Graduate Theses & Dissertations

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Molecular Architectures for Improved Biomaterials Derived from Vegetable Oils – Application to Energy Storage and Lubricants
The replacement of petroleum with renewable feedstock for energy and materials has become a priority because of concerns over the environment and finite nature of petroleum. The structures of the available natural biomass feedstocks fall short in delivering key functionality required in materials such as lubricants and phase change energy storage materials (PCMs). The approach taken in this thesis was to combine select functional groups with vegetable oil derivatives to create novel PCMs and lubricantswhich deliver desired functionality. One series of diester PCMs were prepared with terephthalic acid and fatty alcohols to address known shortcomings of esters. The second class of PCMs are sulfones prepared from oxidation of fatty sulfides to improve thermal energy storage. Overall, the new PCMs presented narrow phase change temperature ranges, high transition temperature (between 67 to 110℃), high transition enthalpy (210 to 266J/g), minimal supercooling and congruent phase transitions unaffected by cooling rates. They also demonstrated higher thermal degradation stability with onset of degradation from 290 to 310℃. The series of lubricants studied consists of sulfide and sulfonyl functional groups attached to the unsaturation sites of oleyl oleate as pendant groups to improve the thermal and flow properties. The new lubricants present subzero crystallization temperatures, very low crystallization enthalpy and dynamic viscosity as high as 180mPas. Furthermore, they also presented high onset of degradation (up to 322℃) and oxidation (up to 298℃). The PCMs and lubricants of the present thesis demonstrate that select functional groups can be used with common structural elements of vegetable oil such as fatty acids, ester groups and unsaturation sites to make a variety of molecular structures capable of delivering desired properties Author Keywords: Crystal Structure, Lubricant, Phase Change Material, Renewable, Structure-Property Relationships, Vegetable Oil
Family Experiences in Nature
Children may be spending less time outdoors in nature than in previous generations, with one potential reason being parents in their role as ‘gatekeepers’ to the outdoors. This study investigated how families are spending their time during the COVID-19 pandemic, and how parents may influence children’s outdoor nature experiences. Parents (N = 121) from across Canada completed measures related to their family’s activities as well as their own connection with nature, attitudes about nature, and childhood nature contact. Results suggest that having easy access to nature, a greater connection with nature, believing in the importance of outdoor experiences, and doing outdoor activities in childhood may be associated with more current family time outside in nature. By understanding the reasons behind parental decisions regarding where and how families spend time outside, strategies can be developed to help parents increase their children’s nature time in the future. Author Keywords: children, family, nature, nature-relatedness, outdoors, parents
Assessing habitat suitability and connectivity for an endangered salamander complex
Habitat loss and fragmentation have significantly contributed to amphibian population declines, globally. Evaluating the state of remaining habitat patches can prove to be beneficial in identifying areas to prioritize in conservation efforts. Pelee Island, Ontario is home to a complex of salamanders including small-mouthed salamanders (Ambystoma texanum), blue-spotted salamanders (A. laterale) and unisexual Ambystoma (small-mouthed salamander dependent population). These populations have declined from intense landscape changes since the late 1800s, particularly from the historical drainage of wetlands. In this thesis, I evaluated the suitability and connectivity of habitat patches occupied by these salamanders to assess the size of, and dispersal capabilities between, remaining habitat patches. I found that there was a low amount of suitable terrestrial habitat available for this complex of salamanders, and existing habitat patches were small and isolated. Forested areas and non-breeding wetlands were considered to be suitable habitat when adjacent to existing breeding locations, suggesting that these habitats should be a focus for conservation efforts. Notably, intervention may be necessary to maintain this amphibian complex as many assemblages are isolated from one another and potential corridors currently consist of primarily unsuitable habitat. Given that much of the salamander complex is reliant on one species for reproduction, the long-term viability of this population of Ambystoma salamanders may rely on the enhancement of suitable habitat near current breeding sites by conservation organizations and local stakeholders. Ultimately, the approach used in this thesis emphasizes the value of evaluating habitat within a fragmented landscape to focus conservation efforts on imperilled species. Author Keywords: amphibians, connectivity, habitat suitability, landscape fragmentation, landscape resistance, unisexual
Memorable Movie Watching
Memorable Movie Watching: Viewer Ruminations about Memory in Four Canadian Films and their IMDb User Reviews explores how four Canadian films released in the decade around the turn of the millennium tell stories of memory and remembering, and how User Reviewers writing on the IMDb.com engage with, respond to, and re–remember those narratives filtered through their own remembered personal experiences. It embraces a new form of audience research by analyzing films alongside voluntary viewer contributions in order to bring these viewers’ voices into the conversation about memory in film and specifically Canadian film.Lilies (John Greyson, 1996), The Hanging Garden (Thom Fitzgerald, 1997), Marion Bridge (Wiebke Von Carolsfeld, 2002), and My Winnipeg (Guy Maddin, 2007) are each fiction films that focus on the main character’s deeply personal childhood memories. A textual analysis of the four films reveals trends in how the filmmakers create memory explorations and memory works [works based on memory] in Canadian film. A further textual and thematic analysis of the IMDb’s 117 User Reviews for these four films reveals how viewers engage with what I term memory narratives and the personal memories these films spark. The four films respectively privilege, through narrative and filmic techniques, each protagonist’s telling of remembered childhood events. Yet when User Reviewers of the films comment on the protagonist’s remembered childhood events, they choose to contest them, citing the unreliability of the remembered and of memory itself. User Reviewers interrogate the film narratives against their own personal experience, all the while asserting that there is significance to be found in the process of remembering. For User Reviewers, this process of remembering involves engaging with the film and then writing about their memories of watching the film and its narrative through their own sparked memories. In this process, they dig for significant meaning even though Users rarely articulate that meaning or specify for whom it is meaningful. In their writing, Users do reveal their own thoughts and beliefs about Canadian film, as well as their knowledge of filmmakers, related texts, Canadian locations, and their own childhood and youth experiences. Key words Memory, Remembering, Canadian Film, User generated content, Audience, Viewer, Thom Fitzgerald, John Greyson, Guy Maddin, Wiebke von Carolsfeld Content Warning Please note: the memory stories depicted in these films, discussed in the User Reviews and in this dissertation are extremely disturbing and may be upsetting to the reader. Author Keywords: Audience, Canadian Film, Memory, Social Media, User Generated Content, Viewer
Anishinaabe Motherhood
The purpose of this qualitative study is to investigate Anishinaabe women’s Traditional Teachings and pedagogies in a contemporary context. Through this exploration, I have uncovered the tensions, challenges, and strengths that Anishinaabe gaashiyag (mothers) face when engaging with these Traditional Teachings and pedagogies. The research methodology I have used is a branch of grounded theory called the Anishinaabe Research Methodology, and it is integral to the Anishinaabe principles of living called the Seven Grandparent Teachings: Wisdom, Love, Respect, Bravery, Honesty, Humility, and Truth. I used a research method called the Nbwaachiwi (the art of visiting) method. I used the ‘Aunties kitchen table’ style of knowledge collection, where it is open-ended and one-on-one - like you would be at your auntie's kitchen table, sharing stories and having tea. By utilizing these principles, I conducted my research through the Anishinaabe-aadiziwin (culture and language – way of life) paradigm. I addressed multilayered Anishinaabe teachings and many connections to the land and spirituality. I have found that Anishinaabe gaashiyag feel pressure to adopt Western modes of raising their children. However, some young women are returning to the traditional Anishinaabe teachings by using traditional birthing techniques, tiknigaans (traditional baby carriers), and evolving our cultural practices to fit modern ways of living. The knowledge I present within this paper can inform mothers who want to learn Traditional Teachings and pedagogies, and thereby resist ongoing intergeneration trauma and colonization. New generations are identifying what the negative effects on raising Anishinaabe children and taking a stand to break ongoing trauma and abuse so that their children do not have to be subjected to it. These mothers are informed about cultural and Traditional Teachings with the hope that they can use this knowledge to assist them on their path to, and during, motherhood. Given the determination of these young mothers to raise their babies using Anishinaabe traditional methods, the future identities and lives of their children may be significantly better in a cultural sense than their predecessors. They will be the products of their mothers’ commitment to the resurgence of Anishinaabe maternal teachings and pedagogies. Author Keywords: Anishinaabe, Indigenous Motherhood, Motherhood, Parenting, Pedagogies, Teachings
Differences and similarities in exploration and risk-taking behaviours of two Myotis bat species.
AbstractDifferences and similarities in exploration and risk-taking behaviours of two Myotis bat species. Laura Michele Scott Behaviours that are repeatable across circumstances and time determine an individual’s personality. Personality and behavioural variation are subject to selective pressures, including risks related to the use of different habitat types. I explored the ecological and evolutionary consequences of habitat selection by comparing the behaviour of two sympatric bat species, Myotis leibii and M. lucifugus. These species display overlap in roosting preferences, however, M. leibii tend to roost in crevices on the ground, while M. lucifugus tend to roost in crevices or cavities that are raised off the ground. I hypothesized that the habitat selection patterns of these two species create behavioural reaction norms at the species level. I predicted that ground roosting behaviour favours bolder personality and more exploratory and active traits when compared with bats that do not ground roost. I examined inter- and intra-specific variation in behaviour using a modified, three-dimensional open-field test and quantified the frequency and duration of behaviours such as flying, landing, and crawling. Bats were continuously video-recorded over 1-hour nocturnal and diurnal trials. I used a priori mixed models with combinations of individual characteristics and life-history traits to select the models that best describe each species. We found that M. leibii (n = 15) displayed more exploratory and bolder behaviours than M. lucifugus while on the ground (n = 21) and higher overall activity during the trial. I also found that M. leibii displayed crawling behaviours and movements consistent with foraging while on the ground which is a rare behaviour in bats and only observed in a few species (Desmodus rotundus and Mystacina tuberculate to my knowledge). Future research should explore biomechanical adaptations associated with ground-foraging in M. leibii. Author Keywords: Bats, Behaviour, Exploration, Myotis leibii, Myotis lucifugus, Roosting
Help-Seeking Behaviours Of Individuals With Workplace Mental Health Injuries
The present study investigated the lived-experiences of individuals with workplace mental health injuries to better understand the thoughts, emotions, and behavioural processes that promote or inhibit help-seeking. This research investigated the interactions and relationships with relevant stakeholders and how they influence help-seeking. Qualitative methodology was employed by conducting semi-structured interviews with individuals (n=12) from various occupational classes who had experienced a workplace mental health injury. Interpretative phenomenological analysis and thematic content analysis were combined to analyze the data. Three main themes emerged: 1) self-preservation through injury concealment or distancing from workplace stressors 2) fatigue relating to complex help-seeking pathways, accumulation of stressors, and decreased ability in treatment decision-making, and 3) (mis)trust in the people and processes involved. These findings may help inform the mechanisms behind help-seeking for workplace mental health injuries, which may have implications for future research, policy development, and workplace processes to better facilitate a path to help. Author Keywords: help-seeking, mental health concealment, self-preservation, trust, workplace mental health, WSIB
Contributions of Mayflies (EPHEMEROPTERA
Walleye (Sander vitreus) are an ecologically and economically significant fish harvestedby recreational and commercial fisheries across Ontario. Adult Walleye are piscivores, but anecdotal evidence from anglers suggests that Walleye often target aquatic insects such as mayfly larvae (Ephemeroptera). My research examined the diet of Walleye caught from May to September in Lake St. Joseph in northern Ontario. I examined the stomach contents of angle harvested Walleye to identify the prey over two summers. Through morphological analysis of stomach contents, mayflies were found to be a significant prey source for Walleye, during larval emergence events in early summer, and to a lesser extent throughout the rest of the summer season. These findings are important for long term management of Walleye populations and associated resources. I also assess the potential and problems of Walleye management and research from my experiences of having worked with industry, government, and university partners on this project. Author Keywords: alternative prey, Food web interactions, invertebrate, piscivore, Predator prey interactions
The Desire to Be Authentic
Authenticity has been demonstrated as an important factor in relationships and sexual health (Impett et al., 2006; Impett, Breines, & Strachman, 2010). Although authentic behaviour is generally beneficial, sharing our true thoughts, feelings, and desires may be especially difficult in sexual contexts. Existing research has demonstrated that individuals find sexual communication awkward, uncomfortable, and embarrassing and may avoid such discussions overall (Shumlich & Fisher, 2020). Despite the evidence that behaving authentically in sexual contexts is uniquely challenging, research has yet to explore sexual authenticity. A primary objective of this study was to develop a measure to assess individuals’ level of sexual authenticity. Study 1 involved performing several exploratory factor analyses on the 23 proposed items, which yielded a 15-item scale that loaded onto three factors: 1) Honest Sexual Communication, 2) Sexual Placating, and 3) Sexual Self-Doubt. These subscales were statistically associated with related constructs such as relationship authenticity, honesty, and sexual deception. In Study 2, confirmatory factor analyses were conducted on two independent samples which provided additional support for the model and evidence for generalizability for the scale. The resulting Sexual Authenticity Scale was then leveraged to examine the relationships between sexual authenticity and its proposed benefits. Overall, sexual authenticity was found to be associated with enhanced sexual communication, sexual consent behaviours, and higher sexual and relationship satisfaction. Author Keywords: authenticity, relationship satisfaction, sexual authenticity, sexual communication, sexual consent, sexual satisfaction
Rural Older Adult Transitions in Care
Aligning health services with aging populations is the fundamental issue of modern Canadian health policy, yet rural older populations still experience compromised patient safety and poor-quality care as they transfer between care settings. As such, contemporary scholars acknowledge that more contextually sensitive studies are needed to better understand the unique health and care experiences of this vulnerable population across the care continuum. Informed by inquiry in critical gerontology, health services and human geography, my dissertation attends to this gap in research by revealing the interplay between older adult health construction and the influence of multidimensional contexts on rural older adult transitions in care. Using a community-based approach, I conduct a case study on Haliburton County that encompasses three phases (e.g., a rural community inventory, go-alongs and semi-structured interviews) and focuses on two types of transitions in care (when an older adult is transferred from a hospital to a long-term care home and when an older adult is transferred from a hospital to a home in the community). In total, 19 patients, 24 informal supports, 51 front-line staff and five administrators/managers participated in my dissertation, resulting in 99 total participants being included in 19 go-alongs and 85 semi-structured interviews. My results indicate that multi-leveled facets of the rural care context continually attend to and hinder rural older adult health during transitions in care. In particular, sectored divisions, urban centrism, biomedicine and ageism inhibit rural care providers from leveraging their strengths to attend to the heterogeneity of rural older adult health and the nuances of rural care contexts. I then argue the need for macro health systems reform to embrace the relationality of rural older adult transitions in care and to capitalize on the strengths inherent in rural communities. To foster knowledge mobilization of my findings, I provide a foundation of information and recommendations for the community partners (Haliburton Highlands Health Services and Seniors Care Network) as well as questions to inform research, policy and practice. Establishing the first study of rural older adult transitions in care where a researcher accompanies older adults and their informal supports across care settings, my dissertation will help prepare Canada for the impact of the aging population and transform transitional care provision to meet the needs of all Canadians in the 21st century. Author Keywords: Canada, Geriatric Care, Health Care, Older Adult Health, Rural Health Care, Transitions in care
Impacts of Cover Crops on Soil Health, Soil Nitrogen Dynamics, and Cytokinin Profiles
In Ontario, the dominant cash crop rotations consist of soybean (SB), which is a leguminous crop grown in rotation with maize (MZ) and winter wheat (WW). In addition to these crops, some farmers integrate cover crops (CC) into crop rotation, especially during the fallow period and winter seasons, to reduce nitrogen (N) losses via nitrate (NO3-) leaching and emission of N2 and the greenhouse gas nitrous oxide (N2O). This thesis focused on understanding the impact of crop phases in a MZ-(SB-WW)-CC rotation on the abundance of N-cycling bacterial communities that mediate nitrification and denitrification pathways. In addition, the influence of CCs on soil cytokinin (CK) profiles, which are plant growth-promoting hormones, were studied in a greenhouse trial to assess their potential impacts when integrating CCs into crop rotations. In particular, the relationship between traditional soil health parameters and the soil CK profiles was studied to understand how CKs might reflect biotic interactions and soil vitality. Results indicate N fertilizer application mono ammonium phosphate (MAP) and starter N:P: K (24:6:24) during WW planting in fall largely supported nitrifying bacterial communities (amoA) and potentially contributed to NO3- leaching. Management of MZ, which included spring-applied MAP resulted in larger denitrifying (nirK) bacterial communities, increasing the potential risk of N-loss via emission of dinitrogen gas (N2) and greenhouse gas N2O. However, CC soils had significantly lower nirK than MZ, reflecting the importance of strong and deep root systems of CCs, which have a higher ability to scavenge the substrates for denitrifying communities (NO3-). This highlights the importance of growing CCs in reducing the potential risk for N-loss via leaching and denitrification. Additionally, in the greenhouse trial, the ability of CCs to affect CK was detected, highlighting the importance of integrating CC in crop rotations. This is particularly noteworthy, given that total CK profiles showed strong associations with traditional soil health parameters such as labile or active carbon and soil microbial community diversity. It was concluded that total soil CK can be used as a novel and dynamic soil health measure. Future research on quantifying N2O fluxes and levels of NO3- in leachates would provide a more precise understanding of the impact of different crop rotation phases on N-dynamics in these fields. Further studies on single or combined measures of soil CKs are warranted to develop its potential as a practical and effective soil health parameter. Author Keywords: Cover crops, Crop rotations, Cytokinin hormone, Nitrogen Cycle, qPCR, Soil health
Nutrient Management in Forest Management Planning
This research evaluates the degree to which nutrients are included in forest management planning. First, the thesis evaluates forest management plans globally to determine the extent to which countries consider key nutrients (N, P, Ca, Mg and K) in their forest management plans. This is followed by a case study in Muskoka, Ontario, of a pilot wood ash recycling program with the goal of restoring calcium and other nutrients in the forests. This pilot project aims to evaluate the benefits of using wood ash as a forest fertilizer, as evidence that the practice merits approval by the provincial government. A text-based literature analysis of current regulations and the Environmental Compliance Approval (appendix 3) submitted to the provincial government for this project was undertaken as this project is currently a not approved practice by the government. Interviews were completed with key stakeholders and experts in the field to understand the benefits and policy hurdles of this program. Based on the documents analysed in this study, it was concluded that both globally and in Canada, nutrient management is not the focus of forest management plans. With respect to the pilot wood ash program, this thesis concluded that there is not enough data published to make the government departments comfortable with approving wood ash as a soil fertilizer. Nevertheless, there is much community support and many perceived benefits to this project, but more supporting data is needed. Author Keywords: Forest, Nutrients, Sustainability, Wood-ash

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Graduate student theses produced at Trent University. You may also browse theses and dissertations by year, program, or author.

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