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Assessing the Waterfowl Forage Value of Wetland Plant Communities
No full textInvasive Phragmites australis continues to threaten wetland biodiversity and reduce food availability for waterfowl across North America. Assessing how vegetation responds to suppression efforts, and how these changes influence forage quality, is essential for informing management. In this study, I adapted the Vegetation Forage Quality Index (vFQI) for use in southern Ontario by developing updated forage value coefficients through expert elicitation. I also introduced a new tool, the Weighted Mean Waterfowl-forage Coefficient (WMWCs), modified to reduce the influence of species richness on the index score. I tested both indices in wetlands of the Long Point and Big Creek National Wildlife Areas, where P. australis suppression was conducted to evaluate the impact of suppression on waterfowl forage value. Field surveys (2022-2023) revealed that the WMWCs, but not the vFQI, successfully distinguished among invaded, treated, and reference sites, detecting improved forage quality in treated areas two years post-treatment. However, neither index was strongly correlated with empirical seed mass data from sediment cores, suggesting that seed biomass alone may not fully reflect foraging value. This study highlights the limitations of richness-sensitive indices like the vFQI and demonstrates the potential of WMWCs as a more robust indicator of wetland forage quality for waterfowl. Recommendations for future work include validation with bird observations and long-term monitoring to better capture temporal recovery dynamics
The Dependence of Halo Mass on Galaxy Size at Fixed Stellar Mass and Colour using Galaxy-Galaxy Lensing
No full textTo advance our holistic understanding of galaxy formation physics, we must examine the relationship between baryonic matter and dark matter (DM) within the universe. In this thesis, we investigate the correlation between dark matter halo mass and galaxy size at fixed stellar mass and colour. Using galaxy-galaxy lensing, we measure excess surface density (ESD) profiles for red, early-type galaxies from the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging survey, with shape measurements from the Ultraviolet Near Infrared Optical Northern Survey (UNIONS). We model the lensing signal using a conditional stellar mass function (CSMF) halo occupation distribution (HOD) calibrated on the AbacusSummit simulations and adopt a power-law relation between halo mass and galaxy size at fixed stellar mass: Mh ∝ r^ηeff . To fit the HOD parameters to the observationally measured ESD vectors, we train and utilize neural-network emulators, a form of non-linear interpolators. The analysis performed in this work follows a two-step process. First, we fit the HOD parameters to the ESD vectors corresponding to three stellar mass bins, not split further into two size bins. We freeze the best-fit HOD parameters and generate the corresponding best-fit mock catalogue. Using this best-fit mock catalogue, we apply our halo mass-size model and fit to the size-split observational ESD measurements. For central galaxies with stellar mass 10.5 ≤ log10(M⋆/M⊙) < 11.2, we find no significant correlation. At higher stellar masses, 11.2 ≤ log10(M⋆/M⊙) < 11.78, we detect a positive correlation with ηcent = 0.51 ± 0.14. A linear fit as a function of the logarithm of stellar mass yields a slope of sηcent = 0.66 ± 0.28, indicating that the halo mass-size correlation strengthens with increasing stellar mass. For satellite galaxies, we observe a negative correlation at low and intermediate stellar masses for the host halo mass-galaxy size relation of ηsat = −0.19 ± 0.05 and ηsat = −0.09 ± 0.05, respectively. The correlation is consistent with zero within the stellar mass range of 11.2 ≤ log10(M⋆/M⊙) < 11.78
Message Received: An Examination of Disabled Voice, Choice, and Understanding in Susan Glickman’s The Discovery of Flight and Lynn Coady’s Watching You Without Me
No full textThis thesis examines how disabled voice, agency, and understanding are represented in two Canadian novels: Susan Glickman’s The Discovery of Flight and Lynn Coady’s Watching You Without Me. Using a framework that I call the “Pendulum of Understanding,” I explore how characters with physical and intellectual disabilities are listened to (or not) by those around them, and how this affects their narrative presence and autonomy. Through close reading and the lens of disability studies theory, I argue that while both novels attempt to centre disabled characters, the type of disability significantly impacts how voice is facilitated and understood. Libby, a physically disabled character with access to assistive technology, is given narrative space and agency. Kelli, who has an intellectual disability, is often filtered through the assumptions of others. This comparison reveals a broader discomfort with voices that require a form of intellectual facilitation, and a tendency to either neglect or assume understanding. Ultimately, this project calls for a more nuanced, ethical approach to imagining disabled voices so that knowledge and humility are balanced to achieve appropriate understanding
Scattering Rate Modeling in Semiconductor Quantum Wells and Quantum Cascade Lasers Using the 8-band k·p Formalism
No full textAccurate modeling of electron scattering is critical for understanding and optimizing carrier transport in semiconductor heterostructures such as quantum wells (QWs) and quantum cascade lasers (QCLs). In this thesis, we present a comprehensive study of scattering rate calculations using an advanced 8-band k·pformalism that incorporates nonparabolic band dispersion, multiband coupling, and k-dependent wavefunctions. This approach allows for precise modeling of subband structures and associated scattering mechanisms, such as longitudinal optical (LO) phonon, impurity, interface roughness (IFR), and alloy disorder (AD) scattering, which strongly influence electron lifetimes and optical transition rates in QCLs. There are mainly two parts of this work. The primary objective of the first part work is to determine the interface roughness (IFR) and alloy disorder (AD) scattering parameters (Λ,∆,VAD) by fitting simulated electron subband scattering rates using the 8-band k·p model to pump-probe measurements for three InGaAs/AlGaAs quantum well samples. This fitting process, although is not sufficient to uniquely determine the AD, IFR parameters, gives a narrow range of those parameters, and serves to validate the accuracy of the 8-band k·p formalism. By only using 1-band model, the scattering rate is overestimated by ∼66% in a QW tuned at λ21 ∼5 µm, while using the 8-band model, a good agreement with the experimental data is obtained by properly choosing the aforementioned parameters. The reason this fitting is insufficient to narrow down those parameters to single value is due to the inherent time resolution of the pump-probe experiments, and the fact that alloy disorder and interface roughness scattering are processes of the same nature. To find the exact value of those parameters, one possible way would be associating this method with other material characterization techniques, such as ultra-high vacuum scanning tunneling microscope or electron tomography. Above all, this analysis confirmed the cruciality to consider not only the correct dispersion but also the k-dependent band-mixing effect. The second part then extended to InAs/AlSb-based QCL structures to investigate the k-dependent confinement effect. When the wavevector k increases from zero, the shape of the wavefunctions will become more concentrated in one quantum well. This phenomenon, neglected in previous studies, directly affect the form factor in Fermi’s Golden Rule and consequently has a significant impact on the transition rate. Two QCL structures are simulated with the same model in the first part. The wavefunctions and dispersion relations for each subband are calculated using 8-band k·pformalism. The primary focus is placed on the photon transition levels, with the higher energy state refered as the Upper Lasing State (ULS) and the lower energy state as the Lower Lasing State (LLS). In the simulation, the pair of subbands whose energy separation most closely matches the experimental photon energy is selected as the ULS and LLS. The ULS is fixed at k= 0, while the LLS is evaluated at various wavevector values k. The qualitative change of the LLS wavefunction with increasing k directly demonstrate the confinement of wavefunction caused by the higher k value. The corresponding quantitative change is also shown by a defined parameter called static dipole, which measures the spatial separation between the expectation values of the ULS and LLS wavefunctions. Since the ULS remains fixed at k= 0, the seperation change
is cauesd by the LLS alone, therefore, is an effective indicator for the LLS confinement effect. This study further underscores the necessity of incorporating both k-dependent wavefunctions and nonparabolicity when calculating scattering rates. What’s more, it further underscores the importance of incorporating k-dependent wavefunctions in accurate scattering rate calculations
Approaching Memorization in Large Language Models
No full textLarge Language Models (LLMs) risk memorizing and reproducing sensitive or proprietary information from their training data. In this thesis, we investigate the behavior and mitigation of memorization in LLMs by adopting a pipeline that combines membership inference and data extraction attacks, and we evaluate memorization across multiple models. Through systematic experiments, we analyze how memorization varies with model size, architecture, and content category. We observe memorization rates ranging from 42% to 64% across the investigated models, demonstrating that memorization remains a persistent issue, and that the existing memorization-revealing pipeline remains valid on these models. Certain content categories are more prone to memorization, and realistic usage scenarios can still trigger it. Finally, we explore knowledge distillation as a mitigation approach: distilling Llama3-8B reduces the extraction rate by approximately 20%, suggesting a viable mitigation option. This work contributes a novel dataset and a BLEU-based evaluation pipeline, providing practical insights for research on LLM memorization
A Seat at the Table: Placemaking in the Hong Kong-Canadian Diasporic Landscape
No full textGathering is present in every aspect of Chinese culture - its customs, traditions, and celebrations. This act of gathering provides community, a shared strength in celebration, but it also reveals the social nuances of the community. In the North American diaspora, it provides protection against prejudice, community, and the tools to teach and grow, offering opportunities for grandparents to teach grandchildren about their culture. Food accompanies this crucial act of gathering as a vehicle for cultural transfers of knowledge. Bringing a group of people of different ages and lives together over food and conversation is an act of solidarity, of sharing, and an expression of care. It has provided the very foundation for the formation of Chinatowns and their surrounding ethnoburbs, as places to keep an eye out for one another amid exclusion, and it is this very act of gathering over food specifically that provided the first stepping stone in the Canadian acceptance of Chinese culture.
The Chinese restaurant provides the arena for food and gathering to take place, a key player in the transfer of cultural knowledge between the generations of Hong Kong-Chinese immigrants that reside in the Greater Toronto Area - namely in Markham, Richmond Hill, and Scarborough. Restaurants are known to adapt and shift with the current times, but in the recent years, through modes of gentrification, an influx of anti-Asian racism following Covid-19, and the aging of the first-generation Chinese immigrants that had in Canada in the late twentieth century, the traditional and beloved Chinese restaurant typology that has anchored neighbourhoods for decades face a much more rapid and drastic change.
Through analysis of Hong Kong settlement patterns across the Greater Toronto Area, this thesis reveals the integral role the restaurant plays in the Hong Kong-Canadian diaspora and its network of businesses. It investigates the often unsaid part of Chinese culture that is intergenerational knowledge sharing, and speculates on what tools may be carried down to the second and third-generation Hong Kong immigrant to imagine what the Chinese restaurant can become. This thesis uses analysis of placemaking and memory, accompanied by interviews and ethnographic drawing studies to come to a written projection of the trajectory of the Chinese restaurant, understanding the ways in which culture defines space and how space can, in return, preserve culture. The research provides an analytical approach to understand the Hong Kong culture that has stood the test of time, through the movement across continents and political upheaval, and speculates on what is needed to maintain its ground against rising threats of financial instability, gentrification, and change in the customer landscape. The Chinese restaurant, a silent yet crucial contributer to the community, may be considered a regular spot today, but is a pillar of Chinese culture, specifically Hong Kong culture, that stands to be preserved
Failure in Disability Game Studies
No full textdisability, game studies, disability game studies, media studies, tabletop roleplaying game, game design, performance, disability performance media, reparative play, simming, neurodivergent, ethnography, research creation, queer failur
Unregulated drug use in Sudbury, Ontario: A rapid ethnography examining risks and harm reduction service access in the North
No full textBackground: Unregulated drug use in Ontario, Canada, has led to high rates of HIV, Hepatitis C, and drug overdose mortality. This crisis disproportionately impacts people who use drugs (PWUD) in Northern, rural, and smaller urban Canadian communities due to barriers such as limited resources and heightened stigma. For example, Sudbury, Ontario, has over double the provincial overdose rate. Supervised consumption sites (SCS) are intended to address these individual and community harms. However, the only SCS in Sudbury, The Spot, closed as of March 2024. The current thesis had the following objectives: i) Understand any perceived impacts of the local SCS closure, ii) Explore how necropolitics and structural violence create harm towards PWUD, iii) Qualitatively visualize areas of drug use, harm reduction sites, and participants’ living locations, iv) Provide recommendations to local organizations to address harm reduction gaps, and v) Provide research that addresses the literature gap regarding the health and well-being of Northern PWUD.
Methods: We conducted a community-based rapid ethnography, which included naturalistic observations, semi-structured interviews (n=27), and spatial mapping. The data were analyzed thematically using a participatory analytic approach.
Results: In Chapter Four, participants identified four key ways the SCS closure impacted them. They reported using substances unsupervised, which increased risks associated with isolated drug use. This led some to begin using drugs in public as a harm reduction strategy, hoping for intervention in case of an overdose; however, public use triggered fears of police intervention and social stigma if they were observed. Furthermore, losing an SCS resulted in social isolation and barriers to accessing harm reduction supplies, as the stigma associated with public health sites caused participants to avoid them altogether.
In Chapter Five, our geospatial analysis of data derived from interviews, ethnographic observations, and peer knowledge allowed for a visualization of drug use, harm reduction access points, and living locations among participants. Our maps illustrate different daily geographies between those who used The Spot and those who did not. Overall, clients of The Spot had activity zones more centralized to downtown Sudbury than those who didn’t use services at The Spot, as the latter had more geographically sparse and distant activity zones.
Conclusion: Northern and rural communities face unique barriers to accessing harm reduction services amid Canada’s current toxic, unregulated drug supply crisis. The closure of the only SCS in Sudbury, Ontario, with no replacement service planned in the foreseeable future, has resulted in participants increasingly consuming unregulated drugs in dangerous ways, leading to an increase of stigma, social isolation, and additional barriers to accessing health services. Furthermore, an apparent geospatial mismatch has been identified between the preferred areas for health services among participants and the locations of those services. Overall, we find that Sudbury’s layout of unregulated drug use is unique, fluid, and influences Sudbury’s high unregulated drug mortality rate
Framing Sustainability: An Analysis of How Cosmetic Brands Integrate Sustainability into Marketing Communication
No full textThe cosmetics industry is a rapidly growing global sector, valued at over $650 billion, with continued expansion driven by lifestyle changes, novel marketing strategies, and digital marketing. However, this growth has raised serious environmental and social sustainability concerns. Amid these challenges, sustainability communication has become a critical arena through which brands position themselves as sustainable and responsible. Understanding how brands frame and integrate sustainability is essential for evaluating the holistic nature, credibility, inclusiveness, and transparency of their marketing practices.
This dissertation explores how sustainability—both environmental and social—is communicated by cosmetic brands through product-level marketing. Situated within the field of sustainability management, the research applies message framing theory as its core theoretical framework to examine how sustainability is defined, constructed, and communicated across different brand categories. Through four interrelated studies, the dissertation provides a multi-dimensional analysis of sustainability communication in the cosmetics industry, with a particular focus on the growing influence of fast beauty, the rise of sustainability-positioned brands, and the evolving expectations around sustainable practices, equity, inclusion, and transparency.
The first manuscript presents a systematic literature review of academic research on sustainability in the cosmetics industry between 1992 and 2022, revealing a strong disciplinary bias toward science and engineering, with limited contributions from the social sciences—particularly in areas such as marketing communication and stakeholder behaviour, as well as a notable lack of research focused on the Canadian context. The second manuscript examines how sustainability is framed in colour cosmetic marketing, specifically lipsticks, using message framing theory and the social construction framework to assess differences in sustainability-related claims, transparency, and greenwashing across leading, fast beauty, and sustainable brands. The third manuscript extends this investigation to skincare products, specifically moisturizers, again guided by message framing theory and the social construction framework. It highlights continued reliance on vague and unverified sustainability-related claims, limited transparency, and the selective construction of sustainable skincare. Both studies draw on mystery shopping and content analysis to explore how sustainability is constructed in brand communication. The fourth manuscript shifts to the social dimension of sustainability by analyzing how brands integrate inclusion and diversity in lipstick and facial moisturizer marketing. This study also used mystery shopping and content analysis, drawing on message framing and social identity framing lenses, it finds narrow and inconsistent presence of inclusive beauty, with most brands aligning representation with marketable ideals.
Together, these studies demonstrate that sustainability communication in the cosmetics industry is often selective, emotionally driven, and shaped by brand positioning and market pressures. Claims such as "natural," "vegan," and "cruelty-free" are commonly emphasized, while complex or controversial topics—such as labour rights, environmental impacts beyond packaging, or accessible design—are frequently omitted. The prevalence of vague and unverified claims points to widespread greenwashing, which risks undermining consumer trust. By integrating content analysis and mystery shopping methods across two product categories and three brand category types, this research reveals how communication practices both reflect and shape the evolving meaning of sustainability in the marketplace.
This dissertation contributes to scholarship in sustainability marketing and management by offering critical insight into the framing strategies that brands use to communicate sustainability. It highlights the need for more transparent, comprehensive, and socially responsible narratives if the cosmetic industry is to align with the broader goals of sustainable development. Communication, as shown here, is not merely a promotional tool—it is a central mechanism through which sustainability is defined, enacted, and contested. In addition, this work develops a conceptual framework for assessing the integration of sustainability into marketing communication at the product level. This framework is adaptable and can be applied to different types of products or services across various brand categories, offering a structured approach for future research and practical evaluation
Design, Fabrication, Packaging, and Characterization of Nano Inertial and FET Sensors
No full textMiniaturization is necessary and unavoidable for the advancement of sensor technology. This thesis explores the effect of miniaturization on performance and proposes solutions to addressed challenges through the development of a novel packaging solution and engineering device interfaces.
First, a theoretical model is developed to understand the impact of miniaturization on sensor properties such as sensitivity and signal-to-noise ratio for nano and micro electro mechanical systems-based (N/MEMS-based) gas sensing applications. Then, these theoretical predictions are experimentally verified through the experimental comparison of NEMS and MEMS-based humidity sensors. The experiments confirm that miniaturization enhances the sensitivity of inertial gas sensors. However, it also introduces challenges such as lower signal-to-noise ratio (SNR) due to attenuated output signals that are more susceptible to noise, thereby motivating the development of improved packaging and interface solutions.
To minimize the noise sources, a novel packaging technique, called built-in packaging, is proposed and performance of MEMS resonators and metal-insulator-metal (MIM) diodes are compared with the conventional techniques such as wire bonding and probing. Experimental results show that built-in packaging methods enhance output signal levels by 12\% while preserving overall performance.
Finally, to implement novel materials into sensing technologies, interface engineering is studied for development of colloidal quantum dot based field effect transistors (CQD-based FETs). These devices can quantify the electrical properties of novel CQDs and highlights the importance of interface engineering. The quantified results accelerates the development of improved CQDs, leading to better photodetector performance in infrared (IR) detection.
Overall, this thesis presents a detailed analysis of the trade-offs in sensor miniaturization and provides critical insight for the advancement of compact and high-performance sensors