33 resultados para Plus long chemin


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We identify an intriguing feature of the electron-vibrational dynamics of molecular systems via a computational examination of trans-polyacetylene oligomers. Here, via the vibronic interactions, the decay of an electron in the conduction band resonantly excites an electron in the valence band, and vice versa, leading to oscillatory exchange of electronic population between two distinct electronic states that lives for up to tens of picoseconds. The oscillatory structure is reminiscent of beating patterns between quantum states and is strongly suggestive of the presence of long-lived molecular electronic coherence. Significantly, however, a detailed analysis of the electronic coherence properties shows that the oscillatory structure arises from a purely incoherent process. These results were obtained by propagating the coupled dynamics of electronic and vibrational degrees of freedom in a mixed quantum-classical study of the Su-Schrieffer-Heeger Hamiltonian for polyacetylene. The incoherent process is shown to occur between degenerate electronic states with distinct electronic configurations that are indirectly coupled via a third auxiliary state by vibronic interactions. A discussion of how to construct electronic superposition states in molecules that are truly robust to decoherence is also presented

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1000 p. (Anexos: 929-965 p.; bibliografía 965-1000 p.). Capítulos de discusión y conclusiones en castellano y francés.

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4 p.

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30 p.

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[EU] Artikulu honetan, gaur-gaurkoa dugun gai bat aztertzen da : Udalerri Euskaldunen Mankomunitatea legezkontrakotzat. jotzen duen Epaia. UEMAren oinarri juridikoak aztertu ondoren, Mankomunitate horren ibilbideak izan dituen eragozpenez arduratzen da lan hau. Egilearen ustez, Udalerri Euskaldunen Mankomunitateak bere ibilbidean aurkitu duen handicap-ik nabarmenena, legearen babes falta izan da, eta Auzitegi Goreneko Epaia, bai formaz, bai edukiaren aldetik, oinarri gabekotzat jo behar dela dio.

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Homenaje a Georges Laplace, realizado en Vitoria-Gasteiz el 13,14 y 15 de noviembre de 2012. Edición a cargo de Aitor Calvo, Aitor Sánchez, Maite García-Rojas y Mónica Alonso-Eguíluz.

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Homenaje a Georges Laplace, realizado en Vitoria-Gasteiz el 13,14 y 15 de noviembre de 2012. Edición a cargo de Aitor Calvo, Aitor Sánchez, Maite García-Rojas y Mónica Alonso-Eguíluz.

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A menudo, el deslumbramiento de los nuevos medios impide el reconocimiento debido a otras alternativas de comunicación social que, de manera persistente y discreta, han llegado a confundirse con nuestra propia vida. Es el caso de este medio invisible, que bien se merecía un congreso dedicado a la mejor radio y a uno de sus mayores inspiradores, Bertolt Brecht, quien ochenta años atrás imaginó una radio interactiva cuando no existía la tecnología necesaria para hacer realidad su sueño. Hoy como ayer, las voces comunicantes de la radio cuentan mil y una historias que los oyentes siguen como si les fuera la vida en ello. Quizá la radio no esté a la cabeza de las industrias creativas, pero su magia sigue desatando la imaginación y la creatividad de las audiencias. Es por eso, y por su cercanía, que da tanta confianza y es tan querida. Nada más lejos de nuestra intención que la autocomplacencia, un virus tanto o más peligroso que el ruido y la cacofonía radiofónica, que de todo hay en el dial. Los participantes en este encuentro nos hemos conjurado a favor de una radio abierta; hecha con cabeza y corazón, como la vida misma; y más acogedora con los jóvenes creadores, que no lo saben todo de la radio, pero, por eso mismo, están mejor preparados para llevar el ritmo que bailan las neuronas de las nuevas audiencias. Una radio que da la palabra a la gente, sabe escuchar, y no se agota en el ejercicio inútil de escucharse a sí misma.

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Background: Recently, with the access of low toxicity biological and targeted therapies, evidence of the existence of a long-term survival subpopulation of cancer patients is appearing. We have studied an unselected population with advanced lung cancer to look for evidence of multimodality in survival distribution, and estimate the proportion of long-term survivors. Methods: We used survival data of 4944 patients with non-small-cell lung cancer (NSCLC) stages IIIb-IV at diagnostic, registered in the National Cancer Registry of Cuba (NCRC) between January 1998 and December 2006. We fitted one-component survival model and two-component mixture models to identify short-and long-term survivors. Bayesian information criterion was used for model selection. Results: For all of the selected parametric distributions the two components model presented the best fit. The population with short-term survival (almost 4 months median survival) represented 64% of patients. The population of long-term survival included 35% of patients, and showed a median survival around 12 months. None of the patients of short-term survival was still alive at month 24, while 10% of the patients of long-term survival died afterwards. Conclusions: There is a subgroup showing long-term evolution among patients with advanced lung cancer. As survival rates continue to improve with the new generation of therapies, prognostic models considering short-and long-term survival subpopulations should be considered in clinical research.

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Background: Bronchiolitis caused by the respiratory syncytial virus (RSV) and its related complications are common in infants born prematurely, with severe congenital heart disease, or bronchopulmonary dysplasia, as well as in immunosuppressed infants. There is a rich literature on the different aspects of RSV infection with a focus, for the most part, on specific risk populations. However, there is a need for a systematic global analysis of the impact of RSV infection in terms of use of resources and health impact on both children and adults. With this aim, we performed a systematic search of scientific evidence on the social, economic, and health impact of RSV infection. Methods: A systematic search of the following databases was performed: MEDLINE, EMBASE, Spanish Medical Index, MEDES-MEDicina in Spanish, Cochrane Plus Library, and Google without time limits. We selected 421 abstracts based on the 6,598 articles identified. From these abstracts, 4 RSV experts selected the most relevant articles. They selected 65 articles. After reading the full articles, 23 of their references were also selected. Finally, one more article found through a literature information alert system was included. Results: The information collected was summarized and organized into the following topics: 1. Impact on health (infections and respiratory complications, mid-to long-term lung function decline, recurrent wheezing, asthma, other complications such as otitis and rhino-conjunctivitis, and mortality; 2. Impact on resources (visits to primary care and specialists offices, emergency room visits, hospital admissions, ICU admissions, diagnostic tests, and treatments); 3. Impact on costs (direct and indirect costs); 4. Impact on quality of life; and 5. Strategies to reduce the impact (interventions on social and hygienic factors and prophylactic treatments). Conclusions: We concluded that 1. The health impact of RSV infection is relevant and goes beyond the acute episode phase; 2. The health impact of RSV infection on children is much better documented than the impact on adults; 3. Further research is needed on mid-and long-term impact of RSV infection on the adult population, especially those at high-risk; 4. There is a need for interventions aimed at reducing the impact of RSV infection by targeting health education, information, and prophylaxis in high-risk populations.

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In the middle of the so-called pension crisis, the ageing of population and the sharp decrease in affiliations to Social Security are threatening the well-functioning of the Spanish public pension system. The purpose of this paper is to present the main challenges to be faced by the Spanish pension system, as well as to shed light on the main determinants that will condition the evolution of pension expenditure over GDP along the following decades. This quantitative analysis, which considers the 2011 and 2013 pension reforms, uses the latest data on the Spanish demographic, labor market and institutional factors in order to project the evolution of the system from the expenditure side up to 2060. For the purpose of analyzing the dynamics and the underlying drivers of pension expenditure, the so-called aggregate accounting approach will be utilized. The alternative scenarios proposed allow for exploring the robustness of the results within the baseline scenario, which constitutes the reference point of projections in the exercise. The analysis concludes that, by the end of the projected period, Spain will count on a similar public pension expenditure ratio as the current one.