Las representaciones sociales del territorio y el ambiente en el sector de la vereda Cabeceras - Llanogrande, municipio de Rionegro - Antioquia La escuela como eje de reflexión y acción sobre la territorialidad

66 páginas : gráficas, fotosEl presente investigación busca indagar, conocer y comprender la naturaleza de las representaciones sociales que sobre el territorio y el ambiente poseen los pobladores de la vereda Cabeceras – LLanogrande, área de influencia de la Institución Educativa Gilberto Echeverri Mejía del Municipio de Rionegro, Departamento de Antioquia. Esta aproximación implica el interpretar marcos conceptuales y metodológicos comunes propios a los referentes centrales de la propuesta: Territorio, Representaciones Sociales y Territorialidad. El autor considera que la etnografía es un método de campo que le permite mediante la entrevista, las historias de vida y la cartografía social, construir junto a los pobladores el relato de la ocupación, percepción, aspiraciones y administración de las espacialidades locales que generan representaciones sociales sobre el territorio, el ambiente y la territorialidad. Busca ser un insumo que permita a las comunidades comprender las dinámicas de elaboración de estas representaciones y mediante esta comprensión potenciar la búsqueda de una territorialidad sostenible, justa, solidaria y equitativa. En este esfuerzo la escuela y sus actores se erigen como mediador de nuevos conocimientos, interpretaciones y reelaboraciones.The present research seeks to investigate, know and understand the nature of the social representations that the residents of the village Cabeceras – LLanogrande have on the territory and the environment, area of influence of the Educational Institution Gilberto Echeverri Mejía of the Municipality of Rionegro, Department of Antioquia. This approach involves interpreting common conceptual and methodological frameworks to the central referents of the proposal: Territory, Social Representations and Territoriality. The author considers that ethnography is a field method that allows him through interviews, life histories and social cartography, to co-construct with the inhabitants the story of the occupation, perception, aspirations and administration of the local spatialities that generate social representations about the territory, the environment and territoriality. It seeks to be an input that allows communities to understand the dynamics of development of these representations and through this understanding enhance the search for a sustainable territoriality, fair, supportive and equitable. In this effort, the school and its actors stand as mediators of new knowledge, interpretations and reworkings.Incluye bibliografíaMaestríaMagíster en Educación Ambienta

Estudio del factor de pérdidas técnicas en redes de distribución de bajo voltaje, para la empresa Eléctrica Regional Norte S.A.

Realizar un estudio del factor de pérdidas técnicas en redes de distribución de bajo voltaje, por estratos de consumo, con la ayuda de herramientas informáticas, en base a un muestreo de los datos históricos proporcionados por la empresa EMELNORTE S.A.El presente estudio determina las pérdidas técnicas presente en las redes de bajo voltaje de la Empresa Eléctrica Regional Norte S.A., a partir de un factor de pérdidas calculado en los estratos C, D y E. Usando como base la metodología del Magister en Ciencias de la Ingeniería Eléctrica Mentor Poveda. Para la identificación de las pérdidas técnicas en las redes secundarias se empleó el software CYME, en el cual se modelo de manera detallada las redes de distribución, adicionalmente se ingresó la demanda máxima registrada en una semana y el consumo de los abonados. Usando para ello las mediciones tomadas con los analizadores de red en el año 2017 y el consumo de los abonados de la base de datos de ArcGIS. En este sentido, se propone determinar valores promedios de factores de pérdidas, los cuales se agrupan según; su estrato de consumo, sistema y potencia del transformador, todo esto usando el programa Excel el cual me permitió ver una variación estándar de los resultados de una manera organizada y precisa. Concluyendo que los datos disponibles en los sistemas de medición actual de la empresa eléctrica EMELNORTE S.A. y el factor de pérdidas calculado, son la base para determinar las pérdidas técnicas en energía en las redes de distribución aéreas desnudas.Ingenierí

Catalysis of Peroxide Reduction by Fast Reacting Protein Thiols

Life on Earth evolved in the presence of hydrogen peroxide, and other peroxides also emerged before and with the rise of aerobic metabolism. They were considered only as toxic byproducts for many years. Nowadays, peroxides are also regarded as metabolic products that play essential physiological cellular roles. Organisms have developed efficient mechanisms to metabolize peroxides, mostly based on two kinds of redox chemistry, catalases/peroxidases that depend on the heme prosthetic group to afford peroxide reduction and thiol-based peroxidases that support their redox activities on specialized fast reacting cysteine/selenocysteine (Cys/Sec) residues. Among the last group, glutathione peroxidases (GPxs) and peroxiredoxins (Prxs) are the most widespread and abundant families, and they are the leitmotif of this review. After presenting the properties and roles of different peroxides in biology, we discuss the chemical mechanisms of peroxide reduction by low molecular weight thiols, Prxs, GPxs, and other thiol-based peroxidases. Special attention is paid to the catalytic properties of Prxs and also to the importance and comparative outlook of the properties of Sec and its role in GPxs. To finish, we describe and discuss the current views on the activities of thiol-based peroxidases in peroxide-mediated redox signaling processes.Fil: Zeida, Ari. Universidad de la República; UruguayFil: Trujillo, Madia. Universidad de la Republica; UruguayFil: Ferrer Sueta, Gerardo. Universidad de la Republica; UruguayFil: Denicola, Ana. Universidad de la Republica; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Radi, Rafael. Universidad de la República; Urugua

Multiscale Modeling of Thiol Overoxidation in Peroxiredoxins by Hydrogen Peroxide

In this work, we employ a multiscale quantum-classical mechanics (QM/MM) scheme to investigate the chemical reactivity of sulfenic acids toward hydrogen peroxide, both in aqueous solution and in the protein environment of the peroxiredoxin alkyl hydroperoxide reductase E from Mycobacterium tuberculosis (MtAhpE). The reaction of oxidation of cysteine with hydrogen peroxides, catalyzed by peroxiredoxins, is usually accelerated several orders of magnitude in comparison with the analogous reaction in solution. The resulting cysteine sulfenic acid is then reduced in other steps of the catalytic cycle, recovering the original thiol. However, under some conditions, the sulfenic acid can react with another equivalent of oxidant to form a sulfinic acid. This process is called overoxidation and has been associated with redox signaling. Herein, we employed a multiscale scheme based on density function theory calculations coupled to the classical AMBER force field, developed in our group, to establish the molecular basis of thiol overoxidation by hydrogen peroxide. Our results suggest that residues that play key catalytic roles in the oxidation of MtAhpE are not relevant in the overoxidation process. Indeed, the calculations propose that the process is unfavored by this particular enzyme microenvironment.Fil: Semelak, Jonathan Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Battistini, F.. Barcelona Institute of Science and Technology; EspañaFil: Radi, R.. Universidad de la República; UruguayFil: Trujillo, M.. Universidad de la República; UruguayFil: Zeida, A.. Universidad de la República; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Diseño conceptual de una aeronave commuter para aterrizajes y despegues cortos.

En el presente proyecto se desarrolla el diseño conceptual de una aeronave regional o commuter tipo STOL (Short Take-Off and Landing), para despegues y aterrizajes cortos, cuya misión principal será realizar misiones militares y civiles como por ejemplo, transporte de pasajeros y carga, paracaidismo, operaciones tácticas, entre otras, dentro del territorio colombiano. El diseño de esta aeronave responde a la convocatoria del Primer Concurso de Diseño Aeronáutico de la Fuerza Aérea Colombiana (FAC). En el proceso de diseño conceptual fueron utilizadas metodologías y procedimientos de diseño clásicas, así como nuevos algoritmos de diseño basados en métodos analíticos, los cuales sirvieron para evaluar y optimizar la aeronave en ciertos aspectos, con el fin de que el diseño fuera semejante a los requisitos de diseño, misión, estándares de aeronavegabilidad y de certificación aplicables a la categoría de la aeronave y a los solicitados por la FAC. También como parte del diseño conceptual, fueron considerados y evaluados los principales parámetros geométricos, aerodinámicos y de rendimiento de la aeronave a través de métodos de diseño teórico/analítico y diseño asistido por computador (CAD). Se desarrollaron especificaciones de desempeño las cuales se compararon con aeronaves de categoría similar, con el fin de justificar, hallar y determinar las ventajas del presente diseño. El avance en cada fase del proceso de diseño se representa en este documento mediante tablas y diagramas, permitiendo su fácil comprensión. (Rodríguez et al (2018). Diseño conceptual y preliminar de una aeronave tipo STOL - VULTUR). El resultado del diseño aquí propuesto se espera, pueda cumplir con los requisitos de diseño conceptual estipulados por la Fuerza Aérea Colombiana (FAC); con el fin de que este mismo sea base para que se puedan desarrollar futuros análisis que hacen parte del diseño preliminar de la aeronave. (Rodríguez et al, 2018).In the present project the conceptual design of a regional aircraft or commuter type STOL (Short Take-Off and Landing) is developed, for short take-offs and landings, whose main mission will be to carry out military and civil missions, such as, passenger transport and cargo, parachuting, tactical operations, among others., within the Colombian territory. The design of this aircraft responds to the call of the First Contest of Aeronautical Design of the Colombian Air Force (FAC). In the conceptual design process, classic design methodologies and procedures were used, as well as new design algorithms based on analytical methods, which served to evaluate and optimize the aircraft in certain aspects, so that the design was similar to the design, mission, airworthiness standards and certification requirements applicable to the category of the aircraft and those requested by the FAC. Also, as part of the conceptual design, the main geometrical, aerodynamic and performance parameters of the aircraft were considered and evaluated through theoretical / analytical design methods and computer-aided design (CAD). Performance specifications were developed which were compared with similar category aircraft, in order to justify, find and determine the advantages of the present design. The progress in each phase of the design process is represented in this document through tables and diagrams, allowing easy understanding. (Rodríguez et al, 2018). The result of the design proposed here is expected, can meet the conceptual design requirements stipulated by the Colombian Air Force (FAC); in order that this same one is base so that future analyzes that are part of the preliminary design of the aircraft can be developed. (Rodríguez et al, 2018)

The extraordinary catalytic ability of peroxiredoxins: a combined experimental and QM/MM study on the fast thiol oxidation step

Peroxiredoxins (Prxs) catalyze the reduction of peroxides, a process of key relevance in a variety of cellular processes. The first step in the catalytic cycle of all Prxs is the oxidation of a cysteine residue to sulfenic acid, which occurs 103–107 times faster than in free cysteine. We present an experimental kinetics and hybrid QM/MM investigation to explore the reaction of Prxs with H2O2 using alkyl hydroperoxide reductase E from Mycobacterium tuberculosis as a Prx model. We report for the first time the thermodynamic activation parameters of H2O2 reduction using Prx, which show that protein significantly lowers the activation enthalpy, with an unfavourable entropic effect, compared to the uncatalyzed reaction. The QM/MM simulations show that the remarkable catalytic effects responsible for the fast H2O2 reduction in Prxs are mainly due to an active-site arrangement, which establishes a complex hydrogen bond network activating both reactive species.Fil: Zeida Camacho, Ari Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; ArgentinaFil: Reyes, Aníbal M.. Universidad de la República; UruguayFil: González Lebrero, Mariano Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Radi Isola, Rafael. Universidad de la República; UruguayFil: Trujillo, Madia. Universidad de la República; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

First genetic assessment of the level of endemism in the avifauna of the Central Sierras in southern South America

The Andes constitute one of the main factors that have promoted diversification in the Neotropics. However, the role of other highland regions in the southern cone of South America has been barely studied. We analyzed the level of endemism in the avifauna of the Central Sierras in Córdoba, a high region in central Argentina, to evaluate the effect of its geographic isolation from the Andes. There are 11 species with endemic subspecies in this region, all of them described based only on differences in morphology (mainly plumage color) with no genetic evidence. We performed the first genetic analyses of seven of these species using mitochondrial DNA obtained from fresh tissue and toe pad samples. Our results show that for three of these species, Catamenia inornata, Phrygilus unicolor and Cinclodes atacamensis, the population in the Central Sierras is clearly differentiated from those of other regions, and the first two of them also show divergence among Andean subspecies. In the remaining species we found a varying degree of differentiation, ranging from a small divergence in Muscisaxicola rufivertex to the presence of different haplotypes but with an apparent lack of phylogeographic structure in Phrygilus plebejus and Sturnella loyca (being the latter the only species with a continuous distribution between the Central Sierras and the Andes) to haplotype sharing in Asthenes modesta. While further analyses including additional markers, morphological characters and vocalizations are needed, our results show that some of the species that have disjunct distributions, with a population in the Central Sierras isolated geographically from the Andes, possess distinct genetic lineages in the Central Sierras that suggest an evolutionary isolation from other populations. These findings highlight the importance of montane regions in general, and the Central Sierras in particular, as drivers of diversification in the Neotropics.Fil: Bukowski Loináz, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lavinia Oblanca, Pablo Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Trujillo Arias, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Kopuchian, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Structural basis of redox-dependent modulation of galectin-1 dynamics and function

Galectin-1 (Gal-1), a member of a family of multifunctional lectins, plays key roles in diverse biological processes including cell signaling, immunomodulation, neuroprotection and angiogenesis. The presence of an unusual number of six cysteine residues within Gal-1 sequence prompted a detailed analysis of the impact of the redox environment on the functional activity of this lectin. We examined the role of each cysteine residue in the structure and function of Gal-1 using both experimental and computational approaches. Our results show that: (i) only three cysteine residues present in each carbohydrate recognition domain (CRD) (Cys2, Cys16 and Cys88) were important in protein oxidation, (ii) oxidation promoted the formation of the Cys16-Cys88 disulfide bond, as well as multimers through Cys2, (iii) the oxidized protein did not bind to lactose, probably due to poor interactions with Arg48 and Glu71, (iv) in vitro oxidation by air was completely reversible and (v) oxidation by hydrogen peroxide was relatively slow (1.7 ± 0.2 M(-1) s(-1) at pH 7.4 and 25°C). Finally, an analysis of key cysteines in other human galectins is also provided in order to predict their behaviour in response to redox variations. Collectively, our data provide new insights into the structural basis of Gal-1 redox regulation with critical implications in physiology and pathology.Fil: Guardia, Carlos Manuel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de Los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires; ArgentinaFil: Caramelo, Julio Javier. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Trujillo, Madia . Universidad de la Republica; UruguayFil: Mendez Huergo, Santiago Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Radi, Rafael . Universidad de la Republica; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de Los Materiales, Medioambiente y Energía; ArgentinaFil: Rabinovich, Gabriel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin

Retornos salariales para Colombia, un análisis cuantílico

Páginas 211-246Este artículo analiza los retornos salariales de los jóvenes y adultos, comparando la influencia de la educación y la experiencia. Se examina principalmente la teoría del capital humano y las críticas a esta, a través del estudio de la relación entre educación, experiencia y salarios. El análisis empírico se basa en el modelo de Mincer, pero mediante las regresiones cuantílicas, para determinar por 10 cuantiles en cada grupo, cómo se dan los retornos salariales. Se comprueba que para los jóvenes hay mayor impacto de adquirir experiencia que la educación sobre los retornos salariales, lo que afecta la inserción laboral y el obtener mayores ingresos laborales.ABSTRACT: This article examines the wage returns of young people and adults, considering the effect of education and experience. It is taken into account, especially, the point of view of human capital theory and its criticisms, to evaluate the relationship between education, experience and salary. The empirical analysis is based on the Mincer model, but through quantile regressions, to determine by 10 quantiles in each group as wage returns are given. It is verified that for young people there is greater impact of acquire experience than education on the wage returns, which affects labor insertion and obtaining higher income.Bibliografía: páginas 242-246Artículo de investigació

Sexual and Reproductive Health for Young Adults in Colombia: Teleconsultation Using Mobile Devices

Background: Sexual risk behaviors associated with poor information on sexuality have contributed to major public health problems in the area of sexual and reproductive health in teenagers and young adults in Colombia. Objective: To report our experience with the use of DoctorChat Mobile to provide sexual education and information among university students in Bogota, Colombia, and knowledge about the sexual risk factors detected among them. Methods: A mobile app that allows patients to ask about sexual and reproductive health issues was developed. Sexual and reproductive risk behaviors in a sample of young adults were measured before and after the use of the app through the validated survey Family Health International (FHI) Behavioral Surveillance Survey (BSS) for Use With Adults Between 15 and 49 Years. A nonprobabilistic convenience recruitment was undertaken through the study´s webpage. After completing the first survey, participants were allowed to download and use the app for a 6-month period (intervention), followed by completion of the same survey once again. For the inferential analysis, data was divided into 3 groups (dichotomous data, discrete quantitative data, and ordinal data) to compare the results of the questions between the first and the second survey. The study was carried out with a sample of university students between 18 and 29 years with access to mobile phones. Participation in the study was voluntary and anonymous. Results: A total of 257 subjects met the selection criteria. The preintervention survey was answered by 232 subjects, and 127 of them fully answered the postintervention survey. In total, 54.3% (69/127) of the subjects completed the survey but did not use the app, leaving an effective population of 58 subjects for analysis. Of these subjects, 53% (31/58) were women and 47% (27/58) were men. The mean age was 21 years, ranging between 18 and 29 years. The differences between the answers from both surveys were not statistically significant. The main sexual risk behaviors identified in the population were homosexual intercourse, nonuse of condoms, sexual intercourse with nonregular and commercial partners, the use of psychoactive substances, and lack of knowledge on symptoms of sexually transmitted diseases and HIV transmission. Conclusions: Although there were no differences between the pre- and postintervention results, the study revealed different risk behaviors among the participating subjects. These findings highlight the importance of promoting high-impact educational strategies on this matter and the importance of providing teenagers and young adults with easily accessible tools with reliable health information, regardless of their socioeconomic status