2,886 research outputs found
Utilización de textos y gráficos en la enseñanza asistida por ordenador
Se realiza un análisis de los aspectos que rigen la utilización de textos, gráficos y animaciones en el desarrollo de materiales didácticos orientados a la Enseñanza Asistida por Ordenador, con el objetivo de obtener mayor eficiencia y calidad en la confección de lecciones. Se destaca la importancia de la imagen y el texto durante el proceso de aprendizaje y se analiza la posibilidad de combinar el ordenador con sistemas electrónicos que aumentan su potencialidad y constituyen nuevas vías de interacción con el estudiante
Utilización de textos y gráficos en la Enseñanza Asistida por Ordenador
Se realiza un análisis de los aspectos que rigen la utilización de textos, gráficos y animaciones en el desarrollo de materiales didácticos orientados a la Enseñanza Asistida por Ordenador, con el objetivo de obtener mayor eficiencia y calidad en la conf
Reflexiones sobre el derecho laboral en el siglo XXI
El derecho del trabajo, por su contenido social, depende en gran medida de las variaciones que en cada tiempo y lugar se produzcan en el contexto económico, político, tecnológico o social. Por tal motivo, debe mantenerse en sus expresiones normativas una especial disponibilidad para ajustarse a esas variaciones y permitir que las relaciones laborales resulten concordantes con la realidad de cada momento. El derecho laboral debe ser dúctil y esto en gran medida se logra por medio de la expresión de los estamentos gubernamentales para introducir en las normas, la Constitución, las leyes y los decretos figuras nuevas que representen la respuesta a los cambios sociales.Dentro de ese contexto, y ante la rigidez que en aspectos laborales se incluyó en la Constitución de 1991, se han venido presentando estudios con el fin de explicar la importancia de dar flexibilidad a lo mismo dentro del objetivo de procurar un mayor estímulo a la creación de empleo, ante la convicción de ser la insuficiencia en las fuentes de trabajo posiblemente el mayor obstáculo para lograr el ideal de un mejoramiento general en las condiciones de vida de las personas
Conceptual Maps: A Resource for the Supported Learning in Technologies
Se describen las características fundamentales de los mapas conceptuales, se resalta su
importancia como instrumento para la organización y sistematización de ideas y
conocimientos y se ofrecen propuestas para su elaboración, especialmente
vinculándolos al diseño y producción de materiales didácticos que sirvan de apoyo a
diferentes modalidades de aprendizaje apoyadas en las tecnologías de la información y
la comunicación.This paper describes the fundamental characteristics of conceptual maps, highlights its
importance as an instrument for organization and sistematization of ideas and
knowledge, and makes proposals for its construction, specially in connection with the
design and production of educational stuff aimed at several information-technology
supported learning modalities
Wind–structure interaction on construction stages for unbalanced segmental brigdes
Behavior due to wind–structure interaction of segmental bridges on construction
stages is presented. The paper deals with the analysis of the bridge “Viaducto km 61+000”
located near the city of Xalapa, in the state of Veracruz, Mexico. This 470 m long bridge with
17.9 m wide cast in place box girder will carry four lanes of traffic over a deep valley, with
piers height from 26 m to 113 m. The superstructure consists of two central spans of 145 m
long and two approach spans of 90 m long. The roadway geometry has vertical and horizontal
curvatures along the entire length of the bridge. The substructure consists of cast–in–place
rectangular hollow piers on bored pile foundations and spread footings. The superstructure is
erected by the unbalanced cantilever method using form travelers. Computational fluid
dynamics based on the finite element method is used to simulate wind forces acting on the
structure, which are coupled to computational structure dynamics on construction stages.
Thus, a stabilized fluid flow formulation is presented together with an ALE scheme while
geometrically non–linear solid dynamics finite elements are used to simulate the bridge
behavior. Both solutions are coupled together using a strong coupling technique to perform an
aeroelastic analysis of the bridge. Differences obtained among numerical approach and code
requirements are presented
Differential antifungal activity of human and cryptococcal melanins with structural discrepancies
Indexación: Scopus.Melanin is a pigment found in all biological kingdoms, and plays a key role in protection against ultraviolet radiation, oxidizing agents, and ionizing radiation damage. Melanin exerts an antimicrobial activity against bacteria, fungi, and parasites. We demonstrated an antifungal activity of synthetic and human melanin against Candida sp. The members of the Cryptococcus neoformans and C. gattii species complexes are capsulated yeasts, which cause cryptococcosis. For both species melanin is an important virulence factor. To evaluate if cryptococcal and human melanins have antifungal activity against Cryptococcus species they both were assayed for their antifungal properties and physico-chemical characters. Melanin extracts from human hair and different strains of C. neoformans (n = 4) and C. gattii (n = 4) were investigated. The following minimum inhibitory concentrations were found for different melanins against C. neoformans and C. gattii were (average/range): 13.7/(7.8-15.6) and 19.5/(15.6-31.2) μg/mL, respectively, for human melanin; 273.4/(125- > 500) and 367.2/(125.5- > 500) μg/mL for C. neoformans melanin and 125/(62.5-250) and 156.2/(62-250) μg/mL for C. gattii melanin. Using Scanning Electron Microscopy we observed that human melanin showed a compact conformation and cryptococcal melanins exposed an amorphous conformation. Infrared spectroscopy (FTIR) showed some differences in the signals related to C-C bonds of the aromatic ring of the melanin monomers. High Performance Liquid Chromatography established differences in the chromatograms of fungal melanins extracts in comparison with human and synthetic melanin, particularly in the retention time of the main compound of fungal melanin extracts and also in the presence of minor unknown compounds. On the other hand, MALDI-TOF-MS analysis showed slight differences in the spectra, specifically the presence of a minor intensity ion in synthetic and human melanin, as well as in some fungal melanin extracts. We conclude that human melanin is more active than the two fungal melanins against Cryptococcus. Although some physico-chemical differences were found, they do not explain the differences in the antifungal activity against Cryptococcus of human and cryptococcal melanins. More detailed studies on the structure should be considered to associate structure and antifungal activity.https://www.frontiersin.org/articles/10.3389/fmicb.2017.01292/ful
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