Dinámica del heleoplancton en relación a las fluctuaciones hidrológicas en aiguamolls de l’Empordà (NE de la península Ibérica). Propuesta de un método sencillo de monitorización basado en la abundancia de grupos taxonómicos

Monitoring of the 'ecological water quality' in 'Aiguamolls de l’Empordà' Natural Park was carried out between September 1996 and August 1997 . The aim of this sampling programme was to design a simple method for rapid detect changes in water quality due to human activity. These include flow regulation by the Park management, nutrient entries from effluents of a nearby wastewater treatment plant or agricultural fertilising. The proposed method is based on the analysis of the abundance of characteristic taxonomic groups of aquatic invertebrates (heleoplankton). The simplicity of the method is ensured by the use of large taxa which are easier to recognise than species. The functioning of aquatic systems has been modelled by means of correspondence analysis between samples and taxa. Results can be summerized in five environmental conditions with a regular community structure. Dominated by one taxon: cladocerans, ostracods, calanoids, cyclopoids and harpacticoids. The dynamics of both freshwater and brackish lagoons can be modelled as displacements between these five groups of environmental conditions. Nevertheless, the “calanoids situation” and the “harpacticoids situation” occur mainly in brackish lagoons, whereas the “cladocerans situation” occurs mainly in freshwater. The four principal axes of data variation have been respectively identified as nutrient turnover rate, hypertrophy, degree of mineralization of the organic matter and eutrophy. The use of these taxa has been validated by comparison with a model obtained from the species. We conclude that in a highly fluctuating system such as the one here, only persistent situations of eutrophy or hypertrophy must be equated to low 'ecological water quality'

Lectores de Saavedra Fajardo en la Alemania ilustrada: Leipzig y la traducción alemana de 'Locuras de Europa'

Se analiza la recepción de Diego de Saavedra Fajardo en la Alemania ilustrada del siglo XVIII, donde se imprimieron y tradujeron algunas obras de este autor. A través del análisis del prólogo que precede la edición alemana de Locuras de Europa, conoceremos el universo editorial que impulsó su aparición en Leipzig y la conyuntura histórico-política que lo propició

Escritura joven en la red = Young writing online

Changes in written communications brought about by technology have led to a revolution in the concepts of literacy and, as a result, in students’ educational needs. However, teenagers appear to use technologies that involve new channels and text genres in the digital environment much more than in their everyday life than in an academic environment, because there is still too much distance between what schools offer students and their own reality. This article shows part of the findings of ethnographic and qualitative research in the line of new studies on teenagers’ critical literacy and vernacular writing practices in the asynchronous communication spaces online. The idea is to offer data and ideas to help overcome the current inertia and distance between some educational activities and young people’s communicative needs

¿Para qué sirven los problemas en la clase de matemáticas? = What is the use of problems in Mathematics lessons?

The results obtained in several yield tests, at an international level (mainly the famous PISA 2003 report, by the OCDE), have raised a multiplicity of performances in order to improve the students' yield regarding problem solving. In this article we set a clear guideline on how problems should be used in Mathematics lessons, not for obtaining better scores in the yield tests but for improving the development of Mathematical thinking in students. From this perspective, the author analyses, through eight reflections, how the concept of problem, transmitted both in the school and from society, influences the students