"Cryptosporidium" en la desinfección solar del agua de bebida

Using a 2×3 first-order full factorial design and under simulated solar radiation and a constant temperature of 30 °C, the influence that the water turbidity (5, 100, and 300 nephelometric turbidity units NTU), the intensity of radiation (200, 600, and 900 W/m2 of global radiation, equivalent to the intensity of solar radiation in equatorial areas described for total and partly cloudy and sunny days, respectively) and exposure time (4, 8, and 12 hours) have on the survival of C. parvum oocysts during solar disinfection processes of drinking water was evaluated. Using the technique of inclusion/exclusion of the fluorogenic vital dye propidium iodide (PI), it was observed that the potential viability of oocysts ranged from a minimum of 54.0% (5 NTU, 900 W/m2, and 12 hours) and a maximum of 91.7% (200 W/m2, 4 hours, regardless of the level of turbidity). Similarly, it was found that the lowest value of oocyst infectivity (30.8%) was obtained for conditions of 5 NTU of turbidity, 900 W/m2 of radiation and 12 hours of exposure time. It was shown that the three parameters, as well as the interactions intensity of radiation-exposure time and turbidity level-intensity of radiation are statistically significant factors that affect to the potential viability and infectivity of C. parvum oocysts. The empirical equations obtained with the different evaluated parameters showed that the largest coefficient with a negative sign corresponded to the intensity of radiation. Thus, it was observed that, independently of exposure time and the turbidity level, the lowest intensity of radiation evaluated (200 W/m2) did not exert statistical significant influence on oocyst survival. By contrast, the percentage of negative PI oocysts (potentially viable) and infectivity determined in the suckling mouse model tend to decrease when water samples were exposed to a radiation level 600 W/m2. At the highest intensity of radiation (900 W/m2) evaluated, statistically significant reductions in the potential oocyst viability and infectivity for both turbidity levels and for different exposure times tested were observed. The obtained equations are valid for predicting the potential viability and infectivity of oocysts of C. parvum in the range of tested conditions

Enseñanza media

Se presenta una ponencia centrada en la importancia de colaboración entre los centros científicos, técnicos e industriales. Y que, en definitiva, corresponde a la enseñanza en los Centros Superiores la responsabilidad de conseguir estos objetivos comunes. Se desarrolla el carácter, contenido y organización de la enseñanza de la Física en las Escuelas Técnicas Superiores, los métodos de enseñanza, y los medios necesarios para conseguir un desarrollo eficaz de los métodos.Ministerio Educación CIDEBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Proyecto de Convivencia IES Sierra de San Quílez

Seleccionado en la convocatoria: Ayudas para desarrollar proyectos de convivencia, Gobierno de Aragón 2007-08El proyecto tiene como finalidad la mejora de la convivencia escolar en un centro de Educación Secundaria. Para ello se plantean varios objetivos que afectan a toda la comunidad educativa, abarcando todos los centros educativos de la localidad y los servicios sociales del Ayuntamiento. Se promueve la mejora del plan de acción tutorial, incluyendo actividades para trabajar habilidades sociales, educación de las emociones y el trabajo cooperativo. La dinamización de la asamblea de delegados y la creación de una escuela de padres, son otros de los objetivos planteados.Gobierno de Aragón. Departamento de Educación, Cultura y DeporteAragónDirección General de Política Educativa; Avda. Gómez Laguna, 25, planta 2; Zaragoza; Tel. +34976715416; Fax +34976715496ES

Thermal Contribution to the Inactivation of Cryptosporidium in Plastic Bottles during Solar Water Disinfection Procedures

To determine the thermal contribution, independent of ultraviolet radiation, on the inactivation of Cryptosporidium parvum during solar water disinfection procedures (SODIS), oocysts were exposed for 4, 8, and 12 hours to temperatures recorded in polyethylene terephthalate bottles in previous SODIS studies carried out under field conditions. Inclusion/exclusion of the fluorogenic vital dye propidium iodide, spontaneous excystation, and infectivity studies were used to determine the inactivation of oocysts. There was a significant increase in the percentage of oocysts that took up propidium iodide and in the number of oocysts that excysted spontaneously. There was also a significant decrease in the intensity of infection elicited in suckling mice at the end of all exposure times. The results of the study demonstrate the importance of temperature in the inactivation of C. parvum oocysts during application of SODIS under natural conditions