Graduate Theses & Dissertations

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Effects of Intensive Agriculture on Stream Nutrient Export in East-Central Ontario, Canada
Recent agricultural land use change in east-central Ontario, including the expansion of intensive agriculture (corn and soybean crops) and tile drainage (TD) infrastructure, may alter the fluxes of both phosphorus (P) and nitrogen (N) to the Lower Great Lakes. Through intensive monitoring of several sub-watersheds that encompassed a range of row crop and TD extents, this study examined differences in stream N and P concentrations both seasonally and during variable flow conditions, to better understand land use/land cover (LULC) relationships with nutrient export. There was no clear relationship between total P (TP; concentration or export) and agricultural LULC, and instead, TP delivery was highly sensitive to flow events, and TP concentrations (especially particulate P; PP) were significantly higher during event flow compared with baseflow. In contrast, the dissolved fraction of P (total dissolved P; TDP) and dissolved nitrogen as nitrate (NO3-N) were not sensitive to flow, but were instead positively related to row crop agriculture, and associations between NO3-N concentrations/export and tile-drained row crop area were particularly strong (concentration r2 = 0.93; export r2 = 0.88). Regression relationships showed that with every 10% increase in row crop area in watersheds, NO3-N and TDP flow-weighted concentrations increased by 0.34 mg/L and 1.5 µg/L, respectively. As well, the same 10% increase in row crop agriculture translated to an increase of NO3-N export of as much as 130 kg/km2. Geospatial records of TD are incomplete in east-central Ontario, which presents challenges for evaluating the contribution of TD to nutrient export. Understanding the response of nutrients to changes in agriculture and agricultural practices is an integral part of watershed management as rapid changes in both urban and agricultural LULC continue to put pressure on water quality in the Lower Great Lakes. Author Keywords: East-Central Ontario, Nutrient Export, Row crops, Streams, Tile Drainage, Water Quality
Calming Chaos in the Classroom
Physical activity and classroom design changes are beneficial means to reduce stress, and enhance well-being. Results across some studies however, are mixed. Shanker Self-Reg™ supports the use of physical equipment and design as a means of managing arousal and tension levels. Previous research lacks rich description of educators’ understanding of equipment and design, Self-Reg, and how this understanding affects the way it is implemented. In the current study, educators’ understanding of Self-Reg, how this understanding influenced educators’ approach to the school environment, and if one workshop was enough to inspire individuals to adopt a Self-Reg approach were explored using thematic analysis. Participants included educators from schools with beginner and intermediate-level experience in Self-Reg. The analysis produced eight themes and 8 sub-themes. Participants’ knowledge of Self-Reg influenced their approach to their environments. Although one workshop may have inspired interest in the framework, it was not enough to shift educators’ current practice. Author Keywords: Arousal, Classroom, Self-Reg, Self-regulation, Stress, Teachers
Finding Community
This thesis explores the history of the Indigenous child welfare system in Manitoba and the effects of the Millennium Scoop on children in care. My research question is: what was the experience of children in care in Manitoba from 1990 to 2015? A related question is: how do survivors find healing? The thesis begins with a discussion of the history of acts, policies, and practices that began with the Indigenous child welfare system during the running of Residential schools. Then the acts, reviews, and policies that have shaped the child welfare system in Manitoba are discussed more thoroughly. The focus of the thesis is on the stories of Phoenix Sinclair, Tina Fontaine, and Natasha Reimer. I share their stories and provide an analysis of how the child welfare system has affected their lives. The negative effects of being a child in care are numerous. Being a child in care leaves behind grief, loss of identity, and loss of security. The systemic issues of the child welfare system include inadequate funding, overloaded case workers, staff burnout, and a lack of transparency. These overarching failures translate into the failure of children in care: details are overlooked, wrong decisions are made, and children are left to fend for themselves. Or they fall into the cracks and do not receive adequate care. This then translates into the deaths of children in care, or they are left to navigate life on their own and forced to create their circle of supports. Despite all the complications and negative impacts, some children can succeed while in care. Natasha’s story is a perfect example of such resilience. Author Keywords: child welfare, indigenous studies, millennium scoop, sixties scoop
Endocannabinoid Treatment for the Behavioural and Histopathological Alterations of Epilepsy
Epilepsy is associated with a variety of cognitive, emotional, and pain-related symptoms, such as impaired memory and learning, increased risk of anxiety and depression, and increased pain sensitivity. Unfortunately, these symptoms are generally untreated with typical pharmacological interventions, which tend to target seizure activity (i.e., ictogenesis) and not the subsequent histopathological and behavioural alterations resulting from epilepsy (i.e., epileptogenesis). Evidence has demonstrated that targeting the endocannabinoid system can alleviate seizure symptoms as well as cognitive, emotional, and pain-related impairments independent of epilepsy. However, research examining the use of endocannabinoid-based treatment for these behavioural symptoms when they are associated with epilepsy is sparse. In the following thesis, two animal models of epilepsy, several behavioural assessments, and immunohistochemical techniques are utilized to assess the effectiveness of endocannabinoid-based treatment for epilepsy’s interictal symptoms. The findings expand our knowledge and offer encouraging evidence for the usefulness of endocannabinoid-based treatment as an epileptogenesis-targeting pharmacological intervention. Author Keywords: animal models, endocannabinoid system, histopathological alterations, interictal symptoms, temporal lobe epilepsy, treatment
Unbridled Potential
Recently, equine assisted learning (EAL) has emerged as a novel approach to building resiliency competencies in at-risk youth. This mixed-methods study presents evaluation results for an 8-week community-based EAL program with 83 young women (age 13-18 years) with a history of interpersonal trauma. Analyses examined changes in self-reported mental health symptoms (posttraumatic, depression) and resiliency factors (sense of mastery, sense of relatedness, emotion regulation) from pre- to post-test and at 1-month and 6-month follow-ups. Changes in outcomes were also correlated with intervention processes (attendance, session ratings) to see if program experiences were associated with differential outcomes. Results showed that EAL has potential in improving resiliency outcomes, at least for those participants who derived greater satisfaction and value from the sessions. Many improvements were sustained over the long term. Participants’ qualitative feedback provided insight into their subjective experiences and highlighted the unique role that horses played in the EAL process. Author Keywords: Emotion Regulation, Equine Assisted Learning, Experiential Learning, Resilience, Sense of Mastery, Sense of Relatedness
Capital Ratios and Liquidity Creation
Using quarterly data from the six largest Canadian banks, we investigate the relationship between regulatory capital ratio and on-balance sheet liquidity created in the Canadian economy by “Big Six”. We find a significant positive relationship between Tier 1 capital ratio and on-balance sheet liquidity creation for Canadian big six banks, implying that large banks in Canada favor risks and rely on capital to fund illiquid assets. In contrast, for smaller banks, the relationship is significantly negative. Our results are robust to dynamic panel regression using 2-Step GMM, two exogenous shocks - COVID-19 crisis and the Global Financial Crisis (2007-2009), mergers & acquisitions activities in the banking industry, and core deposits financing. The COVID-19 pandemic and core deposits adversely impact the Tier 1 capital ratio’s relationship with on-balance-sheet liquidity creation, while the global financial crisis (2007-2009) effect on the association is insignificant. Author Keywords: Big Six, COVID -19, Deposits, Liquidity Creation, Tier 1 Capital Ratio,
Immunotherapies Targeting the Amyotrophic Lateral Sclerosis-Associated Protein TDP-43
Transactive response (TAR) DNA-binding protein of 43 kDa (TDP-43) pathology, including fibrillar aggregates and mutations, develops in amyotrophic lateral sclerosis (ALS) and is characterized by hyperphosphorylation and aggregation patterns, a mechanism largely understudied. In addition, ALS remains without a cure. Herein, in vitro aggregation of phosphorylated TDP-43 was explored, and the anti-TDP-43 antibodies tested for their inhibitor efficacies. Additionally, in vitro phosphorylation of TDP-43 by protein kinases was conducted to identify which protein kinases catalyze phosphorylation. The aggregation of phosphorylated and unphosphorylated full-length TDP-43 protein (pS410) was monitored by transmission electron microscopy (TEM), turbidity absorbance, and thioflavin (ThT) fluorescence spectroscopy. The protein aggregates were largely insoluble, ThT-positive and characterized with heterogeneous morphologies. Antibodies specific to epitopes within the RNA-recognition motifs and the C-terminal domains reduced the formation of β-sheets and insoluble aggregates, with outcomes highly dependent on the type of antibodies, indicating dual functionality. The only protein kinase able to phosphorylate TDP-43 at S410 was MARK4, indicating its role in the onset of PTMs in the protein. Thus, targeting TDP-43 epitopes for inhibition of aggregation and in vitro phosphorylation represent viable biochemical assays for screening protein kinase inhibitors as potential drugs against ALS. Author Keywords: aggregation, ALS, antibody-based inhibition, phosphorylation, protein kinase, TDP-43
Demographic history and conservation genomics of caribou (Rangifer tarandus) in Québec
Genetic variation is the raw material and basis for evolutionary changes in nature. The loss of genetic diversity is a challenge many species are facing, with genomics being a potential tool to inform and prioritize decision making. Whole genome analysis can be an asset to conservation biology and the management of species through the generation of more precise and novel metrics. This thesis uses whole genome re-sequencing to characterize the demographic history and quantify genomic metrics relevant to conservation of caribou (Rangifer tarandus) in Québec, Canada. We calculated the ancestral and contemporary patterns of genomic diversity of five representative caribou populations and applied a comparative population genomics framework to assess the interplay between demographic events and genomic diversity. When compared to the census size, NC, the endangered Gaspésie Mountain caribou population had the highest ancestral Ne:NC ratio which is consistent with recent work suggesting high ancestral Ne:NC is of conservation concern. These ratios were highly correlated with genomic signatures (i.e. Tajima’s D) of recent population declines and explicit demographic model parameters. Values of contemporary Ne, estimated from linkage-disequilibrium showed Gaspêsie having among the highest contemporary Ne:NC ratio. Importantly, classic conservation genetics theory would predict this population to be of less concern based off this metric alone. Inbreeding measures suggested nuanced patterns of inbreeding and correlated to the demographic models. This study suggests that while the Québec populations are all under decline, they harbour enough ancestral genetic variation to replenish any lost diversity, if conservation decisions are made in favour of these populations, specifically supporting NC. Author Keywords:
Assessing the environmental correlates of a lethal amphibian pathogen, Batrachochytrium dendrobatidis, in Ontario wetlands
Many emerging infectious diseases are caused by pathogens that possess free-living life stages, in which they interact with the environment directly rather than through the mediation of a host. These diseases represent major impediments to wildlife conservation; however, the dynamics of their interaction with the environment are poorly studied, often due to the difficulty of detecting these microscopic pathogens in environmental samples. One of these pathogens is Batrachochytrium dendrobatidis (Bd), a fungus that has been linked to declines in many amphibian species. In this thesis I use an emerging technique, environmental DNA detection (eDNA), to detect and quantify Bd in the water of southern Ontario (Canada) wetlands and examine its correlation with a variety of aspects of water quality, surrounding habitat, and seasonal timing. My purpose was to inform not only on potential environment-pathogen dynamics for Bd in northern environments, but to provide insight into the use of eDNA as a disease surveillance tool. I found that not only was there high geographic variation in Bd detection and intensity, but also high temporal variation within the same site on time scales as low as two weeks. While Bd prevalence was not strongly correlated with any of the variables tested, intensity showed strong correlation with canopy cover, with greater canopy cover over a waterbody correlating to lower Bd intensity. My results present several promising avenues for further examination of Bd in northern ecosystems, and indicate that, while caution is warranted in its implementation, eDNA may become an important tool in amphibian pathogen surveillance. Author Keywords: amphibian disease, Batrachochytrium dendrobatidis, disease monitoring, environment-pathogen dynamics, environmental DNA, wildlife disease
Frequency-time and polarization considerations in spectral-focusing-based CARS microscopy
Spectral-focusing-based coherent anti-Stokes Raman scattering (SF-CARS) microscopy is a powerful imaging technique that involves temporally and spectrally stretching ultrashort laser pulses and controlling their frequency-time characteristics. However, a broader and more detailed understanding of the frequency-time characteristics of the laser pulses and signals involved, how they are related, and how they influence important aspects such as the spectral resolution is needed to understand the full potential of SF-CARS systems. In this work, I elucidate these relationships and discuss how they can be exploited to optimize SF-CARS microscopy setups. I present a theoretical analysis of the relationships between the spectral resolution, the degree of chirp-matching, and pulse bandwidth in SF-CARS. I find that, despite allowing better ultimate spectral resolution when chirp-matching is attained, the use of the broadest bandwidth pulses can significantly worsen the spectral resolution if the pulses are not chirp-matched. I demonstrate that the bandwidth of the detected anti-Stokes signal is minimized when the pump is twice as chirped as the Stokes, meaning that (perhaps counter-intuitively) a narrow anti-Stokes bandwidth does not imply good spectral resolution. I present approximate expressions that relate the bandwidths of the pump, Stokes, and anti-Stokes pulses to the degree of chirp-matching and outline how these could be used to estimate the amount of glass needed to attain chirp-matching. I develop a spectral-focusing-based polarization-resolved (SFP-CARS) setup, by modifying our existing system, to explore the merits of integrating polarization-dependent detection as an add-on to existing SF-CARS setups. By using the system to study polarization-dependent features in the CARS spectrum of benzonitrile, I assess its capabilities and demonstrate its ability to accurately determine Raman depolarization ratios. Ultimately, the detected anti-Stokes signals are more elliptically polarized than desired, hindering a complete suppression of the non-resonant background. Nevertheless, I find that the SFP-CARS setup is a useful tool for studying polarization-dependent features in the CARS spectra of various samples and is worthy of further investigation. This work clarifies several technical aspects of SF-CARS microscopy and provides researchers with valuable information to consider when working with SF-CARS microscopy systems. Author Keywords: coherent anti-Stokes Raman scattering, nonlinear microscopy, polarization, spectral focusing, spectroscopy
Experiencing buhts’an qu’inal from sHachel jwohc’ a’tel through sna'el ya'beyel stuc te bin ay ma'yuc
This thesis shows and emphasizes the importance of Indigenous Knowledge (IK) in informing collaborative efforts that promote sustainable economic development in Indigenous communities. It tells the story of a participative research study undertaken with six Tseltal communities located in the Region Selva of Chiapas, Mexico, in the context of the Covid19 pandemic of 2020 and early 2021. In this study, the research participants reflect on their endeavours pursuing projects focused on the economic self-sufficiency of their communities. Their initiatives, which are deeply grounded in Tseltal practices while accompanied by the local non-profit organization IXIM AC, focus on developing economically self-sustaining enterprises in self-organized groups led by local Indigenous women. The findings offer a deep immersion into two aspects that emerge from Tseltal knowledge: The Nucleus of Tseltal community wellbeing and the Four Elements of Buhts’an qu’inal (Tseltal community wellbeing). The study’s results show that these two IK grounded aspects guide the participants’ endeavours in developing sHachel jwohc’ a’tel (Tseltal initiatives of entrepreneurship) while also enabling opportunities for gender transformative collaborative work and sustained engagement in local initiatives of sna'el ya'beyel stuc te bin ay ma'yuc (Tseltal economic development oriented to community wellbeing). Author Keywords: Community Wellbeing, Indigenous Entrepreneurship, Indigenous Knowledges, Indigenous Women, Participative Action Research, Sustainable Development
Forging Masks Through Perceptions of the Maskless in Benjamin Britten’s 'Peter Grimes'
This thesis proposes that Benjamin Britten’s 'Peter Grimes' leads its audience toward actively constructing an attitude toward its maskless protagonist. Grimes’s tragedy results from the social construction of his character from ambiguous and unseen actions. Utilizing the theories of Hannah Arendt and Carl Jung, this thesis proposes that Grimes may have resisted tragedy by constructing a public persona for himself. This thesis analyses the opera’s music and narrative according to the difference between Grimes’s lack of a public persona and the Borough- members’ construction of a mask for him. A central contention of the thesis is that as another element of Britten’s persona, Peter Grimes permitted the composer’s entrance into the public sphere, despite his private inclinations and illegal sexuality. Like the opera’s drama, the opera’s “Sea Interludes” reveals the tragedy resulting from the failure to construct an attitude toward the public world. These “Sea Interludes” work alongside the opera’s drama to induce the audience into a common perception of the opera’s whole. Through ironic relation to the opera’s musical and narrative parts, Benjamin Britten induces his audience’s construction of personae, thereby bringing himself and them into a shared public realm. Author Keywords: Benjamin Britten, E. M. Forster, English Opera, Montagu Slater, Peter Grimes, W. H. Auden

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Format: 2024/04/22