The data of three experiments on observational learning are reported. Experiment 1 assessed the effects of modeling different contingencies between pecking a peg and food reinforcement, on acquisition of the same response in observer pigeons. Results show that the group…

Three experiments assessed the generality of the matching law in situations that differed in the number of avaliable alternatives. in different conditions reinforcement rate varied across levers according to concurren schedules with random-interval components. Barriers (70cm high) separated two, four,…

Many independent variables related te developrnent are better approached with group than single-subject methods, either because experimental manipulation would be unethical or because they are only indexes of the real causal variables. Both kinds of variables can be studied in…

Este artículo se preparó en el año 2002, en base al proyecto de un libro sobre toponímia indígena que el investigador del Instituto Nacional de Antropología e Historia (INAH), Ignacio Guzmán no pudo realizar. La doctora Lastra incluye datos tomados…

El autor de este trabajo propone que el otomí, como familia de lenguas, tiene una construcción de posesión externa que emplea codificación de dativo. Dicho fenómeno se observa en todas las variantes, confirmando que se trata de un rasgo de…

Se presenta un análisis bibliométrico de los países de Oriente Próximo a lo largo del período 1998-2007, centrando el análisis en tres aspectos principales (producción, áreas temáticas y colaboración científica), por medio de Web of Science (WoS) y Scopus. Los…

Considero como lenguas atzincas a las lenguas pertenecientes a la rama otomiana sureña de la familia lingüística otopame (Bartholomew 1994). Dentro de esta rama ubico a las lenguas registradas o mencionadas con los nombres “matlatzinca” y “ocuilteco” en la época…

In this article, the PARES information search and retrieval system is evaluated. PARES is a shared platform that integrates eleven national archival databases. A series of parameters have been posited to assess its adequacy and/or degree of excellence. We have…

Schools are increasingly concerned about the possibility of a student being abducted, or picked up by someone against the wish of his tutor. However, most products and services off ered as part of school security systems do not even address…

In this paper we present the regional climate change scenarios that were used for the assessment of the potential impacts in México on agriculture, livestock, forestry, hydrological resources as well as on human settlements and biodiversity. Those studies were developed…