VictorJuiz/thesis huggingface dataset:
Taxation and Financial Decision Making

Understanding the effects of taxes on the financial decision making process sheds light on the process itself and has important ramifications for policymakers. In this thesis, I study these effects in three different contexts: international acquisitions, executive compensation, and dividend payout. In Chapter 1, I investigate the possibility that tax rather than productivity differences are driving international acquisition decisions. A theoretical model of this process yields two testable implications of tax-induced sorting: that, relative to high-tax domestic bidders, low-tax foreign bidders will specialize in both high profitability target firms and those with low levels of tax deductions. I find support for both of these effects in the U.S. acquisition market using cross-sectional variation in target profitability and industry-level variation in deductions from the tax reform of bonus depreciation. Counterfactual simulations show that this reform induced a large drop in foreign acquisitions, leading to a significant loss of aggregate wealth. In Chapter 2, I study a recent increase in the tax rate on stock options for a subset of firms to learn about the effects of taxation on executive compensation. Using novel executive compensation data, I find that this tax increase resulted in an immediate reduction in both option grants and the share of options in total compensation. There appears to have been limited, if any, substitution towards other components of compensation. Hence, the burden of the tax increase must have been substantially borne by the affected executives. In Chapter 3, I use a 2006 tax cut in Canada to study the effects of dividend taxes on corporate payout. Analysis of discrete dividend events suggest little effect from the reform, in stark contrast with recent evidence from the United States. Difference-in-differences estimates using control groups comprised of firms which were exogenously unlikely to be affected by the reform suggest a small positive effect on net dividend initiations. Finally, fixed effect models of regular dividends reveal a small increase around the reform. However, the type of firms responding casts serious doubt on taxes as the cause. Overall, these results are consistent with the small and open nature of the Canadian economy.

Keywords: Public Finance
Advisor: Smart, Michael
Multinational Democracy and Political Recognition in Spain, 1978-2010

In this dissertation I attempt to build a bridge between normative discussions about multinational democracy and political recognition, and a contextually-sensitive empirical analysis of the Spanish case. I argue that, by looking at the characteristics and political dynamic of Catalonia, the Basque Country and Galicia, we can gain a better understanding of the definition, composition and viability of a multinational democracy. Combining normative discussions and a description of an empirical case (Spain) I seek to bridge both normative and empirical literatures about political recognition and multinationality highlighting the fruitful interconnections between them. In doing so, I attempt to provide adequate tools to normatively assess concrete and actual processes of political recognition in a context-sensitive manner. The dissertation also emphasises the possibilities (and limits) of federalism as a viable political and institutional framework to accommodate multinational demands in a democratic fashion. By looking at the Spanish case and the controversies and challenges that Catalonia, the Basque Country and Galicia present, I believe I offer a better understanding of political recognition. I defend a view of democracy and politics that is open by definition and is amenable to contestation and ongoing negotiations. I contend that the temptation to arrive at a solution as if it were a final and permanent state of affairs should be avoided; rather, the indeterminate and open-ended nature of the processes analysed should be not only tolerated but rather assessed according to the conditions and dynamic of the process of political recognition identified and discussed in my dissertation.

Keywords: Multinationality
Recognition
Spain
Advisor: Carens, Joseph
Topological Dynamics of Automorphism Groups of omega-homogeneous Structures via Near Ultrafilters

In this thesis, we present a new viewpoint of the universal minimal flow in the language of near ultrafilters. We apply this viewpoint to generalize results of Kechris, Pestov and Todorčević about a connection between groups of automorphisms of structures and structural Ramsey theory from countable to uncountable structures. This allows us to provide new examples of explicit descriptions of universal minimal flows as well as of extremely amenable groups. We identify new classes of finite structures satisfying the Ramsey property and apply the result to the computation of the universal minimal flow of the group of automorphisms of P(ω1)/fin as well as of certain closed subgroups of groups of homeomorphisms of Cantor cubes. We furthermore apply our theory to groups of isometries of metric spaces and the problem of unique amenability of topological groups. The theory combines tools from set theory, model theory, Ramsey theory, topological dynamics and ergodic theory, and homogeneous structures.

Keywords: topological dynamics
groups of automorphisms
near ultrafilters
Ramsey property
homogeneous structures
Advisor: Todorcevic, Stevo
Enhancing Diagnostic Accuracy in Oral Radiology: A Case for the Basic Sciences

Background: Cognitive processing in diagnostic oral radiology requires a solid foundation in the basic sciences as well as knowledge of the radiologic changes associated with disease. Although it is generally assumed that in dentistry, students must acquire both knowledge sets, little is known about the role or impact of the basic sciences on clinical reasoning because the two have traditionally been taught separately in the curriculum. Objectives: This dissertation investigates the role of basic sciences in oral radiology and its effects on diagnostic accuracy. The studies were designed to satisfy the following research aims: 1) to examine and compare the effects of integration and segregation of the basic and clinical sciences on diagnostic accuracy; 2) to examine the effects of basic science instructional methodology and diagnostic strategy on diagnostic outcomes; 3) to explore the potential interactions between instructional methodologies used to teach disease categorization and diagnostic strategies; and 4) to examine the effects of testing the basic sciences on diagnostic accuracy in an integrated instructional methodology. Methods: We conducted three quantitative studies, all of which involved a learning phase and an immediate testing phase that assessed diagnostic performance and memory. In each of the studies, learning strategies, and or testing frequency were varied. We also included performance assessment of diagnostic ability and memory, one week after the initial learning phase. Results: Our results show that students who learned basic sciences explanations had higher diagnostic accuracy when using a holistic System 1 type diagnostic strategy than those who did not. We also demonstrated that basic science knowledge was the most effective when directly integrated with the clinical sciences, and this result is further enhanced with testing. Conclusions: We conclude that integrated basic science learning provides a coherent framework that has the potential to significantly improve the diagnostic accuracy of training dentists.

Keywords: dental education
basic science education
clinical reasoning
oral radiology
Advisor: Woods, Nikki
Lam, Ernest W.
Fluence Field Modulated Computed Tomography

Dose management in CT is an increasingly important issue as the number of CT scans per capita continues to rise. One proposed approach for enhanced dose management is to allow the spatial pattern of x-ray fluence delivered to the patient to change dynamically as the x-ray tube rotates about the patient. The changes in incident fluence could be guided using a patient model and optimization method in order to deliver user-defined image quality criteria while minimizing dose. This approach is referred to as fluence field modulated CT (FFMCT). In this work, a framework and optimization method was developed for evaluating the dose and image quality benefits of FFMCT, both in simulated and experimental data. Modulated fluence profiles were optimized for different objects and image quality criteria using a simulated annealing algorithm. Analysis involved comparing predicted image quality maps and dose outcomes to those using conventional methods. Results indicated that image quality distributions using FFMCT agreed better with prescribed image qualities than conventional techniques allow. Dose reductions ranged depending on the task and object of interest. Simulation studies using a simulated anthropomorphic phantom of the chest suggest an average dose reduction of at least 20% compared to conventional techniques is possible, where local dose reductions may be greater than 60%. Across different imaging tasks and objects, integral dose reductions ranged from 20-50% when compared to a conventional bowtie filter. The results of this study suggest that given a suitable collimator approach, FFMCT could reap significant benefits in terms of reducing dose and optimizing image quality. Though the tradeoff between image quality and imaging dose may not be eliminated, it may be better managed using an FFMCT approach.

Keywords: Fluence Field Modulated Computed Tomography
Dose Reduction
Noise
Computed Tomography
Intensity Modulated
FFMCT
Advisor: Jaffray, David A.
Investigating the Relationship Between Cilia and Planar Cell Polarity Signalling During Zebrafish Development

Cilia are microtubule-based organelles that project into the extracellular space and have various functions including transducing sensory information, regulating developmental signalling pathways, and generating directed fluid flow, making them important regulators of vertebrate development and homeostasis. Despite their importance, there are many aspects of cilia formation and function that remain poorly understood. The planar cell polarity (PCP) pathway is a branch of Wnt signalling that provides positional information to cells and is required for polarized morphogenic cell movements. Previous studies of PCP effector proteins suggested that PCP signalling was required for cilia formation. However, these proteins are not specific to the PCP pathway and are shared with other branches of Wnt signalling. To determine the role of a core and specific PCP regulator on ciliogenesis, I examined maternal-zygotic (MZ) vangl2 zebrafish mutants using an in vivo marker of cilia, Arl13b-GFP. Analysis of MZvangl2 mutants revealed that PCP is not required for cilia formation but is required for the posterior tilting and posterior positioning of motile cilia, essential for directed fluid flow. A parallel branch of studies suggested that cilia are actually required to regulate PCP signalling because defects in PCP-mediated morphogenic movements were observed with the knockdown of certain proteins that localize at or near cilia or basal bodies. To determine whether cilia were required to establish PCP, I generated MZ-intraflagellar transport-88 (IFT88) mutants, where ciliogenesis is completely abolished. Analysis of MZift88 mutants revealed that cilia are not directly required for PCP-mediated morphogenic movements. However, I observed that MZift88 mutants had defects in oriented cell divisions (OCD) occurring during gastrulation. Remarkably, these divisions occur prior to cilia formation, suggesting a cilia-independent role for IFT proteins in cell divisions, which may have important consequences on the interpretation of the role of cilia in disease.

Keywords: cilia
planar cell polarity
Advisor: Ciruna, Brian Garrett
A Modeling Framework for the Synthesis of Carbon Nanotubes by RF Plasma Technology

The novel, cost and energy-efficient synthesis of carbon nanotubes (CNTs) by radio-frequency (RF) induction thermal plasma is a promising process for large scale production of CNTs for industrial and commercial applications. Techniques and conditions for producing larger quantities of CNTs have mainly depended on trial-and-error empirical variations of several operating parameters. Therefore, a detailed kinetic mechanism for CNT production in numerical simulations of an RF plasma system is required for understanding the process and identifying the parameters that mainly influence nanotube production. Such a model could also be used to enhance and optimize the design of synthesis systems. In this work, a two-dimensional axisymmetric model was constructed for a RF processing system for the production of CNTs. The plasma field was solved using a computational fluid dynamics (CFD) Eulerian frame of reference. The interactions between the plasma and injected feed particles were considered using momentum, heat and mass transfer source terms in the plasma field governing equations. The trajectory and temperature history of the injected particles into the plasma were computed using a Lagrangian method. The effects of plasma gas composition and the raw material feed rate in the system on the plasma thermo-fluid fields were studied. It was found that when 100% He sheath gas was employed, compared to an Ar-He mixture, the evaporation rate of the injected feedstock particles in the plasma increased due to the higher thermal conductivity of the He gas. Based on the raw material feed rate analysis, a higher loading rate of feedstock reduces down the plasma temperature along the injection zone and increases the average evaporation time of the feedstock in the plasma. A chemistry model for the formation of CNTs from feedstock material was implemented into an in-house two-dimensional axisymmetric parallelized CFD code. 36 elementary chemical reactions representing the formation of CNTs were numerically solved in the computational domain parallelized for execution on 64 Central Processing Units (CPUs). It was shown that the reaction rates of key reactions could be adjusted within their uncertainty range to improve the predicted yield of CNTs to within the yield rate reported from the experiments.

Advisor: Mostaghimi, Javad
Dworkin, Seth Benjamin
Negotiating Responsibilization: Power at the Threshold of Capable Literate Conduct in Ontario

This thesis considers how statistics about adult literacy have produced a new transnational norm of what it means to “be literate” and asks what has been produced by demarcating a calculable threshold of capable literate conduct. Analyzing literacy as a form of conduct enables investigation of the political dimensions of governmental interest in literate conduct and consideration of what subjects, relationships and forms of power are produced by various problematizations. Genealogical analysis of the currently dominant governing rationality, what is termed the psychometrological regime, revealed that Level Three of the International Adult Literacy Survey (IALS) has been constructed as a threshold between people who can act as autonomous, entrepreneurial subjects and those who cannot. In the case of Ontario, this threshold becomes an indicator of “employability” and produces a singular and problematic population who are subjected to coercive educational interventions. Tactics and techniques in the province’s Literacy and Basic Skills (LBS) policy construct literacy programs as sites responsible for transforming subjects below the threshold into human capital assets; this represents a significant departure from the original mission of community-based agencies. Data from interviews with educators in these programs indicate that adult literacy workers occupy an uneasy position between the demands of policy, their pastoral relationships with learners, and the complex realities faced by adults who struggle with print. While these educators may choose to disobey some policy imperatives they nonetheless act, at times unwittingly, as agents of governance. By highlighting the impossibilities produced by the neoliberal problematization of literacy, and the negotiations that literacy workers perform in the face of such dilemmas, this research contributes to thinking through how to transform coercive and authoritarian tendencies currently governing literate conduct.

Keywords: neoliberal governmentality
adult literacy
regimes of calculation
learner-centred
welfare reform
activation
Advisor: Jackson, Nancy
Ag Nanostructures:from Fabrication to Interaction

Electrochemical cycling of Ag surfaces under basic conditions has led to the discovery of a new, simple, rapid and cost effective method for the preparation of nano-structured Ag surfaces with features ranging from 30&ndash;150 nm in diameter. Our results indicated that during cyclic voltammetry, the surface was oxidized, resulting in the formation of soluble Ag complexes which were re-deposited as elemental Ag nanostructures (NSs) on the cathodic scan. The electrochemical properties of the Ag NSs were greatly affected by the presence of organophosphonates and other additives (vide infra), which also influenced the growth of nanostructures. The interaction of these Ag NSs with malathion and paraoxon were explored in more detail using Surface Enhanced Raman Spectroscopy. Results showed that generally smaller nanosized features resulted in high quality surface Raman enhancement. Next, Ag NSs&rsquo; properties in the presence of organophosphonates was investigated in tap water and apple juice in order to address issues related to matrix effects and potential interference from constituents in solution. Electrochemical and localized surface plasmon resonance results demonstrated the ability to detect organophosphonates in real samples, albeit at a lower limit of detections and without any selectivity to any particular organophosphonate. Next, the morphology and corrosion behaviour of Ag surfaces was explored in the absence and presence of surfactants and capping agents. Results demonstrated the protection of Ag surfaces against corrosion in the presence of Tween-20, while potassium citrate presence enhanceed corrosion of silver surfaces, resulting in the formation of a pitted surface with smaller Ag NSs. Lastly, the interactions of 2-cyano-3-(2&prime;-(5&prime;,10&prime;,15&prime;,20-tetraphenyl porphyrinato zinc-(II))yl) acrylic acid-modified Ag NSs with biomolecules were explored using spectro-electrochemical techniques. The photocurrent response of porphyrin-modified Ag NSs was quenched by the addition of adenosine-5&rsquo;-monophosphate (AMP), guanosine-5&rsquo;-monophosphate (GMP) and cytidine5&rsquo;-monophosphate (CMP), with a quenching efficiency of 80%, 68% and 48% for AMP, CMP and GMP, respectively.

Keywords: Silver
Nanostructure
electrochemistry
Interaction
Advisor: Kraatz, Heinz-Bernhard
Passive Air Samplers for Semivolatile Organic Compounds: Experiments, Modeling, and Field Application

Knowledge gaps related to mass transfer processes involved in passive air sampling of semivolatile organic compounds and factors potentially influencing passive sampling rates (PSRs) were addressed with controlled laboratory experiments, mass transfer modeling, and a field sampling campaign. The observed non-uniform SVOC distributions within porous passive sampling media (PSMs) contradict an assumption in an earlier passive air sampling theory and proved the existence of a kinetic resistance on the PSM side. This resistance can affect PSRs as revealed by a new PAS model which is based on fundamental laws of mass transfer in air and porous media. By considering mass transfer processes within the PSM, the model is able to explain the large variations of field calibrated PSRs with temperature and between SVOC species and the two-stage uptake process, which cannot be addressed by the earlier PAS theory. Because the PSM side kinetic resistance invalidates the assumption that depuration compounds added to the PSM prior to deployment are subject to the same kinetic resistance as the sampled SVOCs, PSRs derived from the loss rates of depuration compounds can differ from the actual PSRs of the sampled SVOCs. Using such PSRs could thus introduce additional uncertainty to PAS-derived air concentrations. Experiments using XAD-resin and silica-gel filled mesh cylinder as PSMs for the uptake of SVOCs and water vapor respectively revealed that sorbent in the inner portion of the PSM does not take part in chemical uptake; PSRs are thus proportional to the interfacial transfer area but not the amount of the sorbent. Accordingly, thinner PSM can be used to reduce the amount of sorbent while keeping or even increasing the PSRs. Optimized designs of PASs could be tested time efficiently using the gravimetrical approach based on water vapor uptake by silica gel.

Keywords: passive air sampler
semivolatile organic compound
kinetic resistance
sampling rate
Advisor: Wania, Frank
The Influence of Growth and Development in the Expression of Human Morphological Variation

This analysis examined cranial epigenetic and morphological nonmetric traits in 756 subadults (fetal to <20 years), in European, African, and Asian samples. The goals of this research were to assess: the age and manner in which nonmetric traits develop and if variation between geographic groupings is present in subadults; the role of the adolescent growth spurt in trait expression; the feasibility of utilizing subadult crania in biological distance studies and ancestry assessment. A number of epigenetic and morphological traits show a primarily genetic versus developmental basis, suggested by the fact that there was no difference in trait frequencies between the fetal/0-3 and 15-20 year age categories. Eighty-five percent of epigenetic traits appear before 3 years; 54% were age stable by 3 years, and 75% were stable before age ten. Geographic cranial variation is present at an early age as demonstrated by the appearance of 58% of morphological traits before age 3, and 90% by age 10. Ten and a half percent of morphological traits are age stable before 3 years of age, 48% by age 10. Traits statistically significant between pre-pubertal and pubertal and/or pubertal and post pubertal individuals are hyperostotic, functional, and in some cases, sex dependent. Few epigenetic (1.3%) and morphological traits (7.9%) were found to be sex dependent, possibly because sexually dimorphism may not be fully expressed in individuals in the 15-20 year age category. Features that indicate ancestry develop before puberty, and do not require the onset of puberty and sexual dimorphism to be fully formed. Three-quarters of epigenetic traits were age stable and showed trait frequencies similar to adults before 10 years of age, suggesting subadults could be included in biodistance studies using these traits. Twenty-four morphological traits were statistically significant between geographic groups and show promise for future use in the forensic analysis of ancestry assessment in children.

Keywords: non-metric traits
subadults
growth and development
ancestry
Advisor: Rogers, Tracy