997 resultados para Pino silvestre


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We postulate a two-region world, comprised of North (calibrated after the US) and South(calibrated after China). Our optimization results show the compatibility of the following threedesiderata:(1) Global CO2 emissions follow a conservative path that leads to the stabilizationof concentrations at 450 ppm.(2) North and South converge to a path of sustained growth at 1% per year (28.2%per generation) in 2075.(3) During the transition to the steady state, North also grows at 1% per year whileSouth s rates of growth are markedly higher.The transition paths require a drastic reduction of the share of emissions allocated to North,large investments in knowledge, both in North and South, as well as very large investments ineducation in South. Surprisingly, in order to sustain North s utility growth rate, some output mustbe transferred from South to North during the transition.Although undoubtedly subject to many caveats, our results support a degree of optimism byproviding prima facie evidence of the possibility of tackling climate change in a way that is fairboth across generations and across regions while allowing for positive rates of humandevelopment.

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Estudia el comportamiento de la poblacion de los lobos marinosen Punta San Juan durante 1982-83

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Does risk attitude (aversion or attraction) vary with the level of the income at risk? About half of our subjects chose to insure all levels, whereas another half chose instead not to insure low levels, but to insure high levels.

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We test whether risk attitudes change when losses instead of gains areinvolved. The study of gain-loss asymmetries has been largely confinedto reflected choices, where all the money amounts of a positiveprospect are multiplied by minus one. We define the decomposition reflection = translation + probability switch, and experimentally findboth a translation effect (risk attraction becomes more frequent whengains are translated into losses) and a probability switch effect (riskattraction becomes more frequent when the probability of the best outcomedecreases). Surprisingly, the switch effect is somewhat stronger than thetranslation effect, negating a conventional reflection effect when onestarts with choices between gains with a low probability of the bestoutcome. We conclude by arguing that, while both the translation effectand the switch effect contradict the expected utility hypothesis, thetranslation effect implies a deeper violation of standard preference theory.

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Let there be a positive (exogenous) probability that, at each date, the human species will disappear.We postulate an Ethical Observer (EO) who maximizes intertemporal welfare under thisuncertainty, with expected-utility preferences. Various social welfare criteria entail alternativevon Neumann- Morgenstern utility functions for the EO: utilitarian, Rawlsian, and an extensionof the latter that corrects for the size of population. Our analysis covers, first, a cake-eating economy(without production), where the utilitarian and Rawlsian recommend the same allocation.Second, a productive economy with education and capital, where it turns out that the recommendationsof the two EOs are in general different. But when the utilitarian program diverges, thenwe prove it is optimal for the extended Rawlsian to ignore the uncertainty concerning the possibledisappearance of the human species in the future. We conclude by discussing the implicationsfor intergenerational welfare maximization in the presence of global warming.

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Five new associations of parasitoids in potter wasps (Vespidae, Eumeninae). New associations of host and parasitoids involving potter wasps: Toxophora leucon and Pleurochrysis sp. were found parasitizing Cyphomenes anisitsii, Chrysis sp. (gr. intricans) was found parasitizing Minixi suffusum, Plega beardi was found parasitizing Montezumia pelagica sepulchralis and Macrosiagon sp. was found parasitizing Pachodynerus nasidens.

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Climate science indicates that climate stabilization requires low GHG emissions. Is thisconsistent with nondecreasing human welfare?Our welfare or utility index emphasizes education, knowledge, and the environment. Weconstruct and calibrate a multigenerational model with intertemporal links provided by education,physical capital, knowledge and the environment.We reject discounted utilitarianism and adopt, first, the Pure Sustainability Optimization (orIntergenerational Maximin) criterion, and, second, the Sustainable Growth Optimization criterion,that maximizes the utility of the first generation subject to a given future rate of growth. We applythese criteria to our calibrated model via a novel algorithm inspired by the turnpike property.The computed paths yield levels of utility higher than the level at reference year 2000 for allgenerations. They require the doubling of the fraction of labor resources devoted to the creation ofknowledge relative to the reference level, whereas the fractions of labor allocated to consumptionand leisure are similar to the reference ones. On the other hand, higher growth rates requiresubstantial increases in the fraction of labor devoted to education, together with moderate increasesin the fractions of labor devoted to knowledge and the investment in physical capital.

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Earthquakes represent a major hazard for populations around the world, causing frequent loss of life,human suffering and enormous damage to homes, other buildings and infrastructure. The Technology Resources forEarthquake Monitoring and Response (TREMOR) Team of 36 space professionals analysed this problem over thecourse of the International Space University Summer Session Program and published their recommendations in the formof a report. The TREMOR Team proposes a series of space- and ground-based systems to provide improved capabilityto manage earthquakes. The first proposed system is a prototype earthquake early-warning system that improves theexisting knowledge of earthquake precursors and addresses the potential of these phenomena. Thus, the system willat first enable the definitive assessment of whether reliable earthquake early warning is possible through precursormonitoring. Should the answer be affirmative, the system itself would then form the basis of an operational earlywarningsystem. To achieve these goals, the authors propose a multi-variable approach in which the system will combine,integrate and process precursor data from space- and ground-based seismic monitoring systems (already existing andnew proposed systems) and data from a variety of related sources (e.g. historical databases, space weather data, faultmaps). The second proposed system, the prototype earthquake simulation and response system, coordinates the maincomponents of the response phase to reduce the time delays of response operations, increase the level of precisionin the data collected, facilitate communication amongst teams, enhance rescue and aid capabilities and so forth. It isbased in part on an earthquake simulator that will provide pre-event (if early warning is proven feasible) and post-eventdamage assessment and detailed data of the affected areas to corresponding disaster management actors by means of ageographic information system (GIS) interface. This is coupled with proposed mobile satellite communication hubs toprovide links between response teams. Business- and policy-based implementation strategies for these proposals, suchas the establishment of a non-governmental organisation to develop and operate the systems, are included.

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Contient : Notes pour l'histoire de Colbert, parmi lesquelles on remarque les pièces suivantes ; Tombe de Richard Colbert, dit l'Ecossais ; Lettre du sieur Quesnel à Baluze (26 mars s. d.) ; Copie d'une lettre de Mazarin à Le Tellier (Compiègne, 5 juin 1656) ; Lettre de Colbert à Le Tellier (8 août 1663) ; « Instructions de S. E. à exécuter par M. Jobart, en avril 1651 » ; Lettre de D. Jobart [à Mazarin] (Paris, 2 novembre 1650) ; Lettre du sieur Colbert... à son Eminence (9 avril 1655) ; impr. de 8 pages in-4° ; Lettre adressée à M. de Feret par le maire et les jurés de Bordeaux (5 avril 1592) ; Lettre de M. Forget au sieur Feret, agent du duc de Saxe-Weimar (s. d.) ; Lettre de M. de Charreard au même (Weimar, 16 mars 1662) ; Copie d'une lettre de Louis XIV à [Charles] duc de Lorraine (8 novembre 1661) ; « Epitaphium Caroli ducis Lotharingiae » ; Lettre de M. d'Erlach au sieur Feret (6 juillet s. d.) ; Lettre de M. de Charreard [au même] (Weimar, 5 février 1662) ; Lettre de « G. Gilhomo de Harstall » à M. Charreard (Altenburg, 25 janvier 1662) ; Lettre de M. de Bostel à M. de Saint-Marc ; Lettre de Charles de Lorraine, [duc de Guise,] à M. Brulart (s. d.) ; Lettre de Charles de Bourbon, évêque de Lectoure, à M. Lonsieux (7 avril 1592) ; « Coppie de la lettre du patriarche Cirille [de Constantinople] à la seigneurie et pasteurs de la ville et eglize de Genève, traduite d'Italien en Françoys. » ; Règlement pour la surintendante de la maison de la reine (14 mai 1661) ; Mémoire en faveur de l'établissement d'un parlement à Tours ; Lettre de C. Drelincourt à M. Dubordieu, de Montpellier (Paris, 10 février 1656) ; Trois lettres de M. de Charreard à M. Feret (14 juin-16 septembre 1663) ; Copie de lettres de Drelincourt à Balzac et à Feret, et de Balzac à Drelincourt (26 avril-16 octobre 1651) ; Copie, de la main de Baluze, et envoyée par lui à Madame de Maintenon, d'une lettre de [Constant] d'Aubigné à M. de Bonica (des prisons de Niort, 9 mai 1637), et copie de la lettre de Baluze accompagnant l'envoi ; Lettres adressées à Phélypeaux du Verger par divers personnages : ; Quatre lettres d'Henri de Bourbon [prince de Condé] (25 juin-15 octobre 1645) suivies de la copie de diverses lettres de Louis de Bourbon, comte de Soissons ; Huit lettres de Louis XIV (24 mars 1644-23 juillet 1647) ; Le Tellier (3 septembre 1646) ; [Pierre] Seguier (Paris, 21 décembre 1642) ; Le P. de Lingendes, S. J. (Paris, 12 février 1644) ; [Pierre] Séguier (Paris, 12 mai 1658) ; Trois lettres de Louis de Bourbon [prince de Condé] (13 novembre 1646-13 décembre 1647) ; Neuf lettres de Gaston [duc d'Orléans] (1er décembre 1645-20 mars 1648) ; Vingt-deux lettres de [Silvestre de Cruzy de] Marcillac, évêque de Mende, à Bernard de Saxe-Weimar (3 mai 1636-20 avril 1639)

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Desarrollo de una aplicación para Android que ofrece un método fácil para aprender chino mandarín desde el español.

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La pedagogía crítica acentúa la falta de neutralidad de la escuela respecto a las relaciones de poder que existen en la sociedad. Su propuesta consiste en modificar las relaciones de poder en el aula en el sentido de transformar las relaciones coercitivas –las que reproducen las relaciones existentes– en relaciones colaborativas partiendo del reconocimiento y la participación de los alumnos en las actividades escolares. Desde esta perspectiva, uno de los objetivos de las actividades es que los niños produzcan «textos identitarios», entendidos como artefactos que los alumnos se pueden apropiar para promover su desarrollo cognitivo. El artículo muestra el trabajo educativo integrado desde Educación Infantil hasta 6.º de Primaria de una escuela de la provincia de Girona en la que el 97% de los alumnos es de origen extranjero y cuyo propósito es incrementar las habilidades lingüísticas orales y escritas en la lengua escolar, así como la utilización de otros lenguajes multimedia. La unidad didáctica consiste en la elaboración de un cuento a lo largo de un curso escolar por parte de todo el alumnado con la ayuda de los profesores, de dos autores y de tres ilustradores. Cada ciclo escolar decide los personajes y el escenario y explicita textualmente el transcurso de la acción. Los ilustradores producen las imágenes y los autores posibilitan la transición de aquello que ha elaborado un ciclo al producto del siguiente. La actividad basada en la participación y la utilización de procedimientos democráticos de decisión se inserta en la propuesta educativa y lingüística de la escuela, así como en sus concreciones curriculares. Los resultados muestran que los textos construidos por los niños se apoyan en sus «fondos de conocimiento» sociales y familiares y constituyen una fuente de progreso en la consecución de las competencias básicas y en la construcción de valores democráticos

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Various experimental procedures aimed at measuring individual risk aversion involve alist of pairs of alternative prospects. We first study the widely used method by Holt andLaury (2002), for which we find that the removal of some items from the lists yields asystematic decrease in risk aversion. This bias is quite distinct from other confoundsthat have been previously observed in the use of the Holt and Laury method. It may berelated to empirical phenomena and theoretical developments where better prospectsincrease risk aversion. Nevertheless, we have also found that the more recent elicitationmethod due to Abdellaoui et al. (2011), also based on lists, does not display anystatistically significant bias when the corresponding items of the list are removed. Ourresults suggest that methods other than the popular Holt and Laury one may bepreferable for the measurement of risk aversion.

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Several unit root tests in panel data have recently been proposed. The test developed by Harris and Tzavalis (1999 JoE) performs particularly well when the time dimension is moderate in relation to the cross-section dimension. However, in common with the traditional tests designed for the unidimensional case, it was found to perform poorly when there is a structural break in the time series under the alternative. Here we derive the asymptotic distribution of the test allowing for a shift in the mean, and assess the small sample performance. We apply this new test to show how the hypothesis of (perfect) hysteresis in Spanish unemployment is rejected in favour of the alternative of the natural unemployment rate, when the possibility of a change in the latter is considered.

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This paper proposes a test statistic for the null hypothesis of panel stationarity that allows for the presence of multiple structural breaks. Two different speci¿cations are considered depending on the structural breaks affecting the individual effects and/or the time trend. The model is ¿exible enough to allow the number of breaks and their position to differ across individuals. The test is shown to have an exact limit distribution with a good ¿nite sample performance. Its application to a typical panel data set of real per capita GDP gives support to the trend stationarity of these series

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In this paper we test for the hysteresis versus the natural rate hypothesis on the unemployment rates of the EU new members using unit root tests that account for the presence of level shifts. As a by product, the analysis proceeds to the estimation of a NAIRU measure from a univariate point of view. The paper also focuses on the precision of these NAIRU estimates studying the two sources of inaccuracy that derive from the break points estimation and the autoregressive parameters estimation. The results point to the existence of up to four structural breaks in the transition countries NAIRU that can be associated with institutional changes implementing market-oriented reforms. Moreover, the degree of persistence in unemployment varies dramatically among the individual countries depending on the stage reached in the transition process