Cuando hay que pagar, a veces lo urgente puede esperar

Los precios, en términos de unidades monetarias o de tiempo, influyen poderosamente en nuestras decisiones de consumo e inversión. Una situación en la que tiene especial interés observar la influencia de los precios en el comportamiento de los individuos es cuando éstos están asegurados contra los riesgos financieros de sus acciones. Una vez asegurado, a cambio de una prima o cotización o impuesto, el precio en el punto de consumo pasa a ser cero y el individuo no tiene ningún incentivo para evitar negligencias o frenar su consumo, más allá de las molestias o contrariedades que se deriven del propio consumo. A este comportamiento, lógico y esperable, los economistas lo llamamos "riesgo moral"1. El gran problema del riesgo moral es que para el asegurador es difícil dilucidar hasta qué punto ese mayor gasto es fruto de una conducta poco responsable o realmente se debe a una contingencia fortuita cuya cobertura es precisamente el objeto del seguro.

Perspectives for the Spanish Intervention in Macao in the 19th Century

The purpose of this paper is to analyse some essential events concerning the relationship between Spain and Macao in the middle of the 19th century. Macao remained as a privileged spot for the commercial activities of Spain in China after the opening of the international ports agreed upon in the Treaty of Nanjing in 1842. This encouraged Spanish diplomatic representatives to render special attention to the Portuguese enclave. This became the origin of a shocking proposal for the military conquest of Macao and its surrounding territories by one of these representatives, Sinibaldo de Mas. Although this proposal was never taken under consideration, it helps us to better understand the role Macao played in Spanish strategies in China. Years later, Mas participated as a mediator when the Chinese government attempted to regain sovereignty over Macao by paying an economic compensation to Portugal. The involvement of Sinibaldo de Mas in this project has a strong symbolic meaning, making him a key agent in the relations between Spain and Macao in the 19th century.

Determination of ambroxol in syrups using diffuse reflectance spectroscopy

This paper reports an analytical method for the determination of ambroxol in micellar medium by spot test-diffuse reflectance spectroscopy. The reflectance measurements were performed analyzing the colored compound (λ= 520 nm) produced from the reaction between ambroxol and p-dimethylaminocinnamaldehyde on the surface filter paper. The linear range was from 1.21 × 10"3 to 9.65 × 10"3 mol L-1 (500 - 4000 μg mL-1). The limit of detection and quantification were 3.50 x 10-4 mol L-1 (145 μg mL-1) and 1.16 x 10-3 mol L-1 (481 μg mL-1), respectively. Five commercial samples were analysed and the results obtained by the proposed method were in good agreement with those obtained by the literature method at 95% confidence level.

Photometric procedure for quantitative analysis of Aflatoxin B1 in peanuts by thin-layer chromatography using charge coupled device detector

A photometric procedure was developed for determination of aflatoxin B1 in peanuts by TLC-CCD technique. The quantification and detection limit were 1.2 μg kg-1 and 0.4 ng per spot, respectively, with mean recovery of 98%. The CCD camera is sufficiently sensitive to detect small changes in spots fluorescence intensity and the results for performance confirmed the efficiency of the method. Another important property of CCD detector is its linearity for a wide range of luminous stimulus determined by analysis of five-point calibration curves using the intensity of AFB1 fluorescence versus AFB1 concentration (0.8 to 4.8 ng per spot). The method was applied to the analysis of thirty nine peanut samples and aflatoxin B1 levels ranged from 16 to 115 μg kg-1. The TLC-CCD and the photometric procedure developed in this study demonstrated to be a simple and efficient tool for quantitative analyses of AFB1 in peanut samples.

Desenvolvimento de um método reflectométrico ambientalmente mais amigável para a determinação de metoclopramida em formulações farmacêuticas

A simple and more environmentally friendly method by combined spot test-diffuse reflectance spectroscopy for determining metoclopramide in pharmaceutical formulations is described. The method is based on the reaction between metoclopramide and p-dimethylaminocinnamaldehyde, in the presence of HCl, producing a colored compound (λmáx = 580 nm) on the filter paper. The linear range was from 5.65 x 10-4-6.21x10-3 mol L-1 (r = 0.999). The limit of detection was 1.27 x 10-4 mol L-1. The proposed reflectometric method was applied successfully to the determination of metoclopramide in pharmaceuticals and it was favorably compared with the Brazilian or British Pharmacopoeia methods at 95% confidence level.

The use of tribromoisocyanuric acid to distinguish among primary, secondary and tertiary alcohols

Primary, secondary and tertiary alcohols can be easily distinguished due to their reactivity towards tribromoisocyanuric acid (TBCA). The test is performed by adding TBCA to the alcohol in a test tube heated in a boiling water bath. Orange color develops in the tube containing the primary alcohol, light yellow is observed in the tube containing the secondary alcohol while the tertiary alcohol results in a colorless mixture.