40 research outputs found

    Líneas de defensa y seguridad en redes ad hoc: un estudio sistemático

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    En el mundo conectado en el que vivimos hoy en día, las redes ad hoc juegan un papel muy importante. Sin embargo, son sus principales características las que las hacen vulnerables desde el punto de vista de la seguridad. Es por esto por lo que el presente trabajo se centra en el estudio de la seguridad en este tipo de redes. Así, se ha realizado un análisis bibliométrico para detectar las temáticas mas relevantes y la evolución de la investigación en lo que concierne a la seguridad en redes ad hoc, que muestra, primero, que el campo de estudio sigue activo, y segundo, que las temáticas MANET y VANET son centro de atención. A partir de aquí, se ha realizado una revisión sistemática de la Literatura centrada en la seguridad en redes MANET y VANET y cómo los trabajos del estado del arte clasifican las soluciones encontradas acorde a las principales líneas de defensa: prevención, detección y respuesta. Si bien, abundan las soluciones de detección de ataques o intrusiones, existe cierta confusión a la hora de enmarcar dichas soluciones por línea de defensa. Así, se ha propuesto una nueva taxonomía que, desde nuestro punto de vista, mejora la clasificación tradicional por línea de defensa añadiendo nuevas como la tolerancia. Finalmente, concluimos con la necesidad de la propuesta de soluciones tolerantes que, bien planteadas, mitiguen los efectos del ataque sin necesidad de una detección y una respuesta real, minimizando así el impacto producido por un atacante en el sistema

    Wastewater treatment improvement through an intelligent integrated supervisory system

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    This paper shows the result of years of work by a cooperative research group including chemical engineers, environmental scientists and computer scientists. This research has been focused on the development and implementation of new techniques for the optimisation of complex process management, mainly related to wastewater treatment plants (WWTP). The experience obtained indicates that the best approach is a Supervisory System that combines and integrates classical control of WWTP (automatic controller for maintaining a fixed dissolved oxygen level in the aeration tank, use of mathematical models to describe the process...) with the application of knowledge-based systems (mainly expert systems and case-based systems). The first part is an introduction to wastewater treatment processes and an explanation of the complexity of the management and control of such complex processes. The next section illustrates the architecture of the supervisory system and the work carried out to develop and build the expert system, the casebased system and the simulation model for implementation in a real plant (the Granollers WWTP). Finally, some results of the field validation phase of the Supervisory System when dealing with real situations in the plant are described.Aquest article mostra el resultat de la col·laboració portada a terme durant els darrers anys entre grups d'enginyeria química, enginyeria ambiental i intel·ligència artificial. El treball se centra en el desenvolupament de tècniques per a la millora i supervisió de processos complexos, especialment del tractament biològic d'aigües residuals. L'experiència demostra que la millor opció requereix desenvolupar un sistema supervisor que combini i integri tècniques de control clàssic (controlador automàtic del nivell d'oxigen dissolt en el reactor biològic, ús de models descriptius del procés, etc.) amb sistemes basats en el coneixement (concretament sistemes experts i sistemes basats en casos). El present article descriu la complexitat de la gestió del procés de tractament de les aigües residuals, l'arquitectura integrada que es proposa i el desenvolupament i la construcció de cadascun dels mòduls d'aquesta proposta per a la implementació real a l'estació depuradora d'aigües residuals de Granollers. Finalment, es detallen alguns resultats del procés de validació del seu funcionament enfront de situacions quotidianes de la planta

    Bacterial density rather than diversity correlates with hatching success across different avian species

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    We thank Rosario Millán for technical assistance; Liesbeth de Neve, María Roldán, Juan Rodríguez-Ruiz, Deseada Parejo, Magdalena Ruiz-Rodríguez and Carlos Navarro for sampling nests of some species. We also thank the efforts and comments of two anonymous reviewers that have greatly improved the manuscript. Bird and egg manipulations were performed under the authorization of Junta de Andalucía - Consejería de Medio Ambiente (permit No. SGYB-AFR-CMM, February 19th 2007).Bacterial communities within avian nests are considered an important determinant of egg viability, potentially selecting for traits that confer embryos with protection against trans-shell infection. A high bacterial density on the eggshell increases hatching failure, whether this effect could be due to changes in bacterial community or just a general increase in bacterial density. We explored this idea using intra- and interspecific comparisons of the relationship between hatching success and eggshell bacteria characterized by culture and molecular techniques (fingerprinting and high-throughput sequencing). We collected information for 152 nests belonging to 17 bird species. Hatching failures occurred more frequently in nests with higher density of aerobic mesophilic bacteria on their eggshells. Bacterial community was also related to hatching success, but only when minority bacterial operational taxonomic units were considered. These findings support the hypothesis that bacterial density is a selective agent of embryo viability, and hence a proxy of hatching failure only within species. Although different avian species hold different bacterial densities or assemblages on their eggs, the association between bacteria and hatching success was similar for different species. This result suggests that interspecific differences in antibacterial defenses are responsible for keeping the hatching success at similar levels in different species.Funding was provided by Ministerio de Educación y Ciencia and European founds (FEDER) [CGL2007-61251, CGL2010-19233-C03- 01, CGL2010-19233-C03-03]. JMPS was funded by Ministerio de Educación and Consejería de Innovación, Ciencia y Empresa under International Excellence Campus Program, University of Granada (CEI Granada 2009). RK was supported in part by the Howard Hughes Medical Institute. The Earth Microbiome Project was supported in part by the John Templeton Foundation and the W.M. Keck Foundation

    Estimación de parámetros genéticos para características de crecimiento en borregos Katahdin usando diferentes modelos

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    Genetic parameters for growth traits of Katahdin lambs were estimated using six variants of the animal model. Data on birth weight (BW; n= 13,099), weaning weight adjusted to 75 d (WW; n=11,509) and postweaning weight adjusted to 120 d (AW; n=6,886) were collected for seven years (2004-2010) in 20 states across Mexico. Analyses were carried out by ignoring or including maternal effects. The simplest model included the direct additive genetic effect as the only random effect. The most complete model included direct and maternal genetic effects, their covariance, and the maternal permanent environmental effect. Selection of the best model was based on likelihood-ratio test. When maternal effects were not taken into account, estimates of direct heritability and direct genetic variance were overestimated for all traits. Direct heritability estimates for the best model were 0.18 ± 0.03, 0.30 ± 0.04, and 0.20 ± 0.05 for BW, WW and AW, respectively. Maternal heritability estimates also varied depending on the model; estimates ranged from 0.05 to 0.23, 0.00 to 0.12, and 0.09 to 0.25 for BW, WW and AW. Ignoring maternal effects in the model would result in inaccurate genetic evaluation for growth traits in Katahdin sheep.Se estimaron parámetros genéticos para características de crecimiento en corderos Katahdin, usando seis variantes del modelo animal. Se usó información de pesos al nacimiento (BW; n= 13,099), al destete ajustado a 75 d (WW; n= 11,509) y posdestete ajustado a 120 d (AW; n= 6,886) tomada durante 7 años (2004-2010) en 20 estados de la República Mexicana. Los análisis se hicieron ignorando o incluyendo efectos maternos. El modelo más sencillo incluyó el efecto genético aditivo directo como el único efecto aleatorio. El modelo más completo incluyó los efectos genéticos directo y materno, la covarianza entre ellos, y el efecto del ambiente permanente materno. Para seleccionar el mejor modelo se usó la prueba de razón de verosimilitud. Cuando los efectos maternos no fueron incluidos en el modelo, los estimadores de la heredabilidad directa y de la varianza genética directa resultaron sobreestimados. Las heredabilidades directas con el mejor modelo fueron 0.18 ± 0.03, 0.30 ± 0.04 y 0.20 ± 0.05 para BW, WW y AW, respectivamente. Las heredabilidades maternas también variaron dependiendo del modelo, de 0.05 a 0.23, 0.00 a 0.12, y 0.09 a 0.25 para BW, WW y AW. El ignorar los efectos maternos en el modelo resultaría en una evaluación genética equivocada para las características de crecimiento en borregos Katahdin

    Structure and dynamics of [Nb(η5-C5H4SiMe3) 2(η2-H2BR2)] (R2 = O2C6H4, C8H14, H2) complexes. A combined experimental and theoretical study

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    Dihydrogen elimination from the reaction of the niobocene trihydride Cp‘2NbH3 (Cp‘ = η5-C5H4SiMe3) and the appropriate borane provides a synthetic route to the new borate-containing niobocene complexes [Nb(η5-C5H4SiMe3)2(η2-H2BR2)] (R2 = O2C6H4 (1), C8H14 (2), H2 (3)). The reaction with H2BO2C6H4 or H2BC8H14 proceeds at mild temperature, and the BH3·THF adduct reacts even at low temperature. Complexes 2 and 3 show dynamic behavior in solution. Spectroscopic and theoretical studies were carried out in order to clarify these dynamic processes. In addition, X-ray diffraction studies of 2 were carried out and the results correlated with the theoretical data. Finally, reactions of Cp‘2Nb(H)(L) (L = CO, CN(2,6-Me2C6H3), tBuOOCHCHCOOtBu) with BH3·THF give rise to the complex 3, with the elimination of the appropriate ancillary ligand L.Financial support from the Spanish Comisión Interministerial de Ciencia y Tecnología (Projects PB98-0915, PB98-0916-CO2-01, and PB-95-0023-CO1-CO2) is acknowledged.Peer reviewe

    BIM en la construcción

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    244 páginas.En la actualidad, con la metodología BIM (Building Information Modeling), todos los sistemas de información de los procesos productivos en la obra se han integrado, la información se puede compartir a distancia y en tiempo real con todos los actores involucrados en el proyecto. En estas condiciones, las instituciones generadoras de obras y las empresas prestadoras de servicios se están rediseñando con nuevos modelos de negocios enfocados en satisfacer las actuales demandas y experiencias de los clientes. El libro que aquí se presenta reúne el trabajo de investigación referente a BIM de la Red Académica de Diseño Construcción integrada por académicos de la Facultad de Ingeniería de la Universidad Autónoma de Yucatán, México (UADY), el Worcester Polytechnical Institute (WPI) de Massachusetts, Estados Unidos y del Área de Administración y Tecnología para el Diseño de la Universidad Autónoma Metropolitana, Unidad Azcapotzalco (UAM). También han colaborado con la Red investigadores de la Universidad Politécnica de Madrid (UPM), España y, dentro de la UAM, académicos de la División de Ciencias Básicas e Ingeniería, Departamento de Materiales, del Área de Construcción. Cabe mencionar que los artículos ya han sido publicados con anterioridad en los Anuarios de Administración y Tecnología para el Diseño y las Compilaciones de Artículos de Investigación en Administración y Tecnología para la Arquitectura, Diseño e Ingeniería, productos del trabajo de investigación del Área que edita anualmente desde 1999, como se indica en el índice del presente libro

    Sociodemographic, clinical and laboratory factors on admission associated with COVID19 mortality in hospitalized patients: A retrospective observational study

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    Background To identify and quantify associations between baseline characteristics on hospital admission and mortality in patients with COVID-19 at a tertiary hospital in Spain. Methods and findings This retrospective case series included 238 patients hospitalized for COVID-19 at Hospital Universitario Clı´nico San Cecilio (Granada, Spain) who were discharged or who died. Electronic medical records were reviewed to obtain information on sex, age, personal antecedents, clinical features, findings on physical examination, and laboratory results for each patient. Associations between mortality and baseline characteristics were estimated as hazard ratios (HR) calculated with Cox regression models. Series mortality was 25.6%. Among patients with dependence for basic activities of daily living, 78.7% died, and among patients residing in retirement homes, 80.8% died. The variables most clearly associated with a greater hazard of death were age (3% HR increase per 1-year increase in age; 95%CI 1–6), diabetes mellitus (HR 2.42, 95%CI 1.43–4.09), SatO2/ FiO2 ratio (43% HR reduction per 1-point increase; 95%CI 23–57), SOFA score (19% HR increase per 1-point increase, 95%CI 5–34) and CURB-65 score (76% HR increase per 1- point increase, 95%CI 23–143). Conclusions The patients residing in retirement homes showed great vulnerability. The main baseline factors that were independently associated with mortality in patients hospitalized for COVID-19 were older age, diabetes mellitus, low SatO2/FiO2 ratio, and high SOFA and CURB-65 scores.Fondos Estructurales de la Union Europea (FEDER)Unit of Excellence on Exercise and Health (UCEES), University of Granad

    The Hoopoe's Uropygial Gland Hosts a Bacterial Community Influenced by the Living Conditions of the Bird

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    Molecular methods have revealed that symbiotic systems involving bacteria are mostly based on whole bacterial communities. Bacterial diversity in hoopoe uropygial gland secretion is known to be mainly composed of certain strains of enterococci, but this conclusion is based solely on culture-dependent techniques. This study, by using culture-independent techniques (based on the 16S rDNA and the ribosomal intergenic spacer region) shows that the bacterial community in the uropygial gland secretion is more complex than previously thought and its composition is affected by the living conditions of the bird. Besides the known enterococci, the uropygial gland hosts other facultative anaerobic species and several obligated anaerobic species (mostly clostridia). The bacterial assemblage of this community was largely invariable among study individuals, although differences were detected between captive and wild female hoopoes, with some strains showing significantly higher prevalence in wild birds. These results alter previous views on the hoopoe-bacteria symbiosis and open a new window to further explore this system, delving into the possible sources of symbiotic bacteria (e.g. nest environments, digestive tract, winter quarters) or the possible functions of different bacterial groups in different contexts of parasitism or predation of their hoopoe host.This work was supported by the Ministerio de Ciencia y Tecnología (projects CGL2005-06975/BOSFEDER; CGL2007-61251/BOSFEDER), the Ministerio de Ciencia e Innovación (projects CGL2009-14006/BOSFEDER; CGL2010-19233-C03-01/BOSFEDER; CGL2010-19233-C03-03/BOSFEDER), the Ministerio de Economía y Competitividad (projects CGL2013-48193-C3-1-P/BOSFEDER; CGL2013-48193-C3-2-P/BOSFEDER), and the Junta de Andalucía (RNM 345, P09-RNM-4557). SMRR received a grant from the Ministerio de Ciencia e Innovación (FPI program, BES-2011-047677)
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