OBJECTIVE: Evaluate the relationships between AgNORs polymorphisms and squamous intraepithelial lesions (SIL) and squamous cell carcinoma (SCC) with HPV infection. MATERIALS AND METHODS: A study was carried out on sixty women from the state of Guerrero, Mexico. HPV detection was…

OBJECTIVE: To quantify the physical activity (PA) of students and describe the school environment surrounding PA. MATERIAL AND METHODS: Between November 2005 and March 2006, in Mexico City, we conducted quantitative and qualitative observations to describe the PA and the…

Sixty species of calcareous nannoplankton from the Tepetate formation were recovered from a drill hole near Las Pocitas, Baja California Sur. In spite of its low abundance and erratic distribution throughout the sedimentary column, the great amount of reworked species,…

A suite of mafic dikes intrudes polydeformed, greenschist facies, metapsammites and metapelites of the Salada unit in the eastern part of the Acatlán Complex, southern Mexico. The age of the dikes is constrained by the youngest detrital zircon in the…

The Chiapas Massif, located in the southwestern Maya terrane, is primarily composed of igneous and metaigneous rocks of Late Permian - early Triassic age, although two distinct metasedimentary units have also been recognized. The Sepultura Unit, located in the nothwestern…

A taxonomic checklist for fish larvae and juveniles occurring at Yalahau (June 2001-May 2002), Celestún (July 1994-June 1995), Chelem (July 1999-June 2000) and Río Lagartos (November 1996- October 1997) lagoons located in the northern part of the Yucatán Peninsula is…

Given the seasonal nature of ecosystems such as permanent sinkholes ('cenotes') and temporary wetlands, their fish fauna experience yearly local extinction and colonization processes, with strong fluctuations in population size. We evaluated the genetic diversity, population genetic structure and degree…

Chromium is a commonly identified contaminant in soils and groundwater and is widely used in industries. Disposal of industrial solid wastes can cause health and environmental risks due to the leaching and seepage of Cr(VI) from soil to groundwater. In…

A detailed regional grid of 97 surficial sediment samples is studied for the San Quintín coastal lagoon, which is a shallow embayment located adjacent to a "regionally-rare" intraplate-type basaltic terrain known as San Quintín volcanic field. The influence that this…

The Sierra Madre del Sur, a Mesozoic-Cenozoic magmatic arc in southern Mexico, was studied using U-Pb zircon geochronology. Undeformed to slightly deformed plutons from two transects were sampled at the limit between the Guerrero and Xolapa terranes, in order to…