• Investigating the bone-muscle interaction during growth and development in children

      Ludwa, Izabella A.; Applied Health Sciences Program
      The purpose of this dissertation was to assess functional changes in the muscle-bone unit during normal growth and maturation in peri-pubertal children, and determine if changes in muscle strength are directly related to changes in bone properties. The first part of this work was a systematic review of literature on the effect of physical activity on bone development in children. It was found the best time to see large improvements in bone properties may be during the peri-pubertal years. It was not clear the best type of activity, nor which loading characteristic, should be utilized. This led to the second part of this work, where a non weight-bearing bone, the radius, was investigated in order to separate the influence of muscle properties on bone from ground reaction forces. Children and adolescents (n=172), between the ages of 8-16 years, were examined over a 2-year period. Measurements of somatic maturity, anthropometry, grip strength, bone properties (reflected by speed of sound (SOS)), physical activity (accelerometery), nutrition (24-hour recall), and bone resorption (NTX) were taken. Materials and procedures were identical between studies allowing for both a cross-sectional and longitudinal examination of the muscle-bone unit. Cross-sectionally, results demonstrated relative grip strength, maturity, dietary calcium and NTX explained 21% of the variance in radial SOS (p<0.05). Calcium intake was found to be a significant predictor only after NTX was accounted for, suggesting its effects on the muscle-bone unit may be modulated through bone resorption. In boys, the primary explanatory variables of radial SOS was NTX, followed by grip strength and maturity; where as in girls, it was maturity and dietary calcium. Longitudinally, maturity was found to have indirect effects on radial SOS mediated by grip strength. The influence of maturity on grip strength was similar between sexes, with the effect of grip strength on radial SOS being significantly greater in girls than boys (14.26 vs. 6.60; p<0.05); implying female bones maybe more responsive to muscle forces. Together, these studies provide an overview of muscle-bone unit development during peri-pubertal maturation, demonstrating radial bone properties to be appropriately adapted to muscle function and force independent of physical activity.
    • Investigating the Cluster Chemistry of α-Methyl-2-pyridine methanol (mpmH) with Select 3d Ions

      Abbasi, Parisa; Department of Chemistry
      This thesis describes an investigation of the coordination chemistry of the potentially chiral bridging, chelating ligand, α-methyl-2-pyridinemethanol (mpmH) with select 3d ions for the discovery of polynuclear clusters with single molecule magnet (SMM) properties. Chapter 1 introduces the theory of molecular magnetism, SMMs and the concepts of chiral SMMs, magnetochiral dichroism and multiferroics. In Chapter 2, two NiII clusters, {Ni8} and {Ni18} prepared from rac-mpmH are reported. The {Ni8} cluster crystallizes in a trapezoidal prismatic topology and contains tetrazolate ligands that are formed via a metal-assisted click reaction. The molecular structure of the second {Ni18} cluster is highly disordered comprising of eight edge-sharing cubane subunits. Dc magnetic susceptibility measurements reveal dominant ferromagnetic interactions down to ~18 K, stabilizing spin states with large values, whereas at T < 18 K the antiferromagnetic contribution results in the population of smaller, but appreciable non-zero spin states. Ac magnetic susceptibility measurements confirm the presence of two relaxation processes at two temperature regimes that is extremely rare for a 3d-metal based SMM. The first at low temperature (5 K) is attributed to conventional SMM behavior with τ0 = 3.26 × 10-10 s and Ueff = 11 K. The origin of high temperature (15 K) relaxation process with a large Ueff = 381 K and τ0 = 2.7 × 10-15 s is less clear, but tentatively assigned to spin-glass properties. In Chapter 3, the synthesis and structure of a large mixed-valence [MnII2MnIII28MnIV] polynuclear cluster with a closed cage-like conformation is presented. Ac magnetic susceptibility measurements show the compound is an SMM with Ueff of 58 K, that is large for a 3d cluster, and a τ0 = 3 × 10−8 s. Chapter 4 describes the coordination chemistry of racemic and chiral-mpmH with CuII and FeIII, where the synthesis and magnetostructural properties of a chiral {Cu4} tetramer, a non-chiral 1-D chain, as well as a chiral {Fe6} and a non-chiral{Fe8} cluster are reported. Dc magnetic susceptibility measurements on all four complexes reveal the presence of dominant antiferromagnetic exchange interactions affording S = 0 spin ground states at low temperature that precludes the observation of any SMM behavior.
    • Investigating the Conditional Adaptiveness of Adolescents’ Aggression from an Evolutionary Perspective

      Lapierre, Kiana; Department of Psychology
      Growing evidence supports the evolutionary perspective characterizing aggression as a strategy to achieve proximate adaptive benefits which can indirectly and probabilistically contribute to ultimate evolutionary goals (survival and reproduction). However, aggression may only be adaptive under certain conditions. Therefore, this dissertation investigated various conditions that may affect the adaptiveness of adolescent aggression, namely aggression characteristics (aggressive form, function, and anonymity), target characteristics (power of victim relative to the perpetrator), and perpetrator characteristics (experience of victimization and gender). Study 1 used a person-oriented approach to investigate how proactive and reactive cyber aggression and concurrent experiences of cyber victimization were associated with evolutionarily relevant social advantages and disadvantages in a community sample. Study 2 examined differential associations between aggression involvement and evolutionarily relevant aggressive functions, considering variations in aggressive form, the target’s power relative to perpetrator, and the perpetrator’s gender in a school-based sample. Finally, in a school-based sample, Study 3 investigated (1) how the associations between anonymous perpetration and evolutionary functions of aggression varied by aggressive form and the perpetrator’s gender, (2) how the target’s power and the perpetrator’s gender related to adolescents’ use of anonymous perpetration in each aggressive form, and (3) differential associations between anonymous victimization and victims’ perceptions of harm as a function of aggressive form and gender of the victim. Results suggest that adolescents’ aggression was linked to evolutionarily relevant aggressive functions motivated by competitive (e.g., aggression deterrence, intrasexual competition), impression management (seeking status and mates), sadistic (enjoyment), and reactive (impulsive response to real/perceived threats) functions, and to social advantages (social dominance, dating behaviour) for aggressors who used reactive aggression less frequently. However, aggression involvement was differentially associated with evolutionary motives based on the form, function, or anonymity of aggression, target characteristics, and perpetrator characteristics. Moreover, aggression was associated with costs, especially for cyber aggressor-victims who frequently aggressed reactively, and for victims of anonymous aggression. Thus, adolescents’ aggression may be conditionally adaptive for a narrow range of functions, depending on the characteristics of the aggression, target, and perpetrator. By highlighting the conditional adaptiveness of adolescent aggression, this research may inform efforts to improve interventions addressing aggression.
    • Investigating the Effect of Cell Culture Compositions on Mitochondrial Metabolism, Dynamics, and Transcriptome and Proteome of cells

      Moradi, Fereshteh; Department of Biological Sciences
      The phytoestrogen Resveratrol (RES) is a natural polyphenol that has been detected in more than 70 plant species. RES has structural similarity to mammalian estrogens and can bind to estrogen receptors, eliciting genomic and non-genomic effects. Both RES and physiological estrogens like 17-β-estradiol (E2) have wide-ranging effects on mitochondria. In this thesis, I began by investigating RES’s effects on mitochondrial network dynamics (Chapter 2) and discovered a pro-fusion activity apparently mediated by the mitofusin enzyme Mfn2. RES stimulated mitochondrial network hyper-fusion morphology in all three cell lines investigated (C2C12 (mouse myoblast), PC3 (prostate cancer), and MEFs (mouse embryonic fibroblast)), but the effect was absent in Mfn2-null MEFs. As this work was being completed; several research groups introduced ‘physiologic cell culture media’ that are modeled on the human plasma metabolome. I co-authored a study (not in this thesis) demonstrating that RES’s effects on mitochondrial dynamics are dependent on cell culture conditions. To follow up on this, I investigated whether E2’s mitochondrial effects might also be dependent on the cell culture environment, and showed conclusively that this is indeed the case, using C2C12 cells as a model system (Chapter 3). These results and those published by others in 2017-2019 suggested that medium composition can profoundly affect cellular functions. In Chapter 4, I followed this up by studying how culture conditions affect mitochondrial bioenergetics and network morphology using four cancer cell lines and showed that this is a significant issue. Finally, to gain a more complete understanding of this phenomenon, I completed a full transcriptomic and proteomic analysis of media effects using MCF7 breast cancer cells as a model (Chapter 5). I showed that hundreds of transcripts and proteins are affected according to culture conditions. Taken together, the results presented in this thesis emphasize the significant extent to which the cell culture environment affects experimental outcomes, particularly with respect to mitochondrial bioenergetics and dynamics. This information contributes to the development of cell culture experiments providing results that can be translated in vivo.
    • Investigating the Emotional Impact of Narrative Dialogue on Struggling Readers’ Discovery of Learning Potential

      Moukperian, Sharon; Department of Graduate and Undergraduate Studies in Education
      I investigated the cognitive, emotional and embodied responses to reading of four children/youth who experienced struggles with reading using phenomenology of embodiment (Husserl, 1913/2012; Taipale, 2014) as a theoretical framework and taking the role of an interpretive phenomenological approach (IPA) researcher (Smith & Osborne, 2007; Van Manen, 1997). Narrative theory (Bal, 2009; Chase, 2005; Clandinin & Connelly, 2000; Denison, 2016; White, 2007) supported the primary methodological and research approach complemented by the use of arts-based inquiry (Campbell, 1949/2008; Doherty, 1990; Gladwin, 2014; O’Donoghue, 2006) to probe stories about how participants thought and felt about their reading struggles and through dialogue individual learning strengths were discovered. The narrative approach provided an opportunity to ask how emotions and embodiment played a role in the reading process. I explored children and youths’ embodied experiences through narratives around reading and reading challenges, as they experienced reading difficulties and discovered learning strength during interview conversations about a reading challenge. Life narratives can change as emotions are evoked and described (Angus & Greenberg, 2011; White, 2007, 2011). As a listener, questioner, and recorder of these stories, I was not neutral and my own reflexivity played a role in the data collection [i.e., I was aware that I needed to evaluate my relationship with my participants because I had an influence on them by the observations and dialogues we had (Goldstein, 2017)]. This research focused on: (a) the emotional impact of reading deficits and children/youths’ discovery of cognitive learning strengths; (b) the influence of emotions on the children/youths’ and parents’ perceptions of the struggling reader lived experience; and (c) children/youths’ awareness of their own emotional experiences and cognitive processes when reading leading to connections between the embodied reaction and cognitive processes signaling that this phenomenon related to realizing a learning strength. Implications for future research involve exploring further the dialogic approach to discovering learning strengths and how to apply them to reading challenges that trigger a visceral emotional response. This research contributes to a theory that emotional meta-awareness maybe necessary to guide metacognitive reading strategies. There is a connection between embodied-emotional responses, reading challenges, and the discovery of learning strengths. Metacognitive awareness is heightened by being able to interpret the visceral emotional responses possibly leading children/youth to be aware when they have a learning strength that they can apply independently by listening to their body while completing a challenging reading task.
    • Investigating the Impact of Lessons Based on Marzanoʼs Theory of Learning on Student Attitude, Engagement, and Achievement in Grade 10 Academic Mathematics

      IRVINE, JEFF; Department of Graduate and Undergraduate Studies in Education
      Motivation is an important construct in education, both for its links to student learning and in its own right as a factor in student development. The relationship between motivation and student learning is particularly important in mathematics since numerous studies have demonstrated that motivation in mathematics is linked to student achievement, and that student achievement and student attitudes toward mathematics are reciprocally related. This study investigated the impact of an instructional intervention that specifically addressed two dimensions of motivation: engagement and student attitudes. Based on Marzano’s (1998, 2007) New Taxonomy of Educational Objectives©, a unit of study in Grade 10 Academic Mathematics was developed that utilized targeted activities and complete lessons to positively influence student engagement and attitudes. This mixed methods study used pre–post comparisons as well as treatment-control comparisons of 70 students in 3 classes of Grade 10 mathematics to investigate the impact of the instructional intervention on student engagement, attitude, and achievement in order to determine whether such an intervention could function as an exemplar for development of similar interventions that positively impacted student learning. The results of the study showed statistically significant changes in student engagement and student attitudes, but not for student achievement. Implications of these results pointed to directions for future research in this area.
    • Investigating the Relationships Between Teacher Identity Norms and Collaboration

      Weston, Deborah PA; Department of Graduate and Undergraduate Studies in Education
      The purpose of this study was to investigate how teacher identity norms relate to teacher collaboration among the practices of elementary teachers in Ontario. Using quantitative research methods, the data indicated two clusters of teacher identity norms. The norm cluster of innovation, interdependence, and cooperation showed positive correlations with collaboration and the norm cluster of conservatism, individualism, and competition showed negative correlations with collaboration. The two clusters of norms also correlated with each other. The data showed that teachers highly valued collaboration as part of their teaching practice but did not always experience it in their school setting. The analysis suggested that if schools reinforce norms of innovation, interdependence, and cooperation, collaboration will be nurtured. Further, the data showed that if norms of conservatism, individualism, and competition are continued in school cultures, then collaboration will not be sustained. As a broad educational reform agenda, teacher collaboration is used (a) to support school cultures, (b) to change teaching practices, and (c) to implement policy-based initiatives. This research is expected to benefit teachers in its capacity to inform policy makers concerning the highly complex nature of teacher collaboration and some of the factors that impact it. With an understanding of the relationships between teacher identity norms and collaboration, it may be possible for policy makers to provide appropriate support structures that reinforce collaboration in teachers' practices as well as predict potential levels of collaboration within school cultures.
    • Investigating the role of apoptosis regulator EndoG on exogenous DNA uptake, stability, replication and recombination

      Misic, Vanja; Department of Biological Sciences (Brock University, 2013-11-05)
      Endonuclease G (EndoG) is a well conserved mitochondrial nuclease with dual lethal and vital roles in the cell. It non-specifically cleaves endogenous DNA following apoptosis induction, but is also active in non-apoptotic cells for mitochondrial DNA (mtDNA) replication and may also be important for replication, repair and recombination of genomic DNA. The aim of our study was to examine whether EndoG exerts similar activities on exogenous DNA substrates such as plasmid DNA (pDNA) and viral DNA vectors, considering their importance in gene therapy applications. The effects of EndoG knockdown on pDNA stability and levels of encoded reporter gene expression were evaluated in the cervical carcinoma HeLa cells. Transfection of pDNA vectors encoding short-hairpin RNAs (shRNAs) reduced levels of EndoG mRNA and nuclease activity in HeLa cells. In physiological circumstances, EndoG knockdown did not have an effect on the stability of pDNA or the levels of encoded transgene expression as measured over a four day time-course. However, when endogenous expression of EndoG was induced by an extrinsic stimulus (a cationic liposome transfection reagent), targeting of EndoG by shRNA improved the perceived stability and transgene expression of pDNA vectors. Therefore, EndoG is not a mediator of exogenous DNA clearance, but in non-physiological circumstances it may non-specifically cleave intracellular DNA regardless of its origin. To investigate possible effects of EndoG on viral DNA vectors, we constructed and evaluated AdsiEndoG, a first generation adenovirus (Ad5 ΔE1) vector encoding a shRNA directed against EndoG mRNA, along with appropriate Ad5 ΔE1 controls. Infection of HeLa cells with AdsiEndoG at a multiplicity of infection (MOI) of 10 p.f.u./cell resulted in an early cell proliferation defect, absent from cells infected at equivalent MOI with control Ad5 ΔE1 vectors. Replication of Ad5 ΔE1 DNA was detected for all vectors, but AdsiEndoG DNA accumulated to levels that were 50 fold higher than initially, four days after infection, compared to 14 fold for the next highest control Ad5 ΔE1 vector. Deregulation of the cell cycle by EndoG depletion, which is characterized by an accumulation of cells in the G2/M transition, is the most likely reason for the observed cell proliferation defect. The enhanced replication of AdsiEndoG is consistent with this conclusion, as Ad5 ΔE1 DNA replication is intimately related to cell cycling and prolongation or delay in G2/M greatly enhances this process. Furthermore, infection of HeLa with AdsiEndoG at MOI of 50 p.f.u./cell resulted in an almost complete disappearance of viable, adherent tumour cells from culture, whereas almost a third of the cells were still adherent after infection with control Ad5 ΔE1 vectors, relative to the non-infected control. Therefore, targeting of EndoG by RNAi is a viable strategy for improving the oncolytic properties of first generation adenovirus vectors. In addition, AdsiEndoG-mediated knockdown of EndoG reduced homologous recombination between pDNA substrates in HeLa cells. The effect was modest but, nevertheless demonstrated that the proposed role of EndoG in homologous recombination of cellular DNA also extends to exogenous DNA substrates.
    • Investigating the Role of MicroRNAs in Regeneration and Axonal Pathfinding

      Walker, Sarah; Department of Biological Sciences
      During both development and regeneration, axons must navigate through a complex and changing environment to reach their proper synaptic target. To do so, axons utilize a specialized structure, the growth cone, which senses and interprets guidance cues in its surrounding environment to change the direction of axonal outgrowth. MicroRNAs, which regulate mRNA translation, have recently been shown to regulate both neurite outgrowth and growth cone guidance in response to classical guidance cues during vertebrate development. However, little is known of their regulation of neuronal regeneration in an invertebrate. Thus, the main aim of this thesis was to study the role of microRNAs during CNS regeneration of the pond snail, Lymnaea stagnalis. Specifically, I determined the expression patterns and relative abundance of microRNAs in the regenerating CNS in response to retinoic acid (RA). Using miRNA-Sequencing, I identified one neuronally enriched microRNA, miR-124, that was up-regulated in RA-induced regenerating CNS. Using PCR and in situ hybridization, I characterized its distribution in the snail CNS, and discovered it shared similar expression patterns to that of vertebrates. In cell culture, I found miR-124 was abundant within regenerating motorneurons and was localized to their growth cones. I next determined that miR-124 contributed to RA-induced growth cone turning behaviour. During attractive growth cone turning to RA, the abundance and distribution of miR-124 was altered, in both a cue and context-dependent manner. Finally, I demonstrated that miR-124 targeted the Rho kinase, ROCK, during turning responses to RA, likely to promote the formation of a neurite shaft, or to maintain growth cone polarity. Together, these findings provide the first evidence for a role of microRNAs in mediating growth cone behaviours to RA in regenerating motorneurons.
    • Investigation of Frustrated Quasi-One-Dimensional Quantum Spin-Chain Materials

      Caslin, Kevin; Department of Physics
      Copper arsenite CuAs2O4 and Copper antimonite CuSb2O4 are S=1/2 (Cu2+ 3d9 electronic configuration) quasi-one-dimensional quantum spin-chain compounds. Both compounds crystallize with tetragonal structures containing edge sharing CuO6 octahedra chains which experience Jahn-Teller distortions. The basal planes of the octahedra link together to form CuO2 ribbon-chains which harbor Cu2+ spin-chains. These compounds are magnetically frustrated with competing nearest-neighbour and next-nearest-neighbour intrachain spin-exchange interactions. Despite the similarities between CuAs2O4 and CuSb2O4, they exhibit very different magnetic properties. In this thesis work, the physical properties of CuAs2O4 and CuSb2O4 are investigated using a variety of experimental techniques which include x-ray diffraction, magnetic susceptibility measurements, heat capacity measurements, Raman spectroscopy, electron paramagnetic resonance, neutron diffraction, and dielectric capacitance measurements. CuAs2O4 exhibits dominant ferromagnetic nearest-neighbour and weaker antiferromagnetic next-nearest-neighbour intrachain spin-exchange interactions. The ratio of the intrachain interactions amounts to Jnn/Jnnn = -4.1. CuAs2O4 was found to order with a ferromagnetic groundstate below TC = 7.4 K. An extensive physical characterization of the magnetic and structural properties of CuAs2O4 was carried out. Under the effect of hydrostatic pressure, CuAs2O4 was found to undergo a structural phase transition at 9 GPa to a new spin-chain structure. The structural phase transition is accompanied by a severe alteration of the magnetic properties. The high-pressure phase exhibits dominant ferromagnetic next-nearest-neighbour spin-exchange interactions and weaker ferromagnetic nearest-neighbour interactions. The ratio of the intrachain interactions in the high-pressure phase was found to be Jnn/Jnnn = 0.3. Structural and magnetic characterizations under hydrostatic pressure are reported and a relationship between the structural and magnetic properties was established. CuSb2O4 orders antiferromagnetically below TN = 1.8 K with an incommensurate helicoidal magnetic structure. CuSb2O4 is characterized by ferromagnetic nearest-neighbour and antiferromagnetic next-nearest-neighbour spin-exchange interactions with Jnn/Jnnn = -1.8. A (H, T) magnetic phase diagram was constructed using low-temperature magnetization and heat capacity measurements. The resulting phase diagram contains multiple phases as a consequence of the strong intrachain magnetic frustration. Indications of ferroelectricity were observed in the incommensurate antiferromagnetic phase.
    • Investigation of the effect of microwave irradiation (2.45 GHz) on biological systems at constant bulk temperature

      MAZINANI, SINA; Centre for Biotechnology
      In this thesis the effect of MW irradiation (2.45 GHz) at constant bulk temperature was investigated on several biological systems. Studies on enzymatic activity revealed that MW irradiation could enhance the activity of trypsin, however the enzymatic activity of α-amylase and alkaline phosphatase towards the hydrolysis of starch and 4-nitrophenyl phosphate was not affected. We found that the incorporation of a BODIPY fatty acid (4,4-difluoro-5-methyl-4-bora-3a,4a-diaza-s-indacene-3-dodecanoic acid) into the cell membrane of PC-3 (human prostate cancer) cells was facilitated by microwave treatment at constant temperature. Also, microwave treatment while non-apoptotic, significantly increased the rate of reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by PC-3 cells. Further studies revealed that MW irradiation (10 W, SAR: 700 mW/ml) could significantly increase the uptake of an anticancer drug (doxorubicin) by PC-3 and MCF-7 (human breast cancer) cells at constant bulk temperature. Studies on bacterial growth revealed that MW irradiation could significantly decrease the growth of Escherichia coli at constant bulk temperature and the impact appeared to be transient. A 2D-gel electrophoresis-based proteomic analysis revealed that the expression of a series of proteins likely involved in metabolism was affected by the exposure to the MW irradiation. Overall, the results demonstrated in this study provided additional evidence for the “microwave-specific effects” that are capable of altering the behaviour of biological systems in a way that is quite different from conventional heating (through conduction). Appropriate interpretations of these observations have to also consider the possibility of local heating and/or micro-hotspot formation during MW irradiation. In this respect, the “microwave-specific effects” may not be interpreted either entirely or partially as non-thermal in nature.
    • An investigation of the psychopathy construct and its (novel) correlates in non-clinical samples

      Visser, Beth; Department of Psychology (Brock University, 2011-05-17)
      A substantial research literature exists regarding the psychopathy construct in forensic populations, but more recently, the construct has been extended to non-clinical populations. The purpose of the present dissertation was to investigate the content and the correlates of the psychopathy construct, with a particular focus on addressing gaps and controversies in the literature. In Study 1, the role of low anxiety in psychopathy was investigated, as some authors have proposed that low anxiety is integral to the psychopathy construct. Participants (n = 346) responded to two self-report psychopathy scales, the SRP-III and the PPI-R, as well as measures of temperament, personality, and antisociality. Of particular interest was the PPI-R Stress Immunity sub scale, which represents low anxiety content. I t was found that Stress Immunity was not correlated with SRP-III psychopathy, nor did it share common personality or temperament correlates or contribute to the prediction of anti sociality. From Study 1, it was concluded that it was unlikely that low anxiety is a central feature of the psychopathy construct. In Study 2, the relationship between SRP-III psychopathy and Ability Emotional Intelligence (Le., Emotional Intelligence measured as an ability, rather than as a self-report personality trait-like characteristic) was investigated, to determine whether psychopathy is be s t seen as a syndrome characterized by emotional deficits or by the ability to skillfully manipulate and prey upon the others' emotions. A negative correlation between the two constructs was found, suggesting that psychopathy is best characterized by deficits in perceiving, facilitating, managing, and understanding emotions. In Study 3, sex differences in the sexual behavior (i.e., promiscuity, age of first sexual behaviors, extradyadic sexual relations) and appearance-related esteem (i.e., body shame,appearance anxiety, self-esteem) correlates of SRP-III psychopathy were investigated. The sexual behavior correlates of psychopathy were quite similar for men and women, but the esteem correlates were very different, such that high psychopathy in men was related to high esteem, whereas high psychopathy in women was generally related to low esteem. This sex difference was difficult to interpret in that it was not mediated by sexual behavior, suggesting that further exploration of this topic is warranted. Together, these three studies contribute to our understanding of non-clinical psychopathy, indicating that low anxiety is likely not part of the construct, that psychopathy is related to low levels of ability in Emotional Intelligence, and that psychopathy is an important predictor of behavior, ability, and beliefs and feelings about the self
    • Inviting Leadership From a Belfast Bedroom: Invitational Leadership in Contemporary Schools

      Browne, Brendan Byrne; Department of Graduate and Undergraduate Studies in Education (Brock University, 2013-05-06)
      Educational leadership is challenging, complex, and vitally important to student success. Despite the publication of theories, books, and research on school leadership, a perception of a chasm between theory and practice exists. However, the intentional consideration and implementation of theory can make an enormous impact on practice. This is revealed in this dissertation through the exploration of invitational leadership theory through an autoethnographic study of my leadership journey, as well as the intentionally inviting leadership of Billy Tate, a veteran school principal in Belfast, Northern Ireland. This dissertation uses an amalgamated methodology of interview and observational research embedded within an autoethnography to intimately explore invitational theory in practice through the lens of a new school principal in Southern Ontario and a veteran principal in Belfast. This study provides an intimate understanding of the impact and applicability of invitational educational leadership theory in two unique educational, political, and social contexts and draws conclusions from the consideration of and reflection upon my leadership and Billy Tate’s. This dissertation reveals invitational leadership as a theory of practice that has significantly influenced two very different school leaders and posits that invitational theory is a theory of practice worthy of consideration by educational leaders from around the world.
    • Journeying Toward a Praxis of Indigenous Maternal Pedagogy: Lessons From Our Sweetgrass Baskets

      Brant, Jennifer Rose; Department of Graduate and Undergraduate Studies in Education
      This qualitative inquiry explored the value of Indigenous Maternal Pedagogy, an Indigenous women-centred approach, to consider the effects this unique teaching and learning engagement had on the cultural identity development, holistic well-being, academic success, and community engagement of Indigenous women. Through Indigenous Maternal Methodology, I worked closely with an Elder to implement a series of sharing circles to gather the narratives of Indigenous women who had completed one or more of the classes where Indigenous Maternal Pedagogy was enacted. I connect Maternal Pedagogies with Indigenous epistemologies that embrace the “whole student” within educational contexts. Thus, Indigenous Maternal Pedagogy extends Maternal Pedagogies by drawing from an Indigenous women-centred worldview to establish a teaching and learning environment that can speak to the hearts and minds of students. In the spirit of reconciliation, I position this environment as a safe space where students can be their whole authentic selves and where their realities and lived experiences are positioned as strengths and key assets to establishing an ethical space for cross-cultural and anti-racist dialogue. My final chapter extends Indigenous Maternal Pedagogy to all students and includes a section that aligns this teaching praxis with the Truth and Reconciliation Commission of Canada’s (2016) Calls to Action in the spirit of advancing safe Homeplaces for all learners, educators, and scholars to become involved in reconciliation.
    • Large-scale studies and biophysical analysis of systems involved in plant immunity.

      Kuai, Xiahezi; Centre for Biotechnology
      The field of plant immunity has progressed significantly in the last decade, driven primarily by both forward and reverse genetics and to a lesser extent by molecular biology techniques. However, many unknowns still remain before a more complete picture of this system can be achieved, which hinders our capacity to develop biotechnological solutions to ensure food safety for our growing population. Some of the problems that still need to be tackled relate to the multi-system involvement of some proteins, the interrelation of the different hormones, such as in trade-off systems, and the challenges of translating existing molecular knowledge into crop protection strategies. The goal of this thesis was to develop new methods and to adapt existing ones to address the challenges and push the boundaries of our knowledge of plant immunity as a system. We have adapted ClueGO analyses to visualize functionally grouped Gene Ontology (GO) terms specific to Arabidopsis. We developed a transcription factor- coregulator identification strategy based on double-transcriptome analyses. Finally, we have adapted a biophysical method, differential scanning fluorimetry (DSF). We tested the usefulness of these methods by interrogating different immune proteins/genes of the model plant Arabidopsis thaliana. Here is a summary of the major results obtained. In the realm of basal immunity, we discovered that clade I TGA transcription factors positively regulate this system by repressing WRKY transcription factors, which are negative regulators of the process. Furthermore, we have demonstrated that clade I TGA integrates into the growth- immunity trade-off system regulated by brassinosteroids by antagonizing the brassinosteroids-dependent suppression of basal immunity. In the realm of systemic acquired resistance (SAR), we have demonstrated that clade I TGA recruits a specific novel glutaredoxin as a corepressor to dampen the expression of a set of SAR-regulated genes controlled by salicylic acid (SA) and the SAR-orchestrator, NPR1. Finally, we demonstrated that NPR1 binds SA and that this interaction leads to the destabilization of NPR1. More importantly, the method used to show the latter is scalable and can be used to develop novel chemistries capable of deploying plant immunity in the field.
    • The Larger Stages: The 'Becoming Minor' of South African Theatres.

      Planche, Jill; Interdisciplinary Humanities Program
      ABSTRACT The Larger Stages: The Becoming ‘Minor’ of South African Theatres. By Jill Planche South Africa is layered with entangled histories that have created a fragile landscape of ambiguities where fractured memories are revealed yet remain concealed. The social architecture of apartheid still persists in a legacy of hostile urban geographies and land inequity, while global capitalism and economic disparity are seen in the dramatic contrast between the developing middle class and the poverty of millions. This research project interrogates the way in which contemporary theatre in South Africa is implicated in the country's complex cultural, economic and social realities. Pursuing rigorous qualitative research in the history, practice and criticism of South African theatre; contemporary studies in theatre spatiality; and philosophy, cultural theory and human geography, I explore precisely whose voices are being heard and which audiences are being reached. What role does – and might – theatre play in addressing South Africa’s socio-economic and artistic challenges, both as a barrier and a bridge to audiences? Drawing on the work of such thinkers as Gilles Deleuze, Félix Guattari, Rosi Braidotti and Achille Mbembe, can we anticipate what we might describe as a ‘minor’ theatre that will tell the stories that resonate twenty years after the end of apartheid? The term ‘minor’ refers to the Deleuzian concept of affirmative and dynamic processes to create new political subjects; processes of “becoming” that break from the fixed, proscribed “being,” which in the South African context has been created by centuries of colonialism and decades of state-imposed racial construction. Given the insights afforded by such theorization, I argue that the spaces of performance are potentially dynamic spaces of intersection within this landscape of layered socio-economic and artistic challenges created by a milieu of rooted physical and mental boundaries that have informed the country’s inherited theatrical practices.
    • Leadership and its impact on the success of Social Sciences and Humanities Research Council funded collaborative research projects

      Chandler, Frances; Department of Graduate and Undergraduate Studies in Education (Brock University, 2011-10-18)
      This dissertation investigates the practice of leadership in collaboratively designed and funded research in a university setting. More specifically, this research explores the meaning of leadership as experienced by researchers who were, or still are, engaged on Social Sciences and Humanities Research Council (SSHRC) funded collaborative research projects in a university setting. This qualitative study (Gay & Airasian, 2003) is situated within a social constructivist paradigm (Kezar, Carducci, & Contreras-McGavin, 2006) and involves an analysis of the responses from 12 researchers who answered 11questions related to my overarching research question: What is the impact of leadership on university based collaborative research projects funded by the Social Sciences and Humanities Research Council based on the experiences of researchers involved? The data that emerged supported and enhanced the existing literature related to leadership and collaborative groups in academia. The type of preferred leadership that emerged as a result of this research seemed to indicate that the type of leader that appeared to be optimal in this context might be described as a functional collaborative expert.
    • Leading Restorative Change: A Case Study of Implementing and Sustaining Restorative Culture in an Ontario Middle School

      Webb, Owen D.; Department of Graduate and Undergraduate Studies in Education
      In February of 2008, the Government of Ontario released legislation for Progressive Discipline in Ontario schools. As a means of fulfilling this legislation, some school districts in Ontario implemented the use of restorative practices. Restorative practices are viewed as a positive means for transforming the culture of a school, yet literature suggests some concerns with restorative approaches. While the practice has been used intermittently across the province of Ontario, seen in some districts or in individual schools, there has not been widespread implementation. Literature suggests that the theoretical foundations of restorative practices are not strong. To enrich literature on restorative culture change, there needs to be ongoing assessment of restorative paradigm shifts in schools. The research addresses the need for studying the leading of restorative culture change from a relational perspective. This research undertook a qualitative case study methodology of a middle school in southern Ontario, examining the school’s journey to implement and sustain a restorative culture. The study looked at the role of leadership in pursuing a restorative vision, the response to the vision by the school community, and how restorative practices are employed by the school. The research revealed the value of restorative practices in establishing space, processes, attitudes, and key questions for initiating dialogue, each critical to establishing a strong relational culture. The need for leadership to continually model restorative practices in order that they are established throughout the organization is necessary for sustaining a restorative culture. Finally, the study showed that evaluating the effectiveness of restorative practices using a relational and dialogic paradigm is critical for founding and sustaining a restorative vision, thereby establishing a strong foundation for effective student learning.
    • Learning and recognizing faces across variability in appearance: An examination of children and older adults

      Matthews, Claire M.; Department of Psychology
      Recognizing facial identity requires two skills: telling a person apart from similar looking people and recognizing them across changes in their appearance. Until recently, the vast majority of studies relied on tightly controlled images to examine face learning and recognition. Research using ambient images (i.e., images that capture within-person variability in appearance) is necessary to assess the true challenge of face learning and recognition in daily life. Only a few studies have examined face learning and recognition using ambient images in children, and, to the best of my knowledge, no studies have examined them in older adults. My dissertation was designed to address these gaps in the literature. In Study 1, children aged 6 to 11 were tested to examine two mechanisms that underlie face learning in young adults: Ensemble coding and the ability to benefit from exposure to variability in appearance in a perceptual matching task. My results revealed that both mechanisms are adultlike by the age of 6. First, children extracted the average of a set of images of an identity, regardless of whether those images were presented simultaneously or sequentially. Second, although their overall accuracy was lower than that of young adults, children showed comparable benefit from viewing multiple images of a to-be-learned identity in a perceptual face learning task. In Study 2, I examined whether younger children (4- and 5-year-olds) benefit from exposure to multiple images when learning a new face in a perceptual task. Although viewing multiple images made young children more sensitive to identity, it also led them to adopt a less conservative response bias, driven both by an increase in hits and an increase in false alarms. This increase in false alarms was not found for older children and adults in Study 1, suggesting that the ability to benefit from exposure to variability in appearance during face learning is not fully refined before the age of 6. In Study 3, I provided the first examination of face learning and recognition in older adults using a battery of tasks. On three of the five tasks, older adults showed comparable learning and recognition to young adults: 1) Older adults recognized a familiar face without error; 2) they showed ensemble coding of facial identity, regardless of whether the images were presented simultaneously or sequentially and 3) despite making more errors than young adults overall, they showed comparable benefit from viewing multiple images of a newly encountered face in the perceptual learning task. In the remaining two tasks, older adults showed a different pattern than young adults: 1) Older adults made fewer hits and more false alarms than young adults when matching images of wholly unfamiliar faces; and 2) after being exposed to low variability in appearance in a face memory task, older adults became more conservative than did younger adults, despite showing comparable benefits in sensitivity. My results reveal that the same abilities that show prolonged development during childhood are those undergo changes in aging. Collectively, my dissertation provides novel insights about learning and recognizing facial identity during childhood and aging and has important implications for understanding models of face processing.
    • Lessons learned from a critical appraisal of a fall break policy in higher education: A case study

      Pilato, Kelly A.; Applied Health Sciences Program
      The incidence, severity and persistence of mental health issues is increasing across post- secondary campuses (Zivin et al., 2009; Canada Newswire, 2012) with these students now viewed as a high-risk population (Stallman, 2010). Many Canadian universities are implementing a policy for a fall break in hopes of alleviating students’ stress and anxiety in order to improve mental health, heighten retention, and increase academic productivity. To date, there is limited empirical evidence to guide the development of policy and the delivery of effective practices to alleviate school-related stress and anxiety. This thesis is presented as a three paper, manuscript approach. The focus of this project was to appraise the development and implementation of a fall break and then evaluate its effectiveness in an effort to address rising concerns related to mental health for post-secondary students. Three thousand and seventy-one students in years one to four completed a post-break survey during one week in January of 2013, 2014, 2015. Of those, 1019 were male and 2052 female. Thirty-three students varying in years from one to four participated in focus groups in February of 2013, 2014, 2015. Of those 4 were male and 19 were female. Ten faculty from varying faculties and one informant participated in interviews in spring, 2018. Analyses from the surveys revealed that overall, students are in favour of having a fall break. Even though a small percentage of participants perceived their workload to go up before and after the break, 90% of students agree that the fall break was useful in reducing school related stress levels. However, the focus group, faculty and informant interviews revealed that the timing of the fall break had an impact on how students and faculty experienced the break and thus influenced perceptions on the impact that the break had on student mental health. Comprehensive evidence about whether a fall break policy supports or undermines the mental health of students needs to be assessed using a range of indicators before its implementation. This will help post-secondary institutions determine whether a break in the fall semester can be an effective approach to addressing students’ stress and anxiety.