Identity Formation and Negotiation of Afghan Female Youth in Ontario

The following thesis provides an empirical case study in which a group of 6 first generation female Afghan Canadian youth is studied to determine their identity negotiation and development processes in everyday experiences. This process is investigated across different contexts of home, school, and the community. In terms of schooling experiences, 2 participants each are selected representing public, Islamic, and Catholic schools in Southern Ontario. This study employs feminist research methods and is analyzed through a convergence of critical race theory (critical race feminism), youth development theory, and feminist theory. Participant experiences reveal issues of racism, discrimination, and bias within schooling (public, Catholic) systems. Within these contexts, participants suppress their identities or are exposed to negative experiences based on their ethnic or religious identification. Students in Islamic schools experience support for a more positive ethnic and religious identity. Home and community provided nurturing contexts where participants are able to reaffirm and develop a positive overall identity.

An Exploration Into Doctoral Students' Sense of Community and its Influence on the Formation of Informal Mentoring Relationships

This exploratory mixed method research project was designed to investigate an area of doctoral education that has received little attention in the past. This research focused specifically on the non-intellectual, hoped-for by-products of doctoral education; the dynamic processes of developing and maintaining both a sense of community and informal mentoring relationships. The design of the study captured the experiences of doctoral students and alumni at various time periods in the doctoral program. Participants represented a diverse group of students with differences in professional and academic backgrounds and life stages. A pilot study for this research suggested that the presence of a sense of community and informal mentoring may provide the necessary relationships to support this diversity. The primary question at the forefront of this study was: Do doctoral students feel connected to one another? Five subquestions were developed to address this research topic: Does a sense of community already exist and flourish in doctoral education? Are the programs and resources of the doctoral program organized to nurture the creation and maintenance of a sense of community? Is a sense of community a foundational element in the formation of naturally occurring relationships among doctoral students? What educational and socio-emotional benefits are associated with informal mentoring relationships during the doctoral experience? and Do doctoral students perceive a change in their development as stewards of their discipline over time? The principal methods used to investigate these research questions combined both quantitative and qualitative techniques in a concurrent time sequence. The quantitative portion of the study involved a questionnaire, while the qualitative portion involved two approaches; face-to-face interviews and an open-ended question at the end of the questionnaire. Findings from the study indicated that the presence of both sense of community and informal mentoring enhance the overall quality of doctoral education. Program elements that enhanced or hindered connection between students were identified. Both the dynamics and the emotional, social, and academic benefits of informal mentoring were elucidated. Over time participants perceived changes in their development of the qualities assqciated with stewardship. This study brought the "hoped-for by-products" associated with doctoral education from the background shadows to an illuminated position at the forefront of inquiry.

Hyperosmotic Stress and the Impact on Metabolite Formation and Redox Balance in Saccharomyces cerevisiae and Saccharomyces bayanus strains

Wine produced using an appassimento-type process represents a new and exciting innovation for the Ontario wine industry. This process involves drying grapes that have already been picked from the vine, which increases the sugar content due to dehydration and induces a variety of changes both within and on the surface of the grapes. Increasing sugar contents in musts subject wine yeast to conditions of high osmolarity during alcoholic fermentations. Under these conditions, yeast growth can be inhibited, target alcohol levels may not be attained and metabolic by-products of the hyperosmotic stress response, including glycerol and acetic acid, may impact wine composition. The further metabolism of acetic acid to acetylCoA by yeast facilitates the synthesis of ethyl acetate, a volatile compound that can also impact wine quality if present in sufficiently high concentrations. The first objective of this project was to understand the effect of yeast strain and sugar concentration on fermentation kinetics and metabolite formation, notably acetic acid and ethyl acetate, during fermentation in appassimento-type must. Our working hypotheses were that (1) the natural isolate Saccharomyces bayanus would produce less acetic acid and ethyl acetate compared to Saccharomyces cerevisiae strain EC-1118 fermenting the high and low sugar juices; (2) the wine produced using the appassimento process would contain higher levels of acetic acid and lower levels of ethyl acetate compared to table wine; (3) and the strains would be similar in the kinetic behavior of their fermentation performances in the high sugar must. This study determined that the S. bayanus strain produced significantly less acetic acid and ethyl acetate in the appassimento wine and table wine fermentations. Differences in acetic acid and ethyl acetate production were also observed within strains fermenting the two sugar conditions. Acetic acid production was higher in table wine fermented by S. bayanus as no acetic acid was produced in appassimento-style wine, and 1.4-times higher in appassimento wine fermented by EC-1118 over that found in table wine. Ethyl acetate production was 27.6-times higher in table wine fermented by S. bayanus, and 5.2-times higher by EC-1118, compared to that in appassimento wine. Sugar utilization and ethanol production were comparable between strains as no significant differences were determined. The second objective of this project was to bring a method in-house for measuring the concentration of pyridine nucleotides, NAD+, NADP+, NADH and NADPH, in yeast cytosolic extract. Development of this method is of applicative interest for our lab group as it will enable the redox balance of the NAD+/ NADH and NADP+/ NADPH systems to be assessed during high sugar fermentations to determine their respective roles as metabolic triggers for acetic acid production. Two methods were evaluated in this study including a UV-endpoint method using a set of enzymatic assay protocols outlined in Bergmeyer (1974) and a colorimetric enzyme cycling method developed by Sigma-Aldrich® using commercial kits. The former was determined to be limited by its low sensitivity following application to yeast extract and subsequent coenzyme analyses, while the latter was shown to exhibit greater sensitivity. The results obtained from the kits indicated high linearity, accuracy and precision of the analytical method for measuring NADH and NADPH, and that it was sensitive enough to measure the low coenzyme concentrations present in yeast extract samples. NADtotal and NADPtotal concentrations were determined to be above the lower limit of quantification and within the range of the respective calibration curves, making this method suitable for our research purposes.

A game-theoretic network formation model

We study the dynamics of a game-theoretic network formation model that yields large-scale small-world networks. So far, mostly stochastic frameworks have been utilized to explain the emergence of these networks. On the other hand, it is natural to seek for game-theoretic network formation models in which links are formed due to strategic behaviors of individuals, rather than based on probabilities. Inspired by Even-Dar and Kearns (2007), we consider a more realistic model in which the cost of establishing each link is dynamically determined during the course of the game. Moreover, players are allowed to put transfer payments on the formation of links. Also, they must pay a maintenance cost to sustain their direct links during the game. We show that there is a small diameter of at most 4 in the general set of equilibrium networks in our model. Unlike earlier model, not only the existence of equilibrium networks is guaranteed in our model, but also these networks coincide with the outcomes of pairwise Nash equilibrium in network formation. Furthermore, we provide a network formation simulation that generates small-world networks. We also analyze the impact of locating players in a hierarchical structure by constructing a strategic model, where a complete b-ary tree is the seed network.

The role of retinoic acid in long-term memory formation and synaptic plasticity in the mollusc Lymnaea stagnalis

The active metabolite of vitamin A, retinoic acid (RA), is involved in memory formation and hippocampal plasticity in vertebrates. A similar role for retinoid signaling in learning and memory formation has not previously been examined in an invertebrate species. However, the conservation of retinoid signaling between vertebrates and invertebrates is supported by the presence of retinoid signaling machinery in invertebrates. For example, in the mollusc Lymnaea stagnalis the metabolic enzymes and retinoid receptors have been cloned from the CNS. In this study I demonstrated that impairing retinoid signaling in Lymnaea by either inhibiting RALDH activity or using retinoid receptor antagonists, prevented the formation of long-term memory (LTM). However, learning and intermediate-term memory were not affected. An additional finding was that exposure to constant darkness (due to the light-sensitive nature of RA) itself enhanced memory formation. This memory-promoting effect of darkness was sufficient to overcome the inhibitory effects of RALDH inhibition, but not that of a retinoid receptor antagonist, suggesting that environmental light conditions may influence retinoid signaling. Since RA also influences synaptic plasticity underlying hippocampal-dependent memory formation, I also examined whether RA would act in a trophic manner to influence synapse formation and/or synaptic transmission between invertebrate neurons. However, I found no evidence to support an effect of RA on post-tetanic potentiation of a chemical synapse. Retinoic acid did, however, reduce transmission at electrical synapses in a cell-specific manner. Overall, these studies provide the first evidence for a role of RA in the formation of implicit long-term memories in an invertebrate species and suggest that the role of retinoid signaling in memory formation has an ancient origin.

Calculations on a piece of “Long Point, Head Quarters” stationary with the “Long Point Company, Canada” seal

Calculations on a piece of “Long Point, Head Quarters” stationary with the “Long Point Company, Canada” seal. There are land calculations on this sheet, n.d.

Receipt from Tiffany and Co., New York for engraving on a seal

Receipt from Tiffany and Co., New York for engraving on a seal, Oct. 9, 1884