title: Petrochemistry of the mafic-rich rocks, Lac des Mille Lacs area, northwestern Ontario

contributor:
Irvine, T.N.
Geology

subject:
petrochemistry
mafic-rich rocks
Lac des Mille Lacs
northwestern Ontario
Quetico group
Shebandowan group

abstract: An investigation of the petrology and chemistry of two groups of mafic-rich intrusions from the Lac des Mille Lacs area was carried out. The Quetico group consists of hornblende-rich ultramafic to mafic rocks; the Shebandowan group consists of serpentinized ultramafic rocks and metagabbro. A spectrographic method was employed to quantitatively determine Al2O3, CaO, Co, Cr, Cu, Mn, Ni, Ti, V and Zr in the rocks. This, and other chemical data, indicate that these two spatially related groups, although mineralogically distinct, have similar chemical features, and have apparently crystallized from compositionally similar magmas under different water vapour pressures. Their similarities to ultramafic rocks from other areas provide some implications regarding ultramafic rock types of orogenic areas.

abstract: Thesis

abstract: Master of Science (MSc)


title: Effect of thickness on the structure of cold-rolled aluminum

title: Structure of cold-rolled aluminum

contributor:
Ham, R.K.
Metallurgy

subject:
aluminum
dislocation
Fuch's theory
"loss-fringe" model
cold-rolled

abstract: The relative merits of methods of determining the density of dislocations are reviewed. In particular, consideration has been given to the evidence available tending to indicate a loss of dislocations from foils of deformed metal during thinning processes preparatory to viewing in the electron microscope. By measurement of the electrical resistivity ratio, 293˚K./77˚K., during thinning, annealed specimens of super-purity aluminum foil were shown to obey Fuch’s theory for thin films, but cold-rolled specimens could not be fitted to the theory. This discrepancy has been attributed to the loss of dislocations from the cold-rolled material, and the results are shown to be consistent with a “loss-fringe” model of dislocation loss from the surface.

abstract: Thesis

abstract: Master of Science (MSc)


title: AN ENTERPRISE ENGINEERING APPROACH TO SAFETY MANAGEMENT

contributor:
Maibaum, Tom
Computing and Software

subject:
enterprise engineering
safety management

abstract:
Significant accidents are often related to the performance of a complex socio-technical system (enterprise) involving technology, people, organizations, processes, management and legislation.

Approaches to identify factors that lead to accidents and then take them into account during the design, operation, maintenance and evolution of the socio-technical system (enterprise) are not well defined and not consistently utilized in practice.

The emerging discipline of "enterprise engineering" provides an opportunity to apply an engineering approach to the design, operation, maintenance and evolution of enterprises to improve the likelihood of the enterprise achieving and maintaining its safety goals.

The integration of design principles and approaches from the fields of systems engineering, safety engineering, management science and enterprise architecture into a Safety Enterprise Engineering (SEE) approach based on a consistent model of the enterprise provides the basis of the approach described in this thesis.

A general process model for applying an enterprise engineering approach to safety management is defined.  Design principles from nuclear industry best practice documents are identified and mapped to the general process model.

The Fukushima nuclear accident that occurred in 2011 was used to identify weaknesses in current practices in the nuclear industry.  These weaknesses were compared with best practices, as defined by International Atomic Energy Agency (IAEA) documents, to identify the subset of weaknesses identified from the Fukushima accident that are also weaknesses within the IAEA set of best practices.  The Safety Enterprise Engineering approach was applied to a slice of safety related functionality of a CANDU nuclear utility to demonstrate the degree to which the SEE approach overcomes weaknesses of both current practice and best practice within the nuclear industry.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: An Investigation of Territory Quality in the Smooth-Billed Ani (Crotophaga ani)

contributor:
Quinn, James
Biology

subject:
territory quality
territory
smooth billed ani
crotophaga ani

abstract: Territorial behaviour is exhibited in cooperative breeders. The quality of defended territories can vary, and high-quality sites, which enhance fitness, should be used preferentially over poorer-quality sites. This study was intended to address issues of territory quality within the plural breeding, joint-nesting, smooth-billed ani (Crotophaga ani). I tested the communal joint-nesting threshold hypothesis, which posits that independent pairs will pay the price of group living if compensated by acquiring a superior territory. My results quantified differences in territory quality in terms of time of first breeding and chances for re-nesting or second-brooding. Per capita territory quality correlated negatively with group size, in conflict with the communal joint-nesting threshold hypothesis. Another hypothesis to explain communal behaviour is the habitat saturation hypothesis. This postulates that offspring remain in their natal territory and delay reproduction because of a local absence of suitable breeding habitat. I tested the habitat saturation hypothesis, which was developed to explain the evolution of group living in cooperatively breeding birds. I compared occupied ani territories with vacant sites, using eight ecological variables that may be important to the fitness of a group. In addition, I compared occupied territories with sites that were occasionally occupied. I did not find the habitat of our population of smooth-billed anis to be saturated. Some sites were never occupied because there are territory characteristics that presumably limit breeding. In contrast with expectations of habitat saturation, there were suitable sites available for breeding that were not in use. Results from both hypotheses presented suggest that there are not obvious group-living benefits and that one must consider other explanations for the evolution and maintenance of this system.

abstract: Thesis

abstract: Master of Science (MS)


title: Effects of Resistance Training on Bone Mass and Body Composition in Young Women

title: Exercise and Bone Mineral Density

contributor:
Sale, D.G.
Human Biodynamics

subject:
resistance training
bone mass
young women
body composition

abstract:
Thesis
Master of Science (MS)


title: An Investigation of Two Determinants of the Practice Effect in Tachistoscopic Word Recognition: Response Strength and Fixation

title: An Investigation of the Practice Effect in World Recognition

contributor:
Newbigging, P.L.
Psychology

subject: tachistoscopic word recognition, response strength and fixation, two determinants of the practice effect, practice effect, word recognition, practice effect in word recognition

abstract: Five experiments, involving 265 subjects, were performed with the objective of extending the analysis of response probability as a determinant of the practice effect in tachistoscopic word recognition. The results showed that the response probabilities of words may be manipulated and act as a determinant of the practice effect under certain limited experimental conditions. A more powerful determinant appears to be a general skill in tachistoscopic recognition which improves as a function of the number of stimuli recognized and transfers to the recognition of different stimuli. This skill was examined in the final experiment. The overall results were discussed in terms of both response probability and a general tachistoscopic skill.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Applying measurement theories to the advancement of the Chedoke Arm and Hand Activity Inventory

contributor:
Richardson, Julie
Rehabilitation Science

subject:
measurement
stroke
upper limb
item response theory
Rasch measurement theory
cross-cultural adaptation

abstract:
Background: The use of outcome measures to evaluate upper extremity function after stroke is highly recommended in clinical practice and research. The Chedoke Arm and Hand Activity Inventory (CAHAI) is a recommended measure as it has strong psychometric properties and clinical utility. However, the measure has not been validated in Asia and there are also gaps in the knowledge about the psychometric properties of the CAHAI.
Aim & Objectives: This thesis is dedicated to the continued evaluation of the CAHAI with two main objectives: (1) to develop a Singapore version of the CAHAI, and (2) to re-evaluate the original CAHAI using modern test theories.
Method: We conducted a study to cross-culturally adapt the CAHAI and evaluated the psychometric properties in a stroke sample in Singapore. Two studies were conducted to re-evaluate the original CAHAI using modern test theories. In the first study, item response theory and Rasch measurement theory were used to evaluate the psychometric properties of the measure. Following which, both measurement theories were used to revise the CAHAI in the second study.
Results: Two test items were modified for the Singapore version of the CAHAI, and the measure had good inter-rater reliability (intra-class correlation coefficient = 0.95 – 0.97) and construct validity. The evaluation of the original CAHAI using modern test theories identified three main problems: (1) the scoring scale was not working as intended, (2) local dependency, and (3) the measure was not unidimensional. Revisions to the CAHAI included collapsing the 7-category scale to four categories, deleting two test items, and developing two new shortened versions.
Conclusion: The Singapore version of the CAHAI is a valid and culturally relevant outcome measure that can be used to evaluate post-stroke upper extremity function. The original CAHAI was refined into a new 11- and 5-item versions with a 4-category scale which clinicians may find easier to use.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Unemployment in the City of Brandon

subject: Brandon, Manitoba, 1932, unemployment, unemployment in brandon

abstract: Preface: An unprecedented amount of unemployment throughout the western world challenges men to use their utmost intelligence to combat this monstrous social evil. yet without an understanding of all the available facts concerned, the problem is incapable of solution. The scope of this thesis is confined to the unemployed in the city of Brandon during the month of September, 1931. The purpose is to present certain aspects of the personal circumstances of their lives, and to discuss the bearing of these circumstances on the local unemployment problem. This study is based on the analysis of the registration of the unemployed of the city of Brandon that was made during the week beginning September 21st, 1931. The statistical method of approach was used both in securing the necessary factual basis and in exploring causual relationships.

abstract: Thesis

abstract: Master of Arts (MA)


title: Structure and Function Studies of Mammalian Adenosine Kinase

contributor:
Gupta, R.S.
Biochemistry

subject:
mammalian
adenosine kinase

abstract:
Adenosine kinase (AK) is a purine salvage enzyme which catalyses the phosphorylation of the 5'-hydroxyl of adenosine via ATP. AK is a key enzyme which controls the intra and extracellular concentration of adenosine (Ado). Agents which inhibit the activity of AK have been found to attenuate cellular damage, demonstrating therapeutic utility in a variety of disease processes. In order to design inhibitors of AK with increased efficacy, a better understanding of enzyme activity is required. Previously, a number of novel characteristics of mammalian AK had been discovered. It was shown that the activity of AK is influenced by the presence of pentavalent ions (PVD such as inorganic phosphate (Pi), arsenate and vanadate. A detailed study of the influence of Pi on the kinetic parameters of Chinese hamster (CH) and beef liver AK was performed. These studies suggested that the Km (Ado) decreases and the Ki (Ado) increases asymptotically in the presence of increasing concentrations of Pi. Under the same conditions, the Vmax for activity increases hyperbolically. The effect of phosphate is not limited to the mammalian form of AK. Pi, arsenate and vanadate were all found to have similar effects on AK from yeast, spinach and Leishmania donovani AK. PVI as well as the metabolite phosphoenol pyruvate were also found to stimulate the activity of the enzyme ribokinase (RK) from E. coli, which similar to AK, is a member of the PfkB family of carbohydrate kinases. Although AK and RK show little sequence similarity, the residues at the active site and the 3D structues of these two proteins are very similar. Based on sequence alignment of PfkB family members, we have identified a conserved sequence motif, NXXE, which based upon the available structural information appears to be involved in the binding of phosphate. To confirm and understand the role of this motif in Pi binding, the residues at the NXXE site were altered by site-directed mutagenesis and their effect on activity of the recombinant CH AK was examined. Though the residues at the NXXE site do not directly interact with substrate, nor the putative catalytic base, the resulting proteins were found to have greatly altered phosphate requirement, substrate inhibition characteristics and different magnesium requirements. In the AK structure, aspartic acid at position 316 is presumed to act as the catalytic base. This residue was changed to asparagine and glutamic acid by mutagenesis. The resulting proteins were found to be nearly completely devoid of activity, confirming its critical role in AK activity. The amino acid sequence at the extreme N-terminus of AK has been found to exhibit the greatest variability within and among species, though the rest of the protein remains greatly conserved. To delineate the residues that are involved in the structural stability and activity of AK, systematic deletions of the residues from both the N-and C-terminus were performed, and the structure-activity relationships were examined. It was determined that the first 16 residues of CH AK can be removed without affecting activity. Removal of the next 11 residues resulted in sequential decreases in enzyme stability and activity. These 11 residues are involved in the first B-structure of the protein and are required for the stability of the tertiary structure. All residues at the C terminus were
required for activity, and involved in a hydrogen-bonding network necessary for the stability of the ATP binding site. These studies provide novel insight to the structure-activity relationship of mammalian AK as well as the PfkB family of enzymes. Our work has identified a site distal to the catalytic site, that is implicated in the PVI binding and catalytic effect. Further studies should be aimed at understanding how binding of PVI at this site influences the catalytic activity of AK. Development of inhibitors which bind to this site and modulate the activity of AK should prove very useful in this regard.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A study of the Morphological States in the In Vitro Development of the Proembryo of Pinus Nigra Arn. Var. Austriaca A. & GR.

title: The Development In Vitro of the Proembryo of Pinus

subject:
pinus nigra
in vitro
morphological states
proembryo
austriaca

abstract: The earliest embryonic stages, because of the simplicity of their organization and cellular structure, are logical starting points for developmental studies of plants as a whole. The zygote and early post-zygote phases of embryonic development are periods of minimum cell form differentiation, if the cells possess a potentially to develop in a number of different ways at any stages in their development, it is in all likelihood at this early date. Becoming more and more specialized with continued growth, they finally form tissues and organs with the capacity for specific functions in the division of labour of the mature plant organization. it was felt that the more specialized the cells became, the less impressionable they would be to the influence of an in-vitro environment. Accordingly, this treatise deals with the culture in artificial medium of the early post-fertilization periods in the embryonic growth of Pinus nigra, var. austriaca, in an effort to discover and assess those factors which influence and govern the embryonic development pattern. The present study was begun in 1951 at the suggestion of Professor N.W. Radforth. I wish to express my appreciation to Professor Radforth for his guidance in conducting my research, without which this investigation could not have been carried out. This work was undertaken as part of a programme which has been assisted through a grant from the Ontario Cancer Treatment and Research Foundation, for which Dr. Radforth is the grantee.

abstract: Thesis

abstract: Master of Science (MS)


title: OPTIMIZING FUNCTIONAL PERFORMANCE OF FRAIL OLDER ADULTS AND THEIR CAREGIVERS

contributor:
Thabane, Lehana
Rehabilitation Science

subject:
Frailty
Caregiver
Network meta-analysis
Fracture
RIsk
Pilot
Randomized controlled Trial
osteoarthritis
Preoperative
prediction

abstract:
Aging and age-related frailty are important public health problems. There is a need to develop rehabilitation interventions to reduce the prevalence and disabling effects of frailty. This thesis reports the rationale and design of two studies and findings of three studies aimed to optimize health outcomes of frail older adults and their caregivers. The second chapter describes the protocol of the first network meta-analysis to determine the comparative effect of interventions targeting the prevention or treatment of frailty. In the third chapter, the results of frailty network meta-analysis were presented and 89 RCTs were included. The review shows that physical activity and medication management are the most effective frailty interventions. The fourth chapter describes a protocol of pilot randomized controlled trial (RCT) to examine a preoperative multi-modal frailty intervention in pre-frail/frail older adults undergoing elective joint replacements.
The fifth chapter describes the results of a subgroup analysis of a RCT examining the effect of complex primary care intervention to support caregivers of frail older adults. There were no differences between caregivers of frail older adults and non-caregivers in quality of life, social support, hospitalization, and emergency department visits. The sixth chapter examines the construct validity and discriminative properties of the fracture rating scale (FRS) (a tool designed for fracture risk assessment in long term care (LTC)). The FRS is a valid tool for identifying LTC residents at different risk levels for hip fracture in three Canadian provinces.
The work presented in this thesis is proposing and examining the comparative effect of frailty interventions, a preoperative frailty intervention/ model, a primary care intervention to identify and support caregivers, and a predictive tool to optimize care planning of LTC residents. These findings will support the rehabilitation and care program for older adults and their caregivers and improve their health outcomes.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: There is a need to develop rehabilitation interventions to reduce the prevalence and disabling effects of frailty. This thesis reports the rationale and design of two studies and findings of three studies aimed to improve health outcomes of frail older adults and their caregivers. The second and third chapters of this thesis describe the protocol and results of a review aims to identify the effect of interventions targeting frailty, the review found that physical activity and medication management are the most effective frailty interventions. The fourth chapter describes a study examining the possibility of comparing a complex intervention to usual care in frail older adults undergoing joint replacements. The fifth chapter showed that a primary care intervention did not improve the caregivers’ health outcome. The sixth chapter presents the fracture rating scale, a valid tool for identifying Long-term care residents at risk of hip fracture in three Canadian provinces. These findings aim to improve the care for older adults and their caregivers.


title: The Claims to Healing Made by Christian Science a Critique

subject:
healing
christian science
christian
critique

abstract: This thesis is in three sections: an introductory chapter surveying the contributory factors which gave rise to Christian Science as a healing cult taking into account the life and peculiarities of its founder, Mrs. Baker, Glover, Patterson, Eddy; a chapter on Mrs. Eddy's contact with Mesmerism through Phineas P. Quimby who writings and methods she adopted as her own; and, finally, a chapter wherein the doctrine of "Mind Healing" is evaluated as to its validity, limitations and possibilities. It is contended that the healing taught and practiced by Christian Science is nothing new but merely a reintroduction, under a different name, of the ancient practice of hypnotic suggestion which is, without doubt, effective in healing functional diseases. It is further contended, however, that Christian Science claims to healing of all diseases is fraught with real danger to life since its methods cannot heal organic disease, neither can it claim divine healing since its very philosophy is a denial of true Christianity as also of true Science.

abstract: Thesis

abstract: Bachelor of Divinity (BD)


title: Detailed Simulation of Signal-Level Sensor Data Using Monte Carlo Path Tracing and Photon Mapping

contributor:
Kirubarajan, Thia
Electrical and Computer Engineering

subject: sensor simulation, tracking, fusion, performance evaluation

abstract:
Simulated sensor data from active and passive sensors has numerous applications in target detection and tracking. Simulated data is particularly useful in performance evaluation of target tracking algorithms where the ground truth of a scenario must be known. For real sensor data it is impossible to know the ground truth so simulated data must be used.

This paper discusses existing methods for simulation of data from active sensors and proposes a method that builds on existing techniques from the field of computer graphics. An extension to existing methods is proposed to accommodate the simulation of active sensor data for which timing and frequency information is required in addition to intensity. Results from an existing method of active sensor data simulation are compared to the results of the proposed method. Additionally, a cloud computing framework is proposed and its scalability evaluated to address the fairly large computational load of such a simulation.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Minor Elements in Some Carbonates

contributor:
Shaw, D. M.
Geology

subject: element carbonate

abstract: An investigation of minor elements distribution in sedimentary and metamorphic carbonates was made. A copper oxide D. C. Arc Technique of spectrographic analysis was developed for determination of minor elements in carbonates. Forty-five samples of carbonates extracted from Paleozoic limestones of Alberta and Ontario, Precambrian marbles of Ontario and from Grenville Lens and Vein Carbonates of Ontario and Quebec were analyzed, and the concentrations of Mg, Mn, Fe, Sr, Ba, Pb, Al, Si, Ti, B, Cr, and Ni were determined. The structure and some chemical properties of carbonates were discussed. An attempt to locate the minor elements in the crystal structure was made.

abstract: Thesis

abstract: Master of Science (MS)


title: Interactions of Inflammation and E. coli in Crohn's disease

title: Antibiotics and intestinal inflammation increase host susceptibility towards Crohn’s disease-associated adherent-invasive Escherichia coli

contributor:
Coombes, Brian
Biochemistry and Biomedical Sciences

subject:
Crohn's disease
E. coli
Inflammation
Antibiotics

abstract: Crohn’s disease (CD) is an inflammatory bowel disease characterised by chronic inflammation with a complex pathophysiology involving host, environmental, and microbial factors. The intestinal microbiota is an important regulator of inflammation within the intestine, and a disruption of the interplay between gut bacteria and host immunity is a key factor in CD development. Intestinal inflammation itself is known to cause changes to the intestinal physiology that affect the ability of various bacteria to survive. Additionally, certain environmental risk factors for CD such as antibiotics are also known for their ability to impact the intestinal microbiota. CD is associated with various changes in the intestinal microbiome including increased colonisation with a group of bacteria known as adherent-invasive Escherichia coli (AIEC). The purpose of this study is to investigate how AIEC interact with antibiotics and intestinal inflammation in vivo. Multiple classes of antibiotics were found to increase the colonisation of AIEC and to increase its persistence. These antibiotics caused a loss diversity in the intestinal microbiome, but this did not explain the increased infectivity of AIEC. Antibiotic-induced inflammation was found to produce metabolites that benefitted AIEC growth in the intestine and similar results were found with chemically-induced inflammation. These results show that AIEC can benefit from both antibiotics and other sources of inflammation through inflammation-derived metabolites, which contributes to a greater understanding of the interactions between AIEC and CD.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Crohn’s disease is a type of inflammatory bowel disease that affects many young adults in Canada. It causes a wide range of symptoms including nausea, pain, and diarrhea. While the disease can be treated with surgery and medications, it is considered incurable and affects most individuals for life. The exact cause of Crohn’s disease is not known, but it is thought to be caused by a combination of factors including genetics, environmental exposures, and changes in the number and types of bacterial species in the intestine. Intestinal bacteria play an important role in preventing inflammation in the intestine. An unusual strain of bacteria called adherent-invasive E. coli is found more commonly in Crohn’s disease patients than in healthy individuals. This strain does not cause the disease on its own, but it may interact with other environmental factors that are also associated with Crohn’s disease, such as taking antibiotics. Antibiotic use is a risk factor for developing Crohn’s disease later in life and antibiotics have previously been shown to promote the growth of other E. coli strains in the intestine. In a mouse model of Crohn’s disease, we found that antibiotics made mice more vulnerable to infection with this E. coli strain. This increased vulnerability was because the antibiotics caused inflammation, and we also found that other sources of inflammation benefitted this E. coli strain. These findings help us understand how gut bacteria and other Crohn’s disease risk factors might interact to cause the disease.


title: Some Topics Related to Diversity Indices and Applications

contributor:
Feng, Shui
Mathematics and Statistics

abstract: This thesis discusses three diversity measures: Simpson's Index, Shannon's Index and Berger–Parker Dominance as well as their corresponding True diversity. Evenness measures the balance of a community which carries different information from diversity indices. We give an example on the application of diversity indices by comparing the surname diversity of China and USA. We also use OLS regression to investigate whether diversified investment strategy leads to higher return rate for mutual funds. Our analysis shows that funds that are diversified in investment have higher return rate. Although highly diversified investment does not translate into high return directly, the market where equity enters also plays an important role. Our analysis reveals the potential of investment diversity and provides motivation for diversifying investment strategy. The diversity indices also have the ability of discriminating categories. With linear discriminant analysis (LDA) and classification tree method, we use Simpson's index and year to date return rate to successfully differentiate mutual fund category. In the last part of the thesis, we introduce the Bayesian approach to estimate diversity indices from an observed sample. We propose four estimators of Simpson's Index based on the sampling distribution of relative abundance and investigate their estimating ability.

abstract: Thesis

abstract: Master of Science (MSc)


title: A NEW APPROACH TO IMPROVE  LITHIUM-ION BATTERY LIFETIME IN A RENEWABLE HOME ENERGY STORAGE SYSTEM

contributor:
Narimani, Mehdi
Al-Mutawaly, Nafia
Electrical and Computer Engineering

subject: Solar panels, Lithium-ion batteries, pulsed charge-discharge, energy storage system, battery management system

abstract: This thesis suggests a new approach to extend the lifetime of Lithium-ion batteries for a Home Energy Storage System equipped with a renewable energy source. The new configuration improves the lifetime of the energy storage device by using the pulsed charge-discharge method. The batteries in this system can be charged either using solar panels when solar energy is available or by the grid power during off-peak hours when the electricity cost is at its lowest rate. In the new configuration, the battery bank is split into two equal sections to employ pulsed charge-discharge method. Interrupting the charge or discharge current provides a relaxation time for the lithium ions to diffuse gradually into the electrodes material of Lithium-ion batteries, this reduces the damage in the microstructure of the electrodes and thus it helps to prolong the battery lifetime. The spilt bank strategy improves the longevity of Lithium-ion batteries while maximizing the solar energy utilization. This strategy leads to reduce the reliance on the grid power which decreases the consumer’s total energy cost as well. To show the usefulness of the new approach, different modes of operation are discussed in details along with simulation results. An experimental setup is also developed to evaluate the effectiveness of the new approach in extending the Lifetime of Lithium-ion batteries.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: SOLUTIONS TO HIGH-PRIORITY CHALLENGES IN SYSTEMATIC REVIEWS: Network meta-analysis and integrating randomized and non-randomized evidence

contributor: Clinical Epidemiology/Clinical Epidemiology & Biostatistics

subject:
SYSTEMATIC REVIEWS
Network meta-analysis
randomized and non-randomized evidence

abstract:
Systematic reviews (SR) and meta-analysis (MA) of randomised controlled trials
(RCT) are the trustworthy sources of evidence. However, most systematic
reviews focus on pair-wise comparisons. Network-meta-analysis (NMA) offers
quantitative methods of integrating data from all the available comparisons of
many different treatments for each outcome. In a systematic review of
interventions, Summary of Findings (SoF) tables present the main findings of a
review in a transparent and simple form. However, it is unknown how to present
NMA findings in a tabular format. Moreover, systematic reviews and meta-analysis
of interventions can summarize bodies of evidence from randomized and
non-randomized studies (NRS). Integrating both sources of evidence in a single
study can be challenging particularly in the context of assessing the certainty of
the evidence, as well as presenting findings of both RCTs and NRS sources of
evidence.
In our study, we described how 276 NMA were conducted and how authors
reported their main findings. We also conducted 32 interviews with users of
NMAs and we designed two final NMA-SoF tables. Furthermore, we conducted
two systematic reviews that included RCTs and NRS to address methodological
challenges. Based on our results, we developed two NMA-SoF table formats to report the
main findings of NMAs. The final format was appealing for users and allowed
them to better understand NMA findings. Assessment of quality of individual NRS
remains challenging and further research is needed to increase its
appropriateness in systematic reviews of NRS. We determined that quality
assessment of individual NRS was particularly challenging to implement due to
the complexity of NRS evaluation tools. Our evaluation revealed that effect
estimates of RCTs and NRS were better presented separately.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Systematic reviews (SR) are a summary of studies that address a particular
clinical question. Frequently, SRs are complemented with a statistical aggregation
of results of individual studies to produce a single estimate. Summary of findings
(SoF) tables are designed to present the most relevant information of systematic
reviews and meta-analysis. However, it is unknown how to present network meta-analysis
(NMA) findings in SoF tables. Another challenge relates to the
integration of randomized controlled trials (RCTs) and non-randomized (NRS)
studies. Methodological challenges in systematic reviews need to be addressed
through careful research.
In our study, we appraised how NMA were conducted, and how they presented
their main findings. We designed two versions of SoF tables to present NMA
findings. Moreover, we conducted two systematic reviews that included RCTs
and NRS to address potential challenges in analyzing and presenting their
findings.


title: Construction of an Adenovirus Expression Vector Containing the T4 Den V Gene, Which Can Complement the DNA Repair Deficiency of Xeroderma Pigmentosum Fibroblasts

title: Construction of an AD 5 Vector Containing the T4 Den V Gene

contributor:
Rainbow, Andrew, J.
Biology

subject: adenovirus expression vector, T4 den v gene, DNA repair, DNA repair deficiency, zeroderma pigmentosum fibroblasts, xeroderma, pigmentosum fibroblasts, ad 5 vector

abstract:
This study demonstrates the use of an adenovirus vector
system to study the effect of a DNA repair gene on
untransformed human fibroblasts. The bacteriophage T4
pyrimidine dimer DNA glycosylase (den V) gene has been
inserted into the E3 region of human adenovirus type 5. The
resulting recombinant virus Ad Den V was determined to be
producing correctly initiated RNA from the RSV 3' LTR
promoter used in the den V expression cartridge inserted into
the virus. The effect of the den V gene product on human
fibroblasts 'liras examined by assaying for the percent host
cell reactivation (%HCR) of Vag production for UV irradiated
Ad Den V in comparison to that for a control virus. It was
shown that the %HCR was significantly greater for Ad Den V
as compared to the control virus in xeroderma pigmentosum
(XP) cells. UV survival of adenovirus in XP cells exhibited
a two component nature. Introduction of the den V gene into
XP group A cells increased the D0 value of the first
component of the viral survival curve to a level similar to
that of XPC cells, which showed no change in this component
irrespective of the presence of the den V gene. It has been
suggested that the den V gene is able to partially complement
the deficiency in some XP cells because of its small size,
allowing it to gain access to the DNA damage site where as
the cellular repair enzyme complex can not. Since XPC cells
are proficient in their alteration of DNA secondary structure
prior to DNA excision repair, these results are consistant
with the hypothesis that the first component of UV viral
survival curves reflects the pathway involved in accessing
the damaged sites.
The manuscript of a paper has been included as an
appendix. The work theorizes on the origin of mammalian
immune system diversity and bacteriophage lambda, and their
possible relationship to prokaryotic DNA repair genes.

abstract: Thesis

abstract: Master of Science (MS)


title: THE ECOLOGY OF CLINICAL DECISION MAKING

title: THE ECOLOGY OF CLINICAL DECISION MAKING: PHYSICIANS’ PERCEPTIONS OF FACTORS THAT INFLUENCE CLINICAL PRACTICE DECISIONS AND IMPLICATIONS FOR PROVIDING HIGH-VALUE CARE

contributor:
Jack, Susan
Health Research Methodology

subject:
Clinical Decision-Making
High-Value Care
Overuse
Evidence-Based Medicine
Clinical Practice-Guidelines
Healthcare Costs
Medical Education

abstract: Despite substantial healthcare costs, patient outcomes are sub-optimal in the United States and Canada compared to other countries that spend proportionally less on healthcare. This has led to recognition of the need to improve healthcare value, utilization of tools including clinical practice guidelines and development of initiatives such as the Choosing Wisely Campaign to achieve this goal. In spite of the intuitive appeal of these interventions designed to increase physician awareness of evidence and empower patients to engage in shared decision-making, they have had limited success in changing practice and physician prescribing behaviours. Using a mixed-methods approach, this thesis represents a purposeful attempt to understand the failure of existing approaches through an examination of the factors that influence clinical decision making. Specifically, the thesis integrates quantitative and qualitative methodologies to develop a deeper understanding of clinical decision-making. Consisting of a clinical vignette based survey, the quantitative study explores decision-making in four specific commonly encountered case contexts. After choosing the preferred management option, participants rated the influence of different factors on their decisions. Follow-up questions explored knowledge, attitudes and practices regarding incorporating cost considerations into decision-making. The results of the study were explored further in the qualitative component of the mixed study. The results indicate that clinical decision-making is influenced by an interrelated set of socioecological factors with evidence and clinical practice guidelines playing a secondary role. Because lack of knowledge is not a major factor in guideline discordant care, strategies to improve knowledge will have minimal effect in improving care. The qualitative study included an inquiry into the need for teaching and learning on the topic of cost and cost-effectiveness and sought input from physicians working in diverse settings on methods and topics that need to be included in medical education. The contributions of this thesis include a deeper understanding of the factors that influence clinical decision-making and suggestions for enhancing medical education.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Despite the highest health-care expenditure in the world, patient health outcomes are suboptimal in the United States (US). Additionally, out-of-pocket patient costs are increasingly a cause of financial distress to American patients. Although Canada spends comparatively less than the US on healthcare, it is one of the top ten countries for healthcare spending as a proportion of the gross domestic product. In spite of this level of spending, patient outcomes in the US and Canada are worse when compared to many other economically developed countries that spend relatively less on healthcare. A substantial portion of healthcare spending is for services that do not improve patient outcomes while services proven to improve patient outcomes are underused. Utilizing sequential quantitative and qualitative studies this thesis is a purposeful attempt to identify and examine the factors that influence clinical decision making by physicians. The knowledge gained in this study may help inform the development and evaluation of strategies targeted at increasing adoption of evidence-based practices leading to improved health-outcomes at affordable costs.


title: Integrated Design and Control under Uncertainty

contributor:
Swartz, Christopher
Chemical Engineering

subject: Integrated Design and Control

abstract:
Market variation such as changing utility price or demand can lead to non-static operation of chemical plants, such as in cases where new objectives must be met, or varying operating conditions can be taken advantage of to increase operational profit. Integrated design and control (where both the design and operation are considered simultaneously when the design of the plant is being formulated) can be used to address the challenges that plants that operate under uncertainty may face. When considering demand uncertainty for a plant, not only must the different realizations of demand be considered, but how the plant transitions from one demand to another is also of interest.

Ideally when transitioning, the plant must quickly and feasibly transition from one operating point to another. In the first study of this thesis we consider the benefit of taking into account the demand transitions a plant must undergo; compared to only considering the final operating states. In this study we examine an air separation unit (ASU) since in industrial practice ASUs can often be subject to demand uncertainty. Assessing the impact that an ASU design has on its dynamic response characteristics motivates us to include plant dynamics in the design formulation. Using a two-stage stochastic optimization framework, the optimal design parameters are found for a nitrogen plant operating under uncertain demand. Three design paradigms are explored and compared - a nominal steady-state design, a flexible design that maintains steady-state feasibility, and a dynamically operable design that enforces feasibility of dynamic transitions. The designs obtained are subjected to random demand changes to evaluate the expected economic return under transitions not directly designed for. From this study we see that when the dynamically operable design and the flexible design are both subject to  dynamic transitions, the dynamically operable design in certain cases can provide more economic benefit during transition and at the final steady state.

In the second study of this thesis we address an important issue that arises when uncertainty in the plant operation is captured by utilizing  two-stage stochastic optimization. If the optimization formulation can see the uncertainty profile in its entirety, then it can make control moves and design decisions based on the fact that the optimization problem knows what operating conditions it transitions between. This may not however be a realistic assumption to operate under, as future uncertainty is unknown. Given lack of foresight into future uncertainties it is logical to currently operate at the the optimal steady-state. This poses a bilevel problem for the design and control of a plant because the feasible region is determined by an inner optimization. In this study the Karush-Kuhn-Tucker conditions are incorporated into a two-stage stochastic optimization formulation for a dynamic model of chemical plant to generate a design. This design is then compared to a design generated from an optimization formulation where future knowledge of uncertainty is assumed and it is seen that the former design can provide greater economic benefit.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Investigating Evidence for a Kosterlitz-Thouless Transition in Fe/W(001) Ultrathin Films

contributor:
Venus, David
Physics and Astronomy

subject:
Kosterlitz-Thouless Transition
Ultrathin Films
2DXY
Condensed Matter
Magnetism
Magneto-Optic Kerr Effect

abstract: The magnetic susceptibility of 3-4ML ultrathin Fe/W(001) films was measured in situ under ultrahigh vacuum using the surface magneto-optic Kerr effect (SMOKE). Susceptibility measurements indicate that Fe/W(001) is a 2DXY system, and therefore undergoes a finite-size Kosterlitz-Thouless (KT) transition at the critical temperature T_KT. The films were grown using molecular beam epitaxy (MBE) and were characterized using Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). Three distinct categories of susceptibility signals were observed, and are referred to as Type I, II, and III. The primary difference between these signals is the size of the imaginary susceptibility, which likely corresponds to dissipative effects such as domain wall motion. The critical behaviour of the susceptibility in the paramagnetic region is described in the theory by χ(T)  ~exp〖〖(B/(T/T_KT-1) 〗^a)〗. A least-squares fit to this paramagnetic region from many independently grown films gives values of a=0.50±0.03 and B=3.48±0.16, which are in quantitative agreement with the KT theory. In comparison to 2nd order phase transitions, a power law fit to the paramagnetic region of the susceptibility yields an effective critical exponent of γ_eff≈3.7±0.7, which does not correspond to any known universality class.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The magnetic properties of atomically thin iron films, referred to as Fe/W(001), were investigated using the highly sensitive phenomenon known as the surface magneto-optic Kerr effect (SMOKE). Fe/W(001) films were grown using the well-developed technique known as molecular beam epitaxy (MBE), which involved a slow and controlled thermal evaporation of an iron source onto a tungsten substrate. Film thickness and uniformity were verified using Auger electron spectroscopy, and film structure was determined using low energy electron diffraction. Film growth and all subsequent measurements were performed in situ under ultrahigh vacuum (10-10 mbar) to limit surface contamination. Using SMOKE, the magnetic susceptibility of the Fe/W(001) films was measured as a function of temperature to look for evidence of a unique phase transition known as the Kosterlitz-Thouless (KT) transition. Fitting experimental susceptibility data to the theoretical model for the KT transition presented persuasive evidence that Fe/W(001) films undergo a KT transition.


title: A 180 Mass Spectrometer Tube and its Performance

contributor:
Thode, H. G.
Physics

subject:
spectrometer
mass spectrometer tube
performance

abstract:
Thesis
Master of Science (MS)


title: The Geology of the Bessemer Magnetite Deposit

contributor:
Scott, H. S.
Shaw, D. M.
Geology

subject:
bessemer magnetite
magnetite deposit
geology

abstract: A field and laboratory study of the Bessemer magnetite deposit with a discussion of the possible origin of this deposit. Illustrated with maps and with photographs taken by the author.

abstract: Thesis

abstract: Master of Science (MS)


title: Nonlinear Ultrasonics for In-line Quality Monitoring of Polymer Processing Methods

title: NONLINEAR ULTRASONICS FOR POLYMER QUALITY MONITORING

contributor:
Thompson, Michael
Chemical Engineering

subject:
ultrasonics
polymer processing
quality monitoring
multivariate statistics

abstract:
Ultrasonic testing is a nondestructive structural characterization technique with limited
examples of application for polymeric products due to the high signal attenuation
in this class of materials. Recent developments in this thesis on ultrasonics have
focused on a guided waves test method and used nonlinear analysis of harmonic
frequencies to characterize polyethylene, a semi-crystalline polymer. This sensor
technology was demonstrated in the detection of initial plastic deformation and to
monitor solvent swelling. Frequency regions of low signal attenuation and a nonlinear
ultrasonic parameter using amplitude ratio of harmonic peaks were used to classify
different crystalline morphologies, controlled by thermal treatment. With an established
connection between the ultrasonic spectrum signal and the internal structure of
polyethylene, a quality monitoring tool was developed and applied to a batch rotational
molding process. Multiple traditional quality measurements were correlated with the
ultrasonic signal using multivariate statistical analysis. Finally, an in-line statistical
approach for quality classification and an on-line process monitoring using dynamic
process modeling were validated. The results presented in this study demonstrate the
relevancy of incorporation of the ultrasonic sensor technology to promote advanced
manufacturing practices for the polymer manufacturing industry.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
We have been using ultrasonic devices to investigate different things from medical
diagnosis of prenatal development to nondestructive exploration of small rocks brought
from the Moon. This study takes the ultrasonic testing to the challenge of characterizing
plastics. Using information from the propagation of these inaudible sound waves, we
can explore the entire structure and observe structural changes that can lead to defects
or failures. With the help of computer-based data processing, we investigate these
complex signals creating tools for more efficient manufacturing and safer products like
water and fuel storage tanks.


title: PRACTICAL DEEP LEARNING AGLORITHMS USING ESTIMATION THEORY

title: ESTIMATION STRATEGIES FOR TRAINING OF DEEP LEARNING NEURAL NETWORKS

contributor:
Habibi, Saeid
Ziada, Samir
Mechanical Engineering

subject:
Deep Learning
Fault Detection and Diagnosis
SVSF
RSVSF
EKF
REKF
RSVSF_MF
REKF_MF
Modified-SVSF
Battery SOC
Neural Networks

abstract:
Deep Learning Networks (DLN) is a relatively new artificial intelligence algorithm that gained popularity quickly due to its unprecedented performance. One of the key elements for this success is DL’s ability to extract a high-level of information from large amounts of raw data. This ability comes at the cost of high computational and memory requirements for the training process. Estimation algorithms such as the Extended Kalman Filter (EKF) and the Smooth Variable Structure Filter (SVSF) are used in literature to train small Neural Networks. However, they have failed to scale well with deep networks due to their excessive requirements for computation and memory size. In this thesis the concept of using EKF and SVSF for DLN training is revisited. A New family of filters that are efficient in memory and computational requirements are proposed and their performance is evaluated against the state-of-the-art algorithms. The new filters show competitive performance to existing algorithms and do not require fine tuning. These new findings change the scientific community’s perception that estimation theory methods such as EKF and SVSF are not practical for their application to large networks.
A second contribution from this research is the application of DLN to Fault Detection and Diagnosis. The findings indicate that DL can analyze complex sound and vibration signals in testing of automotive starters to successfully detect and diagnose faults with 97.6% success rates. This proves that DLN can automate end-of-line testing of starters and replace operators who manually listen to sound signals to detect any deviation. Use of DLN in end-of-line testing could lead to significant economic benefits in manufacturing operations.
In addition to starters, another application considered is the use of DLN in monitoring of the State-Of-Charge (SOC) of batteries in electric cars. The use of DLN for improving the SOC prediction accuracy is discussed.

abstract: Thesis

abstract: Doctor of Science  (PhD)

abstract: There are two main ideas discussed in this thesis, both are related to Deep Learning (DL). The first investigates the use of estimation theory in DL network training. Training DL networks is challenging as it requires large amounts of data and it is computationally demanding. The thesis discusses the use of estimation theory for training of DL networks and its utility in information extraction. The thesis also presents the application of DL networks in an end-of-line Fault Detection and Diagnosis system for complex automotive components. Failure of appropriately testing automotive components can lead to shipping faulty components that can harm a manufacturer’s reputation as well as potentially jeopardizing safety. In this thesis, DL is used to detect and analyze complex fault patterns of automotive starters, complemented by sound and vibration measurements.


title: EXPERIENCES OF INPATIENT REHABILITATION FROM THE PERSPECTIVE OF PERSONS WITH ACQUIRED BRAIN INJURY – AN INTERPRETIVE DESCRIPTION STUDY

contributor:
Harris, Jocelyn E.
Rehabilitation Science

subject: acquired brain injury, rehabilitation, interpretive description, qualitative, patient-centered care

abstract:
Background & Purpose: Sustaining an acquired brain injury (ABI) can often lead to admission to an inpatient rehabilitation program. The purpose of inpatient rehabilitation is to provide individualized, patient-centered therapy in order to facilitate community re-integration. Considering the patient perspective is beneficial for informing patient-centered care because clinicians and program administrators may develop greater awareness and understanding of patient needs and preferences. There is a lack of qualitative research investigating patient experiences and perspectives of ABI inpatient rehabilitation, and the majority of existing research was conducted in non-Canadian contexts. The present study was thus designed to describe and interpret patient experiences of an ABI inpatient rehabilitation program in urban Ontario. The purpose was to contribute to a patient lens that inpatient rehabilitation staff could consider in their work.
Methods: An interpretive description approach was adopted for this qualitative study. Twelve participants were purposively sampled from a regional ABI rehabilitation program. They completed semi-structured interviews about their experiences. Interviews were transcribed, coded, and analyzed to identify major themes.
Results: Three major themes were identified from the analysis and arranged around three time points. At the time point prior to admission to inpatient rehabilitation, the theme was “Life Rerouted,” where participants described their lives being diverted from what was “normal” after sustaining an ABI. Inpatient rehabilitation was seen as a way to return to their pre-injury life. The second theme described experiences within inpatient rehabilitation and was entitled, “Autonomy within Rehab.” Under this theme, participants emphasized the importance of personal autonomy over their choices and abilities while in rehabilitation, with three related sub-themes: interactions with clinicians, perceptions of institutional policy, and the involvement of family members. Under a minor theme, not directly related to aspects of autonomy, entitled “social comparisons,” participants also made comparisons of their recovery progress to other patients. The third and final theme reflected participants experiences just after discharge and was entitled, “Life (and Recovery) Go On.” Under this theme, participants described an ongoing recovery process leading to sentiments of both frustration and hope for the future.
Discussion: An overarching key message was developed from these themes: “re-establishing personal identity is important to the recovery process.” Two theories (biographical disruption and relational autonomy) are used to interpret this message and describe the strategies and perspectives adopted by patients during inpatient rehabilitation as they attempted to cope with the psychosocial impacts of ABI on their lives.
Conclusions: The findings of this study provide knowledge and a theoretical lens in which program staff can view and understand patients’ experiences, needs and preferences. These findings may enhance patient-centered care within the context of ABI inpatient rehabilitation.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Financial History of Hamilton

subject: finances, financial history, hamilton, hamilton ontario, history

abstract:
Thesis
Bachelor of Arts (BA)


title: The Doctrine of the Atonement in the Writings of C.S. Lewis

contributor:
Widdicombe, Peter
Religious Studies

subject:
atonement
Chronicles of Narnia
C.S. Lewis
Athanasius
Augustine
Anselm
sanctification
justitia
justice and mercy
The Lion, The Witch, and The Wardrobe

abstract: This dissertation examines the theology of C.S. Lewis in light of the writings of Athanasius, Augustine, and Anselm.  Specifically, it looks at the role that justice and mercy play in each of these theologian’s understanding of the atonement.  It proceeds on the basis that Lewis does in fact have a specific, robust, and coherent understanding of the atonement, and that his theological anthropology and his understanding of sanctification are an outworking of his understanding of the atonement.  Chapter 1 lays out Lewis’ theological orientation and his method.  Chapter 2 engages with Athanasius, Augustine, and Anselm on the atonement, and it lays out the particular concepts that were crucial in their understanding of the atonement, namely the justice and mercy of God.  It outlines the fundamental concepts that we find in seedling form in Athanasius and Augustine and that were brought to full fruition in Anselm.  It also argues that Anselm’s satisfaction theory is best understood as grounded in the nature of God, rather than in Anselm’s feudal, Medieval context.  Chapter 3 examines Lewis on the atonement, and it traces the concepts that Lewis uses to describe and explain Christ’s death and resurrection.  While Lewis does not adhere to any one doctrine or understanding of the atonement, there is a common thread that unites the various pictures that he takes to be true representations of the atonement.  Fundamentally, for Lewis, the atonement is about the restitution of proper order that was disrupted in the Fall.  Chapter 3 examines which theories of the atonement Lewis accepts and which he rejects.  It also traces his understanding of the atonement to his understanding of the nature of God, relying on the concept of justitia defined as proper order, which has its source in the nature of God himself.  In so doing, it aims to show that Lewis’ later understanding of the atonement is fundamentally Anselmian.  Chapter 4 engages with Lewis’ theological anthropology and his understanding of sanctification, focusing on the process of “good infection” and how Lewis envisions the spread of the new life made available after Christ’s act of atonement.  Sanctification, for Lewis, like the atonement, is also fundamentally about proper order.  This plays out in his theological anthropology largely in terms of humility and obedience to God.  Finally, chapter 5 addresses Narnia specifically and traces the concepts of justitia and proper order throughout the series and aims to show that, by focusing on proper order, we can see how the series hangs together as a whole theologically as an outworking of Lewis’ understanding of the atonement.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Antimonide Nanowires for Multispectral Infrared Photodetection

contributor:
LaPierre, Ray
Engineering Physics

subject:
Nanowires
Infrared
Semiconductor
Antimony
Silicon
Selective-area epitaxy
Multispectral
MBE

abstract:
Multispectral capabilities of nanowires (NWs) were explored for InAs and InAsSb NWs on Si(111) substrates. NWs were grown with the vapour-solid (VS) growth mode in a molecular beam epitaxy (MBE) system using an oxide template to control positions and diameters. Early attempts to integrate InSb NWs and silicon substrates proved unsuccessful. Instead studies of InAs NWs on silicon, and eventually InAsSb/InAs NWs on silicon were completed to achieve large-diameter, infrared (IR) sensitive photodetectors.
InAs NWs were grown on silicon substrates to study their morphology characteristics and vertical NW yield. The five different growth modes explored were (1) Au-assisted vapour-liquid-solid (VLS), (2) positioned Au-assisted, (3) vapour solid, (4) positioned Au-assisted VLS using a patterned oxide mask (VLS-SAE), and (5) selective area epitaxy (SAE) using a patterned oxide mask. Optimal temperature and V/III flux ratios for achieving a high vertical yield were found for the SAE growth mode.
Further understanding of the InAs SAE growth mode was gained through modeling of various oxide hole filling scenarios. Each scenario was defined by the arrival rates of the group III and group V materials to the holes. A parameter space is discussed for the growth of high yield InAs NWs, dependent on the V/III flux ratio and temperature of growth.
Large diameter InAsSb NWs for IR absorptance were grown on silicon using a high yield InAs stem. Several NW array diameters were grown simultaneously on the same substrate to measure multispectral photodetection. Diameters were controlled by NW spacing. Fourier transform IR (FTIR) spectroscopy was used to measure absorptance in the NWs. NW diameters spanned 440 – 520 nm which resulted in enhanced absorptance in the short-wave IR region. Simulations of the HE11 resonances of the NW arrays were performed and compared with the FTIR measurements. Initial electrical measurements demonstrated a diameter-dependent photocurrent.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Survey of the Occurence of Oxygen 18 in Natural Sources

contributor:
Thode, H.G.
Chemistry

subject: Oxygen 18, occurence of oxygen 18, survey of oxygen 18, survey of the occurence of oxygen 18, oxygen 18 in natural sources

abstract:
An investigation of the concentration of the heavy isotope
of oxygen, O18, in various samples of water was carried out. Natural
variations as high as 2.9% were found - glacier water being 2.3%
light and Dead Sea water 2.0% heavy, as compared to Lake Ontario water
as standard. Other values - water from tank oxygen + 2.9%, atmospheric
water vapor -0.9%, Atlantic Ocean water +0.4%, Pacific Ocean water
- 0.8% , and atmospheric carbon dioxide - 0.5%. The water samples were
equilibrated with tank carbon dioxide, which was then analyzed using
the mass spectrometer. Some work was also done on photosynthesis.
The free water, water of crystallization, and tissue oxygen (as water) ,
in a normal leaf which had bean photosynthesizing for 8 hours, were
analyzed by equilibration with carbon dioxide as above. It was found
that all of these were more enriched in oxygen 18 than the water with
which they were fed . The free water averaged about 1.3% heavy, water
of crystallization as high as 8.7% heavy, and tissue oxygen varied from
0.5% light to 5.5% heavy. This work only just touches the edges of this
field - many more interesting experiments remain to be carried out later.

abstract: Thesis

abstract: Master of Science (MS)


title: Developing DNA based biosensors for Clostridium difficile detection

title: Developing colourimetric biosensors using functional DNAs for epidemic strains of Clostridium difficile

contributor:
Li, Yingfu
Biochemistry and Biomedical Sciences

subject:
biosensor
Clostridium difficile
functional nucleic acids

abstract:
Over the last 20 years, the incidence of Clostridium difficile infection (CDI) has increased dramatically, making it one of the most common healthcare-associated infections. This has been linked to the emergence of hypervirulent C. difficile strains. Currently, cell cytotoxicity assay (CTA) and toxigenic culture are the gold-standard methods for CDI diagnosis. However, they are time-consuming and labour-intensive. Other methods, like enzyme immunoassays (EIAs) and nucleic acid amplification-based tests (NAATs), allow for rapid testing but have poor sensitivity and/or specificity. Additionally, most of these methods target toxins or their associated genes and are unable to discriminate between epidemic and non-epidemic strains. The work described in this dissertation aims to develop easy-to-use and reliable biosensors for C. difficile, with a particular focus on epidemic strains of C. difficile. The development of the in vitro selection technique has allowed for the discovery of a big array of functional DNA, with excellent ability in both target recognition and enzymatic catalysis. My key interest is to employ functional DNA molecules as target recognition elements to develop colorimetric biosensors for C. difficile detection.
The first research project aimed to develop a colorimetric detection platform that can be coupled with functional DNA molecules to achieve hypersensitive detection of different targets. This test should be easy-to-use, have broad target applicability and not require expensive equipment. To do so, a colorimetric biosensing platform was created, which takes advantage of the signal amplification ability of rolling circle amplification (RCA) and the simplicity of the classic litmus test. In the presence of the target of interest, RCA will be triggered, and the biotinylated RCA products can hybridize a number of the urease-labelled single-stranded DNA and immobilize urease onto magnetic beads through streptavidin-biotin interactions. The urease can then be used to hydrolyze urea, resulting in significant pH elevation, that can be detected easily using a litmus test. To prove the concept, we have demonstrated that this platform can be employed to visually detect thrombin and platelet-derived growth factor (PDGF) with high sensitivity, by coupling it with an anti-thrombin aptamer and an anti-PDGF aptamer, respectively. We have also shown that the biosensing platform can be incorporated into simple paper-based devices.
The second project focuses on the development of a colorimetric DNA detection method for epidemic strains of C. difficile that utilizes both the polymerase chain reaction (PCR) and the litmus test. The strategy makes use of a modified set of primers for PCR to facilitate ensuing manipulations of resultant DNA amplicons: their tagging with urease and immobilization onto magnetic beads. The amplicon/urease-laden beads are then used to hydrolyze urea, resulting in an increase of pH that can be conveniently reported by a pH-sensitive dye. We have successfully applied this strategy for the detection of two hypervirulent strains of C. difficile, which are responsible for the recent increase in the global incidence and severity of C. difficile infections. Furthermore, the viability of this test for diagnostic applications is demonstrated using clinically validated stool samples from C. difficile infected patients.
The goal of the third project was to isolate RNA-cleaving fluorogenic aptazymes (RFAs) targeting an epidemic strain of C. difficile. Four classes of RFA probes were derived using in vitro selection approach where a random-sequence DNA library was reacted with a crude extracellular mixture (CEM) derived from the epidemic C. difficile strain BI/027/NAP1, coupled with a subtractive selection strategy to eliminate cross-reactivities to unintended C. difficile strains and other bacterial species. The isolated RFDs can be used together to generate specific cleavage patterns for strain-specific identification of C. difficile.
Lastly, the final project was to characterize a novel RFA probe (RFA13-1) that was isolated unintentionally using in vitro selection. By using CEM prepared from C. difficile glycerol stock contaminated by Klebsiella aerogenes as the positive target for in vitro selection, we isolated a remarkably active RFA probe, RFA13-1, targeting K. aerogenes. Further studies demonstrated that RFA13-1 could be activated by CEM prepared from several bacteria from the Enterobacteriaceae family. Moreover, the molecular target of RFA13-1 has been identified, which is ribonuclease I. RFA13-1 showed high sensitivity and specificity towards RNase I and could be employed as a tool to study RNase I functions and to detect RNase I or RNase I-containing bacteria.
In summary, I have investigated novel strategies for building a biosensor that is capable of discriminately detecting epidemic strains of C. difficile. I hope that my work can take us one step closer towards the development of easy-to-use and reliable biosensors that can be used in the clinical diagnosis of CDI.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Survey of Deuterium Chemistry

contributor:
Thode, H. G.
Chemistry

subject: deuterium chemistry survey

abstract:
Thesis
Master of Science (MS)


title: Metabolomics approach for gaining insights into pathological mechanisms of irritable bowel syndrome and inflammatory bowel disease

contributor:
Britz-McKibbin, Philip
Chemical Biology

subject: Metabolomics

subject: Microbiome

subject: Irritable bowel syndrome

subject: Inflammatory bowel disease

subject: Urine

subject: Capillary electrophoresis mass spectrometry

abstract: Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are two of the most commonly diagnosed chronic digestive disorders in Western countries with increasing prevalence among Canadians. However, the etiology of IBS and IBD remain poorly understood due to a complex interplay of genetic, psychosocial and environmental factors, which hampers efforts at early detection/screening, accurate diagnosis and effective treatments notably in children. This thesis aims to reveal new biochemical insights into the pathophysiology underlying IBS and IBD when using an untargeted metabolite profiling (i.e., metabolomics) approach on urine and stool specimens based on multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS). Chapter I reviews brief history and current challenges in diagnosis and treatment, as well as current metabolomics literature of IBS and IBD. Chapter II first develops a robust method for high throughput profiling of anionic metabolites in human urine samples when using MSI-CE-MS. For the first time, we demonstrate that incidental capillary fractures are caused by irreversible aminolysis of the outer polyimide coating due to the frequent use of volatile ammonia based buffers under alkaline conditions (pH > 9) in electrospray ionization-MS. Chapter III subsequently applies this validated method to investigate differentially excreted urinary metabolites between adult IBS patients and healthy controls, which indicated significantly accelerated rates of collagen degradation and cell turn-over in IBS patients. Chapter IV later develops a novel stool extraction protocol for characterization of the fecal metabolome together with meta-genomic data for elucidating complex host-gut microflora interactions from a cohort of pediatric IBD patients, including Crohn’s disease and ulcerative colitis. In this pilot study, a panel of discriminating metabolites in urine is shown to allow for differential diagnosis of major pediatric IBD sub-types as an alternative to colonoscopy and histopathology that are invasive, expensive and prone to ambiguous test results. Finally, Chapter V involves a longitudinal metabolomics study that aims to identify metabolic trajectories that predict treatment responses of a cohort of pediatric Crohn’s disease patients following initiation of exclusive enteral nutrition (EEN) therapy. In the end, Chapter VI highlights major outcomes of thesis and future direction of metabolomics in IBS and IBD with a specific focus on improved stool specimen collection and validation of biomarker specificity relative to other related gastrointestinal disorders. In summary, this thesis has demonstrated metabolic processes that are associated with exacerbation of symptoms or remission in subset of IBS and pediatric IBD patients. With follow up studies with larger cohort of patients, potential biomarkers identified in this thesis will contribute the development of more accurate and non-invasive decision making process for diagnosis and treatment, resulting in long-lasting remission and improved quality of life of patients suffering from chronic digestive disorders.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: UNDERSTANDING AND IMPROVING THE QUALITY OF PRIMARY CARE FOR PATIENTS WITH CHRONIC KIDNEY DISEASE

title: QUALITY OF PRIMARY CARE FOR CHRONIC KIDNEY DISEASE

contributor:
Garg, Amit X
Health Research Methodology

subject:
Chronic kidney disease
Quality of care

abstract:
Background: International guidelines provide recommendations for early chronic kidney disease care. This thesis was completed to 1) measure the quality of chronic kidney disease care and identify gaps, 2) identify reasons why patients do not receive recommended care, and 3) determine if these guideline-recommended practices are associated with better patient outcomes.
Methods: Population-based cohort studies were conducted for studies 1, 3 and 4. Using consensus-based indicators, study 1 quantified the quality of care for patients with early chronic kidney disease. Study 2 was a qualitative descriptive study eliciting primary care physicians’ perceived enablers and barriers to follow-up laboratory testing to confirm chronic kidney disease. Study 3 assessed the association between non-steroidal anti-inflammatory drug (NSAID) use versus non-use and adverse clinical outcomes among older adults. Study 4 assessed whether routine serum creatinine and potassium monitoring (versus no monitoring) following angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) initiation among older adults associated with better outcomes.
Results: In study 1, most recommendations were being followed; however, some care gaps were identified. For example, half of the patients with initial abnormal kidney test results did not receive follow-up tests. This finding prompted study 2, where enablers and barriers to this practice were identified. Providers were aware that they should be ordering follow-up tests and had the resources to do so. However, some providers perceived this practice as low priority. In study 3, NSAID use was associated with a higher risk of complications. In study 4, routine ACEi / ARB monitoring did not prevent adverse outcomes.
Conclusions: This thesis provides a better understanding of care gaps for patients with early chronic kidney disease in Ontario, and reasons for one of these care gaps. This research also provides evidence to help strengthen guideline recommendations (NSAID avoidance) or refute them (ACEi / ARB monitoring).

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Chronic kidney disease is a medical condition where a person’s kidney function is permanently reduced. Family doctors are responsible for the care of patients with early chronic kidney disease. However, many patients may not be receiving the right treatments from their family doctors to keep their kidneys healthy. This research used Ontario healthcare data to identify care gaps for patients with early chronic kidney disease. Interviews were then done with family doctors to identify reasons for one of these care gaps; specifically, why doctors do not always repeat blood and urine tests to confirm if patients have chronic kidney disease. Finally, this research looked at whether providing certain treatments led to better patient outcomes. This information can be used to update current guidelines and to inform strategies which help patients with chronic kidney disease receive the best possible care.


title: Exercise-induced signaling in skeletal muscle of spinal muscular atrophy mice

contributor:
Ljubicic, Vladimir
Kinesiology

abstract: Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality and second most prevalent autosomal recessive disorder. SMA is caused by mutations in the survival motor neuron 1 (SMN1) gene resulting in the deficiency of the crucial survival motor neuron protein (SMN). Prescribed physical activity is an emerging therapy for this disorder, however the cellular and molecular mechanisms of exercise in SMA have yet to be fully elucidated. Examining the exercise biology of SMA may prompt the discovery of novel and effective therapeutic avenues for this pathology. Hence, we sought to determine the effects of a single bout of physical activity on intracellular signaling cascades and SMN expression in the skeletal muscle of SMA-like animals. AMP-activated protein kinase (AMPK) and p38 mitogen-activated kinase (p38) expression and activity were unchanged at pre-, early-, and late-symptomatic stages of Smn2B/- mice, which suggests that important molecular machinery for driving exercise adaptations were preserved. We then subjected Smn2B/- animals to an acute, endurance-based exercise protocol and collected skeletal muscle tissue immediately after or 3 hours post-exercise. Physical activity elicited significant activation of the AMPK-p38-peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) axis in Smn2B/- animals, which confirmed the preservation of canonical exercise-induced signaling in the SMA-like condition. Exercise also elicited alterations in the activation of protein kinase B (AKT), extracellular signal-regulated kinase (ERK), and ETS-like gene 1 (ELK). Collectively, these exercise-induced changes in the AMPK-p38-PGC-1α and AKT/ERK/ELK cascades occurred coincident with enhanced SMN expression. Lastly, acute exercise resulted in the normalization of autophagic signaling, indicating that physical activity may serve a novel role in correcting the aberrant autophagy program in SMA. In summary, this study expands our knowledge of the molecular mechanisms of exercise biology in SMA and identifies the AMPK-p38-PGC-1α signaling axis as a potential regulator of SMN expression.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Spinal muscular atrophy (SMA) is a health- and life-limiting neuromuscular disorder that affects every 1 in 10,000 live births. Chronic physical activity is therapeutic in SMA animals and patients, however the underlying mechanisms for these exercise training-induced adaptations have yet to be fully described. Examining these processes may reveal novel therapeutic targets for SMA patients, as well as increase our knowledge of the basic biology of this complex disorder. Thus, the purpose of this thesis was to investigate the cellular effects in skeletal muscle of a single bout of physical activity in a pre-clinical mouse model of SMA. We observed that molecules important for maintaining and remodeling the neuromuscular system were enhanced following exercise in SMA-like mice. Furthermore, activation of proteins that reduce the molecular dysfunction of SMA was also evoked following a single bout of physical activity. Our data identify novel cellular pathways in the exercise biology of SMA.


title: Distribution Channel Conflict: Implications for Channel Governance, and Performance

contributor:
Ray, Sourav
Business Administration

subject:
channel conflict
performance
governance

abstract:
In this dissertation, my focus is on understanding distribution channel
conflict, its relationship with efficient channel governance and its impact on
channel performance. In particular, I will study (1) how the channel conflict
can be defined and interpreted, (2) how channel conflict can affect channel
governance, (3) what would be the performance outcomes of channel conflict,
and (4) how channel conflict can be managed. My theoretical frameworks
borrow mainly from transaction cost economics theory (TCE), and strategic
marketing.
On the empirical side, I employ several methods including meta-analysis
(Two-Stage SEM) as well as different econometrics techniques such as
Conditional Mixed-Process (CMP) regression estimation. My data comes from
diverse sources and are mainly hand collected and created from archival
sources. For the meta-analysis study, I extract empirical results of more than
100 studies on channel conflict since the 1960s. For the other empirical efforts,
the data comes from various sources. The major data collection undertakings
include extracting and integrating data from: (1) Franchise Disclosure
Document (FDD) of more than 1000 franchise firms, (2) firms records, and (3)
specific franchise rankings such as Entrepreneur and Franchise Times’ rankings
spanning from 2004 to 2015.  The dissertation comprises following broad inter-related chapters (excluding Introduction and Conclusion chapters): (1) Managing Channel Conflict:
Insights from the Current Literature, (2) Conflict and Performance in Channels:
A Meta-Analysis, (3) Channel Conflict: Bad for Business?, (4) Adapting to
Channel Conflict: An Empirical Study?, and (5) Two Views on Channel
Conflict. Chapter 1 is a compendium on channel conflict that not only provides a
comprehensive literature review on channel conflict (since the 1960s) but also
identifies gaps and provides some managerial perspectives on channel conflict. One of the identified gaps in Chapter 1 revolves around the role of channel conflict and its relationship with other inter-firm constructs. In Chapter 2, I build on this identified gap by conducting a comprehensive meta-analysis study using Two-Stage SEM (TSSEM) method to aggregate the previous findings on channel conflict and its relationship with other inter-firm constructs particularly channel performance. I also investigate the potential moderators of the conflict-performance link. Chapters 1 and 2 set the stage for the next empirical work. One of the
enduring debates in the channel domain is about the functionality and dysfunctionality of channel conflict. In Chapter 3, I address this directly by exploring the non-linear (inverted U-shaped) relationship between channel conflict and performance. While Chapter 3 explores the empirical relation between conflict and performance, another understudied but important research question is about how firms react to channel conflict. Such reactions can span the range from relying on relational norms to more explicit adjustment in channel governance.
In Chapter 4, I address this by examining the effect of manifest channel conflict on channel governance, controlling for relational norms. In particular, I study how firms adapt their channel governance following litigation. Finally, Chapter 5 is a reflection on the body of knowledge that I have investigated above. This chapter will provide two views on channel conflict by comparing two different channel conflict conceptualizations. I illustrate the
differences between these two views by comparing them based on firms’ objectives, conflict characteristics, and managerial approaches toward channel conflict, providing real-world examples of how firms approach and manage channel conflict.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
In this dissertation, my focus is on understanding distribution channel
conflict, its relationship with efficient channel governance and its impact on
channel performance. Channel conflict is an endemic phenomenon. The
advent of new technologies (such as Internet-of-Things enabled monitoring
systems) and the emergence of the Internet as a primary medium of business
transactions have brought big changes to channel management. Use of
multiple channels to reach consumers and exchange value with business
partners have become much more common with these changes. While
channel conflict has always been an important business concern, these have
rekindled the interest and attention of researchers and managers to the
phenomena.
In this dissertation, I investigate the phenomenon of channel conflict and
its effect on channel governance and business performance by conducting
several independent studies spanning different research methods. The
research findings will address gaps in the extant research literature as well
as offer both theoretical and practical insights for researchers and
practitioners interested in distribution channels strategy and management.


title: Multi-Source Inverter for Electrified Vehicles: Concept, Analytical Design, Efficiency Analysis, an Implementation

contributor:
Emadi, Ali
Electrical and Computer Engineering

abstract:
This thesis focuses on the concept, analytical design, efficiency analysis, and implementation of the multi-source inverter (MSI) for electrified vehicles (EVs).

The fundamentals of power electronics in EVs, including the main powertain architectures and the characteristics of power electronic converters, are discussed. Vehicle-level modeling methods and simulation tools for power electronics are also analyzed.

Located at the heart of the propulsion system, traction inverters play a major role in the performance and competitiveness of a vehicle. Standard industry solutions are reviewed, and a comparison of alternative candidates is presented. The main modulation strategies are also reviewed. For any topology to be seriously considered by the automotive industry, it must be able to compete on cost, reliability, efficiency, and power density. These driving factors are discussed, and the design trade-offs are explained.

In view of the continuous power increase in modern EVs, current industry configurations show some limitations. As an alternative solution, the MSI is suggested to be used as a traction inverter. The fundamental purpose of this power converter is to connect two independent DC sources to the same AC output using a single conversion stage. The concept of the MSI is presented and two circuits are considered. The operating modes during both DC/AC and AC/DC conversions are detailed and new control strategies are proposed. Closed-loop control simulations are performed to verify the MSI operation in each operating mode. A scale-down prototype is experimentally tested with an electric machine and a load to validate the effectiveness of the proposed topology and concept.

A comprehensive analytical design analysis of the switch configuration is presented, and analytical calculations of the capacitor requirements are suggested to select the proper capacitor banks for the MSI. An efficiency model based on the average and RMS currents of the switches is also proposed to evaluate the performance of the inverter. Experiments with the prototypes of both MSI circuits and an R-L load are carried out to validate the theoretical efficiency analysis. Design and efficiency comparisons of the MSI with the voltage source inverter are conducted as well.

The control and simulation of a new power-split powertrain with the MSI is discussed. As one of the most popular EVs on a sales-weighted basis, the Toyota Prius is analyzed as a case study. The suggested powertrain with the MSI aims to reduce the use of the DC/DC converter by offering an additional commutation path between the battery and the MSI. Another advantage of the MSI is the possibility to extend the battery charging opportunities. A vehicle-level simulation model of the traction drive system with the MSI is developed to estimate the potential benefits of the proposed powertrain. Simulations of the conventional and suggested powertrains are performed by applying the same voltage command of the DC/DC converter and power distribution between the battery and the electric machines.

Besides the hybrid power-split powertrains, the MSI can also be integrated into an active hybrid energy storage system. This new configuration aims to interconnect a battery and an ultracapacitor, without the use of any additional power electronic converters. A new control strategy is developed to manage the current distribution between the two sources and aims to take advantage of the high energy density of the batteries and the large specific power of the ultracapacitors, while minimizing battery degradation. Closed-loop control simulations are carried out to verify the operating principle of this novel configuration. The influence of the additional control parameters on the source currents is further investigated through simulations and validated with experiments on an R-L load.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Modelling and Evaluating Suitability of Esocid Habitat in Response to Changes in Water Levels of Georgian Bay (Lake Huron)

title: Evaluating Suitability of Esocid Habitat in Georgian Bay

contributor:
Chow-Fraser, Patricia
Biology

subject:
esocids
Georgian Bay
habitat suitability
water levels
GIS

abstract:
Muskellunge (Esox masquinongy) and Northern Pike (E. lucius) are ecologically and economically important fish species that rely on coastal habitats in Georgian Bay, especially coastal marshes.  These habitats have adapted to the high natural water-level fluctuations of Lake Huron but are threatened by changing water-level conditions associated with global climate change.  The overall goals of this thesis were to identify important esocid habitats and understand how their suitability will be affected by changing water levels.
     First, I used tracking information from radio telemetry studies of esocid populations in spatially distinct regions of Georgian Bay to identify important habitats during breeding and non-breeding seasons. I documented the strong affinity of Muskellunge to re-use specific spawning grounds close to known nursery habitat in coastal marshes.  Both Muskellunge and Northern Pike used coastal marshes during the non-breeding season, and physical habitat structure was a more important driver of habitat use in the summer months than water temperature.
     Next, I created a GIS model using only hydrogeomorphic features (depth, slope, and wave exposure) to map the extent of coastal marshes throughout eastern and northern Georgian Bay to assess how habitat would shift under a range of possible lake elevations scenarios (175.5 – 177.5 m).  The geomorphology at low lake levels favoured large areas of shallow (< 0.5 m) habitat at the expense of deeper habitats (0.5 – 1.5 m) that can support an aquatic vegetation community more suitable for young esocids.  I used a similar approach to develop a Resilience Index to rank coastal marshes according to their resilience/vulnerability to stable low water levels, for use as a regional screening tool to identify critical esocid habitat.  This research advances the understanding of the effects of water levels on coastal marshes and provides applicable tools to assist in conservation and management of these important recreational fisheries.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This Ph.D. thesis describes how changes in water levels may affect habitats used by Muskellunge and Northern Pike, two important species of sport fish, in Georgian Bay (Lake Huron).  Coastal wetlands were identified as critical habitats, especially for early-life stages, and are directly influenced by water levels of the Great Lakes.  I developed several tools to assist in identification, evaluation, and management of coastal wetlands in Georgian Bay, a relatively undisturbed coastal region in Ontario. These tools use physical features of the landscape to predict how wetlands will respond to different lake-level conditions and influence habitat suitability for Muskellunge and Northern Pike, as well as Great Lakes fish communities in general.  My thesis provides tools for environmental agencies to adaptively manage important fish habitat in a period of unpredictable water levels associated with global climate change.


title: Radial Force Shaping of Switched Reluctance Motor Drives for Acoustic Noise Reduction

subject:
Radial Force
Switched Reluctance Machine
Power Electronics
Motor control
Acoustic Noise
Sound Pressure Level

abstract:
Closer attention has been given to the acoustic noise performance of electric motors as electrified powertrains penetrate into the transportation system.  Particularly, switched reluctance machines  (SRMs) introduce a new challenge to the acoustic noise aspects given that the radial force harmonics can excite the natural frequencies of the main circumferential modes.

A practical understanding of the radial force density decomposition is crucial in identifying the primary source of acoustic noise at different operating points, and it is one of the contributions of this thesis. An analytical expression is introduced to identify the temporal harmonic orders that excite different spatial mode shapes. The mode excitation is investigated along with the sound pressure level (SPL) produced by the primary vibrating mode shapes. Acoustic noise characteristics for each mode and the corresponding natural frequency at different speeds have been analyzed by using a waterfall plot.

The acoustic noise generation by conventionally controlled SRMs prevents its use on applications where acoustic comfort is required. Acoustic noise is radiated by the stator frame when a vibration mode is excited by the respective spatial order at a forcing frequency that is close to the stator's modal natural frequency. The excitation surface wave is the radial force density waveform as a function of time and spatial position. From the harmonic content analysis, a phase radial force shaping method is for switched reluctance machines is proposed.

A generic function for the radial force shape is identified, whose parameters are calculated by an optimization algorithm to minimize the torque ripple for a given average torque.  From the phase radial force, a current reference is obtained. The proposed methodology is experimentally validated, with a four-phase 8/6 SRM, by acoustic noise measurements at different speeds and load torque conditions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Cognitive Advanced Driver Assistance Systems (ADAS) Architecture for Autonomous-capable Electrified Vehicles

type: Thesis Video

contributor:
Emadi, Ali
Razavi, Saiedeh
Electrical and Computer Engineering

subject:
Autonomous Vehicles
Electrified Vehicles
Architecture

abstract:
The automotive industry is seen to be making a monumental paradigm shift from manual to semi-autonomous to fully Autonomous Vehicles. An Advanced Driver Assistance System (ADAS) forms a major building block for realizing these next generation of highly Autonomous-capable Vehicles. Although the general ADAS architecture is widely discussed, limited details are available about the functionality of the modules and their interactions, backed up by scientific justification. This limits the utilization of such an architecture for pragmatic implementation. A Cognitive ADAS Architecture for level 4 Autonomous-capable Electrified Vehicles (EV) is proposed in this thesis. Variations for levels 3 and 3.5 (combination of levels 3 and 4, with the primary fallback through a human driver and the secondary through an Automated Driving System) are also presented.

A validated simulation framework is built for highway driving based on the proposed level 4 architecture for an enhanced Tesla Model S. It was concluded that the autonomous control provided a 28% energy economy increase, on average, compared to human driver control. Through a quantitative sensitivity analysis, the optimal Mission/Motion Planning and energy management are seen in addition to a positive impact on the EV battery, motor, and dynamics, realized from the minimized instantaneous fluctuations. These factors are considered to contribute to this significant increase in the energy economy of an autonomous-controlled EV. Furthermore, this impact was seen to be relatively higher for autonomous longitudinal vehicle control compared to lateral. This difference in the improved operation of the Autonomous-capable EV components between the Automated Driving System and the human driver control was seen to be the highest for the battery current.

In overall, an increase in vehicle autonomy, resulted in an improvement in the EV performance, dynamics and operation of the battery and motor, compared to a human driver control.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Early Work (1916-1938) of Austin Clarke

contributor:
John, Dr. Brian
English

subject: austin clarke

subject: early work

subject: 1916

subject: 1938

abstract:
Austin Clarke dedicated himself to the ideal of an independent Irish literature in English. This dedication had two principal consequences for his work: he developed a poetic style appropriate to expressing the Irish imagination, and he found inspiration in the matter of Ireland, in hex mythology and folklore, in her literary, artistic and religious traditions, and in the daily life of modern Ireland. The basic orientation of Clarke's work determines the twofold purpose of this thesis. It seeks to provide a clarifying background for his poetry, drama and fiction up to 1938; and, in examining the texts in their proper context, it seeks to reveal the permanent and universal aspects of his achievement. Clarke's early development in response to the shaping influence of the Irish Revival is examined in the opening chapter. His initial interest in heroic saga is considered, but, principally, the focus is on his effort to establish stylistic links between the Anglo-Irish and the Gaelic traditions, an effort that is seen to culminate with his adoption of assonantal verse as an essential element in his poetic technique. In the second chapter, the emphasis shifts to the thematic consequences of Clarke's involvement with Ireland. His understanding of Irish tradition is discussed, and, in particular, the origins and nature of his imaginative preoccupation with the culture of early Christian Ireland are examined. What emerges is that Clarke perceives a permanent tension in the Irish mind between the Christian and the pagan viewpoints, a conflict of values that he
termed the drama of conscience. The conflict informs each of the major texts analysed in the remainder of the thesis. Pilgrimage and Other Poems, discussed in the second chapter, reveals the recurrence of the tension between the Christian and the pagan traditions in the course of Irish history. Clarke's early plays and novels, which are the focus of the third chapter, relate the conflict to the culture of medieval Ireland. The fourth chapter examines Clarke's own experience cf the conflict as it is presented in Night and Morning. In the recognition that the drama of conscience remains a vital element in Clarke's imagination after 1938, the thesis concludes by indicating the main lines of continuity between the earlier and the later work.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)