VictorJuiz/thesis huggingface dataset:
Investigating the Safety and Therapeutic Potential of Vitamin D3 with Calcium Supplementation in Patients with Multiple Sclerosis
Keywords: Vitamin D
multiple sclerosis

Low vitamin D status has been consistently associated with an increased risk of multiple sclerosis (MS). Further, preclinical and in vitro data demonstrate immune regulatory properties of 1,25-dihydroxyvitamin D that may be beneficial for patients with MS. To date evidence of beneficial in vivo immunomodulation by supplementation with vitamin D3 in humans is lacking. In a one-year, open-label, phase I/II dose-escalation study of vitamin D3 (average ~14,000 IU/d over one year) with calcium (1,200mg/d) in patients with MS, we compared the effects of treatment on safety outcomes, clinical outcomes and selected biomarkers of immune system activity, relative to matched MS patients [age, sex, disease duration, disease modifying therapy, and expanded disability status scale (EDSS)] randomized to receive no supplementation. Mean serum 25(OH)D concentrations were 78.1±27.0 nmol/L at baseline and at one-year were 82.7±34.8 and 179.1±76.1 nmol/L in control and treated groups, respectively. Serum and urinary calcium and all other safety outcomes were unchanged throughout the trial. Compared to controls, treated patients tended to have fewer relapses (McNemar, p=0.09) and a greater proportion had a stable or improved EDSS at study end (p=0.018). We observed significantly reduced lymphocyte proliferative responses to antigenic challenge in the treatment group at one year, compared to baseline and control group responses. High serum 25(OH)D concentrations were not associated with short-term adverse effects in patients with MS, but with evidence of clinical improvement and beneficial immunomodulation.
Intentional traumatic brain injury in Ontario, Canada
Keywords: traumatic brain injury
intentional injury

Violence and traumatic brain injury (TBI) are two major public health concerns. This thesis is comprised of three different research topics; the epidemiology of intentional TBI in Ontario, discharge against medical advice (DAMA) as an undesirable outcome of acute stage, and functional changes after receiving rehabilitation care. To study these areas, three different datasets from the Canadian Institute for Health Information (CIHI) were used. The first epidemiological study on intentional TBI identified 1,409 (8.0%) intentional TBIs and 16,211 (92.0%) unintentional TBIs. Of the intentional TBIs, 389 (27.6%) were self-inflicted TBI (Si-TBI) and 1,020 (72.4%) were other-inflicted TBI (Oi-TBI). The most common causes of Si-TBI were “jumping from high places” and “firearms”. Major causes of Oi-TBI were ‘fight and brawl” and “struck by objects”. Si-TBI was associated with younger age, female gender, and having a history of alcohol/drug abuse. Oi-TBI was also associated with younger age and having an alcohol/drug abuse history and also with male gender. The second study on discharge against medical advice found that 446 (2.84%) TBI patients left hospitals without medical advice. DAMA was significantly associated with intentional injuries in those with self-inflicted TBI and other-inflicted TBI. DAMA was also associated with younger age and a history of alcohol/drug abuse. Using univariate analyses, the third study found that people with intentional TBI had significantly lower FIM gains in the motor area and significantly lower relative function gains (as measured by Montebello Rehabilitation Factor Score) in the cognitive area. Multivariate analyses of the same data showed that intentional TBI was also associated with lower cognitive relative gains, while controlling for age, gender, alcohol/abuse history, and other demographic and clinical variables. Persons with intentional TBI were found to be less likely to be discharged home, controlling for other relevant confounders. In conclusion, a person who has been injured due to assault or suicidal attempt may need more individualized care as they may be at greater risk for adverse rehabilitation outcomes. These findings regarding people with intentional TBI provide a basis for enhancing efforts on prevention of violence-related TBI and DAMA, and also for improving rehabilitation programs and discharge plans for this vulnerable population.
The Effect of Nonconscious Goals on Conscious Goal-based Preferences
Keywords: nonconscious goals
preference
multifinality
taste

This dissertation examines whether a nonconscious goal can change preferences between binary options, one favoring a conscious goal (e.g., undiluted but non-healthy iced tea) and the other a nonconscious goal (e.g., diluted but healthy iced tea). Across four laboratory experiments, we demonstrate that when participants are only given a conscious goal (e.g., to choose the tastier drink), the majority of them seek the alternative that is more instrumental to this goal. However, when a nonconscious goal is also primed (e.g., to be healthy), their preferences can shift to the alternative that is perceived to be instrumental to this goal but is inferior from the conscious goal standpoint. We propose a two-stage model to explain these findings. In the first stage, when a nonconscious goal is primed, individuals attend to goal-relevant cues (e.g., health-signaling label) and automatically form a positive evaluation toward the option that facilitates the nonconscious goal relative to the option that does not satisfy the goal. In the second stage, the positive automatic evaluation is then used to distort perceptions of the option’s conscious goal instrumentality such that the option is perceived as having a more favorable taste compared to when the goal is not primed. While the positive automatic evaluation influences the option’s taste, it does not affect the evaluation of the option’s other attributes (e.g., scent, color). By manipulating the timing of nonconscious goal activation and by adopting an evaluative conditioning task, we find support for our conceptual model while ruling out alternative explanations and identifying a boundary condition of task difficulty. The findings of the experiments contribute to the literature on nonconscious goals 1) by showing that these goals can play a central role in decision making when choice options pit them against conscious goals, and 2) by identifying a mechanism (i.e., attribute distortion) that can resolve goal competition in choice.
Characterization and Modeling of the Remodeling Process that Occurs in Modular Tissue Engineered Constructs Assembled Within Microfluidic Perfusion Chambers
Keywords: tissue engineering
microfluidics
perfusion
endothelial cells
mesenchymal stromal cells
activation
differentiation
remodeling
model
collagen
poloxamine
activation
shear stress
disturbed flow
vascular
modular

Using a modular approach, a vascularized tissue construct is created by embedding functional cells within submillimeter-sized collagen cylinders (modules) while the outside surfaces are seeded with endothelial cells (EC). The void spaces created by randomly packing modules into a container form EC-lined perfusion channels. Upon implantation, the tissues are remodeled by and integrated into the host and experience, to some degree, immune and inflammatory responses. This work utilized microfluidic techniques to study and model the tissue remodeling in vitro in the absence of the host response. When the construct’s tortuous perfusion channels were reproduced in poly(dimethylsiloxane) microfluidic devices and lined with EC, perfusion at higher flow rates reduced EC activation and maintained the desired quiescent EC phenotype. When applying these results to collagen constructs, higher flow rates were not achievable due to the weak mechanical properties of collagen. To increase the collagen’s mechanical strength, a semi-synthetic collagen/poloxamine-methacrylate hydrogel was examined but due to its heterogeneous surface composition, there was inadequate EC attachment and the material was deemed unsuitable for this application. Proceeding with lower flow rates, tissues assembled within microfluidic perfusion chambers from EC-seeded collagen modules showed that over the course of 24 hours, perfusion did not significantly increase activation but instead increased KLF2 expression, a transcription factor involved in the establishment of EC quiescence, and disrupted VE-cadherin bonds between adjacent EC. However, after 1 week of perfusion, the majority of EC were lost. To ameliorate this loss, mesenchymal stromal cells (MSC) were embedded within the modules in order to take advantage of their anti-apoptotic and immunomodulation effects. The MSC temporarily mitigated the loss of the EC but did not prevent it. They did, however, take on a phenotype similar to smooth muscle cells and migrated towards the EC. Perhaps this indicates that the combination of EC, MSC and perfusion drives the creation and assembly of pseudo vessels. Together, the microfluidic techniques used in this study to assemble and perfuse modular tissues revealed new insights into the remodeling process and exposed critical issues surrounding the adaptation of the EC to the combination of perfusion, remodeling and changing flow fields.
The Educational Production of Students at Risk
Keywords: students at risk, K-12 education, evidence-based research, institutional ethnography, Safe Schools Act, Student Success Strategy, education reform, teachers' work, literacy, numeracy, lifelong learning, pathways
education, sociology, philosophy, psychology

Informed by institutional ethnography, and taking the problematic from disjunctures in teacher/participants’ experience between actual practice and official policy, this study is an intertextual analysis of print/electronic documents pertaining to students ‘at risk.’ It unpacks the Student Success Strategy in Ontario secondary schools as organized around discourses on risk and safety. Discriminatory classing and racializing processes construct students ‘at risk’ in ways that reproduce socio-economic inequities through premature streaming into pathways geared to post-secondary destinations: university, college, apprenticeship and work. This study questions the accounting logic that reduces education to skills training in workplace literacy/numeracy, and contradicts the official ‘success’ story that promotes Ontario as a model of large-scale educational change. The follow-up intertextual analyses reveal ideological circles that promote ‘evidence-based research’ and ‘evidence-informed practice,’ while actually gearing education to improving ‘results’ on large-scale standardized tests and manufacturing consent for government policies. Questions arise about the lack of transparency and selective use of educational research. A web of behind-the-scenes activities are made visible at public policy think-tanks (e.g. Canadian Council on Learning; Canadian Language and Literacy Research Network), and two little-researched bodies in educational governance — the Council of Ministers of Education Canada (CMEC) and OECD. Although invisible to teachers, the infrastructure for the Student Success Strategy is the Ontario School Information System (OnSIS); this web-enabled data-management technology has built-in capacity to profile students ‘at risk’ and to instigate accountability and surveillance over teachers’ work, with implications for re-regulating teaching practice towards test scores and aggregate statistics. With the intention of transforming education towards genuine equity, and linking the re-organization of social relations in large-scale reform locally, nationally and globally, this study contributes to critical scholarship on the effects of reform policies on people’s lives and extends knowledge of how translocal text-mediated ruling relations operate in education.
A Novel Process for Fabricating Membrane-electrode Assemblies with Low Platinum Loading for Use in Proton Exchange Membrane Fuel Cells
Keywords: Proton Exchange Membrane Fuel Cells
Platinum Electrocatalyst
Pulse Electrodeposition
Pulse Waveform
Catalyst Layer
Microporous Layer
Hydrophobic Polymer Content

A novel method based on pulse current electrodeposition (PCE) employing four different waveforms was developed and utilized for fabricating membrane-electrode assemblies (MEAs) with low platinum loading for use in low-temperature proton exchange membrane fuel cells. It was found that both peak deposition current density and duty cycle control the nucleation rate and the growth of platinum crystallites. Based on the combination of parameters used in this study, the optimum conditions for PCE were found to be a peak deposition current density of 400 mA cm-2, a duty cycle of 4%, and a pulse generated and delivered in the microsecond range utilizing a ramp-down waveform. MEAs prepared by PCE using the ramp-down waveform show performance comparable with commercial MEAs that employ ten times the loading of platinum catalyst. The thickness of the pulse electrodeposited catalyst layer is about 5-7 µm, which is ten times thinner than that of commercial state-of-the-art electrodes. MEAs prepared by PCE outperformed commercial MEAs when subjected to a series of steady-state and transient lifetime tests. In steady-state lifetime tests, the average cell voltage over a 3000-h period at a constant current density of 619 mA cm-2 for the in-house and the state-of-the-art MEAs were 564 mV and 505 mV, respectively. In addition, the influence of substrate and carbon powder type, hydrophobic polymer content in the gas diffusion layer, microporous layer loading, and the through-plane gas permeability of different gas diffusion layers on fuel cell performance were investigated and optimized. Finally, two mathematical models based on the microhardness model developed by Molina et al. [J. Molina, B. A. Hoyos, Electrochim. Acta, 54 (2009) 1784-1790] and Milchev [A. Milchev, “Electrocrystallization: Fundamentals of Nucleation And Growth” 2002, Kluwer Academic Publishers, 189-215] were refined and further developed, one based on pure diffusion control and another based on joint diffusion, ohmic and charge transfer control developed by Milchev [A. Milchev, J. Electroanal. Chem., 312 (1991) 267-275 & A. Milchev, Electrochim. Acta, 37 (12) (1992) 2229-2232]. Experimental results validated the above models and a strong correlation between the microhardness and the particle size of the deposited layer was established.
The Graded Redfined Assessment of Strength, Senssibility and Prehension (GRASSP): Development of the Scoring Approach, Evaluation of Psychometric Properties and the Relationship of Upper Limb Impairment to Function
Keywords: tetraplegia, outcome measures, function, impairment, upper limb

Upper limb function is important for individuals with tetraplegia because upper limb function supports global function for these individuals. As a result, a great deal of time and effort has been devoted to the restoration of upper limb function. Appropriate outcome measures that can be used to characterize the neurological status of the upper limb have been one of the current barriers in substantiating the efficacy of interventions. Techniques and protocols to evaluate changes in upper limb neurological status have not been applied to the SCI population adequately. The objectives of this thesis were to develop a measure; which is called the Graded Redefined Assessment of Strength Sensibility and Prehension (GRASSP). Development of the scoring approach, testing for reliability and construct validity, and determining impairment and function relationships specific to the upper limb neurological were established. The GRASSP is a clinical measure of upper limb impairment which incorporates the construct of “sensorimotor upper limb function”; comprised of three domains which include five subtests. The GRASSP was designed to capture information on upper limb neurological impairment for individuals with tetraplegia. The GRASSP defines neurological status with numerical values, which represent the deficits in a predictive pattern, is reliable and valid as an assessment technique, and the scores can be used to determine relationships between impairment and functional capability of the upper limb. The GRASSP is recommended for use in the very early acute phases after injury to approximately one year post injury. Use of the GRASSP is recommended when a change in neurological status is being assessed.
Leakage Resilience and Black-box Impossibility Results in Cryptography
Keywords: computer science
cryptography
leakage resilience
pseudo-random generators

In this thesis, we present constructions of leakage-resilient cryptographic primitives, and we give black-box impossibility results for certain classes of constructions of pseudo-random number generators. The traditional approach for preventing side-channel attacks has been primarily hardware-based. Recently, there has been significant progress in developing algorithmic approaches for preventing such attacks. These algorithmic approaches involve modeling side-channel attacks as {\em leakage} on the internal state of a device; constructions secure against such leakage are {\em leakage-resilient}. We first consider the problem of storing a key and computing on it repeatedly in a leakage-resilient manner. For this purpose, we define a new primitive called a {\em key proxy}. Using a fully-homomorphic public-key encryption scheme, we construct a leakage-resilient key proxy. We work in the ``only computation leaks'' leakage model, tolerating a logarithmic number of bits of polynomial-time computable leakage per computation and an unbounded total amount of leakage. We next consider the problem of verifying that a message sent over a public channel has not been modified, in a setting where the sender and the receiver have previously shared a key, and where the adversary controls the public channel and is simultaneously mounting side-channel attacks on both parties. Using only the assumption that pseudo-random generators exist, we construct a leakage-resilient shared-private-key authenticated session protocol. This construction tolerates a logarithmic number of bits of polynomial-time computable leakage per computation, and an unbounded total amount of leakage. This leakage occurs on the entire state, input, and randomness of the party performing the computation. Finally, we consider the problem of constructing a large-stretch pseudo-random generator given a one-way permutation or given a smaller-stretch pseudo-random generator. The standard approach for doing this involves repeatedly composing the given object with itself. We provide evidence that this approach is necessary. Specifically, we consider three classes of constructions of pseudo-random generators from pseudo-random generators of smaller stretch or from one-way permutations, and for each class, we give a black-box impossibility result that demonstrates a contrast between the stretch that can be achieved by adaptive and non-adaptive black-box constructions.
On Improving Multi-channel Wireless Networks Through Network Coding and Dynamic Resource Allocation
Keywords: Computer Networks
Communication
Network Modeling
Network Optimization

Multi-channel wireless networks represent a direction that future state-of-the-art fourth generation (4G) wireless communication standards evolve towards. The IEEE 802.16 family of standards, or referred to as WiMAX, has emerged as one of the most important 4G networks to provide high speed data communication in metropolitan areas. There will be huge challenges in designing the networking protocols to allow WiMAX to provide high quality of services. How to effectively control the errors in the wireless channels and how to efficiently manage the scarce spectrum and power resources in different communication scenarios are crucial for network performance. This thesis aims to solve these challenges to improve the performance of multi-channel wireless networks, using WiMAX as a representative, through a number of techniques. First, we take advantage of the favorable properties of network coding, and design the adaptive MAC-layer and symbol-level network coding protocols. They tightly integrate with WiMAX physical and MAC layers, effectively perform error control, and efficiently utilize scarce wireless spectrum. Second, we investigate multicast services and the femto-cell architecture in WiMAX, and offer a cooperative multicast scheduling protocol as well as a cognitive WiMAX architecture with femto cells. They implement dynamic resource allocation in the networks through techniques of cooperative communication and dynamic optimization. Evaluated with rigorous analysis and extensive simulations, our proposed protocols are able to achieve substantial performance improvement over traditional protocols in the literature.
The Virtues of Shame: Aristotle on the Positive Role of Shame in Moral Development
Keywords: Aristotle
Shame
Moral Development
Habituation

Aristotle famously claims that we become virtuous by performing virtuous actions. He also recognizes the potential puzzle this claim gives rise to: How can we perform virtuous actions unless we are already virtuous? After all, virtuous actions require virtuous motives – they are performed “for the sake of the noble” – and virtuous motives characteristically belong to virtuous people. Many modern commentators presume that Aristotle’s solution rests upon characterizing the actions of learners as actions that are the right things to do in the circumstances but are not done with virtuous motivation. But this leaves Aristotle with the problem of bridging what I call “the moral upbringing gap” – i.e. the gap between the motivationally-neutral actions of learners and the dispositions to act reliably from a virtuous motive that such actions are supposed to produce. This gap emerges because the weaker the link between the way in which the actions of learners are performed and the way in which virtuous actions are done by virtuous agents, the more difficult it will be to understand how the repeated performance of the learners’ actions produce genuinely virtuous dispositions. The main aim of this thesis is to show that (and how) shame plays a crucial role in the process of moral development as the moral emotion that provides continuity between the actions of the learners of virtue and the corresponding dispositions that those actions eventually yield. My view is that Aristotle understands shame not as mere fear of external disapproval, nor as mere tendency to find pleasure in the noble, but as an emotion responsive to praise and blame and consequently to considerations about the nobility and shamefulness of one’s own actions and one’s character. Understood this way, shame provides learners with the sort of motivation that allows them to perform genuinely virtuous actions before they have acquired practical wisdom and the stable dispositions characteristic of virtuous agents. Shame thus bridges the “moral upbringing gap” by providing the kind of motivation that, when entrenched by understanding, constitutes moral virtue.