McGill University Thèses et mémoires publiés en 2004

The year 2003 marks the entering into force of the new Montreal Convention governing certain rules for international carriage by air. This, however, does not mean that the international community, including States, air carriers and their agents, passengers, shippers and consignors, insurance companies and the legal community in general (specially aviation lawyers and judges) shall only rely on this instrument. The Warsaw Convention and its complementary instruments, known as the Warsaw System, is still applicable and in certain circumstances, may be the only existing relation binding States and air carriers, especially in terms of liability and compensatory damages arising from …  Lire la suite

Caulobacter crescentus is an asymmetrically dividing bacterium whose progeny differ in their ability to initiate chromosome replication. The stalked cell can initiate replication, whereas the motile swarmer cell must differentiate into a stalked cell prior to replication. This cell differentiation is obligate and essential for completion of the natural C. crescentus cell-cycle. In model bacteria, such as Escherichia coli, replication is governed by the DnaA protein, however the role of DnaA in C. crescentus replication control has not been studied. To address the requirements for DnaA, a strain was constructed where dnaA was conditionally expressed in C. crescentus. DnaA's absence …  Lire la suite

Elliptic curves are one of the important class of problems in diophantine equations. In this thesis, we describe how to obtain algebraic points (called Heegner points) on elliptic curves. We first go over the necessary definitions and theorems in order to properly study these points and their properties. We pay a particular attention to the property of these point to have integral coordinates or not. We also explain how to make explicit computations of these points and discuss the result of extensive computations made on the elliptic curves of conductor less than 3000, and give a list of the curves …  Lire la suite

Cystic fibrosis (CF) patients have airway neutrophilic inflammation associated with high levels of interleukin-8 (IL-8) and often develop airway hyperresponsiveness (AHR). Aerosolized uridine triphosphate (UTP) has been used to improve mucosal clearance by inducing Cl- secretion. However, nucleotides such as UTP and ATP (adenine triphosphate) also evoke the release of intracellular Ca2+ ([Ca2+]i), which are enhanced by pro-inflammatory mediators, such as IL-1beta. Since most of the CF airway epithelium is lost during infection and inflammation, the underlying airway smooth muscle cells (ASMC) are exposed to IL-8 and extracellular nucleotides. Thus, we were particularly interested in evaluating the effects of IL-8, …  Lire la suite

Microglia are the resident immune cells of the central nervous system (CNS). Although the microglial response can be beneficial, there is increasing evidence for detrimental effects of the microglial activation in cases of acute CNS trauma and neurodegenerative disorders. To better understand the role of these cells in CNS pathogenesis, we have created a mouse model with selective and conditional ablation of microglia as well as other cells of myeloid origin in proliferation. To achieve the elimination of proliferating microglia, transgenic mice that express the suicidal gene herpes simplex virus 1 thymidine kinase (HSV-1 TK) driven by the myeloid specific …  Lire la suite

The upper Bay of Fundy's Cumberland Basin contains an estimated 16,500 hectares of salt marsh, nearly all of which have been diked and converted to agricultural lands since the arrival of the Acadians in the late 17 th century. John Lusby Marsh is a 600 ha salt marsh that was diked and farmed for approximately 250 years, until dikes breached in the late 1940s and the marsh was restored to tidal conditions. A sediment core that contained the reclamation surface was extracted in John Lusby Marsh, and a trial set of eight fossil pollen spectra was compared to the modern …  Lire la suite

The neurotoxin 6-hydroxydopamine (6-OHDA) is widely used to produce a neurochemically selective and progressive destruction of dopamine pathways. The resulting motoric deficits and histopathology reproduces several key features of Parkinson's disease, a neurodegenerative disorder for which there is no known cure. The objective of the present thesis was to characterize the in vivo neurotoxicity of 6-OHDA in dopamine pathways, and to examine the mechanisms underlying dopamine cell death. Infusion of 6-OHDA into different dopamine pathways revealed that the nigrostriatal projection was more vulnerable than the mesolimbic dopamine pathway. In addition, a considerable portion of cell bodies was preserved despite significant …  Lire la suite

Hes1 is a mammalian basic helix loop helix (bHLH) factor that inhibits neuronal differentiation by mediating transcription repression mechanisms together with corepressors of the Gro/TLE family. The interaction of Hes1 with Gro/TLE is mediated by a WRPW tetrapeptide present at the carboxy-terminus of all Hes proteins. Another lies protein, Hes6, also interacts with Gro/TLE through its WRPW motif. Contrary to Hes1, Hes6 promotes neuronal differentiation. It is shown here that Hes6 negatively regulates Hes1 activity by at least two mechanisms. Hes6 promotes a proteolytic degradation of Hes1. Moreover, Hes6 inhibits the interaction of Hes1 with its transcriptional corepressor, Gro/TLE. Hes6 …  Lire la suite

Background. The intention-to-treat (ITT) approach is an analytic approach for the analysis of randomized controlled trials (RCT) in which patients are analysed as randomized regardless of the treatment received. Objective. To evaluate the (1) proportion of articles describing a randomized trial in main medical journals in 2002 reporting the use of ITT, (2) proportion violating a major component of ITT, (3) distribution and management of missing data in the analysis of the studies reporting an ITT analysis. Method. We conducted a cross-sectional literature review of RCTs reported in 10 medical journals in 2002. A single rater, using a standardized form, …  Lire la suite

Remediation of phonological awareness (PA) deficits in preschool age children is essential to the prevention of delayed acquisition of reading abilities. The purpose of this research was to develop and assess the efficacy of a program to teach PA to preschool-aged children with delayed PA. Ten preschoolers with articulation disorders participated in 8 training sessions focusing on phonological awareness (PA) and phonemic perception. These children made significant improvements in their PA abilities such that their post-treatment PA test performance was not significantly poorer than that of normally developing children, but was significantly better than that of children with an articulation …  Lire la suite

Michel Foucault has exerted a pervasive influence on the concept of power in the twentieth century. By expanding the definition of power, and its horizons, beyond the state or organized institutions, he has bestowed power upon the weak as well as the strong, reconceptualized it from a one-dimensional, to an all-pervasive entity. This thesis has adopted this expansive view of power and applied it to a study of the religious life within the Congregation de Notre-Dame of Montreal between 1693 and 1796. On a general level, the study, working within the framework of other research that has attempted to broaden …  Lire la suite

A seizure warning system for intracerebral EEG is proposed. It is designed for clinical use with the intention of identifying sections of EEG containing seizure activity and alerting medical staff as a seizure occurs. The system is based on data filtering, spectral feature extraction, probability analysis using Bayes' theorem, spatial and temporal context analysis, and user tuneability. The system was designed using 407 hours of EEG from 19 patients having 152 seizures. Once developed, the system was tested with a different set of EEGs from 19 patients having a total of 100 seizures during 389 hours. Average results for the …  Lire la suite

The luminescence properties of trans-dioxo rhenium(V) and osmium(VI) [d2] and square-planar platinum(II) and palladium(II) [d8] transition metal complexes have been studied as a function of temperature and pressure. Both types of complexes studied have idealized D4h point group symmetry with the d2 systems representing the tetragonally compressed limit of a six-coordinate complex in the D4h point group and the d8 systems representing the tetragonally elongated limit. The observed luminescence in both classes of complexes has been assigned as a metal-centered (d → d) 3Eg → 1A1g transition. The application of external pressure provides a means to induce minor changes in …  Lire la suite

Scattering samples such as tissue or milk are difficult to analyze using spectroscopy. Due to scattering, the path length of light through samples varies. However, diffuse scattering is repetitive, and can therefore be considered to be a self-similar process. This thesis shows that mathematical techniques which characterize self-similarity can significantly improve spectroscopic quantification in absorbing/scattering media. Often, quantification in scattering samples relies on multivariate analysis of near-infrared (NIR) spectra. Using data from wheat samples and tissue phantoms, it is shown that Haar transform (HT) preprocessing improves quantification. Wavelet domain calibration reduces the need for trial and error preprocessing of spectra, …  Lire la suite

Recent research has argued that the intact functioning of both the left (LH) and right cerebral hemispheres (RE) is integral for comprehending lexically ambiguous words (Chiarello, 1998; Faust & Chiarello, 1998; Faust & Gemsbacher, 1996). While studies of neurologically intact individuals have attributed specific functions to the LH and RH, studies of brain-damaged patients have failed to provide complementary evidence for these hemispheric abilities. In addition, the majority of studies have focused on ambiguity resolution in single-sentence (local) contexts, and, as such, do not address whether each hemisphere is sensitive to different types of context, a factor which could potentially …  Lire la suite

A forced choice reaction time (RT) task was used to assess developmental changes in filtering and the related ability to narrow the focus of the attentional lens among persons with autism as compared to a group of typically developing children matched on different standardized measures. The participants included 35 persons with autism (CAs between 8.3 and 13.2 years, M = 9.8 years) and 35 typically developing children (CAs between 4.8 and 7.3 years, M = 5.9 years) between the mental ages (MA) of 5 and 8 years. The measures used for matching include the Leiter International Performance Scale - Revised …  Lire la suite

Markov Decision Processes (MDPs) and Bayesian Networks (BNs) are two very different but equally prominent frameworks for modeling stochastic environments. As empirical testing and the use of randomized search algorithms gain increasing importance in machine learning and artificial intelligence, there exists a growing need for random models; in particular MDPs and BNs. This thesis aims at providing a focused review of the field of random model generation. We begin by motivating in detail the need for rigorous random MDP and BN generation and survey relevant past research efforts. We outline the different problems involved in generating the models and then …  Lire la suite

With decreasing transistor sizes and increasing circuit complexity, managing the clock skew becomes an increasingly important and challenging task. A novel method of generating and distributing a synchronous clock to multiple nodes in a distributed system will be presented here. Using phase-locked and delay-locked loop techniques, the system establishes total synchronization by adjusting the internal delay between nodes so that all inter-node delays become equal. Matlab Monte-Carlo simulations of an ideal 8 node system are presented which validate the theoretical description as well as gauge the performance of any realistic implementation. A simple yet realistic HSPICE model is used to …  Lire la suite

The British colonial administration in India transformed Muslim law in the nineteenth century through the three concurrent processes of translation, legislation, and adjudication. Although Indian Muslims were gradually displaced in their traditional position as interpreters of that law in the role of muftis, discerning and applying the shari'ah according to Hanafi principles of fiqh, they nonetheless played a vital role in the transformation of Muslim law. Towards the end of the nineteenth century, Muslim participation became more noticeable and significant as they moved into increasingly influential positions in the British judicial administration. Syed Mahmood (1850-1903) was a pioneer in this …  Lire la suite

The clinical use of chemotherapeutic agents against malignant tumors is successful in many cases but suffers from major drawbacks. One drawback is the lack of selectivity which leads to severe side effects and limited efficacy, and another is the emergence/selection of drug-resistance. To limit non-specific toxicity and to improve the efficiency of cancer therapy, "tumor markers", which are proteins generally overexpressed on the surface of tumor cells, can be selectively targeted. Growth factor receptors are one of the most extensively studied groups of tumor markers. The implication of growth factor receptors in the pathogenesis of cancer has clearly been established …  Lire la suite

Recent studies suggest that caspases are involved in neuronal apoptosis and Alzheimer's disease (AD). However, which effector caspase plays an essential role in AD pathogenesis is still elusive. Caspase-6 is implicated as a main effector caspase in human primary neuron culture (LeBlanc et al., 1999; Zhang et al., 2000). Therefore, the first objective of my study is to investigate whether caspase-6 is involved in AD. We generated an antiserum (1277) recognizing the p20 subunit of caspase-6. By using the 1277 antiserum, we investigate fifteen AD and eight control brains from Canadian brain tissue bank. We observe 2-3 fold increase of …  Lire la suite

Twenty-five years of independent, underground, or punk rock music-making in St. John's, Newfoundland, have been defined by geographic isolation. In tracing a historical record of the small city's punk/indie scene, this project seeks to evaluate recent academic discussion surrounding the role of collectivity in artistic 'independence' and examine the impact of prevailing international aesthetics and changing communication technologies on local practice. The self-containment and self-sufficiency of the St. John's music community, largely the product of the city's isolated position on the extreme eastern tip of a large island off the east coast of North America, provide a unique backdrop against …  Lire la suite

We examine the history and performance of the sequential spectral method. We find that the sequential spectral method is related to Waveform Relaxation methods and to iterative schemes that precede its inception by a century. Using the two-dimensional Navier-Stokes equations, we compare the performance of the sequential spectral method with two traditional numerical pseudospectral Galerkin frameworks: a semi-implicit time discretization, and a traditional fully implicit discretization. We depart from preceding implementations of the sequential spectral method by developing an entirely parallel algorithm. We also introduce periodic boundary conditions. We deviate even further from previous implementations by incorporating the Fast Fourier …  Lire la suite

Mutations in the Parkin gene cause a juvenile-onset form of Parkinson's disease (PD) that is transmitted in an autosomal recessive fashion. Studies have shown that Parkin mutations account for far more cases of PD than all other known genetic causes combined. Further, mutations have been identified even in apparently sporadic cases, suggesting a broader role. There is now strong evidence that Parkin functions in the ubiquitin proteasome pathway (UPP), the main system for protein degradation in the cell. Ubiquitin (Ub), a small 76 amino acid protein, can be covalently attached to other proteins. Proteins tagged with Ub are recognized and …  Lire la suite

Various aspects of Ca2+ uptake into greenhouse-grown potato plants and micropropagated potato plantlets were examined, including the movement of Ca2+ into potato plants and tubers, identification of Ca-packing genotypes and assessment of the effect of improved medium Ca2+ level on different parameters such as plantlet growth, microtuber induction, yield and tissue Ca concentration. The effect of exogenous vitamin Ds and UV-elicited endogenous vitamin D synthesis on regulation of 45Ca 2+ uptake into plantlet shoots was also examined. Safranin dye was not as suitable as the tracer 45Ca2+ for monitoring translocation of Ca2+ into tubers. Uptake of Ca2+ into tubers occurred …  Lire la suite

Traditional search methods have always suffered from both spatial and temporal expansion, especially when exploring deeply in search trees. In this thesis, an optimization technique that reduces the search tree depth and at the same time maintains the same quality of search is proposed. This research examines the Genetic Algorithm methodology as a new technique for evolving optimal strategies by evolving the best weights for the evaluation function. Moreover, this research demonstrates the hypothesis of breadth over depth by showing how an increase in the number of features in an optimized evaluation function in a minimax tree can lead to …  Lire la suite

This thesis critically surveys the dynamics of social work modernization in the state of Indonesia. The study examines the polarization, characteristics and trends of social work throughout the history of Indonesia. The survey begins by reviewing the two contexts of the historical developments of social work in both the developed and developing countries of the Third World. This historical overview is pivotal to place the context of social work development in Indonesia. Tracing the origins and the nature of 'social work' in Indonesia under the pre- and colonial rule will further highlight the course of its development. The adoption of …  Lire la suite

During HIV-1 assembly, Gag, GagPol, and Env are assembled into immature viral particles at the plasma membrane, along with viral genomic RNA and other viral and cellular factors. Among the cellular factors are lysyl-tRNA synthetase (LysRS) and tRNALys3, the primer tRNA for reverse transcription. LysRS is a tRNALys-binding protein, and is the enzyme that aminoacylates tRNALys. It is therefore a likely candidate for the signal which targets tRNALys for packaging into HIV-1. Gag alone among the viral proteins is sufficient to package LysRS, but the additional presence of GagPol is required for tRNALys incorporation as well. We propose that the …  Lire la suite

This thesis examines the initiation and dynamics of accommodation in protracted conflicts in the developing world characterized by important stakes and major asymmetries. The case study is the Palestinian-Israeli conflict and in particular Palestinian strategy from 1991--2000. This thesis argues that external politico-military concerns are the main explanatory factors affecting the pursuit of accommodation in this type of case. Powerful third parties play a significant role in initiating/mediating processes of accommodation and in providing assurances/incentives to encourage its pursuit. Bilateral conditions, especially perceptions of irreversible decline by the weaker party and solid expectations of reciprocity from its opponent, are the …  Lire la suite

Finite-Difference Time-Domain (FDTD) is a numerical method often used to analyze interaction of electromagnetic radiation with complex geometries. In this work, we use FDTD method to compute electromagnetic fields in the near-field of several antennas types. These antennas include bowtie antenna, "Dark Eyes" antenna, quarter-wave monopole antenna, monopole-helix antenna and patch antenna. Each one of these structures is modeled and numerically tested using the FDTD-based software, which allows us to incorporate detailed models of the human anatomy in the simulation. We test antennas in two application scenarios: cell phone radiation and breast cancer detection. For cell phone radiation, we study …  Lire la suite

Nigam, Nilima (Supervisor)  Lire la suite

The death penalty occupies an essential place in Victor Hugo's work, notably in his narrative work where he emphasizes the rhetoric resources in attempts to convince his reader of the necessity of abolishing this practice which he considers "barbaric". This memoir suggests a reading of this rhetoric, concentrating on various specific Hugolian arguments and suggesting a global vision of his reasoning. The first chapter demonstrates that the opposition between law and his application lies at the root of the judicial criticism according to Hugo, from which also stems the question of death penalty to begin with. We then study the …  Lire la suite

This work addresses the problem of robust stabilization and robust Hinfinity control of uncertain time-delay systems. The time-delays are considered to be present in the states and/or the outputs, and the uncertainties in the system representation are of the parametric norm-bounded type. Both cases of actuators, with and without saturation are studied, and the state-feedback and output-feedback control designs are presented. Two methods for analysis and synthesis of controllers are used: The first is based on the transfer function, and the second on the use of functionals. In the context of the design method based on transfer functions, the problem …  Lire la suite

The goal of this thesis is to re-evaluate the origins of the Caribou Inuit. The thesis presents theories that have been proposed by Birket-Smith (1929), Burch (1978), and Clark (1978). Each theory represents a diverse perspective regarding Caribou Inuit origins that include, respectively, a proto-Eskimo origin, an immigration origin, and cultural change resulting from European contact. The alternative theory being proposed in this thesis is that change in environmental conditions that resulted from the Little Ice Age caused the most favoured food resource, the ringed seal, to decline significantly in abundance because the necessary ice conditions that are required for …  Lire la suite

The Mill on the Floss, by Victorian novelist George Eliot, is a polylinguistic novel in Bakhtine's sense of the word in that it integrates the linguistic diversity of the society which it depicts. This novel published in 1860 was translated six times into French but never enjoyed a great reception in France. We examine three translations in this thesis: the first is by Francois D'Albert-Durade (1863), the second is by Lucienne Molitor (1957) and the last is by Alain Jumeau (2003). D'Albert-Durade's translation evacuates the linguistic diversity in order to shape the novel to the requirements of the target literary …  Lire la suite

This research uses isonymy (same-surname) methods and models to examine the population structure and migratory history of Quebec, Canada. Through a case study using 1765 and 1881 census and marriage records from 1621-1900, I explore the accuracy of sources as well as develop, test and apply different statistical methods, and experiment with mapping techniques that reveal paths and patterns of French Canadian surnames. Each investigation explores and evaluates a particular method. I noted that multivariate methods, including cluster analysis, relevance networks, and correspondence analysis, not traditionally used in surname analysis offer reliable and informative results, and insights into the hierarchical …  Lire la suite

A key reason for malignant glioma recurrence after radical tumor resection is the failure to control individual invading tumor cells that have moved away from the primary tumor mass. The purpose of this study was to assess the role of ROCK (Rho-kinase), a signaling protein in the Rho GTPase pathway, in malignant glioma invasion in a three-dimensional model system. Primary glioblastoma (GBM) explants or multicellular spheroids were implanted into a three-dimensional collagen type I matrix. Individual tumor cells detached from the explants or spheroids and invaded the matrix, or invaded human fetal astrocyte spheroids. Treatment of implanted spheroids or explants …  Lire la suite

A sampling-followed-by-imaging technique for sizing bubbles in flotation systems has been developed and validated. The technique is based on directing a sample of bubbles into a viewing chamber where they are exposed and digitally imaged using incoherent backlighting. The images are automatically analyzed by means of a threshold criterion. The chamber is sloped to spread the bubbles over the surface of the viewing (glass) window. This configuration reduces bubble overlap and facilitates the definition of the focus plane. To validate the images, measurements were compared with standardized bubble sizes obtained with the displaced-volume method. It was observed that when thresholding …  Lire la suite

Many a robotic pitch-roll wrist uses a bevel-gear differential train to drive the gripper. The innovative design of pitch-roll wrists using spherical cam-roller pairs is currently underway at McGill University's Centre for Intelligent Machines, with the aim of overcoming the drawbacks of bevel-gear trains. This innovative design relies on Speed-o-Cam, a new concept of speed-reduction mechanisms based on cams and pure-rolling contact, intended to replace gears and harmonic drives in applications where backlash, friction, and flexibility cannot be tolerated. The new mechanism consists mainly of a spherical conjugate cam subassembly and two roller-carrying disks. We start with a study of …  Lire la suite

For TRIP steels to be included as a future structural steel in automobile industries, the drawbacks associated with high silicon (more than 1%) must be solved. To this end, TRIP steels, with aluminum as a substitute for the silicon, have been under investigation by many groups. In this work, the approach is to investigate the effect of hot deformation on the microstructure and the mechanical properties of the aluminum containing TRIP steels. The problem with these steels is that the strength is reduced compared to classical Si TRIP steels. In this work, a number of mechanisms could contribute to the …  Lire la suite

In positron emission mammography, the use of planar detector limits the angular coverage and introduces more noise than conventional positron emission tomography. We first studied the sampling artifacts introduced from the use of discrete crystals. The images are reconstructed by back-projecting lines of response from and to the centroid of interaction within the crystal. We postulate that the sampling artifact should be reduced by allowing the lines of response to shift away from the centroid towards the next most probable crystal element. We then studied noise in the peripheral region of the images. The solid angle function is an image …  Lire la suite

Developmental neuron death is determined by the activities of pro-survival and pro-apoptotic proteins. Here, we investigate the functions of three such proteins---p73, p63 and XIAP---in cultured neonatal sympathetic neurons. p73 and p63 are members of the p53 family that exist in both full-length (TA) and truncated (DeltaN) isoforms. First, we ask whether DeltaNp73 mediates sympathetic neuron survival in p53-dependent and/or -independent fashions. Overexpression of DeltaNp73 in sympathetic neurons withdrawn from NGF prevents upregulation of the p53 targets p21waf1 and Apaf-1, induction of the BH3-only protein BimEL, and cleavage of the effector caspase-3. DeltaNp73 also promotes survival in p53-independent manner by …  Lire la suite

The maturing of the telecommunications industry has seen the development and implementation of devices that work at high frequencies of the electromagnetic spectrum. With the rapid deployment of optical networks, there is an increasing demand for low-cost and efficient communications circuitry. In order to interface with such high frequency signals at lower cost, there has been a recent push for very high frequency circuits using low-cost fabrication technologies like digital CMOS. This thesis investigates the usage of legacy architectures and the implementation of different topologies using digital CMOS technology. Various Clock and Data Recovery Phase-Locked Loops have been implemented using …  Lire la suite

This thesis examines the design and characterisation of a compact optical power equalizer module for optical fiber telecommunication applications. The various components of the modules are separately examined in terms of their impact on the overall dimension, performance and loss of the equalizer module. Two components are studied in greater details, namely the micro diffractive optical elements (DOEs), responsible for the multiplexing/demultiplexing of the wavelength channels, and the micromirrors, responsible for creating the beam displacements and thus controlling the attenuation. The DOEs allow for the spatial separation of 64 wavelengths into a two-dimensional array with a compact module. MUMPs surface-micromachined …  Lire la suite

Podgorsak, Ervin (Supervisor)  Lire la suite

Blanche Lemco van Ginkel (1923), a pioneering Canadian woman architect and urban planner, contributed to the most important planning projects in Montreal during the 1960s. She worked in collaboration with H. P. Daniel van Ginkel, and together their planning proposals determined the direction of the future growth of Montreal. At a time of rapid clearance and construction in the city core, and when the Old City was at risk of total demolition, the van Ginkels were committed to the development of a humane architectural environment. The van Ginkels understood Modernism as a movement concerned with ethical, social and technical improvements …  Lire la suite

Incorporation of a learning philosophy into an existing learning environment can be challenging to the point of abandoning the process or failing to realize any improvements. Metaphor, a form of figurative language has the potential to clarify or increase the understanding of an unknown or unfamiliar concept. The metaphoric process accomplishes this through "comparative mapping," where the unknown is understood via an interaction with a known concept in a familiar domain. This can be extrapolated to include understanding a philosophy despite a lack of direct experience, rendering the previously unknown philosophy a known phenomenon. This thesis promotes the use of …  Lire la suite

Shrier, Alvin (Supervisor)  Lire la suite

We examine both quintessence and inflation within the brane-world picture, wherein the world is (4+d)-dimensional, and all standard model fields are trapped on the surface of a p-dimensional brane. We examine the situation where the inter-brane potential is dominated by the exchange of either a massless or a massive mode, for the case where the extra dimensions have the topology of a torus. In doing so, we find that neither potential is flat enough to allow for sufficient inflation. We will also propose a brane-based model where there are two large extra dimensions. In deriving the low-energy theory on the …  Lire la suite

Tolkien's aesthetic enjoyment of distance and antiquity in literature, his interest in the power of imagination, and his use of medieval romances and ancient fairy-tales as a means of rediscovering an enchanted vision of the world are analogous to the literary endeavours of the Romantics. Like them, he perceives that the real world is inherently different from how he imagines an ideal world. This thesis discovers that Tolkien's writings correspond in numerous ways to the modern form of elegiac romance, most notably because of their positive portrayals of mortality, and their depictions of intense yearning. The moral imperative to accept …  Lire la suite