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N-Heterocyclic Carbenes (NHCs) have significantly impacted organometallic chemistry as ligands in transition metal catalysis, offering strong electron-donating properties and high bond dissociation energies. However, their structural versatility is limited by the scarcity of commercial precursors and challenging modification procedures. Furthermore, we have investigated its coordination to transition metals; copper, silver, and palladium. We further demonstrate the effects of its steric parameters by utilizing the Suzuki-Miyaura cross-coupling of aryl chlorides using [(RO-NHC)Pd(allyl)Cl] as precatalysts. This study demonstrates increased catalyst activity with bulkier ligands in Suzuki-Miyaura cross-coupling reactions. We also present simplified procedures for copper NHC complexes using triethylamine with no requirements for special equipment and techniques. Preliminary investigations towards a more economical approach to measuring the electron donating abilities of NHCs were conducted using CuI and AgI cyanide complexes as probes. The outcomes of this research may contribute to the growing research in the applications of NHCs as ligands in catalysis.

Author Keywords: Catalysis, Ligand synthesis, N-Heterocyclic carbenes, Organic Chemistry, Organometallic Chemistry, Transition metal catalysis

In August of 2014, the Sahtú Dene community of Délı̨nę launched a first-of-its-kind, collaborative pilot project entitled "Destination Deline". Fortuitously, the launch coincided precisely with the field research component of this research project, which had originally sought to investigate the marked lack of Indigenous participation, employment and partnership in the Northwest Territories' adventure tourism industry. The primary research objective then shifted, to explore whether Destination Délı̨nę could serve as a cogent model for developing culturally-sustainable Indigenous tourism in the region. This objective served also as a point of entry into a broader academic discussion about Indigenous-Settler relations, Indigenous resurgence, the tourism imaginary, and the role of government in mediating between private sector and Indigenous community interests. Through a series of in-depth, one-on-one interviews with Indigenous tour operators, non-Indigenous adventure tour outfitters, government officials, and community members, this thesis presents a complex and vibrant portrait of an industry in flux.

Author Keywords: Cultural Sustainability, Indigenous Knowledge, Indigenous tourism, Indigenous-Settler relations, Market Imaginaries, Tourism Imaginaries

I investigated the climate vulnerability of a cold-water salmonid by observing the upper thermal tolerance of brook trout (Salvelinus fontinalis) across multiple life stages. Using hatchery- and wild-ancestry fish, I assessed variation in thermal tolerances and carryover effects within and among brook trout life stages and populations that were reared under varying winter thermal regimes as embryos. Embryonic, fry, and gravid adult upper thermal tolerance were tested via CTmax. Warm acclimation was associated with an increase in embryonic upper thermal tolerance. CTmax variability was markedly higher in embryos than juvenile or adult salmonids. Effects of thermal incubation treatments varied by life stage, with incubation temperature and life stage both influencing body size and thermal tolerance. Collectively, these results suggest that brook trout only exhibit short-term carryover effects from thermal stressors during embryo incubation, with no lasting effects on phenotype beyond the first few months (10 weeks) after hatch.

Author Keywords: acclimation response, climate change, ontogeny, salmonid, stress, thermal plasticity

Climate-driven permafrost thaw releases microorganisms and dissolved organic matter (DOM) into northern lakes, where their interactions with microbial communities and seasonal processes shape greenhouse gas emissions. In a factorial experiment mixing DOM and microbes from thermokarst ponds and lakes, we found that both DOM and microbial identity strongly influenced degradation. Lake microbes preferentially consumed thermokarst DOM, producing 3× more CO₂ due to low growth efficiency, while thermokarst microbes altered DOM with little CO₂ release. A survey of 40 lakes across a climate gradient showed CO₂ fluxes peaking in spring from under-ice buildup and CH₄ fluxes peaking in fall after summer accumulation. Dissolved gas concentrations served as early indicators of these events, with CH₄ linked to reduced DOM and CO₂ to multiple pathways. Overall, DOM quality, microbial traits, and seasonal dynamics interact to control lake carbon cycling, emphasizing the need for year-round monitoring under climate change.

Author Keywords: Dissolved Organic Matter (DOM), Fluxes, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), Greenhouse Gases (GHGs), Lakes, Thermokarst

This research explored how systemic barriers contribute to poverty among Black immigrants in the Toronto Census Metropolitan Area (CMA). Using a qualitative approach, I explored how factors like race, immigration status, and other identity factors shape Black immigrants' experiences in the employment and housing markets and healthcare system, consequently predisposing them to experience poverty. A key driver of poverty is the non-recognition of foreign credentials, which pushes highly qualified Black immigrants into low-wage jobs, exacerbated by employers' demand for "Canadian experience." This marginalization severely limits their access to higher-paying opportunities, trapping them in cycles of poverty. Housing discrimination also causes poverty, as racial bias from landlords forces Black immigrants into overpriced or substandard housing conditions, worsened by Toronto's housing crisis. Participants generally reported satisfaction with healthcare. To cope, Black immigrants rely on support from religious institutions and social networks through material and non-material resources. The study concludes with policy recommendations to address these systemic barriers, aiming to reduce poverty and improve integration.

Although stormwater management ponds (SWMPs) are frequently used to mitigate flooding in urban areas, we still do not fully understand how these systems impact water quality in a watershed. Currently, most research focuses on the effectiveness of SWMPs to retain nutrients during high flows, even though there is potential for internal nutrient releases to occur in these systems during low flows. To investigate if SWMPs act as nutrient sources or sinks during low flow conditions, we analyzed how sewershed characteristics, pond properties, and hydrological and limnological factors influenced nutrient dynamics and stoichiometry in 10 SWMPs. Our study ponds were located in Peterborough, Whitby, and Richmond Hill, which are urbanized municipalities in southern Ontario, Canada. During October 2010 to 2011, we took monthly measurements of various carbon (C), nitrogen (N), and phosphorus (P) forms. We collected samples in the inlets, permanent pools, and outlets to determine any changes in concentrations, loads, and stoichiometric ratios into and out of the ponds. At the time of sampling, we also measured a variety of hydrological and limnological parameters. Our findings indicate that more urbanized sewersheds with higher drainage densities tend to have higher inflowing particulate and dissolved nutrient loads. In addition, we found that pond properties such as depth, length-to-width ratio, volume, and age differentially influence the retention of particulate and dissolved C, N, and P forms. Influential hydrological and limnological factors were antecedent moisture conditions, season, and thermal stratification. We found higher particulate P concentrations near the sediments when the catchments were drier and the ponds were ice-free and stratified. As well, we found higher outflowing stoichiometric ratios for DOC:TDN and DOC:TDP. This indicates an enrichment of C compared to N and P and suggests biogeochemical processes may be occurring in SWMPs. Overall, our results demonstrate that SWMPs are complex aquatic systems, and we need to consider biogeochemical processes in our design and maintenance activities, so that the effectiveness of SWMPs is not compromised during low flow conditions as a result of internal nutrient releases.

Author Keywords: Carbon, Nitrogen, Phosphorus, Urban biogeochemical cycling, Urban stormwater pond

Diversity of flowers in flowering plants is understood to facilitate mating success, and yet understanding the relationships between plant sexual diversity and mating patterns remains a challenge. In this thesis, I used Sagittaria latifolia, an aquatic plant with unique sexual systems, to investigate relationships between plant sexual diversity, mating patterns, and reproductive success and to understand their evolutionary consequences. First, I measured the magnitude of sexual selection in a dioecious and a monoecious population of S. latifolia, while accounting for size variation. I showed that sexual selection does operate in natural populations of plants. Estimates of sexual selection were similar in both populations, possibly due to the temporal separation of female and male flowering in hermaphroditic S. latifolia, enabling individuals to act temporarily as unisexuals. Second, I examined how seasonal differences in sex allocation and flowering time can affect male mating opportunities, and the effect on reproductive success in hermaphroditic S. latifolia. I found that shifting allocations to be more male-biased with earlier flowering increased male mating opportunities. However, greater mating opportunities did not equate to higher rates of siring, indicating that factors other than temporal overlap contribute to male reproductive success. Finally, I determined the factors affecting mating and reproductive success of males and male-function hermaphrodites, distinguishing between the predictable effects of plant-level traits and population-level features, and unpredictable effects of stochastic factors. Across both populations, we found that plant-level traits had a greater impact on mating and reproductive success than population-level features. Nevertheless, these effects were frequently masked by stochastic factors. Furthermore, unexplained variation in mating and reproductive success may stem from additional plant traits affecting post-pollination gametophyte-sporophyte interactions. My findings indicate that while sexual selection does operate in natural populations of S. latifolia as expected under Bateman's principles, temporal overlap in flowering, plant traits and population features did not explain patterns of male mating or reproductive success, suggesting that post-pollination factors may be influencing mating outcomes.

Author Keywords: Phenology, Plant mating, Plant reproduction, Sagittaria latifolia, Sex allocation, Sexual selection

Glyphosate burndown and tillage, followed by the cultivation of cash crops, are frequently used techniques in LUC from perennial cropping systems (PS) to annual cropping systems (AS). Agricultural LUC can result in the loss of soil nitrogen (N) via emission of nitrous oxide (N2O), a potent greenhouse gas (GHG). The purpose of this thesis is to investigate the short-term impacts of agricultural LUC from PS to AS on soil health parameters and the nitrogen (N)-cycling bacterial communities responsible for nitrification and denitrification processes that result in the emission of N2O. The study field site was in Stone Mills, Ontario and comprised of four fields: two annual cropping systems were regularly cultivated for cash crops (AS), and two perennial cropping systems had not been cultivated for cash crops for over 50 years (PS). One PS was left intact while the other PS was subjected to LUC (converted system [CS]) from PS to AS within the study period. The results of this study indicate that PS promotes soil health, as illustrated through higher soil organic matter % (2.3 ± 0.2 %), beta-glucosidase activity (0.41 ± 0.04 mmol g-1 dry soil h-1), and N-acetylglucosaminidase activity (0.18 ± 0.03 mmol g-1 dry soil h-1). The PS soils exhibited higher nitrifier (6.0  0.3 log10 copies per g dry soil) and denitrifier (nirS, nirK and nosZI: 7.8  0.05, 8.1  0.1 and 5.0  0.1 log10 copies per g dry soil, respectively) gene abundances compared to AS (amoA, nirS, nirK and nosZI: 5.7  0.1, 7.7  0.04, 7.9  0.1 and 4.8  0.1 log10 copies per g dry soil, respectively). Moreover, LUC from PS to AS deteriorated soil health parameters and significantly decreased the nosZI/16S rRNA gene ratio, leading to potential N loss through N2O emissions. A laboratory incubation study revealed that the use of N-containing fertilizer in conjunction with easily metabolized C cumulatively resulted in 64.2% increase in N2O and 42.1% increase in CO2 fluxes in AS soils compared to PS soils. The AS soils also produced 69.8% more N2O and 13.4% more CO2 when compared to CS soils. The results suggest that the availability of C and N promote R-strategists, leading to increased production of CO2 and N2O. Additionally, results also suggest that LUC mediates fluxes depending on resource availability. The findings of this research demonstrate the significance of LUC in shaping N-cycling microbial communities and GHG emissions, emphasizing the importance of transitioning towards less intensive management practices to ensure the long-term sustainability of the agri-food system.

Author Keywords: annual, denitrification, greenhouse gas, laboratory incubation, nitrification, perennial

Advanced generation/backcrossed (non-F1) hybrids can be challenging to identify when their traits are similar to those of parental taxa, F1 hybrids, or both. This is particularly evident in the North American hybrid zone involving Typha latifolia, T. angustifolia, F1 T. × glauca and non-F1 hybrids. Cattails are challenging to differentiate based on gross morphological characteristics. Microscopic characteristics in female inflorescences have not been previously studied to differentiate parental taxa from non-F1 hybrids. To investigate whether researchers can use microscopic floret and bracteole characteristics for taxonomic identification, I compared pistillate flower length, bracteole length and width, and bracteole colour among taxa. I found that floret and bracteole characteristics can be useful for identifying T. latifolia but cannot accurately differentiate T. angustifolia and F1 T. × glauca from non-F1 hybrids. Further, a flowering bias can lead to the underestimation of the frequency of T. latifolia when using floral characters to examine the relative abundance of cattail taxa.

Author Keywords: advanced-generation hybrids, backcrossed hybrids, invasive species, morphology, species identification, Typha spp.

Vaccine hesitancy continues to influence public health practice in Ontario, particularly within a system that requires parents to complete non-medical exemptions under the Immunization of School Pupils Act, 1990. The purpose of this study was to explore how vaccine-hesitant parents understand their decisions and navigate institutional processes during the exemption pathway. Using Thorne's (2016) Interpretive Description, seven parents from Ontario participated in semi-structured interviews focused on experiences of trust, communication, and interactions with public health. Themes developed were:mutual othering, the role of epistemic conflict, vaccine refusal and exemption as symbolic resistance and restructuring trust through relationships. These findings show that vaccine decision-making is influenced not only by beliefs about safety or access, but also by the relational and moral context in which information is delivered. The study offers insights for public health nursing practice by highlighting the importance of relational approaches, ethical communication, and trust-building within mandatory immunization systems.

Author Keywords: immunization policy, institutional trust, interpretive description, parental decision-making, public health nursing, Vaccine hesitancy