999 resultados para Dumas


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FUNDAMENTOS: Inúmeros indicadores são utilizados para assegurar a qualidade de um serviço; entretanto, a competência médica e o adequado fluxo de realização de um procedimento são determinantes da qualidade final. Nesse contexto, a Sociedade Brasileira de Arritmias Cardíacas pretende recomendar parâmetros mínimos necessários para garantir a excelência dos serviços de monitorização eletrocardiográfica ambulatorial. OBJETIVOS: Recomendar competências médicas mínimas e as informações necessárias para emissão do laudo de Holter. MÉTODOS: O documento foi fundamentado no conceito de medicina baseada em evidência, e nas circunstâncias em que a evidência não estava disponível a opinião de uma comissão de redação foi utilizada para a formulação da recomendação. Essa comissão foi formada por profissionais que apresentam vivência nas dificuldades do método e gestão na prestação de serviços nessa área. RESULTADOS: O profissional responsável pela análise de Holter deve conhecer as patologias cardiovasculares e ter formação consistente em eletrocardiografia, incluindo arritmias cardíacas e seus diagnósticos diferenciais. O laudo deve ser redigido de forma clara e objetiva. Os parâmetros mínimos que devem constar no laudo incluem as estatísticas do exame, assim como quantificação e análise dos distúrbios do ritmo observados durante a monitorização. CONCLUSÃO: A monitorização eletrocardiográfica ambulatorial deve ser realizada por profissionais com vivência em análise eletrocardiográfica e o laudo deve conter os parâmetros mínimos mencionados nesse documento.

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Background: The mechanisms associated with the cardiovascular consequences of obstructive sleep apnea include abrupt changes in autonomic tone, which can trigger cardiac arrhythmias. The authors hypothesized that nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea. Objective: To analyze the relationship between obstructive sleep apnea and abnormal heart rhythm during sleep in a population sample. Methods: Cross-sectional study with 1,101 volunteers, who form a representative sample of the city of São Paulo. The overnight polysomnography was performed using an EMBLA® S7000 digital system during the regular sleep schedule of the individual. The electrocardiogram channel was extracted, duplicated, and then analyzed using a Holter (Cardio Smart®) system. Results: A total of 767 participants (461 men) with a mean age of 42.00 ± 0.53 years, were included in the analysis. At least one type of nocturnal cardiac rhythm disturbance (atrial/ventricular arrhythmia or beat) was observed in 62.7% of the sample. The occurrence of nocturnal cardiac arrhythmias was more frequent with increased disease severity. Rhythm disturbance was observed in 53.3% of the sample without breathing sleep disorders, whereas 92.3% of patients with severe obstructive sleep apnea showed cardiac arrhythmia. Isolated atrial and ventricular ectopy was more frequent in patients with moderate/severe obstructive sleep apnea when compared to controls (p < 0.001). After controlling for potential confounding factors, age, sex and apnea-hypopnea index were associated with nocturnal cardiac arrhythmia. Conclusion: Nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea and the prevalence increases with disease severity. Age, sex, and the Apnea-hypopnea index were predictors of arrhythmia in this sample.

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Bacteria often possess multiple siderophore-based iron uptake systems for scavenging this vital resource from their environment. However, some siderophores seem redundant, because they have limited iron-binding efficiency and are seldom expressed under iron limitation. Here, we investigate the conundrum of why selection does not eliminate this apparent redundancy. We focus on Pseudomonas aeruginosa, a bacterium that can produce two siderophores-the highly efficient but metabolically expensive pyoverdine, and the inefficient but metabolically cheap pyochelin. We found that the bacteria possess molecular mechanisms to phenotypically switch from mainly producing pyoverdine under severe iron limitation to mainly producing pyochelin when iron is only moderately limited. We further show that strains exclusively producing pyochelin grew significantly better than strains exclusively producing pyoverdine under moderate iron limitation, whereas the inverse was seen under severe iron limitation. This suggests that pyochelin is not redundant, but that switching between siderophore strategies might be beneficial to trade off efficiencies versus costs of siderophores. Indeed, simulations parameterized from our data confirmed that strains retaining the capacity to switch between siderophores significantly outcompeted strains defective for one or the other siderophore under fluctuating iron availabilities. Finally, we discuss how siderophore switching can be viewed as a form of collective decision-making, whereby a coordinated shift in behaviour at the group level emerges as a result of positive and negative feedback loops operating among individuals at the local scale.

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Water-dispersible gold nanoparticles functionalized with paramagnetic gadolinium have been fully characterized, and the NMRD profiles show very high relaxivities up to 1.5 T. Characterization using TEM images and dynamic light scattering indicate a particle size distribution from 2 to 15 nm. The gold cores of the nanoparticles do not contribute significantly to the overall magnetic moment.

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Après avoir proposé une définition opératoire du mythe littéraire, et suggéré, sous l'étiquette de « mytholectures », un mode d'approche de cet objet, le travail se subdivise en deux grandes parties.La première, diachronique, cherche à sonder le devenir historique du mythe de Perceval, de Chrétien de Troyes à nos jours ; il s'agit essentiellement d'observer comment la valeur et le sens du mythe se sont élaborés progressivement au fil de ses reprises - comment chaque période, chaque auteur a rencontré le mythe sous un rapport singulier, susceptible de lui fournir un « miroir » qui reflète certaines de ses préoccupations et lui permette, parallèlement, de configurer son expérience du monde. Les principales étapes de ce parcours (qui touche à environ quatre-vingts auteurs) sont Richard Wagner et Julien Gracq.La seconde partie propose deux approches thématiques du mythe de Perceval : l'une d'elles est centrée sur la problématique familiale et les enjeux relationnels qui, de reprise en reprise, ne cessent d'être réinterprétés sous divers angles (dont Oedipe, cet « anti-Perceval », n'est jamais très loin). L'autre axe thématique s'intéresse à la propension marquée du mythe de Perceval à fonctionner comme modèle des deux pôles de l'activité littéraire que sont la lecture (quête de sens) et l'écriture (quête poétique) : divers « arts poétiques percevaliens » (de Wagner à Perec, en passant par Proust ou Handke) closent ainsi le parcours.

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Executive Summary The first essay of this dissertation investigates whether greater exchange rate uncertainty (i.e., variation over time in the exchange rate) fosters or depresses the foreign investment of multinational firms. In addition to the direct capital financing it supplies, foreign investment can be a source of valuable technology and know-how, which can have substantial positive effects on a host country's economic growth. Thus, it is critically important for policy makers and central bankers, among others, to understand how multinationals base their investment decisions on the characteristics of foreign exchange markets. In this essay, I first develop a theoretical framework to improve our knowledge regarding how the aggregate level of foreign investment responds to exchange rate uncertainty when an economy consists of many firms, each of which is making decisions. The analysis predicts a U-shaped effect of exchange rate uncertainty on the total level of foreign investment of the economy. That is, the effect is negative for low levels of uncertainty and positive for higher levels of uncertainty. This pattern emerges because the relationship between exchange rate volatility and 'the probability of investment is negative for firms with low productivity at home (i.e., firms that find it profitable to invest abroad) and the relationship is positive for firms with high productivity at home (i.e., firms that prefer exporting their product). This finding stands in sharp contrast to predictions in the existing literature that consider a single firm's decision to invest in a unique project. The main contribution of this research is to show that the aggregation over many firms produces a U-shaped pattern between exchange rate uncertainty and the probability of investment. Using data from industrialized countries for the period of 1982-2002, this essay offers a comprehensive empirical analysis that provides evidence in support of the theoretical prediction. In the second essay, I aim to explain the time variation in sovereign credit risk, which captures the risk that a government may be unable to repay its debt. The importance of correctly evaluating such a risk is illustrated by the central role of sovereign debt in previous international lending crises. In addition, sovereign debt is the largest asset class in emerging markets. In this essay, I provide a pricing formula for the evaluation of sovereign credit risk in which the decision to default on sovereign debt is made by the government. The pricing formula explains the variation across time in daily credit spreads - a widely used measure of credit risk - to a degree not offered by existing theoretical and empirical models. I use information on a country's stock market to compute the prevailing sovereign credit spread in that country. The pricing formula explains a substantial fraction of the time variation in daily credit spread changes for Brazil, Mexico, Peru, and Russia for the 1998-2008 period, particularly during the recent subprime crisis. I also show that when a government incentive to default is allowed to depend on current economic conditions, one can best explain the level of credit spreads, especially during the recent period of financial distress. In the third essay, I show that the risk of sovereign default abroad can produce adverse consequences for the U.S. equity market through a decrease in returns and an increase in volatility. The risk of sovereign default, which is no longer limited to emerging economies, has recently become a major concern for financial markets. While sovereign debt plays an increasing role in today's financial environment, the effects of sovereign credit risk on the U.S. financial markets have been largely ignored in the literature. In this essay, I develop a theoretical framework that explores how the risk of sovereign default abroad helps explain the level and the volatility of U.S. equity returns. The intuition for this effect is that negative economic shocks deteriorate the fiscal situation of foreign governments, thereby increasing the risk of a sovereign default that would trigger a local contraction in economic growth. The increased risk of an economic slowdown abroad amplifies the direct effect of these shocks on the level and the volatility of equity returns in the U.S. through two channels. The first channel involves a decrease in the future earnings of U.S. exporters resulting from unfavorable adjustments to the exchange rate. The second channel involves investors' incentives to rebalance their portfolios toward safer assets, which depresses U.S. equity prices. An empirical estimation of the model with monthly data for the 1994-2008 period provides evidence that the risk of sovereign default abroad generates a strong leverage effect during economic downturns, which helps to substantially explain the level and the volatility of U.S. equity returns.

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(Résumé de l'ouvrage) Le présent recueil d'hommages veut témoigner de l'importance de l'oeuvre théologique de Jean Richard, professeur à la Faculté de théologie et de sciences religieuses de l'Université Laval. Désireux de signifier leur reconnaissance au père Richard, les auteurs de ce livre ont proposé des textes s'inscrivant dans l'un ou l'autre de ses champs de recherche privilégiés. Le tableau des contributeurs à ces mélanges regroupe des théologiens de tous les âges, hommes et femmes, provenant du Canada, mais aussi des États-Unis et de l'Europe, de langue française, anglaise ou allemande, de confession catholique ou protestante, oeuvrant dans des champs disciplinaires aussi divers que la théologie systématique, la théologie fondamentale, l'éthique théologique, l'exégèse ou encore la philosophie. Cette diversité est révélatrice de la personnalité théologique du père Richard, du caractère international de son réseau d'amitiés et de recherche et de l'ampleur de son influence. Elle témoigne aussi de l'audace d'une oeuvre qui, entreprise dans les années 1960, a dès le départ relevé le défi de l'aggiornamento que venait de poser en toute urgence son Église et qui a très vite conduit son auteur « aux confins », pour reprendre - et pour cause - une expression de son mentor Paul Tillich qui lui sied à merveille. Les contributions réunies dans ce volume ne résultent pas d'un plan concerté. D'autant plus significatifs sont les recoupements thématiques qu'on y observe, qui, par un hasard seulement apparent, restituent les principaux axes de la production théologique du père Jean Richard. L'ouverture au présent et a ses problématiques propres, ainsi que les défis conceptuels par là posés à l'effort théologique constituent les deux constantes de ces contributions, comme de l'oeuvre qui les a inspirées.

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Comprend : Hamlet, prince de Danemark : [drame en 10 parties] / en collaboration avec Alexandre Dumas - Falstaff : tiré de Henri IV : [pièce en 7 parties, en vers] : [Paris, Odéon, 2 octobre 1842] / en collaboration avec Auguste Vacquerie - Paroles : tiré de Tout est bien qui finit bien : [pièce en 1 acte, en vers] : [Paris, Odéon, février 1843] / en collaboration avec Auguste Vacquerie

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Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri) to the upper Miocene, about 5.4-7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination.

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Two new species of Marilia Müller (Odontoceridae), M. aiuruoca sp. nov. and M. huamantincoae sp. nov., are described and figured from Itatiaia massif, Mantiqueira mountain range, southeastern Brazil. The female of M. major Müller, 1880 is described and the species is recorded for the first time from Rio de Janeiro state.

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A new species of Cernotina (Trichoptera, Polycentropodidae) from the Atlantic Forest, Rio de Janeiro State, southeastern Brazil. Cernotina Ross, 1938, with 64 extant species, is a New World genus of caddisflies. In Brazil, there are 31 described species of which 28 are recorded from the Amazon basin. Cernotina puri sp. nov. is described and figured based on specimens collected in the Atlantic Forest, Rio de Janeiro State, Brazil. The new species can be distinguished by the shape of the intermediate appendages and tergum X. The immature stages of C. puri are unknown.