80 % of total heat produced during VO2summit across all acclimations, and in both populations. VO2summit in hypoxia was supported by lipids in deer mice even though carbohydrates would provide an oxygen saving advantage. Also, rates of lipid oxidation increased after acclimation to cold, and cold combined with hypoxia in the high altitude population.

Together these findings suggest that the increased thermogenic capacity of the high altitude wild mice is based both on differences in phenotypic plasticity, and on differences in genotype from the low altitude mice. Adult phenotypic plasticity is pivotal in the thermogenic capabilities of both populations, and it is likely that developmental plasticity also plays an important role.

abstract: Thesis

abstract: Master of Science (MSc)


title: COLLECTIVE CELL MIRATION DURING HEART MORPHOGENESIS IN DROSOPHILA REQUIRES GUIDANCE SIGNALING AND EXTRACELLULAR MATRIX REMODELLING

title: COLLECTIVE CELL MIGRATION OF CARDIOBLASTS DURING HEART MORPHOGENESIS

contributor:
Jacobs, Roger
Biology

subject: Collective cell migration guidance signalling extracellular matrix metalloproteinases mmp slit robo netrin frazzled uncoordinated5 metastasis congenital heart disease heart development morphogenesis filopodia lamellopodia

abstract:
Collective cell migration is a defining feature of many morphogenetic processes.
Diseases such as congenital heart diseases and cancer arise due to mis-regulation of
collective migratory behaviour and animal models have played a pivotal role in dissecting
the molecular mechanisms which underlie this process. During embryonic heart
development, cardiac precursors undergo a stage of collective migration in both
vertebrates and invertebrates. We developed a paradigm to quantitatively assess collective
cell migration of cardiac precursors in live embryos of Drosophila, which is the simplest
genetic model organism with a heart. Therefore, we studied processes which are
commonly observed in most collective cell migration models such as guidance signalling
and extracellular matrix remodelling. Our results demonstrate that leading edge of
migrating cardioblasts is highly active and that this behaviour is regulated by guidance
cues, Slit and Netrin and their respective receptors Robo/Robo2 and Frazzled/Uncoordinated5.
These molecules cooperatively promote leading edge motility and epithelial
characteristics of the cardioblasts. Next, we determined that matrix restructuring around
the cardioblasts requires proteases Mmp1 and Mmp2, which are members of the highly
conserved Matrix Metalloproteinase family. We demonstrate that Mmp1 and Mmp2 have
distinct roles during lumen formation, however, both Mmp1 and Mmp2 are required for
collective motility of the cardioblast leading edge. Hence, we propose that embryonic
heart development in Drosophila is an effective and amenable model of collective cell
migration which can be applied to discover unique mechanisms which coordinate cell
movement in groups.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: IS O REALLY THE UNIVERSAL DONOR?

contributor:
Heddle, Nancy
Health Research Methodology

subject:
Design thesis
O Red Blood Cells
Transfusion

abstract: An association between compatible but ABO non-identical red blood cell (RBC) transfusions and increased in-hospital mortality was identified in an observational study.  A review of the literature was performed to explore plausible biological mechanisms and inflammation was chosen. This thesis describes a body of work that was performed to develop a PICOT research question and design a pilot feasibility randomized crossover trial in patients with myelodysplastic syndrome (MDS) to determine whether there is evidence of an inflammatory response resulting from transfusion of ABO non-identical RBCs compared with the transfusion of ABO identical RBCs.  The work undertaken as part of this thesis included: identifying a theoretical framework to guide the selection of outcome measures that would detect inflammation; identifying an appropriate and feasible population to study; designing the feasibility pilot study to answer the research question that was developed; and a discussion of ethical issues that were considered as the design of the pilot study was developed. The work that was done to develop the elements of PICOT resulted in the following research question: Is it feasible to perform a randomized crossover trial in chronically transfused blood group A patients with myelodysplastic syndrome (MDS), that looks for laboratory evidence of inflammation (in vitro biomarkers measured at baseline and pre-specified times between 1 and 96 hours post transfusion), following the transfusion of group O RBCs (ABO non-identical) compared to transfusion of group A (ABO identical) RBCs?

abstract: Thesis

abstract: Master of Science (MSc)


title: Direct effects of milk oligosaccharides on the inflammatory response in relation to allergy

contributor:
Forsythe, Paul
Medical Sciences

subject: allergy, milk oligosaccharides, immune modulation, dendritic cells, epithelial cells, food allergy

abstract:
Introduction: The incidence of food allergy has increased substantially in developed countries, with limited treatment and/or prevention options. Milk oligosaccharides have shown to modulate immune responses by serving as prebiotic substrates for the intestinal microbiota. However, some studies suggest that oligosaccharides may exert direct immunomodulatory effects, suggesting their therapeutic potential in preventing allergic diseases. We hypothesized that specific milk oligosaccharides including 6’sialyllactose, 2’fucosylactose, 3’sialyllactose and lacto-N-neotetraose may directly exert immunomodulatory effects on dendritic cells (DCs) and epithelial cells (ECs) by altering their phenotype and/or function in vitro.
Methods: The effects of milk oligosaccharides (MOs) on bone-marrow derived DCs and the T84 and MODE-K epithelial cell lines were studied via direct treatment, in vitro. The expression of immunomodulatory cytokines and maturation markers were assessed to measure the effect of MOs on DC phenotype. Pro- and anti-inflammatory cytokines as well as NFκB p65 activity were measured to assess the effect of MOs on DC and EC function. In addition, in vitro stimulation of CD23 with IgE-Antigen complexes were used to study the effects of MOs on ECs in relation to allergy. Lastly, inhibitory antibodies for Siglec-F and PPARγ were used to elucidate the mechanism used by specific MOs to exert their effects.
Results: Of the oligosaccharides studied, 6’siallylactose has direct immunomodulatory effects on DC phenotype and on DC and EC function at high concentrations.  6’sialyllactose increased DC expression of IL-10 and HO-1; it also increased CpG- and LPS- induced IL-10 release and decreased IL-12p70 release. Blocking the PPARγ receptor with GW9662 resulted in attenuation of this latter effect on IL-12p70 release. 6’sialyllactose reduced TNF-α induced IL-8 to a small but statistically significant extent and mKC to a great extent in T84 and MODE-K cells, respectively. In addition, 6’sialyllactose reduced IgE-Antigen stimulated release of IL-8 and CCL20, as well as NFκB p65 activity. Pre-treatment of cells with GW9662 resulted in attenuation of the effect of 6’SL on IL-8 release and p65 activation.  In addition, 2’fucosylactose reduced CCL20 release and NFκB activity substantially, but these effects were not exerted via PPARγ.
Conclusion: Some oligosaccharides are able to directly modulate the inflammatory response in DCs and ECs, via pathways involving PPARγ activation and/or NFκB inhibition.

abstract: Thesis

abstract: Master of Science (MSc)


title: Material Processing and Forming Approaches for Enhancing Room Temperature Formability of Automotive Mg Sheet

contributor:
Jain, Mukesh
Mechanical Engineering

subject: AZ31, formability, annealing, pre-straining, deformation, twins

abstract:
Automotive magnesium sheets typically exhibit poor room temperature ductility which makes them unsuitable for room temperature sheet stamping applications. This research involved aspects of re-processing and forming of AZ31 automotive magnesium sheet to improve its room temperature ductility and bendability (and, more generally, formability). The sheet re-processing studies for formability improvement were carried out by two different methods, (i) cyclic bending-unbending and annealing (or CBUA) and (ii) wire brushing and annealing (or WBA).  These two processing methods led to a complex stress and strain distribution through the thickness and a multi-layered microstructure after annealing. The grain structure, micro-texture, and micro-hardness of each of the layers were studied by optical microscopy, electron back-scattered diffraction (EBSD) and indentation measurements, respectively. The through-thickness grain structure study indicated grain refinement and texture randomization in the surface layers for both CBUA and WBA processed materials.
In addition, the as-received (and fully annealed) sheet as well as processed materials were subsequently deformed in uniaxial tension and bending by a process referred to in the literature as pre-strain annealing (or PSA). The PSA process was studied as a single step as well as multi-step process to assess its effect on formability improvement, underlying changes in microstructural and mechanical behavior, and to explore practical limitations and advantages of the process.
The results from single-step PSA process were also used to develop a microstructure-based constitutive material model to capture and predict the observed mechanical and microstructural response of AZ31 sheet to PSA variables. This model explicitly considered the effect of recovery on recrystallization kinetics, and non-constant nucleation and growth rate.  The model was extended to predict the grain size at the end of recrystallization and within the grain growth stage as well as post-PSA yield and work hardening characteristics. The mechanical property prediction was based on considering the microstructure as a composite of un-recrystallized, recrystallized and coarsened grain structure and by employing a rule of mixture.
The processing and forming methods led to significantly increased cumulative uniaxial tensile ductility and plane strain cumulative bendability of AZ31 sheet at room temperature depending upon PSA process parameters. The experimental and modeling studies collectively helped correlate mechanical properties from various processing conditions and forming methods with microstructural parameters, and to explain the improvement in room temperature formability based on microstructural and textural considerations.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: THE EFFECT OF H2SO4 SURFACE PRE-TREATMENT ON THE STRESS CORROSION CRACKING OF MAGNESIUM ALLOY AZ31B

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

subject:
Magnesium
Stress Corrosion Cracking

abstract:
The stress corrosion cracking (SCC) behaviour of Mg alloy AZ31B was investigated with respect to surface condition. Salt fog U-bend testing was used to identify changes in SCC as a result of surface conditioning pre-treatments. Six surface conditions were investigated: as-received, mechanically-polished, sulphuric acid (H2SO4)-cleaned, mechanically-polished then H2SO4-cleaned, aged H2SO4-cleaned, and acetic acid (C2H4O2)-cleaned. Results showed that the rate of SCC was accelerated and the SCC mode was intergranular for all surface conditioning treatments involving H2SO4-cleaning.
It was found that the accelerated intergranular SCC was a result of three contributing factors: a low pH, the presence of aggressive ions, and a porous film which allowed direct contact between the metal surface and the electrolyte. Characterization of the surfaces using potentiodynamic polarization and cross-sectional images of sample surfaces showed that in the absence of one of these three contributing factors intergranular SCC would not occur.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Hybridization, hidden order, and antiferromagnetism in URu2Si2: electrodynamics studied by infrared spectroscopy

contributor:
Timusk, Thomas
Physics and Astronomy

abstract:
Infrared spectroscopy has been used to study URu2Si2. This heavy fermion material exhibits novel behaviour including a phase transition with an unknown order parameter.
Optical spectroscopy has been applied to study the scattering mechanism of the quasiparticles in the coherent state above the transition. It is found that the scattering is incoherent above the hybridization temperature and gradually develops a Drude peak as the temperature is lowered into the coherent regime. As the temperature approaches the transition from above, the scattering is almost entirely Fermi liquid in character. It is observed that the scaling between the frequency and temperature terms in the Fermi liquid region is anomalous and diverges from the predicted value of 4, with profound implications for the nature of Fermi liquid behaviour generally.
Infrared spectra also clearly show the charge gap in the ordered state. It is found that the gap is anisotropic, with a different character in the c-axis than in the ab-plane of the tetragonal crystal, and that a second small gap appears at lower temperature in the c-axis. The gap does not have a mean-field temperature dependence. The gap is well-modelled by a Dynes density of states with case I coherence factors, typical of a nesting-induced incommensurate density wave.
Doping induces antiferromagnetism in place of the hidden order, and at higher temperatures, which is also studied by spectroscopy. It is found that the Fermi liquid temperature region rises in temperature in tandem with the phase transition, so that the transition is always preceded by Fermi liquid behaviour but with anomalous scaling between frequency and temperature. The character of the charge gap does not change between the hidden order and antiferromagnetic states, indicating that the same mechanism is responsible for the charge gap in both phases.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Higher-Fidelity Modelling and Simulation of the CAN Protocol Stack

contributor:
Lawford, Mark
Wassyng, Alan
Computing and Software

subject:
Controller Area Network
CAN
modelling
simulation
SimEvents
network analysis

abstract: This thesis details a higher-fidelity, scalable simulation tool and model for message response time and bus utilization rate analysis for the Controller Area Network (CAN) protocol stack. This tool achieves higher fidelity than existing commercial and academic simulation tools by including details of the stack implementation that are often neglected, such as receive and transmit hardware buffer availability and usage policy (i.e., which messages are able to be copied to which buffer resources), and the buffer polling or queueing policies. Key details of these features have been identified by a thorough examination of CAN stack behaviour, taking into account the physical considerations of commercial CAN implementations. Inclusion of these details in the simulation can produce better accuracy by exposing certain priority inversion scenarios. Scalability is achieved by using a transaction-based modelling approach and modelling transmissions at the protocol level rather than the physical/bit level. The tool requires minimal user interaction, and system level model generation is automated using an AUTOSAR XML system description file (ARXML format) to specify network topology and message information (transmitter, receiver(s), period, length, etc.), and an Excel spreadsheet file (XLS or XLSX format) to specify node hardware/software implementation details (buffer resource details, polling loop rates, main control loop rates, etc.) as inputs.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Cross-Epistemological Feminist Conversations Between Indigenous Canada and South Africa

contributor:
Strauss, Helene
English and Cultural Studies

subject:
Indigenous literatures
Postcolonial literatures
women's literatures
South Africa
gender
racialization
indigeneity
colonialism
apartheid
resistance
Canada
conversation
epistemology
relationality
social change
feminism
political change
transformation
knowledge production

abstract: This is a project that takes inequality as its starting point to ask not why it persists in all its myriad forms, but rather how we might better understand its resiliency in order to re-orient our responses. It asks how we can re-imagine one another and work across asymmetrical divides in ways that move us towards substantial forms of social justice, actively disallowing the entrenchment of hierarchical valuing systems, and how we can engage with literature as part of reconfiguring ‘equality’ in the process. These questions are traced through Indigenous women’s literatures in Canada and black South African women’s literatures as sites of deeply textured resistance and re-imagined relationality. My analysis focuses on select texts from the 1980s to present in two primary archives: from Indigenous Canada, The Book of Jessica: A Theatrical Transformation (Maria Campbell in collaboration with Linda Griffiths) and Monkey Beach (Eden Robinson); and from South Africa, Mother to Mother (Sindiwe Magona) and Coconut (Kopano Matlwa). I use conversation as my methodological and thematic compass for seeking modes of enabling comprehension across perniciously unequal systems of making meaning and considering the possibilities for transformative knowledge production and textual interpretation at sites of unequal intersubjective exchange. I employ an uneasy comparative practice that I base on horizontal forms of juxtaposition within conversational structures, and I argue that conversation’s generative instability and risky uncertainty open onto hopeful possibilities for transformative change.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: This project examines a small selection of the literatures by Indigenous women writers in Canada and black South African women writers to conceptualize anti-oppressive approaches to working across differences in both literary/scholarly and activist/lived contexts. It uses conversation as a critical methodology for engaging four primary texts and practicing an uneasy comparative method based on horizontal forms of juxtaposition rather than vertical relations of evaluative power: Mother to Mother (Sindiwe Magona) and The Book of Jessica (Maria Campbell and Linda Griffiths); and Coconut (Kopano Matlwa) and Monkey Beach (Eden Robinson). The overall aim is to re-imagine forms of engaging across difference along a range of registers – racialization, gender, nation, class, language, and geographical location – that create conditions for more expansive and substantive forms of social justice than are currently visible. The project draws on feminist, Indigenous, postcolonial, critical race, and related areas of scholarship with an orientation towards social justice.


title: Far-Infrared Absorption in Insb

contributor:
Datars, W. R.
Physics

subject: far-infrared, absorption, semiconductor, electron, magnetic, field, crystal lattice, harmonic

abstract:
 A high-resolution, low-noise far-infrared Fourier transform spectrometer system has been developed and utilized to study optical absorption in the III-V compound semiconductor InSb.

 Its electron effective mass was investigated, using cyclotron resonance absorption, as a function of magnetic field and compared with a theory originated by Kane (1957). The agreement was good and accurate values of the band edge effective mass and effective g factors were determined. Resonant electron-LO phonon coupling between the n = 2 and n = 0 + wLO Landau levels was observed and the polaron effective mass enhancement measured as a function of magnetic field. Comparison with Larsen's theory (1966), permitted an accurate value of the coupling constant to be derived. The temperature dependence of the electron effective mass was shown to be primarily due to dilation of the crystal lattice in confirmation of other workers' suggestions. However, some discrepancy, whose origin is unknown, was found to exist between experiment and theory.

 Single phonon absorption by the longitudinal optic phonon mode at the zone center was observed on the side of
the main Reststrahl band in a thin sample. The shapes, frequencies and intensities of far-infrared absorptions attributable to two-phonon processes were found to compare favourably with a theoretical two-phonon density of states curve calculated by G. Dolling (1972). The parameters used in the theory were derived from inelastic neutron scattering experiments. Two phonon combinations and their locations in the Brillouin zone which give rise to strong features in the two-phonon density of states were identified by comparing theory and experiment. Important critical points were discovered to be located on or near the zone boundary and not only at the symmetry points X and L as previously suggested. The frequency shifts of some two-phonon features were measured as a function of temperature and analyzed in terms of a quasi-harmonic lattice dilation component and an anharmonic component. The two terms were found to be mirror images as a function of temperature.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Effects of Fracture Geometry on Contaminant Transport

contributor:
Dickson, Sarah E.
Civil Engineering

subject:
hydrology
contaminant transport
DNAPL
particle
modelling
invasion percolation

abstract:
An invasion percolation (IP) model was used to illustrate the effects of gravity on DNAPL migration into a horizontal water saturated fracture. While gravity is typically neglected in the conventional approach, this work demonstrated that gravity should often be included when modelling DNAPL invasion in water saturated fractures and provides an equation estimating the difference in invasion pattern between simulations including or neglecting gravity. The IP model was further utilized to examine the invasion of DNAPL saturated fractures by water. These simulated experiments focus on cases where covariance (COV), the ratio of the mean of the aperture field to the standard deviation of the aperture field) as well as when the fracture is inclined or declined from horizontal. Results show that when COV is greater than 0.1, then DNAPL will always remain in the fracture after waterflooding. Furthermore, fracture angles below -15 degrees permit the complete removal of DNAPL, while fractures oriented at higher angles do not.

In order to study the transport of particles in water saturated fractures, physical experiments measuring the transport of 0.046 um and 0.55 um microspheres were undertaken on fractures where the geometry could be imported into a computer for comparative simulation analysis. Results demonstrated that during advection, particles generally travel at less than the velocity of the surrounding fluid. As well, hydrodynamic effects such as shear were shown to influence the effluent concentrations by increasing dispersion. Finally, the physical geometry of the fracture was shown to influence the particle pathway during transport and can limit the chances of particles adhering to a fracture wall, thus reducing dispersion and increasing peak concentration.  The combined results of these studies show that fracture geometry has a significant effect on the mechanisms of transport in saturated fractures.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis describes the transport of contaminants in rock fractures in the environment.  Specifically, the transport of denser than water liquids that are immiscible in water and particles are modelled and analysed.  This work used experiments in order to calibrate these models for analysis.  It was found that the local geometry of the fracture walls heavily influences the invasion pattern of immiscible dense fluids as well as the retention of the fluids after waterflooding (a first step in remediation).  Particle transport was found to be heavily affected by the local geometry in the fracture, specifically lowering the likelihood of attachment to fracture walls limiting the filtration effects, and thus allowing greater contaminants to exit the fracture.  Ultimately, these results lead to a greater understanding of the mechanisms of transport in fractured media.


title: A Log-Linear Analysis of a Set of Medical Data

contributor:
Dunnett, C. W.
Statistics

subject: log-linear, medical, data, liver, drug

abstract: Methotrexate had been suspected to be harmful to the liver in psoriatic patients. The data of a prospective study to find out whether the drug affected the acquisition and worsening of various liver pathology was analysed. Personal particulars which would have adverse effect on the liver were also investigated. Log-linear models were fitted to this set of categorical data in the form of multidimensional contingency tables. It was found that methotrexate would be hepatotoxic if the drug was taken over a prolonged period and/or if the cumulative dose taken was large. Otherwise, methotrexate could be administered to psoriatic patients without causing much harm to the liver.

abstract: Thesis

abstract: Master of Science (MSc)


title: Bivariate Random Effects Meta-Analysis Models for Diagnostic Test Accuracy Studies Using Arcsine-Based Transformations

contributor:
Beyene, Joseph
Mathematics and Statistics

subject: Meta-Analysis; Diagnostic Test Accuracy; Bivariate Random Effects

abstract:
A diagnostic test identifies patients according to their disease status. Different meta-analytic models for diagnostic test accuracy studies have been developed to synthesize the sensitivity and specificity of the test. Because of the likely correlation between the sensitivity and specificity of a test, modeling the two parameters using a bivariate model is desirable. Historically, the logit transformation has been used to model sensitivity and specificity pairs from multiple studies as a bivariate normal.
In this thesis, we propose two transformations, the arcsine square root and the Freeman-Tukey double arcsine transformation, in the context of a bivariate random-effects model to meta-analyze diagnostic test accuracy studies. We evaluated the performance of the three transformations (the commonly used logit and the proposed transformations) using an extensive simulation study in terms of bias, root mean square error and coverage probability. We illustrate the methods using three real data sets.
The simulation study results showed that, for smaller sample size and higher values of sensitivity and specificity, the proposed transformations are less biased, have smaller root mean square error and better coverage probability than the standard logit transformation regardless of the number of studies. On the other hand, for large sample sizes, the usual logit transformation is less biased and has better coverage probability regardless of the true values of sensitivity, specificity and number of studies. However, when the sample size is large, the logit transformation has better root mean square error for moderate and large number of studies. The point estimates of the two parameters, sensitivity & specificity, from the methods using the three real data sets follow patterns similar to those reported by our simulation.

abstract: Thesis

abstract: Master of Science (MSc)


title: Anatomical Refinement in the Projection from the Anteroventral Cochlear Nucleus to the Lateral Superior Olive

contributor:
Gillespie, Deda
Neuroscience

subject:
Auditory
Brainstem
Development
Axon tracing

abstract:
In mammals, the basic computations required for azimuthal sound localization are performed by a group of auditory brainstem nuclei known as the superior olivary complex (SOC). The lateral superior olive (LSO), in the SOC, aids in sound localization by computing intensity differences between sounds arriving at the two ears. It does this by comparing excitatory input from the ipsilateral anteroventral cochlear nucleus (AVCN) with inhibitory input from the ipsilateral medial nucleus of the trapezoid body (MNTB), which is driven by the contralateral AVCN. In order for sounds to be accurately localized, the AVCN-LSO and MNTB-LSO projections must be aligned with each other in a frequency-dependent manner. Rough alignment occurs over the course of development, but a significant amount of circuit refinement is required to achieve adult-like precision. Two types of refinement occur in these pathways: 1) physiological, or functional refinement; and 2) anatomical refinement. Little is known about the latter type of refinement in the AVCN-LSO pathway.
     In order to study this, I conducted a variety of experiments all aimed at anterogradely labeling a small number of cells projecting from the AVCN to the LSO in juvenile rats. I experimented with several approaches in order to develop the technique of ex vivo, sparse axon labeling in this area of the brain. I show the optimal technique developed after testing various tracers, application methods, and incubation times, among others. This optimized technique can now be used in a future experiment that will uncover and describe anatomical refinement in the AVCN-LSO pathway of the auditory brainstem.

abstract: Thesis

abstract: Master of Science (MSc)


title: On the Closed Graph and Open Mapping Theorems

contributor:
Husain, T.
Mathematics

subject: graph, mapping, theorems, convex spaces, functional, linear

abstract: The closed graph and open mapping theorems are two of the deeper results in the theory of locally convex spaces. They are very rich in their applications in functional analysis. This thesis contains some extensions of these theorems in locally convex spaces. We begin with a study of α-spaces, and γ-spaces, which leads us naturally to a study of δ-spaces. On these spaces, we prove closed graph and open mapping theorems. Similar theorems are also proved for certain classes of Br ('&)-spaces. In particular, a closed graph theorem for B(m)-spaces enables us to characterise certain classes of B( &. y)-spaces. A consideration of countability conditions in locally convex spaces enables us to prove open mapping theorems in Br (J )-spaces. These theorems are then used to relate boundedness of linear mappings and their graphs.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Developing a Cytotoxic T Cell Assay to Investigate a CD8+ T Cell Pathology in Megakaryopoeisis in Immune Thrombocytopenia

title: Cytotoxic T Cells in Immune Thrombocytopenia

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
immune thrombocytopenia
CD8+ T cells
megakaryopoeisis
assay development

abstract:
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder, characterized by platelet destruction and/or underproduction. The pathophysiology is heterogeneous and can be mediated by autoantibodies and cytotoxic T lymphocytes (CTLs). While platelet destruction in ITP is well documented, there is little support for platelet underproduction due to the inhibition of megakaryocyte growth and considerably less support for CTL-mediated platelet underproduction. Our objective was to develop an assay that could test for CTL-mediated inhibition of megakaryocyte growth (megakaryopoiesis) in ITP, using healthy controls.
	Peripheral blood from healthy donors was used to prepare hematopoietic stem and progenitor cells (HSPCs). These cells were expanded with StemSpan to culture a large number of megakaryocytes for the CTL assay. Our studies show that CTLs can be stimulated in-vitro using anti-CD3 antibodies and that they can be used after freezing and thawing. We also assessed CTL stimulation via peptide presentation, using viral peptides whom almost 100% of the general population have memory CTL specificity to, in order to activate a lower frequency of CTLs and to model levels of CTL activation in autoimmune disease. Both stimulants were found to stimulate CTLs in healthy donors with donor variability in the IFN-γ ELISpot.
	The CTL assay was developed by co-culturing thrombopoietin (TPO) stimulated HSPCs with autologous CTLs for 7 days to observe inhibition of megakaryocyte growth. To induce CTL stimulation, CTLs were either incubated with anti-CD3 or HSPCs were incubated with viral peptides before co-culturing with CTLs. Results showed that while viral peptides can be used as an internal control for the CTL assay, it could not serve as a positive control as inhibition was donor dependent. Inhibition of megakaryocyte growth in the presence of anti-CD3 stimulated CTLs was observed in all donors, validating its use as an appropriate positive control to study CD8+ T cell pathophysiology in ITP.

abstract: Thesis

abstract: Master of Science (MSc)


title: Advanced Sensors for Environmental Water Monitoring

contributor:
Selvaganapathy, Ravi
Fang, Qiyin
Xu, Chang-Qing
Biomedical Engineering

subject: sensor; water; electrochemistry; anitfouling

abstract:
Nowadays, water pollution significant jeopardizes the continuous clean drinking water supply that results in the damage of human health, and economy development. Adequate sensors are not only able to greatly benefit the treatment process but also can continuous monitoring of the watershed for contaminates which help effectively control pollution and manage the water resources. However, the commercial available sensors are expensive and required frequently maintenance. These limitations make these sensors not sufficient in continuous water monitoring application.
In this thesis, sensors for some of the essential sensing targets including dissolved oxygen, phosphate and chlorine are developed. These sensors are low cost, easy operation and minimum maintenance required. These advantages make the sensors suitable to be applied in the continuously water quality monitoring system in multiple water systems such as drinking water, surface water and wastewater. Furthermore, an all solid state rechargeable palladium nanostructure based reference electrode and a universal dopamine/PEG/albumin antifouling coating technique are also studied in order to further extend the lifetime of these sensor thus reduces the need of maintenance.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Magnetic Dynamos: How Do They Even Work?

contributor:
Vishniac, Ethan
Physics and Astronomy

subject:
Accretion Disk
Magnetic Dynamo
magnetohydrodynamics
Mean Field Theory

abstract:
The origin of cosmic magnetic fields is a important area of astrophysics. The process by which they are created falls under the heading of dynamo theory, and is the topic of this thesis. Our focus for the location of where these magnetic fields operate is one the most ubiquitous objects in the universe, the accretion disk. By studying the accretion disk and the dynamo process that occurs there we wish to better understand both the accretion process and the dynamo process in stars and galaxies as well.

We analyse the output from a stratified zero net flux shearing box simulation performed using the ATHENA MHD code in collaboration with Shane Davis. The simulation has turbulence which is naturally forced by the presence of a linear instability called the magnetorotational instability (MRI). We utilise Fourier filtering and the tools of mean field dynamo theory to establish a connection between the calculated EMF and the model predictions of the dynamically quenched alpha model. We find a positive correlation for both components parallel to the large scale magnetic field and the azimuthal components.

We have explored many aspects of the theory including additional contributions from magnetic buoyancy and an effect arising from the large scale shear and the current density. We also directly measure the turbulent correlation time for the velocity and magnetic fields both large scale and small. We can also observe the effects of the dynamo cycle, with the azimuthal component of the large scale magnetic field flipping sign in this analysis.

We find a positive correlation between the divergence of the eddy scale magnetic helicity flux and the component of the electromotive force parallel to the large scale magnetic field. This correlation directly links the transfer of magnetic helicity to the dynamo process in a system with naturally driven turbulence. This highlights the importance of magnetic helicity and its conservation even in a system with triply periodic boundary conditions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Effects of the Systemic Environment in Health and Disease on Skeletal Muscle Development

contributor: Medical Sciences (Division of Physiology/Pharmacology)

abstract:
Children with cystic fibrosis (CF) show signs of systemic inflammation. Studies suggest that systemic inflammation is related to increased protein breakdown, which, in turn, is related to lower fat-free mass in CF patients. However, the direct implications of systemic inflammation on skeletal muscle tissue development are unknown. The focus of this thesis was to elucidate the effect of systemic factors from children with CF and healthy children on C2C12 myoblast myogenesis in vitro, and to assess whether systemic factors altered by exercise can modulate myogenesis, or provide an anti-inflammatory protection from an inflammatory mediator. Our first study demonstrated that myoblasts treated with pooled CF serum had higher levels of proliferation, as measured by the total number of nuclei, compared to control serum. There was no exercise effect on proliferation in CF, while post-exercise serum from healthy controls showed an increase in proliferation compared to resting serum.
In our next study, we confirmed that myoblasts treated with individual samples of CF serum had greater proliferation than control serum. Differentiation, as measured by the myonuclei fusion index, was decreased in myoblasts treated with CF serum. No exercise effect was observed for proliferation or differentiation. Our final study illustrated that an inflammatory mediator, lipopolysaccharide (LPS), decreased differentiation, as measured by myonuclei fusion index, in myoblasts treated with CF resting serum but increased differentiation in myoblasts treated with control resting serum. Post-exercise recovery from children with CF reversed the effects of LPS, while exercise and recovery serum from healthy controls blunted the effects of LPS. Collectively, our data suggest that systemic factors can have an effect on myogenesis, with differences observed between CF and control serum. Although post-exercise serum did not consistently affect myogenesis, anti-inflammatory effects are evidenced by the protection these factors provided from the effects of an inflammatory mediator.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Divine Violence and Divine Sovereignty: Kierkegaard and the Binding of Isaac

contributor:
Kroeker, Travis
Religious Studies

subject:
Kierkegaard
Carl Schmitt
sovereignty
exception
Jacob Taubes
Erich Auerbach
Jacques Derrida
eschatology
political theology
Political Theology
Fear and Trembling
Binding of Isaac
Akedah
The Gift of Death
Repetition
Abraham
theology

abstract:
This thesis examines the concept of sovereignty, as developed by the jurist Carl Schmitt, and argues that this concept helps to elucidate the very core of Fear and Trembling, a text that continues to be heavily misunderstood despite its great fame in Western thought today.
	Through a close examination of Schmitt’s formulation of the concept of sovereignty and the method by which he develops this concept through Kierkegaard’s concept of the exception in Repetition, I show how Kierkegaard influenced Schmitt and also how Schmitt’s interpretation is useful for reading Fear and Trembling. However, I also show how Schmitt’s usage of Kierkegaard, despite its ingenuity, is misleading, and present a more faithful reading of Kierkegaard’s concept of exception. With this reorientation, I in turn critique Schmitt’s methodology and the way he understands sovereignty.
	Following this reinterpretation of sovereignty, I examine the text of Genesis 22 and Fear and Trembling and examine the theological themes that ground the narrative of the Binding of Isaac. I argue that the problem of the Binding and the arguments set forth in Fear and Trembling cannot be understood adequately without a clear awareness of the image of reality that is presupposed. Here, I make use of Erich Auerbach’s illuminating reading of Genesis 22, and Jacob Taubes’ understanding of eschatology. I then examine the problem of violence as presented in the Binding, and how Kierkegaard departs from both Kant’s and Hegel’s critique of Abraham.
	Finally, I examine Derrida’s reading of Fear and Trembling in The Gift of Death and the way he challenges the height of sovereignty that is implicit within Kierkegaard’s “absolute relation to the absolute.”

abstract: Thesis

abstract: Master of Arts (MA)


title: Sacramental Vision in Annie Dillard's Holy the Firm

contributor:
Kroeker, P. Travis
Religious Sciences

abstract: This thesis explores the central motif of vision in Annie Dillard’s poetic narrative, Holy the Firm. While much of her work is concerned with “seeing” I argue that in this, her most theological text, Dillard is concerned with ushering her reader toward a sacramental vision of the world. Centered on an airplane crash in which a little girl, Julie Norwich, is badly injured, the text grapples with the relationship between the divine and the world. The chapters in this thesis parallel the three days of Dillard’s narrative as she contemplates creation, the fall, and redemption, through the artist, the thinker, and the nun. I argue that the text moves through an aesthetic and sacramental vision of the natural world, to intellectual abstraction in the face of human suffering, and finally to a mystical vision of wholeness in Christ. Ultimately, the divisions between mind, matter, and spirit are transcended, engendering a whole vision of reality. In the climactic scene of the text in which Dillard experiences a vision of Christ being baptized in the bay below her, I argue that Dillard is suggesting the possibility for the continual practice of such a whole vision through the sacramental liturgy of the church.

abstract: Thesis

abstract: Master of Arts (MA)


title: Kinetic modelling for the formation of Magnesium Aluminate Inclusions in the Ladle Metallurgy Furnace

contributor:
Irons, Gordon A.
Materials Science and Engineering

subject:
Spinel inclusions
Kinetics
Ladle metallurgy
Modelling
Steelmaking

abstract: Magnesium aluminate spinel inclusions are a concern in the steelmaking industry since these particles affect the processing and the properties of steel. During the refining of low carbon aluminum killed steel in the ladle furnace; the initial alumina inclusions shift their composition towards higher contents of MgO and eventually they become magnesium aluminate spinel inclusions. This research developed a kinetic model for the transformation of alumina inclusions to spinel in liquid steel. The aspects of simultaneous deoxidation and of solid state cation counterdiffusion were addressed in the model. Coupling the model for spinel inclusions to a kinetic model for the slag-steel reactions in the ladle furnace allowed verifying the modeled concentrations in the inclusions with the plant data measurements of ArcelorMittal Dofasco operations. Good agreement between the experimental and calculated Mg contents in the inclusions was obtained for most of the industrial heats analyzed. Finally, a sensitivity analysis of the coupled kinetic model was performed to compare the effect of the different processing conditions and mass transfer rates on the amount of Mg and spinel in the inclusions. Several results from this work indicate that the rate limiting step on the formation of magnesium aluminate spinel inclusions is the supply rate of dissolved [Mg] from the slag-steel reaction; the supply of [Mg] is in turn controlled by the changes at the slag-steel interface.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: The Making of the Meadowlands: How Ancaster's Fields Became Hamilton's Suburbs

contributor:
Harris, Richard
Geography and Earth Sciences

subject:
Urban planning
land development
suburbs
suburban
NIMBY
Ancaster
Hamilton
case study
land-use conflict
wetlands

abstract: In an age of increasing urbanization, rural communities and agricultural lifestyles are quickly disappearing. Many local, pastoral histories have been buried under the new narratives of modern suburban development. Do such places, located along the rural-urban fringe, contain accounts worth memorializing? This thesis is a case study of the Ancaster Meadowlands—a growing neighbourhood within the City of Hamilton, Ontario. It explores the process of suburban growth and uncovers the local history of a landscape. As a narrative, the study traces land-use change over time, displaying the area’s evolution from a site of Neolithic settlement, to an important Loyalist village, and finally to a large suburban neighbourhood with commercial and residential components. Three principal methods are employed: resident interviewing, key informant interviewing, and archival research. Themes elicited in this study include land-use conflict, NIMBYism, real-estate volatility, and the interconnectedness of politicians and developers. Given that there are few case studies of contemporary suburban development, this study provides a rare illustration of the multi-faceted process of expansion around a Canadian city while also supplying a historical account of local importance.

abstract: Thesis

abstract: Master of Arts (MA)


title: 2D AND 3D ANALYSIS ON THE DEFORMATION AND FRACTURE OF COMMERCIALLY PURE MAGNESIUM

contributor:
Wilkinson, David S.
Materials Science and Engineering

abstract: Carbon dioxide emissions from the transportation sector contribute 25% of Canada’s total greenhouse gas emissions. As a result, the automotive industry aims to reduce emissions by reducing vehicle weight. Magnesium is an excellent candidate for a lightweight structural material. However, the lack of active deformation modes at room temperature limits its formability. This research uses several approaches to examine the deformation and fracture behavior of commercially pure magnesium to help guide the development of materials with acceptable properties. The first approach uses in-situ tensile testing coupled with electron microscopy, applied to thin sheet samples with pre-drilled holes in the gage section. The results reveal the heterogeneous nature of deformation leading to fracture dominated by twin and grain boundary related failure. This is qualitatively different from the damage processes observed in FCC materials such as aluminum and copper. As a consequence, classical theories cannot be used to predict ductile fracture in magnesium. The second approach involves in-situ tensile testing under optical microscopy. Here digital image correlation is used to determine the strain distribution on the surface. Localized deformation is observed at twin and grain boundaries. The results introduce a length scale which is not present in classical continuum theories. Therefore, a crystal plasticity finite element approach is employed to understand the role of the deformation mechanisms during deformation. The last approach couples in-situ tensile testing with x-ray microtomography to observe the fracture processes in sheet materials without pre-drilled holes. Twin and grain boundaries again dominate damage nucleation. Once nucleated voids show rapid growth and linkage. The final fracture occurs by a macroscopic shearing process related to the crystallographic texture. In summary, this project demonstrates how fracture in magnesium is fundamentally different from that in non-HCP metals and what approaches can be used to fully understand this.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Influence of Socio-Demographic Variables On Recreational Trip Type, Trip Length and Trip Frequency

contributor:
Hall, F.
Geography

subject:
recreational travel
recreational model
socio-demographic variables
Systems Theory model
trips

abstract: To date, the greatest success in predicting recreational travel patterns has been made by the Systems Theory Model. However, discrepancies still occur primarily due to the lack of accurate and extensive information on the socio-demographic variables that influence recreational travel. The research verified the assumption that socio-demographic variables warrant consideration in a recreational model. The analysis indicates specifically the types of socio-demographic variables that influence the various types of recreational travel. Due to a small sample size the results are not directly applicable to the model, however, they establish the types of socio-demographic variables that warrant consideration in a large sample survey.

abstract: Thesis

abstract: Bachelor of Arts (BA)


title: Synthesis and Applications of Degradable Thermoresponsive Microgels

title: Synthesis of Degradable Thermoresponsive Microgels

contributor:
Hoare, Todd
Chemical Engineering

subject:
Microgels
Nanocomposite Hydrogels
Drug Delivery
Microfluidics
Self-assembly
Degradability
Enviromentally-responsive

abstract:
Microgels are solvent-swollen cross-linked gel particles with sub-micron diameters and have been widely investigated for drug delivery applications. Thermoresponsive microgels based on poly(N-isopropylacrylamide) (PNIPAM) have attracted particular attention given their potential to enable pulsatile or environment-specific drug release. However, current methods to make thermoresponsive microgels yield functionally non-degradable materials, significantly limiting their utility in vivo.  Herein, hydrazone chemistry was applied to cross-link hydrazide and aldehyde-functionalized precursor polymers together to form degradable PNIPAM microgels on different length scales that enable potential use of thermoresponsive microgels in vivo in a way not currently possible.
For micron-scale microgels, microfluidics was employed to create monodisperse microgels between 30-90 m.  For nano-scale microgels, a temperature-driven aggregation/self-assembly technique was developed that resulted in the formation of microgels with sizes between 200-300 nm. In either case, the microgels can be slowly degraded through hydrazone hydrolysis. Functionalized microgels can be made by incorporating pH-responsive 2-dimethylaminoethylmethacrylate (DMAEMA) or glucose-responsive phenylboronic acid in the precursor polymers.

	The potential utility of degradable microgels in drug delivery was studied using in situ gelling microgel-hydrogel nanocomposites. Changing the microgel cross-link density and whether or not the microgels were physically entrapped or covalently cross-linked to the bulk hydrogel matrix resulted in significant changes in drug release kinetics, with burst release particularly mitigated by increasing the cross-link density of the microgels. Microgels made via microfluidics were then utilized to make fully degradable microgel-hydrogel composites consisting of chemically identical gel chemistries on both the bulk and micro length scales. Carbohydrates (carboxymethyl cellulose and dextran) and PNIPAM gel phases were oriented in different relative geometries to examine how the phase distribution impacted drug release. Results suggest that drug release can be controlled through the selection of polymer type of each phase, with the deswelling phase transitions of PNIPAM playing a particularly large role in slowing release of the drug.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Microgels are solvent-swollen gel particles that have sub-micron diameters and have been widely investigated for a variety of biomedical applications.  Temperature-responsive microgels based on poly(N-isopropylacrylamide) (PNIPAM) hold particular promise given that they can swell and deswell in response to changes in temperature, enabling pulsatile or environment-specific release of a drug.  However, current thermoresponsive microgels are not degradable and therefore have limited utility in the body. In this thesis, degradable temperature-responsive microgels were developed on two length scales (micron and nano-sized) to enable their ultimate use in the body. Microgels responsive to changes in solution pH or the presence of glucose (both clinically-relevant stimuli) were made using similar techniques.  Combinations of these microgels with injectable hydrogels enabled tuning of the rate of drug release by changing physical microgel and/or hydrogel, as investigated both experimentally and theoretically. The research conducted thus has the potential to impact clinical drug delivery vehicle design.