Conversación con Marta Astier sobre agricultura ecológica

Introducción Laura Pérez E, directora de Perspectivas rurales, mantuvo el siguiente dialogo, por correo electrónico con Marta Astier, agroecóloga española con residencia en México, donde finaliza su Doctorado en Ciencias Biológicas en el Área de Ecología.

La función social de la pesca artesanal costera: el caso de Barra de Colorado

PresentaciónEn 1993, la Escuela de Ciencias Biológicas de la Universidad Nacional inició una investigación en la región de las Llanuras del Tortuguero, provincia de Limón, Costa Rica, con el fin social, económico y ambiental de profundizar en el conocimiento de las interacciones presentes en una zona donde los conflictos en torno al uso y la explotación de los recursos naturales han venido en aumento en los últimos años...

Construction of the Cognitive Dimension of the Scientific Literacy in the Students through the Costa Rican Biological Sciences Olympics

This research recognizes the cognitive contributions to the students participating in the Third Costa Rican Biological Sciences Olympics that will define the advancement and strengthening in the construction of its conceptual dimension in the scientific literacy.  This paper is based, mainly, on qualitative approach techniques (ethnographic design:  case study); however, some data are interpreted through quantitative methodologies (descriptive design with an explanatory and exploratory touch) for the analysis of a sample of 54 high school students, finalists in the category A of the Olympics, through the use of tools such as a documentary study and a survey, in July 2009.  The information generated was analyzed using elements of inferential and descriptive statistics, figures and histograms.  It was proved that there is a better cognitive management in the topics assessed, an increase in the students’ academic performance as the tests are applied, a commitment for the academic update supported by the development of several tasks for previous preparation, curriculum contributions unprecedented based on our sample, a consent to optimize student’s knowledge about Biology, which will allow the application of scientific notions to diversify and renew the knowledge, according to what is established in the principles of scientific literacy.

Caracterización molecular por patrones electroforéticos de isoenzimas esterasas en Lemna aequinoctialis y Lemna valdiviana (lemnaceae) de Costa Rica (ING)

The Lemnaceae family lacks morphologic and anatomical characteristics with comparative aims and for that reason the molecular studies has been necessary a differentiation. In Costa Rica there are two species of Lemna: Lemna aequinoctialis and Lemna valdiviana. With the objective of a molecular characterization and differentiation of both species were extracted isoenzymes esterases. The study was carried out in the Molecular Genetics Laboratory of the School of Biological Sciences at Universidad Nacional, Heredia, Costa Rica. The technical electrophoresis in gel of polyacrylamida SDS-PAGE was used. It was difference in the pattern of isoenzymes between both species. According to previous molecular studies based on morphology and anatomy, flavonoides, isoenzymes, and DNA sequences of certain genes both species are very different; in addition they belong to different monophyletics groups. On the other hand, the importance of this molecular characterization is its possible use in water treatment, because the esterases have had important in the bioremediation. Also, species of the Lemnaceae family are used in the water treatment like bioremediation.