133 research outputs found

    Surveillance studies of Lymphocystis disease virus in farmed gilthead seabream (Sparus aurata) by real-time PCR

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    Lymphocystis disease (LCD) is the main viral infection reported to affect cultured gilthead seabream (Sparus aurata) in Southern Atlantic and Mediterranean aquaculture. Its etiological agent is the Lymphocystis disease virus (LCDV), a member of the family Iridoviridae (genus Lymphocystivirus). The only adequate measures for LCD prevention in the aquaculture systems are general prophylactic practices, such as the control of fish to be introduced in the farm facilities in order to detect carrier fish. These animals may pose a risk for the introduction of LCDV in fish farms, as direct contact between fish specimens is considered the main route of LCDV spreading. More recently, asymptomatic carrier breeders, as well as virus contaminated-live food, have been involved in LCDV transmission to fish larvae. The detection of subclinical viral infections in carrier fish requires the use of sensitive diagnostic methods. In this context, the objective of this study was to establish the applicability of a real-time PCR assay for LCDV diagnosis in surveillance studies. In addition, the assay has been evaluated with samples from a gilthead seabream hatchery, in order to prove its utility to trace the origin of LCDV in fish farms. Juvenile fish were collected at four farms with different background regarding to LCD. LCDV was detected in all farms, and 30 to 100% of fish were identified as LCDV-infected. Estimated viral load in caudal fin of asymptomatic fish was two to five orders of magnitude lower than in diseased fish. Carrier fish were also identified in the broodstock from a farm with LCD records by analysing caudal fin samples by qPCR. In this farm, the q-PCR assay developed in this study allowed the quantitative detection of LCDV in all samples collected in the hatchery, including fertilized eggs, larvae and fingerlings, and also rotifer cultures and artemia metanauplii and cysts used for larval rearing.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Simulation of stress-assisted localised corrosion using a Cellular Automaton Finite Element approach

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    In this paper, the overall corrosion damage process is modelled sequentially using cellular automata (CA) to describe the localised corrosion component, and finite element analysis (FEA) to account for the mechanical component resulting from the stress concentration effect of the corrosion defect (pit). Synchronous execution of the CA and FEA, and provision of feedback between both provides a good approximation of stress-assisted pit development. Qualitative and quantitative comparison of simulation results with experimental measurements show good agreement. In particular, the model shows that mechanical effects, notably plastic strain, accelerates the rate of development of localised corrosion

    Gemini surfactant as multifunctional corrosion and biocorrosion inhibitors for mild steel

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    Biocorrosion is an important type of corrosion which leads to economic losses across oil and gas industries, due to increased monitoring, maintenance, and a reduction in platform availability. Ideally, a chemical compound engineered to mitigate against biocorrosion would possess both antimicrobial properties, as well as efficient corrosion inhibition. Gemini surfactants have shown efficacy in both of these properties, however there still remains a lack of electrochemical information regarding biocorrosion inhibition. The inhibition of corrosion and biocorrosion, by cationic gemini surfactants, of carbon steel was investigated. The results showed that the inhibition efficiency of the gemini surfactants was high (consistently >95%), even at low concentrations. Gemini surfactants also showed strong antimicrobial activity, with a minimum inhibitory concentration (0.018 mM). Corrosion inhibition was investigated by electrochemical impedance spectroscopy (EIS) and linear polarisation resistance (LPR), with biocorrosion experiments carried out in an anaerobic environment. Surface morphology was analysed using scanning electron microscopy (SEM)

    Determinación de órganos diana para la multiplicación y persistencia del virus de la enfermedad de linfocistis (LCDV) en dorada (Sparus aurata, L.)

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    La enfermedad de linfocistis es la única patología de etiología viral descrita en dorada cultivada En la cuenca mediterr nea, la prevalencia es cercana al 100 , ocasionando graves p rdidas económicas debido a la imposibilidad de comercializar los peces afectados En el presente trabajo se ha abordado el estudio de la patog nesis del virus de la enfermedad de linfocistis (LCDV) en dorada, además se han establecido los órganos implicados en la multiplicación vírica Para ello, se ha diseñado un protocolo de hibridación in situ empleando sondas RNA marcadas con digoxigenina dirigidas contra el gen que codifica la proteína principal de la cápside (MCP) viral, y se ha evaluado en poblaciones de dorada. En paralelo, se ha procedido a la cuantificación del número de copias de genoma viral por PCR a tiempo real y cuantificación relativa de la transcripción del gen que codifica la MCP viral mediante qRT-PCR. Los resultados obtenidos indican que el LCDV establece una infección sistémica en alevines de dorada, pudiendo detectarse señal de hibridación tanto en órganos internos (hígado, bazo, riñón) como en músculo y aleta. También se han observado diversos daños histopatológicos en animales enfermos, mientras que en animales recuperados de la enfermedad estos daños parecen revertir, aunque en estos animales la infección persiste, si bien sólo a niveles detectables mediante PCR a tiempo real.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    La plataforma siette una herramienta para el aprendizaje de la botánica forestal

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    El avance tecnológico está incorporando nuevas herramientas de aprendizaje para complementar el estudio y realizar prácticas de autoevaluación de valor formativo, ya que mediante el ejercicio de evaluación el estudiante puede reflexionar sobre su progreso y dirigir mejor su esfuerzo en el estudio. En este marco la plataforma SIETTE es un sistema web que permite la creación y mantenimiento de bancos de preguntas, y realización de tests, que implementa la Teoría Clásica de Test (CTT), Teoría de Respuesta al Ítem (TRI), permite realizar Tests Adaptativos Informatizados (TAI), y puede usarse como herramienta para el aprendizaje colaborativo. Siette puede usarse como módulo de evaluación de un Sistema Tutor Inteligente (STI) o conectado a una Plataforma de Teleeducación (LMS) como Moodle. Siette implementa muchas otras opciones para la realización de prácticas de reconocimiento, repaso, y evaluación. Esta comunicación presenta los resultados de varios años de trabajo con esta herramienta, las diversas experiencias de formación y evaluación de conocimientos sobre Botánica Forestal. Se han definido más de 2500 preguntas, la mayoría basadas en imágenes y realizado mas de 4300 sesiones de evaluación en la Escuela Universitaria de Ingeniería Técnica Forestal de la Universidad Politécnica de Madrid en colaboración con la Universidad de Málaga

    Study of the plutino object (208996) 2003 AZ84 from stellar occultations: size, shape and topographic features

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    We present results derived from four stellar occultations by the plutino object (208996) 2003~AZ84_{84}, detected at January 8, 2011 (single-chord event), February 3, 2012 (multi-chord), December 2, 2013 (single-chord) and November 15, 2014 (multi-chord). Our observations rule out an oblate spheroid solution for 2003~AZ84_{84}'s shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semi axes (470±20)×(383±10)×(245±8)(470 \pm 20) \times (383 \pm 10) \times (245 \pm 8)~km % axis ratios b/a=0.82±0.05b/a= 0.82 \pm 0.05 and c/a=0.52±0.02c/a= 0.52 \pm 0.02, can better account for all our occultation observations. Combining these dimensions with the rotation period of the body (6.75~h) and the amplitude of its rotation light curve, we derive a density ρ=0.87±0.01\rho=0.87 \pm 0.01~g~cm3^{-3} a geometric albedo pV=0.097±0.009p_V= 0.097 \pm 0.009. A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003~AZ84_{84}'s limb, that can be interpreted as an abrupt chasm of width 23\sim 23~km and depth >8> 8~km or a smooth depression of width 80\sim 80~km and depth 13\sim 13~km (or an intermediate feature between those two extremes)

    Knowledge, attitudes and preventive practices of primary health care professionals towards alcohol use: A national, cross-sectional study

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    Introduction Primary care (PC) professionals' knowledge about alcohol use has been identified as one of the barriers PC providers face in their clinic. Both PC professionals' level of training and attitude are crucial in the clinical practice regarding alcohol use. Objective To evaluate the knowledge, attitude, and preventive practices of Spanish PC physicians and nurses towards alcohol use. Design An observational, descriptive, cross-sectional, multi-center study. Methodology Location: PC centers of the Spanish National Health System (NHS). Participants: PC physicians and nurses selected randomly from health care centers, and by sending an e-mail to semFYC and SEMERGEN members. Healthcare providers completed an online survey on knowledge, attitude, and follow-up recommendations for reducing alcohol intake. A descriptive, bivariate, and multivariate statistical analysis was conducted (p<0.05). Results Participants: 1, 760 healthcare providers completed the survey (75.6% [95% CI 73.5-77.6] family physicians; 11.4% [95% CI 9.9-12.9] medical residents; and 12.5% [95% CI 10.9-14.1] nurses), with a mean age of 44.7 (SD 11.24, range: 26-64, 95% CI: 47.2-48.2). Knowledge was higher in family physicians (p<0.001), older professionals (Spearman's r = 0.11, p<0.001), and resident trainers (p<0.001). The PC professional most likely to provide advice for reducing alcohol use was: a nurse (p<0.001), female (p = 0.010), between 46 and 55 years old (p <0.001). Conclusions PC providers' knowledge and preventive practices regarding alcohol use are scarce, hence specific training strategies to increase their knowledge and improve their attitude and skills with regard to this health problem should be considered a healthcare policy priority

    Una base de datos de inventarios de vegetación: HISPAVEG

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    Las bases de datos de inventarios de vegetación son una importante fuente de información en relación a un conjunto amplio de aspectos del medio natural, entre los que destacan los efectos de la gestión forestal en la diversidad vegetal, los estudios de autoecología basados en modelos de distribución de especies y la observación a largo plazo de las comunidades vegetales. Desde esta valoración esta comunicación presenta HispaVeg, una base de datos de inventarios de vegetación online, abierta y viva, con las siguientes características y resultados: Permite introducir inventarios de vegetación con diversas metodologías (estructural, como la fisionómica-estructural de Ruiz de la Torre y de la escuela de Zurich-Montpelier). En la actualidad contiene 2.663 inventarios históricos del profesor Juan Ruiz de la Torre realizados entre los años 1950 y 2000, de superficie de parcela entre 400 y 3.600 m2, tanto de formaciones arboladas como de matorrales y pastizales, con número medio de especies por inventario de 34 y distribuidos por toda la España peninsular e Islas Baleares, en un intervalo altitudinal entre 0 y 2880 m
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