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,…

The preferred temperature (PT) of Poecilia sphenops (Pisces, Poeciliidae) (n = 240, 1.13 +/- 0.06 g wet weight, 3.26 +/- 0.88 cm standard length) from Presa Piedra Azul, Oaxaca, Mexico, was measured at acclimation temperature of 20 degreesC, 23 degreesC,…

Diabetes mellitus is a syndrome which affects more and more people in all countries over the world. In Mexico, it is commonly treated with herbal extracts. Such treatment may be of considerable benefit especially during the early stages of the…

Traditional mycological knowledge of most Mexican ethnic groups has proven to be extensive and profound, consuming nearly 300 species of wild mushrooms. In this paper, we identified the mushrooms used by Zapotecs of Ixtlan, Oaxaca, compiled their traditional knowledge and…

The main goal of this study is to document the biogeographical patterns, current status and conservation of 24 species of vascular plants in Mexico, all of them recorded in some risk category in the Mexican official publication named 'Norma Oficial…

Early in the twentieth century it was shown that Mendel's laws apply to plants and animals and that genes reside on chromosomes. In the 1950s the double-helix model of DNA inaugurated the molecular biology era, which culminated at the end…

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…

While biologists have been aware of the existence of native Mexican trouts for over a century, they have received little study. The few early studies that did muchmore than mention their existence began in the 1930s and continued into the…

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…