858 resultados para Space and place
Resumo:
This thesis is concerned with the interaction between literature and abstract thought. More specifically, it studies the epistemological charge of the literary, the type of knowledge that is carried by elements proper to fictional narratives into different disciplines. By concentrating on two different theoretical methods, the creation of thought experiments and the framing of possible worlds, methods which were elaborated and are still used today in spheres as varied as modal logics, analytic philosophy and physics, and by following their reinsertion within literary theory, the research develops the theory that both thought experiments and possible worlds are in fact short narrative stories that inform knowledge through literary means. By using two novels, Abbott’s Flatland and Vonnegut’s The Sirens of Titan, that describe extra-dimensional existence in radically different ways, respectively as a phenomenologically unknowable space and as an outward perspective on time, it becomes clear that literature is constitutive of the way in which worlds, fictive, real or otherwise, are constructed and understood. Thus dimensions, established through extensional analogies as either experimental knowledge or modal possibility for a given world, generate new directions for thought, which can then take part in the inductive/deductive process of scientia. By contrasting the dimensions of narrative with the way that dimensions were historically constituted, the research also establishes that the literary opens up an infinite potential of abstract space-time domains, defined by their specific rules and limits, and that these different experimental folds are themselves partaking in a dimensional process responsible for new forms of understanding. Over against science fiction literary theories of speculation that posit an equation between the fictive and the real, this thesis examines the complex structure of many overlapping possibilities that can organise themselves around larger compossible wholes, thus offering a theory of reading that is both non-mimetic and non-causal. It consequently examines the a dynamic process whereby literature is always reconceived through possibilities actualised by reading while never defining how the reader will ultimately understand the overarching structure. In this context, the thesis argues that a causal story can be construed out of any one interaction with a given narrative—underscoring, for example, the divinatory strength of a particular vision of the future—even as this narrative represents only a fraction of the potential knowledge of any particular literary text. Ultimately, the study concludes by tracing out how novel comprehensions of the literary, framed by the material conditions of their own space and time, endlessly renew themselves through multiple interactions, generating analogies and speculations that facilitate the creation of new knowledge.
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Connue pour son rôle dans la cascade de coagulation, la thrombine, une protéase à sérine, peut également agir par l’intermédiaire de PAR1, un récepteur activé par protéase et couplé aux protéines G liant le GTP (GPCR). La thrombine se lie et clive l’extrémité N-terminale du PAR1 entre l’Arg41 et la Ser42, exposant une nouvelle extrémité terminale qui agit elle-même comme un ligand. La thrombine et une séquence peptidique de cinq acides aminés, composée des résidus Ser42 à Arg46, nommée PAR1-AP, déclenchent dans diverses cellules de mammifères une réponse intracellulaire comportant une composante calcique. Dans cette étude, le système d’expression par baculovirus dans les cellules Sf9 d'insecte nous a permis d'exprimer le récepteur PAR1 du rat à la surface de ces cellules et de réaliser son couplage fonctionnel à leur signalisation intracellulaire (modèle rPAR1-Sf9). La composante calcique de celle-ci, en réponse au PAR1-AP, a ensuite été étudiée en détail à l’aide de la sonde fluorescente Fura-2 et de plusieurs inhibiteurs agissant sur les canaux calciques ou d'autres éléments de la cascade de signalisation du calcium intracellulaire. Lorsque le milieu extracellulaire contient du calcium (Ca2+), la thrombine ou PAR1-AP déclenchent un signal calcique qui consiste en une augmentation rapide de [Ca2+]i suivi d’un plateau relativement soutenu, puis d'un retour lent vers le niveau de base initial. En l'absence de Ca2+ dans le milieu extracellulaire, l'augmentation initiale rapide de [Ca2+]i est suivie d'un retour rapide vers le [Ca2+]i de base. À l’aide d’inhibiteurs de canaux calciques, tels que le lanthane, la nifédipine et le D-600, l'entrée du calcium du milieu extracellulaire dans les cellules est inhibée, abolissant le plateau soutenu de [Ca2+]i. L’inhibition de la pompe Ca2+-ATPase par la thapsigargine supprime la réponse au PAR1-AP après épuisement des sites de stockage de Ca2+intracellulaire. Le TMB-8 agit de façon discordante quant à l’inhibition de la libération de Ca2+ des sites de stockage intracellulaires. La réponse à PAR1-AP n’est pas affectée par le D-609, un inhibiteur de la phospholipase β. L’inhibition de la protéine kinase C (PKC) par le bisindolylmaléimide induit des oscillations en présence de Ca2+ extracellulaire et atténue fortement le signal calcique en absence de Ca2+ extracellulaire. En présence de Ca2+ extracellulaire, l’activation de la PKC par le PBDu tronque le flux de [Ca2+]i tandis que la réponse calcique est abolie en absence de Ca2+ dans le milieu extracellulaire. Le H-89, un inhibiteur de la protéine kinase A (PKA), cause une prolongation de la durée du plateau de [Ca2+]i dans un milieu riche en calcium et la suppression de la réponse à PAR1-AP lorsque le milieu extracellulaire est dépourvu de Ca2+. Les résultats obtenus nous permettent de conclure que la PKC et possiblement la PKA jouent un rôle critique dans la mobilisation du Ca2+ induite par le PAR1-AP dans le modèle rPAR1-Sf9.
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La multiplication dans le corps de Galois à 2^m éléments (i.e. GF(2^m)) est une opérations très importante pour les applications de la théorie des correcteurs et de la cryptographie. Dans ce mémoire, nous nous intéressons aux réalisations parallèles de multiplicateurs dans GF(2^m) lorsque ce dernier est généré par des trinômes irréductibles. Notre point de départ est le multiplicateur de Montgomery qui calcule A(x)B(x)x^(-u) efficacement, étant donné A(x), B(x) in GF(2^m) pour u choisi judicieusement. Nous étudions ensuite l'algorithme diviser pour régner PCHS qui permet de partitionner les multiplicandes d'un produit dans GF(2^m) lorsque m est impair. Nous l'appliquons pour la partitionnement de A(x) et de B(x) dans la multiplication de Montgomery A(x)B(x)x^(-u) pour GF(2^m) même si m est pair. Basé sur cette nouvelle approche, nous construisons un multiplicateur dans GF(2^m) généré par des trinôme irréductibles. Une nouvelle astuce de réutilisation des résultats intermédiaires nous permet d'éliminer plusieurs portes XOR redondantes. Les complexités de temps (i.e. le délais) et d'espace (i.e. le nombre de portes logiques) du nouveau multiplicateur sont ensuite analysées: 1. Le nouveau multiplicateur demande environ 25% moins de portes logiques que les multiplicateurs de Montgomery et de Mastrovito lorsque GF(2^m) est généré par des trinômes irréductible et m est suffisamment grand. Le nombre de portes du nouveau multiplicateur est presque identique à celui du multiplicateur de Karatsuba proposé par Elia. 2. Le délai de calcul du nouveau multiplicateur excède celui des meilleurs multiplicateurs d'au plus deux évaluations de portes XOR. 3. Nous determinons le délai et le nombre de portes logiques du nouveau multiplicateur sur les deux corps de Galois recommandés par le National Institute of Standards and Technology (NIST). Nous montrons que notre multiplicateurs contient 15% moins de portes logiques que les multiplicateurs de Montgomery et de Mastrovito au coût d'un délai d'au plus une porte XOR supplémentaire. De plus, notre multiplicateur a un délai d'une porte XOR moindre que celui du multiplicateur d'Elia au coût d'une augmentation de moins de 1% du nombre total de portes logiques.
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S’inscrivant parmi les travaux actuels sur le lieu, le présent mémoire s'intéresse à la représentation de la maison dans les romans québécois contemporains, notamment chez Catherine Mavrikakis, Élise Turcotte et Ying Chen. Dans le cadre de cette lecture sociocritique, le sociogramme de la Maison est la notion opératoire retenue, les deux composantes conflictuelles du noyau étant le « Home sweet home » et la « maison hantée ». Le travail de déchiffrement s'appuie ainsi sur les caractéristiques de ce binôme réfractées par les textes. À une époque caractérisée par un « hyper-investissement de l'espace privé », pour reprendre l'expression de Gilles Deleuze, la maison dans les romans québécois des années 2000 se révèle plutôt comme un espace marqué par la hantise, loin de l'image rassurante de la maison-nid véhiculée par certains discours en circulation dans la société. Fantômes et spectres envahissent ce lieu de l'intimité et deviennent des figures du quotidien, révélant ainsi le profond malaise des habitants et le refoulement d'un passé problématique. Le sujet se trouve alors confronté à une « inquiétante étrangeté » à l'intérieur même de son foyer.
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Recent advances in tissue engineering and regenerative medicine have shown that controlling cells microenvironment during growth is a key element to the development of successful therapeutic system. To achieve such control, researchers have first proposed the use of polymeric scaffolds that were able to support cellular growth and, to a certain extent, favor cell organization and tissue structure. With nowadays availability of a large pool of stem cell lines, such approach has appeared to be rather limited since it does not offer the fine control of the cell micro-environment in space and time (4D). Therefore, researchers are currently focusing their efforts on developing strategies that include active compound delivery systems in order to add a fourth dimension to the design of 3D scaffolds. This review will focus on recent concepts and applications of 2D and 3D techniques that have been used to control the load and release of active compounds used to promote cell differentiation and proliferation in or out of a scaffold. We will first present recent advances in the design of 2D polymeric scaffolds and the different techniques that have been used to deposit molecular cues and cells in a controlled fashion. We will continue presenting the recent advances made in the design of 3D scaffolds based on hydrogels as well as polymeric fibers and we will finish by presenting some of the research avenues that are still to be explored.
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The study on the fuzzy absolutes and related topics. The different kinds of extensions especially compactification formed a major area of study in topology. Perfect continuous mappings always preserve certain topological properties. The concept of Fuzzy sets introduced by the American Cyberneticist L. A Zadeh started a revolution in every branch of knowledge and in particular in every branch of mathematics. Fuzziness is a kind of uncertainty and uncertainty of a symbol lies in the lack of well-defined boundaries of the set of objects to which this symbol belongs. Introduce an s-continuous mapping from a topological space to a fuzzy topological space and prove that the image of an H-closed space under an s-continuous mapping is f-H closed. Here also proved that the arbitrary product fi and sum of fi of the s-continuous maps fi are also s-continuous. The original motivation behind the study of absolutes was the problem of characterizing the projective objects in the category of compact spaces and continuous functions.
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The present study on chaos and fractals in general topological spaces. Chaos theory originated with the work of Edward Lorenz. The phenomenon which changes order into disorder is known as chaos. Theory of fractals has its origin with the frame work of Benoit Mandelbrot in 1977. Fractals are irregular objects. In this study different properties of topological entropy in chaos spaces are studied, which also include hyper spaces. Topological entropy is a measures to determine the complexity of the space, and compare different chaos spaces. The concept of fractals can’t be extended to general topological space fast it involves Hausdorff dimensions. The relations between hausdorff dimension and packing dimension. Regular sets in Metric spaces using packing measures, regular sets were defined in IR” using Hausdorff measures. In this study some properties of self similar sets and partial self similar sets. We can associate a directed graph to each partial selfsimilar set. Dimension properties of partial self similar sets are studied using this graph. Introduce superself similar sets as a generalization of self similar sets and also prove that chaotic self similar self are dense in hyper space. The study concludes some relationships between different kinds of dimension and fractals. By defining regular sets through packing dimension in the same way as regular sets defined by K. Falconer through Hausdorff dimension, and different properties of regular sets also.
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The present study has been initiated to unravel the distribution of trace metals and its geochemical behavior in the Indian EEZ of the Arabian Sea and Bay of Bengal. Trace metal accumulation in aquatic consumers is of interest to ecologists and environmentalists so as to understand the fate and effect of contaminants in the food web dynamics and the biogeochemical cycling of trace metals. It is well established that oceanic distribution of macronutrients such as nitrate, phosphate and silicate provide critical to biological growth and related geochemical processes. In this study it can be inferred, that there is a need for a better understanding of background informations on trace metal concentrations with respect to space and time and their fluctuations in the Arabian Sea and Bay of Bengal zooplankton. Without a sound knowledge on spatio-temporal fluctuations, it will be impossible to differentiate anthropogenic metal inputs from natural background concentrations with a routine biomonitoring programme. Fe, Cu, Zn, Cd & Pb showed a slight enrichment in zooplankton from the Arabian Sea during spring intermonsoon compared to intermonsoon fall. The relative enrichment of Fe, Cu & Zn in zooplankton from the Arabian Sea during intermonsoon spring than intermonsoon fall was due to favourable bioaccumulation factors of these elements during this season. Nevertheless this study can be looked upon as a starting point for further investigations on these biogeochemically important processes, which are vital in addressing the dynamics of productivity of waters.
Studies on Pseudoscalar Meson Bound States and Semileptonic Decays in a Relativistic Potential Model
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In this thesis quark-antiquark bound states are considered using a relativistic two-body equation for Dirac particles. The mass spectrum of mesons includes bound states involving two heavy quarks or one heavy and one light quark. In order to analyse these states within a unified formalism, it is desirable to have a two-fermion equation that limits to one body Dirac equation with a static interaction for the light quark when the other particle's mass tends to infinity. A suitable two-body equation has been developed by Mandelzweig and Wallace. This equation is solved in momentum space and is used to describe the complete spectrum of mesons. The potential used in this work contains a short range one-gluon exchange interaction and a long range linear confining and constant potential terms. This model is used to investigate the decay processes of heavy mesons. Semileptonic decays are more tractable since there is no final state interactions between the leptons and hadrons that would otherwise complicate the situation. Studies on B and D meson decays are helpful to understand the nonperturbative strong interactions of heavy mesons, which in turn is useful to extract the details of weak interaction process. Calculation of form factors of these semileptonic decays of pseudo scalar mesons are also presented.
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In the present thesis , observations on the ecology of seaweed flora of Kerala, their distribution and zonation pattern, monthly/seasonal density of seaweeds at each station, frequency of occurrence, standing crop, monthly/seasonal/place-wise data on physico—chemical characters of ambient waters at the stations and their influence on seaweed density have been made. This data will help us in the farming of economically important seaweeds, by providing information on the ideal conditions of seaweed biomass production. Biochemical observations on protein, carbohydrate and lipid contents of different species of nutritive value. Seaweeds with high content of proteins, carbohydrates and lipids can be recommended for food and feed formulations after subjecting them to toxicological studies. The study on monthly/seasonal/placewise variation in biochemical composition of seaweeds will provide necessary information on the appropriate time and place of harvesting the algal species for exploiting its constituents .
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During recent years, the theory of differential inequalities has been extensively used to discuss singular perturbation problems and method of lines to partial differential equations. The present thesis deals with some differential inequality theorems and their applications to singularly perturbed initial value problems, boundary value problems for ordinary differential equations in Banach space and initial boundary value problems for parabolic differential equations. The method of lines to parabolic and elliptic differential equations are also dealt The thesis is organised into nine chapters
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In this thesis we investigate some problems in set theoretical topology related to the concepts of the group of homeomorphisms and order. Many problems considered are directly or indirectly related to the concept of the group of homeomorphisms of a topological space onto itself. Order theoretic methods are used extensively. Chapter-l deals with the group of homeomorphisms. This concept has been investigated by several authors for many years from different angles. It was observed that nonhomeomorphic topological spaces can have isomorphic groups of homeomorphisms. Many problems relating the topological properties of a space and the algebraic properties of its group of homeomorphisms were investigated. The group of isomorphisms of several algebraic, geometric, order theoretic and topological structures had also been investigated. A related concept of the semigroup of continuous functions of a topological space also received attention
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The performance of density-functional theory to solve the exact, nonrelativistic, many-electron problem for magnetic systems has been explored in a new implementation imposing space and spin symmetry constraints, as in ab initio wave function theory. Calculations on selected systems representative of organic diradicals, molecular magnets and antiferromagnetic solids carried out with and without these constraints lead to contradictory results, which provide numerical illustration on this usually obviated problem. It is concluded that the present exchange-correlation functionals provide reasonable numerical results although for the wrong physical reasons, thus evidencing the need for continued search for more accurate expressions.
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The present study is aimed at observing the variations, in space and time, of see of the important hydrographic parameters such as sea water temperature, salinity and Resolved oxygen within the coastal waters along the south-west coast of Indiametween Ratnagiri (17°OO*N,73°20'E) and cape comorin ( 8°10'N,77°30*E). Specific data relating to the process of upwelling and sinking was collected mainly to evaluate the extent and intensity of the vertical mixing processes active in the area under study. The study also attempted possible correlations between the observed parameters and the occurrence and migrations of some of the major pelagic fishery resources such as sardine,mackerel and anchovy in the area under study
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The Arabian Sea and the Bay of Bengal are both highly dynamic ecosystems, due to the seasonally reversing monsoon winds, but the processes affecting the mesozooplankton community remain poorly understood. These are important basins exhibiting enhanced biological production as a result of upwelling, winter cooling and other episodic events such as eddies and gyres. Zooplankters are primarily the prey for almost all fish larvae. Seasonal changes in the biogeochemical processes can strongly affect zooplankton density and distribution, which in turn, strongly affect the larval growth, and consequently, the pelagic fish recruitment. It is clear that plankton biomass and biogeochemical fluxes are not in steady state. Acoustic data on mesozooplankton abundance suggests that they also exist in the mesopelagic zone. Earlier studies were confined only to the upper 200 m and hence the structure of mesozooplankton community in the deeper layers was not well known. Copepods are the dominant mesoplankton group, and therefore the majority of the studies were focused on them. The planktonic ostracods are the second major crustacean group and at times, their swarms can outnumber all other planktonic groups. The understanding of the community structure of the ostracods is essential to establish their role in the marine food web. Mesozooplankton is responsible for the vertical flux of organic matter produced by phytoplankton and is assumed to be equivalent to new production (Eppley & Peterson, 1979). Since the fate of newly produced organic matter depends upon their consumers, the zooplankton biomass must be estimated in size fractions or taxonomic components to understand the vertical flux of organic carbon. It is thus important to update our knowledge on different groups of zooplankton on the basis of seasonal and temporal distribution. The distribution in space and time is essential for modeling the carbon cycling that structure the marine ecosystems