Newly Added Theses
Permanent URI for this collectionhttps://hdl.handle.net/10464/1147
Students enrolled in graduate programs at Brock University will be required to submit an electronic copy of their thesis to this repository as part of graduation requirements. Students are required to submit their thesis directly. Instructions on how to do this can be found online
Browse
Recent Submissions
Item Open Access Recognizing Whiteness: An Autoethnographic Examination of Whiteness in My Life(Brock University) Beres, Jacqueline L.; McGinn, Michelle; Department of Graduate and Undergraduate Studies in EducationThe purpose of this research was to examine whiteness not merely as an individual attribute but as an ideological and structural system that organizes everyday life and grants privilege to those perceived as white. Using a blend of critical and evocative autoethnography, I wrote stories about my life experiences. I drew on critical whiteness studies and critical race theory to expose how whiteness operates as a normative force in institutions, social interactions, and academic knowledge production. The analysis I undertook helped me understand how I was welcomed in public spaces like libraries whereas racialized individuals in similar settings have been left questioning whether they were being excluded. My analysis also illuminated how my whiteness insulated me from developing a rich understanding of Black culture, particularly the cultural significance of Black hair. This work prompted me to question the extent to which my conception of “safety” while travelling was, in fact, a coded interpretation of white superiority. In hopes of appealing to a general audience beyond academia, I adopted a non-traditional dissertation format. I used footnotes to deviate from the expected in-text citation system and create an additional, co-occurring text, which I offer as one (albeit very minor) form of action aimed at disrupting white dominance within academia. My research adds to the collection of work, and particularly critical whiteness studies, completed in response to the calls from racialized authors, scholars, and activists for white people to engage in anti-racist action. By weaving personal narrative with systemic critique, my aim is to contribute to dismantling white supremacy and promote sustained, justice-oriented action among white readers committed to anti-racism. Given that white people have a critical responsibility to identify whiteness and eradicate the oppression that we collectively perpetuate, I hope my findings can help white readers as they progress on their personal racial justice journeys. For racialized readers, I hope my study offers additional insight into how white people recognize—and often, fail to recognize—whiteness, along with how we attempt to dismantle whiteness and fight for racial equity.Item Open Access On the Optical Properties of the Misfit Layer Compound (PbSe)1+δ(NbSe2)n(Brock University) Respicio, Paul Carlo; Reedyk, Maureen; Department of PhysicsMisfit layer compounds (MLCs) are layered materials that consist of two different sublattices with a mismatch in at least one of their lattice parameters. This incommensurate mismatch along with charge transfer between the constituent sublattices gives rise to interesting properties and can potentially be tuned for practical applications. These systems can be understood using the framework of rigid band model and the changes in band filling depending on the extent of interlayer charge transfer. This thesis presents the optical properties of (PbSe)1+δ(NbSe2)n and their evolution as the number of NbSe2 layers, n, are varied. NbSe2 is a known transition metal dichalcogenide superconductor and PbSe is a semiconductor with a rocksalt structure. NbSe2 and n=1-3 samples were synthesized via chemical vapour transport and characterized via X-ray diffraction, energy dispersive X-ray spectroscopy, and atomic force microscopy. Further characterization from resistivity and magnetization measurements showed a decrease in the superconducting transition temperature, Tc, with decreasing n. Reflectivity measurements were analyzed using the Drude-Lorentz model and reveal a shift in the plasma frequency to lower energies as n decreases along with the broadening of their interband transitions when compared to pure NbSe2. This behaviour is consistent with increased band filling due to charge transfer from PbSe to NbSe2. Optical conductivity functions were obtained using Kramers-Kronig analysis confirm decreased conductivity for the MLCs and follow a similar pattern found in the resistivity measurements. Finally, frequency-dependent scattering rate and effective mass were obtained from the extended Drude model. Results show a region of purely Drude response in the scattering rate for the MLCs and a trend of decreasing mass enhancement with decreasing n at low wavenumber.Item Open Access Determining the Roles of the Aldehyde Dehydrogenase Enzymes 5 and 6 during Icewine and Table Wine Fermentation in a Commercial Wine Yeast Using CRISPR-Cas9.(Brock University) Ott-Peon, Nadine; Inglis, Debra; Centre for BiotechnologyCanada is known for Icewine which is fermented from grapes naturally frozen on the vine. Grapes are harvested below –8°C and pressed while frozen, trapping ice crystals inside the berries and releasing juice highly concentrated in sugars and acids. The high sugar juice environment (40°Brix) causes hyperosmotic stress for yeast, resulting in water loss, triggering glycerol production to act as an internal osmolyte to draw water back into the yeast cell, resulting in an NAD+ imbalance. Icewine has significantly higher acetic acid versus table wine, where acetic acid production may be used to reduce NAD(P)+ to NAD(P)H via NAD(P)+-dependent aldehyde dehydrogenase proteins (Aldp). Previous research linked the NAD+ redox imbalance during Icewine fermentation with ALD gene expression patterns indicating a role of Ald3p encoded by ALD3 in elevating the acetic acid whereas in table wine, ALD6 expression dominated. In the overall research program from our laboratory, the goal is to remove all five of the ALD genes, individually and in combination, from a commercial yeast genome using CRISPR-Cas9 gene editing. The objective of this project is to remove three (ALD6, ALD5, and ALD4) of the five ALD genes individually from the genome of a commercial wine yeast K1 V1116 using CRISPR-Cas9 gene editing to assess the roles of the aldehyde dehydrogenase enzymes in acetic acid production in both Icewine and table wine using these commercial yeast deletion strains. All copies of ALD6 and ALD5 were successfully knocked out of K1-V1116. The ald6Δ yeast had a significant impact on the acetic acid production with an 86% decrease in acetic acid production during Icewine fermentation and an 85% decrease during table wine fermentation in comparison to the wild-type control yeast. The ald5Δ had a significant but minimal impact on acetic acid production during table wine fermentation and no impact on acetic acid during Icewine fermentation. Under table wine conditions, ald5Δ had a 16% decrease in acetic acid production. One allele of the ALD4 gene was successfully knocked out of K1-V1116, creating a heterozygous ALD4 mutant. This heterozygous mutant was not evaluated in fermentations.Item Open Access Theoretical Investigation of the Electronic Structure in the Reaction Center of Acaryochloris marina(Brock University) Etemadi Some Olyayi Katayoun; Dr Divya Kaur Matta; Centre for BiotechnologyThis thesis explores the electronic structure of photosystem I (PSI) in far-red lightutilizing organism Acaryochloris marina through density functional theory (DFT), with a particular focus on the spin density distribution around the P740 reaction center and its surrounding residues. While the final hyperfine couplings show excellent agreement with experimental values, they reveal a nearly symmetric spin density between the A and B branches, rather than the anticipated localization on the B branch. Various computational parameters, including the choice of functional, optimization method, and model size, were systematically examined to determine their influence on the final results. Among the tested functionals, TPssh produced the most pronounced asymmetry while keeping the hyperfine coupling values close to the experiment. CHARMM-based optimizations yielded lower RMSD values, indicating greater structural accuracy compared to quantum-based optimizations. A detailed residue analysis identified specific amino acids such as Trp660 and Leu623 that play a significant role in modulating spin density, particularly due to their proximity to the reaction center. Interestingly, some residues like Phe653 showed minimal influence despite their size, suggesting that spatial positioning is more critical than steric bulk alone. Additionally, hydrogen bonding networks involving selected residues may further influence electronic asymmetry by stabilizing charge distribution pathways. These computational insights provide a deeper understanding of how local residue environments affect PSI function and may help explain the evolutionary adaptations seen in organisms like Acaryochloris marina, which perform photosynthesis efficiently under far-red light. The study concludes by recommending future QM/MM calculations with expanded QM regions to better capture the protein environment and resolve discrepancies between computational models and experimental data.Item Open Access Physiological and behavioural responses to temperature and humidity in fossorial amphibians(Brock University) Danilo Giacometti; Glenn Tattersall; Department of Biological SciencesAmphibians have been the focus of research investigating physiological and behavioural responses to temperature and humidity for over two centuries. However, fossorial (i.e., underground-dwelling) amphibians remain comparatively understudied despite the unique environmental pressures that they experience. The overarching goal of this thesis was to understand how temperature and humidity affected the physiology and behaviour of fossorial amphibians. By combining phylogenetic methods and laboratory experiments, my chapters address the topics of energetics, hydroregulation, thermoregulation, and overwintering emergence. First, I tested the prevailing hypothesis that fossorial amphibians should have reduced metabolic rates compared to non-fossorial ones. My results did not support this hypothesis, highlighting that a reduction in amphibian metabolism would be evolutionary unlikely given the limited energetic benefit. Next, I assessed the effect of seasonal acclimatisation (spring versus autumn) on the thermal sensitivity of metabolism and water loss in Ambystoma maculatum. My findings suggested that acute changes in temperature affected energy and water budgets. However, acclimatory changes in temperature affected metabolism but not water loss. I then examined how temperature (17°C versus 22°C) influenced behavioural hydroregulation in A. maculatum. I found that salamanders defended a constant vapour pressure deficit between temperatures, which was achieved by targeting higher relative humidity at 22°C than at 17°C. This suggests that salamanders can detect their rates of evaporative water loss, and employ behaviours to limit increased evaporative demand at warmer temperatures. I also evaluated how behavioural thermoregulation differed between seasons (active versus overwintering), and found that A. maculatum engaged in active behavioural thermoregulation despite the prediction that fossorial ectotherms should show little thermoregulatory motivation. Lastly, I assessed how extrinsic (temperature and negative geotaxis) and intrinsic (migration restlessness) factors influenced overwintering emergence in A. maculatum. My results suggested that migration restlessness and negative geotaxis collectively influenced overwintering emergence, shedding light on how fossorial amphibians may navigate complex underground environments. Together, my chapters underscore the intricate coupling between physiology and behaviour in mediating how fossorial amphibians respond toshort- and long-term environmental variation.Item Open Access Testing Northeastern North American Native and Introduced Plants as Cover Crops in an Organic Vineyard(Brock University) Zgurzynski, Kasia; Vasseur, Liette; Department of Biological SciencesCover crops have potential to provide ecosystem services including nitrogen fixation, erosion control, water retention and infiltration, buffering climate variability, and beneficial insect attraction. The objective of my thesis was to examine the potential performance of diverse cover crop species in an organic vineyard. The first component of this study aimed at testing northeastern North American native cover crop species, including Dalea purpurea, Rudbeckia hirta, Glycyrrhiza lepidota, Asclepias tuberosa, Echinacea purpurea, and Symphyotrichum ericoides. In the greenhouse, plants grown in monoculture were compared to those grown in polyculture with all the other species. The performance measurements were based on emergence, flowering, dry biomass, fresh biomass, plant moisture content, root:shoot ratio, and relative interaction index. R. hirta had a significantly higher dry shoot and root weight when grown in polyculture, as opposed to monoculture. D. purpurea also had significantly higher dry root weight in polyculture rather than in monoculture. S. ericoides and G. lepidota had significantly higher dry shoot and root weight in monoculture than in a polyculture. A. tuberosa had the largest root biomass in monoculture, while E. purpurea had the largest root biomass in the individual treatment. The second component aimed to determine the efficacy of two cover crop species (Lobularia maritima and Trifolium incarnatum) in vineyard field conditions. The plants were seeded under the vine rows, and plots were sampled along those seeded rows for each species. One vegetation survey was completed, and two insect surveys. Vegetation was measured as percent cover in the sample plots, and insects were collected on yellow sticky traps. L. maritima abundance was positively correlated with spontaneous plant species abundance, and T. incarnatum abundance was negatively correlated with spontaneous plant species abundance. The presence of the L. maritima was weakly associated with an increase in parasitoids, while T. incarnatum was weakly associated with predatory insects. Where there were more parasitoids, there were fewer leafhoppers. My results suggest a potential of these various species to provide important ecosystem services such as pest control in organic vineyards. Understanding the interactions among cover crop species, their influence on vines and the entire ecosystem requires further studies.Item Open Access Examining the Underlying Mechanisms and Potential Outcomes of Stress Bragging(Brock University) Han Yi; Faculty of Business ProgramsThis study investigates the mechanisms behind stress bragging in workplaces and its impact on individuals and organizations, focusing on impression management (IM) tactics as a mediator. It posits that individuals use stress bragging to achieve desirable workplace outcomes through IM tactics. Despite its prevalence, the interplay between stress bragging and workplace outcomes remains underexplored. This research addresses this gap by examining the dualistic impacts of stress bragging—beneficial outcomes for individuals (e.g., promotability) and detrimental effects for organizations (e.g., social loafing). Additionally, it explores the moderating role of competitive work environments (CWE). The study collected temporally segregated data from employees (n = 355) across diverse industries in the USA and Canada. The findings revealed significant and positive direct effects between stress bragging and negative workplace outcomes, as well as between stress bragging and impression management (IM) tactics. Furthermore, the results provided evidence for the mediating role of IM tactics as the underlying mechanism linking stress bragging to various workplace outcomes, though the proposed moderating effects of competitive work environment (CWE) were not supported. This study is among the first to explore how stress bragging influences workplace outcomes through various IM tactics in an organizational context, offering theoretical and practical insights for navigating and managing such behaviors in the workplace.Item Open Access The Development of Future Thinking in Childhood(Brock University) Kamber, Ege; Mahy, Caitlin; Department of PsychologyHumans’ ability to represent future possibilities, known as future-oriented cognition, encompasses several skills, including saving, prospective memory, episodic future thinking, planning, and delay of gratification. Developmental research has primarily focused on preschool and school-aged children and examined the development of future-oriented cognition in relation to cognitive and language abilities. The current studies contribute to the literature in three ways by examining (a) the early emergence of future-oriented cognition in toddlerhood (Study 1), (b) how children’s home environment relates to their future-oriented cognition (Study 2), and (c) whether three candidate cognitive mechanisms (i.e., constructive episodic simulation, scene construction, and self-projection) can explain school-aged children’s episodic future thinking (Study 3). Study 1 (N = 205 parents of 2- to 3-year-olds) used parent-report questionnaires to show that 2- and 3-year-olds could engage in future thinking skills in their everyday lives (i.e., prospective memory, episodic future thinking, planning, saving, and delay of gratification). Children’s episodic memory and use of time metaphors in daily talk further explained individual differences in children’s future thinking skills. Study 2 (N = 325 parents of 2- to 6-year-olds) also used parent-report measures and found that parents’ future-oriented cognition – but not family socioeconomic status – was related to children’s future-oriented cognition, even after accounting for children’s age, cognitive abilities, and behavioural factors. Study 3 (N = 150 8- to 10-year-olds) used behavioural measures to assess children’s episodic future thinking and other abilities that may rely on the same cognitive mechanisms as episodic future thinking, including episodic memory, episodic thinking for present events, imagination, perspective-taking, and spatial navigation. Structural equation modeling showed that children’s episodic future thinking, episodic memory, episodic thinking for current events, imagination, and spatial navigation shared significant variance, aligning with the constructive episodic simulation and scene construction accounts. However, the data did not support the self-projection account because perspective-taking was unrelated to the other abilities. Together, these studies shed light on the developmental trajectory of future-oriented cognition from the age of 2 to 10, identify its correlates and illuminate potential cognitive mechanisms of episodic future thinking.Item Open Access Exploring the Process of Organizational Change within the Sport Industry: A Stakeholder Perspective(Brock University) McFall, Chandler; Kerwin, Shannon; Thompson, Ashley; Applied Health Sciences ProgramStakeholders in sport organizations often hold unique and diverse perspectives on organizational change, yet literature has been shown to evaluate these perspectives from a static point in time. With change more recently being found to be a dynamic, unpredictable process as opposed to being predictable in nature (Dawson, 2019) this research sought to understand how stakeholders responded to a large-scale organizational change over time. Thus, this study examines the implementation of Long-Term Player Development (LTPD) within a community sport organization, with a particular evaluation of how these stakeholders' responses shifted over time. To investigate this, a constructivist approach was adopted, drawing on semi-structured interviews with key stakeholders involved at various levels of the organization. A total of 12 interviews were conducted, capturing a range of perspectives across paid staff, coaches, and parents. This open-ended method enabled a deeper exploration of the underlying beliefs, emotions, and contextual factors that shaped stakeholder engagement with the change process. Findings were interpreted through a lens of stakeholder theory (Mahon & Waddock, 1992; Freeman, 1984), revealing how individuals navigated personal meaning and emotion during change, and further how their positioning in the organization influenced their responses. Stakeholder reactions were categorized through an updated spectrum of the stakeholder responses to change created by Welty Peachey & Bruening (2011, 2012) (e.g., acceptance, ambivalence, resistance), ranging from proactive engagement to active opposition. These responses were marked by positive or negative shifts in response as new information and experiences emerged, largely dependent on personal goals, values, and expectations. Overall, these reactions were not static but found to be dynamic, shaped by both personal values and organizational actions. This research contributes to sport management literature by offering a deeper understanding of stakeholder engagement in times of change, and highlights the importance of communication relating to stakeholder needs. The findings further demonstrate the value of capturing the unique dimensions of change and stakeholders commonly found within community sport organizations and youth sport.Item Open Access Mental Toughness in Sport: Empirical Distinctiveness and Relationships with Risk-taking and Pain Experiences in Athletes.(Brock University) Blacker, Mishka; Sullivan, Philip; Applied Health Sciences ProgramMental Toughness (MT) is a term typically used to describe the determination and focus of athletes who often thrive or produce clutch performances in pressurized situations (Bédard Thom et al., 2021; Gucciardi, 2017; Jones et al., 2002; Hardy et al., 2014). Despite widespread interest in this concept (Gucciardi et al., 2020), research has tended to focus on the performance enhancing and thriving aspects of MT while only limited research has attended to potentially maladaptive aspects and outcomes (Cowden et al., 2021; Kerr & Stirling, 2017). The purpose of this dissertation was to 1) contribute to the conceptual clarity of MT in athletes, 2) increase knowledge of the relationship between MT and risk-taking by looking at specific types of risk-taking behaviours in sport, and 3) examine and explore relationships between MT, physical endurance, and pain experiences in athletes. The results of this dissertation supported the distinctiveness of MT via the Mental Toughness Index (Gucciardi et al., 2015) in competitive athletes (study 1). Study 2 suggested that when MT is assessed via the MTI, it is not predictive of risk-taking attitudes or behaviours that have the potential to be maladaptive in sport (i.e., competing with pain or injury). Lastly, the results of study 3 built on the equivocal findings reported in previous work (Crust & Clough, 2005; Jones, 2020) evidencing non-significant relationships among MT, physical endurance, pain coping, and pain intensity, suggesting that that these relationships are nuanced and conditional. Future research is recommended to focus on the potential of MT’s additivity with other concepts (e.g., Grit), investigating MT’s association with different kinds of risk-taking (i.e., positive, negative) behaviours over time, and examining MT’s relationship with pain by incorporating self-referenced goals and/or different pain manipulations (e.g., cold pain tolerance, DOMS pain intensity; Whitton et al., 2021), as well as a general recommendation for experimental and longitudinal designs when possible. 2025Item Open Access Advancing detection, genomics, and secretome analysis of oomycete pathogens Phytophthora capsici and Phytopythium vexans to explore mechanisms of pathogenesis and biocontrol solutions(Brock University) Villanueva Oscar; Castle Alan; Ellouz Oualid; Department of Biological SciencesSoilborne oomycete pathogens pose persistent challenges to vegetable production systems, particularly in Ontario, Canada, where Phytophthora capsici and the recently reported Phytopythium vexans have emerged as significant threats. Understanding the molecular mechanisms underlying their pathogenicity is critical for developing informed, site-specific disease management strategies. This thesis integrates comparative genomics, effector biology, and molecular diagnostics to enhance our understanding of their pathogenicity and support effective disease management. The first component of this work focuses on P. capsici, where whole-genome sequencing of two Canadian isolates (55330 and 55898) revealed compact genomes yet retained a broad array of RxLR and CRN effectors. Comparative analyses with reference strains LT263 and LT1534 v11.0 uncovered both conserved and unique effectors, suggesting that local adaptation may be shaping pathogenic potential in response to regional crop pressures. Building on this, the second component shifts to P. vexans, a novel strain recently reported in Ontario from apple tree soil. The SS21 P. vexans strain genome was sequenced and compared with the only two openly available strains HF1(China), and (CBS 119.80) (Iran). The genomic analysis reveals similar genome between the Canadian strain SS21 and the reference genomes, additionally SS21 displayed a reduce CAZymes, RxLR and CRN effectors, suggesting a niche adaptation to a specific Canadian agro-ecosystem. The final component of this thesis focuses on the development of an amplitude-based multiplex droplet digital PCR (ddPCR) assay. Designed for simultaneous quantification of P. capsici, Trichoderma asperellum, and Trichoderma gamsii in soil, this assay was validated in field trials and offers high sensitivity and specificity. The assay displayed a high sensitivity with a limit of detection of 1 pg/µL DNA. The use of multiplex ddPCR offers practical solution for monitoring pathogen and biocontrol populations in complex soil environments.Item Open Access Advancing detection, genomics, and secretome analysis of oomycete pathogens Phytophthora capsici and Phytopythium vexans to explore mechanisms of pathogenesis and biocontrol solutions(Brock University) Villanueva Oscar; Castle Alan; Ellouz Oualid; Department of Biological SciencesSoilborne oomycete pathogens pose persistent challenges to vegetable production systems, particularly in Ontario, Canada, where Phytophthora capsici and the recently reported Phytopythium vexans have emerged as significant threats. Understanding the molecular mechanisms underlying their pathogenicity is critical for developing informed, site-specific disease management strategies. This thesis integrates comparative genomics, effector biology, and molecular diagnostics to enhance our understanding of their pathogenicity and support effective disease management. The first component of this work focuses on P. capsici, where whole-genome sequencing of two Canadian isolates (55330 and 55898) revealed compact genomes yet retained a broad array of RxLR and CRN effectors. Comparative analyses with reference strains LT263 and LT1534 v11.0 uncovered both conserved and unique effectors, suggesting that local adaptation may be shaping pathogenic potential in response to regional crop pressures. Building on this, the second component shifts to P. vexans, a novel strain recently reported in Ontario from apple tree soil. The SS21 P. vexans strain genome was sequenced and compared with the only two openly available strains HF1(China), and (CBS 119.80) (Iran). The genomic analysis reveals similar genome between the Canadian strain SS21 and the reference genomes, additionally SS21 displayed a reduce CAZymes, RxLR and CRN effectors, suggesting a niche adaptation to a specific Canadian agro-ecosystem. The final component of this thesis focuses on the development of an amplitude-based multiplex droplet digital PCR (ddPCR) assay. Designed for simultaneous quantification of P. capsici, Trichoderma asperellum, and Trichoderma gamsii in soil, this assay was validated in field trials and offers high sensitivity and specificity. The assay displayed a high sensitivity with a limit of detection of 1 pg/µL DNA. The use of multiplex ddPCR offers practical solution for monitoring pathogen and biocontrol populations in complex soil environments.Item Open Access NEW ROUTES IN BIOCATALYSIS: EXPLORING THE IMPACT OF GRAFTING SILICONES ONTO PROTEINS/ENZYMES(Brock University) Alizadeh, Najibeh; Dr. Paul M. Zelisko; Department of ChemistryOne of the cornerstones of our research is the use of biocatalysis to mitigate the negative impact of chemical processes on the environment. The majority of natural enzymes are highly efficient and can increase the rate of chemical transformations. However, the industrial application of enzymes is often restricted by several limiting factors such as poor operational or long-term stability, especially during exposure to elevated temperatures, organic solvents, and pH extremes. The chemical modification of enzymes using covalent conjugation is a very common stabilization strategy as it imparts stability and protects the enzyme from denaturation. A number of studies have determined that hydrophobic surfaces can have a very positive impact on the reactivity of various enzymes, particularly lipases. The impact of silicones on proteins, mostly through physical/noncovalent interactions has attracted considerable attention recently. Given our research team’s ongoing work in the area of silicone-proteins/enzymes interactions it was of interest to explore the impact of covalently conjugated silicone polymers on proteins. Herein, a library of hydride-functionalized silicones of differing molecular masses was prepared using the living anionic ring opening polymerization of hexamethylcyclotrisiloxane (D3) to yield poly(dimethylsiloxane) (PDMS) polymers with narrow dispersities (Ð). These polymers were subsequently activated with hydrophilic functional groups including disuccinimidyl carbonate (DSCa) and norbornene dicarboxylate anhydride (NDA) prior to conjugation with proteins/enzymes. Human serum albumin (HSA) was selected as a model protein to study the PDMS/protein chemical interactions prior to the functionalization of enzymes. HSA’s well-documented spectroscopic behaviour as either a native protein or denatured species made it an ideal model to investigate the impact of covalently bonded silicones on proteins. After completion of model protein studies, trypsin and Candida antarctica lipase B (CALB) were modified chemically with functionalized PDMS polymers. The covalent bonding of PDMS polymer chains onto protein/enzyme was studied through matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. The solubility of the protein/enzyme conjugates were examined in various organic solvents including tetrahydrofuran (THF), chloroform, dichloromethane (DCM), dimethylformamide (DMF), and toluene and confirmed by UV-Vis spectroscopy. The impact of silicones on the protein/enzyme structure was investigated by infrared (IR), circular dichroism (CD), and fluorescence spectroscopy. Thermal behaviour of the protein/enzymes before and after modification with PDMS polymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Catalytic function, thermal stability, and the accessibility of active sites of the enzymes of interest after conjugation to the functionalized siloxanes were studied through standard activity assays. This work demonstrates that not only can siloxanes be successfully coupled to proteins, but the bioconjugation also enhances the solubility and activity of enzymes in organic solvents.Item Open Access Perceptions of Ghanaian Women Regarding Breast Cancer Screening Behavior(Brock University) Ashorm Faustina; Crawford Joanne; Applied Health Sciences ProgramBackground: Breast cancer among women is currently the most diagnosed cancer globally, with an estimated 2.3 million cases recorded in 2020. In Ghana, breast cancer constitutes 31.8% of all cancers diagnosed in women in 2020 with an incidence rate of 15 to 35 per 100,000. Research into factors that influence engagement of Ghanaian women in breast cancer screening is limited and the existing literature has produced conflicting results. This research aimed to enhance understanding of Ghanaian women’s knowledge, beliefs and attitudes regarding breast cancer. This study explored Ghanaian women’s perceptions of breast cancer screening behaviour and provided insights to how breast cancer is perceived and approached within this context. By investigating these perceptions, the study sought to uncover the factors influencing Ghanaian women’s participation in early detection and breast screening. Methods: In this study, I employed a qualitative research design based on Interpretive Description by Thorne (2016), focusing on women in the mixed rural community of Apra, Ghana. Data were gathered through semi-structured interviews with 14 local women, with an interview guide informed by constructs from the Health Belief Model (HBM) and the Theory of Planned Behavior. Key constructs, such as perceived barriers, perceived severity, perceived susceptibility, perceived benefits and subjective norms, were explored. Using reflexive thematic analysis, as outlined by Braun and Clarke (2022), the analysis provided in-depth exploration of participants perceptions, highlighting key themes related to their health beliefs and behaviors. Findings: The study revealed that Ghanaian women’s perceptions of breast cancer screening are shaped by cultural beliefs, stigma, and limited knowledge. Key themes included the view of the breast as sacred, leading to reluctance in discussing or undergoing screenings, and the fear of social judgment, with some seeing breast cancer as a moral or spiritual failure. Participants had limited knowledge of breast cancer symptoms but were open to receiving information from healthcare professionals. Additionally, faith in divine protection influenced some women’s reluctance to seek medical care. These findings highlight the need for culturally sensitive health education to promote early detection. Significance and Conclusion: This study contributes to the academic discourse on breast cancer awareness by providing evidence on the perceptions and screening behaviors of Ghanaian women. It highlights the influence of cultural beliefs, social norms, and limited knowledge on early detection practices. The insights gained can inform the development of community-engaged, culturally sensitive health education programs and may guide policies, aimed at improving breast cancer screening uptake and access to breast health services in mixed rural Ghanaian communities.Item Open Access Consumer Desires in the Niagara Wine Industry: A Geodemographic Analysis of Customers at a Niagara Winery(Brock University) Murdoch, Sara; Ripmeester, Michael; Department of GeographyThe wine tourism industry is a global industry. Here, the focus will be primarily on winery visitors in the Niagara Region. More specifically, I explore what motivates them to visit wineries and what they hope to experience during their visits. Given significant competition, wineries must cater their expectations to attract visitors to their cellar doors. The purpose of this thesis is to determine whether geodemographic factors (type of community, municipality, general location) in combination with the demographic (age, gender, education, income) factors have an impact on what motivates people to visit wineries and what they expect once they arrive. More precisely, this thesis aims to answer the research question: “Do visitor origin and associated demographics make a difference in motivation to visit a winery and visitor experience expectations?” While doing so, I examine the two sub-themes. First, and as noted above, I seek to explore whether there is there a correlation between expectations for winery experiences and residence of trip origin and other demographic characteristics. Second, I ask “What winery features are visitors hoping to experience?” Using the mailing lists of one small, recently rebranded boutique winery in Jordan Station, Ontario I distributed web-based surveys to collect data on October 3 and 20, 2023. The survey was distributed through two mailing lists (the general mailing list and wine club list to 1568 individuals. A total of 133 individuals responded. Following the data collection process, I used qualitative and quantitative data analysis including coding, cross tabulations, Chi-Square tests, and location analysis though ESRI Community Analyst to explore the data. The analysis did not provide conclusive answers that suggests that location and geodemographic characteristics were significant in determining motivations to visit the winery. The results did, however, allow me to reach the conclusion that visitors are attracted to the experience and social aspects of wineries over the wine itself. In sum, the data collected can provide valuable information, both practical and academic contributions, on how to cater experiences to a larger audience.Item Open Access Exploring neuronatin as a novel SERCA regulator and its role in murine metabolism and skeletal and cardiac muscle function(Brock University) Braun, Jessica Lena; Fajardo, Val Andrew; Applied Health Sciences ProgramNeuronatin (NNAT) is a paternally expressed gene and protein found to be diversely involved in metabolic homeostasis. The mechanism underlying its metabolic contributions is speculated to be through regulation of the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump given NNAT’s sequence homology with two SERCA regulators, phospholamban and sarcolipin (SLN). Furthermore, previous work has shown that mice lacking NNAT (NnatKO) demonstrate altered glycemic control, reduced energy expenditure, and a propensity towards obesity. The purpose of this thesis was therefore to test the hypothesis that NNAT can act as a SERCA regulator and subsequently influence whole-body metabolism and muscle function. Using a cell model, we demonstrate that NNAT can negatively regulate and uncouple the SERCA pump. In our NnatKO mouse model, we find evidence of NNAT acting as a negative regulator of SERCA in the soleus muscle, though the effects on SERCA function appear to be dependent on housing conditions and biological sex. Under standard housing conditions, no effects of NnatKO were detected on body composition or metabolism, but under translatable conditions, NnatKO mice displayed more fat mass and less lean mass relative to total body weight. Under both housing conditions NnatKO mice have reduced soleus muscle force production with RNA sequencing data suggesting biological sex-dependent changes to structural genes and signaling pathways. When given access to a running wheel, NnatKO mice present with a low exercise volume, though this low volume was still able to increase glucose tolerance and soleus force production, however the genetic reduction of glycogen synthase kinase 3 in NnatKO skeletal muscle had little to no effect on soleus function. Finally, we found NnatKO mice to show signs of structural remodeling to the left ventricle, reductions to cardiac output, and stroke volume, though these effects are not present under translatable conditions. Together, this thesis provides data supporting NNAT as a negative regulator of SERCA and that it is an important component for skeletal and cardiac muscle function. Future work should investigate the mechanisms underlying these changes to muscle function as well as the potential to target NNAT as a therapeutic in aging and disease.Item Open Access SMORE-DRL: Scalable Multi-Objective Robust and Efficient Deep Reinforcement Learning for Molecular Optimization(Brock University) Al Jumaily, Aws; Li, Yifeng; Department of Computer ScienceThe adoption of AI techniques within the domain of drug design provides an opportunity of systematic and efficient exploration of the vast chemical search space. In recent years, advancements in this domain have been driven by AI frameworks, including deep reinforcement learning (DRL). However, the scalability and performance of existing DRL methodologies are constrained by prolonged training periods and inefficient sample data utilization. Furthermore, generalization capabilities of these models have not been fully investigated. To overcome these limitations, we take a multi-objective optimization perspective and introduce SMORE-DRL, a fragment and transformer-based multi-objective DRL architecture for the optimization of molecules across multiple pharmacological properties, including binding affinity to a cancer protein target. Our approach involves pretraining a transformer-encoder model on molecules encoded by a novel hybrid fragment-SMILES representation method. Fine-tuning is performed through a novel gradient-alignment-based DRL, where lead molecules are optimized by selecting and replacing their fragments with alternatives from a fragment dictionary, ultimately resulting in more desirable drug candidates. Our findings indicate that SMORE-DRL is superior to current models for lead optimization in terms of quality, efficiency, scalability, and robustness. Furthermore, SMORE-DRL demonstrates the capability of generalizing its optimization process to lead molecules that are not present during the pretraining or fine-tuning phases.Item Open Access Synthesizing new bio-inspired, siloxane-containing materials: an investigation into renewable silicone materials via the application of physical self-healing processesLaura J. Voigt; Zelisko, Paul; Department of ChemistryThis thesis describes the creation of bio-inspired, silicone-based materials and their properties. The work can be divided into four areas of interest: 1. The synthesis of thymine-containing silicone polymers (TCSPs). The hydrosilylation reaction was utilized to functionalize silicones with thymine, making both backbone and telechelic TCSPs. A majority of these materials were found to be solid elastomers that, at elevated temperatures (~110oC), turned liquid and were able to be reshaped. The materials then solidified after 5 minutes at room temperature, having been completely recycled. In order to try and improve the properties (mainly flexibility) of these materials, both backbone and telechelic TCSPs were mixed together. However, the resulting products were found to be more brittle than the parent materials. 2. The synthesis of adenine-containing silicone polymers (ACSPs). In this section, several different methodologies were followed in an attempt to make adenine-functionalized silicone materials. It was discovered that the same hydrosilylation approach followed in the construction of TCSPs was not possible with adenine. The feasibility of several coupling methods between silicones and adenine were investigated. 3. The synthesis of thymidine-modified silicone materials. The target material in this work was designed to more closely mimic the overall structure of DNA by incorporating a deoxyribose sugar component, and short-chain silicones as a replacement for the phosphate portion of the DNA backbone. Synthesis of a hydrosilylation precursor, as well as the generation of a model compound and polymer system, were demonstrated. 4. Development of amino-acid modified silicones. The Ireland-Claisen rearrangement was employed in the synthesis of -allyl alanine, which was then be protected and reacted with tetramethyldisiloxane to yield an amino acid with a silicone sidechain. Future prospects for this platform technology will be discussed.Item Open Access Doping in Esports: A Content Analysis of Responses to Cuyler “Huke” Garland’s Disclosure of Adderall Use in Call of Duty(Brock University) Bryce Salverda; Dr. Curtis Fogel; Applied Health Sciences ProgramEsports have grown significantly in North America over the past decade. Tournaments which were once played for a couple thousand dollars to a few hundred viewers now have prize pools worth a few million dollars and are watched around the world by millions of people (Greig, 2024). With an increase in popularity comes an increase in scrutiny. This became apparent when Cuyler Garland, also known as Huke, released a video admitting to violating the Call of Duty League’s (CDL) anti-doping policies by using Adderall to gain a competitive advantage. Many First-Person Shooters (FPS), which is a type of Esport, include policies against cognitive enhancing drugs such as Adderall due to its potential performance enhancing capabilities, concern over players health and safety, and the potential for replication by spectators trying to compete at a higher level which includes many youth players. As in traditional sports, the abuse of performance-enhancing drugs (PEDs) can harm the legitimacy of the sport which Esports is already fighting to get past. Using a content analysis approach, this study examines the reaction of key stakeholders across the Esports community regarding the incident, how the league responded, the current policies, and what changes are recommended. Employing constructivist epistemology and a qualitative research design, this study utilized stakeholder theory and thematic analysis to analyze online data focusing on discourse surrounding Huke’s disclosure on YouTube, Twitter, and Blogs. Overall, including the Huke’s original video, the data analyzed in this study include a total of 17 (299.86min) YouTube videos, 91 tweets, 18 blog/news articles, and 7 policies. This analysis of these data revealed that minimal policy and testing procedures currently exist in FPS professional leagues. Furthermore, stakeholders identify various reasons and pressures that players face to use PEDs including to enhance focus, pressure from peers and coaches, coping with long hours of gaming, faster reaction times in the game, and to keep up with other players who are using. While it is difficult to pinpoint the exact prevalence of PED use in FPS Esports, stakeholders reveal that the use is widespread and kept a secret. There are mixed views within the FPS Esports community on just how effective certain PEDs are in enhancing performance, but a seeming consensus on concerns for the health and well-being of Esport players. Stakeholders have called for increased sanctions and testing, alongside more educational awareness training on the potential health impacts of PED use.Item Open Access Investigating the Antiviral Activity of Rosemary Extract Against Zika Virus(Brock University) Masi, Jordan; MacNeil, Adam; Applied Health Sciences ProgramIntroduction: Flaviviruses have increasingly emerged and re-emerged in recent decades, infecting millions of people annually. Zika virus (ZIKV) is particularly concerning due to its associated pathological complications, including microcephaly in newborns and Guillain-Barré syndrome in adults, posing a significant threat to public health. Despite efforts made by the scientific community, no licensed drugs against flaviviruses have been developed. Medicinal plants show promise as a novel source of antiviral agents, as they possess a diverse array of biologically active secondary metabolites, making them potential candidates for therapeutic use. Here, we sought to investigate the antiviral potential of rosemary extract (RE) against ZIKV in human dermal fibroblasts (HFF-1), one of the earliest targets of infection. Methods: ZIKV was treated with various concentrations of RE or its individual major polyphenols, including rosmarinic acid (RA), carnosic acid (CA), and carnosol (CO), and the remaining infectivity of each sample was measured by plaque reduction assay. To evaluate the impact of RE on different stages of the ZIKV replication cycle, HFF-1 cells were treated before, during, and after infection, or the virus was treated before infection. Results: RE exerted potent antiviral activity against ZIKV in both Vero and HFF-1 cells by directly acting on virus particles before infection. Importantly, RE significantly inhibited the later stages of the virus replication cycle by interfering with post-entry mechanisms within the host cell. Moreover, major RE-derived polyphenols CA and CO, but not RA, were shown to significantly reduce ZIKV infectivity. Conclusion: Overall, RE significantly impairs ZIKV infection in vitro by directly interacting with virus particles prior to adsorption and interfering with post-entry processes of the ZIKV replication cycle. This study provides rigorous evidence indicating the potential development of RE as an antiviral agent, warranting further investigation into the mechanisms underlying its inhibitory activity against ZIKV and its effects on other medically important flaviviruses.