McGill University Thèses et mémoires publiés en 2007

Roughly speaking, a group G is omnipotent if orders of finitely many elements can be controlled independently in some finite quotients of G. We proved that pi1(S) is omnipotent when S is a surface other than P2,T2 or K2 . This generalizes the fact, previously known, that free groups are omnipotent. The proofs primarily utilize geometric techniques involving graphs of spaces with the aim of retracting certain spaces onto graphs.  Read more

Microsatellite instability high (MSI-H) colorectal cancers (CRCs) possess such features as heavy infiltration by intraepithelial tumor infiltrating lymphocytes (iTILs), a relatively good prognosis, and truncating mutations in the type II TGFbeta receptor (TGFbetaRII). The aim of this study was to examine the possibility of a connection between these phenomena in MSI-H CRCs. Immunohistochemical analysis identified increased tumor TGFbeta expression as predictive of high iTIL counts in MSI-H CRCs but not in microsatellite stable (MSS) CRCs. Abundant iTILs were associated with longer survival times only for patients with MSS tumors. These results indicate that iTILs in MSI-H CRCs are not part …  Read more

This study qualitatively evaluated the adoption of critical approaches to teaching English as a second or foreign language (ESL) in the particular context of the private language school industry. The research questions focused on the flexibility of the curriculum, on the room it affords for critical pedagogy and on the challenges of implementing critical lesson plans in the ESL classroom. With the help of four teachers, I explored the practical implications of implementing critical lessons in multicultural ESL classrooms at a Canadian private language school. While the general conclusion of the teachers' experiences provides an encouraging and a positive outlook …  Read more

Air transport is of critical importance to move passengers and cargo from one place to another on a global scale. Subsistence, sustenance, growth and profitability of the air transport industry are dependent on the demand for transport from passengers and cargo as the main sources of revenue of the airline industry. The forces of globalization and liberalization, coupled with the very rapid development of low-cost operators, have tempered the growth and profitability of the aviation industry whilst, at the same time, greatly increasing the consumer (passenger and air freight user) advantages in terms of expanding the gamut of their choices, …  Read more

This thesis is a Tamil to English translation of Tirukkaḷirruppaṭiyar (TKP), composed by Uyyavanta Tevanayanar toward the end of the twelfth century C.E. The work contains one hundred quatrains of Tamil poetry composed in veṇpa meter. It is a poetic expansion of Tiruvuntiyar (TU), an earlier composition likely by the author's teacher's teacher. The TKP is a transitional text between the devotional religious bhakti(patti -Tamil) hymns of the nayanmar, who lived between the sixth century and the twelfth, and the Saiva-Siddhanta (Caiva Cittantam-Tamil) Theo-philosophical system, which developed between the thirteenth and the fourteenth centuries. TKP is the second work in …  Read more

PKR has been shown to play an essential role against VSV infection by phosphorylating eIF2alpha leading to the inhibition of protein synthesis. Through this capacity PKR is thought to be a mediator of the anti-viral and anti-proliferative actions of IFNs. In addition to translational control, PKR has been shown to modulate the transcriptional activities of NF-kappaB, Stats and p53. However, experiments with two different PKR-/- mouse models have failed to verify many of the biological functions attributed to PKR. Here, we show that the two PKR-/- MEFs express different PKR truncated proteins suggesting that both PKR-/- models are incomplete knockouts. …  Read more

This thesis describes an experiment using technology to develop conceptual understanding of functions through graphical representations. It examines the effects of including dynamic representations in a conceptual approach to the teaching of functions. The study was implemented over a 5-day period in a Grade 9 class in a small, generally working class, rural school in Eastern Massachusetts. Participating students were observed during class discussions and video analysis, and their written responses and created functions were analyzed. The procedure used in the experiment was based on the Theory of Didactic Situations and used the Didactic Engineering methodology. The structure and sequencing …  Read more

Introduction. After several years of decline, the prevalence of smoking among Canadian adolescents has stabilized at 18%. A lack of knowledge about the process of smoking cessation among adolescents, about how cessation behaviours should be measured, and about the environmental and social factors that influence cessation, has impeded research that would support the development of cessation programs targeted specifically to adolescent smokers that could further reduce the prevalence of smoking. The objectives of this dissertation were to investigate newly initiated adolescent smokers: (i) to identify measures of cessation relevant to the early stages of smoking onset and nicotine dependence; (ii) …  Read more

G protein coupled receptors, G proteins and their downstream effectors adenylyl cyclase (ACs) were thought to transiently interact at the plasma membrane by random collisions following agonist stimulation. However a growing number of studies have suggested that a major revision of this paradigm was necessary to account for signal transduction specificity and efficiency. The revised model suggests that signalling proteins are pre-assembled as stable macromolecular complexes together with modulators of their activity prior to receptor activation. How and where these signalling complexes form and the mechanisms governing their assembly and maintenance are not completely understood yet. Initially, we addressed this …  Read more

This study explores the morphology and electrical behavior of breeding weakly electric fish. Wave-type electric fish communicate by means of a continuous oscillatory electric signal produced by an electric organ. The electric organ discharges at frequencies which are sexually dimorphic in many species of electric fish. This dimorphism is thought to be attributed to female mate choice, although to date, there is no evidence for mate choice or intrasexual competition to have driven the evolution of this signaling dimorphism in wave-type electric fish. Here, I have tracked changes in body shape and electric organ discharge (EOD) frequency of A. leptorhynchus …  Read more

The Mitogen-Activated Protein Kinase (MAPK) pathways are evolutionarily conserved signaling units implicated in the transmission of extracellular cues to intracellular compartments. The ERK, JNK and p38 pathways are the best described MAPK cascades. Their function relies on a core module of three kinases, composed of a MAPK Kinase Kinase (MAPKKK), a MAPK Kinase (MAPKK) and a MAPK, which becomes sequentially phosphorylated upon mitogenic, proinflammatory or stress signals. These modules are used in various developmental contexts and are implicated in the maintenance of homeostasis in adult organisms. Although most of the core components of MAPK signaling pathways have been discovered, the …  Read more

Though historically the word "tachyon" has been used to describe hypothetical particles which propagate faster than the speed of light, in a more modern context the term has been recycled to refer to certain unstable states in field theory. This thesis explores the role of tachyonic instabilities in cosmology considering tachyons which arise in string theory and also more conventional, field theoretic instabilities. Our study of such instabilities is, in part, motivated by attempts to embed inflation into string theory. We will argue that the study of string theory models of inflation is well-motivated and may provide a rare potential …  Read more

The international civil aviation system is currently going through a transitional phase. Deregulation and liberalization of air transport services and privatisation of certain airlines have contributed to the modification of the aviation landscape. In this context, airline alliances play a crucial role. Both the US and EC authorities have been supportive of airline alliances because they believe that alliances have the potential to increase competition and to provide the consumers with benefits. The first part of this thesis intends to provide economic and historical background to highlight the reasons for the multiplication of alliances, as well as the political and …  Read more

Paternal exposure to therapeutic drugs or environmental chemicals can alter the genomic integrity of male germ cells, and consequently, be a source of detrimental effects on embryo development. Preconceptional exposure of male rats to the anticancer alkylating agent, cyclophosphamide, resulted in increased embryo loss, malformations and behavioral deficits in the offspring; these drug effects can be transmissible to subsequent generations. The goal of the studies presented in this thesis is to gain an understanding of the manner by which altered spermatozoal genomic integrity, acquired during preconceptional exposure to a DNA damaging agent, may lead to developmental instabilities in the early …  Read more

Neurotrophins, NGF, NT-3, BDNF and NT4-5, are growth factor proteins key to the regulation of neuronal survival, death of differentiation. Neurotrophins bind two types of receptors, Trk tyrosine kinase receptors and the common p75 receptor. Disturbances in Trk expression or signaling can lead to certain cancers such as neuroblastomas and melanomas (TrkA responsive) and medulloblastomas (TrkC responsive). Less is known about the role of p75 in cancer as it plays such varying roles and regulatory functions. We characterized the in vitro and in vivo growth kinetics, tumorigenic potential and response to chemotherapeutics of PC 12-wt rat pheochromocytoma cells and variants …  Read more

Les programmes écrits pour l'exécution d'ordinateur seront toujours susceptibles au vol d'information. Cette information peut inclure des algorithmes de marque de commerce, des données incluses dans le programme, ou même des données concernant les accès de programme. Suivant les avancées technologiques, les informaticiens construisent des outils de plus en plus puissants pour l'ingénierie inverse telle que le décompilateur. Le langage de programmation de Java est particulièrement ouvert aux attaques de l'ingénierie inverse en raison de son format binaire bien défini, ouvert, et portatif. Nous recherches portent sur un domaine permettant de mieux sécuriser fixer la propriété intellectuelle des programmes en …  Read more

Attention Deficit Hyperactivity Disorder, (ADHD), is one of the most common behavioral disorders in children. The role of culture on ADHD symptoms has received little attention in the literature. As a result, trying to determine the extent of which our current knowledge on ADHD is externally valid for other western as well as non-western societies including developing countries remains the challenge. The purpose of this research was to examine the prevalence of ADHD symptoms in Lebanon, a developing Middle Eastern country. The present study provides the first epidemiological data on ADHD symptoms in Lebanese children and is the first to …  Read more

Interactions entre paiements pour services hydrologiques et transitions forestières: étude de cas du bassin hydrographique du Rio Cuale, Mexique. La conversion de forêts en terrains agricoles est actuellement considérée comme la cause principale de déforestation dans les tropiques. Malgré les tendances à la déforestation tropicale, certaines régions présentent maintenant un revirement du couvert forestier. Ce revirement de zones forestières a été appelé transition forestière et est basé sur le regain d'arbres en zones agricoles. L'objectif de cette étude est d'analyser les changements dans le paysage du bassin versant du Rio Cuale, une région où un mécanisme de compensation nommé 'paiement …  Read more

The potential of lignin and mannanoligosaccharides (MOS), as alternatives to antibiotic growth promoters was evaluated in broilers. Dietary treatments included: (1) negative control (CTL-, antibiotic free); (2) positive control (CTL+, 11 mg/kg virginiamycin); (3) MOS (diet 1 + Bio-Mos: 0.2% to 21 d and 0.1% thereafter); (4) LL (diet 1 + 1.25% Alcell lignin); (5) HL (diet 1 + 2.5% Alcell lignin). Bodyweight and feed conversion were not different when broilers were fed the CTL+, MOS, LL or HL diet. Birds fed MOS or LL had increased jejunum villi height (P < 0.05) and greater goblet cell number per villus …  Read more

We have carried out large scale Monte Carlo simulations of site and bond frustrated Heisenberg models in order to gain insight into experimental phase diagrams on bond and site frustrated magnetic materials. In the case of site frustrated models, we find that spin glass ordering does not take place on either the simple cubic or body-centered cubic lattices which are bipartite. Instead, the model decouples into either one or two percolating clusters of ferromagnetic (antiferromagnetic) sites which order ferromagnetically (antiferromagnetically). The ordering is similar to the situation which exists when ferromagnetic and antiferromagnetic sites do not interact at all. Including …  Read more

Sugar maple (Acer saccharum Marsh.) has experienced diebacks in many parts of its range; these declines have caused researchers to consider the many connected factors governing tree health. Altered availability of base cations due to acidic deposition and climatic extremes (drought, late winter freeze-thaw cycles) have been identified as two main causal stressors. To predict the role of climate on Ca nutrition, I investigated the relationship between the climatic factors of temperature, precipitation, water availability and windstorm on temporal changes to depth of Ca source of sugar maple. I hypothesized that the Ca uptake depth would be deeper after windstorms, …  Read more

This thesis used novel methodologies in dendrochemistry to observe past nutrient and Al change in relation to incremental stem xylem growth to predict current and future forest health. The methods included (1) sequential digestion of wood tissue to remove the elemental fraction that is mobile across tree rings leaving the structurally intrinsic, residual (or less mobile) ion fraction for analysis and (2) transformation of elemental concentrations into multivariate ratios (compositional nutrient diagnosis (CND)) over a time series. Sampling of trees represented a gradient in acidity resilience using three regions of southern Quebec (St. Lawrence Lowlands; Lower Laurentians; and Appalachian Highlands) …  Read more

Sulfuric acid hydrolysis of native cellulose fibers produces stable suspensions of cellulose nanocrystals. Within a specific concentration range, the suspensions spontaneously form an anisotropic chiral nematic liquid crystal phase. This thesis examines the phase separation behaviour of these suspensions, alone and in the presence of added macromolecules. Initially, the effect of hydrolysis conditions on the nanocrystal and phase separation properties for hydrolyzed softwood pulp were investigated and compared to suspensions prepared from hardwood pulp. The macromolecules studied, blue dextrans of varying molecular weights and dye ligand densities, were synthesized and characterized with a number of techniques. The polyelectrolytic nature of …  Read more

A complex physiological system, composed of central and peripheral signals, balances energy intake and expenditure. Among these signals, the enteric and orexigenic hormone ghrelin is a regulator of energy balance with several uncharacterized functions. Although much research has accumulated regarding ghrelin's effects on metabolic parameters, little is known about its other behavioural and cognitive effects. Consequently, this study, using functional magnetic resonance imaging, showed that ghrelin administered intravenously to healthy volunteers increased the neural response to food pictures, as well as faces of fear and disgust, in brain areas regulating the hedonic and incentive evaluation of visual stimuli, such as …  Read more

An increasing number of applications require high-resolution images in situations where the access to the sensor and the knowledge of its specifications are limited. In this thesis, the problem of blind super-resolution is addressed, here defined as the estimation of a high-resolution image from one or more low-resolution inputs, under the condition that the degradation model parameters are unknown. The assessment of super-resolved results, using objective measures of image quality, is also addressed. Learning-based methods have been successfully applied to the single frame super-resolution problem in the past. However, sensor characteristics such as the Point Spread Function (PSF) must often …  Read more

Determination of the heat transfer coefficients for natural and mixed convection in horizontal annuli is important for designing double pipe heat exchangers and for energy storage systems. In part one and two of this study, the 2D numerical solution of the laminar natural convection of water in six internally finned horizontal annuli has been obtained. The fins are attached to the external surface of the inner cylinder. Only the symmetrical half of the horizontal annulus with three equally spaced longitudinal divergent solid and porous fins are considered. The parameters of the problem are Rayleigh number, fin height, permeability and porosity …  Read more

The RasGAP—SH3-domain Binding Protein (G3BP1) is an endoribonuclease that links Ras-signalling pathways and mRNA stability. Though implicated in many cellular roles, a well defined function for G3BP1 has yet to be determined. The aim of the following dissertation is to further implicate G3BP1 in mammalian cellular responses to environmental stress, most notably that of Ultraviolet Radiation. We observe G3BP1 transverse from the cytoplasm to the nucleus upon treatment of HeLa cells with apoptotic levels of UVC. Interestingly, forcing its nuclear accumulation in the absence of stress is sufficient to induce apoptotic characteristics. Preliminary observations suggest that plasma membrane signalling and …  Read more

The development of two different classes of optical sources for TD-OCT and FD-OCT are presented in this thesis. The design of several low-cost, high-performance BBSs, based on the ASE of two SOAs and EDF, are presented. Two different configuration types that were designed in this thesis are found to be effective BBSs. These sources are implemented in a TD-OCT system and therefore imaging performance is discussed as well. Secondly, two different WSSs based on mode-locked SFRLs with applications in SS-OCT are presented. From our experimental results with BBSs, we conclude that: (1) S/C-band output produced by the ASE emitted from …  Read more

This thesis is concerned with optical self-inscription in solgel derived nanocomposite waveguides. During self-inscription, an electromagnetic wave propagating in a photosensitive medium induces a permanent local increase in refractive index. In turn, this change in refractive index creates a waveguide for the electromagnetic wave that induced it. We discuss similarities and differences between optical self-inscription and the well-known optical spatial solitons which arise in media supporting a transient change in refractive index. In particular, we show that, as for spatial solitons, optical self-inscription can give rise to straight waveguides, waveguides with periodic corrugations and two counterpropagating self-writing beams can undergo …  Read more

The following thesis presents the results of six full scale beams tests as part of a research program conducted at McGill University on the effect of steel fibres on the shear capacity of a beam with an aid ratio greater than 2.5. The test specimens had the following dimensions: 4400 mm long, 300 mm wide and 500 mm long. The beams had 4-25M bottom reinforcing bars and 2-20M top reinforcing bars. Two series were designed with different reinforcing details: the "BA" series contained transverse reinforcement spaced at 275 mm center to center while the "BB" series had no transverse reinforcement. …  Read more

Group II introns are self-splicing introns found in bacterial, archaeal and organellar genomes. Some group II introns are also mobile retroelements that are capable of invading DNA using an RNA intermediate. Group II introns are the subject of several evolutionary hypotheses. It was suggested that these mobile elements are able to spread via lateral (horizontal) transfer. The association of many bacterial group II introns with other mobile elements further strengthened this theory. Moreover, group II introns are hypothesized to be the progenitors of nuclear spliceosome-dependent introns, as well as the five small nuclear RNAs (snRNAs) part of the spliceosome. The …  Read more

Les études récentes dans l'oncologie psychosocial qui cherche à adresser les effets sociaux, psychologiques, émotives, spirituelles, qualité de vie, et sur les impacts fonctionnels du cancer ont demontré des résultats positifs pour les interventions créant une signication conçu pour aider ceux qui ont le cancer à faire face à leur maladie. Parmi les malades, ces interventions réussissent à reduire la dépression, et à augmenter la satisfaction de vie, l'amour-propre, l’abilité de se débrouiller avec la maladie, le fonctionment physique, et l'optimisme. Pourtant, malgré ces conclusions positives, les interventions faisant la signification et, plus généralement, le soin psychosocial, n'est pas intégré …  Read more

Synaptic connectivity, as opposed to amyloid plaque or neurofibrillary tangle deposition, correlates most closely with cognitive ability in Alzheimer’s disease. In light of this, neocortical cholinergic, glutamatergic and GABAergic neurotransmitter-specific presynaptic bouton densities and dystrophic neurite incidence were quantified in transgenic models of the Alzheimer’s pathology. Evidence suggests that the amyloid pathology progresses in the following neurotransmitter-specific manner: cholinergic glutamatergic > GABAergic. Each neurotransmitter system displayed an elevation in presynaptic bouton density during early stages of pathology, followed by a subsequent depletion with pathological progression. That the cholinergic system exhibited this pattern of synaptic remodelling, prior to any detectable involvement …  Read more

Brain atrophy has been used as a marker for disease progression in Multiple Sclerosis (MS). SIENA, an automated tool for measuring brain volume change, was tested to see whether MRI slice thickness and gap presence affect longitudinal atrophy measures. Isotropic global scan-rescan images were used to simulate 3 mm and 5 mm axial slice thicknesses with 1 and 2mm gaps, respectively. SIENA remained accurate and precise with increasing slice thickness and gap presence. Furthermore, symmetric pre-registration was crucial for scans with larger slice-thickness and gaps. SIENA was used to observe atrophy in children who have experienced a Clinically Isolated Syndrome …  Read more

In contrast to the common depiction of Rawls's political theory as atomistic, his work is instead deeply connected to some of the fundamentally republican themes of Rousseau's political and philosophical oeuvre: these themes include our natural sympathy with other persons; our innate susceptibility to the pleasures of fellow feeling; the duty of political participation, as well as the importance of civic virtue; and, perhaps most importantly, an emphasis on properly designed political institutions as a necessary source of freedom. What we shall ultimately find in both Rousseau and Rawls, then, is a repudiation of cosmopolitan values in light of their …  Read more

Global education is founded upon numerous theoretical frameworks. In this thesis, following a review of relevant literature, I will carefully consider Pike and Selby's (1995) four-dimensional model of global education. Although I regard theirs as the most promising of recent conceptualizations, it doesn't seem to provide a clear articulation of the specifics of their four dimensions, as well as the way in which these can be fostered in learners. In an attempt to address this incompleteness, I will turn to global communications pioneer Marshall McLuhan whose discussion of the global village contains key concepts and definitions that may provide more …  Read more

This research project investigates the nature of university professors' discipline-specific pedagogical knowledge (DPK). Traditionally, DPK has been examined with the help of constructs from two distinct lines of research: the knowledge base for teaching and disciplinary specificity in university teaching. Yet, the two lines of research have seldom been combined to explore DPK. Furthermore, linkages between those two lines of research point to the potential contribution of research on personal epistemologies. Therefore, the aim of this research is to describe empirically the phenomenon of DPK using constructs from these three lines of research. The research project takes the form of …  Read more

Jaagsiekte sheep retrovirus (JSRV) is a simple betaretrovirus that causes a contagious lung adenocarcinoma in sheep. One unique feature of JSRV is that its envelope (Env) glycoprotein functions as an active oncogene that induces oncogenic transformation in vitro and in vivo. While oncogenesis by JSRV Env protein has been extensively studied, the entry mechanism of JSRV has not been investigated. In this study, we showed that JSRV entry was specifically inhibited by lysosomotropic agents and bafilomycin Al (BafAl), indicating that JSRV is pH-dependent. Interestingly, oncoretroviral pseudotypes bearing JSRV Env protein were not inactivated by an acidic pH treatment, suggesting that …  Read more

The copper-catalyzed synthesis of functionalized pyridines and partially reduced pyridine derivatives has been developed and the results are presented herein. These studies have shown that pyridines (and related aromatic heterocycles) in the presence of chloroformates will undergo effective coupling with terminal alkynes and organoindium reagents using simple copper (I) salt catalysts to give good yields of dihydropyridine products. In addition, performing these reactions in tandem with base or oxidative additives has led to the copper-catalyzed one-pot preparation of substituted aromatic pyridines.  Read more

Les pré-protéines nucléaires, avec une séquence de ciblage interne destinées à la mitochondrie, sont importées via le récepteur Tom70, situé sur la membrane externe de la mitochondrie. Cependant, avant d’être amenées vers la mitochondrie, les pré-protéines sont maintenues dans un état permettant l’importation par un complexe de chaperons dans le cytosol. Le Transporteur du Nucléotide Adénine (ANT), une protéine porteuse de la membrane interne de la mitochondrie suit le cheminement via Tom70 et sa forme mature purifiée est semblable à celle de la pré-protéine. L’ANT purifiée reconstituée dans du lysat de réticulocyte a permit d’identifier par spectroscopie de masse les …  Read more

The extracellular matrix is a vital component of the cardiovascular system, in that, it not only provides structural support but also plays a critical role in the maintenance of cellular stability. One of the major components of the vascular matrix is elastin, which confers vessels with the specialized property of stretch and recoil. Elastin deficiency has been implicated in many vascular diseases and determined experimentally to be a negative regulator of smooth muscle cell proliferation. In zebrafish, two elastin genes have been identified, which are actively expressed during development. Based on this finding, protein production and spatial localization for the …  Read more

Les méthodes de modélisation basées sur la structure tridimensionnelle des protéines sont d'une grande utilité dans le développement de médicaments. Cette thèse résume cinq projets de recherche proposant des avancées dans la méthodologie et les protocoles liés à la découverte et à l'optimisation de petites molécules actives. Le premier projet démontre que le paradigme voulant que la surface moléculaire exposée au solvant soit décrite par le contact d'une sonde sphérique de rayon constant de 1.4Å avec la protéine fait apparaître des poches et des cavités hydrophobes irréalistes sur la surface. Une méthode novatrice est présentée où le rayon de la …  Read more

Insulin-like growth factor-1 (IGF-1) is essential for oligodendrocyte (OL) development, promoting their survival, proliferation and differentiation. Furthermore, IGF-1 null mutant mice have a decrease in CNS myelination and in the number of OL progenitors (OLPs). IGF-1 interacts with the Type I IGF receptor to activate two main downstream signalling pathways, the PI3K/Akt and the Ras-Raf-MEK/ERK cascades, which mediate survival or proliferation of OLPs. The objective of this study is to elucidate the transduction pathways involved in IGF-I-stimulated protein synthesis, important for growth and differentiation of OLs. In other cellular systems, the PI3K/Akt pathway is involved in protein translation. mTOR and …  Read more

Schedulers in optical switches are still electronic, the performance of these units has a significant impact on the performance of the network and could form a bottleneck in high speed networks, such as AAPN. Four time-slotted scheduling algorithms are investigated in this study, PIM, iSlip, PHM and Adapted-SRA. The study addresses the performance of AAPN for each of the algorithms, and evaluates the hardware complexity, estimating the running time of the algorithms. Performance measures were collected from an OPNET model, designed to emulate AAPN. Furthermore, hardware complexity and timing constraints were evaluated through hardware simulations, for iSlip, and through analysis …  Read more

Normal cellular proliferation is controlled by two major pathways, the pRB and the p53 pathways. It is believed that one or both of these two pathways is disrupted in all tumour cells. The functions of pRB are disrupted by viral oncoproteins, which displace important cellular components from a highly conserved region known as the "pocket". The first cellular "pocket"-binding protein identified is the retinoblastoma binding protein 1 (RBP1). RBP1 and the RBP1-like protein BCAA are inherent subunits of the chromatin modifying transcription repression complex mSIN3A/HDAC. By linking the pRB protein to this repression complex, RBP1 is believed to mediate repression …  Read more

One of the central problems concerning research with children is the delineation of appropriate levels of risk exposure. In the U.S. Code of Federal Regulations, the "minimal risk" concept serves as an anchoring measure for allowable risk. While the regulations sought to promote a balance between scientific advances and the protection of children's vulnerable status, ambiguities in the language of the regulations and the regulatory definition of "minimal risk" have given rise to a great deal of confusion. Research ethics boards and the medical community espouse a multitude of varying opinions regarding the interpretation and application of the federal regulations …  Read more

This thesis discusses the prospect of integrating vibrotactile feedback into digital musical instruments. A holistic approach is taken, considering the role of new instruments in electronic music, as well as the concept of touch in culture and experience. Research about the human biological systems that enable vibrotactile perception is reviewed, with a special focus on its relevance to music. Out of this review, an approach to vibration synthesis is developed that integrates the current understanding of human vibrotactile perception. An account of musical vibrotactile interaction design is presented, which includes the implementation of a vibrotactile feedback synthesizer and the construction …  Read more

In modern communications systems, the components supporting wavelength division for increased density are rapidly becoming small compared with the wavelength of light being manipulated. As the size of these devices shrinks there comes a point when the features of interest become smaller than the wavelength and thereby the fundamental properties of light interaction with such structures change dramatically. In these structures and materials, resonances, effective properties, and band-gaps arise and offer designers a new realm of possibilities for the design of high quality factor resonators, filters and switches. The study of structures comprising two different scales compared with the wavelength …  Read more

This thesis examines the influence of Luigi Dallapiccola (1904–1975) on Bruno Maderna's (1920–1973) early serialism by means of a comparative analysis. Two song cycles are compared: Dallapiccola's Liriche greche (1942–45) and Maderna's Tre liriche greche per piccolo coro, soprano solo e strumenti (1948). The author presents separate analyses of each work (Chapters 1 and 2), which form the basis for comparison (Chapter 3). The analysis of Dallapiccola's Liriche greche examines in particular the effects of his non-serial compositional choices on his twelve-tone method. The discussion of Maderna's Tre liriche greche illustrates how his novel methods of serial development result from …  Read more

Clopidogrel is an antiplatelet drug prescribed to prevent stent thrombosis after a percutaneous coronary intervention (PCI). Previous evidence suggests that some widely prescribed statins may inhibit the antiplatelet effects of clopidogrel via competitive metabolism of its activating enzyme cytochrome P450 3A4 (CYP3A4). The objective was to investigate the possibility of an interaction post-PCI between statins and clopidogrel. We carried out a population-based cohort study identifying 10,491 patients using clopidogrel post-PCI (2001-2004). The outcome was a composite of death of any cause, myocardial infarction, unstable angina, repeat revascularization, and cerebrovascular events. We found that co-prescription of CYP3A4-metabolized statins (hazard ratio (HR) …  Read more