VictorJuiz/thesis huggingface dataset:
Inkjet Printed Optoelectronic Devices
Keywords: Infrared
Inkjet
IR
Photodetector
Printing
Quantum Dots

This thesis describes the development of efficient, printable infrared detectors using colloidal quantum dot solids. The realization of such devices, that exploit the benefits of solution- processable materials, has so far been hinderered by the complex chemical processing needed to assemble these semiconductor-nanocrystal films. Recent advances in quantum dot processing have simplified processing and produced quality inks that can be deposited in a single step to make high-performance devices. However, reliance on aggressive solvents that damage dot surfaces prevents their use in inkjet-printing. Here I develop a protocol that achieves uniform and smooth quantum dot films via inkjet-printing. I then demonstrate, for the first time, high sensitivity inkjet- printed photodiodes that are tunable from the near to short wavelength infrared. The resulting devices exhibit detectivities of 1.4x1012 Jones, on par with commercial IR detectors. This new, CMOS-compatible process opens the door to the realization of multiwavelength hyperspectral sensors as novel integrated systems.
Methylmercury Cycling at the Aquatic-terrestrial Interface in a High Arctic Freshwater Continuum
Keywords: Arctic
Contaminants
Freshwater
Methylmercury
Seasonality

Methylmercury (MeHg) is a global toxin which bioaccumulates and biomagnifies through food webs. To discern how MeHg enters Arctic food webs, it is important to understand spatial and seasonal cycling of MeHg at the terrestrial-aquatic interface, processes which are sensitive to climate change. This research determined hotspots of MeHg production and degradation in a High Arctic freshwater continuum, and how these processes varied between ice-on and ice-off conditions. Different compartments of the Skeleton Continuum of Lake Hazen, Nunavut were sampled to capture variation in MeHg production and degradation. Examining interconnectedness of the landscape revealed that production hotspots occur in multiple compartments (lake/pond sediments, pore water), yet downstream degradation hotspots and storage (lake water, wetland soils) prevent MeHg from entering the downstream system. Additionally, high MeHg concentrations found in the springtime (water column, snow) solidify the theory that spring freshet is an important source of MeHg to freshwater systems.
Scaling Blockchain Applications with Pub/Sub
Keywords: Blockchain
Pub/Sub

The world of distributed ledger technology(DLT) has been getting signicant attention. Many new applications want to utilize the trustless model and the high consistency guarantees this technology grants. This thesis aims to identify the needs of various business use cases and explores how DLT technology can be adapted to suit these applications. We recognize existing initiatives to adopt certain DLTs with some applications, however, there still exists gaps between these initiatives and production grade solutions. We provide a list of applications that can utilize the features of DLT technology and propose an encompassing structure to facilitate the needs of these applications. Specically, we focus on a DLT-based publish and subscribe system for a subset of the interested applications. We provide the design and rationale behind the technology selection and analyze the relationship between DLT technology and Pub/Sub.
An Integrated Model For Thermal Analysis of an Aircraft Landing Gear Bogie Pivot Pin
Keywords: Finite Element Analysis
Landing Gear
Thermal Modelling

While operating on rough runways, commercial aircraft landing gear may experience overheating issues on the bogie pivot pin. This thesis is an integrated model that generates the landing gear dynamic behaviour and predicts the temperature of the pin. The integrated model consists of four individual components. Built in MATLAB Simulink, the dynamic model outputs the pin rotation angle and the dynamic loading with a given input runway profile and aircraft characteristics. The structural stress model is an ABAQUS finite element analysis model that determines the contact pressure distribution on the pin contact surface at any given dynamic loading. The dynamic variables and the pressure distribution are collected and used in the heat generation model to calculate the frictional heat generation and distribution. Finally, the heat conduction model in ABAQUS performs thermal analysis to obtain the operational temperature of the bogie pivot pin.
Clinical Decision Support Systems for Opioid Prescribing for Chronic Non-cancer Pain in Primary Care Settings
Keywords: Chronic pain
Clinical decision support systems
Complex interventions
Knowledge translation
Opioids
Primary care

This thesis sought to provide an understanding of the potential benefits and possible limitations of clinical decision support systems (CDSS) for opioid prescribing for chronic non-cancer pain (CNCP) in primary care settings. Findings from the scoping review and the exploratory qualitative study indicated few potential benefits and significant limitations. There were few studies and, although some reported that the CDSS led to more appropriate prescribing, they used lower quality designs. None of the studies examined patient outcomes or assessed for unintended consequences. Many had conflicts of interest. Developers did not appear to be using evidence when designing a CDSS. Investigators did not follow guidance for the evaluation of complex interventions. The research also demonstrated barriers to implementation for a specific CDSS we evaluated, including increased work, an interrupted workflow and poor buy-in. Therefore, more research is needed before widespread implementation of CDSSs for opioid prescribing for CNCP in primary care settings.
An Electrochemical Study on the Effect of Pb on Ni, Cr and Ni-22Cr in Caustic Conditions at 75°C and 230°C Relevant to Steam Generator Tubing Materials
Keywords: chromium
corrosion
lead
nickel
nuclear power plant
steam generator tubing

Mechanistic understanding on the corrosive effect of Pb on Ni-Fe-Cr alloys used for nuclear power plant steam generator tubing is uncertain. The purpose of this research was to determine the specific impact of Pb on Ni, Cr and Ni-22Cr in highly alkaline conditions at moderately high temperatures. By utilizing electrochemical techniques, the study analyzed the plating and stripping of Pb on the different metal/alloy substrates. The Pb based equilibrium potential and the limiting current density for Pb plating were determined to be a function of the pH of the environment. Depending on the metal, different degrees of Pb plating may also occur. Pb stripping seems to happen more efficiently on Ni followed by Ni-22Cr then Cr, and this may have implications on activation effects.
Measuring the Construct of Clinical Utility in the Context of Genetic Testing: A Scoping Review
Keywords: Clinical Utility
Scoping Review

Understanding how clinical utility is measured across a range of clinical scenarios can provide strategies for operationalizing this construct, in turn supporting more consistent and robust evaluations of genetic tests. The current scoping review explored the range of outcomes used to measure the value of genetic testing in the literature, spanning 2015-2017. The search strategy and data analysis were guided by the Fryback and Thornbury (F-T) Hierarchical Model of Efficacy. In total, 194 peer-reviewed evaluative studies that used experimental or observational designs were included in this review. Findings herein suggest that additional clinical areas, more robust study designs and novel strategies for measuring the construct of clinical utility are warranted. Additionally, the results suggest refinements to the meaning and content of the domains embedded in the F-T framework. These results can inform future systematic reviews, research design in genetic test evaluative studies and reflections on the concept of clinical utility.
Association of Left Ventricular Ejection Fraction with Mortality and Hospitalization in an Unselected Echocardiographic Cohort of both Ambulatory and Hospitalized Patients
Keywords: echocardiography
ejection fraction
hospitalization
mortality

The prognostic impact of left ventricular ejection fraction (LVEF) in a broad range of patients, including those hospitalized for cardiac or non-cardiac reasons and unselected ambulatory patients has not been fully evaluated. Echocardiography is the most commonly used imaging modality used to assess LVEF given its versatility and availability, however it does have limitations in accuracy. We sought to examine the association between an echocardiographic-derived LVEF and risk of all-cause mortality, cardiovascular mortality and heart failure hospitalization in an unselected consecutive cohort of patients. We performed a retrospective cohort study of patients who underwent echocardiography in three large-scale tertiary healthcare systems in Ontario, Canada between 2007 and 2013 using linked administrative databases. We found that an echocardiographic-derived LVEF was able to stratify risk of multiple outcomes across a diverse spectrum of patient profiles encountered in everyday clinical practice in both ambulatory and hospitalized patients, including those admitted for non-cardiac reasons.
Local Food Networks and the Pursuit of Autonomy: Examining Agricultural Risk Management in Jalisco, Mexico
Keywords: agrarianism
autonomous geographies
local food
Mexico
risk
rural development

The following thesis explores the impact that market structure may have on how small-scale farmers experience and adapt to risk. Through qualitative research within five local food initiatives in Jalisco, Mexico, I explore the particular risks that producers perceive as being most serious, as well as the strategies used within these markets to mitigate those risks. I argue that many of the adaptive choices that farmers use to stabilize their own livelihoods are enabled by distinct features within direct-to-consumer markets, suggesting that market structure plays a key role in determining the production options available to farmers. In further exploring the politics and material practices used within local food initiatives, I introduce the concept of ‘autonomous food geographies’ to highlight those strategies used to develop institutional contexts within which farmers are able to exert greater control over their own livelihoods.
Eulerian-based Moment Methods for the Modelling of Polydisperse Liquid Sprays
Keywords: liquid sprays
maximum entropy
moment closures

A polykinetic, polydisperse spray model has been developed based upon the anisotropic Gaussian moment closure in velocity space. The Gaussian moment closure presents many desirable properties such as hyperbolicity and realizability, and can be used to describe disperse phase sprays of moderate Stokes number. Spray droplets of different sizes can be described by taking velocity moments to be functions of a size variable. By transporting additional moments in velocity and size, the parameters describing these functions are obtained. A novel kinetic flux function that uses distributions on bounded domain has been proposed and verified against an existing kinetic flux function as well as the HLLE approximate Riemann solver. A fully kinetic, realizability preserving source term scheme is also developed to handle Stokes' law drag and the d^2-law of evaporation. Numerical results for various zero-, one- and quasi-two dimensional problems demonstrate the ability of the model to capture polydisperse phenomena.
Perceived Professional Roles, Moral Communities, Moral Inclusiveness, and Dentists' Treatment Decisions
Keywords: clinical decision-making
dentist-patient relations
dentists' practice patterns
professional ethics
professional role
social responsibility

This thesis examined the relationships between perceived professional role (PPR), moral inclusiveness (MI), and treatment intensity. A 46-item survey was used to measure dentists’ demographic and professional factors. PPR was measured by visual analog scale and by Likert-type scale questions. MI was measured by Likert-type scale questions. Treatment intensity was measured by case scenarios. Univariate, bivariate and multivariable analyses were performed. Dentists identifying as business people had greater odds of having a high treatment intensity. Dentists with high MI had lesser odds of having a high treatment intensity. Dentists identifying as health care professionals had greater odds of having high MI. These findings have implications for public trust and dentistry’s status as a health care profession.
The Canadian Science Advocacy Movement
Keywords: Reflexive Modernity Theory
Social Movements
War on science

In this study I explore the nature of the disruptive mobilized science that erupted in Canada between 2006-2018. I investigate both the culture of Canadian mobilized science and the larger question of why this movement occured. I draw on data from interviews with event organizers, as well as from an analysis of publicly-available rally speeches. I utilize Ulrich Beck’s reflexive modernization theory to demonstrate that the culture of science advocacy organizers is complex, and includes both elements that align with Beck's vision of a “reflexive science,” and elements that seem to represent its opposite, or what Beck calls “modern science.” Social movement theory supports my finding that the movement drew on a set of different institutions that provided resources and facilitative conditions. Further, I find that an alliance between specific “impact” disciplines, such as environmental and health sciences, is another facilitative condition for mobilized science.
Incipient Behaviour of Flashback in a Lean Premixed Swirl Burner
Keywords: Flashback
Lean Premixed Combustion
Swirl Burner

The dynamics of flame flashback were studied in a lean premixed swirl burner with central bluff-body. A range of conditions with varied flow velocities, inlet temperatures, and hydrogen/methane flow rates were investigated. Intermittent movement of the flame into the feed tube, was found over a range of conditions, with consistent trends as the system moved from stable operation to complete flashback. Statistical analysis of chemiluminescence data showed a strong link between characteristic behaviours of the system, such as the statistical frequency of upstream propagating flame protrusions, and the magnitude of the flashback, independent of the inlet conditions. Effects of conditions on the flashback magnitude and abruptness of transition are described. Existing metrics for predicting flashback were found to be inadequate for describing the observed dynamics. Laser diagnostics revealed only a slight statistical drop in axial flow velocity upstream of the flame, which appeared to strengthen as the flame moved upstream.
Longitudinal Examination of Peripheral Blood Biomarkers in Healthy Athletes: Implications for Concussion
Keywords: Athletes
Blood Biomarkers
Concussion

To fully understand how peripheral blood biomarkers reflect concussion pathophysiology, and can possibly improve clinical acumen, a better understanding of how these “concussion biomarkers” are influenced by factors beyond brain injury is required. This thesis examined how neuroinjury-related and inflammatory blood biomarkers change throughout a competitive season in a cohort of interuniversity athletes. Additionally, potential sex differences and the influence of stress on blood biomarkers were assessed. BDNF, IP-10, MCP-1, IL-8, IL-10, and TNF-α changed significantly between four serial sampling time points across the athletic season. Next, PRDX-6, MCP-1, IL-8, and TNF-α were higher in male athletes compared to female athletes. Finally, MCP-1 and TNF-α were positively associated with physical stress, while BDNF and TNF-α were negatively associated with psychological stress. Researchers should be cognizant of the potential influence of time of athletic season, sex, and the influence of both physical and psychological stress when designing future studies.
Model-free Setting-independent Detection of Dynamic Objects in 3D Lidar
Keywords: Lidar
Lidar Odometry
Object Detection

This thesis presents a model-free, setting-independent method for online detection of dynamic objects in 3D lidar data. We focus on a common type of 3D lidar, spinning-lidars, for which its moving-while-scanning operation must be compensated. Our detection method uses motion-compensated scan alignment and a novel freespace querying algorithm to classify between dynamic (currently moving) and static (currently stationary) labels at the point level. A public dataset and benchmark suitable to evaluate our work did not previously exist due to the difficulty of accurately labelling groundtruth. For a quantitative evaluation, we establish a benchmark with motion-distorted lidar data using an open-source 3D simulator for autonomous driving research. We also provide a qualitative evaluation with real data using a commercially available lidar in driving scenarios. Results show that we can do a reasonable job of labelling each lidar point as either static or dynamic without resorting to a model or application-specific assumptions.
Predictors of Dentists’ Participation in Government Dental Programs and Pro Bono Care: Are There Gender Differences?
Keywords: Dentistry
Gender
Government programs
Pro bono
Public programs

Objectives: To determine factors influencing provision of publicly financed dental care and pro bono care among Ontario dentists and whether there are any gender differences. Methods: Secondary data analysis of a 2012 mail survey using bivariate and multivariable linear regression. Results: Dentists in non-married relationships, with more paediatric patients, and non-owners were more likely to participate in government dental programs. Females that hired someone to complete household chores had practices with a lower percentage of patients on government subsidy. Dentists earning $100-200k/year, of European ethnicity, and internationally-trained were more likely to provide pro bono care. Female dentists earning $100-200k/year, of European ethnicity, and internationally-trained were more likely to provide pro bono care. Recently graduated and older male dentists were reported to provide more pro bono care. Conclusion: Male and female dentists have varying predictors influencing provision of publicly financed dental care and pro bono care.
Pregnancy Outcome after in-utero Exposure to Vitamin B2: A Cohort Study
Keywords: Major malformation
Non-inferiority
Pregnancy outcome
Propensity score matching
Reproductive toxicology
Riboflavin

The Recommended Dietary Allowance (RDA) of vitamin B2 (riboflavin) is 1.4 mg/day during pregnancy. Despite the RDA, many of the pregnant women, who call the teratology information service in Toronto, take high doses of riboflavin. Although excess doses of vitamin B2 seem safe, there are no outcome data about excessive vitamin B2 intake during pregnancy. The objective of this study was to characterize pregnancy outcomes with a main focus on the rate of major malformations in women exposed to > 25 mg/day vitamin B2 during pregnancy. Our study showed that high dose riboflavin intake during pregnancy was non-inferior with regard to the risk of major malformation in the offspring (for the chosen non-inferiority margin of 8%) and secondary negative pregnancy outcomes including spontaneous abortions, therapeutic abortions, preterm births, neonates with low birth weight, small for gestational age and large for gestational age (for the chosen non-inferiority margin of 10%).
A Molecular Simulation Study of the Structure and Self-aggregation of Elastin-like Peptides
Keywords: Elastin
Elastin-like peptides
Molecular dynamics
Nuclear magnetic resonance
Self-aggregation
Structure

Elastin confers elasticity to various vertebrate tissues. Elastin and elastin-like peptides are disordered and undergo temperature-induced phase separation. This thesis focuses on two studies of monomeric elastin-like peptides. In the first study, we combine molecular dynamics simulations, nuclear magnetic resonance, and small-angle x-ray scattering to analyze the structure of an elastin-like peptide containing alternating hydrophobic and cross-linking domains reminiscent of elastin. Simulation and experimental results are consistent in terms of local but not global structural properties. The ability of simulations to generate a high resolution structural ensemble allows more precise determination of structural propensities from experimental observables. In the second study, we use molecular dynamics simulations to investigate the temperature dependence of the structural properties of elastin-like peptides. The structural ensemble is governed by the hydrophobic effect and chain entropy. The results are not consistent with models of elastin’s self-aggregation that involves a structural ordering in monomers with increasing temperature.
The Role of Glycosylation on the Spatiotemporal Organization and Function of B-cell Co-receptor CD22
Keywords: B-cells
CD22
glycosylation
signalling

An important inhibitory co-receptor on B-cells is CD22, a sialic-acid binding protein. CD22 is highly glycosylated with six glycans located in the first two extracellular domains. The cytosolic domain contains ITIMs that upon phosphorylation lead to recruitment of inhibitory phosphatase SHP-1. Proximity of CD22 to B cell receptor (BCR) is required for dephosphorylation of signalling molecules leading to signal attenuation; however, we do not understand what mediates CD22 organization and association to BCRs. Since glycans on CD22 can be terminally sialylated, we hypothesize these glycans facilitate homotypic CD22 interactions, and therefore affect CD22 heterotypic interaction with BCRs. Here, we utilized a N-terminal glycosylation mutant (5Q-CD22) and, using super-resolution imaging, we demonstrate that 5Q-CD22 displays increased clustering and closer association to IgM BCR compared to WT-CD22. Importantly, abrogation of these glycans leads to loss of CD22 function, as ITIM phosphorylation upon B-cell activation is decreased and consequently BCR signalling is enhanced.
Acute Kidney Injury in Patients Receiving Systemic Treatment for Cancer: A Population-based Cohort Study
Keywords: Acute Kidney Injury
Cancer
Dialysis
Nephrology
Systemic Treatment
Toxicity

Background: Patients undergoing cancer treatment are at increased risk of acute kidney injury (AKI), but there are few data on incidence and risk factors. Methods: Population-based study of patients initiating systemic therapy for new cancer diagnoses in Ontario, Canada (2007-2014). The primary outcome was hospitalization with AKI or acute dialysis. Results: We identified 163,071 patients, of whom 10,880 experienced AKI. The cumulative incidence of AKI was 9.3%. Malignancies with highest 5-year AKI incidence were myeloma (26.0%), bladder (19.0%), and leukemia (15.4%). Advanced cancer stage, chronic kidney disease (CKD), and diabetes were associated with increased risk. In patients age ≥66, diuretics and angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEi/ARB) were associated with higher risk. Annual incidence of AKI increased from 18 to 52 per 1000-PY. Conclusion: Cancer-related AKI is common and associated with advanced stage, CKD, diabetes, diuretics and ACEi/ARBs. Strategies are needed to address the increasing burden of AKI in this population.