Comment on "Theoretical design of molecular nanomagnets for magnetic refrigeration" [Appl. Phys. Lett. 103, 202410 (2013)]

Garlatti et al. [Appl. Phys. Lett. 103, 202410 (2013)] report theoretical simulations aimed at showing that the best molecular nanomagnets for magnetic refrigeration between T = 10 K and sub-Kelvin region are those made of strongly ferromagnetically-coupled magnetic ions. This Comment revises such conclusion based on results that, apparently, contrast with the established belief in this research field.Comment: 3 pages, 2 figure

Criminal Businessmen, Commodity Frontiers and the Colombian State

This article presents three micro-stories of Colombian businessmen of the criminal type who operated in commodity frontiers, known for the presence of intense public violence. In today's globalization, the Colombian economy made the transition from "coffee and industry" to "cocaine and services". Some authoritarian and modernizing policies of the Colombian State, mainly Uribe’s Defense and Democratic Security Policy, DDSP, 2002- 2010, have been central in the formation of a thick network of crime, business, public violence and politics as usual. Our micro historic analyzes are based mainly on judicial cases that shed light on links at various levels: (a) the growing supranationality of drug trafficking and money laundering crimes; (b) the drug trafficking substrate in the appearance of the new commodity frontiers; (c) drug trafficking as a model of a business training school particularly in Colombia's internal frontiers and (d) the fundamental link between the local and the global in the perspective of organized crime and businesses

Automatic Segmentation of Exudates in Ocular Images using Ensembles of Aperture Filters and Logistic Regression

Hard and soft exudates are the main signs of diabetic macular edema (DME). The segmentation of both kinds of exudates generates valuable information not only for the diagnosis of DME, but also for treatment, which helps to avoid vision loss and blindness. In this paper, we propose a new algorithm for the automatic segmentation of exudates in ocular fundus images. The proposed algorithm is based on ensembles of aperture filters that detect exudate candidates and remove major blood vessels from the processed images. Then, logistic regression is used to classify each candidate as either exudate or non-exudate based on a vector of 31 features that characterize each potensial lesion. Finally, we tested the performance of the proposed algorithm using the images in the public HEI-MED database.Fil: Benalcazar Palacios, Marco Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación; EcuadorFil: Brun, Marcel. Universidad Nacional de Mar del Plata; ArgentinaFil: Ballarin, Virginia Laura. Universidad Nacional de Mar del Plata; Argentin

HDAC4 regulates satellite cell proliferation and differentiation by targeting P21 and Sharp1 genes

Skeletal muscle exhibits a high regenerative capacity, mainly due to the ability of satellite cells to replicate and differentiate in response to appropriate stimuli. Epigenetic control is effective at different stages of this process. It has been shown that the chromatin-remodeling factor HDAC4 is able to regulate satellite cell proliferation and commitment. However, its molecular targets are still uncovered. To explain the signaling pathways regulated by HDAC4 in satellite cells, we generated tamoxifen-inducible mice with conditional inactivation of HDAC4 in Pax7(+) cells (HDAC4 KO mice). We found that the proliferation and differentiation of HDAC4 KO satellite cells were compromised, although similar amounts of satellite cells were found in mice. Moreover, we found that the inhibition of HDAC4 in satellite cells was sufficient to block the differentiation process. By RNA-sequencing analysis we identified P21 and Sharp1 as HDAC4 target genes. Reducing the expression of these target genes in HDAC4 KO satellite cells, we also defined the molecular pathways regulated by HDAC4 in the epigenetic control of satellite cell expansion and fusion

Ricos y famosos

Empresarios colombianos del siglo XIX. Luis Fernando Molino Londoño. Banco de la República-El Áncora Editores, Bogotá, 1998, 187 págs

El papel social de los científicos

Sociedades científicas en Colombia. La invención de una tradición, 1859-1936. Diana Obregón Torres. Banco de la República, Santafé de Bogotá, 1992

Reflexión política con convicción ética

La reconstrucción de Colombia. Escritos políticos. Alfredo Gómez Muller. La Carreta Editores/Planeta Paz, Medellín, 2008, 128 págs

Un texto ágil y crítico que debe estar entre los activos de la historiografía

Historia y nación. Tentativas de la escritura de la historia en Colombia. Alexander Betancourt Mendieta. La Carreta Editores, Universidad de Antioquia, Coordinación de Ciencias Sociales y Humanidades, Universidad Autónoma de San Luis Potosí (México), Medellín, 2007, 293 págs

Las condiciones de la centralización política: a propósito de la Constitución del 86

Desde el Renacimiento, la centralización política y la unidad nacional son rasgos estatales, así como desde la Revolución Francesa la universalización de la ciudadanía es una de las características centrales de la vida democrática. Con relación a la organización del Estado colombiano, los grandes contrapunteos que han elaborado nuestros tratadistas de derecho constitucional colombiano versan, principalmente, sobre el federalismo-centralismo o sobre la naturaleza más o menos autoritaria o más o menos democrática de nuestro régimen presidencial