Validez de la explicación keynesiana de los ciclos económicos en el comportamiento de la economía colombiana

Esta investigación pretende retomar el Enfoque Keynesiano De Los Ciclos Económicos y utilizarlos como herramientas de análisis para tratar de explicar el comportamiento en la economía colombiana en el período 1970 – 2000. Este análisis de la Economía Colombiana se centrará en el estudio de una serie de variables económicas, pero enfatizando en el seguimiento de tres variables por ser determinante para una posible explicación de sus fluctuaciones cíclicas, como son: • La Eficiencia Marginal del Capital. • La Inversión • Las Tasas de Interés Vale decir para mayor claridad, que el análisis de los Ciclos Económicos, como se mencionó en un principio, se hará con base a las doctrinas de J.M. Keynes, por ser uno de los economistas más renombrados gracias a que gran parte de sus teorías tuvieron y tienen aplicabilidad en diversos apartes de la historia de la Economía Mundial

The São Paulo shelf (SE Brazil) as a nursery ground for Doryteuthis plei (Blainville, 1823) (Cephalopoda, Loliginidae) paralarvae: a Lagrangian particle-tracking individual-based model approach

The São Paulo shelf ranges from ~23ºS to 25ºS, comprising nearly 622 km of shoreline. This region sustains historical landings of the tropical arrow squid Doryteuthis plei. As in other coleoid cephalopods, the broodstock dies following spawning and the continuance of the population relies exclusively upon the survival of the paralarvae, which are very sensitive to oceanographic conditions. As a first step towards the understanding of paralarval transport, the shelf area was evaluated in terms of retention/ dispersion potential. A Lagrangian particle-tracking Individual-Based Model was set up using a 3D Princeton Ocean Model model forced with in situ data obtained from July 2009 to July 2011. Neutrally buoyant particles were released every first day of every month in the model, and tracked for 30 days. The retention potential was high for particles released from the bottom all over the study area from the coast to the shelf break (200 m isobath). Offshore losses showed a marked seasonality. Regarding inshore losses, the percentage of particles beached was constant year round and smaller than offshore losses, being higher south of 24ºS. Simulation results seem to agree with present knowledge of the reproductive behaviour of the species in the regionFAPESP/BIOTA Program - 2010/50183-6FAPESP - 2010/15978-8PRCEX-USP - 12.1.895.21.4FAPESP - 2012/14140-6CNPq - 309732/2011-

ESTUDIO ETNOBOTÁNICO DESELAGINELLA LEPIDOPHYLLA (HOOK. ET GREV.) SPRING (SELAGINELLACEAE-PTERIDOPHYTA) EN SAN JOSÉ XICOHTÉNCATLMUNICIPIO DE HUAMANTLA, TLAXCALA, MÉXICO *

An ethnobotanic study of Selaginellalepidophylla (Hook. et Grev.) Spring, fromSan Jose Xicohtencatl, municipality ofHuamantla, Tlaxcala, Mexico was carried out.The methodology used was to poll 100inhabitants of the region. Out of the 100inhabitant polled, 90 of them gaveinformation about the plant, which is usedfor various urinary problems. Besides, insome cases, they mentioned that it was usedto dissolve bile stones. The questions inthe poll included data such as the person’sname, occupation, what is the plant usedfor, other common names known, how is itused, alone or combined with other plants,ways to prepare it and use it. Ten peoplesaid they did not know it. Such species is anew record from Tlaxcala state.Se realizó el estudio etnobotánico deSelaginella lepidophylla (Hook. et Grev.)Spring, en San José Xicohténcatl, municipiode Huamantla, Tlaxcala, México. Lametodología utilizada fue entrevistar a 100personas de la región, de ellas 90 dieroninformación sobre la planta; en todos loscasos la utilizan para diversos problemasurinarios y además algunos también la usanpara disolver cálculos biliares. Paraencuestar a las personas se recurrió a uncuestionario que incluyó datos, como:nombre del usuario, ocupación, usos de laplanta, nombres con los que se conoce,cantidad de la planta utilizada, si la utilizansola o combinada con alguna otra, formasde preparación y vía de administración. Diezpersonas dijeron no conocerla. También laespecie resultó un nuevo registro para elestado de Tlaxcala

El derecho a la protección de datos personales, tecnologías digitales y pandemia por COVID-19 en Colombia

La pandemia COVID-19 ha generado impactos sociales y políticos adicionales a los estrictamente sanitarios, llevando de un aparte a que los países, en el contexto de los estados de emergencia decretados, limiten de manera temporal algunos derechos y libertades civiles, para preservar la vida y salud de los ciudadanos; y de otra parte, han acelerado la transformación digital con el desarrollo y uso de herramientas tecnológicas para complementar las medidas de salud pública. Diversos organismos internacionales han expresado su preocupación respecto a la vulneración del derecho a la protección de datos personales en este nuevo escenario, e incluso han propuesto lineamientos éticos a tener en cuenta. En este artículo se analizarán las medidas que han sido implementadas en Colombia con ocasión de la COVID-19, desde la perspectiva del marco jurídico del derecho a la protección de datos personales vigente, y como los principios y derechos que lo componen, pueden ser reinterpretados a la luz de estas nuevas recomendaciones éticas

Representações Sociais Relativas ao Controle de Peso Corporal para Pessoas com Sobrepeso

The social representations regarding body overweight are related to the understanding of social thought about the body, a physical and symbolic entity resulting from the interaction between the natural organism and the social environment. The purpose of this study was to describe the social representations about body weight control for overweight individuals engaged in these practices. Twenty subjects participated in this study. Data were obtained through an in - depth interview and treated with IRaMuTeQ software for descending hierarchical classification. Weight control was directly related to the practice of diet and diets, followed by physical exercise as a mandatory component for the maintenance of good form and health. Aesthetics and health constituted the same representational field in all descriptions, and it is possible to verify the reproduction of normative standards about beauty and body health in this group of people who seek control of body weight.Las representaciones sociales sobre el sobrepeso corporal están relacionadas con la comprensión del pensamiento social acerca del cuerpo, una entidad física y simbólica resultante de la interacción entre el organismo natural y el ambiente social. El objetivo de este estudio fue describir las representaciones sociales sobre el control del peso corporal para las personas con sobrepeso corporal comprometidas en esas prácticas. Participaron de esta investigación 20 sujetos. Los datos fueron obtenidos por medio de entrevistas en profundidad y tratados con software IRaMuTeQ para clasificación jerárquica descendente. El control de peso fue relacionado directamente a la práctica de la alimentación y dietas, seguido del ejercicio físico como componente obligatorio para el mantenimiento de la buena forma y salud. Estética y salud compusieron el mismo campo representacional en todas las descripciones, siendo posible constatar la reproducción de patrones normativos acerca de la belleza y de la salud corporal en este grupo de personas que buscan control de peso corporal.As representações sociais a respeito do sobrepeso corporal estão relacionadas com a compreensão do pensamento social acerca do corpo, uma entidade física e simbólica resultante da interação entre o organismo natural e o ambiente social. O objetivo deste estudo foi descrever as representações sociais sobre o controle de peso corporal para pessoas com sobrepeso corporal engajadas nessas práticas. Método: Participaram desta pesquisa 20 sujeitos. Os dados foram obtidos por meio de entrevista em profundidade e tratados com software IRAMUTEQ para classificação hierárquica descendente e análise de similitude. Resultados: O controle de peso foi relacionado diretamente à prática da alimentação e dietas, seguido do exercício físico como componente obrigatório para a manutenção da boa forma e saúde.  Conclusão: Estética e saúde compuseram o mesmo campo representacional em todas as descrições, sendo possível constatar a reprodução de padrões normativos acerca da beleza e da saúde corporal neste grupo de pessoas que buscam controle de peso corporal

Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form

Cationic Amino Acid Uptake Constitutes a Metabolic Regulation Mechanism and Occurs in the Flagellar Pocket of Trypanosoma cruzi

Trypanosomatids' amino acid permeases are key proteins in parasite metabolism since they participate in the adaptation of parasites to different environments. Here, we report that TcAAP3, a member of a Trypanosoma cruzi multigene family of permeases, is a bona fide arginine transporter. Most higher eukaryotic cells incorporate cationic amino acids through a single transporter. In contrast, T. cruzi can recognize and transport cationic amino acids by mono-specific permeases since a 100-fold molar excess of lysine could not affect the arginine transport in parasites that over-express the arginine permease (TcAAP3 epimastigotes). In order to test if the permease activity regulates downstream processes of the arginine metabolism, the expression of the single T. cruzi enzyme that uses arginine as substrate, arginine kinase, was evaluated in TcAAP3 epimastigotes. In this parasite model, intracellular arginine concentration increases 4-folds and ATP level remains constant until cultures reach the stationary phase of growth, with decreases of about 6-folds in respect to the controls. Interestingly, Western Blot analysis demonstrated that arginine kinase is significantly down-regulated during the stationary phase of growth in TcAAP3 epimastigotes. This decrease could represent a compensatory mechanism for the increase in ATP consumption as a consequence of the displacement of the reaction equilibrium of arginine kinase, when the intracellular arginine concentration augments and the glucose from the medium is exhausted. Using immunofluorescence techniques we also determined that TcAAP3 and the specific lysine transporter TcAAP7 co-localize in a specialized region of the plasma membrane named flagellar pocket, staining a single locus close to the flagellar pocket collar. Taken together these data suggest that arginine transport is closely related to arginine metabolism and cell energy balance. The clinical relevance of studying trypanosomatids' permeases relies on the possibility of using these molecules as a route of entry of therapeutic drugs

Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

This is the final version of the article. Available from Wiley via the DOI in this record.Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.This paper is a product of the European Union's Seventh Framework Programme AMAZALERT project (282664). The field data used in this study have been generated by the RAINFOR network, which has been supported by a Gordon and Betty Moore Foundation grant, the European Union's Seventh Framework Programme projects 283080, ‘GEOCARBON’; and 282664, ‘AMAZALERT’; ERC grant ‘Tropical Forests in the Changing Earth System’), and Natural Environment Research Council (NERC) Urgency, Consortium and Standard Grants ‘AMAZONICA’ (NE/F005806/1), ‘TROBIT’ (NE/D005590/1) and ‘Niche Evolution of South American Trees’ (NE/I028122/1). Additional data were included from the Tropical Ecology Assessment and Monitoring (TEAM) Network – a collaboration between Conservation International, the Missouri Botanical Garden, the Smithsonian Institution and the Wildlife Conservation Society, and partly funded by these institutions, the Gordon and Betty Moore Foundation, and other donors. Fieldwork was also partially supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico of Brazil (CNPq), project Programa de Pesquisas Ecológicas de Longa Duração (PELD-403725/2012-7). A.R. acknowledges funding from the Helmholtz Alliance ‘Remote Sensing and Earth System Dynamics’; L.P., M.P.C. E.A. and M.T. are partially funded by the EU FP7 project ‘ROBIN’ (283093), with co-funding for E.A. from the Dutch Ministry of Economic Affairs (KB-14-003-030); B.C. [was supported in part by the US DOE (BER) NGEE-Tropics project (subcontract to LANL). O.L.P. is supported by an ERC Advanced Grant and is a Royal Society-Wolfson Research Merit Award holder. P.M. acknowledges support from ARC grant FT110100457 and NERC grants NE/J011002/1, and T.R.B. acknowledges support from a Leverhulme Trust Research Fellowship

Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology

<p>Abstract</p> <p>Background</p> <p>Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City.</p> <p>Methods</p> <p>Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR), and the standardized average annual incidence rates (SAAIR) per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level).</p> <p>Results</p> <p>Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3); acute lymphoblastic leukemia (ALL) was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million), followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million), and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million). The 1-4 years age group had the highest SAAIR for ALL (77.7 per million). For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million) and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million). The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8%) were classified as high risk. There was a positive correlation between the average number of persons per household and the incidence of the pre-B immunophenotype (Pearson's r, 0.789; P = 0.02).</p> <p>Conclusions</p> <p>The frequency of ALL in Mexico City is among the highest in the world, similar to those found for Hispanics in the United States and in Costa Rica.</p