and (ii) the derived state of the breeding (rather than winter) ecological niches of each species., The evolution of migration has long been considered complex and recent work has demonstrated additional complexity: some species follow the same ecological conditions throughout…

Based on traditional medicinal knowledge, it was possible to identify the plant species Solanum chrysotrichum as the source of a new antimycotic agent designated SC-1. Cell suspension batch cultures from this plant were established in shake flasks, in which the…

Although tropical deciduous forest (TDF) is the most widespread tropical forest in Mexico, knowledge on its regeneration
and restoration ecology is still scarce. Here, we compare the diversity of TDF trees and shrubs having published
propagation protocols with the total…

The Upper Cenozoic flora of the Pie de Vaca Formation, Puebla, Mexico, is yielding important elements that contribute to a more complete knowledge of the Tertiary floras of southern latitudes of North America. Among the most abundant plant organs in…

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…

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…

The incorporation of ethnopedological knowledge in soil science and the inclusion of indigenous communities as beneficiaries of the agricultural technology are indispensable premises to make a better use of soil. However, to achieve this, it is necessary to have clearer…

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…