Large Nc scaling of meson masses and decay constants

We perform an ab initio calculation of the Nc scaling of the low-energy couplings of the chiral Lagrangian of low-energy strong interactions, extracted from the mass dependence of meson masses and decay constants. We compute these observables on the lattice with four degenerate fermions, Nf= 4 , and varying number of colours, Nc= 3 –6, at a lattice spacing of a≃ 0.075 fm. We find good agreement with the expected Nc scaling and measure the coefficients of the leading and subleading terms in the large Nc expansion. From the subleading Nc corrections, we can also infer the Nf dependence, that we use to extract the value of the low-energy couplings for different values of Nf. We find agreement with previous determinations at Nc= 3 and Nf= 2 , 3 and also, our results support a strong paramagnetic suppression of the chiral condensate in moving from Nf= 2 to Nf=

The application of terrestrial laser scanner and SfM photogrammetry in measuring erosion and deposition processes in two opposite slopes in a humid Badlands area (Central Spanish Pyrenees)

Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile metres (invasive techniques). In recent times, remote-sensing techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques provide the opportunity to build high-resolution topographic models at centimetre accuracy. By comparing different 3-D point clouds of the same area, obtained at different time intervals, the variations in the terrain and temporal dynamics can be analysed. The aim of this study is to assess and compare the functioning of terrestrial laser scanner (TLS, RIEGL LPM-321) and structure-from-motion photogrammetry (SfM) techniques (Camera FUJIFILM, Finepix x100 and software PhotoScan by AgiSoft) to evaluate erosion and deposition processes in two opposite slopes in a humid badlands area in the central Spanish Pyrenees. Results showed that TLS data sets and SfM photogrammetry techniques provide new opportunities in geomorphological erosion studies. The data we recorded over 1 year demonstrated that north-facing slopes experienced more intense and faster changing geomorphological dynamics than south-facing slopes as well as the highest erosion rates. Different seasonal processes were observed, with the highest topographic differences observed during winter periods and the high-intensity rainfalls in summer. While TLS provided the highest accuracy models, SfM photogrammetry was still a faster methodology in the field and precise at short distances. Both techniques present advantages and disadvantages, and do not require direct contact with the soil and thus prevent the usual surface disturbance of traditional and invasive methods

Publicaciones médicas: ¿ciencia o negocio?

En los últimos años ha aumentado enormemente el número de revistas científicas, de tal manera que hoy día es imposible leer ni siquiera el 1% de lo que se publica sobre nuestra especialidad o sobre los campos que nos interesen. La proliferación de revistas científicas en general y en el campo de la Medicina en especial puede ser debido a muchas razones. Entre ellas destacan, en nuestra opinión, la aparición de Internet y el cambio de la razón de ser de las publicaciones científicas. Comentaremos en esta revisión las razones que han llevado a este hecho.Sociedad Canaria de Osteoporosis (2016)

Impacts of oil palm expansion on avian biodiversity in a Neotropical natural savanna

The consequences of converting tropical rainforest to oil palm are well-documented, but the impacts of oil palm conversion on natural savanna landscapes remain little-known. Natural savannas in South America have been identified as fertile grounds for future oil palm expansion, partly due to perceived low biodiversity impacts relative to forest systems. We quantify the impacts of oil palm conversion for bird communities inhabiting natural savannas in the Colombian Llanos. Bird species richness and abundance were significantly reduced at sampling points in oil palm relative to adjacent natural savannas, with marked concomitant shifts in community composition. Aquatic, forest and grassland specialists all showed significantly lower abundances in oil palm habitat relative to savanna, as did migratory species and carnivorous/insectivorous dietary guilds. In both habitats, point-level species richness and total bird abundance increased with proximity to remnant forest patches. Within savanna, total bird abundance also decreased with proximity to adjacent oil palm, though species richness was not significantly affected. Within oil palm, point-level abundance increased with proximity to savanna, suggesting that communities in both habitats may be impacted by reciprocal edge or spill-over effects. Point-level abundance in oil palm also increased significantly with the presence of an invasive vine ‘kudzu’, a species introduced in some plantations as a soil protection measure, although species richness was not affected. Our work underlines the need for careful monitoring of further large-scale agro-industrial conversion in the Llanos. In particular, we suggest greater efforts to direct oil palm expansion towards already degraded lands (e.g. improved grassland areas currently used for intensive cattle grazing) to ensure remaining natural savannas are spared

High Levels of Blood Lead in Griffon Vultures (Gyps fulvus) from Cazorla Natural Park (Southern Spain)

©2005. This manuscript version is made available under the CC-BY-NC 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted, version of a Published Work that appeared in final form in Environmental Toxicology. To access the final edited and published work see https://doi.org/10.1002/tox.20132The blood lead of 23 griffon vultures (Gyps fulvus) trapped in 2003 was analyzed in order to evaluate exposure to lead in the vulture population of Cazorla Natural Park (in southern Spain). In 2001 the use of leaded gasoline in vehicles was banned in the European Union; however, lead ammunition is still used in Spain in big-game hunting for red deer, fallow deer, mouflon, and wild boar, which are ingested by vultures from September to March. The mean concentration of lead in blood was 43.07 6 31.96 g/dL with a range of 17.39–144.80 g/dL. Only two vultures had lead levels below 20 g/dL, and two others had blood lead concentrations close to 150 g/dL. In view of the results, we think the population of vultures from Cazorla Natural Park is suffering subclinical exposure to lead, with some individuals exposed to high toxicity risk. We concluded that ingestion of lead in the metallic form alone is sufficient to produce these blood lead concentrations, and we recommend the prohibition of lead ammunition for big-game hunting in order to preserve the vulture population

Utilidad y significado de la infraestructura de datos espaciales de España. Hermenéutica de la IDEE

La Infraestructura de Datos Espaciales de España (www.idee.es), en funcionamiento desde el verano del 2004, es un proyecto cooperativo, de autoría colectiva, en el que participan organismos e instituciones de los tres ámbitos de la Administración Pública (general, regional y local), del entorno universitario y del sector privado. Básicamente consiste en un sistema distribuido en la Red que permite a cualquier usuario mediante un simple navegador (browser) la búsqueda, localización, visualización, superposición en pantalla, consulta, análisis y, en ocasiones, descarga de los datos geográficos disponibles en más de quince servidores pertenecientes a diferentes organismos cartográficos de España, que ofrecen mapas a varias escalas, nomenclátores, ortofotos, imágenes de satélite, catastro, etc., todo ello, con cobertura nacional, facilidad de acceso y sencillez de uso

Scoping assessment of free-field vibrations due to railway traffic

The number of railway lines both operational and under construction is growing rapidly, leading to an increase in the number of buildings adversely affected by ground-borne vibration (e.g. shaking and indoor noise). Post-construction mitigation measures are expensive, thus driving the need for early stage prediction, during project planning/development phases. To achieve this, scoping models (i.e. desktop studies) are used to assess long stretches of track quickly, in absence of detailed design information. This paper presents a new, highly customisable scoping model, which can analyse the effect of detailed changes to train, track and soil on ground vibration levels. The methodology considers soil stiffness and the combination of both the dynamic and static forces generated due to train passage. It has low computational cost and can predict free-field vibration levels in accordance with the most common international standards. The model uses the direct stiffness method to compute the soil Green's function, and a novel two-and-a-half dimensional (2.5D) finite element strategy for train-track interaction. The soil Green's function is modulated using a neural network (NN) procedure to remove the need for the time consuming computation of track-soil coupling. This modulation factor combined with the new train-track approach results in a large reduction in computational time. The proposed model is validated by comparing track receptance, free-field mobility and soil vibration with both field experiments and a more comprehensive 2.5D combined finite element-boundary element (FEM-BEM) model. A sensitivity analysis is undertaken and it is shown that track type, soil properties and train speed have a dominant effect on ground vibration levels. Finally, the possibility of using average shear wave velocity introduced for seismic site response analysis to predict vibration levels is investigated and shown to be reasonable for certain smooth stratigraphy's.Ministerio de Economía y Competitividad - BIA2016-75042-C2-1-