Long-term KS_S-band photometric monitoring of L dwarfs

(abridged) We perform photometric time-series analysis of a sample of ten early to mid-L dwarfs in the field over three years of $K_s$-band observations with the OMEGA 2000 infrared camera of the 3.5m telescope on Calar Alto Observatory between January 2010 and December 2012. We perform $K_s$-band differential photometry of our targets (with typical errors of $\pm$15-30~mmag at the 1$\sigma$ level) by subtracting a reference flux from each photometric measurement. This reference flux is computed using three nearby, probably constant stars in the target's field-of-view. We then construct and visually inspect the light curves to search for variability, and use four different periodogram algorithms to look for possible periods in our photometric data. Our targets do not display long-term variability over 1$\sigma$ compared to other nearby stars of similar brightness, nor do the periodograms unveil any possible periodicity for these objects, with two exceptions: 2MASS~J02411151-0326587 and G196-3B. In the case of 2MASS~J02411151-0326587 (L0), our data suggest a tentative period of 307$\pm$21~days, at 40% confidence level, which seems to be associated with peak-to-peak variability of 44$\pm$10~mmag. This object may also display variability in timescales of years, as suggested by the comparison of our Ks-band photometry with 2MASS. For G196-3B (L3), we find peak-to-peak variations of 42$\pm$10~mmag, with a possible photometric period of 442$\pm$7~days, at 95% confidence level. This is roughly the double of the astrometric period reported by Zapatero Osorio (2014). Given the significance of these results, further photometric data are required to confirm the long-term variability.These results suggest that early- to mid-L dwarfs are fairly stable in the $K_s$-band within $\pm$90 mmag at the 3 $\sigma$ level over months to years, which covers hundreds to tens of thousands of rotation cycles.Comment: Accepted for publication in Astronomy & Astrophysic

Measuring Intermediary Determinants of Early Childhood Health: A Composite Index Comparing Colombian Departments

In recent years there has been growing interest in composite indicators as an efficient tool of analysis and a method of prioritizing policies. This paper presents a composite index of intermediary determinants of child health using a multivariate statistical approach. The index shows how specific determinants of child health vary across Colombian departments (administrative subdivisions). We used data collected from the 2010 Colombian Demographic and Health Survey (DHS) for 32 departments and the capital city, Bogotá. Adapting the conceptual framework of Commission on Social Determinants of Health (CSDH), five dimensions related to child health are represented in the index: material circumstances, behavioural factors, psychosocial factors, biological factors and the health system. In order to generate the weight of the variables, and taking into account the discrete nature of the data, principal component analysis (PCA) using polychoric correlations was employed in constructing the index. From this method five principal components were selected. The index was estimated using a weighted average of the retained components. A hierarchical cluster analysis was also carried out. The results show that the biggest differences in intermediary determinants of child health are associated with health care before and during delivery

Sumas y particiones con números poligonales de rango positivo

Se usan resultados recientes relacionados con sumas mixtas de números cuadrados y triangulares con el n de probar que todos los enteros positivos n de la forma n = 8m+ k, m 2 N, k 2 f1; 2; 5; 6g, pueden ser escritos como una suma de tres cuadrados de números de una forma dada. También se usan particiones-P para obtener fórmulas para el numero de algunas composiciones restringidas de un entero positivo n en el cual cualquier suma parcial de las partes es una suma mixta de números cuadrados y triangulares

¿Cuáles son las prácticas culturales realizadas por los hinchas del Deportivo Pereira, que giran alrededor de su equipo y que se alejan de las representaciones sociales actuales que sobre ellos recaen?

Mucho se ha escrito sobre fútbol. Escritores, poetas, intelectuales y académicos, aún sin jugarlo, han dedicado algunas letras a este deporte. Después de allí se ha escrito, aunque en menor cantidad, sobre quizás, el jugador más importante, el” número 12”. El número 12 recuerda cada jugada y está en cada partido; ha visto pasar por el club a los otros once jugadores y ha crecido con la historia de su equipo

El significado del diagnóstico en la trayectoria del enfermo reumático: de la incertidumbre a la disrupción biográfica

El interés de este artículo es analizar el significado del diagnóstico médico en la biografía de los sujetos que padecen alguna enfermedad reumática, a través de un trabajo etnográfico basado en entrevistas en profundidad realizadas a un grupo de quince informantes de la Ciudad de Barcelona afectados por distintos padecimientos reumáticos. Los relatos de los entrevistados permiten abordar cómo los síntomas, disfunciones o limitaciones, experimentadas hasta el momento en que se emite un diagnóstico certero, finalmente pueden ser interpretados a la luz de un modelo que explica esta condición, se reconoce cuál es la enfermedad, se resignifica la sintomatología y se establecen determinadas estrategias de atención y afrontamiento. En este sentido, el diagnóstico médico definitivo logra descifrar el enigma de la condición crónica que aqueja al enfermo y constituye así un punto de inflexión en la trayectoria de atención, que es reconocido como una disrupción biográfica que resignifica el pasado y futuro del sujeto. No obstante, con frecuencia los afectados recorren un complejo itinerario, a veces errático e incierto, para llegar al diagnóstico definitivo, por lo que este momento se identifica retrospectivamente como un hito en la experiencia del padecimiento.This article seeks to analyze the meaning of the medical diagnosis in the biographies of people who suffer from a rheumatic disease. Based in the ethnographic method, in-depth interviews were carried out among fifteen informants affected by different rheumatic conditions from the City of Barcelona. These interviews make it possible to see how the symptoms, dysfunctions or limitations experienced up until the definitive diagnosis can be reinterpreted in the presence of a model that explains the condition and gives it a name, attributing new meaning to the symptoms and establishing certain care and coping strategies. After a period of uncertainty, this definitive medical diagnosis allows for an enigmatic chronic condition from which the person is suffering to be deciphered, representing a turning point in the care trajectory that is understood as a biographical disruption redefining the past and future of the subject. However, it is often necessary for those affected to undergo a complex, erratic and uncertain itinerary to reach the final diagnosis, which is then identified retrospectively as a milestone in the illness experience

Economía Solidaria e interdependencia : aportes desde perspectivas feministas

Con Economía Solidaria (ES) se ha denominado a un conjunto de emprendimientos socioeconómicos colectivos que han surgido en la últimas décadas a nivel mundial, caracterizados por el establecimiento de relaciones horizontales entre sus miembros, el carácter ecosostenible de sus emprendimientos y la conformación de redes colaborativas a nivel local y mundial. Investigadoras feministas plantean que existen ciertos sesgos androcéntricos en la forma de abordar el estudio de la ES. La propuesta en este artículo es ampliar los marcos interpretativos que han analizado estas experiencias. Para ello, parto de realizar un recorrido por las producciones académicas que han abordado la ES desde estudios de género y trabajos feministas, analizando sus aportes y limitaciones. Finalmente introduzco las nociones de interdependencia y sostenibilidad de la vida, herramientas teóricas brindadas desde el feminismo, como un aporte al estudio de estos colectivos.Solidarity economy has been called a set of collective socio-economic endeavours that have emerged around the world in the last decades, characterized by the establishment of horizontal relationships among its members, the sustainable nature of their enterprises and the formation of collaborative networks at local and global level. Feminist researchers poses that there are certain androcentric biases in the way of addressing the study of the SE. In this paper, the proposal is to broaden the interpretive frameworks that have analysed these experiences. For this reason, I begin with a review of the academic productions which have approached SE based on gender studies and feminist works, and I analyse their contributions and limitations. I finally introduce the concepts of interdependence and sustainability of life, theoretical tools provided from feminism, as a contribution to the study of these groups