VNUML vs GNS3 en el desarrollo de laboratorios de redes virtuales

El aprendizaje práctico de redes de computadores es reconocido como un proceso crítico que permite a los estudiantes consolidar los conceptos introducidos en las lecciones teóricas. En este sentido, las tecnologías de virtualización están adquiriendo gran relevancia debido a que permiten desarrollar laboratorios de redes de computadores con un reducido coste de despliegue y gestión. Este artículo presenta un análisis comparativo entre GNS3 y VNUML, que son herramientas de virtualización open-source que han sido empleadas para el desarrollo de laboratorios de red virtuales para llevar a cabo el proceso de enseñanza-aprendizaje en las asignaturas Arquitectura de Redes y Arquitectura de Redes Avanzadas del Grado en Ingeniería Informática impartido en la Universidad de Murcia. El estudio presenta las principales ventajas y/o deficiencias de cada herramienta tanto para profesores como alumnos y se identifican los escenarios en los que parece más adecuada su utilización.SUMMARY -- The practical learning of computer networks is known to be a critical process in order to allow students to consolidate the concepts introduced in theoretical lessons. In this sense, virtualization technologies are becoming popular since they allow to set up a computer network laboratory with a reduced deployment and management cost. This paper presents a comparative analysis performed between GNS3 and VNUML, which are open-source tools for virtualization that have been used for developing virtual network laboratories that support the teaching-learning process in the Networks Architecture and Advanced Networks Architecture subjects of the Computer Engineering degree at the University of Murcia. The study presents the main advantages and/or deficiencies of each tool not only for professors but also for students and identifies the scenarios where the use of each tool seems to be more appropriate.Peer Reviewe

El papel de la atención en el ámbito deportivo : una aproximación bibliométrica de la literatura recogida en la base de datos PSYCLIT

Los procesos atencionales en el deporte son considerados aspectos muy importantes en la labor del deportista. Apoyándonos en los trabajos realizados hasta la fecha (García, Garcés de Los Fayos y Jara, 2001, 2002), nos interesa onocer en profundidad cuál es el estado de la investigación en dichos procesos. Para ello hemos realizado un estudio bibliométrico de la base bibliográfica PsycINFO, del periodo comprendido entre los anos 1887 y 2000. El análisis pretende ofrecer una perspectiva general y global de los trabajos realizados en este período de los siguientes aspectos: productividad general, áreas temáticas, distribución geográfica y desarrollo cronológico de las publicaciones, productividad de las revistas y productividad de los autores.Attentional processes in sports are considered very important aspects in all kinds of athletic activities. Supported by work published to date (García, Garcés de Los Fayos and Jara, 2001, 2002), this paper is an in-depth examination of the status of research on these processes. A bibliometric study of the PsycINFO bibliographic database from 1887 until 2000 was conducted to do so. The analysis attempts to offer a general and global perspective of several aspects of work from this period: general productivity, thematic areas, geographic distribution and chronological development of papers and journals' and authors' productivity

Adaptación de lente de contacto cosmética en un caso de midriasis máxima irrefléxica y estrabismo tras cirugía complicada de cataratas

Se presenta un caso clínico con solución de lente de contacto cosmética para una paciente con midriasis máxima irrefléxica provocada por una complicación en cirugía de cataratas. El caso se complica al tener la paciente, además, una endo e hipertropía en ojo izquierdo (OI). Se realiza un estudio optométrico y contactológico en profundidad para establecer la idoneidad del tratamiento elegido y la solución propuesta y aceptada, que es la de adaptar una LC de material biocompatible y trabajada artesanalmente. Con ella se consigue un resultado muy natural y nos aseguramos que el material respeta por completo la fisiología del ojo. Después de una serie de pruebas adaptativas se consigue dotar a la paciente de la comodidad y similitud facial inicialmente consideradas en la primera visita, quedando así subsanada estéticamente esta atrofia ocular inicial

Obstáculos y dificultades de los maestros en formación inicial en el diseño de unidades didácticas de enfoque investigador: el inventario general de obstáculos

La planificación de la enseñanza constituye un momento de máxima relevancia entre las tareas profesionales del docente. Realizando el análisis de estos procesos y sus resultados con cierto detenimiento, se pueden poner de manifiesto muchas de las opciones didácticas del profesor y aquellos aspectos que actúan como obstáculos cuando reflexiona sobre los objetivos, contenidos, actividades y demás elementos curriculares que debe incluir en el diseño de una determinada unidad didáctica. Los estudios sobre los procesos de planificación de unidades didácticas por los profesores constituyen una línea investigación didáctica muy interesante, por ser próxima a la práctica profesional y proporciona contextos adecuados para el estudio de las barreras en el desarrollo profesional docente, que centra nuestra investigación

Red-light effects sensitized by methylene blue on nitrate reductase from spinach (Spinacia Oleracea L.) leaves

Nitrate reductase from spinach (Spinacia oleracea L.) leaves, which had been inactivated in vitro by incubation with N A D H and cyanide, was fully reactivated in minutes when irradiated in anaerobic conditions with red light in the presence o f m ethylene blue. Both the rate and the extent of reactivation increased with light intensity ( 6 to 100 W - m “ 2) and dye concentration (1 to 10 jiM). On the contrary, photoreactivation was com pletely abolished when N A D H or ethylenediaminetetra-acetic acid were present during irradiation. W e propose that methylene blue, when photo excited, exhibits a redox potential positive enough to reoxidise the CN~-reduced molybdenum complex settled in the inactive enzyme, thus causing its reactivation. On the other hand, prolonged irradiation o f nitrate reductase, under air and in the presence o f methylene blue, promoted an oxygen-dependent irreversible inactivation o f the two partial activities of the enzyme. This inactivation was markedly enhanced in 77% deuterated water and greatly prevented by azide, which indicates that singlet oxygen is the species primarily involved in the photooxidative inactivation o f the enzym

Volatile and phenolic composition of a Chardonnay wine treated with antimicrobial plant extracts before malolactic fermentation

This work is licensed under a Creative Commons Attribution 3.0 License.Previous studies have proven the potential of antimicrobial plant extracts to delay malolactic fermentation (MLF) in red wines. With the final end of extending their applicability in oenology, the aim of this study was to investigate whether the addition of antimicrobial extracts (from eucalyptus leaves and almond skins) to white wines (i.e., Chardonnay wine), as a way to control MLF, would affect wine organoleptic properties, in particular those related to their volatile and phenolic composition. Although addition of both extracts led to statistically significant changes (p<0.05) in the concentration of several volatile and phenolic compounds, only few of them showed contents higher than their sensory thresholds, meaning that the changes observed in their concentration could slightly affect the final wine aroma and astringency. However, use of the extracts in the elaboration of white wines needs to be assessed in future experiments at winery scale, including wine sensorial analysis.This work has been funded by the Spanish Ministry for Science and Innovation (AGL2006-04514, AGL2009-13361-C02-00 and CSD2007-00063 Consolider Ingenio 2010 FUN-C-FOOD Projects), and the Comunidad de Madrid (ALIBIRD P2009/AGR-1469 Project). JJRB and AGR are the recipients of a fellowship from the JAE-Doc Program (CSIC) and DANONE Institute, respectively.Peer Reviewe

Spatial characterization of glacial and periglacial landforms in the highlands of Sierra Nevada (Spain)

Sierra Nevada constitutes the southernmost and highest massif in the Iberian Peninsula, with elevations exceeding 3000m. Two large glacial advances were recorded during the Last Glaciation and several minor advances occurred until the Early Holocene. Since then, periglacial activity has prevailed above 2500m. Here, we present a new and more accurate geomorphological map of the highlands of Sierra Nevada, integrating in a GIS environment i) high resolution satellite imagery, ii) topographic data, and iii) field observations. This approach has allowed a better characterization of the spatial extent of cold-climate morphogenic processes and associated landforms formed during the Last Glaciation and subsequent deglaciation. Despite its extension and high altitude, the steep relief of Sierra Nevada and its southern location conditioned a significantly lower glaciated surface (104.6km2) with respect to other Iberian massifs. We have also inferred the paleoclimatic conditions of the study area through the calculation of Equilibrium Line Altitudes (ELAs). The distribution of the lowest moraines suggests an ELA for the maximum glacial extent at 2525m in the northern slope and 2650m in the southern side, increasing towards the east. Local ELA differences are related to: (i) the influence of the warmer Mediterranean Sea in contrast to the cooler Atlantic Ocean, (ii) the climate with more continental characteristics on the northern slope, and (iii) the microscale control of the local topography. Mean annual air temperatures in the ice-free summit plateaus were between -4/-6°C during the maximum local glacial extent, determining permafrost conditions with intense periglacial dynamics. Rock glaciers and protalus lobes developed until 2500m, the lowest boundary for permafrost regime. The distribution of other glacial and periglacial landforms within the limits of the maximum ice extent provides evidence to better understand the extent of subsequent glacial stages and post-glacial landscape evolution in Sierra Nevada.info:eu-repo/semantics/publishedVersio

Exploitation of washing products of granitic tin-bearing sands from Conquista (Córdoba)

8 páginas, 10 figuras, 3 tablas, 21 referencias.[EN]: An argillaceous material, high in kaolinite, from washing products of granitic sands of Pedroches (Córdoba) formation, is studied. The following determinations were carried out: mechanical analysis, chemical analysis. X-ray diffraction study, DTA-TG and dilatometric analysis, as well as a ceramic study of pressed and fîred bodies for two hours up to 1.300°C, to obttain the sintering diagrams. Through mineralogical analysis, it is concluded that the raw material is very high in kaolinite with variable contents of quartz, illite, feldspars (potassic), an iron oxides (~5% F2O3) mainly as gel. Through firing up to 1.300°C of presssed bodies, we can observe by the X-ray study the appearance and development of new phases among which mullite stands out, together with great vitreous phase formation. The location and great potential of the deposit, as well as the good ceramic properties of this material, permit their use in the good ceramic properties of this material, permit their use in the floor and tile industry due to its iron oxide content, being possible the processing by pressing, extrusion and slip casting.[ES]: Se estudia un material arcilloso con alto contenido en caolinita, procedente del lavado de arenas graníticas de la formación de Los Pedroches (Córdoba). Se han realizado las siguientes determinaciones: análisis granulométrico, químico y mediante difracción de rayos X, estudio térmico por ATD-TG y dilatométrico, así como estudio de las propiedades cerámicas del material en probetas prensadas y cocidas durante dos horas hasta la temperatura de 1.300°C, obteniéndose los correspondientes diagramas de gresificación. El análisis mineralógico del material crudo lo señala,como altamente caolinítico, con variable contenido eh cuarzo, ilita, feldespatos (potásicos) y óxidos de hierro (~5% F2O3), en estado de gel en su mayor parte. Mediante cocción hasta 1.300°C de las probetas prensadas, el estudio mediante difracción de rayos X permite observar la aparición y desarrollo de nuevas fases, entre las que destaca la mullita, junto con abundante formación de fase vítrea. La situación y gran potencia del yacimiento, así como las buenas propiedades cerámicas de este material natural, permiten su empleo en la industria de pavimentos y revestimientos cerámicos gresificados de pasta roja dado su contenido en óxidos de hierro que preparados adecuadamente pueden modelarse por prensado, extrusión y colaje.Peer reviewe

Clinical Validation of Adjusted Corneal Power in Patients with Previous Myopic Lasik Surgery

Purpose. To validate clinically a new method for estimating the corneal power (P,) using a variable keratometric index (nkadj) in eyes with previous laser refractive surgery. Setting. University of Alicante and Medimar International Hospital (Oftalmar), Alicante, (Spain). Design. Retrospective case series. Methods. This retrospective study comprised 62 eyes of 62 patients that had undergone myopic LASIK surgery. An algorithm for the calculation of 11kadj was used for the estimation of the adjusted keratometric corneal power (Pkadj). This value was compared with the classical keratometric corneal power (Pk), the True Net Power (TNP), and the Gaussian corneal power (PcGauss). Likewise, Pkadj was compared with other previously described methods. Results. Differences between PcGauss and P, values obtained with all methods evaluated were statistically significant (p < 0.01). Differences between Pkadj and PcGauss were in the limit of clinical significance (p < 0.01, loA [ - 0.33,0.60] D). Differences between Pkadj and TNP were not statistically and clinically significant (p = 0.319, loA [- 0.50,0.44] D). Differences between Pkadj and previously described methods were statistically significant (p < 0.01), except with PcHaigisL (p = 0.09, loA [ - 0.37,0.29] D). Conclusion. The use of the adjusted keratometric index (nkadj) is a valid method to estimate the central corneal power in corneas with previous myopic laser refractive surgery, providing results comparable to PcHaigisL.This study has been funded by the Project no. GRE12-33 of the University of Alicante

Rational Design and Synthesis of Efficient Sunscreens to Boost the Solar Protection Factor

Skin cancer incidence has been increasing in the last decades, but most of the commercial formulations used as sunscreens are designed to protect only against solar erythema. Many of the active components present in sunscreens show critical weaknesses, such as low stability and toxicity. Thus, the development of more efficient components is an urgent health necessity and an attractive industrial target. We have rationally designed core moieties with increased photoprotective capacities and a new energy dissipation mechanism. Using these scaffolds, we have synthesized a series of compounds with tunable properties suitable for their use in sunscreens, and enhanced properties in terms of stability, light energy dissipation, and toxicity. Moreover, some representative compounds were included in final sunscreen formulations and a relevant solar protection factor boost was measured