VictorJuiz/thesis huggingface dataset:
Teaching Versatility to Post-secondary Violin Students
Keywords: Violin
Versatility
Specialization
music
non-classical
post-secondary
glenn gould school
humber college
york university
university of toronto
strings
performance
curriculum
education
creativity

In this dissertation I examine arguments for teaching post-secondary violin students to be versatile musicians rather than specialists in one genre or area of music. In order to do this, I assess the professional and educational opportunities in Toronto based on interviews with nine professional violinists as well as teachers and administrators at four institutions that offer post-secondary instruction in violin performance. To supplement information gathered through interviews, violinists and violists performing with the National Ballet of Canada and the Esprit Orchestra were asked to respond to a questionnaire regarding their training and work experiences. Data collected through fieldwork is contextualized by an analysis of scholarly writing, periodicals and websites on the topic of current post-secondary music curriculum and pedagogy methods. Throughout the dissertation, I build the case that, despite strong opinions and many years of pedagogy that emphasize the contrary, versatility provides many advantages to professional violinists when compared to specialization. In order to maximize the benefits of versatility in a professional career, I draw on Benjamin Brinner&rsquo;s notion of core competences (Brinner 1995) to posit the skills necessary for professional musicians to pursue successful, enduring careers in Toronto. Applying these core competences to an analysis of violinists&rsquo; training, I explore the violin curriculum of post-secondary music schools in Toronto: The University of Toronto, the Glenn Gould School, Humber College, and York University to examine how students are being trained. In particular, I query how students are being prepared to be profession violinists with a focus on whetherthey are being prepared to be versatile musicians or specialists in one style. I conclude by offering recommendations as to how to better teach versatility based on the findings of the previous chapters. I explain that versatility can be nurtured in the school environment through teacher training and curricular changes that emphasize informal learning approaches, shifts in conventionally held assumptions about musical value and career success, and by encouraging exploration and improvisation as a basis of developing creativity.
Exploring an HIstorical Transition in Early Childhood Education in Ontario
Keywords: Early Childhood
Leadership
Training and Education

This predominantly qualitative study looks at the current changes in early childhood education in Ontario, Canada from an early childhood education leadership perspective. The analysis and recommendations resulting from my dissertation adds to the growing body of work examining the rapidly changing landscape of the early years. My dissertation utilizes a constructivist lens to reconstruct perspectives surrounding matters of importance in a field that is on the cusp of obtaining true professional recognition. With the advent of a self-regulating body (College of Early Childhood Educators) and a shift in management from the Ministry of Children and Youth Services to the Ministry of Education, the study highlights some of the changes occurring in the early years sector, both institutionally and professionally. The ensuing data was collected through 35 interviews of early years champions and 167 surveys from various early years teacher-educators and practitioners, revealing strong topics of discussion that add to the cacophony of voices heralding demands that the early childhood educator be perceived and treated as an equal participant in the education system. Of the 8 themes that emerged from the data analyzed, 3 were the focus of this study. The first theme focused on leadership, including characteristics of leaders and themes of emerging leadership; the second on professionalization of the early years sector (Feeney, 2012): for example, consistency in terminology, pay equity, universality, and issues regarding the current infrastructure; and the third theme investigated was intellectualization as part of the professional process: for instance, current curriculum focus, higher-learning demands, ongoing learning, the value of lab schools, faculty responsibilities, and specialization as a means of differentiated staffing (Zigler, Gilliam, & Barnett, 2011). This study also includes miniature profiles of the early years leaders interviewed, and a synopsis of their personal journeys to leadership. In the concluding chapter, the recommendations presented suggest various ways that current and emerging early years leaders can make positive impact within this transforming sector. Empowerment of self, recognition of professional status, and a view to the long-term visioning of education provides the impetus for change.
Formal Caregivers Assisting Residents with Moderate and Severe Alzheimer’s Disease: Investigating the use of Communication Strategies during Activities of Daily Living
Keywords: Alzheimer's disease
Caregivers
Communication
Activities of daily living

The prevalence of Alzheimer’s disease (AD) in Canada is on the rise, creating the need for evidence-based care practices designed to support individuals with AD and their care providers. Declines in memory, language, visual-spatial, executive abilities, and functional capacity associated with AD create the need for caregiver assistance during the completion of activities of daily living (ADLs). Unfortunately, assisting individuals with more advanced stages of AD is further complicated by communication breakdowns that occur in the dyad (i.e., caregiver and the individual with AD) established to meet a common goal: to complete ADLs. Clinically recommended communication strategies are the current solution used to support caregivers interacting with individuals with AD. However, there are limitations to these recommendations, including that the majority are based on caregiver experience, few are supported by empirical research, and little is known about which strategies are effective when assisting individuals with moderate to severe AD specifically during the context of completing ADLs. This dissertation presents novel research studies that systematically examined formal caregivers’ use of communication strategies while successfully assisting residents with moderate and severe AD during the completion of a representative ADL. Two observational studies and one focus group interview study were conducted to address our hypotheses and research objectives. Key findings from the studies comprising this dissertation were: (1) caregivers used a variety of verbal and nonverbal task-focused communication strategies when successfully assisting residents with AD during the completion of a representative ADL; (2) the task-focused communication strategies caregivers most frequently used were supported by empirical literature and included the use of one direction or idea (i.e., proposition) at a time, closed-ended questions, and paraphrased repetition; (3) when assisting residents with severe AD, caregivers used the resident’s name, one proposition, and paraphrased repetition significantly more than when assisting residents with moderate AD; and (4) the communication strategies that caregivers perceived to use in their care practice indicate that person-centered dementia care is a central aspect to facilitating the completion of ADLs. This research is an important step towards the development of evidence-based communication strategies for caregivers assisting individuals with AD during ADLs.
Technological Change in the Early Middle Pleistocene: The Onset of the Middle Stone Age at Kathu Pan 1, Northern Cape, South Africa
Keywords: Middle Stone Age
South Africa
Lithic Analysis
Human Evolution

This dissertation describes the technological behaviors represented by the ~500-thousand-year-old stratum 4a lithic assemblage from Kathu Pan 1 (KP1), Northern Cape, South Africa, and situates new evidence from this site into evolutionary context. The findings highlight the significance of the early Middle Pleistocene in Africa for understanding behavioral evolution in later Homo. The stratum 4a assemblage at KP1 represents a mainly flake and blade-based industry that employed multiple strategies to produce blanks that were retouched into a variety of forms, including unifacially retouched points. Diverse core reduction strategies at KP1 suggests that KP1 hominins were flexible to the demands of local raw materials, consistent with increased degrees of ‘behavioral variability’ and adaptability. Several lines of evidence indicate that the KP1 points were used as spear tips. Points from sites ~300 thousand years ago (ka) and younger were often used as weapon tips, and evidence for this behavior can now be pushed back to ~500 ka, with important implications for cognition and social behavior among early Middle Pleistocene hominins. Raw materials in the KP1 assemblage were acquired from multiple local sources. Based on comparisons with a sample from the underlying stratum 4b Acheulean assemblage, the stratum 4a assemblage does not exhibit major changes in the kinds or quality of raw material exploited; thus, the technological changes represented by the stratum 4a assemblage are not explained by changes in raw material. New evidence from KP1 poses problems for current models that link the appearance of Middle Stone Age technologies to speciation and dispersion ~300 ka. Middle Stone Age technologies appear in the African archaeological record by ~500 ka. The new timing for the origins of Middle Stone Age technologies provides a parsimonious explanation for technological similarities between the lithic assemblages of Neanderthals and modern Homo sapiens, who share a common ancestor in the early Middle Pleistocene. Limits imposed by the nature of the African archaeological record and chronometric analyses may explain why the antiquity of these technological changes was not previously recognized.
Proximity to Potential Sources and Mountain Cold-trapping of Semi-volatile Organic Contaminants
Keywords: semi-volatile
contaminants
airshed
trajectory
mountain
cold-trapping
pertingency
receptor model
back-trajectory
polycyclic aromatic hydrocarbon
polychlorinated biphenyl
box model
brominated flame retardant
BFR
PCB
PAH
SVOC
geodesic
trajectory statistic

If sufficiently persistent, semi-volatile organic contaminants (SVOCs) can travel long distances through the atmosphere from their points of release and become concentrated in cold, remote regions. As air is sampled for SVOCs to establish both their presence and the success of emission reduction efforts, it becomes helpful to determine sampling site proximity to sources and the origin of the sampled air masses. Comparing three increasingly sophisticated methods for quantifying source proximity of sampling locations, it was judged necessary to account for the actual history of the sampled air through construction of an airshed, especially if wind is highly directional and population distribution is very non-uniform. The airshed concept was improved upon by introducing a ‘geodesic’ grid of equally spaced cells, rather than a simple latitude/longitude grid, to avoid distortion near Earth’s poles and to allow for the comparison of airshed shapes. Assuming that a perfectly round airshed reveals no information about sources allows the significance of each cell of an airshed to be judged based on its departure from roundness. Combining air-mass histories with a 2 year-long series of SVOC air concentrations at Little Fox Lake in Canada’s Yukon Territory did not identify distinct source regions for most analytes, although γ-hexachlorocyclohexane appears to originate broadly in north-eastern Russia and/or Alaska. Based on this remoteness from sources, the site is judged to be well suited to monitor changes in the hemispheric background concentrations of SVOCs. A model-based exploration revealed wet-gaseous deposition as the dominant process responsible for cold-trapping SVOCs in mountain soils. Such cold trapping is particularly effective if precipitation rate increases with altitude and if temperature differences along the mountain are large. Considerable sensitivity of the modeled extent of cold-trapping to parameters as diverse as scale, mean temperature, atmospheric particle concentration and time relative to emission maxima is consistent with the wide variety of observed enrichment behaviour. Concentration gradients of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in air and soil measured on four Western Canadian mountains with variable distance from sources revealed source proximity as the main driver of concentrations at both the whole-mountain scale and along individual mountain transects.
Digitally Controlled DC-DC Converters with Fast and Smooth Load Transient Response
Keywords: dc-dc converter
digital control
switch mode power supply
efficiency
transient response

Modern switch-mode power supplies (SMPS) used for point-of-load (PoL) applications need to meet increasingly stringent requirements on voltage regulation, while minimizing physical volume and optimizing conversion efficiency. The focus of this thesis is the voltage regulation capability of low-power PoL converters during load transients. The main objective is to investigate converter topologies and control techniques that can achieve fast and smooth transient performance without significant penalty in volume and efficiency. The digital control method is used due to its ability to implement sophisticated control algorithms. The first part of this thesis investigates a dual output stages converter, with a small auxiliary output stage connected in parallel with the main output stage. While the main output stage is responsible for steady-state operation and designed to achieve optimum efficiency, the auxiliary stage is activated when a load transient occurs, to help suppress voltage deviation. Experimental results on a 6 V-to-1 V, 3W buck converter shows 35% improvement in peak transient voltage deviation while maintaining the same efficiency profile, compared to an equivalent buck converter. The second part of this thesis introduces a flyback-transformer based buck (FTBB) converter. In this topology, the conventional buck inductor is replaced with the primary winding of the flyback transformer, an extra switch, and a set of small auxiliary switches on the secondary side. During heavy-to-light load transients the inductor current is steered away from the output capacitor to the input port, achieving both energy recycling and savings due to reduced voltage overshoots. The light-to-heavy transient response is improved by reducing the equivalent inductance of the primary transformer winding to its leakage value. Compared to an equivalent buck converter, experiment results on a 6 V-to-1 V, 3 W prototype show three times smaller maximum output voltage deviation during load transients and, for frequently changing loads, about 7% decrease in power losses.
The Nature of Variation in Mutational Properties: Context-dependent Changes in Mutation Rates and Mutational Fitness Effects
Keywords: Mutations, Epistasis, DNA Repair, Drosophila melanogaster, Selection, Mutation Rate

Evaluating the evolutionary role of mutations depends on an understanding of their major properties, including their rate of origin, U, and the distribution of their fitness effects, f(s). While substantial effort has been put into measuring these properties, most studies have only examined their distributions in a single context. In nature, spontaneous mutations are likely to experience heterogeneity in genetic and environmental context, and this could lead to variation in both U and f(s). My thesis investigates the changes in U and f(s) with different genetic and environmental factors in Drosophila melanogaster, in order to elucidate the nature of context-associated variation in mutational properties. Examination of condition-dependent variation in DNA repair showed that high and low conditioned individuals differ in the use of alternative repair pathways. This could ultimately lead to variance in their heritable mutation rates. However, the assumption that condition dependence in repair arises solely due to a presumed trade-off between accuracy and the energetic costs associated with different repair pathways is too simplistic. Instead, physiological considerations appear to mediate condition-dependent changes in DNA repair. Measurements of selection on individual mutations across different genetic and environment contexts showed that context-associated changes in mutational fitness effects are common. I found that heterogeneity in fitness effects across different environments result in changes to the overall mean and variance of f(s). This does not, however, seem attributable to the degree of ‘adaptedness’ of a population to a particular environment (a prediction generated by previous theoretical analysis). On the other hand, f(s) appears to be relatively robust to differences among genotypes, with epistasis averaging close to zero. This finding suggests that genetic and environmental perturbations may affect mutations differently. Overall, my thesis represents the most rigorous empirical investigation to date of the conceptual and theoretical predictions regarding the nature of context-dependent heterogeneity in U and f(s) for multicellular eukaryotes.
Structural Characterization and Membrane Interactions of the Amyloid Peptide PrP(106-126)
Keywords: Amyloid
Structural Biology

The formation of amyloid fibrils is a key characteristic of many neurodegenerative diseases including Alzheimer’s and Parkinson’s diseases. Similarly prion diseases, those associated with the prion protein, are neurodegenerative disorders with characteristic protein aggregates accumulating in the brain of affected individuals. While fibrillar deposits of these disorders have long been associated with end-stage disease pathology, it is currently hypothesized that protein oligomers are the cytotoxic structural form of these systems. Residues 106-126 of the human prion protein have been found to form both amyloid fibrils, as well as toxic amyloid oligomers and thus provide a suitable model system. This thesis aims to describe the structures of the amyloid fibrils and oligomers formed by PrP(106-126), how they are interrelated as well as interaction with model membranes and cytotoxicity. Amyloid fibrils of PrP(106-126) contain long, unbranched filaments that contain β-sheet secondary structure and bind the amyloid-indicating dye, thioflavin-T. These fibrils are comprised of parallel β-sheets, stacked in an antiparallel fashion. The non-fibrillar amyloid oligomers are large, spherical structures that contain β-sheets but do not bind thioflavin-T. It was determined that these oligomers contain parallel β-sheets as well as the same intersheet packing as fibrils of PrP(106-126). Finally, the interaction of PrP(106-126) with lipid bilayers and cells was examined. Oligomers of PrP(106-126) were shown to affect model membranes; with anionic lipids losing integrity and cholesterol-containing lipid mixtures losing domain structure upon peptide addition. Additionally, amyloid oligomers of PrP(106-126) cause cell death across a number of cell lines as well as rat cerebellar slices. Overall, these results indicate that the conversion of oligomers to fibrils may be facilitated due to structural similarities between the two. Additionally, the toxicity of PrP(106-126) oligomers may be attributed to a loss of cholesterol domain structure causing subsequent cell death.
Machine Learning Methods and Models for Ranking
Keywords: Applied Sciences
Artificial Intelligence
Machine Learning

Ranking problems are ubiquitous and occur in a variety of domains that include social choice, information retrieval, computational biology and many others. Recent advancements in information technology have opened new data processing possibilities and signi cantly increased the complexity of computationally feasible methods. Through these advancements ranking models are now beginning to be applied to many new and diverse problems. Across these problems data, which ranges from gene expressions to images and web-documents, has vastly di erent properties and is often not human generated. This makes it challenging to apply many of the existing models for ranking which primarily originate in social choice and are typically designed for human generated preference data. As the field continues to evolve a new trend has recently emerged where machine learning methods are being used to automatically learn the ranking models. While these methods typically lack the theoretical support of the social choice models they often show excellent empirical performance and are able to handle large and diverse data placing virtually no restrictions on the data type. These model have now been successfully applied to many diverse ranking problems including image retrieval, protein selection, machine translation and many others. Inspired by these promising results the work presented in this thesis aims to advance machine methods for ranking and develop new techniques to allow e ective modeling of existing and future problems. The presented work concentrates on three di erent but related domains: information retrieval, preference aggregation and collaborative ltering. In each domain we develop new models together with learning and inference methods and empirically verify our models on real-life data.
A Global Mapping of Protein Complexes in S. cerevisiae
Keywords: Proteomics
Bioinformatics

Systematic identification of protein-protein interactions (PPIs) on a genome scale has become an important focus of biology, as the majority of cellular functions are mediated by these interactions. Several high throughput experimental techniques have emerged as effective tools for querying the protein-protein interactome and can be broadly categorized into those that detect direct, physical protein-protein interactions and those that yield information on the composition of protein complexes. Tandem affinity purification followed by mass spectrometry (TAP/MS) is an example of the latter that identifies proteins that co-purify with a given tagged query (bait) protein. Though TAP/MS enables these co-complexed associations to be identified on a proteome scale, the amount of data generated by the systematic querying of thousands of proteins can be extremely large. Data from multiple purifications are combined to form a very large network of proteins linked by edges whenever the corresponding pairs might form an association. Only a fraction of these pairwise associations correspond to physical interactions, however, and further computational analysis is necessary to filter out non-specific associations. This thesis examines how differing computational procedures for the analysis of TAP/MS data can affect the final PPI network, and outlines a procedure to accurately identify protein complexes from data consolidated from multiple proteome-scale TAP/MS experiments in the budding yeast \textit{Saccharomyces cerevisiae}. In collaboration with the Greenblatt and Emili laboratories at the University of Toronto, this methodology was extended to yeast membrane proteins to derive a comprehensive network of 13,343 PPIs and 720 protein complexes spanning both membrane and non-membrane proteins.