title: Naphthenic Acid Fraction Compounds Reduce the Reproductive Success of Wood Frogs (Rana Sylvatica)

contributor:
Orihel, Diane
Biology

subject:
Ecotoxicology
Reproduction
Development
Amphibian
Oil Sands Process-Affected Water
Naphthenic Acids

abstract: Understanding the toxicity of the organic compounds in oil sands process-affected water (OSPW) is necessary to inform the development of environmental guidelines related to wastewater management in Canada’s oil sands region. In the present study, we investigated the effects of naphthenic acid fraction compounds (NAFCs) on wood frog (Rana sylvatica) mating behaviour, fertility, and offspring viability. Wild adult wood frogs were exposed separately from the opposite sex to 0, 5, or 10 mg/L of OSPW-derived NAFCs for 24 h and then combined in outdoor lake water mesocosms containing the same NAFC concentrations (n= 2 males and 1 female per mesocosm, n = 3 mesocosms per treatment). Mating events were recorded for 48 h and egg masses were measured to determine adult fertility. NAFC exposure had no significant effect on mating behaviour (probability of amplexus and oviposition, amplexus and oviposition latency, total duration of amplexus and number of amplectic events) or fertility (fertilization success and clutch size). Tadpoles (50 individuals per mesocosm at hatching, and 15 individuals per mesocosm from 42 d post-hatch) were reared in the same mesocosms under chronic NAFC exposure until metamorphic climax (61-85 d after hatching). Offspring exposed to 10 mg/L NAFCs during development were less likely to survive and complete metamorphosis, grew at a reduced rate and displayed more frequent morphological abnormalities. These abnormalities included limb effects at metamorphosis, described for the first time after NAFC exposure. The results of this study suggest that NAFCs reduce wood frog reproductive success through declines in offspring viability and that exposure to NAFCs during reproduction and development may affect the recruitment of native amphibian populations in the oil sands region.

abstract: M.Sc.


title: Weaving Knowledge Systems In Wildlife And Ecosystem Health

contributor:
Orihel, Diane
Environmental Studies

rights: Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada

rights: ProQuest PhD and Master's Theses International Dissemination Agreement

rights: Intellectual Property Guidelines at Queen's University

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
Weaving Knowledge Systems
Indigenous Ways of Knowing
Ecotoxicology
Wildlife Health
Indigenous Science

abstract: In the last decade, post-secondary institutions and academics have been called upon to advance their understanding of reconciliation and to mainstream reconciliation in all aspects of the scientific endeavor. Wildlife and ecosystem health is a shared concern between Indigenous and non-Indigenous Canadians and weaving Indigenous and Western-based ways of knowing can provide a holistic approach and understanding to these problems. To date there is no known study that reviews the literature on weaving ways of knowing in wildlife and ecosystem health. We conducted a systematic review of the peer-reviewed and grey literature (6,991 publications) – screening for and including studies that weave Indigenous and Western-based ways of knowing to study wildlife health and environmental contaminants in the Canadian context. We coded information from several categories including publication timing and frequency, study locations, research partners and Indigenous knowledge holder information, wildlife health stressors, ecological scale and research subject, methods and methodologies, Indigenous participation across research stages, and outcomes and results sharing to assess trends related to knowledge weaving. We found 17 studies that satisfied our inclusion criteria, most of which took place in Canada’s north (Yukon, Northwest Territories, Inuvialuit Settlement Region, Nunavut, and Nunavik). Research partnerships most often occurred between First Nation or Inuit knowledge holders and Western-based academics. The health stressors metals (n=8) and avian cholera (n=2), and the species lake trout, lake whitefish, arctic char, caribou, muskoxen, and common eider (n=2) were studied most often. The methodology used to weave ways of knowing was most often community-based participatory research coupled with interviews, tissue sampling, and field data collection. We additionally analyzed two exemplar case studies through a decolonial lens to provide a more in-depth understanding of the process of conducting collaborative research with Indigenous communities. We concluded that research that weaves ways of knowing must not be approached with a ‘one-size-fits-all' mindset but instead should emphasize relationship building, continuous engagement, and ethical practices. Overall, our review highlights potential approaches to conducting collaborative research weaving Indigenous and Western-based ways of knowing and offers insight in how research can respond meaningfully to calls for reconciliation in Canada.

abstract: M.E.S.


title: Gain Conditioning for Linear Model Predictive Control

contributor:
McAuley, Kim
Chemical Engineering

subject:
Gain conditioning
mpc
Linear model predictive control

abstract: Linear model predictive control (MPC) is used in a wide variety of process industries.  Linear MPCs calculate adjustments in multiple manipulated variables (MVs) to ensure that operating constraints are obeyed and that controlled variables (CVs) are maintained near their setpoints.  Industrial practitioners who develop MPC applications are interested in preventing erratic behavior of MPCs, which can be caused by imperfect models with ill-conditioned gain matrices. Currently, control practitioners use time-consuming methods based on relative gain arrays and singular-value thresholding to condition their gain matrices to prevent degraded controller performance.  These techniques tend to require many iterations to successfully condition a large gain matrix.  In the proposed approach I extend an orthogonalization-based parameter-ranking algorithm, which was originally developed to aid parameter estimation in fundamental models, so it can be used to identify and address gain conditioning problems.  The proposed method ranks MVs from most influential to least influential while accounting for correlated steady-state influences of MVs on CVs. Problematic MVs are identified, and a linear optimization algorithm is used to find optimal gain adjustments to condition the gain matrix. To test the effectiveness of the proposed methodology, I use industrial case studies based on fluidized catalytic cracking models.

abstract: M.Sc.


title: A Qualitative Exploration of The Experiences of People with Multiple Sclerosis who Receive Occupational Performance Coaching

contributor:
Kessler, Dorothy
Rehabilitation Science

subject:
Multiple Sclerosis
Self-management
Occupational Performance Coaching

abstract: This study explores how Occupational Performance Coaching (OPC) influences self-management of the daily lives of people with Multiple Sclerosis (PwMS). Specifically, this study used qualitative interviews to examine the experiences of 10 participants with multiple sclerosis (MS) who received 6 sessions of telephone OPC over a ten-week period. Interpretive description was used as the methodological approach. Participants were interviewed prior to and after the OPC intervention. Interviews were transcribed and analyzed using thematic analysis at each time point. Following this an individual case analysis and cross care analysis were conducted to uncover potential differences form pre to post intervention. The analysis revealed themes of resisting MS, living with MS, ongoing challenges, and strategies prior to receipt of OPC. Similar themes emerged following OPC with the exception of the theme of resisting MS and the addition of sub-themes such as planning ahead, being consistent and talking about the plan to the theme of strategies. Individual and cross case analysis revealed that participants described less resistance to their conditions and a shift in their focus from problems towards solutions after receiving the intervention. Findings also showed enhancement of existing strategies and/or development of new strategies used to overcome ongoing challenges in living with MS. The findings of this study further our understanding of the development of self-management skills in PwMS and suggest that OPC could be beneficial in improving self-management skills in PwMS.

abstract: M.Sc.


title: Examining the Impact of Endothelial Bmpr2 Loss on the Growth and Vascularization of Lung Metastases in a Mouse Model of Metastatic Breast Cancer

contributor:
Ormiston, Mark
Translational Medicine

subject: BMPR2

subject: BMP9

subject: Vascularization

subject: Angiogenesis

subject: Breast Cancer

subject: Metastasis

subject: E0771

abstract:
Rationale: Bone morphogenic protein-9 (BMP9) signaling has been shown to play a role in tumour angiogenesis. In a mouse model of metastatic breast cancer, mice lacking the gene encoding BMP9 demonstrated increases in both the number and size of secondary lung metastases, suggesting that BMP9 inhibits both metastatic engraftment and tumour angiogenesis. However, BMP9 can also promote angiogenesis when its type-II receptor, Bmpr2, is lost. We explored the impact of endothelial Bmpr2 loss on the engraftment and growth mammary tumour metastases in the lung.
Methods: L1-Cre mice were crossed with animals possessing the Ai6 transgenic reporter and a Bmpr2-floxed allele to produce offspring that expressed both ZsGreen fluorescent protein and either wildtype (Bmpr2EC+/+), heterozygous (Bmpr2EC+/-) or homozygous null (Bmpr2EC-/-) levels of Bmpr2 selectively in the Cre+ endothelium of their lungs, brain, spleen, and retina. Red fluorescent protein (RFP)-expressing E0771 cancer cells were injected into the lateral tail vein or implanted orthotopically into the mammary fat pad of these animals. For the orthotopic model, mammary tumours were resected at a volume of ~500mm3 and mice were maintained for an additional four weeks to establish secondary lung metastases. Tumour burden in the lungs, liver and brain were quantified by whole organ RFP fluorescence and fluorescence microscopy. For the tail vein model, E0771 engraftment in the lung was assessed 72 hours post injection.
Results: The proportion of mice exhibiting lung metastases did not differ across genotypes. However, Bmpr2EC+/- and Bmpr2EC-/- mice exhibited increased lung tumour burden and vascular density when compared to Bmpr2EC+/+ controls. Similar increases were not observed in the liver or brain, indicating that findings were specific to endothelial Bmpr2 loss in the lung. In the tail-vein model, Bmpr2EC+/- mice had significantly increased engraftment events relative to Bmpr2EC+/+ controls.
Conclusion: Endothelial Bmpr2 loss enhances the engraftment, growth, and vascularization of secondary lung metastases.

abstract: M.Sc.


title: Bio-Cyanidation of Low-Grade and Refractory Gold Ores

contributor:
Ghahreman, Ahmad
Mining Engineering

subject:
Resource utilization
Bioleaching
Sustainability
Gold extraction
Amino acid
Bio-remediation
Cyanide characterization
Microorganism
Bio-hydrometallurgy

abstract: Gold is of the precious metals with high demand and limited global resources. Cyanidation is the most common process to extract gold from its ores. However, due to the decrease in the grade of gold deposits and increase in the complexity of its bearing minerals, cyanide consumption has increased and many environmental problems are caused. Alternatively, bio-cyanidation is a recent technology that employs natural microorganisms to produce cyanide from non-toxic ingredients. In this study, the significant parameters of bio-cyanidation process for gold leaching have been identified, tested, and optimized. First, pH was explored and the results showed that an initial pH of 10 with no further adjustment was optimum for growth and cyanide production by Bacillus megaterium (B. megaterium) where the bacteria generated a maximum of 61.9 mg/L bio-CN. This solution could recover over 87% and 43% gold from oxidic and sulfidic sources, respectively. In the following stage, different cyanide measurement techniques were compared for characterization of the bio-CN in the complicated biogenic system and titration against silver nitrate with end point determination based on potentiometry was the most feasible method to characterize bio-CN. Next, the capability of bacteria to remediate cyanide was studied and a distillation process was employed to isolate the biogenic cyanide (bio-CN) before it is converted into non-cyanide species. In the next stage, the optimum medium ingredients for maximum gold recovery from the sulfidic ore was identified as 12.49 g/L tryptone, 5.36 g/L yeast extract, 2.46 g/L NaCl, and 10.13 g/L glycine, which could deliver 45% gold recovery. In addition, corn steep waste, a low-cost medium ingredient, was investigated as a replacement for the original medium and produced similar results. Additionally, the kinetics of leaching was investigated and showed a mixed mechanism of chemical reaction and diffusion through the solid layer were the obstacles to higher recovery from the sulfidic ore. Finally, the effect of amino acids on bacteria growth, bio-CN production, and gold leaching was explored and suggested 2.84 g/L glycine and 3.00 g/L glutamine as the best condition to deliver a high concentration of bio-CN (86 mg/L).

abstract: PhD


title: Calibrating the Davis-Chandrasekhar Fermi Method With Molecular Cloud simulations

contributor: Physics, Engineering Physics and Astronomy

subject:
Star Formation
Magnetic Field

abstract:
Star formation has long been a process that many astronomers and astrophysicists have sought to understand. Magnetic fields are believed to be one of the key driving phenomena behind this process. Modern research relies on studying computationally rigorous simulations where the magnetic field strength is known throughout the entire simulation process. One common method, coined the Davis-Chandrasekhar Fermi (DCF) method was proposed in 1953, which suggested that dust polarization could be used to measure the dispersion in the orientation of the magnetic field, which could be used to estimate the magnetic field strength of molecular clouds.

In this thesis, we use a pair of Colliding Flow and Collapsing Cloud simulations to estimate the magnetic field strengths using three variations of different DCF methods: the Classical, HH09, and Skalidis DCF methods. We define a correction factor, α, which represents the ratio of the true magnetic field strength divided by estimate obtained from the DCF methods. For the entire simulation map, both the Classical and Skalidis DCF methods tend to under-predict the magnetic field strength (α < 1) for the Colliding Flow simulations but over-predict the magnetic field strength for the Collapsing Cloud simulations (α > 1). For the entire plane-of- sky maps of both the Colliding Flow and Collapsing Cloud simulations, the HH09 DCF method seems to returns consistent results, that is, 0.478 < α < 0.641 but more severely under predict the field strength in maps where the magnetic field is inclined with respect to the plane-of-the-sky.

We also investigated the correlations between the polarization dispersion (σφ), the velocity dispersion (σv), and the number density n with the α values obtained from the DCF methods. We find that the strongest correlation is between σv and α which indicates that the DCF methods tend to estimate higher magnetic field strength estimates, relative to the true values, for simulations with higher σv values. Finally, we found that the of resolution of the simulations influenced the accuracy of the three DCF methods and that lower resolution data leads to higher estimations from the Classical and Skalidis DCF methods.

abstract: M.Sc.


title: A Knee Jerk Reaction: The Removal of Peremptory Challenges in the Canadian Jury System

subject:
Canadian Justice System
Jury System
Bill C-75
Indigenous
Gerald Stanley
Colten Boushie
Peremptory Challenges
Indigenous Underrepresentation

abstract: The acquittal of Gerald Stanley, a white farmer, in the shooting death of Colten Boushie, a young Cree man, created huge public outcry. It was shared in the news that Stanley was acquitted by an all-white jury after his lawyers used five peremptory challenges to remove the only visibly Indigenous People from the jury pool. This thesis uses a qualitative content analysis to analyze parliamentary debates at the Committee and Senate levels as well as news media sources discussing Bill C-75 and the removal of peremptory challenges in response to the Boushie case. These documents were used to analyze whether the decision to remove peremptory challenges was a well thought out decision based on research and evidence or if it was simply a quick-fix response used by the Liberal government to appear to be doing something about Indigenous underrepresentation in the Canadian Justice System. The analysis shows that many felt the decision to remove peremptory challenges was rushed and fell short of correcting the issue of the underrepresentation of Indigenous people on juries. Expert recommendations were ignored by the government and further work is needed to ensure that Indigenous people are properly represented on juries.

abstract: M.A.


title: Characterization of the Antiviral Functions of Interleukin-27 during Dengue Virus Infection of Human Macrophages

contributor:
Gee, Katrina
Colpitts, Che
Biomedical and Molecular Sciences

subject:
Dengue virus
IL-27
Macrophages

abstract: Dengue virus (DENV) causes the most prevalent mosquito-transmitted viral disease, including dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), with an estimated 390 million infections and 20,000 deaths annually. DENV is an arbovirus transmitted by Aedes mosquitoes, which are expanding into new regions of the world as a result of societal and environmental changes; therefore, DENV is emerging as a significant global health threat. Despite its growing relevance, there are still no widely used vaccines or effective antiviral therapies available for DENV. Recent investigations have uncovered that the cytokine interleukin 27 (IL-27) displays antiviral properties against human immunodeficiency virus (HIV), influenza A virus (IAV), hepatitis B virus (HBV), hepatitis C virus (HCV), and Zika virus (ZIKV). Furthermore, IL-27 has been previously shown to regulate the function of monocytes and macrophages, which are the primary cells infected by DENV. However, the role of IL-27 in innate antiviral immune responses against DENV infection and pathogenesis has not been investigated. Therefore, to address this knowledge gap, we set out to determine if: 1) DENV infection of THP-1-derived human macrophages could induce IL-27 expression and 2) if IL-27 could modulate DENV replication in human macrophages. Here, we show that infection of phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells with DENV-2 (strain 16881) resulted in significant induction of IL-27 production. Treatment of uninfected or infected THP-1 macrophages with recombinant human IL-27 (rhIL-27) induced expression of antiviral interferon-stimulated genes (ISGs), such as myxovirus resistance protein 1 (MX1). Furthermore, IL-27 dose-dependently inhibited DENV infection in PMA-differentiated THP-1 macrophages in a manner partially dependent on type I interferons (IFNs). These results identify a role for IL-27 in innate immune defense against DENV infection, potentiating its use as an antiviral agent.

abstract: M.Sc.


title: Phenotyping the chronobiology of microglia

contributor:
Ghasemlou, Nader
Biomedical and Molecular Sciences

subject:
microglia
neuropathic pain
spinal cord
circadian
Bmal1
Rhythmic
SNI
Chronic pain
Chronobiology

abstract: Chronic neuropathic pain affects 7-10% of the population and is caused by damage to the somatosensory nervous system that persist after the initial injury has healed. The development of neuropathic pain is influenced by interactions between neurons and immune cells. Microglia are a component of the innate immune system and help in maintaining homeostasis in the central nervous system (CNS). Following injury, microglia alter their morphology, receptor expression and proliferate near the site of the damaged axons. Previous work has identified a rhythmic pattern to certain microglia functions indicating the presence of an intrinsic clock in these cells. Rhythmicity in neuropathic pain has also been observed by our group in the human population and in the mechanical sensitivity of male mice after spared nerve injury (SNI). We therefore sought to characterize the rhythmic expression of microglia receptors in neuropathic pain and determine if microglia present sex-specific rhythms. Rhythmic expression of microglia surface receptors in the brain and spinal cord (SC) of naïve male and female mice were characterized using flow cytometry. Naïve mice showed sex-dependent rhythmicity in the canonical receptors CD11b and CX3CR1 and the state dependent receptors CD86 and CD206. Using SNI as a model of neuropathic pain, microglia from males and females lost rhythmicity of their canonical receptors but showed sex-dependent rhythms in the receptors CD86 and CD206, unique from naïve mice. Lastly, the effects of disrupting the circadian clock by removing the gene Bmal1 from microglia were analyzed using the von Frey behavioural assay to observe changes in the oscillations of mechanical allodynia in male mice post-SNI. Male mice showed no rhythmic sensitivity after SNI following the excision of the Bmal1 gene from microglia. While rhythmic expression of microglia receptors was evident in both the naïve and neuropathic pain model, more work is needed to elucidate the underlying functions these rhythms regulate and determine how they relate to the modulation of neuropathic pain. This investigation enhances the knowledge surrounding sex-dependent microglia receptor rhythms and provides new avenues for therapeutic development in neuropathic pain.

abstract: M.Sc.


title: “The evils of slavery cannot be mitigated”: The Amelioration and Emancipation of Slavery in the British Empire, 1785-1865

contributor:
Chowdhury, Amitava
History

subject:
Slavery
Emancipation
British Empire
Nineteenth Century
British Caribbean
Amelioration

abstract:
This thesis illustrates that amelioration stalled, postponed, and often blocked the general movement towards emancipation in the British Empire during the late-eighteenth and early-nineteenth centuries. It challenges the predominant notion among historians that there was an automatic sequence from amelioration—the act of improving conditions of slavery—to emancipation—the act of freeing enslaved people. The promises of improvement made between the 1780s and 1830s did not and could not have produced freedom. No matter how Britons used the idea of amelioration, whether for humanitarian or self-interested reasons, the result remained the same: slavery was strengthened through amelioration. Amelioration was incomplete, ineffective, and foredoomed because of its failure to see the enslaved as equal human beings. This is illustrated through intellectual and political understandings of amelioration, as well as the practical implementation of ameliorative policies. Emancipation was produced because of the failure of amelioration rather than its success.

By analyzing parliamentary papers, newspaper articles, colonial dispatches, pamphlets, and a wide array of secondary sources, this thesis examines how pro- and antislavery proponents contemplated and negotiated the meanings and goals of amelioration and emancipation. It traces strands of amelioration in both the British metropole and plantation colonies, with special emphasis in the British Caribbean. The first chapter examines the long arc of amelioration, illustrating that it was not emancipatory and played a key role in discussions on the abolition of the slave trade. In the next chapter, this thesis interrogates the idea of gradual emancipation and shows that reforms emerging in the 1820s—the supposed decade of amelioration—was an obstacle to emancipation. Finally, the third chapter argues that the failure of amelioration, in theory and practice, resulted in the sudden shift from gradual to immediate emancipation in the early-1830s.

abstract: M.A.


title: Building an Intelligent System for Predicting and Fixing Performance Defects

contributor:
Zou, Ying
Computing

subject:
Performance anomalies
Performance defects
Pull request ranking
Fixing effort prediction

abstract:
Software systems have been playing an essential role in supporting our daily activities. Performance anomalies are unexpected performance degradation that deviates from the normal behaviors of software systems. Performance anomalies can cause a dramatically negative impact on users' satisfaction. The increasing scale and complexity of software systems make these systems prone to performance anomalies that are caused by various reasons, such as, misconfiguration, hardware failures, resource contentions, and performance defects. To help development and operation teams to maintain the performance of software systems, prior studies propose various approaches to detect performance anomalies and performance defects. However, prior detection approaches cannot predict the performance anomalies ahead of time; such limitation causes an inevitable delay in taking corrective actions to prevent performance anomalies from happening.

To help developers and operators to prevent anomalies from happening, in this thesis, we conduct a set of studies to predict performance anomalies from run-time monitoring data and predict performance defects at the development phase. More specifically, our approach consists of four aspects: (1) we propose an approach to predict performance anomalies in software systems by analyzing run-time monitoring data; (2) we propose an approach that can predict a large variety of performance defects during development phase; (3) we provide a generic approach that predicts methods with any types of defects (e.g., performance and non-performance defects) and their fixing effort; and (4) we propose an approach to prioritize pull requests to help reviewers review code changes. Through a series of experiments, we observe that our approaches can help the development and operation teams to avoid performance anomalies at the run-time, and capture and fix performance defects at the development phase.

abstract: PhD


title: Surface Chemistry Of N-heterocyclic Carbenes

contributor:
Crudden, Cathleen
Chemistry

rights: Attribution-NonCommercial 3.0 United States

subject:
Self-assembled monolayers
Scanning tunneling microscopy
Surface chemistry
N-heterocyclic carbenes
X-ray photoelectron spectroscopy
Microelectronics

abstract:
The self-assembly of organic ligands on gold and other metal surfaces has been dominated by sulfur-based ligands for decades, despite their well-known thermal and oxidative instabilities. In recent years, N-heterocyclic carbenes (NHCs), have emerged as an exciting new class of carbon-based surfactants for metal surfaces. NHCs bind with unprecedented strength to a variety of metal surfaces, including gold, copper, ruthenium, platinum, and palladium, yielding self-assembled monolayers (SAMs) of exceptional stability. Much attention has been given coinage metal surfaces, where NHCs are shown to form tightly bound, densely packed monolayers.
Due to its inertness and reproducibility, gold is the most popular substrate for organic-on-metal devices. Many basic features of NHC self-assembly on gold surfaces are poorly understood, including the effects of NHC structure, surface coverage, and substrate temperature on mobility, thermal stability, NHC surface geometry, and self-assembly. Herein, some recent developments are described related to NHC self-assembly on Au(111) surfaces, specifically for 1,3-dialkylbenzimidazolylidenes. These contributions are crucial for the successful use of NHC-based monolayers in the preparation of dense monolayers, in the production of patterned surfaces, in catalysis, in biosensor preparation, indeed in virtually every application.
Owing to its high conductivity and low cost, copper is an essential component of integrated circuits which are used in all modern electronic devices. These circuits consist of a series of interconnected electronic components that are embedded into a single piece of semiconducting material. Current fabrication methods consist of a lengthy series of deposition and etching cycles to achieve the desired patterns, however an area-selective deposition process which differentiates metal and dielectric regions would greatly enhance the production of electronic devices. Herein, our initial developments of such a process are described using NHC chemistry, specifically the self-assembly behaviour of NHCs on Cu(111) and their reactivity with oxidized copper surfaces, the determination of optimal NHC source for vapour deposition, and the selective deposition of NHCs on metals in the presence of SiO2.

abstract: PhD


title: Assessing Lake Ecosystem Recovery from Acidification and Responses to Emerging Environmental Stressors: a Paleolimnological Perspective

contributor:
Smol, John
Biology

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Paleolimnology
Diatom
Acidification
Sudbury
Biological Recovery

abstract: Mining and smelting activities have heavily affected the Sudbury (Ontario, Canada) region since the late-19th century, leading to acidification and metal contamination in many ecosystems. Regulations on restricting acidic emissions were enacted in the 1970s, after which many Sudbury-region lakes recorded increasing pH and decreasing metal concentrations. Meanwhile, other emerging stressors have likely affected these lakes over the past few decades. Here, I revisit lakes in the Sudbury region, half a century after the application of remedial efforts, to assess lake ecosystem recovery from acidification and their responses to newly emerging environmental stressors. First, a canonical correspondence analysis is used to assess the relationships between surface-sediment diatom assemblage structure and environmental variables for 80 lakes. Lakewater pH remains the strongest environmental variable shaping diatom species distributions, and so is used to construct a robust inference model (R2boot = 0.73; RMSEP = 0.32). Additionally, by assessing ecological changes experienced by a subset of these lakes (n = 33, in common with Dixit et al. 2002) over the past few decades, two major trends are identified: an overall increase in diatom-inferred pH and a rise in the relative abundance of planktonic taxa. Further, down-core analyses in dated sediment cores are conducted to assess detailed ecological changes for three historically acidified lakes and two reference systems over the past ~200 years. Despite recording marked chemical recovery, the acidified lakes showed minimal or no evidence of biological recovery, with recent diatom assemblages markedly different from pre-disturbance assemblages, likely due to the legacy effects of acidification and climate warming. Biological recovery is lagging chemical recovery in acidified systems half a century after the reduction of acid deposition, and a return to pre-disturbance biological assemblages may never be achieved due to emerging environmental stressors, especially recently accelerated climate warming.

abstract: M.Sc.


title: Evaluating Education: An Economic Analysis of Education in Rural Zimbabwe

contributor:
Cotton, Christopher
Economics

subject: Education Evaluation Economics

abstract: This thesis uses a combination of innovative and existing evaluation techniques to understand the barriers to education in rural Zimbabwe, and to determine the impact of interventions that targeted some of these barriers. Chapter 2 uses a randomized controlled trial combined with text mining analysis of qualitative interviews to demonstrate the impact of a large-scale community mobilization campaign. After three and a half years of exposure to the community mobilization campaigns, community attitudes towards girls' education improved by 0.56 SD, and struggling students performed 0.28 SD better on learning assessments. Using mediation analysis, I show that the increased support likely partially mediated the program's impact on education. Chapter 3 exploits variation from a natural experiment to determine the impact of a severe drought on girls' education outcomes. I show that the drought decreased the opportunity cost of education, leading to an increase in enrolment. However, this did not correspond with an increase in learning, with students from particularly vulnerable households performing worse on learning assessments after the drought. Chapter 4 provides a descriptive analysis of the most important factors associated with education outcomes. By using multiple machine learning methods, I show that lack of support and pregnancy are the biggest barriers to student advancement. These are also barriers to student learning, however, other factors such as self-confidence were relatively more important for learning outcomes. These findings describe the programmatic contributions of this thesis, which provides important insights into the types of barriers students experience, as well the effectiveness of specific education interventions. The second contribution is more methodological, where I show how natural language processing and machine learning methods can be used in future evaluation research.

abstract: PhD


title: Shear Behaviour in Reinforced Concrete Beams Monitored with Distributed Sensors

contributor:
Hoult, Neil A.
Bentz, Evan C.
Civil Engineering

subject:
shear
reinforced concrete
distributed fibre optic sensors
digital image correlation

abstract:
The precise mechanism that provides shear resistance in reinforced concrete has been an unsolved riddle to researchers for decades. This was caused by limitations in the available sensor technology for effectively measuring the response of concrete members. Emerging distributed sensor technologies, namely distributed fibre optic sensors (DFOS) and digital image correlation (DIC), can provide the comprehensive data sets needed to study shear behaviour in reinforced concrete.

DFOS and DIC measurements were used to study the load-response of three large slender beams with varying shear reinforcement designs. The beam specimens contained the equivalent of 20,000-point strain measurements and distributed crack width and slip measurements. From the distributed sensor data, differences in the load-response between the three beams relating to serviceability and strength were investigated. The amount of shear reinforcement was found to affect the percentage of total midspan deflections attributed to shear, equalling about 25% at service conditions and up to 42% at ultimate conditions.  The DFOS was used to understand the failure modes through studying the longitudinal and transverse reinforcement strains where JP-1 failed in shear prior to longitudinal yield, JP-2 failed in shear at the onset of longitudinal yield, and JP-3 which failed due to anchorage with a plastic hinge near midspan reaching up to 1.6% strain. The distributed sensors were also used to study shrinkage, anchorage of stirrup hooks, bending of stirrups caused by shear cracking, amongst other behaviours.

Member equilibrium was studied through constructing free body diagrams (FBD) based on the distributed sensors measurements. This study highlighted how forces across cracks were essential for maintaining equilibrium and that shear forces carried within the flexural compression region of the FBD agreed with past approaches to modelling shear. Consideration of the diagonal compression stress field in members with shear cracks was found to also be necessary, and a method of measuring the angle of principal compressive stress was proposed. The FBD study was used to evaluate the performance of the shear provisions in the ACI 318 code, where V_s was found to be conservative on average. The experimental failure loads were within 14% of the ACI and 11% of the CSA nominal values.

abstract: PhD


title: The Role of Peroxisome Proliferator-activated Receptor γ during Breast Tumour Angiogenesis

contributor:
Nicol, Christopher
Biomedical and Molecular Sciences

subject:
Breast cancer
Tumour angiogenesis
PPARγ

abstract: Breast cancer remains a global health challenge as the most common cancer type worldwide and the leading cause of new cancer cases among Canadian females. Despite recent advances in early screening and targeted therapies, mechanisms of breast cancer progression remain to be fully understood. Peroxisome proliferator-activated receptor (PPAR) γ, expressed in many mammary associated cell types, is traditionally known for its role in adipocyte differentiation and lipid metabolism, but also plays a role in suppressing tumour progression. While there is some discrepancy in the literature, most studies used indirect models to suggest an anti-angiogenic role of PPARγ activation both in vitro and in vivo. This dissertation examines the direct role of PPARγ expression and activation in endothelial cells (ECs), in particular during mammary tumour angiogenesis. Utilizing human and murine aortic ECs, I reveal PPARγ expression and activation with the PPARγ activating drug rosiglitazone (ROSI) in ECs inhibits early angiogenic events in vitro, including EC sprouting, proliferation, and migration/invasion, associated with downregulating vascular endothelial growth factor receptor 2 (VEGFR-2) and cyclin D1 protein expression. I also used female EC-targeted PPARγ knockout (PPARγE-KO) mice and their congenic wildtype controls to show that PPARγ expression in ECs is necessary for the protective effect conferred by ROSI treatment during 7, 12-dimethylbenz[a]anthracene (DMBA)-mediated mammary tumourigenesis in vivo. Finally, I provide the first direct evidence that PPARγ expression and activation with ROSI treatment in mammary ECs exerts inhibitory effects on early angiogenic events in mammary tumours in vivo, but such anti-angiogenic effects may become less critical in late-stage mammary tumours. Collectively, evidence presented in the current dissertation supports the anti-angiogenic benefits of PPARγ activating drugs in at least early-stage mammary tumours, and the use of PPARγ expression in ECs as a potential prognostic and predictive biomarker of therapeutic response in some breast cancer patients.

abstract: PhD


title: Understanding the Effects of Acute Stevia Consumption on Vascular Function in Humans

contributor:
Pyke, Kyra
Kinesiology and Health Studies

subject: Stevia Vascular Cardiovascular

abstract: The consumption of sugar and artificial sweeteners has been associated with impaired vascular functioning and other negative health outcomes (Liu et al., 2012; Meziat et al., 2016; Pearlman et al., 2017; Schiano et al., 2020; Suez et al., 2014; Weiss et al., 2008; Williams et al., 2020). The ingestion of a high-sugar beverage/meal or of 75g of glucose transiently impairs vascular function in vivo (Watanabe et al., 2011). Stevia is a natural non-caloric sweetener that has become a popular substitute for sugar and artificial sweeteners within North American food markets (Sharma et al., 2016; Yilmaz et al., 2013). Stevia has been found to have a beneficial or neutral effect on vascular function in animals and human cells, but despite widespread consumption, no literature has reported the effects of stevia in the integrated human system. It is hypothesized that the consumption of a single dose of stevia will acutely enhance, or at minimum will not impair, the function of the large and small vessels of the arm. Twenty-five healthy men and women (21.6 +/- 2.5 years [mean ± SD]) participated in two laboratory visits in which the function of the large and small vessels of the arm was assessed before and both 15- and 60- minutes after the ingestion of either a stevia beverage (water with 4mg/kg body weight of stevia dissolved into it) or the control beverage (water). Data are [mean ± SD]. There was no effect of stevia on the function of large (p = 0.630) or small vessels (p = 0.848) in the arm. These results suggest that stevia is a better alternative to sugar and artificial sweeteners, as it does not impair vascular function, while also implying that it’s use as a supplement by healthy individuals may be redundant, as it also did not improve vascular function.

abstract: M.Sc.


title: Characterization of the Antiviral Mechanisms of Cyclophilin Inhibitors against Coronavirus Replication

contributor:
Colpitts, Che
Biomedical and Molecular Sciences

subject:
Antiviral
Broad-spectrum antiviral
Innate immunity
Cyclophilins
Coronavirus
Pandemic preparedness

abstract: Coronaviruses (CoVs) are zoonotic positive sense RNA (+ssRNA) viruses with pandemic potential, as evidenced by the recent and ongoing SARS-CoV-2 outbreak, which has posed an incredible global health and socioeconomic burden. Cyclophilin inhibitors (CypI) exert broad-spectrum antiviral activities and are a promising antiviral candidate for future emerging CoVs. While CypI have been shown to restrict CoV replication, the mechanisms underlying the antiviral activity of CypI have yet to be elucidated. In this study, we show that CypI such as the classical CypI cyclosporine A (CsA) and the non-immunosuppressive CypI TMN-355 inhibit infection of endemic human CoVs (HCoVs) HCoV-229E and HCoV-OC43 in A549 lung alveolar epithelial cells. Furthermore, CsA treatment of CoV-infected cells induces expression of antiviral genes, such as MX1. Antagonism of IFN-β by CoV-N proteins was not ameliorated by CsA treatment and activation of canonical interferon (IFN) signalling was not enhanced, suggesting a direct effect of CsA in inducing antiviral gene expression. Consistently, treatment of uninfected A549 cells with CsA induces MX1 expression. Loss of interferon regulatory factor 1 (IRF1) expression reduces CsA antiviral potency, although IRF1 mRNA and protein expression are not robustly impacted by CsA treatment. Further, CsA-mediated induction of antiviral gene expression in HCoV-229E-infected cells is dependent on IRF1 and CypD, but not CypA. . Notably, restriction of HCoV-229E replication by CsA is not affected by inhibition of type I IFN signaling, consistent with an IFN-independent role for IRF1 in inducing ISG expression. Collectively, these findings provide mechanistic insight to contribute to our understanding of the broad-spectrum antiviral activity of CypI. Furthermore, this study identifies previously undescribed mechanisms that act to modulate CsA-mediated enhancement of antiviral gene expression during CoV infection.

abstract: M.Sc.


title: Determinants and Implications of Chinese Involvement in Informal Artisanal and Small-scale Gold Mining in Ghana: Perspectives from the Grassroots

subject:
Artisanal and Small-scale mining
Ghana
Informal
Chinese
Locals
Environment
Engagement

abstract: Despite the increasing relevance of artisanal and small-scale mining (ASM) in poverty reduction in Ghana and in the nation’s mineral production, this mining branch also presents huge environmental and social challenges due to weak regulation. Over the last decade, the proliferation of Chinese gold seekers into Ghana’s ASM, which is reserved officially for Ghanaians, has been noted to contribute to worsening social and environmental destruction especially due to the increasing mechanization of this hitherto rudimentary mining branch. However, the perspectives of key local stakeholders on factors fuelling these Chinese-local informal ‘partnerships’ as well as the enduring impacts on the local mining scene have not been thoroughly explored. The study adopts a qualitative exploratory case study, including semi-structured interviews with key local stakeholders, and complemented by data from the extant literature and mining legislation. First, the findings show that illicit Chinese participation in ASM is underpinned by local grievances and concerns over broader systemic distributional inequities (real and perceived) in Ghana’s mineral policy regime on two related fronts: inequitable mineral wealth distribution and inequitable mining land regimes. Second, findings reveal marked shortcomings of the existing ASM governance framework which in turn drive illegal mining broadly, and also facilitate the infiltration of foreign miners. These include a narrowly conceived ASM formalization framework that disconnects from local level dynamics and practices, inadequate state support for local miners, a porous ASM market regime that enhances the flourishing of illicit gold markets, among others. The findings also show increasing environmental destruction linked to heavy mechanization of the sector as well as differentiated social and economic impacts to rural folks. A silver lining, however, is that some local miners now have access to simple, intuitive and low-cost mining techniques and technologies that have a potential to improve their efficiencies and also enhance environmental quality. Generally, the findings demonstrate the top-down nature of Ghana’s mineral governance and profound information asymmetries that exist between policy and practice. They underscore the need for a more collaborative natural resource governance that engages local stakeholders in ASM governance frameworks in Ghana.

abstract: PhD


title: Codifying Commonwealth Citizenship: The Commonwealth, South Asian Immigration, and Citizenship n the United Kingdom, 1945-1981

subject: History Commonwealth Citizenship Immigration

abstract: In 1948, the United Kingdom formally established two categories: Citizenship of the United Kingdom and Colonies and Commonwealth Citizenship, through the British Nationality Act. Premised upon the Commonwealth of Nations, this broad and extremely inclusive citizenship legislation would define British nationality and citizenship until 1981. The Commonwealth underwent significant changes in the late 1940s as the Dominions implemented their own distinct citizenships, beginning with Canada in 1946. Following their independence, India negotiated membership on more equal terms, emphasizing the inherent tension between member autonomy and unity. As South Asian immigrants asserted their rights to enter and settle in the UK as part of the legal community in the decades following 1948, British policy-makers responded with immigration controls, including the Commonwealth Immigrants Acts in 1962 and 1968, that in the end eroded the Commonwealth. The Commonwealth provides a lens from which to analyse the global dimensions of the late stage of British imperialism and the relationships between members during this period. Within the global context of decolonization, this thesis explores how the very existence of South Asian immigrants challenged the Commonwealth and ultimately resulted in its failure to remain a significant imperial and international organization. The Commonwealth was shaped and used by the UK, Dominions, and Colonies to further their own goals to limit or advance decolonization. The movement of British subjects from the Commonwealth to the UK played a significant role in the history of UK immigration and citizenship policy, eventually resulting in the erosion of the Commonwealth. Events and interpretations of increased South Asian immigration punctuate formal actions and policies enacted by the UK, which challenged both the Commonwealth and imperial unity and universality.

abstract: M.A.


title: New Atlantis: A Venetian Vision of the Americas

contributor:
D'Elia, Anthony
van Deusen, Nancy
History

subject:
Early Modern Venice
Atlantic World
Intellectual History
Colonialism

abstract:
While few Venetians traveled to the Americas in the sixteenth century, a plethora of writers, cartographers, and cosmographers vicariously participated in its conquest. Attributing Iberian achievements in the Age of Exploration to the exploits of their illustrious Republic, these authors routinely saw reflections of themselves within their visions of the New World. At various times, they regarded Venice and Tenochtitlan as replicas of each other, valorized Columbus’ voyage in Venetian terms, and likened indigenous Americans to the earliest inhabitants of their city. Apparent in a variety of maps, texts, and images, these approaches reveal how the Republic’s learned elite pursued a policy of commensurability when representing the relationship between the Old World and the New. Mediated through the myth of Atlantis, this rhetorical strategy ensured Venice’s relevance in an age of Atlantic empires.
At a time when scholars were scouring the classics to comprehend the New World, it is not surprising that several of them identified the Americas as Atlantis. For Francisco López de Gómara and Pedro Sarmiento de Gamboa, the story of a long-lost land bridge secured Spanish claims to the recently discovered continent. For Venetian humanists, however, the myth revealed far more about the structure and nature of the world. Evincing Plato’s theory of harmonia mundi, Atlantis reaffirmed the reciprocal relationship that seemingly existed between Venice and its Aztec counterpart. Evident in the works of Girolamo Fracastoro and Giovanni Battista Ramusio, the equation of New/Old World places and peoples enabled Venetians to ponder the colonial potential of the Americas.

abstract: PhD


title: The Impact of Respiratory Infection on the Nasal Microbiota

contributor:
Sheth, Prameet
Pathology and Molecular Medicine

subject:
Nasal Microbiota
SARS-CoV-2
Next Generation Sequencing

abstract: Background: Viral respiratory infections represent a significant burden of illness with high morbidity and mortality, which has been further magnified in recent years by the emergence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Viruses including SARS-CoV-2, Influenza A Virus (Flu-A), and Respiratory Syncytial Virus (RSV) utilize the nasopharynx for viral entry, replication and infection. The nasopharynx epithelial cell mucous membrane harbors a diverse community of bacteria, called the nasal microbiota (NM). Flu-A can modulate changes in the NM community and lead to pathobiont enrichment. Therefore, here we aim to investigate the NM of individuals with SARS-CoV-2, Flu-A and RSV infection, and identify correlates between the NM community and viral load (VL) and SARS-CoV-2 variants of concern (VOC). Methods: Nasopharyngeal (NP) swabs were collected and tested for SARS-CoV-2, Flu-A, and RSV by validated real-time PCR (RT-PCR) assays. RNA extraction was performed using a Maxwell automatic nucleic acid extractor followed by 16S rRNA Illumina Next Generation Sequencing (NGS) library sample preparation for NGS on a MiSeq Sequencer. QIIME II, Microbiome Analyst and PRISM 9.0.0 were used for data analysis. Results: NP swabs from 118 SARS-CoV-2, 40 Flu-A, 26 RSV positive and 45 negative controls (NC) were included. An increase in alpha and beta bacterial diversity (p<0.001) was observed in the NM of SARS-CoV-2 patients and an enrichment in Streptococcus and Staphylococcus species and depletion of Bifidobacterium and Moraxella species compared to NC’s (p<0.001). Compared to Flu-A and RSV patients, SARS-CoV-2 positives showed enrichment in Streptococcus, and depletion in Haemophilus species (p<0.002). 73/118 SARS-CoV-2 specimens were further sequenced to identify VOC lineage and stratified by VL. No significance in bacterial richness, diversity, or abundance correlated to VL. Only a significant difference in beta diversity was observed between the alpha/delta and omicron cohorts (p<0.001). Conclusions: This study demonstrates that the NM community is different in individuals with respiratory illness and distinct between SARS-CoV-2, Flu-A and RSV infected individuals. This study also demonstrated that NM beta diversity was different between individuals with different SARS-CoV-2 lineages, suggesting virus-NM interplay that may be important in explaining differences in transmission potentials and pathogenesis between SARS-CoV-2 VOCs.

abstract: M.Sc.


title: "I have sene hit more opynly": Authority, Community, and Knightly Interpretation in Malory's Grail Quest

contributor:
Pappano, Margaret
English Language and Literature

subject:
Medieval Literature
Sir Thomas Malory
Le Morte Darthur
Interpretation
Practice Theory

abstract: In adapting the French Vulgate Queste del Saint Graal into his own Grail Quest narrative within Le Morte Darthur, Sir Thomas Malory enters difficult, even dangerous, religious territory. This thesis examines Malory’s “Tale of the Sankgreal” and its many scenes of religious interpretation within the historical context of fifteenth-century England, where concerns over the rise of Lollardy led the Church to attempt to suppress unorthodox religious claims with the goal of maintaining clerical power and status. At the same time, knights hoped that the Church’s political power and control over religion would be lessened so that their own authority might increase. I analyze the ways in which Malory’s knights act as lay interpreters of religious material throughout the Grail Quest, combining close reading of the Morte and textual comparisons with the Queste with historical analysis and practice theory to illuminate what I term “knightly reading.” This unique form of interpretation and meaning-making, defined by constant action, openness to intuition, and a focus on the present moment, strengthens chivalric community even as the Grail Quest physically separates Malory’s knights. I suggest that Malory’s depiction of knightly reading throughout the Grail Quest establishes his knights as legitimate and successful interpreters, challenging clerical authority. Ultimately, Malory elevates the value of knightly fellowship over the spiritual mysteries of the Grail Quest, which can only be experienced in solitude.

abstract: M.A.


title: Using Electronically Delivered Therapy and Brain Imaging to Understand OCD Pathology

contributor:
Alavi, Nazanin
Neuroscience Studies

subject:
Psychotherapy
OCD
Neuroimaging
CBT
Brain Activation
Electronically-Delivered Therapy

abstract: Background: Obsessive-compulsive disorder (OCD) is a debilitating mental health disorder with current psychotherapeutic treatments, while somewhat effective, yielding low accessibility and scalability. A lack of knowledge regarding the neural pathology of OCD may be hindering the development of innovative treatments. Previous research has observed baseline brain activation patterns in OCD patients, elucidating some understanding of the implications. However, by using neuroimaging to observe the effects of treatment on brain activation, a more complete picture of OCD can be drawn. Currently, the gold standard treatment is cognitive behavioural therapy (CBT). However, CBT is often inaccessible, time-consuming, and costly. Fortunately, it can be effectively delivered electronically (e-CBT). Objectives: This pilot study implemented an e-CBT program for OCD and observed its effects on cortical activation levels during a symptom provocation task. It was hypothesized that abnormal activations could be attenuated following treatment. Methods: OCD patients completed a 16-week e-CBT program administered through an online platform, mirroring in-person content. Treatment efficacy was evaluated using behavioural questionnaires and neuroimaging. Activation levels were assessed at resting state and during the symptom provocation task. Results: Significant improvements (p < 0.05) were observed between baseline and post-treatment for symptom severity and levels of functioning. No statistically significant (p = 0.07) improvement was observed in quality-of-life. Participants had mostly positive qualitative feedback, citing accessibility benefits, comprehensive formatting, and relatable content. No significant changes in cortical activation were observed between baseline and post-treatment. Decreases in activation were seen in the orbitofrontal cortex, thalamus, precuneus, fusiform gyrus, and lingual gyrus. Increases in activation in the cingulate were observed. Conclusion: This project sheds light on the application e-CBT as a tool to evaluate the effects of treatment on cortical activation, setting the stage for a larger-scale study. The program showed great promise in feasibility and effectiveness. While there were no significant findings regarding changes in cortical activation, the trends were in agreeance with previous literature, suggesting future work could provide insight into whether e-CBT offers comparable cortical effects to in-person psychotherapy. Applying a greater knowledge of the neural mechanisms of action in OCD can help develop novel treatment plans in the future.

abstract: M.Sc.


title: The Utility of Objective Assessment Technologies in Parkinson’s Disease

contributor:
Levy, Ron
Neuroscience Studies

subject:
Parkinson's Disease
Robotic Assessment
Kinarm

abstract: Parkinson’s Disease (PD) is the second most common neurodegenerative disorder worldwide and is characterized by the heterogeneous representation of bradykinesia, rigidity, tremor, and postural instability. Patients with PD also experience non-motor complications like autonomic, behavioral/mood and cognitive dysfunction. Treatments for PD include dopamine replacement therapies (DRTs) and deep brain stimulation (DBS). Currently, the assessment and progression of these signs and symptoms and effects of treatment are assessed by clinical scales like the Movement Disorder’s Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). However, clinical scale assessment is limited by their use of coarse categorical variables and subjective nature creating issues with inter-rater and intra-rater reliability. In addition, clinicians often rely on patient interviews to assess cognitive status. Technologies that assess a spectrum of PD signs and symptoms have the potential to complement the current clinical assessment of PD by providing objective measures free from clinical bias. However, many available objective assessment technologies focus on the quantification of a single sign or symptom of PD and oversimplify the complexity of the disease. In this project I tested the utility of the Kinarm robotic platform and a movement tracking touchscreen in the assessment of PD motor and non-motor signs and symptoms. First, I explored the Kinarm robot’s ability to quantify bradykinesia, rigidity and postural instability and generate cumulative motor scores to determine the effects of DRTs and STN-DBS. Next, I used a reverse reaching task to simultaneously assess the motor and cognitive effects of STN-DBS.  I converted this task onto a movement tracking touchscreen to allow for portable assessment. Then, I tested if the reverse reaching task could be used to confirm electrode localization in the STN. Finally, I tracked the longitudinal assessment of PD motor symptoms over time.  Both technologies were shown to quantify bradykinesia, loss of response inhibition and treatment with DRTs. The Kinarm robot was also able to quantify rigidity, postural instability, the effects of DBS electrode implantation and the effects of DBS of the subthalamic nucleus. In sum, these technologies can aid in the titration of PD treatments and provide clinically relevant information regarding patient disease profiles.

abstract: PhD


title: Trace Element Occurrence in Wastewater and Effects on Surface Water Quality in the Laurentian Great Lakes and the Grand River, Ontario

contributor: Geological Sciences and Geological Engineering

subject:
Wastewater
Geology
Surface Water
Geochemistry
Environmental Chemistry
Environmental Geology

abstract: Wastewater treatment plays an integral role in maintaining surface water quality in industrialized societies around the world. Wastewater effluent and sewage sludge can both be important vectors of contaminants that are not fully eliminated during treatment, and thus understanding effluent and sludge composition is key to preventing deleterious environmental impacts to receiving environments. Trace elements are one important class of contaminants in wastewater, as their increased use in industrialized societies is reflected in their growing occurrence in anthropogenic waste streams globally. Yet, the potential large-scale sources of trace elements to wastewater and their behavior during wastewater treatment remain poorly understood and potential environmental impacts on receiving environments therefore unclear. Because only a handful of specific parameters in wastewater and sludge are regulated in Canada, not including many trace elements, monitoring of their occurrence and potential impacts is crucial. In this thesis, >40 wastewater treatment facilities in the North American Great Lakes basin were screened for major and trace elements and a black-box approach was deployed to calculate representative estimates for average per-capita trace element loads and basin-scale effluent discharge rates, as well as trace element removal efficiencies across different wastewater treatment technologies. In addition, I report concentrations of major and trace elements in >30 riverine and effluent samples collected in the Grand River catchment, Ontario, in an attempt to assess imprints of effluent discharge on riverine trace element loads. The findings of this thesis demonstrate the effectiveness of wastewater surveillance for a quantitative exploration of anthropogenic versus geogenic trace element emissions and highlight its value to further the understanding of the current state of contaminants in wastewater and sewage sludge and their behavior during the wastewater treatment process.

abstract: M.Sc.


title: Poroelastic Calibration for Hydromechanically Coupled Numerical Discontinuum Models with Application in Low Permeability Hard Rock

subject:
Poroelasticity
Discrete Element Method
Numerical Modelling
Geomechanics

abstract:
Societal demands require the design of underground structures in challenging ground conditions such as densely populated areas with sensitive infrastructure, deep mines, and for the storage of radioactive waste in deep geological repositories. Due to the risk associated with these types of challenging conditions a greater understanding of the geological processes and engineering/ground models is required to produce safe realistic designs.  To obtain a better understanding of the ground’s response the poroelastic response of the rock and flow through the intact rock can be incorporated into numerical models. This thesis provides a process to calibrate grain based poroelastic discontinuum numerical models which simulate the elastic response and fluid flow through low permeability hard rock.
In this thesis, methods for obtaining the poroelastic parameters from laboratory samples of rock are explored.   Alternate methods of obtaining preliminary poroelastic parameters using conventional/ standard rock mechanics laboratory tests and values from literature are provided for preliminary use where data is limited.  A parametric analysis was performed to determine the optimal loading configuration for the numerical apparatus.  The results indicated that a loading configuration where both platens were simultaneously loaded at a rate of less than 0.2 mm/s provided resultant values with error less than 1% and an efficient transfer of stress through the sample.
The proposed process for the poroelastic calibration of laboratory scale numerical samples involves the selection of the solid grain properties and the calibration of the drained response, undrained response and permeability. The grain properties are determined based on the mineralogy and size of the mineral grains of the rock.  The drained calibration consists of calibrating the contact shear and normal stiffnesses to obtain the target drained resultant elastic parameters which are obtained from laboratory tests.  The undrained response is calibrated by adjusting the intergranular aperture to obtain the undrained resultant elastic parameters. Finally, the permeability is calibrated by adjusting the model permeability factor to obtain the target permeability at high and low confining stress. Cobourg limestone is used as an example to demonstrate the parameter selection and calibration process.

abstract: M.A.Sc.


title: Combining Ketamine and Online Cognitive Behavioural Therapy for the Treatment of Posttraumatic Stress Disorder

contributor:
Alavi, Nazanin
Reshetukha, Taras
Neuroscience Studies

subject: Posttraumatic Stress Disorder

subject: Ketamine

subject: Online Cognitive Behavioural Therapy

subject: Pharmacologically enhanced psychotherapy

subject: Trauma

subject: Psychedelic

abstract: Over a third of patients with Post-Traumatic Stress Disorder (PTSD) do not respond to current pharmacological and psychotherapeutic interventions due to a host of neurobiological and social factors. Ketamine is one potential treatment avenue aimed at boosting neuroplasticity, however its effects are short lived. Online Cognitive Behavioural Therapy (eCBT) is another option, targeting a lack of treatment access, however it can struggle to overcome cognitive rigidity in treatment-resistant patients. Administering ketamine in conjunction with psychotherapy is one potential means of potentiating its effects, however, there are few studies investigating this treatment method to date, and none testing ketamine in combination with eCBT. The present study assesses the efficacy of a combined treatment of sub-anesthetic ketamine in conjunction with eCBT. In the study, 10 participants with refractory PTSD were assigned either to an experimental group receiving a combination of ketamine and eCBT over 12 weeks, or they were assigned to a control group where they were passively observed for the same length of time. Both groups were assessed for symptoms of PTSD and comorbid disorders before treatment, at 4-weeks, 8-weeks, and at the end of the 12-week experimental period. Symptoms for participants in the experimental group improved more than in the control group with a large effect size, however the results were not significant. This thesis outlines innovative avenues for addressing treatment resistance in PTSD, and sheds light on treatment access, trauma, and neuroplasticity.

abstract: M.Sc.


title: Clinician perspectives on integrating motor learning theory and principles into rehabilitation

contributor:
DePaul, Vincent
Rehabilitation Science

subject:
rehabilitation
motor learning

abstract:
BACKGROUND
Following a neurological injury, motor learning (ML) and the accompanying theories and principles provide clinicians with the structure and guidelines required to maximize functional recovery. Unfortunately, evidence has shown that ML is not being used to its full benefit within rehabilitation. Therefore, an assessment of how clinicians are implementing ML within clinical practice, and an exploration of the barriers and facilitators they face, should be conducted. The objectives of this study were to 1) describe how confident clinicians are integrating ML into clinical practice, 2) describe how ML is integrated into clinical practice, and the clinician perceived barriers and facilitators, and 3) start to determine what clinicians believe would be beneficial moving forward to begin overcoming these barriers.
METHODS
A sequential exploratory mixed methods approach was utilized. Two surveys comprised the quantitative section; one was distributed to a convenience sample of clinicians attending a motor learning workshop (n = 28) and the second was primarily distributed via the Ontario and Canadian Physiotherapy Associations (n = 60). The content of the first survey and the Theoretical Domains Framework were used to inform question development for qualitative interviews (n = 7).
RESULTS
Quantitative: Surveys highlighted barriers and facilitators to integrating ML into clinical practice, such as time, knowledge and understanding, and patient presentations, identified by previously published literature. The second survey highlighted social support as a facilitator. Based on the scales used in the surveys, clinicians have a mid-range confidence level integrating ML within rehabilitation.
Qualitative: While the interviews also highlighted the barriers and facilitators identified by the surveys, they emphasized the nuances of these barriers. How ML is approached within the literature, the realities of clinical practice, and the limited guidance clinicians receive with ML exacerbates the impact of the barriers on their clinical practice.
CONCLUSIONS
The resulting confidence levels and assessments of how ML theories and principles are integrated into clinical practice shows that there are still gaps in the translation of ML-related knowledge into rehabilitation. A future integrated knowledge translation opportunity should be investigated as a potential method of reducing the impact of these barriers on clinical practice.

abstract: M.Sc.


title: A Study of the Minimum p-value and Related Methods for the Identification of Treatment-Sensitive Groups

contributor:
Tu, Dongsheng
Lin, Chunfang Devon
Mathematics and Statistics

subject:
predictive classification
cutpoint
minimum p-value method
bootstrap
profile method

abstract: In clinical practices, a fundamentally important problem is to identify a subgroup of patients who may benefit more in terms of a clinical outcome from a certain treatment based on a specific clinical variable or biomarker, which is referred as predictive classification in this thesis. The clinical variable or biomarker used for predictive classification is usually continuous and, therefore, a cutpoint needs to be determined for the definition of the subgroup. The commonly adopted methods, the minimum p-value method and the profile method, suffer from the type I error inflation and/or the identifiability issue. In this thesis research, we first propose bootstrap-based methods for the adjustment of the minimum p-value method for predictive classifications with respect to a continuous clinical outcome in both identifiable and non-identifiable cases under random designs and fixed designs, respectively. Since the minimum p-value test statistics diverge at a rate sqrt(n) (n is the sample size) under the framework of the generalized linear model with non-identity link function and the Cox model for respectively categorical and time to event clinical outcomes, bootstrap-based methods are proposed to adjust the profile methods for predictive classifications in both identifiable and non-identifiable cases. The theoretical properties of the proposed adjustments are investigated and simulation studies are conducted to evaluate their fixed sample size performance. In addition, the proposed methods are applied to analyze the data from a cancer clinical trial.

abstract: PhD


title: Who Let the Dogs Die?: The Canine Presence in Canonical American Fiction

contributor:
Varadharajan, Asha
English Language and Literature

subject:
animal studies
american literature
gender studies

abstract: My dissertation examines the presence and characterization of canines in modern and contemporary American novels. I chose popular and canonical texts in which dogs play either a fundamental or ornamental role. The authors under consideration include Jack London, Fred Gipson, W. Bruce Cameron, Harper Lee, Toni Morrison, John Steinbeck, and Kurt Vonnegut. My analyses of each text are informed by recent developments in animal studies with particular attention to Josephine Donovan’s concept of animal-standpoint criticism and Jacques Derrida’s discussions of animality, shame, following, and response. My dissertation focuses on the novels’ depiction of the increasing dependence of canines on their human companions alongside the inevitability of animal sacrifice. This disturbing pattern of the seemingly non-essential and brutal killing of dogs occurs in and has been relegated to the margins of American literature and literary criticism. I interrogate the authorial reliance on dog death for the sake of character development and the production of sentimental affect and insist that the dead dog is an overlooked but ubiquitous literary presence that broadens the parameters by which classic novels can be interpreted. Through chapters on conventionally romantic novels which feature dogs as protagonists and novels in which dogs figure peripherally, my dissertation traces the progress from animal representation to agency and complicates the preferably simplistic discussions of human-animal relationships both in and outside of fiction.

abstract: PhD


title: Self-supervised Learning for IMU-based Human Activity Recognition

contributor:
Etemad, Ali
Electrical and Computer Engineering

subject:
Self-supervised Learning
Contrastive Learning
Human Activity Recognition
Accelerometers
Data Prediction

abstract:
In recent years, human activity recognition has drawn considerable attention due to its application in a variety of areas such as smart homes and health. The pervasiveness of wearable devices and smartphones has provided many research opportunities for human activity recognition using inertial measuring units. In this thesis, we propose the use of self-supervised learning for human activity recognition using the tri-axial data collected from the smartphone-embedded accelerometers. To address the limitations of fully-supervised learning, mainly reliance on labeled data, we propose two self-supervised solutions. Our first solution is a novel method which consists of two steps. First, the representations of unlabeled input signals are learned by training a deep convolutional neural network to predict a segment of masked accelerometer values. Our model exploits a novel scheme to leverage past and present motion along x and y dimensions, as well as past values of the z axis to predict future values in the z dimension. This cross-dimensional prediction approach results in effective pretext training with which our model learns to extract strong representations. Next, we freeze the convolution blocks and transfer the weights to our downstream network aimed at human activity recognition. For this task, we add a number of fully connected layers to the end of the frozen network and train the added layers with labeled accelerometer signals to learn to classify human activities. We evaluate the performance of our method on three publicly available human activity datasets: UCI HAR, MotionSense, and HAPT, outperforming a number of prior works in the area.
In our second solution, similar to our first method, we aim to develop a model that learns strong representations from accelerometer signals, in order to perform robust human activity classification, while reducing the model's reliance on class labels. Specifically, we intend to enable cross-dataset transfer learning such that our network pre-trained on a particular dataset can perform effective activity classification on other datasets (successive to a small amount of fine-tuning). To tackle this problem, we design our solution with the intention of learning as much information from the accelerometer signals as possible. As a result, we design two separate pipelines, one that learns the data in time-frequency domain, and the other in time-domain alone. In order to address the issues mentioned above in regards to cross-dataset transfer learning, we use self-supervised contrastive learning to train each of these streams. Next, each stream is fine-tuned for final classification, and eventually the two are fused to provide the final results. We evaluate the performance of the proposed solution on three datasets, namely MotionSense, HAPT, and HHAR, and demonstrate that our solution outperforms prior works in this field. We further evaluate the performance of the method in learning generalized features, by using MobiAct dataset for pre-training and the remaining three datasets for the downstream classification task, and show that the proposed solution achieves better performance in comparison with other self-supervised methods in cross-dataset transfer learning.

abstract: M.A.Sc.


title: The Processing of Double Refractory Gold Ore: Treatment of Alkaline Pox Feed and Alkaline Pox Discharge

contributor:
Ghahreman, Ahmad
Gibson, Charlotte
Mining Engineering

subject:
Refractory gold ore
Thiosulfate gold leaching
Carbonaceous matter
Flotation
Alkaline pressure oxidation

abstract: This study examined a refractory gold ore containing carbonaceous matter (C-matter) and sulfide minerals from Barrick’s Goldstrike plant; gold is recovered from the ore using pressure oxidation (POX) followed by thiosulfate gold leaching. However, gold recovery is insufficient using the current process, leading to the investigation of poor recovery and possible solutions. Part I and Part II aimed to solve the problem of low gold recovery by taking a divergent approach: Part I determined that the low gold recovery from the alkaline POX discharge was mainly attributed to finely locked gold in the ore. For improved gold liberation and higher gold recovery, treatments were performed: 1) mechanical activation (MA) improved the gold recovery from 59% to 72% as P80 size decreased from 56.5 to 8.54 μm, 2) acid dissolution resulted in an improvement of gold recovery from 59% up to 66% using H2SO4. Part I concluded that the complexity of the ore cannot be fully overcome by the treatments, which motivated the study of pre-treating the ore using flotation to separate C-matter. Part II investigated flotation before POX to produce a C-matter concentrate and a tailings: the C-matter concentrate could be processed in Goldstrike’s roaster, while the tailings could be sent to the alkaline autoclave. Improved gold liberation and higher gold recovery were expected due to the higher efficiency of the roasting process in the treatment of carbonaceous material. Multi-stage flotation using kerosene and MIBC (Methyl isobutyl carbinol) resulted in 70% C-matter recovery and C-matter concentrate grade of 4% using a rougher-scavenger-cleaner flotation circuit. A reagent study demonstrated that 1) higher doses of MIBC increased the flotation rate and reduced the entrainment of gangue minerals, and 2) a kerosene emulsion resulted in higher recovery and faster flotation kinetics than normal kerosene and showed better performance than transformer oil, a novel collector. With the flotation, the overall gold recovery increased from 44% to 60% based on Barrick’s geo-estimation models. Ultimately, this work demonstrated that the main cause of poor performance in thiosulfate gold leaching and flotation was the highly complex nature of Goldstrike’s ore, with very poor liberation of host minerals.

abstract: PhD


title: Canadian Hemophilia Carriers Pregnancy Study: Coagulation Factor Levels and Postpartum Blood Loss

contributor:
James, Paula
Translational Medicine

subject:
Hemophilia Carrier
Postpartum
Postpartum Hemorrhage
Factor VIII
Factor IX
Pregnancy

abstract: Hemophilia is an X-linked recessive bleeding disorder caused by a deficiency in Factor VIII (FVIII) or Factor IX (FIX) that was previously thought to only affect men. Women are carriers for this disorder with recent studies showing that they may also be affected by hemophilia. In recent years, it has been consistently reported that hemophilia carriers (HC) experience excessive bleeding versus normal controls. Furthermore, FVIII and FIX levels have been shown to be decreased in HC in comparison to normal controls. HC have been shown to experience increased rates of postpartum hemorrhage (PPH) in comparison to normal controls. Although PPH treatments are available, there is no consensus on protocols. This thesis aims to quantify bleeding during the postpartum period in HC and normal controls and to examine how changes in coagulation factors during and after pregnancy may impact PPH. Five Hemophilia A carriers and 31 normal controls of similar mean ages consented to participate in the study. Quantification of postpartum blood loss using the validated Pictorial Blood Loss Assessment Chart showed that mean estimated postpartum blood loss was not significantly different between HC and normal controls. Significantly more postpartum bleeding occurred within the first week (512 ± 282 mL) versus the following postpartum weeks in normal controls, p<0.01. Plasma FVIII and FIX levels at 37 weeks gestation, admission for delivery, 12-24 hours post-delivery, postpartum day 7±2, 21±3, and 35±4 were assessed. HC had significantly lower FVIII levels versus normal controls (p<0.05) at each timepoint. Interestingly, post-delivery FVIII levels in normal controls was positively correlated with total postpartum blood loss (rs=0.59, p<0.05). We have shown that the majority of postpartum blood loss occurs within the first week after delivery in both HC and normal controls. The ability of normal controls to raise FVIII in response to blood loss may give insight as to why PPH occurs at an increased rate in HC who have previously been shown to have a reduced ability to raise FVIII levels. The results from this study could inform future treatment protocols potentially targeted at the first week of the postpartum period.

abstract: M.Sc.


title: Bilayer Light-Emitting Electrochemical Cells: Ionic Effects of Solid Polymer Electrolyte

contributor: Physics, Engineering Physics and Astronomy

subject:
Solid Polymer Electrolyte
Light-emitting Electrochemical Cells
Ion Transport
Electrochemical Doping
Electroluminescence

abstract: Polymer light-emitting electrochemical cells (PLECs) are organic solid-state devices that operate on in situ electrochemical doping and the formation of a light-emitting p-n junction. Bilayer LECs consist of a solid polymer electrolyte (SPE) underlayer and a conjugated polymer (CP) top layer. Aluminium electrodes with 2mm gap size were deposited on top of the CP layer and formed a planar configuration. Planar bilayer LECs with large gap sizes brought unique opportunities to visualize the in situ doping propagations with imaging techniques. Separating the CP from the SPE provided the potential to study the SPE layer itself and lead to a better performing light emitting device. In this thesis, four different studies were conducted to explore ionic transportation in the CP, the SPE, and the CP/SPE interface. In the study of salt concentrations in the SPE, the increase in ionic concentrations improved the performance of LECs in terms of doping propagation speed, junction formation time, and cell current. However, a current leveling off was observed at high salt concentrations, while light emitting p-n junction overlaps with the cathode which is undesirable. In the second study, by increasing SPE layer thickness, a significant improvement in device performance was observed, however, no further improvement was observed as the thickness went beyond 500nm. In the study of cationic effects, devices with smaller cation sizes had a higher current and faster doping propagation, whereas devices with large cations require a higher bias voltage and temperature to turn on. The improved performance of bilayer LECs compared to single-layer LECs suggested that interlayer ionic transportation was not the major factor that limited the performance of LECs. In the final chapter, LECs with salt concentrations as low as 0.005 were successfully turned on. For devices with lower salt concentrations, however, no light-emitting p-n junction was formed. These studies demonstrate the importance of ion transport in LEC operation and point to new directions for improving the device performance.

abstract: M.Sc.


title: Looking Through a Biopsychosocial Lens: A Multimethod Examination of Sexuality and Disability in Inflammatory Bowel Disease

contributor:
Tripp, Dean
Psychology

subject:
inflammatory bowel disease
sexuality
disability
healthcare
diversity

abstract: Inflammatory bowel disease (IBD) is a chronic health condition associated with impaired well-being and disability. Biopsychosocial research suggests that psychosocial impacts of IBD play an important role in patient well-being. Sexual well-being is poorly understood in IBD. Sexual difficulties in IBD relate to disability outcomes as well as biopsychosocial variables such as disease activity, depression, anxiety, and body image issues. Factors yet to be examined, such as sexual script flexibility and desire for emotional closeness, are important to consider because they may influence the relationship among IBD disease activity, sexual dysfunction, and disability. In addition to the literature limitations, sexuality is rarely addressed in IBD clinical care. The current dissertation aimed to address these gaps in a longitudinal, multimethod, online study. N = 470 adults with IBD participated. The study hypotheses were mostly supported. Greater levels of IBD disease activity, body image dissatisfaction, and lower sexual script flexibility predicted higher sexual dysfunction. Sexual dysfunction mediated the relationship between disease activity and disability, with this effect being stronger among those with higher levels of sexual script flexibility, as evidenced by a significant moderation effect. Longitudinally, the mediation effect remained significant, but the moderation did not. Desire for emotional closeness was not a significant moderator in any model. Thematic analysis identified themes in participants’ responses about the impacts of IBD on their sexual and intimate lives, and their experiences accessing information and help for such issues in the healthcare system. The impacts of IBD on participants’ sexual lives were complex and biopsychosocial in nature, highlighting that their concerns were beyond just sexual functioning, but included impacts on their relationships and sense of self. Participants’ reports of their healthcare experiences illuminated the nuanced personal and system level factors impacting their perceptions of support and desire to seek out information on sexual functioning from healthcare providers. Finally, sexual and gender minority participants reported worse sexual dysfunction and disability than sexual and gender majorities and were more likely to seek out and obtain information on these issues from healthcare providers. These findings may help to guide biopsychosocial, inclusive, and patient-oriented IBD research and clinical practice.

abstract: PhD


title: The Battle of Lepanto: The Image of The Turk in Renaissance Neo-Latin Poetry

contributor:
D'Elia, Anthony
History

rights: Attribution-ShareAlike 3.0 United States

subject:
Classical Reception
Renaissance
Humanism
Ottomans
Venice
Lepanto
Turks
Juan Latino

abstract: As the sixteenth century was drawing to a close, the Ottoman Empire made a grab for Venetian territory – in this case, Cyprus. This unprovoked attack set in motion a chain of events that resulted in one of the largest naval battles that the contemporary world had ever seen, Lepanto. The unexpected Western victory, after a long history of ever-worsening defeats, prompted an explosion of optimism, confidence, and Neo-Latin poetic composition. These works, produced in the immediate aftermath of the battle, reveal the newfound optimism and perceptions of the Venetians that penned them. Through classical allusions they denounced their enemy as barbarians, tyrants, deceivers, heretics, and even called for crusade efforts, making it clear to all that the Turks were no longer to be feared. While Lepanto itself has been the subject of a great deal of scholarship, there has been a noticeable absence of coverage regarding these celebratory poems. Some scholars look at Lepanto as a minor occurrence, as the Western powers involved failed to capitalize on the victory. This thesis is intended to challenge that view by looking beyond arguments grounded in direct material outcomes (such as territory won or lost). It is also intended to address that gap in the historiography to show that Lepanto had a much greater effect on European morale than previous victories. By drawing on the Neo-Latin poetry collected by Pietro Gherardi, as well as the Austrias Carmen of Juan Latino, we establish how the Turks were viewed by Venetians in that crucial window following the battle. Then, using Lepanto itself as a framing tool, the analysis conducted here compares the Venetian perceptions to those of contemporaries in the century before it. In doing this we establish that Western pessimism and fear was grounded in a record of ever-increasing failure to effectively combat the rising tide of Ottoman power. Lepanto, however, marks a flashpoint where that track-record dramatically reverses, and the specter of Ottoman invincibility was suddenly shattered irrevocably.

abstract: PhD


title: Evaluating the Effect of a Pressure Injury Virtual Simulation Game on Undergraduate Nursing Students’ Knowledge

contributor:
Woo, Kevin
Nursing

subject:
Undergraduate nursing students
Virtual Simulation Games
pressure injuries
wound care
knowledge

abstract:
With the ageing population living longer and the prevalence of chronic diseases, pressure injuries are a serious health concern. The literature has identified some long-standing gaps in undergraduate nursing wound care education and its impact on undergraduate nursing students learning. With virtual simulation games (VSGs) having positive outcomes as experiential learning tools, we conducted a study to evaluate the effect of a pressure injury virtual simulation game on undergraduate nursing students’ knowledge.
In this pilot study, we employed a one-group pre-test-post-test quasi-experimental design among 19 undergraduate nursing students at Queen’s University, Kingston, Ontario. A modified version of the Pieper-Zulkowski Pressure Ulcer Knowledge Test was used as a tool to assess students’ knowledge about pressure injuries (PIs) before and after the virtual simulation game. In the VSG, participants took on the role of a wound care nurse as they completed a comprehensive assessment and treatment of a coccyx pressure injury (PI). At the end of the game, consenting students participated in a virtual debriefing session. We hypothesized that the VSG would significantly increase the knowledge of the assessment and treatment of PIs among undergraduate nursing students.
The dependent t-test comparing the students’ pre-test and post-test knowledge scores showed a statistically significant improvement in the knowledge scores from a pre-test mean score of 9.63 to a post-test mean score of 11.53. However, the independent t-test showed no statistically significant difference in students’ knowledge scores between the lower-year and upper-year undergraduate nursing student groups. At the end of the study, the following themes emerged from the virtual debriefing sessions: self-reflection, active learning, knowledge acquisition, knowledge application, holistic patient care, taking the initiative to acquire or advance one’s knowledge, and recognizing the abnormal. VSGs increase nursing students’ knowledge and help them make appropriate wound care decisions in their clinical placements.
As virtual simulation evolves, we need to continue to generate more robust, well-designed studies with larger sample sizes to support the use of VSGs in nursing education.

abstract: MNSc.


title: “Fairies and Fusiliers”: Warfare and Faerie on the Western Front

contributor:
King, Shelley
English Language and Literature

subject:
First World War
Great War
Faerie
Fairy tale
Modernism
British fiction
Fantasy
Tolkien
Brittain
Carter
Byatt

abstract: This doctoral project addresses the strange meeting between warfare and Faerie in Modernist and contemporary British literature about the First World War. Through a study of four texts, two from survivors of the Great War, two from writers who “did not experience the War, but who inherited its myth” (Hynes A War Imagined xii), this dissertation examines the intersections be-tween faery tale and war story as narratological frameworks, through which these writers attempt to articulate ineffable experiences in the “Perilous Realm[s]” (Tolkien “On Fairy-Stories” 114) of the Western Front and of Faerie. This project traces these intersections, from J.R.R. Tolkien’s short story “The Fall of Gondolin” (1917) and Vera Brittain’s memoir Testament of Youth (1933) to Angela Carter’s faery tale “The Lady of the House of Love” (1979) and A.S. Byatt’s historical novel The Children’s Book (2009). Each of the four chapters addresses one of these texts relative to three key strands of enquiry: first, the ways in which the text narrativizes the historical events of the Great War through a Faerie framework; second, the pervasive and sustained nostalgia for a lost Arcadia, which is often interchangeable with Faerie in the collective childhood memories of the War Generation; and third, the pervasive figure of eternal youth that haunts each text, as the spectre of the fallen young men who “shall grow not old” (Binyon “Fallen” 13): a Peter Pan in khaki, that unifies warfare and Faerie in the haunting figure of the boy-soldier. This project con-tributes to the field of literary criticism on the Great War by addressing an often overlooked, yet frequently recurring, theme: the intrusion of Faerie on the seemingly quotidian space of the battlefield and the uncanny similarities between the monsters of the Faerie realm and the monstrous machinery of the Front.

abstract: PhD


title: Can Securities Regulation Influence Effective Corporate Response to Climate Change in Nigeria? An Analysis of Global Practices and Nigerian Securities Regulation

contributor:
Henderson, Gail
Law

subject:
Climate Change
Securities Regulation
Non-financial Reporting
Sustainability Reporting
Nigeria
Disclosure frameworks
Securities and Exchange Commission

abstract: Climate change and its effects are pervasive and escalating. It poses not only direct environmental risks but also economic and financial risks associated with mitigating and adapting to its effects. Within the corporate sector, its actual and potential effects on businesses is an ongoing discussion. This thesis contributes to this discussion by offering securities regulation as a response to tackling general Nigerian environmental laws’ limitations in influencing companies to effectively respond to climate change through mitigation and adaptation. To determine the efficacy of securities regulation as a response, this thesis conducts a review of the relevant key features of securities regulation, disclosure, and materiality. It also reviews existing research on elements of climate change-related disclosure that led to a positive change in corporate environmental performance and behaviour. It examines key securities and securities-related regulations in Nigeria, focusing on climate change-related disclosure. Lastly, it examines selected voluntary global disclosure mechanisms which provide investors with decision-useful information as well as other jurisdictional climate change disclosure practices in Europe, US and Canada. This thesis finds that the compulsoriness of climate-change-related disclosure and the disclosure framework mandated by securities regulators are key to influencing effective corporate response to climate change and improving corporate environmental performance and behaviour. These findings show that changes to Nigerian securities regulations’ provisions which effectively frame climate change-related disclosure and mandate specific disclosure frameworks can influence effective corporate response to climate change. They can also cause positive changes to corporate environmental performance and behaviour more broadly.

abstract: LL.M.


title: Value-Based Dynamic Caching Over Information-Centric Networks (ICNs)

contributor:
Hassanein, Hossam
Oteafy, Sharief
Computing

subject:
Information-Centric Network (ICN)
Caching
Value-based Caching
Economic Caching
Dynamic Caching and Pricing

abstract:
Information-Centric Network (ICN) is a promising developing communication paradigm focusing on efficient content distribution and retrieval regardless of the content storage location to scale with the projected traffic demand and usage patterns of the Internet. In-network caching in ICN is pivotal in providing fast, reliable, and scalable content dissemination and retrieval.
In this thesis, we aim to maximize the caching utilities based on the valuations of cache contents and cache nodes in ICNs. Most existing ICN caching schemes consider a consumer-centric perspective only for cache valuation. We embed the producer-centric caching perspective along with the consumer-centric perspective for optimal utilization of the inherent caching capability of ICN. This thesis also introduces a value-based economic caching perspective in ICN.
Our research on value-based caching puts forth the following contributions. First, we present a comprehensive taxonomy, and second, we perform qualitative and quantitative performance analyses of some well-known ICN caching schemes. We identify the design factors of our research of value-based caching grounded upon the proposed taxonomy and the performance analyses. Third, we propose a novel content utility value-based dynamic caching scheme for maximizing the aggregated content utility value of an ICN cache service provider. The proposed caching scheme ensures caching diversity and availability of good quality content and demonstrates an acceptable cache hit ratio while maximizing the aggregated content value. Fourth, we propose a novel caching model in which content producers valuate and select cache nodes to cache their contents based on the topological and dynamic attributes of nodes. Our proposed model enables the content producers to maximize the caching utility while reducing delay and increasing cache hit ratio. Fifth, we address the dynamic cache allocation and pricing problem involving multiple content producers and competing ICN cache service providers. We present frameworks, building on producer-driven caching and pricing decisions, leveraging reverse auction-based and utility value-based schemes.
Extensive simulations demonstrate the effectiveness of all our proposed value-based caching schemes in terms of several research-objective-related and standard caching performance metrics. Simulation results suggest that value-based caching can leverage the in-network caching capability of ICN to achieve efficient content dissemination and retrieval.

abstract: PhD