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Taking a ‘One Welfare’ approach to dairy farmer well-being: a qualitative exploration of dairy farmer well-being within the context of animal care and technology
Get PDFFarmers from all commodity groups encounter different stressors; livestock farmers especially grapple with choices that muddle ethical, emotional, and economical boundaries. Canadian farmers experience higher levels of anxiety, depression, perceived stress, and are at an elevated risk of burnout in comparison to the general population, and animal-care related occupations also experience higher levels of psychological distress. Agriculture is rooted in culture and tradition, and being a ‘good farmer’ is frequently part of one’s identity (Burton, 2004). In animal agriculture, on-farm technology is promoted to enhance farmer well-being, animal welfare, and/or environmental sustainability. As such, technology has advantages but the fundamental changes it brings to the farmer-cow dynamic cannot be ignored. The objective of this study was to explore dairy farmer well-being in the context of (1) animal health and welfare, and (2) on-farm technology. I conducted semi-structured interviews to address these objectives and conducted a thematic analysis for each. I found that the emotional and physical act of caring for livestock, as well as the connection to their animals, may play a role in dairy farmer well-being, serving as both a risk and reward. It was evident that technology can be of benefit when used as a tool, if appropriate for the farmer and the specific on-farm context. In both research chapters of the thesis, external pressures were an added source of stress for farmers which underscores that many stressors are out of their control, particularly when it comes to feed sovereignty and weather, uncertainty, economic volatility and labour shortages, and structural inequity.Dairy Farmers of Ontario http://dx.doi.org/10.13039/100015754May 202
On joint communication and sensing in multiple-input multiple-output (MIMO) wireless systems
Get PDFThis thesis advances the understanding of integrated beamforming design for joint communication and sensing (JCAS) systems, where a multi-input multi-output (MIMO) base station (BS) supports downlink communication users while simultaneously estimating parameters of a sensing target. The focus is on characterizing the Pareto boundary between communication performance (measured by mutual information (MI), sum-rate capacity) and sensing performance (measured by Fisher information (FI)), subject to practical system constraints. Two key scenarios are investigated: (1) a single-user, single-sensing-object system with and without equivalent isotropic radiated power (EIRP) constraints, and (2) a multi-user, single-sensing-object system, both subject to a total transmit power budget.
In the single-user scenario without EIRP constraints, a closed-form solution is derived for the Pareto-optimal beamforming design, which is parameterized by a single scalar variable governing the trade-off between MI/sum-rate and FI. This solution is validated against iterative algorithms (e.g., projected gradient descent) and convex optimization (CVX) frameworks, demonstrating its optimality. For the EIRP-constrained case, the problem is reformulated using Lagrangian and Karush-Kuhn-Tucker conditions and solved via a customized gradient descent algorithm. The results confirm that joint beamforming outperforms independent strategies, with the Pareto boundary influenced by the user’s and target’s angles of departure (AoD), antenna configurations,
and EIRP limits.
In the multi-user scenario, uplink-downlink duality is used to decouple the multi-objective optimization problem. Through Lagrangian methods and block-coordinate ascent, an efficient algorithm is developed to maximize the weighted sum of MI/sum-rate across users and FI for sensing. This approach shows that joint beamforming remains Pareto-optimal, efficiently allocating resources to mitigate interference while enhancing sensing accuracy.
Numerical evaluations across various configurations validate the theoretical findings, revealing that EIRP constraints tighten the Pareto boundary, highlighting the need for adaptive power allocation strategies in practical systems.
This work provides a foundation for designing next-generation JCAS systems, emphasizing integrated beamforming as a means to harmonize communication and sensing objectives. The derived frameworks and numerical tools offer valuable insights for optimizing MIMO-based dual-functional networks in applications such as vehicular radar-communication coexistence and 6G perceptive networks.
Keywords: Joint Communication and Sensing (JCAS), Pareto Boundary, Mutual Information (MI), Sum-rate, Fisher Information (FI), Equivalent Isotropic Radiated Power (EIRP), joint beamforming, uplink-downlink duality.October 202
Niche partitioning between sympatrically breeding razorbills and Atlantic puffins during the pre-laying period in coastal Newfoundland
Get PDFTechnological advances in Global Location Sensor (GLS) dataloggers have enabled year-round tracking of seabird location and behavior, providing new insights into their ecology. My thesis used archived GLS datasets from Atlantic puffins (Fratercula arctica, n = 22) and razorbills (Alca torda, n = 28) breeding on the northeast Newfoundland coast (James Island) from 2020-2023. In Chapter 1, I developed a workflow to integrate light and immersion sensor data from these tags to categorize behaviours, including time spent at sea (wet), in burrows/crevices (dry, dark), and at the colony (dry, light). This study highlighted ways to use archived GLS datasets to investigate seabird behavior and phenology during under-studied periods with minimal disturbance. In Chapter 2, I used this workflow to investigate the phenology and time activity budgets of both species during the pre-laying period, when high energy demands for egg formation coincides with low prey availability and, thus, may represent a period of competition. I hypothesized that puffins and razorbills would partition their niches along multiple axes, including diet and breeding phenology, and that time activity budgets would differ. Razorbills arrived at the colony earlier than puffins but laid later, resulting in a longer pre-laying period. Although arrival was similar among years, both species adjusted lay dates (and hatch dates) among years. Females of both species spent more time at sea in most years, while males spent more time in burrows. Puffins spent more time at sea and in their burrows, but razorbills spent more time at the colony outside their rock crevices. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in eggshell membranes (2022- 2023, n ~30 /species/year) indicated no isotopic niche overlap between the two species during pre-laying, with razorbills foraging at a higher trophic level (higher δ15N values) and exploiting a wider range of prey types (greater variation in δ13C values). These findings support the hypothesis that razorbills and puffins partition their niches during pre-laying, suggesting that differences in diet and activity timing may aid coexistence when high abundances of multiple species aggregate nearby breeding colonies. Niche adjustments among years, however, suggest phenotypic plasticity to varying conditions.May 202
StepFree stair climber design
Get PDFThe goal of this project was to develop a wheelchair stair climber to help manual wheelchair users navigate their environments safely and with greater ease. This device addresses the challenge that stairs pose to our client and other wheelchair users, who have difficulty accessing a variety of spaces due to the lack of accessible infrastructure. The StepFree stair climber, operated with assistance, improves accessibility for our client.
During the design process the key requirements considered were smooth and stable operation, compatibility with different staircases and different wheelchairs, and affordability for the client. Additional criteria, such as cost, manufacturability, portability, force reduction ability, user comfort and safety were also evaluated. A tracked wheel design, inspired by high traction mechanisms like those in tanks excavators, best met these requirements.
The StepFree stair climber consists of a dolly-like frame, in which, the user in their wheelchair is secured facing away from the stairs. The frame features tracked wheels which are fixed at an angle such that they can rest on the stairs and transport the device up or down. To achieve controlled and smooth movement up and down the stairs, a button-controlled motorized system, powered by a lithium-ion battery, was used. This system allows the user to be safely transported with minimal force required by the operator.
The StepFree stair climber successfully passed the weight capacity test, carrying over 90 kg of weight without any detectable deflection. Additionally, the device met all collapsible size requirements and had an average device set up time of 4 minutes and 30 seconds, well within the desired time frame and the electrical housing proved to be water-resistant. The device was able to be adjusted to accommodate most wheelchairs tested in a width range of 40-70 cm. Unfortunately, the team was unable to test for the operator force input requirement, number of stairs accommodated and battery life under load, due to the tracks not rotating in the completed assembly. As a result, these tests were considered failed and reported in the verification procedure.
The total project cost was $1,844, reflecting the expenses of a first-generation prototype. However, with industrial-scale manufacturing and custom-made parts, the final product price can be significantly reduced. In future iterations or modifications of this device, it is recommended that a lighter-weight track system and a more powerful motor be selected to better suit the application. A lighter material is recommended for the frame to increase ease of transport, and modifications to the frame and wheel bracket dimensions would increase the range of wheelchairs compatible with the device. By addressing this specific accessibility challenge, the StepFree stair climber has the potential to improve the lives of other manual wheelchair users facing challenges in similar environments
The fifth estate: co-housing for an integrative aging society
Get PDFThe practicum topic aims to address and combat issues of social isolation within Winnipeg’s older population and create a social culture for older adults seeking connection with a community. Following the progressive initiative of many Nordic countries, there is a desire to emulate that same construct of de-stigmatizing aging through the facet of interior design by creating a sense of place and belonging for the older adult community. The Nordic model is appropriate in the Canadian context due to the similar nature of well-developed public health care systems and Scandinavia’s advanced social awareness programming that separates clinical care from livelihood in care facilities.
While post-retirement and aging should be considered a fulfilling stage of life to be celebrated, many people feel isolated, unsure, and fearful of this new chapter. The results of this practicum should challenge the current programming for aging populations, and encourage alternative approaches to housing solutions for older communities. This project is centred around co-housing for older adults as it aims to provide users with a sense of autonomy through independent modes of living, community connection through the use of shared spaces, implementation of intergenerational activity, and allows for continuance of doing the things one loves to do. Through adaptive reuse practices, placemaking, aging in place approaches, and overall environmental consideration, older adults can be given opportunities to come together with their communities, learn from and with one another, and maintain a dignified living environment that speaks to a dynamic variety of needs.February 202
Comparison of machine learning methods with an underlying logistic regression model to detect differential item functioning in patient-reported outcome measures
Get PDFBackground: Patient-reported outcome measures (PROMs) are self-report instruments about health-related quality of life and well-being (i.e., physical and mental health). Assessing the validity of a PROM involves ensuring measurement invariance (MI), which confirms unbiased comparisons across groups. Differential item functioning (DIF), a form of measurement non-invariance, occurs when individuals with the same level of health status respond to an item differently. Many studies about DIF in PROMs focus on demographic characteristics (e.g., age), but other characteristics of individuals, such as the presence of comorbid health conditions, may also contribute to DIF. Machine learning (ML) methods may be advantageous to test for DIF across multiple covariates. The research purpose was to test for DIF using ML tree-based and penalized methods based on logistic regression (LR). The objectives were to 1) compare the performance of two ML methods to detect DIF on multiple covariates, and 2) test the association of demographic and clinical covariates with DIF.
Methods: DIF was tested using an item-focused tree (IFT) with an underlying LR model and a Least Absolute Shrinkage and Selection Operator (LASSO) regression model. For Objective 1, a simulation study was conducted in which data were generated under different analytical conditions by varying sample sizes, DIF effect magnitudes, and correlations among covariates. The performance of both the IFT and LASSO regression models was evaluated using Type I error and statistical power rates. For Objective 2, the association of the covariates with DIF was assessed in the 36-item Short Form Survey items completed by individuals diagnosed with immune-mediated inflammatory diseases. A hold-out bootstrap cross-validation technique was conducted to evaluate the performance of the IFT and LASSO regression models using the Brier score, accuracy, and mean square error (MSE) in test data.
Results: In the simulation study, the Type I error rate for the IFT regression model was below the nominal 5% level across simulation conditions. The LASSO regression model had lower Type I error rates than the IFT model when the correlation between covariates was strong. In conditions with small and moderate DIF effect sizes, the LASSO regression model had greater statistical power than the IFT regression model. In real-world data, the IFT regression model detected eight DIF items, and the LASSO regression model detected 16 DIF items. Sex and hypertension were the most frequent covariates associated with DIF. When both methods flagged an item for DIF, they identified similar associated covariates. The estimated Brier score, accuracy, and MSE were similar for both methods.
Conclusions: Establishing MI in a PROM means that the latent construct is equivalent across population groups defined by socio-demographic and personal health characteristics. MI contributes to equity-focused PROM development. The IFT regression model is recommended to control the rate of false positives, where DIF is incorrectly detected. The LASSO regression model is recommended when DIF effects are small.Emergency Bursary from Rady Faculty of Health Sciences
$9,000 for the first year of the studyFebruary 202
Strategies for promoting the maturation of induced pluripotent stem cell derived cardiomyocytes
No full textHuman induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) have arisen as a significant asset in cardiovascular medicine, facilitating progress in pharmaceutical development, disease modeling, and regenerative therapies. However, a persistent limitation of iPSC-CM is their structural and functional immaturity, which hinders their full translational potential. Various strategies have been explored to enhance the maturation of iPSC-CM, yet no single approach has been entirely successful. This thesis explores strategies that span from environmental mimicry using conductive nanomaterials to targeted metabolic interventions, offering a multifaceted approach to promote the functional maturation of iPSC-CM. Chapter 1 lays the foundation for the thesis by reviewing the biological features of iPSC-CM, their biomedical applications, current efforts to overcome these challenges and the limitations associated with their immature phenotype. Building on the importance of tissue engineering strategies to mimic the native cardiac microenvironment for effective cardiomyocyte maturation, Chapter 2 introduces MXenes, a novel class of two-dimensional, electroconductive nanomaterials. Their potential in tissue engineering applications including cardiac tissue engineering is discussed as a means to deliver structural and electrical cues that support maturation. Chapter 3 outlines the research hypothesis and thesis chapters where each chapter oultines a strategy to mature iPSC-CM. Chapter 4 describes the experimental application of tantalum carbide MXene quantum dots (MQD) embedded in Geltrex scaffolds. These bioactive, conductive matrices promote improved calcium handling, electrophysiological properties, and mitochondrial activity in iPSC-CM. Multi-omics analyses reveal activation of pathways linked to mitochondrial biogenesis, extracellular matrix remodeling and the focal adhesion kinase pathway in MQD-treated iPSC-CM. While the previous chapters focus on the physical environment, Chapter 5 investigates metabolic reprogramming as a mechanism to increase iPSC-CM maturation. Using multi-omics data from different developmental stages of murine hearts, a chemically defined cardiomyocyte maturation medium (CDCMM) is formulated. The CDCMM significantly enhances metabolic and structural maturation of iPSC-CM. To demonstrate the potential of CDCMM media for disease modeling, the iPSC-CM of a patient with Leigh Syndrome were cultured in this maturation media. These patient iPSC-CM in CDCMM performed significantly better than the cells cultured in normal media for mimicking the disease phenotype. Continuing the effect of metabolic reprogramming on the maturation of iPSC-CMs, Chapter 6 explores TCA cycle metabolites supplementation on electrophysiological and functional maturation of iPSC-CM. The treatment of iPSC-CM with TCA cycle intermediates improves mitochondrial respiration, morphology and calcium handling properties of the cells. To conclude, Chapter 7 summarises the key findings presented in Chapters 4, 5, and 6, and subsequently discusses the limitations of the current work along with prospective directions for future research. Overall, this thesis provides three novel approaches for developing physiologically relevant iPSC-CM models for its effective application in cardiovascular research.February 202
A randomised controlled trial comparing epinephrine and dexamethasone to placebo in the treatment of infants with bronchiolitis (BIPED study): a statistical analysis plan
Get PDFBackground: Bronchiolitis is a common lung infection that affects infants and young children. While most children can be treated at home, some require hospitalisation where supportive care, such as fluids and oxygen, is the suggested treatment. Bronchiolitis is the leading cause of infant hospitalisation in developed countries and exerts a significant burden on the healthcare system. The aim of the Bronchiolitis in Infants Placebo Versus Epinephrine and Dexamethasone (BIPED) study is to evaluate the effects of a combination of epinephrine and dexamethasone, given during initial presentation at the emergency department, on hospitalisation for bronchiolitis. This article outlines the statistical analysis plan (SAP) for the BIPED study. The BIPED study is a Phase III, multi-centre, randomised, controlled, double-blinded superiority, placebo-controlled trial to determine whether the combination of epinephrine and dexamethasone is successful in reducing hospitalisation for bronchiolitis up to 7 days following presentation at an emergency department with bronchiolitis. The secondary outcomes include hospital admissions for bronchiolitis at the emergency department enrolment visit, and all-cause hospital admissions, health care provider visits and health care-related costs in the 21 days following enrolment. The safety outcomes are gastrointestinal bleeding, serious bacterial infection, severe varicella and death.
Discussion: The BIPED study will provide evidence on whether a combination of epinephrine and dexamethasone reduces hospitalisation in infants following presentation to the emergency department with bronchiolitis. These data will be analyzed using this SAP, submitted before the data became available for analysis, to reduce the risk of bias in our reported outcomes.
Trial registration: ClinicalTrials.gov NCT03567473. Registered on June 25, 2018
Piezoresistive Behavior of Polypyrrole:Carboxymethyl Cellulose Composites
Get PDFThe unique properties of conducting polymers make them ideally suited for applications in organic electronics, photovoltaics, and energy storage systems. Depending on the specific application, they can outperform metal-based electronics by cost, mechanical flexibility, molecular design opportunities, and environmental impact. Many composites of conducting polymers with polyanions can be processed in water. However, the facile processing of such composites comes at a cost of reduced conductivity. In this manuscript, electronic conductivity dependence on composition for a composite of polypyrrole (PPy) with carboxymethyl cellulose (CMC) has been studied. Secondary ion mass spectrometry and electron energy loss spectroscopy mapping indicate the formation of a nanostructure forming PPy-rich nanospheres with a CMC-rich surface coverage. This structure requires inter-particle electron conduction to occur via quantum tunneling. Variations in the tunneling distance are dependent on the applied pressure, giving rise to a pressure-dependent electronic conductivity and thus piezoresistance. This behavior opens new applications of conducting polymer composites in pressure-sensitive electronic devices, providing metal-free alternatives to quantum tunneling composites
Evaluating river ice elevation, thickness, and roughness using airborne LiDAR
No full textMonitoring river ice processes is essential for understanding ice-related hydraulic dynamics and potential flood risks. In this study, high-resolution top-of-ice elevation was surveyed using airborne LiDAR, providing fundamental information for characterizing the ice cover. This elevation data alone serves as a critical metric for river ice monitoring. Building on this foundation, two critical river ice parameters, ice thickness and ice surface roughness, were analyzed using a novel integrative approach. To evaluate ice thickness in a fluvial setting, field-measured water level data were combined with remotely sensed data, specifically a high-resolution digital elevation model (DEM) of a fluvial ice cover generated from LiDAR measurements. This approach enabled estimation of ice thickness by leveraging the synergy between in situ observations and advanced remote sensing techniques.
Additionally, the study evaluated the performance and capabilities of the remotely piloted aircraft (RPA) Matrice-350 equipped with the DJI L2 LiDAR payload. The RPA platform demonstrated high precision in capturing both elevation data and surface imagery, making it an effective tool for surveying ice-covered rivers in challenging environments. The results highlight the potential of RPA-mounted LiDAR systems for advancing river ice monitoring and analysis.
Finally, the surface characteristics of river ice were systematically analyzed and classified. By applying statistical metrics, the ice surface roughness was categorized into two distinct groups: smooth and rough. This classification provides valuable insights into the spatial heterogeneity of river ice, with implications for hydraulic modeling and ice-related engineering applications.
This study demonstrates the effectiveness of integrating remote sensing techniques with advanced RPA technology to comprehensively evaluate critical river ice parameters. The resulting dataset significantly enhances the understanding of the field of river ice engineering and improves the accuracy of numerical modeling by providing essential inputs for ice jam simulations.February 202