228 research outputs found

    Quinolone Resistance Reversion by Targeting the SOS Response

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    Suppression of the SOS response has been postulated as a therapeutic strategy for potentiating antimicrobial agents. We aimed to evaluate the impact of its suppression on reversing resistance using a model of isogenic strains of Escherichia coli representing multiple levels of quinolone resistance. E. coli mutants exhibiting a spectrum of SOS activity were constructed from isogenic strains carrying quinolone resistance mechanisms with susceptible and resistant phenotypes. Changes in susceptibility were evaluated by static (MICs) and dynamic (killing curves or flow cytometry) methodologies. A peritoneal sepsis murine model was used to evaluate in vivo impact. Suppression of the SOS response was capable of resensitizing mutant strains with genes encoding three or four different resistance mechanisms (up to 15-fold reductions in MICs). Killing curve assays showed a clear disadvantage for survival (Δlog10 CFU per milliliter [CFU/ml] of 8 log units after 24 h), and the in vivo efficacy of ciprofloxacin was significantly enhanced (Δlog10 CFU/g of 1.76 log units) in resistant strains with a suppressed SOS response. This effect was evident even after short periods (60 min) of exposure. Suppression of the SOS response reverses antimicrobial resistance across a range of E. coli phenotypes from reduced susceptibility to highly resistant, playing a significant role in increasing the in vivo efficacy

    Traffic monitoring for assuring quality of advanced services in future internet

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-21560-5_16Services based on packet switched networks are becoming dominant in telecommunication business and both operators and service providers must evolve in order to guarantee the required quality. Increasing bandwidth is no longer a viable solution because of the business erosion for network operators which cannot expect revenues due to the large investments required to satisfy new applications demand of bandwidth. This paper presents devices and a specific architecture of services monitoring platform that allows network operators and service providers to analyze the perceived quality of service and check their service level agreements. Thus, a cost-effective service management, based on direct IP traffic measuring, can be supported on integrated monitoring systems to provide network-centric mechanisms for differentiated quality of service, security and other advanced services.This work has been partially developed in the framework of the Celtic and EUREKA initiative IPNQSIS (IP Network Monitoring for Quality of Service Intelligent Support)

    Quantum mechanical modeling of excited electronic states and their relationship to cathodoluminescence of BaZrO3

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    First-principles calculations set the comprehension over performance of novel cathodoluminescence (CL) properties of BaZrO3 prepared through microwave-assisted hydrothermal. Ground (singlet, s*) and excited (singlet s** and triplet t** ) electronic states were built from zirconium displacement of 0.2 Å in {001} direction. Each ground and excited states were characterized by the correlation of their corresponding geometry with electronic structures and Raman vibrational frequencies which were also identified experimentally. A kind of optical polarization switching was identified by the redistribution of 4dz2 and 4dxz (Zr) orbitals and 2pz O orbital. As a consequence, asymmetric bending and stretching modes theoretically obtained reveal a direct dependence with their polyhedral intracluster and/or extracluster ZrO6 distortions with electronic structure. Then, CL of the as-synthesized BaZrO3 can be interpreted as a result of stable triplet excited states, which are able to trap electrons, delaying the emission process due to spin multiplicity changes

    Efecto de los fertilizantes orgánicos líquidos fermentados en la conductividad eléctrica y concentración de micronutrientes en el suelo cultivado con <i>Lactuca sativa</i> L y <i>Spinnacca oleraceae</i> L.

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    Los Abonos Orgánicos Liquidos Fermentados AOLF utilizados en la agricultura ecológica, presentan altos niveles de P, K, Ca, Mg, S, Fe, Cu, Zn y elevada conductividad eléctrica (EC). Altas concentraciones y frecuentes aplicaciones de AOLF pueden promover salinidad y acumulo de micronutrientes en el suelo. Este estudio evalua el efecto de un AOLF aplicado en dos concentraciones y frecuencias en la CE, la acumulación de Cu, Fe, Mn y Zn y la masa fresca de lechugas y espinacas. El estudio fue realizado en Colombia, estableciendo 5 tratamientos y 3 repeticiones T1: [0%] sin aplicaciones; T2: [10%] cada 8 días; T3: [10%] cada 15 días; T4: [20%] cada 8 días; T5: [20%] cada 15 días. Fueron aplicados 100 ml de AOF planta. Después de 45 Las concentraciones y frecuencias de aplicación no afectaron la producción de masa fresca en las especies. El T4 aumenta la CE y acumulación de Cu y Zn, aumentando el riesgo de salinidad toxicidad de micronutrientes en el suelo.Fermented Liquid Organic Fertilizers AOLF used in organic farming, have high levels of P, K, Ca, Mg, S, Fe, Cu, Zn and high electrical conductivity (EC). High concentrations and frequent applications AOLF can promote accumulation of salinity and soil micronutrient. This study evaluated the effect of a AOLF applied in two concentrations and frequencies in the EC, the accumulation of (Cu, Fe, Mn and Zn) and fresh mass of lettuce and spinach The study was conducted in Colombia, establishing 5 treatments and 3 T1 repeats [0%] without applications; T2: [10%] every 8 days; T3: [10%] every 15 days; T4: [20%] every 8 days; T5: [20%] every 15 days. 100 ml were applied AOF plant. After 45 concentrations and frequencies of application they did not affect the mass production of fresh species. T4 increases the EC and accumulation of Cu and Zn, increasing the risk of toxicity salinity soil micronutrient.A1 Sistemas de producción de base agroecológica (Trabajos científicos).Facultad de Ciencias Agrarias y Forestale

    Efecto de los fertilizantes orgánicos líquidos fermentados en la conductividad eléctrica y concentración de micronutrientes en el suelo cultivado con <i>Lactuca sativa</i> L y <i>Spinnacca oleraceae</i> L.

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    Los Abonos Orgánicos Liquidos Fermentados AOLF utilizados en la agricultura ecológica, presentan altos niveles de P, K, Ca, Mg, S, Fe, Cu, Zn y elevada conductividad eléctrica (EC). Altas concentraciones y frecuentes aplicaciones de AOLF pueden promover salinidad y acumulo de micronutrientes en el suelo. Este estudio evalua el efecto de un AOLF aplicado en dos concentraciones y frecuencias en la CE, la acumulación de Cu, Fe, Mn y Zn y la masa fresca de lechugas y espinacas. El estudio fue realizado en Colombia, estableciendo 5 tratamientos y 3 repeticiones T1: [0%] sin aplicaciones; T2: [10%] cada 8 días; T3: [10%] cada 15 días; T4: [20%] cada 8 días; T5: [20%] cada 15 días. Fueron aplicados 100 ml de AOF planta. Después de 45 Las concentraciones y frecuencias de aplicación no afectaron la producción de masa fresca en las especies. El T4 aumenta la CE y acumulación de Cu y Zn, aumentando el riesgo de salinidad toxicidad de micronutrientes en el suelo.Fermented Liquid Organic Fertilizers AOLF used in organic farming, have high levels of P, K, Ca, Mg, S, Fe, Cu, Zn and high electrical conductivity (EC). High concentrations and frequent applications AOLF can promote accumulation of salinity and soil micronutrient. This study evaluated the effect of a AOLF applied in two concentrations and frequencies in the EC, the accumulation of (Cu, Fe, Mn and Zn) and fresh mass of lettuce and spinach The study was conducted in Colombia, establishing 5 treatments and 3 T1 repeats [0%] without applications; T2: [10%] every 8 days; T3: [10%] every 15 days; T4: [20%] every 8 days; T5: [20%] every 15 days. 100 ml were applied AOF plant. After 45 concentrations and frequencies of application they did not affect the mass production of fresh species. T4 increases the EC and accumulation of Cu and Zn, increasing the risk of toxicity salinity soil micronutrient.A1 Sistemas de producción de base agroecológica (Trabajos científicos).Facultad de Ciencias Agrarias y Forestale

    Efecto de los fertilizantes orgánicos líquidos fermentados en la conductividad eléctrica y concentración de micronutrientes en el suelo cultivado con <i>Lactuca sativa</i> L y <i>Spinnacca oleraceae</i> L.

    Get PDF
    Los Abonos Orgánicos Liquidos Fermentados AOLF utilizados en la agricultura ecológica, presentan altos niveles de P, K, Ca, Mg, S, Fe, Cu, Zn y elevada conductividad eléctrica (EC). Altas concentraciones y frecuentes aplicaciones de AOLF pueden promover salinidad y acumulo de micronutrientes en el suelo. Este estudio evalua el efecto de un AOLF aplicado en dos concentraciones y frecuencias en la CE, la acumulación de Cu, Fe, Mn y Zn y la masa fresca de lechugas y espinacas. El estudio fue realizado en Colombia, estableciendo 5 tratamientos y 3 repeticiones T1: [0%] sin aplicaciones; T2: [10%] cada 8 días; T3: [10%] cada 15 días; T4: [20%] cada 8 días; T5: [20%] cada 15 días. Fueron aplicados 100 ml de AOF planta. Después de 45 Las concentraciones y frecuencias de aplicación no afectaron la producción de masa fresca en las especies. El T4 aumenta la CE y acumulación de Cu y Zn, aumentando el riesgo de salinidad toxicidad de micronutrientes en el suelo.Fermented Liquid Organic Fertilizers AOLF used in organic farming, have high levels of P, K, Ca, Mg, S, Fe, Cu, Zn and high electrical conductivity (EC). High concentrations and frequent applications AOLF can promote accumulation of salinity and soil micronutrient. This study evaluated the effect of a AOLF applied in two concentrations and frequencies in the EC, the accumulation of (Cu, Fe, Mn and Zn) and fresh mass of lettuce and spinach The study was conducted in Colombia, establishing 5 treatments and 3 T1 repeats [0%] without applications; T2: [10%] every 8 days; T3: [10%] every 15 days; T4: [20%] every 8 days; T5: [20%] every 15 days. 100 ml were applied AOF plant. After 45 concentrations and frequencies of application they did not affect the mass production of fresh species. T4 increases the EC and accumulation of Cu and Zn, increasing the risk of toxicity salinity soil micronutrient.A1 Sistemas de producción de base agroecológica (Trabajos científicos).Facultad de Ciencias Agrarias y Forestale

    Theoretical modelling of quaternary GaInAsSb/GaAs self-assembled quantum dots

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    Trabajo presentado al "Quantum Dot", celebrado en Nottingham (UK) del 26 al 30 de Abril de 2010.InAs/GaAs quantum dots exposed to Sb after growth exhibit spectral changes. We study in the present paper an idealized nanostructure consisting of a homogeneous distribution of the quaternary GaInAsSb surrounded by a barrier of GaAs. We nd that the valence band o set is a critical parameter in modelling its electronic structure. Depending on this value, we predict a transition from type-I to type-II band alignment at a di erent Sb concentration. The addition of Sb to reduce the transition energy while keeping a type-I alignment is only of bene t at low Sb concentrationThis work was supported by the Spanish MICINN (projects TEC2008-06756-C03-01/02/TEC, CONSOLIDER INGENIO 2010 CSD2006-0019 and CSD2009-00013), the Junta de Andalucía (PAI research groups TEP-120 and TIC-145; project P08-TEP-03516) and Comunidad Autónoma de Madrid S2009ESP-1503.Peer reviewe

    Hiperendemicidad de fasciolosis y factores de riesgo en niños de edad escolar del distrito de Orurillo, Puno

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    The aim of this study was to determine the association of fasciolosis in school-age children with intestinal parasites, food consumption and animal husbandry. The research was analytical, prospective, cross-sectional, and relational. In total, 295 serological and stool samples were obtained, and an epidemiological interview was carried out on children of both sexes, aged 3 to 19 years from 23 institutions of initial, primary and secondary education, with the informed consent of their parents. The serological diagnosis was made using the IgG immunoblot technique and the IgG ELISA test and the stool diagnosis was made with the rapid sedimentation technique modified by Lumbreras. Risk factors were obtained by epidemiological interview. The prevalence of fasciolosis was 11.2% (95% CI = 7.4-14.9; 33/295). Significant differences were found between educational institutions and communities of origin. Both in univariate and multivariate analyses determined that drinking well water and raising guinea pigs were associated with fasciolosis.El objetivo del estudio fue determinar la asociación de fasciolosis en niños de edad escolar con parásitos intestinales, consumo de alimentos y crianza de animales. La investigación fue de tipo analítico, prospectivo, transversal y de nivel relacional. Se obtuvieron 295 muestras serológicas y coprológicas y se realizó una entrevista epidemiológica a niños de ambos sexos, de 3 a 19 años de 23 instituciones de educación inicial, primaria y secundaria, con el consentimiento informado de sus progenitores. El diagnóstico serológico se realizó mediante la técnica de inmunoblot IgG y la prueba de ELISA IgG y el diagnóstico coprológico se realizó con la técnica de sedimentación rápida modificada por Lumbreras. Los factores de riesgo se obtuvieron mediante entrevista epidemiológica. La prevalencia de fasciolosis fue de 11.2% (IC95%=7.4-14.9; 33/295). Se encontró diferencias significativas entre instituciones educativas y comunidades de procedencia. Tanto en análisis univariado como el multivariado determinaron que beber agua de pozo y criar cuyes estuvieron asociados a fasciolosis
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