Cómo motivar a los estudiantes de secundaria mediante actividades de ciencias atractivas y divertidas

Se presenta una propuesta de formación del profesorado llevada a cabo durante dos cursos académicos (2006/08) con la finalidad de mejorar la motivación e interés de los estudiantes hacia el aprendizaje de las ciencias. Se diseñó e implementó un curso desde la perspectiva de una ciencia comprometida, pero también amena, creativa y divertida, incluyendo actividades interactivas realizadas en colaboración con el Museo de Ciencias Príncipe Felipe, experimentos de laboratorio, textos divulgativos con enfoques CTSA (Ciencia-Tecnología-Sociedad-Ambiente), juguetes científicos, así como el aporte de experiencias provenientes de otros países europeos (Alemania, Francia y Reino Unido). Esta iniciativa, en la que han participado 80 profesores ha sido un instrumento eficaz tanto para la mejora de la motivación como para promover la formación de comunidades de práctica

Multi-transmission-line-beam interactive system

We construct here a Lagrangian field formulation for a system consisting of an electron beam interacting with a slow-wave structure modeled by a possibly non-uniform multiple transmission line (MTL). In the case of a single line we recover the linear model of a traveling wave tube (TWT) due to J.R. Pierce. Since a properly chosen MTL can approximate a real waveguide structure with any desired accuracy, the proposed model can be used in particular for design optimization. Furthermore, the Lagrangian formulation provides for: (i) a clear identification of the mathematical source of amplification, (ii) exact expressions for the conserved energy and its flux distributions obtained from the Noether theorem. In the case of uniform MTLs we carry out an exhaustive analysis of eigenmodes and find sharp conditions on the parameters of the system to provide for amplifying regimes

Unravelling the nature of HD 81032 - a new RS CVn Binary

BVR photometric and quasi-simultaneous optical spectroscopic observations of the star HD 81032 have been carried out during the years 2000 - 2004. A photometric period of $18.802 \pm 0.07$ d has been detected for this star. A large group of spots with a migration period of $7.43 \pm 0.07$ years is inferred from the first three years of the data. H$\alpha$ and Ca II H and K emissions from the star indicate high chromospheric activity. The available photometry in the BVRIJHK bands is consistent with spectral type of K0 IV previously found for this star. We have also examined the spectral energy distribution of HD 81032 for the presence of an infrared colour excess using the 2MASS JHK and IRAS photometry, but found no significant excess in any band abovethe normal values expected for a star with this spectral type. We have also analyzed the X-ray emission properties of this star using data obtained by the ROSAT X-ray observatory during its All-Sky Survey phase. An X-ray flare of about 12 hours duration was detected during the two days of X-ray coverage obtained for this star. Its X-ray spectrum, while only containing 345 counts, is inconsistent with a single-temperature component solar-abundance coronal plasma model, but implies either the presence of two or more plasma components, non-solar abundances, or a combination of both of these properties. All of the above properties of HD 81032 suggest that it is a newly identified, evolved RS CVn binary.Comment: 18 pages, 10 figures, 3 tables, Accepted for the publication in JAp

CycSim—an online tool for exploring and experimenting with genome-scale metabolic models

Summary: CycSim is a web application dedicated to in silico experiments with genome-scale metabolic models coupled to the exploration of knowledge from BioCyc and KEGG. Specifically, CycSim supports the design of knockout experiments: simulation of growth phenotypes of single or multiple gene deletions mutants on specified media, comparison of these predictions with experimental phenotypes and direct visualization of both on metabolic maps. The web interface is designed for simplicity, putting constraint-based modelling techniques within easier reach of biologists. CycSim also functions as an online repository of genome-scale metabolic models

Cómo motivar a los estudiantes de secundaria mediante actividades de ciencias atractivas y divertidas

Se presenta una propuesta de formación del profesorado llevada a cabo durante dos cursos académicos (2006/08) con la finalidad de mejorar la motivación e interés de los estudiantes hacia el aprendizaje de las ciencias. Se diseñó e implementó un curso desde la perspectiva de una ciencia comprometida, pero también amena, creativa y divertida, incluyendo actividades interactivas realizadas en colaboración con el Museo de Ciencias Príncipe Felipe, experimentos de laboratorio, textos divulgativos con enfoques CTSA (Ciencia-Tecnología-Sociedad-Ambiente), juguetes científicos, así como el aporte de experiencias provenientes de otros países europeos (Alemania, Francia y Reino Unido). Esta iniciativa, en la que han participado 80 profesores ha sido un instrumento eficaz tanto para la mejora de la motivación como para promover la formación de comunidades de práctica

Associations between Active Trachoma and Community Intervention with Antibiotics, Facial Cleanliness, and Environmental Improvement (A,F,E)

Trachoma is an infectious disease that is cased by a bacterium, Chlamydia trachomatis, and is the leading cause of preventable blindness estimated to be responsible for 3.6% of blindness globally. The World Health Organization (WHO) recommends a strategy for trachoma control known as SAFE—surgery, antibiotics, facial cleanliness, and environmental improvement. Regular evaluations of trachoma control activities are advocated for by the WHO for decision making, programme planning, and the rational use of programme resources. We undertook a survey to evaluate the effectiveness of the SAFE strategy following three years of interventions in four districts in Southern Sudan. In this paper, we aimed to find out the relationship between the antibiotics, facial cleanliness, and environmental improvement (A,F,E) and active trachoma signs. Our study revealed that prevalence of active trachoma was less in children who had received treatment with azithromycin, had clean faces, had faces washed more frequently, and used latrines compared to children who had not received these interventions. The study findings are important since they make the case for implementing the A,F,E interventions together