993 resultados para Essential Variable
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In this paper we investigate the Boolean functions with maximum essential arity gap. Additionally we propose a simpler proof of an important theorem proved by M. Couceiro and E. Lehtonen in [3]. They use Zhegalkin’s polynomials as normal forms for Boolean functions and describe the functions with essential arity gap equals 2. We use to instead Full Conjunctive Normal Forms of these polynomials which allows us to simplify the proofs and to obtain several combinatorial results concerning the Boolean functions with a given arity gap. The Full Conjunctive Normal Forms are also sum of conjunctions, in which all variables occur.
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One of the impediments to large-scale use of wind generation within power system is its variable and uncertain real-time availability. Due to the low marginal cost of wind power, its output will change the merit order of power markets and influence the Locational Marginal Price (LMP). For the large scale of wind power, LMP calculation can't ignore the essential variable and uncertain nature of wind power. This paper proposes an algorithm to estimate LMP. The estimation result of conventional Monte Carlo simulation is taken as benchmark to examine accuracy. Case study is conducted on a simplified SE Australian power system, and the simulation results show the feasibility of proposed method.
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O objetivo central desta tese foi analisar em que medida, no contexto das décadas de 1990 e 2000, o agronegócio, ao mitigar desajustes nas contas externas e contribuir para o esforço de estabilização dos preços, recebeu incentivos públicos e também benefícios privados, para isso valendo-se da intermediação política de seus representantes em atividade no Congresso Nacional. Inspirada em trabalhos dedicados ao estudo da distribuição de recursos necessários à modernização da produção agrícola, a análise explora explicações possíveis para dados recentes da distribuição do crédito rural subsidiado com base em variáveis de concentração da propriedade de terras e outras, com destaque para aquelas referentes à localização geográfica das propriedades rurais, ao nível educacional dos seus gestores e ao grau de organização dos mesmos. São ainda analisados debates no Congresso que revelam como a escassez de recursos fiscais pode ter acirrado disputas que trouxeram à tona a preocupação diferenciada dos chamados deputados ruralistas com o apoio governamental de que a agricultura empresarial ainda se faz dependente. As mudanças observadas no crédito rural brasileiro desde os anos 1980 revelam uma semitransição no sentido da maior participação de recursos privados e de uma concentração menor de recursos controlados entre grandes produtores. Porém, o processo não eliminou efeitos da capacidade de captação de recursos financeiros de grandes proprietários, que nela parecem ter encontrado compensações em um ambiente hostil criado por políticas de ajuste macroeconômico. Em perspectiva mais ampla, o arcabouço institucional da economia política do agronegócio constitui uma das variáveis básicas para uma caracterização do modus operandi do capitalismo brasileiro. A dependência do setor em relação a recursos controlados e subsidiados pelo Sistema Nacional de Crédito Rural põe em questão a retórica que outrora associava ao Estado apenas as mazelas do da economia e nenhuma de suas virtudes. sendo paradigmático o caso do agronegócio no Brasil, tratado muitas vezes como exemplo de sucesso exclusivo da aliança entre o espírito de empresa do setor privado e as vantagens comparativas do País em termos de recursos naturais. Ao mesmo tempo, a centralidade da intervenção do Estado no desenvolvimento econômico observado no Brasil é o elemento que mais fortemente questiona tentativas de detectar correspondências dominantes com economias liberais tipicamente anglo-saxônicas ou economias tipicamente eurocontinentais.
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ARTICLE 1 : RÉSUMÉ Amputation traumatique: Une étude de cas laotien sur l’indignation et l’injustice. La culture est un contexte essentiel à considérer pour produire un diagnostic et un plan d’intervention psychiatrique. Une perspective culturelle met en relief le contexte social dans lequel les symptômes émergent, et comment ils sont interprétés et gérés par la personne atteinte. Des études ethnoculturelles sur les maladies nous suggèrent que la plupart des gens nous donnent des explications pour leurs symptômes qui ont un fondement culturel. Bien que ces explications contredisent la théorie biomédicale, elles soulagent la souffrance des patients et leur permettent de donner une signification à cette dernière. L’exploration des caractéristiques, contextes et antécédents des symptômes permet au patient de les communiquer au clinicien qui pourrait avoir une explication différente de sa maladie. Cette étude de cas permet de montrer comment le Guide pour Formulation Culturelle du DSM-IV (The DSM-IV Outline for Cultural Formulation) permet aux cliniciens de solliciter un récit du patient en lien avec son expérience de la maladie. Notre étude examine l’utilisation par un patient laotien de « l’indignation sociale » (« Khuâm khum khang ») comme le modèle explicatif culturel de son problème malgré le diagnostic de trouble de stress post-traumatique qui lui fut attribué après une amputation traumatique. L’explication culturelle de son problème a permis au patient d’exprimer la signification personnelle et collective à sa colère et sa frustration, émotions qu’il avait réprimées. Cet idiome culturel lui a permis d’exprimer sa détresse et de réfléchir sur le système de soins de santé et, plus précisément, le contexte dans lequel les symptômes et leurs origines sont racontés et évalués. Cette représentation laotienne a aussi permis aux cliniciens de comprendre des expériences et les explications du client, autrement difficiles à situer dans un contexte biomédical et psychiatrique Euro-américain. Cette étude démontre comment il est possible d’améliorer les interactions entre cliniciens et patients et dès lors la qualité des soins par la compréhension de la perspective du patient et l’utilisation d’une approche culturelle. Mots clés: Culture, signification, idiome culturel, modèle explicatif, Guide pour Formulation culturelle du DSM-IV, indignation sociale, interaction entre patient et intervenant. ARTICLE 2 : RÉSUMÉ Impact de l’utilisation du Guide pour la formulation culturelle du DSM-IV sur la dynamique de conférences multidisciplinaires en santé mentale. La croissance du pluralisme culturel en Amérique du nord a obligé la communauté oeuvrant en santé mentale d’adopter une sensibilité culturelle accrue dans l’exercice de leur métier. Les professionnels en santé mentale doivent prendre conscience du contexte historique et social non seulement de leur clientèle mais également de leur propre profession. Les renseignements exigés pour les soins professionnels proviennent d’ évaluations cliniques. Il faut examiner ces informations dans un cadre culturellement sensible pour pouvoir formuler une évaluation des cas qui permet aux cliniciens de poser un diagnostic juste et précis, et ce, à travers les frontières culturelles du patient aussi bien que celles du professionnel en santé mentale. Cette situation a suscité le développement du Guide pour la formulation culturelle dans la 4ième édition du Manuel diagnostique et statistique des troubles mentaux américain (Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV) de l’Association psychiatrique américaine. Ce guide est un outil pour aider les cliniciens à obtenir des informations de nature culturelle auprès du client et de sa famille afin de guider la production des soins en santé mentale. L’étude vise l’analyse conversationnelle de la conférence multidisciplinaire comme contexte d’utilisation du Guide pour la formulation culturelle qui sert de cadre dans lequel les pratiques discursives des professionnels de la santé mentale évoluent. Utilisant la perspective théorique de l’interactionnisme symbolique, l’étude examine comment les diverses disciplines de la santé mentale interprètent et conceptualisent les éléments culturels et les implications de ce cadre pour la collaboration interdisciplinaire dans l’évaluation, l’élaboration de plans de traitement et des soins. Mots clé: Guide pour Formulation culturelle – Santé mentale – Psychiatrie transculturelle – Analyse conversationnelle – Interactionnisme symbolique
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En esta monografía se propone que las emociones son una forma de relación con el mundo que implica apreciaciones y creencias del sujeto que las experimenta. Si bien es cierto que el cuerpo humano puede ser considerado como un producto de la evolución y, en general, todas sus funciones necesitan del sustento de dicho cuerpo, cuando hablamos de las emociones debemos hablar de su conexión con el carácter, la voluntad, las escalas de valores y muchos otros factores que no pueden ser explicados a partir de una base como la determinación física, dado que las emociones son una variable indispensable para la organización social y, más específicamente, para la moral. Las emociones son definidas, consecuentemente, como una serie de juicios, basados en prioridades y escalas de valor, que califican y median nuestra relación con los objetos del mundo.
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Given an n-ary k-valued function f, gap(f) denotes the essential arity gap of f which is the minimal number of essential variables in f which become fictive when identifying any two distinct essential variables in f. In the present paper we study the properties of the symmetric function with non-trivial arity gap (2 ≤ gap(f)). We prove several results concerning decomposition of the symmetric functions with non-trivial arity gap with its minors or subfunctions. We show that all non-empty sets of essential variables in symmetric functions with non-trivial arity gap are separable. ACM Computing Classification System (1998): G.2.0.
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Predominant usage of V beta 8.2 gene segments, encoding a T-cell receptor (TCR) beta chain variable region, has been reported for pathogenic Lewis rat T cells reactive to myelin basic protein (MBP). However, up to 75% of the alpha/beta T cells in a panel of MBP-specific T-cell lines did not display TCR V beta 8.2, V beta 8.5, V beta 10, or V beta 16 elements. To further investigate TCR usage, we sorted the T-cell lines for V beta 8.2- and V beta 10-positive T cells or depleted the lines of cells with these TCRs. V beta 8.2-positive T cells and one of the depleted T-cell lines strongly reacted against the MBP peptide MBP-(68-88). The depleted T-cell line caused marked experimental autoimmune encephalomyelitis (EAE) even in Lewis rats in which endogenous V beta 8.2-positive T cells had been eliminated by neonatal treatment with anti-V beta 8.2 monoclonal antibodies. T-cell hybridomas generated from this line predominantly used V beta 3 TCR genes coexpressed with TCR V alpha 2 transcripts, which were also used by V beta 8.2-positive T cells. Furthermore, V beta 10-positive T cells reactive to MBP-(44-67) were encephalitogenic when injected immediately after positive selection. After induction of EAE by sorted V beta 8.2- or V beta 10-positive T-cell lines, immunocytochemical analysis of the spinal cord tissue showed a predominance of the injected TCR or of nontypable alpha/beta T cells after injection of the depleted line. Our results demonstrate heterogeneity of TCR beta-chain usage even for a single autoantigen in an inbred strain. Moreover, V beta 8.2-positive T cells are not essential for the induction and progression of adoptive-transfer EAE.
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Heart disease is attributed as the highest cause of death in the world. Although this could be alleviated by heart transplantation, there is a chronic shortage of donor hearts and so mechanical solutions are being considered. Currently, many Ventricular Assist Devices (VADs) are being developed worldwide in an effort to increase life expectancy and quality of life for end stage heart failure patients. Current pre-clinical testing methods for VADs involve laboratory testing using Mock Circulation Loops (MCLs), and in vivo testing in animal models. The research and development of highly accurate MCLs is vital to the continuous improvement of VAD performance. The first objective of this study was to develop and validate a mathematical model of a MCL. This model could then be used in the design and construction of a variable compliance chamber to improve the performance of an existing MCL as well as form the basis for a new miniaturised MCL. An extensive review of literature was carried out on MCLs and mathematical modelling of their function. A mathematical model of a MCL was then created in the MATLAB/SIMULINK environment. This model included variable features such as resistance, fluid inertia and volumes (resulting from the pipe lengths and diameters); compliance of Windkessel chambers, atria and ventricles; density of both fluid and compressed air applied to the system; gravitational effects on vertical columns of fluid; and accurately modelled actuators controlling the ventricle contraction. This model was then validated using the physical properties and pressure and flow traces produced from a previously developed MCL. A variable compliance chamber was designed to reproduce parameters determined by the mathematical model. The function of the variability was achieved by controlling the transmural pressure across a diaphragm to alter the compliance of the system. An initial prototype was tested in a previously developed MCL, and a variable level of arterial compliance was successfully produced; however, the complete range of compliance values required for accurate physiological representation was not able to be produced with this initial design. The mathematical model was then used to design a smaller physical mock circulation loop, with the tubing sizes adjusted to produce accurate pressure and flow traces whilst having an appropriate frequency response characteristic. The development of the mathematical model greatly assisted the general design of an in vitro cardiovascular device test rig, while the variable compliance chamber allowed simple and real-time manipulation of MCL compliance to allow accurate transition between a variety of physiological conditions. The newly developed MCL produced an accurate design of a mechanical representation of the human circulatory system for in vitro cardiovascular device testing and education purposes. The continued improvement of VAD test rigs is essential if VAD design is to improve, and hence improve quality of life and life expectancy for heart failure patients.
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Bond graph is an apt modelling tool for any system working across multiple energy domains. Power electronics system modelling is usually the study of the interplay of energy in the domains of electrical, mechanical, magnetic and thermal. The usefulness of bond graph modelling in power electronic field has been realised by researchers. Consequently in the last couple of decades, there has been a steadily increasing effort in developing simulation tools for bond graph modelling that are specially suited for power electronic study. For modelling rotating magnetic fields in electromagnetic machine models, a support for vector variables is essential. Unfortunately, all bond graph simulation tools presently provide support only for scalar variables. We propose an approach to provide complex variable and vector support to bond graph such that it will enable modelling of polyphase electromagnetic and spatial vector systems. We also introduced a rotary gyrator element and use it along with the switched junction for developing the complex/vector variable's toolbox. This approach is implemented by developing a complex S-function tool box in Simulink inside a MATLAB environment This choice has been made so as to synthesise the speed of S-function, the user friendliness of Simulink and the popularity of MATLAB.
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There is uncertainty over the potential changes to rainfall across northern Australia under climate change. Since rainfall is a key driver of pasture growth, cattle numbers and the resulting animal productivity and beef business profitability, the ability to anticipate possible management strategies within such uncertainty is crucial. The Climate Savvy Grazing project used existing research, expert knowledge and computer modelling to explore the best-bet management strategies within best, median and worse-case future climate scenarios. All three scenarios indicated changes to the environment and resources upon which the grazing industry of northern Australia depends. Well-adapted management strategies under a changing climate are very similar to best practice within current climatic conditions. Maintaining good land condition builds resource resilience, maximises opportunities under higher rainfall years and reduces the risk of degradation during drought and failed wet seasons. Matching stocking rate to the safe long-term carrying capacity of the land is essential; reducing stock numbers in response to poor seasons and conservatively increasing stock numbers in response to better seasons generally improves profitability and maintains land in good condition. Spelling over the summer growing season will improve land condition under a changing climate as it does under current conditions. Six regions were included within the project. Of these, the Victoria River District in the Northern Territory, Gulf country of Queensland and the Kimberley region of Western Australia had projections of similar or higher than current rainfall and the potential for carrying capacity to increase. The Alice Springs, Maranoa-Balonne and Fitzroy regions had projections of generally drying conditions and the greatest risk of reduced pasture growth and carrying capacity. Encouraging producers to consider and act on the risks, opportunities and management options inherent in climate change was a key goal of the project. More than 60,000 beef producers, advisors and stakeholders are now more aware of the management strategies which build resource resilience, and that resilience helps buffer against the effects of variable and changing climatic conditions. Over 700 producers have stated they have improved confidence, skills and knowledge to attempt new practices to build resilience. During the course of the project, more than 165 beef producers reported they have implemented changes to build resource and business resilience.
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Gauss and Fourier have together provided us with the essential techniques for symbolic computation with linear arithmetic constraints over the reals and the rationals. These variable elimination techniques for linear constraints have particular significance in the context of constraint logic programming languages that have been developed in recent years. Variable elimination in linear equations (Guassian Elimination) is a fundamental technique in computational linear algebra and is therefore quite familiar to most of us. Elimination in linear inequalities (Fourier Elimination), on the other hand, is intimately related to polyhedral theory and aspects of linear programming that are not quite as familiar. In addition, the high complexity of elimination in inequalities has forces the consideration of intricate specializations of Fourier's original method. The intent of this survey article is to acquaint the reader with these connections and developments. The latter part of the article dwells on the thesis that variable elimination in linear constraints over the reals extends quite naturally to constraints in certain discrete domains.
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In a rapidly changing world it is essential that we should understand the factors controlling the sustainability of ecosystems. In aquatic ecosystems, both sensitivity and recoverability are influenced strongly by the life cycles of the organisms concerned. The response of individual species to change and their chances of survival in a variable environment can be affected dramatically by the timing and location of disturbances relative to their natural rhythms of fertilisation, dispersal and development. This book illustrates the wide range of issues that must be addressed to understand such relationships. Its purpose is to consider those aspects of life history that make aquatic organisms especially susceptible to (or adaptable to) changing environments -and hence to discuss links between impacts on individuals and the consequent effects on populations and communities.
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La sélénocystéine est le 21e acide aminé encodé génétiquement et on la retrouve à travers les trois domaines de la vie. Elle est synthétisée sur l'ARNtSec par un processus unique. L'ARNtSec se distingue également au niveau structural. La tige acceptrice possède 8 (procaryotes) et 9 (eucaryotes) paires de bases, contrairement aux ARNt canoniques qui ont invariablement 7 paires de bases dans la tige acceptrice. De plus, la tige D a 2 paires de bases additionnelles qui remplacent les interactions tertiaires universelles 8-14, 15-48 qui sont absentes chez l'ARNtSec. D'autre part, la longueur de la boucle variable de l'ARNtSec est plus longue que la majorité des ARNt de type II. Dans ce mémoire, on se concentre sur la région de la boucle variable de l'ARNtSec . La recherche consiste à distinguer les paires de bases de la boucle variable qui sont essentielles à la biosynthèse et l’insertion de la sélénocystéine. De plus, on regarde si la paire de base additionnelle de la tige acceptrice de l'ARNtSec (procaryote) est essentielle pour l'insertion de la sélénocystéine. Pour répondre à ces questions, on a utilisé l'approche expérimentale Évolution Instantanée qui consiste au criblage in vivo d'ARNtSec fonctionnels chez E. coli. Dans ce travail, on montre que l'insertion de la sélénocystéine ne nécessite pas une spécificité de la longueur ou de la séquence de l'ARNtSec. On montre aussi que ni la longueur de la tige acceptrice ou du domaine tige acceptrice/tige T n'est essentielle pour avoir un ARNtSec fonctionnel.
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Tras quince años de la “asociación estratégica UE-ALC”, los múltiples y profundos cambios en el sistema internacional han tenido gran impacto sobre estas relaciones birregionales. Por ello hay que replantear cuáles son los cambios en la percepciones mutuas de las dos regiones, y observar el nuevo contexto geopolítico, tomando nota de la pérdida de influencia de los EEUU en la región y el auge de Asia, especialmente China. La “asociación estratégica” no ha conducido ni a una convergencia de intereses ni a una reconocible compatibilidad normativa. Además, la UE ha perdido su papel de “modelo” para los procesos de integración, en una región que tiene aún más heterogeneidad por sus diferentes modelos de desarrollo. Por ello se hace necesario asumir una geometría variable para la adaptación de las relaciones birregionales a la realidad del siglo XXI.
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The essential oils isolated by hydrodistillation from trunk bark and leaves of Talauma ovata A. St. Hil. (Magnoliaceae), collected in four seasons, were analyzed by capillary GC and GC/MS. Altogether 52 components were identified, The oils were characterized by predominance of cyclic sesquiterpenes. The main components were linalool, trans-beta-guaiene, germaerene D, germacrene B, spathulenol, caryophyllene oxide, viridiflorol and alpha-endesmol. The content of individual components was variable during the year. All oils were screened against several strains of bacteria and yeasts, using the agar well-diffusion technique. The antimicrobial activity of oils showed strong dependence with the season. Significant activity was found for oils obtained in the spring and summer.