Digital Commons Network^™

Developing Structure-Activity-Relationships For Metal-Ligand-Cooperative (Mlc) Complexes Using Pr2nr′2 Ligands, James M. Stubbs

Electronic Thesis and Dissertation Repository

Exploring efficient and environmentally-friendly routes to synthesize molecules is critical for the pharmaceutical and fine chemical industries. One method is to study current catalytic methods to increase selectivity and performance for challenging reactions. Inclusion of an intramolecular acid/base site on the ligand manifold of an organometallic complex has allowed for new mechanistic pathways and enhanced reactivity. This thesis delves into understanding organometallic complexes in catalysis by systematic tuning the ligand properties. Synthesis of P^R₂N^R′₂ ligands was performed to enable the systematic tuning as R and R′ alter the electronic and steric properties of the primary …

Exploring Quality Improvement For Diabetes Care: A Multiple Case Study Of Primary Care Teams In First Nations Communities In Canada, Meghan Fournie

Electronic Thesis and Dissertation Repository

Clinical quality improvement (QI) teams from First Nations communities across Canada participated in an 18-month QI collaborative program called the TransFORmation of IndiGEnous Primary HEAlthcare Delivery (FORGE AHEAD) clinical QI initiative. Community-based participatory research and multiple case study methodologies were utilized to explore the experience of two clinical QI teams from diverse primary care settings in First Nations communities as they engaged in developing and implementing changes in practice to improve the quality of diabetes care. This study provides insight into how clinical QI teams drew upon multiple sources of knowledge and information to inform their QI activities, the importance …

Iron And Copper Homeostasis In Staphylococcus Aureus, Holly A. Laakso

Electronic Thesis and Dissertation Repository

All microorganisms require transition metals for key metabolic processes, thus during infection microbial access to essential metals is tightly regulated by the host in a process termed nutritional immunity. Iron acquisition is critical to the pathogenesis of the formidable human pathogen, Staphylococcus aureus, which utilizes heme-uptake systems and two high-affinity iron-scavenging siderophores, staphyloferrin A (SA) and staphyloferrin B (SB) for iron acquisition. In this study, I identify sbnI as encoding a transcription factor required for expression of genes in the sbn operon, the biosynthetic operon for SB synthesis. I also show that SbnI is a novel hemoprotein, where binding …

A Foucauldian Genealogical Analysis Of Healthy Eating Education Materials In Ontario 1942-2015, Janet N. Loughheed

Electronic Thesis and Dissertation Repository

This study examines the introduction of the Official Food Rules in 1942 and the formation of subsequent dietary self-analysis practices in Ontario curriculum and textbooks. Examination of the influences of nutrition science, Ontario education policy and politics, and Canadian health policies are combined with Foucauldian critical discourse analysis of selected classroom materials. The Grade 4 dietary self-analysis, based on the various forms of the food guide, from 1946, 1974 and 2011 are analysed and compared. Themes of truth, power and identity within this regime of truth are examined. The ordering of food in the Food Rules was a discursive event. …

Perceptions Of Primates And Protected Areas: Ethnoprimatological Implications For Conservation In The Pacoche Refuge, Tamara L. Britton

Electronic Thesis and Dissertation Repository

This research uses an ethnoprimatological approach to investigate people’s perceptions of primates and protected areas through a case study in the Pacoche Marine and Coastal Wildlife Refuge in Manabí, Ecuador. Twenty-one agricultural workers from the community of Pacoche were interviewed using a photo pile-sorting exercise and structured open-ended interviews.

Results regarding perceptions of primates indicate that despite previous local practices, in comparison to other faunal species in the park, primates are no longer commonly targeted for food or medicinal purposes. White-fronted capuchins, while reported to be damaging to corn and orange crops, and commonly viewed as aggressive, were also widely …

Multiliteracies Meaning-Making: How Four Boys’ Video Gaming Experiences Influence Their Cultural Knowledge—Two Ethnographic Cases, Carol Ann Lane

Electronic Thesis and Dissertation Repository

Scholars have acknowledged the potential contribution of video gaming to complex forms of learning, identifying links between gaming and engagement, experiential learning spaces, problem-solving, strategies, transliteracy reflectivity, critical literacy, and metacognitive thinking. Despite this movement toward the inclusion of video gaming in literacy teaching, concerns about certain risks raised by scholars have slowed the adoption of using video games to foster learning.

Using a multiliteracies lens, this multi-case study examined the experiences of four boys engaged with video gaming in two different contexts: a community centre and an after-school video club. By drawing on Feminist Post-Structural Theory, Vygotskian, and video …

Subjectivity In Young Adult Literature (Philip Pullman's His Dark Materials, Marjane Satrapi's Persepolis, Zohre Javaheri

Electronic Thesis and Dissertation Repository

Subjectivity is a crucial concept in children’s books and is discernible both within a particular culture and in comparison among cultures. The stories of the two novels discussed, express a quest for a sense of identity. I explored first, the images of femininity that the fictions offer, and second, the interactions between selfhood, other selves, social and cultural forces, and displacement. I limited my discussion of Bakhtinian theory to the concept of dialogism. Both novels articulate the complexity of ways in which the subjectivity of female adolescents, Lyra and Marjane, is formed in dialogue with different literary works and social …

Psychotropic Effects Of Cannabis Components On The Mesolimbic Dopaminergic System, Christopher Norris

Electronic Thesis and Dissertation Repository

The two most abundant phytochemical compounds in cannabis are cannabidiol (CBD) and ∆⁹-tetrahydrocannabinol (THC). THC is the primary psychoactive component of cannabis and is a partial CB₁ receptor (CB₁R) agonist. THC is believed to be responsible for the motivational and dependence-producing effects of cannabis and causes psychotomimetic and affective processing disturbances. Conversely, CBD, is non-psychoactive, acts as a 5-HT_1A receptor agonist, antagonizes CB₁Rs, and possesses both anti-psychotic and anxiolytic properties. The neural substrate believed to be responsible for many of the effects of cannabis is the dopaminergic, mesolimbic reward pathway which is …

Efficient Alignment Algorithms For Dna Sequencing Data, Nilesh Vinod Khiste

Electronic Thesis and Dissertation Repository

The DNA Next Generation Sequencing (NGS) technologies produce data at a low cost, enabling their application to many ambitious fields such as cancer research, disease control, personalized medicine etc. However, even after a decade of research, the modern aligners and assemblers are far from providing efficient and error free genome alignments and assemblies respectively. This is due to the inherent nature of the genome alignment and assembly problem, which involves many complexities. Many algorithms to address this problem have been proposed over the years, but there still is a huge scope for improvement in this research space.

Many new genome …

Advances In The Modeling Of Heavy-Tailed Distributions, Sang Jin Kang

Electronic Thesis and Dissertation Repository

Several advances are proposed in connection with the approximation and estimation of heavy-tailed distributions, some of which also apply to other types of distributions. It is first explained that on initially applying the Esscher transform to heavy-tailed density functions such as the Pareto, Student-t and Cauchy densities, one can utilize a moment-based technique whereby the tilted density functions are expressed as the product of a base density function and a polynomial adjustment. Alternatively, density approximants can be secured by appropriately truncating the distributions or mapping them onto compact supports. The validity of these approaches is corroborated by simulation studies. …

A High Gain Dc-Dc Full-Bridge Converter, Prashanth Prabhu

Electronic Thesis and Dissertation Repository

High gain DC-DC converters have become increasingly popular in recent years as there is greater need to interface low voltage DC sources such as solar cells and batteries with much higher voltage DC buses. A new high gain DC-DC converter with high gain, galvanic isolation and an integrated passive snubber network is proposed in the thesis. In the thesis, the general operation of the converter is discussed, its modes of operation are explained and its features are reviewed. The design of the converter is then discussed and a set of general guidelines that can be used in the design are …

Characterizing The Role Of Thymine Dna Glycosylase In Transcriptional Regulation And Cancer In Vivo, Mohammad Haider Hassan

Electronic Thesis and Dissertation Repository

Cytosine methylation (5mC) is essential for transcriptional control and genomic stability and is often used as a prognostic marker in cancer. Although 5mC has long been considered a relatively stable epigenetic mark, recent studies have demonstrated that it can be reversed enzymatically by TET proteins which oxidize 5mC into 5-hydroxymethylcytosine (5-hmC), and then to 5-formylcytosine (5-fC) and 5-carboxylcytosine (5caC). This mechanism is known as active DNA demethylation and the base excision repair enzyme Thymine DNA Glycosylase (TDG) plays an essential role in this process by removing 5-fC and 5-caC which are subsequently replaced by the unmethylated cytosine. Importantly, homozygous loss …

Metabolic And Expression Changes Associated With A Mouse Model Of Intrauterine Growth Restriction (Iugr), Bethany N. Radford

Electronic Thesis and Dissertation Repository

Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is suboptimal, resulting in an infant born small for gestational age (<10th percentile) and is associated with metabolic disorders such as type 2 diabetes in adulthood. This study aims to understand tissue-specific adaptations to fetal undernutrition which predispose the individual to metabolic disorders in adulthood. A model of growth restriction in mice was established using 70% of maternal ad libitum total food (g) (E6.5-birth). At weaning, male offspring received standard chow or a HFHS diet. Body weight and random blood glucose levels were measured at 6 months. To assess metabolism at 6 or 7 months, glucose tolerance, pyruvate challenge and hepatic portal vein insulin challenge tests were administered and serum peptide markers for obesity and diabetes were measured. Metabolic cages were also used at 2 and 7 months to measure activity, food intake and respiratory exchange ratios (RERs). Adult liver, adipose and skeletal muscle and fetal liver was collected for RNA sequencing. Maternal nutrient restricted (MNR) offspring were growth restricted with disproportionately smaller fetal livers. 19% of standard chow-fed MNR offspring became glucose intolerant. On an isocaloric high-fat high-sugar diet no differences in MNR growth or glucose metabolism were detected. However, RERs were reduced at all timepoints in MNR on a HFHS relative to MNR on standard chow. Differences in transcription of genes involved in hypoxia signalling were detected and HIF-2a and HIF-3a proteins were increased in fetal liver of MNR offspring. Genes differentially expressed in the fetus were not differentially expressed at 6 months. Gene expression of metabolically regulatory transcripts in liver, adipose and skeletal muscle did not differ in all MNR and glucose intolerant MNR relative to controls. This model results in a susceptible and non-susceptible population of maternal nutrient restricted offspring and supports the concept of hypoxia signalling contributing to fetal adaptations. Understanding adaptations in hepatic hypoxia signalling in response to fetal undernutrition and how they vary in susceptible and unsusceptible populations will provide insight into how fetal nutrition can influence adult metabolism.

Maternal Effects And The Evolution Of Chinook Salmon, Michael Thorn

Electronic Thesis and Dissertation Repository

Pacific salmon (Oncorhynchus spp.) populations are under increasing threat due to habitat degradation, over fishing, invasive pathogens, and climate change. The early life history stage (fertilization – free feeding) is one of the most vulnerable developmental phases and performance at this stage may be a critical factor affecting population persistence. Offspring traits and performance are often greatly influenced by maternal effects, which have the potential to alter patterns of inheritance and selection, and environmental factors such as temperature. However, the contribution of maternal effects to the evolution of offspring traits under varying environmental conditions is still poorly understood in …

Lived Experience And Process Of Engagement In Physical Exercise For Older Adults With Chronic Back Pain, Melissa E. Hay

Electronic Thesis and Dissertation Repository

For older adults, physical exercise is especially important in maintaining functional independence, extending quality of life, and optimizing personal health resources. For patients with chronic pain conditions, exercise participation can significantly improve patient-reported symptoms. Older adults are the most sedentary age group with the majority not meeting the recommended duration and intensity of weekly exercise. Although nonadherence with exercise guidelines may result for a variety of reasons, adverse health conditions including chronic pain are likely of particular concern for older adults. The aim of this research, consisting of two studies employing interpretive phenomenology and constructivist grounded theory, was to understand …

Influence Of The Metastatic Microenvironment On Stem-Like Human Breast Cancer Cells, Ashkan Sadri

Electronic Thesis and Dissertation Repository

Ninety percent of breast cancer-related mortalities result from metastasis. We have previously demonstrated that stem-like ALDHhiCD44+ breast cancer cells are critical for metastasis, and preferentially target the lung and bone marrow (BM). We hypothesize organ tropism occurs through promotion of the ALDHhiCD44+ phenotype. Using a 2D ex vivo model, lung and BM conditioned media (CM) were utilized to assess their influence on stem-like phenotype and behavior. Exposure of human breast cancer cells to lung-CM significantly decreased the proportion of cells with a stem-like ALDHhiCD44+ phenotype, decreased expression of cancer stem cell (CSC)-related genes, and increased gene expression related to migration …

Sol: Segmentation With Overlapping Labels, Karin Ng

Electronic Thesis and Dissertation Repository

Image segmentation is a fundamental problem in Computer Vision which involves segmenting an image into two or more segments. These segments usually correspond to objects of interest in the image, i.e. liver, kidney’s etc. The classic approach to this problem segments the image into mutually exclusive segments. However, this approach is not well-suited when segmenting overlapping objects, e.g. cells, or when segmenting a single object into multiple parts that are not necessarily mutually exclusive. Moreover, we show that optimization methods for multi-part object segmentation with different priors/constraints may better avoid local minima in case of a relaxation allowing parts to …

Automatic Brain Tumor Segmentation By Deep Convolutional Networks And Graph Cuts, Zhenyi Wang

Electronic Thesis and Dissertation Repository

Brain tumor segmentation in magnetic resonance imaging (MRI) is helpful for diagnostics, growth rate prediction, tumor volume measurements and treatment planning of brain tumor. The difficulties for brain tumor segmentation are mainly due to high variation of brain tumors in size, shape, regularity, location, and their heterogeneous appearance (e.g., contrast, intensity and texture variation for different tumors). Due to recent advances in deep convolutional neural networks for semantic image segmentation, automatic brain tumor segmentation is a promising research direction.

This thesis investigates automatic brain tumor segmentation by combining deep convolutional neural network with regularization by a graph cut. We investigate …

It's About Time! Gdm: A Transformative Postpartum Process. A Constructivist Grounded Theory Study, Natalie Giannotti

Electronic Thesis and Dissertation Repository

Abstract

Gestational Diabetes Mellitus (GDM) is defined as glucose intolerance with onset or first diagnosis during pregnancy, and affects 3.7%-18% of Canadian women (Canadian Diabetes Association, 2013). Social support can help women with a history of GDM be successful in achieving optimal health postpartum. The purpose of this constructivist grounded theory (GT) study (Charmaz, 2011) was twofold: (1) To explore the social support processes of women with a history of GDM as they navigate through the healthcare system postpartum, to restore and maintain their health, and (2) To critically examine facilitating factors and barriers to engaging in health behaviours within …

Development Of Nanostructured Glucose Biosensor, Longyi Chen

Electronic Thesis and Dissertation Repository

With the development of nanotechnology and nanomaterials, biosensors incorporated with novel nanomaterials and nanostructures have shown significant potential in point-of-care medical devices because of their rapid interaction with target analytes and their miniaturized systems. Nanomaterials and nanostructures with special chemical, physical and biological characteristics are able to enhance biosensors’ performance in terms of sensitivity and selectivity. Therefore, my study focused on development of special nanostructures used for advanced glucose biosensor. Monitoring of blood glucose level is essential for diabetes management. However, current methods require people with diabetes to have blood test with 5-8 times per day. Compared to other methods, …

Pyrolysis As An Economical And Ecological Treatment Option For Solid Anaerobic Digestate And Municipal Sewage Sludge, Devon J. Barry

Electronic Thesis and Dissertation Repository

The aim of this thesis was to investigate the potential for pyrolysis of solid anaerobic digestate and municipal sewage sludge. Slow, fast, and autothermal pyrolysis experiments were conducted for the anaerobic digestate while slow and fast pyrolysis experiments were carried out for the sewage sludge. Pyrolysis temperatures ranged from 250 to 550 ᵒC. The effect of pyrolysis conditions on the pyrolysis products was examined.

Fast pyrolysis at higher temperatures was favourable for energy recovery in the bio-oil products. Slow pyrolysis was favourable for the biochar products. Lower pyrolysis temperatures favoured energy recovery in the biochar; while higher temperatures increased biochar …

The Production Of Pyrolytic Biochar For Addition In Value-Added Composite Material, Douglas Matthew Cuthbertson

Electronic Thesis and Dissertation Repository

Pyrolytic biochar has recently gained attention for its potential value as a carbon sequestering by-product that can be used in industrial applications. While biochar is typically targeted for soil amendment applications, higher value applications such as addition in consumer products and building materials needs to be investigated.

In this study, biochar is produced from three different Canadian feedstocks using three different pyrolysis methods. The biochar is characterized to determine the effects that feedstock selection and pyrolysis conditions has on biochar properties. The biochar is also incorporated into concrete at varying concentrations to create a lightweight and sustainable material. The effect …

Feature Based Calibration Of A Network Of Kinect Sensors, Xiaoyang Li

Electronic Thesis and Dissertation Repository

The availability of affordable depth sensors in conjunction with common RGB cameras, such as the Microsoft Kinect, can provide robots with a complete and instantaneous representation of the current surrounding environment. However, in the problem of calibrating multiple camera systems, traditional methods bear some drawbacks, such as requiring human intervention. In this thesis, we propose an automatic and reliable calibration framework that can easily estimate the extrinsic parameters of a Kinect sensor network. Our framework includes feature extraction, Random Sample Consensus and camera pose estimation from high accuracy correspondences. We also implement a robustness analysis of position estimation algorithms. The …

Development Of Force-Space Navigation For Surgical Robotics, Corey Daniel Smith

Electronic Thesis and Dissertation Repository

Surgical robotics have been used for many years in orthopaedic procedures in the hip and knee. Robots tend to offer high accuracy and repeatability but add increased cost, complexity, time, and workflow disruption. This work outlines the design and development of a surgical robot that navigates using force feedback. Flexible components tether the patient to the robot and reaction loads are measured allowing the robot to “feel” its way around the pre-operative plan. Differences calculated between measured and desired loads are converted to Cartesian corrections that the robot used to navigate. The robot was tested first using simple square paths …

Embedded Smart-Polymer Sensor Arrays For Elucidating Load Distributions In Orthopaedic Implants, Carolina Micolini

Electronic Thesis and Dissertation Repository

The long-term outcomes of orthopaedic joint implants are only beginning to be understood, making it imperative to monitor the contact loads across the entire implant interface. This capability will elucidate the force transmission and distribution mechanisms exhibited by these implants in-service over time. This study explores the design and implementation of 3D-printed smart-polymer force sensor arrays, consisting of piezoresistive polyaniline (PANI) structures embedded within a polymeric parent phase. This unique multi-material additive manufacturing process was then employed to realize transducers embedded in the humeral component of a replacement prosthetic device conventionally used to restore the functionality of the shoulder joint. …

Narrative Immunities: The Logic Of Infection And Defense In American Speculative Fiction, Riley R. Mcdonald

Electronic Thesis and Dissertation Repository

In this project I analyze the roles that notions of viruses and immunities and their figurations play within the narrative discourse of speculative fiction. Focusing on a series of texts from twentieth- and twenty-first century American fiction, I seek to examine the ways in which the dialectical confrontation between infection and immunity is explored, reified, or challenged on a narrative level. The terms “virus” and “immunity,” so intrinsic to life sciences, have come into use to describe specific micro-organisms and biological processes only within the last 150 years. Yet these terms possess a significantly longer history in political, legalistic, and …

Photocatalytic Hydrogen Production Using A Mesoporous Tio2 Doped With Pt: Semiconductor Synthesis, Oxidation-Reduction Network And Quantum Efficiencies., Jesus Fabricio Guayaquil-Sosa

Electronic Thesis and Dissertation Repository

The present PhD dissertation establishes that hydrogen can be produced using mesoporous TiO₂ as a photocatalyst, doped with platinum atoms (Pt), in a slurry medium, under near-UV irradiation and with ethanol as a sacrificial reagent (scavenger). These mesoporous TiO₂ photocatalysts were prepared using a sol-gel method. The mesoporous Pt-TiO₂ photocatalyst displayed a reduced 2.34 eV band gap compared to the bare TiO₂ (3.20 eV).

Photocatalytic hydrogen production experiments were performed in a Photo-CREC Water II Reactor (PCW-II Reactor). This novel unit provides both radial and axial symmetrical irradiation profiles. Furthermore, macroscopic energy balances developed in this …

Chromatin Organizer Ctcf In Brain Development And Behaviour, Adrienne Elbert

Electronic Thesis and Dissertation Repository

Chromatin architecture is an important regulator of gene expression, which dictates development. Mutations in one copy of the CTCF chromatin organizer gene cause intellectual disability and autism. Polymorphisms in CTCF have also been associated with increased risk for schizophrenia, a condition that overlaps in biological etiology with autism and intellectual disability. In this thesis, we sought to understand the role of CTCF in neurodevelopment using brain-specific conditional knockout and heterozygote mouse models. Using the Ctcf-null animals, we identify a cell-autonomous role for CTCF in regulating cortical interneuron development in the medial ganglionic eminence (MGE) through the transcriptional control of …