VictorJuiz/thesis huggingface dataset:
The Diels-Alder reaction of transient nitrosoguanidines: a new class of N-O heterodienophiles and a novel method for the synthesis of functionalized guanidines

This thesis is a summary of research conducted since September 2001 at the University of Toronto in the laboratory of Dr. Robert A. Batey. This manuscript is divided into two chapters. In chapter one, the Diels-Alder reaction of nitrosoguanidines is discussed. This includes the intermolecular, intramolecular and diastereoselective versions of the reaction. In all cases, the reaction proceeds via oxidation of a hydroxylguanidine to generate a transient nitrosoguanidine intermediate that is subsequently trapped in situ with a 1,3-diene. The reaction proceeds in high yield and excellent regioselectivity and constitutes a new class of N-O heterodienophiles. Chapter two details the synthesis of functionalized guanidines via simple transformations of the initial cycloadducts discussed in chapter one. Simple manipulations of the cycloadducts generated via this novel methodology can generate a number of synthetically useful guanidines in high yield and few synthetic steps. Finally the synthesis of a number of “privileged” guanidine structures is discussed featuring this methodology.
An investigation of the induction of hepatic CYP2E1 by low doses of nicotine in the rat

CYP2E1 is an ethanol and drug-metabolizing enzyme that can also bioactivate hepatotoxins and procarcinogens and generate reactive oxygen species; it has been implicated in the pathogenesis of liver diseases and cancer. Cigarette smoke increases CYP2E1 activity in rodents and in humans, and we have shown that nicotine increases CYP2E1 protein and activity in the rat liver. In the current studies we have shown that the induction peaks at 4 hours post nicotine treatment and requires multiple exposures to nicotine. We have found that CYP2E1 is induced by very low doses of nicotine with an ED50 of 0.01 mg/kg s.c. Our mechanistic studies indicate that nicotine does not regulate CYP2E1 expression by transcriptional mechanisms or by protein stabilization. Cotinine, the main nicotine metabolite is not involved in CYP2E1 induction in our rat model. Our findings indicate that nicotine may increase CYP2E1-induced toxicity in smokers, passive smokers and people treated with nicotine.
Hippocampal regulation of intraprefrontal plasticity in the freely moving rat

To test the hypothesis that the hippocampus participates in memory consolidation by regulating intraprefrontal plasticity, a series of experiments were conducted in a chronic rodent model system consisting of the prefrontal cortex, the hippocampus, and the corpus callosum. Test pulses applied to field CA1 of the hippocampus evoked a monosynaptic negative potential in the prefrontal cortex, N1 (20 ms), whereas test pulses applied to the corpus callosum evoked a monosynaptic P1 (12 ms) wave. The first two experiments studied the effect of hippocampal activation on the amplitude of prefrontal cortex field potentials evoked by stimulation of the corpus callosum. A series of three-pulse tests were administered in which reference and test pulses monitored changes in prefrontal potentials as a function of pathway conditioned, interpulse interval, and conditioning intensity. The tests revealed a hippocampal suppression of cortical input peaking at 200 ms, whereas the neocortex facilitated hippocampal input maximally at 100 ms. The relation of these differences in short-term plasticity to information processing is discussed. In experiment III, a direct test of the assumption that N1 depends on the fornix was made by measuring the response before and after fornix cuts. This permitted corroboration of previous correlative data linking the response to tracing studies. In experiment IV, a protocol of repeated pulse-pairs which elicited the hippocampal induced cortical suppression observed in experiments I and II failed to induce long-term depression (LTD) in the prefrontal cortex. In experiment V, experimental groups received repeated stimulation trains to either the hippocampus, the corpus callosum or to both, over a twenty-five days conditioning period. Long-term potentiation (LTP) of N1 developed rapidly when the hippocampus was tetanized and was required for the gradual development of LTD of the callosal P1 wave. When tested one week after the conditioning phase, hippocampal-prefrontal LTP decayed to baseline, whereas callosal-prefrontal LTD persisted for at least one month. These results are consistent with a conjunctional theory of memory consolidation and a temporary role for the hippocampus in that process. Finally, in experiment VI, a preliminary study of R-apomorphine, a dopamine agonist, showed the drug could block LTD in the prefrontal cortex.
The end of law: Canada's national security legislation and the principle of shared humanity

Canada's Anti-terrorism Act, enacted in the aftermath of September 11th, has been assailed by critics as threatening fundamental rights. The Act's extraordinary powers will likely to be used primarily against Muslim Canadians, thereby creating an inferior subset of citizens and offending what Ronald Dworkin calls the principle of shared humanity. That principle suggests that every person is entitled to equal respect and dignity based on their humanity, rather than status, faith or ethnicity. The Act also makes distinctions between citizens and non-citizens, further revealing how Canada's national security legislation and jurisprudence, especially in the field of immigration, offend shared humanity. While citizens are offered somewhat greater respect than non-citizens, the courts have nevertheless shown exceptional deference to government claims of national security under the Act, as they have historically under other legislation. Even with the advent of the Charter, courts have not fully embraced their oversight role where national security is concerned.
Choosing to play: Adolescent girls and informal music learning

In an attempt to explore the relatively under-researched area of adolescent girls and informal music learning, the author conducted 6 in-depth qualitative interviews with middle-class adolescent girl popular musicians between the ages of 12 and 20 in the Greater Toronto Area in March and April, 2006. The study generated data on the informal learning practices, strategies, tools, and techniques used by participants in order to further their self-directed individual and collective informal music learning, as well as data on early influences on musical participation, the role of teachers and mentors, and constraints to participation. The study's findings suggested that positive early musical enculturation, material and social access, self-perceived effective paid and unpaid teachers/mentors, and supportive peer networks all played a role in helping girls develop their self-directed musical practice. Additionally, participants created dynamic communities of practice, which served as fertile sites for collective informal learning.
Coding and modulation for pixelated optical transmission

Pixelated optical transmission refers to the simultaneous exploitation of space and time to improve the data rates achievable by wireless optical communication. The link is exemplified by an LCD monitor transmitting to a digital camera. This thesis quantifies the maximum performance achievable by such a system, and suggests appropriate coding and modulation schemes. The channel capacity is upper-bounded at 5.36 bits/pixel/use by a pixel-matched system. Spatial discrete multitone modulation (SDMT) allows data rates up to 60 kb/image for a setup consisting of a 450 x 450 pixel transmitter and a 150 x 150 pixel receiver. Using combined Gray/Ungerboeck constellation labelling, multi-level codes protect each address bit independently. Choosing LDPC and Reed-Solomon codes, 82.6% of the SDMT channel capacity is reached at a BER below 10-6. Mode-based SDMT is proposed as a simple technique to allow pixelated transmission over a range of distances without lengthy initialization procedures.
Cytotoxicity assessment of components of the Epiphany resin-percha obturating system by indirect and direct contact Millipore filter assays

The Epiphany System was assessed for cytotoxicity, compared to gutta-percha and AH-Plus sealer. Specimen disks (Resilon, gutta-percha), filled glass rings (sealers), or imbibed cellulose disks (primer, thinning resin) were placed over Millipore filters in direct or indirect contact with a HeLa cell monolayer, incubated for 2h and stained with tetrazolium blue. Cytotoxicity was rated by the surrounding unstained zone: none (0mm), mild (≤ 7mm), moderate (7-12mm), or marked (>12mm). Data were analyzed with 1-way ANOVA and post-hoc pairwise t-tests. Unstained zones indicating moderate cytotoxicity were significantly larger (p<0.05) for Epiphany primer than for thinning resin and for freshly mixed AH-Plus than for Epiphany sealer. Set sealers (24, 48h), gutta-percha and Resilon elicited non-cytotoxic responses. In conclusion, cytotoxicity of set Epiphany sealer and Resilon was comparable to that of set AH-Plus and gutta-percha. Cytotoxicity of freshly mixed Epiphany sealer, primer, and thinning resin did not exceed that of freshly mixed AH-Plus.
The permeation of the chlorophenoxy acid herbicide MCPA through protective glove materials

The permeation of the salt formulation of MCPA through Nitrile, Neoprene, Viton and Natural Rubber revealed trace amounts in the latter three. Nitrile allowed appreciable permeation of MCPA, with a steady state permeation rate of 3.9 μg/min·cm2. The ester formulation of MCPA permeated Neoprene slightly more readily than Nitrile. Similar permeation rates were determined, with 0.016 μg/min·cm 2 for Nitrile and 0.012 μg/min·cm2 for Neoprene, although the lag time was substantially longer for Nitrile than for Neoprene. Diffusion coefficients were comparable. The comparison of polymer swelling to the level of permeation indicated a direct relationship between the two measurements. The prediction of permeation parameters based on the solubility parameter theory is not considered applicable to complex mixtures such as herbicide formulations. Use of the salt formulation is suggested, with Neoprene gloves recommended for dermal protection. Should the ester formulation be used, use of Nitrile gloves are recommended.
Maternal RNA stability analyzed using gene expression profiling in Drosophila

The early development of the Drosophila embryo is controlled by maternal mRNA. At the midblastula transition there are two classes of maternal mRNA, a stable and an unstable class. In this thesis a time course of microarray experiments using the time period from Stage 14 oocytes to 4--6hr after an egg has been deposited, was generated for both wild-type and smg mutant unfertilized eggs. It was determined that approximately 31% of the Drosophila genome is maternally expressed. Approximately 16% of these maternal transcripts were found to be unstable in wild-type unfertilized eggs. Previously it has been determined that in the smg mutant, the unstable transcripts, Hsp83 and nanos are stabilized. In the smg mutant there are about a quarter fewer unstable transcripts, indicating that SMG may be implicated in the degradation of many maternal transcripts.
Design of soluble transmembrane peptides as mimics and inhibitors of membrane protein folding function

Membrane proteins are enticing molecules to study from a structural standpoint because their membrane domains have remarkably uniform architectures---composed of 20--25 residue, canonical alpha-helices. However, as highly hydrophobic molecules, they are equally precarious to study because they pose significant technical challenges involved with their overproduction, purification, handling and subsequent structural analysis. To address this, we developed a method that allowed us to produce large quantities of TM segments through the design and synthesis of so-called "Lys-tagged" TM peptides. Placement of hydrophilic Lys residues at the termini of hydrophobic TM segments rendered peptides completely soluble in water. However, when challenged with a membrane-mimetic environment, these molecules spontaneously inserted and adopted an alpha-helical conformation. Further, these Lys-tagged TM peptides retained their native-like oligomeric states, thus allowing us to readily study the folding and assembly of TM helices. This technology was then applied to the Ff phage major coat protein (MCP) to study residue-specific effects on MCP TM helix-helix interactions; the synthetic approach allowed us to study mutants that were previously unattainable using randomized and saturation mutagenesis protocols on the intact phage. With this enhanced flexibility, a link between the affinity of TM helix-helix interactions and phage viability was described. In a further application of this system, we were able to show that high affinity helix interactive motifs (i.e., GxxxG, and strongly polar residues) were attenuated by their local sequence context. When combined with computer-based simulations and molecular biology approaches, we were able to describe these findings in considerable molecular detail. Finally, we applied the Lys-tagging technology to show that a peptide designed in this way could disrupt the folding of a functional membrane protein. Using the homotrimeric E. coli diacylglycerol kinase (DGK) as a target, we were able to show that a Lys-tagged version of the second TM domain bound to and inhibited DGK function by competing for TM helix packing interfaces. Overall, the work presented here demonstrates the power of the 'domain' approach for providing valuable information regarding the systematic rules which guide the folding and assembly of membrane proteins.
Data mining approach for automated inquiry handling and risk prediction

Inquiry handling is widely used in most large companies to compensate for problems in business processes. However, it remains a manual, labor-intensive process and lack of effectiveness and accuracy. This thesis proposes a systematic framework based on data mining techniques to help automating inquiry handling and predicting potential risks according to inquiries. A target-oriented feature weighting model is applied to pre-process raw inquiry data, and the neural networks are constructed to cluster inquiries into patterns. Since inquiry handling results are also learned during clustering, a processing recommendation can be made when a new inquiry is classified. And a significant change in inquiry patterns, which implies potential risks in the transaction processing system, can be identified by deviation analysis.
Exploring relationship building between social science researchers and Indigenous communities

The aim of this thesis is to explore relationship building between social science researchers and Indigenous communities. Relationship building is important to improving research outcomes, decolonization, and protecting Indigenous knowledges (IKs). The thesis is divided into two sections to bring into focus both theory and practice. In Part I, critical discourse analysis (CDA) has been used to explore how Indigenous research methodologies (IRMs) address relationship building. In Part II, document analysis is used to better understand how the themes generated in Part I are reflected in practice by social science researchers. Themes found in IRMs create space for relationship building in the four realms of being: physical, mental, emotional, and spiritual. Document analysis also suggests that social science researchers are employing both Indigenous and western-based emancipatory research approaches in community-based research with Indigenous communities.
Being Gaijin and being female in the Sakoku culture of Japan: the theme of cultural exile in Meira Chand, Kazuo Ishiguro and Pico Iyer

This thesis argues that three hybrid authors---Meira Chand, Kazuo Ishiguro, and Pico Iyer---writing about Japan express their sense of exile from Japan's exclusionist culture by depicting the condition of Japanese women. Presenting alternative visions of exile, The Gossamer Fly, A Pale View of Hills, and The Lady and the Monk reflect different perceptions of alienation. Chand shows the extreme marginalization suffered by a mixed-race female child within Japan; Ishiguro writes about exile from Japan in terms of displacement and death; and Iyer evinces the isolation he faces in Japan which prompts a unique journey of self-discovery where he seeks a connection with the alienating environment he has voluntarily sought to make "home". All three writers, however, focus on the condition of women in Japan. Because to write about women under Japanese patriarchy is to go to the heart of what is foreign, monolithic, stratified, and menacing about Japan.
A two-phase flow model in three dimensional cylindrical coordinates

A model for two-phase incompressible flows in 3D cylindrical coordinates has been developed, with a focus on accurate implementation of volume tracking, surface tension and flows with high density ratios. The volume of fluid (VOF) method with the piecewise linear interface construction (PLIC) is used to track the interface. The VOF algorithm was greatly simplified by developing a geometrical toolbox for reconstruction. To calculate interface curvature robustly and accurately, which highly affects the accuracy of the surface tension implementation, two approaches (the height function method and a method based on convolved volume fractions) have been implemented, and a technique has been developed to locally select the more accurate curvature. To couple the VOF and flow solvers, which is crucial when solving high density ratios, a method is presented to discretize the Navier-Stokes equations in the fully conservative form. The accuracy of the method is demonstrated through tests such as a static drop, polar cavity flow, and droplet impacts onto flat and cylindrical surfaces.
Development and characterization of open cell materials for acoustic applications

Open cell materials are lightweight and multifunctional, capable of absorbing acoustic energy and supporting mechanical load. The acoustic and mechanical performance of open cell materials can be optimized through processing. In this thesis, the relationship between processing parameters and acoustic and mechanical performance is shown for both polypropylene (PP) and aluminium foams. Polypropylene foams are fabricated using a novel method introduced in this work. The method combines compression molding and particulate leaching to fabricate open cell materials. Aluminium foams are fabricated using perforation technique to open interconnected networks in existing closed cell materials. The results from a parametric study showed that both salt size and salt to polymer ratio affected the acoustic and mechanical performance of polymer foams. However, only perforation ratio was shown to affect aluminium foams. The processing relationships and results presented in this thesis will be relevant to the design of new multifunctional open cell foam materials.
Droplet impact dynamics: effect of varying substrate temperature, roughness, and droplet velocity

An experimental apparatus has been designed and built to photograph high-speed impact of small liquid and molten metal droplets on surfaces of varying temperature and roughness. Two different droplet generators were used in order to produce uniform water droplets (0.55 mm) and molten tin droplets (0.6 mm). A stainless steel substrate was mounted on the end of a rotating flywheel, giving linear velocities of up to 50 m/s. Different stages of droplet impact were photographed by synchronizing the ejection of a single droplet with the position of the rotating flywheel and triggering of a camera. Results are presented first for impact of water droplets on two stainless steel substrates with an average roughness of 0.03 or 0.23 μm and an impact velocity of 10–50 m/s. A mathematical model (Kim et al., 2000), based on linear Rayleigh-Taylor instability theory, was used to predict the wavelength of the fastest growing perturbation around a spreading droplet. The corresponding wave number agreed reasonably well with the number of fingers around the droplet. For the molten tin droplet impact droplet impact velocity (10–40 m/s) and the substrate temperature (120–240°C) were varied. A critical temperature range (160–180°C) was found about which the dynamics of splashing transformed from a fragmentation splashing to a smooth splashing. Finally different stages of tin coating formation were photographed on stainless steel surfaces for two roughness: Ra = 0.05 and 2 μm, and three substrate temperatures: Ts = 120, 180, and 220°C. The impact velocity was held constant at 30 m/s. The maximum deposition efficiency was achieved at a substrate temperature of about 160°C. For Ts < 160°C the deposition efficiency was higher on a rough surface (R a = 2 μm) than on a smooth surface (Ra = 0.05 μm), since splats did not adhere well to the smooth surface. For Ts ≥ 160°C the deposition efficiency was higher on a smooth surface (Ra = 0.05 μm) than on a rough surface (Ra = 2 μm), since splats splashed less on the smooth surface.
Building just, inclusive and equitable communities: cultivating social awareness and responsibility

This thesis is a community action-based inquiry that explores community member's reflexive process of understanding privilege in relation to themselves and their community. The focus of the research was not to bring the voices of those who live on the margins to the reader but rather to uncover how those who live closer to the centre come to realize that positions such as margin and centre exist. Thus, this thesis is a praxical inquiry that navigates the personal and social complexities of understanding our relationship to privilege and the dangers, risks, and responsibility such an inquiry raises when self-awareness and responsibility are core educational principles. Participants reflected on the intersections between social justice and social responsibility, their relationship within the context of community work, and why this analysis was important. A reflexive analysis of the research process is included for its relationship to current educational research and theory.

Keywords: Social ethics
Environmental ethics
Communities
Social values
Responsibility
Equality
The collaborative Inquiry model: a case study

This research is a case study of an Inquiry class which was taught at McMaster University in 2007, and its purpose is to document, analyze, and present a thorough example of a post-secondary Inquiry course and the related philosophical, practical, and pedagogical issues. Much of the scholarship on Inquiry learning focuses on small-group situations and does not investigate the potential for Inquiry in large classrooms. This study shows an example of Inquiry-based learning as enacted in a large classroom and discusses its potential use in that context. Through interview, and the synthesis of common experiences into this research document, we get a detailed view of what factors are involved in successful Inquiry experiences, and we are better positioned to design our education system and classrooms to reflect these insights. This research serves as an example of Inquiry-based practice from which teachers can draw inspiration for new pedagogical practices.