128 research outputs found

    Riesgo químico: estrategias de intervención social

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    Production, use, marketing and emission of chemical substances display the strong links between chemical risks at the workplace, healthcare and environmental pollution. In spite of this fact, the policies for the management of chemical risk are far from being coherent and unified in the different sectors. (Nutritional safety, agriculture, healthcare, environment and occupational health).The Commission of European Communities (EC) has elaborated a White Document on the future policy on chemicals that recognizes the existing lack of control in this domain. We are facing a deep crisis of traditional strategies that are supposed to control chemical risks.It becomes essential to diversify the strategies. Some of them must aim at the improvement of information, others at the assessment of risk situations and some strategies must be directed to evaluate the possible alternatives for the solution of problems.La producción, utilización, comercialización y emisión de sustancias químicas pone de manifiesto los fuertes vínculos existentes entre el riesgo químico en el lugar de trabajo, la salud pública y la contaminación ambiental. A pesar de ello, las políticas de gestión del riesgo químico no han sido coherentes y unificadas en las diferentes áreas (seguridad alimentaria, agricultura, salud pública, medio ambiente y salud laboral).La Comisión de las Comunidades Europeas ha elaborado un Libro Blanco sobre la futura política en materia de sustancias químicas en el que reconoce un importante grado de descontrol. Realmente estamos ante una profunda crisis de ineficacia de las estrategias tradicionales que debían servir supuestamente para controlar el riesgo químico.Se hace necesario utilizar estrategias diversificadas: unas destinadas a mejorar los niveles de información; otras dirigidas a la evaluación de las situaciones de riesgo y otras, de mucho mayor calado, que tengan como objetivo la evaluación de alternativas orientadas a la resolución de los problemas

    Seguimiento de los flujos de calor sensible y calor latente en vid mediante la aplicación del balance de energía METRIC

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    Revista oficial de la Asociación Española de Teledetección[EN] The monitoring of the energy fluxes over vineyard applying the one source energy balance model METRIC (Allen et al., 2007b) are shown in this work. This model is considered operaive because it uses an internalized calibration method derived from the selection of two extreme pixels in the scene, from the minimum ET values such as the bare soil to a maximum that corresponds to full cover active vegetation. The model provides the maps of net radiation (Rn), soil heat flux (G), sensible heat (H), latent heat (LE), evapotranspiration (ET) and crop coefficient (Kc). The flux values have been validated with a flux tower installed in the plot, providing a RMSE for instantaneous fluxes of 43 W m2, 33 W m2, 55 W m2 y 40 W m2 on Rn, G, H and LE. In relative terms are 8%, 29%, 21% and 20% respectively. The RMSE at daily scale for the ET is 0.58 mm day-1, with a value in the crop coefficient for the mid stage of 0.42±0.08. These results allow considering the model adequate for crop monitoring and irrigation purposes in vineyard. The values obtained have been compared to other studies over vineyard and with alternative energy balance models showing similar results. Guardar / Salir Siguiente >[ES] En este trabajo se presenta el seguimiento de los flujos de energía en un cultivo de vid bajo riego, obtenidos a partir del modelo de balance de energía METRIC (Allen et al., 2007b). Este modelo resulta operativo al utilizar un método de calibración interna definido a partir de la selección de píxeles con valores extremos dentro de la escena. De esta manera se obtuvieron mapas de radiación neta (Rn), flujo de calor en suelo (G), calor sensible (H), calor latente (LE), evapotranspiración (ET) y coeficiente de cultivo (Kc). Estos valores fueron validados con registros obtenidos en el sitio, utilizando una torre de flujos turbulentos (covarianza de torbellinos). El RMSE fue 43 W m-2, 33 W m-2, 55 W m-2 y 40 W m-2 en Rn, G, H y LE, los cuales en términos relativos representan un 8%, 29 %, 21% y 20% respectivamente. A escala diaria el RMSE para la ET fue de 0,58 mm día-1, con un valor de Kc máximo y estable de 0,42±0,08. Estos re-sultados permiten considerar que el método es adecuado y operativo para el seguimiento de la evapotranspiración y cálculo de las necesidades hídricas del viñedo evaluadoAl proyecto CERESS (Coupling land surface Energy and water balance from Remote sensing for mapping Evapotranspiration, water Stress and Soil moisture, ref: AGL2011-30498-C02-01) financiado por el Ministerio de Ciencia e Innovación español. El co-autor C. Balbontín N. agradece el financiamiento del Ministerio de Educación de Chile a través de su proyecto FONDECYT Iniciación Cod. 11140843.González-Piqueras, J.; Villodre, J.; Campos, I.; Calera, A.; Balbontín, C. (2015). Monitoring the latent and sensible heat fluxes in vineyard by applying the energy balance model METRIC. Revista de Teledetección. (43):43-54. https://doi.org/10.4995/raet.2015.2310SWORD435443Allen, R., Irmak, A., Trezza, R., Hendrickx, J. M. H., Bastiaanssen, W., & Kjaersgaard, J. (2011). Satellite-based ET estimation in agriculture using SEBAL and METRIC. Hydrological Processes, 25(26), 4011-4027. doi:10.1002/hyp.8408Allen, R. G., Pereira, L. S., Raes, D., Smith, M. 1998. Crop Evapotranspiration. Guidelines for computing crop water requirements. (Vol. 56), Food and Agriculture Organization.Balbontin-Nesvara, C., Calera-Belmonte, A., González-Piqueras, J., Campos-Rodríguez, I., López-González, M. L., Torres-Prieto, E. 2011. Vineyard Evapotranspiration Measurements in a Semiarid Environment: Eddy Covariance and Bowen Ratio Comparison. Agrociencia, 45, 87-103.González-Dugo, M. P., González-Piqueras, J., Campos, I., Balbontín, C., Calera, A. 2012b. Estimation of surface energy fluxes in vineyard using field measurements of canopy and soil temperature. In C. M. U. Neale & M. H. Cosh (Eds.), Remote Sensing and Hydrology (Vol. 352, pp. 59-62). Wallingford: Int Assoc Hydrological Sciences.INM. 2004. Guía resumida del clima de Espa-a 1971-2000. In I. N. d. Meteorología (Ed.). Madrid

    Gene expression profiling and its use in adenocarcinomas of unknown primary origin: A case report

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    Carcinomas of unknown primary origin account for 3-5% of all malignancies. The current literature suggests that metastatic dissemination is able to occur in the absence of primary tumor growth. In metastatic disease that is difficult to diagnose, the origin usually remains unknown even after an exhaustive evaluation of immunohistochemistry (IHC) markers. In the current study, a 49-year-old male presented with lymph nodes metastases of unknown origin. The exci- sional biopsy of an inguinal node revealed an adenocarcinoma growth pattern, but the IHC could not determine the primary origin. A gene profiling test was performed to complete the diagnosis and a salivary gland adenocarcinoma was diagnosed with 90% probability. Subsequently, the patient underwent appropriate chemotherapy for salivary gland adenocarcinoma, and exhibited an improved partial response. The present case study highlights the importance of an accurate diagnosis of the primary tumor and the use of all the current tools available in order to provide patients with the best treatment possibl

    Introduction to protein folding for physicists

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    The prediction of the three-dimensional native structure of proteins from the knowledge of their amino acid sequence, known as the protein folding problem, is one of the most important yet unsolved issues of modern science. Since the conformational behaviour of flexible molecules is nothing more than a complex physical problem, increasingly more physicists are moving into the study of protein systems, bringing with them powerful mathematical and computational tools, as well as the sharp intuition and deep images inherent to the physics discipline. This work attempts to facilitate the first steps of such a transition. In order to achieve this goal, we provide an exhaustive account of the reasons underlying the protein folding problem enormous relevance and summarize the present-day status of the methods aimed to solving it. We also provide an introduction to the particular structure of these biological heteropolymers, and we physically define the problem stating the assumptions behind this (commonly implicit) definition. Finally, we review the 'special flavor' of statistical mechanics that is typically used to study the astronomically large phase spaces of macromolecules. Throughout the whole work, much material that is found scattered in the literature has been put together here to improve comprehension and to serve as a handy reference.Comment: 53 pages, 18 figures, the figures are at a low resolution due to arXiv restrictions, for high-res figures, go to http://www.pabloechenique.co

    Identification of a Novel Response Regulator, Crr1, That Is Required for Hydrogen Peroxide Resistance in Candida albicans

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    Candida albicans colonises numerous niches within humans and thus its success as a pathogen is dependent on its ability to adapt to diverse growth environments within the host. Two component signal transduction is a common mechanism by which bacteria respond to environmental stimuli and, although less common, two component-related pathways have also been characterised in fungi. Here we report the identification and characterisation of a novel two component response regulator protein in C. albicans which we have named CRR1 (Candida Response Regulator 1). Crr1 contains a receiver domain characteristic of response regulator proteins, including the conserved aspartate that receives phosphate from an upstream histidine kinase. Significantly, orthologues of CRR1 are present only in fungi belonging to the Candida CTG clade. Deletion of the C. albicans CRR1 gene, or mutation of the predicted phospho-aspartate, causes increased sensitivity of cells to the oxidising agent hydrogen peroxide. Crr1 is present in both the cytoplasm and nucleus, and this localisation is unaffected by oxidative stress or mutation of the predicted phospho-aspartate. Furthermore, unlike the Ssk1 response regulator, Crr1 is not required for the hydrogen peroxide-induced activation of the Hog1 stress-activated protein kinase pathway, or for the virulence of C. albicans in a mouse model of systemic disease. Taken together, our data suggest that Crr1, a novel response regulator restricted to the Candida CTG clade, regulates the response of C. albicans cells to hydrogen peroxide in a Hog1-independent manner that requires the function of the conserved phospho-aspartate

    PREDICCIÓN DE LAS NECESIDADES HÍDRICAS CON UNA SEMANA DE ANTELACIÓN MEDIANTE TELEDETECCIÓN Y METEOROLOGÍA EN LA FINCA EXPERIMENTAL DEL CENTER PARA CULTIVOS DE MAÍZ

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    [ES] Determinar las necesidades hídricas que los cultivos demandarán a corto plazo juega un papel fundamental en la gestión de explotaciones agrícolas de regadío. De su precisión depende la obtención de mejores rendimientos productivos, económicos y medioambientales. La experiencia llevada a cabo en la finca experimental de la DGDRPF – CENTER del MAGRAMA, obtuvo la predicción de las necesidades hídricas con una semana de antelación durante todo el periodo de monitorización. Basados en la ecuación del coeficiente de cultivo único (Kc), de la metodología FAO56, se predijo la evapotranspiración del cultivo (ETc) en parcelas de maíz en regadío. Para ello, se emplearon técnicas meteorológicas que predijeron la evapotranspiración de referencia (ETo), y técnicas de teledetección basadas en secuencias temporales de índices de vegetación (IV) mediante las cuales se predijo el Kc. Los resultados obtenidos produjeron una ligera sobre estimación de la ETc a final de campaña (8%). Paralelamente, los riegos aplicados fueron validados externamente mediante el empleo de sondas de humedad. En resumen, la experiencia proporcionó resultados adecuados con un bajo número de recursos. Así, la programación del riego se realizó mediante la combinación de técnicas de teledetección y meteorológicas.Garrido-Rubio, J.; González Gómez, L.; Arellano Alcazar, I.; Madurga Del Cura, C.; Navarro Comalrena De Sobregrau, M.; López Tapia, J.; Calera Belmonte, A. (2015). PREDICCIÓN DE LAS NECESIDADES HÍDRICAS CON UNA SEMANA DE ANTELACIÓN MEDIANTE TELEDETECCIÓN Y METEOROLOGÍA EN LA FINCA EXPERIMENTAL DEL CENTER PARA CULTIVOS DE MAÍZ. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1496OC

    First Human Model of In Vitro Candida albicans Persistence within Granuloma for the Reliable Study of Host-Fungi Interactions

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    BACKGROUND: The balance between human innate immune system and Candida albicans virulence signaling mechanisms ultimately dictates the outcome of fungal invasiveness and its pathology. To better understand the pathophysiology and to identify fungal virulence-associated factors in the context of persistence in humans, complex models are indispensable. Although fungal virulence factors have been extensively studied in vitro and in vivo using different immune cell subsets and cell lines, it is unclear how C. albicans survives inside complex tissue granulomas. METHODOLOGY/PRINCIPAL FINDING: We developed an original model of in vitro human granuloma, reproducing the natural granulomatous response to C. albicans. Persistent granulomas were obtained when the ratio of phagocytes to fungi was high. This in vitro fungal granuloma mimics natural granulomas, with infected macrophages surrounded by helper and cytotoxic T lymphocytes. A small proportion of granulomas exhibited C. albicans hyphae. Histological and time-lapse analysis showed that C. albicans blastoconidia were located within the granulomas before hyphae formation. Using staining techniques, fungal load calculations, as well as confocal and scanning electron microscopy, we describe the kinetics of fungal granuloma formation. We provide the first direct evidence that C. albicans are not eliminated by immunocompetent cells inside in vitro human granulomas. In fact, after an initial candicidal period, the remaining yeast proliferate and persist under very complex immune responses. CONCLUSIONS/SIGNIFICANCE: Using an original in vitro model of human fungal granuloma, we herein present the evidence that C. albicans persist and grow into immunocompetent granulomatous structures. These results will guide us towards a better understanding of fungal invasiveness and, henceforth, will also help in the development of better strategies for its control in human physiological conditions

    Genes Differentially Expressed in Conidia and Hyphae of Aspergillus fumigatus upon Exposure to Human Neutrophils

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    Aspergillus fumigatus is the most common etiologic agent of invasive aspergillosis in immunocompromised patients. Several studies have addressed the mechanism involved in host defense but only few have investigated the pathogen's response to attack by the host cells. To our knowledge, this is the first study that investigates the genes differentially expressed in conidia vs hyphae of A. fumigatus in response to neutrophils from healthy donors as well as from those with chronic granulomatous disease (CGD) which are defective in the production of reactive oxygen species.Transcriptional profiles of conidia and hyphae exposed to neutrophils, either from normal donors or from CGD patients, were obtained by using the genome-wide microarray. Upon exposure to either normal or CGD neutrophils, 244 genes were up-regulated in conidia but not in hyphae. Several of these genes are involved in the degradation of fatty acids, peroxisome function and the glyoxylate cycle which suggests that conidia exposed to neutrophils reprogram their metabolism to adjust to the host environment. In addition, the mRNA levels of four genes encoding proteins putatively involved in iron/copper assimilation were found to be higher in conidia and hyphae exposed to normal neutrophils compared to those exposed to CGD neutrophils. Deletants in several of the differentially expressed genes showed phenotypes related to the proposed functions, i.e. deletants of genes involved in fatty acid catabolism showed defective growth on fatty acids and the deletants of iron/copper assimilation showed higher sensitivity to the oxidative agent menadione. None of these deletants, however, showed reduced resistance to neutrophil attack.This work reveals the complex response of the fungus to leukocytes, one of the major host factors involved in antifungal defense, and identifies fungal genes that may be involved in establishing or prolonging infections in humans

    Enzymatic Mechanisms Involved in Evasion of Fungi to the Oxidative Stress: Focus on Scedosporium apiospermum

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    The airways of patients with cystic fibrosis (CF) are frequently colonized by various filamentous fungi, mainly Aspergillus fumigatus and Scedosporium species. To establish within the respiratory tract and cause an infection, these opportunistic fungi express pathogenic factors allowing adherence to the host tissues, uptake of extracellular iron, or evasion to the host immune response. During the colonization process, inhaled conidia and the subsequent hyphae are exposed to reactive oxygen species (ROS) and reactive nitrogen species (RNS) released by phagocytic cells, which cause in the fungal cells an oxidative stress and a nitrosative stress, respectively. To cope with these constraints, fungal pathogens have developed various mechanisms that protect the fungus against ROS and RNS, including enzymatic antioxidant systems. In this review, we summarize the different works performed on ROS- and RNS-detoxifying enzymes in fungi commonly encountered in the airways of CF patients and highlight their role in pathogenesis of the airway colonization or respiratory infections. The potential of these enzymes as serodiagnostic tools is also emphasized. In addition, taking advantage of the recent availability of the whole genome sequence of S. apiospermum, we identified the various genes encoding ROS- and RNS-detoxifying enzymes, which pave the way for future investigations on the role of these enzymes in pathogenesis of these emerging species since they may constitute new therapeutics targets
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