Recent Submissions

  • Using the HEXACO to Capture Psychopathy: Development and Initial Validation of the Power Proxies of Psychopathic Traits

    Power, Jordan P.; Department of Psychology
    Psychopathy, though often considered an abnormal personality construct, has been repeatedly found to be related to “normal” personality traits, and the HEXACO model of personality is particularly capable of capturing the “dark” personality variance integral to the construct. Additionally, while previous research indicates that psychopathy can be applied to both sexes, it has been suggested that psychopathic traits are expressed somewhat differently between men and women. In Study 1, we examined the relations between the Self-Report Psychopathy Scale (SRP) and the HEXACO-60 in a student sample (n = 1,346) in order to create proxy measures for Hare’s two-factor/four-facet model of psychopathy and to investigate sex differences in the associations between the SRP and the HEXACO. We created “general” proxies for use with samples of men and women in addition to male- and female-specific proxies for potential use with samples of exclusively men or women, respectively. The proxies had good psychometric properties and had stronger correlations with several psychopathy-relevant variables than did a previous attempt to measure the SRP facets using HEXACO items. In Study 2, we investigated how the proxies would function in a youth community sample (n = 396). The proxies related to many external variables in a similar manner as that of a previously validated measure of psychopathic traits in youth, suggesting that the proxy scales can be used with younger populations. In Study 3, we used a MTurk sample (n = 471) to update the proxy scales with HEXACO-100 items and to investigate sex differences in the relations between the SRP and the new HEXACO items. Several items were added to each version of the proxy scales and, compared to the original proxies, the updated proxies displayed better psychometric properties and stronger correlations with psychopathy-relevant variables. Overall, this program of research demonstrates considerable overlap between Hare’s model of psychopathy and the HEXACO model of personality. Honesty-Humility and altruism seem to underlie all of the psychopathy scales, whereas aspects of the other HEXACO domains tend to differentiate the psychopathy scales from one another. Further, several sex differences in how psychopathic traits relate to basic personality were identified.
  • 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.
  • Synthesis and Reactivity of Low Valent Silicon and Phosphorus Compounds

    Baradzenka, Aliona; Department of Chemistry
    The research described in this thesis is focused on studying the use of phosphinoamidinato ligand NP (NP = [ArNC(Ph)NPiPr2]– (Ar = 2,6-iPr2C6H3)) to stabilize low-valent main group element compounds. Reduction of silane (NP)SiCl3 by magnesium allows for the high-yield preparation of base-stabilized disilylene [(NP)Si-]2. Although it is stable at room temperature, upon heating it rearranges via intermolecular N-P activation into an N,Si-heterocyclic silylene supported by a phosphine donor. The reactivity of [(NP)Si-]2 in the single bond activation of pinacolborane, phenylsilane and diphenylphosphine was tested. Additionally, the phosphidosilylene (NP)SiPPh2 that is formed in the last reaction was found to perform P-P coupling when reacted with diphenylphosphine. Experimental pursuits were taken to elucidate the mechanism of formation of disilylene [(NP)Si-]2, and some insights into its fluxionality in solution were obtained. Disilylene [(NP)Si-]2 was reacted with Si(II) and Ge(II) chlorides to yield the products of tetrylene insertion into the Si-Si bond, the low-valent compounds [(NP)Si-Si(Cl)2-Si(NP)], [(NP)Si(Cl)2Si-Si(NP)] and [(NP)Si(Cl)2Ge-Si(NP)]. Compound [(NP)Si-Si(Cl)2-Si(NP)] is the kinetic product of the direct insertion of SiCl2 fragment into Si-Si bond of [(NP)Si-]2. The thermodynamic product of the insertion of silicon dichloride is disilylene [(NP)Si(Cl)2Si-Si(NP)] that is the consequence of migration of chlorides to terminal Si center. The reaction of [(NP)Si-]2 with GeCl2 produced only one compound [(NP)Si(Cl)2Ge-Si(NP)] that is a rear example of germylene-silylene. Interaction of [(NP)Si-]2 with SiCl4 and SiHCl3 produced a new example of acyclic disilyl silylene. Reduction of (NP)PCl2 with potassium graphite allowed isolation of the base-stabilized phosphinidene (NP)P. Its reactivity was studied. The use of substrates with E-H bonds like pinacolborane, phenylsilane and diphenylphosphine yielded compounds (NP)Bpin (pin = (OC(CH3)2)2) and NPH, (NP)SiH2Ph and NPH, NPH-P-PPh2, respectively, which are the result of N-P and E-H bond metathesis. Upon reaction with tetrachlorobenzoquinone both phosphorus atoms of phosphinidene (NP)P underwent oxidation. (NP)P reacted with benzaldehyde and phenylisocyanate as a phospha-Wittig reagent. Additionally, (NP)P was transformed into phosphinidene oxide (NP)P=O, iminophosphine (NP)P=Np-Tol and phosphinidene sulfide (NP)P=S. Transient (NP)P=O and (NP)P=Np-Tol were captured by para-tolyl isocyanate to form compound (NP)P(N,N-(Np-Tol)2CO). All the compounds were fully characterized by NMR and for most of them single crystal X-ray structure was obtained.
  • Children’s Developing Use and Understanding of Coercive Language: Applications in a Legal Setting

    Wylie, Breanne; Department of Psychology
    Within adult-child interactions, where children may be the target of coercion, it is important for children to understand and accurately describe their experiences. Coercive language is expressed using deontic modals, distinguishing between terms of obligation (i.e., implying compliance is required) and permission (i.e., implying compliance is optional). Children’s ability to understand and use coercive language is particularly relevant within applied legal settings where children may be required to testify about coercive tactics, and jurors may use this information to form perceptions about the case. Across three studies, my dissertation examined children’s understanding and use of coercive language, and the influence of using terms of obligation and permission on jurors’ perceptions of children’s reports. In Study 1, I examined 160 3- to 6-year-olds' understanding of the deontic modals tell and ask (referring to obligations and permissions) compared to their epistemic understanding of these terms (referring to knowledgeable and ignorant conversationalists), and the role of theory of mind in their understanding. In Study 2, I examined attorney and children’s use of coercive language within 64 transcripts of children’s testimony for cases involving alleged sexual abuse. In Study 3, I examined the influence of coercive language and maltreatment type on 160 adults’ perceptions of coercion and the child, as well as their judicial decision making. Overall, children’s understanding of the terms tell and ask emerged around 5 years of age, supported by their developing theory of mind. Additionally, children (as young as 6 years) and attorneys used terms of obligation and permission to describe coercion, and jurors were sensitive to these linguistic differences, perceiving children using terms of obligation as more coerced and the adult as more to blame. Of benefit, jurors’ decision making was not influenced by language, but rather focused on the nature of the abuse. Altogether these studies provide insight into children’s developing understanding of coercive language and suggest that even when used appropriately by 5 years of age, terms of permission minimize perceptions of coercion and adult blame. These findings demonstrate the need for educating adults about factors (e.g., coercive language) that may influence their perceptions of children’s disclosure.
  • Enzymatic Studies of Bromocyclohexadienediols & Semi-synthesis of Narciclasine Analogues

    Goulart Stollmaier, Juana; Department of Chemistry
    This thesis describes two projects: • cis-Diene bromo diol obtained from the microbial oxidation of bromobenzene was used as a substrate for lipase-catalyzed acylation and epoxidation reactions. The model studies showed that the regiochemistry of the acylation is solvent dependent. The chemoenzymatic epoxidation followed the expected regiochemistry when compared to the chemical epoxidation with m-CPBA, but with the unexpected formation of bromoconduritol-C, an important intermediate whose electrochemical reduction led to the short synthesis of (-)-conduritol-C. • A detailed description is given to the studies of conversion of natural narciclasine to its C-1 enol derivative, followed by the attempted conversion of this material to its triflate, in order to conduct cross-coupling at the C-1 position. However, it resulted in a triflate at C-6 that was successfully coupled with several functionalities. All compounds were fully deprotected and subjected to evaluation of biological activity. Only one derivative showed moderate activity as compared to those of narciclasine and pancratistatin. Spectral and physical data are provided for all new compounds.
  • Novel ways to measure future-oriented cognition: Using parent-report measures and open-ended responses to explore young children’s future thinking development

    Mazachowsky, Tessa; Department of Psychology
    Future-oriented cognition encompasses a set of key abilities that children must develop for successful functioning in daily life including, saving, prospective memory, episodic foresight, planning, and delay of gratification. These future thinking abilities are supported by memory systems (e.g., semantic, episodic), as well as constructive processes, self-projection, and executive functions. Research primarily measures young children’s future-oriented abilities through behavioural tasks, which have various limitations and may not engage future thinking. The current studies introduce new methods to overcome some of these limitations: developing a parent-report questionnaire and examining children’s open-ended responses. In Study 1 (N = 101; Mazachowsky & Mahy, 2020), 3-to 7-year-old’s future thinking was examined to establish the psychometric properties of a new parent-report measure, The Children’s Future Thinking Questionnaire (CFTQ). The CFTQ detected development of children’s future thinking and is a reliable and valid measure. Study 2 (N = 48; Mazachowsky et al., 2020) examined 3-to 5-year-old children’s episodic foresight using a novel, open-ended version of the Picture-book task. Results showed that children were able to generate items for future use and were more successful with age. Children’s explanations for their generated items were typically present-focused and included both episodic and semantic details. Expanding on Study 2, Study 3 (N = 158; Mazachowsky et al., revisions requested) explored 3-to 5-year-old’s explanations for their item choices on two episodic foresight tasks to determine the degree to which these tasks engaged children’s episodic and future-oriented processes. Children provided more future-oriented explanations on the Picture-book task compared to the Spoon task, but episodicity did not differ between tasks. Further, children’s Picture-book task explanations included more first-person personal pronouns compared to the Spoon task, but explanations did not differ in other pronoun use. Together, these studies show that use of a parent-report measure and examination of children’s open-ended responses offer unique insight into the development of young children’s future thinking and engagement in future-oriented processes.
  • Do we become more honest as we age? A multi-methodological approach to studying dishonesty across adulthood

    O'Connor, Alison; Department of Psychology
    Being dishonest with others is a common social behaviour, and it has been proposed that dishonesty increases throughout childhood, peaks in adolescence, and gradually declines across adulthood (i.e., an aging-honesty-effect among older adults). Yet, very little research has comprehensively explored how dishonesty is used and evaluated in later life. Using a multi-methodological approach, the primary goals of my dissertation were to examine if this aging-honesty-effect replicated across methodologies and social contexts and to provide a deeper understanding of the deceptive profiles of older adults to uncover what they lie about, who they lie to, and how they morally evaluate lies. In Study 1, I measured younger and older adults’ willingness to cheat in a spontaneous deceptive paradigm and personality traits of honesty-humility. In Study 2, younger and older adults completed an experience sampling study where they recorded their daily lies for a 7-day period. In Study 3, younger and older adults morally evaluated truths and lies, and participants were recruited in Canada, Singapore, and China to examine if age differences were culturally dependent. Results supported the proposed aging-honesty-effect where older adults were less likely to cheat in a task when given the opportunity (Study 1), they scored higher in the honesty-humility personality trait (Study 1), and they told fewer lies across a 7-day period (Study 2) compared to younger adults. Extending these results beyond lie frequency, Study 2 provided insight into the ways in which younger and older adults use lies in their natural social lives, uncovering that this aging-honesty-effect can vary depending on the type and topic of the lie and the relationship between the liar and the lie recipient. Finally, Study 3 found that not only are older adults more honest themselves, but they evaluate blunt or immodest honesty more favorably and good-intentioned lies less favorably than younger adults, and these effects persisted beyond a Western cultural context. These results provide the foundation for understanding older adults’ use and evaluation of dishonesty and can contribute to constructing a lifespan model of dishonesty from childhood through to old age.
  • The development of sensitivity to threat among children and adolescents

    Heffer, Taylor; Department of Psychology
    Several theories of adolescent brain development suggest that adolescence is a sensitive period of development characterized by the onset of internalizing problems, such as anxiety. Sensitivity to threat, a heightened responsiveness to aversive situations, has been suggested to be a precursor to anxiety, highlighting the importance of understanding sensitivity to threat among children and adolescents. Yet relatively little is known about the development of sensitivity to threat. Further, identifying the neural indicators that are associated with heightened sensitivity to threat would help classify which youth are most at risk for anxiety. The primary goals of my dissertation were: 1) to explore whether adolescents, compared to children, have heightened sensitive to threat, 2) assess which neural indicators are associated with heightened sensitivity to threat, and 3) assess whether individual differences (e.g., in consistency of sensitivity to threat across time and situation) help predict which youth are most at risk for anxiety-related problems. Study 1 of my dissertation examined, with concurrent data, whether adolescents have greater neural sensitivity to negative feedback compared to children. Study 2 examined whether children and adolescents differ in their longitudinal trajectories of sensitivity to threat (e.g., consistency across time). I also was interested in whether these trajectories were associated with frontal asymmetry, a neural indicator associated with avoidance motivations. Study 3 extended the findings from Study 2 to examine consistency across threatening situations. While Studies 1 through 3 investigated whether adolescence is a period of heightened sensitivity to threat, Study 4 of my dissertation used a latent class analysis to investigate whether individual differences in sensitivity to threat, impulsivity, and emotion dysregulation are associated with anxiety and/or risk taking. Results indicated that adolescence (especially when defined by pubertal status), may be a normative period for sensitivity to threat. At the same time, not all youth who are sensitive to threat go on to develop anxiety; thus, it may be that for many adolescents, sensitivity to threat is an adolescent-limited phenomenon, meaning that threat sensitivity may peak in adolescence, but then tapers off into adulthood. Importantly, neural indicators associated with threat sensitivity helped identify which youth may have the highest levels of threat sensitivity. Overall, my dissertation shows that while some level of sensitivity to threat is normative, it is less common for youth to be consistently sensitive to threats and importantly, these youth who are consistently sensitive appear to be most at risk. Taken together, the four studies of my dissertation incorporate EEG, longitudinal designs, multiple indicators of development (age and pubertal status), and self-report data to gain a holistic understanding of sensitivity to threat from childhood to adolescence.
  • Mad Futures Now: Avant-Garde Dishumanism in the Poetry of Claude Gauvreau, Hannah Weiner, and bill bissett

    McEwan, Andrew; Interdisciplinary Humanities Program
    This interdisciplinary dissertation puts the theories and aesthetics of avant-gardism into conversation with recent theories of mental disability arising from critical disability studies and madness studies. It does so in order to develop a critical approach that both expands literary disability studies' formal criticism, and provokes avant-garde theorization to reconsider some of its founding aestheticization and metaphorization of mental disability. Through a close analysis of the poetry and poetics of three North American avant-garde writers who have documented lived experiences of mental disability and ableist harm, including Claude Gauvreau (1925-1971), Hannah Weiner (1928-1977), and bill bissett (b. 1939), this dissertation analyzes the modes by which mentally disabled avant-garde poets integrated disruptive aesthetics with their lived experience. Through this analysis, this dissertation theorizes avant-garde dishumanist aesthetics and social critique. With critical attention to silenced narratives, a combined avant-garde dishumanism presents a complex temporality that acknowledges incompleteness, messiness, and the shifting critical positions of communicative relation in audiences of the present. Avant-garde dishumanist texts trouble normative and dominant ideologies for the purposes of creating experiences of future modes of relation and communication from located and embodied positions of disability. Avant-garde dishumanism finds form in a poetics of linguistic rupture and creation of a sense of more equitable futurity in poetry that resists, speaks back to, and reframes mental ableism. This dissertation ultimately argues for a literary disability studies approach informed by avant-garde poetics to both address the avant-garde's roots in mental ableism, and deepen disability studies' formal textual analysis.
  • Fabrication and Characterization of CoFe2O4-BiFeO3 Core Shell Nanocomposite and SrFe(12−2x)CoxRuxO19 Hexaferrites

    Monfared, Sara; Department of Physics
    This thesis consists of three parts. The first section is about CoFe2O4-BiFeO3 core-shell multiferroic nanocomposite synthesized via a two-step wet-chemical process. The presence of both spinel and perovskite constituents as well as the core-shell structure of nanocomposite have been identified using x-ray diffraction and high-resolution transmission electron microscopy, respectively. Low temperature (5 K) magnetic measurement exhibited a significant exchange bias in the core-shell nanocomposite which confirms promising connectivity of the constituents in the interface. An enhancement in magneto-dielectric of the core-shell nanocomposite over the CoFe2O4-BiFeO3 (0-3)-type nanocomposites has been seen. Further study on the magneto-loss demonstrated the contribution of the magneto-electric and Maxwell-Wagner effects in magneto-dielectric of the core-shell nanocomposite. The second part of this thesis has focused on the bulk of SrFe(12−2x)CoxRuxO19 (x = 0, 0.1, 0.2, 0.3, 0.4) which have been synthesized through the solid-state reaction process. DC magnetic measurement at room temperature exhibited a significant reduction in the coercive field of samples as the concentration of dopants increased. Contrary, an increase in the saturation magnetization was observed in the doped samples. Furthermore, a transition from conical to uniaxial anisotropy has been seen for the doped samples above x=0.3. Thin films of SrFe(12−2x)CoxRuxO19 / (111) SrTiO3 fabricated by a pulsed laser deposition technique, have been studied in the last part of this work. High-resolution parallel beam x-ray diffraction results have shown single orientations for all thin films except one. The thickness of thin films has been determined by the x-ray reflectivity measurement. A certain level of mosaicity has been detected in the prepared films using the rocking curve measurement. The strain and the epitaxial growth of thin films have been investigated utilizing the reciprocal space map technique. Finally, in-plane pole figure measurements revealed high textured films with three-fold and six-fold hexagonal symmetry. The formation of a perpendicular anisotropy in Co-Ru doped Sr-M thin films has been detected from room temperature magnetic measurement. The distribution of Co2+ and Ru4+ ions in different interstitial spaces, the thickness of films, and change in the magneto-anisotropy with a concentration of dopants have a significant effect on the magnetic characteristic of thin films.
  • Sclerostin influences body composition adaptations to exercise training

    Kurgan, Nigel; Applied Health Sciences Program
    Sclerostin is a secreted glycoprotein mainly produced by the osteocyte, which inhibits the canonical Wnt/ß-catenin signalling pathway. In mice, genetic deletion, or inhibition of sclerostin with a neutralizing antibody increases bone mass while also improving insulin sensitivity and lipid homeostasis. Despite sclerostin not being expressed by adipose tissue (AT), reductions in white AT (WAT) mass and adipocyte cross-sectional area can also be observed with sclerostin inhibition, ultimately conferring resistance to a high-fat diet. Resting circulating sclerostin has also been shown to decrease following exercise training. This dissertation includes six studies examining the hypothesis that sclerostin influences adaptations in fat mass in response to exercise training. Study 1 did not identify serum sclerostin’s response to acute exercise with a top-down proteomic analysis. Study 2 of this thesis utilized a targeted approach and found sclerostin increases in the circulation transiently following acute exercise in adolescents with excess adiposity while those with normal weight have a blunted response. Study 3 utilized a longitudinal study design and found a diet and exercise intervention that leads to a reduction in fat mass attenuates sclerostin’s post-exercise increase in adolescents with excess adiposity. Study 4 identified sclerostin was present in human AT and decreased following exercise training in adults with excess adiposity. Study 5 characterized sclerostin’s response to acute exercise within serum and WAT depots of a mouse model and showed that serum sclerostin is elevated during recovery only in obese mice compared to lean mice and the monomeric form of sclerostin is reduced in scWAT during recovery from acute exercise and is abolished in visceral WAT in response to an obesogenic diet. Study 6 showed that prevention in the reduction in sclerostin seen with exercise with daily injections of recombinant sclerostin also prevents the reduction in scWAT mass and adipocyte cell size and increased lean mass seen with exercise training. These changes may be related to a shift in fuel utilization. Taken together, this thesis provides evidence that sclerostin is influenced by adiposity and exercise training and fluctuations in sclerostin content can regulate adaptations in fat mass and lean mass, which may be mediated by changes in metabolism.
  • Advancing a Youth-Centered Pedagogy that Fosters Physical Literacy by Working with Youth and YMCA Recreation Providers

    Petersen, Jennie; Applied Health Sciences Program
    Participation in sport and physical activity declines in children at approximately 11-14 years of age. Efforts to support long-term participation in physical activity have focused on the promotion of physical literacy, which offers a holistic view of the factors affecting youth participation. Limited research has explored pedagogical approaches that can support youth physical literacy and engagement in recreational sport and physical activity contexts. This dissertation investigates pedagogical approaches aimed at supporting youth physical literacy in a YMCA recreation context using action research. An important objective was to support change in YMCA organizational pedagogical practices. Practical implications for the implementation of physical literacy are discussed throughout. Interviews with 10 youth and eight coaches involved in YMCA recreational sport and physical activity programs were conducted in the first study of this dissertation. Factors that supported youth engagement included sense of enjoyment, learning and accomplishment, and comfort with peers in the program. Youth described feeling disengaged when they felt a low sense of autonomy, excluded, or if there was potential for embarrassment. Gender stereotypes were identified as a contributing factor leading to lower levels of participation and engagement in girls. Coaches who had previously taken physical literacy related training perceived improvements in their instructional ability to engage youth. In the second study, 31 youth participated in a series of focus group meetings exploring what approaches to physical literacy resonate amongst youth. During a wrap-up meeting with YMCA stakeholders, youth participants shared their ideas and courses of action. Findings demonstrated that the presence of a caring adult, interacting with peers of a similar age, opportunities to have input and co-create their programs, games-based approaches, and the flexibility of their program structures were important factors for enhancing youth involvement in sport and physical activity. In the last study, a youth-informed recreation instructors training was designed, developed, and co-created with six YMCA stakeholders over the course of seven focus group meetings. A key outcome was the development of a recreation instructor training, called Working ‘with’ Youth in Sport and Physical Activity. Findings provide insight on the challenges that recreation organizations face with implementing physical literacy concepts.
  • The Role of CRISPR-Mediated Phage Resistance in the Development of Phage-Based Biocontrol for Erwinia amylovora

    Parcey, Michael; Centre for Biotechnology
    In the post-antibiotic era, resistance in pathogenic bacteria is projected to significantly hinder crop production and become one of the leading causes of death. This has necessitated the development of therapies to address antibiotic resistant microbes and prolong the period for which antibiotics remain a viable treatment option. A prominent alternative technology that has recently re-emerged is the use of bacterial viruses known as phages. Phages selectively lyse their bacterial hosts during the replication process but must avoid phage resistance mechanisms to eliminate a bacterial population. In this dissertation, the impact of phage resistance on biocontrol efficacy is examined using the phytopathogen Erwinia amylovora. The primary source of acquired phage immunity in bacteria is the CRISPR-Cas system. However, the absence of methodologies to study Erwinia phages, and a lack of genomic data for E. amylovora, has previously hindered this avenue of research. Quantitative real time PCR assays were developed to simultaneously monitor both the E. amylovora and phage populations. The individual steps of the phage lytic cycle during infection were characterized by further modification of this methodology. Through this, phage candidates ΦEa46-1-A1 and ΦEa21-4, that previously demonstrated high biocontrol potential, were shown to produce a large number of progenies over a short period of time. A comparative genomic analysis using 127 sequenced isolates of E. amylovora was then completed. This study proposed three primary clades of E. amylovora which infect apples in North America. A novel bioinformatic pipeline was subsequently developed to analyse the CRISPR regions of E. amylovora and the activity of the CRISPR-Cas system was then confirmed. While each clade of E. amylovora exhibited a unique CRISPR arrays, none of the identified CRISPR spacers provided inherent protection against any biocontrol candidate. CRISPR-mediated phage resistance was confirmed in E. amylovora against biocontrol candidate ΦEa21-4 but only in isolates with primed CRISPR-Cas systems. Still, phage resistance to ΦEa21-4 was observed through an unknown resistance mechanism in wild-type isolates. Overall, this work demonstrates new techniques to improve trial outcome prediction and lays the foundation for further investigation into the phage resistance mechanisms of E. amylovora.
  • Positive Experiences, Dreams, and Expectations of International Master’s Students at a Southern Ontario University: An Appreciative Inquiry

    Ankomah, William Sarfo; Department of Graduate and Undergraduate Studies in Education
    This study used appreciative inquiry (AI) as a methodological and theoretical framework and positive psychology theory to investigate international master’s students’ positive experiences, dreams, and expectations in their programs and institution to inform policies, programs, and practices. Although the literature describes international students’ mixed experiences in Canada, including developing critical thinking skills, making friends with other nationals, culture shock, and financial challenges, previous studies seldom focus on life-affirming conditions that enrich and improve such students’ schooling experiences. The first three stages of AI’s 4-D cycle—discovery, dream, and design—informed the study’s data collection methods (14 semi-structured individual interviews and three focus group discussions) to generate strength-based data for analysis, resulting in five key themes: (a) personal well-being and sense of belonging, (b) instructors’ pedagogical practices, (c) financial constraints and employment opportunities, (d) career development, and (e) policies. Based on its findings, the study makes six recommendations to inform international graduate student policy and practice: (a) allow international master’s students to study with their domestic counterparts, (b) increase international student diversity, (c) regularize socializing events for students and community members, (d) bridge the gap between theory and practice (hands-on experience), (e) work with all stakeholders to make international master’s students’ tuition fees more affordable, and (f) create on- and off-campus employment opportunities. Participants’ first-person accounts emphasize the need to include student voices in their own education and also shift the conversation from a deficit lens to a more positive discourse to balance the narratives around international students’ experiences.
  • Extending Intergroup Contact Theory to Men’s Anti-Women Biases

    Earle, Megan; Department of Psychology
    Men’s exploitation of women in heterosexual relationships is commonplace, both through sexually assaulting or otherwise taking advantage of women’s bodies, and in exploiting women for domestic labour such as housework and childcare. In the current investigation, we first present evidence for the co-occurrence of men’s willingness to sexually exploit and their willingness to domestically exploit their partners, then assess predictors and emotional processes underlying such hostility. Specifically, in Chapter 2, we develop a two-dimensional scale of willingness to exploit women with male participants (Study 1a; n = 103) and provide evidence that sexual exploitation willingness and domestic exploitation willingness are indeed separate, but related, factors. In Study 1b, we perform confirmatory analysis of this measure in two additional samples (n = 129 and n = 632 respectively) and provide evidence of construct validity for the scale. Then, Study 1c (n = 281) we provide evidence for stability of the construct over time, as well as its ability to predict behavioural indicators of exploitation. In Chapter 3, we investigate predictors and emotional processes underlying anti-women hostility and willingness to exploit women drawing on intergroup contact theory. In a correlational investigation (Study 2; n = 229), we find that perceived negative experiences with women predict greater anti-women bias via greater anger toward women. We then confirm this pattern of results using an experimental manipulation in Study 3 (n = 174), finding indirect effects of anger toward women in the relation between negative contact condition (vs. control) and greater anti-women bias. Positive contact, in contrast, has little relation with more positive attitudes toward women. Finally, in a three-wave longitudinal investigation (n = 577), Study 4 presents evidence for more nuanced relations between perceived contact, anger, and anti-women hostility; the findings suggest that not only do negative contact experiences predict downstream anger toward women, but also that anger and anti-women attitudes feed into men’s perceptions of their contact experiences with women. Overall, these findings reveal that perceived negative (but not positive) contact with, and anger toward, women are particularly relevant to understanding anti-women biases in heterosexual relations and future directions for reducing anti-women hostility are discussed.
  • Structural, Magnetic, Dielectric, and Optical Properties of DyCrO3 and GeNi2O4 Materials

    Indovski, Biljana; Department of Physics
    GeNi2O4 is a cubic spinel with two antiferromagnetic transitions at low temperatures, while DyCrO3 has an orthorhombic perovskite structure with an antiferromagnetic transition at a higher temperature. Thin films of these compounds are widely researched for their applications in spintronics. The investigation of the structural, magnetic, dielectric, and optical properties of deposited thin films of these two materials can contribute to a better understanding of their physical characteristics which may lead to possible applications. In this research, DyCrO3 and GeNi2-xMgxO4 (x=0, 0.03) epitaxial thin films were deposited on SrTiO3 substrates using the pulsed laser deposition technique. As the c-lattice parameter of the orthorhombic DyCrO3 and a-lattice parameter of the cubic GeNi2O4 are almost having the same value, this is giving a rise to a small strain in their epitaxial thin films. Therefore, composite thin films of the DyCrO3 and GeNi2-xMgxO4 (x=0, 0.03) materials were also deposited. The structural properties of these thin films were examined using different X-ray techniques such as an X-ray diffraction, X-ray reflectivity, reciprocal space mapping, and in-plane pole figures. The results were analyzed to determine the preferred orientation, the thickness of the thin films, the presence of strain and defects, and the degree of epitaxy. The reciprocal space mapping results reveal a dependence between the thickness of the thin films and the presence of defects in the epitaxial films. The in-plane pole figure results show the presence of domains with different orientation in several thin films, although the results from the high-resolution X-ray diffraction indicate a single orientation in those films. The temperature dependence of magnetization in epitaxial thin films was measured in order to examine the magnetic anisotropy for the magnetic field normal and parallel to the surface of the films. These results indicate the presence of magnetic anisotropy in several thin films. GeNi2O4 is an interesting antiferromagnet as it has two closely spaced antiferromagnetic transitions that are the result of a spin reorientation in two types of {111} planes. Therefore, to better understand the ordering of the spins with respect to the {111} planes, additional measurements and analysis of the results were done on GeNi2O4 single crystals. The temperature dependence of magnetization was measured for the magnetic field applied parallel and perpendicular to the {111} planes. In addition, the temperature dependence of Raman spectra of a GeNi2O4 single crystal was measured and analyzed. These single crystal results of GeNi2O4 provide a better understanding of spin-phonon coupling and spin ordering and reorientation in this spinel compound.
  • Understanding Nepali Youth’s Community Participation in the Post-Disaster Context

    Maharjan, Nabin; Department of Child and Youth Studies
    As Nepal witnessed the significant contribution of youth in the 2015 earthquake crisis, their community participation received nation-wide attention and acknowledgement (GoN, 2015, and Sherriff, 2016); however, a little attention has been paid to understand their participation practices and perspectives. Witnessing youth active participation in the community, this study has attempted to explore their engagement in the post-disaster context of Nepal by using Cornwall’s (2000a) situated practices, and Stammers’ (2009) paradox of institutionalization as conceptual frameworks. This study adopted Participatory Action Research (PAR) method to explore the nature of youth engagement, factors for their community (dis)engagement, and youth’s conceptualization of participation based on their own lived experiences. 36 Nepali youth, who were actively engaged in the community (seven as co-researchers and 29 as research participants), participated in this study. Data were collected using Cooperative Inquiry (CI) workshops, interviews and focus group discussions, field visits, and social media content analysis. Later, data were analyzed using thematic analysis; and five key themes emerged from the collected data. These themes not only illustrated how youth were engaged in complex and hybrid ways, but also revealed the influence of socio-cultural and economic situation, and institutional practices on youth (dis)engagement in the community. The study exhibits the necessity of incorporating youth’s perspectives on participation and changing youth participation practices rather than mere adult-centric narratives of youth participation or institution-driven, tokenistic and unsustainable youth mobilization practices in Nepal.
  • (A). Regulation of B-/Z-DNA transition in modified oligonucleotides; (B). Synthesis of cationic BODIPY analogues for antimicrobial and anticancer applications

    Joshi, Dhruval Kumar; Centre for Biotechnology
    A. In this work, LNA-dG was incorporated into d(CG)6 sequence in a site-specific manner through the phosphoramidite chemistry-based solid phase synthesis to investigate the impact of this modification on the B→Z-DNA transition. Circular dichroism study showed that the incorporation of a single LNA-dG unit into d(CG)6 at internal positions virtually suppressed Z-DNA formation at 4 M NaCl concentration, whereas the presence of single LNA-dG unit towards the terminal ends showed only partially inhibition of B→Z-DNA transition. To further understand the influence of chemical modification on B→Z-DNA transition, modification at C8-position on LNA-dG residue was explored. Towards this goal, compounds such as 8-bromo-5′-dimethoxytrityl-N-dimethylformamidine-(2′-O,4′-C-methylene)-guanosine-3′-O-(2-cyanoethyl)-N,N-diisopropy phosphoramidite and 8-bromo-2′-deoxy-5′-O-dimethoxy-N-[(dimethylamino)methylene]-2′-fluoroguanosine-3′-O-(2-cyanoethyl)-N,N-diisopropyl phosphoramidite were synthesized. B. In this study, N,N,N-trimethyl-2-(4,4-difluoro-2,6-diiodo-4-bora-3a,4a-diaza-s-indacen-8-yl) ethylammonium iodide 111 was successfully synthesized. Singlet oxygen generation experiments suggested that BODIPY 111 is ~2.5 times more efficient with respect to Rose Bengal (RB) in generating singlet oxygen. However, based on the cell-culture experiment, BODIPY 111 treated culture plates showed only slight reduction in CFUs compared to Rose Bengal and control plates. BODIPY compounds 107 (iodinated-fluoro-BODIPY), 130 (brominated-fluoro-BODIPY) and 110 (brominated-meso-dimethylamine-fluoro-BODIPY) showed excellent stability both in dark and in light conditions and were found to be very efficient in generating singlet oxygen when compared to RB.
  • 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.
  • Effects of Exogenous Lipopolysaccharide Exposure on Bone Outcomes in Rodent Models

    Bott, Kirsten; Applied Health Sciences Program
    Chronic low-grade inflammation has been identified as a potential contributor to the pathophysiology of osteoporosis. A key mediator may be lipopolysaccharide (LPS) released from gram-negative bacteria in the gut that can enter circulation stimulating an inflammatory response and upregulate bone resorption. Since rodent models mimic the loss of bone mineral density (BMD) and structure that occurs in humans, rodents offer an accelerated model for studying these inflammation-mediated changes. Therefore, the objective of this thesis was to characterize a rodent model of LPS-induced bone loss using repeated in vivo μCT scans to establish a time course effect of LPS longitudinally and for this purpose three studies were conducted. Study 1 & 2 were run simultaneously using the same control mice. Study 1 demonstrated that repeated irradiation had a negative impact on trabecular bone in both male and female CD-1 mice, while cortical bone was only negatively impacted in the females. In study 2, continuous delivery of exogenous LPS via osmotic pumps for 12 weeks elevated serum LPS in both male and female CD-1 mice but did not alter trabecular or cortical bone structure or BMD at any of the scanning timepoints. Results from Study 2 may in part have been influenced by the effects of repeated irradiation from the in vivo μCT scans at 4-week intervals for a total of 4 scans analyzed in Study 1. In study 3, a systematic review was conducted to better characterize a model of LPS induced bone loss and identify factors that may impact the effects of LPS on bone outcomes in rodent models. Regardless of study duration, exogenous LPS negatively impacted trabecular bone structure and BMD but not cortical bone structure, due to an upregulation in bone resorption. Together these data suggest that exogenous LPS can induce alterations in bone structure and BMD in rodent models, however a clearly defined model of exogenous LPS induced bone loss has yet to be fully characterized.

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