Down and out or up and in? Polarization-based measures of the middle class for Latin America

This document presents a systematic review of empirical approaches to the identification and measurement of the middle class as the concept is used in the applied literature. It then presents an arguably less arbitrary definition of the middle class which is based on sound principles of distributional analysis and derived from income polarization measures. The document illustrates the differences between the existing approaches and the proposed methodology with a comparative analysis of the extent and evolution of the middle classes since the early 1990s in six Latin American countries. The polarization-based measurements of the middle class are shown to exhibit a greater degree of homogeneity in terms of some key socioeconomic characteristics than other measures employed in the literatureFil: Cruces, Guillermo Antonio. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Lopez Calva, Luis Felipe. Banco Mundial; Estados UnidosFil: Battistón, Diego Ezequiel. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

The decline in inequality in Latin America: How much, since when and why

Between 2000 and 2009, the Gini coefficient declined in 13 of 17 Latin American countries for which comparable data exist. The decline was statistically significant and robust to changes in the time interval, inequality measures and data sources. In depth country studies for Argentina, Brazil, Mexico and Peru suggest that there are two phenomena which underlie this trend: (i) a fall in the premium to skilled labor (as measured by returns to education); and (ii) higher and more progressive government transfers. The fall in the premium to skills results from a combination of supply and demand factors and, in Argentina—and to a lesser extent in Brazil--, from more active labor market policies as well.Income inequality, wage gap, government transfers, Latin America.

Subtopologías separables y Cocientes de grupos fuertemente realcompactos

Esta tesis tiene dos temas principales, que inspiraron la elaboración de dos artículos: Isomorfismos continuos sobre grupos separables (ver [21]). Cocientes de grupos fuertemente realcompactos (ver [22]). En la Introducción se presentan los antecedentes históricos que motivan el estudio de los problemas atacados en esta tesis. El Capítulo 1 “Preliminares” se divide en 4 secciones. En la sección 1.1 se da una introducción a los grupos topológicos y se mencionan las características más importantes que serán utilizadas en este trabajo. En la sección 1.2 se introduce el concepto de subtopología y se enuncian resultados ya conocidos. En la sección 1.3 se definen diferentes tipos de completitud tanto en espacios como en grupos topológicos y se presenta el concepto de grupos fuertemente realcompactos y fuertemente Dieudonné completos. Por último, en la sección 1.4, se especifica la notación y definiciones básicas que se usaran a lo largo de la tesis. En el Capítulo 2 “Subtopologías Separables” se estudia el problema de las condensaciones sobre espacios separables e isomorfismos continuos sobre grupos topológicos separables. En el teorema 2.1.2 se dan condiciones suficientes para que un espacio topológico tenga una subtopología separable y se dan ejemplos que muestran que ninguna de estas condiciones se puede quitar (ver los ejemplos 2.1.3, 2.1.4 y 2.1.5). Además se prueba que estas condiciones fallan cuando se busca una subtopología de grupo separable, dando ejemplos de grupos topológicos que tienen una subtopología separable pero no una subtopología de grupo separable (ver el ejemplo 2.2.3). En el ejemplo 2.2.5 se construye un espacio de Tychonoff numerablemente compacto y no separable que admite una condensación sobre un espacio compacto separable de cardinalidad 2c . En la sección 2.3 se demuestra que a todo grupo Abeliano de cardinalidad menor o igual que 2c se le puede asignar una topología de grupo Hausdorff separable, es decir, que independientemente de sus características algebraicas, siempre podemos asignar una topología de grupo Hausdorff separable a un grupo Abeliano de cardinalidad menor o igual que 2c (ver el teorema 2.3.11). En el Capitulo 3 “Cocientes de grupos FRC y FDC” se estudian las características que tienen los grupos topológicos fuertemente realcompactos y los grupos fuertemente Dieudonn´e completos. En la sección 3.1 se demuestran propiedades que tienen las P-modificaciones de grupos topológicos y se describe la completación de Raıkov de la P-modificación de un grupo en términos del grupo original. En la sección 3.2 se estudian también los cocientes de los grupos fuertemente realcompactos y de grupos fuertemente Dieudonné completos con respecto a subgrupos completamente metrizables y Cech-completos. Nuestros argumentos nos llevan a estudiar la relación entre ˇ la P-modificación del cociente de grupos y el cociente de las P-modificaciones en la sección 3.3. Por ´último, en el Capítulo 4 “Conclusiones” se presentan las observaciones finales del trabajo y se hacen preguntas que quedan sin responder y que pueden ser interesantes para una investigación futura

Income and beyond: Multidimensional poverty in six Latin American countries

This paper presents empirical results of a wide range of multidimensional poverty measures for: Argentina, Brazil, Chile, El Salvador, Mexico and Uruguay, for the period 1992–2006. Six dimensions are analysed: income, child attendance at school, education of the household head, sanitation, water and shelter. Over the study period, El Salvador, Brazil, Mexico and Chile experienced significant reductions of multidimensional poverty. In contrast, in urban Uruguay there was a small reduction in multidimensional poverty, while in urban Argentina the estimates did not change significantly. El Salvador, Brazil and Mexico together with rural areas of Chile display significantly higher and more simultaneous deprivations than urban areas of Argentina, Chile and Uruguay. In all countries, access to proper sanitation and education of the household head are the highest contributors to overall multidimensional poverty.Multidimensional poverty measurement, counting approach, Latin America, Unsatisfied Basic Needs, rural and urban areas.

Engineering professors' conceptions on basic topics of electromagnetism in Mexico

Electromagnetism is one of the introductory physics subjects common to many engineering programs in Mexico and other countries. There are several studies about students’ misconceptions regarding the contents of electromagnetism courses but the information about teachers’ misconceptions which is one of the main factors that contribute to students’ misconceptions, is not very extensive. It is a fact that teachers, as well as students, have problems with the scientific knowledge of some concepts (Pardhan & Bano, 2001). Since they are responsible for helping students to fully understand and give a proper meaning to these concepts, it is very important to find out what teachers know about these concepts, to generate teacher formation programs that help them in the improvement of their teaching activities. Moreover, most of the existing studies focus on identifying misconceptions about the properties of electric charges (Furió-Mas & Guisasola Aranzabal, 2008), electric field, Gauss’s law, electric current (Hashish et al., 2020) and voltage, but none of them is centered around the basic concepts in electrostatics and the strong relations between them. This work is part of a qualitative research with a descriptive design and presents the results of a 2-tier instrument combined with a semi-structured interview, designed to identify the conceptions that in-service engineering teachers have about the concepts of electrostatic force, electric field, electric potential, and the relation between them, distinguishing between correct conceptions, misconceptions, and lack of knowledge. RESULTS Information about the teachers’ academic training and teaching experience will be presented, correlating this information to the conceptions that teachers have about the basic electrostatics concepts. Due to the academic training and teaching experience that in-service teachers have, predominance of misconceptions over lack of knowledge is expected. REFERENCES Furió-Mas, C., & Guisasola Aranzabal, J. (2008). Dificultades de aprendizaje de los conceptos de carga y de campo eléctrico en estudiantes de bachillerato y universidad. Enseñanza de Las Ciencias. Revista de Investigación y Experiencias Didácticas, 16(1), 131–146. https://doi.org/10.5565/rev/ensciencias.4148. Hashish, A. H., Seyd-Darwish, I., & Tit, N. (2020). Addressing Some Physical Misconceptions in Electrostatics of Freshman Engineering Students. International Journal for Innovation Education and Research, 8(2), 01–07. https://doi.org/10.31686/ijier.vol8.iss2.2161. Pardhan, H., & Bano, Y. (2001). Science teachers’ alternate conceptions about direct-currents. International Journal of Science Education, 23(3), 301–318. https://doi.org/10.1080/095006901750066538

Multivariate cluster analysis to study motility activation of Solea senegalensis spermatozoa: a model for marine teleosts

Computer-assisted sperm analysis (CASA) and clustering analysis have enabled to study sperm subpopulations in mammals, but their use in fish sperm has been limited. We have used spermatozoa. from Senegalese sole (Solea senegalensis) as a model for subpopulation analysis in teleostei using two different activating solutions. Semen from six males was activated using 1100 mOsm/kg solutions: artificial seawater (ASW) or sucrose solution (SUC). Motility was acquired at 15, 30, 45, and 60 s post-activation. CASA parameters were combined into two principal components, which were used in a non-hierarchical clustering analysis, obtaining four subpopulations (CL): CL1 (slow/non-linear), CL2 (slow/linear), CL3 (fast/non-linear), and CL4 (fast/linear). We detected spermatozoa lysis, especially in ASW. Sperm motility was higher for SUC and decreased with time. The subpopulation proportions varied with time and activating treatment, showing both an increase in CL1 and CL2 and a decrease in CO and CL4 with time. Both CL3 and CL4 were higher in samples activated with SUC, at least in early post-activation. Proportions of CO and CL4 at 15 s were associated with higher quality at 60 sand with lower lysis. A second clustering analysis was conducted, classifying the males accordingly to their motility subpopulations. This analysis showed a high heterogeneity between samples. Subpopulation analysis of CASA data can be applied to Solea spermatozoa, allowing identification of potentially interesting sperm subpopulations. Future studies might benefit from these techniques to establish the relationship of these subpopulations with fish sperm quality and fertility, helping to characterize males according to their reproductive potential.info:eu-repo/semantics/publishedVersio

Evidence and Policy Lessons on the Links between Disaster Risk and Poverty in Latin America

Extreme climate-related events have a direct impact on the welfare of households. The frequency and magnitude of those shocks appear to be closely linked to increasing vulnerability of households and communities in developing countries. Yet, the link between natural disasters and living standards is complex and causality is difficult to capture empirically. Among other reasons, there is a two-way relationship between the vulnerability to natural disasters and poverty, and disentangling the direction of the causal impacts is rather challenging, especially in terms of the intensity of the effects of the events and not only their incidence. This paper pursued two main goals. First, the empirical analysis estimated the relation between natural events and social indicators at the local level, establishing a causal link whenever possible. Second, analysis was carried out at the household level in order to determine the potential role played by coping mechanisms to influence long-term impacts on welfare

Architecture for automatic recognition of group activities using local motions and context

Currently, the ability to automatically detect human behavior in image sequences is one of the most important challenges in the area of computer vision. Within this broad field of knowledge, the recognition of activities of people groups in public areas is receiving special attention due to its importance in many aspects including safety and security. This paper proposes a generic computer vision architecture with the ability to learn and recognize different group activities using mainly the local group’s movements. Specifically, a multi-stream deep learning architecture is proposed whose two main streams correspond to a representation based on a descriptor capable of representing the trajectory information of a sequence of images as a collection of local movements that occur in specific regions of the scene. Additional information (e.g. location, time, etc.) to strengthen the classification of activities by including it as additional streams. The proposed architecture is capable of classifying in a robust way different activities of a group as well to deal with the one-class problems. Moreover, the use of a simple descriptor that transforms a sequence of color images into a sequence of two-image streams can reduce the curse of dimensionality using a deep learning approach. The generic deep learning architecture has been evaluated with different datasets outperforming the state-of-the-art approaches providing an efficient architecture for single and multi-class classification problems

Bancos de semillas en dos estadios sucesionales de bosque andino en el noreste de Colombia

"Background: Soil seed banks play an important role in post-disturbance regeneration and succession of species from different successional stages. Questions: 1) What is the most effective method for determining the composition and structure of the soil seed bank of Andean forests? 2) What is the composition and structure of soil seed banks in old-growth forest and shrubland sites in the Andean montane tropical forest of the North Santander region of Colombia? Study site: Andean forest, Pamplona, Colombia Methods: We surveyed the soil seed bank in two successional stages of Andean forest and examined its structure using two sampling methods: direct separation and germination. Results: Soil seed bank density was higher (18-fold in old-growth forest and 666-fold in shrubland) with the direct separation method than with germination; however, under the germination method, we found four species that we did not detect through the direct separation method. Soil seed banks from shrublands were mainly dominated by species from disturbed areas (91 %), while those from the old-growth forest presented early, intermediate and late species; e.g., Miconia summa, Myrsine dependens and Solanum sp., respectively. In the old-growth forest (especially for late species), density increased with depth. This pattern was not observed in shrubland. Seeds obtained by using the direct separation method presented low (< 7 %) viability. Conclusion: We consider the two methods to be complementary and recommend the use of both for a thorough characterization of soil seed banks from Andean forests. At different successional stages in the Colombian Andean forest, the soil seed bank may contain early, intermediate and late species, and it therefore plays an important role in the regeneration of this threatened ecosystem.""Antecedentes: Los bancos de semillas del suelo juegan un papel importante en la regeneración de especies de diferentes etapas de sucesión. Preguntas: 1) ¿Cuál es el método más eficaz para la descripción de la composición y la estructura del banco de semillas del suelo de los bosques andinos? y 2) ¿Cómo es la composición y estructura de los bancos de semillas del suelo en un bosque primario y un matorral en el bosque andino en Colombia? Sitio de estudio: Bosque andino en Pamplona, Norte de Santander, Colombia Métodos: Se estudiaron el banco de semillas del suelo en dos etapas de sucesión de bosque andino y se examinó la estructura mediante dos métodos de muestreo: separación directa y la germinación. Resultados: La densidad del banco de semillas en el suelo fue mayor (18 veces en bosques primarios y 666 veces en matorral) con el método de separación directa que con el método de germinación; Sin embargo, bajo el método de germinación, se encontraron cuatro especies que no detectamos a través del método de separación directa. Los bancos de semillas de matorrales fueron dominados principalmente por especies de las áreas perturbadas (91 %), mientras que en el bosque primario se encontraron especies de estados sucesionales tempranos, intermedios y tardíos, por ejemplo, Miconia summa, Myrsine dependens y Solanum sp., respectivamente. En el bosque maduro (especialmente para las especies de estapas sucesionales tardías), la densidad aumenta con la profundidad. Este patrón no se observó en el matorral. Aunado a esto, las semillas obtenidas mediante el método de separación directa presentaron baja (7 % <) viabilidad. Conclusión: Consideramos que los dos métodos son complementarios y recomendamos el uso de las dos metodologías para una adecuada caracterización de los bancos de semillas del suelo de los bosques andinos. El banco de semillas del suelo puede contener especies de diferentes estadios sucesionales, por lo que tiene un papel importante en la regeneración del bosque andino de Colombia.

Diseño de concreto poroso f’c=175 Kg/cm2 remplazando fibra de caucho para mejorar la permeabilidad y compresión, Morales 2023

La presente investigación titulado “Diseño de concreto poroso f’c=175 Kg/cm2 remplazando fibra de caucho para mejorar la permeabilidad y compresión, Morales 2023”, tiene por objetivo principal, el diseño de concreto poroso adecuado (f'c=175 kg/cm2) agregando fibra de caucho en diferentes porcentajes para mejorar las propiedades mecánicas como hidráulicas. El propósito de este estudio es utilizarlo para desarrollar superficies que sean tanto drenantes como duraderas. El enfoque utilizado es cuantitativo, la metodología fue del tipo aplicada y de carácter experimental, debido que la variable independiente fibra de caucho fue manipulada y como variable dependiente tenemos la resistencia a compresión y permeabilidad, la muestra y población fue de 36 probetas cilíndricas reemplazando la grava con fibra de caucho en porcentajes de 1.50%, 2.50% y 3.50% y determinando las resistencias a compresión a los, 7, 14 y 28 dias de acuerdo a la NTP. Los hallazgos revelaron que la mejor proporción de remplazo es 2.50% de fibra de caucho, dado que se observó una mejora en la resistencia a compresión a 28 días, alcanzando un valor de 182.40 kg/cm2, y una permeabilidad de 0.523 cm/s. Además, se considera que el costo por m3 es S/. 338.24, precio que resulta favorable para su aplicación