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The Heterogeneity of Adolescent Factors: Investigating Individual, Interpersonal, and Contextual Factors
No full textFriendship is an essential relationship, and its importance is particularly pronounced in adolescence. While it is known to be an important peer relationship, it is both dynamic and complex, meaning there are many aspects of adolescent friendship that remain to be understood. With my dissertation, I explore the heterogeneity of adolescent friendships utilizing a combination of self- and peer-reported variables at the level of the individual, the interpersonal, and the contextual. In Study 1, I explored the relationship between individual differences and friendship change over time. Specifically, I considered the role of different HEXACO personality traits in relation to reciprocal friendship quantity, formation, maintenance, and dissolution over a one-year period. My findings suggest that while specific personality traits are not associated with friendship formation in my sample, some traits (e.g., Conscientiousness, Openness to Experience) are associated with friendship quantity and friendship maintenance. In Study 2, I investigated the potentially overlapping interpersonal contexts of friendship and aggression, comparing the concurrent outcomes of victimization and perpetration between friends to those found between non-friends. Results indicated that for both victimization and perpetration, the context of friendship alters the concurrent outcomes associated with aggression. In Study 3, I considered broad, contextual factors that may influence adolescent friendship. With a two-part study, I explored the role of a variety of social media platforms on in-person and online friendships. In the first part of the study, I employed social network analysis, with results suggesting that there is considerable, but not complete, overlap between adolescents’ in-person and online friendship networks. With the second part of Study 3, I found evidence for positive direct and indirect associations between use of specific social media platforms, the importance of technology for social connection, and levels of friendship closeness. Altogether, the three studies of my dissertation further our understandings of the heterogenous nature of adolescent friendships at different levels of analysis. These findings suggest that future research should be undertaken with this heterogeneity in mind, to help inform and promote healthy relationships in adolescence
Cultural Resistance: An Ethnographic and Phenomenological Case Study of Palestinian Music Educator Mohamed Fadel's Life and Work
Full text linkThis ethnographic and phenomenological case study examines the lived experiences of pioneering Palestinian music educator Mohamed Fadel (b. 1956-). Instrumental in establishing in 1986 the first music conservatory in Jordan, named the National Music Conservatory, he subsequently developed the string and outreach programs of the Edward Said National Conservatory of Music in villages and refugee camps in the neighbouring occupied Palestinian territory beginning in 1995, directing the outreach program until his retirement in 2021. The inquiry draws on postcolonial theory, critical pedagogy, and conscientization theory to position the data. These include lengthy and in-depth conversations with Fadel and four additional research participants, visual and print materials, observations, reflexive and collaborative poetry, and fieldwork narratives written in the style of literary journalism, as narrative vignettes. Four key themes frame the discussion: (a) Fadel as a Palestinian goodwill ambassador who embraces Western classical music and pedagogy as symbols of universality and cosmopolitanism; (b) teaching music as an individual and national accomplishment, leading to community cultural capital as resistance; (c) being in a liminal space between the contested occupied Palestinian territory and the West; (d) modelling independence, courage, and empowerment with which to resist colonization, occupation, and oppression. The study celebrates the advancement of Palestinian musical culture – Arabic and Western-based – in the occupied Palestinian territory, and its use as part of non-violent cultural resistance against colonization, occupation, and oppression of Palestinian people, and thus as counterhegemonic
Exploring the Relationships Between Executive Functions and Reading Intervention Responsiveness in Children with Reading Disability
Full text linkBackground:
Notwithstanding the emergence of rigorous, evidence-based interventions, some students with reading disability (RD) still fall behind in reading skill. Copious amounts of evidence support a link between children’s executive functions (EF) and learning, including acquisition of reading skill specifically. Nonetheless, the relationship between EF and reading intervention outcomes have seldom been studied.
Objectives:
The purpose was to understand the extent to which EF predict reading intervention outcomes for students with RD.
Methods:
In the present study, 115 children with RD in Grade 3 and 4 completed an intensive, evidence-based 70-hour reading intervention for one hour per day over the course of fourteen weeks. EF in both neuropsychological (e.g., D-KEFS) and behavioural (e.g., BRIEF) measurements were observed at pretest, categorized as inhibition, shifting, working memory, emotional control, and reasoning/metacognition. Reading skills in the form of word recognition, decoding, fluency, and passage comprehension were measured before and after intervention. Standard scores were computed for EF and reading measures. Reading gains were converted into reliable change scores using the reliable change index (RCI).
Results:
Approximately 27% of correlations between EF and pretest reading were statistically significant. Analyzing reading gains, most correlations with EF were non-significant. The few significant coefficients lost significance following Bonferroni correction for multiple comparisons. Next, a composite EF deficit category was generated to differentiate participants who did or did not have below average EF across multiple measures, which 29 participants met and 86 did not. While t-tests revealed that the multi-deficit group had significantly lower gains in fluency than the group without multiple deficits (ps<.05), differences were not significant following Bonferroni correction. Finally, a chi-square analysis using the multi-deficit grouping and categorical reliable change in reading did not yield any significant results.
Implications:
While children’s EF relates to reading skill before the reading intervention, EF does not relate to gains in reading skill from the beginning to the end of intervention. This finding suggests that small group, structured interventions can mitigate learning barriers posed by executive dysfunction. However, the patterns of relationships between EF and reading fluency suggest that more research is needed
Understanding the effects of isoDGR in neurodegeneration
No full textWith the global population aging, the prevalence of chronic diseases such as Alzheimer’s disease and vascular dementia is increasing, emphasizing the urgent need to understand the underlying molecular mechanisms. Degenerative protein modifications (DPMs), including isoAsp-Gly-Arg (isoDGR) motif which is formed via spontaneous deamidation of NGR sequence, are increasingly recognized as contributors to age-related tissue dysfunction. Traditionally considered untreatable molecular damage, isoDGR has been shown to mimic integrin-binding motifs and trigger inflammatory responses, yet its role in neurodegeneration remains poorly understood.
In this study, we investigated the effects of isoDGR-motif on key brain cell types, including brain endothelial cells (bEnd3) and neurons (N2A) using in vitro models. IsoDGR exposure induced cellular senescence, characterized by increased β-galactosidase activity, elevated p16 and p53 expression, nuclear translocation of p27, and reduced Lamin B1 levels. We also observed enhanced oxidative stress, particularly mitochondrial ROS, and impaired cell proliferation. Importantly, isoDGR disrupted endothelial monolayer permeability by altering tight junction (ZO-1) and adherens junction (VE-Cadherin) protein expression, increasing permeability and impairing cell migration. ICAM-1 and VCAM-1 expression was also increased in bEnd.3 cells. Together, these findings indicate that isoDGR promotes neuroinflammatory and neurovascular dysfunction, the hallmarks of neurodegenerative disease.
This thesis establishes isoDGR as a potential pathophysiological relevant driver of cellular dysfunction in the aging brain. Targeting DPMs such as isoDGR may represent a novel therapeutic approach to mitigate neurodegeneration and extend health-span
The Impact of Sibling Relationships on Mental Health
Full text linkSiblings have the potential to be impactful on an individual throughout their life, particularly due to the intimate nature of sibling relationships and the bonds that can be formed; this is in line with John Bowlby’s theory of attachment, which was the theoretical framework used as a base for this research. Previous studies have found that siblings can offer social and emotional support that is unique from the support that might be found in other interpersonal relationships (Walęcka-Matyja, 2018), which is why fostering positive sibling relationships can be of great value (Voorpostel & Van Der Lippe, 2007). The purpose of the current study was to examine the impact of sibling relationship perceptions on undergraduate students’ mental health. Mental health challenges are predominant, with approximately one in two Canadians currently experiencing, or having experienced in the past, a diagnosable mental health condition by the age of 40 (Centre for Addition and Mental Health, n.d.). Undergraduate students attending Brock University (n=245) were invited to participate in the online study involving the Lifespan Sibling Relationship Questionnaire (LSRS; Riggio, 2000) and the Depression, Anxiety, and Stress Scale (DASS-21; Lovibond & Lovibond, 1995), which were used to assess sibling relationship perceptions as well as experiences with symptoms of mental health challenges. Results revealed that sibling relationship perceptions have the potential to have an impact on one’s mental health; characteristics of the sibling relationship, including birth order and gender were also considered and found to have an impact on mental health outcomes. Implications of the findings, as well as limitations of the study and future directions are also discussed
Synthetic Approaches to Fluoroalkenes with Applications in Hydroetherification-type Reactivity
Full text linkFluorinated compounds are at the forefront of numerous advancements in the life science and this significance continues to drive research efforts toward identifying approaches for their controlled and selective synthesis. Indeed, the inclusion of fluorine in a molecule can significantly enhance the solubility, lipophilicity, permeability, protein binding, and bioavailability of drug candidates. Among organofluorine compounds, fluoroalkenes have recently gained prominence in drug development and pharmaceuticals with active roles as bioisosteres.
Herein, I report a direct and practical method for synthesizing fluorinated alkenes, including gem-difluoroalkenes and monofluoroalkenes with high E-isomeric selectivity. This approach benefits from commercially available, cheap and/or plentiful precursors, mild reaction conditions, operational simplicity, broad substrate scope and good to excellent yields. Fundamental to this development was the use of widely available and inexpensive solid support Merrifield peptide resin as a scavenger for removing by-product triphenylphosphine oxide and residual unreacted triphenylphosphine, which simplifies isolation of the fluorinated alkene products.
Building upon the efficient preparation of gem-difluoroalkenes, I further explored unprecedent Markovnikov addition of hydroxylamines to these substrates. This investigation led to the introduction of a novel fluorinated functional group, coined FON, created from ketone bioisostere difluoromethylene (CF2) unit and N−O building block. Notably, this novel motif was anticipated to show unique stereoelectronic properties and potential biological activities, as it represents a fluorinated homologs of β-phenethyl ethers. This group is synthesized in one-step via metal-free hydroetherification-type reaction with exclusive chemo- and regioselectivity for a diverse substrate scope. The value of this reactivity is proven at gram-scale synthesis and site-selective deuterium incorporation
Investigating Forearm Muscle Activity Across Violin String Heights
Full text linkThe purpose of this work was to evaluate differences in forearm and upper trapezius
muscle activity and co-contraction indices during performance of a four-octave G-major scale on
two identical violins with a low and a high string height. Surface electromyography was
collected from six forearm muscles and bilaterally from the upper trapezius. While seated in a
comfortable position, participants performed five trials of the scale on each violin at 60 beats per
minute, with two-minute rest periods between trials. Mean and peak muscle activity, as well as
co-contraction indices were analyzed. The high string condition elicited significantly higher
mean and peak activity than the low string violin, as well as higher co-contraction indices for the
FDS-EDC pair. Hand position also influenced muscle activity independent of the condition, with
the higher hand positions associated with increased demands. These findings suggest that
increased string height and hand position place greater physical demands on violinists, which
may in turn contribute to injury risk
Exploration of Concerns Affecting the Mental Well-being of Disabled Students Who Withdrew from Post-Secondary Education in Ontario
Full text linkDisabled students are enrolling in post-secondary education in Canada at higher rates than in the last decade. Despite this improvement in enrollment, only a smaller percentage of them graduated. Systematic and structural barriers affect the health and participation of disabled students in academic activities. Therefore, understanding the experiences of disabled students and the factors that led them to withdraw from post-secondary education is necessary. Informed by critical disability studies and academic ableism, I sought to understand the factors that affect the mental well-being of disabled students and how they lead them to withdraw from post-secondary education in Ontario. This research utilized an interpretative phenomenological analysis methodology to investigate their life experiences. Five (n = 5) disabled students who withdrew from post-secondary education were recruited for online interviews via social media. Five descriptive themes were developed from the data, capturing the experiences of the participants: (1) positive beginnings undermined by insurmountable endings, (2) disabled students' encounters with academic ableism, (3) retrogressive emotional experience of disabled students, (4) withdrawal as a slow unravelling of hope and belonging, and (5) envisioning change. Identifying that some began with good mental well-being, while others described challenges as they progress in their studies. This study described impending issues that impact well-being and identified potential areas for intervention in post-secondary education to avert the withdrawal of disabled students. Likewise, areas where ableism still exists in post-secondary institutions were identified. The results also provide recommendations for society, academic institutions, and policymakers to support disabled students in successfully navigating post-secondary education
Advancing detection, genomics, and secretome analysis of oomycete pathogens Phytophthora capsici and Phytopythium vexans to explore mechanisms of pathogenesis and biocontrol solutions
Full text linkSoilborne oomycete pathogens pose persistent challenges to vegetable production systems, particularly in Ontario, Canada, where Phytophthora capsici and the recently reported Phytopythium vexans have emerged as significant threats. Understanding the molecular mechanisms underlying their pathogenicity is critical for developing informed, site-specific disease management strategies. This thesis integrates comparative genomics, effector biology, and molecular diagnostics to enhance our understanding of their pathogenicity and support effective disease management.
The first component of this work focuses on P. capsici, where whole-genome sequencing of two Canadian isolates (55330 and 55898) revealed compact genomes yet retained a broad array of RxLR and CRN effectors. Comparative analyses with reference strains LT263 and LT1534 v11.0 uncovered both conserved and unique effectors, suggesting that local adaptation may be shaping pathogenic potential in response to regional crop pressures.
Building on this, the second component shifts to P. vexans, a novel strain recently reported in Ontario from apple tree soil. The SS21 P. vexans strain genome was sequenced and compared with the only two openly available strains HF1(China), and (CBS 119.80) (Iran). The genomic analysis reveals similar genome between the Canadian strain SS21 and the reference genomes, additionally SS21 displayed a reduce CAZymes, RxLR and CRN effectors, suggesting a niche adaptation to a specific Canadian agro-ecosystem.
The final component of this thesis focuses on the development of an amplitude-based multiplex droplet digital PCR (ddPCR) assay. Designed for simultaneous quantification of P. capsici, Trichoderma asperellum, and Trichoderma gamsii in soil, this assay was validated in field trials and offers high sensitivity and specificity. The assay displayed a high sensitivity with a limit of detection of 1 pg/µL DNA. The use of multiplex ddPCR offers practical solution for monitoring pathogen and biocontrol populations in complex soil environments
Documenting COVID-19 in Niagara collection, 2020-2021
Full text linkThe COVID-19 pandemic in 2020 resulted in a dramatic change to everyday life. The closure of schools, offices, and businesses, as well as public health protocols such as social distancing and mandatory mask-wearing, resulted in a significant disruption to normal routines. To capture this experience in Niagara, community members were asked to submit material that reflected this new reality. Some of the material submitted includes digital photographs, videos, written observations, and social media posts. Surveys were also posted quarterly during the first year of the pandemic that could be completed and submitted. Some of the issues addressed in the surveys include mandatory masks, lockdowns, border closures and vaccines.The collection consists of a website containing 344 digital items such as photographs, videos, social media posts, and written observations. These items were submitted by Niagara community members to a website created by Brock University Archives & Special Collections to document the experiences of the COVID-19 pandemic in Niagara. Community members were invited to submit their photographs, written observations, videos, or other material that reflected their experience during the pandemic. There were also quarterly surveys posted during the first year of the pandemic that community members could complete and submit to record their thoughts and experiences. To reflect these different types of submissions the collection is divided into two categories: Submitted Content (such as photos, videos, social media posts) and Questions and Answers (survey results). In both categories, items were listed in chronological order by date of submission. Digital submissions to the archive were closed in April 2023