Análisis de impacto de las unidades educativas del milenio en el periodo 2013-2017

In this impact analysis of Unidades Educativas del Milenio (UEM), quantitative and qualitative methods were used to study the factors that motivated the execution of the project, the monetary costs and the benefits thereof expressed in socio-economic welfare measures...En este análisis de impacto sobre las Unidades Educativas del Milenio (UEM), se empleó métodos cuantitativos y cualitativos para estudiar los factores que motivaron a la ejecución del proyecto, los costos monetarios y los beneficios del mismo expresados en medidas de bienestar socioeconómico..

Forecasting volatility in agricultural commodities markets considering market structural breaks

Master of ScienceDepartment of Agricultural EconomicsGlynn TonsorThis decade has seen movements in commodity futures markets never seen before. There are many factors that have intensified price movements and volatility behavior. Those factors likely altering supply and demand include governmental policy within and outside of the U.S, weather shocks, geopolitical conflicts, food safety concerns etc. Whatever the reasons are for price movements it is clear that the volatility behavior in commodity markets constantly change, and risk managers need to use current and efficient tools to mitigate price risk. This study identified market structural breaks of realized volatility in corn, wheat, soybeans, live cattle, feeder cattle and lean hogs futures markets. Furthermore, this study analyzes the forecasting performance of implied volatility, historical volatility, a composite approach and a naïve approach as forecasters of realized volatility. The forecasting performance of these methods was analyzed in the full period of time of our weekly data from January 1995 to April 2014 and in each identified market regime for each commodity. Previous research has analyzed forecasting performance of implied volatility, a time series alternative and a composite method. However, to the best of my knowledge, they have not worried about market structural breaks in the data that might influence the performance of the mentioned forecasting methods in different periods of time. Overall, results indicate that indeed there are multiple market structural breaks present in the volatility datasets across all six commodities. We found differences in the forecasting performance of the analyzed methods when individual market regimes were analyzed. There seems to be evidence that corroborates the idea in the literature about the superiority of implied volatility over a historical volatility, a composite approach and a naïve approach. Additionally, implied volatility encompassed all the information contained in the historical volatility and the naïve measure across each identified market regime in all six commodities. Our results show that when both implied volatility and historical volatility are available, the benefit of combining those measures into a composite forecasting approach is very limited. Our results hold true for a short term 1 week ahead realized volatility forecast. It would be of interest to see how results vary for longer forecasting time horizons

Effect of the external fields in high Chern number quantum anomalous Hall insulators

A quantum anomalous Hall state with high Chern number has so far been realized in multiplayer structures consisting of alternating magnetic and undoped topological insulator layers. However, in previous proposals, the Chern number can be only tuned by varying the doping concentration or the width of the magnetic topological insulator layers. This drawback largely restrict the applications of dissipationless chiral edge currents in electronics since the number of conducting channels remains fixed. In this work, we propose a way of varying the Chern number at will in these multilayered structures by means of an external electric field applied along the stacking direction. In the presence of an electric field in the stacking direction, the inverted bands of the unbiased structure coalesce and hybridize, generating new inverted bands and collapsing the previously inverted ones. In this way, the number of Chern states can be tuned externally in the sample, without the need of modifying the number and width of the layers or the doping level. We showed that this effect can be uncovered by the variation of the transverse conductance as a function of the electric field at constant injection energy at the Fermi level

Proteína C reactiva, marcador inflamatorio asociado con ANCA en tuberculosis pulmonar

Antecedentes: la proteína C reactiva es uno de los marcadores inflamatorios denominados “reactantes de fase aguda” que se produce en el hígado en respuesta a procesos infecciosos o inflamatorios. En los pacientes con tuberculosis se ha descrito la formación de anticuerpos anticitoplasma de neutrófi los (ANCA). Objetivo: determinar la concentración de proteína C reactiva, evaluar su comportamiento como marcador de la respuesta inflamatoria y analizar su correlación con los ANCA en los pacientes con tuberculosis pulmonar, antes y después de iniciar el tratamiento antifímico. Pacientes: se eligieron pacientes con sospecha de tuberculosis pulmonar. Una vez confirmado el diagnóstico, se obtuvieron las muestras de suero para analizar los datos clínicos y de laboratorios. La determinación de ANCA se realizó con estuches comerciales de inmunofluorescencia y la de proteína C reactiva con ELISA, antes y después de iniciar el tratamiento antifímico. Resultados: se obtuvieron 50 muestras de suero de pacientes con tuberculosis pulmonar. En la primera (94%) y segunda obtención (90%) de los sueros se registró un valor de proteína C reactiva menor de 5 mg/L. El valor promedio de proteína C reactiva fue de 3.05 ± 8.27 mg/L en la primera muestra y de 4.49 ± 11.2 mg/L en la segunda (p = 0.46). Los pacientes positivos a ANCA tuvieron valores más altos de proteína C reactiva en su segunda muestra (p = 0.001). Discusión: existe una asociación entre la proteína C reactiva y la producción de anticuerpos anticitoplasma de neutrófilos en un subgrupo de pacientes con tuberculosis pulmonar. Su significación es incierta, pero quizá desempeñan alguna función patogénica en la respuesta inflamatoria pulmonar

Quantum nanoconstrictions fabricated by cryo-etching in encapsulated graphene

More than a decade after the discovery of graphene, ballistic transport in nanostructures based on this intriguing material still represents a challenging field of research in two-dimensional electronics. The presence of rough edges in nanostructures based on this material prevents the appearance of truly ballistic electron transport as theo\-re\-tically predicted and, therefore, not well-developed plateaus of conductance have been revealed to date. In this work we report on a novel implementation of the cryo-etching method, which enabled us to fabricate graphene nanoconstrictions encapsulated between hexagonal boron nitride thin films with unprecedented control of the structure edges. High quality smooth nanometer-rough edges are characterized by atomic force microscopy and a clear correlation between low roughness and the existence of well-developed quantized conductance steps with the concomitant occurrence of ballistic transport is found at low temperature. In par\-ti\-cu\-lar, we come upon exact 2$e^{2}/h$ quantization steps of conductance at zero magnetic field due to size quantization, as it has been theoretically predicted for truly ballistic electron transport through graphene nanoconstrictions

Evaluation of Energy Recovery Potential by Anaerobic Digestion and Dark Fermentation of Residual Biomass in Colombia

This study provides the first overview in Colombia on energy recovery potential by anaerobic digestion (AD) and dark fermentation (DF) of three different residual biomasses: coffee mucilage (CFM), cocoa mucilage (CCM), and swine manure (SM). First, AD and DF models were developed based on the ADM1 model. Then, simulated biogas production yields were compared to experimental data to validate the models. The results of comparative simulations indicate that energy recovery potentials from biogas for the different Colombian departments range from 148 to 48,990 toe, according to the local production amounts of CFM, CCM, and SM in 2017. The study provides crucial information that can be used to assess the best design, operation mode, and locations of AD and DF plants in Colombia. The results indicate that biogas production performances and energy recovery yields improve by increasing CFM/SM and/or CCM/SM ratios of the feed, and by increasing organic load from 2 to 26 gCOD∙l−1

¿Los fines de la pena, propios de un estado social y democrático de derecho, se materializan en el proceso penal en Colombia?

La presente tesis de Maestría en Derecho Penal de la Universidad Libre, Seccional Bogotá, titulada ¨¿LOS FINES DE LA PENA PROPIOS DE UN ESTADO SOCIAL Y DEMÓCRATICO DE DERECHO, SE MATERIALIZAN EN EL PROCESO PENAL EN COLOMBIA?¨, es realizada a partir de la consulta bibliográfica doctrinaria, jurisprudencia y especialmente, desde el ejercicio de la actividad jurisdiccional de aplicador de justicia y la defensa técnica publica de los autores. La perspectiva de la pena, sus fundamentos constitucionales, legales y del bloque de constitucionalidad, en el entendió de que la pena es la última reacción institucional de carácter judicial o administrativo, ante la comisión de un hecho penalmente punible por parte de un sujeto imputable. , sirven de fundamento para el establecimiento de sus fines, el conocimiento de la evolución de la pena y el entendimiento de los entes o instituciones encargadas de su ejecución, son motivo de estudio, así como las funciones que ha tenido históricamente la pena como son: la prevención general, la prevención especial, la socialización del penado, el restablecimiento de los derechos de la víctima o las víctimas, la venganza por la realización del delito, la retaliación, la resocialización

Dental conditions in rheumatic diseases.

Objectives. Review oral manifestations of rheumatic diseases since these can be a diagnostic challenge.Procedures. We performed a PubMed search using terms of rheumatic diseases, autoimmune disease and oral manifestations and also reviewed related guidelines and classifications.Results. We describe the clinical presentations of rheumatic diseases, such as scleroderma, rheumatoid arthritis, Sjögren's syndrome, Systemic lupus erythematosus and others that present specific oral manifestations. We also review the association between periodontal disease and autoimmunity that has been recently described in the literature.Conclusions. The oral manifestations of rheumatic diseases are diverse and can represent a challenge for medical and dental professionals

Comparación Entre El Programa De Becas Estudiantiles De La Universidad Nacional De Luján Y Los Programas De Becas Nacionales

Durante los últimos años investigamos si el Régimen de Becas Internas Estudiantiles que ofrece la Universidad Nacional de Luján (UNLu) es una herramienta efectiva para la disminución del abandono. Pudimos verificar, para las cohortes comprendidas entre los años 2007 a 2010 que la tasa de abandono para quienes acceden a alguna de las becas que integran el Régimen de Becas estudiantiles de la UNLu es muy inferior a la observada para quienes no accedieron a ese beneficio. Esta disminución, que alcanza al 35%, fue analizada considerando a los 2.130 estudiantes que participaron del sistema de becas de la UNLu entre los años 2007 y 2010 (el 12,6% de los estudiantes de esas mismas cohortes). En este trabajo, analizamos el abandono de aquellos estudiantes que acceden a los sistemas de becas tanto nacionales como privados para comparar los resultados obtenidos al estudiar el Programa de Becas de la UNLu. Nuestra hipótesis de trabajo fue que independientemente del origen de los fondos que financian los diversos programas de becas y los requisitos que se establecen para acceder a los mismos, la tasa de abandono se encuentra fuertemente influenciada por el valor del estipendio que recibe el becario. Como conclusión, encontramos que la tasa de abandono disminuye en función del monto anual del estipendio que percibe el becario solo para el Programa de Becas de la UNLu, no verificándose el mismo comportamiento para los Sistemas de Becas externos. También analizamos el comportamiento de la tasa de egreso para los sistemas de becas internos y externos a la UNLu, encontrando el mismo comportamiento que con la tasa de abandono: la tasa de egreso aumenta a medida que aumenta el estipendio solo para el Programa de Becas de la Universidad