Brock University Digital Repository
Brock University's Digital Repository is an online archive showcasing and preserving the Brock community's scholarly output as well as items from the Library's Archives & Special Collections. Researchers can disseminate their work by depositing it in this Open Access repository, which provides free, immediate access to users while also allowing Brock scholars to track downloads and views of their scholarship. The Digital Repository is also the home of the Brock University E-Thesis Portal.
For more information, see the repository's policies and procedures.
Communities in Brock University Digital Repository
Select a community to browse its collections.
Recent Submissions
Exploring the Structural, Magnetic, Optical, and Catalytic Properties of High-Spin Materials
(Brock University) Bakhshi, Hamed; Pilkington, Melanie; Department of Chemistry
This thesis explores the design, synthesis, and characterization of lanthanide-based
coordination frameworks (MOFs) and heterometallic 3d/4f complexes, with a focus on tunable
magnetic behavior, photophysical properties, and catalytic performance. Four complementary
research directions were pursued, each addressing key challenges in molecular magnetism,
luminescence and sustainable catalysis. The first project examines a family of isomorphous Dy(III),
Gd(III), and Tb(III)-MOFs constructed from 2',5'-bis(methoxymethyl)-[1,1':4',1''-terphenyl]-4,4''
dicarboxylic acid (H2L2.1). Systematic post-synthetic solvent exchange led to tunable structural
perturbations that profoundly affected the magnetic relaxation dynamics and photophysical
behavior of the Dy-MOF. Alternating current (ac) magnetic studies of the Dy-MOF series revealed
distinct relaxation pathways linked to subtle crystallographic changes. A second ligand, 2',5'
bis(ethoxymethyl)-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid (H2L2.2), demonstrated how minimal
chemical modifications to the linker can afford new MOFs with conserved coordination geometries
and consistent magnetic and luminescent properties across the lanthanide series. These results
underscore the sensitivity of magnetic relaxation and energy transfer processes to both the
framework structure and local symmetry. In the second project, three novel, isostructural Dy-, Gd-
and Tb-MOFs were synthesized from 4,4′-(1,2,4,5-tetrazine-3,6-diyl)dibenzoic acid (H₂TZDC). ac
magnetic studies revealed the MOFs exhibit complex temperature-dependent slow magnetic
relaxation, attributed to combined quantum tunneling (QTM), Orbach, and Raman mechanisms.
Notably, the Gd-based system displays rare frequency-dependent relaxation, rationalized by a small
axial anisotropy in the crystal field. Photoluminescence studies on this series of MOFs reveal
inefficient ligand-to-metal energy transfer, attributed to mismatched electronic energies. In the third
study a series of tetranuclear {Cu₄Ln₄} clusters assembled from the rac-mpzmH ligand are reported.
Magnetostructural studies reveal that weak Cu–Ln antiferromagnetic coupling, strong Cu–Cu
ferromagnetic interactions, and variations in the coordination geometries collectively govern the
magnetic behaviour. Field-induced slow relaxation was observed in the {Cu4Dy4} cluster, while the Tb
and Er analogues exhibited active QTM, effectively suppressing relaxation over the energy barrier
even in the presence of an external magnetic field. The photoluminescence was largely quenched by
the Cu(II) centers, although trace Ln-centered emission was observed in the {Cu4Tb4} cluster. These
results highlight the interplay between nuclearity, bridging geometry, and electronic structure in
determining the magnetic and optical properties. Project 4 focuses on heterometallic 3d/4f
complexes of the form [TM₂Ln(TX-TACN)]⁺ (TM(II) = Cu and Zn; Ln(III) = Gd, Dy, Tb, Eu and Ho); and TX
TACNH3 = N,N′,N″-tris(3,5-dimethyl-2-hydroxybenzyl)-1,4,7-triazacyclononane) as catalysts for the
cycloaddition of CO₂ with epoxides. X-ray diffraction studies revealed that all the complexes
comprise of a linear TM–Ln–TM motif with a subtle variation in the coordination geometry dependent
upon the 3d ion. Catalytic studies showed that the Zn(II)-based complexes significantly outperform
their Cu(II) counterparts, achieving high turnover numbers and frequencies for propylene oxide
conversion. Selectivity studies using cyclohexene oxide demonstrate stereochemical control and
unique reactivity pathways. The catalytic performance varies with the 4f metal and counterion,
demonstrating the modularity and adaptability of these systems for green chemistry applications.
Teaching Teachers to Teach Thinking
Lane Clark
The purpose of this study was to enhance educators' understanding and ability to teach critical and creative thinking skills effectively. Through a conceptual analysis of relevant theories and pedagogical practices, this study synthesized effective methods for teaching and assessing these skills and developed a research-based self-assessment tool to help educators evaluate and improve their approaches. While this tool offers valuable support, it remains unvalidated and should be applied with caution until further testing is conducted. This study contributes to the literature by clarifying ambiguous terms and deepening the understanding of these complex concepts, providing a synthesis of academic literature from diverse studies and making this information more accessible for teacher reference and application. Ultimately, the self-assessment tool serves as a preliminary framework for teachers to refine their pedagogy, ensuring students are better equipped with essential skills for success both in and beyond school.
Understanding the effects of isoDGR in neurodegeneration
(Brock University) Ridhi Patel; Newman Siu Kwan Sze; Applied Health Sciences Program
With 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 Relations Among Attentional Difficulties, Perfectionism, and Procrastination in Young Children
(Brock University) Maguire, Madeline; Mahy, Caitlin; Department of Psychology
Adults with attentional difficulties and adults who display certain aspects of perfectionism both show higher levels of procrastination (Niermann & Scheres, 2014; Sirois et al., 2017). Determining whether these relations are present early in the lifespan is crucial, as this would indicate that children with these tendencies are possibly at risk of experiencing the adverse outcomes of chronic procrastination (e.g., Beutel et al., 2016; Sirois et al., 2003). Therefore, the present study investigated the relations among attentional difficulties, perfectionism, and procrastination in preschool children. We also examined age as a potential moderator of these associations to determine whether they show stability across the preschool period. Finally, we explored whether self-control or emotion regulation mediate these relations, as theories suggest that deficits in these abilities drive adult procrastination (Sirois & Pychyl, 2013; Steel, 2007). Parents of 3- to 6-year-olds (N = 274; Mage = 33.6, SD = 5.8; 168 mothers) completed online questionnaires measuring their child’s procrastination tendencies (Fuke et al., 2023), attentional difficulties (Conners, 2009; McGoey et al., 2007), self-control (Gioia et al., 2003), and emotion regulation (Conners, 2009). Parents also completed a new questionnaire developed for the current study in which they reported on their child’s perfectionism. We found that while attentional difficulties and procrastination were positively correlated with each other, perfectionism and procrastination were negatively correlated with each other. Neither of these associations was moderated by children’s age, suggesting that both relations are relatively stable throughout the preschool years. In addition, the association between attentional difficulties and procrastination was partially mediated by self-control, but neither self-control nor emotion regulation mediated the association between perfectionism and procrastination. Since the current study was cross-sectional, future research should seek to examine these mediational pathways longitudinally. However, our findings provide evidence that children with attentional difficulties may benefit from intervention to reduce their procrastination, whereas children with perfectionistic tendencies may not demonstrate increased procrastination until later in development.
Recognizing Whiteness: An Autoethnographic Examination of Whiteness in My Life
(Brock University) Beres, Jacqueline L.; McGinn, Michelle; Department of Graduate and Undergraduate Studies in Education
The purpose of this research was to examine whiteness not merely as an individual attribute but as an ideological and structural system that organizes everyday life and grants privilege to those perceived as white. Using a blend of critical and evocative autoethnography, I wrote stories about my life experiences. I drew on critical whiteness studies and critical race theory to expose how whiteness operates as a normative force in institutions, social interactions, and academic knowledge production. The analysis I undertook helped me understand how I was welcomed in public spaces like libraries whereas racialized individuals in similar settings have been left questioning whether they were being excluded. My analysis also illuminated how my whiteness insulated me from developing a rich understanding of Black culture, particularly the cultural significance of Black hair. This work prompted me to question the extent to which my conception of “safety” while travelling was, in fact, a coded interpretation of white superiority. In hopes of appealing to a general audience beyond academia, I adopted a non-traditional dissertation format. I used footnotes to deviate from the expected in-text citation system and create an additional, co-occurring text, which I offer as one (albeit very minor) form of action aimed at disrupting white dominance within academia. My research adds to the collection of work, and particularly critical whiteness studies, completed in response to the calls from racialized authors, scholars, and activists for white people to engage in anti-racist action. By weaving personal narrative with systemic critique, my aim is to contribute to dismantling white supremacy and promote sustained, justice-oriented action among white readers committed to anti-racism. Given that white people have a critical responsibility to identify whiteness and eradicate the oppression that we collectively perpetuate, I hope my findings can help white readers as they progress on their personal racial justice journeys. For racialized readers, I hope my study offers additional insight into how white people recognize—and often, fail to recognize—whiteness, along with how we attempt to dismantle whiteness and fight for racial equity.