VictorJuiz/thesis huggingface dataset:
Estimating Air Pollution with Regulatory Monitors and Supplementary Data from Low-cost Sensors and Remotely Sensed Imagery

This thesis has two main objectives: assessing the accuracy of long-term air pollution concentration estimates produced from portable monitoring campaigns, using temporal adjustments; and second, developing spatial models of air pollution concentrations with remotely sensed imagery and machine learning within a land use regression framework. Objective one was achieved by simulating mobile monitoring campaigns and estimating long-term concentrations with multiple temporal adjustments. The results indicated that sample size greatly influenced the accuracy of long-term estimates produced with temporal adjustments and that adjustments which accounted for the log-normal distribution of air pollution observations produced more accurate estimates. Objective two was achieved through the development of annual and seasonal models for NO2 and PM2.5 at three study sites. The results showed that deep learning models were the most accurate however these models could not capture spatial patterns of air pollution from the spectral signature of the land use surrounding monitors.

Keywords: Air Pollution
Exposure
GIS
Advisor: Adams, Matthew D
Image Based and Biomechanical Characterization of Osteoblastic Vertebral Metastases

The negative consequences of fracture in the metastatic spine motivates improved bone quality assessment and fracture risk prediction. This study aims to automate preclinical microcomputed tomography (µCT) image identification of osteoblastic metastatic disease in vertebrae, characterize how metastases affect the material/mechanical properties of bone tissue and extend finite element (FE) modeling to include pathological changes to evaluate damage and fracture behaviour. A combination of image analysis techniques (µCT-based stereological analysis, back scatter electron microscopy) and computational modeling (voxel-based µFE modeling of post-yield mechanical behaviour experimentally validated through sequentially imaged mechanical testing) is used to characterize the structural and material level impact of osteoblastic disease in vertebral trabecular bone. Methods for automated segmentation of osteoblastic lesions are also developed with µCT feature extraction and random forest classification methods to enable identification of pathologic tissue. Advanced preclinical understanding of osteoblastic disease can provide a foundation for improved guidelines for clinical treatment decision-making.

Keywords: Machine Learning
Micro Computed Tomography
Micro Finite Element Modeling
Spine Biomechanics
Vertebral Metastasis
Advisor: Whyne, Cari
Enhancing Cognition by using Low-cost In-home Portable Sleep Equipment: A Feasibility Study

Obstructive sleep apnea (OSA), which causes pauses in breathing during sleep, increases the risk of developing cognitive impairment. In-laboratory polysomnography (iPSG) is the gold standard to diagnose OSA, but few patients are screened by iPSG due to refusal to spend a night in a sleep laboratory. Home sleep apnea testing (HSAT) may be a more accessible alternative, as it is simple to use, conveniently administered in a patient’s own home, and validated against iPSG. This study investigated the feasibility and practicality of using HSAT in cognitively impaired clinic patients and assessed the prevalence and factors associated with OSA. HSAT was found to be feasible and practical to assess for OSA. OSA was also prevalent in this population. As OSA is a modifiable risk factor for patients with cognitive impairment, HSAT has the potential to lead to expedited treatment for OSA, which may potentially improve health-related outcomes such as cognition.

Keywords: Ambulatory
Cognitive Impairment
Dementia
Feasibility
Home Sleep Apnea Test
Obstructive Sleep Apnea
Advisor: Boulos, Mark I
Black, Sandra E
Sex Specific Selection by a Parasitoid on Body Size in its Newly Recognized Host

We identified the tree cricket Oecanthus nigricornis (Orthoptera; Gryllidae) as a host species used by the parasitoid fly Stylogaster neglecta (Diptera: Conopidae). We describe several life history aspects of the parasitoid-host interaction including: the identification of a host, timing of parasitism, estimates of incubation time, preferred life stage of host, and variance in rates of parasitism across space. We also examined size biases in parasitism amongst crickets to determine if there is selection on body size. We found that there was a significant effect of sex, whereby males are more likely to be parasitized than females, and an interaction between the square of body size (non-linear selection) and sex. Upon examining the effect of body size individual for each sex, we found that in males, there was positive linear selection on body size and positive non-linear selection on body size, indicating higher parasitism in smaller and intermediate sized crickets.

Keywords: Parasitoids
Selection
Sex
Advisor: Gwynne, Darryl T
Characterization of the Teneurin C-terminal Associated Peptide (TCAP) and Latrophilin Ligand-receptor Pair in an Immortalized Skeletal Muscle Cell Line

Teneurin C-terminal associated peptide (TCAP) is an ancient and conserved bioactive peptide that is evolutionarily related to corticotropin releasing factor (CRF). Recently, synthetic TCAP-1 was shown to increase cellular energy availability and alter contractile performance in rodent skeletal muscle. However, the exact receptor signalling mechanism through which this occurs is unknown. Based on evidence of their interaction in vitro, we hypothesized that TCAP-1 signals through latrophilins—a family of Adhesion G-protein coupled receptors—to elicit its effects in muscle. To test this, I knocked-down and knocked-out latrophilins in the immortalized mouse myoblast C2C12 cell line by small interfering RNA (siRNA) and CRISPR/Cas9 gene editing methods, respectively, and examined the efficacy of TCAP-1 in knockdown and knockout cells. We determined that latrophilin-1 is necessary for TCAP-1-mediated increases in intracellular calcium, NADH turnover, and PGC-1a expression. This establishes, for the first time, that the TCAP-latrophilin ligand-receptor pair has a functional role in skeletal muscle.

Keywords: Latrophilin
Receptor Signalling
Skeletal Muscle
TCAP
Teneurin
Advisor: Lovejoy, David A
Transit Access to Subsidized Food Stores in the American Midwest

In the United States, low-income and racial minority populations have higher rates of diet-related disease, food insecurity, and transit use. SNAP, which provides low-income households with money for groceries at authorized retailers, creates an altered food procurement environment. How transit networks affect access to SNAP retailers is assessed by calculating transit travel times to all transitable SNAP stores of neighborhoods in 33 MPOs in the American Midwest. Low-income, Black, Hispanic, and public assistance populations, which are disproportionately affected by food insecurity, living in neighborhoods with low transit access scores are then identified. These neighborhoods are compared to USDA low-income, low-access neighborhoods. Results indicate low transit access is experienced in fringe-urban, majority white, car-dependent neighborhoods. However, 117,460 Black people, 121,589 Hispanic people, and 89,185 low-income people live within these neighborhoods. Future research and policy should target suburban and exurban regions to accommodate a non-negligible portion of potentially food insecure populations.

Keywords: Food Environment
SNAP
Transit Access
Transport Poverty
Advisor: Widener, Michael J
Modelling of 3D Printed Fiber-reinforced Plastic Composites by Classical Laminate Theory

Fused filament fabrication (FFF) is a rapidly growing 3D printing technology in which molten plastic is extruded to build an object layer-by-layer. Although it is mostly used for prototyping, the use of fiber-reinforced thermoplastics (FRP) may enable FFF 3D printed parts to be used in load-bearing applications. The objective of this study was to confirm that the stiffness of FFF 3D printed FRPs can be predicted, based on the raster orientation, using Classical Laminate Theory (CLT), and to use the model to improve the mechanical properties of 3D printed parts. With simple characterizations of the in-plane properties, CLT accurately predicted the elastic moduli of various 3D printed composite laminates and sandwich panels in tensile, flexural, and torsional loading modes. Before this study, CLT had not been validated for FFF 3D printed FRPs. CLT can be used to help designers tailor the raster pattern of each layer for specific stiffness requirements.

Keywords: 3D printing
Classical Laminate Theory
composite laminate
fiber-reinforced plastic
Fused filament fabrication
sandwich panel
Advisor: Kortschot, Mark T
Data-driven Investigation of Factors Affecting Surface Transit Speed and Reliability in Toronto

Cities are increasingly interested in implementing low-cost, small-scale spot treatments to improve transit performance. This research uses a data-driven approach to understand where and why poor transit performance occurs, which is necessary when selecting locations to treat and their appropriate treatments. Automatic vehicle location, general transit feed specification, and ride check data are used to generate a descriptive analysis measuring performance of eight high-frequency bus routes in Toronto at the route, segment, stop, and intersection levels. Clustering and regression models of transit performance at intersections along these routes are developed to determine which features most affect bus speeds and delays. These analyses show that locations with greater traffic cycle split have significantly higher speeds and lower delays, and thus signal timing adjustments are suggested as an effective transit-priority spot treatment. The analyses also suggest queue jump lanes and turning restrictions to be effective when signal timing cannot be adjusted.

Keywords: Clustering
Delay
Improvements
Speed
Transit
Advisor: Shalaby, Amer
Development and Modelling of an Aeration Control System for Precision Aquaculture

Dissolved oxygen is an important parameter of water quality in aquaculture. Aeration has been known to improve oxygen levels and yields, but its use is uncommon in many developing world environments due to high costs. As a more effective implementation, this thesis presents the use of a feedback diffused aeration control system to maintain adequate oxygen levels and increase energy savings. To demonstrate the potential, a model was developed to describe the interaction between the aerator and the pond and to predict the oxygen profiles of the water. Time-series simulations were performed to estimate the potential savings for a pond in Bangladesh, with and without the use of a feedback system. Results showed that the use of a control system led to an average of 66.0% in energy savings. Field validation experiments indicated an average prediction error of 3.64% and 4.91% for the top and bottom layers of the pond.

Keywords: Aeration
Aquaculture
Computational Fluid Dynamics
Control Systems
Dissolved Oxygen Modelling
Advisor: Bilton, Amy
Narratives of Down Syndrome: Representations of Intellectual Disability in Children's Storybooks

This thesis investigates how we can engage with intellectual disabilities in a deeper, more relational way through the cultural artefacts of children’s storybooks. Using primarily a disability studies framework and informed by childhood studies, I map and reflect on how dominant relationships with intellectual disability, such as medicine and education, define Down syndrome and intellectual disabilities as developmental problems. My application of disability studies seeks to disrupt notions of disability as being only a medical or educational problem. This project offers a way of understanding Down syndrome in a sociocultural context (Karmiris, 2017; Titchkosky Michalko, 2009; Titchkosky, 2001, 2003, 2007, 2011; Mitchell Snyder, 2015; Michalko, 2002; Weiss, 2015). I comment on how adult-centred representations of Down syndrome re-produce adult-centred expectations of all children. Furthermore, disability studies offers a nuanced account of how ableism might originate in the very institutions that claim to address the “problem” of Down syndrome.

Keywords: Childhood Studies
Disability Studies
Down Syndrome
Representations
Storybooks
Advisor: Titchkosky, Tanya
Capacity Planning and Scheduling of a Nursing Resource Team NRT)

A Nursing Resource Team (NRT) is a pool of nurses hired by the hospital to provide on-demand support for understaffed units. Similar to regular nurses, the schedule for NRT nurses must be posted weeks in advance which poses a challenge with respect to scheduling nurses under uncertainty of demand during a planning horizon of multiple weeks. We formulate the problem of determining the optimal number of NRT nurses, and their allocation to different shifts of a planning horizon as a stochastic program. Under the assumption of known demand distributions, the problem can be solved using an integer programming solver. Since demand distributions are not known in practice, we propose a simple heuristic solution for the problem that only requires average demand information and evaluate its performance using numerical experiments. Finally, we present a case study of our proposed approach using data from the NRT of the Scarborough Centenary Hospital.

Advisor: Sarhangian, Vahid
Carter, Michael
The Relationship Between Maintenance and Manipulation Components of Working Memory and Prefrontal and Parietal Brain Regions in Bipolar Disorder

Working memory has been found to be impaired across mood states in bipolar disorder. Working memory is delineated into separate components, maintenance and manipulation, where manipulation is involved in higher-order cognitive processes. No study to date has used a task differentiating the components of working memory and associated them with underlying structural brain regions in bipolar disorder. Therefore, this study aimed to examine behavioral visuospatial working memory performance and structural brain indexes in prefrontal and parietal regions in 26 bipolar patients and 24 controls. Bipolar patients were less accurate on the working memory task, without a greater deficit in the manipulation condition. Moreover, bipolar patients had thinner cortices in the prefrontal and parietal regions, areas associated with working memory. Thicker cortices in the prefrontal regions were associated with greater maintenance accuracy in bipolar patients and a thicker parietal cortex was associated with faster manipulation response times in controls. Keywords: bipolar disorder, visuospatial working memory, maintenance, manipulation, structural neuroimaging

Keywords: Bipolar Disorder
Maintenance
Manipulation
Structural Neuroimaging
Visuospatial Working Memory
Advisor: Goghari, Vina M
Using a Novel Conflict Paradigm to Understand the Role of the Medial Temporal Lobe in Approach-avoidance Conflict Decision-making and Outcome Uncertainty

The anterior hippocampus (aHPC) has been implicated in processing approach-avoidance (AA) conflict. Previous paradigms have utilized stimuli that comprise of spatial or context features and elicit both conflict and uncertainty. Therefore, it is unclear whether the aHPC is recruited when decontextualized objects are used and to which specific type of information the hippocampus is sensitive. To address these questions, the current study used a novel paradigm to directly compare the effects of conflict and uncertainty on AA behaviour while participants underwent functional magnetic resonance imaging (fMRI). Participants’ behavioral responding was driven by conflict as opposed to uncertainty and high AA conflict was associated with perirhinal cortex but not aHPC activity, which is consistent with the notion of stimulus specificity within the medial temporal lobe. Importantly, there was no interaction between conflict and uncertainty suggesting that medial temporal lobe involvement during AA decision-making is driven by conflict rather than uncertainty.

Advisor: Lee, Andy
Goghari, Vina
Optimal Energy Management and Storage Sizing for Electric Vehicles

Battery degradation reduces the performance and lifetime of electric vehicles (EVs). Us- ing energy storage devices with dierent characteristics alongside the battery can mini- mize degradation while ensuring that the storage system is always able to satisfy driving demands. However, this introduces the additional complexity of designing the devices and controlling them in real-time. In this thesis, we rst provide a computationally tractable method to optimally manage power sharing between dual energy storages using approximate linear programming (ALP). We furthermore propose a problem to deter- mine the optimal sizes of the two storages that allows a trade-o between vehicle range and other costs associated with increased storage size. We validate our approaches on a real EV design. Numerical results show that our energy management controller allows for optimal power-sharing with tunable approximation in the number of basis vectors of the ALP, and that our sizing procedure provides a design with locally minimal cost.

Keywords: Approximate dynamic programming
Batteries
Electric vehicles
Energy storage
Markov Decision Process
Supercapacitors
Advisor: Taylor, Joshua A
Integrated Analyses of Stress and Recovery Responses in Poplar

Efficient responses to environmental change are important for long-lived plants, like trees. We investigated how Populus balsamifera responds to two distinct but related abiotic stresses - osmotic and ionic stress – during acute perturbation and recovery. Based on a pilot experiment and photosynthetic characteristics, one genotype (AP4326) was investigated in greater detail. Responses during the initial phases of both stresses indicated some degree of tolerance. Response patterns in growth and stomatal behavior, diverged as the stress progressed and were even more pronounced during recovery, allowing to discriminate osmotic and ionic effects. Exposure to 150mM NaCl was identified as a critical threshold with 50% survival rate, thus contributing to our understanding of response capacities of P.balsamifera. Soil elemental analyses provided insights into soil conditions experienced under ionic stress. These findings will enhance our understanding of plasticity and survival in trees and will be useful for informed planning of plantations or reclamation efforts.

Keywords: Abiotic stress
Drought
High salinity
Poplar
Advisor: Braeutigam, Katharina
The Relationship between Life Satisfaction and Hospitalizations for Ambulatory Care Sensitive Conditions: A Population Cohort Study

Life satisfaction (LS) has been shown to be inversely related to negative health outcomes such as morbidity and mortality. Ambulatory care sensitive conditions (ACSC) are conditions for which timely and effective outpatient care can prevent acute episodes. This study is a prospective population-based cohort study of adults from Ontario that tests the hypothesis that poor life satisfaction is associated with an increased risk of avoidable hospitalizations. Weighted distributions of demographic, socioeconomic, health status and behaviour characteristics according to ACSCs and life satisfaction were calculated. Proportional hazards models associated with baseline life satisfaction were used to calculate the risk of preventable hospitalizations. Joint effects models were used to see if socioeconomic status (SES) modified this relationship. Men, the elderly and those with lower household income were more likely to be hospitalized with an ACSC. After controlling for age, sex, SES, and lifestyle factors, poor LS had a strong relationship with hospitalizations for ACSCs (HR = 2.42, p

Keywords: ambulatory care sensitive conditions
happiness
hospitalizations
life satisfaction
population health
Advisor: Rosella, Laura
Using CRISPR/Cas9 to Identify Gene Interactions with Hexosamine Biosynthesis and N-Glycan Remodeling Pathway Enzymes

Genetic studies by classical mutagenesis and screening methods have revealed many molecular interactions and regulatory relationships in animal models. The hexosamine biosynthesis pathway and N-glycosylation are upregulated in most cancers and have shown to play a role in many cancer cell phenotypes. In this thesis, a CRISPR/Cas9 genome-wide targeted mutagenesis approach was employed to identify gene interactions with chosen genes-of-interest from these two pathways: NAGK, GFPT1, MGAT1 and MGAT5. The gene interactions identified suggest relationships between our genes-of-interest and cell-cell adhesion, cytoskeleton, and folate and nucleotide metabolism. Further characterization of metabolite levels in the gene-of-interest knockout cells was done to help understand potential gene interactions from the screen. For example, metabolic imbalance in mutant cells likely indicates cell stress and reactive oxygen species, consistent with PRDX1, an antioxidant, being a suggested genetic interactor in multiple screens. These findings provide new insight on vulnerabilities and genomic redundancies in cancer cells.

Keywords: Cancer
Genetics
Metabolism
Advisor: Dennis, James W
Improving the Hearing Status Discrimination of the Health Utilities Index, Mark 3

Health state utility measurement is pivotally important to cost-utility analyses. The Health Utilities Index, Mark 3 (HUI3), like other generic instruments, has content limitations that threaten the validity of its utility estimates for hearing-impaired health states. The Hearing attribute of the HUI3 was redesigned to better characterize the abilities and disabilities of individuals with hearing loss. Items were generated though systematic literature review, expert focus groups, and patient interviews. Importance of items to individuals with hearing loss guided domain selection and design. The novel HUI Hearing attribute classifies hearing status according to 7 sub-attributes: speech, environmental sounds, sound localization, listening effort, tinnitus, music, and assistive hearing devices. It has substantially improved content validity for hearing-impaired health states compared with existing utility instruments. HUI-Hearing is a comprehensive health status classification system that aims to facilitate appropriate health resource allocation through accurate discrimination of health states important to patients with hearing loss.

Keywords: Health economics
Health-related quality of life
Health technology assessment
Hearing loss
Measurement
Utility
Advisor: Krahn, Murray D
Simulation-based Validation of Harmonic-constrained Optimal Power Flow

In modern grids, the increasing penetration of renewable sources requires the integration of power electronic converters. However, the nonlinear characteristics of those converters will introduce voltage and current harmonics, which decrease power quality, overload transformers, cause vibrations in generators and motors, and increase grid losses. Therefore, it is necessary to analyze power system models with harmonics. In this thesis, optimal power flow with constraints on total voltage harmonic distortion is simulated. OpenDSS is used to validate the solution of harmonic-constrained optimal power flow. Numerical tests on two IEEE feeder systems demonstrate the accuracy of the approach.

Keywords: Energy Systems
Frequency Coupling Matrix
Harmonic Power Systems
Optimal Power Flow
Advisor: Taylor, Joshua Adam