Significant changes in the isotopic composition of groundwater in the upper catchment of Rio Guanajuato, Mexico, were detected in two independent sets of samples for 3 % of the 1600 high-production wells in the area. Sampling was done in December…

In this paper we report the oldest geologic world record of Ptychodus mortoni, from the Vallecillo Member (Agua Nueva Formation), at Vallecillo, Nuevo León, northeastern Mexico. The presence of the ammonite Watinoceras coloradoense, allows the placement of the sediments of…

A complete description of Vallecillichthys multivertebratum Blanco and Cavin, 2003, is provided. This ichthyodectiform fish was collected in the Vallecillo Member of the Agua Nueva Formation (Upper Cretaceous: lower Turonian) at Vallecillo, Nuevo León State, northeastern Mexico. On the basis…

A new unusual Uropodina mite (Uroobovella vazquezae sp. nov.) is found in the tropical part of Mexico. The new species is easy to separate from the other known Uroobovella species on the basis of the cavities on dorsal and ventral…

A new species, Hypoxis colliculata from Oaxaca and Chiapas, México is presented here. It belongs to the group with black seeds and is separated from the other species by the colliculate sculpturing of the seeds.

Monstera florescanoana (Araceae), a new species in section Monstera, endemic to central Veracruz, Mexico, is described and illustrated. This species appears to be most closely related to Monstera siltepecana Matuda and Monstera dubia (Kunth) Engl. et K. Krause.

Identification keys, diagnoses, hosts, and distribution data are provided for adults of the 26 species of Ixodes known from Mexico. Data are from specimens deposited in the Colección Nacional de Ácaros (CNAC), Instituto de Biología, Universidad Nacional Autónoma de México,…

Copidaster cavernicola n. sp. is described from an anchialine cave system in Cozumel, Mexico. Copidaster cavernicola differs from its congeners in having 1-8 papulae in each papular area, and numerous excavate pedicellariae on all surfaces, except between furrow spines and…

The objective of this paper is to present a model to design effective Production Improvement Programs (PIP) in order to contribute in the solution of the problematic situations generally faced by the Mexican manufacturing micro, small and medium-sized enterprises (M-SME).…

The association between gastrointestinal H. pylori infection and thrombocytopenia was studied in a single institution in Mexico, over a 5-year period. In 99 individuals with H. pylori infection, the prevalence of thrombocytopenia was 14%, whereas in 23 consecutive patients with…