740 research outputs found

    Cryptanalyzing a discrete-time chaos synchronization secure communication system

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    This paper describes the security weakness of a recently proposed secure communication method based on discrete-time chaos synchronization. We show that the security is compromised even without precise knowledge of the chaotic system used. We also make many suggestions to improve its security in future versions.Comment: 11 pages, 3 figures, latex forma

    Potential EEG biomarkers of sedation doses in intensive care patients unveiled by using a machine learning approach

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    Objective. Sedation of neurocritically ill patients is one of the most challenging situation in ICUs. Quantitative knowledge on the sedation effect on brain activity in that complex scenario could help to uncover new markers for sedation assessment. Hence, we aim to evaluate the existence of changes of diverse EEG-derived measures in deeply-sedated (RASS-Richmond agitation-sedation scale -4 and -5) neurocritically ill patients, and also whether sedation doses are related with those eventual changes. Approach. We performed an observational prospective cohort study in the intensive care unit of the Hospital de la Princesa. Twenty-six adult patients suffered from traumatic brain injury and subarachnoid hemorrhage were included in the present study. Long-term continuous electroencephalographic (EEG) recordings (2141 h) and hourly annotated information were used to determine the relationship between intravenous sedation infusion doses and network and spectral EEG measures. To do that, two different strategies were followed: assessment of the statistical dependence between both variables using the Spearman correlation rank and by performing an automatic classification method based on a machine learning algorithm. Main results. More than 60% of patients presented a correlation greater than 0.5 in at least one of the calculated EEG measures with the sedation dose. The automatic classification method presented an accuracy of 84.3% in discriminating between different sedation doses. In both cases the nodes' degree was the most relevant measurement. Significance. The results presented here provide evidences of brain activity changes during deep sedation linked to sedation doses. Particularly, the capability of network EEG-derived measures in discriminating between different sedation doses could be the framework for the development of accurate methods for sedation levels assessment.Fil: Sanz García, Ancor. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Pérez Romero, Miriam. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Pastor, Jesús. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Sola, Rafael G.. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa. Servicio de Neurocirugia. Grupo de Epilepsia; EspañaFil: Vega Zelaya, Lorena. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Vega, Gema. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Monasterio, Fernando. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Torrecilla, Carmen. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; EspañaFil: Pulido, Paloma. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa. Servicio de Neurocirugia. Grupo de Epilepsia; EspañaFil: Ortega, Guillermo José. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Análisis de la relevancia y factibilidad de indicadores de calidad en las unidades de nutrición

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    Introducción: La evaluación de la calidad en las actividades sanitarias exige la elección de unos indicadores acordes con los resultados que queremos medir. De todos los posibles, debemos priorizar aquellos que nos permitan obtener la información más relevante sin sobrecargar el trabajo habitual de nuestras Unidades. Objetivo: Conocer la opinión de los socios de SENPE respecto a la relevancia y la viabilidad del uso de una selección de indicadores de calidad para su aplicación en nutrición clínica. Métodos: Encuesta remitida mediante correo electrónico a los socios de SENPE solicitando a los mismos su opinión sobre 12 indicadores de calidad, valorándose cada uno en cuanto a su relevancia y factibilidad de la aplicación en su medio. Resultados: Contestaron 40 encuestados de 40 centros diferentes de 12 comunidades autónomas. En general, los indicadores fueron considerados más relevantes que factibles. Los indicadores mejor puntuados fueron: “identificación en las bolsas de nutrición artificial”, “posición semi-incorporada del paciente con nutrición enteral por sonda nasogástrica” y “protocolos clínicos básicos”. Considerando los indicadores por grupos (de estructura, proceso o resultado) los mejor valorados fueron: “identificación del paciente en las bolsas de nutrición artificial” (estructura), “posición semi-incorporada” y “protocolos clínicos básicos” (proceso), y “cumplimiento del objetivo calórico” (resultado). Conclusión: Los resultados de la encuesta permiten seleccionar indicadores prioritarios para su aplicación en las Unidades de NutriciónIntroduction: The quality assessment in health activities requires the choice of indicators in line with the results we want to measure. Of all possible, we should prioritize those that allow us to obtain the most relevant information without overloading the regular work of our units. Objective: To determine the opinion of the members of SENPE regarding the relevance and feasibility of using a selection of quality indicators designed for use in clinical nutrition. Methods: E-mail survey sent to members of SENPE asking them their views on 12 quality indicators, evaluating each in terms of their relevance and feasibility of implementation in their environment. Results: 40 respondents answered from 40 centers in 12 different regions. In general, the indicators were considered more relevant than feasible. The indicators best rated were: “identification in artificial nutrition bags, “semi-recumbent position in patient with nasogastric tube feeding” and “basic clinical protocols”. Considering the type of indicator: “patient identification in the bags of artificial nutrition (structure),” a semi-incorporated “and” basic clinical protocols (process), and “fulfillment of the caloric goal” (result). Conclusion: The results of the survey can make a selection of indicators that could be considered for first-line introduction in a Nutrition Uni

    Novel Genes Involved in Resistance to Both Ultraviolet Radiation and Perchlorate From the Metagenomes of Hypersaline Environments

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    Microorganisms that thrive in hypersaline environments on the surface of our planet are exposed to the harmful effects of ultraviolet radiation. Therefore, for their protection, they have sunscreen pigments and highly efficient DNA repair and protection systems. The present study aimed to identify new genes involved in UV radiation resistance from these microorganisms, many of which cannot be cultured in the laboratory. Thus, a functional metagenomic approach was used and for this, small-insert libraries were constructed with DNA isolated from microorganisms of high-altitude Andean hypersaline lakes in Argentina (Diamante and Ojo Seco lakes, 4,589 and 3,200 m, respectively) and from the Es Trenc solar saltern in Spain. The libraries were hosted in a UV radiation-sensitive strain of Escherichia coli (recA mutant) and they were exposed to UVB. The resistant colonies were analyzed and as a result, four clones were identified with environmental DNA fragments containing five genes that conferred resistance to UV radiation in E. coli. One gene encoded a RecA-like protein, complementing the mutation in recA that makes the E. coli host strain more sensitive to UV radiation. Two other genes from the same DNA fragment encoded a TATA-box binding protein and an unknown protein, both responsible for UV resistance. Interestingly, two other genes from different and remote environments, the Ojo Seco Andean lake and the Es Trenc saltern, encoded two hypothetical proteins that can be considered homologous based on their significant amino acid similarity (49%). All of these genes also conferred resistance to 4-nitroquinoline 1-oxide (4-NQO), a compound that mimics the effect of UV radiation on DNA, and also to perchlorate, a powerful oxidant that can induce DNA damage. Furthermore, the hypothetical protein from the Es Trenc salterns was localized as discrete foci possibly associated with damaged sites in the DNA in cells treated with 4-NQO, so it could be involved in the repair of damaged DNA. In summary, novel genes involved in resistance to UV radiation, 4-NQO and perchlorate have been identified in this work and two of them encoding hypothetical proteins that could be involved in DNA damage repair activities not previously described.Fil: Lamprecht Grandío, María. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Cortesão, Marta. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Mirete, Salvador. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Benguigui de la Cámara, Macarena. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: de Figueras, Carolina G.. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Pérez Pantoja, Danilo. Universidad Tecnológica Metropolitana; EspañaFil: White, Joseph John. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Rosselló Móra, Ramon. Instituto Mediterráneo Estudios Avanzados; EspañaFil: González Pastor, José Eduardo. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; Españ

    Quality Parameters of Spanish Lemons with Commercial Interest

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    The Spanish Mediterranean region concentrates the largest producers of lemons (Citrus limon Burm. f.) at the national level where the 98.4% of the cultivated area of lemons corresponds to the varieties “Verna” and “Fino”. In this study, the morphological and chemical variations of the fruits obtained in five variety/rootstock combinations were investigated in order to determine the influence and impact of the rootstock on the physicochemical properties of the fruits. The assay was carried out using three lemon varieties (“Fino 95”, “Fino 49” and “Verna”) grafted onto two different rootstocks (Citrus macrophylla and Citrus aurantium). The varieties were selected due to be consolidated commercial varieties, while the rootstocks are the most commonly used in the world. Both the morphological characteristics of the fruits (colour, weight, size) as well as their physicochemical characteristics (total soluble solids, titratable acidity, maturity index, antioxidant activity, sugars, and organic acids) were evaluated. Based on the results, the lemons with the best physicochemical and the best compositional characteristics were obtained in the “Fino 95” and “Fino 49” lemons grafted onto C. aurantium rootstock presented the highest quality fruits

    Operational forecasting of daily summer maximum and minimum temperatures in the Valencia Region

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    Extreme-temperature events have a great impact on human society. Thus, knowledge of summer temperatures can be very useful both for the general public and for organizations whose workers operate in the open. An accurate forecasting of summer maximum and minimum temperatures could help to predict heatwave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The objective of this work is to evaluate the skill of the regional atmospheric and modelling system (RAMS) model in determining daily summer maximum and minimum temperatures in the Valencia Region. For this, we have used the real-time configuration of this model currently running at the Centro de Estudios Ambientales de Mediterráneo Foundation. This operational system is run twice a day, and both runs have a 3-day forecast range. To carry out the verification of the model in this work, the information generated by the system has been broken into individual simulation days for a specific daily run of the model. Moreover, we have analysed the summer forecast period from 1 June to 31 August for 2007, 2008, 2009 and 2010. The results indicate good agreement between observed and simulated maximum temperatures, with RMSE in general near 2 °C both for coastal and inland stations. For this parameter, the model shows a negative bias around −1.5 °C in the coast, while the opposite trend is observed inland. In addition, RAMS also shows good results in forecasting minimum temperatures for coastal locations, with bias lower than 1 °C and RMSE below 2 °C. However, the model presents some difficulties for this parameter inland, where bias higher than 3 °C and RMSE of about 4 °C have been found. Besides, there is little difference in both temperatures forecasted within the two daily RAMS cycles and that RAMS is very stable in maintaining the forecast performance at least for three forecast days

    Influence of New Citrus Rootstocks on Lemon Quality

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    Citrus fruits are one of the main crops produced in the world with oranges, tangerines, lemons and grapefruits being among the most important. Among them, lemons are beneficial for human health because of their antioxidant activity, phenols and vitamin C. This study evaluates three rootstocks obtained in a Spanish breeding program (Valencian Institute for Agricultural Research (IVIA)): Forner-Alcaide 5 citrus rootstock (‘FA 5’), Forner-Alcaide 13 (‘FA 13’) and Forner-Alcaide 517 (‘FA 517’) grafted onto cultivars `Eureka´, `Verna´, `Fino 49’ and `Betera´. The results determined that rootstocks have influenced cultivars in terms of a decrease in the fruit size, weight, and thickness of the peel; but has increased the percentage of juice and soluble solids. With respect to phenol content and antioxidant activity, higher values were found with all cultivars studied on rootstocks ‘FA 13’, followed by ‘FA 517’. Cultivars that were most influenced by rootstocks were 'Bétera' and 'Eureka' in physical properties, while in chemical properties they were 'Verna' followed by 'Fino 49'. This investigation demonstrated the interaction of rootstocks on different cultivars in morphological, biochemical and nutraceutical characteristics
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