title: Sutureless Aortic Valve Replacement

subject:
Aorta
SuAVR
Sutureless
Aortic Valve Replacement

abstract: Aortic Stenosis (AS) is the most common valvular heart disease. Aortic valve replacement (AVR) is the only acceptable treatment for AS. Several replacement methods are available to treat AS including conventional surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR), and Sutureless aortic valve replacement (SuAVR). SAVR showed excellent long-term results. However, it is an invasive procedure and is denied in substantial number of patients. TAVR showed excellent results and outcomes when compared to SAVR. However, it is associated with increased rate of paravalvular leaks that may impact long term outcomes. SuAVR has developed to overcome the drawbacks of SAVR and TAVR. SuAVR is associated with favorable short and midterm outcomes when compared to SAVR and TAVR. In this thesis, we summarize the safety, the evidence and the perceptions of using SuAVR in Canada.  In Chapter1, we evaluated the use of SuAVR Perceval bioprosthesis in retrospective single center study of 415 patients with AS. SuAVR showed excellent immediate post-operative and hemodynamics outcomes. In chapter 2, we sought to establish perceptions and patterns to SuAVR use among Canadian cardiac surgeons. Sixty-Six Canadian cardiac Surgeons responded to the survey. Surgeons reported influential factors, barriers to use SuAVR, and their interest in a trial comparing SuAVR versus TAVR. Surgeons were likely to use SuAVR in high risk patients with hostile aortic root, small aortic annulus and in patients undergoing concomitant procedures whereas cost was the main limiting factor to use SuAVR in Canada. Majority of surgeons reported their interest in participating in a trial comparing SuAVR with TAVR. In chapter 3, we systematically reviewed and meta-analyzed the international evidence of using SuAVR versus SAVR and TAVR. SuAVR showed favorable or comparable results to SAVR and TAVR. However, long term and randomized data are needed to confirm these results.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Aortic valve stenosis (AS) is considered the most common valvular heart disease, which caused by narrowing of the aortic valve. Aortic valve replacement (AVR) is the only acceptable treatment to relieve the stenosis. Several strategies are available including conventional surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR), and sutureless aortic valve replacement (SuAVR). SAVR is an invasive procedure and denied in a considerable number of patients with aortic stenosis due to aging and presence of multiple diseases leading to higher risk of complications. TAVR is less invasive option and showed excellent results when compared to SAVR. However, it was associated with complications. SuAVR has developed to overcome some of the drawbacks of SAVR and TAVR. SuAVR is associated with short operation time and less complications compared to SAVR and TAVR. This thesis summarizes the safety, perceptions and evidence surrounding the use of SuAVR.


title: Computing Lyndon Arrays

contributor:
Deza, Antoine
Franek, Frantisek
Computing and Software

subject:
Combinatorics on Words
String Algorithmics
Strings
Suffix Sorting
Lyndon Substrings
Lyndon Arrays
Maximal Lyndon Substrings

abstract:
There are at least two reasons to have an efficient algorithm for identifying all maximal Lyndon substrings in a string: first, in 2015, Bannai et al. introduced a linear algorithm to compute all runs in a string that relies on knowing all maximal Lyndon substrings of the input string, and second, in 2017, Franek et al. showed a linear co-equivalence of sorting suffixes and sorting maximal Lyndon substrings of a string (inspired by a novel suffix sorting algorithm of Baier).
In 2016, Franek et al. presented a brief overview of algorithms for com- puting the Lyndon array that encodes the knowledge of maximal Lyndon substrings of the input string. It discussed four different algorithms. Two known algorithms for computing the Lyndon array: a quadratic in-place algorithm based on iterated Duval’s algorithm for Lyndon factorization and a linear algorithmic scheme based on linear suffix sorting, computing the inverse suffix array, and applying the NSV (Next Smaller Value) algorithm. The overview also discusses a recursive version of Duval’s algorithm with a quadratic complexity and an algorithm emulating the NSV approach with a possible O(n log(n)) complexity. The authors at that time did not know of Baier’s algorithm. In 2017, Paracha proposed in her Ph.D. thesis an algorithm for the Lyndon array. The proposed algorithm was interesting as it emulated Farach’s recursive approach for computing suffix trees in linear time and introduced τ-reduction; which might be of independent interest.
This was the starting point of this Ph.D. thesis. The primary aim is: (a) developing, analyzing, proving correct, and implementing in C++ a linear algorithm for computing the Lyndon array based on Baier’s suffix sorting; (b) analyzing, proving correct, and implementing in C++ the algorithm proposed by Paracha; and (c) empirically comparing the performance of these two algorithms with the iterative version of Duval’s algorithm.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Exercise, Fatigue and Serum Inflammatory Cytokine Changes in People with Relapse Remitting Multiple Sclerosis: A Pilot Study

contributor:
Hicks, Audrey
Science

subject: Relapse Remitting Multiple Sclerosis

subject: Fatigue

subject: Serum Inflammatory Cytokines

subject: Depression

subject: Physical Activity Guidelines for people with MS (PAGs)

subject: Strength

subject: Aerobic Fitness

subject: Quality of Life

abstract: Fatigue is a prevalent and debilitating symptom that affects up to 97% of individuals with multiple sclerosis (MS). It can negatively influence the socioeconomic status, activities of daily living and quality of life for the affected individuals. Fatigue is multidimensional and abstract, thereby making it complex to understand, target and treat. Over the past 20 years, physical activity has become more recognized as a management method that could help with the alleviation of fatigue. One of the reasons could be due to the anti-inflammatory effects of exercise. However, due to the multi-factorial nature of fatigue and the heterogeneity of the training intervention protocols, the potential mechanisms that underlie the relationship between fatigue and exercise are still not fully understood. In 2013, Latimer-Cheung and colleagues developed an evidence based physical activity guideline (PAGs) for people with MS. Since then, studies have shown consistent beneficial effects of exercise on reducing fatigue in people with MS by adhering to the PAGs. To date, however, there are no published studies that examined the potential mechanism that underlie the beneficial effect of the PAGs on reducing fatigue. The primary purpose of this thesis was to evaluate the effects of adhering to the PAGs on fatigue in people with MS and to assess whether any exercise-induced changes in fatigue were associated with changes in inflammatory cytokines. The secondary purpose of this thesis was to evaluate the effects of exercise on depression, strength, aerobic fitness, muscular endurance and quality of life. This study had a wait-list control design. Participants with relapse remitting multiple sclerosis (RRMS) were recruited and randomized to begin with either a 12-week supervised exercise training program (G1) or a wait-list control period (G2). The training program involved at least 30 minutes aerobic training and resistance training for major muscle groups twice per week. The G2 group maintained their regular lifestyle. After 12 weeks, G1 reverted back to their usual lifestyle and G2 began their 12-week supervised exercise training. Following training, we found a reduction in fatigue and depression with increased strength and quality of life. No changes were observed in pro-inflammatory cytokines, aerobic fitness or muscular endurance. This is the first study that examined the underlying potential mechanism for the beneficial effects of exercise by adhering to the PAGs. Following the PAGs for 12 weeks results in significant improvements in fatigue, depression, strength and quality of life. However, our results do not support the role of inflammatory cytokines in mediating these improvements.

abstract: Thesis

abstract: Master of Science in Kinesiology


title: Unidirectional Low Temperature Thermal Networks: Enabling Thermal Distributed Energy Resources

contributor:
Cotton, James
Lightstone, Marilyn
Mechanical Engineering

subject: Low Temperature Thermal Networks District Heating Energy Thermal Unidirectional Distributed Resources

abstract:
This thesis investigates the potential of Unidirectional Low Temperature Thermal Networks (UD-LTTN) as a means to improve community-level energy efficiency through the integration of Thermal Distributed Energy Resources (TDER). UD-LTTN systems are the next generation of District Heating and Cooling (DHC) systems, and utilize decentralized heat pumps to enable distributed generation, reduce thermal pipe losses and decrease system-wide exergy destruction. By providing these benefits, these systems have the potential to decrease the total energy utilization of a community, when compared to traditional DHC systems.
To better understand the potential of UD-LTTN systems, an equation-based modelling library was created in the open-source simulation code “Modelica.” This library was then used to perform a comparative analysis between both a UD-LTTN system and DHC system when applied to the same case study. This analysis compared each system based on total energy utilization and carbon emission production for a variety of cases. Additional thematic analysis was then done to understand how the comparative analysis results extend to the more general field of UD-LTTN system design. The results found that UD-LTTNs systems can reduce the total energy generations requirements by capturing energy from decentralized waste energy resources within the community. However, other factors such as electrical generation sources, peak power capacity and pumping power requirements are important considerations when determining the true effectiveness of these innovative systems.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: INVESTIGATING THE COMPATIBILITY OF BIODIESEL ON POLYETHYLENE THROUGH NONDESTRUCTIVE AND TRADITIONAL METHODS

contributor:
Thompson, Michael R.
Vlachopoulos, John
Chemical Engineering

abstract:
Being the most abundant cause of unexpected brittle failures of polymers, environmental stress cracking (ESC) is a major issue for the plastics industry, accounting for approximately 15-40% of all plastic part failures in service. ESC is an intriguing phenomenon that is not yet well understood, which relates to the accelerated failure of a stressed polymer whilst the presence of an active medium, such as biodiesel. Unexpected failures of polyethylene parts in tanks aboard marine vessels that were operated with biodiesel has generated concerns in the polymer industry over the compatibility of this relatively new fuel, making investigations into these failures both urgent and essential for the process of change towards renewable fuel standards.
Experimental trials carried out for a two-stage project investigating the compatibility of fresh and degraded biodiesel with polyethylene were used to suggest a plasticization mechanism targeting tie molecules (often related to micellular contaminants in a contacting medium) as the probable pathway for ESC of polyethylene with biodiesel. Preliminary analysis was done using the Bell Test (ASTM D1693) showing evidence of pure biodiesel as a stress cracking agent with an aggressiveness similar to a 10% biodiesel in water solution for which the majority of trials used.                                                                                Results from the first stage of this study revealed evidence of differing modes of interaction for biodiesel and toluene (a known plasticizing agent) with the semi-crystalline polymer structure. The second stage utilized acoustic analysis to monitor internal stresses during long-term aging to better explain the theory of ESC for polyethylene with biodiesel, showing that both plasticization and ESC behaviors occurred.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Understanding the compatibility of polymers with chemicals that they are exposed to is essential, particularly those used for liquid storage components like fuel tanks, making it vital to consider both short-term and long-term interactions under environmental conditions that regularly fluctuate. A two-stage project based on experimental trials has been conducted, using traditional testing methods and a novel non-destructive testing method based on ultrasonics, to evaluate the compatibility of biodiesel with different grades of Imperial Oil ltd. polyethylenes. In the first stage of the study, the plasticization effect of fresh and degraded biodiesel (in comparison to toluene) was investigated on polyethylene. Results were used in the second stage of this experiment to propose a plasticization mechanism targeting tie molecules as the proposed pathway for environmental stress cracking of biodiesel with polyethylene.


title: The Burden of Cancer: Individual and Societal Outcomes

contributor:
Longo, Christopher
Health Policy

subject:
cancer
labour market outcomes
economic burden
health
cancer diagnosis
earnings

abstract:
It is paramount that an accurate assessment of the impact of a cancer diagnosis is available with which to plan future resource allocation and to highlight the area to direct future policy initiatives.
	In the second chapter I take a modelling approach to estimate the economic burden of bladder cancer due occupational exposure. Using a multi-stage Markov model, I estimate direct, indirect, and intangible lifetime costs of bladder cancer starting in the year 2011. The results of this analysis indicate that there is a substantial economic burden associated with occupational bladder cancer. Of the three components that make up the total economic costs, intangible costs represent the largest proportion, followed by indirect and direct costs.
In the third chapter, I use a data set created via a linkage of several administrative data resources to estimate the relationship between cancer diagnosis and annual labour market earnings. Using the Mahalanobis' distance and propensity score matching combined with a difference-in-difference regression, I isolate the impact of cancer diagnosis on labour market earnings of cancer survivors by comparison to their peers without cancer. There are two conclusions that can be derived from the results. First, I found that cancer survivors recover a fraction of their labour market earnings over time as they are further removed from the time of the cancer diagnosis. Secondly, I found the heterogeneous effects of cancer where most cancer survivors showed a persistent loss of labour market earnings except breast, cervix, and skin  cancer survivors in the less-active age group.
	In the fourth chapter I examine the impact of cancer on health using three commonly used health indicators: life expectancy, Health Utility Index, and health-adjusted life expectancy. Specifically, I decomposed the differences between individuals with and without cancer in above-mentioned indicators by age and cancer type—considering all cancer types, then specifically breast, colorectal and prostate cancers. The results of the study indicate the heterogeneous effects of cancer on health outcomes and provide a repository of health outcome information that other researchers and policymakers can use.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
In 2017, there were approximately 206,200 new cancer diagnoses in Canada, and 1 in 2 Canadians are currently expected to develop cancer in their lifetime. The chances are that most Canadians may know someone—likely more than one person—who has been afflicted with cancer. As more Canadians are diagnosed with cancer and survive, researchers are increasingly trying to understand and describe the short- and longer-term impact of cancer on health and social role engagement (particularly paid work) of afflicted individual, with the intent of identifying ways to minimize adverse outcomes.
	The following chapters investigate the impact of a cancer diagnosis on annual labour market earnings, health, and the aggregation of these and other impacts on the societal economic burden. Chapter 1 sets the context for the entire thesis and draw out the overall objectives and motivations of the work. In Chapter 2 I conduct a comprehensive costing evaluation to estimate the economic burden of occupational cancer, taking a societal perspective, and provide a detailed breakdown of items that contribute to the economic burdens of cancer. In Chapter 3 I estimate the change in labour market earnings due to cancer diagnosis over a period of 5 years to uncover the heterogeneous effects of cancer type on labour market earnings. Finally, in Chapter 4 I estimate the impact of cancer on health using three different health indicators. In Chapter 5 I summarize the findings and contributions of each study.


title: Loneliness as a modern construct: exploring the recent literature on loneliness as a global health crisis

title: Exploring the recent literature on loneliness as a global health crisis

contributor:
Baumann, Andrea
Global Health

subject:
Loneliness
Health Risk
Global Health
Public Health
Public Policy
UK
Japan

abstract: Global Health MSc Thesis

abstract: The construct of loneliness is well explored within the arts and humanities, but has only recently been considered to be a condition that should be addressed by public health policy. Definitions explored include common sense, existential loneliness, and the cognitive approach. The governments of Japan and the UK have implemented policy that specifically addresses loneliness as a result of its recent identification as a health concern linked to dementia, heart disease, hypertension, and greater risk of morbidity. This thesis undertook an integrative literature review across the arts, humanities, sciences, and grey literature to provide a comprehensive picture of a modern conceptualization of loneliness. The results of this thesis find that loneliness is both a health risk and social problem that is being addressed at the municipal and federal levels in Japan and the UK. However, the question remains as to whether loneliness should be considered a public health concern or a social concern. More international collaboration on the impact of loneliness on populations is recommended.

abstract: Thesis

abstract: Master of Health Sciences (MSc)

abstract: The construct of loneliness is well explored within the arts and humanities, but has only recently been considered to be a condition that should be addressed by public health policy. The governments of Japan and the UK have implemented policy that specifically addresses loneliness as a result of its recent identification as a health concern linked with dementia, heart disease, hypertension, and greater risk of morbidity. This thesis undertook an integrative literature review across the arts, humanities,  sciences, and grey literature to provide an expansive picture of a modern conceptualization of loneliness. The results of this thesis find that loneliness is both a health risk and social problem which can be appropriately addressed by government action. However, the question remains as to whether loneliness should be considered a public health concern or a social concern. More international collaboration on the impact of loneliness  on populations is recommended.


title: Biomarkers of biogeochemical carbon cycling at three aquifer sites in Bangladesh

title: Biomarkers in three Bangladesh aquifer sites

contributor:
Slater, Gregory
Geography and Earth Sciences

subject:
biogeochemistry
PLFA
microbial biomarkers
sterols
sewage input
arsenic
groundwater
contamination

abstract:
The role of aquifer microorganisms in controlling arsenic contamination of Bangladesh aquifers via oxidation of organic carbon coupled with reduction of sedimentary iron oxyhydroxides and concomitant arsenic dissolution is generally accepted. What remains to be ascertained is the in situ biogeochemical mechanisms of cycling different carbon sources and directly relating indigenous microbiota to arsenic release.
Using biomarker fingerprint approaches, this dissertation expanded the presently growing research in the biogeochemical carbon cycling controlling arsenic contamination in Bangladesh aquifers. Comprehensive profiles of microbial cell membrane components (PLFA and sterols) at three different aquifers tested the regional distribution of aquifer microbial community abundance, structure, and organic input potential across Araihazar. The highly variable bulk viable microbial biomass observed across these three sites confer both regional-scale and localized heterogeneous distributions of in-aquifer microbial communities which control carbon cycling in the aquifer. The lack of correlation between PLFA biomarkers and dissolved arsenic challenges the assumption that greater extent of microbial community metabolism results in an increase in arsenic in groundwater. Natural abundance radiocarbon isotope Δ14C analysis of cell membrane PLFA and available carbon pools (SOC, DOC, DIC) confirmed that young organic carbon substrates are being cycled at two of the three sites investigated here. This corroborates previous reports at nearby sites (Site B and F) thereby contributing to a well-constrained carbon source which actively support microbial metabolism over a regional scale. Sterol biomarker distributions were characterized to determine potential sources of organic input into the aquifer. In particular, the importance of raw human and/or animal sewage waste as a source of labile carbon was assessed by measuring the faecal biomarker Coprostanol and comparing its abundance to other sources of biogenic sterols using sewage input proxies (Sewage Contamination Index, Coprostanol/Cholesterol ratio). This was motivated by previous findings which correlated sewage contamination with dissolved arsenic at depth at nearby sites. While sewage contamination was low in the shallow aquifers at these sites, it is more likely that plant organic matter supported the elevated microbial abundance at shallow depths. On the other hand, evidence presented in this project suggests that sewage contamination intrudes into deeper aquifers (e.g. buried Pleistocene) and contributes to the vulnerability of previous pristine aquifers to future arsenic contamination.

abstract: Thesis

abstract: Master of Science (MSc)


title: METHODS FOR MODELING THE SPREAD OF INFECTIOUS DISEASE

contributor:
Bolker, Ben
Dushoff, Jonathan
Biology

subject:
infectious disease
rabies
mathematical model
epidemiology

abstract:
Mathematical and statistical models are widely used in studying infectious disease. They provide important insights – including mechanisms of the spread of infectious disease, forecast epidemic size and duration, and effects of intervention strategies – which are useful in studying and combating infectious disease. Over the last couple of decades, modeling techniques have advanced tremendously due to improvements in computational power, data availability, and data accessibility; this enables researchers to use various modeling approaches to capture more realistic aspects of infectious disease epidemics. Despite having flexible modeling techniques, these approaches use different modeling assumptions to incorporate information and propagate uncertainty, often arriving at inconsistent conclusions. My work focuses on exploring and improving methods for modeling the spread of infectious disease; in particular, exploring the state of the art techniques for disease modeling in real epidemic outbreaks and simulation settings.
Motivated by a synthetic forecasting challenge inspired by the 2014 West African Ebola outbreak, I compared simple Markov chain Monte Carlo approaches to simulated epidemics (Chapter 2). Using high-resolution data from an ongoing rabies contact- tracing study, I apply robust techniques to reassess global historical risk estimates of canine rabies (Chapter 3), and show that disease trait correlations bias generation time estimates, with implications for conclusions about control (Chapter 4). In Chapter 5, I developed a method to improve modeling trait relationships while incorporating phylogenetic relationships by reformulating phylogenetic mixed models to improve flexibility and speed.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: PUBLIC AND VULNERABLE POPULATIONS’ PARTICIPATION IN HEALTH-SYSTEM PRIORITY SETTING

contributor:
Kapiriri, Lydia
Abelson, Julia
Wilson, Michael
Health Policy

subject:
priority setting
public participation
vulnerable populations
health system

abstract: There is a growing body of literature about public participation in health-system priority setting in different contexts and levels of governance, however, explicit focus on vulnerable populations’ participation is lacking. This dissertation incorporated a mix of methodological approaches to address this gap. First, a scoping review was used to synthesize the literature on priority-setting frameworks to understand whether and how applications of the frameworks involve the public and vulnerable populations in different contexts. Second, an interpretive description study was used to examine stakeholder participation at the district level in a low-income country, Uganda. Third, a qualitative description study design was used to qualitatively assess vulnerable women’s participation in health-system priority setting within a district in Uganda, from the perspectives of both vulnerable women and decision-makers. The research chapters complement and build on one another to make substantive, methodological, and theoretical contributions. Specifically, insights gained from the scoping review demonstrate that while priority-setting frameworks may require participation of all stakeholders, in practice certain stakeholder groups, namely the public and especially vulnerable populations, are not consistently integrated into priority-setting processes. The empirical research provides a rich understanding of the roles of different stakeholders in the priority-setting process and provides explanations about why vulnerable women, as a subset of the public, are not participating. This adds to the evidence base that policy-makers can access to guide future attempts to engage publics in health-system priority setting. These studies collectively contribute to a wider understanding of public’s and vulnerable populations’ participation in health-system priority setting in low-income contexts where health disparities are pronounced, and health resources are especially scarce. Policy-makers should aim to support vulnerable populations’ participation in health-system priority setting. Clear articulation of which vulnerable populations should participate and how they should participate can facilitate priority-setting processes. Co-developing participatory methods, frameworks, and guides with vulnerable populations can reinforce their participation and lead to mechanisms of participation that are more responsive to their needs.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Public participation is often considered a cornerstone of fair and legitimate priority setting. Yet, little is known about whether and how the participation of vulnerable populations is operationalized in the field of health-system priority setting. An in-depth understanding of who participates and who does not, and how participation is enabled and/or hindered is essential to ensure that policy-makers can support participation. This dissertation addresses gaps in knowledge through: 1) a literature synthesis examining the operationalization of stakeholder participation within priority-setting frameworks, with specific attention to the publics’ and vulnerable populations’ participation, in cases where the frameworks have been applied to health-system priority setting; 2) supportive qualitative evidence on the roles, leverages, and challenges of different stakeholders’ participation in district-level health-system priority setting in Uganda; and 3) examining vulnerable women’s participation within one Ugandan district, specifically outlining barriers to their participation, and solutions to address these barriers and support vulnerable women’s participation in health-system priority setting. Collectively these studies can inform policy-making and development of public participation strategies that specifically target vulnerable populations for participation in health-system priority setting.


title: Stories from Parents: Raising Proud Inuk Children - "It Starts at Home"

contributor:
Gabel, Chelsea
Global Health

subject:
parenting
education
Inuit
language
identity development

abstract:
Background: The Colonization, the residential school system, the Indian Act, TB sanatoriums, and the dog sled slaughter have all impacted the health of Inuit and resulted in intergenerational trauma. The impact of these events resulted in loss of culture, identity, language, and ways of living a subsistence lifestyle. Within Nunavut, Inuit are healing and are revitalizing inunnguiniq, which is the journey to obtain knowledge and skills that will help us enter society and live a good life.
Methods: Using a community-based participatory research approach 20 in-person semi-structured interviews were conducted in Iqaluit, Nunavut during November and December 2018, with parents/caregivers who were raising their Inuit children. The questions allowed the parents to broadly answer questions surrounding parenting, the supports and challenges, and stories about raising an Inuk child in today’s society. Data analysis was guided by grounded theory.
Findings: Using NVivo 12 Windows, three prominent themes were identified: 1) language, 2) education, and 3) identity development. Each theme is a reflection of how the parents who participated in this project and their own upbringing have impacted and influenced their parenting decisions. 1) Language connects to our culture and our identity. 2) The parents expressed obtaining a formal and informal education. Certain aspects of the Inuit culture cannot be taught in indoor classrooms, therefore the parents expressed the need for a more balanced education curriculum that incorporates Inuit culture as well as life skills development. 3) Identity development focused on raising their children to learn certain Inuit values, which were miksirkarnirq (having a strong foundation), pijitsirniq (serving, respecting and helping others), pilimmaksarniq (becoming skilled), and avatitinik kamattiarniq (being aware of our environment).
Conclusion: Raising an Inuk child to retain their language, gain a robust balanced education, and develop a strong Inuk identity starts at home. Parents and caregivers need to receive the support from all organizations that support childhood development in order to further support raising their child.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Understanding how parents are raising their Inuk children in today’s society is the focus of this project. The project involved speaking with parents/caregivers and learning about their experiences being parents/caregivers. The main ideas that many parents/caregivers spoke about were the importance of language, education (both formal and informal), and identity development. Parents recommended that parents themselves should take the initiative to raise their children – it starts at home. In addition, parents recommended that the community and organizations should support parents/caregivers that may not have the skills or knowledge to raise their children. Overall, the importance of everyone working together and contributing to raising the child was highlighted.


title: Coating of High Strength Steels with a Zn-1.6Al-1.6Mg Bath

title: Selective Oxidation and Reactive Wetting of High Strength Steels by a Zn-1.6Al-1.6Mg Bath

contributor:
McDermid, Joseph R.
Materials Science and Engineering

subject:
reactive wettting
advanced high strength steel
high strength steel
dual phase steel
selective oxidation
annealing process atmosphere
bare spot defects
bare spot
continuous hot-dip galvanizing
galvanizing
Zn-Al-Mg coating
Zn-Mg-Al coating
ZM coating
ZAM coating

abstract: Recently, Zn-XAl-YMg coatings have emerged as lighter-weight substitutes for traditional Zn-based coatings for the corrosion protection of steels; however, little is currently known concerning the interactions between the oxides present on advanced high strength steel (AHSS) surfaces and the Zn-Al-Mg bath. In the current contri- bution, the selective oxidation and reactive wetting of a series of C-Mn AHSS were determined with the objective of providing a quantitative description of this pro- cess. The process atmosphere pO2 was varied using dew points of −50◦C, −30◦C and −5◦C. The surface oxide chemistry and morphology were analysed by means of SEM and XPS techniques. Reactive wetting of the selectively oxidized surfaces using a Zn-1.6 wt.% Al-1.6 wt.% Mg bath was monitored as a function of annealing time at 60 s, 100 s and 140 s at 800◦C. The resulting bare spot defects in the Zn-1.6 wt.% Al-1.6 wt.% Mg coating were assessed by means of SAM-AES and FIB, while coating adhesion was analysed by 180◦ bend tests. Annealing the steel substrates resulted in the formation of surface MnO, which varied based on pO2 and Mn alloy content, and that this MnO greatly reduced the wettability of the steel by the Zn-1.6 wt.% Al- 1.6 wt.% Mg bath, resulting in bare spot defects. It was determined that the reactive wetting of the steel substrate was dependant on the oxide morphology and oxidation mode, which was a function of both alloying content of Mn in the steel and annealing pO2 process atmosphere (dew point). Finally, it was concluded that the bare spot area percentage on the coated panels was statistically invariant for annealing times of between 60 s and 140 s at 800◦C.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Metallic coatings are applied to steels that are not naturally corrosion resistant. The aim of this research was to determine how well a coating containing zinc, aluminum and magnesium adhered to high strength automotive steel. It was deter- mined that manganese oxides formed on the steel during heating prior to applying the metallic coating. The manganese oxides prevented good adhesion between the steel and the coating, resulting in bare spot defects in the coating. The bare spot defects are undesirable as they leave the steel exposed and therefore susceptible to corrosion and are unsightly when painted.


title: Reproductive consequences of nesting site decisions in a marine toadfish (Porichthys notatus)

contributor:
Balshine, Sigal
Juanes, Francis
Psychology

subject:
Oviposition site selection
Behavioural ecology
Environmental gradient
Intertidal ecology
Parental care
Plainfin midshipman
Reproductive success

abstract: Full thesis document accompanied by all data files and R scripts to reproduce analyses in both data chapters (2 & 3).

abstract: Animals should favour breeding locations that maximize their lifetime reproductive output. Parents ought to rear young in sites that positively affect offspring but sometimes these same sites inflict costs on parents. How parents balance their own needs against those of their offspring when selecting a site for reproduction remains unclear, particularly in animals that provide extended parental care at one location. Further, few studies have linked variation in life history traits to reproductive site choices within a single species. In this thesis, I addressed both knowledge gaps by studying the plainfin midshipman (Porichthys notatus), a marine toadfish where fathers provide sole parental care to broods of young in intertidal and shallow subtidal nests for up to two months. In Chapter 2, I measured the costs incurred by caring males and the benefits conferred to offspring in nest sites along a tidal gradient. Males suffered similar rates of body condition deterioration in all nests across the intertidal gradient. Young developed more quickly in intertidal nests compared to subtidal nests, but broods in the highest intertidal nests suffered the highest mortality rates, despite receiving more parental care from the males at these nest sites. We found the most competitive males in lower intertidal nests, a trend that agrees with life history theory—in species with relatively slow offspring development, parents should accrue greater reproductive benefits from nest sites where offspring benefits are highest. In Chapter 3, I describe a laboratory experiment designed to examine how warm water and air exposure (two abiotic conditions that vary dramatically within the intertidal) affect development and survival of plainfin midshipman young, and how these effects vary with maternal traits. Exposure to warm water enhanced embryonic and larval development rates; this effect was attenuated by air exposure. Juveniles raised in warm water also exhibited superior swimming performance, while air-exposed young suffered higher mortality rates. Although larger juveniles emerged from larger eggs, development rates were similar across egg sizes. Offspring survival increased with maternal body condition in cold water but decreased with maternal body condition in warm water. Juvenile body sizes increased with maternal condition in cold water without emersion, and in warm water with emersion—the two ecologically relevant rearing environments. Thus, low condition mothers might accrue greater benefits by depositing their eggs in nests at higher tidal elevations—where development is more rapid—further supporting the idea that among-individual variation in the expression of life history traits might influence nest site preferences in these fish. In sum, my research (Chapters 2 & 3) elucidates the link between life history traits and the spatial component of animal reproductive strategies.

abstract: Thesis

abstract: Master of Science (MSc)


title: NavNets: 3D Path-planning system

contributor:
von Mohrenschildt, Martin
Computing and Software

subject: NavNets NavMesh Path-planning Path-finding

abstract:
The current state of 3D path-planning leaves room for improvement. To navigate a 3D
environment, techniques which were developed for 2D navigation are used and slightly
adapted to generate convincing motion. However, these techniques often constrict the
motion to a single plane. This constriction is not only a limitation, but also increases
the error. We created a new method to compute a path in a 3D world without a planar
constraint. We will discuss the computation of a Navigation Volume Network (NavNet),
and how it finds a path. A NavNet is the 3D generalization of NavMeshes, and holds
boundary and connection information which is utilized when planning a path for motion.
Similar to how NavMeshes allow path-planning by simplifying the ground meshes, the
NavNet simplifies the search space by approximating the 3D world through sampling.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: STABILIZING THE SELF: IMMIGRANT LABOUR AND RETHINKING PRECARITY

contributor:
Rethmann, Petra
Anthropology

subject:
ethnography
South Asian immigrant women
labor
Precarity

abstract: This thesis is an investigation into migration, identity and labour among South Asian immigrant women in the Greater Toronto Area. It is an ethnographic exploration of how South Asian migrant’s relationship with precarity and how it informs the process of subjectification when faced with the realities of downward mobility. I focus on the practices and narrative repertoire that aid the relationship between labour and the making of the self. This inquiry has implications for the study of migration and expands on previous conceptualization in the literature on precarity.

abstract: Thesis

abstract: Master of Arts (MA)


title: GSN Models of Safety Assurance for the Automotive Industry

contributor:
Lawford, Mark
Computing and Software

abstract:
The technological landscape of the automotive industry is constantly evolving, reinforcing the need for all systems to be safe and reliable for consumers. Assurance case templates can be used by automakers within their system safety process as a clear and consistent method to demonstrate the safety assurance of system level designs. To represent the assurance case templates, within this work we will be utilizing Goal Structuring Notation (GSN), an argumentation notation that enables the creation of conceptual assurance case models.

This work will outline and adhere to a standardized process for modelling an explicit representation of the safety case of an assurance argument as a GSN template using the implicit assurance argument within safety process documentation. Future work will be explored regarding the application of the utilized methods to other work products within the system safety process, as well as emerging methods that can be used to represent assurance case templates.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Digital Dads: The Culture of Fatherhood 2.0

contributor:
Gillett, James
Sociology

subject: fatherhood, parenting, family roles, gender, masculinity, culture, blogging, social media, ethnography

abstract: This dissertation examines a community of men who write online parenting blogs—known as “dad bloggers.” The emergence of dad bloggers in North America is nascent, under-researched, and a result of recent shifts in work-family arrangements, gender expectations, and the proliferation of social media technologies. Accordingly, this dissertation is designed to provide three distinct, yet interrelated, contributions to the literature on: families and parenthood; gender and masculinities; and media communications and communities. Taking a cyber-ethnographic approach, this is the first study of dad bloggers to collect online and offline data in order to investigate personal, interpersonal, and public meaning-making practices. The entire dataset consists of 1,430 blog posts written by 45 bloggers, approximately 50 hours of fieldwork conducted at The Dad 2.0 Summit conferences from 2016 to 2018, and 5 in-depth interviews. In three substantive chapters, I address: (1) the collective actions and goals that shape dad bloggers’ group culture and public engagement; (2) the creation and dissemination of meanings for fatherhood in an online context; and (3) the negotiation of gendered family roles and articulation of masculinity discourses by fathers. Collectively, this research provides new empirical and theoretical insights about the social construction of fatherhood in the contemporary digital age.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Development of an Axial Yielding Energy Dissipation Device for Controlled Rocking Masonry Walls

contributor:
Wiebe, Lydell
Ezzeldin, Mohamed
Civil Engineering

abstract:
The damage caused due to a seismic event can leave a city destabilized. However, the negative effects can last much longer because of the inability to reoccupy critical infrastructure systems due to their demolition and eventual rebuild. In order to minimize the recovery time following a seismic event, energy dissipation devices can be installed to absorb the majority of the seismic damage and subsequently maintain the main structure serviceable. One researched solution is by allowing controlled rocking of a masonry wall. A controlled rocking masonry wall uses its own gravity load along with a yielding energy dissipating device as a restoring force to return the wall to its original vertical alignment.

Through iteration, a new axial yielding energy dissipation device was designed in the current study to be installed to a controlled rocking masonry wall. The proposed device was designed to provide the required supplemental energy dissipation, while also being replaceable in the event of seismic damage. The device takes inspiration from structural buckling restrained braces, which includes a yielding steel core, a rubber debonding layer, and a confining grout all within a steel casing. The device is bolted into the wall foundation as well as into a special steel portion of the wall that prevents toe damage and provides a rigid section for the installation of the device. Furthermore, the overall design of the new device maintains the footprint of a standard masonry wall.

After initial conceptual development of an axial yielding device, half-scale testing was performed to assess the seismic performance of nine specimens with different design parameters. Quasi-static uniaxial testing, through adapters on a uniaxial tester, was performed to simulate the actual boundary conditions for the bolted ends of the specimens. Parameters investigated in the current study included the cross-sectional area of the yielding core, the thickness of a rubber debonding layer, and the effective length of the core. An OpenSees model was then developed to simulate the seismic performance of the new device. The model was validated against experimental results and further verified using mechanics to evaluate the maximum force of the device when designed with different geometrical configurations. The results of the study show promise of both a feasible energy dissipation device and an effective tool for estimating performance prior to conducting detailed design.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
Earthquakes can cause incredible damage to cities specifically to their critical infrastructure systems. The economic effects of such seismic damage can last for a prolonged time due to the inability to repair crucial structures, such as hospitals and schools. The need for easily designable and repairable energy dissipation devices is crucial for all structures, but especially masonry structures due to the lack of current research.

This thesis describes the development, testing, and modelling of a new axial yielding energy dissipation device for controlled rocking masonry walls. The experimental work demonstrated that the new device can achieve an acceptable level of performance through appropriate energy dissipation and force capacities for the intended application. The numerical developed model was shown to be an effective tool for predicting the seismic performance of the device.


title: Hydrogel-Based Intranasal Drug Delivery Platforms

title: Engineering Starch Nanoparticle/Chitosan Emulsion-Templated Nanogels and In Situ-Gelling Hydrogels for the Intranasal Delivery of Anti-psychotic Medication

contributor:
Hoare, Todd
Mishra, Ram
Biomedical Engineering

abstract:
Current strategies for oral or injectable antipsychotic drug delivery typically demonstrate low bioavailability to targeted brain regions, incentivizing the development of novel delivery strategies. Delivery via the nasal cavity circumvents multiple barriers to the reaching the brain: the blood-brain barrier, first-pass metabolism and gut degradation, but requires specific drug-carrier characteristics (e.g. pH, mucoadhesion) to be effective. Employing the use of nanoparticle drug carriers (~50nm in size) within this route can further improve efficacy, due to their enhanced tissue penetration abilities. Although existing intranasal delivery platforms have demonstrated great therapeutic value, there is a lack of controlled release features–an extremely valuable addition to this pathway.
Described in this thesis are biodegradable bulk hydrogels consisting of oxidized starch nanoparticles (SNPs) and carboxymethyl-chitosan (CMC) which allow for both intranasal mucosal adherence and functional controlled release of anti-psychotic drug (PAOPA) in an MK-801 pre-clinical model of schizophrenia. Results indicate that PAOPA-loaded SNP-CMC in-situ gelled hydrogels provide a sustained released profile such that they alleviate negative symptoms associated with schizophrenia (decreased social interaction time) for up to 72 hours at a decreased dosage (0.5mg/kg) when compared to acute symptom alleviation at a higher (1mg/kg) intra-peritoneal drug dosage. Also described is the formulation of nanoemulsion templated nanogels (~200nm) for eventual intranasal delivery applications. Nanogels (also consisting of SNP-CMC) demonstrated relevant degradation profiles resulting in SNP release, which may be employed for future tissue penetration applications within the nasal cavity. It is anticipated the bulk hydrogel platform (and nanogel system, once further studied) will lower required drug doses and ultimately improve clinical outcomes in treating mental illness.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: INVESTIGATION OF NEUROPROTECTIVE TARGETS FOR PARKINSON’S DISEASE AND THEIR ROLE IN PATHOPHYSIOLOGY WITH A SECONDARY LOOK AT A MOLECULAR TARGET FOR SCHIZOPHRENIA

title: MOLECULAR TARGETS FOR CENTRAL NERVOUS SYSTEM DISORDERS

contributor:
Mishra, Ram
Neuroscience

subject:
Parkinson's Disease
Schizophrenia
MANF
Synapsin II
CDK5/p25
TP5

abstract: Disorders of the central nervous system (CNS) continuously pose problems for current therapeutics. In part, this is due to the uncertainty of underlying pathophysiological changes that give rise to specific disorders. Parkinson’s disease (PD) specifically is a neurodegenerative CNS disorder with unknown origins of dopaminergic degeneration in the substantia nigra. Current therapies are reactive in nature and no existing neuroprotective therapies are available. Two hypotheses have been proposed to contribute to dopaminergic degeneration in PD: endoplasmic reticulum (ER) stress and oxidative stress. This thesis investigates molecular targets involved in each of these responses (mesencephalic astrocyte-derived neurotrophic factor (MANF) and cyclin-dependent 5 (CDK5)/p25 respectively) to support a multi-hit hypothesis in PD neural degeneration. Using behavioural and biochemical analysis, a reduction in MANF was found to participate in the ER stress hypothesis and CDK5/p25 hyperactivation is a viable neuroprotective target related to the oxidative stress hypothesis. Both pathways are evidenced in PD pathology and this thesis proposes specific targets for both pathways in the development of necessary neuroprotective therapies. Subsequently, included in this thesis is a chapter about the unmet pharmacological alleviation of negative and cognitive symptom domains in another CNS disorder of unknown pathophysiology: schizophrenia (SZ). These untreated symptoms are thought to be caused by irregularities in the signalling of multiple neurotransmitter systems. This chapter investigates the role of synapsin II, a protein involved in regulating signalling of multiple neurotransmitters, in manifesting negative and cognitive SZ symptoms and analyzes brain glucose metabolism. Reduced synapsin II levels were consistently implicated in the underlying physiology, and therefore synapsin II is proposed as a potential pharmacological target for these unmedicated symptomologies. Overall this thesis uses interrelated studies to propose novel molecular targets to address unmet therapeutic needs based on evidence of their involvement in the pathophysiology of PD and SZ.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Brain diseases like Parkinson’s disease (PD) and Schizophrenia (SZ) are difficult to treat because their cause has not been discovered. PD shows degeneration of cells in the brain but the cause for degeneration is unknown. This makes developing treatments to protect cells from dying difficult. Two pathways are suggested to cause cell death in PD. This thesis proposes that both pathways are responsible for degeneration through a combined effort. Here, both pathways are shown to lead to cell death resembling PD and specific molecules are suggested as targets for developing protective treatments. Like PD, SZ has symptoms that cannot be treated because the cause is unclear. A protein was investigated for producing SZ-like symptoms and found to have potential for treatment design. This thesis aims to understand molecular changes in the brain leading to PD, with a look at SZ and how they can be used for better treatment design.


title: Employing Functional Nucleic Acids as Molecular Recognition Elements Within Modular Biosensors

contributor:
Yingfu, Li
Biochemistry and Biomedical Sciences

subject:
aptamer
DNAzyme
functional nucleic acid
biosensor
cancer
biosensing
colorimetric
fluorescence

abstract: Advances in our ability to detect biological targets relevant to human health have come from the engineering of biological molecules into assemblies capable of performing target-induced signal generation. Such assemblies, known as biosensors, are composed of a molecular recognition element (MRE) and a signal generating transduction element. One MRE class that has received great attention in recent years is functional nucleic acids, which include DNA aptamers and DNAzymes. Since 1990, a large number of functional nucleic acids have been reported. However, broad commercial use of functional nucleic acids in applications that benefit human health is sparse. The goal of this thesis is to expand the usefulness of functional nucleic acids. The thesis is made of four projects. In the first project I developed a simple colorimetric biosensor for the detection of a toxic metal ion using a reported RNA-cleaving DNAzyme coupled with urease as the signal reporter. This is followed by a project where I developed a highly effective method for the synthesis and purification of the DNA-urease conjugate needed for the biosensor.  I then turned my attention to the search for high-affinity DNA aptamers that bind VEGF-165, an important human protein found to be relevant in the progression of cancers. Given that VEGF-165 is a homodimeric protein, in my third project I looked into the suitability of reported DNA aptamers for this protein for the creation of dimeric aptamers with higher binding affinity. I examined multiple factors that may affect the successful engineering of dimeric aptamers and determined that none of the existing aptamers are compatible for creating a productive dimeric aptamer. With this finding, I made an effort to create our own aptamers for this protein target. I was able to isolate a new aptamer that appears to be an excellent candidate for creating a higher affinity DNA aptamer. Overall, my work adds to our increasing appreciation of the functional capability demonstrated by single-stranded DNA molecules. More importantly, I hope the methods I have developed and new functional DNA molecules I have generated in this thesis will continue to drive the development of the functional nucleic acid field and contribute to the health research community’s efforts to increase human longevity.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Music Hall and the Age of Resistance

title: Music Hall and the Age of Resistance: A Study of the Censorship Practices Which Influenced the Form of the Victorian Music Hall Leading to the 1912 Royal Command Performance and Beyond

contributor:
Grisé, Catherine
English and Cultural Studies

subject: Music hall, London County Council, Marie Lloyd, self-reflexive censorship, Censorship, Resistance, Victorian Era, Edwardian Era, Class-Relations, Female Performance, Taste-Making

abstract: Building on Penelope Summerfield’s argument that the end of the Victorian music hall in the early twentieth century signaled not “death” but a class-conscious evolution of the genre prompted by a “process of deliberate selection later made to look natural and inevitable,” this project examines the acts of censorship and resistance which characterised the final years of the Victorian music hall. Selecting the 1912 Royal Variety or Royal Command Performance as the “end” point of the genre, and limiting my focus to London music halls, this project examines competing aims of working, middle, and upper class participants: it suggests that the upper-class aspirations of the managers of London’s music halls, paired with middle-class moral desire for social control over the working-classes, eventually enforced by the London County Council in the mid-late nineteenth century, saw the rise of “respectability” in the genre while severing its ties to London’s working classes. Juxtaposing ephemeral evidence produced by or focused on London music halls in the late nineteenth century (leading up to and including the 1912 Royal Command Performance) with contemporary research on the classed nature of social control and censorship practices, this thesis intends to make the classed-struggle for power and ownership over the identity of London’s music halls evident. In doing so, the thesis alludes to the potential success of a third wave of music hall or the neo-music hall, to replace out-dated reflections of the music hall revival sparked by “The Good Old Days” and nostalgia post World War II.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: This thesis pairs an analysis of meeting minutes, newspaper articles, song-sheets, and theatrical programmes from London’s Victorian music halls with contemporary music hall scholarship and studies of censorship to add to the discussion of the genre’s “end” or “death.” Using the work of Judith Butler, this thesis is divided into a study of how censorship transformed the music hall’s landscape, content, and culminating performance from its onset. As a result, this thesis argues that the controlling factors which shaped the genre led to what other music hall scholars have considered its end. By identifying the styles and modes of censorship used in the evolution of the English music hall genre, and in in-period methods of resistance to social control, this project suggests the radical potential of the music hall form as a contemporary style of theatre.


title: Change Impact Analysis in Simulink Designs of Embedded Systems

contributor:
Lawford, Mark
Wassyng, Alan
Computing and Software

subject:
Software Engineering
Change Impact Analysis
Model-Based Design

abstract:
This thesis presents the \emph{Boundary Diagram Tool}, a tool for change impact
   analysis of large Simulink designs of embedded systems. The Boundary Diagram Tool extends
   the Reach/Coreach Tool, an existing tool for model slicing
   within a single Simulink model, to trace the impact of model changes through
   multiple Simulink models and to network
   interfaces of an automotive controller. While the change impact analysis results can be viewed directly within the Simulink models, the tool also
   uses various block diagrams  to represent the impact analysis results with different levels of abstraction, motivated by industrial needs. In order to effectively present the complex  impact analysis results, various  techniques for visual representation of large graphs are employed.
    Furthermore, the Reach/Coreach Tool as an underlying model slicing engine was significantly improved. The Boundary Diagram Tool is currently being integrated
   into the software development process of a large automotive
   OEM (Original Equipment Manufacturer). It provides support during several phases of the change management process: change request analysis and
   evaluation, as well as the implementation, verification and integration of software changes. The tool
   also aids impact analyses required for compliance with functional
   safety standards such as ISO 26262.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Changes in metabolic regulation of the carbohydrate oxidative pathway in exercising high altitude deer mice

title: Metabolic regulation in exercising high altitude deer mice

contributor:
McClelland, Grant
Biology

subject:
High altitude
Adaptation
Deer mouse
Muscle
Metabolism
Metabolic regulation

abstract: Hypoxia encountered at high altitude (HA) can limit energy production via aerobic metabolism in animals. Carbohydrate oxidation (CHO) has a greater ATP yield/mole O2 than fat oxidation, and HA-native deer mice show an increased reliance on CHO during submaximal exercise after hypoxia acclimation as an O2-saving strategy. However, hypoxia acclimation does not increase glycolytic capacity in muscle. We therefore tested the hypothesis that altered metabolic regulation of the CHO pathway allows HA mice to achieve higher rates of CHO during submaximal exercise. The objective of our study was to identify the effects of hypoxia acclimation on the regulation of two key proteins in the CHO pathway and their activation with exercise. Using first generation (G1) laboratory born and raised HA deer mice acclimated to normoxia or chronic hypoxia, we examined the metabolic regulation of muscle glucose uptake by glucose transporter (GLUT) 4 and of pyruvate oxidation by pyruvate dehydrogenase (PDH). The gastrocnemius was electrically stimulated in situ under anaesthesia and acute normoxia at two submaximal workloads relative to maximal force production, which was measured using a force transducer. In frozen gastrocnemius following stimulation or rest, GLUT4 protein content was measured via Western blotting of the sarcolemmal membrane fraction and PDH activity was measured using a radiolabelled assay. We found no differences in sarcolemmal GLUT4 content with stimulation, but PDH activity was increased in hypoxia, indicating increased rates of carbohydrate breakdown at similar workloads after acclimation. These data were compared to data from wild HA deer mice sampled at their native altitude. In support of our hypothesis, these data show that the metabolic regulation of the carbohydrate oxidative pathway changes with acclimation to support higher CHO rates during submaximal exercise. These data will help uncover the mechanistic underpinnings responsible for the exercise fuel use strategies observed exclusively in HA-native mice.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: At high altitude, oxygen availability is low and can be challenging for active animals. Preferential carbohydrate oxidation is a metabolic strategy used by high altitude-native deer mice to fuel exercise because of its high energy yield per oxygen consumed. Despite the increase in carbohydrate breakdown, the capacity for muscles to use carbohydrates did not change, suggesting that the regulation of this metabolic pathway may be changing instead. We measured the contributions of two proteins involved in carbohydrate metabolism in active muscle, pyruvate dehydrogenase (PDH) and glucose transporter 4 (GLUT4), at different muscle workloads and after acclimation to high altitude conditions. We found no differences in GLUT4 content, but PDH activity was higher in hypoxia-acclimated mice at similar intensities, indicating increased rates of carbohydrate breakdown after acclimation. These data suggest that the regulation of the carbohydrate metabolic pathway changes with acclimation to support higher rates of carbohydrate oxidation during exercise.


title: Capacity Expansion of Electric Vehicle Charging Network: Model, Algorithms and A Case Study

contributor:
Huang, Kai
Computational Engineering and Science

subject: logit choice model

subject: facility location

subject: capacity expansion

subject: electric vehicle charging network

subject: branch-and-price

abstract: Governments in many counties are taking measures to promote electric vehicles. An important strategy is to build enough charging infrastructures so as to alleviate drivers’ range anxieties. To help the governments make plans about the public charging network, we propose a multi-stage stochastic integer programming model to determine the locations and capacities of charging facilities over finite planning horizons. We use the logit choice model to estimate drivers’ random choices towards different charging stations nearby. The objective of the model is to minimize the expected total cost of installing and operating the charging facilities. Two simple algorithms are designed to solve this model, an approximation algorithm and a heuristic algorithm. A branch-and-price algorithm is also designed for this model, and some implementation details and improvement methods are explained. We do some numerical experiments to test the efficiency of these algorithms. Each algorithm has advantages over the CPLEX MIP solver in terms of solution time or solution quality. A case study of Oakville is presented to demonstrate the process of designing an electric vehicle public charging network using this model in Canada.

abstract: Thesis

abstract: Master of Science (MSc)


title: CHLORIDE EFFECTIVE DIFFUSION COEFFICIENT OF CONCRETE

contributor:
Chidiac, Samir E
Civil Engineering

subject:
Concrete
Chloride
Durability
Diffusion Coefficient
Model

abstract:
For concrete, a sustainable design requires considering both mechanical properties and durability. One of the major deterioration modes of reinforced concrete structures is the entry of chloride ions and corrosion of embedded metals, which is mainly controlled by diffusion as the mass transport mechanism. Therefore, it is pivotal to quantify the chloride diffusion coefficient of concrete, which controls the rate of chloride ingress. Several testing methods exist for quantifying diffusivity of concrete. However, the current test methods are time consuming and demanding.
The primary goal of this study is to develop models for quantifying the chloride diffusion coefficient of concrete. As such, initially, the most recent and prevailing analytical models proposed in the scientific literature were critically reviewed and the parameters controlling the chloride diffusion coefficient of concrete were identified. Then, the cement degree of hydration of concrete – as a key parameter which controls the properties of concrete – its measurement methods, and the uncertainties associated with different quantification methods were scrutinized. Finally, three models were developed to quantify the chloride diffusivity of concrete.
The first model quantifies the chloride diffusivity of concrete in terms of its electrical resistivity based on the modified Nernst-Einstein equation. The model accounts for the ionic concentration of the pore solution through the alkalis released due to hydration of cementing materials and the alkali uptake of hydration products, the pore solution conductivity, and the interaction between the ions in the pore solution. The second model, which provides a phenomenological relationship for chloride diffusivity of concrete in terms of its compressive strength, accounts for the tortuosity factor of the mixture, aggregate volume fraction, porosity, compressive strength, and cementing materials content and composition. The third model is developed based on the mixture constituents and the cement degree of hydration of concrete. The model accounts for tortuosity factor through the volume fraction of aggregate particles, the interfacial transition zone thickness and diffusivity, cementing materials type and chemical composition, bulk cement paste transport properties through water to cementing materials ratio, cement degree of hydration, supplementary cementing materials type and replacement levels.
In order to assess the accuracy and precision of the proposed models, an experimental program was developed and conducted. The following variables were considered for the experimental program: the volume fraction of coarse aggregate, water to cementing materials ratio, total cementing materials content, and supplementary cementing materials type and replacement levels. The experimental results along with the reported data in the scientific literature were used to validate the proposed models. The results revealed the capability of the models to capture the documented observations, as well as the high accuracy and precision of the proposed models for quantifying the chloride diffusivity of concrete in a wide range of concrete mixtures composition and age. The developed models provide designers, practicing engineers and standard/code developers with accurate, precise and consistent models for quantifying the chloride diffusion coefficient of concrete as a direct measure of its durability.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Networks, Experts, and Paradoxes: Older Adults' Experiences of Polypharmacy and Perceptions of Deprescribing

contributor:
Gillett, James
Health and Aging

subject: polypharmacy, deprescribing, older adults

abstract: As medical researchers test the feasibility of deprescribing programs to reduce medication burden associated with polypharmacy, limited scholarly consideration has been given to the perspectives of the older adults largely targeted by these programs. This dissertation makes central the voices of older adults experiencing polypharmacy and/or deprescribing. Presented as a collection of three articles, this work explores the perspectives of older adults on their use of medication in the context of both polypharmacy and deprescribing. Data were collected using in-depth semi-structured qualitative interviews with older adults concurrently using 5+ prescription medications. The first article draws on Habermas’ writing on the contribution of communicative action in negotiating trust within complex social relationships. This analysis highlights the social nature of medication work and challenges to communicative action within personal and professional health systems. The second article applies embodiment theory to understand the way older adults’ construct unique forms of expertise regarding their health, resulting from a lifetime of experiences living as and in their bodies. The last article uses social constructionist theories on systems of classification to show the way dichotomies in medical classifications are often paradoxical. This article offers insight into the work older adults do to optimize their use of medicines in the context of these paradoxes. This study, in its entirety, indicates a need for collective efforts to identify and address the problems of polypharmacy while facilitating appropriate polypharmacy for older adults with complex multiple co-morbidities. Doing so encourages a reframing of polypharmacy as a complex phenomenon about which clinical judgments are made through an ongoing collaboration with the patient and family.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Development of a Flexural Yielding Energy Dissipation Device for Controlled Rocking Masonry Walls

subject:
Controlled Rocking Masonry Walls
Energy Dissipation Device
Flexural Yielding
Seismic Design
Base Shear

abstract:
Steel flexural yielding arms can be an effective energy dissipation device for several seismic force resisting systems, including controlled rocking masonry walls. In controlled rocking masonry walls, uplift of the wall from the foundation is allowed in a way that can localize damage and minimize post-earthquake residual drifts. However, along with other modes of failure, sliding of the rocking walls can increase drifts and damage if not adequately addressed. Controlled rocking systems have different alternatives to prevent sliding, which include the use of additional mechanical components (e.g. metal stoppers) at the corners to resist lateral forces while allowing the wall rocking motion. However, these mechanical components hinder the constructability of the wall in some cases. The use of an energy dissipation device (i.e. steel flexural yielding arm) to also prevent the wall sliding mechanism has not been fully explored to date. The development of an easily replaceable energy dissipation device with the ability to simultaneously resist sliding demands is expected to maintain the overall performance of controlled rocking masonry walls, while also enhancing post-earthquake repairability.
The objective of the current study is to experimentally investigate the effect of axial forces on the behaviour of steel flexural yielding arms under cyclic loading. In this respect, the study first presents a description of the experimental program, test setup, and instrumentation. Next, the experimental results of the tested specimens are discussed in terms of the effect of axial forces on the load, displacement, and energy dissipation capacities of the tested devices. Finally, new design equations that account for axial forces are proposed and verified against the experimental data along with a finite element model. Based on the results, recommendations are given for the further development of externally attached and replaceable flexural yielding arms for controlled rocking masonry walls.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
Controlled rocking masonry walls can be a cost-efficient alternative to traditional masonry shear walls because of their enhanced performance, specifically to reduce and localize structural damage induced by seismic loads. However, a controlled rocking wall requires additional energy dissipation devices or post-tensioning techniques to compliment the rocking wall to achieve the desired performance.
	This thesis explores and improves a type of energy dissipation device for controlled rocking masonry walls and aims to provide detailed design specifications for professional engineers. A design and considerations from previous studies are discussed, followed by the experimental validation, and finally new design equations are proposed for this type of reliable, flexural energy dissipation device.


title: THE RELATIONSHIP BETWEEN OBJECTIVELY MEASURED HABITUAL PHYSICAL ACTIVITY IN PRESCHOOLERS AND PERIPHERAL ARTERY ENDOTHELIAL FUNCTION IN SCHOOL-AGED CHILDREN

contributor:
MacDonald, Maureen
Kinesiology

subject:
endothelial function
flow-mediated dilation
pediatric
physical activity
brachial
artery

abstract: The development of atherosclerotic lesions and endothelial cell damage can originate during early childhood. Endothelial cells produce and release vasodilatory chemicals, which dictate the artery’s ability to vasodilate or vasoconstrict. Brachial artery FMD is a non-invasive, reproducible and a sensitive technique used to detect changes in arterial diameter and is correlated with coronary artery endothelial function. Cross-sectional studies have indicated increases in arterial diameter in children between the ages of 6-18 years however, a longitudinal, observational design study has not been conducted to understand how arterial diameters and FMD change over time in children, with considerations for the influences of physical activity and sex. The purpose of this study was to understand the impact of age and sex on arterial diameter and FMD and investigate the effects of habitual moderate-to-vigorous physical activity (MVPA) during both the school-age and preschool years on endothelial function trajectories during the school-age years. Over three years, 418 children between 3-5 years old participated in the HOPP study annually, and 279 of these children attended the lab when they were between 6-12 years old for an additional 3 annual visits in the SKIP study. Habitual MVPA was measured for 7 days in both the HOPP and SKIP studies each year, and FMD was measured each year during SKIP. Linear mixed-effects modeling was implemented to study the trend in FMD and the influence of chronological and biological age, sex and MVPA on arterial function; effects are reported as unstandardized estimates (Est). Boys had larger baseline and peak brachial artery diameters compared to girls (p<0.001). Girls had larger brachial artery FMD compared to boys (6.82±3.39 vs. 6.23±3.50 %, p<0.001). There was an effect of MVPA in the SKIP study on allometrically scaled FMD (Est. -0.017, p=0.03), but not on relative FMD (Est. -0.01, p=0.17). MVPA in the preschool years did not predict school-aged scaled FMD (Est. 0.11, p=0.24) or FMD (Est. -0.003, p=0.64). The observed trends in brachial artery diameter and FMD are in-line with expected changes in growth and maturation in children. Children who engaged in more habitual MVPA during the childhood years, but not the preschool years, demonstrated changes endothelial function during the school-age years.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: It is clear that preliminary signs of atherosclerosis begin during the early years of childhood, and typically precede the development of future cardiovascular disease. Engaging in habitual physical activity at higher intensities, has been shown to positively influence cardiovascular health, specifically in central and peripheral arteries. This study sought to investigate the trends in vascular heath over time in children and examine the effect of moderate-to-vigorous physical activity engagement during the preschool years on vascular health during the school-age years. Our results suggest that as children age, their arteries get bigger in size and that school-aged girls have elevated vascular function when compared to boys. Children who engage in greater amounts of moderate-to-vigorous physical activity during their school-age years does not influence measures of vascular health. Additionally, engagement in habitual moderate to vigorous physical activity during the preschool years does not impact these vascular health relationships during the school-age years.


title: The Nanoscale Structure of Human Female Osteoporotic Bone Investigated by Transmission Electron Microscopy

contributor:
Grandfield, Kathryn
Schwarcz, Henry P.
Biomedical Engineering

subject:
Bone
Osteoporosis
Transmission Electron Microscopy
Ion Milling
Biomaterials
Ultrastructure
Fracture
Image Analysis

abstract: Bioindicators of the nanoscale structural quality of bone were investigated using ion milling and transmission electron microscopy of osteoporotic bone from human female donors.

abstract: Bone is a complex hierarchical biomaterial constantly undergoing remodeling events initiated by cell signaling and fulfilled by migratory bone cells. In osteoporosis, a multitude of signaling factors cause bone resorption to proceed quicker than bone reformation, resulting in a lower bone mineral density (BMD) and porosity as seen by thinning of the cortex and trabeculae. However, the structural motifs of these altered regions of the skeleton have not been understood on the nanoscale. In this thesis, transmission electron microscopy (TEM) was used with an image analysis technique termed nanomorphometry, developed to enable the measurement of nanoscale structural features in human bone. Several nanoscale bone quality bioindicators relevant to the collagen fibrils and bone mineral (mineral lamellae, ML) components were defined and tested (collagen fibril diameter, interfibrillar spacing, ML thickness & ML stack thickness) among two donor cohorts of post-menopausal osteoporotic female patients and age- and sex-matched controls. In one cohort, the anatomical region investigated was the intertrochanteric crest of the femur, while in the second, the femoral neck was studied. The bone sections were prepared using an ion milling workflow yielding electron-transparent views of the bone ultrastructure. Blinded image analysis of the ultrastructure revealed that in both cohorts, the thickness of the MLs was significantly larger in osteoporotic samples versus their controls. In the former cohort, it was found that anti-resorptive drug use in the treated group did not return the ML thickness back to control levels. In the latter cohort, the ML thickness correlated more closely with the proximal femur bone mineral density (BMD) than the age of the patient. These findings suggest that the morphology of the nanoscale mineral phase is affected by osteoporosis, an effect indirectly observed by other techniques, and warrants further exploration into the implications of this effect on bone quality, fragility and strength.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: Human bone is a biomaterial with many levels of organization from the macroscale down to the nanoscale. The material consists of roughly 30 weight % organic components (collagen, non-collagenous proteins) and 67 weight % inorganic components (calcium phosphate minerals) deposited by bone cells. Osteoporosis is a bone disease commonly associated with increased bone porosity and bone fragility. In this study, the effect of osteoporosis on the nanoscale structure of bone was directly imaged and investigated using transmission electron microscopy (TEM). Two advanced ion milling techniques (broad beam and focused ion beam) were used to thin the bone specimens for TEM. Bioindicators relating to the structure and size of collagen and mineral components in osteoporotic versus control bone were quantified in an unbiased image analysis workflow. Findings indicated an increase in the thickness of poly-crystalline bone mineral lamellae in the nanoscale structure of human osteoporotic bone from two human donor cohorts.


title: CAS: Ally or Not? The Views of Young Adult Canadians with Indian Subcontinent Heritage

contributor:
Dumbrill, Gary
Social Work

subject:
CAS
Child Welfare
AOP
Confluence
Critical Race Theory
Indian Subcontinent
Anti-Oppressive Practice
Young Adults
Greater Toronto Area
GTA

abstract: The goal of this study was to assess how child welfare services are conceptualized and viewed by Canadian young adults with heritage from the Indian Subcontinent. Five second-generation young adults with heritage from the Indian Sub-continent were interviewed about their thoughts, attitudes, and opinions toward the Children’s Aid Societies when they were youths, and also currently. Findings showed that lack of awareness around the function of CAS, observations of negative CAS-community interactions, and overt/subvert whiteness in the system all contributed to participants not trusting CASs during their childhood and teenage years. Participants felt that the CAS systems are designed for the white population and not for children and youth of South Asian descent. Reflecting back on when they were youths, instead of viewing CASs as a source of support or help in times of family trouble, participants indicated that they and their parents would seek support from trusted friends, family, or community members. Now young adults themselves, and envisioning having their own families in the future, participants said that if needed they would access the same friend, family and community supports rather than approaching a CAS. That being said, participants expressed that they would be open to accessing CAS services but that this would be a last resort given their perception that the CAS is not designed for them or their community. Participants expressed a desire to be able to access CAS services, but not until CAS deal with their own whiteness. In addition to being less Eurocentric, participants also recommended a number of changes CAS make so that they better serve communities with Indian Sub Continent heritage, these include increased community engagement, information campaigns, increased presence of workers/foster families from South Asian communities).

abstract: Thesis

abstract: Master of Social Work (MSW)


title: EFFECTS OF A MULTI-INGREDIENT SUPPLEMENT ON MUSCLE STRENGTH AND HYPERTROPHY IN YOUNG MEN AND WOMEN: A DOUBLE-BLINDED RANDOMIZED CONTROLLED TRIAL

contributor:
Parise, Gianni
Kinesiology

subject:
Supplement
Hypertrophy
Nutrition
Whey Protein

abstract: Resistance exercise training (RET) is a well-known stimulus for muscle protein synthesis. Protein supplementation, in conjunction with RET, has been shown to yield greater accretion of lean body mass than RET alone. Few studies have compared two multi-ingredient, isonitrogenous supplements of differing quality protein. Therefore, the purpose of the current study was to determine whether there was an augmented effect of a high-quality whey protein multi-ingredient nutritional supplement on hypertrophy in young adults following a RET program. We hypothesized that the multi-ingredient supplement would induce hypertrophy to a greater extent than the control supplement in young adults. Twenty-six (13 male, 13 female) healthy young adults (22 ± 2 years [mean ± SD]) were randomly assigned to either the multi-ingredient nutritional supplement (SUPP, n=12: 20g whey protein, 2g leucine, 2.5g creatine monohydrate, 300mg calcium citrate, 1000IU vitamin D) or control beverage (CON, n=12: 20g collagen protein, 1.4g alanine, 0.6g glycine) groups, ingesting their respective supplements twice daily. Measurements were obtained prior to and after a 10-week linear RET program. Dual-energy X-ray absorptiometry (DXA), ultrasound, one-rep maximum (1RM), and biopsies from the vastus lateralis muscle were performed. A 2-way ANOVA (time by supplement) revealed significantly larger increases in lean body mass (LBM), as assessed via DXA, from the active supplement compared to the control (SUPP: +4.1 ± 1.3kg CON: +2.8 ± 1.7kg, p=0.004). We conclude that the consumption of a multi-ingredient nutritional supplement increased lean body mass to a greater extent than to that observed in the CON group in healthy young adults.

abstract: Thesis

abstract: Master of Science in Kinesiology

abstract: Resistance exercise training (RET) is known to augment muscle size, a process known as hypertrophy. Several factors may affect hypertrophy, such as supplementation with protein and amino acids, increasing an individual’s potential to maximize muscle hypertrophy beyond RET-induced gains. However, little is known regarding the effectiveness of multi-ingredient supplements and the synergistic effects they may exhibit on hypertrophy and strength gains. The present thesis shows the effect of a specific multi-ingredient supplement that contained: whey protein, creatine, calcium, vitamin D, and leucine, compared to a low-quality collagen-based supplement, on measures of hypertrophy and strength in young adults. Interestingly, the active supplement (SUPP) induced greater gains in lean body mass (LBM), type II muscle fibre CSA, and bicep CSA and thickness compared to the control (CON), but not strength. These findings provide insight into a novel formulation of ingredients on exercise-induced increases in hypertrophy in young adults.


title: Effects of low-dose ionizing radiation in utero on postnatal growth and cardiovascular physiology in BALB/cJ mice

contributor:
Wilson, Joanna
Biology

subject:
Ionizing radiation
Fetal Programming
Blood Pressure
Cardiovascular

abstract: Diagnostic radiation is typically avoided during pregnancy, as the effect of low-dose radiation exposure on the fetus is uncertain. The objective of this study was to determine if ionizing radiation exposure during late fetal development would cause an adverse intrauterine environment, and lead to growth restriction of offspring and a hypertensive phenotype later in life. To study this, pregnant BALB/cJ mice were exposed to ionizing radiation at 5, 10, 50, 100, 300 or 1000 mGy on gestational day 15. Offspring were weighed weekly from the age of weaning until a mature age of 16 weeks. Cardiovascular effects were assessed every other week via heart rate and blood pressure measurements using tail plethysmography. The expression of genetic markers for endothelial dysfunction, inflammation, mitochondrial capacity, and regulation of the oxidative stress response in the aorta and heart for the 1000 mGy was assessed from tissue collected at 17 weeks of age. We observed no effects of low to mid dose (5-300 mGy) radiation on offspring growth and blood pressure. Growth restriction was observed in male and female offspring exposed to high-dose radiation (1000 mGy). In the heart, there was no observed effect on mitochondrial capacity and oxidative stress response genes. In the aorta, we observed decreased TNF-α expression in male offspring, which may be linked to the growth restriction but was not considered a sign of cardiovascular dysfunction. There were no observed effects of exposure to 1000 mGy on cardiovascular function. This study provides knowledge on the possible effects of radiation on in utero development, which broadens the knowledge on the range of stressors capable of affecting offspring growth and development.

abstract: Thesis

abstract: Master of Science (MSc)


title: "Where Everyone Waddles Like Me": An examination of the autistic community on Tumblr.com

contributor:
Badone, Ellen
Anthropology

subject:
autism
autistic
aspergers
aspie
biosociality
biosocial
advocacy
self-advocacy
online ethnography
internet ethnography
internet community
online community
biosociality online
modern biosociality online
instant messenger interviews
online interviews
interview methodology
interview methodology autism
quality of life
internet
autonomy
online autonomy
autistic autonomy
autism internet
autistic internet
blog
blogging
microblogging
culture online
autism blogging
#actuallyautistic
Autism Speaks

abstract: I hope this can be used for a greater good than pure study.

abstract: This study used a novel combination of interview methodologies, made possible through the nature of instant messaging, and ethnographic methods in order to determine the value of the autistic community on Tumblr.com to its members. Ethnographic study yielded insights about the dialectic quality of any community on Tumblr, autistic community included, as well as the sense of autonomy users have on the site that is different if not greater than what they may practice in the physical world. Interview data suggest a neutral to positive view of the community and its culture overall, though further research with a greater sample of participants is required in order to confirm these findings. Information can be shared quickly between members, and this information provides greater insight into a given user’s autism, be it diagnosed or otherwise, or insight into navigating the neurotypical world. Autism positivity and neurodiversity advocacy is common among participants and the blogs they subscribe to, popularising the idea thereof in the mainstream while validating the identity of autistic people online and offline. This ethos makes its way into more casual site discussions, with memes and other entertainment being shaped by these experiences. The autistic community on Tumblr is an excellent example of a modern biosocial community online, and serves as Hacking’s engine of normalisation both on the site outside of the autistic community and in the physical world through real life events and adoption of site terminology and discourse.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: Using a purpose-built blog to learn about site culture and a series of online interviews to discover participant experiences, this study explores the culture of the autistic community on Tumblr and its impact on its members. The autistic community on Tumblr is a place that its members have more freedom to act and express themselves (through art, videos, shared stories etc.) than in the physical world. Through being a way to vent difficult experiences, get information, and enjoy site content made by and for them (in addition to broader appeal media), site users report a neutral to positive effect on their overall quality of life because of the site. Further research is required to confirm any of the patterns in the work.


title: DEVELOPMENT OF DNA CONSTRUCTS, BACTERIAL STRAINS AND METHODOLOGIES TO CHARACTERIZE THE IBS/SIB FAMILY OF TYPE I TOXIN-ANTITOXINS IN ESCHERICHIA COLI

contributor:
Li, Yingfu
Biomedical Engineering

subject:
small non-coding RNA
Toxin-Antitoxin

abstract:
Almost all bacteria contain genes that may lead to their growth stasis and death.Normally, these toxins are believed to be neutralized with their cognate antitoxinsfrom a toxin-antitoxin (TA) operon. These modules are also abundant in pathogenic bacteria suggesting a role for them both in normal bacterial physiology and pathogenicity. Their functions have been subject to intense debates. Due to the cell killing capability of the toxin and the gene silencing capability of the antitoxin, they have been utilized for basic research, biotechnology and medical applications. However, further advancements of these applications have been impeded by our limited knowledge of the biology of TAs. Among these TA systems is the Ibs/Sib (A-E) family. Here, we discuss our efforts in characterizing these systems, with a focus on the IbsC/SibC member. Studying them has shown to not be straightforward due to the complexity of their underlying mechanisms and the current approaches being laborious and lacking sensitivity to be applied to these low abundant molecules. We have developed fluorescence-based platforms to take advantage of sensitive and high throughput and resolution techniques such as Fluorescence Assisted Cell Sorting (FACS) to study these molecules instead of
relying on traditional culturing methods. While developing these platforms, we gained insights about the biology and regulation of these molecules. To expand this knowledge, we actively pursued investigating the regulation of these molecules at the transcriptional and post-transcriptional levels, both in their native context and in artificial systems. The rest of this thesis summarizes our efforts in solving one of the biggest pieces of the Ibs/Sib puzzle, namely their physiological expressions. With the strategies we have optimized for specific detection of these low abundance molecules, and the knowledge of their biology and regulation presented, we are now at an exciting phase to interrupt the long pause in the study of functions by these molecules and advancement of TA-based applications.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Almost all bacteria contain genes that may lead to their growth stasis or death. Normally, these toxins are believed to be neutralized with their cognate antitoxins. In spite of the efforts to understand these toxin-antitoxin (TA) systems, their physiological roles are subject to intense debate. These systems are hard to study mainly because 1) they are only activated under specific conditions and 2) they are low in abundance. Current approaches are not high throughput and sensitive enough. In this thesis, we developed DNA constructs, bacterial strains and methodologies to facilitate the study of these molecules, particularly the Ibs-Sib family. We next employed these tools to gain a fundamental knowledge of their
expression under different conditions, which revealed surprising information about the function of these molecules. We believe that future studies can greatly benefit from the tools offered here to tremendously enhance our understanding of these systems and lead to useful applications.


title: Cardiac function responses to stair climbing-based high intensity interval training in individuals with coronary artery disease

contributor:
MacDonald, Maureen J
Kinesiology

subject:
cardiac rehabilitation
exercise training
echocardiography
coronary artery disease
left ventricular twist
longitudinal strain
cardiac function
stair climbing-based HIIT

abstract: Cardiac rehabilitation (CR) exercise training, which traditionally involves the prescription of moderate intensity continuous exercise, can slow the progression of heart disease and improve cardiorespiratory fitness (CRF). Cardiac function is typically investigated using calculations of ejection fraction (EF) from echocardiography, yet EF measures do not provide information about the unique twisting motion of the heart. Novel measures of cardiac function, such as LV twist, myocardial performance index (MPI) and global longitudinal strain (GLS), may provide additional information about changes in LV mechanics associated with exercise training for individuals with coronary artery disease (CAD). The aims of this study were to investigate the changes in cardiac function, using both standard and novel measures, at baseline (0 weeks; T1), post-initial training (4 weeks; T2), and post-training (12 weeks; T3) in response to either stair climbing-based high intensity interval training (STAIR) or traditional moderate intensity continuous training (TRAD). We recruited 16 individuals with CAD (61±7years; 1W) and randomized them into TRAD and STAIR groups (n=8/group). Standard (CRF and EF), and novel (LV twist, MPI, GLS), measures of cardiovascular function were assessed at all three timepoints. CRF improved in both groups, after 4 and 12 weeks (STAIR: T1:22.1±4.2, T2:24.7±4.9, T3:25.4±5.2 and TRAD: T1:22.8±2.5, T2:25.2±4.9, T3:26.0±5.0 mL/kg/min; P<0.005) of CR exercise.  We observed an increase in apical rotation (P=0.01) and LV twist (P=0.03), but no changes in either traditional (EF P=0.15), or novel (MPI P=0.19; GLS P=0.81) measures of cardiac function over time, in either group. It is possible that the relatively short training period (12 weeks) was not sufficient to result in significant changes in cardiac function, despite improvements in CRF.  Future research should assess both standard and novel indices of cardiac function over longer exercise training periods to determine the ideal indices for tracking changes over time with interventions in this population.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Cardiac rehabilitation exercise is an important part of recovery after a heart attack, and it has been shown to improve heart function measured using standard ultrasound assessments. Studies have suggested that novel measures of heart function may be more sensitive in comparison to these standard ultrasound measures, yet these novel measures have not been examined in individuals completing stair-climbing based high intensity cardiac rehabilitation exercise training. This work examined the changes in both novel and standard ultrasound measures of heart function after either stair climbing-based high intensity interval training or traditional moderate intensity exercise training in individuals who have heart disease. While this study found that both stair climbing based high intensity interval training and traditional cardiac rehabilitation both resulted in increases in cardiorespiratory fitness after 12 weeks of training, no changes were observed in any of the standard measures of heart function. Supporting the concept that novel measures of heart function might be more sensitive, as some training associated changes were observed in the novel measures of heart function.