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Recent Submissions

Access status: Open Access ,
UTILIZING MACHINE LEARNING TO DETECT TOR TRAFFIC: A REALISTIC DATASET AND A PRELIMINARY ANALYSIS
(2025-12-15) Sadik, Md Rafiqul Islam; Not Applicable; Master of Computer Science; Faculty of Computer Science; Not Applicable; Dr. Xichen Zhang; Not Applicable; Dr. Samer Lahoud; Dr. Qiang Ye
With the increasing use of anonymization technologies such as the Tor network, the ability to accurately differentiate Tor traffic from conventional Internet traffic has become an important challenge for network analysis and security monitoring.This thesis presents a fully controlled and reproducible framework for generating realistic Tor and Non-Tor traffic datasets to support the evaluation of encrypted traffic detection techniques. The framework integrates a Debian workstation, a Whonix gateway for Tor routing, and a noise-free AWS-based web server, combined with Selenium-driven automation to execute identical user activities over both Tor-based and Non-Tor-based network paths.Using this environment, a comprehensive dataset was generated across six application categories: web browsing, video streaming, file transfer, instant messaging, voice over IP, and video conferencing. A set of six machine-learning models-Decision Tree, Random Forest, XGBoost, Multilayer Perceptron (MLP), Convolutional Neural Network (CNN), and Recurrent Neural Network (RNN) was evaluated on the generated dataset. Experimental results demonstrate that traditional treebased models, particularly Random Forest and XGBoost, consistently outperform deep-learning approaches, achieving high detection accuracy in distinguishing Tor from Non-Tor network flows across all traffic types.These findings highlight both the effectiveness of classical machinelearning approaches and the importance of realistic dataset generation in advancing encrypted traffic classification research.
Access status: Open Access ,
Continuous Ceilometer-Derived Mixed Layer Height Observations at an Eddy Covariance Flux Tower Site in the Semi-Arid U.S. Southwest
(2025-12-15) Mengering, Deklan; No; Master of Science; Department of Physics & Atmospheric Science; Not Applicable; n/a; Not Applicable; Rachel Chang; Daniel Nadeau; Manuel Helbig
The planetary boundary layer (PBL) is the atmospheric layer directly influenced by the Earth’s surface. The height of the top of the PBL (PBLH) is a key parameter that determines the extent of vertical mixing, which plays a crucial role in micrometeorology, pollution dispersion, and the exchange of energy and matter between the land and the atmosphere. In the past, PBLH estimates have relied largely on observations with low temporal resolution (radiosondes) or on modelling outputs (reanalysis). However, growing interest in the integration of PBLH measurements at surface energy flux tower sites has highlighted the temporal, spatial, and financial trade-offs that come with different PBL height measurement techniques. Of the available techniques, ceilometers offer a promising solution, as they have the potential for wide-range integration at a comparatively low cost. However, there is no publicly available, cross-platform algorithm for the detection of the PBL using ceilometer data. In this study, we developed a Python-based algorithm that can be applied to Lidar backscatter profiles from different ceilometer types. We use this algorithm to create a 5-year time series of PBLH estimates from a semi-arid high desert ecosystem in Arizona. The ceilometer PBLH estimates were compared to PBLH estimates using three independent approaches: reanalysis data, nearby National Weather Service radiosonde observations, and on-site field radiosonde campaigns. We use these estimates to validate the PBL heights derived using the newly developed algorithm. The time series of PBLH measurements is then used in combination with surface energy flux observations to investigate the relationship between PBL growth dynamics and the surface energy balance measured at a nearby flux tower. The maximum daily mean PBLH occurred in June, reaching 3100 m when the median Bowen ratio for the month was 2.6. The PBLH then decreased by 200 m in July, and another 300 m in August when the Bowen ratios dropped to 0.7 and 0.2, respectively. The results show that strong land-atmosphere coupling is characteristic for the site, with both the terrestrial (i.e. soil moisture to surface flux) and the atmospheric (i.e., surface flux to boundary layer atmosphere) legs playing an important role for the seasonal dynamics of PBLH. This study demonstrates how ceilometer-derived PBLH estimates at surface energy flux tower sites can be used to improve the current understanding of land-atmosphere coupling.
Access status: Open Access ,
UNDERSTANDING THE EXPERIENCE OF PHYSICAL DISABILITY AMONG PEOPLE LIVING WITH HIV: A QUALITATIVE STUDY
(2025-12-16) Shahzadi, Anita; No; Master of Science; School of Physiotherapy (Rehabilitation Research); Received; na; No; Caitlin McArthur; Kelly O'Brien; Lisa Barrett; Sorayya Askari; Adria Quigley
Since the advent of antiretroviral therapy, people living with HIV (PLHIV) are living longer but increasingly experience physical disability. The primary objective of this study was to understand the experience (presence and impact) of physical disability among PLHIV. The secondary objective was to understand the influence of extrinsic and intrinsic contextual factors. Interview guide developed using the Episodic Disability Framework and items from existing physical performance measures. Semi-structured interviews conducted online were audio-recorded, transcribed verbatim, and analyzed using hybrid inductive-deductive thematic analysis. Fifteen participants completed the World Health Organization Disability Assessment Schedule (WHODAS 2.0), indicating moderate disability, while interviews revealed seven themes: physical symptoms and impairments; reconstituting day-to-day activities; social disconnection and relationship changes; the episodic nature of disability and uncertainty; intrinsic strategies for resilience and adaptation; extrinsic unmet rehabilitation and service needs; and triggers. The findings from this study contribute to understanding the experience of physical disability among PLHIV.
Access status: Embargo ,
Detecting Influenza A Viruses in Surface Water: A Comparison of Passive Sampling to USEPA Method 1615
(2025-12-16) Prest, Taylor; Not Applicable; Master of Applied Science; Department of Civil and Resource Engineering; Not Applicable; n/a; Not Applicable; Amina Stoddart; Gordan Price; Graham Gagnon
Climate change, urbanization, and agricultural intensification are increasing the risk of viral contamination in surface waters, which act as reservoirs and transmission pathways for waterborne viruses. Influenza A (INFA), specifically, avian influenza strains, carried primarily by wild waterfowl, pose significant threats to animal, human, and economic health, making freshwater environments optimal for early surveillance. This study evaluated the performance of granular activated carbon (GAC)-based passive samplers paired with reverse transcription quantitative polymerase chain reaction (RT-qPCR) for detecting INFA, avian influenza H5, and pepper mild mottle virus (PMMoV) genes in lakes and rivers across Nova Scotia. Passive samplers were deployed weekly at four lakes and one river, with INFA concentrations ranging from 1.7 × 104 to 5.6 × 1012 GC sampler-1 and H5 from 6.2 × 104 to 1.8 × 1011 GC sampler-1. PMMoV was detected at two sites. Detection frequency corresponded with fall migration and waterfowl presence, while emphasizing the influence of wildlife, agriculture, and wastewater inputs. When compared to an adapted USEPA Method 1615 (electropositive filtration), GAC based passive sampling displayed comparable INFA detection, detected H5 where filtration did not, and missed PMMoV detections captured by filtration. Field and bench-scale analyses of NanoCeram filtration indicated no significant difference in detection across tested flow rates (4, 7, 10 LPM) and volumes (84.6 to 360 L). These findings highlighted the strong potential of GAC-based passive sampling as a feasible and complementary tool for avian influenza surveillance in freshwater systems.
Access status: Open Access ,
HEALTH SYSTEM READINESS TO ADDRESS THE NEEDS OF SURVIVORS OF DOMESTIC AND SEXUALIZED VIOLENCE DURING AND BEYOND PREGNANCY: A MIXED-METHODS STUDY OF SURVIVORS AND REPRODUCTIVE HEALTHCARE PROVIDERS IN NOVA SCOTIA, CANADA
(2025-12-15) Cullum, Jessie; No; Master of Science; Department of Community Health & Epidemiology; Not Applicable; NA; No; Michelle Dimitris; Jill Hayden; George Kephart; Alexa Yakubovich
Background: Intimate partner violence, the most common form of violence against women, was declared an epidemic in Nova Scotia in September 2024. The perinatal period is a time of heightened vulnerability to IPV and its health impacts, making reproductive healthcare (RHC) an opportune intervention point. However, the capacity to manage VAW across RHC in Nova Scotia is unknown. Objectives: (1) To describe the health status, experiences of violence, and characteristics of service access among survivors of domestic and sexualized violence (DV/SV) with recent pregnancies across Eastern Canada, and (2) to describe the readiness (including knowledge, opinions, and practices) of RHC professionals (RHCPs) in Nova Scotia to manage DV/SV. Methods: This convergent mixed-methods study used data from The Interprovincial Violence Against Women Project, which conducted online surveys with survivors who sought supportive services since the onset of the COVID-19 pandemic in March 2020 and health professionals working across Nova Scotia. Two study samples and subsamples were included in the present study: (1) 188 survivors, including 63 survivors with recent pregnancies; and (2) 1,649 healthcare providers, including 206 RHCPs. I descriptively analyzed quantitative data, applied reflexive thematic analysis to qualitative data, and then integrated each strand to address each of my objectives. Results: Survivors with recent pregnancies reported increased exposure to physical IPV and substantial barriers to care, including fear of police and child protective services, which were expanded upon in the first qualitative theme “control exerted by justice-related bodies.” They often reported chronic illness and heightened vulnerability to physical IPV, which the second qualitative theme, “the impact of COVID-19 restrictions on survivor-mothers” demonstrated were intensified during the COVID-19 pandemic. RHCPs reported limited preparedness to assess the safety of a survivor’s child, which contrasted the third theme, “centering the family and child impacts of DV”, where child safety was highlighted as a priority of their role. Lastly, they also reported a limited capacity to address DV/SV among patients, which the final qualitative theme “responding to perinatal DV/SV through a trauma-informed lens” contextualized as a lack of capacity to provide trauma and violence-informed care, a key strategy used by RHCPs to address DV/SV. Conclusions: This thesis is the first Canadian mixed-methods study to investigate both the needs of perinatal survivors and the capacity of RHC to attend to these needs. Findings reinforce the unique needs of survivors in and around pregnancy, including experiences of more severe intimate partner violence and considerable barriers to care, often centred around inadequate childcare support and fear of justice involvement. RHC should adapt intervention strategies for addressing DV/SV among patients that attends to these unique needs, including tailored training for providers and appropriate resourcing for safe and effective identification and response, including referral supports.
Access status: Open Access ,
EFFECT OF MICRONIZED COPPER AZOLE (MCA) ON FUNGAL AND DECAY RESISTANCE OF CANADIAN TIMBER SPECIES
(2025-12-13) Sullivan, Erin; Not Applicable; Master of Science; Faculty of Agriculture; Not Applicable; NA; No; Dr. Kimberly Pennie; Dr. Lord Abbey; Dr. Sophia He; Dr. Chijioke Emenike
The efficacy of the wood preservative micronized copper azole (MCA) was evaluated using two fungal studies: a bioassay plate study and a soil/block study. Five fungal species and six Canadian wood species were used for the experiments. The bioassay study tested all fungal species against ten different treatments. The soil/block study examined both fungal and wood species at nine different treatments. The bioassay revealed MCA concentrations of 1.5% and 2.0% were most effective at inhibiting fungi growth on petri plates. While the MicroShades natural brown (MSNB) additive dye yielded no significant effect on preservative performance. The soil/block study found that Canadian wood species treated with MCA were able to perform equally, and in some cases better, than the industry standard chromated copper arsenate (CCA). Results were concentration-specific and fungi-dependant for many wood species. Overall, MCA-treated Canadian wood species are effective in preventing mass loss against wood-rot fungi.