• Ojibwe Elders' Experiences of Peace: To Teach Our Well-Being With the Earth

      Lafleur, Gail Sarah; Department of Graduate and Undergraduate Studies in Education (Brock University, 2013-11-15)
      This research focuses on exploring the Anishinaabek/Ojibwe worldview founded upon the spiritual relationship with Mother Earth as the Anishinaabek view of peace to teach our well-being with earth. This research explores the experiences of four 21st century traditional Anishinaabek elders through describing their ways of knowing and of being as it relates to the Anishinaabek worldview of respect and peace with nature. This respect for Mother Earth and respecting earth’s way−akii-bimaadizi is articulated and shared regarding elders’ experiences of teaching our well-being with earth−Akinomaage mino akii-ayaa and is based upon Anishinaabek spirituality. This research details the Anishinaabek worldview from the elders’ shared experiences of earth as teacher and elder. Ten themes emerged from the data. These themes included (a) going back to our original gifts and instructions/building your sacred bundle/sharing your sacred bundle, (b) wisdom−nbwaakaawin: connecting the dots/original instructions/medicine−mshkiki/environmental consciousness, (c) sacred teachings/learning from the elders, (d) relationships/honoring elders/eldership, (e) political experiences and awareness, (f) a way of being in Anishinaabek research, (g) survival, (h) peace is our worldview demonstrated, (i) be aware of colonialistic thinking, (j) Akinomaage: earth as context. The researcher also shares her reflections as a researcher and as an Anishinaabekwe: Ojibwe woman.
    • On the Ball Implementation of Canada Basketball’s Athlete Development Model

      Whitaker-Campbell, Tammy; Applied Health Sciences Program
      The purpose of this dissertation was to explore the perceived benefits and challenges of Canada Basketball’s athlete development model (ADM)/long-term athlete development (LTAD) by administrators, learning facilitators, and coaches at Canada Basketball to better understand the barriers to and enablers of this process. The methodological approach used for the study was an exploratory case study. Methods were established that were consistent with the iterative nature of case study. In total, 5 participants who identified as administrator/learning facilitator/coach, 6 participants who identified as /learning facilitator/coach, and 1 participant who identified as a coach participated in the study. In-depth semi-structured interviews were conducted with each participant that provided new insight into participants’ perceptions of and experiences with ADM/LTAD relative to their positions. Analysis revealed themes related to perceived (a) benefits while using ADM/LTAD; and (b) and challenges with using ADM/LTAD. These findings provide a preliminary assessment of one sport specific athlete development model and may inform research of other sport-specific athlete development programs. Several implications of the study findings are discussed and suggestions are posed for future research.
    • Opening a can of worms : perceptions and practices of teachers in Newfoundland and Labrador incorporating the role of a therapist

      Maich, Kimberly.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2009-05-28)
      Educational trends of inclusion and collaboration have led to changing roles of teachers, including an emphasis on personal support. To provide for social, emotional, and behavioural needs, teachers may adopt a therapeutic role. Many models for such support are proposed, with most models including the importance of student-teacher relationships, a focus on social, emotional, and behavioural development, and direct instruction of related skills. This study includes 20 interview participants. In addition, 4 of the 20 interview participants also took part in a case study. It examines whether participants adopt a therapeutic role, their beliefs about student-teacher relationships, whether they provide interventions in personal issues, and instructed social, emotional, and behaviour skills. Findings show that teachers adopt an academic role as well as a therapeutic role, believe student-teacher relationships are important, are approached about personal issues, and instruct social, emotional, and behavioural skills. Talking and listening are commonly used to provide support, typically exclusive of formal curricular goals. The challenges in providing front-line support issues that may be shared within an established student-teacher relationship are considered. Support in turn for teachers who choose to provide support for personal issues in the classroom within a therapeutic role are suggested, including recommendations for support and referral related to specific social, emotional, or behavioural scenarios that may arise in the school community.
    • Opening truth to imagination : the pragmatism of John Dewey and Richard Rorty

      McClelland, Kenneth A.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2006-05-28)
      This study explores in a comparative way the works of two American pragmatist philosophers-John Dewey and Richard Rorty. I have provided a reading of their broader works in order to offer what I hope is a successful sympathetic comparison where very few exist. Dewey is often viewed as the central hero in the classical American pragmatic tradition, while Rorty, a contemporary pragmatist, is viewed as some sort of postmodern villain. I show that the different approaches by the two philosophers-Dewey's experiential focus versus Rorty's linguistic focus-exist along a common pragmatic continuum, and that much of the critical scholarship that pits the two pragmatists against each other has actually created an unwarranted dualism between experience and language. I accomplish this task by following the critical movement by each of the pragmatists through their respective reworking of traditional absolutist truth conceptions toward a more aesthetical, imaginative position. I also show how this shift or "turning" represents an important aspect of the American philosophical tradition-its aesthetic axis. I finally indicate a role for liberal education (focusing on higher nonvocational education) in accommodating this turning, a turning that in the end is necessitated by democracy's future trajectory

      Frampton, Mark B.; Centre for Biotechnology (Brock University, 2013-02-22)
      The first part of this thesis studied the capacity of amino acids and enzymes to catalyze the hydrolysis and condensation of tetraethoxysilane and phenyltrimethoxysilane. Selected amino acids were shown to accelerate the hydrolysis and condensation of tetraethoxysilane under ambient temperature, pressure and at neutral pH (pH 7±0.02). The nature of the side chain of the amino acid was important in promoting hydrolysis and condensation. Several proteases were shown to have a capacity to hydrolyze tri- and tet-ra- alkoxysilanes under the same mild reaction conditions. The second part of this thesis employed an immobilized Candida antarctica lipase B (Novozym-435, N435) to produce siloxane-containing polyesters, polyamides, and polyester amides under solvent-free conditions. Enzymatic activity was shown to be temperature dependent, increasing until enzyme denaturation became the dominant pro-cess, which typically occurred between 120-130ᵒC. The residual activity of N435 was, on average, greater than 90%, when used in the synthesis of disiloxane-containing polyesters, regardless of the polymerization temperature except at the very highest temperatures, 140-150ᵒC. A study of the thermal tolerance of N435 determined that, over ten reaction cycles, there was a decrease in the initial rate of polymerization with each consecutive use of the catalyst. No change in the degree of monomer conversion after a 24 hour reaction cycle was found.
    • The osmoadaptive response of the wine yeast Saccharomyces cerevisiae K1-V1116 during icewine fermentation

      Martin, Stephanie J.; Centre for Biotechnology (Brock University, 2008-05-28)
      The adapted metabolic response of commercial wine yeast under prolonged exposure to concentrated solutes present in Icewine juice is not fully understood. Presently, there is no information regarding the transcriptomic changes in gene expression associated with the adaptive stress response ofwine yeast during Icewine fermentation compared to table wine fermentation. To understand how and why wine yeast respond differently at the genomic level and ultimately at the metabolic level during Icewine fermentation, the focus ofthis project was to identify and compare these differences in the wine yeast Saccharomyces cerevisiae KI-Vll16 using cDNA microarray technology during the first five days of fermentation. Significant differences in yeast gene expression patterns between fermentation conditions were correlated to differences in nutrient utilization and metabolite production. Sugar consumption, nitrogen usage and metabolite levels were measured using enzyme assays and HPLC. Also, a small subset of differentially expressed genes was verified using Northern analysis. The high osmotic stress experienced by wine yeast throughout Icewine fermentation elicited changes in cell growth and metabolism correlating to several fermentation difficulties, including reduced biomass accumulation and fermentation rate. Genes associated with carbohydrate and nitrogen transport and metabolism were expressed at lower levels in Icewine juice fermenting cells compared to dilute juice fermenting cells. Osmotic stress, not nutrient availability during Icewine fermentation appears to impede sugar and nitrogen utilization. Previous studies have established that glycerol and acetic acid production are increased in yeast during Icewine fermentation. A gene encoding for a glycerollW symporter (STL1) was found to be highly expressed up to 25-fold in the i Icewine juice condition using microarray and Northern analysis. Active glycerol transport by yeast under hyperosmotic conditions to increase cytosolic glycerol concentration may contribute to reduced cell growth observed in the Icewine juice condition. Additionally, genes encoding for two acetyl CoA synthetase isoforms (ACSl and ACS2) were found to be highly expressed, 19- and II-fold respectively, in dilute juice fermenting cells relative to the Icewine juice condition. Therefore, decreased conversion of acetate to acetyl-CoA may contribute to increased acetic acid production during Icewine fermentation. These results further help to explain the response of wine yeast as they adapt to Icewine juice fermentation. ii
    • Part Time University Teaching in Ontario: A Self-Study

      Cope Watson, Georgann; Department of Graduate and Undergraduate Studies in Education (Brock University, 2013-09-06)
      This qualitative self-study explored the disappointment I felt as a part-time university teacher in a mid-sized, primarily undergraduate Ontario university, where I experienced difficulty integrating my beliefs about teaching into my practice of teaching. The purpose of this qualitative study was to inquire into why it was difficult for me, representative of a part-time university teacher in a mid-sized, primarily undergraduate university, to enact the critical pedagogical practices I espoused in my teaching philosophy. The secondary purpose was to apply the findings of the study to reframe my university teaching practice in a way that met my need to enact my beliefs about university teaching while complying with the broader geo-political conditions of part-time university teaching in Ontario (Loughran, 2006; Russell & Loughran, 2007). This study is grounded in the sociological theoretical framework of critical pedagogy (Freire, 1970; Giroux, 1988, 2010; McLaren, 2003) and the methodological framework of The Self-Study of Teacher Education Practices (S-STEP). This study combined the methods of Brookfield’s (1995; 2002) critically reflective practice and Cole and Knowles (2000) practice of reflexive inquiry with Creswell’s (2005) methods of thematic analysis to answer the research question: Why is it difficult for me to enact my beliefs about university teaching as a part-time teacher in an Ontario university? Findings suggest the geo-political contexts of part-time university teaching work can impact a teacher’s ability to enact his/her beliefs about teaching within his/her practice of teaching.
    • Partnership for arts integration : exploring the experiences of teachers and artists working with integrated arts programs

      Attenborough, Debra.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2008-05-28)
      This research acknowledges the difficulties experienced by teachers presenting integrated arts curricula. Instructional support is offered by arts organizations that provide arts partnerships with local schools boards. The study focuses on the experiences of 8 teachers from a Catholic school board in southern Ontario who participated in integrated arts programs offered by The Royal Conservatory of Music's Learning Through the Arts™ (LTTATM) program and a local art gallery's Art Based Integrated Learning (ABIL) program and examines their responses to the programs and their perception of personal and professional development through this association. Additionally, questions were posed to the . "aftisfs"from-tneSe]Jfograrrrs;-and"they liiscus·sed·how"participating in-collaboration with teachers in the development of in-school programs enabled them to experience personal and professional development as well. Seven themes emerged from the data. These themes included: teachers' feelings of a lack of preparedness to teach the arts; the value of the arts and arts partnerships in schools; the role of the artists in the education of teachers; professional development for both teachers and artists; the development of collegiality; perceptions of student engagement; and the benefits and obstacles of integrating the arts into the curriculum. This document highlights the benefits to both teachers and artists of arts partnerships between schools and outside arts organizations.
    • Patterns of Endocrine, Behavioural, and Neural Function Underlying Social Deficits after Social Instability Stress in Adolescent Rats

      Hodges, Travis; Department of Psychology
      Adolescence is a time of social learning as well as a period of heightened vulnerability to stressors and enhanced plasticity, compared with adulthood. Previous research found that repeated social instability stress (SS; daily isolation and return to an unfamiliar peer from postnatal day (PND) 30 - 45) administered in adolescent rats alters social function when tested in adulthood. The main goal of my thesis research was to characterize how SS in adolescent rats affects the development of social brain regions and social behaviour when tested soon after the procedure. In chapter 2, I found that SS potentiated corticosterone release in rats repeatedly paired with an unfamiliar cage-mate after isolation compared with rats that were paired with an unfamiliar cage-mate for the first time after isolation on PND 45. In chapter 3, I found that in social interaction tests (i.e., not in home cage), SS rats had lower social interactions despite having higher social approach with unfamiliar peers relative to control (CTL) rats. Social stimuli carried the same reward value for SS and CTL rats based on tests of conditioned place preference, and SS in adolescence impaired social recognition. Further, SS increased oxytocin receptor density in the nucleus accumbens and dorsal lateral septum in rats compared with CTL rats. In chapter 4, I found that the correlations between time spent in social interaction with an unfamiliar peer and Fos immunoreactivity (a marker of neural activity) in the arcuate nucleus, dorsal lateral septum, and posterior medial amygdala were in the opposite direction in SS rats to those in CTL rats. In chapter 5, I found differences in the expression of proteins relevant for synaptic plasticity and in dendritic arborisation in the lateral septum and medial amygdala. My findings of behavioural and neural differences between SS and CTL rats highlight the heightened vulnerability of the brain to the quality of social experiences during the adolescent period that may lead to long-lasting deficits in social function in adulthood.
    • Perceptions of Adolescent Males and Their Parents as to Factors That Influence the Young Men's Academic Performance

      Tierney, Patrick J.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2014-12-10)
      Postsecondary enrolments of young males has been declining since the mid-1980s. The decline can be attributed, at least in part, to boys and young men being unable to compete for a fixed number of available places in institutions of higher learning, whether in community college or university. This inability to compete stems from their academic performance in secondary school. This study interviewed adolescent males and their parents as to their perceptions of a number of factors that may contribute to their academic performance. Those factors included noncognitive skills, dimensions of character, perceptions of teachers, general attitudes towards school, and likes and dislikes on a range of course subjects. One of the most important findings was that only one of the seven adolescent male participants was considering a future career that would require a university degree. Other findings showed the young men's noncognitive skills were weak, particularly in relation to time management skills and their unwillingness to ask for help with schoolwork and homework. Most of the young men expressed a dislike for mathematics beyond high school, a subject key to the study, of the natural sciences, engineering, technology, and business. Recommendations include school reforms both inside the classroom and beyond. Additionally, a framework using project management theory and practice has been proposed to improve noncognitive skills, dimensions of character, and executive function.
    • Perceptions of Change in Self-Efficacy to Pursue Postsecondary Education for Students with Exceptionalities Participating in a Postsecondary Transition Program

      Ismailos, Linda; Department of Graduate and Undergraduate Studies in Education
      This mixed-methods study explored a postsecondary transition program’s effect on the development of self-efficacy for post-secondary studies and the likelihood to apply to post-secondary studies among students with exceptionalities. The study also examined how their perceptions of change in self-efficacy compared to their non-exceptional peers in the program. Participants included Grade 11 and 12 students with and without exceptionalities who were at risk of non-completion of their secondary school diploma from 2 participating boards of education at a college in Ontario, Canada. Students participated in a series of pre- and post-program completion surveys and were further invited to participate in a personal follow-up interview to explore the impact of their experience in the program on their plans for postsecondary education. Secondary school teachers working in a supportive role with students in this program were also interviewed to explore their perceptions of change in the students over the duration of the program. Findings demonstrated that students both with and without exceptionalities benefitted from the program through a number of elements that resulted in increased self-efficacy to succeed in postsecondary education, and an increased likelihood to apply to a postsecondary program in the future. Findings, however, indicated that the two groups of students did not share the same perceptions of how the program might have contributed to their increased self-efficacy. Following program completion, students with exceptionalities were more likely to describe their personal mastery experiences in a postsecondary academic program and their process of metacognitive skill development, whereas their peers without exceptionalities were more likely to describe a positive experience on a college campus as the primary contributing factor for their increased academic self-efficacy. The study further discusses the elements that contributed to the change experienced by the students with exceptionalities and offers a visual framework for the elements involved in the development of academic self-efficacy for students with exceptionalities. Interpretations and suggestions as to how these insights could inform future policy and practice are discussed.
    • Phage-mediated biological control of Erwinia amylovora: The role of CRISPRs and exopolysaccharide

      Yagubi, Abdelbaset; Department of Biological Sciences
      Fire blight, caused by bacterium Erwinia amylovora, is a very serious disease affecting apple, pear and other fruit plants. The development of phage-based biopesticides is currently in progress in our lab. Emergence of phage-resistant bacteria is a valid concern. Two attributes of the bacterial host that may contribute to the development of resistance were studied, the Clustered Regularly Interspaced Short Palindromic Repeats/ CRISPR-associated (CRISPR/Cas) system and exopolysaccharide (EPS) interaction with phages. The structure of E. amylovora CRISPR/Cas system was determined in 8 E. amylovora isolates from different geographical regions. Three CRISPR-array sets named CR1, CR2 and CR3 were detected in 4 isolates, and only 2 arrays were determined in the rest of the isolates. No significant similarity was found between spacers in any of these systems to phage DNA sequenced in this study or from GenBank. Also the Cas level of expression was not stimulated during phage infection. Introduction of extra copies of Cas genes to enhance expression did not result in phage resistance. Nevertheless, E. amylovora CRISPR/Cas system was found to be efficient in blocking the transformation of plasmids carrying protospacers matched spacers in CRR1 and CRR2. Among phages that have been sequenced in this study are ΦEa9-2 and ΦEa35-70. ΦEa9-2 (Podoviridae) genome is 75,568 bp, and found to be related to coliphage N4. ΦEa35-70 (Myoviridae) genome is 271,084 bp, and found to carry a potential EPS depolymerase gene. Activity of ΦEa35-70 EPS depolymerase was only detected when cloned and expressed in E. coli, but His-tagged purified protein did not exhibit any EPS-depolymerase activities. This study offers critical information for the design of novel and effective phage-based biopesticides for the control of E. amylovora. It provides a new knowledge on the molecular structure and function of CRISPR/Cas system and EPS-phage interaction.
    • Physical Activity and Fitness in Children with Developmental Disorder

      Rivilis, Irina; Applied Health Sciences Program (Brock University, 2012-05-17)
      Introduction: Developmental coordination disorder (DCD) is a prevalent condition characterized by poor motor proficiency that interferes with a child‟s activities of daily living. Children with DCD often experience compromised health-related fitness components such as cardiorespiratory fitness (CRF). Purpose: To better understand the physical activity and fitness characteristics of children with probable DCD (pDCD), with a particular focus on CRF. Specifically: (1) to present a synopsis of current literature; (2) to determine the longitudinal trajectories of CRF; (3) to compare the submaximal CRF of children with and without pDCD. Methods: A comprehensive, systematic literature review was conducted of the recent available data on fitness and physical activity and pDCD (Chapter 2). This review provided the background for the other two studies included in this thesis. In Chapter 3, a prospective cohort design was used to assess how CRF in children with pDCD changes over time (56 months) relative to a group of typically developing controls. Using a nested-case control design, 63 subjects with pDCD and 63 matched controls from the larger sample were recruited to participate in the lab-based component of the study (Chapter 4). In this investigation CRF was examined using the oxygen cost of work (VO2) during an incremental test on a cycle ergometer. Results: The literature review showed that fitness parameters, including CRF and physical activity levels, were consistently reduced in children with pDCD. Chapter 3 demonstrated that the difference in CRF between children with pDCD and typically developing children is substantial, and that it tends to increase over time. Results from VO2 assessments showed that children with pDCD utilized more oxygen to sustain the same submaximal workloads compared to typically developing children. Conclusions: Findings from this thesis have made several important contributions to our understanding of children with pDCD. Since differences in CRF between children with and without pDCD tend to worsen over time, this adds to the argument that interventions intended to improve CRF may be appropriate for children with motor difficulties. This thesis also presented the first evidence suggesting that DCD involves higher energy expenditure, and could help explain why children with pDCD perform poorly on tasks requiring CRF.
    • Physical Correlates of Sexual Orientation: The Association of Height, Birth Weight, and Facial Structure with Sexual Orientation.

      Skorska, Malvina N.; Department of Psychology
      Researchers have examined whether certain physical characteristics are associated with sexual orientation to gain insight into the mechanisms that may be implicated in its development. Three relatively new and/or understudied physical correlates (height, birth weight, facial structure) were investigated to determine whether they are reliably associated with sexual orientation and to gain insight into the specific mechanism(s) that may be driving the association between these physical correlates and sexual orientation. In Study 1, gay men were found to be shorter, on average, than heterosexual men in a nationally representative US sample. There was no significant height difference between lesbian and heterosexual women. No evidence was found that stress and nutrition at puberty mediated the association between sexual orientation and height in men. Thus, other mechanisms (e.g., prenatal hormones, genetics) likely explain the sexual orientation-height link. In Study 2, firstborn gay male only-children had, on average, a significantly lower mean birth weight than firstborn children in four other sibship groups. There was also evidence of increased fetal loss among mothers of gay male only-children. Birth weight and fetal loss have been shown to be indicators of a mother’s immune system responding to a pregnancy. Thus, Study 2 provides support for the idea that a maternal immune response (and one that appears to be distinct from the maternal immune response hypothesized to explain the traditional fraternal birth order effect) is implicated in sexual orientation development. In Study 3, lesbian and heterosexual women differed in 17 facial features (out of 63) at the univariate level, and four were unique multivariate predictors. Gay and heterosexual men differed in 11 facial features at the univariate level, and three were unique multivariate predictors. Some of the facial features related to sexual orientation implicated a sexual differentiation related mechanism (e.g., prenatal hormones), whereas others implicated a non-sexual differentiation mechanism (e.g., developmental instability) to explain the sexual orientation-facial structure association. In addition to extending the empirical literature on the physical correlates associated with sexual orientation, the studies included in this dissertation extend our understanding of the various mechanisms likely implicated in the development of sexual orientation.
    • Plant rhizosphere specificity and variability in the insect and plant adhesins, Madl and Mad2, within the genus Metarhizium suggest plant adaptation as an evolutionary force

      Wyrebek, Michael; Centre for Biotechnology (Brock University, 2013-04-19)
      Metarhizium is a soil-inhabiting fungus currently used as a biological control agent against various insect species, and research efforts are typically focused on its ability to kill insects. In section 1, we tested the hypothesis that species of Metarhizium are not randomly distributed in soils but show plant rhizosphere-specific associations. Results indicated an association of three Metarhizium species (Metarhizium robertsii, M. brunneum and M. guizhouense) with the rhizosphere of certain types of plant species. M. robertsii was the only species that was found associated with grass roots, suggesting a possible exclusion of M. brunneum and M. guizhouense, which was supported by in vitro experiments with grass root exudate. M. guizhouense and M. brunneum only associated with wildflower rhizosphere when co-occurring with M. robertsii. With the exception of these co-occurrences, M. guizhouense was found to associate exclusively with the rhizosphere of tree species, while M. brunneum was found to associate exclusively with the rhizosphere of shrubs and trees. These associations demonstrate that different species of Metarhizium associate with specific plant types. In section 2, we explored the variation in the insect adhesin, Madl, and the plant adhesin, Mad2, in fourteen isolates of Metarhizium representing seven different species. Analysis of the transcriptional elements within the Mad2 promoter region revealed variable STRE, PDS, degenerative TATA box, and TATA box-like regions. Phylogenetic analysis of 5' EF-Ia, which is used for species identification, as well as Madl and Mad2 sequences demonstrated that the Mad2 phylogeny is more congruent with 5' EF-1a than Madl. This suggests Mad2 has diverged among Metarhizium lineages, contributing to clade- and species-specific variation. While other abiotic and biotic factors cannot be excluded in contributing to divergence, it appears that plant associations have been the driving factor causing divergence among Metarhizium species.
    • Players and Avatars: The Connections between Player Personality, Avatar Personality, and Behavior in Video Games

      Worth, Narnia; Department of Psychology
      The increasing variety and complexity of video games allows players to choose how to behave and represent themselves within these virtual environments. The focus of this dissertation was to examine the connections between the personality traits (specifically, HEXACO traits and psychopathic traits) of video game players and player-created and controlled game-characters (i.e., avatars), and the link between traits and behavior in video games. In Study 1 (n = 198), the connections between player personality traits and behavior in a Massively Multiplayer Online Roleplaying Game (World of Warcraft) were examined. Six behavior components were found (i.e., Player-versus-Player, Social Player-versus-Environment, Working, Helping, Immersion, and Core Content), and each was related to relevant personality traits. For example, Player-versus-Player behaviors were negatively related to Honesty-Humility and positively related to psychopathic traits, and Immersion behaviors (i.e., exploring, role-playing) were positively related to Openness to Experience. In Study 2 (n = 219), the connections between player personality traits and in-game behavior in video games were examined in university students. Four behavior components were found (i.e., Aggressing, Winning, Creating, and Helping), and each was related to at least one personality trait. For example, Aggressing was negatively related to Honesty-Humility and positively related to psychopathic traits. In Study 3 (n = 90), the connections between player personality traits and avatar personality traits were examined in World of Warcraft. Positive player-avatar correlations were observed for all personality traits except Extraversion. Significant mean differences between players and avatars were observed for all traits except Conscientiousness; avatars had higher mean scores on Extraversion and psychopathic traits, but lower mean scores on the remaining traits. In Study 4, the connections between player personality traits, avatar traits, and observed behaviors in a life-simulation video game (The Sims 3) were examined in university students (n = 93). Participants created two avatars and used these avatars to play The Sims 3. Results showed that the selection of certain avatar traits was related to relevant player personality traits (e.g., participants who chose the Friendly avatar trait were higher in Honesty-Humility, Emotionality, and Agreeableness, and lower in psychopathic traits). Selection of certain character-interaction behaviors was related to relevant player personality traits (e.g., participants with higher levels of psychopathic traits used more Mean and fewer Friendly interactions). Together, the results of the four studies suggest that individuals generally behave and represent themselves in video games in ways that are consistent with their real-world tendencies.
    • Posttraumatic stress disorder symptoms might be destroying your intimacy : a test of mediational models in a community sample of couples

      Perrier, Colin; Department of Psychology (Brock University, 2011-03-08)
      The present research focused on the pathways through which the symptoms of posttraumatic stress disorder (PTSD) may negatively impact intimacy. Previous research has confirmed a link between self-reported PTSD symptoms and intimacy; however, a thorough examination of mediating paths, partner effects, and secondary traumatization has not yet been realized. With a sample of 297 heterosexual couples, intraindividual and dyadic models were developed to explain the relationships between PTSD symptoms and intimacy in the context of interdependence theory, attachment theory, and models of selfpreservation (e.g., fight-or-flight). The current study replicated the findings of others and has supported a process in which affective (alexithymia, negative affect, positive affect) and communication (demand-withdraw behaviour, self-concealment, and constructive communication) pathways mediate the intraindividual and dyadic relationships between PTSD symptoms and intimacy. Moreover, it also found that the PTSD symptoms of each partner were significantly related; however, this was only the case for those dyads in which the partners had disclosed most everything about their traumatic experiences. As such, secondary traumatization was supported. Finally, although the overall pattern of results suggest a total negative effect of PTSD symptoms on intimacy, a sex difference was evident such that the direct effect of the woman's PTSD symptoms were positively associated with both her and her partner's intimacy. I t is possible that the Tend-andBefriend model of threat response, wherein women are said to foster social bonds in the face of distress, may account for this sex difference. Overall, however, it is clear that PTSD symptoms were negatively associated with relationship quality and attention to this impact in the development of diagnostic criteria and treatment protocols is necessary.
    • Predicting performance on fluid intelligence from speed of processing, working memory, and controlled attention

      Anum, Adote.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2006-05-28)
      Fluid inteliigence has been defined as an innate ability to reason which is measured commonly by the Raven's Progressive Matrices (RPM). Individual differences in fluid intelligence are currently explained by the Cascade model (Fry & Hale, 1996) and the Controlled Attention hypothesis (Engle, Kane, & Tuholski, 1999; Kane & Engle, 2002). The first theory is based on a complex relation among age, speed, and working memory which is described as a Cascade. The alternative to this theory, the Controlled Attention hypothesis, is based on the proposition that it is the executive attention component of working memory that explains performance on fluid intelligence tests. The first goal of this study was to examine whether the Cascade model is consistent within the visuo-spatial and verbal-numerical modalities. The second goal was to examine whether the executive attention component ofworking memory accounts for the relation between working memory and fluid intelligence. Two hundred and six undergraduate students between the ages of 18 and 28 completed a battery of cognitive tests selected to measure processing speed, working memory, and controlled attention which were selected from two cognitive modalities, verbalnumerical and visuo-spatial. These were used to predict performance on two standard measures of fluid intelligence: the Raven's Progressive Matrices (RPM) and the Shipley Institute of Living Scales (SILS) subtests. Multiple regression and Structural Equation Modeling (SEM) were used to test the Cascade model and to determine the independent and joint effects of controlled attention and working memory on general fluid intelligence. Among the processing speed measures only spatial scan was related to the RPM. No other significant relations were observed between processing speed and fluid intelligence. As 1 a construct, working memory was related to the fluid intelligence tests. Consistent with the predictions for the RPM there was support for the Cascade model within the visuo-spatial modality but not within the verbal-numerical modality. There was no support for the Cascade model with respect to the SILS tests. SEM revealed that there was a direct path between controlled attention and RPM and between working memory and RPM. However, a significant path between set switching and RPM explained the relation between controlled attention and RPM. The prediction that controlled attention mediated the relation between working memory and RPM was therefore not supported. The findings support the view that the Cascade model may not adequately explain individual differences in fluid intelligence and this may be due to the differential relations observed between working memory and fluid intelligence across different modalities. The findings also show that working memory is not a domain-general construct and as a result its relation with fluid intelligence may be dependent on the nature of the working memory modality.
    • Probes of tocopherol biochemistry: fluorophores, imaging agents, and fake antioxidants

      Ghelfi, Mikel; Department of Chemistry
      The body has many defence systems against reactive radical species, but none are as crucial in the protection of lipid membranes as vitamin E. As a result of a selection process mediated by the α-tocopherol transfer protein (α-TTP), α-tocopherol is the only form of vitamin E retained in the body. This chaperon protein has been well studied because of its role in vitamin E transport. Furthermore, malfunctions of α-TTP cause vitamin E deficiency leading to ataxia and other neurodegenerative disease. Protection of neuronal tissue is critical and is reflected in the high retention of α-tocopherol in the central nervous system. Neuronal tissues receive α tocopherol from astrocytes, cells that are linked to hepatic tissue and able to express α-TTP, however the exact path of delivery between these cells is still unclear. A technique called fluorescent microscopy allows the tracking of fluorescent molecules in cells to find their location and interactions with other parts of the cell. The focus of this study is the synthesis of a fluorescent tocopherol analogue with a long absorption wavelength, high photostability, and that binds selectively to  α-TTP with high affinity. Most health benefits associated with vitamin E consumption are based on its capability to inhibit lipid peroxidation in cell membranes by scavenging reactive oxygen species (ROS). Oxidative damage in membranes puts cells in a “stressful” state, activating signalling events that trigger apoptosis. Vitamin E down-regulates apoptotic functions like inflammation, macrophage activation and cell arrest in a stressed state, returning the cell back to normal functioning. At the same time, vitamin E has a preventive effect for atherosclerosis, Alzheimer’s and cancer. With the deeper understanding of cell signalling processes associated with vitamin E the question arose whether protein interactions or the ROS scavenging is responsible for cell survival. To test this hypothesis, a non-antioxidant but α-TTP binding tocopherol analogue was synthesized and administered into oxidatively stressed, α-TTP deficient cells. If the cells were unable to restore homeostasis and stop apoptosis with the new molecule, this would suggest that the antioxidant function of α-tocopherol is the reason for survival. Cancer is regarded as one of the most detrimental diseases with a high mortality rate. One key aspect in medical research is the increased drug specificity towards targeting cancer. Chemotherapy applies cytotoxic compounds, which weaken the immune system because both malignant and healthy cells are destroyed. The specificity of the anti-cancer drugs are enhanced when encapsulated into liposomes that bear target-directing molecules such as antibodies which recognize cancer cell specific antigens on the cell membrane. The question remains if the encapsulated drug reaches the cancer or not. Magnetic resonance imaging (MRI) and computed tomography (CT) are used to find malignant tissue in the body. CT imaging uses highly charged X-ray particles to scan the patient, possibly having damaging cytotoxic effects. Obtaining MRI results require the use of contrast agents to enhance the quality of images. These agents are based on transition metals, which potentially have chronic toxicity when retained in the body. Alternatively short-lived radiotracers that emit a γ-photon upon positron decay are used through a process called positron emission tomography (PET). Rapid decay times make the use of PET a less toxic alternative, however the decay products might be toxic to the cell. For this reason a vitamin E based PET agent was created, which produces naturally safe decay products based on known metabolites of vitamin E, useful to track liposomal delivery of chemotherapeutic agents. This work describes the non-radioactive synthetic procedures towards a variety of vitamin E PET analogues. The cytotoxicity of the most promising vitamin E PET tracer was evaluated along with its synthetic byproducts.
    • The production and synthetic utility of the dioxygenase-derived metabolites of substituted aromatics

      Froese, Jordan; Centre for Biotechnology
      The substrate scope and selectivity of toluene dioxygenase overexpressed in E.coli JM109 (pDTG601A) was investigated with series of ortho-halobenzoates and para-substituted arenes. Palladium-catalyzed carbonylation methodology was developed to convert halogenated cis-dihydrodiol metabolites to the corresponding carboxylates and a comparison of the overall efficiency between the enzymatic and chemical methods of access was made. Some of the metabolites produced by toluene dioxygenase were employed in a synthetic approach toward tetrodotoxin. Enzymatic dihydroxylation of benzoic acid with R. eutropha B9 provided the corresponding ipso-diol that was used in the first total synthesis of pleiogenone A, a bioactive natural product. Experimental and spectral data are provided for all new compounds.