VictorJuiz/thesis huggingface dataset:
Design and Synthesis of Phosphonate-based Multidentate Polymeric Ligands for Improving Optical and Colloidal Stability of Upconverting Nanoparticles
Keywords: polymer coatings
surface modification
upconverting nanoparticles

Lanthanide-doped upconverting nanoparticles (UCNPs) have shown great potential in the field of biomedical research, including the areas of drug delivery, bioimaging and theranostics. However, major challenges still remain for the preparation of biologically compatible UCNPs owing to their susceptibility to surface quenching and poor colloidal stability in aqueous media. Herein, we proposed a surface modification strategy that employs phosphonate-based polymeric ligands to provide NaYF4:Yb,Er nanoparticles with the long-term optical and colloidal stability required for biological applications. Specifically, UCNPs were coated with poly(isobutylene-alt-maleic anhydride) (PIMA) copolymer consisting of different phosphonate anchoring groups and polyethylene glycol (PEG) blocks at varying ratios. A series of mono-, di- and tetraphosphonate-PIMA-PEG ligands were designed and synthesized, and the effect of these ligands on the optical properties and colloidal stability of UCNPs were investigated in both water and 1X PBS solution.
The Role of Inflammation in the Development of Behavioral Changes and Seizure Susceptibility After Experimental Traumatic Brain Injury
Keywords: Behavioral Changes
Inflammation
Lipopolysaccharides
Minocycline
Seizure Susceptibility
Traumatic Brain Injury

The robust inflammatory response following traumatic brain injury (TBI) can be both beneficial and detrimental. This study directly compares the effects of increasing or decreasing TBI-related inflammation on behavioral outcome and seizure susceptibility. Fluid percussion injury was induced in four groups of young adult male Sprague- Dawley rats: 1) sham injury; 2) TBI; 3) TBI with minocycline; 4) TBI with lipopolysaccharide (LPS). Rats underwent a series of behavioral tests including composite neuroscores, rotarod, novel object recognition and Barnes maze at various time points within the first month post-injury. Approximately nine months after injury, a subset of rats from each group was subjected to a pentylenetetrazol – induced seizure test. Decreasing inflammation by minocycline ameliorated increased seizure susceptibility in injured rats. Upregulating inflammation with LPS did not modify the seizure susceptibility. Both minocycline and LPS revealed mixed effects on behavioral outcomes. Findings suggest a dual role of inflammation after TBI.
Classification of Respiratory Physiology with Airwave Oscillometry using Multi-layer Perceptron
Keywords: airwave oscillometry
artificial intelligence
clinical application
machine learning
pulmonary function test

Airwave Oscillometry(OSc) is a novel pulmonary function test with the advantages of effort independent operation and high sensitivity to heterogeneous lungs over conventional tests. However, OSc results are high dimensional without well-established interpretation guideline, posing challenge for clinician’s understanding and limiting its clinical utility. While recent advances in Multi-layer Perceptron (MLP), a machine learning model that has proven capability of complex pattern recognition and classification, this thesis proposed to automate OSc output classification using MLP. We have compared the performance of MLP classifying OSc patterns with different number of hidden layers, investigated the effects of training sample size and input selection on the performance of the classification. The classification performance varied with training-validation division and output categories. We found that MLP with hidden layers outperformed MLP without hidden layer and the highest validation accuracy was 82% for binary classification of respiratory physiology with OSc data using a 2-hidden-layer MLP.
Dynamic Memory Allocation Techniques for High-level Synthesis
Keywords: Algorithms and Data Structures
Dynamic Memory Allocation
High-Level Synthesis

The omission of support for several software-defined constructs within High-Level Synthesis (HLS) have hindered it’s broad adoption. Dynamic memory allocation is one feature that is not within the traditional supported subset. This works expands the synthesizable subset of the C languages for HLS tools, by including dynamic memory allocation algorithms (i.e. malloc and free). We define a variety of high-level synthesis approaches to support malloc and free. We first provide a library of HLS-friendly allocation algorithms, libmem, which is studied for performance and area impacts. We also define a framework to improve the performance and area of dynamic memory allocation mechanisms in HLS applications. Our framework employs a variety of dynamic and static program analyses to identify the required size of the heap memory space, parallelize dynamic memory allocators and save precious on-chip BRAM. We evaluate our work with a variety of benchmarks, and demonstrate the usefulness of including dynamic memory allocation within HLS.
Connection Building, Narrative Sharing, and Diverse Knowledge: Survivor Healing Desires
Keywords: assault
consciousness
feminism
gender based sexual violence
healing
trauma

Canadian Women’s Foundation (2016) asserts women are ten times as likely to experience sexual assault compared to men, gender based violence the only crime not declining (p. 1). Statistics Canada’s (1993) most detailed data found nearly 40 percent of Canadian women will be sexually assaulted after 16 years old, estimating only 10% report (p. 24) and only accounting for one variation of sexual violence; the number of women who experience this larger concept of victimization is likely higher. Mental health adversities can develop post-trauma; working past these experiences is of the utmost importance. Reflecting on available literature, my experiences, and qualitative interviews with six survivors in northern Ontario, it was found survivors value: 1) building connections, 2) narrative sharing, and 3) diverse knowledge. Literature on feminist principles, personal experiences of healing through a feminist awareness, and the three findings in this study suggest feminist principles may assist survivors in healing.
Testing Catalysts for their Activity and Sulfur Tolerance under Simulated Smouldering Environment
Keywords: Catalyst
Reinvent the Toilet Challange
Smouldering
Sulfur poisoning

Catalysts are frequently used to treat exhausts from automotive vehicles and chemical industries but their ability to treat emissions generated from the incineration of human waste is still unexplored. Three catalysts were examined in this thesis: 0.5% Pt/Al2O3 by Alfa Aesar, 0.5% Pt/Al2O3 by Hulteberg Group and 2%Pt-La2O3/25% ZrO2 -75% SiO2 by Riogen Inc. The results show that the three catalysts survived 4h of exposure to simulated smouldering effluent gas compositions. Propane and carbon monoxide oxidations after 12 h of accelerated poisoning conditions showed an increase and decrease in catalytic activity, respectively. Upon regeneration, the Riogen zirconia supported catalyst showed nearly complete reversal of decreases in sulfur-poisoning induced CO activity, while only partial reversal was seen for the two alumina supported catalysts. Lastly, adsorption and desorption studies showed that much more sulfur dioxide was desorbed from the zirconia-based catalyst than alumina-based catalysts - consistent with activity reversal observations.
Exploring the Course of Symptom and Functional Needs among Patients Experiencing a First Episode Psychosis using the Ontario Common Assessment of Need
Keywords: early psychosis intervention
first episode psychosis
needs assessment
OCAN

Current measures of functioning that use global scores may overlook important needs that do not improve over the course of treatment in early psychosis intervention (EPI) services, requiring item level analyses. This thesis investigated changes in symptom and functional needs over the course of treatment and factors associated with met need using Ontario Common Assessment of Need (OCAN) data from EPI services in Ontario. OCAN assessments were obtained for 156 patients. Need status was assessed at admission and at 12 to 15 months post-admission for psychotic symptoms need and two functional needs, daytime activities and company. The proportion of patients with met/no need increased over time for each need, although findings were only statistically significant for functional needs. The strongest predictor of met/no need at follow-up for each need was baseline met/no need status. The OCAN is a useful tool to help EPI services target interventions to improve functional outcomes.
Understanding Machine Learning Classifier Decisions in Automated Radiotherapy Quality Assurance
Keywords: applied machine learning
automated radiotherapy quality assurance
explanatory machine learning

The complexity of the radiotherapy planning demands a rigorous quality assurance (QA) process to ensure patient safety and to avoid irreversible errors. Machine learning classifiers have been explored to augment the scope and efficiency of the traditional QA process. However, one important gap in relying on the treatment planning QA classifiers is the lack of understanding behind a specific classifier prediction. We examine the topic of interpretable machine learning, and apply appropriate post-hoc model-agnostic local explanation methods to understand the decisions of a regions of interest (ROIs) segmentation/labeling classifier as well as a plan acceptance classifier. For each classifier, a local interpretable model-agnostic explanation (LIME) framework and a team-based Shapley values framework are constructed. LIME framework approximates the predictions of the underlying classifier around the locality of a specified instance with an interpretable linear model, so the explanations are obtained from inspecting the feature weights. Team-based Shapley values framework explains the classifier decisions by calculating the average marginal contribution of each feature group across all coalitions of feature groups for a specified instance. The results demonstrate the importance of evaluating QA classifiers using interpretable machine learning approaches, and show that both QA classifiers are moderately trustworthy and can be used to confirm the expert decisions. The results also suggest that the current version of the QA classifiers should not be viewed as a replacement for human QA process.
Holocene Winter Paleoclimate Reconstructions from Ice-Wedge Archives in the Northwestern Canadian Arctic
Keywords: High-Latitude
Holocene
Ice Wedges
Marine Aerosols
Water Isotopes

Ice wedges, a direct cold-season precipitation archive, capture a season rarely represented in Arctic paleoclimate proxy records. This thesis utilizes Holocene ice wedges from the Tuktoyaktuk Coastlands (Beaufort Sea coast) to i) develop a winter temperature record from ice-wedge stable water isotopes (δ18O and δD), and ii) to explore the potential of marine aerosol contributions to ice-wedge ion geochemistry to inform past sea ice conditions and paleogeography. A long-term increase in water isotopes from ~7,400 to ~640 yr b2k indicates increasing winter temperatures, following increasing winter insolation at 69°N. Likewise, an increase in the sea-salt component of the major ion record from ~4,600 to ~640 yr b2k may indicate increasing open water conditions in the Beaufort Sea or decreased continentality of the study site. This research supports the potential of ice wedges to provide insight into winter climate dynamics in Arctic regions where glacial ice-core records are unattainable.
Use of Activity Trackers to Count Steps of the Older Emergency Department Patient: A Feasibility, Validity and Reliability Study.
Keywords: Activity Trackers
Emergency Department
Feasibility
Mobility
Older Adults
Validity

Background: Walking is an every-day, multipurpose form of mobility. Decreasing mobility levels are reported in older hospitalized patients, but quantitative assessment of such mobility is needed. This study aims to assess the performance of accelerometer-based activity trackers; with specific application to evaluating the feasibility, validity and reliability of accelerometer-based activity trackers when measuring steps of older ED patients. Methodology: A systematic review of the literature was conducted to find the most valid and reliable trackers including research-grade and consumer devices. A prospective, observational study was conducted using 3 trackers to assess the feasibility and validity of measuring step count of older adults in the ED. Results: Forty participants (97.5%, 74.6 years, 41% females) wore the trackers during their ED stay. The Fitbit Zip® showed the best performance with an ICC of 0.83. Conclusions: The use of activity trackers is feasible and valid for capturing mobility of older ED patients.
The Endothelial Barrier is not Rate-limiting to Insulin Action in the Myocardium
Keywords: cardiac vasculature
endothelial permeability
insulin transport

Diabetes is characterized by the impaired function of the pancreatic hormone insulin. The exit of insulin from the capillaries requires its passage across endothelial cells. Whether the endothelium acts as a rate-limiting barrier to insulin transport is controversial.We hypothesized that if the endothelial barrier is rate-limiting to insulin transport, then increasing endothelial permeability will accelerate insulin action on downstream tissues. To address the question, we developed a murine ex vivo aortic perfusion model which delivers insulin to the heart. We demonstrated that despite conditions that significantly increased cardiac vascular permeability, insulin action was not accelerated. These data indicate that the endothelial barrier is not rate-limiting to insulin action in the myocardium. Efforts to decrease insulin resistance should focus on downstream tissues or regulation of blood flow rather than the transendothelial transport of insulin.
Feeling through Food: Examining Experience and Exclusion within Alternative Food Movements in Parkdale, Toronto
Keywords: Alternative food systems
Embodiment
Emotional geographies
Exclusion
Political ecology
Sense of place

This thesis questions the role and relevance of alternative food movements by analyzing resident perspectives, emotions, everyday experiences and embodiment of food. Building on studies of exclusion and privilege in alternative food systems, the case study emphasizes emotions, resident perspectives and experiences to examine the success, or lack thereof, of alternatives in Parkdale, Toronto. The Political Ecology of the Body framework is used to analyze interconnections between structural forces, knowledge production, and relational ontology in alternative food systems, the neighbourhood food environment, and Parkdale. The thesis argues that exclusion is felt and embodied in alternative food spaces, decreasing the relevance to everyday food decisions. Furthermore, residents’ associations between place, gentrification and (alternative) food venues influence which spaces are felt to (not) serve community needs and threatens sense of place, reinforcing how exclusion is embodied and situated with the neighbourhood food system.
Simulating the Use of High Altitude, High Endurance Drones for Wildfire Monitoring
Keywords: drones
fire monitoring
travelling salesman problem

The threat of wildfire in Canada will increase as climate change results in weather conditions that are more conducive to fire ignition and spread, and as more Canadians decide to spend time in and near our forests. To improve fire management, wildfire agencies must consider the adoption of new tools and processes such as pseudo-satellite unmanned aerial vehicles (UAVs). Using solar energy, these UAVs can theoretically remain stratospheric for months. With an appropriate thermal imaging system, these UAVs could be an asset for earth observation. To determine their fire monitoring potential, daily fire monitoring problems were created, and the shortest route observing all fires was found by solving integer linear programming problems (ILPs). These optimal routes were modelled as Traveling Salesperson Problems (TSPs) and solved using IBM’s CPLEX solver. A simulation of fire seasons using historic data was facilitated by Python and CPLEX to evaluate the performance of these UAVs.
Water Security and Access to Basic Services: Assessing Urban Vulnerabilities in the Global South
Keywords: basic services
global south
slums
urban infrastructure
urban vulnerability
water security

Spatial and social inequalities among residents represent major vulnerabilities to urban resilience. In this thesis, inequalities in access to basic infrastructure and distribution of urban resources are assessed in the Global South context. First, 122 studies on slum infrastructure are reviewed and the most frequently assessed quantitative indicators determined. Access to municipal services is among the most prevalent indicators. Then, the challenge of basic services provision in 2030 is scoped for six developing cities. Large investments or conservation efforts are expected to be required, especially for waste collection and water provision. Finally, a district-level urban water security framework is developed and applied to six case studies. The results show that water insecurity tends to increase from the city-centre to its periphery. Water insecurity also shows a strong negative correlation with income. The quantitative information and insights provided here can aid in planning of more equitable and resilient cities.
The Rate of Hemorrhagic Transformation and Safety of Antithrombotic Therapy in Pediatric Cardioembolic Arterial Ischemic Stroke
Keywords: Antithrombotic Therapy
Cardioembolic Arterial Ischemic Stroke
Congenital Heart Disease
Hemorrhagic Transformation
Pediatric Arterial Ischemic Stroke

Antithrombotic therapy (ATT) is currently recommended for stroke prevention in pediatric cardioembolic arterial ischemic stroke (CE-AIS). Rates of hemorrhagic transformation (HT) in pediatric CE-AIS are unknown. This single-center retrospective study of CE-AIS in children evaluated factors associated with HT to explore the relationship between ATT, HT and clinical outcome. Eighty-two children met inclusion criteria [male 44 (54%); neonates 23 (28%); median age 0.43 years (0.08 – 4.23)]. HT occurred in 20 of 82 children (24%), 5 (6%) of whom had symptomatic intracranial hemorrhage. Four (5%) had major systemic hemorrhage. HT was not associated with antiplatelet vs. anticoagulant use nor combination therapy. Children with univentricular physiology were less likely to have HT [10% vs. 90%; p=0.03] and had higher rates of recurrent stroke, prior to definitive cardiac repair, despite receiving ATT. However, the risk-benefit ratio of ATT remains unknown in the context of each primary cardiac diagnosis and warrants further study.
An Analysis of Latent Class Mixed Models in Severe Hemophilia A
Keywords: Hemophilia
Joint Damage
Latent Class Modelling
Prophylaxis

The primary objective was to assess if heterogenous patterns of joint damage exist within severe hemophilia A. We assessed whether age at first joint bleed, blood type, mutation type, trough level and treatment adherence could significantly predict group membership. We conducted a latent class mixed modelling analysis to determine how many heterogenous groups existed within the cohort. We used the Bayesian Information Criterion, classification quality and clinical utility to determine which was the best fitting model. A multinomial logistic regression was used to predict the odds of class membership. We identified three distinct classes; persistent low, moderate increasing and rapidly increasing joint scores. Using a multinomial regression model, we found that only age at first joint bleed predicted membership into class three, relative to class one. Using knowledge of disease trajectories, researchers can tailor the treatment of hemophilia A to best accommodate predicted prognosis and provide cost effective solutions.
Stochastic Slope Stability Analysis Accounting for Heterogeneity in Rock Mass
Keywords: Heterogeneity
Limit equilibruim
Rock mass
Slope stability
Spatial model
Stochastic

Rock mass heterogeneity could influence the stability of open pit slope. As such, slope stability approach that accounts for rock mass heterogeneity could provide an efficient slope design. This thesis proposes and implements stochastic modelling approach that characterizes the spatial variability of geomechanical properties to evaluate the stability of pit slopes in an iron ore open pit mine. 3D spatial models of geomechanical properties are developed to quantify the heterogeneity of the rock mass and to identify potential risk of pit wall failure by accounting for the influence of joints orientations with respect to the pit wall. The block models of the geotechnical attributes were then embedded as input into a discretized 3D limit equilibrium model to conduct stochastic heterogeneity stability analysis of the pit slopes. The modeling results is used to determine the probability of pit wall failure at different pit sectors which enables optimization of pit slope design.
The Health Burden and Direct Health Care Costs of Acute Isolated Upper Extremity Trauma in Ontario
Keywords: hand trauma
health economics
health services research

Acute hand and wrist trauma, a top reason for emergency department (ED) visits internationally, is an understudied public health issue in Canada. This research sought to characterize the burden of isolated hand, wrist and specific proximal upper extremity trauma (UET) in Ontario, Canada using linked administrative healthcare data between 2006-2016. Study one identified that UET in adults age 18-65 is the most common reason for ED visits (incidence rate: 211/10,000 person-years). Repeated episodes represented 24.8% of all ED visits, creating a large burden of preventable visits. Study two estimated the three year attributable cost (AC) of surgical UET using an incidence-based propensity score matched cohort study. The estimated AC of severe UET was $7519.80 and $8528.90 at one and three years, respectively. The AC translates into approximately $36 million annually for surgical UET, which accounts for only 2.5% of all episodes, indicating a substantial burden created by the entire cohort.
Cyberattacks Against Power System Synchronization Systems
Keywords: Cyber-physical systems
cyberattack
microgrid
power system restoration
synchronization systems

Synchronization systems play a vital role in the day-to-day operation of power systems as well as their restoration after cascading failures. Hence, their resilience to cyberattacks is imperative. In this paper, we demonstrate that a well-planned false data injection cyberattack against the synchronization system of a generator is capable of tripping it and may cause subsequent instability and blackout. Moreover, we present the analytical framework behind the design and implementation of the cyberattack. Afterwards, we propose an eﬀective, cyber-resilient mitigation strategy for synchronization systems which is based on adding a limiter to the synchronization control loop. The notion of cyberattacks against synchronization systems is veriﬁed for a microgrid using SIMULINK and OPAL-RT real-time simulator.