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Papers by Jorge Andrés Marin

Revista de Economía del Rosario, 2005

This work presents a tool for the additivity test. The additive model is widely used for parametr... more This work presents a tool for the additivity test. The additive model is widely used for parametric and semiparametric modeling of economic data. The additivity hypothesis is of interest because it is easy to interpret and produces reasonably fast convergence rates for non-parametric estimators. Another advantage of additive models is that they allow attacking the problem of the curse of dimensionality that arises in non- parametric estimation. Hypothesis testing is based in the well-known bootstrap residual process. In nonparametric testing literature, the dominant idea is that bandwidth utilized to produce bootstrap sample should be bigger that bandwidth for estimating model under null hypothesis. However, there is no hint so far about how to choose such bandwidth in practice. We will discuss a first step to find some rule of thumb to choose bandwidth in that context. Our suggestions are accompanied by simulation studies.

Revista de Economía del Caribe, 2014

En este artículo se basa en el interés de los autores por investigar los determinantes económicos... more En este artículo se basa en el interés de los autores por investigar los determinantes económicos subyacentes en el mantenimiento de la paz en el posconflicto. Para lograr el objetivo se seleccionó una muestra de países que después de atravesar por conflictos armados internos han logrado alcanzar la paz. La extensa cantidad de variables socioeconómicas disponibles en las bases de datos analizadas hace necesario utilizar una metodología de análisis de componentes principales para elegir aquellas con mayor poder explicativo. En adición, se construye un modelo probabilístico para determinar cuáles variables tienen una mayor probabilidad de sostener la paz. La evidencia sugiere que entre los factores más relevantes que incrementan la probabilidad de una paz duradera son: la ayuda internacional, el capital físico, la infraestructura, la tecnología, las condiciones macroeconómicas y el valor agregado de la producción nacional. Palabras clave: Conflicto armado interno, estudios de paz, desarrollo económico, posconflicto, modelos probit.

Infectio, 2013

Citoplasma de las neuronas corticales cerebrales con inclusiones eosinófilas compatibles con cuer... more Citoplasma de las neuronas corticales cerebrales con inclusiones eosinófilas compatibles con cuerpos de Negri (arriba). Neuronas de Purkinje donde se observan inclusiones eosinófilas compatibles con cuerpos de Negri (abajo)

In this paper we study the effect of family and school background on students' academic perfo... more In this paper we study the effect of family and school background on students' academic performance, who attended public schools in Medellín. Two approaches are implemented in this work. Firstly, we investigate the effect of covariates on different segments of scores' distribution by quantile regression. Secondly, we are interested in estimating the school effect on average academic performance by estimating

After reading and thinking seriously about the teachings in Tim Harford’s books, The Undercover E... more After reading and thinking seriously about the teachings in Tim Harford’s books, The Undercover Economist and the Logic of Life, they confirmed me that every behavior and act, not only in the market but also along life, have hidden interests and everybody is conscious about them. What do I mean by “conscious”? I mean that almost all our choices are

Respiration, 2009

In 12 chronic bronchitic out-patients, during 3 successive days, the variations of FEV1 and Vmax2... more In 12 chronic bronchitic out-patients, during 3 successive days, the variations of FEV1 and Vmax25 were studied at 15, 30, 45,60, 120, and 180min after inhalation of: (1) [0.1 mg fenoterol (F) associated with 0.04 mg ipratropium bromide (IB)]; (2) [0.2 mg salbutamol (S)], and (3) [0.5 mg terbutaline (T)]. There were no secondary effects resulting from any treatment. Maximum

Chest, 1995

Study objective: To assess the usefulness of noninva¬ sive nasal mask ventilation (NMV) in the tr... more Study objective: To assess the usefulness of noninva¬ sive nasal mask ventilation (NMV) in the treatment of an exacerbation of chronic respiratory insufficiency in patients stable enough to be admitted to a non-ICU ward. Design: A prospective study in which the beneficial effect of NMV was compared with conservative treat¬ ment. Setting: A ward of respiratory medicine of a tertiaryreferral teaching hospital. Patients: The study group included 15 patients with acute respiratory acidosis. These patients had pH less than 7.35 and PaC02 more than 60 mm Hg, respiratory rate of 30 breaths or less per minute, hemodynamic stability, and alertness and willingness of cooperation with the NMV treatment. The control group consisted of 16 patients who fulfilled the same arterial blood gas requirements, retrospectively selected from the dis¬ charge forms of the ward of respiratory medicine for the year 1993. Interventions: Patients underwent NMV for two ses¬ sions per day (one in the morning and one in the afternoon), each session lasting 4 h. A volumetric res¬ pirator (Monnal D; Taema; Paris, France) was used in four patients with restrictive disease. A positive-pres¬ sure ventilator (DP90; Taema; Paris, France) was used in 11 patients with obstructive disease. Control pa¬ tients received standard medical, oxygen, and chest physical therapy. Results: As compared with pre-NMV values, mean pH was significantly higher at 4 h of NMV after the patient's ventilatory adaptation (t=8.814, p<0.001) and at the end of NMV (t=12.06, p<0.001). Ventilatory support also produced a significant improvement in hypercapnia (pre-NMV vs NMV after the patient's ventilatory adaptation, t=6.675, p<0.001; pre-NMV vs

Infectio, 2003

Base de dados : LILACS. Pesquisa : 422689 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 422689 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Texto completo. experimental, Documentos relacionados. Id: 422689 ...

Lecturas de Economía, 2009

Este artículo caracteriza y estudia la eficiencia de un conjunto representativo de firmas en el s... more Este artículo caracteriza y estudia la eficiencia de un conjunto representativo de firmas en el sector de calzado y marroquinería de cuero en Bogotá, Bucaramanga, Cúcuta y el Área Metropolitana de Medellín. El análisis se basa en una encuesta sobre múltiples factores de la producción en esta industria (insumos, integración de actividades, gestión administrativa, innovación, exportaciones, etc.). Nuestros resultados indican que una parte razonable de la varianza total es explicada por la varianza asociada al término de ineficiencia. adicionalmente, en esta muestra existen rendimientos marginales decrecientes en el uso del factor trabajo y, aunque muchas de las empresas son relativamente eficientes, el sector está aún lejos de funcionar en la frontera de posibilidades de producción. Palabras clave: Eficiencia, frontera estocástica, calzado y cuero. Clasificación JEL: C13, C20,D24 Abstract: In this paper, we characterize and study the efficiency of a representative set of firms in the...

Revista de Economía del Rosario, 2005

This work presents a tool for the additivity test. The additive model is widely used for parametr... more This work presents a tool for the additivity test. The additive model is widely used for parametric and semiparametric modeling of economic data. The additivity hypothesis is of interest because it is easy to interpret and produces reasonably fast convergence rates for non-parametric estimators. Another advantage of additive models is that they allow attacking the problem of the curse of dimensionality that arises in non- parametric estimation. Hypothesis testing is based in the well-known bootstrap residual process. In nonparametric testing literature, the dominant idea is that bandwidth utilized to produce bootstrap sample should be bigger that bandwidth for estimating model under null hypothesis. However, there is no hint so far about how to choose such bandwidth in practice. We will discuss a first step to find some rule of thumb to choose bandwidth in that context. Our suggestions are accompanied by simulation studies.

Revista de Economía del Caribe, 2014

En este artículo se basa en el interés de los autores por investigar los determinantes económicos... more En este artículo se basa en el interés de los autores por investigar los determinantes económicos subyacentes en el mantenimiento de la paz en el posconflicto. Para lograr el objetivo se seleccionó una muestra de países que después de atravesar por conflictos armados internos han logrado alcanzar la paz. La extensa cantidad de variables socioeconómicas disponibles en las bases de datos analizadas hace necesario utilizar una metodología de análisis de componentes principales para elegir aquellas con mayor poder explicativo. En adición, se construye un modelo probabilístico para determinar cuáles variables tienen una mayor probabilidad de sostener la paz. La evidencia sugiere que entre los factores más relevantes que incrementan la probabilidad de una paz duradera son: la ayuda internacional, el capital físico, la infraestructura, la tecnología, las condiciones macroeconómicas y el valor agregado de la producción nacional. Palabras clave: Conflicto armado interno, estudios de paz, desarrollo económico, posconflicto, modelos probit.

Infectio, 2013

Citoplasma de las neuronas corticales cerebrales con inclusiones eosinófilas compatibles con cuer... more Citoplasma de las neuronas corticales cerebrales con inclusiones eosinófilas compatibles con cuerpos de Negri (arriba). Neuronas de Purkinje donde se observan inclusiones eosinófilas compatibles con cuerpos de Negri (abajo)

In this paper we study the effect of family and school background on students' academic perfo... more In this paper we study the effect of family and school background on students' academic performance, who attended public schools in Medellín. Two approaches are implemented in this work. Firstly, we investigate the effect of covariates on different segments of scores' distribution by quantile regression. Secondly, we are interested in estimating the school effect on average academic performance by estimating

After reading and thinking seriously about the teachings in Tim Harford’s books, The Undercover E... more After reading and thinking seriously about the teachings in Tim Harford’s books, The Undercover Economist and the Logic of Life, they confirmed me that every behavior and act, not only in the market but also along life, have hidden interests and everybody is conscious about them. What do I mean by “conscious”? I mean that almost all our choices are

Respiration, 2009

In 12 chronic bronchitic out-patients, during 3 successive days, the variations of FEV1 and Vmax2... more In 12 chronic bronchitic out-patients, during 3 successive days, the variations of FEV1 and Vmax25 were studied at 15, 30, 45,60, 120, and 180min after inhalation of: (1) [0.1 mg fenoterol (F) associated with 0.04 mg ipratropium bromide (IB)]; (2) [0.2 mg salbutamol (S)], and (3) [0.5 mg terbutaline (T)]. There were no secondary effects resulting from any treatment. Maximum

Chest, 1995

Study objective: To assess the usefulness of noninva¬ sive nasal mask ventilation (NMV) in the tr... more Study objective: To assess the usefulness of noninva¬ sive nasal mask ventilation (NMV) in the treatment of an exacerbation of chronic respiratory insufficiency in patients stable enough to be admitted to a non-ICU ward. Design: A prospective study in which the beneficial effect of NMV was compared with conservative treat¬ ment. Setting: A ward of respiratory medicine of a tertiaryreferral teaching hospital. Patients: The study group included 15 patients with acute respiratory acidosis. These patients had pH less than 7.35 and PaC02 more than 60 mm Hg, respiratory rate of 30 breaths or less per minute, hemodynamic stability, and alertness and willingness of cooperation with the NMV treatment. The control group consisted of 16 patients who fulfilled the same arterial blood gas requirements, retrospectively selected from the dis¬ charge forms of the ward of respiratory medicine for the year 1993. Interventions: Patients underwent NMV for two ses¬ sions per day (one in the morning and one in the afternoon), each session lasting 4 h. A volumetric res¬ pirator (Monnal D; Taema; Paris, France) was used in four patients with restrictive disease. A positive-pres¬ sure ventilator (DP90; Taema; Paris, France) was used in 11 patients with obstructive disease. Control pa¬ tients received standard medical, oxygen, and chest physical therapy. Results: As compared with pre-NMV values, mean pH was significantly higher at 4 h of NMV after the patient's ventilatory adaptation (t=8.814, p<0.001) and at the end of NMV (t=12.06, p<0.001). Ventilatory support also produced a significant improvement in hypercapnia (pre-NMV vs NMV after the patient's ventilatory adaptation, t=6.675, p<0.001; pre-NMV vs

Infectio, 2003

Base de dados : LILACS. Pesquisa : 422689 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 422689 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Texto completo. experimental, Documentos relacionados. Id: 422689 ...

Lecturas de Economía, 2009

Este artículo caracteriza y estudia la eficiencia de un conjunto representativo de firmas en el s... more Este artículo caracteriza y estudia la eficiencia de un conjunto representativo de firmas en el sector de calzado y marroquinería de cuero en Bogotá, Bucaramanga, Cúcuta y el Área Metropolitana de Medellín. El análisis se basa en una encuesta sobre múltiples factores de la producción en esta industria (insumos, integración de actividades, gestión administrativa, innovación, exportaciones, etc.). Nuestros resultados indican que una parte razonable de la varianza total es explicada por la varianza asociada al término de ineficiencia. adicionalmente, en esta muestra existen rendimientos marginales decrecientes en el uso del factor trabajo y, aunque muchas de las empresas son relativamente eficientes, el sector está aún lejos de funcionar en la frontera de posibilidades de producción. Palabras clave: Eficiencia, frontera estocástica, calzado y cuero. Clasificación JEL: C13, C20,D24 Abstract: In this paper, we characterize and study the efficiency of a representative set of firms in the...