El principio nullum crimen sine iure en Derecho Internacional contemporáneo

El presente trabajo aborda la evolución y el contenido actual del principio nullum crimen sine iure en el ordenamiento jurídico internacional. Analiza su desarrollo desde su configuración—al término de la Segunda Guerra Mundial como un “principiodejusticia”—hasta su actual definición como un“derecho subjetivo individual” limitativo de la soberanía de los Estados.Explica que no debe ser un tipo específico de norma(en particular,una norma escrita con rango de ley)la que determine el carácter punible de una conducta; antes de su comisión solo exige que la misma sea constitutiva de delito conforme al sistema de fuentes previsto paralacreación del Derecho Penal en el ordenamiento jurídico nacional o internacional de que se trate.Por último,analiza cómo se configura con base en los requisitos de laaccesibilidad de la norma que recoge la conducta prohibida,y la previsibilidad de la responsabilidad penal en la que incurre su autor en el momento de ejecutarla.

Visual processing of concentric sine-wave gratings in adolescents and adults

The aim of this study was to compare the contrast visual processing of concentric sinusoidal gratings stimuli between adolescents and adults. The study included 20 volunteers divided into two groups: 10 adolescents aged 13-19 years (M=16.5, SD=1.65) and 10 adults aged 20-26 years (M=21.8, SD=2.04). In order to measure the contrast sensitivity at spatial frequencies of 0.6, 2.5, 5 and 20 degrees of visual angle (cpd), it was used the psychophysical method of two alternative forced choice (2AFC). A One Way ANOVA performance showed a significant difference in the comparison between groups: F [(4, 237)=3.74, p<.05]. The post-hoc Tukey HSD showed a significant difference between the frequencies of 0.6 (p <.05) and 20 cpd (p<.05). Thus, the results showed that the visual perception behaves differently with regard to the sensory mechanisms that render the contrast towards adolescents and adults. These results are useful to better characterize and comprehend human vision development.

Beyond the mincer equation: the internal rate of return to higher education in Colombia

In order to present an estimation of the Internal Rate of Return (IRR) to higher education in Colombia we take advantage of the methodological approach provided by Heckman, Lochner and Todd (2005). Trying to overcome the criticism that surrounds interpretations of the education coefficient of Mincer equations as being the rate of return to investments in education we develop a more structured approach of estimation, which controls for selection bias, includes more accurate measures of labor income and the role of education costs and income taxes. Our results implied a lower rate of return than the ones found in the Colombian literature and show that the Internal Rate of Return for higher education in Colombia lies somewhere between 0.074 and 0.128. The results vary according to the year analyzed and individual’s gender. This last result reinforces considerations regarding gender discrimination in the Colombian labor market.