VictorJuiz/thesis huggingface dataset:
Continuous microfluidic reactors for polymer particles

In this thesis, we present a versatile new method for preparing highly monodisperse droplets, polymer particles, double emulsions, and self-assemblies of droplets in continuous microfluidic reactors. Recently, microfluidic systems are significantly being used in many areas of chemistry and biotechnology to achieve improved performance. Microfluidics provides the ability to automate highly repetitive laboratory tasks by replacing huge cumbersome equipment with miniaturized and integrated systems, and it enables the handling of small amounts, e.g., from microliters to femtoliters of fluids, reactants and products. These methods have the following useful features: (1) the generation of extremely monodisperse droplets, (2) the generation and control of both the shape and the size of the droplets, (3) the use of a wide variety of materials, including: gels, monomers, polymers, copolymers, and polymers doped with functional additives, (4) a possibility of in situ solidification of the droplets by means of photopolymerization and/or thermopolymerization, and (5) the ability to scale up the production of large quantities of particles. We focus on the effect of the properties of the disperse and continuous phases on the emulsification process, the effect of the polymerization rate on the production of high-quality particles, the role of the material and geometry of the microfluidic device in droplet formation, and the synthesis of particles with different shapes and compositions.

Keywords: Polymer engineering
Materials science
The value of languages in an élite English-French bilingual school

Drawing on Bourdieu's (1999) theory of language and symbolic power, this thesis examines the distribution and valorizations of linguistic resources in an élite English-French bilingual school in Toronto, Canada. Focusing on observations of classroom and non-classroom interactions, interviews with students, teachers, and administrators, and documentary analysis, the study analyzes the type of educational provision offered by the school and the participants' perceptions of the school's language policy and linguistic practices. The research findings showed that the school provides its students with two kinds of highly valued symbolic capital, English-French bilingualism and internationally recognized educational credentials, and thus, prepares them to enter an international élite job market. The school functions primarily in the interests of anglophone and English-speaking allophone students. It promotes a strong interest in multilingualism in European dominant languages, with a special emphasis placed on Spanish. English remains the dominant language of the school.

Keywords: Education, Bilingual, Social aspects
Education, Bilingual, Ontario
Bilingual schools, Canada
Multilingualism, Social aspects
Multilingualism, Ontario
Satellite-derived estimation of the surface albedo of Peyto Glacier Basin

Estimating the spatial variation of reflectivity across a glacier surface is critical to the performance of models calculating glacier mass balance. This study uses Landsat images from 3 days in 1994 to determine the spatial variation in surface albedo across the Peyto Glacier Basin, Alberta, Canada. A bulk parameterized radiation model was successfully tested with Modtran in order to calculate incoming irradiance, and improve and ease our atmospheric correction requirements for the satellite data. A two-stream up/down radiation model using path radiance and vertical transmission for a homogeneous atmosphere was used to correct the outgoing irradiance values. Corrections to reflectivity for the impact of topography, anisotropy, and narrowband to broadband conversion were successfully applied following the procedure established from researchers at the Institute for Marine and Atmospheric Research (IMAU), Utrecht, The Netherlands. Estimated surface albedo values correspond well with published values and previous field observations carried out on Peyto Glacier. The sensitivity of albedo to variations in the angle of incidence and elevation across the Peyto Glacier Basin is also demonstrated.
Consent and dissent on Evangelical talk radio

Consent and Dissent on Evangelical Talk Radio aims at addressing some of the consistencies and indeterminacies in evangelical identity when it is opened up to itself and to the public, via the forum of live, call-in talk radio show. The text is the product of four years' work transcribing, analysing, synthesising, and describing some sixteen hours of the evangelical program Lifeline, broadcast weekday afternoons at 110,000 watts from Buffalo, NY, on WDCX-FM, and on affiliate stations across New York State. While a great many themes appeared in the nearly 2500 shows broadcast over the 7¾ years that Lifeline was on the air, those in the sample, drawn from the last four years of the broadcast, address a wide variety of common areas of evangelical concern: the creation/evolution debate (in Chapter Three), therapeutic counselling and family dynamics (Chapter Four), and third-party candidates, militant patriot groups, cults, homosexuality, and persecution (Chapter Five). The exchanges demonstrate how deeply, casually, and effectively evangelicalism can enter into the secular domain, as well as work upon itself, in addressing such concerns. Brought into special focus are the two hundred minutes of conversational interaction in the sample involving sixty-five callers, men, women, and youth from both the United States and Canada These moments are rendered through Conversation Analysis to bring attention to bear on the minutiae of communicative interplay. Observed closely, these moments offer a sense of how evangelical speakers orient themselves tacitly, through the protocols of communicative action and theological correctness, towards both one another and the world. What the conversations demonstrate are both methodical and passionate responses to the pressures of an age of globalisation and destabilised identities. There where believers are enjoined systematically to arrange and habituate themselves to particular ways of thinking and acting, analysis of evangelical talk radio presents a revealing point of intersection between the self-formation of persons and of the social systems that both nourish and threaten those persons.
The VicR/K signal transduction system in Streptococcus mutans

Two-component signal transduction systems (TCSTS) function as "molecular switches" that facilitate diverse genetic and physiological responses in bacteria to external environmental fluxes. Since accumulating evidence highlights their significance for bacterial adaptation, survival and virulence, these systems are considered as enticing targets for antibacterial therapy. The work presented here provides insight into the VicR/K TCSTS in Streptococcus mutans , which is a primary pathogen associated with dental caries in humans. The vicR/K genes are part of the vicRKX tricistronic operon that encode a response regulator and a membrane-bound sensor protein, respectively. To characterize these genes, PCR-ligation mutagenesis was utilized to construct non-polar deletion mutants of vicK and vicX genes. In contrast, attempted deletion of vicR proved to be lethal. However, a mutant that overexpressed vicRKX was isolated and used for further characterization. By utilizing a variety of molecular and genetic tools, the vic genes were shown to influence sucrose-dependent adhesion, biofilm formation and genetic competence development in S. mutans. Moreover, they were also shown to modulate expression of gtfB/C/D, ftf and gbpB, whose products are associated with biofilm formation and virulence in S. mutans. Furthermore, analysis of the VicK protein sequence revealed the presence of a redox-sensing domain, which has been associated with sensing intracellular oxidative stress in other bacteria. Not surprisingly, under paraquat-induced oxidative stress, all vic mutants showed aberrant growth relative to wild type. In vivo experiments conducted with specific pathogen-free rats harboring the VicK mutant revealed that despite its ability to produce more smooth-surface plaque, the incidence of caries was not affected by VicK mutagenesis relative to its parent. More recently, vicR/K genes were shown to be negatively regulated by the ComD/E TCSTS involved in quorum sensing in S. mutans, thus suggesting possible cross-communication between these systems. Preliminary examination of the global transcription profile of the VicK-deletion mutant and its parent revealed 56 altered transcripts, which included genes belonging to cell wall biosynthesis, nutrient uptake and stress tolerance. Overall, the present study not only provides substantial insight into how S. mutans uses signal transduction to regulate caries-conducive phenotypes, but also contributes to our general understanding of streptococcal genetics and physiology.
Feasibility and effect of a structured aerobic exercise intervention to reduce depression post-traumatic brain injury

The effect of exercise as a treatment for depression was tested on persons living with the effects of a traumatic brain injury (TBI). The overall objective of this pilot study was to establish the effectiveness and feasibility of a structured aerobic exercise intervention in a group of adult outpatients with mild-to-moderate post-TBI depression. A pre and post test design was used to assess the effect of a 12-week exercise intervention on depressive symptoms among 4 adults aged 18-55 with TBI, and was tested using the Hamilton Rating Scale for Depression. Attendance levels and participant perceptions of the interventions gathered in standardized individual interviews were also analyzed. Participants showed a reduction of depressive symptoms and there was improvement in both physiological and self-esteem measures. This study provides a basis for larger studies with controlled designs.
Phonological encoding skills in persons who stutter

Psycholinguistic theories of stuttering attribute a crucial role to a phonological encoding deficit, although controversy exists regarding the precise nature and extent of this deficit. Two experiments discussed in the present thesis tested phonological encoding skills in persons who stutter (PWS). In Experiment 1, 10 PWS and 11 persons who do not stutter (PNS) were tested in a phoneme-monitoring task performed during silent picture naming. Performance in this task was compared to a tone monitoring task, a picture naming task, and a simple motor task. PWS were significantly slower in phoneme monitoring as compared to PNS. No significant group differences were present for response speed in the auditory monitoring, picture naming and simple motor tasks, nor did the two groups differ for percent errors in any of the experimental tasks. In Experiment 2, 10 PWS and 12 PNS were tested further in the phoneme monitoring task. The phonological complexity of the target items was varied such that participants monitored either compound words or noun phrases. Performance in this task was compared to phoneme monitoring in aurally presented target words to investigate whether any differences observed in silent naming were also evident in perception. Furthermore, group performance in rhyme monitoring was investigated. Analysis of the phoneme monitoring data from silent naming indicated significant group differences in monitoring the phonologically complex noun phrases as compared to compound words; significant differences were not obtained in perception. The PWS were also significantly slower than the PNS in rhyme monitoring for both silent naming and perception. The theoretically driven approach in the present thesis offered support for a delay in phonological encoding during phoneme monitoring in PWS. In the absence of group differences in the percentage of errors in monitoring, the phonological encoding deficit is attributed to mechanism-specific as opposed to strategy-based differences. Such differences, evident in both segmental and rhyme encoding, carry implications for the timely conversion of the phonological to the phonetic code for speech execution. The findings are discussed within the context of existing psycholinguistic theories of stuttering and phonological encoding.
The solubility of kraft recovery boiler precipitator ash

Precipitator ash typically contains sodium sulfate (Na 2SO4), sodium carbonate (Na2CO3), sodium chloride (NaCl) and potassium salts. The solubility of precipitator ash in water is important information for ash treatment processes to maximize the removal efficiency of chloride and potassium while minimizing the losses of sodium and sulfur. Various techniques have been proposed to treat the precipitator ash due to its enrichment in Cl and K that play an important role on fouling and corrosion problems in recovery boilers. This thesis concerns a study on the solubility data of the system Na +, K+, Cl, CO32- and SO 42- in water using a thermodynamic model, OLI. The study results show that Cl concentration in the liquid increases with and increase in ash concentration, while sulfate concentration decreases. Temperature has little effect on the composition of the liquid phase for temperatures between 30 and 100°C, but has significant effect below 30°C.
Novel mechanisms of hepatic CYP2C11 regulation by aromatic hydrocarbons

The aryl hydrocarbon receptor (AHR) mediates most of the toxic and adaptive responses elicited by aromatic hydrocarbons. These chemicals suppress the transcription of the growth hormone-regulated, male-specific rat hepatic cytochrome P450 2C11 gene (CYP2C11) via an unknown mechanism. I hypothesize that the promoter and 5'-flanking region of this gene mediate suppression following aromatic hydrocarbon treatment. Extended lengths of the CYP2C11 5'-flank were cloned into a promoterless luciferase plasmid. Suppression of CYP2C11 constructs was not observed upon treatment of transfected rat 5L, BP8, or mouse Hepa-1 cells with 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) or 3-methylcholanthrene (MC). In human HepG2 cells, a construct containing 10.1-kb of the 5'-flank displayed a pronounced 6-fold induction by TCDD, which was blocked by α-naphthoflavone, an AHR antagonist/partial agonist. Deletion analysis identified a region between -1.8 and -1.3-kb, which contains a dioxin-responsive element (DRE) previously demonstrated to bind the AHR, that contributes to the paradoxical induction. A critical role for the DRE was confirmed by site-directed mutagenesis. The CYP2C11 constructs were studied in living rats, where an intact endocrine system and the full complement of transcription factors needed for suppression of the endogenous gene are present. Using hydrodynamic-based injections to deliver plasmid DNA to the liver of live rats, we studied the MC-responsiveness of luciferase constructs containing 10.1-kb, 5.6-kb and 2.4-kb of the CYP2C11 5'-flank. MC suppressed CYP2C11-luciferase activity of the 10.1-kb and 5.6-kb constructs to below 50% of vehicle levels by 24 h and 72 h. Luciferase activity of the 2.4-kb construct was decreased to 63% of vehicle levels 24 h after MC treatment, but no suppression was detected by 72 h. This suggests that negative regulatory element(s) responsible for CYP2C11 reporter suppression by MC exist in the first 2.4-kb of this gene; however, additional cis-acting elements located between -5.6 and -2.4-kb mediate persistent reporter suppression. CYP2C11-luciferase constructs display a potentially misleading cell-specific paradoxical induction in vitro that is AHR-dependent and DRE-mediated. This is the first demonstration of aromatic hydrocarbon-mediated suppression of a CYP2C11 -luciferase construct, suggesting that the 5'-flanking region and promoter mediate down-regulation of this gene in the intact rat.

Keywords: Molecular biology
Toxicology
Pharmacology
Princess point palaeoethnobotany

This dissertation explores the human-plant interrelationship of Princess Point in southern Ontario. Princess Point is one of a number of prehistoric populations that inhabited the Lower Great Lakes region and is likely ancestral to later Iroquoian horticultural societies. This complex dates from about 1570 to 970 B.P., ascribing it to the early Late Woodland of southern Ontario. The goal of this study is to explore early horticulture, together with plant use generally, in southern Ontario, and to gain a better understanding of a time when people were changing their subsistence pattern from one based on wild plant resources to one that incorporated crops. Nearly 1700 litres of soil samples were analyzed, resulting in the identification of over 3400 macrobotanical remains. The study also explores the microbotanical techniques of biochemical analysis of organic residues and phytolith analysis. Princess Point represents the first shift to a subsistence pattern that incorporated horticulture into a hunting, fishing, and plant collecting lifeway. The earliest dates for evidence of corn horticulture in Ontario are from Princess Point. By Glen Meyer, a reliance on agriculture had increased in Ontario. The continued use of many plant species exists from Princess Point to Glen Meyer; however, Princess Point exhibits a greater frequency of the greens and grains category. An interconnectedness between Princess Point and those populations to the south in the Northeast is seen. Starchy and oily-seeded annuals, such as chenopod, erect knotweed, and purslane, are common both in the Northeast and with Princess Point. This study concludes that rather than simply replacing wild plants, Princess Point incorporated maize horticulture into their economic pattern and continued to be dependent on wild plant foods, especially fleshy fruits, and greens and grains. By exploring the continuum of mild interaction with the environment to intensive interaction, it is possible to obtain a better understanding of all phases of the human-plant interrelationship. This study hopes to stimulate ongoing research on early horticulture in Ontario and encourage continued investigations of Princess Point, together with the time periods before and after Princess Point.
Structural and kinetic investigations of methanobacterium thermoautotrophicum nicotinamide mononucleotide adenylyltransferase

Nicotinamide mononucleotide adenylyltransferase (NMNATase) catalyzes the reaction of NMN+ or NaMN+ with ATP in the synthesis of the ubiquitous coenzyme NAD+. The crystal structure of Methanobacterium thermoautotrophicum NMNATase determined using MAD phasing revealed a nucleotide-binding fold common to α,β phosphodiesterase proteins. An NAD+ molecule and a sulfate ion were bound in the active site allowing the identification of residues involved in product binding. Several residues lining the ATP-binding site of NMNATase were mutated in an effort to better characterize their roles in substrate binding and catalysis. These included Arg11 and Arg136, which had been implicated as substrate binding residues, as well as His16 and His19, part of the HXGH active site motif and postulated to be of importance in catalysis. Kinetic studies revealed that both Arg11 and Arg136 contributed to the binding of the substrate, ATP. When crystallized as purified from E. coli , the structures of the Arg mutants also revealed NAD+ and SO4−2 molecules trapped at their active sites. The alanine mutants at positions His16 and His19 retained approximately 5% and 1.5%, respectively, of WT NMNATase activity indicating that His19 is a key catalytic group. The structure of H19A revealed molecules of NMN + and SO4−2 in its active site. Surprisingly, this H19A mutant also displayed a novel and distinct mode of NAD+ binding when co-crystallized in the presence of NAD+ and SO 4−2. To further characterize the roles played by several residues in the active site, Arg47, which does not directly interact with any of the substrates phosphate groups, was changed to lysine and glutamic acid, the amino acid found at the corresponding position in M. jannaschii . Surprisingly, the R47E, as well as the R11K and R136K mutants trapped a molecule of NADP+ in their respective active sites. This NADP+ was bound in an orientation quite different from that of NAD+ in the native enzyme complex. In order to understand the role of the NADP+ molecule in the active site of NMNATase, it was co-crystallized with WT protein. Further investigation established NADP+ as a competitive inhibitor of the enzyme with a K i against ATP of 65 μM.
The design, implementation and testing of the thermal control system of the CanX-2 nanosatellite, and, The preliminary design of the attitude determination and control system for the generic nanosatellite bus

The University of Toronto's Space Flight Laboratory operates the Canadian Advanced Nanospace eXperiment program in order to develop low-cost nanosatellites for education and research. Building of the laboratory's expertise in microsatellite system design, this unique program trains highly skilled space system engineers for the Canadian public and private sectors while producing low-cost, quick-to-launch satellite platforms for the scientific and engineering communities. Major projects completed through this program include the CanX-2 nanosatellite, which stands to be one of the most advanced in its class through sophistication and capability. Master's students at the Space Flight Laboratory channel their various backgrounds into highly qualified areas of expertise by developing key subsystems for CanX missions. This thesis will describe the development of the passive thermal control subsystem for CanX-2, and the preliminary design of the attitude determination and control subsystem for the CanX-3 astronomy mission and the CanX-4 CanX-5 formation flight mission.
Ad-hoc top-k query answering for data streams

The efficient evaluation of top-k queries has been an active research topic and many different instantiations of the problem, in a variety of settings, have been studied. However, current techniques are not directly applicable to highly dynamic environments and on-line applications, like data streams. Recently, techniques supporting top-k queries on data streams have been introduced. Such techniques are restrictive however, as they can only efficiently report top-k answers with respect to a pre-specified (as opposed to ad-hoc) set of queries. In this thesis we introduce a novel geometric representation for the top-k query problem that allows us to raise this restriction. Utilizing notions of geometric arrangements, we design and analyze algorithms for incrementally maintaining and querying a data set organized in an arrangement representation under streaming updates. The performance of our core technique is augmented by incorporating tuple pruning strategies. A thorough experimental study evaluates the efficiency of the proposed technique.
Discovering new paths for global citizenship education in Brazil: three casestudies

In the last two decades, citizenship education has expanded its vision as it absorbed global perspectives on education. These perspectives have shaped many educational initiatives around the world whose positive impacts can, in turn, illuminate the global education field. This thesis seeks to discover how global citizenship education has manifested itself in Brazil from the beginning of the nineties onwards. It explores the genesis of global citizenship initiatives found in non-formal and formal settings in Brazil, in the light of three concrete case studies. Qualitative research was conducted in order to provide insights in assessing the field of global education in Brazil. The research illustrates that global citizenship education in Brazil has been manifested under different titles such as environmental and peace education initiatives. They have been implementing holistic concepts of global education mainly in non-formal education settings.

Keywords: Citizenship, Brazil
International education
Multicultural education
Education and state, Brazil
Globalization