title: On the Topology and Control of Six-Phase Current-Source Inverter (CSI) for the Powertrain of Heavy-Duty EVs

subject:
Current-source inverter
Powertrains for EV
Space vector modulation
Multiphase Drives

abstract:
The electrification of transportation is increasingly of interest to governments around the world as a means of contributing to the achievement of climate change goals. Transportation is a significant source of greenhouse gas emissions, but it is also the backbone of the global economy and local mobility. Electrification is widely seen as a promising pathway to reducing greenhouse gas emissions from transportation while continuing to support economic growth.
Multiphase machines have distinctive features that draw attention in the transportation electrification domain due to their features. Recently, powertrains based on the current-source inverter (CSI) are getting more attention to be a more reliable structure for Electric Vehicles (EVs) by replacing the dc-link capacitor with a choke inductor. This thesis combines these two technologies to develop a more reliable, compact powertrain for heavy-duty electric vehicles.
First, a survey covers the recent advances in several aspects such as topology, control, and performance to evaluate the possibility and the future of exploiting them more in EV applications. The six-phase drives are extensively covered here because of their inherent structure as a dual three-phase system which eases the production process. The survey presents the different topologies used in dual three-phase drives, the modulation techniques used to operate them, the status of using multiphase drives in traction applications industrially, and the upcoming trends toward promoting this technology.
New powertrain configurations for heavy-duty electric vehicles (HDEV) are proposed based on current-source inverters (CSI) and asymmetrical six-phase electric machines. Since the six-phase CSI comprises two three-phase CSIs, multiple configurations can arise based on the connection between the two CSIs. In this context, the proposed powertrain configurations are based on parallel, cascaded, and standalone six-phase CSIs. The standalone topology is based on separating the two three-phase converters by supplying each converter with a dedicated dc-dc converter.
A new and straightforward method is proposed to extend the six-phase standalone CSI. The proposed technique employs the vector space decomposition (VSD) to mitigate the inverter current harmonics and extend the linear modulation region by about 8%. For motor drive applications, increasing the fundamental output component can reflect higher torque production capability for the same drive size, given that thermal limits are not exceeded.
Moreover, to increase the drive's reliability, space vector modulation (SVM) techniques are developed to operate the six-phase CSI while reducing the common-mode voltage (CMV) content associated with the switching of semiconductors. The SVM techniques select the switching states associated with the minimum CMV value offline to eliminate the need for measurements.
Experimental validation of the proposed algorithms is presented to operate a scaled-down six-phase PMSM fed by the proposed powertrain configuration. These proposed techniques make the CSI- based powertrain a promising solution for future HDEVs in terms of cost, performance, and reliability.

abstract: Thesis

abstract: Candidate in Philosophy


title: Psychological and Occupational Outcomes Among Canadian Respiratory Therapists During the COVID-19 Pandemic

contributor:
McKinnon, Margaret
McCabe, Randi
Neuroscience

subject:
respiratry therapists
COVID-19
mental health
healthcare providers
PTSD
turnover intention

abstract: Despite pre-COVID-19 pandemic evidence to suggest that respiratory therapists (RTs) may experience elevated symptoms of anxiety and distress due to the nature of their occupation, the extant literature on healthcare providers (HCPs’) experiences during the pandemic is largely limited to other HCP groups, such as nurses and physicians. Global reports demonstrate widespread adverse psychological impacts to HCPs during the pandemic, including symptoms of depression, anxiety, burnout, moral distress and post- traumatic stress disorder (PTSD). Furthermore, occupational impacts, namely turnover intention, are increasingly reported as the pandemic persists. This Master’s thesis investigated the psychological and occupational impacts associated with COVID-19 pandemic service among Canadian RTs during the Spring of 2021. A review of the relevant literature on HCPs' experiences during the pandemic is presented in Chapter 1, along with a synthesis of knowledge on RTs. An exploration of psychological and functional outcomes among RTs during the COVID-19 pandemic is presented in Chapter 2. Here, almost half of the sample reported clinically relevant symptoms of depression, anxiety and stress, and one in three RTs screened positively for likely PTSD. In Chapter 3, we investigated consideration of position departure, finding that one in four RTs were considering leaving. Despite over half of those considering leaving screening positive for likely PTSD, adverse psychological experiences contributed little to the predictive model of departure consideration compared to past consideration to leave. We posit that longstanding organizational issues may play an important role in RTs’ consideration to leave. Overall, these studies expand the literature investigating the impact of COVID-19 pandemic service among HCPs and advance knowledge on the impacts of pandemic service among RTs who have, up until recently, been neglected. Altogether, the evidence presented in this thesis suggests that RTs require adequate mental health supports and resources alongside their HCP colleagues during and beyond the COVID-19 pandemic.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Healthcare providers (HCPs) have reported psychological distress and thinking about leaving their jobs during the COVID-19 pandemic, but little is known about respiratory therapists’ (RTs’) experiences. This thesis explored how Canadian RTs have been affected during the COVID-19 pandemic. In Study 1, we asked RTs about mental health and functioning and found that RTs had symptoms of depression, anxiety, stress and moral distress, with one third of the RTs likely meeting criteria for Post-Traumatic Stress Disorder. In Study 2, we asked RTs if they were thinking about leaving their jobs and found that one in four were considering leaving. RTs who were considering leaving had greater negative psychological symptoms, but analyses suggested that ongoing issues in healthcare may play a greater role in RTs leaving their jobs. Together, these studies show that RTs had negative psychological impacts and were considering leaving their jobs, just like other HCPs during the pandemic.


title: Fundamental Studies on Microbial Lead Reduction and Polyhydroxyalkanoate Production

title: Lead bio-reduction and Polyhydroxyalkanoate Production

contributor:
Kim, Younggy
Civil Engineering

subject:
Lead Reduction
Polyhydroxyalkanoate Production
Feast-famine enrichment
Cupriavidus necator
PHA-accumulating bacteria
Plasticicumulans acidivorans

abstract: Lead contamination threatens human life and the environment. The biological reduction of Pb(II) to metallic Pb is an attractive solution for Pb(II) pollution. Delftia acidovorans, Azonexus caeni, and Comamonas testosteroni were isolated and studied for their capabilities to utilize Pb(II) as a terminal electron acceptor. D. acidovorans strain Pb11 and A. caeni strain Pb2 cultures showed a 5.2- and 8.1-fold growth at 10.0 mg-Pb(II)/L in 3 d, respectively. Petroleum-based plastics are another emergent environmental concern. Polyhydroxyalkanoates (PHAs), a sustainable alternative to conventional plastics, are biodegradable polymers produced by PHA accumulators under autotrophic or heterotrophic conditions. In this thesis, the growth and enrichment of PHA accumulators, such as Plasticicumulans acidivorans and Cupriavidus necator, were investigated as they can accumulate 90% of their cell weight as PHA. An energetic model was developed to calculate theoretical PHA yields. The true autotrophic and heterotrophic PHB yields were estimated as 2.97 (g_PHB/ 〖mol〗_(H_2 )) and 0.66 (g_PHB/ g_acetate), respectively. Moreover, the growth of C. necator was investigated in lab-scale experiments under various autotrophic, heterotrophic, and mixotrophic conditions. When C. necator was cultivated in two-stage systems, high optical densities were attained in less than 24 h. In addition, a mathematical model for the competition between PHA and non-PHA accumulators in the feast-famine enrichments was developed. The calibrated and validated model for P. acidivorans suggested that microbial diversity in mixed cultures impacted the enrichment process. Another aspect of this thesis was to propose an innovative method for enriching PHA accumulators in mixed cultures. By applying autotrophic and autotrophic-heterotrophic enrichment strategies, C. necator dominated the mixed cultures (> 90%) in less than five days. Based on this thesis findings, it can be concluded that biotechnology applications in Pb(II) remediation and PHA production could reduce the severe impacts of Pb contamination, petrochemical plastics, and climate change due to elevated CO2 levels.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This thesis aimed to provide sustainable biotechnological solutions to three environmental challenges: lead contamination, petroleum-based plastics, and elevated CO2 levels in the atmosphere. Certain metal-reducing bacteria can grow by consuming toxic Pb(II) ions from aqueous environments and thus reduce their toxicity. Furthermore, various microorganisms can store biodegradable polymers, known as polyhydroxyalkanoates (PHAs), in their cells. The stored PHA polymers can be extracted and processed to produce biodegradable plastics. PHA accumulators can produce significant amounts of PHA by utilizing organic substrates or CO2. Therefore, PHA-based plastics can reduce environmental deterioration due to non-degradable plastics and elevated CO2 levels. Lab-scale experiments and mathematical modeling can provide a better understanding of the growth and enrichment of PHA accumulators in engineered PHA-production systems. Research findings in this thesis will allow cost-effective and sustainable production of biodegradable plastics from organic wastes and flue gas.


title: A Foundation for Learning: Parent's Perceptions of the McMaster Children and Youth University (MCYU)

title: Addressing the Factors That Shape Parent Involvement in the McMaster Children and Youth University (MCYU)

contributor:
Maclachlan, John
Geography

subject: Education

subject: Parent Involvement

subject: Grounded Theory

subject: Socio-Ecological Model

subject: Cultural Capital

subject: Intrinsic Values

subject: Extrinsic Values

abstract: The McMaster Children and Youth University (MCYU) was founded at McMaster University in Hamilton Ontario, Canada. The MCYU delivers free educational programming to children and youth to empower and prepare youth, especially those at a socioeconomic disadvantage, to aspire to higher education (MCYU, 2022). Parents are invited to attend the lectures alongside their children, making parent involvement a key component of the program (MCYU, 2018; Paquin et al, 2018). Participation in educational activities, such as out-of-school programming, school-run field trips, or extracurriculars have been correlated with improved academic achievement and social adjustment (Holloway & Pimlott-Wilson, 2014; Weininger et al., 2015). However, children and youth from disadvantaged backgrounds are less likely to participate in learning enrichment activities outside of school (Siddiqui et al., 2019). These barriers to participation have often been attributed to lower economic status (Chanfreau, et al., 2016; Farthing, 2014; Holloway & Pimlott-Wilson, 2014; Siddiqui et al., 2019). A grounded theory study was employed addressing the following question: How do socio-ecological factors shape parental decision-making for childhood involvement in the MCYU? Twenty parents who participate in the MCYU were interviewed and asked to complete an accompanying survey. After thorough data collection and analysis, the results indicated that positive educational experiences in the lives of parents shape their approach to their children’s education. Their life experiences have led to an intrinsic and extrinsic desire to learn, and the MCYU is an invaluable tool for parents to instill these values in their children through 1) education, 2) exposure, 3) enjoyment, and 4) engagement. This research may inform an expansion of MCYU type programs across Canada as well as aid the MCYU in reaching members of the community who are unable to benefit from the program. While the MCYU is for kids, the appeal for parents should be emphasized in future iterations.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: The McMaster Children and Youth University (MCYU) was founded at McMaster University in Hamilton Ontario, Canada. The MCYU delivers free educational programming to children and youth to empower and prepare youth, especially those at a socioeconomic disadvantage, to aspire to higher education (MCYU, 2022). Parents are invited to attend the lectures alongside their children, making parent involvement a key component of the program (MCYU, 2018; Paquin et al, 2018). This research addresses the following question: How do socio-ecological factors shape parental decision-making for childhood involvement in the MCYU? The results indicated that positive educational experiences in the lives of parents shape their approach to their children’s education. Their life experiences have led to an intrinsic and extrinsic desire to learn, and the MCYU is an invaluable tool for parents to instill these values in their children through 1) education, 2) exposure, 3) enjoyment, and 4) engagement.


title: EMERGENCY MANAGEMENT OF CRITICAL BLEEDS IN PATIENTS WITH IMMUNE THROMBOCYTOPENIA: DEVELOPING A NOVEL METHODOLOGY FOR RARE DISEASES GUIDELINES

contributor:
Arnold, Donald
Health Research Methodology

subject: GRADE, hematology, guidelines, rare disease, immune thrombocytopenia

abstract:
The day that I joined McMaster University and the Department of Health Research Methods, Evidence, and Impact as a Master student, I did not foresee the amazing journey I was embarking on or the impact of my academic achievements. I was continuously challenged to think critically and apply my ideas to real world problems. Seeing the opportunity to make a difference in clinical research and patient care inspired me to begin my PhD studies. Creating knowledge and applying it practically was a difficult task, however, the opportunities to share my research in a dynamic and complex field with the world fuelled my motivation. Completing a PhD has been an incredible privilege for which I will always be grateful.
To my family – Mamma, Papa, Mark and Matthew – thank you for your undying and unconditional love, support, and encouragement. A pandemic forced us to come together, and having your support 24/7 (literally) made the journey more enjoyable.
To my closest friends, thank you for being a part of my life and supporting my ambitions. We all recognized my ambitiousness would set me on a difficult path and completing a PhD was not my original plan. Thank you for inspiring me to take on the challenge and ensure my work was truly impactful. Thank you for encouraging mental strength, being understanding and willing to lend a hand, reminding me that I can achieve anything I set my mind to, and inspiring me to dare.
To my supervisory committee members and independent study supervisor, thank you for your continued interest in my work and for always supporting my ambitions. I am grateful for your patience and belief that I would succeed in completing what I had sought to achieve. Thank you for the chance to work together, and for your constant support and mentorship throughout my PhD journey.
To the faculty, staff and fellow students at the Department of Health Research Methods, Evidence, and Impact, and the McMaster Centre for Transfusion Research, thank you for providing the resources, friendship, and guidance I needed to achieve greatness.
To the panel members of the ITP Emergency Management Guideline, thank you for believing in this project and making this work possible. I look forward to implementing the results of our efforts into clinical practice.
To the ITP patient community, thank you for entrusting me with the task of improving patient care and supporting me along the way. You have enabled me to be a voice for change. To the rare disease community, I know the completion of my PhD journey will not be the end of our work together.
To the funding agencies who allowed this project to be possible, the Canadian Institutes of Health Research and Platelet Disorder Support Association, thank you for supporting my PhD journey and the completion of this important work.
To my doctoral supervisor, Dr. Donald Arnold, it has been an honour and privilege to have learned from you and received your guidance throughout my PhD journey. Since our initial meeting, when I hobbled into the McMaster Centre for Transfusion Research offices several minutes late, I felt that your kindness and honesty would be the perfect form of mentorship to push me towards success. Thank you for recognizing my ambition and reminding me to keep focused. I will continue to apply this lesson throughout my life and strive for ‘depth’. For many years, you have been my mentor who I reached out to for advice, support, honest feedback, and encouragement. Thank you for imparting your knowledge to me over my PhD journey and teaching me how to be an inspirational mentor who highlights the strengths of their students while simultaneously supporting their growth. Although I may have finally reached the destination in my PhD journey, I know that we will continue to collaborate for many years to come.

abstract:
Developing clinical practice guidelines (CPGs) for rare diseases is methodologically challenging. As each disease has so few patients, published literature includes low-quality studies or studies that do not directly address the questions of interest. As a result, CPG panelists have limited evidence on which to base their recommendations. Historically, when no evidence was available, CPGs have relied on physician opinion. This does not align with the mandate of CPGs which transparently identifies, appraises, and relies on evidence.
The challenges of developing CPGs for rare diseases are exemplified by immune thrombocytopenia (ITP), a rare autoimmune disease that affects approximately 1 in 8,000 people. It predominantly affects females and young adults, and is characterized by low blood platelets that increase the risk of bleeding. Bleeding emergencies in ITP patients are critical, life-threatening events that can cause life-long morbidity and associated health care costs. Treatment of ITP bleeding emergencies requires a rapid, coordinated approach that involves emergency department staff, hematologists, pharmacy, and the laboratory. However, there is no evidence-based CPG for the management of ITP bleeding emergencies.
The objectives of my PhD thesis are (1) exploring the heterogeneity of ITP diagnosis using antiplatelet autoantibodies; (2) developing a standardized definition of ITP bleeding emergencies; (3) outlining the synthesis of existing evidence on the treatment of ITP bleeding emergencies through a systematic review; and (4) developing a novel methodology to address the lack of evidence in rare disease CPGs and applying it to develop a CPG for the management of ITP bleeding emergencies.

abstract: Thesis

abstract: Candidate in Philosophy

abstract:
Guidelines for rare diseases can be hard to develop because of a lack of information. Doctors and researchers make decisions on rare disease management based on their experiences, which can be limited. Low blood platelets and emergency bleeding can be caused by a rare disease called immune thrombocytopenia (ITP). When emergency bleeds occur, patients need care from the Emergency Department immediately. The problem is that there is no standard way for doctors to treat these ITP bleeding emergencies.
My PhD thesis project will fill an important gap for ITP emergency treatment. First, we will assess how ITP patients are diagnosed. Second, we will define an ITP bleeding emergency. Third, we will collect existing information about ITP bleeds. Fourth, we will overcome the challenge of not having enough information by collecting new data from patient records. The method we use to develop ITP guidelines can be used for other rare diseases.


title: Molecular Mechanisms Underlying SSRI-induced Non-alcoholic Fatty Liver Disease

contributor:
Holloway, Alison
Medical Sciences

subject: Selective Serotonin Reuptake Inhibitor

subject: SSRI

subject: Fluoxetine

subject: NAFLD

subject: Non-Alcoholic Fatty Liver Disease

subject: Steatosis

subject: de novo Lipogenesis

subject: Serotonin

subject: Metabolic Disorder

subject: Prostaglandin

subject: mir-122

subject: microRNA

subject: peroxisome proliferator-activated receptor gamma

subject: PPARG

subject: 15-deoxy-Δ12,14PGJ2

subject: 15d-PGJ2

subject: Ptgs1

subject: Ptgs2

subject: Liver

subject: MAFLD

abstract: This thesis aims to investigate fluoxetine, a widely prescribed SSRI antidepressant, for its role in the pathogenesis of NAFLD and uncover novel mechanisms by which it may contribute to drug-induced steatosis. We demonstrated that increased hepatic lipid accumulation was mediated, in part, via elevated serotonin production. The inhibition of hepatic serotonin synthesis prevented lipid accumulation in fluoxetine-treated hepatocytes demonstrating a causal role for serotonin in fluoxetine-induced hepatic steatosis. Interestingly, in several studies, serotonin signaling has been shown to impact prostaglandin biosynthesis. As prostaglandins have been implicated in the development of NAFLD, and fluoxetine has previously been shown to alter the production of prostaglandins I assessed the role of prostaglandins in fluoxetine-induced hepatic lipid accumulation. Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes, increased production of prostaglandin 15-deoxy-Δ12,14PGJ2 (PPARG agonist), and elevated PPARG targets involved in fatty acid uptake. Fluoxetine-induced lipid accumulation, 15-deoxy-Δ12,14PGJ2 production, and the expression of PPARG lipogenic genes were attenuated with a PTGS1 specific inhibitor. Taken together these findings suggested that fluoxetine-induced lipid accumulation was mediated via PTGS1 and its downstream product 15-deoxy-Δ12,14PGJ2. Given that Pparg was elevated following fluoxetine treatment, and PPARG regulates microRNA involved in hepatic lipid accumulation, my final project focused on PPARG’s role in altered miRNA expression. Indeed, fluoxetine treatment increased the miRNA expression of miR-122, an effect that was attenuated when fluoxetine treatment was combined with the PPARG antagonist GW9662, suggesting a fluoxetine-PPARG-miR122 axis contributing to hepatic steatosis. While these studies have only been performed in vitro, an understanding of the molecular changes associated with SSRI treatment may lead to the development of strategies to prevent the increased risk of adverse metabolic outcomes associated with the use of SSRI antidepressants.

abstract: Dissertation

abstract: Doctor of Philosophy (Medical Science)

abstract: In adults, major depressive disorder (depression) is one of the most common psychiatric illnesses. Recent data suggests that there are more than 4.1 million Canadians who currently suffer from depression. Depression is commonly treated using selective serotonin reuptake inhibitor (SSRI) antidepressants. While these antidepressants do help manage depressive symptoms, they can also cause unwanted side effects including a build-up of fat in the liver, leading to fatty liver disease. The goal of my research is to understand the link between SSRI use and the development of fatty liver disease. This thesis investigates the effects of fluoxetine (Prozac®), a commonly used SSRI antidepressant, on molecular pathways that can lead to the development of fatty liver disease. An understanding of the molecular changes with SSRI treatment may lead to the development of strategies to prevent the harmful effects of SSRI antidepressants on the liver.


title: Tracking real-world changes in osteoarthritic gait patterns using wearable sensors

contributor:
Kobsar, Dylan
Kinesiology

subject:
wearable sensors
osteoarthritis
gait
biomechanics

abstract: Intra-articular corticosteroid knee injections (ICIs) were used as a tool to determine the sensitivity of wearable inertial sensors and machine learning algorithms in identifying meaningful changes in gait patterns amidst day-to-day fluctuations in out-of-laboratory gait. Specifically, three overarching aims were proposed; I) Determine if three gait trials could define an everyday typical gait pattern, II) investigate if post-injection atypical strides are significantly different from pre-injection atypical strides and III) explore the relationship between changes in pain and atypical strides. Nine knee OA patients (7M/2F) were recruited from St. Joseph’s Healthcare Hamilton. Participants completed a total of four walking trials prior to the ICI and three following. Participants were fitted with two wearable sensors on each shank just below the knee, and one sensor on the lower back during every trial. Data from these sensors were processed to train and test a one-class support vector machine (OCSVM). Individual gait models were created based on three out of the four pre-injection trials. Each trained model was tested on a withheld pre-injection trial and three post-injection trials to determine the number of typical and atypical gait cycles. Self-reported pain was analyzed throughout the study and compared to the percent of atypical strides seen during each walk. It was found that three gait trials could not define a typical gait model and that post-injection atypical strides were not significantly different from with-held pre-injection atypical strides. Finally, large variations and fluctuations in self-reported pain were observed on a week-to-week basis, which were not significantly correlated to atypical strides observed. This study was the first to investigate the sensitivity of wearable inertial sensors and machine learning algorithms to detect changes in real-world gait patterns and provides foundational work for using wearable sensors to monitor and triage knee OA patients.

abstract: Thesis

abstract: Master of Science (MSc)


title: Deposition of Gallium Phosphide on Silicon by Metalorganic Chemical Vapor Deposition

contributor:
Lewis, Ryan
Engineering Physics

abstract:
This thesis explores the deposition of GaP on GaP (100)-4° and (111)A, and Si
(100), (100)-4° and (111) surfaces using metalorganic chemical vapour deposition
(MOCVD) for epitaxial growth. The effects of Sb as a surfactant is also investigated.
GaP/Si/GaP heterostructures are an ideal candidate for efficient difference
frequency generation into the mid-infrared spectrum through engineered quasiphase
matched (QPM) templates. The difference in polarity at the GaP/Si interface
makes defect-free GaP/Si growth challenging to accomplish, but the minimal
lattice mismatch and infrared transparency makes it a promising economical approach
to achieve high-speed satellite communication. Developing orientation patterned
(OP) templates requires controlling whether primarily Ga-Si or P-Si bonds
form at the interface, as these bonds are what dictate the domains orientation.
The choice of pre-treatment conditions, growth conditions, and precursor species
can affect the interface bonding and twin formation, both crucial factors in developing
OP-QPM templates. This work extends previous studies by exploring new
experimental conditions and the resulting film morphology. Conditions for smooth
GaP surfaces using TMGa and PH3 are found. Heteroepitaxy of GaP on (100)
and (100)-4° Si both yielded nano-sized crystallites with a 550 °C pre-treatment
and growth, but nanowires under 750 °C pre-treatment. Both yield larger dot-like
crystallites under the 750 °C pre-treatment and growth. The GaP/Si(111) surface
yields similarly-sized crystallites under the 550 °C pre-treatment and growth
conditions, but with significant densities of spiraling nanowires. Under the 750 °C
pre-treatment and 550 °C growth, micron-sized crystallites with few nanowires,
and larger chain-like clusters form. Sb was found to play a significant role in the low-temperature nucleation on Si (100) and suppression of nanowires on Si (111).
These results contribute to the understanding of GaP epitaxial growth by MOCVD
and Sb as a surfactant for GaP/Si heterostructures.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Linguistic Complexity and Creativity across the COVID-19 Pandemic: A Corpus Analysis

type: Thesis Video

contributor:
Kuperman, Victor
Cognitive Science of Language

subject:
aging
creativity
COVID-19
lexical diversity
syntactic complexity
corpus linguistics

abstract: The current study investigated the language behaviour of older adults before and during the COVID-19 pandemic. Linguistic complexity (LC)—a measure of lexical and morpho-syntactic richness—is an index of both cognitive functioning and creativity. The increased physical and social isolation during the pandemic yielded reports of heightened levels of creativity as well as cognitive decline, bringing forth two counter-directed predictions: (1) given the threat to cognitive functioning posed by the pandemic, LC may steadily decrease following the onset of the pandemic, or; (2) consistent with the creativity boost reported during lockdowns, LC may be greater after the onset of the pandemic. This work analyzed the syntactic and lexical complexity of texts from the CoSoWELL corpus (v1.0), a collection of personal narratives written by 1028 mature adults (55+) collected at five test sessions spanning before (t1) and after (t2-t5) the beginning of the pandemic. Two lexical variables (type-token ratio; noun-verb ratio) and six syntactic variables (two syntactic variants of type-token ratio; embeddedness; D-ratio; longest dependency path; mean length utterance) were used to calculate LC. All measures saw statistically significant gains from t1 to t2, and further increased across subsequent test sessions. These findings confirmed the second hypothesis and, I argue, support a pandemic-related boost to creativity.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The COVID-19 pandemic has been isolating, and isolation is a mixed bag: being alone promotes self-reflection and overthinking, and doing too much is linked to stress and mental illness. However, more time spent in solitude is also linked to greater creativity. Creativity means more new ideas, which come through as longer, more detailed sentences, with less repetition. This research looked at stories by older adults about their lives, written before and during the pandemic. Surprisingly, the language in the stories became more descriptive and diverse over time—meaning people were being more creative after COVID-19 hit. In the wake of this lonely storm, one silver lining has emerged: whether in spite of or because of this pandemic, creativity is flourishing.


title: Evaluating the Effects of Covalency on Anti-Tumour Immune Function Using Syngeneic Tumour Models

contributor:
Rullo, Anthony
Medical Sciences

subject:
Immunology
Chemical biology

abstract:
Synthetic immunology aims to utilize synthetic chemistry and molecules to modulate natural immunological functions against cancer cells. Synthetic molecules developed for use in immunotherapy are antibody recruiting molecules (ARMs) that can utilize antibodies in human serum as a weapon against cancer cells. The development of ARMs has inspired the creation of a novel class of synthetic immunotherapeutics - covalent antibody recruiting molecules (cARMs). cARMs not only bind but covalently label specific antibodies to recruit them to the tumour cell surface. First generation cARM molecules consist of a human prostate specific membrane antigen (hPSMA) target binding domain, an antibody labeling acyl imidazole ester domain, and an anti-dinitrophenyl (DNP) antibody binding domain. The ALD domain instigates an irreversible covalent bond to label anti-DNP antibodies which enables the generation of a tumour therapeutic antibody directly in vivo which can enact immune cell function against tumour cells. cARMs have been proven to recruit anti-DNP antibodies to hPSMA expressing cells and mediate selective antibody-dependent cellular phagocytosis/cytotoxicity (ADCP/ADCC) against cancer cells in in vitro assays.
Following the development of a mouse model, initial in vivo studies demonstrated significantly improved survival in tumour bearing mice that were treated with ARM and cARM.  In vivo labeling studies displayed successful labeling of anti-DNP antibodies in circulation by cARMs and the presence of labeled antibodies for at least 72hrs in circulation. Conversely, ARM mediated antibody binding was considerably less at all examined time points. Resolving autoinhibition limitations of cARMs allowed for enhanced and improved labeling of anti-DNP antibodies both in vitro and in vivo. This enhancement in labeling could allow for improved ternary and immune active quaternary complex formation to mediate tumour cell death. In vivo tumour studies demonstrated increased survival in tumour bearing mice treated with non-autoinhibited cARM when compared to ARM. Furthermore, innate immune cell populations were shown to increase in peripheral blood of tumour bearing mice treated with ARM and cARM. While cARM treatment dosing and concentration are yet to be optimized, this thesis demonstrates the potential of cARMs as an immunotherapeutic. cARMs can be synthesized to target a variety of cancer cell specific antigens, selectively label antibodies, and has the potential to recruit multi-specific therapeutic antibodies against heterogeneous tumours.

abstract: Thesis

abstract: Master of Science (MSc)


title: PHOSPHOINOSITIDE-3 KINASE IN SEVERE ASTHMA

contributor:
Nair, Parameswaran
Health Sciences

subject:
Asthma
Phosphoinositide 3-kinase
Steroid insensitivity
Mixed-granulocytic asthma
Airway infections

abstract:
Introduction: A subgroup of severe asthmatics (SA) remain uncontrolled with persistent airway eosinophilia despite high dose glucocorticosteroids (GCS) termed “steroid insensitivity.” A significant proportion of this subgroup get recurrent airway infections. Phosphoinositide-3 kinase (PI3K) pathway may contribute to both GCS insensitivity and further susceptibility to recurrent infections.
Objectives: The effect of GCS and PI3K antagonism was evaluated on GCS induced eosinophil apoptosis as a mechanism of GCS insensitivity in healthy, mild to moderate and severe asthmatics. Furthermore, we investigated the relationship between PI3K activation, histone deacetylase (HDAC) and macrophage receptor with collagenous structure (MARCO) expression in SA±recurrent bacterial bronchitis.
Methods: Blood eosinophils, isolated from healthy subjects (HS) and asthmatics, were incubated with increasing concentrations of dexamethasone (0.1, 1 and 10 uM) and a pan-PI3K antagonist (LY294002 at 1 and 2 uM). Cell viability was assessed using PrestoBlue cell viability assay, Trypan Blue exclusion test and PE-Annexin-V/7-AAD apoptosis detection (flow cytometry). Furthermore, PI3K activity, MARCO and HDAC levels were measured in macrophages isolated from healthy subjects and SA (±history of recurrent bacterial bronchitis). In a subgroup, sputa were examined for in situ PI3K activity and gene expression of PI3K isoforms by digital PCR.
Results: In HS, a time-dependent increase in eosinophil apoptotic% was observed (1.9% at baseline, 25.7% at 16h and 31% at 24h) (p=0.06, p=0.005 respectively). Dexamethasone 10uM increased it to 40.1% at 16h (p=0.03). Dexamethasone induced eosinophil apoptosis was less in severe asthmatics (34.2%) vs. to mild-to-moderate asthmatics (46.7%) (p=0.05) suggesting steroid insensitivity. This was not reversed by co-incubation with LY294002 2uM (39.9% vs. 53.3%) (p=0.04) (Fig. 1B). Asthmatics with recurrent lung infections had higher blood PI3K activity (demonstrated as inverse of biotinylated-PIP3, p=0.02), MARCO expression (p=0.01), and trend for lower HDAC expression (p=0.067) vs. healthy donors. PI3KCD (encoding catalytic 𝛿 isoform) gene expression relative to HPRT1 (housekeeping gene) was increased in SA-infection group (p=0.03). A higher number of asthmatics with recurrent lung infections were on oral corticosteroids (p=0.015) and replacement immunoglobulins (p=0.016).
Conclusions: Evaluating dexamethasone-induced apoptosis in blood eosinophil can assess GCS sensitivity ex vivo. Severe asthmatics demonstrate GCS insensitivity, which was not reversed by a pan-PI3K antagonist. PI3K activity is increased in SA with a previous history of recurrent lung infections, which is associated with a decrease in HDAC and MARCO expression.  Targeting PI3K pathway, specifically the 𝛿 isoform, may be a potential therapeutic target in SA with mixed-granulocytic bronchitis.

abstract: Thesis

abstract: Master of Science in Medical Sciences (MSMS)

abstract: Eosinophils are a type of blood cell that is responsible for causing asthma symptoms and flare-ups. Steroids (in both inhaled and oral forms) decrease eosinophils and so are the main treatment for asthma. But a group of asthmatics continues to have symptoms and eosinophils in their lung secretions even with maximum dose of steroids. Some of these asthmatics also get repeated bacterial lung infections. In blood samples, we studied one of the proteins (phosphoinositide-3 kinase, PI3K), which may be responsible for poor response to steroids and repeated infections. We looked at the effect of steroids on eosinophils extracted from blood samples of healthy people, asthmatics with mild disease and asthmatics with severe disease. We also measured PI3K levels and related proteins in blood and sputum samples from healthy people, asthmatics who get repeated bacterial lung infections (more than two in the previous two years) and asthmatics without recurrent lung infections. We found that eosinophils obtained from asthmatics with severe disease were harder to kill with steroids. But, this was not reversed with a PI3K blocking agent. We also found that asthmatics with a previous history of repeated bacterial lung infections had a higher PI3K level. High PI3K activity was associated with a decrease in two other proteins – histone deacetylase (HDAC) and macrophage receptor with collagenous structure (MARCO). Decrease in HDAC can result in a lower response to steroids, which may result in an increase in eosinophils in the lungs. Lower levels of MARCO can cause a patient to have higher sensitivity to recurrent bacterial infections. Overall, this may lead to a dangerous cycle where repeated lung infection will lead to high PI3K activity, which will cause worse asthma control and more infections. More studies are needed to evaluate drugs that block PI3K, which may be helpful in asthmatics who are less responsive to steroids and also get repeated infections.


title: Globular Cluster System Properties by Host Galaxy Environment

contributor:
Harris, Bill
Physics and Astronomy

subject:
Elliptical galaxies
Galaxy halos
Galaxy formation
Globular star clusters

abstract: I present Hubble Space Telescope photometry in optical (F475X, 475 nm) and near-infrared (F110W, 1.1 μm) bands of the globular cluster (GC) system of the inner haloes of a sample of 15 brightest cluster galaxies (BCGs).  I also present a quantitative model of the relation between (F475X - F110W) colour and cluster metallicity, using simulated GCs.  The sample comprises massive elliptical galaxies in a range of environments, from sparsely populated groups to dense clusters.  Because the material available for large galaxies to accrete varies with environment and GC systems of such galaxies are built up through accretion, I expect the metallicity distribution of the GC systems in my sample to vary with galaxy environment.  GC systems in massive elliptical galaxies tend to follow a bimodal colour distribution, with two subpopulations of blue (metal-poor) and red (metal-rich) clusters.  The photometry is used to create a completeness-corrected metallicity histogram for each galaxy in my sample, and to fit a double Gaussian curve to each histogram in order to model the two subpopulations.  Finally, the properties of the GC metallicity distribution are correlated against each BCG environment.  I found that almost no GCS properties and host galaxy environmental properties are correlated, with the exception of weak but consistent correlations between number of GCs and nth-nearest neighbour surface density and between blue fraction and nth-nearest neighbour surface density.

abstract: Thesis

abstract: Master of Science (MSc)


title: Design of a Switched Reluctance Motor for a Light Sport Aircraft Application

contributor:
Bilgin, Berker
Electrical and Computer Engineering

subject:
Direct drive motor
Electric aircraft propulsion
Finite element analysis
Genetic algorithm
Switched reluctance motor
Light sport aircraft
High power density motor design
Green aviation
Control integration
High torque density
Aerospace motor
All electric aircraft
Permanent magnet free electrical motor
Switched reluctance machine

abstract: With the rapid growth of air travel, concerns about the emissions of greenhouse gas emissions resulting from the air transportation sector are growing. Although the current battery technologies might not be adequate for all-electric regional aircraft, the energy density of the current battery technologies could be adequate to electrify light-sport aircraft used for training and recreation. Due to the nature of the propeller load and noise isolation of the cabin, switched reluctance motors can be an excellent candidate for the propulsion system of electrified light-sport aircraft. The proposed SRM is designed to replace a 70 kW permanent magnet synchronous motor used in the aerospace industry with similar volume constraints and operational requirements. In order to meet the high-power density requirements of this application, a design framework is proposed which includes several layers of the design process. The design objectifies are the average torque, torque ripple, and radial forces by integrating the control and geometry design into the proposed framework. A comprehensive design process is carried out with the proposed framework, and a detailed coil design process is performed. The rotor cut-outs are designed to reduce the weight of the motor. The thermal performance of the motor has been analyzed for the calculated motor losses and the cooling system constraints.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Slaves, Saviours, and Sewing Machines: An Ethnography of Cambodia's Commercial Sex Immediascape

contributor:
Biruk, Cal
Anthropology

subject:
aid
anti-trafficking
sex trafficking
sex workers
Cambodia

abstract: Cambodia’s commercial sex industry has long been the subject of transnational concern, yet this enduring problematization has yielded little in the way of lasting ‘solutions.’ Central to constructions of Cambodia’s sex trafficking problem are stories – narrative and numerical – that are not entertainment or fact, respectively, but political and ideological discourses that structure social problems and their solutions while masquerading as unmediated. In this media ethnography, I thematically analyzed aid documentaries, websites, reports, and tax returns to explore how sex trafficking in Cambodia is constructed in aid discourses as a problem to be solved. I argue that anti-trafficking rhetoric, narrated over iconographies of Cambodia’s savagery, entangles notions of material and moral poverty. Documentaries construct Cambodian families as both broke and broken, and thus as giving rise to Cambodian sex trafficking’s central, archetypal dyad: the bad mother and the innocent daughter. I further articulate how the trope of the innocent daughter is contingent on her framing as a ‘sex slave.’ These reductive discursive constructions enable similarly oversimplified solutions. The solution to ‘bad mothers’ is ‘better parents,’ enacted through maternalistic and paternalistic interventions; the solution to ‘sex slavery’ is ‘freedom at all costs,’ articulated through raid and rescue interventions. I suggest that articulations of the civilizing mission run through anti-trafficking discourses and interventions, evidenced by their attempts to use numbers to render the complexities of sex trafficking knowable and therefore manageable, but also in their commitment to ‘developing' the Cambodian sex slave through rehabilitation programs that replace sex trafficking with more civilized, though still exploitative, forms of gendered labour. The ways in which sex trafficking in Cambodia is constructed in aid discourses as a problem to be solved therefore ensures the ongoing presence of the anti-trafficking apparatus in Cambodia and the ongoing exploitation and abuse of the Cambodian girls subjected to aid interventions.

abstract: Thesis

abstract: Master of Arts (MA)


title: Determining the Control Objectives of a Switched Reluctance Machine for Performance Improvement in Generating Mode

subject:
Switched Reluctance Machine
Generating Mode
Performance Improvement
Experimental Setup

abstract:
Switched reluctance machines are becoming more prevalent in various motor drive applications due to their simple construction, robust design, fault tolerant operation, and relatively low-cost construction. There are nonetheless some drawbacks to the switched reluctance machines operational behavior which limit its potential market penetration. The electromagnetic torque ripple is one of those limitations. However, unlike most four-quadrant variable speed electric motors, switched reluctance machines need additional control considerations to operate in generating mode to maximize power returned while minimizing torque ripple.
The goal of this thesis is to explore different control schemes which are used in motoring mode and compare their performance in generating mode for different operational points. Using the lessons learned from the comparisons in generating mode, key optimizations objectives are established to improve the switched reluctance machines performance for generating applications. A multi-objective optimizer is used to select conduction angles using established objectives of maximizing torque and minimizing torque ripple. The proposed generating-specific objectives are compared to the motoring-specific objectives to validate the generating performance improvement for a wide torque-speed range.
Finally, a setup is constructed to validate the generating performance of a 3-phase 12/8 SRM using the new optimization objectives and it is compared with conventional objectives.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Innate Immune Memory and Pulmonary Exposure to Lipopolysaccharides

title: Examination of Phenotypic and Functional Changes in Innate Immune Memory Following Local Mucosal Exposure to Lipopolysaccharide

contributor:
Xing, Zhou
Medicine

subject:
Trained Innate Immunity
Local Mucosal Exposure
Lipopolysaccharides
Innate Immune Memory

abstract: Innate immune memory has become an increasingly popular area of research in the last decade. However, much of the work done on innate immune memory using inflammatory agents such as BCG, C. albicans, and β-glucan has been pursued through systemic administration, which has been shown to induce training in circulating monocytes. In addition, little is known about whether microbial ligands can induce training. Here, we show that local mucosal exposure to an acute dose of LPS induces long-lasting phenotypic changes in airway macrophage populations. LPS-exposed macrophages display increased glycolytic metabolism and differential cytokine expression upon restimulation, whereas circulating monocytes are not affected. Finally, we show that LPS exposure provides long-lasting protection against Streptococcus pneumoniae in the lung, likely due to the higher acquisition of CD11b, which is indicative of macrophage activation and phagocytosis. As much of the work on innate immune memory has been done through systemic administration of training agents, this project aims to fill existing knowledge gaps in the induction of innate immune memory upon local mucosal exposure to inflammatory agents.

abstract: Thesis

abstract: The innate immune system is one of the first defenders in our bodies that fight against a variety of pathogens. In the last decade, the innate immune system was found to be capable of having memory, meaning it reacts faster or at a heightened magnitude in response to a wide range of subsequent pathogens after it is trained by an agent. This project explores the effect a bacteria wall component, LPS, has on the lung environment and examines if it will induce memory in the lung. Our findings show that intranasal exposure to LPS changes the cellular landscape in the lung. LPS-exposed airway innate immune cells become more activated and provide subsequent protection against bacterial infections. This work has implications for using LPS as a vaccine adjuvant in order to provide protection against a variety of pathogens in addition to specific protection brought by the vaccine.


title: ANDROGYNOUS AND GENDERED FACE PERCEPTION

contributor:
Sekuler, Allison
Bennett, Patrick

subject: face perception

abstract:
Studies in face perception often use androgynous faces as a tool. The common assumption
about androgynous faces is that they lie at the halfway point of a continuum that
features "male" and "female" at the extremes. However, this definition has not been verified
by research. This thesis uses a variety of methods, with an emphasis on data-driven
methods, to test common assumptions about androgynous faces. Chapter 2 compared
morphed faces, which were created using the common definition of facial androgyny,
to naturally androgynous faces. Although the two groups were rated as equally androgynous,
the naturally androgynous faces were rated as significantly more feminine.
Chapter 3 focused on understanding androgynous face perception while minimizing prior
assumptions. In a series of experiments, participants handled androgyny-related tasks
and stimuli in a way that was qualitatively and quantitatively different than their gendered
counterparts. Overall, these results suggest androgyny as a category cannot be
accurately summarized as halfway between male and female and that a more nuanced
approach to studying face gender is needed.

abstract: Thesis

abstract: Master of Science (MSc)


title: Examination of induction of innate immune memory of alveolar macrophages and trained innate immunity following respiratory exposure to infectious agents

subject:
Trained innate immunity
alveolar macrophages
innate immune memory
β-glucan
respiratory mucosal
heterologous infection

abstract: In the last decade, the potential of β-glucan, a fungal cell wall component, to induce epigenetic and functional modification of innate immune cells, signified as trained innate immunity (TII) has been demonstrated in several pre-clinical and clinical studies. Parenteral administration of β-glucan has resulted in centrally induced TII in the bone marrow/circulating monocytes. Such trained innate immune cells play a critical role in protection against secondary infections. However, there are now indications that inducing local long-lasting immunity at mucosal barrier tissues such as the lung is warranted for protective immunity against respiratory pathogens. Currently, it remains unclear whether respiratory mucosal administration of β-glucan will induce long-lasting resident-memory macrophages and TII and if so, what are the underlying mechanisms of development and maintenance of memory macrophages at respiratory mucosa. To address this, and kinetics of immune responses in the lung were studied. Profound changes in airway macrophage (AM) pools were observed starting from 3 days post-exposure, which was associated with monocyte recruitment, and this was followed by a series of phenotypic shifts in AMs. The altered AM phenotype profile persisted for up to 8 weeks post-exposure. Importantly, β-glucan-trained AMs demonstrated heightened MHC II expression, enhanced responses to secondary stimulation and improved capacity to perform bacterial phagocytosis. Furthermore, mice with, β-glucan-trained AMs displayed higher rates of survival and improved bacterial control, in the lung and periphery, following a lethal S. pneumoniae infection. Our findings together indicate that a single intranasal delivery of β-glucan is able to train AMs. Further work into epigenetics, metabolism, and the contribution of AMs in protection is needed.

abstract: Thesis

abstract: Master of Health Sciences (MSc)

abstract: The immune system has been classically divided into two major compartments known as the innate and adaptive immune system. For decades, the predominant consensus amongst the field was that only the adaptive immune system can form memory against any pathogens encountered. It has been well established that plants and invertebrates only possess an innate immune system and still show boosted responses and enhanced protection against previously encountered as well as new pathogens. Recently, such capacity for innate immune memory has also been demonstrated in humans and pre-clinical animal models. Innate immune memory provides non-specific, broad- spectrum protection whereas adaptive memory is specific to a singular pathogen. Inducing broad-spectrum protection can be crucial for the future of human medicine. Activation of both adaptive and innate immune arms could prove to be extremely beneficial in vaccination strategies. Through the use of a pre-clinical model, we have found that administering β-glucan, a component of fungal cell wall, directly into the lung significantly alters the phenotype and functionality of lung immune cells, and also provides enhanced protection against a heterologous infection.


title: OPTIMAL SPEED PLANNING TO MINIMIZE ENERGY USE OF AUTONOMOUS BATTERY ELECTRIC AND FUEL CELL HYBRID ELECTRIC VEHICLES

contributor:
Bauman, Jennifer
Electrical and Computer Engineering

subject:
Optimization
Electric vehicles
speed profile
EMS

abstract:
Electric vehicles with autonomous driving are the future of transportation, as they
are sustainable, efficient, environmentally friendly, and can provide collision-free
congestion-free driving. However, the sensing and control technology adds new accessory
loads which increase the vehicle energy use. Thus, it is critical to minimize energy use
where possible, and optimal speed planning is a promising way to achieve this goal and is
thus the topic of study for this thesis.
First, a low-computation framework for the onboard calculation of energy-optimal
cruising speed of battery electric vehicles is proposed. The framework is used to investigate
the critical parameters for energy-optimal cruising speed determination, and it includes
major internal and external vehicle losses, uses accurate motor-inverter efficiency maps as
look-up tables, and does not require knowledge of the future route. This framework is
validated using three electric vehicle models in MATLAB/SIMULINK.
Secondly, a novel two-level model predictive control (MPC) speed control
algorithm for battery electric autonomous vehicles as a successive convex optimization
problem is proposed. The proposed successive convex approach produces a highly accurate
optimal speed profile while also being solvable in real-time with the vehicle's onboard
computing resources. This algorithm is used to perform a variety of simulated test cases,
which show an energy savings potential of about 1% to 20% for different driving
conditions, compared to a non-energy-optimal driving profile.
Lastly, the research is expanded to consider fuel cell hybrid electric vehicles
(FCHEVs), which have the added need for an optimal energy management strategy inv
addition to optimal speed planning. Novel successive and integrated convex speed planning
and energy management algorithms are proposed to solve the minimum hydrogen
consumption problem for autonomous FCHEVs. The simulation results show that the
proposed integrated method, which considers fuel cell system efficiency in the optimization
objective function for speed planning, leads to 0.19% to 2.37% less hydrogen consumption
compared to the successive method on short drive cycles with varying accessory loads. On
the same test cycles, the integrated method uses 10.12% to 21.62% less hydrogen than an
arbitrary constant-speed profile.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Autonomous vehicles are expected to be the future of transportation, however, the
high continuous electrical accessory power needed for control and perception is a
challenge. Fortunately, there is an inherent property of speed planning for autonomous
vehicles that can help deal with this problem. This thesis focuses on optimal speed planning
to minimize energy use, proposing convex methods considering detailed internal and
external losses for battery electric vehicles (BEVs), and optimal speed planning integrated
with optimal energy management for fuel cell hybrid electric vehicles (FCHEVs). The
proposed framework in this thesis is accurate while maintaining a low computational effort,
which are the desired criteria for real-time algorithms.


title: Benefits of Additive Noise in Composing Classes of Functions with Applications to Neural Networks

contributor:
Ashtiani, Hassan
Computing and Software

subject:
Generalization
Learning Theory
Neural Networks
Covering Number
Noise

abstract:
Let F and H be two (compatible) classes of functions. We observe that even when both F and H have small capacities as measured by their uniform covering numbers, the capacity of the composition class H o F={h o f| f in F, h in H} can become prohibitively large or even unbounded. To this end, in this thesis we provide a framework for controlling the capacity of composition and extend our results to bound the capacity of neural networks.
Composition of Random Classes: We show that adding a small amount of Gaussian noise to the output of cF before composing it with H can effectively control the capacity of H o F, offering a general recipe for modular design. To prove our results, we define new notions of uniform covering number of random functions with respect to the total variation and Wasserstein distances. The bounds for composition then come naturally through the use of data processing inequality.
Capacity of Neural Networks: We instantiate our results for the case of sigmoid neural networks. We start by finding a bound for the single-layer noisy neural network by estimating input distributions with mixtures of Gaussians and covering them. Next, we use our composition theorems to propose a novel bound for the covering number of a multi-layer network. This bound does not require Lipschitz assumption and works for networks with potentially large weights.
Empirical Investigation of Generalization Bounds: We include preliminary empirical results on MNIST dataset to compare several covering number bounds based on their suggested generalization bounds. To compare these bounds, we propose a new metric (NVAC) that measures the minimum number of samples required to make the bound non-vacuous. The empirical results indicate that the amount of noise required to improve over existing uniform bounds can be numerically negligible. The source codes are available at https://github.com/fathollahpour/composition_noise

abstract: Thesis

abstract: Master of Science (MSc)

abstract:
Given two classes of functions with bounded capacity, is there a systematic way to bound the capacity of their composition? We show that this is not generally true. Capacity of a class of functions is a learning-theoretic quantity that may be used to explain its sample complexity and generalization behaviour. In other words, bounding the capacity of a class can be used to ensure that given enough samples, with high probability, the deviation between training and expected errors is small.
In this thesis, we show that adding a small amount of Gaussian noise to the output of functions can effectively control the capacity of composition, introducing a general framework for modular design. We instantiate our results for sigmoid neural networks and derive capacity bounds that work for networks with large weights. Our empirical results show that the amount of Gaussian noise required to improve over existing bounds is negligible.


title: A role identity perspective on paramedic mental health

contributor:
McConnell, Meghan
Health Research Methodology

subject:
Paramedic
Mental Health
Role Identity
Mixed Methods

abstract:
Introduction

Role identity theory explains that people derive a sense of purpose and meaning from holding social roles, which, in turn, is linked with health and well-being. Paramedics have a respected role in society but high rates of mental illness. I used role identity theory to explore what might be contributing to poor mental health among paramedics.

Objectives

My objectives were to estimate the prevalence of Post-Traumatic Stress Disorder (PTSD), depression, and anxiety; assess for relationships with a measure of paramedic role identity; and finally, explore how role identity conflict could lead to distress.

Methods

I used a mixed methods approach situated in a single paramedic service in Ontario, Canada, distributing a cross-sectional survey during the fall 2019/winter 2020 Continuing Medical Education (CMEs) sessions while also interviewing a purposively selected sample of 21 paramedics. The survey contained a demographic questionnaire, a battery of self-report measures, and an existing paramedic role identity scale. Each interview was transcribed verbatim and analyzed thematically with role identity theory as a conceptual framework.

Results

In total, 589 paramedics completed the survey (97% of CME attendees), with 11% screening positive for PTSD, 15% for major depressive disorder, 15% for generalized anxiety disorder, and 25% for any of the three. Full-time employees, women, those with ‘low’ self-reported resilience, and current or former members of the peer support team were more likely to screen positive. The dimensions of paramedic role identity were not associated with an increased risk; however, I defined a framework through the interviews wherein chronic, identity-relevant disruptive events contribute to psychological distress and disability.

Conclusions

Our prevalence estimates were lower than have been previously reported but point to a mental health crisis within the profession. Role identity theory provided a useful framework through which to reconceptualize stressors.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Role identity theory explains having a sense of purpose and meaning people from social roles (such as a parent or volunteer) is good for health and well-being. Paramedics are an important part of Canada’s public safety infrastructure and generally hold a respected position in society, but there is growing recognition of a mental health crisis within the profession. I used role identity theory to explore why and how role identity theory could contribute to poor mental health among paramedics. By surveying and interviewing paramedics from a single paramedic service in Ontario, Canada, I discovered that 25% of active-duty paramedics met the criteria for either post-traumatic stress disorder, depression, or anxiety. The risk varied across demographic categories, including gender. During the interviews, I discovered that role identity conflict – a discrepancy between what the paramedic thinks their role should be and what is achievable – can lead to significant psychological distress.


title: VALIDITY OF THE CENTRAL SENSITIZATION INVENTORY IN PATIENTS WITH KNEE OSTEOARTHRITIS

contributor:
Carlesso, Lisa
Rehabilitation Science

subject:
Knee Osteoarthritis
Central Sensitization

abstract: Osteoarthritis is the 12th leading cause of years lived with disability globally and by 2040 more than 10 million Canadians will have knee osteoarthritis (KOA). Pain in persons with KOA is well-recognized, persistent and chronic with central sensitization (CS) being prevalent in ~30%. CS is measured by psychophysical testing and patient-reported methods such as the Central Sensitization Inventory (CSI). The CSI was developed using subgroups of people with chronic pain, but not those with KOA. Therefore, validity of the CSI in people with KOA is lacking. CS as indicated by psychophysical tests is associated with CSI scores lower than the recommended cut score. Therefore, we aimed to evaluate the validity of the CSI through Rasch analysis in persons with KOA. We then sought to determine the agreement of the Rasch calibrated (RC-CSI) version of the CSI with the original and to evaluate the validity of the RC-CSI with psychophysical tests in people with KOA. In the first study, the CSI was able to fit Rasch model. After iterative analysis, we found the CSI to be a singular construct with acceptable unidimensionality while retaining all 25 items. Only two items - frequent urination (item 21) and Skin problems (item 19) showed a pattern of uniform differential item functioning by age and sex respectively. Moreover, we generated a RC-CSI cut score of 31.37 that we used to compare with the original cut score of 40. In second study, the findings suggested a lack of agreement between the two versions of the CSI demonstrating small bias. When exploring sensitivity and specificity with psychophysical tests, the RC-CSI showed little clinical value over the original CSI. We therefore recommend that the original CSI should be used with individual clients as our preliminary findings suggest that there is no added benefit to using the RC- CSI.

abstract: Thesis

abstract: Master of Science Rehabilitation Science (MSc)


title: A Conceptual Analysis of Poverty

contributor:
Waluchow, Wilfrid J.
Philosophy

subject:
Conceptual Analysis
Poverty
H.L.A. Hart
Capabilities
Vulnerability
Human Rights
Egalitarianism
Freedom
Homelessness
Philosophy

abstract: This Thesis employs the traditional philosophical method of conceptual analysis to look at the concept of poverty, employing H.L.A. Hart’s meta-evaluative approach to that method, as described by W.J. Waluchow.   Our common understanding of poverty is that it merely denotes a lack of financial resources, but if one digs deeper into how we actually think about poverty and our practices with regard to the concept, we see that the meaning of that concept is not only about a lack of resources, but about how that deprivation affects us:  the vulnerabilities created and the negative effects upon one’s capabilities to meet their basic needs. Those basic needs refer not only to subsistence level goods like food and shelter, but as Amartya Sen argues, one must also have the capability to avoid the shame associated with an inability to afford the goods that one is generally expected to have the ability to obtain in order to be considered free from poverty.  Thinking about poverty in terms of capabilities thereby resolves the dichotomy between absolute and relative conceptions of poverty, as well as many of the counterfactuals deployed against the relative conceptions of poverty that are commonly found in affluent societies.   The relationship between poverty and shame is also supported by empirical studies of the shame experienced by poor persons in disparate contexts.  Poverty is also a moral concept that includes a moral call to action, and we require moral reasoning in order to decide which basic needs one must be able to meet to be considered free of poverty. After first advocating for a non-moral conceptual framework for poverty, I therefore also address three closely-related moral concepts, human rights, equality, and freedom, that variously constitute and inform the concept of poverty, and assist us with our moral reasoning in that regard.

abstract: Thesis

abstract: Master of Arts (MA)

abstract:
LAY ABSTRACT

Our common understanding of poverty is that it relates to a lack of financial resources, but if one digs deeper into how we actually think about poverty we see that it is not only about the lack of resources, but about the vulnerabilities created and the negative effects upon one’s capabilities to meet their basic needs. Those basic needs refer not only to subsistence level goods like food and shelter, but also to the goods that one is commonly expected to have the ability to obtain in order to be considered free from poverty by other persons in the society in which one lives.   Poverty is also a moral concept and we require moral reasoning in order to decide which basic needs one must be able to meet to be considered free of poverty.


title: Sensorimotor Integration Following Training on a Tactile Discrimination Maze Task

contributor:
Nelson, Aimee
Kinesiology

subject:
SAI
LAI
AF
Sensorimotor Integration
TMS
Tactile Discrimination

abstract: Sensorimotor integration refers to the process of combining incoming sensory information with outgoing motor commands to control movement. Short-Latency Afferent Inhibition (SAI), Long-Latency Afferent Inhibition (LAI) and Afferent Facilitation (AF) are three neurophysiological measures collected using Transcranial Magnetic Stimulation (TMS) to assess sensorimotor integration in humans. No studies to date have investigated the influence of tactile discrimination training on these measures. This study aimed to determine whether SAI, LAI, and AF are modulated following training on a custom-designed sensorimotor task which required participants to use their sense of touch to successfully navigate 3D printed maze with interchangeable paths. The maze training was separated into “high difficulty” and “low difficult” conditions which reflected the tactile challenge embedded within the maze. On an additional visit, no maze training was performed to serve as a control condition. Despite evidence of performance improvements during training, there were no significant changes in SAI, LAI or AF following training in either condition. Further, there was no correlation between the % change in SAI/LAI and improvements in total dwell time on the maze. As the functional significance of these measures is still unclear, these findings suggest that changes in SAI, LAI or AF may not be a valid metric to measure meaningful or functional changes related to skills or performance improvements induced by training.

abstract: Thesis

abstract: Master of Science in Kinesiology

abstract: Sensorimotor integration refers to the combination of incoming sensory information with outgoing motor commands in the nervous system to control movement. Short- Latency Afferent Inhibition, Long-Latency Afferent Inhibition and Afferent Facilitation are three measures that probe sensorimotor integration in humans using Transcranial Magnetic Stimulation. Although these measures have been well studied in both healthy and clinical populations in a variety of contexts, the influence of sensorimotor training on these measures remains unclear. This thesis aimed to determine if SAI, LAI and AF change following training on a novel tactile discrimination maze task. Further, the relationship between changes in sensorimotor integration and improvements in maze performance was explored. SAI, LAI and AF were not shown to be influenced by training, and there was no association between the changes in these measures and improvements in maze performance.


title: Combining Listening in Noise and Divided Attention with Pupillary Response to Explore Attentional Resource Use

contributor:
Milliken, Bruce
Psychology

subject:
Attention
Listening in Noise
Divided Attention
Attention Allocation
Pupil Dilation
Cognitive Effort

abstract: The concept of attention is complex and multifaceted and can be approached from many perspectives. One such perspective is of attention as a limited pool of resources. Kahneman’s (1973) model of limited capacity provides a basis for understanding constraints on attention, including the costs of divided attention. In the same vein as Kahneman’s model, the Framework for Understanding Effortful Listening (FUEL; Pichora-Fuller et al., 2016) applies the concept of limited attentional capacity to the demands of listening in a variety of contexts. The current work examines novel combinations of the methods commonly used in the field of Cognitive Hearing Science to address questions about the nature of attention allocation when listening in noise and under the constraints of divided attention. I first combined listening in noise with a secondary continuous working memory task and measured pupillary response as an index of cognitive work and listening effort. Here, I found that listening task demands affect performance on the working memory task. The shared demands of listening and working memory were not, however, evident in the pupil dilation patterns. As a result, I followed these findings by employing a different divided attention method. With the use of a temporally discrete secondary task that either closely overlapped with the listening task or did not closely overlap, I found the same carryover effects of listening demands on secondary task. Most importantly, I found that these demands interacted and were clearly present in the pupil dilation patterns, demonstrating the importance of the timing of the task demands. Together, the studies in this thesis provide evidence that these two secondary tasks access the same attentional resources as those accessed in the primary listening task and that this overlapping demand for resources can be seen in the pupillary response.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Listening to speech in a noisy environment is a cognitively difficult and effortful task. Attending to more than one task at a time is similarly demanding and effortful. These two kinds of tasks are assumed to use the same limited pool of cognitive resources that we have available to us. This thesis combines listening in noise with divided attention tasks to demonstrate this overlap in demands for cognitive resources using novel combinations of these kinds of tasks. Additionally, this thesis uses the pupillary response—a well-studied index of cognitive effort—to further examine the nature of these overlapping task demands. These studies found that the demands of these tasks do, in fact, overlap, and contribute evidence to the current literature supporting the underlying assumption that these two tasks, and the pupillary response as a measure of effort, are accessing the same pool of limited resources.


title: ELECTROCHEMICAL SENSORS FOR SENSITIVE AND SPECIFIC DETECTION OF ORGANOPHOSPHATE, HEAVY METAL ION, AND NUTRIENT

contributor:
Puri, Ishwar
Zhitomirsky, Igor
Engineering Physics

subject:
Electrochemical sensors
Water pollutants
Organophosphate
Heavy metal ion
Nutrient
Cyclic voltammetry
Carbon nanotubes
Metal oxides

abstract:
In an electrochemical sensor, the sensing performance is mainly dependent on the mass transport of the analyte towards the working electrode-electrolyte interface and working electrode properties. Carbon nanomaterials like carbon nanotubes are widely employed to modify the working electrode properties for sensitive detection. A simulation model is formulated to investigate the effects of modifying a planar bare electrode with carbon nanotubes on electrochemical detection of fenitrothion (FT, an organophosphate). The model revealed that porous electrodes caused the change in mass transport regime and influenced FT’s electrochemical response. The results aided in understanding the influence of the porous electrode on analyte detection and thus assisted in the fabrication of an ultrasensitive electrochemical sensor.
Simulation supported synthesis of a highly sensitive ink to produce highly porous and electrocatalytic electrodes. Activated carbon (AC) possesses high porosity and surface area, but they suffer from lower electrical conductivity. To enhance their conductivity, AC was co-doped with nitrogen and sulfur. Multiwalled carbon nanotubes were incorporated to further improve their porosity and electrocatalytic properties. The synthesized nitrogen-sulfur co-doped activated carbon coated multiwalled carbon nanotube (NS-AC-MWCNT) ink produced highly porous electrocatalytic electrodes. The sensor revealed a 4.9 nM limit of detection (LOD) under optimized conditions. However, it failed to overcome the enzymatic sensors’ performances. The ultrasensitive performance was achieved by incorporating a detecting agent in the ink that instilled analyte capture ability. Metal oxides like ZrO2, MnO2, and MgO possessed affinity towards organophosphate (fenitrothion), heavy-metal ion (lead), and nutrient (nitrite). Metal oxides were modified with 3,4-dihydroxylbenzaldehyde (DHBA) – Chitosan (CHIT) to produce well dispersed and uniformly coated stable electrodes. The ZrO2-DHBA-CHIT/NS-AC-MWCNT sensor achieved a remarkable limit of detection of 1.69 nM for FT. The sensor's performance exceeded the enzymatic-based sensors. The commonly found chemical interferents had negligible interference. The sensor produced reliable and satisfactory performance in lake and tap water. The MnO2-DHBA-CHIT/NS-AC-MWCNT/GCE and MgO-DHBA-CHIT/NS-AC-MWCNT/GCE sensors produced an enormous improvement in the sensor performance compared to unmodified electrodes for lead and nitrite detection. The preliminary results on detecting other pollutants like lead and nitrite showed the importance of the methodology in providing a platform for a new class of metal oxide-based sensors.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
The growing population and rapid industrial development are affecting the water quality worldwide. The major water pollutants are organophosphates, heavy metal ions, and nutrients. These water pollutants are harmful, and their bioaccumulation poses a major health concern. In the USA alone, water quality issues are predicted to cost $210 billion annually. Therefore, sensors to detect water pollutants are developed to monitor their environmental footprints. Electrochemical sensors are popularly used to detect water pollutants owing to their low-cost and high sensitivity.
The objective of this dissertation was to fabricate highly sensitive and specific electrochemical sensors to detect organophosphate (e.g., fenitrothion, FT), heavy metal ion (e.g., lead), and nutrient (e.g., nitrite). The sensors were fabricated with ink based on nanomaterials like carbon nanotubes and detecting agents like metal oxides. The fabricated sensors achieved very high sensitivity and specificity and can detect water pollutants in lake and tap water.


title: Electrochemical Approaches for Water Treatment: Metal Separation and Associated Industrial Contaminant Removal

contributor:
de Lannoy, Charles
Chemical Engineering

abstract:
Since the industrial revolution of the 18th century, rapid growth occurred in the energy, electronic, fertilizers, pesticides, detergents, pharmaceutical, mining and paper industries, among others. Consequently, wastewaters produced from these various industries is highly contaminated with hazardous pollutants including toxic metals and organic contaminants as well as useful resources such as phosphates and precious metals. It is necessary to remove hazardous pollutants from industrial wastewater to meet the environmental disposal regulations or to enable safe recycling of the treated wastewater in other applications. It is also economically beneficial to separate the valuable resources from the industrial waste solutions. Several technologies have been employed for metal and other contaminants (e.g., organics and minerals) removal from industrial wastewater including chemical precipitation, coagulation and flocculation, membrane separation, ion exchange, adsorption, chemical oxidation, and biodegradation. Chemical precipitation, coagulation and flocculation, and chemical oxidation processes have a high chemical consumption. Adsorption and ion exchange do not require a high chemical consumption while separating pollutants from wastewater, nevertheless acids and chemical reagents are required for the regeneration of sorbents and ion exchange resins for their reuse in subsequent processes. Membrane technologies suffer from membrane fouling and scaling, which require the use of chemical reagents and antiscalants to mitigate these problems. The use of bacteria in biodegradation is a common alternative in many wastewater, but this process requires a toxic-free environment, which is rarely the case in industrial wastewaters due to the presence of toxic metals in most of the industrial effluents. As such, this process is not appropriate for most industrial separations, requiring additional unit operations to remove toxic metals before the biodegradation processes which causes higher operational and capital cost.
The objective of this thesis is to substitute metal and associated contaminants conventional removal methods with novel electrochemical approaches to decrease the chemical consumption, lower the environmental impact, extract precious metals and to decrease the overall unit operations during industrial wastewater treatment.
 In the first part of the thesis, using chemical coagulants was substituted by electrochemically induced in-situ coagulants to remove toxic metals from mixed industrial wastewater. The newly introduced technique utilized the presence of iron in the waste solution and converted it into iron hydroxide coagulants through the reaction of iron with the hydroxyl groups generated via water electrolysis at a stainless-steel cathode. The generated coagulants interacted with the toxic metals (i.e., arsenic, cadmium, lead, nickel, copper, chromium) in the wastewater and separated them from the solution. To decrease the overall unit operations of the mixed industrial wastewater treatment, the associated organic pollutants in the waste solution were simultaneously degraded. A dimensionally stable anode (DSA) was used to oxidize the organic contaminants in the solution simultaneously with the metal coagulation occurring at the cathode. The electrochemical oxidation-in-situ coagulation (ECO-IC) process resulted in a treated solution with a substantially lower heavy metal content, lower organic content, greater effective diameter of the suspended particles, and distinct phases that can be separated for further treatment.
In the second part of the thesis, a closed-loop continuous cycle for metal adsorption and electrodesorption using CNT sorbents was invented.  In this process, 1) metals are adsorbed onto the surface of CNTs, 2) the metal-saturated CNTs are filtered onto a microfiltration (MF) membrane to form a temporary membrane electrode, 3) the CNT-coated membrane is used as an anode in an electrochemical cell, 4) an applied electric potential desorbs the metals from the CNT-membrane, and 5) the CNTs are separated from the membrane to be reused as adsorbents in a closed-loop process. The closed-loop regenerative cycle allowed recycling the effective but expensive CNT sorbents in subsequent adsorption-electrodesorption cycles. The electrochemical regeneration of CNTs eliminated the need for using acids and chemical reagents for CNTs regeneration. The proposed technique was successfully employed for adsorption and electrodesorption of copper (a model toxic metal) from aqueous solutions and gold (a model precious metal) from acidic chloride solutions mimicking e-waste leachate. The results of this study demonstrate a chemical-free method for metal removal that achieves removal at rates comparable to conventional chemical methods and adsorbent regeneration as high as that achieved with chemical methods.
In the third part of the thesis, limitations and sources of error during electrochemical water treatment were identified to be taken into consideration by future researchers. In the first phase of this research, sources of error arising in batch electrochemical cells were illustrated. Batch electrochemical experiments are considered the baseline for testing porous electrodes and electrochemical membranes (ECMs) in water treatment applications (including metal separation and contaminant removal) before being used in continuous processes. It was identified that electrochemical dissolution of metal fasteners holding porous conductive membranes in batch electrochemical cells occur, even when keeping the metal fasteners outside the electrolyte solution. This phenomenon can confound water treatment experimental results in batch cells. The reason for this phenomenon was investigated and a simple solution to prevent it was proposed. In the second phase of this research, limitations on using metal feed spacers as electrodes during gypsum solution (secondary pollutants produced during metal removal from mining wastewater) RO filtration was identified. Using electro-assisted filtration has a lower environmental impact than using antiscalants for preventing gypsum scale formation on RO membranes. Nevertheless, using metal feed spacer electrodes for this purpose was not effective due to low generation of hydrogen gas and the spacers' anodic electro dissolution. Inert electrodes to electro dissolution (i.e., CNTs coated polypropylene feed spacers) are proposed as an effective and economic option for electro-assisted filtration of gypsum solutions.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: With rapid industrial development, industrial wastewaters are heavily contaminated with hazardous pollutants and valuable resources. As a result, there are social and economic needs for efficient industrial wastewater treatment to remove harmful contaminants and to extract useful compounds. Metals of particular interest in industrial wastewaters are organized into two categories, toxic metals (e.g., arsenic, zinc, nickel, mercury, and cadmium) and precious metals (e.g., gold, silver, platinum, and palladium). An effective metal separation from industrial waste solutions is a major goal for the sustainable development of industrial processes. Conventional metal removal technologies have intensive chemical consumption producing secondary pollution. Here, we introduce two novel environmental approaches for metal removal with minimal chemical consumption. The first approach replaces chemical coagulants with electrochemically generated in-situ coagulants for toxic metal removal from industrial wastewater. The second approach introduces a closed loop continuous process for adsorption and electro-desorption of toxic and precious metals from aqueous solutions using carbon nano tubes (CNTs) sorbents. The closed-loop continuous regenerative process enables the use of highly effective CNT sorbents for metal removal from waste solutions. The desorption process is based on electrochemical regeneration of CNTs from metals, which avoids the need for acids or other solvents to regenerate the CNT sorbents.


title: An investigation of emotion dysregulation during the perinatal period: Implications for perinatal mental health and psychological treatments

title: Emotion dysregulation during the perinatal period

contributor:
Green, Sheryl M.
McCabe, Randi E.
Psychology

subject:
Emotion dysregulation
Perinatal
DBT skills
Perinatal mental health

abstract:
Introduction: The perinatal period, which consists of pregnancy and up to one year postpartum, is considered a period of vulnerability. During this time, women are at higher risk than at other times in their lives of developing a mental health disorder, particularly anxiety and depressive disorders. Perinatal mental health disorders have a tremendous negative impact on not only the mother, but also their children who may develop cognitive, behavioural, and emotional problems that last well into adulthood. Emotion dysregulation has been implicated in both anxiety and depressive disorders and, due to endocrine changes during the perinatal period, may play an important role in perinatal mental health. Perinatal emotion dysregulation has yet to be explored. The purpose of this thesis was to 1) better understand the link between emotion dysregulation and perinatal mental health, 2) assess whether current perinatal treatments effectively target emotion dysregulation, and 3) develop an effective psychological treatment protocol for perinatal emotion dysregulation.
Methods: We designed and conducted three studies to meet our research aims. The first study compared emotion reactivity and emotion regulation, two aspects of emotion dysregulation, in perinatal women with an anxiety and/or depressive disorder to better understand perinatal emotion dysregulation. The second study examined the bidirectional relationship between Cognitive Behavioural Therapy (CBT) for perinatal anxiety and emotion dysregulation to examine whether emotion dysregulation moderates CBT treatment outcomes and whether CBT is an effective treatment modality for perinatal emotion dysregulation. This was examined in two samples of participants: participants from a randomized controlled trial and routine clinical care.  In the third study, we developed a novel Dialectical Behavioural Therapy (DBT) informed treatment program for perinatal emotion dysregulation and examined the effectiveness of the program through a pilot study.
Results: Our research revealed several important findings. First, heightened emotional reactivity may be a protective factor during the perinatal period; less flexibility in emotional reactivity and difficulties with emotion regulation were associated with worse perinatal mental health, and relationship dissatisfaction. Second, CBT was an effective treatment for low levels of emotion dysregulation but not for moderate or severe perinatal emotion dysregulation. Only 16% of routine clinical care participants and 28% of participants from the randomized controlled trial demonstrated clinically reliable change in emotion dysregulation. Emotion dysregulation did not moderate CBT treatment outcomes on anxiety or depression. This suggest that emotion dysregulation appears to be a distinct factor that may warrant more specialized treatment. Third, our short term, DBT informed, skills group was effective in significantly reducing perinatal emotion dysregulation. The DBT informed treatment may be more effective in targeting perinatal emotion dysregulation than CBT as illustrated by 48% of participants demonstrating clinically reliable change compared to the 16%-28% in the CBT treatment.
Conclusions: This line of research allows us to have a better understanding of perinatal emotion dysregulation and may aid in the development of best practice assessment and treatment guidelines for emotion dysregulation during the perinatal period. Limitations and future directions are discussed.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: METHODOLOGICAL QUALITY OF CHIROPRACTIC MIXED METHODS RESEARCH

title: Methodological Quality of Chiropractic Mixed Methods Research: A Meta- Epidemiological Review and Application in a Health Services Evaluation of Chiropractic Integration and Prescription Opioid Use

contributor:
Busse, Jason W
Health Research Methodology

subject:
Mixed Methods Research
Chiropractic
Methodological Quality
Opioids

abstract:
Background: An increasing number of mixed methods studies have been conducted across health care professions in recent years. However, little is known about the methodological reporting quality among mixed methods studies involving chiropractic research.
Objective: To examine the methodological quality of published chiropractic mixed methods studies, provide recommendations for improving future chiropractic mixed methods research, and apply these recommendations in two mixed methods health services evaluations of chiropractic integration and prescription opioid use for spinal pain. Methods: We conducted a meta-epidemiological review of the chiropractic mixed methods literature and examined reporting quality using the Good Reporting of A Mixed Methods Study guideline and risk of bias using the Mixed Methods Appraisal Tool. We used generalized estimating equations to explore factors associated with higher methodological quality. We applied our findings in two sequential explanatory mixed methods investigations of the association between chiropractic care and opioid prescribing for non-cancer spinal pain.
Results: Among eligible mixed methods studies, we found that many were both poorly reported and at risk of bias. Publication in journals with an impact factor and/or more recent publication were significantly associated with higher methodological quality. In our sequential explanatory analyses, we found that receipt of chiropractic care was associated with decreases in initial opioid prescribing and long-term opioid use, and our qualitative results suggested these relationships were multi-factorial.                                                                           Conclusion: We identified areas for improvement in the methodological reporting quality of chiropractic mixed methods research. Our mixed methods studies suggest that integration of chiropractic services into primary care centres may reduce the use of opioids for spinal pain.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: We reviewed the literature to assess the methodological reporting quality of mixed methods studies involving chiropractic research and found that most studies had important omissions. We applied these results to optimize methodologic reporting of two mixed methods studies on the association between chiropractic care and opioid prescribing. We found that patients with non-cancer spinal pain were less likely to receive an initial prescription for opioids if they accessed chiropractic care. Further, among chronic pain patients receiving opioids, we found that providing access to chiropractic care reduced their chances of continuing to receive opioids. The qualitative aspect of our studies provided important context to inform how patients and their primary care providers felt access to chiropractic care had reduced reliance on prescription opioids. These findings will increase awareness among researchers for opportunities to improve reporting quality of mixed methods research and highlight the potential role of chiropractic care in helping to address the opioid crisis.


title: Mindfulness and Cognitive Control: Examining the Convergence of Two Constructs

title: Mindfulness and Cognitive Control

contributor:
McNeely, Heather
McKinnon, Margaret
Psychology

subject:
Mindfulness
Cognitive Control
Dispositional Mindfulness
Mindfulness Training
EEG
ERP

abstract: Mindfulness and cognitive control are overlapping constructs. Mindfulness involves maintaining awareness of the current experience by sustaining attention to relevant information and disengaging from irrelevant information. Cognitive control refers to the set of processes involved in selecting and monitoring information relevant to our goals, while ignoring or inhibiting information irrelevant to these goals. This dissertation contains three studies that examine the convergence between mindfulness and cognitive control. The first study examined the relationship between self-reported mindfulness and behavioural correlates of cognitive control using the Digit Stroop task within two experimental contexts: when task difficulty was not manipulated (non-titrated) and when task difficulty was increased (titrated). The results demonstrate that self-reported mindfulness predicted behavioural performance, but only when cognitive control processes were sufficiently challenged by increasing task difficulty. The second study examined the precise neural mechanisms underlying the relationship between mindfulness and cognitive control using electroencephalography (EEG) to identify changes to event-related potentials (ERPs) during the non-titrated Digit Stroop task after two weeks of daily training. By introducing a novel active control training condition (guided visual imagery meditation) that contrasted passive attention regulation with the focused attention regulation in mindfulness, the results isolated electrophysiological correlates of cognitive control that were uniquely tied to mindfulness training, including increased efficiency in conflict detection, delayed attentional capture by incongruent stimuli, faster conscious evaluation of all stimuli, and delayed automatic detection of all errors. The third study replicated and extended these findings by examining changes to ERPs when the cognitive control system was challenged using the titrated Digit Stroop task. Compared to the active control group, the mindfulness group showed enhanced sensory processing, resistance to stimulus-driven attentional capture and faster conscious evaluation of all stimuli after training. Taken together, this dissertation establishes an empirical relationship between behavioural and electrophysiological correlates of mindfulness and cognitive control.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Mindfulness is a way of paying attention, on purpose, in the present-moment and nonjudgmentally. By focusing attention on present goals and redirecting attention from distractions, mindfulness enhances moment-to-moment awareness of fluctuations in cognitive demands. As a result, meditators can develop greater control over a set of cognitive processes that promote useful behavioural responses. This deliberate practice overlaps with a construct known as “cognitive control”—a set of cognitive processes that facilitate information processing and behaviour to vary adaptively from moment to moment depending on current goals. This dissertation examines the relationship between mindfulness and cognitive control using electroencephalography (EEG) to record ongoing brain activity during two variations of a cognitive control task designed to manipulate difficulty. The results show that self-reported mindfulness predicts cognitive control performance when task difficulty is increased and that two weeks of daily mindfulness training leads to changes in neural activity underlying this cognitive control performance.