Electronic Thesis or Dissertation

Interspecific hybridization rates can vary depending on genomic compatibilities between progenitors, while subsequent hybrid spread can vary depending on hybrid performance and habitat availability for hybrid establishment and persistence. As a result, hybridization rates and hybrid frequencies can vary across regions of parental sympatry. In areas around the Laurentian Great Lakes, Typha × glauca is an invasive plant hybrid of native Typha latifolia and introduced Typha angustifolia. In areas of parental sympatry in Atlantic Canada and outside of North America, T. × glauca has been reported as either rare or non-existent. I investigated whether the low frequencies of hybrids documented in Nova Scotia, Atlantic Canada, are influenced by reproductive barriers that prevent hybrid formation or environmental factors (salinity) that reduce hybrid performance. I identified an abundance of hybrids in the Annapolis Valley (inland) and a scarcity of hybrids in coastal wetlands through preliminary site surveys throughout Nova Scotia. In Annapolis Valley populations, flowering times of progenitor species overlapped, indicating that asynchronous flowering times do not limit hybrid formation in this region. Viable progeny were created from interspecific crosses of T. latifolia and T. angustifolia from Nova Scotia, indicating that there are no genomic barriers to fertilization and germination of hybrid seeds. Typha × glauca germination in high salinity was significantly lower than that of T. latifolia, but there was no difference at lower salinities. Therefore, while germination of hybrid seeds may be impeded in the coastal wetlands where salinity is high, inland sites have lower salinity and thus an environment conducive to hybrid germination. However, I found that once established as seedlings, hybrids appear to have greater performance over T. latifolia across all salinities through higher ramet production. Moreover, I found that T. latifolia sourced from Ontario had reduced germination and lower survivorship in high salinities compared to T. latifolia sourced from Nova Scotia, which could indicate local adaptation by T. latifolia to increased salinity. These findings underline that interactions between environment and local progenitor lineages can influence the viability and the consequent distribution and abundance of hybrids. This, in turn, can help explain why hybrids demonstrate invasiveness in some areas of parental sympatry but remain largely absent from other areas.

Author Keywords: flowering phenology, Hybridization, invasive species, physiology, pollen compatibility, salinity tolerance

Glucocorticoids (e.g., corticosterone (CORT)) are hypothesized to mediate decisions regarding reproductive investment during breeding, but the directionality of the relationship is not clear. The CORT-fitness hypothesis posits that high levels of CORT arise from challenging environmental conditions in which an individual will conserve resources for future reproduction or self-maintenance, and thus result in lower reproductive success (a negative relationship). In contrast, the CORT-adaptation hypothesis suggests that, during energetically demanding periods, CORT will mediate physiological or behavioural changes that result in increased reproductive investment and success (a positive relationship). Inconsistencies arise due to the various species and life-history stages studied, and the complex interactions between fitness and glucocorticoids. Using an experimental approach, I investigated the relationship between CORT and reproductive success by manipulating baseline CORT levels in female tree swallows Tachycineta bicolor prior to laying using silastic implants. Implants failed to raise CORT levels of females during either incubation or the nestling stage, and maternal treatment had no effect on indices of fitness at either stage. Using a correlative approach, partial support for the CORT-adaptation hypothesis was found: There was a positive relationship between CORT and hatching success. This only occurred when CORT was measured during incubation, when baseline CORT levels may stimulate increased reproductive effort and success. In contrast, during the nestling stage baseline CORT levels were not related to reproductive investment or success. Maternal CORT levels during incubation also did not influence nestling phenotype, although nestling stress CORT levels were higher in individuals that survived to fledging. In conclusion, CORT mediates reproductive effort and success during some breeding stages, but it is still unclear why this is the case and whether this same pattern will prevail in other contexts.

Author Keywords: corticosterone, HPA axis, maternal effects, reproductive success, tree swallow

Ustilago maydis (D.C.) Corda is a biotrophic pathogen that secretes effectors to establish and maintain a relationship with its host, Zea mays. In this pathosystem, the molecular function of effectors is well-studied, but the regulation of effector gene expression remains largely unknown. This study characterized Zfp1, a putative U. maydis Zn(II)2Cys6 transcription factor, as a modulator of effector gene expression. The amino acid sequence of Zfp1 indicated the presence of a GAL4-like zinc binuclear cluster as well as a fungal specific transcription factor domain. Nuclear localization was confirmed by tagging Zfp1 with enhanced green fluorescent protein. Deletion of zfp1 resulted in attenuated hyphal growth, reduced infection frequency, an arrest in pathogenic development, and decreased anthocyanin production. This phenotype can be attributed to the altered transcript levels of genes encoding predicted and confirmed U. maydis effectors in the zfp1 deletion strain during pathogenic growth. Complementation of zfp1 deletion strain with tin2, an effector involved in anthocyanin induction, suggested this effector is downstream of Zfp1 and its expression is influenced by this transcription factor during in planta growth. When wild-type zfp1 was ectopically inserted in the zfp1 deletion strain, pathogenesis and virulence were partially restored. This, coupled with zfp1 over-expression strains having a similar phenotype as the deletion strains, suggested Zfp1 may interact with other proteins for full function. These findings show that Zfp1, in conjunction with one or more binding partners, contributes to U. maydis pathogenesis, virulence, and anthocyanin production through the regulation of effector gene expression.

Author Keywords: effector, pathogenesis, transcription factor, Ustilago maydis, Zea mays, zinc finger

In current knowledge-based economy, knowledge might be viewed as the most valuable organizational resource in sustaining any organization. Organizational knowledge originates from cognitive learning by individuals situated within organizations. In organizational learning, situated learning of knowledge by individuals is shared to create sustainable organizational competency. Yet, there is inadequate research to understand how situated learning operates as a social learning system within Community of Practice ('CoP'). Through a case study of a multi-level, non-profit CoP in Ontario, Canada, this qualitative explanatory research contributes to the extant literature by building a unique theoretical framework that provides conceptual insights on linkages between organizational knowledge, social learning system, and organizational competency, in sustaining the organizational CoP. Using Straussian grounded theory methodology, qualitative primary data from in-depth interviews, participant observations, and documents were triangulated and analysed abductively to reveal an emerging dynamic knowledge-based social learning theory towards explaining how situated learning sustains this learning CoP.

Author Keywords: Community of Practice, Grounded Theory, Organizational Knowledge, Organizational Learning, Organizational Sustainability, Situated Learning

This thesis investigates the current composition of traditional settlements located in and around the remains of the ancient, walled and moated, regal-ritual epicenter of Bagan, Myanmar. This study also provides some suggestions as to strategies that may be employed by future settlement archaeology projects in the region. To achieve the aims of this study, an ethnoarchaeological approach was employed at ten village sites located on the Bagan plain: Thè Pyin Taw, Thè Shwe Hlaing, Zee Oo, Kon Sin Kyi, Kon Tan Gyi, Minnanthu, Hpauck Sein Pin, Thah Tay Kan, East Pwa Saw, and West Pwa Saw. The data obtained from these villages, compounds, and houses is used to generate a version of the average Bagan village, compound (i.e., house lot), and house. The model Bagan village, compound, and house are in turn used to provide the basis for suggestions to be used in future settlement archaeology projects.

Author Keywords: Ancient Tropical Societies, Bagan, Ethnoarchaeology, Myanmar, Settlement Archaeology, Southeast Asia

This qualitative study examines the applicability, impact, best practices, sustainability and livestock welfare implications of mobile processing service operation in central Ontario. Grounded theory concepts were utilized to analyze data generated from semi-structured interviews and a community focus group, supplemented by an initial exploratory literature review, and focused review approach to refine emergent categories. It was found that there is interest in, applicability for, and food system-sustainability benefit from mobile processing services, but market competition and regulatory context impede the profitability of operation, not just for mobile service, but for existing provincial plants. Public support for mobile or regionalized processing resources could address many of the sustainability concerns in our regional livestock production and consumption systems, but where appetite for such political action does not exist, solutions are required if we hope to address the continuing centralization, commodification, traditional profit-maximization and negative externality generation of our industrialized agri-food production system.

Author Keywords: agri-business production and distribution, livestock welfare, mobile abattoirs and livestock processing, regional food systems, rural-urban relations, sustainability

The AeolianBox is an educational and presentation tool extended in this thesis to

represent the atmospheric boundary layer (ABL) flow over a deformable surface in the

sandbox. It is a hybrid hardware cum mathematical model which helps users to visually,

interactively and spatially fathom the natural laws governing ABL airflow. The

AeolianBox uses a Kinect V1 camera and a short focal length projector to capture the

Digital Elevation Model (DEM) of the topography within the sandbox. The captured

DEM is used to generate a Computational Fluid Dynamics (CFD) model and project the

ABL flow back onto the surface topography within the sandbox.

AeolianBox is designed to be used in a classroom setting. This requires a low

time cost for the ABL flow simulation to keep the students engaged in the classroom.

Thus, the process of DEM capture and CFD modelling were investigated to lower the

time cost while maintaining key features of the ABL flow structure. A mesh-time

sensitivity analysis was also conducted to investigate the tradeoff between the number of

cells inside the mesh and time cost for both meshing process and CFD modelling. This

allows the user to make an informed decision regarding the level of detail desired in the

ABL flow structure by changing the number of cells in the mesh.

There are infinite possible surface topographies which can be created by molding

sand inside the sandbox. Therefore, in addition to keeping the time cost low while

maintaining key features of the ABL flow structure, the meshing process and CFD

modelling are required to be robust to variety of different surface topographies.

To achieve these research objectives, in this thesis, parametrization is done for meshing process and CFD modelling.

The accuracy of the CFD model for ABL flow used in the AeolianBox was

qualitatively validated with airflow profiles captured in the Trent Environmental Wind

Tunnel (TEWT) at Trent University using the Laser Doppler Anemometer (LDA). Three

simple geometries namely a hemisphere, cube and a ridge were selected since they are

well studied in academia. The CFD model was scaled to the dimensions of the grid where

the airflow was captured in TEWT. The boundary conditions were also kept the same as

the model used in the AeolianBox.

The ABL flow is simulated by using software like OpenFoam and Paraview to

build and visualize a CFD model. The AeolianBox is interactive and capable of detecting

hands using the Kinect camera which allows a user to interact and change the topography

of the sandbox in real time. The AeolianBox's software built for this thesis uses only

opensource tools and is accessible to anyone with an existing hardware model of its

predecessors.

Author Keywords: Augmented Reality, Computational Fluid Dynamics, Kinect Projector Calibration, OpenFoam, Paraview

Coldwater streams are becoming increasingly impacted due to urbanization. Using environmental surveys, mark-recapture and telemetry, I assessed factors influencing seasonal brook trout (Salvelinus fontinalis) habitat use and movement in urban headwater streams in central Ontario between 2017-18. Generalized additive models were used to assess which habitat variables best explained seasonal yearling and older brook trout abundance, while generalized least squares models were used to assess overall trends in radio-tagged brook trout movement. My research demonstrated dynamic patterns in habitat use and movement by urban stream-dwelling brook trout. Yearlings were primarily influenced by water quality (stream temperature, conductivity), while older brook trout were most strongly influenced by stream morphology (depth, undercut bank). Movement occurred disproportionately around the spawning season and was more limited in the smaller, more altered stream. These findings may be used to inform fisheries managers on crucial timing and location of brook trout habitat refugia within urbanized environments.

Author Keywords: Brook trout, coldwater stream, groundwater, habitat use, radiotelemetry, urbanization

Community-based research (CBR) is a method of discovery that can provide pragmatic methods of advocating for and enabling community change. CBR literature and practice has focused on securing educational and job skills training outcomes for students rather than the communities, and community outcomes CBR and partnership frameworks were truly meant to serve. This research evaluates the effectiveness of a research brokering organization, and the community outcomes that can be meaningfully related back to established partnerships and research. A linked contribution and realist evaluation were employed to consider the contributions of U-Links Centre for Community-Based Research to capacity building in Haliburton County, for host organizations, local municipalities and the public. A community survey (n=65), interviews with past project hosts and management committee members (n=26) anecdotal project exploration, internal document review, and participant observation from living in the region and working within the organization, offers qualitative and quantitative data to support this contribution narrative, while also theorizing key factors for developing projects with high contribution potential. Five key factors were found which can act as both contexts and mechanisms of community-based research mobilization: relevance, relationships, resources, rigour and reach.

Author Keywords: capacity building, community, community-based research, contribution analysis, evaluations, research impact

Blocking fossil fuel infrastructure projects like pipelines is increasingly being seen as a legitimate way for civil society groups to reduce global carbon emissions. This research project is an exploratory case study of the Trans Mountain pipeline in British Columbia and its opposition. My research question asks, 'What has each tactic/strategy of opposition in the campaign to stop the Trans Mountain pipeline expansion accomplished, and how have they been effective? How can they be done more effectively?' Through interviews and an autoethnography, my research explores the effectiveness of activists in this campaign. I analyze the results of my findings within social movement theory and other activist definitions of effectiveness from my literature review. The more significant findings from my research are that activists need to do a better job educating the public on the issue, need to direct more of their resources towards promoting a solution to the issue and make alliances with other movements and groups. This research project contributes to the literature on the effectiveness of oppositional strategies and tactics of pipeline resistance, as well as social movement theory.

Author Keywords: British Columbia, pipeline, protest, strategy, tactic, Trans Mountain