VictorJuiz/thesis huggingface dataset:
Building Peaceful Secondary School Climates: A Comparison of Anti-violence, Equity, Engagement and Community-Building Practices

Regularized daily practices in schools that exacerbate competition and exclusion in social relationships create environments in which conflicts are more likely to escalate into severe violence (Aronson 2000). School practices that rely on harsh punishment to prevent violence are often ineffective because punishment tends to fracture or impede the development of healthy relationships (Gladden 2002). This qualitative case study research examines various practices employed in three Ontario public high schools, linked to reducing the incidence of violence. Based on semi-structured interviews with school administrators, staff members and students, contextualized in relation to analysis of publicly-available documents, I describe, compare and analyze anti-violence, relationship-building, engagement and community-building practices and their perceived effectiveness in building peaceful school climates. Results show that proactive opportunities for students to develop a strong sense of attachment to their school, practice cooperation, and develop positive student-student and adult-student relationships seemed to be associated with building and/or sustaining peaceful school climates. School practices that placed students in cooperative horizontal relationship structures with peers, and communicative vertical relationship structures with adults, seemed to encourage peaceful interactions and support the development of social capital (relationship resources) for some student participants. In contrast, punitive practices to conflict and violence, such as suspensions, showed no evidence of building peace. Opportunities to engage in restorative peacemaking dialogue practices, although minimally used, seemed promising to resolve broken relationships in each school. This research supports the theory that reducing competition and exclusion and cultivating cooperative social relationships are promising practices that can reduce the risks of physical violence, bullying and other forms of aggression in schools. Unlike correlative survey research that may link incidence of aggression to individual student characteristics, this research points to proactive patterns of policy implementation and practice by school-based staff--based on inclusive interaction instead of harsh and exclusionary punishment--that may contribute to the achievement of sustainably peaceful climates.

Keywords: Educational Administration Policy
Relationship Building
School Climate
Social Psychology
Sociology of Education
Violence Bullying PreventionE Intervention
Advisor: Bickmore, Kathy
Theory of Charge Transport through Vibrating Molecules

In this Thesis we study several aspects of charge transport through single molecule junctions. Focusing on the interaction of the electrons with vibrations we devise toy-models which capture the consequences of many-body interactions for transport properties of the junction. We begin with the study of heating, cooling and stability of the molecular bridge. First, the dynamics of the vibrational mode is followed using the master equation. Using this approximate technique, we identify the regimes in which the electronic current is pumping energy into the vibrational mode, or alternatively, absorbing energy from it. An important conclusion of this study is that at large currents, the pumping of energy into vibrations may result in uncontrolled heating, making the structure unstable; Alternatively, at small biases, extraction of energy from vibrations is possible, resulting in a cooling behavior. We extend the model to include a dissipative environment, such as the vibrating backbone of the molecule or the solvent, and demonstrate that dissipation may alleviate structural instability. From the comparison of the behavior of a strongly anharmonic mode (two-level system) with a fully harmonic mode a surprising conclusion is reached: the cooling/heating analysis in both cases produces qualitatively similar results. Finally, we confirm the microscopic equivalent of the Second Law, the charge and energy Fluctuation Theorem, at the level of second order markovian master equation. In order to study exactly the vibration assisted electron transport through a donor-acceptor junction we develop a numerical scheme based on the influence functional path integral (INFPI) and quasi-adiabatic path integral (QUAPI) methods. With this tool, the results obtained with the perturbative kinetic master equation are confirmed validating the approximations used there. We further extend the model to include direct electronic tunneling. Encouraged by the similarity of transport behavior in harmonic and strongly anharmonic junctions, we compare the non-equilibrium Anderson-Holstein model of electron interacting with a harmonic mode to its variant, in which the infinite ladder of the harmonic mode is truncated. In this case, interestingly, the two models show significant differences: strong vibrational anharmonicity does not allow for the Franck-Condon blockade or current hysteresis effects found in the harmonic model. Instead, it introduces a novel many-body off-resonance blockade. We conclude with the study of electronic decoherence due to the interaction with vibrations. To this end, we consider three cases of electronic transport through a molecular junction: fully coherent (rigid molecule), fully dephased and purely inelastic. We demonstrate that the three cases produce characteristic energy profiles and may be distinguished from one another via the measurement of the thermopower.

Keywords: charge transport
dissipation
influence functional path integral method
quantum master equation
quantum physics
Advisor: Segal, Dvira
Foreshortening Leads to Overestimation of Angles

The hypothesis tested here is that vision's misuse of foreshortening, such as in an optic array's texture gradient, may lead to errors in the perception of angles. While errors may increase with optical slant, they may also be reduced by the use of optic information for the shape of surfaces. The first hypothesis was tested in five experiments. In the first four, observers estimated acute angles between a line receding away from the observer into depth - the z dimension -- and a line oblique to the z-dimension presented on the ground (Experiments 1 and 2) or a wall (Experiments 3 and 4). In Experiment 5, observers estimated angles between a slanted edge of a square platform and an oblique line lying on top of the surface. Foreshortening was increased by increasing the observer-to-target distance along the z-line (Experiments 1-4) and by reducing the distance from the eye to the surface bearing the target (Experiments 2, 4, 5). As expected, target angles were increasingly overestimated with foreshortening in Experiments 1-4. In Experiment 5, target angles on the slanted surface were not overestimated (they were underestimated modestly). Further, geographical slants were overestimated for surfaces. This was true for surfaces covered in different textures (randomly or cardinally oriented texture elements), in line with the foreshortening hypothesis.

Keywords: depth perception
foreshortening
perception of angles
perspective
slants
surfaces
Advisor: Kennedy, John M.
Niemeier, Matthias
The Role of Elongation Factor P in Salmonella enterica serovan Typhimurium Stress Response and Pathogenesis

Elongation factor P (EF-P) is a universally conserved bacterial translation factor that resembles a tRNA in both shape and size. It is post-translationally modified by the enzymes PoxA and YjeK to generate the fully active β-lysylated form, which is then hydroxylated by YfcM. EF-P functions to rescue ribosome stalls at difficult-to-translate motifs, such as those encoding multiple prolines. Although EF-P was previously described as an essential gene in E. coli, I successfully generated an efp knockout in Salmonella enterica serovar Typhimurium. The S. Typhimurium efp mutant exhibits pleiotropic phenotypes that overlap with those of the poxA and yjeK mutants. These phenotypes include increased susceptibility to antibiotics and detergents; impaired growth in low osmolarity media; enhanced resistance to the compound S-nitrosoglutathione (GSNO); and reduced motility on soft agar plates. I showed that relatively few cytoplasmic and membrane proteins are differentially expressed in the poxA, yjeK, and efp mutants relative to wild-type S. Typhimurium. Previous work by our lab showed that the S. Typhimurium poxA and yjeK mutants are attenuated in a mouse model of infection. I extended those findings to the efp mutant and further demonstrated that the mutants are defective for invasion, intracellular replication, and Sif formation in HeLa cells. The SPI-2 effector protein SifA is known to be essential for Sif formation and contains a PPP motif. Using translation fusion assays and immunoblotting, I showed that SifA translation is dependent on EF-P and that this dependency is abrogated upon mutation of the PPP motif to PLP. I also observed that efp mutants have reduced SPI-2 gene expression, likely due to the fact that the activity of the OmpR-EnvZ two-component system is impaired. Taken together, my findings identify several novel EF-P targets and shed light on the ways in which loss of EF-P affect the fitness of S. Typhimurium.

Keywords: Elongation factor P
Pathogenesis
Salmonella
Stress response
Translation
Advisor: Navarre, William W
Passaged Chondrocytes: A Source of Cells for Cartilage Tissue Engineering

The interest in bioengineered cartilage for the replacement of damaged articular cartilage has gained momentum in recent years. One of the issues limiting clinical translation has been identifying an appropriate cell source. To address this we identified that hyaline cartilage can be formed through the co-culture of a small number of primary articular chondrocytes with twice passaged chondrocytes. Not only were passaged human cells able to redifferentiate, but after separation from the primary cells, maintained their differentiation and formed cartilagenous tissue. This tissue was rich in collagen type II and aggrecan, the major molecules present in hyaline cartilage. There was little collagen type I. Tissue characterization studies demonstrated that redifferentiation was occurring during the first week of culture. Co-culture of primary and passaged cells in side-by-side culture indicated that a soluble factor was responsible for redifferentiation and that direct cell-cell contact was not essential. A serum-free culture system was developed and tissue characterized to confirm that the cells maintained phenotype, in order to be able to examine the secretome. Protein analysis through mass spectrometry and immunohistochemical staining of tissue sections indicated that versican, aggrecan, and types II and XII collagens were accumulated early within the first 3 days, by passaged chondrocytes were redifferentiating and formed cartilage tissue in vitro. This suggested that these molecules may be necessary to provide a microenvironment that supports hyaline cartilage formation. Further study is required to determine if these molecules are also accumulated by passaged human chondrocytes and their role in promoting hyaline cartilage formation. In addition these molecules also may then serve as markers that can be used to identify culture conditions and/or scaffolds that will favour articular cartilage formation by passaged chondrocytes and facilitate rapid screening of culture conditions for chondrogenic inducing potential. Together these studies facilitate the clinical transition of regenerative medicine approaches to cartilage repair.

Keywords: Cartilage
Chondrocyte
Dedifferentiated
Osteoarthritis
Redifferentiate
Tissue Engineering
Advisor: Kandel, Rita A
Gross, Allan E
Assembling Surface Linker Chemistry and Minimization of Biosensor Non-specific Adsorption

The development of a preparation method for biosensing interface on hydroxylated surfaces is presented in this manuscript. This method involves the use of thiosulfonate-based linkers to construct robust and durable SAMs (Self-Assembling Monolayers) onto hydroxylated surfaces. The resulting SAMs have the ability to chemoselectively immobilize thiol-containing molecules under aqueous condition in a single, straightforward, reliable and coupling-free manner. This method is then implemented in the construction of biosensing interfaces for EMPAS (ElectroMagnetic Piezoelectric Acoustic Sensor) dedicated to the detection of avidin. Efforts were devoted to improving the performance of the biosensing interface by reducing/preventing non-specific adsorption. Improvements were systematically observed with the incorporation of an OEG (Oligo(Ethylene Glycol)) backbone and a diluent (i. e. SAM molecules without a head functional group). The hydroxyl head function and short length of the diluent were crucial in preventing non-specific adsorption. This showed that both enthalpy-driven and entropy-driven mechanisms work in conjunction in order for the surface to achieve high resistance in non-specific adsorption. Expansions of this method to silicon nitride (Si3N4), aluminium nitride (AlN) and gold (Au) were pursued. Lastly, a previously undocumented EMPAS coil circuit design was reported and discussed.

Keywords: EMPAS
non-specific adsorption
OEG
short SAM
thiosulfonate
TUBTS
Advisor: Thompson, Michael
An Investigation of Metallurgical Reactions with Levitated Droplets

The study of gas-metal interactions has industrial significance in metallurgical processes. Despite the vast production volume, the high temperature kinetics of these processes are far from fully understood. The difficulty in accounting for the effects brought by the large temperature gradients that commonly exist between gas and liquid metal phases remains a major challenge. It is therefore essential to understand and quantify the influence of these conditions on mass transfer during metallurgical reactions. In the production of stainless steel, one of the main objectives is to minimize oxidative loss of valuable alloying elements such as chromium during the decarburization process. Carbon dioxide has a lower oxidizing potential compared to oxygen gas, and could provide a potential solution to the problem of alloy loss during the oxidation refining of stainless steel. From an economic standpoint, in order to fully utilize the advantages associated with using CO

Keywords: Decarburization
Levitated droplets
Mass transfer
Silicon refining
Stainless steel
Thermal diffusion
Advisor: McLean, Alex
Barati, Mansoor
"Dancing to the Tune of the Donor": Donor Funding and Local Implementation of Initiatives to Assist Orphans and Other Vulnerable Children in Uganda, 1986 - 2011

This study is an inquiry into the exercise of power in the mainstream development apparatus, drawing from the case example of the dynamics among local and foreign organizations and agencies working to assist orphans and other vulnerable children (OVC) in Uganda during the period 1986 to 2011. It examines the initiatives of locally-founded non-governmental organizations (NGOs), local chapters of international NGOs (INGO), and the government of Uganda to attend to the physical, social, and emotional needs of OVC (through the provision of food, education, health care, housing, and social support). This overall "response" to OVC illustrates the influences of donor-recipient relations of power and mainstream development discourse and practices in shaping governmental and non-governmental initiatives. Drawing from Michel Foucault's theory of governmentality, the study considers donor rules, regulations, and discursive practices in relation to NGO practices in a context of international development aid, conceptualizing these regulations and practices as illustrative of technologies of power and domination and technologies of the self. Through a historical analysis, it contextualizes, periodizes, and interprets the dynamics of the responses to the needs of OVC on the part of the various players involved. It traces the emergence and consolidation of the concepts of human rights, child rights, and community participation within mainstream development discourse from World War II until the present to illustrate how this discourse plays out in the field of OVC initiatives in Uganda. The analysis suggests that donor conditions are constituted and perpetuated not through hegemonic control over funding recipients but through often insidious power dynamics reflected in everyday practices, interactions, and discourse. This implies active participation on the part of NGOs in perpetuating as well as resisting the relations of power that push them to attend to donor needs and requirements. The study finds that local representatives of NGOs (small and large, locally- and foreign-founded and managed) are beginning to alter the character of heavily donor-influenced OVC initiatives in Uganda through resisting, tweaking, and interpreting donor rules, regulations, and discourses to meet their own needs. Their dance "to the tune of the donor", as NGO and government agency representatives termed it, is more complex than simply following the donors' lead, and necessitates NGOs' continuous participation and resistance. Although not revolutionary in the sense of concerted action against a powerful other, particularly small locally-founded NGOs' resistance has the potential to reorient the mainstream development apparatus that dominates contemporary efforts to assist OVC in Uganda.

Advisor: Birn, Anne-Emanuelle
(In)Humanity on Trial: On the Ground Perceptions of International Criminal Tribunals

The purpose of this dissertation is to understand how international criminal tribunals (ICTs) are received in different contexts. The dissertation is driven by the following puzzle: Why has there often been a negative response to international criminal tribunals (ICTs) in local communities that have been victim to the crimes that these institutions are prosecuting? I examine this puzzle through local responses to the International Criminal Tribunal for former Yugoslavia (ICTY) in Bosnia and Herzegovina (BiH) and Serbia, and the International Criminal Tribunal for Rwanda (ICTR) in Rwanda. The findings are based on three research trips to each country, including nine consecutive months of fieldwork in Rwanda and six consecutive months of fieldwork in BiH and Serbia, and over 136 successful semi-structured and open-ended interviews with a variety of local actors. My data suggest that the two ad hoc tribunals were not successful at establishing themselves as legitimate and credible mechanisms of transitional justice. The locals in each country believed that they were not the primary beneficiaries of ICTs, and that that the ICTs paid insufficient attention to the dynamics between tribunal demands and proceedings, and political events on the ground. My findings show that, first, in each case, local actors in power - those connected to past regimes who were responsible for the 1990s atrocities, and those who were part of new regimes - adapted well to the conditions set by ICTs, manipulating the tribunals for their own political goals and influencing the perception of these institutions among the local populations. Second, ICTs had a serious impact on domestic politics, feeding into power struggles between domestic and international actors and between factions on the ground. This outcome had significant implications for political transitions in the three countries, many of which were unintended and contrary to the aims and expectations of the tribunals.

Keywords: Africa
Europe
human rights
international criminal law
transitional justice and reconciliation
war crimes and genocide
Advisor: Handley, Antoinette
On the Nature of Allosteric Interactions at the M2 Muscarinic Receptor

G protein-coupled receptors (GPCRs) are allosteric machines that constitute the largest family of membrane bound receptors. Members of the family 1a GPCRs such as the M2 muscarinic cholinergic receptor transduce the binding of an extracellular ligand to an intracellular messenger. The size of the receptor that participates in signalling is debated and as such the mechanism of signalling is uncertain. In addition, each of these receptors possess two distinct but conformationally linked sites, an orthosteric site and an allosteric site which engage in a process of allosteric modulation; the mechanism of which is also uncertain. For modulation, debate centers on the roles of electrostatic repulsion, steric hindrance and conformational stability. For signalling, the differences in these effects at monomers and oligomers on modulation are unexplored. Here we have explored the role of monomers and oligomers on modulation in kinetic studies and at equilibrium. Allosteric ligands slow orthosteric ligand kinetics and the time required for equilibration. This prolonged incubation is typically not considered in presumed equilibrium measurements that rationalise modulation in terms of monomers. Binding at equilibrium, however, reveal multiphasic effects which identify varying types of interactions and the oligomeric nature of the receptor. These interactions can be categorised into two types of allosteric modulation: inter-molecular, which occurs between an allosteric site at one receptor and the orthosteric site at another; intra-molecular, which occurs between the allosteric and orthosteric sites of the same receptor. Inter-molecular effects suggest a conformational interplay among receptors which was demonstrated by a FRET based probe, engineered mutants and kinetic-based mechanistic models. Inter-molecular effects and conformational stability, as examined by molecular dynamics, account for varied types of allosteric modulation (i.e., positive and negative) and may underlie high-affinity binding of allosteric ligands. Intra-molecular effects appear to result from electrostatic repulsion between highly charged ligands that engage in steric hindrance. The net result tends to negative allosteric modulation and low-affinity binding of allosteric modulators. Overall, binding of allosteric ligands at equilibrium identify that the M2 muscarinic receptor is a tetramer and the oligomer, not a monomer, allows for the various types of allosteric modulation.

Keywords: allosteric modulators
cooperativity
G protein coupled receptors
mechansitic modelling
molecular dynamics
Muscarinic receptors
Advisor: Wells, James W