554 research outputs found

    Un complejo de diques cĂłnicos en la isla de La Gomera. Islas Canarias

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    In this paper, a cone-sheet intrussion, developed into the trachytic-phonolitic complex, is explained; as well as a new geological map is presented. Dikes, of trachytic and phonolitic composition often shows cooling margins, aphanitic texture and maffic inclussions. They cut through the basal complex, salic lava-flows and also fragmentary salic-deposits. Ir order to know the geological structure of the dikeswarn, strike and dip of many dikes was measured and lastly were plotted by stereographic projection. It is concluded that corresponds to a cone-sheet complex intrusion.En esta nota, se describe la existencia de una intrusión filoniana de diques cónicos al norte de la isla de La Gomera; igualmente se presenta la cartografía geológica del complejo traquítico-fonolítico, inédita hasta el momento de este trabajo, al cuál pertenece el sistema filoniano como uno de los episodios más importantes en su evolución. Los diques, de composición traquítica y fonolítica; muestran frecuentemente bordes de enfriamiento; textura afanítica y a menudo otras inclusiones xenolíticas de rocas básicas. Se desarrollan tanto a través del complejo basal; como de coladas sálicas y depósitos fragmentarios de igual naturaleza, preexistentes en el área estudiada. Las medidas sistemáticas de la orientación de estos diques y el posterior tratamiento de los datos en proyección estereográfica equiareal, permite definir una pauta cónica en el complejo filoniano

    The Variable Scale Evacuation Model (VSEM): a new tool for simulating massive evacuation processes during volcanic crises

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    Volcanic eruptions are among the most awesome and powerful displays of nature's force, constituting a major natural hazard for society (a single eruption can claim thousands of lives in an instant). Consequently, assessment and management of volcanic risk have become critically important goals of modern volcanology. Over recent years, numerous tools have been developed to evaluate volcanic risk and support volcanic crisis management: probabilistic analysis of future eruptions, hazard and risk maps, event trees, etc. However, there has been little improvement in the tools that may help Civil Defense officials to prepare Emergency Plans. Here we present a new tool for simulating massive evacuation processes during volcanic crisis: the Variable Scale Evacuation Model (VSEM). The main objective of the VSEM software is to optimize the evacuation process of Emergency Plans during volcanic crisis. For this, the VSEM allows the simulation of an evacuation considering different strategies depending on diverse impact scenarios. VSEM is able to calculate the required time for the complete evacuation taking into account diverse evacuation scenarios (number and type of population, infrastructure, road network, etc.) and to detect high-risk or "blackspots" of the road network. The program is versatile and can work at different scales, thus being capable of simulating the evacuation of small villages as well as huge cities

    ÂżSon los alumnos capaces de atribuir a los microorganismos algunas transformaciones de los alimentos?

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    In this paper we investigate if primary school students are able to relate microorganisms with food transformations. The subjects of this study were 343 4th. and 7th. grade children from Lugo (Spain) and the instrument used consisted of four multiple choice questions. The results shed light on the difficulties students have at these levels when they try to apply their ideas to interpret biological phenomena. Finally, we discuss some implications for Science teaching and learning

    A Review of ENSO Influence on the North Atlantic. A Non-Stationary Signal

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    ReviewThe atmospheric seasonal cycle of the North Atlantic region is dominated by meridional movements of the circulation systems: from the tropics, where the West African Monsoon and extreme tropical weather events take place, to the extratropics, where the circulation is dominated by seasonal changes in the jetstream and extratropical cyclones. Climate variability over the North Atlantic is controlled by various mechanisms. Atmospheric internal variability plays a crucial role in the mid-latitudes. However, El Niño-Southern Oscillation (ENSO) is still the main source of predictability in this region situated far away from the Pacific. Although the ENSO influence over tropical and extra-tropical areas is related to different physical mechanisms, in both regions this teleconnection seems to be non-stationary in time and modulated by multidecadal changes of the mean flow. Nowadays, long observational records (greater than 100 years) and modeling projects (e.g., CMIP) permit detecting non-stationarities in the influence of ENSO over the Atlantic basin, and further analyzing its potential mechanisms. The present article reviews the ENSO influence over the Atlantic region, paying special attention to the stability of this teleconnection over time and the possible modulators. Evidence is given that the ENSO–Atlantic teleconnection is weak over the North Atlantic. In this regard, the multidecadal ocean variability seems to modulate the presence of teleconnections, which can lead to important impacts of ENSO and to open windows of opportunity for seasonal predictability.We thank the Climatic Research Unit (CRU), the National Centers for Environmental Prediction (NCEP), the Met Office Hadley Centre and the US National Hurricane Center (NHC) for the Land Precipitation, reanalysis, SST and HURDAT2 datasets, respectively. Belen Rodríguez-Fonseca, Roberto Suárez-Moreno, Jorge López-Parages, Iñigo Gómara, Elsa Mohino, Teresa Losada and Antonio Castaño-Tierno are supported by the research projects PREFACE (EUFP7/2007-2013 Grant Agreement 603521) and MULCLIVAR (CGL2012-38923-C02-01-Spanish Ministry of Economy and Competitiveness). Blanca Ayarzagüena is supported by the Natural Environment Research Council (grant number NE/M006123/1). Julián Villamayor is granted through a scholarship from the MICINN—Spanish government (BES-2013-063821

    Evaluation of inflammatory cytokine secretion by human alveolar macrophages.

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    The alveolar macrophage (AM) secretes interleukin 1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8), all of them inflammatory cytokines involved in the pathogenesis of many lung diseases. The aim of the present work was to evaluate the basal and stimulated secretion of these cytokines by human AMs. Human AMs were collected by bronchoalveolar lavage (BAL) from four healthy controls and 13 patients with diffuse interstitial lung disease (five cases of sarcoidosis, three of hypersensitivity pneumonitis and five of idiopathic pulmonary fibrosis). AMs were cultured in the presence or absence of different concentrations of lipopolysaccharide (LPS), phorbolmyristate and gamma-interferon. IL-1beta, TNF-alpha, IL-6 and IL-8 levels were measured in BAL fluid and culture supernatant using specific enzyme-linked immunosorbent assays. The substance found to stimulate the secretion of inflammatory cytokines to the greatest extent was LPS at a concentration of 10 microg/ml. Regarding the secretion of IL-1beta, four observations were of interest: basal secretion was very low; LPS exerted a potent stimulatory effect; considerable within-group variability was observed; and there were no significant differences in the comparisons among groups. With respect to TNF-alpha secretion, the results were similar. The only striking finding was the higher basal secretion of this cytokine with respect to that of IL-1beta. Regarding the secretion of IL-6, the same pattern followed by TNF-alpha was found. However, it should be stressed that the increase induced by LPS was smaller than in the two previous cytokines. Regarding the secretion of IL-8, three findings were patent: the strong basal secretion of this cytokine; the moderate increase induced by LPS; and the existence of significant differences among the different groups with respect to the stimulated secretion of this cytokine, which reached maximum values in patients with idiopathic pulmonary fibrosis. Finally, it should be noted that the pattern of cytokines observed in the BAL fluid was similar to that found in cultured AM supernatants. The pattern of inflammatory cytokine secretion by AMs differs from that of other cells of the mononuclear phagocyte system (MPS). In this sense. AMs secrete low amounts of IL-1, moderate amounts of TNF-alpha and IL-6, and high quantities of IL-8. Adherence is an important stimulus in the secretion of these molecules and LPS elicits an increased secretion inverse to the basal secretion. There is considerable individual variability in the secretion of inflammatory cytokines by the AMs of patients with interstitial lung disease and the AMs of these patients are primed in vivo for the secretion of these cytokines. The results of our study, carried out in vitro, can be extrapolated to the in vivo setting

    Raman-Mössbauer-XRD studies of selected samples from “Los Azulejos” outcrop: A possible analogue for assessing the alteration processes on Mars

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    The outcrop of “Los Azulejos” is visible at the interior of the Cañadas Caldera in Tenerife Island (Spain). It exhibits a great variety of alteration processes that could be considered as terrestrial analogue for several geological processes on Mars. This outcrop is particularly interesting due to the content of clays, zeolite, iron oxides, and sulfates corresponding to a hydrothermal alteration catalogued as “Azulejos” type alteration. A detailed analysis by portable and laboratory Raman systems as well as other different techniques such as X ray diffraction (XRD) and Mössbauer spectroscopy has been carried out (using twin-instruments from Martian lander missions: Mössbauer spectrometer MIMOS-II from the NASA-MER mission of 2001 and the XRD diffractometer from the NASA-MSL Curiosity mission of 2012). The mineral identification presents the following mineral species: magnetite, goethite, hematite, anatase, rutile, quartz, gregoryite, sulphate (thenardite and hexahydrite), diopside, feldspar, analcime, kaolinite and muscovite. Moreover, the in-situ Raman and Micro-Raman measurements have been performed in order to compare the capabilities of the portable system specially focused for the next ESA Exo-Mars mission. The mineral detection confirms the sub-aerial alteration on the surface and the hydrothermal processes by the volcanic fluid circulations in the fresh part. Therefore, the secondary more abundant mineralization acts as the color agent of the rocks. Thus, the zeolite-illite group is the responsible for the bluish coloration, as well as the feldspars and carbonates for the whitish and the iron oxide for the redish parts. The XRD system was capable to detect a minor proportion of pyroxene, which is not visible by Raman and Mössbauer spectroscopy due to the “Azulejos” alteration of the parent material on the outcrop. On the other hand, Mössbauer spectroscopy was capable of detecting different types of iron-oxides (Fe3+/2+-oxide phases). These analyses emphasize the strength of the different techniques and the working synergy of the three different techniques together for planetary space missions.The work was supported by the MICINN with the Project AYA-2008-04529.Peer reviewe
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