543 research outputs found

    A Cointegration Analysis of the Long-Run Supply Response of Spanish Agriculture to the Common Agricultural Policy.

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    Using cointegration techniques, we estimate two models that capture the long-term relationship between Spanish prices and agricultural production. The models were estimated over Spanish agricultural data from 1970 to 2000, a period spanning Spain’s implementation of the Common Agricultural Policy in 1986 and the application of the MacSharry Reforms in 1992. The models, as well as plausible counterfactual scenarios constructed to assess the production changes induced by the CAP, lead to three principal results. First, we find that Spanish agricultural output is responsive to agricultural prices. Second, we find that the MacSharry reforms have been instrumental in restraining agricultural production. Third, we find that Spanish agricultural output would have been higher if Spain had not applied the CAP. These results are important and have broad implications. First, they strengthen the position of those reformers both within and outside of Europe that argue for lower price supports as an appropriate policy for stemming European agricultural surpluses. Second, they indicate that recent EU reforms, which have in effect extended the MacSharry reforms, are appropriate measures for curbing European agricultural surpluses.Keywords: Price Support Policy; MacSharry Reforms; Cointegration Techniques; European Economic Integration.

    Joint effect of ageing and multilayer structure prevents ordering in the voter model

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    The voter model rules are simple, with agents copying the state of a random neighbor, but they lead to non-trivial dynamics. Besides opinion processes, the model has also applications for catalysis and species competition. Inspired by the temporal inhomogeneities found in human interactions, one can introduce ageing in the agents: the probability to update decreases with the time elapsed since the last change. This modified dynamics induces an approach to consensus via coarsening in complex networks. Additionally, multilayer networks produce profound changes in the dynamics of models. In this work, we investigate how a multilayer structure affects the dynamics of an ageing voter model. The system is studied as a function of the fraction of nodes sharing states across layers (multiplexity parameter q ). We find that the dynamics of the system suffers a notable change at an intermediate value q*. Above it, the voter model always orders to an absorbing configuration. While, below, a fraction of the realizations falls into dynamical traps associated to a spontaneous symmetry breaking in which the majority opinion in the different layers takes opposite signs and that due to the ageing indefinitely delay the arrival at the absorbing state.Comment: 10 pages, 8 figure

    Internal friction in advanced Fe-Al intermetallics

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    We have measured the internal friction and the dynamic modulus of an Fe–38 at.% Al alloy using a forced torsion pendulum working between 10−3 and 10 Hz. The measurements have been carried out as a function of temperature (from room temperature to 1200 K) and as a function of frequency. Two peaks have been observed in the internal friction spectra, at about 780 and 1100 K, which are largely superposed in the intermediate temperature range. Both peaks and the corresponding modulus defect shift in temperature with the oscillation frequency, and can be attributed to relaxation mechanisms. Previous results in the literature seem to indicate that the low temperature peak is the Zener relaxation of Al atoms. The activation energy of the high-temperature peak, referred to as P1 peak because it has not been studied previously, has been determined to be Hact = 2.87 eV, from the results of measurements at different temperatures and frequencies. We discuss the possible mechanisms, which could be responsible of this P1 peak, and suggest that it could be attributed to the intrinsic movements of left angle bracket1 0 0right-pointing angle bracket perfect dislocations over the Peierls barrier by kink pair formation in the B2 ordered FeAl

    Methodology for the metric restoration of the historical cartography applied to Francisco Coello's cartografic series of the Royal Site of Aranjuez

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    Hojas Kilométricas (Kilometric Sheets). Specifically, the study focuses on those sheets referring to the city centre and surrounding area of the Royal Site of Aranjuez, a town in the south of the Province of Madrid. The aim of this study is to restore the actual size and measurements of scanned images of the Hojas Kilométricas. This would allow us, among other things, to reestablish both the format and scale of the original plans. To achieve this goal it is necessary to rectify and then georeference these images, i.e. assign them a geographic reference system. This procedure is essential in the overlaying and comparison of the Hojas Kilométricas of the Royal Site with other historical cartography as well as other sources related to the same area from different time periods. Subsequent research would allow us, for example, to reconstruct the time-evolution of the urban area, to spot new construction and to pinpoint the locations of any altered or missing buildings or architectural features. In addition, this would allow us to develop and integrate databases for GIS models applicable to the management of our cultural heritage

    Viscoelastic behavior of a polyester resin concrete reinforced with nonmetallic bars under bending loads

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    This paper deals with the study of a highly durable polyester polymer concrete reinforced with glass fibre reinforced polymer rebars. The paper describes the properties of this specific concrete, which were tested using different experimental techniques such as porosimetry, scanning electron microscopy and petrography. Likewise, characterisation in a macro-scale was carried out to define the mechanical properties of the material (modulus of elasticity, stress-strain curve, ultimate strength and bond). Based on the latter properties, the paper presents a relatively simple method to estimate the ultimate bearing capacity of beams under bending load. The calculation method has been verified by testing beams and full-scale elements. At the end, and due to the viscoelastic nature of the polymer, several considerations will be made in order identify safety factors dependent on the loads nature: permanent loads (deferred deformations) and live loads.Peer ReviewedPostprint (author’s final draft

    Staphylococcus aureus poststernotomy mediastinitis: Description of two distinct acquisition pathways with different potential preventive approaches

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    ObjectiveDetermining the acquisition routes of infection is crucial to designing specific preventive approaches against Staphylococcus aureus poststernotomy mediastinitis.MethodsFrom 2002 to 2004, a nasal sample was obtained from patients before cardiac surgery. We collected clinical and microbiologic data of all episodes of S aureus poststernotomy mediastinitis. A case–control study (3:1) was performed to confirm the role of previous preoperative nasal colonization by S aureus as a risk factor for S aureus poststernotomy mediastinitis. Pulsed field gel electrophoresis molecular analysis of nasal and surgical site S aureus isolates was performed to analyze their relatedness in each patient with poststernotomy mediastinitis and with other patients of the study cohort.ResultsS aureus nasal cultures were positive in 228 (15.9%) of 1432 patients: methicillin-susceptible S aureus in 222 (15.5%) and meticillin-resistant S aureus in 6 (0.4%). S aureus poststernotomy mediastinitis was diagnosed in 17 (1.2%) of 1432 patients: 9 (3.95%) of 228 in colonized patients versus 8 (0.66%) of 1204 in noncolonized patients (P < .0001). Seven of 9 patients (1.2%) with methicillin-susceptible S aureus had an identical isolate by pulsed field gel electrophoresis in preoperative nasal and surgical-site cultures, but no clonal relatedness was shown among the isolates from these 9 patients. None of the 8 patients with methicillin-resistant S aureus poststernotomy mediastinitis had an identical isolate by pulsed field gel electrophoresis in preoperative nasal and surgical-site cultures, and the same clone of methicillin-resistant S aureus was responsible for all these cases.ConclusionsNasal colonization often precedes methicillin-resistant S aureus poststernotomy mediastinitis, which suggests that decontamination is adequate for preventing methicillin-resistant S aureus poststernotomy mediastinitis, whereas hospital infection control measures seem to be the major factor for preventing methicillin-resistant S aureus poststernotomy mediastinitis

    Aspectos generales de la metodología para calculo del Margen Bruto Estándar 2000. Documento de Trabajo de la Cátedra Jean Monnet 3/04. con R. Mora y E. J. de la Torre.

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    El objetivo de este documento de trabajo es presentar la metodología para el cálculo del Margen Bruto Estándar con periodo de referencia 1999, 2000 y 2001 (MBE 2000) y para el conjunto de categor´ıas agr´ıcolas definidas en el anexo de la Decisi´on de la Comisión 2003/369/CE. En este documento, dichas categorías vienen recogidas en el cuadro 2 del anexo. Este documento de trabajo se divide en tres secciones. En la sección 1 se presenta el marco metodológico general recogido en la legislaci´on comunitaria, prestando especial interés a la definición de MBE. Las secciones 2 y 3 presentan, de forma resumida, la metodología seguida para el cálculo de los coeficientes MBE 2000 de las categorías de cultivos y ganados respectivamente.Gross Standar Margin, Farm Accounting Data Network, Land prices, agricultural productivity, irrigated land, regional specialization.

    Geometric documentation of the flour factory "El Puente Colgante" in Aranjuez (Madrid).

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    The goal of this communication is to offer, through computer-aided design tools, a methodology to recover and virtually reconstruct disappeared buildings of our industrial historical heritage. It will be applied to the case of the flour factory "El Puente Colgante" (The Suspended Bridge) in Aranjuez, which was demolished in 2001. The process is as follows: After a historical analysis of the evolution in time of the flour factory, a field work provides data allowing an info graphic reconstruction of the factory. Once this information has been processed, a lifting of the current state is made with AutoCAD, and a three-dimensional model is built with the Rhinoceros application. Then images of the ensemble are obtained with the applications Rhinoceros and V-Ray, ending with a postproduction with Photoshop. The proposed methodology has permitted to obtain a three-dimensional model of the flour factory ?El Puente Colgante? in Aranjuez, with an accurate virtual reconstruction of its original state prior to demolition. The procedure exposed is susceptible to be generalized for any other example of industrial architecture

    El color en la cartografía histórica

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    El uso del color en la cartografía histórica no es un simple recurso estético para ilustrar planos, mapas y cartas. Fundamentalmente es un convencionalismo gráfico para representar la realidad de manera convincente. También, en algunas ocasiones, el color adquiere, incluso, un valor simbólico. En esta comunicación trataremos de analizar el uso del color en la cartografía histórica, desde el signo y desde el significado, es decir, desde la materialización del pigmento que colorea un fragmento del plano según una codificación determinada, hasta la percepción que transmite el color y la tonalidad del elemento representado. Hacemos mención de los materiales que forman un color, de las técnicas de iluminación y lavado de planos y de la progresiva normalización de los diversos criterios en su uso
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