Homogeneous and locally homogeneous solutions to symplectic curvature flow

J. Streets and G. Tian recently introduced symplectic curvature flow, a geometric flow on almost K\"ahler manifolds generalising K\"ahler-Ricci flow. The present article gives examples of explicit solutions to this flow of non-K\"ahler structures on several nilmanifolds and on twistor fibrations over hyperbolic space studied by J. Fine and D. Panov. The latter lead to examples of non-K\"ahler static solutions of symplectic curvature flow which can be seen as analogues of K\"ahler-Einstein manifolds in K\"ahler-Ricci flow.Comment: 15 page

Semiparametrically efficient rank-based inference for shape I. optimal rank-based tests for sphericity

We propose a class of rank-based procedures for testing that the shape matrix $\mathbf{V}$ of an elliptical distribution (with unspecified center of symmetry, scale and radial density) has some fixed value ${\mathbf{V}}_0$; this includes, for ${\mathbf{V}}_0={\mathbf{I}}_k$, the problem of testing for sphericity as an important particular case. The proposed tests are invariant under translations, monotone radial transformations, rotations and reflections with respect to the estimated center of symmetry. They are valid without any moment assumption. For adequately chosen scores, they are locally asymptotically maximin (in the Le Cam sense) at given radial densities. They are strictly distribution-free when the center of symmetry is specified, and asymptotically so when it must be estimated. The multivariate ranks used throughout are those of the distances--in the metric associated with the null value ${\mathbf{V}}_0$ of the shape matrix--between the observations and the (estimated) center of the distribution. Local powers (against elliptical alternatives) and asymptotic relative efficiencies (AREs) are derived with respect to the adjusted Mauchly test (a modified version of the Gaussian likelihood ratio procedure proposed by Muirhead and Waternaux [Biometrika 67 (1980) 31--43]) or, equivalently, with respect to (an extension of) the test for sphericity introduced by John [Biometrika 58 (1971) 169--174]. For Gaussian scores, these AREs are uniformly larger than one, irrespective of the actual radial density. Necessary and/or sufficient conditions for consistency under nonlocal, possibly nonelliptical alternatives are given. Finite sample performances are investigated via a Monte Carlo study.Comment: Published at http://dx.doi.org/10.1214/009053606000000731 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Affordable Learning Solutions and Interactive Content in Engineering Mechanics

Digital Affordable Learning Solutions (ALS) provides students with quality yet affordable educational content and enables instructors to utilize multimedia and interactive technology as effective ways of delivering course material. The reduced course content expenses not only allow more students to access the educational material, but also permit the instructors to customize and adapt the material to their teaching style. Incorporation of interactive technology through visually appealing media such as animations, graphics, simulations, videos, and three-dimensional models promotes students\u27 interest in learning theoretical and abstract subjects in science and engineering. In this study, the incorporation of an interactive eBook as an affordable learning solution in Mechanics of Materials is discussed. Features offered in the eBook include responsive three-dimensional models, animations, lecture videos, course summaries, algorithmically generated problem sets, pop-up hints, and guided steps. Such an eBook provides various avenues for students to learn and practice concepts, and has yielded very encouraging results, including increased student performance and positive feedback from the students themselves. The presented interactive eBook has the potential to inspire other educators and course designers to develop and implement interactive tools in their pedagogical approach

"Movimientos en Andalucía para prohibir los transgénicos" : pasos para incidir en la prohibición de los transgénicos en un territorio. El caso de Andalucía

Una vez levantada la moratoria europea para la siembra de cultivos genéticamente modificados en 2004, varias organizaciones que habían trabajado en la lucha contra los transgénicos entran en una nueva fase de lucha, en la que se buscan alianzas civiles más estables en Andalucía. Pero no es hasta noviembre de 2007, fecha en la que tienen lugar en Sevilla la "3º Conferencia Internacional de Coexistencia de Organismos Modificados Genéticamente" organizada por la Comisión Europea y la contra-conferencia "Contaminación genética: la imposible coexistencia", el momento en el que se establecen las bases del trabajo coordinado que luego impulsarían el trabajo de la PALT.El objetivo general de la PALT es conseguir una Andalucía Libre de Transgénicos, libre de cultivos comerciales y de experimentación y libre de importaciones de granos y alimentos elaborados a partir de cultivos transgénicos. Para contribuir a este objetivo general se ha puesto en marcha la campaña "Con Soberanía Alimentaria, sin Transgénicos" que se concreta en tres objetivos específicos: 1) Incidencia y presión política; 2) información y sensibilización a la ciudadanía; y 3) Denuncia, visibilización y movilización

La recherche libre en danger

Article ? Mirage

Material calavera

En el mes de octubre de 2010 los proyectos “Arte Libre y Sin Barrotes y Matapalo Cartonera”, coordinaron una semana de trabajo conjunto en el interior del Centro de Rehabilitación de Varones de Guayaquil. El objetivo fundamental de esta labor consistía en trabajar junto a los internos del Pabellón ‘El Buen Samaritano’ un álbum de memoria en el cuál se plasmaran las “historias” de los internos, a partir de objetos que apelaban a sus recuerdos

La céramique d’Argentomagus

Les travaux du PCR Argentomagus se sont activement poursuivis en 1998. Rappelons que ce programme de recherche concerne l’étude de la céramique dans la région située entre Loire et Creuse, pour une période allant de La Tène D2 à la fin du Bas-Empire, cadre qui permet de mieux cerner les phénomènes d’approvisionnement et de faire la part entre les importations à longue et moyenne distance et les locaux. Bilan des travaux effectués et des travaux en cours La réunion du 16 juin 1998 s’est tenue ..

Inequality within Philippine Provinces: Determinants and Validity of the Kuznets Curve

Several studies evaluating the determinants of growth and poverty have been conducted, but there is limited literature on inequality determinants, in particular inequality of income distribution within Philippine provinces. Using a five-year panel data of 73 provinces, this study tests the validity of the Kuznets curve and evaluates the determinants of intraprovince inequality using Gini coefficient. The results show that the inverted U-shaped Kuznets curve is observed and that human and physical capitals are significant in decreasing both income and consumption inequality. There is lower inequality among agricultural households compared to non-agricultural households. However, agricultural households have lower average income. Policy interventions should prioritize human capital investment, address the poor income performance of agricultural households, and focus on more pro-poor growth policies

Editorial

La revista El Centauro, con ediciones semestrales, es el medio de divulgación investigativa de la Universidad Libre seccional socorro, su finalidad es socializar los adelantos generados por las diversas disciplinas del saber de la institución, las publicaciones de énfasis multidisciplinares son el paradigma elocuente del trabajo metodológico