La red geodésica del volcán Popocatépetl para el monitoreo de la actividad volcánica

Uno de los métodos más utilizados para la detección temprana de cambios en el estado de actividad de un volcán, que pudieran a llegar a traducirse en un proceso eruptivo de carácter destructivo, es el método geódesicopara la medición de deformaciones de los edificios volcánicos. Aquí se describen la metodología y los resultados de las observaciones geodésicas realizadas en el volcán Popocatépetl desde principios de 1992 utilizando métodos de triangulalateración e inclinometría, y se evalúan los resultados en términos del riesgo volcánico (AU)

Cholecystokinin suppresses food intake by a nonendocrine mechanism in rats.

A cholecystokinin monoclonal antibody (CCK MAb) was used to immunoneutralize CCK to test the hypothesis that CCK produces satiety by an endocrine mechanism. We first characterized the effects of CCK MAb on pancreatic secretion. Conscious rats with jugular vein and bile-pancreatic duct cannulas received CCK MAb or control antibody intravenously 30 min before a 2-h maximal dose of CCK-8 (200 pmol.kg-1.h-1 i.v.) or access to food. CCK MAb caused dose-related inhibition of amylase secretion. CCK MAb (2 mg/kg) completely blocked the response to CCK-8 and inhibited the response to food by 89%. In feeding experiments, rats with free access to food received CCK MAb or control antibodies (2 mg/kg iv) 2 h after lights off. CCK MAb had no effect on 1.5- or 3.5-h food intake. Another group of rats received CCK MAb (4 mg/kg i.v.) or a combined injection of type A and type B CCK receptor antagonists devazepide and L-365,260 (1 mg/kg each i.v.). CCK MAb had no effect on feeding, whereas the receptor antagonists stimulated 1-, 2-, 3-, and 4-h intake by 62, 45, 43, and 29%. These results suggest that endogenous CCK stimulates pancreatic enzyme secretion at least partially by an endocrine mechanism and produces satiety by a nonendocrine mechanism.