VictorJuiz/thesis huggingface dataset:
Integer and Stochastic Programming Approaches to Scheduling Nursing Staff at Long-term Care Homes

We study nurse scheduling problems for long-term care homes motivated by a collaboration with the City of Toronto Long Term Care Homes Services (LTCH) division. The current scheduling process at the LTCH division is time-consuming and the absenteeism rates are high among part-time nurses. First, we formalize a complex set of seniority requirements, incorporate nurse preferences into the scheduling process, and propose a hierarchical optimization procedure to generate schedules which maximize demand fulfillment and the preferences of the nurses. We develop a spreadsheet-based scheduling tool to automate the generation of schedules and discuss the results and challenges of an implementation at a large care home in Toronto. Second, we propose a stochastic version of the model which explicitly accounts for the uncertainty introduced by absenteeism. We investigate solution methods for the proposed model and find that the resulting schedules can lead to a considerable reduction in the absenteeism rate.

Keywords: integer programming
long-term care
nurse absenteeism
nurse preferences
nurse scheduling
stochastic programming
Advisor: Sarhangian, Vahid
Bodur, Merve
Characterizing the Hospital Burden of Diabetic Foot Ulcers Across Canada: A Population-Based Analysis

The burden of diabetic foot ulcers (DFUs) on the Canadian healthcare system remains poorly defined. First, the accuracy of diagnostic coding for identifying a DFU-related hospitalization was assessed (Study 1). Second, three case-control studies were conducted using Canada-wide DFU-related hospitalizations. In Study 2A, DFU cases comprised the top-10% with the highest acute care hospital costs, and DFU controls were from below the top-10%. Studies 2B and 2C similarly defined cases/controls, but for acute length of stay and number of hospitalizations, respectively. Patient-level variables were tested between DFU cases vs. DFU controls. In Study 1, DFU diagnosis codes showed high prediction compared to hospital records. Sepsis and chronic kidney disease (CKD) conferred the greatest excess cost (Study 2A), whereas lower limb amputation (LLA) and peripheral artery disease (PAD) conferred the greatest excess length of stay (Study 2B) and recurrent hospitalizations (Study 2C), respectively. Early prevention/treatment of CKD, PAD, and LLA might reduce DFU-related high-intensity hospital care use.

Keywords: diabetic foot ulcers
epidemiology
health services
population-based analysis
Advisor: Al-Omran, Mohammed
de Mestral, Charles
GAC Caps as a Potential Treatment Barrier for Drinking Water Cyanotoxins

Incorporation of GAC in media filtration is a useful means for improving treatment outcomes via adsorption and subsequent enhanced biological treatment. Although beneficial, complete GAC replacement often results in higher operational costs. A seven-month pilot study examined the benefits of replacing the top few centimeters of anthracite media with GAC “caps” to enhance control of a cyanotoxin as well as organics. Removal of the cyanotoxin cylindrospermopsin by GAC adsorption was assessed utilizing a surrogate dye. A GAC capped filter demonstrated higher reduction when compared to a control throughout the study period. However, increased operational time resulted in lower reduction. While installation of a GAC cap increased biomass density (ATP), it did not improve DOC or DBP FP removal. Chlorine demand was significantly reduced, representing a potential side-benefit. This study presents evidence that incorporation of GAC caps can provide a low-capacity barrier for cylindrospermopsin exposure over multiple months of continuous operation.

Keywords: Biomass
Cyanotoxins
Disinfection By-products
Drinking Water
Granular Activated Carbon
Advisor: Andrews, Robert C
Assessing the Feasibility of Using Pressure Sensing Insoles to Measure Physical Fatigue due to Prolonged Standing

Surgeons often experience physical fatigue from prolonged standing in the operating room, causing pain and discomfort that may affect their well-being and performance. A unintrusive and reliable measure of surgeon physical fatigue does not currently exist. We designed the first proof-of-concept study to test if pressure sensing insoles can be used to identify the physical fatigue caused by prolonged standing. 10 participants stood for 2 hours, rested for 1 hour, then stood for another 2 hours. The average pressure and peak pressure on the left medial forefoot increased after the second standing session (p

Advisor: Grantcharov, Teodor TG
Preparation of Microplastics for Use in Environmental Research

Microplastics <20 µm are being increasingly reported in treated drinking water as well as in surface waters. As such, ongoing microplastic-related research in various fields is beginning to focus on smaller particle sizes as these appear to be most important from a human health perspective. However, no standardized methods for preparing microplastics of this size have been reported in the literature. This study proposes a cryomilling-based method for preparation of aqueous stock suspensions. Polymers of 22 different types were obtained from the Centre for Marine Debris Research, Hawai’i Pacific University and subjected to cryomilling. This process produced polymers ranging from 2-125 µm of which 98% were classified as fragments with 2% as fibers. Size distributions for polyethylene terephthalate (PET) and polypropylene (PP), which are frequently reported in environmental samples, were determined using microscopy. Approximately 80% of the particles resulting from cryomilling were <20 μm long in the major dimension. A stock suspension prepared using PET was employed to illustrate and assess recovery for previously reported sampling equipment involving in-line filtration. Recoveries exceeding 80% were observed for individual 5 µm size increments between 2 and 45 µm, with an overall recovery of 86.8%. Results of these trials suggest that stock suspensions of microplastics are heterogeneous and cannot be treated in a similar manner to chemical solutions. In conclusion, this study represents a forward step towards harmonization of environmental microplastic research methods and improve comparability of future studies.

Keywords: Cryomilling
Method development
Polymer kit
QA/QC
Stock suspensions
Advisor: Andrews, Robert
Developing Reflective Practice Among Teachers of Mathematics: A Case Study of Four Teachers

This qualitative case study of four middle and secondary school mathematics teachers examines how teachers' reflective practice supported their selection of strategies that align with the needs of current mathematics education according to the Ten Dimensions of Mathematics Education (McDougall, 2004). The findings suggest that teachers’ reflection practice through collaboration with other teachers and creating a positive safe environment within their classroom for students' feedback impacts their design of classroom practices. They prioritize planning and preparing for the dimensions that are being discussed in the meetings with other teachers. Another major finding is that high level reflective teachers' attitudes toward teaching mathematics is consistent with the needs of current mathematics education. Lastly, meeting individual needs of students is the dimension that all teachers in this study, regardless of their level of reflection, were struggling to reflect and plan for it. Overall, each teacher reported reflective practices that appeared to align with the “Attitudes and Practices for Teaching Math Survey”.

Keywords: Meeting Individual Needs
Reflective Practice
Safe Environment
Teacher Collaboration
Advisor: McDougall, Douglas DM
Evaporator Scaling at a Zero-effluent BCTMP Mill

Over the last few decades, many pulp mills have implemented measures to reduce water consumption and maximize effluent reuse. With increasing closure of the effluent cycle, species can accumulate in the process streams and deposit in equipment and piping which negatively impacts the mill operations and product quality. This work focuses on scale formation in the evaporators of a zero-effluent bleached chemi-thermo-mechanical pulp (BCTMP) mill in Canada. The evaporators are used to concentrate the effluent and recover water for process use. In this work, the liquor-side scale deposits were characterized, and a mass balance study was carried out to identify the sources of scaling components in the streams to the evaporators. The third part of this work involved solubility experiments to determine the effects of temperature, degree of concentration, and pH on the solubility of the scaling components. The mass balance and solubility data provide information the mill can use to develop mitigation strategies.

Keywords: Pulp and Paper
Advisor: DeMartini, Nikolai
Understanding the Effects of Fox Movement on the Spread of Sarcoptic Mange in Urban Settings – An Individual-based Modelling Approach

The threat of disease spread to humans is greater in urban settings where contact between wildlife and human populations occurs frequently. Movement of host species plays a key role in maintaining transmission of direct-contact disease. Understanding how wildlife hosts move in fragmented urban landscapes is therefore imperative for disease control efforts. In cities, disease spread can be affected by the ability of a host to move through urban features, or by behavioural changes that are pathogen induced. Using the urban-adapted red fox (Vulpes vulpes) and its associated disease sarcoptic mange (Sarcoptes scabiei) in the city of Toronto, I ask: How does movement of foxes according to landcover type affect the spread of mange? And how does variable movement of susceptible and infected foxes influence mange transmission? These questions are addressed using an individual-based modeling approach, where two movement behaviours of foxes in a city are compared: random and least-cost path. To assess the effects of movement ability according to disease status (here, susceptible-biased, and infected-biased movement), I compare a range of movement probabilities. For each scenario, the number of effective contacts and the effective reproduction number (Re) are estimated. Findings suggest that mange spread may be accelerated when movement is based on landcover types and when there is equal movement ability of susceptible and infected foxes. This study emphasizes the importance of including realistic movement behaviours when modelling the dynamics of mange and disease spread in urbanized landscapes.

Keywords: Disease Ecology
Disease Modelling
Individual-based Modelling
Spatial Ecology
Urban Ecology
Advisor: Fortin, Marie-Josée
Assessment of Concordance between Chair-side Ultrasonography and Clinical Palpation in Detecting Trigger Points in Masticatory Myofascial Pain Syndrome

Objectives: To 1) provide a foundational summary for masticatory myofascial pain syndrome; 2) provide a foundational summary for ultrasonography and; 3) investigate the concordance between ultrasonography and clinical palpation in identification of myofascial trigger points.Methods: A narrative review summarizing masticatory myofascial pain syndrome and its possible diagnostic aids. We discussed the physics and armamentarium of ultrasonography as a potential diagnostic aid. Thirdly, we conducted a scoping review of the uses of ultrasonography in the dental literature. Followed by a scoping review of the usefulness of ultrasonography in masticatory myofascial pain syndrome. Finally, a cross-sectional study of the concordance of ultrasonography and the current reference standard. Results: The diagnostic strategies for masticatory myofascial pain syndrome vary, and the diagnostic aids are not well developed. There could be a broad and multi-use role for ultrasonography in dentistry. Studies assessing the concordance of ultrasonography to palpation are needed since palpation is considered an imperfect standard. The concordance of ultrasonography to palpation is fair to moderate.

Keywords: clinical palpation
Concordance
myofascial pain
temporomandibular disorder
Trigger Points
Ultrasonography
Advisor: Azarpazhooh, Amir
Laboratory Evaluation of Cemented Paste Backfill Shear Strength Development Up to 600 kPa

Cemented Paste Backfill (CPB) is increasingly favoured as a backfill method in underground mining. The mechanical behaviour of CPB is critical for a rational mix design. This study focused on shear strength development of CPB using a laboratory vane apparatus, complemented by other assessments of CPB’s properties including set times, and changes in Electrical Conductivity. The effects of vane insertion and shearing rate were studied. A comparison was made between the laboratory vane shear strength (LVSS) and unconfined compressive strength (UCS). A constant relationship between LVSS and UCS was found to depend on mix design, but they did not follow the assumption of undrained clay behaviour. The experimental results suggest that the laboratory vane test can be used reliably on relatively soft materials, thereby giving a shear strength index for CPB. However, more work is required to determine how this measured vane shear strength is best used for backfill design.

Keywords: Cemented paste backfill
electrical conductivity
laboratory tests
unconfined compression test
vane test
vicat needle test
Advisor: Grabinsky , Murray
Investigating the Interplay between Germ Granules and sRNA Pathways in C. elegans

Germ granules are phase-separated, membrane-less organelles present only in the germlines of animals. The C. elegans germline contains four distinct germ granules (P granules, Z granule, Mutator foci, and SIMR foci) that contain numerous sRNA pathway components and have been implicated in the proper functions of many sRNA pathways, which consist of AGOs and sRNAs (miRNAs, piRNA, and endo-siRNAs). In this thesis I will address the relationship between germ granules and sRNA pathways in C. elegans by examining the overlap of five of the eight AGOs that localize to germ granules in the young adult stage with P and Z granules, and how AGO localization and germ granules change in ago mutants. Finally, I will also briefly discuss the establishment of a system to identify new germ granules proteins through BioID.

Advisor: Claycomb, Julie
Evaluation of Operating Modes for Intelligent Power Wheelchair Systems

Independent mobility is important for daily living and many chronic conditions related to aging can limit access to mobility aids. To decrease barriers, research has proposed intelligent wheelchair systems. Progress has been made to develop these systems, but a gap in feedback on the needs, preferences, and attitudes exists. As such, a study has been conducted where power wheelchair users are asked to evaluate various operating modes. The original study intended to have participants drive a system that simulated operating modes; however, due to the COVID, changes were made. The study was moved online where participants were shown simulations and asked to complete a survey. The survey evaluated perceived effort and asked to rank preferences of the modes with different scenarios. Results showed that there was a preference to steering correction mode, that these modes could be useful, and there exists a willingness to try; however, there were also concerns.

Advisor: Mihailidis, Alex
A Comparison of Primary Maxillary Incisor Zirconia and Composite Resin Strip Crowns: A One-year Feasibility Study

Purpose: The main objectives of this study were to compare the one-year clinical outcomes of primary maxillary incisor composite resin strip crowns (SC) and zirconia crowns (ZC) and the frequency of pulp therapy associated with each technique.Methods: Children aged 18 to 48 months were randomly assigned to ZC or SC group during treatment under general anesthesia. Raters classified each incisor as intact (I), damaged (D) or requiring treatment (TR), 6 and 12 months following placement. Results: 76 ZC and 101 SC were placed for 59 participants. ZC were more likely to be rated I than SC at 6 months (OR=4.2; 95% CI, 1.3-13.3; P=0.01) or 12 months (OR=4.0 ; 95% CI, 1.2-13.0; P=0.02). There was no statistical difference in the frequency of pulp therapy for incisors restored with ZC or SC (OR= 0.8; 95% CI, 0.3-2.1; P=0.7). All incisors randomized to the ZC group were restored with ZC. Conclusions: ZC were more likely than SC to remain intact through time and were not associated with a greater frequency of pulp treatment.

Keywords: Composite
Crown
Incisor
Maxillary
Paediatric
Zirconia
Advisor: Casas, Michael J
Investigating the Effects of Cyclic Stretching on Lung Cancer Cells using an Automated Microfluidic System

Despite extensive past lung cancer research, there still lacks an understanding of the relationship between the disease and its environmental factors, notably the cyclic mechanical stress induced by breathing. Here, a cell stretching platform, consisting of a polydimethylsiloxane (PDMS)-based cell culture device and a vacuum pump-based actuation system controlled and automated by an Arduino microcontroller was proposed to induce physiologically relevant levels of stretching stimuli on PC-9 human lung cancer cells. This system is inexpensive and easy to use, and ahs a novel membrane design that allows the platform to be miniaturized and operated in cell culture incubators. Results show cyclic stretching altered PC-9 cell morphology and reduced cell viability. Stretched cells also exhibited lower expressions of epithelial markers such as E-cadherin as well as higher expressions of mesenchymal markers and EMT transcription factors such as ZEB1/2 and Twist1/2. Stretching also led to increased cell motility due to the deterioration of vinculin.

Advisor: Liu, Xinyu
Effect of Tooth Bleach on Dentin Fatigue Resistance In Situ

Background: Negative effects of bleaching on dentin have been reported in vitro.Objective: To determine the effect of carbamide peroxide bleaching on dentin fatigue resistance using a clinically-relevant in situ model. Materials and Methods: Sterilized human dentin specimens (1.2x1.2x10mm) were secured into bleaching trays. Treatment consisted of overnight application of either bleach (10% carbamide peroxide, n=23) or control (glycerin, n=26) in situ for 14 nights. Returned dentin specimens underwent fatigue testing. Kaplan-Meier survival analysis and a log rank test (p

Keywords: bleach
dentin
fatigue resistance
peroxide
tooth
Advisor: Tam, Laura E
De Souza, Grace
The Componential Model of Reading: A Comprehensive Examination of Word Reading in Syrian Refugee Children

Using the componential model of reading (CMR) as a theoretical framework (Aaron et al., 2008), this study provided a broad examination of the English word reading ability in Syrian refugee children. The direct and indirect contributions of cognitive, ecological, and psychological domains to word reading ability were examined. Participants included 133 Syrian refugee children (M age = 9.39) who had recently been resettled in Canada. All participants were native speakers of Arabic and had received between 2 and 30 months of English instruction (M = 18.24, SD = 6.08). Results from structural equation modeling revealed that all three domains contributed significantly to word reading. The cognitive domain impacted word reading directly, while both the ecological and psychological domains contributed to word reading indirectly via mediation of the cognitive domain. These findings validate and extend the CMR as a model for understanding the English literacy development of recently resettled refugee children.

Keywords: bilingualism
English language learners
home literacy environment
refugees
socioemotional wellbeing
word reading
Advisor: Chen, Becky
“Center” and “Periphery”: Ethnic Artists of the Yuan (1279-1368) and the Cultural Interactions Among the Yuan Literati Community

The establishment of Mongol sovereignty brought the deep sorrow of Chinese people for their lost homeland. However, it cannot be overlooked that this was also a period of intensive cultural communication that embraced the diverse arts. The Yuan paintings also underwent a dynamic artistic revolution. Ethnic artists also played important roles in this artistic revolution, but their contribution and surviving paintings were barely mentioned in scholarly publications. Through presenting case studies of three prominent ethnic artists: Zhang Yanfu (ca.1300-1350), a Mongol Daoist priest; Boyanbuhuadejin (d.1359), a Qara Qocho Uyghur prince; and Sadula (ca.1300-1360), a Uyghur poet, my thesis examines how ethnic artists involved in the cultural interactions among the literati community that reveals not only the distinct trajectory of each artist’s artistic development, but also a different perspective of the Yuan painting history with an emphasis on those artists on the periphery of the cultural networks.

Keywords: Cultural Interactions
Ethnic Artist
Literati Community
Yuan Dynasty
Advisor: Purtle, Jennifer
Detecting Student Depression Using Smartphone Data

Technological solutions to screen for depression are being researched to combat the rise of mental health problems in post-secondary students. Specifically, machine learning models can be trained on smartphone datasets to detect depression. However, model performance is hindered by limitations of existing datasets, such as: (1) sparse depression labels and (2) neglecting individual circumstances variables. To address the problem with sparse labels, we explored multiple instance learning on an existing sparsely labelled dataset. We also collected a new dataset containing more frequent depression labels and individual circumstances variables using a custom-built mobile application. Overall, our best performing multiple instance learning model outperformed other models with 0.661 AUC. We also achieved up to 0.992 AUC in depression detection using our own dataset. Ultimately, this work contributed to building a better quality smartphone dataset that can train more accurate depression detection machine learning models, helping future students seek timely care.

Keywords: depression detection
digital phenotyping
machine learning
mental health technology
multiple instance learning
smartphone data
Advisor: Mihailidis, Alex am
Khan, Shehroz sk
Use of Nudges to Facilitate Parental Decision-making Regarding Behavior Guidance Options for Dental Treatment for Preschool Children: An Exploratory Study

Objectives: This exploratory study examined the use of behavioral economics principle of nudging to facilitate parental decision-making regarding behavior guidance techniques for dental treatment of preschool children. Methods: A decision aid describing behavior guidance techniques for dental treatment in preschool children was developed. Forty-eight parents were recruited and allocated to one of three groups: Control, Traffic Light nudge, and Pictorial nudge groups. Using the decision aid, parents selected their choice of behavior guidance technique for four case vignettes and provided feedback regarding the decision aid. Results:Parents had a favorable response toward the decision aid. Parents in the Traffic Light group showed trends of choosing basic behavior guidance modalities. Parental choices of behavior guidance techniques differed from the Pediatric Dentist Selection for all case vignettes. Conclusions: Behavioral economic nudges incorporated in a decision aid appeared promising in guiding parental decision-making regarding behavior guidance techniques for dental treatment of preschool children.

Keywords: behavior economics
nudges
nudging
pediatric dentistry
Advisor: Nainar, S.M Hashim