VictorJuiz/thesis huggingface dataset:
The Comparative Performance of Micro- and Nano-topographically Complex Endosseous Implant Surfaces in Normoglycemic and Hyperglycemic Subjects

Endosseous implants have notably high success rates, yet a small percentage of implants still fail for unidentified reasons. Recent literature points to hyperglycemia, resulting from untreated or undiagnosed diabetes, as a possible contraindication in an otherwise apparently healthy population. To investigate the effect of surface design on peri-implant healing in the presence of hyperglycemia, STZ-treated rats were implanted with custom rectangular implants of two surface topographies: grit blasted (GB) and grit-blast with a calcium phosphate nanotopography (GB-DCD). Tensile testing was conducted at 5, 7, and 9 days post-operative. Results demonstrated hyperglycemia to delay early stages of the peri-implant healing. Contact osteogenesis was increased along the GB-DCD surface, even in an environment of uncontrolled hyperglycemia, and the GB-DCD surface outperformed the GB surface in both healthy and hyperglycemic animals, showing peri-implant bone matured more rapidly on nanotopographically complex surfaces, even in the presence of uncontrolled hyperglycemia.

Keywords: Nano Surface
Mechanical Testing
Bone
Bone-bonding
Osteoconduction
Contact osteogenesis
de novo bone formation
Implant design
Titanium
Calcium phosphate
Hyperglycemia
Diabetes
Drill defect
Bone healing
Micro Surface
Surface topography
Advisor: Davies, John Edward
A Holocene Paleolimnological Record from the Turkey Lakes Watershed Long-term Monitoring Site in Central Ontario, Canada

A Holocene lake sediment record spanning 7300 years from Wishart Lake, in the Turkey Lakes Watershed central Ontario, was produced to determine the main drivers of long-term change in the lake ecosystem. The mid-Holocene sediments are dominated by benthic diatoms, around 4000 yrs BP, diatoms in the genera Cyclotella and Tabellaria increase. Comparisons with nearby pollen records show that changes in local vegetation and diatom assemblages occurred synchronously, suggesting a response to nutrient changes caused by vegetation succession. The most recent sediments, dated using activity of 210Pb and the Ambrosia pollen rise, show increases in planktonic Cyclotella spp., particularly around the Ambrosia rise (1880 AD). Thus, the diatom changes in the recent sediments suggest a response to multiple stressors. However, due to some buffering capacity in watershed soil, recent acidification of the lake has not taken place despite nearby industrial air pollution, tracked since 1980 by an on-site monitoring program.

Keywords: paleoclimatology
diatoms
acidification
chrysophytes
climate change
multiple stressors
Algoma region
aquatic ecology
Advisor: Finkelstein, Sarah A.
An Exploration of Cell Receptor Labeling via Dark Field Imaging and Quantifying Densely Bound SERS Labels via Raman Signal Strength

Two experiments explore the application of plasmonic nanoparticles to cellular pathology. The first devised a platform by which gold-silver nanoparticles act as differentiable labels for cell surface receptors under dark field imaging. By conjugating particles of various constitutions with receptor-targeting antibodies, particles scatter characteristically according to their plasmon peak. The second experiment programmed receptor placement via the patterning of two substrates and used the binding of SERS nanoparticles to explore the quantification of such targets at high-density. On one substrate, anchor pairs established receptors at specified distances in order to define the relationship between scattering intensity and the distance between SERS particles. On the second, anchor regions are filled with increasing densities of receptors and the particle-saturated substrates are probed to relate scattering intensity to particle density. This should discover the density-threshold between linear and non-linear scattering and inform the quantification of particles in the exponential density regime.

Keywords: nanoparticles
SERS
dark field imaging
diagnostic labels
electron beam patterning
plasmonics
Raman scattering
antibody targetting
Advisor: Walker, Gilbert C.
Evaluation of the Toronto Palatal Lift Prosthesis for Patients with Hypernasal Resonance Disorders

Statement of the problem. Hypernasality resulting from velopharyngeal insufficiency or incompetency is a resonance disorder that has negative consequences for speech production and intelligibility of afflicted individuals. Purpose. The purpose of this prospective study is to ascertain if a palatal lift prosthesis with a generic silicon velar lamina, termed the Toronto Palatal Lift Prosthesis (TPLP), can assist velopharyngeal valve function to reduce hypernasality in patients. Methods. A prospective study of six patients treated with the TPLP was compared by the outcome measures of nasalance scores, perceptual evaluations, and patient satisfaction to those obtained using a contemporary acrylic palatal lift prosthesis. Results. The six patients had varying degrees of reduction in hypernasality and acceptance of the TPLP. Conclusion. On the basis of this preliminary study on the TPLP it is possible to fabricate a palatal lift prosthesis with a generic silicon velar lamina that reduces hypernasality in select patients.

Keywords: palatal lift
hypernasality
speech aid
velopharyngeal incompetence
velopharyngeal insufficiency
maxillofacial prosthetics
speech disorders
removable dental prosthetics
Advisor: Bressmann, Tim
Aqueous Phase Photo-oxidation of Water Soluble Organic Compounds (WSOC): Kinetics, Mechanisms and Method Characterization

The aqueous phase photo-oxidation of water soluble organic compounds (WSOC) extracted from α-pinene ozonolysis secondary organic aerosol (SOA) was investigated using high resolution time-of-flight chemical ionization mass spectrometry (CI-ToFMS). The results have shown that WSOC get more functionalized and fragmented as the reaction proceeds. The capabilities of three reagent ions, were assessed; specifically, (H2O)nH+ ionizes organic compounds with carbon oxidation state (OSC) ≤ 1.3, whereas CH3C(O)O- and I(H2O)n- ionize highly oxygenated organics with OSC up to 4, with I(H2O)n- showing more selectivity. The aqueous phase OH oxidation of cis-pinonic acid and tricarballylic acid (a surrogate for 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), recognized as a tracer of α-pinene SOA) were also studied. The respective rate constants at 301 K were measured to be 3.4(±0.5)×10^9 M^-1s^-1 at pH=2 and 3.1(±0.3)×10^8 M^-1s^-1 at pH=4.6. This work also illustrates possible aqueous phase mechanism for MBTCA formation from cis-pinonic oxidation.

Keywords: atmospheric chemistry
organics
oxidation
aqueous phase
SOA
aerosols
mechanism
kinetics
CI-ToFMS
reagent ions
MBTCA
pinonic acid
Advisor: Abbatt, Jonathan P. D.
Analyzing Intact Meiocytes of Wild-type Arabidopsis thaliana and Meiotic Mutants, ahp2 and spo11-2-2, using Confocal Microscopy

The purpose of this study was to assess the utility of confocal microscopy to examine nuclear organization and chromosome pairing for intact Arabidopsis male meiocytes. The efficiency of the confocal technique was evaluated by analyzing wild-type nuclei throughout meiosis. Early-mid leptotene meiocytes demonstrated the presence of several propidium iodide stained signals within the nucleolus prior to the onset of chromosome pairing in zygotene. Pachytene chromosomes were completely paired and were traced to confirm the Arabidopsis karyotype. Additionally, the confocal technique was employed on meiotic mutants, ahp2 and spo11-2-2, to characterize their meiotic defects. Leptotene ahp2 meiocytes and zygotene meiocytes in both meiotic mutants appeared normal. In contrast, pachytene meiocytes in ahp2 and spo11-2-2 mutants demonstrated a wide-spread lack of paired chromosomes. Despite this general lack of pairing, a small amount of chromosome pairing was detected on the short arms of NOR-bearing chromosomes 2 and 4 in ahp2 and spo11-2-2 mutants.

Keywords: Arabidopsis
Confocal Microscope
ahp2
spo11
Advisor: Hasenkampf, Clare
Functionalization of the Photonic Crystal Slab Biosensors

This work describes the functionalization and testing of Si3N 4-based photonic crystal slabs (PCS) for label-free biosensing. PCS support optical resonance modes that are sensitive to the local re- fractive index. Knowing that surface binding events change the local RI, analyte binding to the activated sensor can be detected. Various functionalization recipes were tried, and one was preferred for the biosensing experiments due to its higher yield and uniformity. Additionally, thickness of the topmost sensor layer was studied to assess biosensor performance quantified through sensitivity metrics. On the systems level, a reusable clamping system and customized micro uidic channels were designed, fabricated, and implemented on the PCS biosensors to enable device refurbishment. Proof-of-principle biodetection experiments were carried out using the established functionaliza- tion protocol on the in-house fabricated PCS. Conjugation of streptavidin and bovine serum albumin to the sensor surface was observed through wavelength shifts of the resonant modes.

Keywords: photonic crystals
biosensing
surface chemistry
label-free sensing
Advisor: Levi, Ofer
Genomic Characterization of Pleural Solitary Fibrous Tumours

Pleural solitary fibrous tumours (pSFTs) are uncommon soft tissue tumours of the pleura. that may recur and contribute to the patients’ demise. We analyzed a group of benign and malignant pSFTs for copy number alterations and for common mutations in oncogenes and tumour-suppressor genes. Malignant SFTs demonstrated more copy number alterations, especially 8q (c-myc) gain, 10q (include PTEN) loss, and 13q (Rb1) loss. Mutations were rare in this limited study.

Keywords: Solitary fibrous tumours
copy number variations
mutation
paxillin
Advisor: Tsao, Ming-Sound
The Nickel-responsive Binding and Regulation of Two Novel Helicobacter pylori NikR–targeted Genes

Nickel is an essential transition metal for the virulence and survival of Helicobacter pylori in the acidic human stomach. The nickel– and proton– dependent transcriptional regulator HpNikR is important for maintaining nickel homeostasis inside the cytosol by regulating multiple H. pylori genes. A previous ChIP-sequencing experiment with H. pylori G27 and HpNikR identified two novel genes currently annotated as putative iron-transporters, HpG27_866 and HpG27_1499. In vitro DNA-binding assays with the promoter sequences of the two genes revealed nickel-dependent HpNikR binding with an affinity of ~10-7 M. The recognition site of HpNikR was identified on HpG27_1499 by footprinting assays, which loosely correlates with the HpNikR pseudo-consensus sequence. Furthermore, HpG27_1499 transcription showed nickel-dependent repression in WT H. pylori, and no changes in an isogenic ΔnikR strain. These data suggest that HpG27_1499 could be a nickel importer that is regulated by HpNikR in a nickel-responsive manner.

Keywords: Helicobacter pylori
nickel
HpNikR
DNaseI footprinting
DNA mobility shift assay
qRT-PCR
transcription factor
metalloprotein
Advisor: Zamble, Deborah
Motivational Effects of Gamification of Piano Instruction and Practice

Gamification refers to the process whereby game design and game mechanics are applied in non-game contexts to influence behaviour. This research study explores the effects of gamification on piano students' practice of technical elements such as scales, chords, and arpeggios, within the private lesson environment. A control and a treatment group of 10 piano students each were formed across two different private piano studios. A game called Technique Tower was designed for the treatment group, in which the players experienced game elements such as rewards (points, badges, and levels), avatars, and the sharing of their progress in an online social context. Gamification was found to have a positive effect on the number of technical elements students mastered, and on their attitude toward practicing technical elements, while self-efficacy levels were not affected. The educational implications for this finding are discussed.

Keywords: educational technology, music, piano, gaming, gamification, motivation, learning, online, technical development, technique, scales
Advisor: Woodruff, Earl
Exploring Ontario Grade Ten Students' Decisions to Select or Reject School Physics

Declining science enrolment, with the greatest decline in physics, has generated concern surrounding students’ future abilities to function in an increasingly scientific and technology-focused society. In an attempt to understand why students select or reject physics, a multiphase qualitative phenomenological study was designed, with the following questions: (a) Why do students select or reject physics courses? (b) What role does physics identity play in student course selection? (c) What other factors, extrinsic or intrinsic, affect their choices to pursue physics? Questionnaire, interview, focus group and student drawing data indicate students reject physics when it is not required for further studies in university based on their belief that physics is a difficult math-reliant subject, they do not identify with physics, and they are unsure what physics is and what they would study. Recommendations include teaching physics aligned with students’ interests, and teaching physics to promote a positive physics student identity.

Keywords: physics identity
secondary school
phenomenology
Advisor: Pedretti, Erminia
Efficacy of Reward Allotment on Children's Motivation and Learning: Toward a Potential Means of Developing 21st Century Knowledge Building Skills

The present study assesses the effects of reward allotment for a highly motivating game through the examination of students’ variations in response to different schedules of reinforcement. Fifty-four Chinese children from preschool to grade three participated by playing a number-matching game on Sifteo cubes. Two types of reward allotment—a 25%-chance-of-winning reinforcement schedule, and an escalating 25-75% reinforcement schedule—were examined in the number-matching game. Overall, the results proved that both reinforcement schedules effectively sustained children’s motivation in playing the game. In this experimental study I hypothesized that if the findings could be replicated in an extremely simple game that does not have the manifold array of additional motivators found in commercial successful video games, we could have a powerful motivating element to be used in educational games, given that digital games are potentially beneficial in helping students to develop 21st-century skills such as collaborative and problem-solving skills.

Keywords: Digital Game
Educational Games
Sifteo Cubes
Intrinsic/Extrinsic Motivation
Reinforcement Schedules
Engagement
21st Century Knowledge Building Skills
Advisor: Woodruff, Earl
An Exploratory Study of Adolescent Moral Identity and its Relations to Social Justice Awareness

The present mixed-methods study examined adolescents’ moral identity development and its relation to their awareness of problems of social justice. Fifty-eight inner-city adolescents in Grades 9 and 12 ranked personal values according to their self-relevance or importance and a sub-sample also provided responses to interview questions that were coded qualitatively for maturity of moral identity. A written questionnaire assessed the adolescents’ awareness of issues of racism, sexism, and classism. It was found that adolescents held moral values at significantly higher levels of importance than non-moral values, with no differences between grades. However, trends suggested that females placed somewhat greater emphasis on moral values in terms of centrality or importance to the self and also expressed slightly more mature explanatory responses than males. Adolescents’ moral identity and social justice awareness were not correlated. These findings highlight the need to foster the development of morally motivated, socially aware individuals.

Keywords: adolescent
moral identity
social justice
Advisor: Arnold, Mary Louise
Consciousness and Praxis: Informal Learning in Social Movements

The no borders movement has been an important site of anti-imperialist resistance, and as such it provides a valuable point of entry into problematizing the contradictions that constitute the relations of consciousness, praxis and ideology. By tracing the recent history of no borders activism in relation to the intensification of neoliberalism, and the prevalence of diffuse models of power, the analysis illustrates the ways in which critical praxis has been limited by the current milieu. Working from an anti-racist feminist perspective I utilize examples drawn from no borders activism to demonstrate the very real limits of informal and incidental learning in social movements. The analysis argues against the supplanting of consciousness with subjectivity as a way to avoid the problems associated with structuralist analysis. Instead, I have suggested that critical education for social action requires a dialectical engagement with the social relations that we live in, contest and transform.

Keywords: Informal learning
Anti-racist feminism
Advisor: Mojab, Shahrzad
Constructing and Assessing Individualized Secondary Mathematics Knowledge: A Case Study of Three Teachers using Laptop Computers

This study examines how secondary school mathematics teachers adapt their teaching practice to integrate the laptop into classroom instruction and how the implementation is effective in meeting the individual needs of students. A case study of three mathematics teachers at a co-educational, independent International Baccalaureate (IB) World School in Ontario was conducted. Through interviews and classroom observation sessions, five major findings emerged: (1) reflection on improving teaching practice is necessary to successfully meet learning goals; (2) the teacher’s role is to facilitate the construction of knowledge; (3) the classroom is a rich learning environment where the students feel comfortable taking risks with technology and analyzing and discussing relevant real-world connections; (4) a variety of tasks and strategies must be employed to engage students interest, relate to their lives, elicit discussion and meet student ability and aptitude; and (5) laptops and/or tablets provide opportunities for the construction of knowledge.

Keywords: Mathematics
Secondary
Laptops
Individual needs
Advisor: McDougall, Douglas Emerson
Higher Education Policy-building in Kurdistan Region of Iraq: Perceptions of University Representatives

This study examines the perceptions and operational assumptions of university representatives with regard to the new higher education policy-making in Kurdistan. It attempts to explore the development and implementation of the policy’s first priority, the aim to bridge the gap between quality and quantity in higher education. A mixed-methods case study research is employed by applying qualitative methods in a series of interviews carried out with nine faculty members from a University in the Kurdistan Region. The interviews were followed by a survey of a representative sample of 305 faculty members from all faculties of the university, with responses from 148. Both research methods explored the implementation of quality assurance initiatives under the quality teaching reforms. The aim is to identify what type of quality culture in higher education is being encouraged and if it will enable higher education to serve as a bridge for Kurdistan to the global knowledge economy.

Keywords: Quality Culture
Quality Assurance
Quality
Knowledge Economy
Higher Education Policy Policy
Kurdistan-Iraq
Neoliberalism
Democracy
Advisor: Hayhoe, Ruth
Lost Identities: The Credentialing of Immigrant Engineers from the Former Soviet Union in Ontario

This study examines how the credentialing process for foreign-trained engineers implemented by the Professional Engineers of Ontario (PEO) affects newcomers from the former Soviet Union and Russia seeking to re-enter the profession. Applying critical sociological theory to its analysis of data generated through qualitative methods, it highlights how the ethnic, racial, and educational background of applicants shapes their encounters with the PEO and the outcome of their applications. It sheds light on the crises of identity and in social and family relations experienced by these individuals, as well as the lack of supporting services to address such crises. This study contributes to existing literature on the subject by taking a new approach to the credentialing of foreign-trained engineers in Ontario, focusing on the perspective of individual applicants rather than structural factors. It concludes with specific recommendations on how the process could be improved and the regulatory body itself reformed.

Keywords: internationally trained engineers
credentialing
regulatory body
identity crisis
Advisor: Todorova, Miglena
What is my Pedagogy? Shifting Understandings and Practices of Teachers in Government Schools in Kashmir, India

India’s pledge towards universalization of elementary education by 2015 is a desirable goal. Having achieved progress towards universal accessibility to schooling, the problem of providing quality schooling through a necessary paradigm shift, is still a major challenge. This qualitative research study seeks to portray the nature of pedagogy in four elementary classrooms in Srinagar, Kashmir and understand its shifting nature with reference to the National Curriculum Framework (2005). Specifically, this study examines teachers’ classroom pedagogical practices, their understandings of pedagogy, the ways they encourage and manage student participation in classroom and the level of support and training they receive from government agencies. The findings of this study will have implications for both teachers and students, their specific roles, their understanding of pedagogy, classroom practices and more importantly students. This study recommends ‘contextually suitable’ pedagogical methods, informing teachers about effective teaching strategies, and outlining specific classroom participation strategies for students.

Keywords: Pedagogy
Traditional teacher-centered pedagogy
Progressive student-centered pedagogy
Critical pedagogy
National Curriculum Framework
Jammu and Kashmir
Advisor: Evans, Mark
Administrator Perceptions of Ontario's Teacher Performance Appraisal Process

This study examines the views of administrators (i.e. principals and vice-principals) in Ontario, Canada with regards to the province’s Teacher Performance Appraisal process. A total of 178 responses were collected to a web-based survey that examined five areas: 1) Preparation and training; 2) Classroom observations; 3) Preparing the formal evaluation; 4) The impact on teaching practice; and 5) Improving the process. Results indicate that administrators did not receive extensive training and of the training they did receive, most did not find it very useful. Most administrators did not feel strongly that the classroom observations adequately assessed teacher practice and most did not feel that there had been substantial improvement in teacher practice in their schools as a result of the process. The most common suggestions for improvement were to have more classroom observations, some of which are unannounced; evaluate teachers more frequently; and have more than two rating categories.

Keywords: teacher evaluation
school administration
Advisor: Bascia, Nina