This paper presents a version of frames suitable for representing knowledge for a class of reconition problems. An initial section gives an intuitive model of frames, and illustrates a number of desirable features of such a representation. A more technical…

Over the next five years, computer games will find their way into a vast number of American homes, creating a unique educational opportunity: the development of "computer coaches" for the serious intellectual skills required by some of these games. From…

Web-based learning environments are becoming increasingly popular in higher education. One of the most important web-learning resources is the virtual laboratory (VL), which gives students an easy way for training and learning through the Internet. Moreover, on-line collaborative communication represents…

En el cerebro de mamíferos adultos tiene lugar la formación de nuevas neuronas (neurogénesis) de forma limitada a partir de células madre neurales residentes en dos nichos discretos, localizados en el ventrículo lateral y el hipocampo. En la retina existe…

While birdsong is a model system for animal communication studies, our knowledge is derived primarily from the study of only one sex and is therefore incomplete. The study of song in a role-reversed species would provide a unique opportunity to…

Studies of tropical secondary forest succession face strong limitations due to the slow pace of succession and the time-consuming task of monitoring processes. The occurrence of tree rings in secondary forest trees may help expand our knowledge on succession in…

Se realizó un estudio piloto para evaluar la aceptación y efectividad de dos materiales educativos (Cartilla y Fotocartel), elaborados a partir del conocimiento tradicional que poseen las comunidades seleccionadas en tres humedales llaneros, con el propósito de propiciar cambios en…

Originalmente escrito en inglés, el articulo trata de subrayar una transición en la
actitud y pensamiento de A. O. Hirschman para referirse a la problemática del desarrollo construida en América Latina del mismo modo en que la reciente literatura
anglosajona…

Defining qualified reasoning as reasoning containing such loose qualifying words as 'probably,' 'usually,' 'probable, 'likely,' 'ceteris paribus,' and 'primafacie, Ennis argues that typical cases of qualified reasoning, though they might be good arguments, are deductively invalid, implying that such arguments…

Natural history collections are the authoritative source of knowledge about the identity, evolutionary relationships, and attributes of species with which we share this planet. As such, collections of research specimens play a central and critical role in the conservation and…