La travesía obsoleta: la indefensión del consumidor

La obsolescencia programada es el deseo de tener algo un poco más nuevo, un poco mejor, un poco más rápido de lo necesario. El texto estudia este fenómeno a la luz del Estatuto del Consumidor – Ley 1480 de 2011 para determinar si el consumidor colombiano está suficientemente protegido con él.

La seguridad internacional. A la luz de las estructuras y las dinámicas regionales: una propuesta teórica de complejos de seguridad regional

El siguiente estado del saber contiene las principales definiciones, herramientas y variables en relación con la teoría de los complejos de seguridad regional elaborada por Barry Buzan y Ole Weaver. Según esta teoría, el actual escenario político internacional puede ser analizado a la luz de diferentes ámbitos regionales, cuyas estructuras están definidas por complejas interacciones en materia de seguridad entre el conjunto de unidades que allí residen. Los factores geográficos cobran relevancia en este marco teórico dado que, en la mayoría de los casos, las amenazas generan mayor interdependencia entre las unidades adyacentes que entre las distantes. Se propone una variada tipología de complejos de seguridad regional que cubre gran parte del planeta, se explican las razones de la ausencia de tales complejos y se exponen las posibilidades de cambio en el seno de las estructuras. Este esquema académico permite un análisis más certero de las dinámicas que, en los albores del siglo XXI, caracterizan a la distribución internacional del poder y a la arquitectura global de la seguridad.-----This state of knowledge shows the main definitions, tools and variables regarding the Theory of Regional Security Complexes developed by Barry Buzan and Ole Weaver. This theory sets that the international political field should be analyzed through specific regional circuits, whose structures are defined by rich security interactions among the units integrating them. The geographical factors gain relevance in this context given that, in most of the cases, the threats produce a bigger interdependence between neighbors than between units separated by long distances. Thus, the theory proposes a worldwide varied tipology of regional security complexes, explaining the reasons of the absence of such complexes as well as the possibilities of change inside the structures. At the beginning of the XXIst century, this academical framework enables us to develop a deeper analysis about the dinamics that characterizes the international distribution of power and the global architecture of security.

Tissue- specific DNA methylation profiles in newborns

Experimental and epidemiological studies demonstrate that fetal growth restriction and low birth weight enhance the risk of chronic diseases in adulthood. Derangements in tissue-specific epigenetic programming of fetal and placental tissues are a suggested mechanism of which DNA methylation is best understood. DNA methylation profiles in human tissue are mostly performed in DNA from white blood cells. The objective of this study was to assess DNA methylation profiles of IGF2 DMR and H19 in DNA derived from four tissues of the newborn. We obtained from 6 newborns DNA from fetal placental tissue (n = 5), umbilical cord CD34+ hematopoietic stem cells (HSC) and CD34- mononuclear cells (MNC) (n = 6), and umbilical cord Wharton jelly (n = 5). HCS were isolated using magnetic-activated cell separation. DNA methylation of the imprinted fetal growth genes IGF2 DMR and H19 was measured in all tissues using quantitative mass spectrometry. ANOVA testing showed tissue-specific differences in DNA methylation of IGF2 DMR (p value 0.002) and H19 (p value 0.001) mainly due to a higher methylation of IGF2 DMR in Wharton jelly (mean 0.65, sd 0.14) and a lower methylation of H19 in placental tissue (mean 0.25, sd 0.02) compared to other tissues. This study demonstrates the feasibility of the assessment of differential tissue specific DNA methylation. Although the results have to be confirmed in larger sample sizes, our approach gives opportunities to investigate epigenetic profiles as underlying mechanism of associations between pregnancy exposures and outcome, and disease risks in later life.