VictorJuiz/thesis huggingface dataset:
Morphology and Interfaces in Polymer Blends Studied by Fluorescence Resonance Energy Transfer (FRET)
Keywords: FRET
Core Shell Polymer Blend
Interface Thickness
Miscibility

This thesis describes a fundamental study of the miscibility and the nature of the interface between components of core-shell polymer blends using the technique of Fluorescence Resonance Energy Transfer (FRET) coupled with data analysis that involves Monte-Carlo simulations. Our aim in this study was to develop a fundamental methodology to quantitatively determine the width of the interface between the two components in binary polymer blends. At the current state of the art, data analysis of FRET experiments requires translational symmetry. In the system under study, uniform core-shell structures satisfy this criterion. Thus, in this work our focus was directed toward the study of a blend system with a core-shell structure. For this FRET study, I have identified a number of potential donor and acceptor dye pairs that fluoresce in the visible range of the spectrum and can be chemically attached to polymers. Among them, I selected, as the donor and the acceptor, a pair of naphthalimide dyes that have not previously been used for FRET experiments. Model experiments showed that while the fluorescence decay profile of the donor chromophore was exponential in solution, it was not exponential in polystyrene (PS) or poly(methyl methacrylate) (PMMA) films. Thus, I carried out refinements to existing FRET theory to interpret the data generated by using these dyes. Also, I derived a new model to predict the fluorescence intensity of non-exponential decaying donor dyes in core-shell systems. I selected a model system composed of a PS core surrounded by a PMMA shell. The PS core particles were prepared by miniemulsion polymerization to obtain cross-linked PS particles with a narrow size distribution. Seeded emulsion polymerization under starved-fed condition was employed to synthesize monodisperse dye-labeled core-shell particles. The extent of miscibility and the nature of interface between the core and the shell polymers were retrieved from a combined study by Monte-Carlo simulations and analysis of the donor fluorescence intensity decays. Agreement between the retrieved interface thickness and the literature data on PS-PMMA validates the methodology developed here for the use of such donor dyes in FRET studies on polymer blends.
An Exploration of the Impact on Individuals Who Have Experienced Multiple Losses From Death Over Time
Keywords: multiple losses
bereavement
meaning-making in loss
narrative research

The study explores the experience of individuals who have lost a number of close people in their life, through death, over the course of their adult lifetime. Twelve individual interviews (11 women, 1 man) are presented in narrative form and explored for their content and meaning. The experience of multiple loss was revealed to be unique and varied for each participant and each loss was experienced independently from the others, concomitant on the relationship to the deceased, the nature and timing of the death and the relevance to the participant’s identity. Similar themes occurred across and within cases that are attributable to having lost a number of close others. Common effects were seen in participants’ experiential knowledge of grief and its vicissitudes, death and its processes, and life and its meaningfulness. Participants believed that their losses have had a profound effect on them, changing their lives immutably. Changes were perceived in terms of impact on the way they view the world, themselves and their relationships. Individuals perceived both positive and negative effects. Analogous with current research and theories in the field many of the participants reported experiencing personal growth as a result of their losses. The present study extends past research findings by attributing these effects to the accumulation of losses. A model for understanding the process of meaning-making in multiple loss was devised. Respondents were apt to process one death at a time, incorporate its meanings and effects on them, compare the effects to each other by contrasting the distinct experiences, and create a framework for meaning that was mutable. There were typical features of these meanings that were characteristic to the tone of the narrative. Stories of multiple loss tended to have an unresolved, a transformational or a growth related tone. An enhanced model of meaning- making in loss is described that augments current models of meaning-making in coping with loss. The implications of these findings for theory and practice are discussed.
Modeling of and Driver Design for a Dielectric Barrier Discharge Lamp
Keywords: Plasma Modeling
Power Electronics
Finite Volume Method
Dielectric Barrier Discharge

Dielectric Barrier Discharge (DBD) excimer lamp is a very attractive source for Ultraviolet (UV) radiation. It has a number of advantages compared to the mercury lamp which is the main lamp used in the industry for UV production. Some of these advantages are instant UV radiation (no warm-up period), narrow UV spectrum, longer life times and simple construction. The DBD UV lamp can be used in number of applications like water disinfection, Plasma Display Panels (PDP) and surface treatment in the semiconductor industry. Yet, the full industrial application of this lamp still faces some problems mainly related to finding the optimum electrical driver to maximize the efficiency of such a lamp. This includes the type of the electrical waveform to generate and the power electronic driver to produce it. In this thesis, firstly a physically based circuit model for the DBD lamp using the Finite Volume Method (FVM) is developed. This model provides the electrical and optical characteristics of the lamp. Using this model the sensitivity of the lamp efficiency to the proposed electrical waveform has been determined. Secondly, the order of this FVM model has been reduced to obtain a model which is used in the design procedure of the proposed driver. Since the DBD lamp has a capacitive nature, a current controlled driver is proposed in this thesis as opposed to most of the published drivers which are voltage controlled drivers. The design of this driver is intended to enhance the electrical to optical efficiency of the lamp and therefore enhancing the overall efficiency of the system. The driver topology permits direct control of the peak lamp current and the operating frequency of the supplied current to the DBD lamp. The width of the current pulses is determined by the transformer magnetizing inductance and the lamp capacitance. Experimental results of the proposed driver connected to a XeCl DBD lamp are presented to validate the performance of the driver and to prove the concept of such a current controlled driver. The proposed driver performance is compared to a voltage source driver which was also implemented. The proposed driver produced higher overall system efficiency but at the expense of a reduction in the driver efficiency as compared to the voltage source driver. The complete system, which consists of the developed FVM based model and the equivalent circuit of the proposed driver, was simulated and the results were compared to the experimental results to validate the accuracy of the developed model for the DBD lamp.
"Three Hundred Leagues Further into the Wilderness" Conceptualizations of the Nonhuman during Wendat-French Culture Contact, 1609-1649: Implications for Environmental Social Work and Social Justice
Keywords: environmental social work
Wendat-French culture contact
human-nonhuman relations

This study concerns an essential but, until recent years, little explored area of social work: environmental social work. The social work profession has long considered persons in their environment; however, use of the term environment has typically referred to social rather than nonhuman physical dimensions of space and place. It is common knowledge that we face today a number of serious environmental challenges, but less common is an understanding of how things came to be as they are. Why, for example, did things not develop differently? Why is our human-nonhuman relationship so strained? This research asserts human conceptualisations of the nonhuman other influence treatment of not only the nonhuman but also other human beings. Having an interdisciplinary focus involving social work, environmental studies and early Canadian history, Wendat and French conceptualisations of the nonhuman are explored through an ecofeminist framework in a culture-contact context to initiate consideration of, and in due course attending to, the uneasy intersection of the human and the nonhuman, social work and environmental issues, and current Aboriginal-non-Aboriginal relations. Through locating our environmental crisis within a historical context, it is possible to unsettle some contemporary assumptions about the human-nonhuman relationship, drawing attention to the fact that things could have been otherwise, that the environmental challenges experienced today were not inescapable. While there are certainly many ways to approach a history of our present environmental crisis, this investigation in the Canadian context involving a clearly defined case of culture contact between the Wendat and French in the early seventeenth century offers a variety of advantages deriving, in part, from the comparable but different complexities belonging to each group and the opportunity to explore two highly dissimilar cultural practices and belief systems from the time of initial contact. This study examines in detail how the two cultures understood and interacted with the nonhuman, and each other, through a forty-year period from 1609-1649. From this historical exploration of Wendat and French worldviews and land-use practices implications for social work are described and a model for place-based social work is generated.
Studies on Signal Transduction Mechanisms in Rhabdomyosarcoma
Keywords: rhabdomyosarcoma
cell signaling
tumor suppressor
oncogene
metastasis
insulin-like growth factor
chemokine
cancer
translocation
signal transduction
estrogen receptor
integrin-linked kinase
JNK
c-jun
embryonal
alveolar
mTOR
myosin light chain

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood, with two predominant histologic subtypes: embryonal and alveolar. These histologies display distinct clinical courses, and despite refinements in dose and duration of multimodality therapy, the 5-year overall survival of patients diagnosed with metastatic RMS remains <30%. Thus, there is an urgent need to define novel targets for therapeutic intervention. Interrogation of cancer cell signal transduction pathways that regulate the pathogenic behaviours of tumor cells has been successful in defining targets in numerous tumor types. These have ultimately yielded clinically-relevant drugs that have improved the disease-free and overall survival of patients diagnosed with cancer. Work contained in this thesis describes the interrogation of several potential targets for inhibition in RMS. Interruption of RMS cell proliferation, survival and apoptosis is examined through disruption of the protein kinase integrin-linked kinase (ILK) and the nuclear receptor estrogen-receptor β. ILK, in particular, is demonstrated to have dual competing functions through the regulation of c-jun amino-terminal kinase (JNK) signaling: an oncogene in alveolar, and a tumor suppressor in embryonal RMS. These findings are recapitulated in other tumor cell lines, indicating that expression levels of JNK1 correlate with ILK function in a broad spectrum of tumor types. Furthermore, interruption of rhabdomyosarcoma cell migration as a surrogate marker of metastasis is examined through disruption of the stromal-cell derived factor 1α/chemokine (CXC)receptor 4 signaling network, as well as through cooperative interactions between ILK and the mammalian target of rapamycin. Finally, we demonstrate that the insulin-like growth factor pathway is a potential target for therapeutic inhibition, which also distinguishes tumors of embryonal and alveolar histology. These studies provide a rationale for the development of novel agents, as well as the use of established drugs targeting these pathways in rhabdomyosarcoma.
Chemical Genetic Interrogation of Neural Stem Cells: Phenotype and Function of Neurotransmitter Pathways in Normal and Brain Tumor Initiating Neural Precursor Cells
Keywords: Chemical Biology
Neural Stem Cells
Neurotransmitters
Cancer

The identification of self-renewing and multipotent neural stem cells (NSCs) in the mammalian brain brings promise for the treatment of neurological diseases and has yielded new insight into brain cancer. The complete repertoire of signaling pathways that governs these cells however remains largely uncharacterized. This thesis describes how chemical genetic approaches can be used to probe and better define the operational circuitry of the NSC. I describe the development of a small molecule chemical genetic screen of NSCs that uncovered an unappreciated precursor role of a number of neurotransmitter pathways commonly thought to operate primarily in the mature central nervous system (CNS). Given the similarities between stem cells and cancer, I then translated this knowledge to demonstrate that these neurotransmitter regulatory effects are also conserved within cultures of cancer stem cells. I then provide experimental and epidemiologically support for this hypothesis and suggest that neurotransmitter signals may also regulate the expansion of precursor cells that drive tumor growth in the brain. Specifically, I first evaluate the effects of neurochemicals in mouse models of brain tumors. I then outline a retrospective meta-analysis of brain tumor incidence rates in psychiatric patients presumed to be chronically taking neuromodulators similar to those identified in the initial screen. Lastly, by further exploring the phenotype and function of neurotransmitter pathways in purified populations of human NSCs, I determined that neurotransmitter pathway gene expression exists in a functionally heterogeneous phase-varying state that restricts the responsiveness of these populations to various stimuli. Taken together, this research provides novel insights into the phenotypic and functional landscape of neurotransmitter pathways in both normal and cancer-derived NSCs. In additional to a better fundamental understanding of NSC biology, these results suggest how clinically approved neuromodulators can be used to remodel the mature CNS and find application in the treatment of brain cancer.
Autonomous Infrastructure Based Multihop Cellular Networks
Keywords: wireless communications
multihop cellular networks
CDMA
cooperative networks
autonomous infrastructure
relaying
pilot power protocol
optimal transmission range

In a multihop cellular network, mobile terminals have the capability to transmit directly to other mobile terminals enabling them to use other terminals as relays to forward traffic towards the base station. Previous studies of networks consisting of a single cell found that the SINR in a multihop cellular network is slightly lower than in a traditional cellular network. However, multihop cellular networks may have a higher capacity than traditional cellular networks due to their potential for lower intercell interference. For this reason, the effects of intercell interference are investigated in this thesis. Our simulations of a network with many cells show that multihop cellular networks have a higher SINR than traditional cellular networks due to the near elimination of intercell interference. However, multihop cellular networks still suffer from large amounts of interference surrounding the base station because all traffic either emanates or is destined to the base station making it the capacity bottleneck. To resolve this problem, we propose a novel architecture called the autonomous infrastructure multihop cellular network where users can connect their mobile terminals to the backbone network giving them the functionality of an access point. Access points receive traffic from other terminals and send it directly onto the backbone, as would a base station. This reduces the traffic handled by the base station and increases network capacity. Our analysis and simulations show that in autonomous infrastructure multihop cellular networks, the SINR at the base station is higher, the power consumption is lower and the coverage is better than in normal multihop cellular networks. Access points require parameters like their transmission range to be adjusted autonomously to optimal levels. In this thesis, we propose an autonomous pilot power protocol. Our results show that by adjusting a parameter within the protocol, a required coverage level of terminals can be specified and achieved without knowledge of the location or density of mobile terminals. Furthermore, we show that the protocol determines the transmission range that is optimal in terms of SINR and power consumption that achieves the required coverage while effectively eliminating the bottleneck that existed at the base station.
Multiparty Communication Complexity
Keywords: communication complexity
number on forehead
class separation
determinism
randomization
nondeterminism
stack machines
lower bound

Communication complexity is an area of complexity theory that studies an abstract model of computation called a communication protocol. In a k-player communication protocol, an input to a known function is partitioned into k pieces of n bits each, and each piece is assigned to one of the players in the protocol. The goal of the players is to evaluate the function on the distributed input by using as little communication as possible. In a Number-On-Forehead (NOF) protocol, the input piece assigned to each player is metaphorically placed on that player's forehead, so that each player sees everyone else's input but its own. In a Number-In-Hand (NIH) protocol, the piece assigned to each player is seen only by that player. Overall, the study of communication protocols has been used to obtain lower bounds and impossibility results for a wide variety of other models of computation. Two of the main contributions presented in this thesis are negative results on the NOF model of communication, identifying limitations of NOF protocols. Together, these results consitute stepping stones towards a better fundamental understanding of this model. As the first contribution, we show that randomized NOF protocols are exponentially more powerful than deterministic NOF protocols, as long as k ≤ nC for some constant c. As the second contribution, we show that nondeterministic NOF protocols are exponentially more powerful than randomized NOF protocols, as long as k ≤ δ·log n for some constant δ < 1.</p> For the third major contribution, we turn to the NIH model and we present a positive result. Informally, we show that a NIH communication protocol for a function f can simulate a Stack Machine (a Turing Machine augmented with a stack) for a related function F, consisting of several instances of f bundled together. Using this simulation and known communication complexity lower bounds, we obtain the first known (space vs. number of passes) trade-off lower bounds for Stack Machines.
Ancient Rhetoric and the Synoptic Problem
Keywords: Religion
New Testament

Only recently have studies of the synoptic problem begun to ground their assessments of literary dependence in ancient conventions. In an effort to appreciate more fully the evangelists’ modus operandi, our study examines their appeal to Greco-Roman rhetoric, the “science of speaking well.” Focusing on a rhetorical form called the chreia (xrei/a), we examine rhetorical techniques and reasons for chreia adaptation, particularly reasons why authors changed this form in theory and in the practice of the Hellenistic authors Plutarch and Josephus. With these reasons in mind, we assess literary dependence among the synoptic gospels, focusing on one chreia in the Triple Tradition (Matt. 9:14-17/Mark 2:18-22/Luke 5:33-39) and another in the Double Tradition (Matt. 12:22-37/Mark 3:20-35/Luke 11:14-36). Our study illustrates that hypotheses of Markan priority, like the Farrer Hypothesis and Two-Document Hypothesis, are more rhetorically plausible than hypotheses of Matthean priority. While Matthew and Luke’s adaptations of Mark reflect the rhetorical reasoning that we should expect, Mark’s reasoning is often problematic, for Mark repeatedly works against the fundamental rhetorical principles of clarity and propriety.
Life Histories of Culturally Diverse Canadian Leaders: A Study of Agency and Identity
Keywords: agency
leadership development
cross cultural studies
Canadian immigrants

This qualitative study explores the life history of four immigrants from diverse cultures, who have effectively navigated cultural differences and attained high-level leadership positions in Canada. The leaders’ life stories highlight key experiences that have influenced their identities, that is, the distinctive characteristics that are the source of their individual self definition and self-respect. The purpose of the study is to understand how social identity influences immigrants’ sense of personal agency and their capacity to shape individual potentialities into personal abilities. The study is situated in the leadership field within the multicultural Canadian context. It is grounded in my personal experiences as an Iranian-Canadian immigrant and guided by multidisciplinary literature on leadership, culture, identity, and motivation. Globalization, economic interdependence, and growing cross-national mobility have changed the face of the Canadian multicultural society. The clash of world-views, values, and life styles have become unavoidable, with arguably all Canadians experiencing the feeling of being “other” in their interactions with members of other cultures. Within the new Canadian mosaic, cultural consciousness is on the rise leading to increasing ethnic distinctiveness. It has become a factor distinguishing individuals by their differences as well as grouping them together by their similarities. Living in a multicultural environment as an immigrant has implications on issues of identity, but these implications have not yet been thoroughly explored. Much of existing cultural research is based on national orientation and contentious dualism (e.g., individualism and collectivism). But, cultures are dynamic and diverse. Understanding cultural constructs at the individual rather than the national level demonstrates the complexity and variability of individuals in the exercise of personal agency and the construction of identity. Through sharing and understanding the experience of four immigrants in leadership positions across diverse organizations, researchers may learn about immigrant challenges and ways these four individuals reconcile differences and conflicting cultural values. The resulting practical implication is (a) increased self and social awareness for immigrants with high potential for leadership, (b) enhanced multicultural knowledge for current organizational leaders, and (c) improved interpersonal relationships within a broad multicultural community.