application/pdf

In Ontario, farmers commonly use a MZ (Maize (Zea mays L.))-SB (Soybean (Glycine max))/WW (Winter wheat (Triticum aestivum)) – CC (mixed cover crop) rotation to maximize economic benefits. This study aimed to investigate the short-term impacts of the crop rotation phases and their associated management practices in this diversified cash crop rotation on soil health and the abundance of nitrogen (N)-cycling soil microbial communities (SMCs). Additionally, the abundance of N-cycling SMCs and plant-available N in both surface (0-5 cm) and rooting zone (5-15 cm) depths were characterized in tile-drained (TD) and non-TD fields. In the present study, soils collected under the CC phase had the highest labile carbon levels (10-17% higher) and water-stable aggregates (35-50% higher) compared to the other two crop phases. Lower nitrifying (amoA) gene abundances and soil NO3--N levels were observed in the CC phase compared to the MZ and SB-WW phases, suggesting a potential for decreased nitrification in the CC phase. The presence of SB potentially influenced the soil N concentration in the subsequent WW phase likely due to the release of symbiotically fixed N in the SB-WW phase. Further, higher amoA abundances and NO3--N in the SB-WW phase imply a potential for increased nitrification in the SB-WW phase. Additionally, higher amoA/nosZI and nirS+nirK/nosZI ratios were observed in the MZ phase than in SB-WW and CC phases, suggesting a potential capacity for increased N2O emissions from the reactions mediated by N-cycling SMCs in soils planted to MZ during fall sampling days. In the TD and NTD field study, higher NO3--N levels were observed in TD-SB-WW fields at 5-15 cm vs. 0-5 cm depths, which was possibly facilitated by tile drainage. The TD-CC fields displayed higher nosZI gene abundances and lower nirS+nirK/nosZI abundance ratios, suggesting a greater potential capacity for decreased N2O emissions in soils planted to CCs during the spring sampling days. When examining changes in plant available N by soil depth, reduced downward movement of NO3- through shallow soil depths (0-15 cm depth) was observed in the CC phase compared to cash crops. This short-term study highlights the potential contribution of the CC phase, particularly within TD agricultural fields, for improving soil health and reducing potential N2O emissions. Together, these results suggest that management-associated differences in crop rotation phases have temporary effects on soil health and the abundance of SMCs. Future studies linking N-cycling SMC's potential activity and field-scale N2O fluxes will provide a better insight into the longer-term sustainability of Ontario's cash crop management systems.

Author Keywords: denitrification, maize-soybean-winter wheat- cover crop rotation, nitrification, soil depth, Sustainable agriculture, tile-drainage

The detection of ciguatoxins (CTXs) in biological samples is challenging due to their low concentrations, the presence of various congeners, and the absence of standardized methods. This study uses high resolution mass spectrometry (HRMS) with P-CTX-3B as a reference standard. The protonated molecules ([M+H]+) were most prevalent, especially when acetonitrile/water was utilized, providing enhanced sensitivity. Optimized collision energies of 15 eV for protonated molecules and flow rates of 10 µl/min enhance sensitivity and peak intensities, respectively. Acetonitrile/water (ACN/H2O) is recommended as the primary solvent for HRMS method, an aspect underexplored in existing literature. The detection of CTX-3B in fish tissue samples proved to be challenging, caused by variations in ion peak intensities and matrix effects, requiring a deeper exploration of the impact of complex matrices on CTX detection. The study emphasizes the need for a reliable internal standard to mitigate these effects and highlights the ongoing challenge of developing a rapid, simple, and sensitive detection method. The study's specific focus on the P-CTX-3B analogue significantly contributes to methodology development for this congener, serving as a foundational step in understanding and detecting CTX. Despite notable progress, the study acknowledges the absence of an ideal assay, outlining key challenges for future research on ciguatera analysis. It underscores the continuous necessity for method reevaluation, testing, and the broader goal of establishing a more clarified and rugged method for the identification of CTX in fish.

Author Keywords: Analytical Chemistry, Ciguatera Fish Poisoning, Ciguatoxin, High-Resolution Mass Spectrometry, Optimization, P-CTX-3B

This thesis investigates the tensions, gaps and opportunities presented by outdoor play-based learning. Written by a founder of the Forest School concept in Canada, this exploration revolves around two research questions: How can we (re)conceptualize outdoor play-based learning in formal education for children aged 0-8, and how can we integrate and reinvigorate both pedagogical theory and practice to support educators in embedding outdoor playful learning practices?

The research methodology applies autobiographical experience and conceptual frameworks to historical and current pedagogical theory, in an anti-oppressive and feminist research orientation that challenges received notions of what "counts" as knowledge (Brown & Strega, 2005, p. 6) – much in the same way that play challenges truisms about what constitutes education.

Key findings include situating outdoor play-based learning within the theoretical landscape, understanding outdoor play-based learning as an emerging current of environmental education, defining a set of core principles for outdoor play-based learning, and re-examining the role of the educator.

Author Keywords: Early Learning, Pedagogy, Play, Play-Based Learning, Playful Pedagogies, Risky Play

Nikawiy narratives including Mother to daughter, nation to nation, spirit and intent, and Treaty Enforcement are based on nikawiy (my mother's) teachings that I interpret as my inherent role as Nehiyaw iskwew (Cree woman) specifically for governance and numbered Treaty Enforcement. My methodology 1is also based on nikawiy's Circle of Life, Pimatisiwin, Calendar (Poitras, 1996) curriculum that is related and included in the "universe is listening to me" paskwaw moostoos Treaty Law School (Poitras, 2016). We are from the Peepeekisis Cree Nation in what is now known as Saskatchewan. My mother osawastimahkoop iskwew is originally from Onion Lake on what is now the border between Alberta and Saskatchewan. Peepeekisis is in Treaty Four territory and Onion Lake is in Treaty Six territory.Is there a 'gap' for the role of Indian women and Nehiyawak Iskwew in the numbered Indian Treaty negotiations and generally in leadership? 2Though such a 'gap' may be said to be relatively common knowledge perhaps from the time of the treaty negotiations, a comprehensive and chronological review has yet to be produced that may address this. Treaty Four was entered into in 1874 and Treaty Six was entered into in 1876. Before this and in historical accounts, this gap may also be apparent and indicative of European/settler ethnocentrism based on white male research and documentation of this history.3 The colonial disruption of the Indian Residential School, in particular, would have also impacted oral transmission of any history including the role of women in the treaty negotiations that might also denote a role in governance and leadership. In a contemporary context now, the question for this role is the search for inherent foundations that may be identified as the base to contemporary governance and leadership frameworks for Nehiyaw Iskwewak (Cree women) in Treaty Four and Treaty Six.

1 Protocol has been offered to nikawiy to request her interpretation of "methodology' meaning.2 I could not find any written historical accounts for the role of Cree women during numbered Treaty negotiations. I know that, in general, there are few sources for Indian women in leadership, and particularly for any historical accounts of Indian women leadership. In Treaty Four and Treaty Six, there are no written accounts of Nehiyaw iskwew (Cree women) involvement in these treaty negotiations. The signatories to these treaties are documented as Nehiyaw napew (Cree men) only. Historical accounts document what Cree men leaders/Chiefs may have stated at this time. 3 A reason for the lack of any Cree women documentation in historical accounts of numbered Treaty negotiations is that there could be a lack of understanding for the role of Cree women by the European men who wrote these accounts. Generally, Europeans were coming from white patriarchal societies where women did not commonly have leadership roles.

Author Keywords: Calendar of Life, Cree

The bringing together of Indigenous (IK) and Environmental science Knowledge (ESK) has garnered significant attention in environmental research. This intersection has been recognized for enhancing understanding of various contemporary environmental challenges. Despite its acknowledged importance, there remains a notable gap in understanding how these knowledge systems are brought together, specifically at the level of data analysis, presentation, and interpretation of results. Furthermore, even less is known regarding the appropriate and effective use of any one approach and method in its application. Therefore, this thesis was guided by the question, 'What approaches and methods have been used previously to bring together Indigenous and Environmental science Knowledge in environmental research, and what are the challenges and limitations of any one approach and method in practical application?' This question is investigated through the conduct of a systematic map and application of a case study scenario. A search protocol was developed and served as a guide for the conduct of a systematic map. This protocol detailed how articles focused on bringing together IK and ESK would be systematically gathered and analyzed (Chapter 2). The resulting systematic evidence base highlighted four main approaches used in the peer-reviewed literature to bring together IK and ESK, namely: (1) a narrative approach to mixing; (2) the use of statistical analysis; (3) use spatial overlap in GIS; and (4) mixing IK and ESK using illustrative figures (Chapter 3). In order to gain a more in-depth understanding of the identified approaches and methods, their use was explored through the application of a case study scenario on environmental factors influencing Arctic Char (Salvelinus alpinus) growth in the Inuvialuit Settlement Region (Chapter 4). Although more data collection and analysis is needed to understand the relationship between environmental variables on Arctic Char growth in lakes surrounding Ulukhaktok, the attempt to link Indigenous Knowledge of lake ice change with Environmental science Knowledge on landlocked Arctic Char growth, coupled with insights informed from a review of relevant literature, led to the development of criteria that may be used in future research to test the identified approaches and methods. This thesis makes contributions to the academic literature by documenting and examining the types of approaches used to bring together IK and ESK at the level of data analysis, offering insights into the complex and evolving landscape of linking IK and ESK in environmental research.

Author Keywords: Arctic, Arctic Char, Environmental research, Environmental science Knowledge, Indigenous Knowledge, Knowledge linking

Northern flying squirrels (NFS) are mycophagous specialists (fungi-dominated diet) thatmay be displaced with southern flying squirrel (SFS) range expansion, thereby limiting fungal dispersal in forest communities. To understand the implications of squirrel species turnover on mycophagy, we investigated the home ranges of both flying squirrel species who are living in stable sympatry. We found no significant difference in home range sizes and identified spatial overlap between the two species. Through habitat selection ratios we found SFS were strongly selecting for deciduous-dominated habitats more than NFS. Lastly, we conducted microscopy on flying squirrel scat and found NFS were eating more fungi than SFS. We conclude that the squirrels are sharing the same habitat landscape but are finding ways to partition the habitat accordingly to allow for sympatry. SFS may contribute to the spore-dispersal cycle similarly to their northern counterpart through moderate fungus consumption and large home range sizes.

Author Keywords: diet, flying squirrels, Glaucomys, home range, mycophagy, sympatry

Climate change is a major conservation concern, especially for many cold-adapted species. The rate of warming due to climate change will likely outpace adaptive responses, and many populations will likely need to rely on phenotypic plasticity to cope with environmental warming. It is currently unclear whether plasticity in physiological responses to warming will be sufficient to offset the negative consequences of chronic environmental warming in ectotherms. I studied within-generation and transgenerational plasticity in two cold-adapted species of fishes, lake trout (Salvelinus namaycush) and brook trout (S. fontinalis), following temperature acclimation. Adults of both species were acclimated to either cold or warm temperatures and offspring were generated using a fully factorial breeding design, whereby the family thermal histories included crosses made within each temperature treatment and bidirectional crosses between temperatures. Offspring families were subdivided into two groups and acclimated to either warm or cold temperatures, so that offspring thermal experience matched or mismatched that of one or both parents. Offspring metabolic rate and critical thermal maximum during an acute thermal challenge were measured for both species. Limited transgenerational plasticity was detected in both species, but had a lesser effect than within-generationacclimation. In brook trout, the paternal contribution was greater than the maternal contribution. In lake trout, a mismatch in thermal acclimation, where the offspring were cold-acclimated but the parents warm-acclimated, resulted in elevated offspring metabolic rate without a corresponding increase in growth, suggesting that a mismatch in temperatures across generations could be detrimental to offspring. Using RNA-sequencing, transgenerational plasticity was linked to differential gene expression in the liver of lake trout offspring, in that genes were differentially expressed depending on the parental acclimation temperatures. Within-generation warm acclimation had the greatest effect on gene expression profile of offspring, with more genes differentially expressed under conditions of within-generation warm acclimation compared with transgenerational warm acclimation. Although it has been suggested that transgenerational plasticity may help to buffer the impact of warming due to climate change, my work implies that transgenerational plasticity, like within-generation plasticity, will be insufficient for these two species of cold-adapted salmonids to cope with climate change.

Author Keywords: Brook trout, Climate change, Lake trout, Phenotypic plasticity, Thermal tolerance, Transgenerational plasticity

Pharmacological cognitive enhancement is the use of prescription drugs to improve cognitive functioning in healthy individuals. Multiple ethical concerns have been raised by such use. The purpose of this project was to develop a reliable and valid measure to assess public attitudes about this issue. Participants were university students in Studies 1 (N = 465), 2 (N = 580) and 3 (N = 156). In Study 1 principal components analysis reduced the 90-item Attitudes Toward Pharmacological Cognitive Enhancement Scale to 42 items that loaded onto four components: Cheating/Unfairness, Motivation, Expected Benefits and Safety. Subscale scores differentiated users and nonusers. In Study 2 confirmatory factor analyses supported the model and statistically significant associations were found with related constructs such as attitudes toward performance-enhancing drugs, and prescription drug expectancies. In Study 3 test-retest reliability over a 3-week interval was above .70 for 3 of 4 subscales. Implications and future directions are discussed.

Author Keywords: attitudes, cognitive enhancement, nonmedical use of prescription drugs, scale development, smart drugs

The Wabigoon River is known for an historic mercury (Hg) pollution source, caused by a chlor-alkali facility operating in the 1960s. As legacy Hg contamination continues to cause serious adverse health effects to the local communities living in the Wabigoon River region, it is imperative to undertake additional research to understand the deposition and transport of historical mercury in this system and more importantly, its conversion into methylmercury (MMHg) which renders it bioavailable for ongoing bioaccumulation. The aim of this dissertation was to evaluate the transport and accumulation of Hg species by doing a spatial and temporal analysis of concentrations of mercury and methylmercury along the Wabigoon River, as well as assessing rates of methylation and demethylation, identifying areas of higher methylmercury production. Results show that locations downstream from the pollution source still show elevated mercury concentrations, with levels at least five times higher in water and up to 134 times higher in sediments compared to background levels. Among selected study sites, the Hydroelectric dam, the Wabigoon Rapids wetland and Clay Lake were identified to have high capacity for methylmercury production in the system, with notably Clay Lake presenting a higher potential for methylmercury accumulation due to the observed lower methylmercury demethylation rate. Furthermore, the impact of wetting and drying cycles on Hg methylation in riverbed and wetland locations within the Wabigoon River system was investigated through a laboratory simulation. Findings indicated increased susceptibility of riverbed locations to wetting and drying cycles.

Author Keywords: Demethylation, Mercury, Methylation, Methylmercury, Wabigoon River

Access to human blood for forensic research and training in bloodstain pattern analysis (BPA) can be difficult due to many ethical, safety and cost concerns. Mammalian blood alternatives can be sourced, especially from local and willing abattoirs, but some concerns remain, and the added difficulties of high variation and species-specific differences in cellular components pose other issues. Therefore, synthetic alternatives to human blood provide practical options for the BPA community. This thesis explores the use of alginate hydrogels as a base material for forensic blood substitute (FBS) development. Hydrogels are first explored as a suitable environment for DNA stability and functionality and compared to other polymer systems. The ability of DNA to remain intact while undergoing electrospray ionization (ESI) is also investigated. The FBS design focuses on mimicking the fluid properties and genetic capabilities of whole human blood – a material not developed in FBSs previously. ESI was used to develop microparticles (MPs) that serve as cellular components of human blood (the red blood cells – RBCs, and white blood cells – WBCs). The microparticles were ionically crosslinked using calcium to provide small MPs (RBCs) or covalently crosslinked with functional DNA to provide larger WBC-like functional particles. The integration of these novel MPs into alginate-based materials is optimized and their use in BPA scenarios is explored. The FBS is tested in BPA scenarios of dripping experiments, impact patterns, and the ability to extract and amplify the contained DNA. In addition, the stability (or shelf-life) of the FBS was also assessed. The FBS exhibited similar spreading ratios to blood and demonstrated feasibility in use for impact angle (a) determination and impact pattern creation. Importantly, the DNA contained within the FBS could be processed with analogous protocols used in DNA evidence processing, enhancing its applicability to BPA research and training.

Author Keywords: Alginate hydrogels, Bloodstain pattern analysis, Electrospray ionization, Forensic blood substitutes, Forensic materials, Synthetic DNA design