• A comprehensive examination of adolescent gambling

      Chalmers, Heather.; Department of Psychology (Brock University, 2004-05-28)
      The purposes of this study were: a) to examine the prevalence and consequences associated with adolescent gambling, b) to examine the factors which influence adolescent gambling,. c) to detennine what factors discriminate among four groups of gamblers (no-risk/non-gamblers, low-risk gamblers, at-risk gamblers, and high-risk/problematic gamblers), and d) to examine the relation of gambling to nine other risk behaviours (i.e., alcohol use, smoking, marijuana use, hard drug use, sexual activity, minor delinquency, major delinquency, direct aggression, and indirect aggression). Adolescents (N = 3,767) from 25 secondary schools completed a twohour survey that assessed involvement in risk be~aviours as well as potential predictors from a wide range of contexts (school, neighbourhood, family, peer, and intrapersonal). The majority of adolescents reported gambling, although the frequency of gambling participation was low. The strongest predictors/discriminators of gambling involvement were gender, unstructured activities, structured activities, and risk attitudes/perceptions. In addition, the examination of the co-occurrence of gambling with other risk behaviours revealed that for high-risk/problem gamblers, the top three most frequent co-occurring high-risk behaviours were direct aggression, minor delinquency and alcohol. This study was the first to examine the continuum of gambling involvement (i.e., non-gambling to high risk/problematic gambling) using a comprehensive set ofpotential predictors with a large sample of secondary school students. The findings of this study support past research and theories (e.g., Theory of Triadic Influence) which suggest the importance ofproximal variables in predicting risk behaviors. The next step, however, will be to examine the direct and indirect 1 effects of the ultimate (e.g., temperament), distal (e.g., parental relationship), and proximal variables (e.g., risk attitudes/perceptions) on gambling involvement in a longitudinal study.
    • Conceptions of Quality and Approaches to Quality Assurance in Ontario’s Universities

      Goff, Lori-Ann; Department of Graduate and Undergraduate Studies in Education (Brock University, 2015-02-13)
      Many international, political, and economic influences led to increased demands for development of new quality assurance systems for universities. Like many policies and processes that aim to assure quality, Ontario’s Quality Assurance Framework (QAF) did not define quality. This study sought to explore conceptions of quality and approaches to quality assurance used within Ontario’s universities. A document analysis of the QAF’s rationale and structure suggested that quality was conceived primarily as fitness for purpose, while suggested indicators represented an exceptional conception of quality. Ontario universities perpetuated such confusion by adopting the framework without customizing it to their institutional conceptions of quality. Drawing upon phenomenographic traditions, a qualitative investigation was conducted to better understand various conceptions of quality held by university administrators and to appreciate ways in which they implemented the QAF. Three main approaches to quality assurance were identified: (a) Defending Quality, characterized by conceptions of quality as exceptional, which focuses on administrative accountability and uses a hands-off strategy to defend traditional notions of quality inputs and resources; (b) Demonstrating Quality, characterized by conceptions of quality as fitness for purpose and value for money, which focuses on accountability to students and uses centralized engaged strategies to demonstrate how programs meet current priorities and intended outcomes; and (c) Enhancing Quality, characterized by conceptions of quality as transformation, which focuses on reflection and learning experience and uses engaged strategies to find new ways of improving learning and teaching. The development of a campus culture that values the institution’s function in student learning and quality teaching would benefit from Enhancing Quality approaches to quality assurance. This would require holistic consideration of the beliefs held by members of the institution, a clear articulation of the institution’s conceptions of quality, and a critical analysis of how these conceptions align with institutional practices and policies.
    • The Conceptualization and Exploration of Place Allegiance: Towards a Unified Model of Person-Place Relationships within Outdoor Recreation

      Howard, Ryan; Applied Health Sciences Program
      The academic study of place has been generally defined by two distinct and highly refined discourses within outdoor recreation research: place attachment and sense of place. Place attachment generally describes the intensity of the place relationship, whereas sense of place approaches place from a more holistic and intimate orientation. This study bridges these two methodological and theoretical separate areas of place research together by re-conceptualizing the way in which place relationships are viewed within outdoor recreation research. The Psychological Continuum Model is used to extend the language of place attachment to incorporate more of the philosophy of sense of place while attending to the empirical strength and utility of place attachment. This extension results in the term place allegiance being coined to depict the strong and profound relationships outdoor recreationists build with their places of outdoor recreation. Using a concurrent mixed methods research design, this study explored place allegiance via an online survey (n = 437) and thirteen in-depth qualitative interviews with outdoor recreationists. Results indicate that place allegiance can be measured through a multi-dimensional model of place allegiance that incorporates behaviours, importance, resistance, knowledge and symbolic value. In addition, place allegiance was found to be related to an individual's influence on life course and his/her willingness to exhibit preservation and protection tendencies. Place allegiance plays an important role in acknowledging the importance of authentic place relationships in an effort to confront placelessness. Wilderness recreation is an important avenue for outdoor recreationists to build strong place relationships.
    • Conservation laws of magnetohydrodynamics and their symmetry transformation properties

      Pshenitsin, Dmitry; Department of Physics
      All kinematic conservation laws along with their symmetry transformation properties are derived for the system of magnetohydrodynamic equations governing incompressible viscous plasmas (or any other conducting fluid) in which the dynamic and magnetic viscosities are constant. Reductions of this system under translation symmetries, axial rotation symmetries, and helical symmetries are considered. For each reduced system, all kinematic conservation laws and point symmetries are obtained. The results yields several new conservation laws which are expected to be relevant for physical applications of magnetohydrodynamics.
    • Considerations for the Development and Optimization of Wine made from Partially Dehydrated Grapes in Ontario, Canada

      Kelly, Jennifer; Centre for Biotechnology
      The appassimento process for making wine can mitigate climatic challenges associated with cool climate winemaking, as fruit is dried post-harvest, reducing vintage-to-vintage variation due to varying fruit quality. Resultant wines fermented from dried grapes are high in ethanol and described as rich and intensely flavoured. One of the quality challenges facing wine made from partially dehydrated grapes is elevated levels of undesirable oxidation compounds, such as ethyl acetate, acetic acid and acetaldehyde. In this study we aim to characterize wines made from a local yeast isolate, Saccharomyces bayanus CN1, which demonstrates limited osmotolerance and may have application to this wine style, as it is a lower producer of such compounds. Wines made with the yeast of interest were compared to wines made with the accepted commercial yeast, Saccharomyces cerevisiae, EC1118. Fermentations were established over two vintages at one and three target starting sugar concentrations and a control, respectively. Wines were chemically (enzymatic) and sensorially analyzed. Wines (year two) were subject to volatile organic compound (VOC) and volatile fatty acid (VFA) measurements via Gas Chromatography-Mass Spectrometry. Another consideration for the development of this wine style is the inclusion of Botrytis cinerea, a pathogenic fungus that commonly develops during grape drying, and may impart favourable sensorial characteristics. Grapes were dried to 28.0°Brix and were fermented with EC1118 at 0 and 10% B. cinerea infection. A consumer preference test (n=153) that measured liking of wines (CN1 and 0% and10% B. cinerea infection) was conducted. Results indicate that CN1’s upper limit for fermentation to dryness is 27.5°Brix. All CN1 wines had significantly lower concentrations (p<0.05) of oxidation compounds than the commercial yeast, and oppositely, higher glycerol levels, along with comparable ethanol concentration to EC1118 wines. Significant differences in the concentrations of VOCs and VFAs, such as 2-phenylethanol and hexanoic acid were observed both within °Brix treatments and amongst yeast strains. Sensorially, the wines differed in intensity for a number of attributes. The consumer study revealed no preference between wines vinified with the different yeast strains. This work will contribute to the optimization of this wine style in cool climate winemaking regions and beyond.
    • Creating Space, or Just Juggling? Exploring the Adoption of Innovation in Community Sport

      Jurbala, Paul; Jurbala, Paul; Applied Health Sciences Program
      Previous research into community sport organization (CSO) has focused heavily on capacity and resource deficits and the ways in which CSOs manage under these constraints. This study explores mechanisms influencing CSOs as they adopt and implement an innovation: Long-Term Athlete Development (LTAD). A critical realist, extensive-intensive design spanning 36 months was used. The first, extensive phase of the study examines the contextual mechanisms influencing the approach of CSOs to adopting the LTAD innovation. Resource dependence and institutional perspectives are integrated to describe the forces acting on CSOs, how these manifest in structures, and how the structures channel the agency of CSO leaders as they work to balance resources and deliver programs. A contextual model of CSO operation under conflicting institutional logics is presented. The second, intensive phase examines the question of how CSOs plan, learn, and consolidate learning into structure as they integrate an innovation. Here, an engaged case study methodology was used to focus on the efforts of a single CSO over a one-year period as it worked to implement LTAD while managing multiple resource constraints. A learning cycle was used to explore processes of embedded agency resulting in structural change. CSOs are conceptualized as juggling resource constraints while balancing conflicting institutional logics: the communitarian logic promoted by resource controllers such as municipalities and Provincial Sport Organizations, and the individualist logic followed by CSO members. The results of the study demonstrate how CSOs compete for resources while balancing these institutional pressures and how when possible, CSOs manipulate institutional factors to gain legitimacy and contingent access to resources. In this competitive environment, LTAD represents a new institutional pressure. CSOs determine whether to adopt LTAD in part based on whether resource controllers signal that compliance will bring legitimacy and enhance resource access. When resource- controlling organizations introduce standards like LTAD intended to improve CSO program quality, the unintended result can be inter-CSO competition for legitimacy that can lead to the systematic privileging of large CSOs at the expense of smaller ones, driving professionalization and potentially increasing costs of sport participation.
    • Creativity and the schizophrenia spectrum unveiled : the similarities and the differences

      Michalica, Kerri; Department of Psychology (Brock University, 2010-10-27)
      This study examined the commonalities and the differences between creativity and the schizophrenia spectrum. The variables measured as potential commonalities and differences were creativity, schizotypy, cognitive inhibition, spatial ability, balancing skills, positive and negative presence, absorption, mystical experiences, childhood abuse, and neuroticism. Three community groups were recruited, consisting of 31 artists, 10 people with schizophrenia, and 31 comparisons matched for gender and age with the artists. A larger student group consisting of 102 students was also recruited in order to examine the correlations among the same variables within a larger, more normative, group. The largest commonality between the artist and the schizophrenic groups, who represented the extreme end of the schizophrenia spectrum, was the propensity to mystical experiences. The greatest differences between the artist and the schizophrenic groups were that the artists were higher in creativity, performed better on spatial abilities, had better balance, had more positive states of presence, and were lower in neuroticism than the schizophrenic group. In the student group, creativity was correlated with spatial ability, positive presence, absorption, and mystical experiences. In addition, creativity was significantly related to two facets of schizotypy, unusual experiences and impulsive nonconformity. In other words, students high in certain facets of schizotypy, who may share certain characteristics with those who have schizophrenia, are higher in creativity, but people who are on the extreme end of the schizophrenia spectrum, who have been diagnosed with schizophrenia, are not. The differences between the artist and schizophrenic groups on spatial ability, balance, sense of presence, and neuroticism may help to determine whether mystical experiences help to integrate creative work or destabilize and disorganize the sense of self. It may be that mystical experiences can be used more positively by the creative individuals than people with schizophrenia, in that artists and people high in creativity were higher in positive traits such as positive presence and lower on negative variables such as neuroticism, and introvertive anhedonia.
    • Critical Connections: Teachers Writing for Social Justice

      Smith, Sherry Ramrattan; Department of Graduate and Undergraduate Studies in Education (Brock University, 2012-07-31)
      This qualitative research study explores how teachers who write social justicefocused curriculum support resources conceptualize curriculum and social justice. Curriculum used in schools reflects underlying assumptions and choices about what knowledge is valuable. Class-based, cultural, racial, and religious stereotypes are reinforced in schooling contexts. Are the resources teachers create, select, and use to promote social justice reproducing and reinforcing forms of oppression? Why do teachers pursue social justice through curriculum writing? What are their hopes for this work? Exploring how Teachers' beliefs and values influence cy.rriculum writing engages the teachers writing and using curriculum support resources in critical reflective thought about their experiences and efforts to promote social justice. Individual and focus group interviews were conducted with four teacher-curriculum writers from Ontario schools. In theorizing my experiences as a teacher-curriculum writer, I reversed roles and participated in individual interviews. I employed a critical feminist lens to analyze the qualitati ve data. The participants' identities influenced how they understand social justice and write curriculum. Their understandings of injustices, either personal or gathered through students, family members, or oth.e. r teachers, influenced their curriculum writing . The teacher-curriculum writers in the study believed all teachers need critical understandings of curriculum and social justice. The participants made a case for representation from historically disadvantaged and underrepresented groups on curriculum writing teams. In an optimistic conclusion, the possibility of a considerate curriculum is proposed as a way to engage the public in working with teachers for social justice.
    • Cryptic species status of Anopheles (Diptera: Culicidae) mosquitoes in Canada using a multidisciplinary approach

      Thielman, Aynsley; Department of Biological Sciences (Brock University, 2012-04-04)
      Many species of Anopheles mosquitoes (Diptera: Culicidae) are now recognized as species complexes whose members are often indistinguishable morphologically but identifiable based on ecological, genetic, or behavioural data. Because the members of species complexes often differ in their vector potential, accurate identification of vector species is essential for successful mosquito control. To investigate the cryptic species status of Anopheles mosquitoes in Canada, specimens were collected from across the country and examined using morphological, molecular, and ecological data. Six of the seven traditionally recognised species from Canada were collected from locations in British Columbia, Quebec, Newfoundland and Labrador, and throughout Ontario, including Anopheles barberi, An. earlei, An. freeborni, An. punctipennis, An. quadrimaculatus s.l., and An. walkeri. Variation in polymorphic traits within An. earlei, An. punctipennis, and An. quadrimaculatus s.l. were quantified and egg morphology examined using scanning electron microscopy. Morphological identification of adult and larval specimens suggested that two described cryptic species, An. perplexens and An. smaragdinus, were present in Canada. DNA sequence data were analysed for evidence of cryptic species using three molecular markers: COl, ITS2, and ITS!. Intraspecific COl variation was very low in most species «1 %), except for An. punctipennis with 2% sequence divergence between those from British Columbia (BC) and Ontario (ON), and An. walkeri with 7% sequence divergence between populations from Manitoulin Island (NO) and Long Point Provincial Park (LP). Similar patterns were also seen using ITS2 and ITS 1. Therefore, molecular data revealed the presence of two putative cryptic species within two species examined (i.e., An. walkeri and An. punctipennis), corresponding to collection location (i.e., NO vs. LP and BC vs. ON, respectively). Surprisingly, there was no molecular support for the presence of either An. perplexens or An. smaragdinus in Canada despite the morphological assessments. Ecological data from all collection sites were recorded and are available in an online database designed to manage all collection and identification data. Current bionomic information, including regional abundance, larval habitat, and species associations, was determined for each species. This multidisciplinary study of Anopheles mosquitoes is the first detailed investigation of these potential disease vectors in Canada and demonstrates the importance of an integrated approach to anopheline systematics that includes molecular data.
    • Defence of Agaricus bisporus against toxic secondary metabolites from Trichoderma aggressivum.

      Sjaarda, Calvin; Department of Biological Sciences (Brock University, 2013-09-12)
      Trichoderma spp are effective competitors against other fungi because they are mycoparasitic and produce hydrolytic enzymes and secondary metabolites that inhibit the growth of their competitors. Inhibitory compounds produced by Trichoderma aggressivum, the causative agent of green mold disease, are more toxic to the hybrid off-white strains of Agaricus bisporus than the commercial brown strains, consistent with the commercial brown strain’s increased resistance to the disease. This project looked at the response of hybrid off-white and commercial brown strains of A. bisporus to the presence of T. aggressivum metabolites with regard to three A. bisporus genes: laccase 1, laccase 2, and manganese peroxidase. The addition of T. aggressivum toxic metabolites had no significant effect on MnP or lcc1 transcript abundance. Alternatively, laccase 2 appears to be involved in resistance to T. aggressivum because the presence of T. aggressivum metabolites results in higher lcc2 transcript abundance and laccase activity, especially in the commercial brown strain. The difference in laccase expression and activity between A. bisporus strains was not a result of regulatory or coding sequence differences. Alteration of laccase transcription by RNAi resulted in transformants with variable levels of laccase transcript abundance. Transformants with a low number of lcc transcripts were very sensitive to T. aggressivum toxins, while those with a high number of lcc transcripts had increased resistance. These results indicated that laccase activity, in particular that encoded by lcc2, serves as a defense response of A. bisporus to T. aggressivum toxins and contributes to green mold disease resistance in commercial brown strains.
    • Deindustrialization and Urban Regeneration: Nietzsche, Activism, and Organically Emergent Forms of Civic Engagement in Windsor/ Detroit

      Yocom, Grant Kenneth; Interdisciplinary Humanities Program
      The deindustrialization of cities represents a moment of cultural and political weakness and insecurity about what it means to be urban. Specifically, within Windsor and Detroit the traditionally rooted modes of production and habitation that have framed the cultural and political landscape as well as the identities of these urban centers are in a state of massive transition. Within these urban centers we find engaged residents mobilizing critical, self-critical and projective dispositions capable of meeting the challenges of their context, as well as issuing inquiries that put the inquirer on the spot, produce discomfort, and have potency: the capacity to change the way the inquirer thinks, acts and inhabits urban landscapes. These practices are vital responses to the questions that drive our lived-experience of city life and are in the end matters of survival. This work deploys an interpretation of the new category of philosopher forecasted by Nietzsche in Beyond Good and Evil in order to explore this moment when culture and politics meet at street level in the transitional deindustrializing cities of Windsor and Detroit. This is a difficult moment to make articulate. Many of the criticisms and prescriptions at work in the particular projects that we will examine are expressed as action: performed critique. These urban centers themselves have the capacity to become foxholes of sorts. Cities have a degree of receptivity to urban activism, and thus can become discrete political entities that mediate between culturally rooted criticisms and the larger political landscape. These cities in turn have the capacity to generate larger political effects. Urban activist initiatives, addressed in this project both theoretically and in their particularity, are rooted in the local and the biological in a manner that intimately ties experiences of suffering at the hands of economic and political systems responding to their acts of resistance. Activist collectives aim to inflict a wound to the overall culture, thus inoculating not only the immediate urban culture, but culture more generally with something new and empowering. This work explores the tension between embedded criticisms and proposals performed by urban activists and the trenchant forces that frustrate these actions.
    • Delineation of within-site terroir effects using soil and vine water measurement. Investigation of Cabernet Franc

      Hakimi-Rezaei, Javad; Department of Biological Sciences (Brock University, 2009-01-28)
      . The influence of vine water status was studied in commercial vineyard blocks of Vilis vinifera L. cv. Cabernet Franc in Niagara Peninsula, Ontario from 2005 to 2007. Vine performance, fruit composition and vine size of non-irrigated grapevines were compared within ten vineyard blocks containing different soil and vine water status. Results showed that within each vineyard block water status zones could be identified on GIS-generated maps using leaf water potential and soil moisture measurements. Some yield and fruit composition variables correlated with the intensity of vine water status. Chemical and descriptive sensory analysis was performed on nine (2005) and eight (2006) pairs of experimental wines to illustrate differences between wines made from high and low water status winegrapes at each vineyard block. Twelve trained judges evaluated six aroma and flavor (red fruit, black cherry, black current, black pepper, bell pepper, and green bean), thr~e mouthfeel (astringency, bitterness and acidity) sensory attributes as well as color intensity. Each pair of high and low water status wine was compared using t-test. In 2005, low water status (L WS) wines from Buis, Harbour Estate, Henry of Pelham (HOP), and Vieni had higher color intensity; those form Chateau des Charmes (CDC) had high black cherry flavor; those at RiefEstates were high in red fruit flavor and at those from George site was high in red fruit aroma. In 2006, low water status (L WS) wines from George, Cave Spring and Morrison sites were high in color intensity. L WS wines from CDC, George and Morrison were more intense in black cherry aroma; LWS wines from Hernder site were high in red fruit aroma and flavor. No significant differences were found from one year to the next between the wines produced from the same vineyard, indicating that the attributes of these wines were maintained almost constant despite markedly different conditions in 2005 and 2006 vintages. Partial ii Least Square (PLS) analysis showed that leaf \}' was associated with red fruit aroma and flavor, berry and wine color intensity, total phenols, Brix and anthocyanins while soil moisture was explained with acidity, green bean aroma and flavor as well as bell pepper aroma and flavor. In another study chemical and descriptive sensory analysis was conducted on nine (2005) and eight (2006) medium water status (MWS) experimental wines to illustrate differences that might support the sub-appellation system in Niagara. The judges evaluated the same aroma, flavor, and mouthfeel sensory attributes as well as color intensity. Data were analyzed using analysis of variance (ANOVA), principal component analysis (PCA) and discriminate analysis (DA). ANOV A of sensory data showed regional differences for all sensory attributes. In 2005, wines from CDC, HOP, and Hemder sites showed highest. r ed fruit aroma and flavor. Lakeshore and Niagara River sites (Harbour, Reif, George, and Buis) wines showed higher bell pepper and green bean aroma and flavor due to proximity to the large bodies of water and less heat unit accumulation. In 2006, all sensory attributes except black pepper aroma were different. PCA revealed that wines from HOP and CDC sites were higher in red fruit, black currant and black cherry aroma and flavor as well as black pepper flavor, while wines from Hemder, Morrison and George sites were high in green bean aroma and flavor. ANOV A of chemical data in 2005 indicated that hue, color intensity, and titratable acidity (TA) were different across the sites, while in 2006, hue, color intensity and ethanol were different across the sites. These data indicate that there is the likelihood of substantial chemical and sensory differences between clusters of sub-appellations within the Niagara Peninsula iii
    • Delineation of within-site terroir effects using soil and vine water measurements in Riesling vineyards within the Niagara Peninsula

      Willwerth, James Joseph; Department of Biological Sciences (Brock University, 2012-04-04)
      The major focus of this dissertation was to explain terroir effects that impact wine varietal character and to elucidate potential determinants of terroir by testing vine water status (VWS) as the major factor of the terroir effect. It was hypothesized that consistent water status zones could be identified within vineyard sites, and, that differences in vine performance, fruit composition and wine sensory attributes could be related to VWS. To test this hypothesis, ten commercial Riesling vineyards representative of each Vintners Quality Alliance sub-appellation were selected. Vineyards were delineated using global positioning systems and 75 to 80 sentinel vines per vineyard were geo-referenced for data collection. During the 2005 to 2007 growing seasons, VWS measurements [midday leaf water potential ('l')] were collected from a subset of these sentinel vines. Data were collected on soil texture and composition, soil moisture, vine performance (yield components, vine size) and fruit composition. These variables were mapped using global information system (GIS) software and relationships between them were elucidated. Vines were categorized into "low" and "high" water status regions within each vineyard block and replicate wines were made from each. Many geospatial patterns and relationships were spatially and temporally stable within vineyards. Leaf'l' was temporally stable within vineyards despite different weather conditions during each growing season. Generally, spatial relationships between 'l', soil moisture, vine size, berry weight and yield were stable from year to year. Leaf", impacted fruit composition in several vineyards. Through sorting tasks and multidimensional scaling, wines of similar VWS had similar sensory properties. Descriptive analysis further indicated that VWS impacted wine sensory profiles, with similar attributes being different for wines from different water status zones. Vineyard designation had an effect on wine profiles, with certain sensory and chemical attributes being associated from different subappellations. However, wines were generally grouped in terms of their regional designation ('Lakeshore', 'Bench', 'Plains') within the Niagara Peninsula. Through multivariate analyses, specific sensory attributes, viticulture and chemical variables were associated with wines of different VWS. Vine water status was a major contributor to the terroir effect, as it had a major impact on vine size, berry weight and wine sensory characteristics.
    • Demolishing the Competition: The Association between Competitive Video Game Play and Aggression among Adolescents and Young Adults

      Adachi, Paul; Department of Psychology
      The link between video game play and aggression is an important issue as video games The link between video game play and aggression is an important issue as video games are the fastest growing form of entertainment in the world. Past research on this association has been focused primarily on the link between video game violence and aggression; however, this research has confounded the effect of video game violence versus competition on aggression. The main goal of the current dissertation, therefore, was to examine the short- and long-term associations between competitive video game play and aggression. In addition, the longitudinal work on this association to date has been limited to adolescent samples, but not young adults. Thus, the second goal of the dissertation research was to investigate whether video game play predicts aggression in the long-term among young adults in addition to adolescents. To address these goals, three studies were conducted. Study 1 consisted of a series of experiments examining the short-term effect of video game violence versus competition on aggression. Study 2 examined the long-term association between competitive video game play and aggression among adolescents, and Study 3 examined this long-term link among young adults, in addition to adolescents. Taken together, the results of the three dissertation studies converged to suggest that video game competition, rather than violence, may be a stronger predictor of aggression in both the short- and long-term. Overall, the current research represents an important advance in our understanding of the association between video game play and aggression, and leads to a new direction in the video game and aggression literature. are the fastest growing form of entertainment in the world. Past research on this association has been focused primarily on the link between video game violence and aggression; however, this research has confounded the effect of video game violence versus competition on aggression. The main goal of the current dissertation, therefore, was to examine the short- and long-term associations between competitive video game play and aggression. In addition, the longitudinal work on this association to date has been limited to adolescent samples, but not young adults. Thus, the second goal of the dissertation research was to investigate whether video game play predicts aggression in the long-term among young adults in addition to adolescents. To address these goals, three studies were conducted. Study 1 consisted of a series of experiments examining the short-term effect of video game violence versus competition on aggression. Study 2 examined the long-term association between competitive video game play and aggression among adolescents, and Study 3 examined this long-term link among young adults, in addition to adolescents. Taken together, the results of the three dissertation studies converged to suggest that video game competition, rather than violence, may be a stronger predictor of aggression in both the short- and long-term. Overall, the current research represents an important advance in our understanding of the association between video game play and aggression, and leads to a new direction in the video game and aggression literature.
    • Design of Redox-active Ligands: In Pursuit of Stable Radicals, their Complexes, and Assembly of Paramagnetic Coordination Clusters.

      Bonanno, Nico Matteo; Department of Chemistry
      This thesis describes the design, synthesis, properties, and coordination chemistry of redoxactive ligands. This thesis also explores new ways of expanding our ligand systems, in order to improve their binding capacities. We accomplished this by utilizing familiar redox-active moieties and structures to those published previously in our group, but with enhanced topological capacities and predictable structural outcomes. Chapter 1 begins with a general outline of the fundamental principles that govern organic radicals including; their reactivity, their properties and applications, and how these can be applied to the design of ligands for polynuclear assembly. Chapter 2 starts with a brief overview of arylazo ligands and the synthesis of a new hydrazone substituted phenalenol ligand (2.1). In the following section (2.2) we use this ligand to produce homoleptic ligand mixed-valence complexes featuring trivalent cobalt and iron metals. The chapter is concluded (2.3) with the synthesis of a new ditopic aryl-azo ligand and its cobalt coordination chemistry involving a neutral tetra-radical/tetra-nuclear molecular grid featuring valence tautomerism. Chapter 3 begins with the design and synthesis of a new ditopic diamino phenol ligand, which was found to oxidize to a neutral stable phenoxyl radical (3.1-3.2). The solution properties, which include reversible pi-dimerization of this stable radical are also described (3.3), and later the substitution chemistry of this new ligand is explored (3.4). In chapter 4, we describe the coordination chemistry of this new ditopic aminophenol ligand, which includes assembly into several coordination clusters involving copper (4.2), iron (4.3), nickel (4.4), and zinc (4.5). These coordination clusters feature the ligand in a variety of oxidation states; including rare examples of dianion “aminyl” radical clusters. In chapter 5, we begin with a description of a new synthetic derivative which can be used for the construction of larger tetratopic or asymmetric diamino phenol ligands. In 5.2 we describe the synthesis of a tetratopic aminophenol ligand along with its reactivity and aerial oxidation to a tri-phenoxyl radical. In 5.3, we conclude the thesis with the use of an asymmetric diamino phenol ligand and it’s Cu(II/III) coordination chemistry, which displayed unique reactivity with molecular oxygen.
    • Design, development and assessment of the Java Intelligent Tutoring System

      Sykes, Edward R.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2006-05-28)
      The "Java Intelligent Tutoring System" (JITS) research project focused on designing, constructing, and determining the effectiveness of an Intelligent Tutoring System for beginner Java programming students at the postsecondary level. The participants in this research were students in the School of Applied Computing and Engineering Sciences at Sheridan College. This research involved consistently gathering input from students and instructors using JITS as it developed. The cyclic process involving designing, developing, testing, and refinement was used for the construction of JITS to ensure that it adequately meets the needs of students and instructors. The second objective in this dissertation determined the effectiveness of learning within this environment. The main findings indicate that JITS is a richly interactive ITS that engages students on Java programming problems. JITS is equipped with a sophisticated personalized feedback mechanism that models and supports each student in his/her learning style. The assessment component involved 2 main quantitative experiments to determine the effectiveness of JITS in terms of student performance. In both experiments it was determined that a statistically significant difference was achieved between the control group and the experimental group (i.e., JITS group). The main effect for Test (i.e., pre- and postiest), F( l , 35) == 119.43,p < .001, was qualified by a Test by Group interaction, F( l , 35) == 4.98,p < .05, and a Test by Time interaction, F( l , 35) == 43.82, p < .001. Similar findings were found for the second experiment; Test by Group interaction revealed F( 1 , 92) == 5.36, p < .025. In both experiments the JITS groups outperformed the corresponding control groups at posttest.
    • Designing, Testing, and Implementing BIAS (Body Image Awareness Seminars): A Positive Body Image Program

      Bailey, Kaytlin Alysse; Applied Health Sciences Program
      Dissatisfaction with the body is prevalent in North America and body image researchers have called this phenomenon a norm, suggesting it is abnormal for people to love their bodies. Positive body image programs are needed now more than ever but currently they are scarce, and this is especially true for individuals outside adolescent and university student populations. This dissertation describes the design, testing, and implementation of a new positive body image program called BIAS (Body Image Awareness Seminars). This program is unique in three ways: 1) it was created by working with participants using action research, 2) it is applicable to a diversity of people including older adults and people with physical disabilities, and 3) it was informed by positive body image research. In study 1, initial interviews and focus group meetings revealed a potential knowledge gap in understanding body image between body image researchers and the non-academic community. Participants described a need to understand body image better in order to improve their body image experiences. This study led to the conclusion that psychoeducation is an important component of a positive body image program which significantly informed the design of BIAS. Study 2 describes the creation of BIAS using action research. Very few body image programs have been designed using participatory methodologies. Instead, most body image researchers create and implement body image interventions without any participant feedback. Study 2 highlights both the advantages and disadvantages of using action research in the design, testing, and implementation of the BIAS program. Study 3 is an evaluation of the effectiveness of BIAS. Using mixed methods, qualitative and quantitative data were analyzed and both concordance and discordance of results were reported. Participants’ body image was found to significantly improve and this improvement was sustained 6-weeks later. Additional findings include participants experiencing self-compassion, greater knowledge about body image, and becoming positive body image advocates. Study contributions to both the body image and mixed methods literature are discussed.
    • Determinants and Consequences of Dehumanization: An Interspecies Model of Prejudice

      Costello, Kimberly; Department of Psychology (Brock University, 2013-01-14)
      Dehumanizing ideologies that explicitly liken other humans to “inferior” animals can have negative consequences for intergroup attitudes and relations. Surprisingly, very little is known about the causes of dehumanization, and essentially no research has examined strategies for reducing dehumanizing tendencies. The Interspecies Model of Prejudice specifies that animalistic dehumanization may be rooted in basic hierarchical beliefs regarding human superiority over animals. This theoretical reasoning suggests that narrowing the human-animal divide should also reduce dehumanization. The purpose of the present dissertation, therefore, was to gain a more complete understanding of the predictors of and solutions to dehumanization by examining the Interspecies Model of Prejudice, first from a layperson’s perspective and then among young children. In Study 1, laypeople strongly rejected the human-animal divide as a probable cause of, or solution to, dehumanization, despite evidence that their own personal beliefs in the human-animal divide positively predicted their dehumanization (and prejudice) scores. From Study 1, it was concluded that the human-animal divide, despite being a robust empirical predictor of dehumanization, is largely unrecognized as a probable cause of, or solution to, dehumanization by non-experts in the psychology of prejudice. Studies 2 and 3 explored the expression of dehumanization, as well as the Interspecies Model of Prejudice, among children ages six to ten years (Studies 2 and 3) and parents (Study 3). Across both studies, White children showed evidence of racial dehumanization by attributing a Black child target fewer “uniquely human” characteristics than the White child target, representing the first systematic evidence of racial dehumanization among children. In Study 3, path analyses supported the Interspecies Model of Prejudice among children. Specifically, children’s beliefs in the human-animal divide predicted greater racial prejudice, an effect explained by heightened racial dehumanization. Moreover, parents’ Social Dominance Orientation (preference for social hierarchy and inequality) positively predicted children’s human-animal divide beliefs. Critically, these effects remained significant even after controlling for established predictors of child-prejudice (i.e., parent prejudice, authoritarian parenting, and social-cognitive skills) and relevant child demographics (i.e., age and sex). Similar patterns emerged among parent participants, further supporting the Interspecies Model of Prejudice. Encouragingly, children reported narrower human-animal divide perceptions after being exposed to an experimental prime (versus control) that highlighted the similarities among humans and animals. Together the three studies reported in this dissertation offer important and novel contributions to the dehumanization and prejudice literature. Not only did we find the first systematic evidence of racial dehumanization among children, we established the human-animal divide as a meaningful dehumanization precursor. Moreover, empirical support was obtained for the Interspecies Model of Prejudice among diverse samples including university students (Study 1), children (Studies 2 and 3), and adult-aged samples (Study 3). Importantly, each study also highlights the promising social implication of targeting the human-animal divide in interventions to reduce dehumanization and other prejudicial processes.
    • Development of a bacteriophage-based biopesticide for fire blight

      Lehman, Susan M.; Department of Biological Studies (Brock University, 2007-05-28)
      Fire blight is an economically important disease of apples and pears that is caused by the bacterium Erwinia amylovora. Control of the disease depends on limiting primaly blosson1 infection in the spring, and rapidly removing infected tissue. The possibility of using phages to control E.amylovora populations has been suggested, but previous studies have. failed to show high treatment efficacies. This work describes the development of a phage-based biopesticide that controls E. amylovora populations under field conditions, and significantly reduces the incidence of fire blight. This work reports the first use ofPantoea agglomerans, a non-pathogenic relative ofE. amylovora, as a carrier for E. amylovora.phages. Its role is to support a replicating population of these phages on blossom surfaces during the period when the flowers are most susceptible to infection. Seven phages and one carrier isolate were selected for field trials from existing collections of 56 E. amylovora phages and 249 epiphytic orchard bacteria. Selection of the . /' phages and carrier was based on characteristics relevant to the production and field perfonnance of a biopesticide: host range, genetic diversity, growth under the conditions of large-scale production, and the ability to prevent E. amylovora from infecting pear blossoms. In planta assays showed that both the phages and the carrier make significant contributions to reducirig the development of fire blight symptoms in pear blossoms. Field-scale phage production and purification methods were developed based on the growth characteristics of the phages and bacteria in liquid culture, and on the survival of phages in various liquid media. Six of twelve phage-carrier biopesticide treatments caused statistically signiflcant reductions in disease incidence during orchard trials. Multiplex real-time PCR was used to simultaneously monitor the phage, carrier, and pathogen populations over the course of selected treatments. In all cases. the observed population dynamics of the biocontrol agents and the pathogen were consistent with the success or failure of each treatment to control disease incidence. In treatments exhibiting a significantly reduced incidel1ce of fire blight, the average blossom population ofE.amylovora had been reduced to pre-experiment epiphytic levels. In successful treatments the phages grew on the P. agglomerans carrier for 2 to 3 d after treatment application. The phages then grew preferentially on the pathogen, once it was introduced into this blossom ecosystem. The efficacy of the successful phage-based treatnlents was statistically similar to that of streptomycin, which is the most effective bactericide currently available for fire blight prevention. The in planta behaviour ofE. amylovora was compared to that ofErwinia pyrifoliae, a closely related species that causes fire blight-like synlptoms on pears in southeast Asia. Duplex real-time PCR was used to monitor the population dynamics of both species on single blossonls. E. amylovora exhibited a greater competitive fitness on Bartlett pear blossoms than E. pyrifoliae. The genome ofErwinia phage <l>Ea21-4 was sequenced and annotated. Most of the 8-4.7 kB genome is substantially different from previously described sequences, though some regions are notably similar to Salmonella phage Felix 01 . Putative functions were assigned to approximately 30% of the predicted open reading frames based on amino acid sequence comparisons and N-terminal sequencing of structural proteins.
    • Developmental and gonadal regulation of hypothalamic-pituitary-adrenal axis function in adolescent and adult rats

      Green, Matthew; Department of Psychology
      The hypothalamic-pituitary-adrenal (HPA) axis regulates the release of stress hormones and its function is dependent on various factors including prior exposure to stressors, circulating gonadal hormones, and developmental status. The overarching goal of this thesis was to uncover the potential mechanisms mediating developmental changes in HPA function and its regulation by gonadal hormones during adolescence and early adulthood. In Chapter 2, I found that pre-pubertal (postnatal day [P]35) and post-pubertal (P45) adolescents responded to an acute stressor with greater release of corticosterone (the main stress hormone in rodents) compared with adults (P75). To determine whether differences in corticosterone release were related to ongoing maturation of HPA feedback, I investigated glucocorticoid receptor (GR) activity and mRNA expression of receptors (Nr3c1, Nr3c2) and their co-chaperones (Fkbp5, Fkbp4, Bag1) in the hippocampus. I provide novel evidence that P35 males have more, not less, GR translocation from the cytosol to the nucleus in response to stress compared with P75 males. Gene expression remained relatively stable across development, except for Fkbp4, which codes for a pro-translocation protein and was up-regulated in P35 males relative to expression in P75 males. Thus, there are developmental shifts in the hormonal response to stress that are likely unrelated to GR activity in the hippocampus. In Chapter 3, I investigated whether differences in HPA function are explained by gonadal status; in adult males, testosterone reduces HPA function. Age-related differences in corticosterone release persisted when orchiectomized (OCX) males at each age were administered testosterone. Moreover, the effect of testosterone changed across the adolescent period; relative to those that got blank implants, testosterone had no effect on post-stress concentrations of corticosterone at P35, increased concentrations at P45, and tended to reduce concentrations at P75. Testosterone reduced expression of AVP in the PVN at all ages, but did not affect Fos (a marker of neuronal activation) expression. I hypothesized that the age-specific effects of testosterone on corticosterone were related to differential conversion to metabolites (e.g., estradiol), which I tested using androgen receptor (AR) and estrogen receptor (ER) antagonists (flutamide and tamoxifen, respectively) in the presence of testosterone or dihydrotestosterone (DHT). Testosterone produced a similar, albeit non-significant, age-specific pattern of effects on corticosterone as described above, and I found little evidence for effects of receptor antagonists. Androgens reduced post-stress concentrations of progesterone in all age groups, and flutamide prevented the effect. Together, this study provides evidence for developmental shifts in stress responses and their regulation by gonadal hormones. In Chapter 4, I examined the influence of estradiol on HPA function in adult female rats as a first step toward understanding developmental shifts. Ovariectomy (OVX) reduced post-stress concentrations of corticosterone compared with sham OVX and OVX females given estradiol alone or in combination with progesterone. I also found that OVX females had greater cytosolic expression of GR, possibly increasing sensitivity to corticosterone. In a second experiment, I found that progesterone partially mitigated the effect of estradiol on corticosterone release and that gene expression of stress hormone receptors (Nr3c1, Nr3c2), their co-chaperones (Fkbp5, Fkbp4, Bag1), and a co-activator (Src-1) did not change as a function of ovarian hormones. Together, these studies build on previous research investigating developmental and gonadal regulation of HPA activity and provide novel findings regarding potential mechanisms underlying their actions.