• Raising Creativity: Exploring How Creativity Can be Nurtured in Educational Contexts

      Zak, Rebecca; Department of Graduate and Undergraduate Studies in Education (Brock University, 2014-09-09)
      The question of how we can encourage creative capacities in young people has never been more relevant than it is today (Pink, 2006; Robinson as cited in TEDtalksDirector, 2007; Eisner as cited in VanderbiltUniversity, 2009). While the world is rapidly evolving, education has the great challenge of adapting to keep up. Scholars say that to meet the needs of 21st century learners, pedagogy must focus on fostering creative skills to enable students to manage in a future we cannot yet envision (Robinson as cited in TEDtalksDirector, 2007). Further, research demonstrates that creativity thrives with autonomy, support, and without judgment (Amabile, 1996; Codack [Zak], 2010; Harrington, Block, & Block, 1987; Holt, 1989; Kohn, 1993). So how well are schools doing in this regard? How do alternative models of education nurture or neglect creativity, and how can this inform teaching practice all around? In other words, ultimately, how can we nurture creativity in education? This documentary explores these questions from a scholarly art-based perspective. Artist/researcher/teacher Rebecca Zak builds on her experience in the art studio, academia, and the art classroom to investigate the various philosophies and strategies that diverse educational models implement to illuminate the possibilities for educational and paradigmatic transformation. The Raising Creativity documentary project consists of multiple parts across multiple platforms. There are five videos in the series that answer the why, who, how, what, and now what about creativity in education respectively (i.e., why is this topic important, who has spoken/written on this topic already, how will this issue be investigated this time, what was observed during the inquiry, and now what will this mean going forward?). There is also a self-reflexive blog that addresses certain aspects of the topic in greater depth (located here, on this website) and in the context of Rebecca's lived experience to complement the video format. Together, all video and blog artifacts housed on this website function as a polyptych, wherein the pieces can stand alone individually yet are intended to work together and fulfill the dissertation requirements for Rebecca's doctorate degree in education in reimagined ways.
    • Reactivity of a Low Valent Gallium Compound

      Kassymbek, Aishabibi; Department of Chemistry
      The work described in this thesis is conducted to expand the reactivity of the β-diketiminate gallium(I) compound, NacNacGa (NacNac=[ArNC(Me)HC(Me)NAr]−, Ar=2,6-iPr2C6H3). The reactivity of NacNacGa towards various unsaturated compounds is studied. In particular, reaction between NacNacGa and phenyl isothiocyanate resulted in the oxidative addition of the C=S bond under ambient conditions, leading to the isolation cyclization product NacNacGa(κ2-S2CNPh) and sulfide isocyanide-bridged dimer (NacNacGa)2(μ-S)(μ-CNPh). Additionally, a [1+4] cycloaddition with a conjugated aldehyde (methacrolein) and a [1+2+3] cycloaddition with isocyanate and carbodiimide are presented. The oxidative cleavage of P=S bond of triphenylphosphine sulfide at increased temperatures gave the previously reported sulfide bridged gallium dimer. In situ oxidation of NacNacGa in the presence of substrates featuring donor sites led to the C-H activation reactions. As such, C-activation of pyridine N-oxide, pyridine, cyclohexanone, DMSO, and Et3P=O by a transient NacNacGa=O resulting in the corresponding gallium hydroxides is demonstrated. DFT calculations suggested initial formation of adducts between substrates and NacNacGa=O followed by a C-H bond abstraction from the substrate. Similarly, a transient gallium imide NacNacGa=NSiMe3, generated from the reaction of NacNacGa with trimethylsilyl azide, is shown to cleave C-H bonds of pyridine, cyclohexanone, ethyl acetate, DMSO, and Et3P=O with the formation of gallium amides. In an attempt to isolate a gallium alkylidene, NacNacGa was treated with trimethylsilyl(diazomethane). Instead, a monomeric gallium nitrilimine and a metalated diazomethane were obtained. The gallium nitrilimine undergoes 1,3-addition reaction with phenylsilane and catecholborane forming gallium hydrazonides. Its reaction with diborane resulted in the formal nitrene insertion into the B-B bond to produce a gallium diborylamide. DFT calculations revealed intermediate gallium alkylidene formation from the reaction of NacNacGa with diazomethane that upon reaction with the second equivalent of diazomethane leads to a gallium nitrilimine.
    • Reactivity of Aluminum Carbenoid with Unsaturated Substrates

      Dmitrienko, Anton; Department of Chemistry
      Reactivity patterns of the β-diketiminate aluminum(I) complex NacNacAl towards a variety of unsaturated molecules were determined. Reaction of NacNacAl with one equivalent of benzophenone affords η2(C,O) adduct III-2 that undergoes cyclization reactions with benzophenone (III-3), aldimine (III-4), quinoline (III-5), pyridine (III-6), phenyl nitrile (III-7), trimethylsilyl azide (III-8), and a saturated cyclic thiourea (III-9). The latter reacted via unusual C−N cleavage. Analogous η2-coordination products were prepared with p-tolyl benzoate (IV-6), N,N-dimethylbenzamide (IV-9) and (1‐phenylethylidene)aniline (IV-13). Addition of pyridine to such species results in [2+2] cycloaddition products analogous to III-6, except for the case of p‐tolyl benzoate when a migration of the alkoxy group from the ester moiety accompanied by hydrogen transfer from pyridine preserves the aromaticity within the latter. Chemoselective couplings between aliphatic ketones and pyridine were exemplified by reactions with non-enolizable (1R)-(‒) fenchone and enolizable yet sterically encumbered isophorone. The reaction with the CH‐acidic ketone (1R) (+) camphor afforded a hydrido alkoxide (IV-11) as the result of enolization. Whereas the reaction of NacNacAl with (1R)‐(−)‐fenchone in the absence of pyridine led to CH activation in the isopropyl group of the NacNac ligand. NacNacAl demonstrated diverse reactivity in reactions with N‐heterocycles. 4 Dimethylaminopyridine induces rearrangement of NacNacAl by deprotonation of backbone methyl group of the ligand. C−H activation of the methyl group of 4‐picoline produced a species with a reactive terminal methylene. Reaction of NacNacAl with 3,5 lutidine led to the cleavage of the sp2 C−H bond (4‐position). Another reactivity mode was observed for quinoline, which undergoes 2,2′‐coupling. Finally, a reaction of NacNacAl with phthalazine produced a product of the N−N bond cleavage. NacNacAl reacted with a series of polycyclic aromatic hydrocarbons via [4+1] cycloaddition. While a reaction with anthracene was irreversible, with the formation of products of activation of the lateral and central rings, reactions with phenanthrene, triphenylene, and fluoranthene were reversible. Heating reaction mixtures at 90 °C yielded dialuminum hydride VI-6. Mechanistic studies showed that the reaction proceeds via dissociation of polycycles with the release of NacNacAl that undergoes further intermolecular transformations. All novel complexes were characterized by spectroscopic methods and X-ray diffraction analysis for most of them.
    • Recognizing Own- and Other-race Faces: Cognitive Mechanisms Underlying the Other-Race Effect

      Zhou, Xiaomei; Department of Psychology
      Other-race faces are discriminated and recognized less accurately than own-race faces. The other-race effect (ORE) emerges during infancy and is robust across different participant populations and a variety of methodologies (Meissner & Brigham, 2001). Decades of research has been successful in characterizing the roots of the ORE, however certain aspects regarding the nature of own- and other-race face representations remain unspecified. The present dissertation attempts to find the commonalities and differences in the processing of own- vs. other-race faces so as to develop an integrative understanding of the ORE in face recognition. In Study 1, I demonstrated that the ORE is attributable to an impaired ability to recognize other-race faces despite variability in appearance. In Study 2, I further examined whether this ability is influenced by familiarity. The ORE disappears for familiar faces, suggesting a fundamental difference in the familiar and unfamiliar other-race face recognition. Study 3 was designed to directly test whether the ORE is attributable to a less refined representation of other-race faces in face space. Adults are more sensitive to deviations from normality in own- than other-race faces, and between-rater variability in attractiveness rating of individual faces is higher for other- than own-race faces. In Study 4, I investigated whether the ORE is driven by the different use of shape and texture cues. Despite an overall ORE, the transition from idiosyncratic shape to texture cues was comparable for own- and other-race faces, suggesting that the different utilization of shape and texture cues does not contribute to the ORE. In Study 5, applying a novel continuous-response paradigm, I investigated how the representations of own- and other-race face are stored in visual working memory (VWM). Following ample encoding time, the ORE is attributable to differences in the probability of a face being maintained in VWM. Reducing encoding time caused a loss of precision of VWM for other- but not own-race faces. Collectively, the results of this dissertation help elucidate the nature of representations of own- and other-race faces and clarify the role of perceptual experience in shaping our ability to recognize own- and other-race faces.
    • Regulation of Systemic Acquired Resistance through the Interaction of Arabidopsis thaliana Transcription factors TGAI and TGA2 with NPRI

      Rochon, Amanda; Centre for Biotechnology (Brock University, 2012-07-31)
      Arabidopsis thaliana is an established model plant system for studying plantpathogen interactions. The knowledge garnered from examining the mechanism of induced disease resistance in this model system can be applied to eliminate the cost and danger associated with current means of crop protection. A specific defense pathway, known as systemic acquired resistance (SAR), involves whole plant protection from a wide variety of bacterial, viral and fungal pathogens and remains induced weeks to months after being triggered. The ability of Arabidopsis to mount SAR depends on the accumulation of salicylic acid (SA), the NPRI (non-expressor of pathogenesis related gene 1) protein and the expression of a subset of pathogenesis related (PR) genes. NPRI exerts its effect in this pathway through interaction with a closely related class of bZIP transcription factors known as TGA factors, which are named for their recognition of the cognate DNA motif TGACG. We have discovered that one of these transcription factors, TGA2, behaves as a repressor in unchallenged Arabidopsis and acts to repress NPRI-dependent activation of PRJ. TGA1, which bears moderate sequence similarity to TGA2, acts as a transcriptional activator in unchallenged Arabidopsis, however the significance of this activity is J unclear. Once SAR has been induced, TGAI and TGA2 interact with NPRI to form complexes that are capable of activating transcription. Curiously, although TGAI is capable of transactivating, the ability of the TGAI-NPRI complex to activate transcription results from a novel transactivation domain in NPRI. This transactivation domain, which depends on the oxidation of cysteines 521 and 529, is also responsible for the transactivation ability of the TGA2-NPRI complex. Although the exact mechanism preventing TGA2-NPRI interaction in unchallenged Arabidopsis is unclear, the regulation of TGAI-NPRI interaction is based on the redox status of cysteines 260 and 266 in TGAl. We determined that a glutaredoxin, which is an enzyme capable of regulating a protein's redox status, interacts with the reduced form of TGAI and this interaction results .in the glutathionylation of TGAI and a loss of interaction with NPRl. Taken together, these results expand our understanding of how TGA transcription factors and NPRI behave to regulate events and gene expression during SAR. Furthermore, the regulation of the behavior of both TGAI and NPRI by their redox status and the involvement of a glutaredoxin in modulating TGAI-NPRI interaction suggests the redox regulation of proteins is a general mechanism implemented in SAR.
    • Relation of temperament and authoritative parenting on subtypes of adolescent behaviour

      Reker, Dana L.; Department of Psychology (Brock University, 2011-03-08)
      Over the years, researchers have investigated direct, conditional, and meditational pathways of adolescent aggression in relation to both temperament and parenting behaviours. However, no study to date has considered these relations with respect to a measure of aggression differentiated by form (e.g., overt, relational) and function (e.g., proactive, reactive). The present study examined the differential association of adolescent temperament and authoritative parenting on four subtypes of aggression. Participants included mothers, fathers, and one adolescent (between the ages of 10-19) from 663 families, recruited through random digit dialing. Parents reported on their child's temperament and occurrence of aggressive behaviours in addition to the perception of their own authoritative parenting. Adolescents reported on their own temperament and aggressive behaviours as well as on both their mother and father's authoritative parenting. Multiple regression analyses confirmed predictions that some aspects of temperament and authoritative parenting provide motivation towards the engagement of different aggressive behaviours. For example, higher negative affect was related to reactive types of aggression, whereas a strong desire for novel or risky behaviours related to proactive aggression. However, differences in effortful control altered the trajectory for both relationships. Higher levels of self-regulation reduced the impact of negative affect on reactive-overt aggression. Greater self-regulation also reduced the impact of surgency on proactive-overt aggression when age was a factor. Structural equation modeling was then used to assess the process through which adolescents become more or less susceptible to impulsive behaviours. Although the issue ofbi-directionality cannot be ruled out, temperament characteristics were the proximal correlate for aggression subtypes as opposed to authoritative parenting dimensions. Effortful control was found to partially mediate the relation between parental acceptancelinvolvement and reactive-relational and reactive-overt aggression, suggesting that higher levels of warmth and support as perceived by the child related to increased levels of self-regulation and emotional control, which in tum lead to less reactive-relational and less reactive-overt types of aggression in adolescents. On the other hand, negative affect partially mediated the relation between parental psychological autonomy granting and these two subtypes of aggression, supporting predictions that higher levels of autonomy granting (perceived independence) related to lower levels of frustration, which in tum lead to less reactive-relational and reactive-overt aggression in adolescents. Both findings provide less evidence for the evocative person-environment correlation and more support for temperament being an open system shaped by experience and authoritative parenting dimensions. As one of the first known studies examining the differential association of authoritative parenting and temperament on aggression subtypes, this study demonstrates the role parents can play in shaping and altering their children's temperament and the effects it can have on aggressive behaviour.
    • Relationship Building with Aboriginal Elders in the Publicly Funded Secondary School Classroom: A Study of Ethical Space from an Aboriginal Persepective

      Longboat, Catherine; Department of Graduate and Undergraduate Studies in Education (Brock University, 2015-01-06)
      This is a current story of ethical space in education that is often neglected in the design of educational experiences for Aboriginal students. This story is told through an Aboriginal lens rooted in the structured Two Row Wampum Belt relational agreement between Aboriginal peoples and Settlers. Through ethnographic narrative based on an extensive literature review, individual in-depth interviews, and a personal journal, this study documents the processes of acceptance, silence, complications, and then rejection to position Aboriginal Elders as inclusive bodies of knowledge in publicly funded secondary school classrooms. Aboriginal Elders are valued as Knowledge Holders, as Aboriginal teachers, guides, and mentors. Yet, the complexities of colonial rights, politics, and policies continue to intrude deeply into the lives of Aboriginal peoples to cause silence, confusion, and struggle rather than an evolution of new knowledge amongst two co-existing solitudes under the original terms of the Two Row Wampum Belt. The study was delayed and then came to an end when the school boards and local schools scrutinized its operating policies and unresolved funding issues. This study demonstrated that despite the Two Row Wampum Belt agreement that promised a co- existent relationship between Aboriginal peoples and Settlers, the strategy of inviting Aboriginal Elders to work alongside teachers in the classroom was viewed as being in conflict with the Settler’s institutional/educational objectivities, and, as such, was denied to Aboriginal students.
    • Rematerializing the Immaterial: A Comparative Study of Vancouver's Conceptual Art and Writing

      Polyck-O'Neill, Julia; Interdisciplinary Humanities Program
      Rematerializing the Immaterial: A Comparative Study of Vancouver’s Conceptual Art and Writing examines the contemporary situation of the Vancouver art world and addresses the twin schools of conceptualism in the city, the Vancouver School of photoconceptualism and the Kootenay School of Writing (KSW). The dissertation, which explores conceptual art’s impact on Vancouver’s cultural reputation broadly, brings visual art into conversation with conceptual writing and examines how specific definitions and ideas of and relating to conceptual art have shaped the discourse of conceptualism in Vancouver. As the title suggests, many of the ideas central to conceptual art and conceptualism implicate questions of materiality – particularly as American curator and art critic Lucy Lippard’s notion of “dematerialization” is concerned – and whether conceptualism is a material or intellectual enterprise. Drawing on the research and theorization of scholars such as Lippard, Leah Modigliani, Peter Osborne, Jeff Derksen, Jason Wiens, Scott Watson, Alexander Alberro, Kenneth Goldsmith, Caroline Bergvall, and Adrian Piper, I argue that Vancouver conceptualism is both materially and critically, intellectually engaged with the social, cultural, political, and economic histories and realities of Vancouver. Examining the creative and critical work of such artists and writers as Derksen, Stan Douglas, Fred Wah, Jeff Wall, and Lisa Robertson, I observe how, as a kind of critical- and often para-linguistic assemblage, these forces form a discernable poetics of Vancouver, incorporating art histories, criticism, formal conventions, ideas of and engagement with the archive, and impactful events in the city’s historical unfolding to shape the way Vancouver conceptualism circulates locally and internationally. By means of a reconsideration of Vancouver’s art world, including key artworks, poems, archives, and events, I seek to demonstrate how conceptualist photography and writing are complex and varied practices that engage at once with theory, art history, and social and cultural histories in the city.
    • Responses to Reflection in Two Invertebrate Species

      May, Holly; Department of Biological Sciences
      The present thesis investigates the responses to reflection in both the crayfish Procambarus clarkii and the fruit fly Drosophila melanogaster. Responses to reflection in crayfish depend on social status and the current work suggests that learning and memory consolidation are required for these responses to be altered. Crayfish were treated to either massed or spaced training fights prior to reflection testing. The results show that subordinate crayfish treated to spaced training display a response typical of subordinate crayfish but subordinate crayfish treated to massed training exhibit a response typical of dominant crayfish. Fruit flies are shown to be attracted to reflection and responses to reflection are described here for the first time. Responses in fruit flies are shown to be dependent on social status. The frequency of behaviours were altered in isolated flies but not socialized flies. The addition of pheromones cVA and 7,11-HD were used to investigate how the addition of chemical cues altered responses to reflection in fruit flies. Socialized fruit flies treated with cVA exhibited an increase in the frequency of behaviours on both mirrored and clear glass walls, while isolated flies exhibited a decrease. Socialized flies treated with 7,11-HD spent more time on mirrored walls compared to glass walls, whereas the frequency of all behaviours were decreased in isolated flies treated with 7,11-HD.
    • Resveratrol slows cell growth by targeting the Warburg effect and stimulating mitochondria metabolism

      Fonseca, Joao; Centre for Biotechnology
      Resveratrol (RES) is a plant-derived polyphenol that has been widely studied due to its health promoting effects, which are associated with RES ability to positively impact mitochondria function. Here, I investigated the interaction between RES’s effects on growth and metabolism in PC3 prostate cancer cells and demonstrated that RES-mediated growth inhibition is coincidental with an increase in mitochondrial network fusion, biogenesis and cellular respiration. This indicates that a metabolic reprogramming towards oxidative phosphorylation might be essential for RES antiproliferative effects. Indeed, when RES-induced metabolic reprogramming was prevented either by growing cells in galactose or stabilizing hypoxia inducible factor-1α (HIF-1α) expression, RES effects on growth and metabolism were attenuated or even abolished. Furthermore, consistent with RES ability to reduce HIF-1α levels, I observed that RES’s cell growth inhibitory effects were enhanced under hypoxia. This denotes the importance of conducting in vitro studies under conditions that better represent the physiological environment. However, , most in vitro studies are performed at supraphysiological levels of oxygen (O2) (18% O2; compared to the usual 1-5% O2 range observed in vivo) and glucose (25mM, which is close to five-times higher than normal plasma (glucose) in a healthy human). This artificial environment can affect a wide variety of cellular activities that may compromise in vitro studies’ reliability. It is therefore important to determine how cell culture conditions might affect RES in vitro effects. This was achieved by growing PC3 human prostate cancer and C2C12 mouse myoblasts cells under different culture conditions: physiological O2 (here considered 5% O2) and glucose levels (5mM); physiological O2 and high glucose (25mM); supraphysiological O2 (18% O2) and high glucose (25mM). Overall, RES effects on cell proliferation and mitochondrial network were less effective when cells were grown at 5% O2 and 5mM glucose (media condition that best resembles the physiological environment). In conclusion, these findings demonstrate the importance of oxygen and glucose levels as key determinants of RES in vitro antiproliferative effects, which may contribute to the discrepancy observed for resveratrol’s effects both in vivo and in vitro.
    • A Rhetorical Model of Autism: a Pop Culture Personification of Masculinity in Crisis

      Matthews, Malcolm; Interdisciplinary Humanities Program
      ABSTRACT In my dissertation, I argue that significant rhetorical mechanisms are at work in the production and consumption of portrayals of autism in literature, TV, and film. My project is driven by a central question: In what ways do portrayals of autism function as a visual rhetorical reconfiguration of masculinity that reimagines and repurposes disability in the service of the promotion of Humanist notions of white male hegemony in a technocentric era? I begin with Hans Asperger’s 1944 claim that autism is “a variant of male intelligence.” I connect that originary declaration with contemporary observations by Stuart Murray that autism is a form of “metaphorized hypermasculinity” and with Simon Baron-Cohen’s controversial insistence that autism represents a version of “The Extreme Male Brain.” Such testimonials, coupled with results from my own analysis and taxonomy of autistic characters throughout emerging popular culture manifestations, has led me to hypothesize that autism in portrayal serves as a survival guide for the white Western male in an era that threatens to be post-racial, post-ableist, post-phallocentric, and even post-anthropocentric. Fictional adolescent autists (e.g.: Christopher Boone, Nathanial Clark, and Colin Fischer), living autists (e.g.: David Paravicini, Daniel Tammet, and Temple Grandin), autistic “techno-savants” (e.g.: Spock, Rain Man, Sheldon Cooper), and speculatively diagnosed historical figures (e.g.: Alan Turing, Andy Warhol, and Bobby Fischer), advance a distinct “autism aesthetic” and function as rhetorical texts whose readings expose an unexplored intersection of disability, masculinity, ethnicity, and digital technology. Such characters illustrate in visual rhetorical terms how certain traits of autism are being romanticized in a digital era to equate ethnic whiteness with intellect and with a re-branded form of techno-masculinity. By providing a Rhetorical Model of autism as a link between autism as a clinical condition and as a cultural construct, I aim to form a more complete picture of autism and of its role in popular consciousness. As an interdisciplinary project, my dissertation draws upon the vocabularies and methodologies of gender, disability, and media studies. Under the unifying umbrella of visual rhetoric, I explore ethnicity, sexuality, and symbol-manipulation on the autism spectrum as they relate to Western man’s hope for a unifying techno-human singularity and his anxiety over the possible obsolescence of conventional constructions of masculinity. At stake are notions of hegemonic masculinity and of autism as a rhetorical artifact with real world implications.
    • Riffing on a Theme: Faculty Experiences With Service-Learning in a Food Security Research Network in Ontario

      Harrison, Barbara; Department of Graduate and Undergraduate Studies in Education (Brock University, 2013-04-10)
      While service-learning is often said to be beneficial for all those involved—students, community members, higher education institutions, and faculty members—there are relatively few studies of the attraction to, and effect of, service-learning on faculty members. Existing studies have tended to use a survey design, and to be based in the United States. There is a lack of information on faculty experiences with service-learning in Ontario or Canada. This qualitative case study of faculty experiences with service-learning was framed through an Appreciative Inquiry social constructionist approach. The data were drawn from interviews with 18 faculty members who belong to a Food Security Research Network (FSRN) at a university in northern Ontario, reports submitted by the network, and personal observation of a selection of network-related events. This dissertation study revealed how involvement with service-learning created opportunities for faculty learning and growth. The focus on food security and a commitment to the sustainability of local food production was found to be an ongoing attraction to service-learning and a means to engage in and integrate research and teaching on matters of personal and professional importance to these faculty members. The dissertation concludes with a discussion of the FSRN’s model and the perceived value of a themed, transdisciplinary approach to service-learning. This study highlights promising practices for involving faculty in service-learning and, in keeping with an Appreciative Inquiry approach, depicts a view of faculty work at its best.
    • Role Differences in the Perception of Injustice

      Gosse, Leanne L.; Department of Graduate and Undergraduate Studies in Education (Brock University, 2012-07-30)
      The current dissertation examined role differences in the perception of injustice; specifically, differences in how victims and offenders respond to a situation that they both agree is unfair. Past research has demonstrated that role affects reactions to transgressions and injustice, including recall of transgressions, and attributions of blame and responsibility (e.g., Baumeister, Stillwell, & Wotman, 1990; Mikula, Athenstaedt, Heschgl, & Heimgartner, 1998). However, to date, little work has examined role differences in perceptions of why an event is perceived as unfair (i.e., how an injustice is framed) or how justice should be restored. These were the perceptions I focused on in the present thesis. I also examined potential concerns that may motivate victims' and offenders' justice reactions, as well as the potential interaction between role and relationship quality in predicting justice reactions. In Studies 1 and 2, several of the predicted role differences in concerns were found; however, these did not lead to the expected differences in framing and restoration. In Study 1, using a vignette methodology, I found differences primarily in how victims and offenders believed justice should be restored. Overall, the significant role effects showed an accommodating response pattern (e.g., offenders proposed punishment more than did victims and neutral observers, whereas victims recommended minimal compensation more than did offenders and neutral observers), inconsistent with previous research and my hypotheses. Study 2, which employed a sample of romantic couples, substantiated the accommodating pattern found in Study 1. Study 3, which sampled a broader range of relationships, also showed i \ examples of accommodating reactions. In addition, Study 3 provided some support for the hypothesized interaction between role and relationship quality, such that responses were more accommodating as relationship quality increased. For example, offenders more strongly endorsed methods of restoration such as offender apology and recognition of the relationship with increasing relationship quality. Overall, the results from this dissertation support the general notion that victims and offenders respond to injustice differently, and, in-line with previous research on other justice-related responses (e.g., Mikula et at, 1998), suggest that victims and offenders show an other-serving, accommodating tendency in justice reactions when relationship quality is high.
    • The Role of Experience in the Organization and Refinement of Face Space

      Short, Lindsey; Department of Psychology (Brock University, 2014-09-12)
      Adults code faces in reference to category-specific norms that represent the different face categories encountered in the environment (e.g., race, age). Reliance on such norm-based coding appears to aid recognition, but few studies have examined the development of separable prototypes and the way in which experience influences the refinement of the coding dimensions associated with different face categories. The present dissertation was thus designed to investigate the organization and refinement of face space and the role of experience in shaping sensitivity to its underlying dimensions. In Study 1, I demonstrated that face space is organized with regard to norms that reflect face categories that are both visually and socially distinct. These results provide an indication of the types of category-specific prototypes that can conceivably exist in face space. Study 2 was designed to investigate whether children rely on category-specific prototypes and the extent to which experience facilitates the development of separable norms. I demonstrated that unlike adults and older children, 5-year-olds rely on a relatively undifferentiated face space, even for categories with which they receive ample experience. These results suggest that the dimensions of face space undergo significant refinement throughout childhood; 5 years of experience with a face category is not sufficient to facilitate the development of separable norms. In Studies 3 through 5, I examined how early and continuous exposure to young adult faces may optimize the face processing system for the dimensions of young relative to older adult faces. In Study 3, I found evidence for a young adult bias in attentional allocation among young and older adults. However, whereas young adults showed an own-age recognition advantage, older adults exhibited comparable recognition for young and older faces. These results suggest that despite the significant experience that older adults have with older faces, the early and continuous exposure they received with young faces continues to influence their recognition, perhaps because face space is optimized for young faces. In Studies 4 and 5, I examined whether sensitivity to deviations from the norm is superior for young relative to older adult faces. I used normality/attractiveness judgments as a measure of this sensitivity; to examine whether biases were specific to norm-based coding, I asked participants to discriminate between the same faces. Both young and older adults were more accurate when tested with young relative to older faces—but only when judging normality. Like adults, 3- and 7-year-olds were more accurate in judging the attractiveness of young faces; however, unlike adults, this bias extended to the discrimination task. Thus by 3 years of age children are more sensitive to differences among young relative to older faces, suggesting that young children's perceptual system is more finely tuned for young than older adult faces. Collectively, the results of this dissertation help elucidate the development of category-specific norms and clarify the role of experience in shaping sensitivity to the dimensions of face space.
    • The role of microRNAs and retinoid signaling during spinal cord regeneration in the adult newt.

      Lepp, Amanda; Department of Biological Sciences
      The molecular events after spinal cord injury that lead to the establishment of a permissive environment and epimorphic regeneration remain unclear. Two molecular pathway regulators that may converge to create a spinal cord regeneration-permissive environment in the urodele are retinoic acid (RA) and microRNAs (miRNAs). Recent evidence suggests that RARβ-mediated signaling is necessary for tail and caudal spinal cord regeneration in the adult newt. MicroRNAs are attractive candidates as mediators of retinoid signaling during regeneration, as their pleiotropic effects are vital in situations where global changes in gene expression are required. Thus, the overall aim of this thesis was to determine if miRNAs are involved in tail and caudal spinal cord regeneration in the adult newt, and if they act as regulators and/or effectors of retinoid signaling during this process. I have demonstrated here, for the first time, that multiple miRNAs are dysregulated in response to spinal cord injury in the adult newt, as well as in response to inhibition of retinoid signaling. Two of these miRNAs, miR-133a and miR-1, appear to target RARβ2 transcripts both in vivo and in vitro. Inhibition of RA signaling via RARβ with a selective antagonist, LE135, alters the pattern of expression of these miRNAs, which leads to an inhibition of tail regeneration. These data are indicative of a negative feed back loop, albeit potentially an indirect one. I also aimed to examine which miRNAs are affected by inhibiting RA synthesis during regeneration, and provided a long list of miRNAs that are dysregulated. These data provide the foundation for future studies on the putative roles of these miRNAs, as well as their function in retinoid signaling. Overall, these studies provide the first evidence for a role for miRNAs as mediators of retinoid signaling during caudal spinal cord regeneration in any system.
    • The role of mobile elements in recent primate genomes

      Tang, Wanxiangfu; Department of Biological Sciences
      Mobile elements (MEs), which constitute ~50% of the primate genomes, have contributed to both genome evolution and gene function as demonstrated by ample evidence discovered over the last few decades. The three studies in this thesis aims to provide a better understanding of the evolutionary profile and function of MEs in the primate genomes by taking a computational comparative genomics approach. The first study represents a comprehensive analysis of the differential ME transposition among primates via identification of species-specific MEs (SS-MEs) in eight primate genomes from the families of Hominidae and Cercopithecidae using a comparative genomics approach. In total, 230,855 SS-MEs are identified, which reveal striking differences in retrotransposition level in the eight primate genomes. The second study represents a more focused analysis for the identification of a new type of MEs, which we term “retro-DNA” for non-LTR retrotransposons derived from DNA transposons, in the recent primate genomes. By investigating biallelic DNA transposons that have both the insertion and pre-integration alleles in ten primate genomes, a total of 1,750 retro-DNA elements representing 750 unique insertion events are reported for the first time. The third study provides an analysis of the mechanism underlying the differential SINE transposition in the primate genomes. In this study, Alu profiles are compared and the Alu master copies are identified in six primate genomes in the Hominidae and Cercopithecidae groups. The results show that each lineage of the primates and each species owns a unique Alu profile exclusively defined by the AluY transposition activity, which is determined by the number of Alu master copies and their relative activity. Overall, work in this thesis provides new insights about MEs and their impact on the recent primate genomes by revealing differential ME transposition as an important mechanism in generating genome diversity among primate lineages and species through discovering a new type of MEs and preliminary analysis of the mechanism underlying the differential ME transposition among primates. Furthermore, taking advantage of the recently available primate genomes and transcriptomes data, the work in this thesis demonstrates the great potential of the comparative genomic approach in studying MEs in primate genomes.
    • The Role of Protein Following Intense Exercise in Competitive Youth Athletes

      McKinlay, Brandon; Applied Health Sciences Program
      The overall purpose of this thesis was to examine the role of post-exercise dairy protein consumption (isolated and whole-food) on recovery indices (performance and muscle damage) and inflammation following intense exercise within the context of different ecologically valid sporting environments, i.e., acute competition and a short-term period of intensified training, in competitive youth athletes. For this, two studies were conducted. Study 1 (Chapter 3) investigated the effect of whey protein consumption following a high-intensity interval swim session (HIIS) among adolescent swimmers on subsequent performance, muscle soreness, plasma creatine kinase and inflammatory cytokines, compared with isoenergetic carbohydrate and flavoured water in the acute (0–8 h) and short-term (8–24 h) recovery periods. Study 2 (Chapter 4) examined the effects of increased protein consumption, via plain Greek yogurt, compared with an isoenergetic carbohydrate control on performance recovery, inflammation, and muscle damage, during a 5-day simulated soccer training camp in competitive adolescent female soccer players. The collective findings indicate that during both acute and short-term periods of intensified exercise, the provision of dairy protein regardless of form (isolated or whole food), provided no added benefit at enhancing performance recovery or ameliorating muscle damage above that of energy matched carbohydrates. However, it does appear that the consumption of calories, regardless of type (e.g., carbohydrates or dairy protein), when rapid recovery is required, offers greater performance retainment than water. Therefore, during periods of intensified exercise that may be accompanied by inadequate recovery, the replenishment of energy should be the primary focus. Further, in both studies the consumption of dairy protein following exercise leads to an augmented anti-inflammatory response (i.e., increased IL10), not observed in the control conditions (i.e., water or energy-matched carbohydrates). Thus, it is possible that dairy protein consumption post-exercise may benefit the acute immune response. This possibility requires further study.
    • The role of retinoic acid in long-term memory formation and synaptic plasticity in the mollusc Lymnaea stagnalis

      Rothwell, Cailin; Department of Biological Sciences (Brock University, 2015-02-04)
      The active metabolite of vitamin A, retinoic acid (RA), is involved in memory formation and hippocampal plasticity in vertebrates. A similar role for retinoid signaling in learning and memory formation has not previously been examined in an invertebrate species. However, the conservation of retinoid signaling between vertebrates and invertebrates is supported by the presence of retinoid signaling machinery in invertebrates. For example, in the mollusc Lymnaea stagnalis the metabolic enzymes and retinoid receptors have been cloned from the CNS. In this study I demonstrated that impairing retinoid signaling in Lymnaea by either inhibiting RALDH activity or using retinoid receptor antagonists, prevented the formation of long-term memory (LTM). However, learning and intermediate-term memory were not affected. An additional finding was that exposure to constant darkness (due to the light-sensitive nature of RA) itself enhanced memory formation. This memory-promoting effect of darkness was sufficient to overcome the inhibitory effects of RALDH inhibition, but not that of a retinoid receptor antagonist, suggesting that environmental light conditions may influence retinoid signaling. Since RA also influences synaptic plasticity underlying hippocampal-dependent memory formation, I also examined whether RA would act in a trophic manner to influence synapse formation and/or synaptic transmission between invertebrate neurons. However, I found no evidence to support an effect of RA on post-tetanic potentiation of a chemical synapse. Retinoic acid did, however, reduce transmission at electrical synapses in a cell-specific manner. Overall, these studies provide the first evidence for a role of RA in the formation of implicit long-term memories in an invertebrate species and suggest that the role of retinoid signaling in memory formation has an ancient origin.
    • The role of skeletal muscle PLIN proteins at rest and following lipolytic stimulation

      MacPherson, Rebecca EK; Applied Health Sciences Program (Brock University, 2013-12-16)
      This thesis investigated the subcellular location of skeletal muscle PLIN proteins (PLIN2, PLIN3, and PLIN5) as well as protein interactions with ATGL and HSL at rest and following lipolytic stimulation. In addition, the serine phosphorylation state of PLIN2, PLIN3, and PLIN5 was determined at rest and following lipolytic stimulation. An isolated whole muscle technique was used to study the effects of contraction and epinephrine-induced lipolysis. This method allowed for the examination of the effects of contraction and epinephrine alone and in combination. Further, the soleus was chosen for investigating the role of PLIN proteins in skeletal muscle lipolysis due to its suitability for isolated incubation, and the fact that it is primarily oxidative in nature (~80% type I fibres). It has also been previously shown to have the greatest reliance on lipid metabolism and for this reason is ideal for investigating the role of PLIN proteins in lipolysis. Immunofluorescence microscopy revealed that skeletal muscle lipid droplets are partially co-localized to both PLIN2 and PLIN5 and that contraction does not affect the amount of colocalization, indicating that PLIN5 is not recruited to lipid droplets with contraction (PLIN2 ~65%; PLIN5 ~56%). Results from the immunoprecipitation studies revealed that with lipolysis in skeletal muscle the interaction between ATGL and CGI-58 is increased (study 2: 128% with contraction, p<0.05; study 3: 50% with contraction, 25% epinephrine, 80% contraction + epinephrine, p>0.05). Further PLIN2, PLIN3, and PLIN5 all interact with ATGL and HSL, while only PLIN3 and PLIN5 interact with CGI-58. Among these interactions, the association between PLIN2 and ATGL decreases with lipolytic stimulation (study 2: 21% with contraction, p<0.05). Finally our results demonstrate that PLIN3 and PLIN5 are serine phosphorylated at rest and that the level of phosphorylation remains unchanged in the face of either contractile or adrenergic stimulation. In summary, the regulation of skeletal muscle lipolysis is a complex process involving multiple proteins and enzymes. The skeletal muscle PLIN proteins likely play a role in skeletal muscle lipid droplet dynamics, and the data from this thesis indicate that these proteins may work together in regulating lipolysis by interaction with both ATGL and HSL.
    • Sclerostin Response to Exercise: Association with Bone Turnover, Oxidative Stress and Inflammation

      Kouvelioti, Rozalia; Applied Health Sciences Program
      The purpose of this thesis was to compare the response of sclerostin, a bone-specific glycoprotein that downregulates bone formation, to two modes (high impact vs non-impact) of high intensity interval exercise and to examine its relationship to potential exercise-induced changes in bone turnover (Study 1), oxidative stress (Study 2) and inflammation (Study 3). For the three studies included in this thesis, 40 healthy, young (18-25 years old) female and male adults performed two high intensity interval exercise trials in random order. Trials consisted of eight repetitions of 1 min high intensity running or cycling (mean heart rate 90% of maximum), separated by 1 min passive recovery intervals between repetitions. Blood samples were collected pre-exercise, and 5 min, 1h, 24h and 48h post-exercise. Sclerostin, bone turnover markers (cross linked telopeptide of type Ⅰ collagen [CTXI], procollagen type I amino-terminal propeptide [PINP]), oxidative stress markers (thiobarbituric acid reactive substances [TBARS], protein carbonyls [PC]) and inflammatory cytokines (interleukin-1β [IL-1β], -10 [IL-10], -6 [IL-6], and tumor necrosis factor-alpha [TNF-α]) were measured in serum. In the first two studies, sclerostin showed a significant time effect, but no significant exercise mode effect or interaction in both females (study 1) and males (study 2). In study 3, sclerostin showed a significant main effect for sex and a significant sex-by-time interaction. Specifically, sclerostin significantly increased from pre- to 5 min post-exercise and returned to baseline levels within 1h post-exercise with greater increase in males than females (47% vs. 34%, respectively). Furthermore, there were no correlations between sclerostin’s exercise-induced increase and the corresponding changes in bone turnover and oxidative stress markers. In contrast, sclerostin’s increase 5 min post-exercise was significantly correlated with the corresponding increase in the inflammatory cytokines, especially TNF-α, which along with sex, significantly explained 34% of the variance in its post-exercise elevation. In conclusion, in both young females and males, one session of high intensity interval exercise leads to an increase in sclerostin immediately post-exercise, and this increase is of similar magnitude following high impact and no impact exercise. Furthermore, the increase in sclerostin 5 min post-exercise seems to be associated with the exercise-induced inflammation.