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Microplastic sedimentation in the northern Gulf of Mexico
No full textTo effectively mitigate plastic pollution, it is imperative to understand the transport of
microplastics in the water column. This research provides insights into the potential pathways of
microplastic sedimentation in the northern Gulf of Mexico (nGoM), such as incorporation into
fecal pellets and interactions with marine snow. The nGoM is a complex marine ecosystem,
affected by naturally occurring forces, such as strong currents and anthropogenic activities, such
as eutrophic river plumes and oil spills. It is a semi-enclosed sea that is regularly exposed to
inputs of sediments and nutrients, transported by large water systems such as the Mississippi,
Mobile and Atchafalaya rivers. For six consecutive years (2012 to 2018), time series samples
were collected with a McLane sediment trap, positioned within the nGoM (28°40.8 N 88°21.7
W), in the plume of the Mississippi, at a depth of 1520 m. We hypothesize that microplastic
sedimentation is driven by sinking marine particles. For the most final trap sampling year
(September 2017 to August 2018), we compare the seasonality of the vertical flux of particulate
organic carbon and nitrogen (POC/PON), calcium carbonate (CaCO₃) and biogenic silica
(bSiO₂), to the sedimentation of marine microplastics larger than 20μm. To prepare microplastics
for analysis, a gentle digestion step was used to remove excess organic material. Subsequently,
microplastics were isolated via density separation using a sodium tungstate dihydrate solution
(Na₂WO₄·2H₂O, density 1.6 g cm-₃). Potential microplastic particles are counted and
characterized by size, colour and shape using a compound microscope and Raman spectrometry
is used to determine the types of microplastics present. This research will strengthen our
understanding of sedimentation pathways of microplastics in the nGoM and similar
environments and ultimately contribute to the efforts to improve the health of anthropogenically
impacted marine systems
Echoes of my father: an autoethnographic exploration of fatherhood, memory, and learning
No full textThis thesis is an autoethnographic exploration of fatherhood, memory, and learning in post-revolutionary Iran. Rooted in personal narrative, it traces how my relationship with my father, at once historian, teacher, and companion in thought, shaped my identity as a daughter and a learner. Through storytelling, reflection, and cultural analysis, I examine how his quiet presence, emotional attentiveness, and trust in my intellectual abilities challenged conventional expectations of gender and authority in our society. Rather than offering a general account of Iranian fatherhood or womanhood, this thesis traces the singular yet resonant story of one man whose gentle, curious, and steadfast way of being opened space for dignity, mobility, and learning. It considers how memory becomes a method of both inquiry and connection, allowing the past to speak not only through facts, but through gestures, silences, bookshelves, and everyday rituals of care. The work culminates in a return to my hometown of Tabriz, where I hope to fulfill my father's long-held dream of opening a public library in his name. In doing so, I reflect on how private histories can offer quiet resistance to dominant narratives and how acts of remembrance can become forms of continuity, rooted not in nostalgia but in commitment. This thesis contributes to broader conversations about education, cultural memory, and identity by foregrounding lived experience, especially the ways in which learning takes shape through relationships that honor presence, trust, and mutual growth
Experimental investigation of mooring line damping for floating offshore wind turbines
No full textThis thesis investigates how different mooring line configurations affect the damping of floating offshore wind turbines. To study this, forced oscillation experiments were carried out at a 1:60 scale in the Memorial University of Newfoundland towing tank. A studless chain was tested in three setups: a semi-taut line, a bare catenary, and a buoy-assisted catenary. The tests were performed using a programmable linear actuator to impose low-frequency surge motions, while line tension and motions were carefully recorded.
The semi-taut line showed an increase in energy dissipation with larger oscillation amplitudes, especially when the line assumed a taut state. At shorter oscillation periods, drag forces dominated, resulting in higher energy dissipation but lower equivalent damping. For the catenary cases, static tests showed that the bare chain had higher initial stiffness than the buoy-assisted line, where the buoy reduced restoring stiffness by lifting the chain mid-span. Dynamic tests confirmed that energy dissipation increased with amplitude in both cases, but the buoy-assisted system showed stronger nonlinear effects, including slack–snap events. These led to much higher dynamic tensions, up to 8.2 times the minimum tension, compared with 2.9 times for the bare chain. The bare chain followed a near-linear trend between energy dissipation and the excitation parameter (ω²q³); the buoy case showed clear deviations
The politics of electoral reform in Canada: a case study of the 2015 unattempted reform
No full textElectoral reform is often promised but rarely delivered in established democracies, especially under First-Past-the-Post systems. This thesis examines Canada's 2015 federal electoral reform initiative as an unattempted reform, a proposal launched but never seriously pursued. It asks why the reform was initiated, what shaped its trajectory, and whether the governing Liberal Party's commitment was sincere or strategic. Using a qualitative single-case design, the study applies Shugart's (2008) model of reform initiation and Jacobs' (2014) process-tracing strategy. Two tools, congruence analysis and process tracing, assess whether inherent and contingent conditions for reform were present and evaluate sincerity of the Liberal Party's commitment. Evidence comes from parliamentary debates, reports, party documents, media coverage, polls, and election results. The findings show reform was initiated despite absence of systemic failure or strong incentives, and the Liberal Party's shifting stance reveals a strategic rather than sincere motivation. This exposes a blind spot in Shugart's model and leads to a sincerity filter, a tool to distinguish credible from symbolic gestures. The thesis contributes a theoretical refinement, a tool for assessing sincerity in electoral reform, and an empirical account of Canada's 2015 unattempted reform, with broader implications for understanding why electoral reform so often remains unrealized in First-Past-the-Post democracies
How emotional dysregulation and impulsivity impact the relationship between ADHD symptoms and binge eating symptoms in young adults
No full textADHD and binge-eating frequently co-occur. However, associated mechanisms of this comorbidity are still being investigated. Two possible mechanisms are emotional dysregulation and impulsivity. Emotional dysregulation has been identified as a core feature of ADHD and is also related to binge-eating. However, most studies on emotional dysregulation have only assessed dysregulation of negative emotions. Impulsivity is a core symptom of ADHD and empirical studies have shown that impulsivity is also associated with binge-eating behaviour. Research has not yet examined the combined impact of emotional dysregulation and impulsivity on the relationship between ADHD symptoms and binge-eating. The present study examined three research questions in young adults. First, are ADHD symptoms associated with binge-eating in young adults? Second, does emotional dysregulation mediate the relationship between ADHD symptoms and binge-eating? Both negative and positive emotional dysregulation will be examined. Third, does impulsivity moderate the direct relationship between ADHD and binge-eating, and does impulsivity moderate the mediation? Participants consisted of 451 young adults between the ages of 18 to 25 years recruited through psychology courses and advertisements on campus and social media between Fall of 2021 and Spring of 2022. Participants completed online questionnaires measuring ADHD symptoms, binge-eating behaviour, positive and negative emotional dysregulation, and impulsivity. Results showed that ADHD symptoms were significantly associated with binge-eating. Negative emotional dysregulation fully mediated this relationship and positive emotional dysregulation partially mediated this relationship. Low levels of impulsivity moderated the mediation when negative emotional dysregulation was the mediator, such that the mediation became stronger when impulsivity was at mean or low levels. Impulsivity did not moderate the direct relationship between ADHD symptoms and binge-eating
symptoms. Impulsivity did not moderate the mediating effect of positive emotional dysregulation on the relationship between ADHD symptoms and binge-eating symptoms. The present study highlights the importance of emotional dysregulation and impulsivity in the assessment and treatment of binge-eating in people with ADHD. In addition, the current findings suggest that an adapted approach may be needed when treating people for binge-eating problems who also have ADHD symptoms
Toward an ecological sublime: integrating Kant's aesthetics with Naess's ecosophy
No full textThis thesis develops the notion of the ecological sublime by integrating Immanuel Kant's aesthetics of the sublime with Arne Naess's ecosophy. Addressing climate change, biodiversity loss, and environmental degradation necessitates more than mere technical or policy interventions; it calls for a profound philosophical transformation of humanity's relationship with nature. Kant's sublime frames encounters with enormous natural forces as instances that validate human reason and moral autonomy. At the same time, Naess's ecosophy rejects anthropocentrism in favour of biospherical egalitarianism and the ecological self. Although Kant's framework often sustains a human-nature dualism, his idea of disinterested judgment resonates with Naess's critique of instrumentalism, creating fertile ground for dialogue. This study proposes that the emotional intensity of the sublime can be shifted from human transcendence to ecological kinship, thereby erasing the distinctions between self and nature.
The study examines the primary inquiry regarding the reconsideration of Kantian disinterested judgment to strengthen Naess's principle of biospherical egalitarianism. Sub-questions investigate the potential redefinition of the negative pleasure associated with the sublime as ecological humility instead of rational mastery, and how such a redefinition may stimulate ecological responsibility. Through a critical examination of Kant, Naess, and contemporary scholars, the thesis develops a normative framework positing that respect for nature strengthens ethical obligation. The ecological sublime consequently shifts aesthetic experience into ecological humility, harmonizing emotion with action.
This synthesis enhances environmental philosophy by redefining the sublime as a source of moral motivation instead of human superiority. It has real-world effects on ecological education, policy-making, conservation, and eco-art, where emotional experiences can inspire ecological commitment. The ecological sublime offers an emotionally powerful ethical basis for dealing with environmental problems by changing the idea of the sublime from power to devotion. Ultimately, it rethinks protecting the environment not as a duty to others, but as a way to find oneself in a shared biosphere
Machine learning for malware and intrusion detection: dataset design, cost-aware models, and research pitfalls
No full textInformation technology has reduced constraints of physical distance and delays associated with traditional methods in areas such as medicine, economy, industry, and
beyond. However, it also presents potential threats such as hackers and cybercriminals.
As information technology advances, threats become smarter and more complex,
cat-and-mouse-game that continuously increases in complexity.
Machine learning improves security tools such as malware or intrusion detection by
taking advantage of past experiences. Machine learning requires high-quality datasets
to create effective models.
The first paper in this thesis, eBPF-Powered Dynamic Analysis for Linux
Malware Detection: A Dataset and Experimental Study, explores the application
of machine learning to detect malware. The paper also introduces an automated
eBPF-based data collection pipeline using Docker containers to generate labeled malware
and clean environment traces. We construct a dataset of clean and infected
Linux operating systems and use various machine learning techniques to identify patterns
in Linux system calls that indicate whether the operating system is infected or
not, achieving a detection F1-Score of up to 99% with Random Forest models.
Machine learning can also be used to develop intrusion detection systems. Two
critical components of such systems are the dataset and the models. However, popular
network attack datasets suffer from imbalances, with significant disparities in the
number of instances between different classes (e.g., benign traffic can have thousands
of samples, while rare attack types may have fewer than 50). This imbalance can
severely affect model performance; for example, rare attack classes may be underrepresented
by a ratio of 40:1 compared to benign traffic, which can significantly reduce
recall for these classes. To address this issue, over- and undersampling methods balance
datasets before feeding them into the algorithms. However, undersampling may overlook important data, whereas oversampling can introduce redundancy, ultimately
weakening the model's performance. Furthermore, the speed with which an intrusion
detection tool makes decisions plays a vital role in its effectiveness. The second paper
in this thesis, titled Cost-Aware Machine Learning for Intrusion Detection:
A Performance Trade-Off Study, demonstrates that by sacrificing an insignificant
amount of accuracy, it is possible to achieve models that are tens of times faster
and significantly less memory-consuming, making them practical for real-time deployment.
This is accomplished by exploring the combination of different deep learning
and machine learning models, along with various over- and under-sampling methods.
Furthermore, the paper proposes twelve prediction cost functions that integrate these
trade-offs alongside traditional performance measures. A slow intrusion detection tool
can otherwise become a bottleneck in a network, highlighting the need for models that
balance accuracy and efficiency.
The third paper, titled Power and Pitfalls of ML-Based Intrusion Detection Systems, examines key challenges in developing machine learning-based intrusion
detection systems, with a focus on both dataset generation and model design.
It highlights issues such as the lack of representative datasets and the limited generalizability
of models. This paper examines ten significant research barriers and
their interconnections, which means that a barrier may lead to one or more barriers.
The study includes a statistical analysis of dozens of research papers, revealing the
current state of the field. Two best-practice checklists are proposed to guide future
work in dataset creation and IDS research, with the aim of improving the quality and
reliability of publications in this domain.
Together, these three studies provide a comprehensive framework for designing
more accurate, efficient, and trustworthy machine learning-based security tools such
as malware or intrusion detection systems. By combining practical data generation,
cost-aware modeling, and critical analysis of research pitfalls, this thesis contributes
to more robust and realistic security research and practice
Towed video surveys of the Davis Strait deep-sea marine environment: investigating the behaviour of mobile demersal species
No full textThe deep-sea Arctic environment presents a demanding habitat to evaluate. This region has unique and highly specialized species. Understanding their baseline behavioural tendencies is essential to determine how these species will react to a changing environment and monitoring methods. A proven method to collect baseline information is video technology. I compared and critiqued five types of technology: a drop camera, a Baited Remote Underwater Video (BRUV) system, a camera sled, a Remotely Operated Vehicle (ROV), and an Autonomous Underwater Vehicle (AUV). I analyzed footage collected by two video technologies, a towed video sled and a BRUV, for fish behaviour, orientation, assemblage, and vertical structure association. Results focused on Coryphaenoides rupestris (Roundnose grenadier), Macrourus berglax (Roughhead Grenadier), Synaphobranchus kaupii (Kaup's arrowtooth eel), Antimora rostrata (Blue Hake) and Family Myctophidae (lanternfishes). I created behavioural analysis trees to relate species' behaviour and orientation. I determined that behavioural traits displayed by species were likely correlated with life history traits. None of the species analyzed displayed a strong affinity for vertical structure. Overall, the towed video sled and BRUV were valuable tools for information collection. This research is expected to expand the foundation of baseline information available for mobile demersal species in the Davis Strait region
Reducing food waste through behavioral economics at the consumption level: evidence from a scoping review and an interventional study
No full textApproximately one-third of all food produced globally, around 1.3 billion tonnes, is wasted each
year. In high-income countries, much of this waste occurs at the consumption stage, in households,
restaurants, and institutional settings. In Canada, food waste accounts for over $60 billion annually.
This thesis investigates the potential of behavioural economics, specifically nudging, as a strategy
to reduce food waste through two integrated research components. The first is a four-week
intervention conducted in a restaurant in St. John's, NL. The intervention implemented three
nudging strategies to encourage customers to reduce waste. Food waste was measured daily
through leftover weight and takeout container usage. Results showed a reduction in plate waste
and an increase in the number of takeout boxes used. Findings demonstrated that low-cost and
non-intrusive nudges can positively influence consumer behavior in food service settings.
The second component is a scoping review that examines the global literature on behavioral
interventions to reduce food waste at the consumer level. The review identifies a range of
strategies, including portion design, incentives and social norm messaging, and summarizes their
effectiveness across different settings (e.g., households, restaurants, cafeterias). This research
provides practical implications for academic scientists, policymakers, food service providers, and
sustainability advocates
Social, lifestyle, and genetic determinants of multimorbidity clusters in middle-aged and older Canadian adults: an analysis of the clsa data
No full textBackground: Multimorbidity, defined as the co-occurrence of two or more chronic conditions, is increasingly prevalent among aging populations. Although lifestyle and socioeconomic factors contribute substantially, the genetic underpinnings of multimorbidity remain poorly understood.
Objectives: This thesis aimed to identify the most common multimorbidity (MCM) among middle-aged and older Canadian adults, and to investigate the prevalence, associated risk factors, and genetic susceptibility of MCM.
Methods: This study included 30,097 participants from the comprehensive cohort of the Canadian Longitudinal Study on Aging. Survey-specific multivariate logistic regression was used to identify significant risk factors of MCM. A polygenic risk score (PRS) was derived for each participant. The modification effects of the PRS on the association between age and risk of MCM were examined by a Genome-wide interaction study.
Results: Osteoarthritis–hypertension emerged as the MCM with a prevalence of 16.5% among middle-aged and older Canadian adults. Seven factors including increasing age, retirement, poor perceived health, sleep problems, obesity, urban core residence, and living in eastern provinces were significantly associated with increased risk of MCM. Ten genetic variants with an interaction term p-value <10-5 were selected to be included in the calculation of PRS for each participant. The participants in the top PRS tercile (top 1/3 PRS) exhibited the greatest risk of MCM. For each additional year of age, MCM risk increased by 13% (Adjusted Odds Ratio (AOR)=1.13, 95% Confidence Interval (CI): 1.11 – 1.15) in the top-PRS group compared with 9% (AOR=1.09, 95%CI: 1.07 – 1.12) in the middle PRS tercile and 10% (AOR=1.10, 95%CI: 1.08 – 1.12) in the low PRS tercile group.
Conclusion: Both social-environmental and genetic determinants jointly influence multimorbidity, highlighting the need for integrated prevention strategies and precision aging interventions in Canada