VictorJuiz/thesis huggingface dataset:
Ammonium’s Impact on Phase Changes in Urban Grime
Keywords: Ammonium
Atmospheric Chemistry
Nitrate
Phase Change
Urban Grime

Urban grime is a mixed organic-inorganic film that develops on impervious surfaces that allows partitioning of trace atmospheric species from the gas phase. Its chemical composition and physical properties vary, but nitrate and sulfate are always present. Our group recently reported rapid photochemistry of nitrate deposited on films, where the product formation rate depends upon ambient relative humidity. Nitrate’s physical state in grime may affect its photochemistry. Raman spectroscopy was used to differentiate between solid and solution-phase nitrate and sulfate while measuring various mixtures of NaNO3, (NH4)2SO4, Na2SO4, CaCl2, on vacuum grease under dried and humidified conditions, to explore phase changes in a grime-like environment. In the presence of (NH4)2SO4 or CaCl2, nitrate displays a solution-like spectrum even in dried samples. Due to the importance of ammonium’s presence to the phase of nitrate, we performed experiments that monitor evolution of gas phase ammonia from illumination of ammonium-containing proxy grime samples.
Measurement of Turbulent Boundary Layer Induced Surface Pressure Fluctuations
Keywords: Aeroacoustics
Turbulent boundary layer
Wall-pressure

The turbulent boundary layer (TBL) noise generated inside an aircraft can have a detrimental impact on humans. In an effort to better understand TBL physics and measurement techniques, measurements of the fluctuating wall-pressure beneath a TBL have been performed in an anechoic wind tunnel. The measurements were made using an array of pressure microphones provided by Bombardier Aerospace. Analysis of frequency spectra indicated several shortcomings of the array, namely a low saturation limit and electrical issues, however the low speed spectra agree well with the Goody prediction model. Furthermore, an investigation of the relationship between wall-pressure and velocity fluctuations was performed using a pinhole mounted microphone and simultaneous hot-wire boundary layer measurements. This revealed flow interference from the hot-wire apparatus, obscuring the expected relationships and trends. Several areas of improvement have been identified, including higher saturation limit microphones, LDA for velocity measurements, and increasing rigidity of the experimental setup.
Using Paired Associative Stimulation and Cortical Silent Period to Examine Neural Plasticity in Healthy and Depressed Youth
Keywords: Cortical Silent Period
Developmental Plasticity
Neural Plasticity
Paired Associative Stimulation
Transcranial Magnetic Stimulation

Background: Major depressive disorder (MDD) is a disorder that typically arises in youth. MDD may results from impaired neural plasticity that can be probed and treated with transcranial magnetic stimulation (TMS). Methods: We evaluated the feasibility of using two common TMS measures, paired associated stimulation (PAS) and cortical silent period (CSP), in youth. PAS and CSP are thought to index NMDA- and GABA-B dependent plasticity, respectively. Results: In our first experiment, we examined 34 healthy adolescents aged 13-19. We found that PAS induced motor cortical plasticity at 15- and 30-min post-PAS. PAS also lengthened CSP in males but not females. In our second experiment, we applied PAS and CSP to a case series of 6 depressed adolescents aged 16-24 and found that both measures were feasible, safe, and tolerable in this population. Conclusions: PAS and CSP are feasible, safe, and tolerable TMS indices of neural plasticity in youth.
Hereditary Breast Cancer in Selected Populations: Screening RECQL Gene in Ontario, Canada, and Exploring BRCA1/2 and PALB2 in the Caribbean
Keywords: BRCA1/2
Caribbean and Ontario
Hereditary breast cancer
Mutations and breast cancer risk
PALB2
RECQL

Hereditary breast cancer (i.e., cancer due to an inherited mutation) is imperfectly understood: while 5 to 10 % of breast cancer is hereditary, only 50 % of breast cancer susceptibility has been explained. Increased hereditary breast cancer understanding fosters high-risk patient identification, prevention, early diagnosis, and targeted treatment. To achieve increased knowledge of the hereditary breast cancer landscape, both generation of new information and implementation of prior knowledge in new settings are required. Accordingly, this project had two goals: Firstly, we screened RECQL, a new susceptibility gene candidate, among Ontario breast cancer patients. Secondly, we examined three established genes – namely, BRCA1, BRCA2, and PALB2 – among breast cancer patients in Trinidad and Tobago and Jamaica. Overall, we found that further work was needed to validate RECQL in a heterogeneous population, and that Caribbean screening and prevention could be ameliorated by the inclusion of certain susceptibility genes on gene panels.
The Impact of the Mount Polley Tailings Pond Failure on the Sedimentary Record of Quesnel Lake, British Columbia
Keywords: lakes
Mount Polley
sedimentation
turbidity current

The Mount Polley tailings pond failure that occurred on August 4, 2014 provided an opportunity to understand the effects of point-source sedimentation events in the sedimentary record. Six sediment cores that were taken at both distal and proximal locations in Quesnel Lake (B.C.) were used to identify if turbidity currents or subaqueous debris flows were generated. Geotechnical (grain size and LOI), mineralogical and copper metal concentrations confirmed the presence of turbidite deposits in four cores. All of these turbidites contained a coarser-grained base and an uppermost fine-grained cap. Two out of the four turbidite deposits that were most proximal to the spill mouth contained mixed basal layers that may signify the energy of the current at that depth. Sediment is focused in the deepest part of the basin. The spill sediments will compress over time but will represent sedimentation rates at 4-5 orders of magnitude larger than Holocene natural rates.
Detection of Cystic Fibrosis Transmembrane Conductance Regulator ∆F508 Gene Mutation Using a Paper-Based Nucleic Acid Hybridization Assay and a Smartphone Camera
Keywords: cystic fibrosis
digital imaging
fluorescence
oligonucleotides
paper
quantum dots

Diagnostic technology that utilizes paper substrates and device cameras offers opportunities for development of cost effective point-of-care technologies. The translation of assays operating in aqueous solution require further development for implementation in paper substrates. This report presents and compares two methods for determination of oligonucleotides that serve as indicators of Cystic Fibrosis, differentiating wild type and mutant type sequences containing a 3-base deletion. The transduction strategy operates by selective hybridization of dye-labelled oligonucleotides (target or reporters) to capture probes immobilized on quantum dots, and hybridization results in emission of dyes via resonance energy transfer. Detection is based on hybridization of fluorophore labelled target, or hybridization of unlabelled target and labelled reporter in a sandwich assay format. Selectivity to determine mismatched sequences required control of stringency conditions using formamide as a chaotrope. It was determined that both formats can distinguish between wild type and mutant type samples on paper substrates.
The Body Triad, Whiteness and Agency: The Not-So-Sporty Experiences of Punjabi-Canadian Women
Keywords: body
physical activity
Punjabi-Canadian
racism
South Asian
whiteness

This thesis explored the physical activity (PA) experiences of 18 Punjabi-Canadian women living in the Greater Toronto Area. It argues that the choice not to participate in PA is an act of agency reflective of the pressures placed on the women. The theoretical frameworks used were the centrality of women’s bodies in social and cultural reproduction, whiteness and critical race theory. The methods used were focus groups coined “chai and chats.” Results revealed that the “Body Triad,” a term I coin, consisting of the “Fat Body,” “Skinny Body” and “Muscular Body” and the dominance of whiteness in Canada impacted the women’s decision to not participate in PA. As a result, the women negotiated these pressures by talking back, “feeling blessed” and challenging existing gendered and racial assumptions about their bodies. This study showed the relationship between gender, immigration and whiteness where Punjabi-Canadian women’s bodies were central to the discussion.
The Community of CrossFit: An Ethnographic Inquiry
Keywords: crossfit
exercise
health
physical cultural studies
sport sociology

CrossFit has only recently emerged in the sporting landscape and has already developed a massive following. The program is part sport, part exercise system, and is known for its unconventional approach to fitness which combines high intensity exercises with functional fitness, all performed in a group setting. Creating a community is one of the largest claims of the organization and is accredited with much of the positive experiences that keep members coming back. This thesis uses ethnographic data (participant observation and ethnographic) interviews to explore the dynamic of community in one CrossFit box. Findings suggest that CrossFit is best theorized as a community of practice and that studying physical cultures through the framework of community is an effective method to study physical culture by accounting for multiple variables including; personal relationships, autonomy, conflict, and more, amongst members of the group.
Shomeric Islands: Youth Forming Critical Pedagogies in the New Millennium
Keywords: collaborative inquiry
community education
critical pedagogy
local transformation
social movements
youth leadership

This research engages Toronto youth in explorative discussions on the educational community framework of the Hashomer Hatzair socialist Jewish youth movement, as an approach to critical pedagogy conducted by and for young people. Employing a practitioner inquiry methodology, the study positions movement members as insiders and knowledgeable practitioners of their common context who engage with central questions related to education and social organization, including raising critically equipped leaders with a drive to incite change. Presented as a multilayered narrative that weaves together community dialogues, the study begins with an illustration of the movement’s modal features, and subsequently documents reflections among Hashomer Hatzair youth educators on their work to move beyond existing arrangements of educational practice in the modern neoliberal era. Findings reveal the significance of centring youth and others from the periphery as seasoned critical partners in fostering local change and resistance.
Cavopulmonary Assist Device to Bridge Failing Fontan Circulations
Keywords: Cavopulmonary Assist
Computational Fluid Dynamics (CFD)
Fontan
Hemolysis Index

A novel cavopulmonary assist strategy with a multi-lumen cannula powered by an external centrifugal pump is proposed for use in failing Fontan patients. Steady-state computational fluid dynamics simulations are used to characterize hemodynamic performance in an idealized and two patient-specific Fontan pathway models for a wide range of cardiac outputs and pump intake flows, while further transient simulations are conducted for one of the patient-specific models with a periodic cardiac output and coupled to a Windkessel model. Simulations show that the proposed cannula can provide sufficient pressure gain required for cavopulmonary assist. A rigid 3D printed cannula prototype is also tested inside a mock circulation loop. Improvements in mean Fontan pressures from a typical failing circulation occurred at certain flow cases with cannulated assist while venous return flows were altered significantly in the presence of the cannula.
The influence of assessor training on scoring and feedback: A qualitative study of assessor perceptions
Keywords: Assessment
Assessors

Assessor training is essential for defensible assessments of physician performance. This study explored the perceived influence of training and assessment tools on assessors’ conduct of assessments. Using a constructivist grounded theory approach, we interviewed 13 assessors about the effects of training and scoring tools on their conduct of assessments. Participants reported that training taught them about the potential variability of assessor judgement and prompted more reflective scoring. Using the new scoring tools reportedly led participants to sample performance data differently, choose ratings in accordance with the scoring tools, and provide more detailed feedback to assessed physicians. Participants did not perceive training or the tools to substantially affect their numeric ratings, but noted an increased confidence in scoring. Participants involved in developing the tools reported more pronounced effects of training and the tools. These findings support the continued study of assessor training programs as a method of enhancing assessor consistency.
Synthesis and Characterization of Small Molecule Dysregulators of the Bacterial ClpP Protease
Keywords: ACP
Caseinolytic protease P
ClpP
E. coli
N. meningitidis
Phosphorous

Caseinolytic protease P (ClpP) is a protease highly conserved in bacteria and eukaryotes. With an ATPase partner, it functions to maintain protein homeostasis and regulated elimination of folded proteins. Without its ATPase partner, bacterial ClpP can only degrade small peptides. Recently, Activators of Self-Compartmentalizing Proteases (ACPs) were discovered, using a high-throughput screen, that activate the protease in the absence of its ATPase partner. Co-crystal structures with E. coli ClpP showed ACPs bind in two configurations. Improving on initial hits and to completely fill the binding pocket, 16 new phosphine oxide-based compounds (ACP6) were synthesized and investigated for their ability to enhance the ClpP peptidase activity. Several of the ACP6 analogs showed increased activity against E. coli ClpP compared to the initial ACPs. This work showed that a new class of compounds can also activate bacterial ClpP and can be pursued as chemical leads for the development of antibiotics.
SPORADIC: An Anytime Architecture for Intermittent Computing
Keywords: Approximate Computing
Energy Harvesting
Intermittent Computing

Energy-harvesting is an emerging computing paradigm that allows systems to run solely off energy harvested from their environment. However, these systems are subject to frequent and unpredictable power outages. Ensuring forward progress under such circumstances is crucial. Energy-harvesting applications are typically amenable to approximation. We propose SPORADIC, a set of anytime approximation techniques: Subword pipelining, Subword vectorization and Skim points. Subword pipelining and Subword vectorization decompose data words so that they can be processed as subwords, sequentially from most to least significant. Skim points fundamentally decouple the checkpoint location from the recovery location upon a power outage. SPORADIC transforms the processing on energy-harvesting devices from all-or-nothing to as-is computing. We find that under frequent power outages, SPORADIC yields speedups of 2.16× and 3.02× on non-volatile and checkpoint-based volatile processors, while still producing high-quality outputs.
Characterization of the Microbial Community in a Sequentially Fed Anaerobic Digester Treating Solid Organic Waste
Keywords: Anaerobic Digestion
Candidate Division WS6
Clostridium butyricum
Microbial Community
Organic waste

A lab-scale solid phase anaerobic digester of novel design that treats organics waste was operated at for 88-weeks at the University of Toronto. Characterizing the microbial community inside the digester enables fundamental understanding of the system performance and operational limits. The microbial community was characterized through amplicon sequencing and correlated with operating parameters such as, biogas production rate. Clostridium spp. and organisms from Candidate Division WS6 were the two most dominant bacterial phylotypes and Methanobacterium and Methanoculleus were the two most dominant archaeal phylotypes. A direct relationship between the population of Clostridium spp., proportion of food waste, and biogas production rate was found while Candidate Division WS6 showed better adaptability to fibre rich substrate conditions. Shortened hydraulic retention time of leachate affected the microbial community. Shifts in dominant hydrogenotrophic methanogen spices were observed when HRT was decreased. Clostridium spp. were largely responsible for the enhanced “synergistic” biogas production from fibers.
Investigating the Effects of Automated Vehicle Driving Operations on Road Emissions and Traffic Performance
Keywords: Automated vehicles (AV)
Driving behaviour
Emission modelling
Greenhouse gas (GHG) emissions
Traffic microsimulation
Traffic operations

Automated vehicles (AV) will inevitably have an impact on the movement of people and goods. Assessing the effects of AVs on land use, congestion and the environment have become of great interest to researchers. This study explores the effects of AVs and vehicle electrification on greenhouse gas emissions using traffic microsimulation and emissions modeling. The driving behaviour parameters of a traffic simulation package, most relevant to AVs, are tested within the ranges deemed to be representative of potential AV operations. The effects of AVs are evaluated under both uninterrupted and interrupted traffic flow operating environments, as well as under high and low traffic demand. The main findings indicate that automated vehicles can bring positive changes in terms of emission and traffic flow performance. The significance of the impacts is more evident when AVs are tuned to more aggressive driving settings and especially under high traffic conditions in uninterrupted flow operations.
The Physician Trainee Environment and its Associated Effects on Trainees and their Patients
Keywords: Patient care
Physician trainee environment
Survey
Trainee learning
Trainee wellbeing

Introduction: The physician trainee’s work and educational environment impacts patient care and trainee learning and is understudied. Methods: A cross-sectional survey of trainees at a paediatric hospital evaluated learning, patient care, and adverse trainee events (crashes, needlestick injury, inappropriate personal comments, assaults or threats). Results: Completed surveys described 132 trainee months and 101 duty periods; 49 (37 %) respondents reported an adverse trainee events. Learning was rated median (IQR) of 6 (5-7) on a 10-point scale. Patient care was rated 4 or more in a 5-point scale by 93%. Multivariable analyses found staff supervision and attendance at education sessions independently associated with increased learning. Trainee adverse events were associated with seniority and working fewer nights. Conclusion: Preliminary distribution shows questions are understood, a modest distribution of safety responses, and few positive relationships, in this single center pilot. Future iterations in multiple centers can evaluate these questions further.
Indoor Environmental Quality in Social Housing: review, thermal comfort and odour control
Keywords: Indoor Air Quality
Social Housing
Thermal Comfort

In this work, I explored the indoor environmental quality (IEQ) in social housing, and also discussed the indoor pollution associated with the operation of sources of scents that may be common in these units. I found that public housing residents may be disproportionally exposed to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and pesticides. I also found that poor thermal comfort conditions are prevalent in social housing, mostly due to excess heat. Lastly, I found that incense and ultrasonic oil diffusers, which are commonly used to produce pleasant scents indoors, generate considerable amounts of PM2.5. Considering the negative health effects associated with poor IEQ conditions, my results suggest that minimizing sources of pollution and improving comfort conditions should be prioritized in any retrofits planned in social housing developments, as similar improvements have been found to be effective in improving occupant health and reducing exposure to pollutants.
A Qualitative Investigation of the Mental Health Needs of Syrian Refugees and Immigrants
Keywords: immigrants
mental health
psychological
refugees
social support
Syrian

The mental health of Syrian refugees has become extremely important for refugee and mental health scholars worldwide. A scoping review of 14 publications was conducted to synthesize current findings on this issue, which displayed a gap in understanding Syrian coping strategies and well-being. A qualitative investigation was done to explore the mental health perceptions and related resources of Syrians that migrated to Canada both before and after the war. Thirty semi-structured interviews were conducted with Syrian immigrants, 15 non-refugees and 15 refugees. The purpose was to investigate perspectives on mental health, resilience, and desired or received services. Study findings showed refugees’ mental health was affected by traumatic events and their resettlement process. Non-refugees expressed feelings of sadness because their homeland has been destroyed. All participants sourced social support as extremely helpful in their lives and was preferred over professional help. These findings can help develop appropriate mental health resources.
Laboratory and Analytical Study of Shattering Jelly Roll Smelt
Keywords: Jelly Roll Smelt
Pulp and Paper
Recovery Boiler
Smelt Shattering
Viscous Liquid Atomization

During kraft chemical recovery, smelt created in a recovery boiler is shattered into droplets before falling into a dissolving tank. Although a rare occurrence, highly viscous smelt is created when the smelt temperature is close to the smelt freezing temperature, so-called jelly roll smelt. The viscosity of jelly roll smelt is estimated as between 10^4 to 10^5 cP. In this research, a laboratory study was conducted and an analytical model was developed to study the shattering of such highly viscous smelt. The study shows that an increasing viscosity undermines the shattering effectiveness by delaying the complete breakup of the liquid stream, and creating large droplets. The analytical model is based on the physics of co-axial atomization, and is shown to fit the lab scale droplet size distribution very well. Given the shattering conditions, the model appears able to estimate the droplet size distribution and maximum shatterable viscosity.
Caffeinated FPGAs: FPGA Framework for Training and Inference of Convolutional Neural Networks With Reduced Precision Floating-Point Arithmetic
Keywords: Convolutional Neural Network
FPGA
Inference
Low Precision
Training

This thesis presents a framework for performing training and inference of Convolutional Neural Networks (CNNs) with reduced precision floating-point arithmetic. This work aims to provide a means for FPGA and machine learning researchers to use the customizability of FPGAs to explore the precision requirements of training CNNs with an open-source framework. This is accomplished through the creation of a High-Level Synthesis library with a Custom Precision Floating-Point data type that is configurable in both exponent and mantissa widths, with several standard operators and rounding modes supported. With this library a FPGA CNN Training Engine (FCTE) has been created along with a FPGA CNN framework FPGA Caffe, which is built on Caffe. FCTE has a peak performance of approximately 350 GFLOPs, and has been used to show that a mantissa width of 5 and exponent width of 6 is sufficient for training several models targeting the MNIST and CIFAR-10 datasets.