La Matemática Moderna en el Bachillerato.

Reflexión acerca de la introducción de la Matemática moderna en el Bachillerato. Esta preocupación se ha manifestado en diversos países, y en muchos Centros de España y del extranjero se han hecho importantes ensayos individuales que han servido de base de discusión, para un ulterior plan que deberá extenderse algún día a toda la Enseñanza Media. Puesto que la Matemática moderna se ha introducido de modo definitivo en la enseñanza universitaria, está fuera de duda que la enseñanza media debe dejar al alumno en condiciones de que al llegar a la Universidad o a las Escuelas Superiores se encuentre con un tipo de matemática que no ofrezca graves discontinuidades con lo que ha estudiado anteriormente. Una primera cuestión a resolver es la determinación de la edad en que el alumno de Bachillerato debe entrar en contacto con esta nueva matemática. Diversos organismos han estado de acuerdo en que debe retrasarse hasta los catorce o quince años; lo que en España corresponde a la etapa del Bachillerato superior. Sin embargo, no debemos olvidar que la Matemática no puede contentarse can ser un sistema lógico-deductivo. Para el futuro técnico, o científico no matemático, o profesional de cualquier rama que es el estudiante de Bachillerato, la Matemática es ante todo una representación de la realidad. En cuanto a los contenidos matemáticos que se tocan destaca: la teoría de conjuntos, las relaciones de equivalencia y por último los números racionales.

Seed and seedling surface-sterilization for in vitro culture of tillandsia gardneri (Bromeliaceae)

Tillandsia gardneri is a bromeliad with ornamental value and a wide geographical distribution over Brazil. However, due to habitat loss and illegal overcollection in the wild it is included as a vulnerable species in the official list of endangered plants of the State of Rio Grande do Sul, Brazil. The development of a protocol for T. gardneri seed propagation in vitro may be useful for reintroducing plants in their natural habitats, and for germplasm conservation. A difficult problem encountered during the establishment of an in vitro culture is explants disinfection, especially when working with endangered species, from which explant availability is restricted. Thus, the establishment of a sterilization protocol is crucial for the initiation and success of a micropropagation system for T. gardneri. The objective of this study was to evaluate the effect of sodium hypochlorite concentration and exposure time in seed and seedling surface disinfection, tissue sensitivity and development. Sodium hypochlorite solutions (10 or 20%/5, 10 or 15 min; 25%/5 or 10 min; and 50%/5 min) were effective in eliminating seed superficial contaminants. There was no significant difference among the effective sterilization treatments in relation to seed germination (%), and seedling length and number of leaves, after 120 days in vitro. Also, no damage to seed and seedling tissues were observed. Surface sterilization of seedlings, for initiation of an in vitro culture, required higher concentrations of sodium hypochlorite (25%/15 min; 20 or 50%/5, 10 or 15 min; and 40%/5 and 10 min) for controlling fungal and yeast contamination, compared to seed sterilization. No significant differences among these treatments were found in relation to seedling length and number of leaves, after 60 days in vitro.

Belonging to a „Billion Strong Global Religion“: Hinduism Today, Hindu Communities and conversion to Hinduism in the Śaiva Siddhānta Church

The Śaiva Siddhānta Church (ŚSC), based in Kauai HI, USA, has been holding rites of conversion to Hinduism since the 1960s. These rites include studying one’s “former” religion, officially declaring severance from it in the presence of a minister or mentor, choosing and officially adopting a new Hindu name as well as aligning with “the Hindu community”. Starting from here, this paper will address the question of community with respect to (1) the meanings of the term, (2) the idea of Hinduism as “a global religion” upheld by numerous “communities” worldwide and (3) the relevance of “community” in the conversion process. For doing so, I will draw on source material published by the Himalayan Academy, a branch of the ŚSC, in the global magazine Hinduism Today, in book publications and on their various websites.