Waterborne diseases in the state of Mexico, Mexico (2000-2005).

This paper reports a spatial-temporal examination of waterborne disease data from the State of Mexico, 2000 to 2005, by county as the spatial unit. It was found that the incidence of waterborne disease did not decrease during the period under study. Inequality between metropolitan areas and rural zones was observed. People living in population centres had lower incidence of water-related diseases, possibly due to better access to services. In all cases, children under five years old suffered a much higher relative morbidity than the population in general. Improvement of the water distribution network between 2000 and 2005 could explain the decrease in morbidity from 30% to 15%, for the total population, and from 34% to 18.5%, for children under five years old. Coverage of sewer services over the period was not substantially improved; as a result the coefficient of determination remained nearly constant: 16.5% for the total population and 25% for children under five. Maintenance and operation deficiencies in the water distribution and wastewater sanitation systems play an important role in the incidence of this type of disease. It was found that the institutional division of the territory does not correspond to the actual distribution of the risk areas.

A maize insulin-like growth factor signals to a transduction pathway that regulates protein synthesis in maize.

Insulin and insulin-like growth factors (IGFs) are well-characterized regulators in higher eukaryotic cells that control biological processes such as cell growth and survival, and selective translation of mRNAs. This research presents the purification of a 20 kDa protein, isolated from maize tissue, with IGF activity. The protein was purified from 48 h-germinated maize embryonic axes by G-50 Sephadex fractionation followed by affinity chromatography through a bovine insulin antibody-Sepharose column. This protein proved to significantly speed up maize germination and seedling growth. At the molecular level, Zea mays IGF (ZmIGF) enhanced phosphorylation of S6 ribosomal protein (rp) on the 40 S ribosomal subunit, in a similar way as observed when bovine insulin is applied to maize axes during germination. Rapamycin, a specific inhibitor of the insulin-stimulated signal transduction pathway, prevented S6 rp phosphorylation in maize axes. Moreover, ZmIGF stimulated [(35)S]methionine incorporation into rps, above the level of overall cytoplasmic proteins. Either incubation with anti-insulin antibody, heat treatment (60 degrees C) or trypsin digestion abolished this ZmIGF effect. It is proposed that ZmIGF is an endogenous maize growth factor that regulates the synthesis of specific proteins through a pathway similar to that of insulin or IGFs in animal tissues.