VictorJuiz/thesis huggingface dataset:
Structure and Properties of Nano- and Meso-scale Materials Prepared by Designed Self-Aasembly of Nanoparticles
Keywords: Nanoparticles
Self-Assembly

The work presented in this thesis explores the homo- and co-assembly process, structural characteristics and properties of nano- and meso-scale, one- and three-dimensional structures composed of nanoscale building blocks. In chapter 3, we developed a method for terminating the colloidal polymerization process of gold nanorods by post-assembly photocrosslinking of polymer ligands. By functionalizing gold nanorods with a hydrophobic polymer containing pendant double bonds, we were able to compartmentalize a hydrophobic photoinitiator. We could then suppress the association ability of the polymer ligands by covalently crosslinking them using photoirradiation. The averaged aggregation number of the polymers could be predicted from the kinetics of molecular step-growth polymerization. Furthermore, we found that following crosslinking, the inert-rod distance reduced, and the nanorod co-linearity increased, both allowing for better electromagnetic coupling between the nanorods. In chapter 4, we further explored the resemblance between colloidal and molecular polymerization reactions by applying strategies from molecular copolymerization to the co-assembly of gold nanorods with different dimensions into random and block copolymer structures (plasmonic copolymers). The approach was extended to the co-assembly of random copolymers of gold and palladium nanorods. We showed that the formation of random copolymers is achieved regardless of the composition, size, or concentration if both co-monomers are present at the beginning of the copolymerization. Block copolymers were prepared by combining one pre-polymer with the second monomer, or two pre-polymers. A kinetic model validated and further expanded the kinetic theories developed for molecular copolymerization reactions. Chapters 5 and 6 explore a bottom-up method to produce composite materials from spherical nanoparticles with different core-composition, surface-characteristics, and concentrations and cellulose nanocrystals. A relationship was established between the physical properties of the spherical particles and the characteristics of the co-assembled composite by extensive structural and optical characterization of mixed suspensions and composite solid films.
Group Decision Making with Partial Preferences
Keywords: machine learning
optimization
preference elicitation
psychometrics
rank aggregation
social choice

Group decision making is of fundamental importance in all aspects of a modern society. Many commonly studied decision procedures require that agents provide full preference information. This requirement imposes significant cognitive and time burdens on agents, increases communication overhead, and infringes agent privacy. As a result, specifying full preferences is one of the contributing factors for the limited real-world adoption of some commonly studied voting rules. In this dissertation, we introduce a framework consisting of new concepts, algorithms, and theoretical results to provide a sound foundation on which we can address these problems by being able to make group decisions with only partial preference information. In particular, we focus on single and multi-winner voting. We introduce minimax regret (MMR), a group decision-criterion for partial preferences, which quantifies the loss in social welfare of chosen alternative(s) compared to the unknown, but true winning alternative(s). We develop polynomial-time algorithms for the computation of MMR for a number of common of voting rules, and prove intractability results for other rules. We address preference elicitation, the second part of our framework, which concerns the extraction of only the relevant agent preferences that reduce MMR. We develop a few elicitation strategies, based on common ideas, for different voting rules and query types. While MMR can be applied in a distribution-free context, in many practical environments decision makers have access to historical datasets of, and probabilistic knowledge of agent preferences. To leverage such information, we first address the problem of learning probabilistic models of preferences from pairwise comparisons---the building block of many preference structures---for which previous techniques cannot handle. Then we extend our framework to a multi-round elicitation process that leverages probabilistic models to guide and analyze elicitation strategies. We empirically validate our framework and algorithms on real datasets. Experiments show our elicitation algorithms query only a fraction of full preferences to obtain alternative(s) with small MMR. Experiments also show our learning algorithms can learn accurate mixture models of preference types, which we then use to guide the design of one-round top-k elicitation protocols.
Toying with Healthy Eating: Developing a Play-based Nutrition Education Program
Keywords: Netnography
Nutrition education
Ontario kindergarten
Play-based teaching
Social media
Teachers' perspectives

Kindergarten-aged children are a key group for establishing lifelong healthy eating behaviours. However, current school-based nutrition education programs have reported little success in achieving this important goal. Though a number of different reasons account for programs' limited success, I focused on creating a kindergarten nutrition education program rooted in theory that also considered the needs and preferences of the teachers who implement such programs in their classes. Consequently, the present thesis describes the process of developing a preliminary draft of a kindergarten play-based nutrition education program, Sociodramatic Nutrition Activities for Kindergartens (SNAK). With the overarching goal of developing SNAK, I drew upon traditional and innovative data in order to learn about play-based teaching and healthy eating in kindergartens through a two phase process: 1. Program Landscaping, where I analyzed provincial and territorial ministry of education healthy eating kindergarten curricula and conducted a netnography (comprised of analyzing kindergarten teachers' social media discussions and interviewing a sample of kindergarten teachers). 2. Program Development, where I developed SNAK based upon findings derived from phase one. Analysis of the curricula, social media discussions, and teacher interviews revealed a myriad of factors that influence teachers when they implement play-based teaching and healthy eating in kindergarten classes. Findings both replicate and suggest new research questions for the nutrition and education literature. These findings also greatly benefited the development of SNAK. Future SNAK research includes further development and pilot testing to determine if kindergarten children (and teachers) can benefit from the program. Furthermore, I also describe how I combined traditional and innovative data and the insights obtained through netnography. Opportunities for developing programs and forming hypotheses can be found through examining the vast amount of teacher social media discussions, and I encourage other researchers to seek out innovative data.
Preschool Children`s Early Spelling and Writing
Keywords: educator
English as a Second Language
phonological awareness
preschool
spelling

Abstract This dissertation work was motivated by an attempt to better understand preschool children's early spelling and writing. Much of the literature focuses on reading, and yet spelling and writing provide a functionally meaningful context for children to use their growing knowledge of print and their ability to analyze language into sound to recode speech to print. The primary goals of the three studies that make up this thesis were: (1) to identify the component skills that predict preschool children's early word spelling and name writing (Study 1 found in Chapter 2), (2) to identify group differences in bilingual preschool children's early literacy and spelling ability relative to monolingual children (Study 2 found in Chapter 3), and (3) to investigate the efficacy of professional development to support preschool educators' ability to engage preschool children in talk related to print and phonological awareness (Study 3 found in Chapter 4). The findings of this dissertation both corroborate and add to the early spelling literature. Word spelling involves a distinct role of phonological awareness (blending), while name writing does not. This suggests that spelling involves recoding sound to print while name writing may make use of an orthographic form acquired through repeated exposure to seeing one's name in print. Further, bilingual children demonstrated distinct profiles in emergent literacy skills relative to a group of monolingual children depending on parent report of the amount of time they heard or spoke a minority language at home. Finally, coaching by a speech language pathologist as part of an emergent literacy professional development program enhanced preschool educators' use of interactions related to phonological awareness and the children's engagement in talk related to this predictor of early literacy ability. The thesis concludes with a discussion of the limitations of the studies as well as future directions for research (Chapter 5).
Synthesis and Size-separation of Colloidally-stable Silicon Nanocrystals for the Investigation of their Size-dependent Optical Properties
Keywords: Density Gradient Ultracentrifugation
Photoluminescence
Silicon Nanocrystals
Size-Selective Precipitation
Size-Separation

Silicon nanocrystals (ncSi) possess unique optical properties that vary predictably with crystal size, which means they can be tailored to suit specific requirements for use in optoelectronic devices and biological applications. The work presented in this thesis outlines contributions made in developing size-separation methods to obtain uniform-sized samples of colloidally-stable ncSi from non-uniform ensembles, which result from most common syntheses that produce colloidally-stable particles. Non-uniform samples of ncSi were prepared using the straightforward thermal processing of sol-gel glasses, followed by HF etching to liberate hydride-capped ncSi from an encapsulating matrix. Thermal hydrosilylation was employed to passivate the ncSi surface with both allylbenzene and 1-decene. Density gradient ultracentrifugation and size-selective precipitation methods were used to isolate size-separated ncSi, which enabled definitive characterization of size-dependent optical properties including photoluminescence (PL), PL absolute quantum yields, and PL lifetimes. A detailed investigation of the chemical reactivity of allylbenzene-capped ncSi with different gaseous atmospheres as probed by in situ luminescence spectroscopy, conducted under both continuous and intermittent illumination, helped elucidate the roles of O2, H2O and mixtures of O2/H2O, with respect to oxidation of ncSi as a function of size. The results presented in this thesis have played a crucial role towards obtaining a complete understanding of ncSi, a most promising material, and providing vital information that will aid in developing and tailoring perceived applications in advanced materials and biomedical devices.
Virtuosos of the Ordinary: Comparative Interpretations of Daoist and Stoic Thought
Keywords: Daoism
Ethics
Stoicism

"Virtuosity in the ordinary" is an idea, attributed by this work to the ancient Stoicism and Zhuangzi's Daoism, that it is possible to achieve an extraordinary excellence in the realm of ordinary, mundane activities. This possibility is based on the view that there is a perfect fit between one's psychological and cognitive faculties and the structure of reality. By achieving such a perfection, one not only achieves personal fulfillment but also fulfills one's role in the overarching scheme of things. Within this interpretive framework, the work reconstructs two different versions of this idea in two different cultural contexts. By so doing, it pursues two goals. First, it seeks to use the comparative perspective to engage with existing interpretations of Stoicism and Zhuangzi's Daoism. In particular, it challenges the view that Stoics were rigid moralists utterly indifferent towards the ordinary world and values, and the tendency to understand Zhuangzi as an anti-rationalist. Second, it tries to interpret the differences between Stoic and Daoist versions of the virtuosity in the ordinary in light of larger divergences between the two intellectual traditions. It suggests that the overarching conceptual dichotomy in the ancient Greek and Roman tradition was that of rational and non-rational, while in the Chinese tradition it was that of artificial and natural.
An Investigation of Complementary Autonomic Measurements as an Approach to Improve Single-switch Access for Children with Profound Physical Disabilities
Keywords: Access technology
Cerebral palsy
Interaction errors
Paediatric rehabilitation
Physiological measurements

The combination of single-switch access and scanning is arguably one of the most versatile solutions in restoring communication and environmental control for children with profound physical disabilities. Erroneous switch behaviours due to failures in decoding functional intent heighten the risk of declining use and technology abandonment, especially if those errors restrict participation. Complementary information about the user's internalized monitoring of single-switch scanning and reactions to switch output could lead to strategies for managing error instances as opposed to merely, and perhaps futilely, preventing them. This thesis investigates the possibility of using measurements of a switch user's autonomic nervous activity during single-switch scanning as complementary information. The thesis comprises three studies. The first study explains a process involving learning and mastery behaviours, whereby repeated exposure to isolated error instances can diminish the confidence of a proficient switch user and instill apprehension towards switch use. The findings of this study strongly motivate the need for augmenting single-switch access with complementary information to manage error instances. The second study demonstrates, at an ensemble level, the existence of autonomic responses (cardiac deceleration and increased phasic electrodermal activity) to correct, accidental and missed switch activations by three paediatric single-switch users. The third study analyzes a representation of the cardiac activity measurement (line length time series derived from the empirical mode decomposition of the inter-beat interval time series) that can independently track the state of single-switch scanning on an individual switch event basis, without any prior knowledge of the location of scanning events and dwell time. These findings encourage further study of autonomic measures as complementary information channels to enhance single-switch access.
The Application of Feedback in Secondary School Classrooms: Teaching and Learning in Applied Level Mathematics
Keywords: Applied Level Mathematics
Feedback
Grade 9
Metacognition
Secondary
Self-regulation

The power of feedback has been established as an effective support for teaching and learning. The formative nature of feedback has been shown to have positive but varied effects for the learning and self-regulation of students. The varied effect of feedback has important implications for teachers to support the needs of students in grade 9 applied level mathematics. The present study examined the instructional strategies that teachers use to help students seek, evaluate and apply feedback in mathematics. The investigation also focused on the determining the strategies that teachers use to support the self-regulation of students and overcome pedagogical barriers in applied level mathematics. Teachers of grade 9 applied level mathematics were involved in collaborative inquiry to discern their professional practices and to discuss effective means of providing feedback to students. Three interviews form the basis of a descriptive case study to investigate the factors that teachers perceive as important to the provision of feedback in the teaching and learning of grade 9 applied level mathematics. The findings of the investigation reveal that teachers in grade 9 applied level mathematics perceive students to experience significant difficulty evaluating the merits of feedback. The lack of basic skills and proficiency in mathematics provide significant limitations on the ability of students in applied level classrooms to judge the value of feedback. The findings show that students in applied level classrooms have experienced many years of failure which detracts from their confidence and success in learning. The study identifies affective supports that are necessary to create a safe learning environment and the program planning that teachers use to support the mathematical communications of students. The findings show that teachers value the immediacy of feedback, establish a learning environment that is conducive to frequent rehearsal and practice and require students to justify their understanding by focusing on oral communication. The findings also highlight discrepant results from the body of research on the use of feedback. The study demonstrates that teachers may be aware of the value of strategies that support metacognition, however, the use of learning goals, success criteria and manipulatives to support feedback and communications may not be intentionally applied.
Primitive Neural Stem Cells in the Mouse Brain
Keywords: neural stem cells

Neural stem cells (NSCs) reside in the tissue lining the lateral ventricles of the adult mouse brain. At the top of the hierarchy are primitive (p)NSCs that arise in advance of definitive (d)NSCs embryonically. After the discovery that pNSCs persist in the adult mouse brain, I sought out to characterize pNSCs and determine whether they express the pluripotency gene Oct4 in the adult brain as the do embryonically. Next, I addressed the cell cycle time of pNSCs and whether they are activated to proliferate to repopulate dNSCs after dNSC and downstream progenitor ablation. Finally, I identified cell type specific markers of pNSCs and pharmacological methods to selectively target and activate endogenous pNSCs. These selective markers can be used for future studies to enrich for pNSCs and to develop future therapies to target pNSCs endogenously. Together, this thesis presents evidence that pNSCs are an Oct4-expressing, reserve population at the top of the NSC hierarchy capable of repopulating dNSCs.
Homeland Activism, Public Performance, and the Construction of Identity: An Examination of Greek Canadian Transnationalism, 1900s-1990s
Keywords: diaspora
Greek Canadians
homeland activism
political protest
public performance
transnationalism

This thesis examines cases of Greek Canadian transnationalism throughout the twentieth century. It utilizes a large database of oral interviews, newspaper records, both Greek and English language publications, and a variety of archival documents, including government correspondence, community records, and Royal Canadian Mounted Police files, to investigate the ways that Greek immigrants, and to a lesser extent their Canadian-born children, responded to political and humanitarian crises in Greece and engaged in homeland practices. Focusing on Greek Canadians' use of public performances, namely cultural presentations, humanitarian relief campaigns, commemorative celebrations, and public protests, in mobilizing broader support for their cause, I argue that such transnational acts nurtured a diasporic space that drew Greek Canadians into a public dialogue on the meaning of Greek immigrant identity. Mediated by immigrant elites and shaped by particular conditions in both Greece and Canada, Greek Canadians' transnationalism contributed significant material and symbolic aid to Greece, but also served as a vehicle for them to privilege and project their ethnic and national identities on a public stage. Though, to be clear, no single narrative emerged, as multiple authors professed to represent the majority of Greeks even while women and working-class men were relegated to less public roles and, often, engagement in homeland affairs engendered political and ideological strife among Greeks. While chapter one addresses various forms of public and private transnationalism among early twentieth century Greek immigrants, each of the remaining chapters provide a detailed case study of homeland activism. Chapter two examines Greek Canadians' humanitarian aid work in the Greek War Relief Fund during the Second World War, and chapters three and four focus on Greeks' political engagement in response to the right-wing military dictatorship and competing claims over Macedonia. In exploring how homeland practices and politics became localized in the diaspora, this thesis demonstrates the significance of transnationalism in the construction of Greek immigrant identity.
How Does Diversity Impact Innovation in Research Network? A Multilevel Study of the GRAND NCE
Keywords: Diversity
Innovation
Motivation
Multidisciplinary collaboration
Multilevel networks
Scholarly network

In this dissertation, I study the interplay between network structure and group characteristics of diversity as well as the motivation of members in a collaborative research network and the innovative outcomes produced by its members. To achieve this goal, I examine GRAND (an acronym for Graphics, Animation and New Media), a Canadian network with over 200 researchers funded by the Canadian government. I develop a framework which combines multilevel models and social network analysis, in order to understand how memberships in multiple projects, disciplinary diversity in research projects, members' motivation to participate in multidisciplinary collaborations (MDCs), and prior collaborations influence GRAND members' cross-disciplinary collaborations as well as creation of innovation. I conducted qualitative analysis to explain the complexity of MDCs by discussing the difficulties brought about by disciplinary diversity, the disciplinary differences in MDC norms, researchers' perceptions of disciplinary boundaries, and the various types of MDC activities. The findings show that the network structure and multidisciplinary culture emphasized by GRAND indeed foster intellectual interactions cross disciplinary boundaries. However, disciplinary diversity does not directly lead to innovation. Instead, its effect is mediated by diversity in researchers' ego networks. Furthermore, motivation also has a strong effect on diversity in ego networks rather than on innovative outcomes. In other words, diversity in interaction rather than diversity in composition creates innovation, and the former type of diversity can be increased by a high level of motivation and membership in multiple projects. This study has confirmed the strengths of network form of organizations. The findings suggest that allowing members to be involved in multiple work units provides them with more opportunities to interact with their colleagues from various disciplines and thus, produce innovative outcomes.