Dynamic screening and energy loss of antiprotons colliding with excited Al clusters

We use time-dependent density functional theory to calculate the energy loss of an antiproton colliding with a small Al cluster previously excited. The velocity of the antiproton is such that non-linear effects in the electronic response of the Al cluster are relevant. We obtain that an antiproton penetrating an excited cluster transfers less energy to the cluster than an antiproton penetrating a ground state cluster. We quantify this difference and analyze it in terms of the cluster excitation spectrum.Comment: 23 pages, 4 figures, to be published in Nuclear Instruments and Methods B as a proceeding of the IISC-19 Workshop on Inelastic Ion-Surface Collision

Direct resolution of unoccupied states in solids via two photon photoemission

Non-linear effects in photoemission are shown to open a new access to the band structure of unoccupied states in solids, totally different from hitherto used photoemission spectroscopy. Despite its second-order nature, strong resonant transitions occur, obeying exact selection rules of energy, crystal symmetry, and momentum. Ab-initio calculations are used to demonstrate that such structures are present in low-energy laser spectroscopy experimental measurements on Si previously published. Similar resonances are expected in ultraviolet angle-resolved photoemission spectra, as shown in a model calculation on Al.Comment: 12 pages, including 4 figure

Observational evidences of strain-induced periodic stratification (SIPS) in the Gualdalquivir Estuary

http://isms.gal/wp-content/uploads/2018/06/eof-libro-abstracts-definitivo.pdfThe G&M14 stratification-circulation diagram allows to classify estuaries on the basis of river flow and tidal forcing in terms of the freshwater Froude number and a mixing parameter that accounts for the vertical structure of the water column [Geyer & MacCready, 2014]. In this study, instead of computing these parameters for the whole estuary as was originally proposed by these authors, both are computed locally, at different stretches along the Guadalquivir estuary. The analysis is based on the data collected at 21 stations in a 3 year continuous monitoring campaign (2008–2011), during which the estuary experienced a wide range of environmental conditions [Navarro et al., 2011]. Remarkably, the results reveal that conditions in the inner stretches fall most of the time in the Strain-Induced Periodic Stratification (SIPS) regime mapped in the G&M14 diagram [Simpson et al., 1990]. Near the mouth, the estuary is mostly partially-mixed. Freshwater discharges may shift the state of the lower stretches toward a salt-wedge structure whose location depends strongly on the fresh water volume discharged. Estimates of the Simpson number during the same period confirm this picture. The SIPS regime implies that the covariance between eddy viscosity and vertical shear of the longitudinal current drives part of the subtidal circulation, even more efficiently than the classical gravitational circulation does [Burchard & Hetland, 2010]. This may have a significant impact on the estuarine suspended matter distribution. Results further point out the limitations of estuarine classification of estuarine systems as a whole on the basis of stratification-circulation diagrams. Even spatially close stretches may transit different regions of the G&M14 diagram. A specific stretch of an estuary may change its structure and its state in the stratification-circulation diagram may undergo large excursions under changing environmental conditions

Las didácticas específicas: consideraciones sobre principios y actividades.

Las didácticas específicas son parte significativa de la didáctica general, formas de su concreción. Su objeto es hacer educativo el conocimiento que les concierne en cada caso. La dificultad estriba en la forma de su comunicación. En este sentido se busca concretarlas, con finalidad aclaradora, para las matemáticas y las ciencias de la naturaleza

The reptile type specimens preserved in the Museo Nacional de Ciencias Naturales (CSIC) of Madrid, Spain

13 páginas, 3 figuras y 2 tables.A first complete list of the reptile type specimens preserved in the Museo Nacional de Ciencias Naturales (CSIC) of Madrid (updated until 15 July 2012) is provided. The collection houses a total of 318 type specimens representing 24 taxa belonging to 6 families and 12 genera. There are 22 taxa represented by primary types (19 holotypes, 2 neotypes and 1 lectotype) and at least one paratype, and only two taxa are exclusively represented by one secondary type (paratype). The collection is specially rich in Spanish endemisms. Special attention is deserved by the type series of many subspecies of Podarcis lilfordi described by A. Salvador and V. Pérez-Mellado. All type specimens are housed in the Herpetological collection except Blanus mariae and Psammodromus occidentalis type series and Psammodromus hispanicus (neotype) which are preserved in the DNA/Tissues Collection.For the technical support we thank the projects CGL2008-04164 (Dr. I. de la Riva, Principal Investigator), HUM2007- 62687 (Dr C. Martín, Principal Investigator) and Fauna Ibérica Project CGL2007-66786-C08-01 (Dr. Marian Ramos, Principal Investigator).Peer reviewe

Leucemia linfocítica crónica y su respuesta al tratamiento en un perro

Se presenta un caso clínico de leucemia linfocítica crónica en una perra, describiendo el curso de la enfermedad, los métodos diagnósticos empleados y su respuesta al tratamiento quimioterápico.A case of chronic lymphocytic leukemia in a bitch is presented. In this paper we describe the evolution of the disease, the diagnosis protocol and the response to a chemotherapeutic treatment

Desigualdades en salud materno-infantil: impacto de una intervención

ResumenSe evalúa en términos del impacto poblacional una intervención sociosanitaria materno-infantil en un área urbana de Barcelona (el distrito de Ciutat Vella) de renta familiar baja. La intervención se basó en facilitar el acceso a los servicios sociales y sanitarios a embarazadas y recién nacidos. Eldiseño del estudio es cuasiexperimental con un grupo de control no equivalente y medidas múltiples en el tiempo. Se comparan las tasas de mortalidad infantil y perinatal acumuladas del distrito de Ciutat Vella con las del resto de la ciudad antes (1983-86) y después de la intervención (1987-89, 1990-92).Los resultados muestran que las diferencias iniciales existentes entre las tasas de mortalidad de las dos poblaciones desaparecen después del desarrollo del programa. La mortalidad infantil en Ciutat Vella pasó de 17,7/1.000 nacimientos en 1983-86 a 13,1/1.000 nacimientos en 1987-89 y a a 13,4/1.000 nacimientos en 1990-92, mientras que en el resto de la ciudad las tasas pasan de 9,5 a 8, 8 y 7,7/1.000 nacimientos, respectivamente.Se concluye que los programas sociosanitarios integrados en zonas urbanas pequeñas de baja renta familiar pueden contribuir a la reducción de las desigualdades en salud materno-infantil.SummaryWe present the evaluation of the population impact of a social and health maternal and child intervention, implemented in a low income urban area (Ciutat Vella) in Barcelona, Spain. Intervention was based on increasing access to health and social services for pregnant women and for the children. A quasiexperimental design with a nonequivalent control group and multiple measurements was used. We compared infant and perinatal cumulative mortality rates between Ciutat Vella District and the rest of the city, before (1983-86) and after the intervention (1987-89, 1990-92).Results showed that the significant differences found previously to the program betwen the mortality rates disappeared with the development of the program. Infant mortality in Ciutat Vella was 17.7/.000 births in 1983-86, and became 13.1/1.000 births in 1987-89, and 13,4 in 1990-92; in the rest of the city, infant mortality was 9.5/1.000 births in 1983-86, and became 8.8/ and 7.7/1000 births respectively.A comprehensive social and health care program implemented in small low income areas may contribute to reduce inequalities in maternal and child health

The Villalcampo Shear Zone (Zamora, Spain), geometry, kinematics and the physical conditions of the strain

[Resumen] En este trabajo se presenta una cartografía detallada de un sistema de cizalla que incluye la zona de cizalla de Villalcampo propiamente dicha y las bandas asociadas. Este sistema tiene carácter regional, afecta a granitos intruidos después de la segunda fase hercínica y a sus encajantes metamórficos en un área de al menos 150 Km2. El estudio geométrico y cinemático de las bandas, la distribución de las rocas de falla, así como el estudio microestructural han permitido interpretar todo el sistema como una cizalla subvenical dextra de carácter dúctil-frágil, que termina hacia el NW en un abanico extensional y que se prolonga hacia el SE en otra amplia área interpretada como un duplex extensional. El valor de la cizalla 'Y es de 1,55 y el desplazamiento mínimo calculado es de 3,7 Km. Todas las bandas de cizalla que incluye el sistema de Villalcampo y las venas o filones asociados pueden relacionarse con un único campo de esfuerzos en el que la trayectoria del esfuerzo principal al, subhorizontal y de dirección aproximadamente N-S sufre una desviación en la zona terminal de la banda en sentido diferente según el labio de que se trate, tal como propone Anderson (1951). Para caracterizar el régimen y los mecanismos de la deformación se ha realizado un análisis microestructural detallado de las rocas de falla y un estudio petrográfico y de la petrofábrica de las milonitas. Se concluye que los yacimientos de oro de Pino están controlados estructuralmente por este sistema de cizalla ya que aparecen en venas extensionales ocupadas por milonitas brechificadas; las condiciones de la deformación de carácter alternativamente dúctil-frágil habrtan permitido la migración de fluidos mineralizadores y el sellado de las fracturas en ciclos repetidos. Se propone como hipótesis que los yacimientos de estaño y wolframio que aparecen en la región de Villaseco-Almaraz de Duero puedan estar controlados también por el duplex extensional de este sistema de cizalla.[Abstract] The present work reports" on a detailed mapping of the Villalcampo shear system, including the Villalcampo shear itself together with related shears and veins. This regional shear system affects granites intruded after the second hercynian deformation phase and their metamorphic host rocks over an area of about 150 Km2. A st~ctural study of the shear bands, encompassing geometric and kinematic criteria and also the distribution of fault rocks, has allowed the authors to interpret the whole of the system as a ductile-fragile subvenical dextral shear spaying to the NW in an extensional fan that is prolonged to the SE over a broad area interpreted as an extensional duplex. The value of the shear strain, 'Y = 1.55, and the minimum displacement, s = 3.700 m, is calculated. The distribution of shear bands and veins is coherent with the notion of a single stress field where the principal stress, o"¡, is subhorizontal and has a N-S trajectory that deviates to the tips of the main shear, as proposed by Anderson (1951). With a view to gaining insight into the shearing regimen and the physical conditions of the deformation, a microestructural exploration of the fault rocks was carried out together with a petrographical and petrofabric study of the mylonites. It is concluded that the Pino ore veins -with Au mineralization- are structurally controlled by this shear system because they are related to the extensional veins infilled by brecchiated mylonites. Additionally, it is proposed that the deformation conditions would have alternated between brittle and ductile; this would have permited the migration and sealing of microfractures by mineralizing fluids during repeated cycles. As an hypothesis, it is proposed that the Sn and W ores situated in -the Villaseco -Almaraz area are possibly related to the extensional duplex