Dimensões do subdesenvolvimento econômico na Colômbia, 1980-2015

El objetivo de este trabajo es identificar las condiciones de subdesarrollo que presenta la economía colombiana en el período 1980-2015. Se asume como marco teórico del subdesarrollo el enfoque estructuralista latinoamericano, estudiando especialmente el concepto de heterogeneidad estructural y la incorporación del progreso tecnológico. En consecuencia, se examina la política agropecuaria en Colombia, frente a la in­corporación del progreso tecnológico y la dinámica estructural. Para hallar evidencia empírica se construyen índices de crecimiento y tasas de participación, y se estiman coeficientes de correlación, cuyos resultados permiten concluir que la economía colombiana presenta condiciones de subdesarrollo en el período de observación.The objective of this article is to identify the underdevelopment conditions of the Colombian economy between 1980 and 2015. The Latin American structuralism approach is assumed as the theoretical framework of the underdevelopment, specifically studying the concept of structural heterogeneity and incorporation of technological progress. Hence, the agricultural and livestock breeding policy in Colombia is evaluated versus the incorporation of technological progress and structural dynamic. In order to find empirical evidence, growth indices and participation rates are built and correlation coefficients are estimated, results of which allow concluding that Colombian economy showed underdevelopment conditions during the period subject matter of this research.O objetivo deste trabalho é identificar as condições de subdesenvolvimento que a economia colombiana apresenta no período 1980-2015. Assume-se como referencial teórico do subdesenvolvimento a abordagem estruturalista latino-americana, estudando especialmente o conceito de heterogeneidade estrutural e a incorporação do progresso tecnológico. Em consequência, examina-se a política agropecuária na Colômbia ante a incorporação do progresso tecnológico e da dinâmica estrutural. Para encontrar provas empíricas, constroem-se índices de crescimento e taxas de participação, bem como se estimam coeficientes de correlação, cujos resultados permitem concluir que a economia colombiana apresenta condições de subdesenvolvimento no período de observação. Albán, Álvaro (2011). Reforma y contrareforma agraria en Colombia. En: Economía Institucional, Vol. 13, No. 24, Universidad Externado de Colombia, p. 327-35

Resolving the Detailed Structure of Cortical and Thalamic Neurons in the Adult Rat Brain with Refined Biotinylated Dextran Amine Labeling

Biotinylated dextran amine (BDA) has been used frequently for both anterograde and retrograde pathway tracing in the central nervous system. Typically, BDA labels axons and cell somas in sufficient detail to identify their topographical location accurately. However, BDA labeling often has proved to be inadequate to resolve the fine structural details of axon arbors or the dendrites of neurons at a distance from the site of BDA injection. To overcome this limitation, we varied several experimental parameters associated with the BDA labeling of neurons in the adult rat brain in order to improve the sensitivity of the method. Specifically, we compared the effect on labeling sensitivity of: (a) using 3,000 or 10,000 MW BDA; (b) injecting different volumes of BDA; (c) co-injecting BDA with NMDA; and (d) employing various post-injection survival times. Following the extracellular injection of BDA into the visual cortex, labeled cells and axons were observed in both cortical and thalamic areas of all animals studied. However, the detailed morphology of axon arbors and distal dendrites was evident only under optimal conditions for BDA labeling that take into account the: molecular weight of the BDA used, concentration and volume of BDA injected, post-injection survival time, and toning of the resolved BDA with gold and silver. In these instances, anterogradely labeled axons and retrogradely labeled dendrites were resolved in fine detail, approximating that which can be achieved with intracellularly injected compounds such as biocytin or fluorescent dyes