Density, structure and dynamics of water: the effect of Van der Waals interactions

It is known that ab initio molecular dynamics (AIMD) simulations of liquid water, based on the generalized gradient approximation (GGA) to density functional theory (DFT), yield structural and diffusive properties in reasonable agreement with experiment only if artificially high temperatures are used in the simulations. The equilibrium density, at normal conditions, of DFT water has been recently shown by Schmidt et al. [J. Phys. chem. B, 113, 11959 (2009)] to be underestimated by different GGA functionals for exchange and correlation, and corrected by the addition of interatomic pair potentials to describe van derWaals (vdW) interactions. In this contribution we present a DFTAIMD study of liquid water using several GGA functionals as well as the van der Waals density functional (vdW-DF) of Dion et al. [Phys. Rev. Lett. 92, 246401(2004)]. As expected, we find that the density of water is grossly underestimated by GGA functionals. When a vdW-DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections. We analyze the origin of the density differences between all the functionals. We show that the vdW-DF increases the population of non-H-bonded interstitial sites, at distances between the first and second coordination shells. However, it excessively weakens the H-bond network, collapsing the second coordination shell. This structural problem is partially associated to the choice of GGA exchange in the vdW-DF. We show that a different choice for the exchange functional is enough to achieve an overall improvement both in structure and diffusivity.Comment: 11 pages, 9 figures, submitted. Revised versio

Palinología del paleolítico medio y superior de Cova Beneito (Muro, Alicante)

Es presenten els resultats pal.linológics de una secció estratigrafica que correspon al paleolltic superior de la Cova Beneito (Muro, Alacant), la qual completa la seqüencia paleolítica que ara inclou nivells musterians, aurinyacians, solutrians, gravetians i solutreo-gravetians. La secció pol.linífera s'hi tmba escassament a 1-2 m d'una altra estudiada anterionnent, la qual va resultar esteril. Els espectres pol.línics mostren que el paleolltic superior de la zona es va desenvolupar en condicions d’aridesa ambiental prou marcades, la qual cosa està en corrodància amb les dades que s'observen a altres diagrames pol.linics per a l'estadi isotbpic 2 en domini continental. Dins d'un context global, la seqüencia de la Cova Beneito dóna suport a la hipòtesi que durant l'intetpleniglacial wunnià es produrien expansions, no necessàriament, coetànies, de nuclis de vegetació mediterrània, l'amplitud i duració de les quals dependrien de les condicions locals.In this study, the palynology of an Upper Paleolithic stratigraphical section from Cova Beneito (Muro, Alicante) is presented. It completes all the Paleolithic record including Mousterian, Aurignacian, Solutrian, Gravettian and Solutreo Gravenian industries. The polliniferous section is placed 1-2 m apart from a former one which became sterile. According to the pollen spectra, the Upper Paleolithic environment could have been one of severe aridity. This agrees with the conventional palynology in continental domain for the isotopic stage 2. Overall, the Beneito pollen record supports the view that, during the middle last glacial stage, Mediterranean vegetation couM have been widespread, but with the response of vegetation to the climatic change largely depending on local conditions.Se presentan los resultados palinológicos de una sección estratigráfica correspondiente al Paleolítico superior de Cova Beneito (Muro, Alicante), completando así la secuencia paleolítica que ahora incluye niveles musterienses, auriñacienses. solutrenses, gravetienses y solutreo-gravetienses. La sección polinífera se halla apenas a 1-2 m de otra estudiada anteriormente, la cual resultó estéril. Los espectros polínicos muestran que el Paleolítico Superior de la zona se desarrolló en condiciones de aridez ambiental bastante marcadas, lo cual concuerda con los datos que se manejan en otros diagramas polínicos para el estadio isotópico 2 en dominio continental. En un contexto global, la secuencia de Cova Beneito sirve de apoyo a la hipótesis de que durante el interpleniglacial wurmiense se produjeron expansiones, no necesariamente coetáneas, de núcleos de vegetación mediterránea cuya amplitud y duración dependerían de las condiciones locales

Actividades enzimáticas en Basidiomicetos formadores de ectomicorrizas en Pinus radiata D. Don.

La reproducción de enzimas extracelulares por las ectomicorrizas moviliza una fracción importante de los compuestos presentes en el suelo. Se presentan resultados de las actividades enzimáticas relacionadas con la movilización de nitrógeno y fósforo para cuatro especies de hongos formadores de ectomicorrizas, Suillus luteus (L.: Fr.) F. Gray, Xerocomus badius (Fr.:Fr.) Gilbert, Boletus pinicola (Vitt.) Venturi y Pisolithus tinctorius (Pers.) Coker & Couch. Se considera el valor potencial de las actividades enzimáticas como criterio en la selección de hongos inoculantes. Los valores altos suponen una mayor utilidad de los hongos corno inoculantes en condiciones de vivero.Extracellular enzyme production by ectomycorrhizae is able to movilize an important soil fraction. We report enzyme activities related with nitrogen and phosphorus movi I ization in four ectomycorriza-forming fungi: Suillus luteus (L.: Fr.) F. Gray, Xerocomus badius (Fr.:Fr.) Gilbert, Boletus pinicola (Vitt.) Venturi andPisolithus tinctorius (Pers.) Coker & Couch We examine the potential value of enzyme activity as a criterion for selecting inoculant fungi. High values are considered as profitable for inoculants under nursery conditions

THE DEPLOYABLE ARCHITECTURE COMMEMORATES THE 25 YEARS OF PEACE. 50THAnniversary of Emilio Pérez Piñero’s Pavilion

[EN] Emilio Pérez Piñero carried out a transportable pavilion for exhibitions based on a flat reticular deployable structure made out of aluminium. A roof of 8.000 sqm covered the commemorative exhibition Spain 64. This structural achievement was meant to be used as a propaganda tool by the Spanish government of that time, in order to highlight the successes accomplished since the end of the Spanish Civil War, within the framework of the National propaganda campaign named 25 Years of Peace. Commissioned by the Spanish Ministry of Information and Tourism, the pavilion was subsequently installed in Madrid, San Sebastian and Barcelona.[ES] Emilio Pérez Piñero realiza un pabellón transportable para exposiciones basado en una estructura reticular desplegable plana fabricada en aluminio. La cubierta de 8.000 m2 alberga la exposición conmemorativa España 64. Con este hito estructural el gobierno de la época pretendía dar a conocer los logros conseguidos desde el final de la Guerra Civil española, en el marco conmemorativo de los XXV Años de Paz. El Ministerio de Información y Turismo fue el promotor de este encargo que estuvo instalado en Madrid, San Sebastián y BarcelonaPérez Belda, EA.; Pérez Almagro, MC. (2016). La arquitectura desplegable conmemora los XXV años de paz. 50 Aniversario del Pabellón de Emilio Pérez Piñero. EGA. Revista de Expresión Gráfica Arquitectónica. 21(28):146-155. doi:10.4995/ega.2016.6307.SWORD1461552128Aróstegui, J. y Godicheau, F., (ed.) 2006. Guerra Civil: Mito y Memoria. Madrid: Marcial Pons.Banham, R., 1976. Megastructure. Urban futures of the recent past. London: Thames and Hudson.Calvo López, J., & Sanz Alarcón, J. P. (2011). ARQUITECTURA PLEGABLE PARA UNA DÉCADA PRODIGIOSA La obra de Emilio Pérez Piñero y la arquitectura de los años sesenta. EGA. Revista de expresión gráfica arquitectónica, 16(17). doi:10.4995/ega.2011.888Drew, P., 1972. Third Generation: The Changing Meaning of Architecture. New York: Praeger.Escrig, F., 1993. Las estructuras de Emilio Pérez Pi-ero. Arquitectura Transformable. Textos de Arquitectura. Sevilla: Escuela Técnica Superior de Arquitectura de Sevilla, pp. 11-32.Friedman, Y., 1979. La arquitectura móvil. Barcelona: Poseidon.Nicolás Marín, E., 2005. Un desarrollo marcado por los contrastes (1962-1975), en La libertad encadenada. Espa-a en la dictadura franquista 1939-1975. Madrid: Alianza Editorial.Pérez Almagro, M. C., 2013. Estudio y normalización de la colección museográfica y del archivo de la Fundación Emilio Pérez Pi-ero (tesis doctoral). Murcia: Universidad de Murcia.Pérez Belda, E. A., 1996. Constructive problems in the deployable structures of Emilio Pérez Pi-ero, in Escrig, F & Brebbia, CA (ed.). Mobile and Rapidly Assembled Structures II, MARAS 96. Southampton: Computational Mechanics Publications, pp. 23-34.Pérez Pi-ero, E., 1964. Notas sobre las estructuras. Arquitectura vol. 6, nº 66, pp. 22-25.Puertas del Río, L., 1989. Estructuras desmontables y desplegables. Estudio de la obra del arquitecto Emilio Pérez Pi-ero (tesis doctoral). Madrid: Escuela Técnica Superior de Arquitectura de la Universidad Politécnica de Madrid.Robles Piquer, C., 2011. Memoria de cuatro Espa-as. República, guerra, franquismo y democracia. Barcelona: Planeta, pp. 251-261.Tusell, J., 2005. Dictadura franquista y democracia 1939- 2004. Barcelona: Crítica

Characterization of a new partitivirus strain in Verticillium dahliae provides further evidence of the spread of the highly virulent defoliating pathotype through new introductions

The soilborne pathogen Verticillium dahliae, causal agent of Verticillium wilt, has a worldwide distribution and many hosts of agronomic value. The worldwide spread of a highly virulent defoliating (D) pathotype has greatly increased the threat posed by V. dahliae in olive trees. For effective disease management, it is important to know if the D pathotype is spreading long distances from contaminated material, or if D pathotype isolates may have originated locally from native V. dahliae populations several times. We identified a double-stranded RNA mycovirus in an olive D pathotype isolate from Turkey. Sequencing and phylogenetic analysis clustered the virus with members of the family Partitiviridae. The virus was most similar to a partitivirus previously identified in a V. dahliae isolate from cotton in China (VdPV1), with sequence identities of 94% and 91% at the nucleotide level for RNA1 and RNA2, respectively. The virus therefore corresponded to a strain of the established species, and we designated it VdPV1-ol (VdPV1 from olive). The identification of the same viral species in these two fungal isolates from geographically distant origins provides evidence of their relationships, supporting the hypothesis of long-distance movement of V. dahliae isolates.This research was supported by the Spanish Ministry of Science and Innovation (Grants AGL2009- 13445), and the Junta de Andalucía (Grant FEDER P07-TIC-02682) and AGL2013-48980-R.Peer reviewe

Incidence, seasonality and serotypes of rotavirus in Gipuzkoa (Basque Country), Spain. A 14-year study

Over a 14-year period (1984–97) the presence of rotavirus in stool samples from children under 15 years with acute gastroenteritis was studied by enzymoimmunoanalysis. Serotyping (G1–G4) was performed using monoclonal antibodies. A total of 17348 children under 15 were investigated. Rotavirus was detected in 3637 (21·0%) specimens, 74·6% of which were from children younger than 2 years old. G1 and G4 were the most frequent serotypes. In 1991–7, the minimum incidence of rotavirus gastroenteritis in children under 4 years of age was 21·7 cases/1000 children/year. By the age of 5 years, at least 1 out of 11·3 children and probably 1 out of every 5–6 children in this area had experienced an episode of rotavirus gastroenteritis that required medical care. In the 1984–90 period a clear seasonality was not observed but in the second period of the study (1991–7), seasonality was marked, with peak activity in winter

Hybrid Cross-Entropy Method/Hopfield Neural Network for Combinatorial Optimization Problems

Abstract. This paper presents a novel hybrid algorithm for combinatorial optimization problems based on mixing the cross-entropy (CE) method and a Hopfield neural network. The algorithm uses the CE method as a global search procedure, whereas the Hopfield network is used to solve the constraints associated to the problems. We have shown the validity of our approach in several instance of the generalized frequency assignment problem