VictorJuiz/thesis huggingface dataset:
Development and Characterization of a Microfluidic System to Model the Transendothelial Migration Mechanism of the Lyme Disease Pathogen Borrelia burgdorferi
Keywords: blood-borne bacteria
extravasation modeling
microfluidics
real time fluorescence microscopy
shear stress
transendothelial migration

Blood-borne bacteria like the Lyme disease pathogen Borrelia burgdorferi cause infection by migrating across the vascular endothelial barrier into target tissues. The mechanisms by which this occurs are poorly understood, largely because model systems inadequately mimic the in vivo environment or are too inefficient to dissect mechanisms. This unmet need is addressed in this thesis by the development of a microfluidic system and live cell imaging methods to model and study transendothelial migration of bacteria in vitro under physiologically relevant conditions. Real-time transmigration kinetics of B. burgdorferi across intact endothelium were obtained, for the first time, under static and flow conditions. Validation studies confirmed that B. burgdorferi transmigrate actively, with similar kinetics to conventional Transwell systems under static conditions. Additionally, physiological shear stress conditions appeared not to significantly alter transmigration kinetics. These data were uniquely obtainable with the microfluidic platform, supporting its utility for studying extravasation of blood-borne pathogens of worldwide significance.
Intravenous Delivery of a D1-D2 Interfering Peptide with Antidepressant-like Effects
Keywords: Antidepressant
Depression
Dopamine
Peptide
Receptor interaction

Depressive disorders are common, debilitating diseases. Current treatments on the market are unsuccessful for many patients, have high rates of remission, and many side effects. After finding that the D1-D2 dopamine receptor complex is upregulated in post-mortem patients that suffered from major depressive disorder, our lab developed a peptide drug that interferes with this complex to serve as an antidepressant drug. Our lab has previously tested the efficacy of the D1-D2 interfering peptide through intracranial administration and intranasal administration. A major component of preclinical drug testing is finding the optimal method of administration. In this study, we find that the peptide has antidepressant- like effects compared to saline in rats in the forced swimming test at doses greater than 1.5nmol/g. These findings are an important step in the preclinical research of a peptide with antidepressant-like effects.
Spatial Patterns of Natural Resource Depletion among Rain Forest Communities in the Peruvian Amazon: The Role of Protected Areas and Indigenous Territories in the Conservation of Key Species
Keywords: biodiversity
conservation
indigenous territories
Peruvian Amazon
protected areas

Human-induced environmental change is not a new phenomenon in biologically rich areas of western Amazonia. Rain forest communities have long modified their environments, pursuing a diverse portfolio of economic activities for subsistence and income generation. Globally, protected areas (PAs) are the chief conservation strategy. While the effectiveness of different PA models continues to be debated, recent research acknowledges the significance of extractive PAs and indigenous territories to the conservation of biodiversity in human-modified landscapes. Using community census data collected from rain forest communities in the data poor region of the Peruvian Amazon (N=919), spatial clustering and regression analyses are applied to evaluate the effect of proximity to extractive PAs and indigenous territories on relative availability of key species. Controlling for important environmental, market, and community characteristics, our research indicates that extractive PAs and indigenous territories have helped to preserve the availability of key species by certain measures that we isolate in the work.
The Effect of Congeners on Trait Evolution and Sexual Dimorphism in Lesser Antillean Anolis Lizards
Keywords: Anolis
Character displacement
Evolution
Macroevolution
Phylogenetics
Sexual dimorphism

The central goal of this work is to examine how species interactions affect trait evolution over macroevolutionary timescales. The Lesser Antilles offer a relatively closed system where the trait evolution of two closely related coexisting species can be compared to the trait evolution of solitary species. Competition as a selective force is predicted to affect a wide variety of characters. Trait divergence that increases interspecific resource partitioning can manifest in morphological, ecological, behavioural, or physiological differences. The present study is concerned with the evolution of body size, functional shape, and sexual dimorphism. Chapter 1 consists of several tests for character displacement on one and two-species islands, with the goal of evaluating the effect of congener presence on trait evolution. Chapter 2 tests the hypothesis that competition influences the degree of sexual dimorphism observed in Lesser Antillean anoles; this hypothesis is compared to an alternative explanation for the evolution of sexual dimorphism, Renschâ s rule.
Assessing the Impacts of Imperfect Detection in Stream Fish Communities through Multispecies Occupancy Modelling
Keywords: Community
Detection
Modelling
Occupancy
Stream

Regardless of sampling effort, it is rare to detect all individuals or species in a given survey. This issue, more commonly known as imperfect detection, can have negative impacts on data quality and interpretation, most notably leading to false absences for rare or difficult-to-detect species. In this study, I set out to determine the impacts of imperfect detection on estimates of species richness and community structure in a stream fish assemblage. Multi-species occupancy modelling was used to estimate species-specific occurrence probabilities while accounting for imperfect detection, thus creating a more informed dataset. This dataset was then compared to the original to see where differences occurred. In my analyses, I demonstrated that imperfect detection can lead to large changes in estimates of species richness at the site level and summarized differences in the community structure and sampling locations, represented through correspondence analyses.
Exploring Art and Science Integration in an Afterschool Program
Keywords: Curriculum Integration
Holistic Education
Science Education
STEAM (science
technology
engineering
art
math)
Student Engagement

Science, technology, engineering, arts and math (STEAM) education integrates science with art, presenting a unique and interesting opportunity to increase accessibility in science for learners. This case study examines an afterschool program grounded in art and science integration. Specifically, I studied the goals of the program, itâ s implementation and the student experience (thinking, feeling and doing) as they participated in the program. My findings suggest that these programs can be powerful methods to nurture scientific literacy, creativity and emotional development in learners. To do so, this program made connections between disciplines and beyond, integrated holistic teaching and learning practices, and continually adapted programming while also responding to challenges. The program is therefore specially suited to engage the heads, hands and hearts of learners, and can make an important contribution to their learning and development. To conclude, I provide some recommendations for STEAM implementation in both formal and informal learning settings.
A Mobile Application for Dual-task Gait Assessment of Cognitive Status
Keywords: Cognitive assessment
Dual-task
Gait
mHealth
Mobile application
Physical therapy

Disturbances in gait during dual-task walking is a promising and well-researched indicator that can be recognized in early stages of cognitive impairment. Changes in gait in the dual-task condition have been shown to be associated with increased incidence of dementia, as well as the risk of falling in older adults. As well, advances in consumer electronics have enabled the use of body-fixed sensor systems to quantify gait features, allowing for simple and objective gait measurement in clinical settings. To date, there appears to be no tool that allows for the administration, evaluation and longitudinal study of dual-task gait. In this thesis, I combine recent efforts in both dual-task gait research and consumer wearable devices to develop a smartphone-based system for dual-task gait evaluation in the context of cognitive assessment. I also explore the barriers and facilitators that influence healthcare provider's perception of mobile and wearable technologies in their practice.
Vitamin D Insufficiency in Children with Duchenne Muscular Dystrophy
Keywords: Duchenne Muscular Dystrophy
Insufficiency
Osteogenesis Imperfecta
Supplementation
Systemic Lupus Erythematosus
Vitamin D

Duchenne muscular dystrophy (DMD) is an X-linked condition caused by mutations in the dystrophin gene, resulting in muscle function loss. Children with DMD are at risk for compromised bone health due to loss of ambulation and corticosteroid treatment. A retrospective study was conducted to determine if vitamin D levels were reduced in this population. The serum 25-OHD and 25-OHD standardized per unit of vitamin D supplementation in DMD patients were both lower than another cohort of patients with disability (Ostegenesis Imperfecta), and a cohort treated with glucocorticoids (Systemic Lupus Erythematosus). Controlling for the season, the significant determinants of serum 25-OHD as well as serum 25-OHD per unit of supplementation were the childâ s underlying condition, disease duration, and weight Z-scores. Our study suggests that children with DMD have on average lower serum 25-OHD despite high levels of supplementation in comparison to a glucocorticoid treated population, and a population with disability.
Design of a High-power White Light Source with Colloidal Quantum Dots and Non-rare-earth Phosphors
Keywords: colloidal quantum dots
high-power light emission
K2TiF6:Mn4+
phosphor
white light source
YAG:Ce

This thesis describes the design process of a high-power white light source, using novel phosphor and colloidal quantum dot materials. To incorporate multiple light emitters, we generalized and extended a down-converting layer model. We employed a phosphor mixture comprising of YAG:Ce and K2TiF6:Mn4+ powders to illustrate the effectiveness of the model. By incorporating experimental photophysical results from the phosphors and colloidal quantum dots, we modeled our system and chose the design suitable for high-power applications. We report a reduction in the correlated color temperature by ~600K for phosphor and quantum dot systems, enabling the creation of a warm white light emission at power densities up to 5 kW/cm2. Furthermore, at this high-power, their emission achieves the digital cinema initiative (DCI) requirements with a luminescence efficacy improvement up to 32% over the stand-alone ceramic YAG:Ce phosphor.
Youth Sport Participation and Peer Support in the Context of Physical Disability: A Qualitative Perspective
Keywords: Adapted Sport
Disability
Motivation
Peer Support
Sport
Youth

Despite the benefits of sport participation, there is a limited understanding on how to initiate and maintain sport participation among youth with physical disabilities. The purpose of this study was to qualitatively explore the role of peers in supporting sport participation among youth with physical disabilities using self-determination theory’s (SDT) mini-theories as guiding frameworks. Interviews were conducted with eight youth with physical disabilities using youth-engaging strategies, and inductively-deductively thematic analysis. Youth participated in a variety of sports, predominantly at the recreational level. Peers’ changing roles throughout the youths’ progression was expressed in line with the three basic psychological needs of SDT. Multi-level need thwarting and supporting behaviours were also highlighted to play a role in sport engagement, and the manifestations of their sport internalization. Peers may assist in creating positive sport experiences for youth with physical disabilities by fulfilling the basic psychological needs of SDT.
Optimizing Chemical Dosage in Municipal Wastewater Disinfection with Model-based Control
Keywords: CFD
Chemical
Disinfection
Optimization
Process
Wastewater

This research thesis developed a feedforward model-based chemical dose control algorithm for municipal wastewater disinfection process and an algorithm to simulate unsteady stochastic process conditions using steady state computational fluid dynamics particle tracks. The control algorithm and simulation model utilize mechanistic models that describe disinfectant decay, CT, and disinfection levels. CT is the product of the effluent disinfectant concentration and the process average residence time. The models are integrated into the particle tracks generated from the disinfection process simulation. By utilizing the mechanistic models and the particle tracks, the control algorithm and the simulation model predict and control the process disinfection performance. The control algorithm is a feedforward control that predicts the disinfection performance, and it is not affected by the long feedback signal dead time commonly found in municipal wastewater disinfection. This thesis has shown that the mode-based dose control algorithm has reduced the disinfectant consumption up to 17%.
Impact of Distal Coronary Embolization in Acute Myocardial Infarction in a Porcine Model
Keywords: Acute Myocardial Infarction
Distal Coronary Embolization
No-Reflow

The effects of distal coronary embolization (DCE) on myocardial injury following acute myocardial infarction (AMI) is controversial. The objective of this thesis is to elucidate the effects of alterations in coronary perfusion due to DCE of biological clot material following AMI in the porcine heart. AMI was induced for 60-minutes followed by injection of microthrombi or saline. Cardiac MRI was conducted at baseline, 72-hours and 6-weeks. Infarct size was significantly elevated in DCE animals versus controls at 72-hours and to a more modest extent at 6-weeks. Global and regional cardiac function was similar between groups at the three time points. Molecular studies at 72-hours revealed that DCE animals had significantly higher MMP-2 levels compared to controls. In conclusion, DCE imparts significant biological effects at early timepoints, which are less pronounced over 6-weeks. This study has important clinical implications and helps to better understand the importance of DCE in AMI.
Development and Utilization of a Novel In vivo Multi-modal Non-invasive Platform for Detecting Ocular Toxicity of Sustained Drug Delivery Systems
Keywords: biomaterial
confocal scanning laser ophthalmoscope
electroretinography
ocular toxicity
slit lamp
sustained drug delivery

This study describes the development and early utilization of a novel in vivo multi-modal non-invasive ocular toxicity platform to evaluate the compatibility of materials suitable for sustained intra-ocular drug release, using electroretinography (ERG), confocal scanning laser ophthalmoscopy (cSLO) and slit lamp examination. First, normally occurring variants of a commonly used rat strain were identified, and then followed by proof-of-principle experiments asking if ocular toxicity could be detected in vivo following challenge with systemic injection of sodium iodate (NaIO3) and intravitreal injection of the biomaterial chitosan, two known ocular toxins. Five novel biomaterials were then tested: 594 eyes were investigated by in vivo testing and of these, 70 eyes, were studied by traditional terminal histology using hematoxylin and eosin (H). We concluded that the in vivo toxicity platform offers an efficient approach to identify potential ocular toxicity that augments and guides H examination and reduces the number of animals required.
Characterization of Indian and Canadian Fly Ash for Use in Concrete
Keywords: characterization
classification standard
fly ash
particle size analysis
particle size imaging
pozzolanic reactivity

The chemical, physical, and morphological properties of fly ash samples from nine Indian and Canadian coal-fired stations were characterized in this research work. The effect of particle size distribution, not adequately addressed in the standards and the literature, on water requirement and pozzolanic activity of the various fly ash samples was examined. The particle size distributions for the nine Indian and Canadian sources were measured using Laser Diffraction Analyzer (LDA). Each LDA measurement was verified by a corresponding scanning electron micrograph. Particle size analysis appears critical to determining the suitability of the practices presently in use for collection and processing fly ash. The effects of fly ash variability on concrete properties were determined within three series of experiments. The findings of this study have potential to form the basis for drafting recommendations to modify existing prescribed limits in the standard specifications for fly ash for use in cement and concrete.
Design of Mobile Application Using Location Based Adaptive Automation
Keywords: adaptive
automation
human factor
mobile
process control
usability

Process industry workplaces are increasingly more automated and require workers to collaborate with an automated agent. Implementing mobile devices in such workplaces is expected to improve task performance and restore multi-sensory cues by providing information to workers at the point of work. Focus group was conducted with 23 field workers to identify challenges that they currently face and proposed opportunities to address them. This resulted in identifying 19 challenges and 7 opportunities to address them using mobile devices. I designed one opportunity that used Adaptive Automation to deliver location-specific equipment operational data to workers at the point of work. Usability results from four participants validated the application and earned an excellent mean System Usability Scale score of 85. The design is expected to provide workers with real-time and projected operational data using a mobile device, providing smart services and allowing them to deliver more accurate equipment diagnosis during maintenance work.
'In Mockery of the Narcissus of the Universe': Hisham Bustani in the Digital Age
Keywords: Georg Lukacs
Hisham Bustani
Tarek El Ariss
Walter Benjamin

Based on close readings of Hisham Bustani’s short story “Nightmares of the City” and his collection of flash prose The Perception of Meaning, this thesis seeks to identify the main forces at play in Bustani’s writing. The form and content of it are closely intertwined and both must be taken into consideration when trying to understand the significance of his work. Bustani is a strong adherent to the short prose form. The shortness of his pieces can create the illusion that the meaning behind them is simple and fleeting. However, this is not the case. Bustani’s writing always contains a narrative and there is always a purpose to his writing. Bustani has said that he intends to encourage free reading and free understanding in his work. In light of these considerations, this thesis attempts to explain the literary devices and effects at play in Bustani’s work.
The Effect of Peripheral Nerve-injury on Depression and Anxiety-like Behaviours in Mice
Keywords: Anxiety
Chronic Pain
Depression
Mice
Neuropathic Pain
Sex Differences

Past animal studies examining the relationship between depression and chronic pain have used only male rodents and often only assessed behaviours 7 to 14 days after an injury. To determine whether chronic pain results in a sexually dimorphic presentation of depression-like behaviours, I conducted a series of experiments assessing male and female mice at 14, 28, and 42 days after a peripheral nerve injury. I found that mice did not show any changes in behaviours 14 or 28 days. At 42 days post-surgery male mice with a nerve injury showed significantly more depressive-like behaviours than the sham group, however females did not. This suggest that results from male rodents may not be generalizable to females and that studies assessing mental health and chronic pain in rodents should assess behaviour over longer periods of time as to be more representative of long-term pain experiences.
Practice Patterns in the Treatment of Acute Achilles Tendon Ruptures in Ontario, Canada
Keywords: Change in practice
Evidence-based medicine
Knowledge translation

Despite emerging evidence favouring â functionalâ non-operative treatment (i.e., early mobilization) over the surgical repair of acute Achilles tendon ruptures, very few studies have evaluated the impact of this evidence on practice patterns. As such, the overall objective of the current study was to determine whether the findings of a landmark Canadian trial assessing the optimal management of acute Achilles tendon ruptures influenced a change in practice among orthopaedic surgeons in Ontario, Canada. The epidemiology and trends in management of acute Achilles tendon ruptures were evaluated using population-based health administrative data and demonstrated an increasing incidence of ruptures and decreasing rate of surgical repair. Using interrupted time-series analysis, an abrupt and sustained decrease in surgical repair rate was found to be highly associated with the presentation of landmark trial results at a major orthopaedic conference. Future work will assess the effect this change in practice has had on outcomes after Achilles tendon rupture.
Development, Characterization, and Prototyping of Ultra Flexible Thin-film Electrochemical Energy Storage Devices
Keywords: Energy storage
Flexible electrode
Supercapacitor

With the rapid development flexible electronics, there is a demanding need for fully flexible, lightweight energy storage systems with high energy and power densities. Herein, two major types of novel hybrid composite electrodes for electrochemical capacitors (ECs) were studied, namely substrate supported composite powder electrodes and fully flexible standalone electrospun core-shell fiber electrodes. For hybrid composite powder electrodes, graphene nanoplatelets (GnPs)/polyaniline (PAni), multi-wall carbon nanotubes (MWCNT)/PAni, aluminum oxide (Al2O3)/PAni, and titanium dioxide (TiO2)/PAni, were created with in-situ chemical polymerization for optimized electrochemical performance. The electrospun core-shell structured electrodes were made using polyethylene terephthalate (PET) from recycled beverage bottles as the core material in combination with PAni and GnPs shells in forming high specific surface area three-dimensional networks to facilitate efficient ion transfer ensuring ideal charge storage behaviours along with improved mechanical properties. Finally, working EC prototypes were constructed and characterized with various electrolyte systems and novel composite current collectors.
Communication Augmented Scheduling for Cloud Computing with Delay Constraint and Task Dependency
Keywords: Application Deadline
Cloud Computing
Computational Offloading
Cost Minimization
Dependency
Scheduling

Cloud computing can augment the capabilities of resource-poor mobile devices with the help of resourceful servers. It allows reduction of energy consumption and makespan by offloading computationally-intensive applications to the cloud. We consider a system consisting of a remote cloud and a network of heterogeneous local processors. We aim to identify the optimal scheduling decision for a mobile application comprising of dependent tasks, such that the total cost is minimized subject to an application deadline. We propose the Communication Augmented Latest Possible Scheduling (CALPS) algorithm to obtain an approximate solution for this NP-hard problem in polynomial time. We also identify a lower bound to the optimal solution and propose techniques to utilize this lower bound solution to obtain improved versions of the CALPS algorithm. Using simulation results, we compare the proposed solution approaches with each other and with existing work.