VictorJuiz/thesis huggingface dataset:
Characterizing Impinging Jet Noise with Applications to Recovery Boiler Sootblowing

In Kraft pulp mill recovery boilers, sootblowing is a method that uses highpressure steam jets to remove deposit buildup from the heat exchanger network. Deposit continually builds up and leads to severe fouling that causes mill shutdowns. A recording environment was developed to obtain information on the noise produced by jets in various situations representative of sootblowing. The results collected demonstrated the effects of several variables on the jet noise. Increases in the jet velocity were found to produce more turbulence, which led to an increased production of noise. The distance between the jet nozzle and impinging object, as well as the object’s shape, size, and roughness, were responsible for noticeable changes in the jet noise produced. Thus, it is suggested that boiler fouling would be detectable with acoustic monitoring. Furthermore, using characterizations obtained in the results, the approximate deposit size, shape, and roughness can be estimated for improved monitoring.

Advisor: Wong, Willy
Association of Left Ventricular Ejection Fraction with Mortality and Hospitalization in an Unselected Echocardiographic Cohort of both Ambulatory and Hospitalized Patients

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.

Keywords: echocardiography
ejection fraction
hospitalization
mortality
Advisor: Lee, Douglas S
High-speed SAR ADC Design in SiGe BiCMOS Technology

This thesis investigates architectures and design techniques for high-bandwidth SAR ADCs in SiGe BiCMOS technology to be used in 64 GBaud fibre-optic systems. First, a 6-bit SAR ADC operating with the highest sampling rate of 3 GS/s was designed and characterized in a 55nm SiGe BiCMOS process. The circuit achieved an ENOB larger than 3.8-bits at 3.0 GS/s, and larger than 4.3-bits at 2.5 GS/s. The ADC consumes 70mW resulting in a FOM of 1.326 pJ/conversion at 2.5 GS/s. Next, a novel SAR architecture was developed and integrated in a time-interleaved, 6-bit, 64GS/s SAR ADC. It uses the same 55nm process, and a total of 16 SAR lanes. Simulation results demonstrate over 4-bits ENOB up to a 19GHz input signal, and up to 3.6-bits ENOB at 31GHz. The ADC power consumption is 1.57W, resulting in a FOM of 2.07 mW/bit/GHz.

Advisor: Voinigescu, Sorin P
Local Food Networks and the Pursuit of Autonomy: Examining Agricultural Risk Management in Jalisco, Mexico

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.

Keywords: agrarianism
autonomous geographies
local food
Mexico
risk
rural development
Advisor: Isakson, Ryan
Eulerian-based Moment Methods for the Modelling of Polydisperse Liquid Sprays

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.

Keywords: liquid sprays
maximum entropy
moment closures
Advisor: Groth, Clinton P. T.
Perceived Professional Roles, Moral Communities, Moral Inclusiveness, and Dentists' Treatment Decisions

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.

Keywords: clinical decision-making
dentist-patient relations
dentists' practice patterns
professional ethics
professional role
social responsibility
Advisor: Quiñonez, Carlos R
The Canadian Science Advocacy Movement

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.

Keywords: Reflexive Modernity Theory
Social Movements
War on science
Advisor: Delfanti, Alessandro
Incipient Behaviour of Flashback in a Lean Premixed 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.

Keywords: Flashback
Lean Premixed Combustion
Swirl Burner
Advisor: Steinberg, Adam M.
Longitudinal Examination of Peripheral Blood Biomarkers in Healthy Athletes: Implications for 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.

Keywords: Athletes
Blood Biomarkers
Concussion
Advisor: Hutchison, Michael G
Mechanical Analysis of Short Fiber Composites Manufactured by Inverted Stereolithography

Additive manufacturing, or “3D printing”, is a rapidly expanding technology that produces components with complex geometry using computer aided design software. Unfortunately, an intrinsic lack of mechanical properties inhibits 3D printed parts from being used in many load bearing applications. In this study, glass fibers were introduced to reinforce an acrylic resin to increase the elastic modulus of inverted stereolithography (ISLA) printed specimens. The elastic modulus of the resultant short glass fiber composites increased with increasing fiber content, up to 10 vol% fiber addition. However, flow induced fiber alignment caused the high aspect ratio reinforcements to orient transversely to the applied load. This significantly limited the contribution of the fibers to the overall modulus of the composite. A variety of flow diversion techniques were implemented, but the ISLA workflow did not produce a fiber reinforced part that had a superior elastic modulus to that of existing particle reinforced composites.

Advisor: Kortschot, Mark T
Characteristics of Patients with Severe and Non-severe Permanent Tooth Trauma Presenting to a Pediatric Hospital Emergency Department Over a Five-year Period

Purpose: To describe trends and characteristics of patients with severe and non-severe permanent tooth trauma who presented to the emergency department (ED). Methods: A retrospective chart review over a five-year period was conducted. Results: A general decline in presentation of patients with non-severe permanent tooth trauma was noted at a rate of 10.7% per year (p

Advisor: Barrett, Edward J
Model-free Setting-independent Detection of Dynamic Objects in 3D Lidar

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.

Keywords: Lidar
Lidar Odometry
Object Detection
Advisor: Barfoot, Timothy David
Predictors of Dentists’ Participation in Government Dental Programs and Pro Bono Care: Are There Gender Differences?

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.

Keywords: Dentistry
Gender
Government programs
Pro bono
Public programs
Advisor: Quinonez, Carlos
Pregnancy Outcome after in-utero Exposure to Vitamin B2: A Cohort Study

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%).

Keywords: Major malformation
Non-inferiority
Pregnancy outcome
Propensity score matching
Reproductive toxicology
Riboflavin
Advisor: Ito, Shinya
A Molecular Simulation Study of the Structure and Self-aggregation of Elastin-like Peptides

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.

Keywords: Elastin
Elastin-like peptides
Molecular dynamics
Nuclear magnetic resonance
Self-aggregation
Structure
Advisor: Pomès, Régis
The Role of Glycosylation on the Spatiotemporal Organization and Function of B-cell Co-receptor CD22

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.

Keywords: B-cells
CD22
glycosylation
signalling
Advisor: Treanor, Bebhinn L
Acute Kidney Injury in Patients Receiving Systemic Treatment for Cancer: A Population-based Cohort Study

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.

Keywords: Acute Kidney Injury
Cancer
Dialysis
Nephrology
Systemic Treatment
Toxicity
Advisor: Kim, S. Joseph
Wald, Ron
RanBP2 Regulates the Translation of the IL6 Reporter and Nuclear mRNA Export of Reporters Containing a 5’ Splice Site Motif

Previously, a sequence element resembling a consensus 5’ splice site (5’SS) motif was found to function as a nuclear retention element when found in the 3’ untranslated region (UTR) of the fushi taratsu (ftz) reporter mRNA. I have identified RanBP2 as one of the protein factors that is involved in the nuclear retention of 5’SS-containing transcripts such as ftz. Mutations in RanBP2’s N-terminal region confer genetic risk for the pediatric neurological disease called acute-necrotizing encephalopathy (ANE1). ANE1 patients experience pathological cytokine protein production after flu infection. RanBP2 has previously been found to translationally regulate mRNAs encoding for secretory proteins. I have now shown that RanBP2 can repress the translation of the IL6 reporter mRNA, which is one of the secreted cytokine proteins aberrantly up-regulated in ANE1 patients. I’ve shown that RanBP2 requires the let7 miRNA binding site within the IL6 3’UTR to carry out this translational regulation.

Keywords: ANE1
IL6
miRNA regulation
mRNA export
mRNA translation
RanBP2
Advisor: Palazzo, Alexander F
Elucidating the Roles of H3K4 Methyltransferases in Caenorhabditis elegans Small RNA Pathways

Endogenous small RNA pathways utilize several classes of small RNAs to direct gene regulation, both in the cytoplasm at the post-transcriptional level and in the nucleus at the transcriptional level. One mechanism of small RNA/AGO-mediated transcriptional regulation is the alteration of histone modification profiles, which thereby alters chromatin conformation and accessibility of gene promoters to the transcriptional machinery. Defects in components of nuclear endogenous RNAi pathways, such as AGOs, have been shown to lead to heritable changes in the distribution of histone methylation in Caenorhabditis elegans and other organisms. However, the mechanism by which small RNA pathways regulate histone methylation is not well understood. I investigated the mechanism by which small RNA pathways affect and engage with H3K4 methylation pathways in C. elegans. While I did not uncover effects on H3K4 methylation or roles for H3K4 methyltransferases in epigenetic resetting or heritable silencing of an RNA interference target, this study has revealed a previously uncharacterized putative histone methyltransferase as an H3K4 methyltransferase.

Keywords: Epigenetics
H3K4
Histone methylation
Histone methyltransferase
Small RNA pathways
Advisor: Claycomb, Julie M
Psychiatric Utilization Prior to Cancer Diagnosis: Implications for Survival Outcomes and Suicidal Death Among Incident Solid Organ Cancer Patients

Background: A cancer diagnosis is associated with psychiatric morbidity. I assessed the impact of pre-cancer psychiatric utilization (PU) on cancer-specific mortality (CSM), and the effect of cancer on suicidal death. Methods: Solid-organ cancer patients were assigned a PU gradient (PUG) score, 0 – none; 1 – outpatient; 2 – emergency department; 3 – admission. A multivariable cause-specific hazard model (CSHM) assessed the effect of PUG score on CSM. To assess the effect of cancer on suicide, patients were matched to non-cancer controls and compared using marginal CSHM. Results: Compared to PUG 0, PUG 1 patients had increased risk of CSM (HR 1.05, 95%CI 1.04-1.06), as did PUG 2 (HR 1.36, 95%CI 1.30-1.42) and 3 (HR 1.73, 95%CI 1.63-1.84). Cancer patients were more likely to die of suicide than controls (HR 1.34, 95%CI 1.22-1.48). Conclusions: Pre-cancer PU is independently associated with worse CSM. A cancer diagnosis is associated with increased suicide risk compared to controls.

Keywords: Cancer
Oncology
Psychiatric Utilization
Psychiatry
Advisor: Kulkarni, Girish S