English
The effects of forest disturbance on dissolved organic carbon in the Algoma region, central Ontario
Many communities in Canada rely on water sourced from boreal forest headwaters for their drinking water. The Boreal Shield Ecozone is highly susceptible to climate change which threatens to exacerbate the effects of natural and human-driven disturbances such as wildfire, insect infestation and harvesting on water quality. Therefore, examining source water quality in headwater catchments within the Boreal Shield Ecozone is crucial to elucidating the potential implications of these disturbances to water treatment processes in the context of a changing climate. A synoptic water sampling investigation was conducted to evaluate how dissolved organic carbon (DOC) quantity and quality and disinfection by-product formation-potential (DBP-FP) quantity varied across space and time in the Algoma region of central Ontario. Over a five-month timeframe (June 2021 - October 2021), 168 streamflow estimates and 176 water samples were collected across 30 catchments (catchment areas from 0.2 - 106.8 km2) which varied in their forest disturbance histories. DOC concentration ([DOC]) ranged from 2.4 - 38.2 mg L-1 and tended to be higher in harvest-dominated sites, while no discernible differences in SUVA254 were observed between catchment types. DOC export estimates ranged from 1.0 - 63.2 g C m-2 over a 141-day period (June 5th - Oct. 23nd, 2021). Fluorescence indices for quantifying DOC composition suggested that all catchments were dominated by humified and terrestrially sourced carbon. DBP-FP values were positively correlated to UV-254 (r = 0.76 - 0.78) and [DOC] (r = 0.85 - 0.88), such that DBP-FP spatiotemporal patterns were strongly coupled to DOC dynamics. Multiple linear regression analysis identified that open water was negatively related to [DOC] and SUVA254 and explained the most variability in their spatiotemporal patterns. In addition, catchment area, which was negatively related to [DOC] and SUVA254, and legacy insect infestation and harvesting disturbance helped improve model explanatory power. Other predictor variables, such as slope, wetland cover, coniferous forest cover and recent forest disturbance (i.e., 5-year harvesting and 5-year insect infestation), showed relatively poor explanatory power. Variability in DOC export estimates may be explained by harvesting disturbance (adjusted r2 = 0.68 - 0.82). The results of this study emphasise that complex processes across the terrestrial-aquatic continuum, which are influenced by several factors, such as runoff, forest disturbance and landscape heterogeneity, govern the spatiotemporal patterns in water quality across boreal headwaters within the Algoma region.
Aboriginal Adult Education and Training: The History of Hydro Development in Manitoba and the Establishment of Atoskiwin Training and Employment Centre in Nisichawayasihk Cree Nation
This thesis focuses on the Atoskiwin Training and Employment Centre of Excellence (ATEC) in NelsonHouse, Manitoba, and its contribution to Aboriginal adult education and the economic development of the Nisichawayasihk Cree Nation (NCN). The study examines ATEC within the larger history of NCN's relationship with its land, hydroelectric development in northern Manitoba, and Wahbung: Our Tomorrows, the 1971 alternative blueprint to the federal White Paper. I argue that ATEC has played a key role in nurturing a resurgence of the social and economic capacity of people in Nelson House.
The research approach used in this study is ethnographic, drawing on the researcher's livedexperiences and relationships with the community and ATEC. Supporting qualitative data were collected through interviews with ATEC staff and students, allowing for an in-depth exploration of their experiences, perspectives, and the impact of ATEC on their lives and employment opportunities. The thesis examines the historical context of ATEC. It also explores the challenges and achievements of ATEC during two distinct phases: the initial phase focused on training for skilled and unskilled labourers during the construction of the Wuskwatim hydroelectric dam, and the subsequent phase after the dam's completion.
The research shows how ATEC has contributed to the economic and social capacity of NelsonHouse, analyzing its impact on community development and employment opportunities. It also points out the need for greater control, infrastructure and resources for Aboriginal adult education in rural and northern areas. The thesis concludes by discussing the findings and suggesting potential areas for improvement and growth in ATEC's programming and delivery methods.
Author Keywords: Aboriginal, Adult Education
Bottom-up pathways for arthropods and forest breeding birds in a southern Ontario forest
Long-term avian population declines, particularly for the avian insectivore guild, are a conservation concern. With widespread and continuing population trends, climate change and its negative effects on avian food resources is a plausible cross-species driver. My goal was to evaluate whether bottom-up trophic effects of climate change could be influencing avian populations. I used a space-for-time approach to assess the influence of snowpack and soil moisture variability on arthropods and subsequent effects on nest survival. In the 2010 and 2011 growing seasons, I sampled arthropods, soil moisture (soil volumetric water content; VWC), snowpack (snow water equivalent; SWE), forest floor depth (L, F, H layers) and soil texture in conifer plantations and mixed deciduous forest in Southern Ontario's Ganaraska Forest (~4, 400 ha). I used additive linear mixed effects models to assess the responses of arthropod groups' (e.g., order or class) relative biomass (g/day) and abundance (count/day) to those variables. Influences for each arthropod group's biomass and abundance were typically in the same direction. Maximum annual SWE significantly positively influenced most arthropod groups and annual relative difference in VWC positively influenced one quarter. In mixed directions, forest type influenced half of the groups and soil texture and forest floor depth each affected less than one quarter. I then used structural equation models to evaluate relationships between SWE, VWC, the biomass of three arthropod functional guilds, and logistic-exposure model calculated daily nest survival rates for American Robin (Turdus migratorius), Eastern Wood-Pewee (Contopus virens), Least Flycatcher (Empidonax minimus), Ovenbird (Seiurus aurocapilla), and Red-eyed Vireo (Vireo olivaceus). Arthropod guilds included diet-based food, predaceous arthropods and soil-dwelling bioindicators. SWE significantly positively influenced food biomass in all five models and negatively influenced predaceous arthropods in three models. Soil moisture had a mix of positive, negative, and null effects. Eastern Wood-Pewee and Red-eyed Vireo nest survival positively related to food and negatively related to predaceous arthropod biomass. American Robin, Least Flycatcher and Ovenbird nest survival did not appear to be related to arthropod biomasses. Through bottom-up relationships, predicted climate change-induced reductions in snowpack may cause food resource declines and negatively affect some forest breeding bird populations.
Author Keywords: Arthropod biomass, Bottom-up, Forest birds, Nest survival, Path analysis, Precipitation
The effect of cytokinins on the metabolite secretome of Giardia intestinalis during trophozoite growth, nutrient deprivation, and encystation
Giardia intestinalis is the causative agent of a diarrheal disease in mammals, but the mechanisms of disease pathogenesis are unclear. While proteins secreted by Giardia affect the host cells, the potential of hormone secretion has not been investigated to date. Cytokinins (CKs) are classified as phytohormones, but little is known about their role beyond plants. Mass spectrometry-based intracellular analysis revealed CKs typical of tRNA degradation, and extracellular analysis showed CK-riboside scavenging by Giardia with concurrent secretion of CK-free bases. Metabolomics profiling of culture supernatants showed similar trends where nucleosides were up taken, and nucleobases were secreted. The dynamics of amino acids, nucleosides and nucleobases were altered by CK-supplementation during encystation, along with inhibition of encystation. In summary, this is the first study to report CK synthesis and metabolism by Giardia along with the effects of CKs on the metabolite secretome of Giardia, while establishing a link between CK and nucleoside metabolism.
Author Keywords: Cytokinins, Giardia, mass spectrometry, metabolomics, parasite, secretome
When Parents Phub: Investigating its Relationship with Children's Digital and Problem Behaviours
In today's digital era, smartphone use is having a profound effect on family life. There is growing concern about parental phubbing, which occurs when parents ignore their children in favour of using their phones. This study examined how parental phubbing was associated with children's problematic media use (PMU), and problem behaviours (internalizing, externalizing,attention) during middle childhood. The role of the parent-child relationship, measured by closeness and conflict, was also explored given its well-established influence on child development. Participants included 99 parents/guardians of 6-8-year-olds and 87 parents/guardians of 9-12-year-olds. Data on all variables were collected through online surveys. Across both groups, phubbing was associated with children's PMU. Among the 6-8-year-old's, phubbing was also linked to internalizing and externalizing problems. In this age group, parent-child closeness buffered phubbing effects while conflict mediated the relationship between phubbing and children's behaviour. These findings enhance our understanding of parental phubbing within Canadian family contexts.
Author Keywords: Middle Childhood, Parent-Child Relationship, Phubbing, Problem Behaviours, Problematic media use
Psychometric Properties of a Short Coping Measure: An Investigation of the Coping Inventory for Stressful Situations – Short Form (CISS-SF)
Objective: The Coping Inventory for Stressful Situations (CISS) is a widely used measure of trait coping that was developed to assess three basic coping styles: task-oriented, emotion-oriented, and avoidance-oriented coping. This thesis examined the psychometric properties of a short form for the CISS (CISS-SF). Method: Data from a large longitudinal sample of adults were used to conduct analyses testing the measure's factor structure, internal and test-retest reliabilities, and construct validity with respect to mental health outcomes. Results: The 3-factor model provided acceptable fit to the sample data. Internal reliabilities for the scales were acceptable across multiple administrations (by gender and age), while 1 and 2-year test-retest correlations were also consistent with what would be expected for stable coping style constructs. Relationships were found to be consistent with previous research on coping. Conclusion: Overall, the results suggest that the CISS-SF is a valid and reliable brief multi-dimensional measure of coping styles.
Author Keywords: basic personality, coping, coping styles, mental health, psychometrics
Impulsivity, cannabis use, risk-taking behaviour and performance on vigilance, attention, and decision making tasks
This study aimed to explore relationships between impulsivity scores, cannabis use, and performance on vigilance, attention, and decision making tasks. We also investigated whether cannabis use related to self-reported risk taking behaviours, including risky driving, openness to engage with cryptocurrency markets, or gambling behaviour. The regular recreational cannabis users had significantly higher impulsivity scores and tendency to use other substances than non-users. The regular cannabis users had better performance efficiency than non-users for hit targets on the vigilance task, but not the other two target trial types. The regular cannabis users made significantly fewer errors than non-users on the verbal Stroop task. There were no significant performance differences on the Iowa Gambling Task between the regular recreational cannabis users and non-users. None of our other hypotheses explorations yielded statistically significant results.
Author Keywords: cannabis, cryptocurrency, gambling, impulsivity, Stroop, vigilance
Modelling Cholera Transmission with Delayed Bacterial Shedding and Disinfection Control
This study focuses on the world dynamics of a cholera model that includes delayed bacterial shedding and water disinfection. From the method of the next generation matrix, a basic reproduction number is found that sets a threshold of disease persistence. It is shown that the disease disappears if $R_0<1$, which means that the disease-free equilibrium is globally asymptotically stable. The system is not destabilized by the delay, which leads to periodic oscillations. The numerical simulations validate the theoretical analysis, which illustrates the importance of delay and disinfection in cholera prevention and control.
Author Keywords: Basic reproduction number, Cholera, Delay differential equations, Disinfection, Lyapunov function, Stability analysis
Widening the Lens: Feminist Learning in Counselling and Psychotherapy
This study examines the formal, informal, and non-formal learning experiences offeminist-identified counsellors and psychotherapists working within the Violence Against Women (VAW) and Gender-Based Violence (GBV) sector of community- based social services in Ontario, Canada. Using critical, feminist polyethnography and intersectional and feminist theories, this study discusses the participants' and researcher's experiences in the field. The participants' narratives contribute to the understanding of intersectional feminist pedagogies in counselling and psychotherapy practices and spaces. Additionally, the study offers recommendations for post- secondary programs, wise practice approaches to intersectional clinical supervision, and a framework for community of practice models of peer supervision.
Author Keywords: adult learning, feminism, feminist theory, intersectional theory, psychotherapy, social work
Describing Symptom Heterogeneity in Obsessive-Compulsive Disorder: Relationships Between and Stability Within the Overt Symptom and Core Dimensions Models
Two dimension-based models have emerged that capture the high symptom heterogeneity observed in obsessive-compulsive disorder (OCD)—one grouping symptoms by their overt presentation, the other identifying core dimensions of underlying symptom motivations. This paper presents two studies that explore (1) the relationship between these two models, and (2) the stability of the models and dimensions they each represent. Study 1 found that the core dimension motives jointly predicted overall OCD symptom severity, and that each core dimension further predicted unique nonoverlapping overt symptom dimensions. Study 2 demonstrated that despite high instances of item-level symptom change, both models and their respective dimensions were longitudinally stable, with exception to overt symptoms relating to harm/injury/bad luck. Both studies support further consideration of these models as clinical resources and support the candidacy of the core dimensions as endophenotypes for OCD. Results, limitations, clinical implications, and future directions are discussed.
Author Keywords: Core Dimensions, Endophenotype, Obsessive-Compulsive Disorder, Overt Symptoms, Stability, Symptom Models