Recent Submissions

  • 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.
  • 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.
  • An In-depth Examination of Personality and Aggression Across Different Contexts

    MacDonell, Elliott; Department of Psychology
    Acts of aggression are associated with a variety of negative outcomes. Accordingly, research has aimed to identify the personality traits that give rise to different forms of aggressive behaviour. Recent work has indicated that the factor of Honesty-Humility is associated with a variety of deviant behaviours, including aggression towards others; however, the nuances of these relationships require further investigation. This dissertation aimed to address several gaps in this literature through three main studies. In Study 1, we extended previous findings to younger populations, examining the associations between Honesty-Humility and aggression longitudinally in a large sample of children and youth. These findings demonstrated a bidirectional relationship between Honesty-Humility and aggression over time, such that low levels of Honesty-Humility resulted in higher levels of aggression and vice versa. In Study 2, we explored the specific facets of Honesty-Humility to determine if they differentially predict proactive and reactive aggression. Despite the theoretical link between Modesty and reactive aggression, we found limited support for this association, especially when controlling for proactive aggression. Overall, the Sincerity and Fairness facets were found to strongly predict both forms of aggression. Lastly, Study 3 explored the associations between Honesty-Humility and deviance, aggression, exploitation, and victimization in a workplace context. Robust relationships were found between Honesty-Humility and several deviant behaviours, further emphasizing the importance of this trait. In particular, when provided with the opportunity to aggress, individuals low in Honesty-Humility were more likely to do so, regardless of their level of power in the situation. Collectively, these findings indicate that Honesty-Humility is the strongest predictor of aggressive and deviant behaviour among the broad factors of personality. However, this dissertation extends previous findings by demonstrating the applicability of Honesty-Humility across different contexts and by providing a nuanced understanding of the components responsible for this relationship.
  • “Getting Everyone on the Same Page” An Integrated Transition Planning Process for Youths with an Intellectual/Developmental Disability with a Social Return on Investment Perspective

    Readhead, Anne; Department of Child and Youth Studies
    Transitioning out of high school is a significant step in a young person’s life. The Tri-Sector TAY Planning process in the Niagara Region of Ontario, Canada has developed a single integrated transition plan for youths with an intellectual and/or developmental disability (I/DD). This plan unfolds collaboratively, with education and community professionals meeting at the same planning table with the family and the youth beginning at the age of 14 years. Notably, no new government funding was provided to support this process. The case study reported herein explored both the potential benefits of the Tri-Sector Planning process and the ways in which this multi-sector planning procedure might be improved. Semi-structured interviews were conducted with fourteen participants, including youths, parents, and professionals. A qualitative thematic data analysis was conducted. Collaboration was identified as an important component of the multi-sector integrated planning process, critical to promoting successful outcomes for youths, including gainful employment and entry into post-secondary education. On the question of possible improvements to the procedure, promoting increased youth engagement and agency during the planning process emerged as an important consideration. In addition, a Social Return on Investment (SROI) quantitative and qualitative data analysis was completed on the case study data to examine the identified impacts of the process. Even with the investment into the Niagara Region Tri-Sector TAY Planning process based only on an estimate of funding from participating organizations, the net SROI ratio was 1.00:4.92, illustrating that for every $1.00 of funding contributed by participating organizations, the after-cost impact benefit was $4.92.
  • The Mental Representation of Visual Information

    Robitaille, Joel; Department of Psychology
    Despite working in relative independence, the working memory and imagery literatures investigate the mental representation of visual information. Recent reports investigating the neural structure and their associated functional activity responsible for the creation and maintenance of these cognitive representations suggest a significant overlap between these fields of study. Because each field has adopted methodologies that does not allow for a direct comparison of the mental representation described by their respective literatures, it is difficult to determine whether imagery and working memory representations are related. Hence, the current thesis further investigates the properties of the visual representation of visual information to bridge between the imagery and working memory fields. In a first study, I compare the psychophysical properties of simple stimuli commonly used in working memory reports with more complex objects adopted by the imagery field. In the course of three experiments, I demonstrate that the cost of stimulus complexity predominantly affects the quality of the mental representation while still providing evidence of a shared cognitive mechanism driving the formation and maintenance of these representations. In a second study, I evaluate the impact of mental rotation on these mental representations as well as whether the adoption of different paradigms, along with different performance metrics, assess the same cognitive construct. Here again, I show strong evidence in support of a common cognitive mechanism driving the performance across mental manipulation and through assessment methods. Finally, the last study attempted to track the manipulation of these visual representations by applying an encoding model to raw EEG activity. While I show evidence of the orientation-relevant activity during perception, the encoding model does not detect reliable enough activity to allow for tracking the orientation of the stimulus during retention and mental rotation. Together, this thesis provides evidence of a shared cognitive mechanism that drives visual working memory and imagery representation, but tracking these mental representations using EEG activity during manipulation remains unclear.
  • De novo sequencing, annotation, and characterization of the genome of Lavandula angustifolia (Lavender)

    Nattamai Malli Pooranachandhiran, Radesh; Centre for Biotechnology
    Lavender (Lavandula angustifolia) is a perennial plant native to the Mediterranean region, best known for its essential oil (EOs) that have numerous applications in the pharmaceutical, cosmetic and perfume industries. We performed sequencing of the L. angustifolia genome and report a detailed analysis of the assembled genome, focusing on genome size, ploidy, and repeat content. The lavender genome was estimated to be around 870 Mbp (1C=0.96 pg) using a quantitative PCR method. Genome size was further validated through analysis of raw genome sequences using Kmergenie, providing a conclusive end to the lavender genome size dispute. The repeat element composition of the genome was analyzed using de novo (RepeatModeler) and library-based methods (RepeatMasker) and was estimated to be around 45% of the full genome or ~57% of the non-gap genome sequences. Further characterization revealed Long Terminal Repeat (LTRs) retrotransposons as the major repeat type, which contribute to ~18% of the genome, followed by DNA transposons at ~8.5% of the genome. Interestingly, unlike most other plant genomes, the lavender genome has many more Copia than Gypsy elements, both showing a trend of recent increasing activity. Furthermore, these LTRs, especially Copia elements, have shown active participation in gene function including genes for essential oil production, with Copia elements contributing to ~30 % of the coding DNA sequence (CDS) regions, in addition to promoter, intron and untranslated (UTR) regions. The lavender genome also has an unusually high number of miniature inverted-repeat transposable elements (MITEs) compared to other model plant genomes, with the number being ~88,000, which is close to that (~90,000) of the much larger maize genome. Analysis also revealed the lavender genome with a high proportion at polyploidy level, which is strongly biased towards regions containing essential oil genes, with polyploidization events in the lavender genome occurred between 16 to 41 Mya. In conclusion, our results reveal the lavender genome to be highly duplicated and with past and ongoing active retrotransposition, making the genome optimized for EO production.
  • The Role of Protein Following Intense Exercise in Competitive Youth Athletes

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

    McAlpine, Michael D.; Applied Health Sciences Program
    The consumption of tea has many proposed health benefits thought to likely be the result of an abundance of unique polyphenols. In particular, one exciting potential health benefit of tea is its capacity to have bone supportive effects when consumed throughout life. Prior to testing the potential bone supportive effects, it was important to characterize several types of tea and determine the ideal steeping time for each tea, maximizing the quantity of polyphenols while also maintaining taste (Study 1). Results from this study were congruent with manufacturer’s recommendations. Following this, several types of teas and tisanes were tested in an in vitro osteoblast model to determine if there were any alterations in quantity of mineral produced (Study 2). Findings demonstrated that all teas effectively increased mineralization at a dietary concentration of polyphenols, but red rooibos tea appeared to produce the greatest effects. The next important aspect which needed to be clarified was if there was an optimal concentration of red rooibos tea that elicited maximal results (Study 3). To determine this, a dose response study was conducted in the same osteoblast model as study 2 and mineral quantity was measured. From this study a positive dose-dependent response was observed without any signs of toxicity, suggesting that high concentrations may be beneficial. Following the initial in vitro studies it was important to test red rooibos tea in a physiologically relevant model of elevated bone turnover, pregnancy and lactation (Study 4). Female Sprague-Dawley rats were randomized to one of the following groups: PREG TEA (pregnant and received a supplemental level of red rooibos: ~2.6 g /kg body weight/day in water), PREG WATER (became pregnant and received water), or NONPREG CON (age-matched, non-pregnant control) from 2 weeks prior to pregnancy (age 8 weeks) through to 4 months post-lactation. Results demonstrated that there were immediate losses of both trabecular and cortical bone following lactation. However, cortical bone rapidly recovered in both pregnancy groups while the majority of trabecular outcomes only partially recovered and appeared to have permanent reductions. When comparing the two pregnancy groups, there were no differences in cortical bone post-lactation but there were significant improvements in several of the trabecular outcomes in rats that received red rooibos herbal tea. The findings from this thesis demonstrated in progressively more complex and physiologically relevant models that tea does have the capacity to be bone supportive, particularly during periods of high turnover.
  • 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.
  • Understanding the Complex Mental Health Challenges of Children and Adolescents Seeking Community-based Care

    Gallant, Caitlyn; Department of Psychology
    Studies have shown that children and adolescents with neurostructural and/or neurodevelopmental challenges experience worse mental health outcomes than their neurotypical peers, including more extensive service use, more severe symptomatology, and greater functional impairment. Despite the poor prognoses of these children and adolescents, few studies have investigated the neurocognitive contributions to mental health complexity among those seeking community-based mental health services. At present, environmental/social and behavioural factors remain the primary focus of treatment plans and much of the research examining this complex population has targeted psychosocial determinants. However, interventions based on these factors alone are not always effective, as they fail to account for neurocognitive challenges, which can significantly contribute to psychiatric presentations. This dissertation involves two studies that aimed to address these gaps in the literature and inform current practices in paediatric community mental health settings. Using Structural Equation Modeling (SEM), Study 1 tested the generalizability of a path model predicting service use among those with (n = 66) and without (n = 97) neurodevelopmental disorders (NDs). As expected, those with NDs had higher levels of symptomatology and greater service use than those without, and there were notable differences in the predictive pathways across ND groups. Similar paths were found between externalizing challenges and service use among all children/adolescents; however, the paths from internalizing challenges, early life adversity, and sex were only significant among the ND group, indicating that neurodevelopmental status is an important moderator of outcomes. In Study 2, a mixed methods approach was employed to examine how neuropsychological information could help inform current practice. Qualitative results confirmed that neuropsychological factors are often overlooked when utilizing current approaches and that observable symptoms, rather than underlying causes, are a primary focus of treatment. Further, neurocognitive deficits were found to be associated with self-reported interpersonal difficulties and caregivers’ reports of externalizing; however, only caregiver-reported externalizing challenges correlated with poorer treatment outcomes. Importantly, neurocognitive challenges were associated with long-term treatment responses, suggesting that these factors may be an important therapeutic target. Collectively, these findings indicate that using an exclusively psychosocial treatment approach, without considering neuropsychological factors, may not be effective among complex cases.
  • Apprehending Stigma: Towards a Reparative Trauma-informed Decolonial Reading of HIV-related Stigma

    Long, Carmen; Interdisciplinary Humanities Program
    Applying a decolonial trauma-informed framework that brings together different disciplinary systems, this project investigates responses to the stigma associated with the Human Immunodeficiency Virus (HIV) in the literary work of two Canadian and two South African writers. I approach the literary journalism of Stephanie Nolen and Jonny Steinberg and the novels of Tomson Highway and the late Phaswane Mpe as testimony in which Steinberg, Nolen and Mpe contest Western epistemologies and Highway foregrounds Indigenous knowledges. The four texts reframe stigma as operating within much larger systemic violences and operations of power than can be envisioned within a politics of recognition, indexed to the expository logic of Eve Kosofsky Sedgwick’s paranoid position. Locating HIV-related stigma as emerging within the context of intergenerational collective trauma rooted in colonial violence makes possible the kind of reparative work that Sedgwick envisions, as well as an engagement with the infinite possibilities of encounter as an ethical response to this socially polarizing phenomenon that has proven so difficult to dislodge. Attentive to specific racialized and minoritized colonial histories, this project unravels the entanglement of events and conditions that coalesce around HIV in watershed moments when decolonial work collides with ongoing histories of colonial violence. Such a trauma-informed, decolonial lens offers a non-positivist framework to unsettle, potentially, the stasis of stigma reduction.
  • Exploring Mental Health in Sport: The Behaviors, Perspectives and Needs of Stakeholders

    Murphy, Jessica; Applied Health Sciences Program
    Student-athletes are at high risk for poor mental health. Leaders within the varsity sport environment influence athlete mental health and help-seeking. This dissertation explored the behaviors, perspectives and needs of athletes, coaches, and athletic trainers as it pertains to mental health in sport. Three studies were conducted, the first utilized the Theory of Planned Behavior to explore factors associated with coach-athlete conversations about mental health. A coach’s Attitude towards having a conversation with an athlete significantly influenced their Intention to do so. Perceived Behavioral Control (PBC) significantly influenced the relationship between Social Norms and Intention. Both PBC and Social Norms had a significant relationship with the Behavior (having a conversation about mental health with an athlete). The second study applied a conceptual model from Horn’s Working Model of Coach Effectiveness to explore how an athlete’s perception of coach behavior impacts attitudes and help-seeking behaviors. Psychological distress levels influenced an athlete’s Perception of their coach’s behavior. Openness to help-seeking was significantly related to help-seeking Behaviors and influenced the relationship between personal characteristics and help-seeking. Perception of coach behaviors influenced the relationship between psychological distress and help-seeking from a coach. The last study sought to determine the acceptance of an online varsity sport-specific mental health resource. Preliminary results were promising; The PEER Network was frequently used over the study period and participants had positive and supportive feedback. Overall, results from the three studies suggest that perceived ability and social support may influence whether coach-athlete conversations about mental health occur. Due to the effects of these variables, coach mental health training should focus on improving the skills required for these conversations and normalizing mental health in sport. As an athlete’s perception of coach behavior mediated the relationship between psychological distress and help-seeking, training should also focus on clear ways to show athletes that coaches are supportive of mental health. Athlete-specific training should try and improve attitudes towards help-seeking and highlight the value from seeking help. The PEER Network may be an easily accessible and context-specific way of achieving these educational goals for members of the varsity athletic community.
  • Teachers’ Experiences of Implementing a Pedagogical Approach for Meaningful Physical Education

    Beni, Stephanie; Applied Health Sciences Program
    Dominant forms of physical education (PE) have been criticized for their inability to promote lifelong movement, with many scholars arguing in favour of an approach oriented toward meaningful experiences in PE. The Meaningful PE approach has been designed in response to this but has yet to be tested extensively in practice. The purpose of this dissertation has been to study teachers’ experiences of learning about and implementing the Meaningful PE approach. Five teachers based in Ireland and 12 teachers based in Canada participated in two separate studies lasting eight weeks and across two school years, respectively. Qualitative data were collected in the form of semi-structured interviews, non-participant observations, community of practice (CoP) meeting transcripts, and reflections. Results of this dissertation are presented in four articles. Article One highlights the experiences of Irish primary classroom teachers, demonstrating preliminary support for the approach from classroom teachers with little background in PE. Article Two focuses on Canadian elementary teachers’ experiences of implementing the Meaningful PE approach with their students and on the factors that influenced their implementation decisions. Primary factors influencing implementation included teachers’ prior experiences and beliefs, students’ responses to the implementation process, and external organizational pressures. Article Three focuses on Canadian teachers’ experiences of learning about Meaningful PE through a professional (PD) initiative designed around characteristics of effective PD outlined in the literature. Teachers were most supportive of the use of a CoP and modelling of the approach to foster their learning about Meaningful PE, while also highlighting several tensions between ideal and practical forms of PD, taking personal and organizational barriers into account. Article Four focuses on my experience of becoming a facilitator of teachers’ PD through facilitating a CoP for teachers. This article highlights the important role of identity in the process of learning to become a facilitator and navigating the tensions associated with that process. Collectively, this dissertation makes a significant contribution to the literature by a) informing the refinement of the Meaningful PE approach, b) offering insights into educational implementation research, and c) adding to the literature on teachers’ professional learning when being introduced to innovations.
  • Thermal tasting: methodological considerations and implications for alcohol behaviour.

    Thibodeau, Margaret; Department of Biological Sciences
    Thermal tasting is a phenomenon whereby some individuals perceive thermally-induced taste sensations when their tongue is warmed or cooled. These individuals, known as thermal tasters (TT), report a variety of thermally-induced tastes and the tastes reported can vary with temperature regime used and location on the tongue tested. TT are typically compared to thermal non-tasters (TnT), individuals who do not experience thermally-induced sensations. The literature suggests that TT give higher intensity ratings to orosensory stimuli than TnT; however, small sample sizes and differences in classification schemes between studies confound our understanding of TTS (thermal taste status). It is unknown whether the increased orosensory responsiveness of TT is universal or whether it is driven by a subgroup of TT. Furthermore, up to 50% of individuals are non-classifiable (NC). The largest database of individuals who have undergone TTS screening was compiled to address the literature gaps. Findings indicate that TT are more responsive than TnT to orosensory stimuli, regardless of the classification scheme used. The orosensory responsiveness of NC is not homogeneous, suggesting that NC are not a separate group but rather misclassified TT and TnT. Sweet TT are more likely than non-sweet TT to experience thermally-induced sensations during lingual warming. Similarly, sour TT are more likely than non-sour TT to report thermally-induced tastes during cooling. However, no differences in orosensory responsiveness based on these or other subgroups are identified, suggesting that the heightened orosensory responsiveness of TT is universal across this phenotype. The final study sought to characterize the binary interactions between ethanol and four orosensory stimuli (fructose, quinine, tartaric acid and alum sulphate) both overall and by comparing TT and TnT. In general, TT are more responsive than TnT to all stimuli in the study. Few interactions between TTS and stimulus intensity exist suggesting that TT and TnT perceive the sensations elicited by alcoholic beverages similarly, albeit at different intensities. Together, the thesis helps inform best practices for TTS screening and classification, provides insights into TTS mechanisms and furthers our understanding of alcoholic beverage perception.
  • Looking in the Mirror of Authenticity: A Self-Study of Teacher Education Practice

    Huizenga, Jack; Department of Graduate and Undergraduate Studies in Education
    This study explored the notion of authenticity within the context of teacher education. A qualitative research approach was chosen employing methods associated with self-study in order to explore the dissonance I experienced as a relatively new teacher educator. The purpose of the study was to explore the significance and potential of authenticity in teacher education. The study involved teacher candidates in an elementary science curriculum and instruction course that I was teaching. Teacher candidates reflected on their learning experiences in a course in which I intentionally applied the concept of authenticity. The study also involved experienced teacher educators whom I engaged in conversations as critical friends. Analysis of the teacher candidates’ reflections revealed that the notion of authentic learning resonated with these soon to be teachers. Analysis of the conversations with teacher educators revealed an important distinction between teaching the subject authentically and teaching the student authentically.

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