title: AN EXAMINATION OF THE GUT MICROBIOME IN PATIENTS WITH OBSESSIVE-COMPULSIVE DISORDER VERSUS HEALTHY CONTROLS

title: THE GUT MICROBIOME IN OBSESSIVE-COMPULSIVE DISORDER

contributor:
Van Ameringen, Michael
Neuroscience

subject:
OCD
MICROBIOME
PSYCHIATRY
MENTAL HEALTH
ANXIETY
GASTROINTESTINAL

abstract:
Obsessive-Compulsive Disorder (OCD) is a debilitating, chronic neuropsychiatric disorder estimated to effect approximately 1-2% of the Canadian population. Our understanding of the pathophysiological mechanisms involved in OCD is unclear, as evidenced by the moderate response associated with treatments targeting these putative pathways. As such, there is a need to explore novel mechanisms of disease. Recent research has focused on the gut-brain axis and highlighted the potential role of the gut microbiota in psychiatric conditions. Further, the role of inflammation is also gaining traction in psychiatric research. This thesis investigates the role of these commensal gut bacteria in OCD, by examining stool samples of unmedicated, non-depressed OCD outpatients and healthy community controls. Given that systemic inflammation is a suggested pathway by which gut bacteria effect behaviour, morning levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor-necrosis factors-α (TNF-α) were also examined. To our knowledge, this thesis is the first investigation of the gut microbiome in OCD. This thesis describes: (1) a critical review of the literature developing a theoretical basis for a role of microbial dysbiosis in OCD; that (2) three specific genera and species richness/diversity are lower in OCD patients compared to controls; (3) mean CRP, but not IL-6 and TNF-α, is elevated in this sample of OCD patients; and (4) gastrointestinal symptom severity and prevalence of irritable bowel syndrome is higher in OCD. Taken together, this thesis is the first study to provide evidence for microbial dysbiosis in OCD. Although systemic inflammation may not mediate the relationship between reduced diversity and OCD symptomatology, these results provide evidence for mild  systemic
inflammation. Further gastrointestinal and psychiatric symptom severity are positively correlated, but not specific to patients with IBS. These results suggest the gut microbiome may be a potential pathway of interest for future OCD research, clinical implications are also made.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Skin Friction and Fluid Dynamics of a Planar Impinging Gas Jet

contributor:
Ziada, Samir
McDermid, Joseph
Mechanical Engineering

subject: Fluid dynamics

abstract:
Impinging gas jets have many engineering applications, including propulsion, cooling, drying, and coating control processes. In continuous hot-dip galvanizing, a molten zinc-based coating is applied to a steel substrate for corrosion protection. Planar impinging gas jets (industrially called air-knives) are employed to wipe the protective coating from the steel sheet to control the final coating weight. The maximum skin friction and pressure gradient developed by the impinging gas jet on the steel sheet heavily influences the final coating weight. In the thesis, the maximum skin friction developed on an rigid impingement plate positioned downstream of a planar impinging gas jet (scaled-up model air-knife) is measured using oil film interferometry (OFI). A maximum skin friction map based on the jet operating conditions is established, which can be used in conjunction with industrial coating weight models for film thickness prediction, and can be further employed in the assessment and verification of computational fluid dynamic (CFD) models.

    As impinging gas jets reach higher flow velocities, inherent instabilities in the jet can amplify due to feedback loops created between the jet exit and the impingement plate. The flow field characteristics under resonance conditions are known to exhibit large amplitude jet column oscillations, and strong coherent fluid structures propagating down the impinging shear layers. This work examined the global effect of planar impinging gas jet oscillations on the maximum mean skin friction developed in the stagnation region using external jet forcing. Reductions in maximum mean impingement plate skin friction were confirmed and found to be caused by increased levels of fluid entrainment under jet forcing conditions.

    The fluctuating velocity fields under external jet forcing was also examined. The velocity fluctuations due to both the coherent motion of the jet column, and the turbulence were obtained and analyzed using fluid dynamic tools such as particle image velocimetry (PIV) and proper orthogonal decomposition (POD). The fluctuating velocity of the planar impinging gas jet displayed increased levels of fluctuation intensity and unique flow field characteristics under external forcing, as well as, exhibited similar features to that of a high speed impinging planar gas jet under fluid resonance conditions. Overall, it is determined that enhanced planar impinging gas jet oscillations (or equivalent air-knife oscillations) is associated with adverse fluid effects, which degrade the wiping performance of the jet.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title:
Existentialism in Metamodern Art
The Other Side of Oscillation

contributor:
Donaldson, Jeffery
English and Cultural Studies

subject:
Metamodernism
Postmodernism
Aesthetics
Existentialism
Ethics
Modernism
Northrop Frye
Literary Criticism

abstract:
The discourse surrounding art in the early 21st century seeks to explain our artistic practices in terms of a radically distinct set of conventions, which many have dubbed ‘metamodern.’ Metamodernism abides neither by modernist aspirations of linear progress, nor by the cynical distrust of narratives familiar to postmodernism. Instead it appears to be based on an entirely different set of premises, relating to betweenness, oscillation, and metaxis, generating art with a dual capacity for irony and sincerity.
While metamodernism seeks to break the mold of the conventions that preceded it, it also avoids delimitation and prescription, and this traps it in an impossibility. To truly supplant the postmodern, the metamodern state of betweenness must be equally definite and formally circumscribed. In this project, I argue that metamodernism can be defined as an aesthetic of liminality – a state of thresholds and transitions – and that such a definition opens new avenues for understanding its core axioms. The second goal of the project is to reflect on where the metamodern state of transition might lead, and what future forms it promises. The project relies on literary theory, chiefly that of Northrop Frye, on analysis of the discourse surrounding contemporary aesthetics, as well as on occasional forays into philosophy, anthropology and sociology.
The project concludes that metamodernism’s core tenets are best understood as existentialist in nature, abiding by the tradition of existentialist writers such as Kierkegaard, Nietzsche, Merleau-Ponty, and others. Identifying an existential underpinning to metamodern art is also to uncover an ethical substrate to what otherwise appears to be a freeform aestheticism. The ties between existentialism and metamodernism provide a case study for a broader look at the relationship between ethics and aesthetics, which might be pursued in future work.

abstract: Thesis

abstract: Master of Arts (MA)

abstract:
There is a growing consensus among scholars that early 21st century art can no longer be explained in terms of familiar aesthetic conventions. The term ‘metamodernism’ is catching on as a description of our new era. Metamodernism is understood as an oscillation between two modalities – modernism and postmodernism – generating art that is more idealistic and romantic than what we have seen in previous decades, while retaining its capacity to be ironizing and self-aware.
However, the discourse surrounding metamodernism has been tentative, provisional, and difficult to circumscribe. In avoiding any overarching claims or settled positions, metamodernism risks remaining only a radicalisation of previous conventions rather than a genuine evolution. The goal of this project is to come to grips with the core tenets of metamodernism, to present them more clearly and distinctly, and to suggest what the scholarship surrounding metamodernism might need to move beyond its current constraints.


title: Soft X-ray Spectromicroscopy of Radiation Damaged Perfluorosulfonic Acid

contributor:
Hitchcock, Adam P.
Chemistry

subject:
PEMFC
PFSA
Perfluorosulfonic acid
PTFE
Radiation damage
Soft X-rays
Electron damage
STXM
TEM
Electron microscopy
ionomer
fuel cells

abstract:
Climate change has propelled the development of alternative power sources that minimize the emission of greenhouse effect gases. Widespread commercialization of polymer electrolyte membrane fuel cell (PEM-FC) technology for transportation and stationary applications requires
cost-competitiveness with improved durability and performance. Advantages compared to battery electric vehicles include fast refueling and long distance range. One way to improve performance and minimize costs of PEM-FC involves the optimization of the nanostructure of the catalyst layer. The rate limiting oxygen reduction reaction occurs at a triple-phase interface in the cathode catalyst layer (CL) between the proton conductor perfluorosulfonic acid, PFSA, the Pt catalyst particles decorating the electron conductor carbon support and gaseous O2 available through the porous framework of the carbon support. Visualization and quantitation of the distribution of
components in the CL requires microscopy techniques. Electron and X-ray microscopy have been used to characterize the distribution of the PFSA relative to the carbon support and porosity in CLs. Understanding and limiting the analytical impact of radiation damage, which occurs due to
the ionizing nature of electrons and X-rays, is needed to improve quantitation, particularly of PFSA. This thesis developed scanning transmission X-ray microscopy (STXM) methods for quantitation of damage due to electron and soft X-ray irradiation in PFSA materials. Chemical
damage to PFSA when irradiated by photons and electrons is dominated by fluorine loss and CF2-CF2 amorphization. The quantitative results are used to set maximum dose limits to help optimize characterization and quantitation of PFSA in fuel cell cathode catalyst layers using: analytical electron microscopy, X-ray microscopy, spectromicroscopy, spectrotomography, spectroptychography and spectro-ptycho-tomography.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Polymer electrolyte membrane fuel cells are an alternative, environmentally friendly power
source for transportation and stationary applications. Major challenges for mass production
include cost competitiveness, improved durability and performance. A key component to enhance
the performance and lower costs involves understanding and improving the spatial distribution of
the perfluorosulfonic acid (PFSA) polymer in the catalyst layer. The ionizing nature of electrons
and X-rays used in microscopy characterization tools challenges PFSA characterization since this
material is radiation sensitive. This thesis developed measurement protocols and methods for
quantitative studies of radiation damage to PFSA and other polymers using scanning transmission
X-ray microscopy. The chemical changes to PFSA films irradiated with photons, electrons and
ultraviolet (UV) photons were studied. The quantitative results identify limits to analytical
electron and soft X-ray microscopy characterization of PFSA. The results are used to optimize
methods for soft X-ray microscopy characterization of PFSA in fuel cell applications.


title: The Peripheral Immunophenotype in Neurodevelopmental Disorders

contributor:
Bowdish, Dawn
Health Sciences

subject:
Immunology
Autism Spectrum Disorder
Neurodevelopmental Disorders
Monocytes
Inflammation

abstract:
The factors contributing to the severity of the neurodevelopmental disorders autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are largely unknown. Previous studies have indicated immune abnormalities in these disorders, such as increased inflammation and altered immune cell numbers. We, in collaboration with the Province of Ontario Neurodevelopmental Disorder (POND) Network, analyzed markers of intestinal permeability and inflammation in children diagnosed with ASD or ADHD, as well as typically developing controls. Plasma from these participants was used to investigate levels of soluble inflammation, denoted by circulating acute phase proteins, as well as circulating levels of markers of intestinal epithelial damage and bacterial translocation. Peripheral blood mononuclear cells were isolated from these participants and used to construct an immunophenotype of ASD and ADHD, focusing on monocytes and monocyte activation and maturation. These data were then compared with scores of behaviour severity to identify associations between inflammation and behaviour in these disorders.
	We identified increased soluble inflammation in ASD, indicated by increased circulating C-reactive protein. We associated this inflammation with intestinal permeability, indicated by increased circulating LPS. Classical monocyte frequency was significantly lower in ASD and these monocytes displayed an altered migratory phenotype, indicated by a reduction in CCR2 expression. Furthermore, we have identified potential maladaptive monocyte responses to soluble inflammation in both ASD and ADHD, with altered monocyte phenotypes in response to inflammatory mediators compared to typically developing controls. Finally, we identified that changes in monocyte phenotype are associated with more severe behaviours in both ASD and ADHD. These findings imply that inflammation and immune abnormalities contribute to the severity of neurodevelopmental disorders.

abstract: Thesis

abstract: Master of Science (MSc)


title: Speech perception of Canadian English sibilants: Processing of acoustic information or underlying (articulatory) vocal tract configurations?

contributor:
Pape, Daniel
Service, Elisabet
Cognitive Science of Language

subject:
phonetics
speech perception

abstract: Acoustic and articulatory speech perception theories are proposed to explain how listeners map acoustic signals to phonetic categories. Different from acoustic theories, articulatory theories hypothesize that listeners would recover articulatory information during the mapping. To test this hypothesis, we altered the acoustic information of the Canadian English sibilants /s/ and /ʃ/ while keeping their articulatory information to signal places of articulation of the original sibilants. The manipulated sibilants were articulatorily cued as the original sibilants, but acoustically cued as the alternative sibilants (/s/ as /ʃ/ and /ʃ/ as /s/). We conducted an identification task to examine whether altering acoustic information would switch our Canadian English listeners’ identification. The listeners identified acoustically /s/-like /ʃ/ completely as the alternative sibilant /s/, but the acoustically /ʃ/-like /s/ as 60% the alternative sibilant /ʃ/ and 40% the original sibilant /s/. There was a categorical switch in the /ʃ/ stimuli but not the /s/ stimuli. This asymmetry of identification between two sibilants can be explained by two accounts: an acoustic plus articulatory account would be that the listeners relied more articulatory information only when identifying /s/ but not /ʃ/; and a purely acoustic account would be that the asymmetry was only a result of still existing small acoustic differences. While the acoustic plus articulatory account cannot explain why articulatory information only influenced the /s/ identification of the /s/ stimuli even after adding a set of assumptions, the purely acoustic account allows us to explain our results consistently without additional assumptions. Although our results cannot be used as evidence to reject the possibility that listeners will recover articulatory information, the results do suggest that even if we assume that articulatory information is recovered, acoustic information is more dominant than articulatory information in the identification process, at least for Canadian English /s/ and /ʃ/.

abstract: Thesis

abstract: Master of Science (MSc)


title: Exploring host genetic differences in gastrointestinal microbiota and homeostasis, through the production of fecal miRNA

contributor:
Foster, Jane
Neuroscience

subject: Gut microbiota;Antibiotics;MicroRNA; Host Genetics: Gut-Brain Axis

abstract: Research has shown that our gut microbiota confers many beneficial functions, including aiding the development of the immune system, metabolism, modulating stress reactivity and behaviour. The diverse population of the gut microbiota has been shown to be heterogeneous between individuals, with host genetic factors emerging as a contributor to gut microbiota composition. Recent work suggests that microRNA may act as a mediator of communication between the host and resident gut microbiota. Here we explore host genetic differences in gut microbiota composition and fecal miRNA profiles in two inbred mouse strains BALB/C and C57BL/6, in relation to gastrointestinal homeostasis. Furthermore, we evaluate the role of host genetics in response to perturbation of the gut microbiota using broad-spectrum antibiotic treatment. Distinct differences in the gut microbiota composition evaluated by fecal 16s rRNA gene sequencing between BALB/c and C57BL/6 mice were found with notable significant differences in genera Prevotella, Alistipes, Akkermansia and Ruminococcus. Significant host genetic differences were also observed in fecal miRNA profiles evaluated using the nCounter Nanostring platform. A BLASTn analysis was used to identify conserved fecal miRNA target regions in bacterial metagenomes, which identified numerous bacterial gene targets. Of those miRNA targets that were conserved in our dataset, 14 significant correlations were found between fecal miRNA and predicted taxa relative abundance. Treatment with broad-spectrum antibiotics for a period of 2 weeks resulted in BALB/c mice exhibiting a decrease in barrier permeability while C56BL/6 barrier permeability remained unchanged, demonstrating a host-specific physiological response to antibiotics at the gastrointestinal barrier. Differential response to antibiotics was also observed in the expression of barrier regulating genes in both host strains. Individual taxa were found to respond differentially by host strain, with Parabacteroides and Bacteroides associating with changes in barrier function. Together these findings suggest that host genetics play a role in determining the host-microbe relationship in both healthy homeostatic conditions and altered microbial conditions.

abstract: Thesis

abstract: Master of Science (MSc)


title: Electrosynthesis and Characterization of Superparamagnetic Organic-Inorganic Nanocomposite Films

title: Synthesis and Characterization of Nanocomposites

contributor:
Niewczas, M.
Zhitomirsky, I.
Materials Science and Engineering

subject:
electrosynthesis
superparamagnetic film
films
nanocomposite
organic
inorganic

abstract: New electrochemical methods were developed to fabricate superparamagnetic organic-inorganic nanocomposites. The methods were based on the electrosynthesis of (gamma)Fe2O3, Mn3O4 and NiFe2O4 in situ in a polymer matrix. Various composite materials were developed using new electrochemical strategies, which were based on the use of strong and weak polyelectrolytes and polymer-metal ion complexes. The deposited films were studied by XRD, TG, DTA, SEM and AFM. The results show that cathodic deposits with thickness of several microns can be obtained on various conductive substrates. The results reveal that the weight percentage of inorganic phase in the deposits reduced with the increase of the polymer concentration in the electrochemical bath solution. The particle size distribution was measured by HRTEM and evaluated by theoretical models interpreting the magnetic measurement data. The two methods are in good agreement with each other. The results show that the average particle sizes of Mn3O4 and (gamma)-Fe2O3 can be adjusted by the selection of polymers with different functional properties, the polymer concentration in the solutions and annealing temperatures. The particle size distribution in the developed composites followed the lognormal distribution. A double-lognormal distribution was required to interpret the magnetization data of the system containing strong interparticle interactions, and to interpret the double-peak phenomenon observed in the imaginary part of the susceptibility in some nanocomposites. DC magnetization and AC susceptibility measurements were used to study the relationship between the magnetic properties .and the average particle size by studying the superparamagnetic behavior and ferrimagnetic phase transitions of (gamma)-Fe2O3 and Mn3O4 nanoparticles in the temperature range of 2 K - 300 K. The results show that the blocking temperature TB is mainly controlled by the average particle size of the nanoparticles, and increasing the average particle size results in an upward shift of the TB. One observes no frequency dependence of TB, which indicates strong interparticle interaction in the nanoparticle assembly, in agreement with the structural results. The results revealed superparamagnetic behavior in Mn3O4 nanoparticles below the ferrimagnetic Néel temperature TN, and that TB was identified by a peak in the temperature lower than the ferrimagnetic transition peak marked by TN in the AC measurement. It is found that both TB and TN of Mn3O4 depend on the average particle size, and reducing the average particle size of Mn3O4 from 3.5 nm to 2.8 run results in a shift of TB from 14 K to 7 K, and TN from 36 K to 31 K (bulk Mn3O4 TN= 42 K)

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Plant Closure and the Politics of Worker Ownership: The Inglis Case

contributor:
Cuneo, Carl
Sociology

subject: plant worker politic ownership inglis

abstract: This thesis is a case study of the 1989 closure of the Inglis Ltd. plant in Toronto, Ontario. The purpose of the study is to examine worker-ownership as a labour strategy in a period of economic restructuring. In the Inglis case, Local 2900 of the United Steelworkers of America developed a response to closure comprised of three elements: negotiating improvements on the terms of closure specified by contract and by legislation; participation in a state-sponsored Labour Adjustment Committee; and a study of the prospects for worker-ownership as an alternative to plant closure. Through document analysis and interviews with union members, officials, and consultants, the relation between these three strategic elements is outlined. Gramsci's concept of "passive revolution" is employed to analyze the role of the state in economic restructuring and in the plant closure. It is argued that the state's role in economic restructuring has fostered forms of worker-ownership which are difficult to translate into effective labour strategy. State reforms embodied in plant closure legislation and adjustment programs have simultaneously channelled labour responses away from worker-ownership and towards severance negotiations and adjustment activities.

abstract: Thesis

abstract: Master of Arts (MA)


title: Design of an Ultra-Wide Band based Indoor Positioning System

contributor:
Zheng, Rong
Computing and Software

subject:
Ultra-Wide Band
Indoor Positioning System
Hardware design
Two-Way Ranging

abstract: In recent years, the indoor positioning system (IPS) has attracted significant interests in both academical research and industrial development. It has seen many applications, such as hostage search and rescue, indoor navigation, and warehouse management, all of which can take advantage of precise positioning. However, in indoor environments, traditional methods, like the Global Positioning System (GPS), are usually either unreliable or incorrect because of the complicated physical characteristics of various objects reflecting and dispersing signals, such as the presence of people, walls, obstructions, and furniture. In contrast to other technologies such as WiFi and Bluetooth, which are not suitable to extract accurate timing information, UWB technology has the potential to reach center-meter level accuracy in indoor positioning. In this thesis, we developed a real-time, low-cost, IPS based on commercial-off-the-shelf UWB transceivers. Both the Two Way Ranging (TWR) and Time Difference of Arrival (TDOA) approaches have been implemented to obtain a target's location. To alleviate the effect of multipath propagation, we detect the presence of outliers by comparing the first path signal level and estimated receiving signal level. Moreover, we have designed the Printed Circuit Board (PCB) and evaluated performance by deploying the system both in a lab environment and in a two-story historical building during the 2018 Microsoft Indoor Localization Competition. The results show that we achieve a 28.9cm 95%-quantile 2D tracking error in the lab environment and a 92cm average tracking error for 3D localization on the Microsoft Indoor Localization Competition site.

abstract: Thesis

abstract: Master of Science (MSc)


title: Data-Driven Modeling and Control of Batch and Batch-Like Processes

contributor:
Mhaskar, Prashant
Chemical Engineering

subject:
Batch Processes
Subspace Identification
Process Control
Rotational Molding
HyCO
Batch Crystallization

abstract:
This thesis focuses on data-driven modeling and control of batch and batch-like processes. These processes are highly nonlinear and time-varying which, unlike continuous operations, are characterized by the finite duration of operation and absence of equilibrium conditions. This makes  the modeling and control approaches available for continuous processes not readily applicable and requires appropriate adaptations of the available approaches to handle a) batch data structure for modeling and b) a control objective different than that of maintaining a steady-state operation as often encountered in a continuous process.
With these considerations, this work adapted the batch subspace identification for modeling and control of a variety of batch and batch-like processes. A particular focus of this work was on the application of the proposed ideas on real engineering systems along with simulated case studies. The applications considered in this work are batch crystallization, a hydrogen plant startup dynamics in a collaboration with Praxair Inc. and a rotational molding process in collaboration with the polymer research group at McMaster University. For the seeded batch crystallization process, subspace identification techniques are adapted to identify a linear time invariant model for the, otherwise, infinite dimensional process. The identified model is then deployed in a linear model predictive control (MPC) strategy to achieve crystal size distribution (CSD) with desired characteristics subject to both manipulated input and product quality constraints. The proposed MPC is shown to achieve superior performance and the ability to respect  tighter product quality constraints as well as robustness to uncertainty in comparison to an open loop policy as well as a traditional trajectory tracking policy using classical control. In another contribution, merits of handling  data variety in a subspace identification framework was demonstrated on the crystallization process. The proposed approach facilitates the specification of a desired shape of the particle size distribution required at the termination of the batch process. Further, novel model validity constraints are proposed for the subspace identification based control framework. In the collaborative work on hydrogen plant startup, it is recognized as a batch-like process due to its similarity to batch processes. Firstly, in this work a high fidelity model of the Hydrogen unit was developed with relevant startup and shutdown mechanisms. This setup is used to mimic the trends in the key process variables during the startup/shutdown operation. The simulated data is used to identify a state-space model of the process and validated on new simulated startup. Further, the approach was demonstrated on real plant data from one of the Praxair's plants. The predictive capabilities of the model provide ample handle for the plant operator for averting failures and abrupt shutdown of the entire plant. This is expected to have immense economic advantages. Finally, the subspace identification based modeling and control approach was applied to a lab-scale rotational modeling (RM) process. It is a polymer processing technique that is characterized by the placement of a polymer resin inside a mold, subsequent closure of the mold, followed by the simultaneous application of uni-axial (as is the case in the present work) or bi-axial rotation and heat. The resin is deposited on the mold wall where it forms a dense unified layer following which, the mold is cooled while still rotating the mold. Once demolding temperatures are achieved, the finished part is removed from the mold. Its potential as a manufacturing process for polymeric components is limited by a number of concerns including difficulties in process control, in particular, determining efficiently the process operation to yield the desired product consistently, and produce new products. This work has contributed by developing optimal control strategies for the process to achieve user-specified product quality and reject variability across batches. The results obtained demonstrate the merits of the proposed approach.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Homomorphic Processing of Surface Recorded EMG Signals

contributor:
de Bruin, H.
Electrical Engineering

subject:
homomorphic
EMG signal
surface

abstract: Electromyographic (EMG) signals contain both neural and muscle information. Consequently, EMG signals can be modelled as the composition of two component signals, one of these being a low frequency neural input, the other a relatively high frequency, constant spectrally shaped, stationary, unitary muscle response. Utilizing this model and homomorphic processing estimates of the two component signals can be obtained. These estimates contain neural and muscle information respectively. This thesis establishes the basis for the use of this multiplicative model. It also outlines the application of multiplicative homomorphic processing to EMG signals. The results of this processing are shown to be valid and to contain useful information. The thesis concludes that the model is both appropriate and useful. It also points out that the use of this model and homomorphic processing allows the simultaneous extraction of both neural and muscle information from the EMG signal,a result which is not possible with other currently used processing techniques.

abstract: Thesis

abstract: Master of Engineering (ME)


title: FUNCTIONAL CHARACTERIZATION OF PUTATIVE MITOTIC BOOKMARKING FACTORS IN PLURIPOTENCY MAINTENANCE

contributor:
Draper, Jonathan
Biochemistry and Biomedical Sciences

subject:
Mitotic Bookmarking
Hdgf
Parp1
Psip1
Pluripotent Stem Cells
Cell Fate Regulation

abstract: Pluripotent stem cells are a special population of stem cell with indefinitely self-renewal and unlimited differentiation capability, which makes them an attractive avenue for regenerative medicine and disease modeling. Therefore, it is important to understanding the fundamental mechanisms that govern and maintain their pluripotent state. A phenomenon termed mitotic bookmarking has recently been suggested as a potential mechanism involved in the stable propagation of cellular identity through the cell cycles. Candidate-based studies have identified mitotic bookmarking factors that are retained on the mitotic chromatin and preserve the transcriptional memory of the cell. Nevertheless, there is a poor understanding of which proteins can serve as mitotic bookmarks, as well as the chromatin dynamics of bookmarked sites during mitosis and the start of the G1 phase. We have previously identified a list of putative mitotic bookmarking factors in pluripotent stem cells, from which we tested the role of PARP1, HDGF, and PSIP1 as potential bookmarks for the propagation of the pluripotent state through mitosis. Here we showed that the absence of PARP1 at the M-G1 transition impairs self-renewal capability of pluripotent stem cells without affecting the proliferation and cell cycle progression. Conclusive evidence that establishes a role for HDGF or PSIP1 in mitotic bookmarking of pluripotent stem cells has yet to emerge. However, our work provides a new avenue for exploring the functional importance of mitotic bookmarks in pluripotent maintenance.

abstract: Thesis

abstract: Master of Science (MSc)


title: Thesis: A SPECTROSCOPIC STUDY OF POLYMER ELECTROLYTE MEMBRANES

title: A SPECTROSCOPIC STUDY OF STRUCTURE AND DYNAMICS IN PROTON-CONDUCTING POLYMERS FOR HYDROGEN FUEL CELLS

contributor:
Goward, Gillian R.
Chemistry

subject:
Solid-State NMR
Electrochemistry
Hydrogen Fuel Cell
PFSA
Polymer Electrolyte
STXM
NEXAFS
Physical Chemistry

abstract: This thesis focuses on the state-of-the-art spectroscopic approaches in studying polymer electrolytes for proton exchange membrane fuel cells.  With the aim to optimize architectural and chemical design of hydrogen fuel cells, a variety of perfluorosulfonic acid (PFSA) membranes were explored to establish characteristics that ultimately improve PFSA electrolyte performance.  The results of the detailed spectroscopic analyses helped to unveil a structure performance relationship.  Solid-state nuclear magnetic resonance (ssNMR) spectroscopy was used to distinguish F and C environments, while scanning transmission X-ray microscopy coupled with X-ray absorption spectroscopy provided complementary chemical structural information with direct access to S and O environments.  The combination of these two techniques provided advantages in identifying subtle chemical alterations in PFSAs.  Furthermore, a novel ssNMR technique was developed with the purpose of probing local dynamics from the polymer perspective.  This ¬¬19F dipolar recoupling ssNMR approach was validated and applied to PFSA membranes by monitoring the normalized double quantum build-up curves as a function of relative humidity (%RH) and temperature, and the polymer side chain showed higher local motion as response to temperature and %RH elevation compared to the backbone.  The effective dipolar coupling constant was extracted to represent local dynamics and compared amongst tested PFSAs.  A standardized metric, the dynamic order parameter, was also introduced and applied to the materials to quantitatively compare them within the same class.  This new method provided an alternative way to extract site-specific local dynamics profile for materials with multiple resonances.  Additionally, the combination of in situ fuel cell performance evaluation and ex situ ssNMR characterization created a connection between fundamental chemistry and bulk electrochemical measurements.  As the first study to correlate these physicochemical properties to material performances, this work parameterized the structural impact at a molecular level and provided insight into improving polymer electrolyte materials.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Proton exchange membrane fuel cells, which help to reduce the reliance on fossil fuels by locally producing only water and heat, have received a significant amount of research attention as an alternative power generator for vehicular and stand-alone energy applications.  Perfluorosulfonic acid (PFSA) membranes, the most common commercial polymer electrolyte materials, have been investigated using modern analytical spectroscopies.  Solid-state nuclear magnetic resonance (ssNMR) spectroscopy and synchrotron-based scanning transmission X-ray microscopy were used in elucidating material compositions with complementary information. Moreover, an advanced ssNMR method was developed and applied to a variety of PFSAs.  Polymer backbones and side chains were separated spectroscopically, and were distinguished based on different local dynamics profiles extracted from the ssNMR experiments.  Additionally, bulk material performance evaluations from electrochemical analyses were correlated to PFSA side chain local dynamics profiles.  The integrated spectroscopic study illustrated in this thesis provided insight into understanding the structure-performance relationship of PFSA electrolytes.


title: Making Connections: Investigating the Link Between Stoic Grammar and Stoic Logic

contributor:
Johnstone, Mark
Hitchcock, David
Philosophy

subject: Philosophy, Stoicism, Greek, Grammar, Logic

abstract: This thesis investigates the connection between two branches of the Ancient Stoics’ study of dialectic, or what we would call “logic.” Specifically, we look at the overlap between the fields of Stoic logic (the Stoics’ study of propositions) and Stoic grammar (the Stoics’ study of language). While Stoic logic is now highly regarded as a field of study, Stoic grammar is often seen as irrelevant or inferior when compared to other systems of grammar. For the Stoics, however, the two were not so separable. Over three chapters, I look into the value of studying Stoic grammar as a way to approach the field of Stoic logic through a thorough investigation of the Stoic concept of the sundesmoi, or connectors. In the first chapter, I provide a rough ancient historiography of the sources available to us on Stoic grammar. Although we do not have many extant works which discuss Stoic grammar at length, I highlight four which are of particular value to us. In the second chapter, I do close readings of the Stoics’ definitions of sundesmoi, comparing them to definitions given by their grammatical rivals known as the Alexandrian grammarians. By comparing the Stoics’ definition to the Alexandrians’ more technical one, it is possible to see what made the Stoics’ definitions unique. Finally, the third chapter looks at examples of types of connectors and their use in proposition formation. Looking at the examples “if,” “and,” and “or,” I identify the ways in which these particular connectors align and differ from the Stoics’ general definition of sundesmoi. I conclude by considering how looking at the sundesmoi from a grammatical perspective allows us to approach Stoic logic in a different way. Stoic grammar may be more obscure than other forms of grammar, but it is useful for approaching Stoic philosophy more generally.

abstract: Thesis

abstract: Master of Philosophy (MA)

abstract: This thesis investigates the connection between two branches of the Ancient Stoics’ study of dialectic, or what we would call “logic.” Specifically, we look at the overlap between the fields of Stoic logic (the Stoics’ study of propositions) and Stoic grammar (the Stoics’ study of language). While Stoic logic is now highly regarded as a field of study, Stoic grammar is often seen as irrelevant or inferior when compared to other systems of grammar. For the Stoics, however, the two were not so separable. Indeed, in the thesis, I argue that although Stoic grammar is obscure to modern audiences, it is a useful tool for understanding other branches of Stoic philosophy, particularly Stoic logic. Using the Stoics’ conception of connectors (sundesmoi) as a case study for investigating Stoic logic and Stoic grammar, I show the benefits of understanding Stoic grammar as a way to approach Stoicism as a whole.


title: Generalized Gaussian Multiterminal Source Coding in the High-Resolution Regime

contributor:
Balakrishnan, Narayanaswamy
Chen, Jun
Mathematics and Statistics

subject:
Rate distortion
Source coding

abstract: Source coding, a central concept in information theory, is the study of encoding and decoding data. Depending on the topological structure of the sources, i.e. how the sources are connected with encoders, different rate distortion functions are used. In this thesis two different encoding schemes---distributed and decentralized---are discussed and compared with a benchmark (centralized) coding structure. Specifically, all structures for two and three sources are discussed and a special case for the multi-source (more than three sources) is calculated. This work gives a pathway to characterize the generalized multiterminal source coding systems by finding the difference in the rate distortion limits from the optimal centralized coding system. It is shown that in specific cases, some decentralized systems can achieve the Shannon lower bound in a high resolution regime.

abstract: Thesis

abstract: Master of Science (MSc)


title: Nonlinear Dynamics of the Heart Rate Variability Signal

contributor:
Kamath, Markad
Electrical and Computer Engineering

subject:
heart
heart rate
nonlinear
signal
variability

abstract: The heart rate variability (HRV) signal has been employed as a measure of sympathovagal balance in the human autonomic nervous system (ANS). It is known that aging affects the functional characteristics of the ANS. It has been suggested that complexity as measured by nonlinear dynamical indices, decays with age. We developed several algorithms and test protocols to characterize nonlinear dynamics in the HRV signal and to test the hypothesis that aging reduces the complexity within the HRV signal. Continuous HRV signal was obtained from 93 healthy subjects (41 males and 52 females) ranging in age between 5 and 78 years under controlled laboratory conditions in supine state. Subjects were from pediatric (PED, 5-12 years, n=15, 9 male, 6 female), adolescent (ADO, 13-17 years, n=16, 6 male, 10 female), adult (ADL, 18-30 years, n=22, 12 male, 10 female), middle aged (MDA, 31-60 years, n=21, 8 male, 13 female) and elderly (ELD, 61+ years, n=19, 6 male, 13 female) age groups. The length of data was 1000 or more R-R intervals for adequate computation. Stationary Holter HRV data from these controls were also used for the present study. Our results are as follows: There is a continuous systematic decay in the power-law scaling (beta), which decreases from -1.162 ± 0.388 for the PED group to -1.95 ± 0.6 for the ELD group (F = 6.649, p < 0.001; R = 0.475, p < 0.001. Approximate entropy (ApEn) decreases with age from 1.456 ± 0.093 for the PED group to 1.272 ± 0.135 for the ELD group (F = 7.82, p < 0.001; R = 0.519, p < 0.001. The detrended fluctuation analysis (DFA) of short-term data yielded an increase in short-range DFA scaling exponent (alpha)1 from 0.774 ± 0.204 for the PED group to 1.138 ± 0.289 for the ELD group (F = 7.535, p < 0.001), and in long-range DFA scaling exponent (alpha)2 increased from 0.667 ± 0.082 for the PED group to 0.86 ± 0.172 for the ELD group (F= 4.841,p < 0.001). The detrended fluctuation analysis (DFA) of long-term data yielded an increase in short-range DFA scaling exponent (alpha)1 from 1.052 ± 0.218 for the PED group to 1.204 ± 0.205 for the ELD group (F = 1.922), and in long-range DFA scaling exponent (alpha)2 increased from 0.961 ± 0.081 for the PED group to 1.076 ± 0.102 for the ELD group (F = 4.06, p < 0.01). Surrogate data analysis demonstrated that the hypothesis that the HRV signal is generated by a linear stochastic process is not always rejected. In summary, the HRV signal lends itself to an analysis using nonlinear dynamical methods and studies in patients may yield useful clinical information in the future.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Spin Structure Factor Calculations using Matrix Product States

contributor:
Sorensen, Erik
Physics and Astronomy

subject:
condensed matter physics
matrix product states
tensor networks

abstract: The spin structure factor is the dynamical information coming from inelastic neutron scattering.  In this work we develop the technology of tensor networks as a numerical tool to be able to compute physical observables reliably for one-dimensional quantum systems.  The main technical message of this thesis is that tensor networks provide a controlled way to compute spin structure factors.  The algorithms in this thesis are tested on the anisotropic Majumdar--Ghosh model and the results of these simulations are presented and discussed.

abstract: Thesis

abstract: Master of Science (MSc)


title: Physiology of social ascension in a group-living cichlid fish

contributor:
Balshine, Sigal
Psychology

abstract: Animals living in groups often form social hierarchies as a result of competition over limited resources. While the behavioural and physiological consequences of social rank in stable groups have been well studied, few investigations have considered how these traits vary during times of social transition. In this thesis, I used a group-living cichlid fish, Neolamprologus pulcher, to investigate how subordinate males adjust their physiology as they ascend to social dominance. Specifically, I focused on the mechanisms responsible for the regulation of stress (Chapter 2) and growth (Chapter 3). In Chapter 2, I found that subordinate males rapidly assumed behavioural dominance in their social groups following an experimentally created vacancy. However, 72 h post ascension ascenders had higher transcript abundance of key steroidogenic genes in the head kidney and maintained elevated circulating cortisol levels, consistent with cortisol levels of subordinates. Cortisol production appeared to decline as groups regained social stability, because cortisol levels were lowest in ascenders that performed few aggressive acts towards their group mates. Ascenders also had higher transcript abundance of glucocorticoid receptors 1 and 2 in the preoptic area of the brain, supporting an enhanced capacity for negative feedback regulation of cortisol production. In Chapter 3, I found that ascending males became more active, performed more social behaviours, and increased their growth. These energetically-costly adjustments seemed to be fuelled by utilizing onboard energy stores, because ascenders exhibited a 50% reduction in liver glycogen reserves but did not increase food intake. In addition, faster growth during social ascension appeared to be mediated by reduced production of insulin-like growth factor binding proteins, likely increasing bioavailability of the growth stimulating hormone, insulin-like growth factor 1. Overall, the results of my thesis enhance our understanding of the regulatory mechanisms responsible for physiological differences observed in social hierarchies, and provide insight into how these regulatory mechanisms change during periods of social transition.

abstract: Thesis

abstract: Master of Science (MSc)


title: Determining the Distributed Karhunen-Loève Transform via Convex Semidefinite Relaxation

contributor:
Chen, Jun
Electrical and Computer Engineering

subject:
multiterminal source coding
Karhunen–Loève transform
rate–distortion function

abstract:
The Karhunen–Loève  Transform (KLT) is prevalent nowadays in communication and
signal processing. This thesis aims at attaining the KLT in the encoders and achieving
the minimum sum rate in the case of Gaussian multiterminal source coding.
In the general multiterminal source coding case, the data collected at the terminals
will be compressed in a distributed manner, then communicated the fusion center
for reconstruction. The data source is assumed to be a Gaussian random vector in
this thesis. We introduce the rate-distortion function to formulate the optimization
problem. The rate-distortion function focuses on achieving the minimum encoding
sum rate, subject to a given distortion. The main purpose in the thesis is to propose a
distributed KLT for encoders to deal with the sampled data and produce the minimum
sum rate.
To determine the distributed Karhunen–Loève  transform, we propose three kinds
of algorithms. The  rst iterative algorithm is derived directly from the saddle point
analysis of the optimization problem. Then we come up with another algorithm by
combining the original rate-distortion function with Wyner's common information,
and this algorithm still has to be solved in an iterative way. Moreover, we also propose
algorithms without iterations. This kind of algorithms will generate the unknown
variables from the existing variables and calculate the result directly.All those algorithms can make the lower-bound and upper-bound of the minimum
sum rate converge, for the gap can be reduced to a relatively small range comparing
to the value of the upper-bound and lower-bound.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Preparation of resistant starch with heat moisture treatment, acid modification, enzymatic modification, and epoxidation methods

contributor:
Thompson, Michael
Chemical Engineering

subject:
resistant starch
debranching enzyme
esterification reaction
acid modification
pea starch
epoxidation
heat moisture treatment
dual modification

abstract:
The main objectives of this study were to develop an effective process to produce modified pea starch with enhanced enzyme resistance property (RS) for food applications. The work compares a non-chemical method (heat moisture treatment) versus a chemical method (crosslinking).  One type of commercial pea starch (Nutri-Pea) was used exclusively as the raw material in this study. A number of methods were used to characterize the properties of the modified pea starches: water solubility index (WSI), titration (conversion, iodine value), intrinsic viscosity, infrared spectroscopy (FT-IR), Englyst digestion method, total starch content, and rapid visco analysis (RVA).
    The effects of heat-moisture treatment on native pea starch and enzyme treated pea starch were examined. The results showed that the produced samples with both native starch and enzyme treated starch exhibited a sharp increase in intrinsic viscosity. Overall, this method was deemed undesirable and not extensively examined past preliminary evaluations.
    The main focus of the study was on a citric acid crosslinking reaction, chosen for its food compliancy. A temperature of 120 oC was considered ideal for the reaction. FT-IR confirmed the presence of the citric acid incorporation in the starch samples. To improve the extent of reaction, Butanetetracarboxylic acid (BTCA) was considered as a replacement for citric acid and its treated samples showed higher conversion and lower water solubility index than that of the citric acid treated samples. Sodium propionate (NaP) was also considered in the reaction, this time as a food-grade catalyst and found to have minor benefit in cross-linking. BTCA/NaP treated sample reached the highest conversion of the study (96.8±2.3 %) and the lowest WSI (13.1±2.0 %), which increased the RS fraction of the starch from 18% to 32%. The RVA pasting profiles examined were too low to compare due to the high degree of cross-linking.
    Further improvements to RS were sought by debranching the starch before acid crosslinking. A BTCA/NaP treated sample with enzyme treatment showed a low WSI (31.7±2.3 %) yet substantially higher RS fraction (80.81±0.18 %). Similar to the non-debranched acid modified samples, there were no significant RVA pasting results because of the high cross-linking.
    Finally, crosslinking with an epoxidized oil was tested to continue looking at food-grade solution yet possible increase the rate of the crosslinking reaction. The results of WSI indicated that this method had little influence on cross-linking, possibly due to the low epoxidation efficiency of vegetable oils, as determined by iodine value.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: IMAGE RESTORATIONS USING DEEP LEARNING TECHNIQUES

contributor:
Wu, Xiaolin
Electrical and Computer Engineering

subject:
Image restoration
Deep learning

abstract:
Conventional methods for solving image restoration problems are typically built on an image degradation model and on some priors of the latent image.  The model of the degraded image and the prior knowledge of the latent image are necessary because the restoration is an ill posted inverse problem.  However, for some applications, such as those addressed in this thesis, the image degradation process is too complex to model precisely; in addition, mathematical priors, such as low rank and sparsity of the image signal, are often too idealistic for real world images.  These difficulties limit the performance of existing image restoration algorithms, but they can be, to certain extent, overcome by the techniques of machine learning, particularly deep convolutional neural networks.  Machine learning allows large sample statistics far beyond what is available in a single input image to be exploited.  More importantly, the big data can be used to train deep neural networks to learn the complex non-linear mapping between the degraded and original images.  This circumvents the difficulty of building an explicit realistic mathematical model when the degradation causes are complex and compounded.

In this thesis, we design and implement deep convolutional neural networks (DCNN) for two challenging image restoration problems: reflection removal and joint demosaicking-deblurring.  The first problem is one of blind source separation; its DCNN solution requires a large set of paired clean and mixed images for training.  As these paired training images are very difficult, if not impossible, to acquire in the real world, we develop a novel technique to synthesize the required training images that satisfactorily approximate the real ones. For the joint demosaicking-deblurring problem, we propose a new multiscale DCNN architecture consisting of a cascade of subnetworks so that the underlying blind deconvolution task can be broken into smaller subproblems and solved more effectively and robustly.  In both cases extensive experiments are carried out.  Experimental results demonstrate clear advantages of the proposed DCNN methods over existing ones.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Psychogeographic Otherworlds: Experiencing Englishness with Alan Moore and Iain Sinclair

contributor:
Grise, Catherine
Donaldson, Jeffery
Serruys, Nicholas
Ho, Elizabeth
English and Cultural Studies

subject:
Psychogeography
Alan Moore
Urban theory
Iain Sinclair
Nostalgia
London
Heritage

abstract: This thesis concerns the practice of ‘psychogeography’ in London, England, and the ways in which psychogeographic writings provoke in city-dwellers an acute sense of disorientation, as though the everyday were otherworldly. My study is intended as a response to Guy Debord’s claim that ‘psychogeography’ investigates “the precise laws […] of the geographical environment” on “the emotions and behaviour of individuals” (Debord qtd. in Coverley 88): any revolutionary enterprise must point to the future, the very notion of which can only be imprecise and un-empirical – psychogeography is not necessarily an exception. I argue that for Alan Moore and Iain Sinclair, the psychogeographic imperative is rather to imagine the implosion of Londonscape as it is well known, since only spatial structures that thus unravel may offer mystical insights that are, as yet, unspoiled by neoliberal/Thatcherite politics and the accompanying ambition to re-vamp English history in a nostalgic light. This study presents psychogeography not simply as a strategy of political resistance but as a visceral and metaphysical experience; it draws upon SF theories of worlding and the philosophical notion of Dasein to address some concerns that have arisen in post-imperial Britain, such as the desire to define English identity, i.e., ‘Englishness.’

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation studies Alan Moore’s and Iain Sinclair’s use of psychogeography to examine the city of London. Psychogeography is an implosive, fragmented writing style that estranges the meaning of the urban everyday. Subject to psychogeographic depiction, London becomes a city altogether foreign, if not to say fantastical. I argue that psychogeography is both a strategy of political resistance and a visceral experience – one that could influence common ways of reading English history and culture (i.e. ‘Englishness.’)


title: Evolutionary Genomics of Xenopus: Investigations Into Sex Chromosomes, Whole Genome Duplication, Speciation, and Hybridization

contributor:
Evans, Ben
Biology

subject:
genome evolution
sequencing
sex chromosome turnover
phylogenetics
purifying selection
pseudogenization
endangered species

abstract:
African clawed frogs (Xenopus) have been scientific and medical model species for
decades. These frogs present many curious features, and their genomic history is no
exception. As such, a variety of evolutionary genomic questions can be addressed with
these species in a comparative framework, owing to the great array of genetic tools
available and a large number of abundant species. The sex chromosomes of this group
are evolutionarily young, and this thesis establishes that there has been an additional
change in what constitutes the sex chromosomes in one species of Xenopus. This allows
us to compare the evolutionary trajectory of newly established sex chromosomes. By exploring
the genetic content of these systems, profiling their recombinational activity, and
assessing the extent of nucleotide divergence between the sex chromosomes, we find that
sex chromosome evolution may be predictable in some aspects, and highly unpredictable
in others. In addition, this genus is uncharacteristic for vertebrates in the frequency with
which lineages undergo whole genome duplication. In this thesis, we explore the selective
dynamics operating on duplicate genes over time, and the rate at which duplicate copies
are purged from the genome from multiple Xenopus species. These investigations provide
an animal perspective on the subject of biased subgenome evolution, characteristic
of allopolyploids. The last two chapters of this thesis redefine the species boundaries for
the most intensively studied Xenopus species (X. laevis), and explore the genetic extent
of hybridization between the common X. laevis and the endangered X. gilli. Overall,
this thesis provides a broad look at several aspects of Xenopus evolutionary genomics,
providing novel contributions to the fields of sex chromosome research, whole genome
duplication, and speciation and hybridization.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Understanding the Global and Regional Landscape of Fractures, and the Impact of Sex on Hospital Admission Delays, in Women Across 17 Low and Middle-Income Countries

contributor:
Bhandari, Mohit
Global Health

subject:
Musculoskeletal Trauma
Women's Health
Health Burden of Injuries
Global Health
Pre-Hospital Health Care
Social Determinants of Health
Low- and Middle- Income Countries

abstract:
Musculoskeletal trauma including fractures, represents a significant burden of disease for Low- and Middle-Income Countries (LMICs). Within LMICs, women possess reduced agency to make health care decisions and represent a vulnerable population. In this thesis, I aimed to characterize priority fractures among women within LMICs, and investigated whether women were delayed in hospital admission following an orthopaedic trauma. In Chapter 1, I introduce and review the existing literature on injury burden, health care deficiencies, and gender inequities within LMICs.
In Chapter 2, we analyzed regional distributions of fracture burdens across 9,934 female orthopaedic trauma patients across 17 LMICs. Half of our study patients were ≥ 60 years old. We determined that the major burden of orthopaedic trauma among women within LMICs were fractures among the elderly. Fracture burden in Africa was notably different. A majority of patients were between the ages 18-59, and common fractures included tibia/fibula and femur fractures.
In Chapter 3, we analyzed 26,910 orthopaedic trauma patients across 17 LMICs to determine whether women were delayed in hospital admission by >24 hours. After controlling for confounds, sex was not a significant predictor of delay. We found that instead, the severity and type of fracture influenced the delay of patient’s hospital admission. Closed fractures, falling-related injuries, pelvic, spine and hip fractures were associated with increasing delay. Irrespective of sex and region, inter-hospital referrals accounted for nearly half of the reasons patients were delayed.
These two chapters highlight regional trends in orthopaedic burden sustained by women, pointing to the high frequency of fragility fractures. In addition, this thesis identifies critical gaps within LMICs’ health care systems infrastructure, demonstrating the need for improved hospital referral systems and ambulatory services. This analysis will enable policymakers, and future researchers to target interventions to address the rising global burden of injuries especially among women.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Fractures represent life-threatening injuries within Low- and Middle-Income Countries (LMICs), and globally are a top-ten leading cause of death and disability. Within LMICs, due to gender inequalities, women may be restricted from receiving hospital care following an injury. We investigated the most common types of fractures in women within LMICs and determined that women most frequently experienced fractures due to old age. We further examined whether women were delayed in reaching a hospital after sustaining a fracture, and found that sex did not significantly play a role in determining delay. Instead, injury associated factors, such as the type and severity of the fracture influenced whether a patient was delayed. In addition, transferring patients between hospitals was the most common reason for delay. As a result, policymakers in LMICs should explore strategies to treat the high burden of fractures in the elderly and improve communication between hospitals to reduce delays.


title: STRUCTURE AND PHYSICAL PROPERTIES OF TRANSITION METAL BASED COMPOUNDS

contributor:
Niewczas, Marek
Materials Science and Engineering

subject: Heusler compounds, G-Phase, Laves Phase, Neutron diffraction, Czochralski, Half-metallicity, Geometric frustration, Canted antiferromagnetism, Short range order.

abstract:
Crystalline systems formed with transition metal elements tend to exhibit strong magneto-structural coupling that gives rise to unusual but exciting physical phenomena in these materials. In this dissertation, we present our findings from the studies of structural and physical properties of single phase compounds Co2MnSi, Ni16Mn6Si7 and Mn(Ni0.6Si0.4)2. In addition, the stability of a Ni2MnSi composition in a multiphase system is discussed by both theoretical and experimental approaches. All the works have been conducted with a focus on explaining the fundamental behaviors of these systems that have not been adequately addressed by other studies in the literature.

We present an experimental and theoretical investigation of the half-metallic Heusler compound, Co2MnSi to address disorder occupancies and magnetic interactions in the material. Contrary to previous studies, our neutron diffraction refinement of the polycrystalline sample reveals almost identical amount of Mn and Co antisite disorders of ~6.5% and ~7.6%, respectively which is also supported explicitly by our first-principles calculations on the system with defects. A reduction of the net moment of Co2MnSi due to an antiferromagnetic interaction introduced by disordered Mn is observed by our theoretical study. The neutron refinements at 298 K, 100 K, and 4 K further supports such reduction of moments. The work also reports the growth of single crystal by the Czochralski method and determination of a Curie temperature of ~1014 K measured by both the electrical resistivity and dilatometry measurement.

Studies of a Ni2MnSi Heusler system reveal two new systems i.e., the Ni16Mn6Si7 G-phase and the Mn(Ni0.6Si0.4)2 based Laves phase with complex crystal structures. These systems exhibit strong magneto-structural coupling that could lead to interesting physical behaviors. The lack of thorough understanding of the properties of these materials inspired us to undertake the present studies.
We address the geometrically frustrated two-dimensional magnetic structure and spin canted weak ferromagnetic behavior of Ni16Mn6Si7. Our magnetization and specific heat measurements on a Czochralski grown single crystal sample depicts the paramagnetic to antiferromagnetic transition at 197 K, and a second phase change at 50 K. Furthermore, a gradual drop of zero field cooled magnetic susceptibility is observed below 6 K that is associated with the spin freezing effect. The neutron diffraction on the polycrystalline powder samples at the temperatures of interest reveals that the antiferromagnetism is governed by the magnetic ordering of the Mn ions in the octahedral network.  Below the Néel temperature of 197 K, the 2/3 of Mn atom moments form a two-dimensional magnetic arrangement, while the 1/3 moments remain geometrically frustrated. The phase transition at 50 K is found to be associated with the reorientation of the 2D moments to a canted antiferromagnetic state and development of ordering of the frustrated paramagnetic ions. Magnetization measurements as a function of temperature and magnetic field in principal directions, permit to determine the anisotropic magnetic behavior of Ni16Mn6Si7 in terms of the magnetic structure obtained by the neutron diffraction measurements. We also report an irreversible smeared spin-flop type transition for the system at a higher magnetic field.
The diffuse scattering due to the short-range ordering is a commonly occurring phenomenon in Laves phase materials. The occurrence of such distinct atomic arrangement can considerably influence the physical behavior of the material. Nevertheless, no structural reconstruction of such atomic distribution in Laves phase has ever been reported in the literature. In this work, we present the structural ordering, and the associated physical behavior of an antiferromagnetic Ni-Mn-Si Laves phase with a composition Mn(Ni0.6Si0.4)2. The possibility of unique short-range ordering in the material is first concluded based on our single crystal diffraction analysis. With the high-resolution transmission electron microscopy and electron energy loss spectroscopy analysis, our work resolves the distinct atomic ordering of the Laves phase system. The investigations reveal the origin of the short-range ordering to arise from a unique arrangement between Ni and Si. The study also presents the atomic resolution mapping of the Si atoms which has never been reported by any previous studies. With further electrical conductivity measurement, we find one of the consequences of the unique ordering reflected in a semiconducting like temperature dependence of the compound. The neutron diffraction at 298 K suggests Mn(Ni0.6Si0.4)2 to be a strong antiferromagnetic system, which is further supported by the successive magnetic susceptibility measurement. The Néel temperature is determined to be 550 K.
We also address the stability of the hypothetical ferromagnetic Heusler compound Ni2MnSi which has been proposed to be a stable system by numerous theoretical studies. Our first-principles work corroborates those studies with a negative formation enthalpy of -1.46 eV/formula unit. However, after numerous attempts to synthesize the composition, we conclude that a single phase Heusler Ni2MnSi compound cannot form under ambient conditions. Our results show that the system crystallizes as a mixture of the two Ni-Mn-Si compounds, i.e., the Ni16Mn6Si7 type G-phase and Mn(Ni0.6Si0.4)2 based Laves phase. Our work provides a possible explanation for the unstable Ni2MnSi Heusler compound with the calculation of formation enthalpy of the hypothetical Heusler system in terms of the computed energies of the neighboring phases Ni16Mn6Si7 and Mn(Ni0.6Si0.4)2.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Existence and Regularity of Solutions to Some Singular Parabolic Systems

contributor:
Bronsard, Lia
Alama, Stanley
Mathematics and Statistics

subject:
Partial differential equations
Parabolic systems
Singular systems

abstract: This thesis continues the work started with my previous supervisor, Dr. Shaohua Chen. In [15], the authors developed some tools that showed the boundedness or blowup of solutions to a semilinear parabolic system with homogeneous Neumann boundary conditions. This system, the so called ’Activator-Inhibitor Model’, is of interest as it is used to model biological processes and pattern formation. Similar tools were later adapted to deal with the same parabolic system in [3], in which the authors prove global boundedness of solutions under homogeneous Dirichlet conditions. This new problem is of mathematical interest as the solutions may grow singular near the boundary. Shortly after, a different system was considered in [4], where the authors proved global boundedness of solutions to a system featuring similar singular reaction terms. The goal of this thesis is twofold: first, the tools developed that allow us to tackle these sorts of problems will be demonstrated in detail to showcase its utility; the second is to then use these tools to generalize some of these previous results to a larger class of singular parabolic systems. In doing so, we expand the classical literature found in [14] and other notable works, where nonsingular equations are extensively treated. The motivation for the first should be clear. While there are numerous bodies of text treating nonsingular problems, there are no collections available dealing with these types of singularities exclusively. This is of practical use to other mathematicians studying partial differential equations. The motivation for the second is, perhaps, more practical. There are a growing number of models found in physics, chemistry and biology that may be generalized to a singular type system. Through allowing those individuals to treat these problems, we may gain valuable insights into the real world and how these processes behave.

abstract: Thesis

abstract: Master of Science (MSc)


title: Fruit, vegetable, and legume consumption and cardiovascular disease and mortality in an international population

contributor:
Mente, Andrew
Health Research Methodology

subject:
Epidemiology
Nutrition
Population health
Cardiovascular disease

abstract:
Background: Diet is an important modifiable risk factor for cardiovascular disease.
Numerous studies have examined the association between dietary intake and
cardiovascular disease in North America and Europe, but little information is available on
potential associations in many geographic regions including South Asia, South America,
Africa, China, and the Middle East. Presently, it is unclear whether the findings from
Western countries are applicable to these regions where population characteristics,
background diet, and disease risk differ. This thesis aims to investigate the relationship
between diet and cardiovascular disease and mortality in a heterogeneous, international
population.
Methods: Baseline data from the Prospective Urban Rural Epidemiology (PURE) study
was used to investigate the availability, affordability, and consumption of fruits and
vegetables. Additionally, PURE baseline and follow-up was used to examine the
association between foods (fruits, vegetables and legumes) and macronutrients (total and
fat subtypes, carbohydrate and protein) and cardiovascular outcomes and mortality.
PURE is a prospective cohort study in individuals aged 35 to 70 years in 18 high-income
middle-income and low-income countries on five continents. Availability and affordability of fruits and vegetables was collected from centrally located grocery stores
and market places in each PURE community. Diet was measured using country and
region-specific food frequency questionnaires at baseline. Case-report forms, death
certificates, medical records and verbal autopsies were used to capture data about major
cardiovascular events, and death during follow-up. The cost and diversity of fruits and
vegetables was documented and mean fruit and vegetable intake by their relative cost was assessed. Associations between fruit, vegetable and legume consumption with risk of
cardiovascular outcomes and mortality were examined. We investigated the association
between macronutrients and risk of mortality and modeled nutrient replacement using
energy-adjustment and joint effect models.
Results: Results from the PURE study indicate that consumption of fruits and vegetables
is low worldwide, particularly in low-income countries, and this is associated with low
affordability. Higher fruit, vegetable and legume consumption was associated with a
lower risk of non-cardiovascular, and total mortality and benefits appear to be maximal at
three to four servings per day. This finding indicates that health benefits can be achieved
at intake lower than most dietary recommendations, an approach that is likely to be more affordable in poor countries. Higher carbohydrate intake was positively associated with
an increased risk of mortality, while total and fat subtypes, and protein was inversely
associated with death. For the nutrient replacement analysis, the joint effect method
demonstrated higher agreement with the single nutrient results compared to the
conventional energy-adjustment method. This result suggests that traditional nutrient
replacement modeling is not appropriate for international populations with diverse
nutrient intake.
Conclusions: Dietary intake varies across geographic regions and interventions to
improve diet and nutrition recommendations should be tailored to the geographic setting.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Optimal Finite Alphabet NOMA for Uplink Massive MIMO Channels

contributor:
Zhang, Jian-Kang
Electrical and Computer Engineering

subject:
Massive MIMO
NOMA

abstract:
This thesis focuses a noncoherent two-user uplink system with each user having a single antenna and a base station equipped with a large number of antennas. It is assumed that small scale channel fading is Rayleigh fading and varies in every one time slot.
For such massive MIMO uplink system, we consider an optimal finite-alphabet non-orthogonal multiple access (NOMA) design with each user utilizing nonnegative binary modulation.  A fast noncoherent maximum likelihood (ML) detection algorithm for the sum constellation of the two users and a corresponding closed form symbol error
probability (SEP) formula are derived.  In addition, the lower and upper bounds on SEP are established to quantitatively characterize how quickly SEP decays when the number of base station antennas goes to infinity. Two important concepts: full receiver diversity and geometrical coding gain, are introduced. Particularly for two users and three users  systems, with each user transmitting nonnegative binary constellation, we obtain an optimal closed form sum constellation that maximizes both the receiver diversity gain and geometrical coding gain. Computer simulations validateour theoretical analysis and demonstrate that our proposed optimal constellation attains significant performance gains over the currently available constellation design for the same massive MIMO upink system.\ Our future work is to develop an algorithm for devising an optimal AUDCG for the considered system in a more general case.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Development of a Thick Gas Electron Multiplier Based Beta-ray Detector

contributor: Radiation Sciences (Medical Physics/Radiation Biology)

subject:
Gas Multiplication
Monte Carlo
Thick Gas Electron Multiplier
Beta-ray

abstract: A new beta-ray detector using the Thick Gas Electron Multiplier (THGEM) technology is presented. Traditional proportional counters have been considered the standard for many decades for radiation contamination monitoring. However, it has always been challenging to detect low energy beta-emitters such as 3H and 14C. In order to extend the low energy cut-off of these beta particles, it is important to keep the electron multiplication gain as high as possible. To accomplish this goal, we have developed a new gaseous beta-ray detector using THGEMs. Founded on previous THGEM avalanche simulations [1] and predecessor detectors, a novel prototype THGEM beta-ray detector was designed and fabricated. Its signal performance, effective gain and gain stability were comprehensively studied for single and double-THGEM configurations using an alpha source. The first time THGEM detector response to beta-rays was observed for various operating conditions and compared with Monte Carlo N-Particle Transport 6 (MCNP6) Monte Carlo simulations.

abstract: Thesis

abstract: Master of Science (MSc)


title: 3D-printed titanium implants with titania nanotubes: dual-scale topography for bone applications

contributor:
Grandfield, Kathryn
Materials Science and Engineering

subject:
titanium
bone implant
surface modification
titania nanotubes
anodization
osseointegration

abstract:
Bone implants procedures involve millions of people every year worldwide. One of the main factors determining implant success is related to the ability of the prostheses to osseointegrate, i.e. to create a structural and functional connection with the living bone.
Titanium and titanium alloys are widely used biomaterials for bone implants, due to their superior biocompatibility and corrosion resistance, suitable mechanical properties, and natural ability to osseointegrate. To further enhance the inherent tendency of this class of materials to bond with the host bone tissue, the surface of Ti-based implant is often modified to improve cell responses in terms of adhesion, proliferation and differentiation, all factors contributing to successful osseointegration. In particular, surface topography, both at the micro- and nanoscale, can enhance the implant-living bone interaction.
Herein, a possible surface modification strategy aimed at the creation of a dual-scale topography on two different titanium alloys, Ti-6Al-4V and Ti-5Al-5Mo-5V-3Cr, is presented. Dual-scale topography was obtained by electrochemically anodizing samples manufactured by selective laser melting to combine their intrinsic microtopography with the nanotopography offered by titanium dioxide nanotubes (TNTs) generated by anodization. Characterization of the as-printed and as-anodized samples was performed to evaluate parameters of significance in the context of osseointegration. Concerning wettability, it was observed that surfaces with TNTs exhibited high hydrophilicity. The influence of the anodization process parameters on TNTs morphology was examined, and linear dependence of the nanotube diameter on the voltage was identified. Annealing of the as-anodized samples showed that anatase was produced, while preserving the nanotube integrity. Preliminary studies to assess the bioactive properties of the samples showed the spreading of bone-like cells on these substrates and the deposition of mineral during simulated body fluid testing. Therefore, both studies provided promising results to corroborate the hypothesis that dual-scale topography could potentially improve osseointegration.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Bone implants are often made of titanium-based materials, which, despite their suitable properties, may not sufficiently bond with the living bone tissue. This can lead to implant loosening and failure. To produce customized implants, additive manufacturing, or 3D-printing, can be employed. However, these surfaces require substantial post-processing to produce features capable of promoting bone integration. In this work, a dual-scale surface topography to combine the advantages of both micro- and nanoscale roughness was created using electrochemical anodization on 3D-printed titanium alloy substrates. Preliminary physical, chemical, and biological characterizations suggest that the creation of titania nanotubes on the 3D-printed surfaces of Ti-6Al-4V and Ti-5Al-5Mo-5V-3Cr could improve their ability to bond with bone.


title: Microstructural Characterization of Al-Fe Intermetallics in  Aluminum Alloy 7xxx during Controlled Solidification

contributor:
McDermid, Joseph
Mechanical Engineering

subject: Microstructural Characterization

abstract:
Aluminum 7xxx series alloys have been a major focus for lightweight automotive
structural components to achieve the targeted weight reductions by auto industries and, in
turn, to increase the vehicle fuel efficiency. AA 7xxx series wrought alloy components
have been widely used by the aerospace and automotive industries for many decades due
to their low density and high strength. However, although near net shape casting of these
alloys has many benefits versus wrought alloys; this processing route has been a
challenge for the researchers and the auto industry because of limitations due to
castability issues such as like hot tearing and die soldering. One possible mitigation
strategy involves the addition of iron (Fe) as one of the major alloying element and then
subsequently optimizing the alloy chemistry and solidification parameters in terms of die
soldering.
The objective of this thesis is to determine the microstructural evolution of any Al-Fe
intermetallic phases with respect to cooling rate during solidification for a range of AA
7xxx series alloy compositions. Fe was added at three different levels in a total of nine
alloy composition developed from a Taguchi experimental matrix based on the
interaction of three composition levels for four alloying elements. The alloys were cast
using a custom built casting rig while the cooling rates were measured along the length of
a directionally solidifying sample.
The thermocouple measurements were analyzed to determine the velocity of the
solid/liquid interface, overall cooling rate and thermal arrest points for later correlation to
variations in the microstructural development of any Al-Fe intermetallic phase particles
present in the experimental alloys. Metallographic samples were taken at locations with

iv

known cooling rates to determine the resultant microstructure. Scanning electron
microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS) were performed to
obtain elemental analyses of the Al-Fe intermetallic phases for present in the samples.
The Fe maps obtained by EDS were processed and analyzed using Image-J software to
determine the size distribution and area fraction of the Al-Fe intermetallic phases as a
function of alloy composition and solidification rates. Also, a regression analysis was
used to develop a statistical model to predict the variation of intermetallic particle size
and area fraction of the Al-Fe intermetallic phases as a function of alloy composition and
cooling rate.
Based on the experimental investigation and analysis of the nine Al 7xxx-Fe alloys the
results can be summarized as follows: (1) Cooling rate has a strong influence on the
chemistry and morphology of the Fe intermetallic particles: It was determined that the
dominant intermetallic species changes from the equilibrium Al3Fe to the metastable
Al6Fe alloys for cooling rates in excess of approximately10 °C/s. (2) Alloy cooling rate
does significantly affect the area fraction of the Fe intermetallic particles. It was
determined that the morphology of the Al-Fe particles transitions from a relatively low
aspect ratio particles to a high aspect, needle-like particles for cooling rates less than
approximately 10 °C/s. (3) Alloying elements such as Zn, Cu, and Mg does not influence
the Fe intermetallic chemistry and the area fraction of the intermetallics.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: The Opposing Planar Jet Oscillator

contributor:
Ziada, Samir
Mechanical Engineering

subject:
PIV
Jet Oscillations
Opposing Jets
PIV Pressure
Aeroacoustics
Flow-Induced Noise

abstract:
The fundamental nature of the flow oscillations which are generated by two opposing planar jets is investigated. Particular attention is given to the underlying mechanism which sustains the oscillations over a wide range of flow parameters. The jet columns are observed to undergo large lateral deflection oscillations once in each direction per cycle, in an asymmetric manner. Extensive characterization of the jet oscillations over a wide range of flow parameters is established, including both the aeroacoustic response, as well as the unique flow features which are synchronized with the oscillations. The impingement region and circulation regions in each quadrant of the flow field are shown to play essential roles in sustaining the oscillations, as the pressurization of the impingement region causes the jets to initially deflect away from the centerline, while the low-pressure regions which form in the circulation zones drive the jet columns back towards, and ultimately across, the centerline. A number of interesting observations are made regarding the oscillation characteristics, including a dependence of the oscillation frequency on the jet aspect ratio, which helps explain much of the discrepancy in the Strouhal numbers reported in the literature to date. Furthermore, the nature of the sound-source field is investigated including the directionality of the various frequency components which are radiated.

Unique mitigation strategies of the opposing planar jet oscillations are also explored by attempting to disrupt the circulation regions through the use of splitter plates. The oscillations are weakened considerably as the development and convection of the circulation zones is impeded. Preventing the circulation flow from interacting with the jet exit region drastically increases the effectiveness of the splitter plates, as even short splitter plates are shown to completely eliminate the oscillations. This demonstrates a very effective mitigation strategy of the opposing planar jet oscillator which is ideal for a variety of practical applications.

One of the main challenges of the current investigation into the opposing planar jet oscillator is the extent to which the detailed time-varying pressure field can be resolved. Since it is not possible to experimentally detail the time-varying pressure field of the opposing planar jets, a novel PIV-based pressure field mapping technique is developed and benchmarked. A separate apparatus consisting of a planar jet impinging on a v-shaped plate is utilized to benchmark the proposed technique. This technique effectively resolves the features of the time-varying pressure field which are synchronized with the flow oscillations and helps circumvent many of the challenges which existing PIV pressure field mapping techniques face. It also provides a valuable tool for researchers to simultaneously determine the kinematic and dynamic aspects of various flow phenomena in a variety of fields, especially those in the area of aeroacoustics and fluid-structure-interaction.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Multiperiod Refinery Planning: Development and Applications

contributor:
Swartz, Christopher L.E.
Chemical Engineering

subject: petroleum refinery multiperiod refining lagrangean decomposition optimization planning lagrangian nonlinear

abstract:
The purpose of this work aims to develop and explore a nonlinear multiperiod petroleum refinery model based on a real-world model. Due to the inherent complexity and interconnected nature of petroleum refineries, various studies are implemented to describe the multiperiod model.
The model is based around maximizing the profit of a petroleum refinery, starting from the crude inputs through the crude distillation unit, to the intermediate product processing through various unit operations, and finally to the blending of the final products. The model begins as a single period model, and is re-formulated as a multiperiod model by incorporating intermediate product tanks and dividing the model into partitions.
In solving the multiperiod model, the termination criteria for convergence was varied in order to investigate the effect on the solution; it was found that it is acceptable to terminate at a relaxed tolerance due to minimal differences in solution.
Several case studies, defined as deviations from normal operation, are implemented in order to draw comparisons between the real-world model and the model studied in this thesis. The thesis model, solved by CONOPT and IPOPT, resulted in significant gains over the real-world model.
Next, a Lagrangean decomposition scheme was implemented in an attempt to decrease computation times. The decomposition was unable to find feasible solutions for the subproblems, as the nonlinear and nonconvex nature of the problem posed difficulty in finding feasibilities. However, in the case of a failed decomposition, the point where the decomposition ends may be used as an initial guess to solve the full space problem, regardless of feasibility of the subproblems. It was found that running the decomposition fewer times provided better initial guesses due to lower constraint violations from the infeasibilities, and then combined with the shorter decomposition time resulted in faster computation times.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Petroleum refineries consist of complex units that serve a certain purpose, such as separating components of a mixed stream or blending intermediate products, in order to create final commercial products, e.g. gasoline and diesel. Due to the complexity and interconnectivity in a refinery, it is difficult to determine the optimal mode of operation. Thus, by formulating the refinery in mathematical form, optimization techniques may be used to find optimal operation. Furthermore, optimization problems can be formulated in a multiperiod fashion, where the problem is repeated over a set time horizon in partitions. The advantage is a higher detail in the operation of the refinery but this comes at a cost of higher computation time. In this work, a multiperiod refinery is formulated and studied by exploring model size, computation times, comparison of solvers, and solution strategies such as decomposition.


title: On the measurement and interpretation of health inequality, income inequality, and income-related health inequality

title: Essays on Health, Inequality and Fairness

contributor:
Hurley, Jeremiah
Health Policy

subject: health inequality

subject: income inequality

subject: socio-economic-related health inequality

subject: stated preference experiment

subject: concentration-based indices

subject: inequality aversion

abstract:
Governments, international agencies, and researchers routinely assess health and income inequalities and inequities so as to better communicate the evidence of their levels and trends to both policy-makers and the general public. Measuring the extent to which differences in health or income are unequal or unfair is, however, complex. This thesis contains three chapters centrally concerned with inequalities, though the focus differs across chapters. Chapter 2 helps address the gap between the requirements of indices often used for measuring income-related health inequality and current research practice by providing a non-technical review and critical assessment of the recent literature. This chapter should function as a guide for policy researchers and analysts to help them be more critical consumers of studies that use these indices while also helping applied researchers in choosing inequality measures that have the normative properties they seek. Most measures of inequality make assumptions about the extent to which society is averse to inequality. Moreover, analysts often assume that attitudes toward inequalities in health or income are the same. Chapter 3 is the first study using a mixed-methods approach to assess public attitudes toward inequalities in income, health, and income-related health inequality to determine preferences and how attitudes toward inequalities in these domains differ. Chapter 2 and 3 contribute to a greater understanding of the measurement and interpretation of inequalities.

While chapters 2 and 3 focus on inequalities among individuals within a society, chapter 4 focuses on inequalities globally among societies. Chapter 4 examines global health inequalities that result from medical care use using the example of long-standing drug technologies for treating hypertension. The study links availability and affordability of blood-pressure-lowering medicines with individual use and health outcomes. Chapter 4, therefore, provides an empirical illustration on how country-specific policies can play an important role in either countering or exacerbating health differences.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis concerns itself with different aspects of inequality related to health and income, though the focus differs across chapters. The second and third chapters of this thesis contribute to a greater understanding of the measurement and interpretation of inequalities. Whereas the fourth chapter provides empirical evidence on how country-specific policies can counteract or exacerbate health differences. Chapter 2 comprehensively reviews and critically assesses the literature on the technical and normative properties of indices commonly used for measuring income-related health inequality thereby addressing the gap between the requirements of these indices and current research practice. Chapter 3 investigates public attitudes toward inequalities in income, health, and income-related health inequality to determine preferences and where attitudes toward these inequalities differ. Chapter 4 examines global health inequalities that result from medical care use using the example of long-standing drug technologies for treating hypertension and links availability and affordability of medicines with individual use and health outcomes.


title: Development of a Thin CVD Diamond Detector as a Transmission-Type Alpha Particle Counter at McMaster University Biological Microbeam Facility

contributor:
Byun, Soo Hyun
Thompson, Jeroen
Medical Physics

abstract: Microbeams have been applied in radiobiology research for decades. The goal is to irradiate single cellular and subcellular targets with individual charged particles. This study describes the simulation and fabrication of a super-thin single crystalline chemical vapor deposited diamond membrane, intended to act as a radiation detector and a vacuum window at the McMaster University biological microbeam facility. The ultimate goal is to deliver very accurate and controlled doses to cellular targets through single-particle alpha irradiation. To study the options of the material and detectors, Monte Carlo simulations were employed to simulate the energy loss and beam broadening through different materials and component con gurations, including vacuum window, air gap, and petri dish. A transmission-type detector based on a super-thin diamond membrane was selected because of the minimal energy loss and beam broadening. Two diamond detectors (250 um and 50 um thick) were fabricated for initial alpha source tests following plasma etching, cleaning, sputtering, and electrical connection. Promising signals proved the feasibility of diamond as an alpha counter, and the spectra were collected. However, the diamond detector could not maintain the counting rate in the stability experiments, and the counting efficiency is not consistent with Monte Carlo simulations for this alpha source test geometry.

abstract: Thesis

abstract: Master of Science (MSc)


title: Cornhusk Doll Workshop: Promoting Health with Female Youth Living on Six Nations Reserve No. 40.

contributor:
Gabel, Chelsea
Health Sciences

subject:
Health Promotion
Female Youth
Six Nations Reserve No. 40
Cornhusk Doll Workshop

abstract: Involving Indigenous youth in health promotion research within the broader field of public health allows us to investigate health literacy, while promoting, protecting, and combating complex health issues. This project uses a community-engaged research approach, as well as a research workshop methodology and draws on qualitative methods to answer the following study objectives: (1) To what extent do female youth living on Six Nations Reserve No. 40 understand and engage in health promotion; (2) In what ways did a cornhusk doll workshop engage and strengthen female youth understanding on the topic of health promotion; and (3) What resources are necessary for female youth to successfully engage in health promotion. Findings were grouped into three main themes: Healthy Development, Healthy Relationships, and Healthy Policies.

abstract: Thesis

abstract: Master of Public Health (MPH)


title: Two-phase Targeted Maximum Likelihood Estimation for Mixed Data Meta-Analysis

contributor:
Balakrishnan, Narayanaswamy
Schnitzer, Mireille
Statistics

abstract: This thesis focuses on extension of Inverse Probability of Censoring Weighted Targeted Maximum Likelihood Estimation (IPCW-TMLE) which was initially proposed for two-stage sampled data. We adapt this framework to the setting of mixed Aggregate Data (AD) and Individual Patient Data (IPD) meta-analysis. Our methods are motivated by a systematic review investigating treatment effectiveness for Multi-Drug Resistant Tuberculosis (MDR-TB) where studies consist of mixed IPD and AD, and where treatments are not necessarily observed across all studies. We focus on the estimation of the expected potential outcome under a given treatment and then compare the results using different methods in two simulation studies. We also discuss the challenges and demonstrate our estimation approach when there exist studies that do not have access to the treatment of interest, using the concept of transportability. We use the jackknife estimator to estimate the variance and evaluate the coverage probability of different methods in the simulation study. The results showed near unbiased results along with a close to nominal coverage probability when using IPCW-TMLE method.

abstract: Thesis

abstract: Master of Science (MSc)