702 research outputs found

    Curs d'informàtica a Arnes

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    Cases de turisme rural a la Terra Alta

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    Comparison of Simple and Rapid Extraction Procedures for the Determination of Pesticide Residues in Fruit Juices by Fast Gas Chromatography–Mass Spectrometry

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    Three sample treatment methods, based on QuEChERS, solid-phase extraction (SPE) and solid-phase microextraction (SPME), were compared and evaluated in order to obtain the best conditions to determine pesticide residues in fruit juice by fast gas chromatography–mass spectrometry (single quadrupole GC-MS). Analysis were performed under selected ion monitoring, acquiring the three most abundant and/or specific ions for each analyte and using their relative intensity ratios as a confirmatory parameter. The 3 methodologies (QuEChERS, SPE and SPME) were validated taking 15 selected pesticides as model compounds, using commercial apple juice. QuEChERS procedure was based on the AOAC Official Method 2007.01, using acetonitrile (containing 1 % acetic acid) as extraction solvent and primary–secondary amine during the dispersive solid-phase extraction. Oasis hydrophilic–lipophilic balance cartridges were used for SPE, and polyacrylate fibers were used for direct immersion SPME procedure. Three isotopically labeled standards were added to the samples before extraction and used as surrogate standards. Validation parameters as recoveries, limits of detection, and limits of quantification (LOQ), as well as matrix effects and sample throughput, were obtained and compared for the three extraction procedures. QuEChERS was considered faster and led to the best quantitative results. In this way, validation was extended to up to 56 pesticides by applying QuEChERS in multi-fruit juice samples, obtaining LOQs ranging from 2 to 20 μg/L for most compounds. Accuracy and precision were evaluated by means of recovery experiments at two concentration levels (10 and 100 μg/L), obtaining recoveries between 70 and 120 % in most cases and relative standard deviations below 15 %. Finally, the QuEChERS method was applied to the analysis of commercial juices, including mango–apple, pineapple, grapefruit and orange

    Prueba de habilidades practicas cisco CCNP

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    En el siguiente documento se presentara el desarrollo y solución paso a paso de 3 escenarios de red simuladas en packet tracer , estos escenarios corresponden a la prueba de habilidades prácticas del diplomado CISCO CCNP, el desarrollo de los 3 escenarios antes mencionados abarcaran las temáticas base que comprende el programa de formación permitiendo así reforzar lo aplicado durante el desarrollo de el mismo, cada desarrollo contara con la descripción detallada del script utilizado sobre cada uno de los equipos que comprenden las redes propuestas, pruebas de ping, respuesta, validación de funcionamiento de VLANS etc.The following document presents the development and step-by-step solution of 3 network scenarios simulated in packet tracer, these correspond to the CISCO CCNP diploma skills test, the development of the 3 steps in advance will cover the basic issues that It will include the training program so that it is adapted so that it is applied during the development, so that the description is complied with so that it can be applied to be used. etc. Each scenario will have a detailed description of the solution script and validation tests on the requested requirements, validating its development step by step In the solution of these 3 scenarios will be the implementation of several of the configuration that we can see in the course of the diploma, from naming the team to give an encryption, enable VLANs, protocols, tunnels among others

    The role of GC-MS/MS with triple quadrupole in pesticide residue analysis in food and the environment

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    Gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) using a triple quadrupole (QqQ) analyzer has in the last few years become a powerful technique for the determination of pesticide residues due to its robustness, and excellent sensitivity and selectivity. This review gives an overview of currently published applications of GC-MS/MS with a QqQ analyzer for pesticide residue analysis of different food and environmental sample matrices. This technique allows the reliable quantification and identification of low pesticide concentrations for non-polar (semi) volatile compounds belonging to different chemical families. It has allowed a notable improvement of methods performance in comparison with the traditional GC methods with single stage quadrupole MS

    Application of gas chromatography time-of-flight mass spectrometry for target and non-target analysis of pesticide residues in fruits and vegetables

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    In this work, the capability of gas chromatography coupled to time-of-flight mass spectrometry (GC–TOF MS) for quantitative analysis of pesticide residues has been evaluated. A multiclass method for rapid screening of pesticides (insecticides, acaricides, herbicides and fungicides) in fruit and vegetable matrices has been developed and validated, including detection, identification and quantification of the analytes. To this aim, several food matrices were selected: high water content (apples, tomatoes and carrots), high acid content (oranges) and high oil content (olives) samples. The well known QuEChERS procedure was applied for extraction of pesticides, and matrix-matched calibration using relative responses versus internal standard was used for quantification. The sample extracts were analyzed by GC–TOF MS. Up to five ions using narrow window (0.02 Da)-extracted ion chromatograms at the expected retention time were monitored using a target processing method. The most abundant ion was used for quantification while the remaining ones were used for confirmation of the analyte identity. Method validation was carried out for 55 analytes in the five sample matrices tested at three concentrations (0.01, 0.05 and 0.5 mg/kg). Most recoveries were between 70% and 120% with relative standard deviations (RSDs) lower than 20% at 0.05 and 0.5 mg/kg. At 0.01 mg/kg, roughly half of the pesticides could be satisfactorily validated due to sensitivity limitations of GC–TOF MS, which probably affected the ion ratios used for confirmation of identity. In the case of olive samples, results were not satisfactory due to the high complexity of the matrix. An advantage of TOF MS is the possibility to perform a non-target investigation in the samples by application of a deconvolution software, without any additional injection being required. Accurate-mass full-spectrum acquisition in TOF MS provides useful information for analytes identification, and has made feasible in this work the discovery of non-target imazalil, fluoranthene and pyrene in some of the samples analyzed

    Seguridad y eficiacia de una nueva pauta de suplementación en pacientes con fibrosis quística e insuficiencia de vitamina D

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    Cystic fibrosis; Vitamin D; Multicentre studyFibrosis quística; Vitamina D; Estudio multicéntricoFibrosi quística; Vitamina D; Estudi multicèntricObjectives Based on the European and American Cystic Fibrosis (CF) consensus recommendations, an increase in vitamin D (VD) supplementation in patients with CF and insufficient or defficient levels was proposed. The objective of our study was to determine the safety and efficacy of this new protocol. Material and methods Multicentre nonrandomized uncontrolled experimental study. Patients with insufficient levels (<30 ng/mL) received increasing doses of VD (between 800 and 10 000 IU/day). Patients were followed up for 12 months, during which their vitamin and nutritional status, pulmonary function and calcium and phosphate metabolism were assessed. Statistical analysis: t test for paired data and multivariate logistic regression analysis. Results Thirty patients aged 1–39 years (median, 9.1) completed the follow-up. Two patients were dropped from the study on account of 25-OH VD levels greater than 100 ng/mL at 3 months without clinical or laboratory signs of hypercalcaemia. At 12 months, we observed an increase of 7.6 ng/mL (95% CI, 4.6−10 ng/mL) in the mean 25-OH VD level and an improvement in vitamin status: 37% achieved levels of 30 ng/mL or greater, 50% levels between 20 and 30 ng/mL and 13% remained with levels of less than 20 ng/mL. We found no association between improved VD levels and pulmonary function. Conclusions The proposed protocol achieved an increase in serum VD levels and a decrease in the percentage of patients with VD insufficiency, although it was still far from reaching the percentages of sufficiency recommended for this entity.Objetivos Basándonos en los documentos de consenso europeo y americano de Fibrosis Quística (FQ) se propone un incremento de la suplementación de vitamina D (VD) en pacientes con FQ y niveles insuficientes. El objetivo de nuestro estudio fue conocer la seguridad y la eficacia de este nuevo protocolo. Material y métodos Estudio multicéntrico, experimental no aleatorizado ni controlado. A los pacientes con niveles insuficientes (<30 ng/mL) se les administró dosis crecientes de VD (entre 800 y 10000 UI/día). Se realizó seguimiento durante 12 meses analizando estatus vitamínico, nutricional, función pulmonar y metabolismo fosfo-cálcico. Análisis estadístico: pruebas t para datos apareados y regresión logística con análisis multivariable. Resultados 30 pacientes entre 1 y 39 años (mediana 9,1) completaron el estudio. Se retiraron 2 por niveles de 25 OH VD > 100 ng/mL a los 3 meses sin encontrarse signos clínicos ni analíticos de hipercalcemia. Tras 12 meses se observó un incremento de 7,6 ng/mL (IC 95% 4,6−10 ng/mL) de los niveles medios de 25 OH VD. El 37% alcanzaron niveles ≥30 ng/mL, un 13% <20 ng/mL y un 50% entre 20 y 30 ng/mL. No se observó asociación de la mejoría de los niveles de VD con la función pulmonar. Conclusiones Con el protocolo propuesto se consigue un incremento de los niveles séricos de VD y una disminución del porcentaje de pacientes con insuficiencia de la misma, aunque todavía muy lejos de alcanzar los porcentajes de suficiencia recomendados para esta entidad.This study received funding from the Fundación Ernesto Sánchez Villares (05/2015) and the Fundación Nutrición y Crecimiento

    La responsabilidad social corporativa

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    Breve recorrido por la Responsabilidad Social Corporativa (RSC), desde su origen hasta nuestros días. Viendo cómo está en España y en Aragón. Así como la Memoria de Sostenibilidad, como parte fundamental en el Balance Social, que nos da una visión de la situación de la RSC en la empresa

    Assessing and mapping cultural ecosystem services at community level in the Colombian Amazon

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    Understanding the significance that cultural ecosystem services (CES) have for traditional communities will provide useful input to the design of more appropriate regional or territorial plans for the area in which they are located. We conducted semi-structured surveys in 11 indigenous communities within the corregimiento La Pedrera, of the Colombian Amazon. We analysed the CES established in the region through a study of their preferences in relation to the service providing units (SPUs) identified, using the Shannon diversity index method as an indicator of ‘diversity of use’. More CES were identified in communities with a larger population; education and recreation were the two most prevalent CES categories in the study area. Our findings also highlight the cultural importance of bodies of water, which were strongly linked with Spiritual and Sense of Place CES. Furthermore, the integration of qualitative and quantitative assessments enables a better understanding of the importance CES which have for the local communities involved in the study and may assist in the management of the indigenous territory.EDITED BY Matthias Schröte
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