This work is part of the results of the research of the Laboratory of Invertebrates of the Facultad de Ciencias UNAM, partially financed by the Comision Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO) developing during 2006-2007. The…

Palm leaves are an important resource for family households. The effect of harvest on leaf production, growth and fecundity of wild individual palm trees has been studied, but little is known about palm harvest in agro-forestry systems. In the Maya…

These notes contain a series of ten lectures delivered at the ''Universidad Nacional Autonoma de Mexico'' on its ''Primer Seminario de K-Teoria Algebraica''. They provide an introduction to the subject as well as to the other expositions in this volume.…

dentification of groups that are similar in their floristic composition and structure (habitat types) is essential for conservation and forest managers to allocate high priority areas and to designate areas for reserves, refuges, and other protected areas. In this study,…

Evaluation of public programming currently tends toward plans that are set in advance of any sampling and adhered to throughout. Because increments in the knowledge profile during the course of an evaluation might beckon adjustment of the working procedure, fixed…

A new terrestrial species of Pseudoeurycea is described from the mountains of the Mixteca region of Oaxaca. Compared with other members of the genus, the new species is relatively slender and short-legged. The background color of the dorsum of this…

Although our biological knowledge regarding cactus species is thorough in many areas, only in recent years have ecologists addressed their demographic behavior. Here we attempt a first review of the present knowledge on cactus demography, including an analysis of the…

Este artículo presenta el resultado del estudio de un amplio conjunto
de bases de conocimiento multilíngües actualmente disponibles que pueden ser de
interés para un gran número de tareas de procesamiento semántico a gran escala. El
estudio incluye una amplia…

A new tertiary stibine and bismuthine containing C-heterocyclic selenophene ring have been synthesized. Tris(2-selenophenyl)stibine (1) and tris(2-selenophenyl) bismuthine (2) and characterized by IR, MS, H-1, C-13, COSY, HETCOR NMR spectroscopy. Crystal structures of stibine and bismuthine have been determined. In…

In various species of crayfish it has been proposed that different extra-retinal photoreceptors and pacemakers could be involved in the photo entrainment mechanisms. The identity of the neural structures responsible for this phenomenon is not known. The objective of this…