title: Effects of Varying Quantum Well Barrier Height and Quantum Well Number on the Intrinsic Frequency Response of InGaAsP/InP Multiple Quantum Well Semiconductor Lasers

contributor:
Simmons, J. G.
Engineering Physics

subject:
quantum well barrier
quantum well number
intrinsic frequency response
InGaAsP/InP
quantum well semiconductor laser

abstract: This thesis reports on an extensive investigation into the intrinsic frequency response of various MQW lasers as determined from parasitic-free relative intensity noise (RIN) measurements. Eleven structures were designed, grown and fabricated at Nortel Technology's Advanced Technology Laboratory in Ottawa. Five of the laser structures had active regions containing 10 QWs. The barrier layer composition for these structures was varied such that the emission wavelength corresponding to the barrier band-gap increased from 1.0 pm to 1.2 pm in 0.05 pm steps. The remaining six structures had a constant barrier layer emission wavelength of 1.1 pm but the number of quantum wells was varied from 5, 7, 8 to 14 in 2 well steps. In all structures the QWs were embedded in a graded- index-separate-confinement-heterostructure waveguiding region and were strained to 1.0 percent in compression. The devices processed from these structures were Fabry-Perot type lasers having cavity lengths ranging from 254 pm to 1016 pm. Resonance frequency and damping values as a function of injection current and single facet optical power, as well as optical spectra just below threshold, were obtained for over one hundred devices. From this data the response coefficient D, K factor, group velocity (vg), photon energy (hv), mirror loss (am), and internal absorption (aint) were characterized. Using these characterized parameters dg/dN, dg/ds, and the maximum theoretical intrinsic 3 dB bandwidth (fmax) were calculated. The effects of varying QW number, barrier height, and cavity length on all these parameters was investigated. Limitations with using the single mode rate equation model for these characterizations is discussed. As well, potential limitations with the basic design of the structures studied in this thesis as revealed by the results are explored.

abstract: Thesis

abstract: Candidate in Philosophy


title: Some Problems in the Determination of the Latent Heat Liquid Helium

title: Latent Heat of Liquid Helium

contributor:
Mate, G. F.
Physics

subject:
liquid helium
latent heat

abstract: A cryostat has been constructed for the determination of the latent heat of evaporation of liquid helium-4 from 1.8°K to the critical point. It has not yet proved possible to stabilize the cryostat behaviour sufficiently and thermal oscillations of the type reported by Taconis are strongly suspected as being the source of the difficulty. Modifications that were carried out in the design of the equipment to improve its behaviour were limited in their success so that two conclusions were reached. Firstly, a separate investigation of the problem of Taconis resonate® is necessary before reliable results can be obtained, Secondly, the existing cryostat could in the meantime readily be converted to other cryogenic uses.

abstract: Thesis

abstract: Master of Science (MS)


title: Optical Gain and Amplified Spontaneous Emission in Lead Salt Semiconductor Thin Film Waveguides

contributor:
Garside, B. K.
Jessop, P. E.
Engineering Physics

subject:
optical gain
amplified spontaneous emission
lead salt semiconductor
thin film waveguides

abstract:
The work described in this thesis involves the measurements of the optical gain and amplified spontaneous emission (A.S.E) spectrum of Pb1-xSnxTe epilayers and the establishment of conditions under which optically pumped Pb1-xSnxTe laser using a CO2 laser as pump source can be produced. Pb1-xSnxTe epilayers have been grown by a hot wall epitaxy (HWE)
technique on BaF2 single crystal substrates and the optical gain which can be produced in these layers has been measured by pumping the films transversely with a N2 laser. A model for optical gain and stimulated emission as a function of pump intensity has been developed which has permitted for the first time in these materials, a direct comparison between the magnitude of the gain pumping rate, and the optical gain generated. The measured optical gain is in very good agreement with the model predicted gain. Good fits to the measured stimulated emission spectra were also obtained from the model prediction. It is shown that the gain for a given pump wavelength has a drastic dependence on the material doping density. According to the model, CO2 laser optically pumped Pb1-xSnxTe laser can be readily achieved, provided that epilayer doping densities can be reduced to values of 1017 cm-3 or less. Nevertheless, doping densities even in nominally undoped layers are generally at least an order of magnitude too high. In some initial attempts to achieve lower doping densities, using a thermal annealing technique, doping densities as low as 2 x 10 17 cm-3 have been obtained and significant pump absorption was achieved at CO2 laser wavelength, as predicted by the model.

abstract: Thesis

abstract: Master of Engineering (ME)


title: A Component Based 3D Collision Avoidance System

contributor:
Szabados
Spence, Allan
Electrical Engineering

subject:
3D collision avoidance
collision avoidance

abstract: The Coordinate Measuring Machine (CMM) is a key improving the reliability and quality of production. During operation, however, collision between the CMM, probe system, and parts may result in costly damage. Avoiding potential collisions is always an important issue for CMM inspection. This thesis reports design and implementation of an online collision detection system for CMMs. Compared to previous offline collision detection implementations, the new online collision detection system can react to potential collision situations in real time. The collision avoidance system architecture and algorithms are described in this thesis. Each possible CMM translation and probe rotation case is considered. Every component in this system is connected by certain communication protocol and distributed on different computers according to the requirements of applications. This design brings more flexibility to this system. The system components for inspection path planning, collision detection, and CMM motion control are distributed to separate computers, with a TCP/IP based protocol used for communication. This modular, component based design provides more flexibility.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Image-Based Passive Acquisition of Range Data

contributor:
Capson, David
Electrical Engineering

subject:
image-based range data
range data
passive acquisition
passive acquisition of range data

abstract: An image-based technique for passive acquisition of three-dimensional (3-D) range data is proposed. The distance is extracted, in this technique, from the estimation of focus conditions on images produced through a monocular imaging system under natural illumination. The image taken from a 3-D object is generally out-of-focus (defocused). For each surface point, the severity of defocus on the image depends upon how far away the point is from the imaging system and how camera (optical) parameters are adjusted. Each setting of the parameters can be recorded physically, and associated in object-space with the inverse of a distance that corresponds to the position for the sharpest imaging under this setting. Therefore, for a given surface point the defocus severity is a function of such an inverse object-distance. It can be shown that this function is symmetrical to, and monotonic on both sides of, a point corresponding to the inverse distance of the surface point. To estimate the parameters of the function (one of which is the inverse distance of the surface point), 3~4 images need to be taken under different camera settings with known associated inverse distances in object-space, determined through a once-for-all calibration procedure. Defocus severity is evaluated from a calculation on the window image that corresponds to a small area around the surface point, and the inverse variance in the window is suggested in this technique for the best performance. The 3-D surface geometry is acquired by applying the algorithm, in parallel, to all surface points in the field of view. Various aspects of the technique are discussed and several algorithms are developed. The technique is implemented on an opto-digital imaging system and evaluated under different conditions. A number of objects are tested to demonstrate its performance.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Analysis and Design of Thin Film Coatings and Deep-Etched Waveguide Gratings for Integrated Photonic Devices

title: Deep-Etched Waveguide Gratings for Photonic Devices

contributor:
Li, Xun
Huang, Wei-Ping
Electrical and Computer Engineering

subject:
thin film coatings
deep-etched waveguide grating
integrated photonic device

abstract: This thesis aims at investigating the feasibility of realizing antireflection (AR) and high-reflection (HR) to the semiconductor waveguide end facet using monolithically integratable deep-etching technology to replace the conventional thin film dielectric coating counterpart. Conventional AR coating and HR coatings are the building blocks of semiconductor optical amplifier and semiconductor lasers. In this thesis, the AR coating and HR coating are first studied systematically and comprehensively using two computational electromagnetics approaches: plane wave transmission matrix method (TMM) and finite difference time domain (FDTD) method. The comparison of the results from the two approaches are made and discussed. A few concepts are clarified based on the different treatment between the AR coatings for bulk optics and those for semiconductor waveguide laser structure. The second part uses the same two numerical tools and more importantly, the knowledge gained from the first part to analyze and design deep-etched waveguide gratings for the advantage of ease of monolithic integration. A variational correction to the TMM is provided in order to consider effect of the finite etching depth also in the plane wave model. Specially, a new idea of achieving AR using deep-etched waveguide gratings is proposed and analyzed comprehensively. A preliminary design is obtained by TMM optimization and FDTD verifications, which provides a minimum power reflectivity in the order of 10-5 and a bandwidth of 45nm for the power reflectivity less than 10-3. In order to eliminate the nonphysical reflections from the boundary, the perfectly matched layer (PML) absorbing condition is employed and pre-tested for antireflection analysis. The effects of etching depth and number of etching grooves are specifically analyzed for the performance of proposed structures. Numerical results obtained by FDTD method indicate a promising potential for this alternative technologies.

abstract: Thesis

abstract: Master of Engineering (ME)


title: An Engineering Graphics Application System

contributor:
Smyth, W. F.
Computation

subject:
engineering graphics application
graphics application

abstract: EGAS is the acronym for the Engineering Graphics Application system, developed specifically to facilitate engineering design. It provides interactive drafting tools for civil engineering, mechanical engineering and architectural graphics, and is particularly useful to structural engineers. EGAS has been developed based on X in a Unix environment.

abstract: Thesis

abstract: Master of Science (MS)


title: A Hermeneutics of Technology: Don IHDE's Postmodern Philosophy of Technology

title: A Hermeneutics of Technology

contributor:
Madison, G. B.
Philosophy

subject:
hermeneutics
technology
postmodern philosophy

abstract: If traditional, modem philosophy of technology fails to genuinely understand the phenomena of technology, then emancipatory reflection, such as Don Ihde's, is required for philosophy of technology to have a future. Ihde's postmodern perspective and hermeneutic framework re-understands the meaning, knowledge and truth of technology as correlated with consciousness and embedded in cultures, while clarifying the relation between the interpreter and the technology he seeks to understand. The first part of my thesis argues that Ihde's philosophy of technology is generally postmodern for the following two main reasons: (1) Ihde's adaptation of the Husserlian model of intentionality, the basis of his phenomenology of human-technology relations, undermines the subject-object distinction prevalent in modem philosophy of technology, thereby recognizing the correlation between consciousness and technology; (2) by uncovering the cultural embeddedness of technologies, Hide rejects the emphasis of modem inquiry on the issue of whether we "control" technology, or it "controls" us. The second part of my thesis argues that Ihde's postmodern philosophy of technology is a hermeneutics of technology. His definition of technology, as an intentional understanding-relation with things, conceives of technology in terms of understanding itself. An implication of this emphasis on technology in praxis, rather than as substance, conceives of technology in a properly human way under the rubric of human agency, and although he never phrased it in this way, takes the techne out of technology. Finally, Hide's inquiry into technology is a call to learn the art of response-ability when attempting to understand technology.

abstract: Thesis

abstract: Master of Arts (MA)


title: AMMNet: an Attention-based Multi-scale Matting Network

contributor:
Chen, Jun
Electrical and Computer Engineering

subject:
Deep Learning
Computer Vision
Alpha Matting

abstract: Matting, which aims to separate the foreground object from the background of an image, is an important problem in computer vision. Most existing methods rely on auxiliary information such as trimaps or scibbles to alleviate the difficulty arising from the underdetermined nature of the matting problem. However, such methods tend to be sensitive to the quality of auxiliary information, and are unsuitable for real-time deployment. In this paper, we propose a novel Attention-based Multi-scale Matting Network (AMMNet), which can estimate the alpha matte from a given RGB image without resorting to any auxiliary information. The proposed AMMNet consists of three (sub-)networks: 1) a multi-scale  neural  network designed to provide the semantic information of the foreground object, 2)  a Unet-like network for attention mask generation, and 3) a Convolutional Neural Network (CNN) customized to integrate high- and low-level features extracted by the first two (sub-)networks.  The AMMNet is  generic in nature and can be trained end-to-end in a straightforward manner. The experimental results indicate that the performance of AMMNet is competitive against the state-of-the-art matting methods, which either require additional side information or are tailored to images with a specific type of content (e.g., portrait).

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: CORTICAL EXCITABILITY AND INHIBITION IN POST-CONCUSSION SYNDROME

contributor:
Nelson, Aimee
Kinesiology

subject:
Concussion
Transcranial magnetic stimulation
mTBI
motor cortex

abstract: Post-concussion syndrome (PCS) is a poorly understood sequela of mild traumatic brain injury (mTBI), more commonly referred to as concussion. While PCS is known to affect a subset of individuals following injury, it remains unclear how and why specific individuals incur chronic symptoms. Concussions disrupt normal neurophysiologic function within the brain, however the neurophysiologic underpinnings of PCS are unclear. Using transcranial magnetic stimulation (TMS), it is possible to non-invasively investigate neurotransmission in clinical populations such as those with PCS by stimulating the primary motor cortex (M1) and recording motor outputs in a contralateral hand muscle. A study was conducted using TMS to measure corticospinal excitability, intracortical facilitation and inhibition, and transcallosal inhibition in M1 of a group with PCS and a non-injured, healthy control group. Greater corticospinal excitability, and specific reductions in intracortical and transcallosal inhibition were observed in the PCS group, providing evidence of impaired neurotransmitter receptor activity. Importantly, these findings differed from previous observations in recovered concussion groups using similar stimulation techniques. Furthermore, it was observed that these neurophysiological differences may relate specifically to the presence of depression symptoms rather than general concussion symptoms. The physiologic and clinical implications of the findings of this thesis are discussed, and novel research avenues warranting investigation are identified.

abstract: Thesis

abstract: Master of Science in Kinesiology


title: Investigating the Behavioural and Molecular Mechanisms of Lurasidone Hydrochloride in a Mk-801 Model of Schizophrenia

contributor:
Mishra, Ram
Neuroscience

subject: Schizophrenia

subject: Mesencephalic Astrocyte-Derived Neurotrophic Factor

subject: NMDA Receptor

subject: Intranasal

subject: Lurasidone Hydrochloride

subject: Neurophramacology

subject: Antipsychotic Drug

subject: Neuroscience

abstract: Schizophrenia is a debilitating neuropsychiatric disorder that affects approximately one percent of the global population. Aberrant N-methyl-D-aspartate receptors and endoplasmic reticulum stress have been implicated in the pathogenesis of schizophrenia. Despite a century of extensive research, outcomes from best-practice treatments remain dismal. Lurasidone hydrochloride is a novel atypical antipsychotic drug with a unique receptor binding profile that can potentially treat the heterogeneous symptomology of schizophrenia. However, discrepancies in experimental design (i.e. animal models used, symptoms assessed etc.) have yielded conflicting results surrounding the procognitive and antidepressant properties of lurasidone. Furthermore, the limited aqueous solubility of lurasidone poses a considerable challenge for improving antipsychotic drug delivery to the brain and limiting the prevalence of adverse side effects. These obstacles coupled with the elusive pathophysiology of schizophrenia and its incurable nature, highlight the importance of investigating novel therapeutic targets and their underlying mechanisms to improve treatment and enhance the quality of life of patients with schizophrenia. This thesis sought to accomplish three primary objectives: (1) validate the behavioural efficacy of lurasidone hydrochloride; (2) investigate the role of mesencephalic astrocyte-derived neurotrophic factor as a potential therapeutic target of lurasidone; and (3) evaluate the therapeutic potential of intranasal lurasidone administration as a novel method for antipsychotic drug delivery. The data presented within this thesis suggest that repeated lurasidone treatment may be effective at treating the positive, negative, and cognitive symptoms of schizophrenia, but not sensorimotor gating deficits. Furthermore, sub-chronic lurasidone treatment in rats significantly increased the relative expression of mesencephalic astrocyte-derived neurotrophic factor in the rat prefrontal cortex, a primary site of impairment observed in schizophrenia. Lastly, we conclude that lurasidone administered via the nasal route using a novel poly(oligo ethylene glycol methacrylate)-based nanogel formulation required four times less drug to achieve a therapeutic response comparable to traditional intraperitoneal routes. The findings presented within this thesis suggest that lurasidone might be a favourable atypical antipsychotic drug that exerts its therapeutic effects through the modulation of neurotrophic factor expression in the brain regions affected by schizophrenia. This thesis offers new insight that can help guide future studies toward improving the prognosis of patients suffering from schizophrenia.

abstract: Thesis

abstract: Master of Science (MSc)


title: DEVELOPING SOCIAL CAPITAL THROUGH PROFESSIONALLY-ORIENTED SOCIAL NETWORK SITES

contributor:
Head, Milena
Business Administration

subject: social network sites, social capital, social network analysis, networking value, LinkedIn

abstract: Previous research has mainly focused on the social capital formation process on Facebook. In general, professionally-oriented social network sites (P-SNSs), such as LinkedIn, are under-researched in the Information Systems discipline. In addition, current studies do not include the effects of important elements of social network sites (SNS) such as one’s profile on social capital formation. As such, the main objective of this research is to propose and validate a model that explains the process by which individuals develop and accrue social capital through using P-SNSs. The theoretical framework of the proposed research draws upon Social Network Analysis, Social Media Analysis, and Social Capital Theory. Using an online survey of 377 LinkedIn users, this study finds that: (1) P-SNS users’ actions (perceived profile disclosure, active participation, and passive consumption) have significant positive effects on perceived social connectedness; (2) perceived social connectedness on P-SNSs has a significant positive effect on perceived networking value on these sites; (3) perceived profile disclosure and passive consumption have significant positive effects on network size; (4) active participation does not have any effect on network size; and (5) network size does not have a significant effect on perceived networking value. Overall, this investigation advances our understanding of how social capital is formed in P-SNSs. Additionally, by including the profile disclosure construct in the research model, this is the first study in the P-SNS context that investigates the role of the user profile in the social capital formation process, along with user actions such as active participation and passive consumption. From a practical perspective, this study has implications for different audiences such as job seekers, policy-makers, and P-SNS providers, assisting them in playing a more effective role in the social capital formation process on P-SNSs.

abstract: Thesis

abstract: Doctor of Business Administration (DBA)

abstract: In recent years, people increasingly spend their time on various social network sites (SNSs) such as Facebook and LinkedIn. This raises a serious question as to how people gain actual benefits from using these sites. This research examines this question from the lens of social capital. As such, the main objective of this research was to propose and validate a model that explains the process by which individuals develop social capital through professionally-oriented SNS such as LinkedIn. This study finds that to gain actual benefits from professionally-oriented SNS, such as networking value, people need to feel connected to their social networks on the site. This feeling of connection requires that people actively participate on the site (e.g., share a post) rather than just reading and following other people’s posts. Also, to connect with more people, individuals should disclose more information on the site.


title: Individual Breastfeeding and Weaning Histories in Iron Age South Italy using Stable Isotope Analysis of Incremental Dentine Sections and Bone Collagen

contributor:
Prowse, Tracy
Anthropology

subject: Stable Isotope Analysis; Breastfeeding; Weaning; Iron Age South Italy

abstract: This thesis investigates breastfeeding and weaning patterns in an Iron Age (7th – 4th century BCE) sample of subadults (n=12) and adults (n=9) buried at the sites of Botromagno, Parco San Stefano and Padreterno in southern Italy. Stable isotope analysis of both human tooth dentine and bone collagen for each subadult, and tooth dentine for adults, was undertaken to create early-life feeding histories. The dentine serial sections were used to determine the onset and completion of weaning for each individual, as well as distinguish general trends in early feeding practices at these Iron Age sites. Results indicate that the average onset of weaning in subadults occurred at 8 ± 3.4 months and weaning was completed by 4 years of age at the latest for all individuals; however, the patterns of breastfeeding and weaning were variable in this sample. This study also explores variation in early childhood diet between survivors and non-survivors (i.e., < 4 years of age). Non-survivors were weaned more rapidly than survivors – possibly contributing to their earlier death – and some non-survivors demonstrated elevated δ15N values that may have been a result of physiological stress.  It is, however, difficult to distinguish signals of breastfeeding versus stress in young children who were still likely consuming breast milk. Finally, differences in isotope data between dentine serial sampling and bulk-bone sampling of rib and femoral collagen from the same individuals were investigated. The results show that the combined use of dentine and bone data contribute to more nuanced interpretations of weaning. Further, rib samples represent diet closer to the time of death than femoral samples, as faster bone turnover rate in ribs allow for the incorporation of more recent dietary changes.

abstract: Thesis

abstract: Master of Arts (MA)


title: GridDehazeNet: Attention-Based Multi-Scale Network for Image Dehazing

subject:
image dehazing
deep learning

abstract: We propose an end-to-end trainable Convolutional Neural Network (CNN), named GridDehazeNet, for single image dehazing. The GridDehazeNet consists of three modules: pre-processing, backbone, and post-processing. The trainable pre-processing module can generate learned inputs with better diversity and more pertinent features as compared to those derived inputs produced by hand-selected pre-processing methods. The backbone module implements a novel attention-based multi-scale estimation on a grid network, which can effectively alleviate the bottleneck issue often encountered in the conventional multi-scale approach. The post-processing module helps to reduce the artifacts in the final output. Experimental results indicate that the GridDehazeNet outperforms the state-of-the-art on both synthetic and real-world images. The proposed hazing method does not rely on the atmosphere scattering model and we provide an explanation as to why it is not necessarily beneficial to take advantage of the dimension reduction offered by the atmosphere scattering model for image dehazing, even if only the dehazing results on synthetic images are concerned.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: On the Optimality of the Greedy Policy for Battery Limited Energy Harvesting Communications

subject:
Bellman equation
Energy harvesting
Greedy policy
Power control
Throughput

abstract:
Wireless network for connecting the devices and sensors to communicate and sense is quite attractive nowadays for a wide range of applications.
The scaling of the wireless network to millions of nodes currently is impractical if the process is supplied by battery energy. The batteries need to be periodically replaced or recharged due to the limited battery size. One solution is harvesting ambient energy to power the network. In this thesis, we consider a battery-limited energy harvesting communication system with online power control. Assuming independent and identically distributed (i.i.d.) energy arrivals and the harvest-store-use architecture, it is shown that the greedy policy achieves the maximum throughput if and only if the battery capacity is below a certain positive threshold that admits a precise characterization. Simple lower and upper bounds on this threshold are established. The asymptotic relationship between the threshold and the mean of the energy arrival process is analyzed for several examples. Furthermore, value iteration method is applied for solving the Bellman equation to obtain the optimal power allocation policy. The optimal policy is analyzed for several examples.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Event-Related Potentials in Concussion Detection and Recovery

contributor:
Connolly, John F.
Service, Elisabet
Kuperman, Victor
Cognitive Science of Language

subject:
concussion
EEG
event-related potentials
cognitive function
neuroscience
brain injury

abstract: Concussion, defined as a functional injury with complex symptomatology, affects millions annually and has been classified as a serious public health concern. Clinical tools currently available for concussion assessment fail to objectively measure cognitive function and thus, are inadequate for proper evaluation of the cognitive dysfunctions associated with the injury. As a result, investigation into the neurological consequences associated with concussion has become a prominent focus in neuroscience research. Traditionally, neuroimaging methods have been used primarily on concussion detection, while behavioural and neuropsychological assessments have been used for both concussion detection and cognitive-performance tracking. However, to date, minimal work has explored the use of neuroimaging to track the consequences of concussion at the neurophysiological level. Accordingly, the present thesis sought to investigate the clinical applicability of electroencephalography (EEG) as an effective neuroimaging tool capable of concussion detection, as well as its ability to objectively track neurophysiological changes over time. Event-related potentials (ERPs) were used to assess specific functions, or more accurately, dysfunctions of select cognitive processes as reflected by electrophysiological changes in the brain. Specifically, the Mismatch Negativity (MMN), N2b, and P300 were investigated to evaluate memory, attention, and executive control in concussed populations. The results of this thesis demonstrated alterations in each of the aforementioned ERPs, signifying cognitive dysfunctions linked to neurophysiological abnormalities in concussed populations. Of particular importance, Chapter 2 revealed the first instance of MMN abnormalities in a concussed population, Chapter 3 was the first to assess concussed adolescents at the acute stage of their injury, and Chapter 4 demonstrates the potential of ERPs to track neurophysiological changes from the acute to post-acute stages of the injury. Ultimately, the findings presented in this dissertation support the clinical viability of using ERPs to not only detect cognitive dysfunctions associated with concussion, but also to objectively track neurophysiological changes on the path to recovery.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: On the Characteristics of Dividing Steam-Water Flow in a Horizontal Tee Junction

contributor:
Shoukri, M.
Mechanical Engineering

subject:
dividing steam-water flow
horizontal tee junction

abstract: The results of an experimental investigation of the separation phenomena in dividing two-phase flow is presented. This work involved the commissioning of a steam-water loop to obtain detailed data on the characteristics of steam-water flow in a horizontal tee junction. Measurements included the pressure and void fraction distributions as well as the total flow rate and quality along the inlet and branching legs. A detailed set of experiments were performed enabling the effects of flow split, inlet quality and inlet mass flux on the separation and pressure characteristics to be determined. For the annular inlet flow conditions considered herein, total separation was approached when more than 40% of the inlet flow was removed through the branch. At lower branch flow rates, the degree of phase separation was strongly dependent on the branch flow split and the inlet quality. The pressure change from the inlet through the run of the tee was modelled from an axial momentum balance at the junction for both homogeneous and separated flow assumptions. The separated flow momentum correction factor was distributed about a value of unity indicating that the branching flow carriers little or no axial component of momentum. The pressure change from the inlet through the branch was considered in terms of reversible an'd irreversible components for separated and homogeneous flow assumptions. Both models yielded loss coefficients that were strongly dependent on the branch flow split and inlet quality.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Stepping Beyond Behaviour: Explainable Machine Learning for Clinical Neurophysiological Assessment of Concussion Progression

contributor: Dr. John F. Connolly, Dr. James P. Reilly

subject:
Concusssion
Mild Traumatic Brain Injury
Machine Learning
Explainable Machine Learning
Deep Learning
Injury Progression
Clinical Tools
Functional Connectivity
Electroencephalography
Event-Related Potentials

abstract: The present dissertation details a sequence of studies in mild traumatic brain injury, the progression of its effects on the human brain as recorded by event-related electroencephalography, and potential applications of machine learning algorithms in detecting such effects. The work investigated data collected from two populations (in addition to healthy controls): 1) a recently-concussed adolescent group, and 2) a group of retired football athletes who sustained head trauma a number of years prior to testing. Neurophysiological effects of concussion were assessed across both groups with the same experimental design using a multi-deviant auditory oddball paradigm designed to elicit the P300 and other earlier components. Explainable machine learning models were trained to classify concussed individuals from healthy controls. Cross-validation performance accuracies on the recently-concussed (chapter 4) and retired athletes (chapter 3) were 80% and 85%, respectively. Features showed to be most useful in the two studies were different, motivating a study of potential differences between the different injury-stage/age groups (chapter 5). Results showed event-related functional connectivity to modulate differentially between the two groups compared to healthy controls. Leveraging results from the presented work a theoretical model of mild traumatic brain injury progression was proposed to form a framework for synthesizing hypotheses in future research.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Cardiac Troponins in Critical Illness

contributor:
Whitlock, Richard P
Health Research Methodology

subject:
troponin
critical care

abstract:
Troponin elevations are frequent during critical illness and associated with higher short-term mortality. Whether troponin elevations in that population independently confer a worse prognosis remains a matter of debate and how to manage patients with troponin elevations in the intensive care unit is unknown. Myocardial injury after noncardiac surgery is a well-defined entity, but can the same criteria be applied in patients who transition in the intensive care unit? Most patients present a troponin elevation early after coronary artery bypass surgery. How should a myocardial infarction be defined in these patients?  This thesis comprises 7 chapters that inform these knowledge gaps.
Chapter 1 is an introduction providing the rationale for conducting each of the included studies.
Chapter 2 reports on the PROTROPIC pilot study evaluating the feasibility of a larger study to assess whether troponin elevations in critical illness independently predict mortality.
Chapter 3 presents the use of secondary cardiovascular prevention medications and cardiac risk stratification in the PROTROPIC pilot study participants.
Chapter 4 is a systematic review and meta-analysis of randomized controlled trials evaluating the efficacy and safety of statins in critically ill patients.
Chapter 5 describes patients admitted to the intensive care unit after noncardiac surgery in the VISION cohort. This substudy also evaluates whether admission to the intensive care unit modifies the prognosis associated with myocardial injury after noncardiac surgery.
Chapter 6 evaluates the prevalence and prognosis associated with different definitions of myocardial infarction after coronary artery bypass grafting using data from the CORONARY trial.
Finally, Chapter 7 discusses the conclusion, limitation, and implications of the research presented in this PhD thesis.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: Qualitative analysis of a three-tiered food-web in achemostat with multiple substrate inflow

contributor:
Wolkowicz, Gail Susan Kohl
Mathematics and Statistics

subject:
Mathematical modelling
Dynamical systems
Mathematical biology
Anaerobic digestion

abstract: We analyze a simplified mathematical model of the complete degradation of monochlorophenol. The model takes form of a system of six ordinary differential equations, the dynamics of which can be reduced to the dynamics of a three-dimensional system on the invariant set. We extend the previous analysis by considering multiple substrate inflow. We also focus on the bifurcations occurring in the system and their biological meaning.

abstract: Thesis

abstract: Master of Science (MSc)


title: Universal Health Coverage and Access to HIV Treatment and Care in the Eastern Caribbean

contributor:
Grignon, Michel
Health Policy

subject:
universal health coverage
universal access
HIV
Caribbean
Health Policy
Physicians
Affordability
Sustainable Development Goals

abstract: This dissertation includes four papers— two conceptual and two empirical— on universal health coverage introduced in global health as a policy concept to improve access to health care. The conceptual papers review the selection process for the Sustainable Development Goal indicator on universal health coverage and propose parameters to guide an evaluation framework for universal health coverage. The first two papers show that including participants from as many sections of the health sector and policy community is recommended in policy formulation and evaluation, and recognize that decision-making might be slower as a result. While the first two papers focus on the third Sustainable Development Goal to achieve universal health coverage, the following two empirical papers focus on the sixth Millennium Development Goal which committed to provide universal access to treatment and care for people living with HIV. The first empirical paper shows how physicians in six Eastern Caribbean countries (Antigua and Barbuda, Dominica, Grenada, St. Kitts and Nevis, St. Lucia and St. Vincent and the Grenadines) cope with the lack of resources for treatment and care. Access was implemented broadly emphasizing the availability of HIV treatment and care while ensuring that everyone who needed antiretrovirals did not incur out-of-pocket costs. In most cases, this meant receiving care in the public system which was mostly centralized and where people living with HIV had concerns about their privacy being compromised in societies where HIV stigma was prevalent. The second empirical paper shows that in St. Lucia, third-line antiretrovirals could be unaffordable to as much as 98 % of the population, depending on how affordability is measured. The papers collectively demonstrate how the Millennium Development Goals provided an opportunity for policy learning by comparing the implementation of universal access for HIV treatment and care with universal health coverage in the Sustainable Development Goals.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: The dissertation recognizes the challenges with defining and measuring universal health coverage and with providing access to treatment and care for human immunodeficiency virus (HIV) in the Eastern Caribbean. The first conceptual paper documents the process of selecting indicators for universal health coverage in the Sustainable Development Goals. The second conceptual paper advances recommendations for evaluating universal health coverage. The following two studies then empirically assess the challenges with access to health care for people living with HIV in the Eastern Caribbean. The third paper shows how physicians cope with the lack of appropriate resources and highlights the issue of privacy for patients. The fourth paper uses data from St. Lucia to assess the affordability of antiretrovirals and highlights the difficulties of measuring financial affordability.


title: Resistance exercise-induced muscle hypertrophy

title: Endogenous and exogenous factors and their influence on resistance exercise training-induced muscle hypertrophy

contributor:
Phillips, Stuart
Kinesiology

subject:
resistance exercise
skeletal muscle
hypertrophy
strength
testosterone

abstract: Resistance exercise training (RET) can lead to muscle hypertrophy; however, the relative contribution that exogenous (protein supplementation and specific training variables) versus endogenous (biology inherent to the individual) factors have on RET-induced muscle hypertrophy is controversial. In Study 1, we provided an evidence-based conclusion that protein supplementation during periods of RET results in a small but statistically significant increase in RET-induced muscle hypertrophy. In Study 2, we corroborate previous research and observed that the amount of mass lifted per repetition (load) did not determine RET-induced muscle hypertrophy in resistance-trained men when RET was performed to volitional fatigue. In Study 4, we observed similar muscle fibre activation following resistance exercise with lighter versus heavier loads when both were lifted until volitional fatigue. In Studies 2 and 3, we observed no relationship between circulating anabolic hormones (e.g., testosterone) and RET-induced muscle hypertrophy. Nonetheless, in Study 3, we found significantly greater muscle androgen receptor content in the top versus the bottom quintile of respondents for muscle hypertrophy following 12 weeks of RET indicating that androgen receptor content, and not circulating androgen concentration, may be an important determinant of hypertrophy. Finally, in Study 5, we observed that RET-induced muscle hypertrophy was an consistent within an individual (independent of load and limb) but considerably different between participants. Together, these data suggest that the exogenous factors we studied – protein supplementation and load (when RET was performed to volitional fatigue) – had a relatively small influence on RET-induced muscle hypertrophy. In contrast, we found that endogenous variables, such as intramuscular androgen receptor content and likely other genetic influences, appear to contribute more to the significant heterogeneity seen in RET-induced muscle hypertrophy. Future research in this area should prioritize understanding the biology that underpins the individual variability in RET-induced muscle hypertrophy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Resistance exercise training (RET) increases muscle size (hypertrophy); however, the relative influence that protein supplementation, specific training variables, and individual (genetic) variation have on the RET-induced hypertrophy is controversial and largely unknown. Broadly, data in this thesis show that protein supplementation slightly augments RET-induced hypertrophy, and that the magnitude of RET-induced hypertrophy may be related to the number of androgen (e.g., testosterone) receptors inside an individual’s muscle. In contrast, we found that neither load nor hormones affect RET-induced hypertrophy. Interestingly, data in this thesis also show that RET-induced hypertrophy is consistent within an individual but varies considerably between people, which illustrates the greater influence that individual variation has on RET-induced hypertrophy. We conclude that when RET is performed with a high degree of effort, protein supplementation and specific training variables confer a relatively small benefit on RET-induced hypertrophy compared to the influence of biological variability between people.


title: Exploring neonatal resuscitation competencies in residents and recently graduated pediatricians

contributor:
Williams, Connie
Health Science Education

subject:
Neonatal resuscitation
Competency acquisition
Post graduate training

abstract:
Introduction:  The practice of neonatal resuscitation involves superior technical skills, an ability to lead an interdisciplinary team as well as make clinical decisions based on complex dynamic transitional physiology within a narrow timeline. These skills are a mandatory component of pediatric residency training and have been assessed using standardized assessment tools such as certifying board exams, procedure checklists, and in training exams. Recent literature has raised concerns about trainees’ competency in the technical skills for neonatal resuscitation. This project sought to explore trainees’ perceptions of competency for neonatal resuscitation, as well as potential barriers that challenge this process.

Methods:  This project employed an interpretive design qualitative methodology, using an a priori educational theory incorporating the principles of social cognitive theory, deliberate practice, distributive practice, and ‘choke phenomenon’. Semi structured focus groups of residents and pediatricians were used for data collection. Interpretive analysis in the style of Crabtree and Miller was employed. Validity criteria as described by Lincoln and Guba were applied. Institutional ethics board approval was obtained.

Results: The participants identified four attributes for competency in neonatal resuscitation required to ensure successful transition towards readiness for independent practice: (a) medical expertise, (b) leadership, (c) transferability, and (d) self-efficacy. The enablers and barriers towards acquisition of these four aspects during residency training and transition to practice were identified and explored.

Conclusions: Through the self-reported experiences of trainees and practitioners and informed by educational theory, this study describes a “across rocky seas” graduated conceptual model of a sailing ship for competency acquisition in neonatal resuscitation. An understanding and application of this model may thus inform the development of new competency-based curricula.

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
The practice of neonatal resuscitation is challenging because practitioners are dealing with an infant who is critically ill, requiring multiple interventions within a very short duration of time.  Despite residency training, literature reports challenges with acquiring and maintaining resuscitation skills.  Using qualitative methods, specifically interpretive design, this project sought to explore trainees’ perceptions of competency for neonatal resuscitation, as well as potential barriers to this process. The principles of repeated exposure over different times in training, performance under pressure and the confidence in one’s abilities required to achieve a specific goal were used to inform data collection and analysis.

The participants identified four attributes for competency in neonatal resuscitation required to ensure successful transition towards readiness for independent practice: (a) medical expertise, (b) leadership, (c) transferability, and (d) self-efficacy.  Informed by educational theory, these constructs were then used to describe a conceptual model for competency acquisition in neonatal resuscitation


title: Applications and advances of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology in nutrition and child health

title: Applications and advances of GRADE in nutrition and child health

contributor:
Guyatt, Gordon Henry
Health Research Methodology

subject:
GRADE
Network meta-analysis
Evidence Synthesis
Nutrition
Child health

abstract:
The relationship between human health and nutrition is complex and limited widely accepted guidance on proper methods of evidence synthesis is available for nutritional issues. While concepts and methods of evidence synthesis in pharmacological treatments can be mostly applied to nutritional interventions, characteristics unique to the nutrition- and dietetics-related topics can lead to distinct challenges that may not be encountered in evidence synthesis of traditional medical interventions. In addition to traditional methods for pooling the results, state-of-the-art methodologies such as GRADE or network meta-analysis, while being widely used in many medical fields, their use in the field of nutrition and food science is surprisingly rare.
This thesis begins with the assessment of methodological quality of available public health guidelines on sugar intake to determine the extent to which nutritional guidelines follow currently available guidance in evidence synthesis and making practice recommendations. Subsequently, we present two examples of proper implementation of evidence synthesis methods in standard pairwise meta-analysis and indirect treatment comparison and handling of relevant challenges including applications of GRADE approach. Further, this thesis presents a network meta-analysis in the field of nutrition and child health in which the challenges of conducting multiple treatment comparison are tackled and a new approach for presenting and making conclusion from network meta-analysis results is proposed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: ABERRANT METABOLIC AND SIGNALING PATHWAYS UNDERLIE IMPAIRED STEM CELL FUNCTION IN HUMAN OBESITY

contributor:
Doble, Bradley
Biochemistry and Biomedical Sciences

abstract:
Obesity is a major health problem, and it is increasing at an alarming pace in developed and developing countries worldwide. Obesity increases the likelihood for many other diseases, such as type 2 diabetes, coronary heart disease, metabolic syndrome, hyperlipidemia, and some types of cancer. Chronic calorie-overload, genetic predisposition, and physical inactivity are the primary factors contributing to energy imbalance during obesity. In response to a positive energy balance, adipose tissues start expanding to store excessive nutrients in the form of lipids via two mechanisms: 1) by recruiting more adipocyte progenitors, resulting in increased adipocyte number – adipocyte hyperplasia; and 2) through an excessive accumulation of lipids in existing adipocytes – adipocyte hypertrophy. The former process is considered a metabolically healthy way to expand adipose tissue, while the latter is associated with the development of complications, such as insulin resistance. During conditions of chronic energy excess, as is found in obesity, adipose tissue loses its ability to recruit/activate progenitors, and adipose tissue expansion occurs primarily through adipocyte hypertrophy, ultimately resulting in inflamed and dysfunctional adipose tissue. Although studies have looked at hypertrophic and hyperplastic processes during adipocyte development, we still lack a meaningful understanding of the molecular mechanisms contributing to the reduced adipogenesis observed in obesity.
In this thesis, I created a metabolic map of healthy and obese human adipogenesis in vitro by using global transcriptomics, proteomics and functional cellular bioenergetics tools, providing a more systematic understanding of normal and obesity-influenced human adipogenesis. I isolated and characterized adipose tissue-resident stem cells (ADSCs) from different healthy, overweight, and obese individuals to create an in vitro model for studying obesity. I found that cells from morbidly obese individuals inherently retained obesity-associated metabolic derangements, and hence, can serve as a cellular model that is very well-suited to study the factors contributing to the reduced adipogenesis that is observed in the context of obesity. By utilizing this model, I identified metabolic aberrations at molecular and functional levels in the two major cellular energy-generating pathways, glycolysis and oxidative phosphorylation. I demonstrate that these pathways drive impaired stem cell function during adipogenesis in obese patient-derived ADSCs. Further, I was able to rescue impaired stem cell function and adipogenesis by stimulating metabolism and improving mitochondrial health in obese cells. In addition, through “omics” approaches, I identified a number of signaling pathways that are aberrantly regulated during obese versus healthy adipogenesis. One such pathway, which was prominently dysregulated in obese cells was the Wnt signaling pathway, wherein observed dynamic changes in Wnt antagonist expression, required for normal adipogenesis, did not occur in these cells. Functional studies revealed that aberrant Wnt signaling closely associated with defects in metabolism, which paralleled my earlier observations obtained through functional metabolic studies in obese cells, suggesting that cellular metabolism can be potentially targeted to improve stem cell function in obese cells. Building on that notion, I developed and validated a novel high-throughput functional drug-screening assay targeting obese adipogenesis, based on functional measurements of metabolic parameters such as mitochondrial activity and induction of the browning of white adipocytes.
Overall, this study presents novel insights into the mechanisms that modulate human adipogenic differentiation in obesity, by using disease-relevant in vitro models that can serve as a platform for the discovery of novel therapeutics, offering the opportunity to identify novel targetable pathways and biomarkers for the management of obesity and its associated metabolic complications.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Three Essays on the Brand-Channel Interface: How Brand Equity Influences Distribution Channel Governance and Management

contributor:
Kacker, Manish
Business

subject:
Brand Equity
Distribution Strategy
Brand-Channel Interface
Gray Market
Grey Market
Parallel Importation
Marketing Strategy
Event Study
Distribution Channels
Gray Markets
Channel Management
Branding

abstract:
In this dissertation, I explore some facets of the strategic interaction between brand equity and distribution channels. Specifically, I examine how brand equity influences the firm’s channel governance and channel management strategies. In this regard, I address the following two general research questions: (a) does a firm’s brand equity influence the way it governs its distribution channel? How? (b) Does a firm’s brand equity influence the way it manages its distribution channel? How?
Using a wide assortment of archival data sources (e.g., Bond's Franchise Guide, Entrepreneur’s Franchise 500, Factiva, LexisNexis, University of Chicago’s Center for Research in Security Prices, Compustat, Statista, firms’ annual reports, Bloomberg and Wall Street Journal databases, and companies’ official websites), two large multi-year data sets, a variety of econometric techniques (e.g., Event Study, Multiple Regression, Probit, Multi-level Mixed-Effects Linear Models, Multinomial Logistic Regression, Generalized Linear Models, Multinomial Probit, Maximum Likelihood, Bayesian Panel Vector Autoregression), and drawing on several theories from marketing, economics, business law, and strategic management, I uncover some interesting strategic interactions taking place at the brand-channel interface. This dissertation comprises five chapters: three empirical studies (chapters 2, 3, and 4), an introduction, and a conclusion chapter.
In the introduction chapter, I provide a snapshot of the current state of knowledge in the brand-channel interface research domain and illustrate how I situate this dissertation within that body of research. Besides, I provide a more nuanced view about the specific research questions each study addresses and a glimpse into the findings and implications of each study, as an entry to the dissertation.
In chapter 2, using a large panel data set of North American, franchise-level annual observations for the period from 2001 to 2009, I assess the causal link between brand equity and channel governance structure, and discuss the managerial implications of this relationship in the areas of channel governance and capital allocation decision-making.
In chapters 3 and 4, I stay within the same overarching theme of this dissertation and delve into a business phenomenon taking place at the brand-channel interface – gray markets. Despite the interdisciplinary research interest in gray markets, it remains one of the least empirically researched topics in business management due to the well-known data accessibility issues. To circumvent those data barriers that impede empirical research on gray markets, I adopt a novel approach for data collection and analysis. To that end, I study the gray market combating behavior of more than 3,000 public companies, company-by-company, for a period of twenty years. Then, using a collection of archival data sources I assemble a unique data set to use in my analyses. In chapter 3, I undertake the first empirical inquiry into the effect of gray market combating on firm performance and the contingencies that govern this effect.  In chapter 4, I conduct a comprehensive review of the gray market combating mechanisms present in the literature, review available theoretic arguments about them, posit theoretical relationships, and conduct the first assessment of the financial efficacy of those different combating mechanisms. Then, I identify a number of firm-level factors that may drive the firm’s choice of gray market combating mechanism. The findings of these two studies address some long-standing, focal research questions in the gray market literature, provide managers with many valuable, actionable insights and recommendations, and put before policymakers some novel, revealing scientific evidence that may help them in dealing with the gray market controversy (e.g., whether the net impact of gray markets on firm performance and social welfare is benign or harmful, the necessity and/or merit of an active legislative role).
The conclusion chapter closes this dissertation by reflecting on the new knowledge created by this research and highlighting its significance to theory, practice, and policymaking.

abstract: Thesis

abstract: Doctor of Business Administration (DBA)

abstract:
The relationship between brand equity and distribution channel strategy is recognized in practice and is of particular interest to senior managers. However, research in marketing on the topic is scant and our understanding of this relationship remains limited. This dissertation endeavors to advance our knowledge in that area by investigating how a firm’s brand equity affects its channel management and channel governance behavior.
Using a variety of research methods and statistical techniques, along with two large multi-year, multi-sector data samples, I document some interesting strategic interactions taking place at the brand-channel interface. Notably, I detect a causal influence for brand equity on the way a firm governs its distribution network. Additionally, I observe that brand equity is not only a major driver of certain strategic channel management initiatives (e.g., gray market combating), but also a key determinant of the financial efficacy of those initiatives.
The findings of this research pose significant implications for theory, practice, and policymaking and address some questions that puzzled practitioners and scholars for more than three decades.


title: MANF, ER STRESS AND THE PATHOPHYSIOLOGY OF PARKINSON’S DISEASE

abstract: Nearly 10 million people worldwide live with Parkinson’s Disease (PD), a disease marked by the degeneration of midbrain dopaminergic neurons. Current treatments are symptomatic and can incur undesirable side effects. The recently discovered neurotrophic factor (NTF), known as mesencephalic astrocyte-derived neurotrophic factor (MANF), has proven to be an interesting candidate to study within the context of PD because this NTF is involved in endoplasmic reticulum (ER) homeostasis and the unfolded protein response (UPR), both of which are abnormal in PD. MANF is an evolutionary conserved NTF identified in both invertebrate and vertebrate species that is mainly localized within the ER and has demonstrated to be neuroprotective against midbrain DA neuron degeneration in vitro. Intracellular MANF helps stop the unfolded protein response (UPR) during ER stress and therefore prevents the cell from going into apoptosis. Lentiviral mediated shRNA knockdown of MANF in rats has led to the manifestation of PD like symptoms and motor deficits mainly due to the death of dopaminergic neurons in the substantia nigra (SN). mRNA analysis of the ER stress marker glucose-regulated protein 78 (GRP78) and the transcription factor C/EBP homologous protein (CHOP) have shown increased levels apoptosis following MANF knockdown. Furthermore, the phytochemical curcumin is a spice that has been widely acknowledged for its anti-oxidant and anti-apoptotic properties and in-vitro investigation of its protective role has revealed that curcumin prevents 6-hyrodroxydopamine induced cytotoxicity and that it upregulates MANF expression and therefore employs MANF during its protective cascade. These findings, therefore, acknowledge MANF’s significance as a neuroprotective agent and hence points to its future development as a potential agent against neurodegenerative disorders.

abstract: Thesis

abstract: Master of Science (MSc)


title: Rejection Sensitivity and Borderline Personality Disorder

contributor:
Boylan, Khrista
Neuroscience

subject:
Borderline personality disorder
rejection sensitivity
adolescence

abstract: This thesis presents research aimed at examining rejection sensitivity in adolescent girls with borderline personality disorder (BPD) features. Although rejection sensitivity has been discussed more generally in the literature, few studies have identified how this construct may contribute to psychopathology in adolescence. There is also limited research regarding outcome behaviours that may be associated with high rejection sensitivity as well as factors that contribute to the manifestation of this construct. Here, this thesis aims to further the understanding of rejection sensitivity in adolescence and provide evidence to support the clinical utility of examining and offering treatment for this factor in youth presenting with BPD features. Although research has shown that BPD and high rejection sensitivity are strongly correlated, few studies have investigated the outcomes that may result from having this comorbidity. In the first paper of this thesis, disordered eating was examined as an outcome behaviour in a clinical sample of girls with BPD features. The results showed that girls who met diagnostic criteria for BPD had significantly higher disordered eating behaviour and that rejection sensitivity, operationalized as fears of abandonment, mediated this relationship. In the second paper of this thesis, the relationship between self-esteem, BPD features and perceived peer rejection was investigated in a longitudinal community sample of adolescent girls. We tested the sociometer hypothesis (Leary, 2005) that self-esteem served as a metric to detect the degree of belongingness in a group context. The results indicated that the relationship between BPD features and perceived peer rejection depended on self-esteem over time. Overall, the two studies presented in this thesis contribute to the knowledge regarding rejection sensitivity in adolescents with BPD features and explores correlates and outcomes of this relationship to aid in the identification of novel treatments to target and ameliorate rejection sensitivity in this population.

abstract: Thesis

abstract: Master of Science (MSc)


title: Assessing Variability in Microrna Concentrations in Serum Throughout the Menstrual Cycle in Women with and Without Endometriosis

contributor: Medical Sciences (Division of Physiology/Pharmacology)

subject:
miRNA
endometriosis
reference RNA

abstract: Endometriosis is an estrogen dependent disease characterized by the growth of endometrial epithelium and stromal cells outside the uterine cavity. Lack of a clinical test results in a diagnostic delay of between 6-12 years.  Recent studies suggest that miRNAs may be useful diagnostic tools; however, results remain equivocal. Use of different reference miRNA and definitions of control groups are factors postulated to contribute to the inconsistent findings in the literature. Serum samples were collected from women (n=53) undergoing laparoscopic surgery. Reference RNAs and symptomatic vs asymptomatic control groups were studied. Comparisons were made between cases and controls, controls and treated vs non-treated cases, and controls, endometriosis and adenomyosis. Data were compared by Mann Whitney U tests and Kruskal Wallis tests. A p value  0.05 was considered statistically significant. Our major finding was that reference RNA selection and categorization of patients influenced results. When using the most appropriate reference and comparing to asymptomatic controls, miR-9 was upregulated and miR-451a was downregulated in women with endometriosis. When using the most appropriate reference and comparing to symptomatic controls, miR-9 and 141 were downregulated in women with endometriosis. miR-9 and 141 were also downregulated in women receiving treatment. When using the most appropriate reference and comparing to women with adenomyosis, miR-451a, 20a and 122 were downregulated in women with endometriosis. While miRNA is the newest and has most promise as a diagnostic biomarker, miRNA expression results are extremely sensitive to multiple experimental variables. Literature continues to approach miRNA research using different definitions of control populations and different reference RNA. To replicate results and advance the search for miRNA as a diagnostic biomarker for endometriosis, a common methodology between labs will be necessary.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Endometriosis affects 10% of women within their reproductive lifespan. Since the gold standard for diagnosing endometriosis is laparoscopy, a diagnostic biomarker for endometriosis is of utmost importance. Currently there is no universally acceptable biomarker and circulating levels of miRNA appear to be promising but results have yet to be replicated. Replication of results may be dependent on reference RNA and definitions of control groups.


title: A Multinuclear Magnetic Resonance Study of Alkali Ion Battery Cathode Materials

contributor:
Goward, Gillian
Chemistry and Chemical Biology

subject:
Solid-state NMR
Sodium ion batteries
Lithium ion batteries
Cathode materials
Sodium vanadium fluorophosphate
Density functional theory calculations
Monte carlo calculations
NMC622
NMC
Two dimensional exchange spectroscopy

abstract:
The need for highly efficient energy storage devices has been steadily increasing due to growing energy demands. Research in electrochemical energy storage in the form of batteries has consequently become crucial. Currently, the most commercialized battery technology is the lithium ion battery (LIB). Concerns over the relatively limited global lithium supply, however, have led to the development of sodium ion batteries (SIBs). Solid-state nuclear magnetic resonance (ssNMR) spectroscopy is an ideal technique for analyzing battery materials as it can potentially distinguish between different ions within the material.
The most typical cathode for commercial LIBs are the family of NMC layered oxides with the general form Li[NixMnyCo1-x-y]O2, which consist of Li layers between sheets of transition metals (TMs). The pj-MATPASS NMR technique, in conjunction with Monte Carlo simulations, was applied to investigate the ionic arrangement within TM layers of NMC622 (Li[Ni0.6Mn0.2Co0.2]O2), which revealed the presence of ion clustering in the pristine form of this material.
This thesis also investigated the promising SIB cathode, Na3V2(PO4)2F3 (NVPF). NVPF has the capability to produce energy densities comparable to those of LIBs and is well understood from a structural standpoint, however ion dynamics within the material are still undetermined. A series of materials have, therefore, been synthesized with the general form, Na3V2-xGax(PO4)2F3 (where x = 0, 1, and 2), where diamagnetic Ga3+ was introduced into the structure to enable the establishment of a structural correlation with observed Na-ion dynamics. It, therefore, became possible to explore ionic site exchange using 23Na ssNMR. Density functional theory (DFT) calculations have also been performed alongside ssNMR to confirm chemical shift assignments and provide structural insight. Additionally, electron paramagnetic resonance (EPR) spectroscopy was also used to investigate the paramagnetic nature of NVPF and its variants. Insights into the ionic arrangement and very fast Na-ion dynamics within these materials were revealed.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The need for highly efficient energy storage devices, especially in the form of batteries, has been steadily increasing due to growing energy demands. Presently, the most commercialized types of batteries are lithium ion batteries (LIBs). Concerns over the relatively limited global lithium supply, however, have led to the development of sodium ion battery (SIB) alternatives. Various solid-state nuclear magnetic resonance (ssNMR) techniques have been employed in this thesis to investigate both LIB and SIB cathode materials. The LIB cathode Li[Ni0.6Mn0.2Co0.2]O2 was examined with a combination of ssNMR and Monte Carlo simulations, and it was found that ion clustering occurs in the pristine form of these materials. The promising family of SIB cathodes, Na3V2-xGax(PO4)2F3, was studied by a combination of ssNMR, ab initio calculations, and EPR, which allowed for a correlation to be established between the crystal structure and the fast ion dynamics within these materials.


title: Contributions to statistical methods for meta-analysis of diagnostic test accuracy studies

title: Methods for meta-analysis of diagnostic test accuracy studies

contributor:
Beyene, Joseph
Mathematics and Statistics

subject:
Statistical methods
meta-analysis
diagnostic test accuracy studies
outlying studies
influential studies
skewness
random-effects model
robust models
sensitivity
specificity

abstract: Meta-analysis is a popular statistical method that synthesizes evidence from multiple studies. Conventionally, both the hierarchical and bivariate models for meta-analysis of diagnostic test accuracy (DTA) studies assume that the random-effects follow the bivariate normal distribution. However, this assumption is restrictive, and inferences could be misleading when it is violated. On the other hand, subjective methods such as inspection of forest plots are used to identify outlying studies in a meta-analysis of DTA studies. Moreover, inferences made using the well-established bivariate random-effects models, when outlying or influential studies are present, may lead to misleading conclusions. Thus, the aim of this thesis is to address these issues by introducing alternative and robust statistical methods. First, we extend the current bivariate linear mixed model (LMM) by assuming a flexible bivariate skew-normal distribution for the random-effects. The marginal distribution of the proposed model is analytically derived so that parameter estimation can be performed using standard likelihood methods. Overall, the proposed model performs better in terms of confidence interval width of the overall sensitivity and specificity, and with regards to bias and root mean squared error of the between-study (co)variances than the traditional bivariate LMM. Second, we propose objective methods based on solid statistical reasoning for identifying outlying and/or influential studies in a meta-analysis of DTA studies. The performances of the proposed methods are evaluated using a simulation study. The proposed methods outperform and avoid the subjectivity of the currently used ad hoc approaches. Finally, we develop a new robust bivariate random-effects model which accommodates outlying and influential observations and leads to a robust statistical inference by down-weighting the effect of outlying and influential studies. The proposed model produces robust point estimates of sensitivity and specificity compared to the standard models, and also generates a similar point and interval estimates of sensitivity and specificity as the standard models in the absence of outlying or influential studies.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Diagnostic tests vary from the noninvasive rapid strep test used to identify whether a patient has a bacterial sore throat to the much complex and invasive biopsy test used to examine the presence, cause, and extent of a severe condition, say cancer. Meta-analysis is a widely used statistical method that synthesizes evidence from several studies. In this thesis, we develop novel statistical methods extending the traditional methods for meta-analysis of diagnostic test accuracy studies. Our proposed methods address the issue of modelling asymmetrical data, identifying outlier studies, and optimally accommodating these outlying studies in a meta-analysis of diagnostic test accuracy studies. Using both real-life and simulated datasets, we show that our proposed methods perform better than conventional methods in a wide range of scenarios. %Therefore, we believe that our proposed methods are essential for methodologists, clinicians and health policy professionals in the process of making a correct judgment to using the appropriate diagnostic test to diagnose patients.


title: Explicit Emotional Memory in Major Depressive Disorder During Clinical Remission

contributor:
Frey, Benicio
Kapczinski, Flávio
Neuroscience

subject:
Emotion
Depression
Major Depressive Disorder (MDD)
Memory

abstract: This thesis comprises research investigating explicit EM biases in MDD during acute depression and euthymia (i.e., clinical remission). First, a systematic review was conducted to investigate whether acutely depressed and euthymic MDD participants display an explicit EM bias. An ‘explicit EM bias’ was operationally defined to denote enhanced memory for negative or positive stimuli compared to matched healthy controls (HCs). Studies that were included in this systematic review investigated explicit EM using free recall and recognition memory paradigms. The main finding from this investigation was that acutely depressed MDD participants do not display an explicit EM bias. An unintended consequence of this investigation was the identification that research on explicit EM in MDD during euthymia is surprisingly sparse. Next, building upon the findings from our systematic review, we conducted an empirical investigation of explicit EM within a sample of well-characterized euthymic MDD participants compared to age/sex/gender/IQ-matched HCs. In this study, participants performed incidental encoding (i.e., emotional reactivity) and recognition memory tasks (separated by one week). These tasks employed emotionally-valent picture stimuli obtained from the International Affective Picture System. Results from this study revealed that, compared to matched HCs, euthymic MDD participants do not display an emotional reactivity or explicit EM bias. Taken together, the findings from this thesis suggest that explicit EM represents a sub-domain of cognition that may be unaffected in individuals with MDD. Our findings have important implications for the unified model of depression and may represent a basis upon which future research can build in an attempt to understand the nuanced cognitive phenotypes associated with MDD.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Major depressive disorder (MDD) is one of the most common mental disorders worldwide. It is estimated that over 10% of Canadians will experience MDD at some point in their lifetime. The symptoms of MDD include, among other things: depressed mood, loss of interest in regular daily activities, and impairments in cognition (e.g., attention, emotion, memory, etc.). Clinicians and researchers have argued for years that MDD is associated with negative cognitive biases, including increased attention to, and more accurate memory for, negative information; however, attention, emotion and memory are general forms of cognition, and the existence of cognitive biases for specific sub-domains of cognition in MDD are largely unknown. Given that MDD has a negative effect on emotion and memory, one potentially important sub-domain of cognition is explicit emotional memory (EM; i.e., conscious memory for emotionally-stimulating information). The purpose of the current thesis was to investigate whether MDD, during both the active (i.e., acute) and euthymic (i.e., clinically-remitted) stages, is associated with explicit EM biases compared to healthy volunteers. This thesis discusses how patterns of explicit EM may be important for our understanding of the development of MDD.


title: A Pilot Study of Episodic Future Thinking in a Treatment Seeking Addiction Sample

contributor:
Amlung, Michael
Neuroscience

subject:
episodic future thinking
addiction
alcohol use disorder
behavioural economics

abstract:
Rationale: Individuals with addictive disorders commonly exhibit a shortened temporal window, which interferes with treatment focusing on long-term sobriety. Episodic Future Thinking (EFT) involves generating personalized cues related to anticipated, positive events at various future time points. EFT has been shown to reduce the reinforcing value of addictive substances; however, this has only been shown in non-treatment samples.
Purpose: To examine the feasibility, cumulative, and sustained effects of implementing EFT in a treatment seeking addiction sample over a 1-week protocol on decision-making and alcohol motivation.
Methods: Twenty-eight treatment seeking individuals were randomly assigned to either undergo an EFT intervention or a control Episodic Recent Thinking (ERT) protocol. Assessments were completed at baseline, end of week 1, and a 1-week follow-up. Measures included a delay discounting task, hypothetical alcohol purchase task, clinical outcome measures, and cognitive mechanism measures.
Results: There were significant reductions in alcohol demand indices, delay discounting rates, and an increase in mindful attention awareness after both acute and extended exposure to EFT. Furthermore, the EFT group showed greater reductions compared to the ERT group after extended exposure to their cues.
Conclusion: The results suggest that early implementation of EFT in a treatment seeking addiction sample is beneficial to counteract motivating factors for relapse. This study lays the foundation for future clinical trials for EFT as a supplemental therapy for addictions treatment.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: People with substance use disorders have a significantly shortened time perspective compared to healthy controls. This means that these individuals struggle with thinking about future events beyond several days to a week. Shortened time perspective can be a significant barrier to addiction treatments that typically focus on long-term positive benefits of sobriety or low-risk use. This study examined whether mindful thinking about future events impacted decision-making and motivation for alcohol and drugs. The study used an experimental protocol known as Episodic Future Thinking (EFT) that involves participants interacting with personalized cues related to positive future events. Prior research using EFT in addiction samples has found that interacting with future cues significantly increases delay of gratification, reduces cigarette use, and decreases reinforcing value of alcohol. In this study, we recruited 28 participants with an alcohol use disorder (AUD). Participants practiced EFT training over a two-week protocol. We tested decision making, alcohol craving, and other variables following a single EFT protocol, and changes in these measures over repeated practice. We found significant changes in alcohol craving, decision making, and mindfulness awareness. The study provides proof-of-concept for using EFT in an AUD treatment population and lays the foundation for future clinical trials of EFT as a complement to existing addiction treatments.


title: Synthesis and Characterization of Magnetic  Nanoparticles to Incorporate into Silicon Waveguides to Be Used as Optical Isolators

contributor:
Turak, Ayse
Knights, Andrew
Engineering Physics

abstract:
Integrated optical isolators will become necessary as optical networks continue to grow and the need for monolithic integration and greater functionality increases. The use of magnetic nanoparticles as Faraday rotators to achieve isolation has been widely researched and reported. Therefore, magnetic nanoparticles are of particular interest.

Magnetic γ - Fe2O3 and SnO2 nanoparticles were synthesized using the diblock copolymer reverse micelles method. The processes were shown in detail with the aid of Raman spectroscopy to reveal the iron oxide evolution. Moreover, the magnetic properties of the nanoparticles were evaluated by superconducting quantum interference device (SQUID) magnetometer. Using a low temperature annealing process, we showed that higher percentage of γ-Fe2O3 phase was produced and could be incorporated in practical devices. One practical use is to be used as Faraday rotators in an optical isolator.

The size of the nanoparticles can be changed simply by changing the loading ratio of FeCl3 or using different polymers to yield different sizes of the nanoparticles. The size and dispersion of the nanoparticles were determined using atomic force microscopy (AFM-QNM) and scanning electron microscope (SEM). With a good control in terms of size and dispersion, the magnetic γ-Fe2O3 were employed on silicon waveguides to test for optical isolation. The results showed no optical isolation from the γ-Fe2O3 nanoparticles; this is likely due to the modal phase mismatch between the cladding and the nanoparticles. With a few changes in the design of the waveguides and dropping of the nanoparticles; we can have a fully functional integrated optical isolator on silicon.

abstract: Dissertation

abstract: Master of Applied Science (MASc)


title: Vibration Assisted Drilling of Carbon Fiber Reinforced Polymer and Titanium Alloy for Aerospace Application

contributor:
Elbestawi, M. A.
Mechanical Engineering

subject:
Vibration Assisted Drilling
CFRP
Ti6Al4V
Burr formation
CFRP/Ti6Al4V stack
Residual stress
Advanced machining
drilling
Chip morphology
Subsurface examination
Delamination free
tool wear

abstract:
The physical and mechanical characteristics of carbon fiber reinforced polymers (CFRP) and Ti6Al4V make them widely used in the aerospace industry. The hybrid structure of CFRP/ Ti6Al4V material has been used in the new generation of aircraft manufacturing. The drilling process of these materials is often associated with unfavorable machining defects such as delamination, burr formation, reduced surface integrity, and tensile residual stresses. These machining defects are attributed to high thermal load, continuous chip morphology, and poor chips evacuation efficiency. Vibration-assisted drilling (VAD) uses an intermittent cutting process to control the uncut chip thickness and chip morphology. VAD has potential advantages include low thermal load, high chips evacuation effectiveness, and longer tool life.
This thesis presents an experimental investigation into the effect of VAD machining parameters on the cutting energy, CFRP delamination, surface integrity, geometrical geometry, Ti6Al4V burr formation, induced residual stresses, and tool wear during the drilling process of CFRP, Ti6Al4V, and CFRP/Ti6Al4V stacked materials. Moreover, a kinematics model is developed to link the observed results to the independent machining parameters (i.e., cutting speed, feed rate, modulation amplitude, and modulation frequency). The experimental work covers a wide range of machining parameters using four levels of frequencies (83.3, 125, 1500, and 2150 Hz).
The VAD results show up to 56 % reduction in the cutting temperature with a significant enhancement in the CFRP entry and exit delamination, geometrical accuracy, surface integrity, and burr formation. The use of VAD also generates compressive stresses, hence improving the part fatigue life.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Exploring the Information Needs of Youth Living with Cerebral Palsy and their Parents During the Transition to Adulthood

contributor:
Gorter, Jan Willem
Rehabilitation Science

subject:
Information needs
Transition to adulthood
Cerebral palsy
Parents
Youth

abstract:
Background
The transition to adulthood is a time of information needs for youth living with cerebral palsy (CP) and their parents. Access to information and being provided information may assist youth and their parents in making informed decisions. Youth with CP and parents of youth living with CP have reported lack of information as a challenge during the transition to adulthood. Little is known about the information needs of youth with CP and parents during the transition to adulthood from their perspective.
Objectives and Methods
The objective of this thesis was to explore the information needs of youth with CP and parents during the transition to adulthood. A scoping review was conducted seeking to understand what was known in the transition literature about the information needs of youth with CP and parents (Chapter 2). To clarify the methodological framework of this dissertation the application of interpretive description (ID) to a case study example within childhood disability research was explored (Chapter 3). The information needs during transition in a sample of young adults living with CP were explored using ID (Chapter 4). The information needs of parents of youth with CP currently in the transition to adulthood were then explored, using ID because it was learned in the study of adults living with CP that their parents initiated information seeking or had information needs of their own during transition (Chapter 5).
Findings
Primary findings from this dissertation include the recognition, from both the scoping review and the two studies, that both youth living with CP and parents of youth living with CP in the transition to adulthood have information needs during the transition to adulthood. More specifically, both youth and parents are seeking to receive information related to goals in adult life, such as employment, postsecondary education, leaving the family home and relationships. Youth prefer to receive their information from peers living with CP. Parents prefer to receive information from peers, but some also desire a direct connection with service providers. Other parents recommend adults living with CP as an information source. Youth and parents agree that information should be delivered in individualized tailored ways. In addition to rehabilitation professionals, youth and parents highlighted the need for information from educators and other community providers.
Implications for Clinical Practice
Rehabilitation professionals have an important role in helping to provide tailored information. Rehabilitation professionals can initiate conversations about the transition to adulthood around the beginning of high school that focus on improving the self-management of youth of their own transitional journey. In addition to having conversations with clients, rehabilitation professionals should also connect clients with community supports.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Position Sensorless Control of Interior Permanent Magnet Synchronous Machines with a Single DC-Link Current Sensor

contributor:
Emadi, Ali
Electrical and Computer Engineering

abstract:
Interior Permanent magnet synchronous machines (IPM) have the capability of improving its flux weakening operation and satisfying higher torque requirement due to the rotor saliency structure. However, to reduce the cost and volume, sensorless control and single current control are under investigation in decades.

The thesis develops a sensorless control method with a single dc-link current sensor for IPMs without shifting PWM waveform. The main challenge is the immeasurable region, which is divided into sector boundary region and low modulation region. An observer-assisted current reconstruction method is proposed to deal with the sector boundary region. This assistive model-based observer is a Luenberger type observer that estimates the back electromotive force (EMF) based on the error between the reconstructed and estimated currents. An adaptive band-pass filter is applied to eliminate the unexpected harmonics due to the lack of current samples in the sector boundary region. The algorithm is implemented and verified by simulation.

However, the observer-assisted method is unfeasible in the low modulation region, where even one phase current is hardly acquired. A six-direction injection method with a modified reconstruction scheme is proposed when the system operates at low speed. The injected signal forces the reference voltage vector outside the low modulation region. But the unaligned measurement of the phase current increases the position estimation error and causes a third-order harmonic. The modified reconstruction scheme takes advantage of the symmetrical switching state to average the phase current measured in the different intervals, which improves the position estimation accuracy. The saliency-based sensorless control with the modified current reconstruction method is verified by simulation.

At last, the experimental tests are conducted to verify the proposed methods of medium to high-speed operation and low-speed operation, respectively.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Domestic Dining Performances in Three of Elizabeth Gaskell's Novels

title: Domestic Dining Performances

contributor:
Grise, Catherine
Kehler, Grace
English

subject:
dining
performance
gaskell
nineteenth century
labour
leisure
goffman
domesticity

abstract: This paper examines the everyday details of the domestic dining scenes in Elizabeth Gaskell’s Mary Barton (1848), Cranford (1853), and North and South (1855). By viewing dining etiquette in terms of a dramaturgical metaphor, this paper attempts to demonstrate the cooperation, complexity, labour, and significance of the self-aware performances that structure nineteenth-century domestic dining scenes in relation to the sense of pleasure and community care that those scenes produce both for their duration and for the external ‘everyday’.

abstract: Thesis

abstract: Master of Arts (MA)


title: Increased Mortality in Younger Patients with Inflammatory Bowel Disease Associated Colorectal Cancer: A Population-based Cohort Study

contributor:
Seow, Hsien
Pond, Gregory
Eskicioglu, Cagla
Health Research Methodology

subject:
Inflammatory Bowel Disease
Colorectal Cancer
Population Based Research

abstract:
Background
Reported outcomes for colorectal cancer associated with Inflammatory Bowel Disease are inconsistent. We compared survival outcomes in colorectal cancer patients with and without Inflammatory Bowel Disease using a population-based cohort and elicited prognostic factors associated with survival
Methods
Adult patients with a diagnosis of colorectal cancer in 2007-2015 were identified from the Ontario Cancer Registry. Those with Inflammatory Bowel Disease were detected via the validated Ontario Crohn’s and Colitis Cohort. Primary outcome measure was overall survival from time of colorectal cancer diagnosis until the date of death. Secondary outcome measures included treatments received and publicly-provided health care costs.
Results
Colorectal cancer was diagnosed in 67,137 with Inflammatory Bowel Disease present in 783 (1.2%). The Inflammatory Bowel Disease-associated colorectal cancer patients were younger at diagnosis (median range 55-59 vs 70-74, p<0.001). Five-year survival in Inflammatory Bowel Disease-associated patients was 56.4% (95% CI 52.6-59.9) and 57.0% (95% CI 56.6-57.4) in sporadic colorectal cancer (p=0.8). Inflammatory Bowel Disease was a significant predictor of death (Hazard Ratio=1.45, 95% CI 1.29-1.63, p<0.001) after adjusting for other variables. In patients under 50, 5-year survival was significantly (p<0.001) reduced in the Inflammatory Bowel Disease population (56.8%, 95% CI 49.4-63.5) compared with the sporadic colorectal cancer population (71.4%, 95% CI 70.0-72.7). Similar results were observed in those 50-64 years old.
Conclusion
Young patients (<65) with Inflammatory Bowel Disease-associated colorectal cancer have worse survival outcomes than young (<65) patients with sporadic colorectal cancer. These findings inform prognostication and may direct future research for this high-risk population.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Interactive Process of Negotiating Workplace Accommodations for Employees with a Mental Health Condition

contributor:
Gewurtz, Rebecca
Rehabilitation Science

subject:
workplace accommodations
disability management
mental health conditions
mental illness
work disability

abstract:
Employee mental health claims have become a costly burden for Canadian workplaces, therefore many organizations are seeking to adopt progressive disability management strategies to support employees with mental health conditions who are either returning to work or trying to remain at work. Developing and implementing effective workplace accommodation practices is one such strategy to support employees. Negotiating workplace accommodations has been recommended in the literature to be an interactive process between the employee and workplace stakeholders. However, there is very limited knowledge regarding the ways in which discussing and negotiating accommodations unfolds, or how employees and stakeholders experience the process of negotiating accommodations. This thesis includes the results of a qualitative study exploring how negotiating accommodations unfolds between employees with mental health conditions and workplace stakeholders, and a sub-analysis of the larger study data exploring how social capital can impact the negotiation process.
In order to capture varied perspectives, in depth interviews were conducted with employees in diverse roles who self-identified as having a mental health condition that required accommodation, and stakeholders who were experienced in negotiating accommodations. A qualitative descriptive design was used to iteratively collect and analyze data. Constructive and interpretive strategies including initial and focused coding, memo writing and clustering were used to identify themes about negotiating accommodations.
The negotiation process, as reported by participants in this study, was found to be a non-linear, social and political process that unfolded as a combination of micro formal and informal sub-processes, in contrast to the concrete, formal accommodation process mandated by some organizational policies. In addition, there were a number of factors that were experienced as either helpful or challenging in the process of negotiating accommodations.
Social capital arose as an important element influencing how employees with mental health conditions accessed accommodations. The findings of a qualitative sub-analysis of the original data set focused on the ways in which workplace social capital impacted the experience of requesting and negotiating accommodations. Some elements of social capital were found to be dynamic, with workers able to accumulate, rebuild and spend social capital in the course of their employment. Employee reputation, employee self-confidence and likeability with coworkers and managerial staff arose as key elements of social capital. Other elements of social capital were external perceptions constructed by coworkers and workplace stakeholders, such as return-on-investment of accommodating and judgements of value to the organization. Overall, workplace social capital appeared to impact how employees experienced the process of requesting and negotiating accommodations, but it was not the determining factor of whether accommodation requests were granted.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: This Master’s thesis focused on the process of discussing and negotiating workplace accommodations between workers with mental health conditions and workplace stakeholders. Six workers with mental health conditions and 6 other workplace stakeholders who had experience negotiating accommodations shared their experiences in interviews.  Study findings highlighted that the negotiation process can be complex and non-linear, and is impacted by social and political factors. Workplace social capital had an impact when workers with mental health conditions requested and negotiated accommodations. For example, employee self-confidence, “likeability” (as perceived by coworkers and management), reputation as a good performer and perceived value to the organization appeared to shape how workers experienced the process of negotiating accommodations. Worker status and position also reportedly had an impact on access to supports. It should be noted, however, that social capital was only one of the factors that workers needed to be successfully accommodated, and their social capital could be at risk of being exhausted due to behavior or performance issues. This thesis expands our understanding of the accommodation negotiation process, and the impact of social and political forces on disability management strategies.