title: Elucidating the Mechanisms Underlying Genetic Background Effects Utilizing Drosophila melanogaster Wing Tissue

title: Genetic Background Effects

subject:
Genetics
Genetic Background
Drosophila melanogaster
Genetic Background Effects
Allelic Series
Drosophila Genetic Reference Panel

abstract: When investigating the developmental roles of genes on phenotypic expression it may seem reasonable to assume that a mutation would result in consistent phenotypic change. However, increasing evidence has shown this is not often the case, and the “wild-type” genetic background of an individual plays a large role in phenotypic expression of mutations and severity of genetic mediated diseases. Previous work has demonstrated that degree of genetic background effects shows a non-linear relationship with severity of mutational effects. This relationship is characterized by alleles of moderate phenotypic expressivity showing the relatively greatest degree of background dependence and between genotype variability in comparison with alleles of severe and modest phenotypic expressivity. Our previous work has shown this relationship for Drosophila melanogaster wing size through a scalloped (sd) allelic series crossed to naturally derived strains from the Drosophila Genetics Reference Panel (DGRP). I explored these effects with a miniature (m) allelic series where the results from our experiment suggest a vastly different response. m when compared to sd is characterized by a more linear relationship, whereby alleles of moderate phenotypic effect do not show increased background dependence nor increased variability within and between strains. Furthermore, our results suggest a strong correlation across DGRP strains with respect to m mutational severity and that the effect m has on wing shape is not largely due to wing size. Our working hypotheses for why this might be occurring is due to the increased interaction of sd with other aspects of wing development relative to that of m, the differences in when the genes are playing active roles in wing development, or the effects the mutations have on the wing to affect size. To add to our previous results employingutilizing sd, I am beginnings to elucidate the non-linear relationship of genetic background effects with severity of mutational effects at a gene expression level. I am accomplishing this through crossing autilizing a sd allelic series crossed to six naturally derived DGRP strains used in previous experiments involving wing size. Preliminary results agree with previous work on genetic background effects, displaying a non-linear relationship with the severity of mutational effect. I aim to continue to explore this relationship including more genotypes and investigating more genes to better elucidate the mechanistic causes of genetic background effects.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: When investigating the roles of genes on phenotype it may seem intuitive that a mutation affecting gene function would display a consistent change in phenotype. Increasing evidence has asserted that this may not always be the case and genetic background effects may affect the genotype-phenotype relationship affecting experimental design, disease treatment and evolutionary trajectories. Here, we investigate the mechanisms involved in these genetic background effects utilizing Drosophila melanogaster wing tissue. We outline a change from the typically observed non-linear relationship between genotype and phenotype and for the first time quantify shape change effects by the miniature mutation.


title: Role of Betaine in Transmethylation Reactions in the Barley Plant

title: Origin of the Methylenedioxy Groups of the Alkaloid Protopine

contributor:
Kirkwood, S
Chemistry

subject: Methylenedioxy Groups, Betaine, Transmethylation, Barley, Alkaloid Protopine

abstract:
The role of the labile methyl groups of betaine in the transmethylation reactions in the barley plants was investigated using carbon-14 methyl labelled betaine. The N-methyl groups of N-methyl tyramine, hordenine and choline were found to arise from betaine. Betaine was also administered to castor bean seedlings and the alkaloid ricinine Isolated. It was found that Its N- and 0- methyl groups did not arise from betaine methyl.
The origin of the methylenedioxy and N-methyl groups of the alkaloid protopine was also investigated by the tracer technique. Carbon-14 methyl labelled L- methionine, carbon-14 methyl labelled choline and carbon- 14 labelled sodium formate were fed to Dicentra species and the extent and position of labelling of the protopine molecule determined by degradation

abstract: Thesis

abstract: Master of Science (MS)


title: The Numerical Solution of Differential Equations by Third and Fourth Order Runge-Kutta Methods.

contributor:
Kenworthy, D. J.
Mathematics

subject: Gunge-Kutta, Gunge-Kutta methods, differential equations, third and fourth order, truncation errors, numerical solution

abstract: An examination of third and fourth order Runge-Kutta methods which can be utilized to solve various ordinary differential equations is considered.

abstract: Thesis

abstract: Master of Science (MS)


title: Biosynthesis of Hydrastine and Berberine

contributor:
Spenser, I. D.
Chemistry

subject: Biosynthesis, hydrastine, berberine, radioactive tyrosine, Hydrastis canadensis, Robinsons hypothosis of biogenisis

abstract: The biosynthesis of hydrastine and of berberine was investigated by feeding radioactive tyrosine and dopamine to Hydrastis canadensis L. It was shown that both hydrastine and berberine are specifically derived from two molecules of tyrosine, but that the ratio of incorporation of the two molecules of radiotyrosine was not unity, but varied with time. Dopamine was also incorporated into hydrastine without randomization, but only one molecule was utilized. The results, which are consistent with Robinson’s hypothesis of biogenesis, throw light on some of the individual steps of the biosynthetic path by which hydrastine and berberine are derived.

abstract: Thesis

abstract: Doctor of Science  (PhD)


title: Engagement of Anti-GRP78 Autoantibodies with Cell Surface GRP78 on Endothelial Cells Drive Tissue Factor Activation

contributor: Medical Sciences (Blood and Cardiovascular)

subject:
Cardiovascular Disease
Atherothrombosis
Thrombosis
GRP78
Cell Surface GRP78
Anti-GRP78 autoantibody

abstract: Atherothrombosis is the underlying contributor of cardiovascular disease whereby the thrombotic events following atherosclerotic plaque rupture are linked to tissue factor (TF) and its procoagulant activity (PCA). We have reported previously that the 78-kilodalton glucose-regulated protein (GRP78) observed on the cell surface of tumour cells acts as a novel signalling receptor to regulate TF PCA. Cell surface GRP78 also acts as a neoantigen known to promote an immune response that leads to the generation of anti-GRP78 autoantibodies. Given that the proinflammatory cytokine tumour necrosis factor α (TNFα) is known to contribute to atherosclerotic lesion development and promote TF expression, I investigated whether the anti-GRP78 autoantibodies against cell surface GRP78 can regulate TF PCA in TNFα-treated cultured endothelial cells. In this M.Sc. thesis, I demonstrated that TNFα treatment promotes TF PCA, an effect mediated by NF-κB activation. Additionally, treatment with TNFα was observed to elevate cell surface GRP78 expression levels. Further, anti-GRP78 autoantibodies enhanced TF PCA in endothelial cells pre-treated with TNFα. These effects of the anti-GRP78 autoantibodies were further enhanced in cells pre-treated with ER stress-inducing agents, also known to enhance cell surface GRP78 levels. I also showed that anti-GRP78 autoantibodies can also elevate intracellular Ca2+ levels, which is known to contribute to TF activation. Sequestering the anti-GRP78 autoantibody or blocking the anti-GRP78 autoantibody from cell surface GRP78 attenuated anti-GRP78 autoantibody-induced TF PCA. In this study, we identified small chemical compounds predicted to bind to cell surface GRP78 (termed GRP78 binders) that inhibited anti-GRP78 autoantibody-induced TF PCA. Together, these findings provide evidence that the anti-GRP78 autoantibodies can contribute to enhanced TF PCA and that disrupting the engagement of the anti-GRP78 autoantibody to cell surface GRP78 with these GRP78 binders may represent a potential therapeutic strategy for the treatment and management of atherothrombosis.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Blood clots formed following vascular injury are associated with the procoagulant activity of a protein called tissue factor. Based on the observation that autoantibodies against another protein called GRP78, which is found at the cell surface of activated endothelial cells, can promote the development of plaques in arteries. I found that the anti-GRP78 autoantibodies can promote tissue factor procoagulant activity in activated endothelial cells by enhancing cytoplasmic Ca2+ levels. Additionally, I also found small molecules that may block the ability of the anti-GRP78 autoantibody to interact with cell surface GRP78 to activate cell surface GRP78, which may represent a potentially novel treatment strategy in the formation of blood clots.


title: TASK-SHIFTING THE TREATMENT OF MATERNAL POSTPARTUM DEPRESSION TO TREAT MOTHERS WHILE MITIGATING NEGATIVE CONSEQUENCES ON INFANT EMOTION REGULATION

title: POSTPARTUM DEPRESSION AND INFANT EMOTION REGULATION

contributor:
Van Lieshout, Ryan
Health Sciences

subject:
Emotion regulation
Neurophysiology
Infancy
Postpartum depression
Cognitive behavioural therapy

abstract:
Objectives: To determine whether task-shifting the treatment of Postpartum depression (PPD) is effective in both treating mothers and mitigating the potential negative effects of PPD exposure on infant emotion regulation (ER).
Methods: In Study 1, a randomized controlled trial (RCT) with a waitlist control group was used to examine whether a nine-week group Cognitive Behavioural Therapy (CBT) intervention delivered by peers can effectively treat PPD in mothers. Study 2 used data from this same RCT to determine if maternal PPD treatment with peer-delivered group CBT intervention would lead to adaptive change in markers of ER in their infants. Finally, Study 3 used data from a RCT with a treatment-as-usual control group to examine whether maternal treatment with a Public Health Nurse (PHN)-delivered group CBT intervention led to adaptive change in markers of infant ER.  In both Studies 2 and 3, markers of infant ER included two neurophysiological measures and a maternal-report measure of infant temperament.
Results: Study 1 found that peer-delivered group CBT led to significant improvements in symptoms of depression and anxiety in mothers and reductions in symptoms remained stable six months after treatment initiation. Study 2 found evidence of change in two neurophysiological measures of infant ER following maternal treatment with peer-delivered intervention, but not in the maternal-report measure of infant temperament.  Finally, Study 3 found evidence of change in a single neurophysiological marker of infant ER following maternal treatment with the PHN-delivered intervention, but found no change following maternal treatment in a second neurophysiological marker and maternal-report measure of infant ER.
 Conclusions: The studies in this thesis highlight the potential of using task-shifting to fill a gap in the healthcare system’s treatment of PPD. This work suggests that interventions delivered by peers and PHNs may not only be effective in treating those with PPD, but may also benefit their infants by mitigating any PPD-related consequences on infant ER development. This thesis contributes to the evidence that suggests timely maternal treatment of PPD may disrupt the transmission of psychiatric risk from parent to infant.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Postpartum depression (PPD) is common and has consequences for both mothers and their infants. The negative impact of PPD exposure on infant emotion regulation (ER) is especially harmful because of its association with later psychopathology. As a result, the objectives of the present thesis were to i) determine whether task-shifting the treatment of PPD is effective in treating mothers while ii) mitigating the potential negative effects of PPD exposure on infant ER. The results of this thesis indicate that a task-shifted, peer-delivered treatment is effective in treating mothers with PPD and that treating mothers with a task-shifted treatment may also lead to adaptive changes in infant ER. This thesis indicates that task-shifting the treatment of PPD may improve outcomes for mothers, prevent PPD-related consequences on infant ER development, and ultimately, improve future outcomes for their infants.


title: Convening Authority in Global Education: a Case Study of the OECD's Assessment of Higher Education Learning Outcomes

contributor:
Porter, Tony
Political Science

subject: OECD; global governance; higher education; authority; legitimacy; case study research

abstract:
How is authority convened in global education? In 2008, the Organization for
Economic Co-operation and Development (OECD), an “elusive institution” that is
nonetheless “routinely heralded as a leading organ of global governance” (Woodward,
2009: xiv), launched a cross-national, cross-cultural feasibility study that would reveal the
contours of authority and legitimacy in global education governance. The Assessment of
Higher Education Learning Outcomes (“AHELO”) feasibility study convened the world’s
pre-eminent education experts along with education policy leaders in government and
academia to assess whether it was technically and practically feasible to capture the
value-added, or “learning gain,” associated with university education. The emergence of a field of academic study around the “global education policy field” (Lingard et al. 2007) coincides with important questions related to authority and legitimacy in global education governance. The study of global governance itself acknowledges that non-state (e.g., private, technical, epistemic) forms of authority not only help problematize, frame, and propose solutions to pressing public policy decision-making needs; non-state actors constitute key actors in the global governance architectures. My case study of AHELO offers an important empirical contribution to the nascent global education policy literature while enhancing our theoretical understanding of authority in structures of education governance spanning the OECD member states. Projects such as AHELO - often portrayed as expressions of a relentless force such as education neoliberalism, globalization, the audit society, or the dominance of wealthy
states of the world - are in fact are quite tenuous constructions that rely on a challenging
integration of legitimacy and stakeholders at transnational, national, and subnational
levels. This dissertation offers compelling and original empirical insight into an
innovative, historically-significant and yet politically unfeasible global education project.
My dissertation presents global education governance as a “field” in which different
actors compete for recognition of authority in the higher education policy space. In some
OECD contexts, including the case studies presented in my dissertation, expert authority
must compete with academic and university associations, governmental authorities, and
even the authority of indicators like global university rankings. My case studies
demonstrate how this field is contested in different political economies - shedding light on
competition for authority in ways that are particular to variable political settings.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
This dissertation offers original research into a unique and innovative education
project at the Organization for Economic Co-operation and Development (OECD). The
key goals of my study involved: a) identifying the organizational, governmental, and
private/technical actors involved in the architecture of global education governance; b)
exploring the sources and limitations of these various authorities within the scope of a
transnational study commissioned by the OECD; and c) challenging the concept of policy
“failure” as a way to advance my study’s theoretical and empirical contribution to
Political Science. Beyond contributing to a multi-disciplinary research agenda in global education
governance, my study appeals to academic researchers, university administrators, and
education policy leaders seeking to understand the broader implications of comparative
education assessments, such as AHELO, on higher education policy reforms across
linguistically and culturally diverse national contexts.


title: Second-Generation Tamil Youth & Their Experiences Accessing Community-Based Mental Healthcare Services

title: Second-Generation Tamil Youth Mental Health

contributor:
Wahoush, Olive
Nursing

subject:
Second-Generation
Youth
Tamil
Mental Health
Community-Based Services

abstract:
Background: Second-generation Tamil youth experience intergenerational trauma from their first generation parents, along with various other mental health stressors which can continue well into adulthood. Early intervention and access to community-based mental healthcare services can serve as a protective factor and prevent chronic mental health issues. However, cultural and access barriers prevent second-generation Tamil youth from accessing much needed mental healthcare support. The purpose of this study is to explore how second-generation Tamil youth describe their experiences accessing community-based mental healthcare services and to identify barriers and facilitators to accessing mental healthcare services.
Methods: This study used Qualitative descriptive design and was informed by the Penchansky and Thomas Access framework with Saurman’s addition. Nine second-generation Tamil youth in the Greater Toronto Area were interviewed using a semi-structured interview guide to collect information about their experiences accessing community-based mental healthcare services. Concurrent data analysis was conducted to promote rich data collection which helped identify themes among participant responses. Each theme helped identify barriers and facilitators to accessing community-based mental healthcare services. The thematic analysis clarified details and descriptions of the experiences of second-generation Tamil youth.
Results: Data analysis revealed six themes that fit within the dimensions of access: awareness, availability, acceptability, affordability, accessibility and accommodation. Findings from this study helps identify barriers and facilitators to accessing community-based mental healthcare services as experienced by participants.
Conclusion: While second-generation Tamil youth were able to describe their experiences accessing community-based mental healthcare services, not all participants were successful in accessing a service. Further research is necessary to explore key strategies to ensure accessible mental healthcare support for second-generation Tamil youth, to better meet their unique needs, and to remove barriers preventing early access to services.  Findings from this study are important to help inform the practice of nurses and practitioners, policy, and public education to better support the unique needs of the second-generation Tamil population and other newcomer groups and promote mental health.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Second-generation Tamil youth are an understudied population with a growing need for mental health support. This study describes the experiences of second-generation Tamil youths and their access to community-based mental healthcare services in the Greater Toronto Area. Nine participants were interviewed using a semi-structured interview guide to collect data on their experiences accessing community-based mental healthcare services. Concurrent data analysis was conducted with data collection, and themes around the dimensions of access emerged: awareness, availability, acceptability, affordability, accessibility and accommodation. Further research is necessary to explore key strategies to implement when providing mental healthcare support to the second-generation Tamil youth population to better meet their unique needs, and tackle barriers preventing early access to services. Findings from this study are important to help inform the practice of nurses and practitioners alike, policy, and education to better support the unique needs of the second-generation Tamil population and promote mental health.


title: The Epidemiology of Stress and Obesity over the Life Course

abstract:
Background: Obesity and stress share a complex relationship. It has been found that obesity and stress are constantly influencing each other, sharing a cyclical association. Stress can be caused by psychological, social, or physical determinants. Understanding this relationship is particularly of interest as a high proportion of people in Canada have obesity, and obesity is not only a disease itself but is a risk factor for several other diseases.
Objectives: The objectives of this thesis were: 1) To understand the impact of disasters, including pandemics, on obesity and cardiometabolic risk; 2) To describe stress during the COVID-19 pandemic by socioeconomic factors; 3) To determine how early life adversity and obesity impacted stress during the COVID-19 pandemic; 4) To evaluate the association between early life adversity and adulthood obesity, and to determine if this association was mediated by nutrition.
Methods: To address objective 1 a systematic review was conducted. For objectives 2-4, data from over 50,000 adults aged 45 and older from the Canadian Longitudinal Study on Aging (CLSA) was used. This study is unique as it is a nationally representative cohort with comprehensive measures of both obesity and stress, including adverse childhood experiences (ACEs), as well as in-depth data from the COVID-19 pandemic. For objective 2, a cross-sectional study was conducted and for objectives 3 and 4, longitudinal studies were conducted. Multivariable Poisson, negative-binomial and multinomial logistic regression models were used to evaluate associations. To address objectives 3 and 4, novel epidemiologic methods were applied, including effect modification, evaluated on the additive and multiplicative scales and mediation evaluated using causal mediation methodologies.
Results: Overall the results of these theses studies support a strong bidirectional relationship between stress and obesity This was observed for various stressors at different periods throughout the life course. The systematic review identified that the indirect harms of disasters, including pandemics, have lasting effects on cardiometabolic outcomes, including obesity. Stress experienced during the COVID-19 pandemic varied across several socioeconomic factors, and obesity was associated with stress experienced during the pandemic. Although ACEs did not modify this association, it was found to independently be associated with stress during the COVID-19 pandemic. ACEs were found to be strongly associated with adulthood obesity, but there was no evidence to suggest this was mediated by nutrition in later life.
Conclusions: The findings from this thesis confirm that regardless of the type of stress, or the timing of exposure, obesity and stress are strongly associated. Using a life course perspective allows for a comprehensive assessment of potential risk factors of experiences that occur during adulthood, such as disease development or experiences during a stressful event. People are susceptible to worse experiences during adulthood, which may be related to a variety of factors including adversity during childhood, socioeconomic factors or chronic disease. This should be considered when developing prevention strategies and interventions targeting those at the highest risk.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Impact of Transcatheter Aortic Valve Replacement on Coronary Hemodynamics using Clinical Measurements and an Image-Based Patient-Specific Lumped Parameter Model

contributor:
Motamed, Zahra
Biomedical Engineering

subject: Cardiovascular Modelling, Lumped Parameter Modelling, Heart Disease Modelling

abstract:
Cardiovascular disease, including coronary artery disease and aortic valve stenosis, impacts tens of millions of people annually and carries a massive global economic burden. Advances in medical imaging, hardware and software are leading to an increased interest in the field of cardiovascular computational modelling to help combat the devastating impact of cardiovascular disease. Lumped parameter modelling (a branch of computational modelling) holds the potential of aiding in the early diagnosis of these diseases, assisting clinicians in determining personalized and optimal treatments and offering a unique in-silico setting to study cardiac and circulatory diseases due to its rapid computation time, ease of automation and relative simplicity.
In this thesis, cardiovascular lumped parameter modelling is presented in detail and a patient-specific framework capable of simulating blood flow waveforms and hemodynamic data in the heart and coronary arteries was developed. The framework used only non-invasive clinical data and images (Computed Tomography images, echocardiography data and cuff blood pressure) as inputs. The novel model was then applied to 19 patients with aortic stenosis who underwent transcatheter aortic valve replacement. The diastolic coronary flow waveforms in the left anterior descending artery, left circumflex artery and right coronary artery were validated against a previously developed patient-specific 3D fluid-structure interaction model for all 19 subjects (pre and post intervention). There were strong qualitative and quantitative agreements between the two models.
After the procedure, aortic valve area and net pressure gradient across the aortic valve improved for almost all the subjects. As for the hemodynamic data, according to the model, there was substantial variability in terms of the increase or decrease post intervention. On average, left ventricle workload and maximum left ventricle pressure decreased by 4.5% and 13.0% while cardiac output, mean arterial pressure and resting heart rate increased by 9.9%, 6.9% and 1.9% respectively. There were also subject specific changes in coronary blood flow (37% had increased flow in all three coronary arteries, 32% had decreased flow in all coronary arteries, and 31% had both increased and decreased flow in different coronary arteries). All in all, a proof-of-concept cardiac and coronary lumped parameter framework was developed, validated, and applied in this thesis.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The heart is a vital part of the cardiovascular system, which helps deliver and regulate blood flow through the entire human body. The coronary arteries are a crucial part of this system since they deliver blood directly to heart muscles. For numerous reasons, the cardiovascular system can become diseased over time and require clinical treatment. Coronary artery disease and aortic valve stenosis are among the most prevalent cardiovascular diseases globally. While medical imaging on its own is a crucial part of the disease management and treatment process, advanced computational models can further enhance the process and provide clinics with data and predictions they might otherwise miss. In this thesis, a patient specific computational framework capable of simulating blood flow waveforms and cardiovascular data in the heart and coronary arteries using only non-invasive clinical data and images was developed and validated. The novel model was applied to a series of patients with aortic stenosis who underwent heart valve replacement with the aim of studying the impact on coronary blood flow and global cardiovascular metrics.


title: Control of the mechanical and optical properties of SiNx-based films for optical and strain engineering applications

contributor:
Mascher, Peter
Landesman, Jean-Pierre
Levallois, Christophe
Engineering Physics

subject:
Silicon Nitride
Plasma Deposition
Optical properties
Mechanical properties
Strain Engineering
Degree Of Polarization

abstract:
Due to their attractive properties, silicon nitride (SiNx) based films have been recognized as essential dielectric films in the microelectronic and optoelectronic industries. In this PhD thesis, we describe how we can control the refractive index and the mechanical properties of SiNx and silicon oxynitride (SiOyNx) films by tuning the deposition process parameters. We use two different plasma-enhanced chemical vapor deposition reactors: a standard capacitively coupled reactor with radiofrequency excitation and an electron cyclotron resonance reactor with microwave excitation. We discuss the fabrication and characterization of multilayer structures as an optical application of our thin films. We focus on characterizing and understanding these thin films’ optical properties through spectroscopic ellipsometry. We also study their mechanical properties experimentally using the wafer curvature measurement technique, microstructure fabrication, and nanoindentation measurements.
Finally, we show accurate measurements of the strain distribution induced within GaAs wafers when such thin films are structured in the shape of elongated stripes of variable width, using standard optical lithography and plasma etching. For this, we map the anisotropic deformation, measuring the degree of polarization of the spectrally integrated photoluminescence (PL) generated within GaAs by excitation with a red laser. PL from bulk cubic semiconductors such as GaAs is unpolarized, whereas anisotropic strain produces some degree of polarization. These maps were measured either from the semiconductor surface or from cleaved cross-sections. They provide a detailed and complete image of the crystal deformation in the vicinity of the structured stressor film. Then, we performed some finite element simulations to reproduce the experimental maps. We believe our simulation scheme is helpful for designing the photonic components, e.g., to predict the local changes in the refractive index due to the photoelastic effect.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Impacts of spruce budworm defoliation on stream food webs and mercury cycling

contributor:
Kidd, Karen
Biology

subject:
Stream ecology
Food webs
Stable isotope analysis
Mercury

abstract:
Forested streams are closely linked to terrestrial catchments which affects their biogeochemical cycling and carbon inputs. Catchment disturbances alter stream water quality and food webs, including changes in productivity. Such changes in stream conditions can potentially alter consumers’ reliance on autochthonous (in-stream) or allochthonous (terrestrial) sources and mercury bioaccumulation. A recent outbreak of the spruce budworm (SBW) that feeds on spruce and fir trees has provided the unique opportunity to examine stream food web responses across watersheds experiencing a range of defoliation in the Gaspé Peninsula, Québec.
This project compares streams in twelve watersheds which were selectively sprayed to control SBW and create a gradient in defoliation. Food web samples (food sources, invertebrates, fish) were analyzed for stable isotopes of carbon and nitrogen in 2019 and 2020 to characterize food web structure, and algal productivity was measured in 2019.  Hierarchical partitioning models were used throughout the study to compare the contributions of various local and landscape conditions to stream responses. Models indicated that watershed defoliation contributed to increasing autochthonous production, although some invertebrates were more allochthonous in heavily defoliated watersheds, and brook diets were unaffected by defoliation.
Next, food web samples were analyzed for methylmercury (food sources, invertebrates) or total mercury (fish) and trophic magnification slopes were determined for each stream food web. Mercury levels in carnivorous invertebrates and brook trout were driven by dissolved organic carbon (DOC), but not consumer autochthony or watershed defoliation. Additionally, rates of trophic magnification were not related to defoliation severity or DOC.
This study found that defoliation contributed to increasing autochthonous production and invertebrate consumer allochthony. However, this disturbance did not increase consumer mercury levels or biomagnification in stream food webs. These findings suggest that intervention to reduce defoliation would mitigate algal responses and dietary shifts, but not mercury cycling as it is influenced by DOC levels in the streams of this region.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: A recent spruce budworm outbreak is causing widespread defoliation of spruce and fir trees, but the impacts to stream environments, including primary production, its consumption, and contaminant levels, are largely unknown. Streams are sensitive to conditions in the surrounding terrestrial environment, as such changes can affect the diets of stream invertebrates and fish and are also linked to increased contaminant levels in aquatic organisms. Specifically, mercury is a metal that is transferred through diet and can reach toxic levels in fish. This study found that defoliation is contributing to increased algal production in streams in the Gaspé Peninsula, Québec. However, some stream invertebrates consumed more terrestrial material in streams that had heavier defoliation. Furthermore, defoliation and algal diets did not increase levels of mercury in aquatic organisms, but this contaminant was affected by increasing concentrations of dissolved organic carbon in the streams. These findings suggest that forest defoliation can alter organisms’ diets but not mercury levels.


title: Microbial Glycoside Hydrolases and Host Cell Signaling

contributor:
Surette, Michael G.
Biochemistry and Biomedical Sciences

subject: GHs, Microbiome, Glycans, TLRs,

abstract: Glycans, carbohydrate-based macromolecules, are present on the surfaces of all prokaryotes and eukaryotes cells. They play critical roles in cell-cell interactions, and host glycans also provide both binding sites and nutrition for commensal microbes. Many bacteria use glycoside hydrolases (GHs) on host-generated glycans and dietary glycans for nutrition and to modulate attachment sites and host protein function. The microbiota found in a single human gut sample has greater than 10,000 GH genes, and many of these gene products have specificity for host glycans. In eukaryotes, glycosylation of cell surface receptors is critical for proper localization and function, including receptors for innate immune signalling. The hypothesis of this project is that human-associated microbiota can express and secrete GHs that can alter the functioning of host immune signalling pathways. In this work, I measure GHs enzyme activity, use bacterial cell-free supernatant and purified enzymes to determine if they can modulate host cell signalling pathways, and examine glycans cell surface modifications by fluorescence microscopy using fluorescent-labelled lectins.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Glycans are sugars that cover cells of animals, plants, and microbes. These sugars on the external surface of the cell help them interact with and protect them from the environment. For our microbiomes – the microbes that live on or in us- glycans on both microbe and our cells are important for interactions between them and us. Many bacteria produce enzymes (such as glycoside hydrolases) that change or remove sugars from the cell surface to obtain nutrients and manipulate host proteins. These enzymes can be attached to the bacterial cell surface or released into the environment, where they can interact with glycans attached to mucosal surface and immune cells. The modification of cell glycans from the immune system can modulate inflammatory responses that could change the way gut cells react to certain kinds of food, such as legumes and wheat. My work focuses on understanding how human gut microbiome can use these tools to reshape glycans and their effects on our health.


title: Health Inequalities in Housing: Housing cost burden, Housing assets, and Mortality

contributor:
Dunn, James
Grignon, Michel
Young, Marisa
Health and Aging

subject:
Housing
Housing cost burden
Mortality
Health inequalities
Housing asset

abstract:
Despite a growing body of studies on the relationship between housing and health, it is
unclear whether and how (a) the housing cost burden deteriorates health and whose health
it deteriorates, (b) housing assets interact with income in influencing one’s health, and (c)
protective policy measures alleviate mortality risks predicted by housing cost burden.
This thesis aims to reduce these knowledge gaps. First, in Chapter two, I synthesize prior
literature that focused on the association between housing cost burden and health and
discussed methodological issues. Also, the chapter proposes future research directions.
Chapter three, co-authored with Dr. Michel Grignon, Dr. Marisa Young, and Dr. James R.
Dunn, assesses the potential moderating effect of housing asset level on the link between
income and mortality. Although housing assets and income are independently related to
mortality risks, the value of housing assets did not significantly moderate the link
between income and mortality. Income-related inequalities in mortality are observed
among each group of housing asset level. Our findings offer insight into the importance of
redistribution of resources that can reduce risks of premature mortality and achieve
healthy aging. Chapter four documents that housing cost burden was significantly
associated with preventable mortality, treatable mortality, and suicide during post-Global
Financial crisis (2009-2017). Also, in countries with an increased level of social spending,
higher levels of social housing stock, and rent control, the observed association was
substantially attenuated. Taken together, the findings of the three chapters contribute to understandings about the link between housing and health by (a) synthesizing the prior
literature and mechanisms, (b) estimating housing inequalities in health, and (c)
highlighting the protective roles of social and housing policies that reduce health
inequalities.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
This thesis aims to investigate housing inequalities in health and the roles of protective
social and housing policies in reducing health inequalities. The second chapter, as a
scoping review, synthesizes prior literature that estimates the association between housing
cost burden and health, and explores potential mechanisms linking housing cost burden to
health. Chapter three relies on one of the nationally representative linkage datasets in
Canada in order to estimate the association between housing asset, income, and mortality
in Canadian older adults. It reveals that the value of housing assets and income predicts
mortality risks, but housing assets do not significantly change the link between income
and mortality. The fourth chapter examines whether and how housing cost burden is
associated with avoidable mortality in OECD countries. Also, the roles of preventive
measures including social spending and housing policies are revisited. The thesis
strengthens the rationale for identifying housing as one of the important social
determinants of health.


title: Design and Optimization of TiO2 Nanomaterial-based Photoelectrochemical Biosensors

title: Photoelectrochemical Biosensing

contributor:
Soleymani, Leyla
Zhitomirsky, igor
Engineering Physics

subject:
Photoelectrochemistry
Electrochemistry
Metal oxide
Nanostructures
Biosensing
Titanium dioxide
Embedded systems
Photovoltaics
Nanotechnology
Biotechnology
Dye-sensitization
Functional materials

abstract:
Recently, there has been a shift in the global healthcare paradigm, which is prioritizing a more patient-centric approach causing an increase in the demand for rapid and point-of-care (PoC) biomolecular detection. Electrochemical (EC) signal transduction has been used to great effect to meet some of this demand by constructing biosensors with high sensitivity and low limit-of-detection (LOD). However, signal generation in EC biosensors requires input bias potentials to activate electrochemical redox reactions. This means EC systems are inherently built-in with high background noise that limits the performance of biosensors. Biosensors with photoelectrochemical (PEC) signal transduction have recently shown great promise in being able to deliver biomolecular detection on par with, if not better than, EC biosensors. PEC biosensing directly improves upon EC signal transduction by combining EC signal readout with optical excitation as the bias input, and generally being able to achieve similar performance with simpler bioassay designs. In this scheme, the input and output of the signal transduction are decoupled from each other, significantly reducing background signal in biosensors to enhance their sensitivity. Despite being highly effective, PEC biosensors have yet to find commercial breakthrough as they have so far only shown quantitative analysis on a limited set of biomarkers and have not shown to be PoC-capable. In this thesis, we developed new strategies to improve PEC signal transduction so that it could be applied to build robust ultrasensitive PoC biosensors with high dynamic range, simple operation, and low LOD for detecting a wide variety of different disease biomarkers.
The most popular photoactive materials used in the fabrication of PEC biosensors are TiO2 nanomaterials on account of their availability, chemical stability, high catalytic efficiency, tunable morphology, and ideal band energy levels for driving useful EC reactions. However, unmodified TiO2 suffers from several drawbacks that limit its photocurrent generation efficiency, such as poor visible range absorbance due its wide bandgap and fast charge carrier recombination. Alongside the additional difficulty of biofunctionalization, PEC biosensors fabricated from TiO2 nanomaterials are limited in their bioanalytic performance. In order to make improvements on PEC biosensors, we modified the surface of TiO2 nanomaterials by chelating them with catecholate molecules. The surface modification with catecholates formed charge transfer complexes on TiO2, which resulted in enhanced photoexcitation due to enhanced electron injection attributable to intermolecular orbital excitations in the catecholate molecules. The catecholate ligands also added improved colloidal stability and additional functional groups that aided with biofunctionalization. This resulted in multifunctional TiO2 nanoparticles with improved photocurrent signal generation and enhanced visible range photoabsorption. We took this one step further by taking advantage of the high binding affinity of catecholates on TiO2 surfaces to create novel synthesis methods that created high surface area nanostructures. Photoelectrodes fabricated from these new TiO2 nanostructures had nanoporous morphology and were able to capture biomolecules more efficiently. Using our novel TiO2 nanomaterials, we fabricated signal-off biosensors that were able to detect DNA biomarkers and IL-6 protein (cancer and inflammatory biomarker) in urine with an LOD of 1.38 pM and 3.6 pg mL-1, respectively.
We further explored hybrid semiconductor structures by combining TiO2 nanomaterials with other materials such semiconductors with different bandgaps or plasmonic metal nanoparticles (NP). Using the aforementioned catechol-assisted synthesis techniques, we were able to produce different morphologies of TiO2 nanomaterials with distinct phases: anatase TiO2 nanorod assemblies and rutile TiO2 NP. The two different TiO2 nanomaterials have different bandgaps and can be used to form semiconductor heterostructures. By combining rutile TiO2 NPs with DNAzymes, a type of synthetic functional nucleic acid, we created a photoactive molecular switch that worked by making and breaking heterostructures between the two TiO2 nanomaterials. We used DNAzymes specific to E. coli bacteria to develop a highly sensitive signal-on bacterial detection platform that was able to detect E. coli in lake water samples with an LOD of 18 CFU mL-1. Using catecholate-assisted photoreduction synthesis, we developed an efficient and novel method for decorating TiO2 NP with silver (Ag) NP. The resultant nanomaterial featured TiO2 NP surfaces modified with Hematoxylin (HTX) dyes and covered with sub-nanometer sized silver NP. The band structure of TiO2/HTX/Ag NP hybrid material involved high energy electron generation through decay of surface plasmons in the Ag NP and then enhancing the photoelectron injection process between HTX and TiO2. This significantly enhances the photoexcitation and photoabsorbtion, resulting in the material with the highest photocurrent generation as presented in this thesis. By taking advantage of thiol-metal bonds, we used the TiO2/HTX/Ag NP material system in the fabrication of a highly sensitive signal-off microRNA (prostate cancer biomarker) sensor with an LOD of 172 fM in urine.
Special attention was paid to the design of PEC bioassays in this work so that they are miniaturized and easy to use, and thus suitable for PoC applications. Because PEC signal transduction generates ultrahigh signals compared to other transduction methods, it allows bioassay designs to remain simple without sacrificing performance. This allowed us to create bioassays with very few operational steps, that excel in reliability and ease-of-use. To further improve PoC capability, we explored multiplexing with the biosensor made from TiO2/HTX/Ag NP. Here we were able to demonstrate multiplexing with PEC signal transduction for the first time. Another major barrier to PEC biosensors becoming widespread is the requirement of large benchtop instrumentation such as potentiostats and light sources. To address this challenge, we designed a portable smartphone-interfacing potentiostat with a built-in LED light source to support PEC biosensing. This device, named the PECsense was as versatile as any commercial potentiostats, having features such as adjustable recording periods, variable illumination periods, automatic data processing and being able to record both anodic and cathodic photocurrents. The PECsense was demonstrated to be used successfully as a signal reader in a PEC DNA detection assay.
Ultimately, we designed several ultrasensitive PEC biosensors used for the detection of four different diagnostic biomarkers. Combined with the exploration of miniaturized design, multiplexing and portable signal-reading, our designed PEC biosensors were made PoC-capable. The work in this thesis presented innovations in areas of nanotechnology, material synthesis, solid-state physics, biotechnology and embedded systems for the advancement of biomolecular detection and PoC diagnostics.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Biosensors show great promise for use in point-of-care diagnostics and health monitoring systems. Such deceives combine biorecongition with signal transduction for analyzing biologically relevant targets. Photoelectrochemical (PEC) mode of signal reading, particularly those based on TiO2 nanomaterials, have shown great promise in delivering point-of-care biosensors that have excellent diagnostic performance. In this thesis, our goal was to develope new techniques for creating low-cost, easy-to-use and ultrasensitive photoelectrochemical biosensors. To achieve this goal, our work here can broadly be split into three objectives. Firstly, we focused on developing new material synthesis methods to improve traditional TiO2 nanomaterials so they can be more useful in PEC biosensors. These methods involved combining TiO2 with organic molecules known as catecholates and metal nanoparticles. This work created material systems that are able to generate high signals and more easily interface with biomolecules for improving PEC biosensor sensitivity. For the second objective, we used our newly developed enhanced TiO2 nanomaterials as the foundation for designing various bioassays for the detection of a wide range of different biological targets such as DNA, RNA, proteins and bacteria. This served to demonstrate the robustness of PEC signal reading as a tool for various markers of diseases. Despite PEC biosensors being a powerful tool in healthcare, they have seen very little commercial breakthrough, which can primarily be attributed to needing bulky benchtop instruments and light sources for signal reading. For the last objective, we worked on designing a handheld smartphone-operated signal-reader for PEC biosensing with its own built-in light source.


title: Finding Our Say:  The Lived Experiences of Young Adults caring for an Older Adult with Alzheimer’s Disease or a Related Dementia (ADRD)

contributor:
Griffin, Meridith
Health and Aging

subject: young caregiver, young adult caregiver, young carer, elder, older adult, gerontology, caregiver, care work, caregiving, dementia, Alzheimer’s, informal care

abstract:
In the literature, the experience of ‘care’ and ‘caregiving’ has been well documented and widely researched. Caregivers are recognized as people (family and friends) who provide unpaid substantial care for family members. Over time, research has increased awareness of caregivers as a distinct social group and has also contributed to caregiving being a widely recognized social issue. However, despite this increased awareness and continued concern for caregivers, much of the literature focuses on adult caregivers. As a result, the experiences of other caregiving populations, such as the youth and young adults, continues to be overlooked and underrepresented. Therefore, there is a need to explore and understand the unique experience of this population and how they give meaning to their experiences.
Young caregivers (YCs) are children (5-18) and young adults (18-25) who provide substantial (unpaid) care for a family member who has an illness or disability (Stamatopoulos, 2016). Research on this population is scant and there exists many notable gaps in the literature in terms of diversity, age-based differences, programming and best practices for intervention. More specifically, there is a gap in understanding the experiences of young caregivers who are affected by progressive and incurable chronic brain diseases such as Alzheimer’s Disease or a Related Dementia. As such, this dissertation explores the experiences of YACs affected by ADRD, in terms of their personal experiences with ADRD (knowledge, dementia care and care practices), perceptions of their caregiving role and how they navigate the caregiving role. It builds on scholarship on young caregivers to broaden existing knowledge by using a phenomenological approach, known as Interpretive Phenomenological Analysis, to explore their caregiving experiences and the meaning they give to these experiences in-depth (n=12).  It also aims to challenge the dominant assumptions about young caregivers by giving voice to this population by situating the young caregivers as the experts in their own lives. Findings indicate that the caregiving experience for YACs is complex, and situated within a larger socio-political context, which impacts the overall experience of care. Overall, the findings contribute to knowledge on the experiences of care among YACs and highlight the need for more inclusive research and practices on addressing caregiving among this group.

abstract: Dissertation

abstract: Candidate in Philosophy

abstract: This dissertation explores the lived experiences of young adult caregivers (YACs) caring for an older adult with Alzheimer’s Disease or a Related Dementia. Research on this group of caregivers is limited, particularly YACs (ages 18-25) who provide substantial (unpaid) caregiving for an older adult affected by Alzheimer’s or a Related Dementia. Therefore, a key aim of this research is to generate awareness and shed light on the nature of caregiving as experienced by this overlooked population of caregivers. As such, this dissertation aims to understand how young caregivers give meaning to, interpret and make sense of their caregiving experience. To understand the caregiving experience of YACs, I conducted interviews with 12 YACs from Canada and the United States and analyzed their perspectives in detail. The findings shed light on the many factors that shape the caregiving experiences. In addition, the findings show that more research is needed to understand the differences amongst young caregivers to better support their needs. In general, the research can contribute to existing knowledge on young adult caregivers, as well as relevant programs and policies.


title: Development of a Multiscale Analysis Methodology for Analysis of Transients in a Small Lead Cooled Advanced Reactor

title: TRANSIENTS IN A SMALL LEAD COOLED REACTOR

contributor: Engineering Physics and Nuclear Engineering

subject:
nuclear
CFD
SMR
lead-cooled reactor
simulation
thermal-hydraulics
transient
sensitivity analysis

abstract: In the recent years there has been growing interest in small modular reactors (SMRs). Before this type of reactors are deployed it is necessary to assess their safety with the newest available tools. This thesis focuses on one SMR, the SEALER reactor, which is a 3 to 10 MWe lead cooled reactor intended for remote communities or mines. The designer of the SEALER reactor has previously identified a possible issue during a loss of flow transient. At the beginning of the transient, the mass flow at the pumps undergoes a fluctuation that could lead to reverse flow if amplified. The first part of the thesis was to perform an uncertainty and sensitivity analysis using an existing lumped-parameter model. Two types of transients were studied: unprotected loss of flow and unprotected overpower. Results show that, for both transients, temperatures remain well below safety limits for the entire parameters space. However, it is also found that reverse flow at the pumps is possible by changing some parameters in a realistic way. It was therefore decided to develop a more realistic model to study the same transients, which constitutes the second and main part of the thesis. The new model uses CFD for simulating the flow of coolant in the entire primary circuit. The complex components (fuel channels, pumps and steam generators) are replaced with a simple geometry and appropriate heat and momentum sources/sinks. The CFD simulation is coupled with a custom-made code for solving heat transfer in the fuel pins and to point kinetics for neutronics. To demonstrate the viability of the model, a validation exercise was performed to ensure that the CFD part is able to reproduce experimental data with important features, like temperature stratification and a jet into a plenum. Results from the new model confirm the mass flow fluctuation if a small pump flywheel is used. For a flywheel of reasonable size, transients are slow without any mass flow fluctuation, and temperature variations are small.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: In the recent years, new types of small nuclear reactors for producing electricity are being developed. The motivation of this thesis is to investigate a particular safety aspect of one of those reactors. One of the main tasks of a nuclear reactor is to transport heat from the core, where the nuclear reaction produces heat, to the component that produces steam which will then activate a turbine to generate electricity. This is achieved by circulating a fluid between those two parts of the reactor with the help of pumps. Any new reactor needs to be designed in a way that if the pumps stop working, no component will overheat and the reactor will shut down safely. This thesis investigates this safety aspect by developing a computer model that can simulate the behavior of the reactor in the case of a loss of pump power. The main takeaway is that the computer model works well and the results from the simulations show that the reactor remains safe in such an accident scenario.


title: Advances in Wireless Communications: Multi-user Constellation Design and Semantic Information Coding

contributor:
Chen, Jun
Davidson, Timothy
Electrical and Computer Engineering

subject:
Multiple access
Multi-hop relay
Semantic source coding

abstract:
The realization of high data rate wireless communication and large-scale connectivity with seamless coverage has been enabled by the introduction of various advanced transmission technologies, such as multiple access (MAC) technology and relay-assisted communications. However, beyond the accurate representation and successful transmission of information, in many applications it is the semantic aspect of that information that is really of interest.
   This thesis makes contributions to both the technology of conventional wireless communications and the theory of semantic communication. The main work is summarized as follows: We first consider an uplink system with K single-antenna users and one base station equipped with a single antenna, where each user utilizes a binary constellation to carry data. By maximizing the minimum Euclidean distance of the received sum constellation, the optimal user constellations and sum constellation are obtained for K=3 users. Using the principle of lattice coding, that design is extended to the K-user case. In both settings, the sum constellation belongs to additively uniquely decomposable constellation group (AUDCG). That property enables us to reduce the maximum likelihood multi-user detector to a single-user quantization based receiver. The symbol error probability (SEP) formula is derived, showing that our proposed non-orthogonal multiple access (NOMA) scheme outperforms the existing time division multiple access (TDMA) designs for the same system. Our design also sheds light on the general complex constellation designs for the MAC channel with arbitrary user constellation size. Specifically, K-user constellations with any 2^Mk size can be obtained using combinations of the proposed binary constellations. Next we concentrate on a multi-hop relay network with two time slots, consisting of single-antenna source and amplify-and-forward relay nodes and a destination node with M antennas. We develop a novel uniquely-factorable constellation set (UFCS) based on a PSK constellation for such system to allow the source and relay nodes to transmit their own information concurrently at the symbol level. By taking advantage of the uniquely-factorable property, the optimal maximum likelihood (ML) detection was equivalently reduced to a symbol-by-symbol detection based on phase quantization. In addition, the SEP formula was given, while enable us to show that the diversity gain of the system is one. For semantic communication, a new source model is considered, which consists of an intrinsic state part and an extrinsic observation part. The intrinsic state corresponds to the semantic feature of the source. It is not observable, and can only be inferred from the extrinsic observation. As an instance of the general model, the case of Gaussian distributed extrinsic observations is studied, where we assume a linear relationship between the intrinsic and extrinsic parts. We derive the rate-distortion function (in both centralized encoding and distributed encoding) of semantic-aware source coding under quadratic distortion structure by converting the semantic distortion constraint of the source to a surrogate distortion constraint on the observations.
   With proposed AUDCG and UFCS-based designs, high data rates as well as low detection latency can be achieved. Our modulation division method will be one of the promising technologies for the next generation communication and the analysis of the source coding with semantic information constraints also provides some insights that will guide the future development of semantic communication systems.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
The proliferation of smart phones and electronic devices has spurred explosive growth in high-speed multimedia services over the next generation of wireless cellular networks. Indeed, high data rates and large-scale connectivity with seamless coverage are the dominant themes of wireless communication system design. Moreover, beyond the accurate representation and successful transmission of information, the interpretation of its meaning is being paid more attention nowadays, which requires the development of approaches to semantic communication.

The goal of this thesis is to contribute to the development of both conventional and semantic communication systems. Two advanced transmission technologies, namely, multiple access and relay-assisted communications are considered. By taking advantage of the special structures of digital communication signals, new approaches to multiple access and relay-assisted communications are developed. These designs enable high data rates, while simultaneously facilitating low-latency detection. Since there has been very limited analysis of the source coding of a vector source subject to semantic information constraints, we also study the rate distortion to trade-off for vector sources in both the case of centralized encoding and the case of distributed encoding, and we establish some insights that will guide the future development of semantic communication systems.


title: Ethics of the ordinary, amplified in the intensive care unit - Nurses' responses to moral distress experienced in their professional practice during the COVID-19 pandemic

contributor:
Jack, Dr. Susan
Nursing

subject:
Moral distress
Intensive care
Nurse
Critical care
Nursing ethics
COVID-19

abstract:
Background: Nurses working in intensive care units are at high risk for experiencing moral distress, a response to an ethical event, in which a nurse recognizes or partakes in an action that does not align with their values. In response, nurses may experience negative health effects, which drives attrition. This can negatively impact patient care and the stability of healthcare organizations. There is a scarcity of high-quality and effective organizational interventions to mitigate moral distress, and even lesser work has been done to understand nurses’ practice-based needs to ameliorate moral distress. New conditions of moral distress in the context of COVID-19 have increased the relevance of these shortcomings.

Aim: The purpose of this study was to learn about intensive care unit nurses’ responses to moral distress experienced in their professional practice during the COVID-19 pandemic.

Methods: This interpretive descriptive study explored the experiences of 40 intensive care unit nurses, who self-reported experiencing moral distress in their professional practice during the COVID-19 pandemic (March 2020 – Sept 2021). Data generation included a demographic questionnaire, including the Measure of Moral Distress - Healthcare Professionals survey, and one-to-one semi-structured virtual interviews. The categorization and synthesis of the data was guided by methods of reflexive thematic analysis and rapid qualitative analysis.

Results: Findings indicated that nurses regularly navigated pre-existing and novel ethical events in practice, which were exacerbated in the context of the COVID-19 pandemic. In response, they often experienced moral distress under the complex interplay of two overarching and broad conditions: (1) when nurses’ voices were not heard; and (2) when patients received substandard levels of care, that was not patient-centered, pain free, or that did not align standards of care. Moral distress experienced by nurses resulted in negative outcomes across serval health domains, that drove feelings of burnout and attrition. To cope, nurses engaged in patterns of action, avoidance, and acquiesce. Finally, they made recommendations for mitigative interventions rooted in their desire to be heard, in efforts to optimize patient care and nurse well-being.

Conclusion: Intensive care unit nurses’ voices need to be amplified and valued, in the context of various healthcare organizations (e.g., practice, research, education and polity), to mitigate moral distress and the associated negative outcomes.

abstract: Thesis

abstract: Master of Health Sciences (MSc)


title: Metabolic Adaptations to Life at High-Altitude: Evolved Increases in Oxidative Capacity Across Many Skeletal Muscles in High-Altitude Deer Mice, Peromyscus maniculatus

contributor:
Scott, Graham R.
Biology

abstract: The cold and hypoxic conditions at high altitude necessitate high metabolic O2 demands to support thermogenesis while hypoxia reduces O2 availability. Skeletal muscles play key roles in thermogenesis, but our appreciation of muscle plasticity and adaptation at high altitude has been hindered by past emphasis on only a small number of muscles. We examined this issue in deer mice (Peromyscus maniculatus). Mice derived from both high-altitude and low-altitude populations were born and raised in captivity and then exposed as adults to normoxia or hypobaric hypoxia (12 kPa O2 for 6-8 weeks). Maximal activities of citrate synthase (CS), cytochrome c oxidase (COX), β-hydroxyacyl-CoA dehydrogenase (HOAD), hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) were measured in 20 muscles involved in shivering, locomotion, body posture, ventilation, and mastication. Principal components analysis revealed an overall difference in muscle phenotype between populations but no effect of hypoxia acclimation. High-altitude mice had greater activities of mitochondrial enzymes and/or lower activities of PK/LDH across many (but not all) respiratory, locomotory, and postural muscles compared to low-altitude mice. In contrast, chronic hypoxia exposure had very few effects on metabolic phenotype across muscles. Further examination of CS in the gastrocnemius showed that population differences in enzyme activity stemmed from differences in protein abundance and mRNA expression, but not from population differences in CS amino acid sequence. Overall, our results suggest that evolved increases in oxidative capacity across many skeletal muscles, at least partially driven by differences in transcriptional regulation, may contribute to high-altitude adaptation in deer mice.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: High altitude environments are often considered to be harsh environments for animals to inhabit. This stems from the concurrent challenge of low oxygen availability coupled with year-round cold temperatures. Despite these challenges, there exist many high-altitude species including birds, mammals, and humans, whom have each, over time, developed suites of adaptations that aid them in successfully living at high altitude. My thesis focuses on the role of skeletal muscle adaptation in supporting life at high altitude. To address this, I compared the capacity for key steps in oxidative and anaerobic metabolism in the skeletal muscles of low-altitude and high-altitude species of North American deer mice. My thesis contributes to our understanding of how skeletal muscles can support adaptations to life at high altitude.


title: REFRAMING RITUAL GESTURES IN DIALOGUE: GESTURE STUDIES AND SACRAMENTAL RITUALS

contributor:
Kroeker, P. Travis
Religious Sciences

subject: ritual, gesture, sacraments, language

abstract: Ritual gestures have traditionally been understood as conventional bodily actions that are an external accompaniment to language. This thesis challenges this understanding by exploring the relevance of the modern field of gesture studies to Roman Catholic understandings of ritual gestures. Following the field of gesture studies, which argues that gestures are indeed part of language, this thesis argues that ritual gestures are a fundamental part of the content and structure of the “sacramental dialogue” that occurs between ritual participants in Roman Catholic sacramental rituals. Despite a number of overlapping interests, researchers in the field of gesture studies have given very little attention to ritual gestures and religious studies scholars have in turn given very little attention to the field of gesture studies. This thesis represents the first comprehensive attempt to build a bridge between these fields. Using conceptual blending theory, this thesis shows that gestures in ritual settings can actually function similarly to gestures in everyday settings because they both occur within the context of dialogue. The nature and function of three sacramental gestures in the Roman Catholic tradition are examined within the context of the metaphorical concept of “sacramental dialogue”: palm-up open hand (PUOH) gestures, the raising of the Eucharistic elements, and the breaking of the Eucharistic bread. It is shown that these and other ritual gestures are rich multi-modal communicative actions that contribute to the structure and content of the sacramental rituals in ways that words cannot. Ritual gestures are therefore a fundamental part of the structure and content of the sacramental dialogue and cannot be adequately understood apart from words as non-verbal accompaniments or in terms of words as symbols.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)

abstract: Ritual gestures have traditionally been understood as conventional bodily actions that are an external accompaniment to language. This thesis challenges this understanding by exploring the relevance of the modern field of gesture studies to Roman Catholic understandings of ritual gestures. Following the field of gesture studies, which argues that gestures are indeed part of language, this thesis argues that ritual gestures are actually a fundamental part of the content and structure of the “sacramental dialogue” that occurs between ritual participants in Roman Catholic sacramental rituals. This thesis examines the nature and function of three sacramental gestures within the context of sacramental dialogue: palm-up open hand (PUOH) gestures, the raising of the Eucharistic elements, and the breaking of the Eucharistic bread. This thesis also represents the first comprehensive attempt to build a bridge between the fields of religious studies and gesture studies.


title: Human-in-the-Loop Model Predictive Trajectory Generation for Flocks of Drones

contributor:
Sirouspour, Shahin
Electrical and Computer Engineering

subject:
Aerial Robotics
Trajectory Generation
Model Predictive
Himan-in-the-Loop

abstract:
This thesis presents a novel architecture for human-in-the-loop control of multiple drones. The design of such systems must address several challenges at the same time. The drones must avoid collisions with each other and with obstacles in their task environment while following operator's command as closely as possible to navigate their environment. To this end, they should be able to adjust their pre-defined desired formation and, if needed, transition to alternative formations to ensure collision-free operation in their task environment while following the operator's commands.

The proposed control strategy is a central algorithm with multiple stages and relies on formulating and solving convex optimization problems in real time to achieve the control objectives. The operator provides reference velocity commands for the flock of drones to move them in the task environment. The algorithm creates linear collision avoidance constraints and distributes the operator's commands among the drones through a number of intermediate steps. It generates reference trajectories for the drones motion by solving a model-based optimization problem over a receding horizon. Conventional trajectory controllers generate the control inputs for individual drones.

Prospective formation shapes are obtained for the drones by formulating and solving parallel convex optimizations, considering the operator's reference command and the obstacle-free space. While keeping the convexity of the optimization problem, the proposed algorithm allows for the presence of obstacles in the middle of the formation. This is achieved by properly assigning obstacle-free regions to each agent separately in the formation. In addition, safe convex regions in the form of linear inequality constraints are generated in the direction of the operator's commanded velocity. Moreover, constraints are introduced to avoid inter-drone collisions at each step. Trajectory optimization is formulated as a quadratic programming problem similar to model predictive control schemes to minimize deviation from human operator's command.

The effectiveness of the proposed control algorithm is initially verified by simulating two different operational scenarios. Furthermore, the algorithm is implemented on actual hardware to operate a flock of three drones in a laboratory setting. The implementation of the algorithm in C++  utilizes high-performance computation techniques to achieve sufficiently high real-time control update rates for smooth and stable operation of the drones.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract: The rise of unmanned aerial vehicle technology and the increase in their accessibility have made them viable solutions for serious missions such as search and rescue operations. Complex cooperative tasks can be conducted via a collection of drones which can show higher levels of robustness and agility as a system. Although repetitive and simple actions can be easily automated, real-world problems are unpredictable in which complex decision-making is involved. Such scenarios can be tackled by the presence of a human supervisor to empower the system with strong cognitive capabilities. This thesis presents a multi-layer control framework for human-in-the-loop operation of a flock of unmanned aerial vehicles. This method continuously optimizes the drones trajectories to adhere as closely as possible to operator's motion commands while avoiding collisions among them and with obstacles in their task environment. This new control framework is successfully validated in both simulations and experiments in a laboratory environment.


title: MULTI-SOURCE DUAL ACTIVE BRIDGE DC/DC CONVERTER FOR MORE ELECTRIC AIRCRAFT: DESIGN, CONTROL, AND PERFORMANCE OPTIMIZATION

contributor:
Narimani, Mehdi
Electrical and Computer Engineering

abstract: System reliability and design optimization are the main concerns in power electronic converters of more-electric aircraft (MEA). The fundamental distribution networks of aircraft are reviewed to establish context. The Isolated DC-DC converters are considered the building blocks of modern aircraft electrical power distribution systems (EPDSs). The DC/DC converters transfer power from the main generation direct current (DC) bus to various loads aboard the aircraft. As a result of the electrical power demand increase in the emerging EPDSs of MEA architectures, more energy storage systems (ESSs) are utilized in the distribution network. A single DC/DC converter unit is conventionally dedicated to each energy source. This thesis focuses on replacing several DC/DC converters used in the existing distribution networks by more optimized multi-source converter units. Standard industry and literature topologies are reviewed including structures aimed for multi-source system integration. The topology proposed in this thesis aims for a multiple sources/loads integration to improve the power density of the distribution network. The different operating modes of the proposed topology add flexibility to the system enabling power flow between different sources, while controlling the power supplied to the low voltage (LV) network on the aircraft. Better system utilization is achieved as compared to conventional solutions. The system stability is improved considering that the multi-source dual active bridge (MSDAB) topology can be configured to stabilize the high-voltage DC (HVDC) generation bus in case of voltage sag. A power-flow mechanism between the different sources utilizing the magnetizing inductance of the transformer is proposed and discussed as one of the operating modes of the converter. A design process using genetic algorithm (GA) optimization is introduced to optimally select the converter parameters to minimize the converter RMS current. The mathematical model of the proposed MSDAB topology is developed based on Fourier transform of key converter waveforms. The optimization is split into two layers; the first is to select the hardware components and the second is to optimize the converter control parameters. Simulation and experiments of the control schemes were performed to validate optimal operation of the proposed converter. A review of the magnetic components in MEA DC/DC converters is conducted. The high-frequency transformer utilized in such converters is the major contributor to the size and weight besides the thermal management system. An optimization design methodology is introduced to minimize the transformer core size and improve the converter performance through optimized winding configurations. Different magnetic materials, winding configurations, and core paralleling are considered in the optimization process. The trade-offs between the converter efficiency and transformer power density are discussed. The transformer parasitic elements effect on the converter performance is presented. Multi-layer minimum gradient (MLMG) winding configurations are proposed to eliminate the high-frequency oscillations (HFO) caused by the transformer parasitics. The proposed configurations resulted in better converter performance with 20$\%$ improvement in the transformer volume as compared to a similar conventional configuration.  Three different transformer configurations are implemented and validated experimentally using an impedance analyzer. The improvements in the converter performance are highlighted through finite element analysis (FEA) simulations and converter experiments.

abstract: Thesis

abstract: Doctor of Engineering (DEng)


title: Capturing Antibiotic Resistance Genes in the Human Gut Microbiome After Probiotic and Antibiotic Exposures

title: FACTORS IMPACTING ANTIBIOTIC RESISTANCE IN THE MICROBIOME

contributor:
Wright, Gerard D
Biochemistry and Biomedical Sciences

subject:
Antibiotic resistance
Microbiome
Probiotics
Preterm infants
Antibiotics
Next-generation sequencing

abstract:
Antibiotic-resistant bacteria and their often-untreatable infections are increasing globally.
The determinants that confer reduced susceptibility to antibiotics are encoded in the genetic
information, or genes, of bacteria. Sequencing-based approaches to identify antibiotic
resistance genes (ARGs) in diverse environments, such as the gut microbiome, are limited
in throughput and inaccessible due to high costs. The microbiome and its associated ARGs
are shaped by many factors throughout early life, which have yet to be fully characterized.
In this thesis, I developed an approach to capture ARGs in the gut microbiome and study
the effect of various early-life exposures.
First, I describe a set of over 37,000 probes to target over 2,000 ARGs. This targeted
sequencing approach was designed and validated against samples of DNA isolated from
multi-drug resistant bacteria. This probeset proved superior to metagenomic shotgun
sequencing in capturing the rare portion of ARGs from a human gut microbiome sample. Second, I investigated the potential benefits of providing probiotics to infants born preterm
 in reducing antibiotic resistance in their gut microbiomes. Preterm infants that received
probiotics had a reduced burden of ARGs associated with potentially pathogenic bacteria
at 5 months of age compared to non-probiotic-supplemented preterm infants.
Finally, I explored the potential consequences of macrolide antibiotic exposure on ARGs
in the gut microbiome of children with diarrhoea in Botswana, Africa. Compared to the
standard treatment for diarrhoea, a three-day dose of azithromycin did not result in an
increased selection for ARGs after 60 days.
This thesis tackles the challenge of comprehensively detecting antibiotic resistance in the
gut microbiome. A better understanding of the impact of early-life exposures, including
probiotic and antibiotic treatments, in the prevention or maintenance of ARGs in the gut
microbiome of children will help reduce unnecessary selective pressures and the
persistence of antibiotic resistance into later life.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Infection rates associated with antibiotic-resistant bacteria are increasing. The traits that
allow bacteria to survive antibiotics are encoded by their genetic information or genes.
 There is a wide diversity of antibiotic resistance mechanisms available to bacteria and
comprehensive methods to detect them are needed. My work presents the development and
validation of an approach to capture and sequence all known antibiotic resistance genes.
With this tool, I investigated the early life exposures that shape antibiotic resistance in the
diverse community of bacteria encompassing the human gut microbiome. First, I revealed
 the protective effects of providing beneficial bacteria, or probiotics, to preterm infants.
Next, I uncovered a minimal impact of antibiotic treatment in selecting for antibiotic
resistance genes in children with diarrhoea. Improved tools to understand antibiotic
resistance in early-life and the factors that modulate its prevalence will help reduce the
persistence of antibiotic-resistant bacteria in later life.


title: The effect of acclimation temperature on hypoxia tolerance of mummichog killifish (Fundulus heteroclitus)

contributor:
Scott, Graham
Biology

subject: O2 transport; anaerobic metabolism; gill remodelling; respiration; teleost; thermal breadth

abstract: Climate change is leading to rapid change in aquatic environments, increasing the mean and variability of temperatures, and increasing the incidence of hypoxia. We investigated how acclimation to constant temperatures or to diel temperature fluctuations affect hypoxia tolerance in mummichog killifish (Fundulus heteroclitus). Killifish were acclimated to constant cool (15˚C), constant warm (25˚C), or a diel temperature cycle (15˚C at night, 25˚C during day) for 6 weeks. I then measured hypoxia tolerance (time to loss of equilibrium in severe hypoxia, tLOE; critical O2 tension, Pcrit), whole-animal metabolism, gill morphology, haematology, and tissue metabolites at 15˚C and 25˚C in a full factorial design. Among constant temperature groups, tLOE was highest and Pcrit was lowest in fish tested at their acclimation temperature. Warm acclimated fish had lower metabolic rate at 25˚C and greater gill surface area (less coverage of lamellae by interlamellar cell mass, ILCM), but cool acclimated fish had greater brain glycogen stores. Therefore, effects of constant temperature acclimation on hypoxia tolerance were temperature specific and not exhibited broadly across test temperatures, and they were associated with different underlying mechanisms. Hypoxia tolerance was less sensitive to test temperature in fish acclimated to fluctuating temperatures compared to fish acclimated to constant temperature. Acclimation to fluctuating temperatures also increased haemoglobin-O2 affinity of the blood (decreased P50) compared to constant temperature groups. Therefore, acclimation to fluctuating temperatures helps maintain hypoxia tolerance across a broader range of temperatures, and leads to some distinct physiological adjustments that are not exhibited by fish acclimated to constant temperatures.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Human disturbance is leading to increased variability of environmental temperature as well as increased incidence and severity of aquatic hypoxia (low oxygen conditions). The effect of elevated temperatures on hypoxia tolerance is well studied, however little is known about how environmentally relevant temperature variability impacts hypoxia tolerance in fish. To address this research gap, I examined the effects of constant temperature and fluctuating temperature regimes on the hypoxia tolerance of mummichog killifish. I provide evidence that acclimation temperature impacts hypoxia tolerance, gill structure, haematology and energy stores in the brain. My thesis demonstrates that thermal history can alter temperature-sensitive physiological traits that fish use to cope with stressors such as low oxygen. These findings contribute to the existing body of work that documents the interactive effects of combined stressors in changing ecosystems on the physiology of fish.


title: Exploring the lived experience of IPV in Bermuda

format: Full-text application/pdf

subject:
Intimate Partner Violence
Bermuda

abstract:
Intimate partner violence (IPV) in Bermuda has received minimal recognition as a social
problem in Bermuda. Limited academic research has been conducted. With increasing rates of
IPV occurring in Bermuda, this illuminated the need for further exploration.
Familialism is a strongly subscribed cultural belief that reinforces the silence in
Bermudian society. Therefore a single case study was conducted. This case study is about a
black Bermudian woman who experienced IPV during her relationship with the father of her
children.
Her narrative provides insight into a social problem that is obscured by cultural beliefs.
She illustrated various elements of Bermudian culture that are intertwined and contribute to the
perpetuation of IPV.
She was motivated by her commitment and dedication to her family to challenge cultural
beliefs and access social support. A combination of both informal and formal social support
enabled her to navigate through her IPV experience.
It is the hope that this case study will serve as the foundation for future research on IPV
in Bermuda in order to attain a better understanding of the social issue, to create awareness about
IPV and to develop comprehensive social policies.


title: Voices of the Teachers: The relationship between stress and job satisfaction of French Immersion Program and English language program of teachers

subject:
French immersion
Education

abstract:
The purpose of this study was to compare the challenges that French Immersion

Program and English Language Program teachers experience in their profession and

investigate the relationship between these challenges and teachers’ stress and job

satisfaction. As well, specific focus was placed upon identifying the strategies used by

teachers to cope with job related stress and the relationship between these strategies,

stress, and job satisfaction. Sixty-six full time teachers participated in this study. They

completed a seven-part questionnaire which was designed to collect data about teachers’

workload, work challenges, affective challenges, sources of affective challenges, coping

strategies, job satisfaction, and career intention. Findings indicated that French

Immersion Program teachers were more likely to identify the interpersonal challenges as

challenging issues whereas the English Language Program teachers were more likely to

identify the student-related issues as challenging. In addition, interpersonal challenges,

student-related issues, and outside influences were related to stress. Also, stress was

negatively correlated to job satisfaction suggesting that the higher the level of selfreported

stress the lower the level of job satisfaction. When investigating the relationship

between the self-reported stress, job satisfaction, and the coping strategies used during

school hours, set priorities, and discuss issues with the administration were positively

correlated with the job satisfaction level. In addition, set priorities, maintain a positive

attitude, set realistic goals, and discuss issues with the administration were negatively

correlated with the self-reported total stress. No significant correlations were found

between the self-reported stress, job satisfaction, and the coping strategies used after

school hours.


title: Let’s talk about sex: A glimpse into Nova Scotia youths’ perceptions of high school sexuality education

subject:
Education
High school
Public opinion
Attitudes
Teenagers
Sexual hygiene
Sex instruction
Nova Scotia
Youth

abstract:
Teen sexuality is a topic of great importance because youth are becoming sexually

active at ages that belie their teen years and are experiencing pregnancy and sexually

transmitted infections (STIs) at high rates. Not only does this warrant attention, but it also

necessitate research and education. Sexuality education is essential for providing sexual

health to all Canadians, especially Canadian youth. Yet, even though all provinces and

territories offer youth-based sexual health education, the comprehensiveness,

effectiveness, and quality of the programs vary significantly. Further, the Canadian

Guidelines for Sexual Health Education are not being adhered to in all Nova ScotiaÃ¢  s

high schools.

The main objective of this research was to investigate the perceptions of a select

group of Nova Scotian youth with regard to sexuality education. Bearing in mind aspects

of critical theory, particularly ComstockÃ¢  s (1982) method for critical research and

SmithÃ¢  s (1995) notion of the line of fault, face-to-face interviews were conducted with ten

Nova Scotian youth (eight females, two males) to determine their perceptions of the

effectiveness of sexuality education in the Nova Scotia school system. All interviews

were tape-recorded and later transcribed. Interviews were analyzed using grounded

theory techniques (Bernard, 2000), relying primarily on open and axial coding.

Results indicated that participants were not satisfied with the sexuality education

that they received in high school. Four themes were apparent. Interviewees felts that the

iii

sexuality information that they received in high school was limited in its coverage.

Although most participants realized that teachers have little control over sexuality

education curriculum, they felt that their sexuality education facilitators were unqualified

and uncomfortable. All youth interviewed expressed a desire to have additional and

improved sexuality education resources in Nova ScotiaÃ¢  s high schools. In addition, it was

clear from the interviews that a holistic view of sexual health is not being promoted in

Nova Scotia high schools. Several recommendations for sexuality education practice are

provided.


title: The role of hope in school-aged children’s emotional well-being in relation to school environment and optimism/pessimism

subject:
Optimism in children -- Nova Scotia
Middle school students -- Psychology.
Depression in children -- Diagnosis

abstract: Interactions between classroom climate, dispositional optimism, and hope were examined in the prediction of emotional well-being in early adolescent students. The present study consisted of 98 students (32 boys, 65 girls, 1 unknown) in grades six, seven, and eight with a mean age of 12.51 years (SD = .95). Participants completed questionnaires regarding their classroom environment, future expectations, hopeful thinking, depression, and life satisfaction. Hierarchical multiple regression analyses revealed eleven interactions between classroom climate/dispositional optimism and hope in the prediction of depression and life satisfaction. As an example, it was found that classroom competitiveness was negatively related to satisfaction with friends for students low in hope but not for students with high hope. Implications of these interactions are discussed in terms of hope as a psychological strength and its role in promoting emotional well-being in early adolescent students.


title: Achieving Healthy Body Weights in the Teenage Years: Evidence-based Practice Guidelines for Community Nutrition Interventions

subject:
Teenagers
Obesity in adolescence
Nutrition
Body weight

abstract:
Background: Adolescent obesity has become a significant public health problem. Conservative estimates, based on self-reported data, indicate overweight and obesity rates among Canadian adolescents aged 12 to 17 soared from 14% in 1978/79 to 29% in 2004.
This persistent upward trend has serious long-term implications on the physical and psychological well being of adolescents and accounts for billions of dollars in health care costs. For this reason, prevention has been recognized as a priority health issue. While interventions have begun to target school-aged children and adults in clinical settings, few advances have been made to halt the escalating problem among adolescents. This population has unique needs with increasing independence transitioning into adulthood. Reversing the trend requires comprehensive interventions that mitigate personal, social and environmental barriers to healthy lifestyle choices.
There is currently little consensus on best practices for dietetic adolescent obesity prevention and management. Community strategies are recommended as the most efficacious and feasible way to reach the greatest number of youth and support healthy lifestyle development. Evidence based guidelines are currently not available and are needed to guide nutrition practice in this area.
Methods: A thorough systematic review and evidence analysis yielded 48 prevention and treatment interventions meeting the studies inclusion criteria. The evidence was graded and drafted into recommendations and an algorithm guideline displaying how each recommendation relates to nutrition intervention. A panel of independent, national experts assessed the guidelines for validity, acceptability and applicability with a tool adapted from the AGREE Collaborations Appraisal of Guidelines for Research and Evaluation Instrument. These experts covered different areas of expertise, including community nutrition, public health, adolescent health, academia and endocrinology.
Results: The research findings confirm the need for comprehensive strategies, which include components of nutrition education and physical activity, address social and environmental influences and use schools as delivery vehicles for health promotion and health education. For obesity treatment interventions, promising strategies incorporated diet plans, family involvement and behaviour modification techniques in multidisciplinary interventions. Computer based strategies and peer modelling may also be developmentally appropriate strategies for health promotion health in the adolescent population.
Conclusions: The results of this study indicate several interventions conducted over the past 10 years have had a positive effect in preventing or reducing adolescent obesity over the short and/or long term. The findings support the development of comprehensive, multi-disciplinary obesity prevention and treatment interventions and the use of peer modeling, family based and computer based strategies.


title: Young Offenders'   Perceptions of their Experiences within the Canadian Youth Justice System

subject:
Public opinion
Juvenile justice
Maritime Provinces
Juvenile delinquents
Attitudes
Rehabilitation

abstract: Apart from Hazel, Hagell, and Brazier (2002), little qualitative research exits that draws upon the perspectives of young offenders related to their experiences within the youth criminal justice system. Understanding how young people perceive their experiences within the youth justice system provides valuable insight into how current apprehension/arrest, court, sentencing, and youth justice programs and services affect young offenders, given that many young offenders lack understanding of the criminal justice (Baum & Wheeler, 1968; Erickson, 1982; Hazel et al., 2002; Langley, Thomas, & Parkinson, 1978; Peterson-Badali, Koegl, & Ruck, 1999).The present exploratory study obtained the perspectives of former young offenders related to their experiences within the Canadian youth justice system. In-depth individual interviews were conducted with seven (1 female, 6 males) participants who described their responses and adjustments to being apprehended and sentenced by the law. The interviews were held in semi-structured, audio-taped sessions, maintaining strict ethical principles of confidentiality and voluntary participation. Transcribed interviews were analyzed using cross-comparative, discovery-based, grounded theory methodology, that identified a core category of Transitioning, four major descriptive categories, Transitioning Through the law, Home Life, Young Offending Life and Youth Justice Experiences, and Post Young Offending and Future Outlook, and a theoretical explanation of the basic psychosocial processes undertaken by young offenders in response to their involvement with the law. Recommendations are offered for preventative approaches to young offending and improvements to the youth criminal justice system, with implications for young offenders, their families and communities, and youth justice programming and services. Given the variety of factors and influences that contribute to youth offending, it is suggested that a systemic approach, that draws from larger societal concern for the welfare of its homes, families, communities, and citizens, be developed, that looks to directly address such critical social issues as poverty, home violence, racism, barriers to education and mental health access, and family breakdown. With the recognized and profound influence of the home environment upon childrenâ s development, it is suggested that the Nova Scotia Department of Community Services increase the availability of early intervention programs dedicated to parental education and support, in order to engage with and assist at-risk families. In addition, it is suggested that the Nova Scotia Department of Justice work more closely with the Nova Scotia Department of Community Services and community-based services, to share, where appropriate, young offendersâ case information, in order to best plan responsibly and knowledgably the programs of individual young offenders.