English

The emergence of fungal hybrid pathogens threatens sustainable crop production worldwide. To investigate hybridization, the related smut fungi, Ustilago maydis and Sporisorium reilianum, were selected because they infect a common host (Zea mays), can hybridize, and tools are available for their analysis. Hybrid dikaryons exhibited filamentous growth on plates but reduced virulence and limited colonization in Z. mays. Select virulence genes in the hybrid had similar transcript levels on plates and altered levels during infection of Z. mays relative to each parental dikaryon. Virulence genes were constitutively expressed in the hybrid to determine if its pathogenic development could be influenced. Little impact was observed in hybrids with increased expression of effectors known to modify host response and metabolism. However, increased expression of transcriptional regulators of stage specific pathogenic development increased the hybrid's capacity to induce symptoms. These results establish a base for investigating molecular aspects of fungal hybrid pathogen emergence.

Author Keywords: effectors, hybrid pathogenesis assays, Sporisorium reilianum, transcription factors, Ustilago maydis, virulence factors

Heterosis, expressed as phenotypic superiority over parental species, typically peaks in first generation hybrids (F1s), while later generations (F2 +) exhibit lower fitness. The decrease in hybrid fitness is called hybrid breakdown. The overall incidence of hybrid breakdown in invasive hybrid zones remains poorly understood. The Laurentian Great Lakes (LGL) region contains a hybrid zone comprised of: native Typha latifolia, Typha angustifolia, and hybrid Typha × glauca. F1 T. × glauca display heterosis and are invasive, while later generation hybrids are relatively rare. To investigate possible hybrid breakdown, I compared seed germination and plant growth of backcrossed and advanced-generation (F2) hybrids to F1s and T. latifolia. I found evidence for hybrid breakdown in F2s and backcrossed hybrids, expressed as reduced growth and germination rates. Expression of hybrid breakdown in F2s and backcrosses may explain their relative rarity in the LGL hybrid zone.

Author Keywords: Advanced-generation hybrids, Backcrossed hybrids, Hybridization, introgression, Invasive species, plant competition

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

The integration of genetic and environmental information can help wildlife managers better understand the factors affecting a species' population structure and their response to disturbance. This thesis uses genetic techniques to assess the broad and fine scale population structure of mountain goats in Alaska. The first chapter aims to determine the number of genetically distinct subpopulations and model the demographic history of mountain goats in Alaska. The second chapter investigates the population structure and demographic history of mountain goats in Glacier Bay National Park and examines the impact that climate change will have on these mountain goats. My results indicate that Alaska has eight subpopulations which diverged during the Wisconsin glaciation. In Glacier Bay, population structure is reflective of the landscape during colonization, and mountain goat population density and movement corridors are likely to decline due to future climate change.

Author Keywords: Alaska, biogeography, gene flow, landscape genetics, mountain goat, population genetic structure

The human cornea is required to exhibit specific material properties to maintain its regular shape under typical intraocular pressures which then allow for its correct optical functionality. In this thesis, the basis of continuum solid mechanics and the finite element method are introduced. We use finite element modelling to simulate the extension of an effective-1d, linear-elastic bar, a cornea-like body governed by Poisson's equation, and the deformation of a loaded, linear-elastic, cube. Preliminary results for the deformation of a simulated, linear-elastic, cornea have also been achieved using the finite element approach.

Author Keywords: continuum solid mechanics, corneal biomechanics, finite element method, intraocular pressure

Dairy goat farming has become increasingly popular in recent years in Ontario. This qualitative study done by semi-structured interviews, examines the why and the wherefore of the opinions held by dairy goat farmers in Ontario in regards to sustainable agriculture. It was found that these farmers feel that sustainable agriculture is important. These farmers believed their farms to be sustainable and have implemented sustainable farming practices that reflect these interests. Their primary interest is to maintain their farmland for the use of future generations as well as maintaining the economic and environmental sustainability of their farms. There is currently a lack of scientific information available for dairy goat farmers in Ontario. Challenges presented by the participants should be researched so as to better serve this budding industry which may become one of the most sustainable livestock industries in Ontario.

Author Keywords: agriculture, dairy goat, farmer opinion, farming, sustainability, sustainable agriculture

"The Paper Chase: A Survey of Student Newspapers on Ontario Campuses in the 1960s" is a regional study of three University campuses in Ontario — the University of Toronto, Queen's University and Trent University — and examines each of these institutions' respective student newspapers, The Varsity, The Queen's Journal, and The Arthur as a primary source analysis. In broader terms, this thesis looks to theoretically historicize the themes of "life," "love," and "liberty" on Ontario campuses in the 1960s. Its central question is whether Ontario's youth experienced a cultural revolution like that portrayed in popular memory of the period, which profoundly appears in other sixties cultural interpretations in Canada and the United States. By framing student life through student newspapers' gamut, this thesis calls into question the lionization of some cultural decade elements. It determines students were, in fact, in some ways much more conservative in their outlook than earlier literature or the popular memory of the period suggests. History has much to say about students who rebelled. This thesis focuses on those who did not.

Author Keywords: Conservatism, Counterculture, Queen's University, Sixties, Trent University, University of Toronto

The digital typesetting of mathematics can present many challenges to users, especially those of novice to intermediate experience levels. Through a series of experiments, we show that two models used to represent mathematical structure in these typesetting applications, the 1-dimensional structure based model and the 2-dimensional freeform model, cause interference with users' working memory during the process of transcribing mathematical content. This is a notable finding as a connection between working memory and mathematical performance has been established in the literature. Furthermore, we find that elements of these models allow them to handle various types of mathematical notation with different degrees of success. Notably, the 2-dimensional freeform model allows users to insert and manipulate exponents with increased efficiency and reduced cognitive load and working memory interference while the 1-dimensional structure based model allows for handling of the fraction structure with greater efficiency and decreased cognitive load.

Author Keywords: mathematical cognition, mathematical software, user experience, working memory

This research is a critical analysis of coordinated access as an approach to addressing homelessness focusing on Peterborough, Ontario as a case study. This study is situated in scholarship that explores the presence of strategies of New Public Management in social service and healthcare delivery. Balancing the methods of Smith's (2005) Institutional Ethnography and Bacchi's (2009) What is the Problem Represented to Be approach I investigate the way that Federal, Provincial and Municipal homelessness policies organize themselves as instruments of power and I connect this analysis to the accounts of staff working within the homelessness response system. I discover the frame of vulnerability through which homelessness is addressed to be an individualizing mechanism that facilitates the downloading of responsibility for social welfare to local governments without adequate resources. I argue that the consequence of an under resourced system is that only the most extreme forms of suffering can be addressed, and the tools used to decipher who is most vulnerable do not account for structural inequalities.

Author Keywords: Coordinated Access, Homelessness, Homelessness Policy, Institutional Ethnography, Neoliberalization, New Public Management

The objective of this thesis is to develop and implement a heritage plan for the Nassau Mills Complex, a locally-significant Euro-Canadian historical site that operated on what is now Trent University's campus in Peterborough, Ontario. Within the framework of public archaeology and Cultural Heritage Management (CHM), emphasis is placed on the importance of protecting the site and its historic remains in order for present and future generations to appreciate and enjoy. Data was gathered by way of field and archival research, as well as through consultations with various archaeological and museological professionals. Of particular concern is evaluating how the Complex is significant to Peterborough, how it should be commemorated, public engagement and the importance of information accessibility, and the potential issues that may arise as a result of this project. In addition, recommendations regarding how the site and its collections should be preserved and presented to the collective society are also examined.

Author Keywords: Cultural Heritage Management, Nassau Mills Complex, Peterborough, Preservation, Public Archaeology, Trent University