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Estimation of Hydromechanical Properties of Unsaturated Soils Using Machine Learning Techniques
No full textCompacted unsaturated soils are widely used in the construction of embankments, pavements, subgrades, foundations, retaining walls, railways and slopes, and their hydro-mechanical behavior is influenced by both net normal stress and matric suction. Although the theoretical framework of unsaturated soil mechanics is well established, routine determination of matric suction, the soil water characteristic curve (SWCC), and related hydro-mechanical properties remain labor-intensive, slow and often impractical for engineering practice applications. This difficulty is more pronounced in compacted soils because microstructural effects and slow suction equilibration complicate both measurement and interpretation. These challenges motivated the development of simplified methods by various researchers for predicting or estimating hydro-mechanical properties in many regions over the last three decades. In these methods, SWCC, which is defined as a relationship between the water content (i.e., volumetric or gravimetric) or degree of saturation and soil suction, has been used as a tool along with saturated soil properties for reliably predicting the variation of unsaturated soil properties with respect to suction. This background is widely used in the design and modeling of the behavior of various geo-infrastructure. Nevertheless, studies related to assessing the in-situ behavior of various infrastructures remain a significant limitation. For example, reliable and continuous measurement of in-situ matric suction has been a challenge. This limitation also continues to hinder the in-situ measurement of SWCC, which is useful to assess the performance of geo-infrastructure. Another example is natural precipitation that can alter matric suction through water infiltration, leading to variations in unsaturated soil properties. Reliable information of matric suction, along with the other hydro-mechanical properties is required for the reliable hazard assessment of geo-infrastructures. Such information can be useful in suggesting correction and maintenance/repair measures to alleviate possible geotechnical failures.
To address some of these challenges, a critical literature review is conducted within the scope of the research, focusing on the measurement techniques and prediction methods for matric suction and the SWCC. Building on insights from this review, this thesis proposes a series of advanced machine learning (ML) frameworks that integrate data-driven modeling with the fundamental principles of unsaturated soil mechanics. The research addresses four interrelated challenges in the estimation and prediction of key properties of unsaturated soils.
The first objective aims to estimate matric suction from soil properties that are routinely obtained through standard laboratory testing. Two prediction models are developed: namely, Particle Swarm Optimization Support Vector Regression (PSO-SVR) and Multivariate Adaptive Regression Splines (MARS) are developed in this study. PSO-SVR demonstrates that the soil matric suction can be predicted with a reasonably high accuracy, while MARS facilitates efficient input selection and sensitivity analysis. By combining their strengths, an integrated framework is proposed and validated using published datasets of matric suction from literature, particularly for low-plasticity soils within a suction range of 0 to 1500 kPa. This approach reduces reliance on direct matric suction measurement and supports more rapid risk assessments of geotechnical infrastructure.
The second objective addresses the specific challenges associated with fine-grained compacted soils, whose hydro-mechanical behavior is highly sensitive to microstructural characteristics. In practice, measuring matric suction in these soils is considerably more complex and time-consuming than in low-plasticity soils, due to slower equilibration rates, greater structural sensitivity, and the need for specialized high-capacity devices. Recognizing these difficulties, this study develops a hybrid ML framework that integrates PSO-SVR with Multi-Gene Genetic Programming (MGGP). This approach leverages the high predictive capability of PSO-SVR and the transparent, interpretable structure of MGGP, enabling both robust estimation and empirical formula derivation. A novel ML-based parameter, termed the effective degree of aggregation, is introduced to quantitatively represent the influence of soil structure and aggregation under varying initial water contents, thereby improving the model's responsiveness to microstructural variations. Sensitivity analyses are conducted to identify the most influential input features, ensuring the resulting models are both physically meaningful and practically applicable. The explicit empirical equations derived from the MGGP component facilitate direct use in engineering applications without requiring complex computational tools. The framework is validated against measured data, showing strong agreement and demonstrating its utility for the practical estimation of matric suction in compacted fine-grained soils.
The third objective focuses on predicting the SWCC, a widely adopted and efficient tool in geotechnical design for estimating hydro-mechanical properties of unsaturated soils. Traditional methods for determining the SWCC often rely on extensive laboratory testing and curve-fitting procedures, which can be time-consuming and sensitive to data variability, particularly in compacted fine-grained soils. To address these limitations and improve modeling robustness, a hybrid ML framework is developed by integrating Extreme Gradient Boosting (XGBoost) and Multi-Layer Perceptron (MLP) algorithms with thermodynamic principles. This framework approximates the Fredlund and Xing (1994) (FX) SWCC model by relating its fitting parameters to fundamental soil properties through ML regression. A novel empirical parameter, the Free Energy Deviation Index, is introduced and calibrated based on thermodynamic theory to quantitatively capture structural changes associated with different initial compaction water contents. Sensitivity analysis highlights the critical influence of soil structure on SWCC behavior. The proposed model demonstrates strong predictive performance against published experimental data and supports both forward estimation and inverse calibration, enabling more flexible and accurate integration of SWCC modeling into geotechnical engineering practice.
Finally, a hybrid data-driven and physics-informed neural network (DD-PINN) framework is developed to characterize the rainfall-induced evolution of hydro-mechanical properties, namely coefficient of permeability and shear strength, which are critical inputs for the design and stability analysis of geo-infrastructures in unsaturated soils. In Stage I, an XGBoost–MLP proposed in Chapter 5 estimates the parameters of the FX-SWCC equation directly from basic index properties, eliminating labor-intensive laboratory testing and large labeled datasets. In Stage II, the predicted FX-SWCC parameters are embedded in a PINN model that enforces Richards' equation as a physical constraint to simulate the spatiotemporal evolution of matric suction and water content under transient boundary conditions. Shear strength is subsequently evaluated using the widely used Vanapalli et al. (1996) equation, while the coefficient of permeability is obtained via the Mualem (1976) relationship. By coupling a data-driven module that infers FX–SWCC parameters from basic index properties with a physics-informed PINN that enforces Richards' equation to predict the spatiotemporal evolution of SWCC, the proposed DD-PINN framework delivers mesh-free, physically consistent, and computationally efficient predictions of rainfall-induced changes in suction, coefficient of permeability, and shear strength, providing a unified tool for advanced slope-stability assessment and geo-hazard analysis.
Recognizing that no single ML technique can address the breadth of tasks in unsaturated soil mechanics, this thesis examines black box, interpretable, data-driven, and physics-informed ML approaches and develops four practical frameworks that integrate these methods with the governing principles of unsaturated soil mechanics. This integration improves the estimation, prediction, and interpretation of hydromechanical behavior of unsaturated soils. The proposed frameworks provide efficient, interpretable, and physically grounded tools for estimating matric suction, modeling the SWCC, and predicting the rainfall-induced evolution of the coefficient of permeability and shear strength, thereby supporting rational design, performance evaluation, and hazard mitigation in geo-infrastructure founded on unsaturated soils
Neuroimaging Pedophilia and Fetishism: A Distinct ‘Brainprint’ of Sexual Preference
No full textPedophilia is defined as a persistent sexual interest in prepubescent children and has long been the subject of considerable concern due to its association with sexual offending against children. Despite progress in the neuroscientific understanding of pedophilia, the structural and functional mechanisms underlying it remain unclear, as does its distinctiveness from other paraphilic interests in the brain, which have yet to be investigated using neuroimaging. Additionally, much of the extant research has failed to control for criminality, raising concerns over construct validity. The objectives of this project were to compare non-contact-offending pedophilic men (n=9), fetishistic men (n=15), and teleiophilic men (with sexual interests in sexually mature female adults) (n=16) on measures of brain structure, sexual processing, and self-report tools to better understand the neural underpinnings of pedophilia and, for the first time, compare it to another paraphilia: foot fetishism. Study 1 examined structural maps of gray matter volumes across the brains of our three groups using voxel-based morphometry (VBM), Study 2 utilized diffusion tensor imaging (DTI) to investigate white matter microstructure, and Study 3 used a novel fMRI picture task to compare patterns of functional brain activity when viewing sexually salient paraphilic and non-paraphilic stimuli. Interviews surveyed paraphilic interests, sexual compulsivity, criminality, trauma, and demographic variables. The results of our studies support previous research demonstrating structural and functional differences between pedophilic and teleiophilic individuals, and for the first time distinguished a “brainprint” of pedophilia from that of foot fetishism in exclusively non-contact-offending samples. VBM results demonstrated significantly lower gray matter volumes in the two paraphilic groups across several large, widespread clusters, which were most pronounced in the pedophilic group, particularly in frontal and temporal/limbic regions. DTI results demonstrated significant differences in white matter health between teleiophilic men and the two paraphilic groups, with no differences between men with pedophilia and men with foot fetishism. fMRI results showed unique activity patterns during visual sexual processing of preferred stimuli between all three groups, with significant increases in the overall use of neural resources among both men with pedophilia and men with fetishism. Together, these results open the door for a new line of research on paraphilia
Recommendations for the diagnosis and management of eosinophilic esophagitis in adults and children in Canada: a Delphi consensus project
No full textAbstract Background Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus that effects both pediatrics and adult patients in Canada and is increasing in prevalence. No Canadian focused best practice recommendations currently exist to guide clinical practice. Methods The study used a modified Delphi technique to develop evidence and expert opinion-based recommendations for providing care for patients with EoE. The Delphi process consisted of 3 rounds of quantitative surveys and qualitative consensus meetings. Experts were included in the Delphi if they had experience caring for EoE patients in Canada within one of the following professional groups: allergist, adult gastroenterologists, pathologists, pediatric gastroenterologists, and dieticians. Results Delphi rounds were completed between May 1, 2024, and June 30, 2024. A total of 31 experts in EoE care from across Canada were recruited to participate in the Delphi consensus process. All participants completed all three rounds of Delphi surveys. The final statement includes 38 recommendations for the care of patients with EoE organized into three sections: definition, diagnosis, and management. A Table of research gaps is provided to stimulate further knowledge development on this topic. Conclusion This consensus statement includes actionable recommendations to support quality care of patients with EoE at any age across Canada. We encourage EoE centers in Canada to come together in a multi-disciplinary form to not only provide clinical care but also do much needed research on Canadian specific topics and gaps in EoE care
Postoperative weight-bearing restrictions and rehabilitation after periacetabular osteotomy: a systematic review
No full textAbstract Aims This systematic review aimed to synthesize current evidence on postoperative rehabilitation strategies, particularly weight-bearing restrictions after periacetabular osteotomy (PAO). Methods A systematic review was conducted following PRISMA 2020 guidelines. PubMed, Web of Science, and Embase were searched until January 12, 2025. After duplicate removal, studies were screened by title, abstract, and full text using predefined criteria. Studies were included if they reported postoperative weight-bearing protocols after isolated PAO; studies with additional procedures, non-human data, or lacking mobilization details were excluded. Primary endpoints included postoperative weight-bearing instructions, duration of partial weight-bearing, and brace use. Secondary endpoints included hip function, return to sports, and complications. Data extraction was performed independently by two reviewers. Bias was assessed using the MINORS tool. Results The majority of studies recommended partial weight-bearing immediately postoperatively, commonly initiated on postoperative day one (18% of studies), typically lasting six (21%) to eight (18%) weeks. Variations included toe-touch, tip-touch, touch-down, flat-foot, protected, or restricted weight-bearing. Crutches were frequently recommended (48%). Bracing was infrequently reported (5%), with limited details provided. Return to sporting activities varied widely, typically recommended between six and twelve months postoperatively. Complication rates were diverse, with delayed weight-bearing showing a lower incidence of pelvic fractures compared to immediate full weight-bearing. Conclusion This review highlights substantial variability and imprecise terminology in existing PAO mobilization protocols and a lack of standardization. Future research should prioritize prospective comparative studies to clarify safe, effective postoperative mobilization strategies. Establishing standardized, evidence-based rehabilitation guidelines could enhance patient outcomes, reduce complications, and decrease practice variability following PAO
Evaluation of OspC as a Vaccine Antigen for Lyme Disease
No full textLyme disease (LD), caused by bacteria of the Borrelia burgdorferi sensu lato complex, is the most common vector-borne illness in North America. While effective antibiotic treatments are available for LD, 10-20% of patients will develop post-treatment Lyme disease syndrome, significantly reducing their quality of life and emphasizing the need for novel prophylactics. Notably, there is currently no commercially available vaccine for the prevention of LD in humans. Outer surface protein C (OspC), an immunogenic lipoprotein found on the surface of B. burgdorferi, is a promising antigen for LD vaccine development as it is highly expressed by the bacteria during early mammalian infection. However, the development of a broadly protective OspC-targeting vaccine is challenged by the vast antigenic variation of OspC, with over 20 different ospC major allele groups.
In this thesis, I evaluate the protective efficacy of LD vaccines targeting OspC using a variety of next-generation vaccine platforms in a C3H/HeN mouse model. I demonstrate that monovalent DNA and mRNA vaccines encoding OspC type A delivered by lipid nanoparticles (LNPs) elicit a functional OspC-specific antibody response that confers complete protection against homologous B. burgdorferi infection, dissemination, and pathologies. This work highlights the applicability of clinically approved LNP formulations for the delivery of pDNA vaccines in addition to conventional RNA payloads. Furthermore, I show that a modified vaccinia virus-vectored vaccine encoding OspC type A can confer complete protection against homologous B. burgdorferi infection comparable to a veterinary LD vaccine through the induction of potent OspC-specific antibody and CD4+ T cell responses.
Finally, this thesis demonstrates the protective efficacy of a polyvalent mRNA vaccine encoding five common OspC types. The optimal LNP formulation was first evaluated by comparing the potency, expression kinetics, biodistribution, and immunogenicity of different LNP formulations delivering either DNA or mRNA encoding firefly luciferase. Additionally, the infection profiles of the five corresponding B. burgdorferi strains were characterized to identify strain-specific differences before systematic challenge of the pentavalent OspC mRNA vaccine. The candidate mRNA vaccine afforded protection against multiple strains expressing different OspC types and reduced associated pathologies. This study is the first demonstration of multi-strain protection of an OspC vaccine in the absence of outer surface protein A. Overall, this thesis illustrates the efficacy and immune mechanisms of next-generation vaccines targeting OspC and provides a foundation for the rational design of future LD vaccines
Visual Hunger: Number 1 / Appétits visuels : numéro 1
No full textThe growing integration of food into media content and digital culture is transforming our perceptions of food, sustainability, and global food systems. Food now serves as a powerful tool for storytelling, fueling the rise of influencers, celebrity chefs, dedicated food channels, and broader cultural industries. This pervasive media presence reflects a pressing need to critically examine the visual and narrative appetite for food—how it is consumed, represented, and commodified across both local and global contexts.
L’intégration croissante de la nourriture en tant qu’objet central des contenus médiatiques et de la culture numérique reconfigure en profondeur nos représentations de l’alimentation, de la durabilité alimentaire et des systèmes alimentaires mondiaux. Mobilisée comme vecteur discursif, la nourriture participe à la construction de récits culturels et médiatiques, tout en soutenant l’émergence d’influenceurs, de chefs médiatisés, de chaînes spécialisées et de multiples industries culturelles. Cette mise en visibilité généralisée invite à une analyse critique de l’exploitation médiatique de la nourriture – de sa mise en récit à sa consommation symbolique – tant à l’échelle locale que mondiale.Foreword
Lara Mainville
Préface
Lara Mainville
Introduction: Why Visual Hunger?
Dina Salha
Introduction : pourquoi Appétits visuels ?
Dina Salha
Nailed It! Imperfection in the Age of the Curated Image
Maya Bugorski
Chef ’s Table: Serving up a Hot Plate of Cultural Identity and Resistive Narratives with a Side of Gender Normative Ideals
Stephanie Platero Martinez
Abject Food Content, Mukbang, and Online Food Media
Drew Williamson
The Notion of Food Journalism through Social Media Influencers: Understanding and Unpacking the Overlap
Bianca Polcar
Literature in a "Digital Ecology": Interdisciplinary Digital Collaboration in Contemporary English Canadian Literature
No full textThis project delineates an emerging genre of cross-disciplinary, geographically located, collaboratively produced Canadian digital literature in English. Drawing on thinking from the fields of new materialism, the digital humanities, architectural theory, cultural geography, and ecology, this dissertation applies a whole systems approach to four recent works in order to highlight a generic impulse toward the emergent, the indeterminate, and the provisional - what Doreen Massey calls "[l]oose ends and ongoing stories." By mapping this impulse across these projects, this dissertation examines the spatial, structural, and infrastructural ecologies they embody, tracing their emergent patterns and reading in them a broader generic concern with social, economic, and environmental inequities. The works this project studies are Canadian, but their interactive digital form extends their relevance and potential impact beyond national borders. Throughout this project, I argue that these works engage audiences in multi-sensory, interactive reading environments, producing localized, participatory readers more attuned to the ecological, economic, industrial, and cultural complexities of the real places they examine and to the creative navigation of the challenges marking our current geological era.
This dissertation is divided into four chapters, each of which examines a recent spatial, structural, and infrastructural ecology attending to the material and the ephemeral. The first chapter posits that, by way of its interactive multimodality, Sachiko Murakami's Project Rebuild leads readers into a generative contingency, privileging not established patterns or fixed structures but instead a generous fluidity that makes space for more equitable social, material, and economic relations in urban Canada. The second chapter examines Aaron Tucker et al.'s Loss Sets, which, I argue, generates a productive textual lacuna that forces audiences to read the gaps and omissions forming the compositional substance of the project. The third chapter turns to Madeleine Thien's Vancouver of the Mind, which, I suggest, approaches Vancouver's historic and ongoing displacements and dispossessions by formal and structural means, applying the logic of digital multidisciplinarity and invited collaboration to its examination of the gaps, absences, and injustices occurring in and emerging from its spatial referent. The final chapter argues that in Fred Wah and the High Muck a Muck Collective's High Muck a Muck: Playing Chinese: An Interactive Poem, rivers, migratory routes, mountain ranges, and other arterial forms work in conjunction with the project's multimodality to materialize relational structures and cultivate in audiences a proprioceptive approach to the reading process, strengthening their sense of the connective tissue which binds them to the places, spaces, and structures of the world.
In applying a macroecological lens to this emerging genre, and acknowledging the broad readership such digital works invite, this project aims to build a set of observational tools and to cultivate a responsive relationality with the systems and patterns running through the works I study and the places and structures they represent
Development of digital learning tools for medical education with agile scrum methodology
No full textAbstract Background The COVID-19 pandemic has underscored the importance of digital learning tools in medical education. However, there is little evidence exploring how or whether such tools are being developed for family medicine curricula. We provide a narrative analysis of how the University of Ottawa’s Department of Family Medicine (DFM) developed innovative learning tools using an interdisciplinary, research-based approach and Agile Scrum Methodology. Methods In March 2020, the DFM created an interdisciplinary team to support development of digital tools for medical education. Members of the DFM were invited to participate in the project during two faculty-wide webinars held on May 13, 2020. Participants identified three topic areas for which digital learning tools were to be created: Choosing Wisely Canada recommendations, Hypertension, and Quality Improvement (QI). Representatives from the Faculty of Engineering were recruited to support IT development for the tools, while researchers from the Bruyère Research Institute provided support for methodology and analysis. Results Three teams developed prototypes for digital learning tools: a “choose your own adventure” game to teach Choosing Wisely Canada criteria, an interactive hypertension clinic, and a “QI escape room” focused on quality improvement strategies. One team created a website to host learning tools, and the final team generated an evidence library for product development. Conclusion Adhering to these methodologies helped us to manage interdisciplinary teams and support their success, with all five teams completing their objectives. The interdisciplinary and incremental approach of Scrum methodology allowed for gaps to be identified and addressed in real time. Scrum demonstrates promise and should receive further consideration as a method for developing learning tools in medical education
On-the-Ground Realities of Health Program Delivery in Addressing Community Needs: A Community-Based Participatory Research Approach in the Moose Cree First Nation
No full textIndigenous communities in northern remote Canada face disproportionate health disparities, including high rates of food insecurity and prevalence of diet-related chronic diseases stemming from colonial disruption of traditional food systems and increased reliance on poor-quality market foods. This study described how Indigenous-led health programs, the Healthy Babies, Healthy Children Program and the Diabetes Prevention Program, in Moose Cree First Nation (MCFN) respond to food insecurity drivers and support community health and wellness. It also documents the on-the-ground realities of program delivery, including operational challenges faced by the programs. Grounded in community-based participatory research (CBPR), this research involved firsthand participation in program delivery alongside the Moose Factory Health Center coordinators, complemented by semi-structured interviews with community members (n=6) and health center staff (n=3), and participant feedback from program activities. High food costs, limited access and availability, and poor food quality continue to drive food insecurity in the community. Health programs responded through culturally grounded, family-oriented nutrition education activities, including cooking and gardening workshops, food demonstrations, and baby food preparation sessions. Beyond their formal objectives, these programs function as vital community support systems, providing tangible resources, fostering social connections, and serving as frontline responders to non-clinical immediate family needs. However, systemic barriers significantly constrained program delivery, including inadequate funding, limited infrastructure, staffing shortages, and ongoing COVID-19 impacts. The findings demonstrate that while Indigenous-led health programs play crucial roles in addressing food insecurity and promoting community wellness, they require sustainable funding models that reflect the true costs of service delivery in northern, remote communities. The study emphasizes the need for policy transformation from top-down approaches toward community-informed, Indigenous-led governance that supports holistic health programming aligned with Indigenous concepts of health and self-determination
The association between exposure to food marketing and dietary intake among youth in six countries
No full textAbstract Background While food marketing to youth is associated with harmful behavioural and dietary outcomes, few studies have assessed differences in this relationship between countries. This study examined the association between exposure to food marketing and dietary intakes among youth in six countries. Methods A cross-sectional analysis of International Food Policy Study 2023 Youth Survey data examined the relationship between self-reported exposure to marketing for less healthy (fast food, sugary drinks, sugary cereals, snacks, desserts/treats) and healthy (fruits, vegetables) food categories across various media/settings in the past 30 days and consumption of these foods yesterday among youth 10-17 years-old in Canada, Australia, Chile, Mexico, the United Kingdom and the United States (n=9057). Associations of food consumption with exposure to marketing of food categories and marketing techniques (e.g., characters, famous people) in food advertisements, and differences in associations between countries, were examined using binary and ordinal logistic regression. Results In all countries, youth reporting more frequent exposure to marketing of all less healthy food categories had higher odds of having consumed those foods yesterday (p < 0.05 for all), except snacks in Mexico. Compared with no exposure to marketing techniques, exposure to ≥ 1 marketing technique(s) in less healthy food advertisements was associated with higher odds of having consumed sugary drinks (AOR: 1.44; 95% CI: 1.21, 1.72), fast food (AOR: 1.69; 95% CI: 1.40, 2.03), sugary cereals (AOR: 1.26; 95% CI: 1.05, 1.51) and desserts/treats yesterday (AOR: 1.42; 95% CI: 1.18, 1.71) among youth in all countries. Consumption of snacks was associated with exposure to ≥ 1 marketing technique(s) in less healthy food advertisements in Australia (AOR: 1.61; 95% CI: 1.09, 2.34), Chile (AOR: 1.63; 95% CI: 1.12, 2.36) and Mexico (AOR: 2.13; 95% CI: 1.39, 3.26). Positive associations between frequency of exposure to marketing of fruits and vegetables and the number of times these foods were consumed yesterday were observed in all countries (p < 0.05), except vegetable consumption in the UK. Conclusions These results support the association between exposure to food marketing and consumption of marketed foods. Findings were similar between countries, reinforcing the need for global implementation of restrictions on food marketing to youth