Stellar populations in the bulges of S0s and the formation of S0 galaxies

The stellar populations in the bulges of S0s, together with the galaxies' dynamics, masses and globular clusters, contain very interesting clues about their formation. I present here recent evidence suggesting that S0s are the descendants of fading spirals whose star formation ceased.Comment: 4 pages. To appear in the proceedings of IAU Symposium 245, "Formation and Evolution of Galaxy Bulges," M. Bureau, E. Athanassoula, and B. Barbuy, ed

A C++11 implementation of arbitrary-rank tensors for high-performance computing

This article discusses an efficient implementation of tensors of arbitrary rank by using some of the idioms introduced by the recently published C++ ISO Standard (C++11). With the aims at providing a basic building block for high-performance computing, a single Array class template is carefully crafted, from which vectors, matrices, and even higher-order tensors can be created. An expression template facility is also built around the array class template to provide convenient mathematical syntax. As a result, by using templates, an extra high-level layer is added to the C++ language when dealing with algebraic objects and their operations, without compromising performance. The implementation is tested running on both CPU and GPU.Comment: 21 pages, 6 figures, 1 tabl

An algorithm for the Cartan-Dieudonn\'e theorem on generalized scalar product spaces

We present an algorithmic proof of the Cartan-Dieudonn\'e theorem on generalized real scalar product spaces with arbitrary signature. We use Clifford algebras to compute the factorization of a given orthogonal transformation as a product of reflections with respect to hyperplanes. The relationship with the Cartan-Dieudonn\'e-Scherk theorem is also discussed in relation to the minimum number of reflections required to decompose a given orthogonal transformation.Comment: 25 page

Factor productivity in the Argentinean agriculture

This paper is aimed at investigating the endogeneity of the total factor productivity in the Argentinean agriculture. In a simple model ofendogenous technological change, the implementation of new techniques of production would depend upon sectoral relative prices, and upon the overall endowment of capital and land relative to labor. It is found that the estimations using data covering the years 1939-1984 do not reject the hypothesis of endogeneity of technological change as a function of the aforementioned variables. It is also found that the fiscal deficit negatively affects the implementation of new techniques. The coefficient of labor in the value added of the agricultural sector (cereals and oilseeds, livestock and fisheries) is 0.28 according to the estimates of the 1973 input-output matrix data, a value that is very close to the estimate used in this paper.Total factor productivity, available and implemented technologies, cointegrated vector autoregressions, Barttlet correction, eigenvalues

A new projection method for finding the closest point in the intersection of convex sets

In this paper we present a new iterative projection method for finding the closest point in the intersection of convex sets to any arbitrary point in a Hilbert space. This method, termed AAMR for averaged alternating modified reflections, can be viewed as an adequate modification of the Douglas--Rachford method that yields a solution to the best approximation problem. Under a constraint qualification at the point of interest, we show strong convergence of the method. In fact, the so-called strong CHIP fully characterizes the convergence of the AAMR method for every point in the space. We report some promising numerical experiments where we compare the performance of AAMR against other projection methods for finding the closest point in the intersection of pairs of finite dimensional subspaces

Integrando otras formas de evaluar en la formación inicial del profesorado: el uso de Kahoot en Educación Ambiental

En este trabajo se presenta la implementación de la aplicación Kahoot como herramienta de evaluación en el marco de una asignatura optativa de Educación Ambiental en el 4º curso del Grado en Educación Infantil. Se diseñaron un total de cinco cuestionarios tipo Quiz que fueron integrados en distintos momentos de la asignatura. Al inicio, el Kahoot diseñado sirvió para solventar y abrir un espacio de discusión en el grupo-clase sobre las dudas surgidas en torno al concepto de Medio Ambiente. También sirvió para explorar las concepciones previas mantenidas por los futuros maestros/as de infantil sobre contenidos relevantes en Educación Ambiental. Finalmente, se utilizó un Kahoot grupal para evaluar un proyecto llevado a cabo en la asignatura en torno al Huerto Ecológico Universitario (HEU). Las valoraciones de la docente y del alumnado sobre el uso del Kahoot como innovación en la asignatura fueron muy positivas; en el caso del alumnado, el 48,8% y el 43,9% mostró estar muy de acuerdo y completamente de acuerdo respectivamente, con la herramienta web empleada, respecto al 2,4% de los estudiantes que se mostraron estar ni acuerdo ni en desacuerdo. En el caso de la docente, valora muy positivamente la relación tiempo invertido y potencial didáctico que proporciona el Kahoot y sobre todo poder adaptar las preguntas en función del objetivo a evaluar en cada momento de la asignatura