DalSpace Institutional Repository
DalSpace is a digital service that collects, preserves, and distributes digital material produced by the Dalhousie community.
- To learn about content guidelines, policies, and how to deposit, view the Help documents.
- Contact us to get started submitting content to DalSpace at dalspace@dal.ca
Communities in DSpace
Select a community to browse its collections.
Recent Submissions
ELECTROMAGNETIC WAVE MANIPULATION USING METASTRUCTURES
(2025-08-21) Asim, Arslan; Yes; Doctor of Philosophy; Department of Electrical & Computer Engineering; Not Applicable; Dr. Jiri Ctyroky; Yes; Dr. Yuan Ma; Dr. Alan Fine; Dr. Michael Cada
The field of electromagnetics has seen significant growth in research on optically resonant materials during the twenty-first century. While the idea of novel light-matter interaction kept reverberating throughout human history, it was during the latter half of the last century that formal conceptualization of the topic was seen, especially in the form of negative refractive index/ plasmonic materials. Over the last couple of decades, this area of research has seen exponential growth resulting into an exciting field of study known as metamaterials. Today, optical metamaterials represent a broad class of resonant materials with unnatural characteristics. This dissertation explores research in optically resonant materials from different angles. It attempts to connect the dots across different domains in the realm of metamaterials. Mathematical modeling has been used to understand the propagation characteristics of plasmonic waves. The results from analytical models have been compared with numerical studies. Computational simulations have also been conducted to design photonic metamaterial structures; the structures mainly consist of plasmonic and dielectric materials. The feasibility of such nanoscale structures for biomedical sensing applications has been explored by investigating how changes in refractive indices create changes in spectral responses of the resonators. Experimental work has been carried out using chemically active optical materials. Optodes have been developed using certain nanomaterials that can selectively trace potassium ions in a solution by displaying changes in absorption levels at specific frequencies. On-chip optical manipulation has been performed to observe the differences between simulation and experimental results. The objective has been to achieve suitable results for different industrial applications like biosensing and communications.
Understanding Stakeholder Perspectives, Policies, and Practices for Adoption of Canada’s Food Guide and Sustainable Diets in Pilot Test Sites
(2025-08-22) Nnuro, Kelvina Esther Esi; Not Applicable; Master of Science; Faculty of Agriculture; Received; N/A; Not Applicable; Dr. Ji Lu; Dr. Atanu Sakar; Dr. Charlyn Black; Dr. Kathleen Kevany
Significant shifts in nutritional habits have been observed throughout Canada and the rest of the world, resulting in a rise in the number of people suffering from under-over- and/or malnutrition, which then contributes to the prevalence of non-communicable chronic diseases. Additionally, current dietary habits have impacted the environment negatively and contributed to losses in culinary skills and cultural food knowledge. An evidence-based approach that has proven effective in addressing these challenges is the adoption of sustainable diets, which is dependent on the development of supportive food environments. This study examines policies and practices, and explores stakeholder perspectives concerned with the adoption of Canada’s Food Guide (CFG) and sustainable diets within institutional food environments.
ADOLESCENT CANNABIS USE, PSYCHOTIC-LIKE EXPERIENCES, AND THEIR IMPACT ON BRAIN WHITE MATTER IN A SAMPLE OF DEVELOPING ADOLESCENTS
(2025-08-21) Ponto, Nicole; Not Applicable; Master of Science; Department of Medical Neuroscience; Received; Frank MacMaster; Not Applicable; Sabina Abidi; Matthias Schmidt; Candice Crocker; Philip Tibbo
Adolescence is a sensitive period of white matter development, during which cannabis use and psychotic-like experiences (PLEs) each increase risk for later psychotic disorders. This thesis examined whether cannabis use and PLEs have interactive effects on adolescent white matter microstructure and neuroinflammation. A total of 123 adolescents (aged 15–16; 36 cannabis users, 87 non-users) completed structured interviews and MRI scans. To address methodological limitations, I first developed and validated the first adolescent population-specific white matter atlas (n = 54 screened healthy adolescents). Using this atlas, I then compared white matter metrics across cannabis users, PLE+ individuals, and controls. No significant group differences or cannabis × PLE interactions were observed. Exploratory analyses highlighted sex differences and associations with continuous cannabis use. These findings provide a novel foundation for adolescent diffusion MRI and suggest that larger samples and dimensional measures are required to clarify neurodevelopmental risk pathways to psychosis.
Evaluating the Usability of DronePIT: A VR Drone Pilot System with Expert Pilots
(2025-08-19) Ranapurwala, Amaan; Not Applicable; Master of Computer Science; Faculty of Computer Science; Received; Dr. Rina Wehbe; Not Applicable; Dr. Joseph Malloch; Dr. Derek Reilly; Dr. Mayra Barrera Machuca
In the last few years, industries like infrastructure, energy, and emergency services have started using drones for aerial inspections due to their low cost and size. Yet, training drone pilots remains costly, time-intensive, and limited by physical constraints. One way to solve this issue is to use Virtual Reality (VR), as an alternative for traditional courses. This thesis presents \system, a VR drone training system designed in collaboration with drone industry professionals that incorporates real-world training scenarios. The system has three phases to simulate learning, navigation, and inspection tasks. Twelve experienced drone pilots evaluated \system in a usability study. Participants interacted with \system, completed standardized usability and workload questionnaires (including the VRSQ, and NASA-TLX), and participated in post-experience interviews. Behavioural metrics such as trajectory efficiency, task completion times, and control stability to understand pilot performance were also captured.
Results indicate that participants perceived \system as highly usable, with minimal simulator sickness and low cognitive load. Participants also reported that the virtual flying experience closely matched their real-world expectations and habits. Behavioral data showed that expert pilots navigated and controlled the drone in VR in ways that mirrored their real-life techniques, supporting the idea that VR can elicit authentic motor and decision-making patterns when designed appropriately. This thesis contributes to the broader field of VR-based training by highlighting how evaluating task-specific systems with expert users can improve learning outcomes and reduce the cost and risk of VR training systems.
“I was just taking to suit myself”: Jack Turner’s Photographic Life from Western Prince Edward Island to the Western Front
(2025-08-21) Bulger, Meaghan Kathleen; Not Applicable; Master of Arts; Department of History; Not Applicable; n/a; Not Applicable; Dr. Kassandra Luciuk; Dr. Sara Spike; Dr. Lisa Binkley
Photography is a technological engagement with the act of seeing, and its presumed “authenticity” through technological reproducibility was both valued and feared by the Canadian government. A gunner from O’Leary Prince Edward Island named Brenton Harold “Jack” Turner defied censorship regulations to document his war. From 1915-1919, Turner bore unflinching photographic witness to both the horrors of modern warfare and the necessity of community, without which his clandestine photographs would not exist. The war changed his relationship with photography, and he did not pick up a camera for decades afterwards; perhaps he only saw a landscape he may have felt partially responsible for destroying. Eventually, Turner returned to his wartime images, processing those harrowing experiences into “memory objects.” In inspiring empathy for the individual soldier-photographer reflecting on his experiences, Turner's reflective pieces challenge the national imaginary of the Great War by bearing material witness to the personal trauma of warfare.
PEROXISOME-METABOLISM IN THE REGULATION OF IMD (TNF) PATHWAY
(2025-08-21) Mu, Yizhu; No; Doctor of Philosophy; Department of Microbiology & Immunology; Not Applicable; Dr. Daniela Ribeiro; No; Dr. Zhenyu Cheng; Dr. Nicanor Gonzalez-Morales; Dr. Deniz Top; Dr. Francesca Di Cara; Dr. Paola Marcato
Aberrant NF-κB signaling drives chronic inflammation. Using Drosophila melanogaster, I investigated the Immune Deficiency (IMD) pathway, analogous to mammalian TNF signaling, which activates NF-κB against Gram-negative bacteria. My research identified peroxisomes as novel regulators of this pathway. Peroxisome-derived diacylglycerol (DAG) promotes the formation of Imd amyloid-like structures in macrophages, a critical step for NF-κB activation. Immunofluorescence and qPCR revealed that amyloid formation strongly correlates with transcription of antimicrobial genes, whereas peroxisome-deficient cells failed to form amyloids and mounted poor immune responses. Overall, my Ph.D. research uncovers a conserved immuno-metabolic circuit in which peroxisomes control TNF-NF-κB activation, providing insights into host defence and potential therapies for TNF-mediated immune disorders in humans.