2,896 research outputs found

    Los Sistemas de Información Geográfica en salud ambiental

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    This paper gives a brief introduction to the Geographic Information Systems (GIS) and its applications to the field of Environmental Health (EH). It starts with a conceptual exposition in order to show the potential of GIS’s as an space temporal analysers, and as an aids to take decisions. Some specific cases are analysed, these cases represent success applications of new technology to EH. A brief survey of the more popular software for GIS, free and commercial, is presented. It is also shown the connexion of this software with statistical software and other kind of specialize software in order to build computer tools for working in EH. Finally, some strategies are given for a deepen involvement of GIS in EH.En esta ponencia se presenta una breve introducción a los Sistemas de Información Geográfica (GIS, Geographic Information System) y sus aplicaciones en el área de Salud Ambiental (SA). Se inicia con una exposición conceptual para mostrar el potencial de los GIS como analizadores espacio-temporales, y como ayudas a la toma de decisiones. Se analizan algunos casos concretos, que han resultado un éxito, en la aplicación de las nuevas tecnologías en SA. También se hace una breve revisión del software más popular para un GIS, comercial y libre, y su conexión con otro software estadístico y especializado para construir herramientas informáticas apropiadas con las que trabajar en SA. Finalmente, se ofrecen algunas estrategias para logra una mayor utilización de los GIS en SA

    A spatial contextual postclassification method for preserving linear objects in multispectral imagery

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    Classification of remote sensing multispectral data is important for segmenting images and thematic mapping and is generally the first step in feature extraction. Per-pixel classification, based on spectral information alone, generally produces noisy classification results. The introduction of spatial information has been shown to be beneficial in removing most of this noise. Probabilistic label relaxation (PLR) has proved to be advantageous using second-order statistics; here, we present a modified contextual probabilistic relaxation method based on imposing directional information in the joint probability with third-order statistics. The proposed method was tested in synthetic images and real images; the results are compared with a "Majority" algorithm and the classical PLR method. The proposed third-order method gives the best results, both visually and numerically

    On the monitoring of surface displacement in connection with volcano reactivation in Tenerife, Canary Islands, using space techniques

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    Geodetic volcano monitoring in Tenerife has mainly focused on the Las Cañadas Caldera, where a geodetic micronetwork and a levelling profile are located. A sensitivity test of this geodetic network showed that it should be extended to cover the whole island for volcano monitoring purposes. Furthermore, InSAR allowed detecting two unexpected movements that were beyond the scope of the traditional geodetic network. These two facts prompted us to design and observe a GPS network covering the whole of Tenerife that was monitored in August 2000. The results obtained were accurate to one centimetre, and confirm one of the deformations, although they were not definitive enough to confirm the second one. Furthermore, new cases of possible subsidence have been detected in areas where InSAR could not be used to measure deformation due to low coherence. A first modelling attempt has been made using a very simple model and its results seem to indicate that the deformation observed and the groundwater level variation in the island may be related. Future observations will be necessary for further validation and to study the time evolution of the displacements, carry out interpretation work using different types of data (gravity, gases, etc) and develop models that represent the island more closely. The results obtained are important because they might affect the geodetic volcano monitoring on the island, which will only be really useful if it is capable of distinguishing between displacements that might be linked to volcanic activity and those produced by other causes. One important result in this work is that a new geodetic monitoring system based on two complementary techniques, InSAR and GPS, has been set up on Tenerife island. This the first time that the whole surface of any of the volcanic Canary Islands has been covered with a single network for this purpose. This research has displayed the need for further similar studies in the Canary Islands, at least on the islands which pose a greater risk of volcanic reactivation, such as Lanzarote and La Palma, where InSAR techniques have been used already

    Use of plant extracts to block bacterial biofilm formation

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    Proceedings of the I Congress PIIISA celebrado en la Estación Experimental del Zaidín (Granada), en mayo de 2013.We live surrounded by bacteria; in fact, in only one gram of soil we can find millions of bacterial cells. Our body houses more than 1014 bacteria. Even though some of these microorganisms can cause us problems, such as caries, actually most of them help in the proper functioning of our organism. Generally, bacteria coexist setting up communities associated to solid superficies, this is to which we refer as biofilms, that serve as a survival strategy. This type of formation cause serious sanitary problems for both humans and animals. Nowadays, chemical or natural compounds able to block this formation are looked for. In this project, we have set out how to use extracts of different plants with the purpose of testing their effects against biofilms of two bacterial species: Escherichia coli and Pseudomonas putida.This work was supported in part by grant BFU2010-17946 from the Plan Nacional de I+D+I.Peer reviewe

    Anthocyanins: Molecular Aspects on Their Neuroprotective Activity

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    Anthocyanins are a type of flavonoids that give plants and fruits their vibrant colors. They are known for their potent antioxidant properties and have been linked to various health benefits. Upon consumption, anthocyanins are quickly absorbed and can penetrate the blood-brain barrier (BBB). Research based on population studies suggests that including anthocyanin-rich sources in the diet lower the risk of neurodegenerative diseases. Anthocyanins exhibit neuroprotective effects that could potentially alleviate symptoms associated with such diseases. In this review, we compiled and discussed a large body of evidence supporting the neuroprotective role of anthocyanins. Our examination encompasses human studies, animal models, and cell cultures. We delve into the connection between anthocyanin bioactivities and the mechanisms underlying neurodegeneration. Our findings highlight how anthocyanins\u27 antioxidant, anti-inflammatory, and anti-apoptotic properties contribute to their neuroprotective effects. These effects are particularly relevant to key signaling pathways implicated in the development of Alzheimer\u27s and Parkinson\u27s diseases. In conclusion, the outcome of this review suggests that integrating anthocyanin-rich foods into human diets could potentially serve as a therapeutic approach for neurological conditions, and we identify promising avenues for further exploration in this area

    Boosting the visible-light photoactivity of Bi2WO6 using acidic carbon additives

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    We have explored the role of the physicohemical properties of carbon materials as additives to bismuth tungstate on its structure, optical properties, and photocatalytic activity for the degradation of rhodamine B under visible light. For this purpose, C/Bi2WO6 hybrid composites were prepared following two different routes: (i) physical mixture of the catalyst components, and (ii) one-pot hydrothermal synthesis of the semiconductor in the presence of the carbon additive. Three carbons with different properties were selected as additives: biomass-derived activated carbon, carbon nanotubes and carbon spheres obtained from polysaccharides. Data has shown the outstanding role of the acidic/basic nature of the carbon additive, and of the synthetic method on the photocatalytic performance of the resulting composites. For a given additive, the degradation rate of RhB is greatly improved for the catalysts prepared through a one-step hydrothermal synthesis, where there is low shielding effect of the carbon matrix. Carbon additives of acidic nature boost the surface acidity of the hybrid photocatalyst, thereby enhancing the photodegradation of RhB under visible light via a coupled mechanism (photosensitization, semiconductor photocatalysis and carbon-photon mediated reactions).The authors thank the financial support of MINECO (grants CTM2011/23378 and CTQ2011/26617) and PCTI Asturias (Fondos Feder 2007-2013, grant PC10-002). RJC thanks PCTI Asturias for her Severo Ochoa fellowshipPeer reviewe

    On rational cuspidal projective plane curves

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    In 2002, L. Nicolaescu and the fourth author formulated a very general conjecture which relates the geometric genus of a Gorenstein surface singularity with rational homology sphere link with the Seiberg--Witten invariant (or one of its candidates) of the link. Recently, the last three authors found some counterexamples using superisolated singularities. The theory of superisolated hypersurface singularities with rational homology sphere link is equivalent with the theory of rational cuspidal projective plane curves. In the case when the corresponding curve has only one singular point one knows no counterexample. In fact, in this case the above Seiberg--Witten conjecture led us to a very interesting and deep set of `compatibility properties' of these curves (generalising the Seiberg--Witten invariant conjecture, but sitting deeply in algebraic geometry) which seems to generalise some other famous conjectures and properties as well (for example, the Noether--Nagata or the log Bogomolov--Miyaoka--Yau inequalities). Namely, we provide a set of `compatibility conditions' which conjecturally is satisfied by a local embedded topological type of a germ of plane curve singularity and an integer dd if and only if the germ can be realized as the unique singular point of a rational unicuspidal projective plane curve of degree dd. The conjectured compatibility properties have a weaker version too, valid for any rational cuspidal curve with more than one singular point. The goal of the present article is to formulate these conjectured properties, and to verify them in all the situations when the logarithmic Kodaira dimension of the complement of the corresponding plane curves is strictly less than 2
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