Couplings between Chern-Simons gravities and 2p-branes

The interaction between Chern-Simons (CS) theories and localized external sources (2p-branes) is analyzed. This interaction generalizes the minimal coupling between a point charge (0-brane) and a gauge connection. The external currents that define the 2p-branes are covariantly constant (D-2p-1)-forms coupled to (2p-1) CS forms. The general expression for the sources --charged with respect to the corresponding gauge algebra-- is presented, focusing on two special cases: 0-branes and (D-3)-branes. In any dimension, 0-branes are constructed as topological defects produced by a surface deficit of (D-2)-sphere in AdS space, and they are not constant curvature spaces for D>3. They correspond to dimensionally continued black holes with negative mass. On the other hand, in the case of CS (super) gravities, the (D-3)-branes are naked conical singularities (topological defects) obtained by identification of points with a Killing vector. In 2+1 dimensions, extremal spinning branes of this type are BPS states. Stable (D-3)-branes are shown to exist also in higher dimensions, as well. Classical field equations are also discussed and in the presence of sources there is a large number of inequivalent and disconnected sectors in solution space.Comment: 29 pages, no figures; version accepted in PRD; extended introduction and several references added; some sections have been reorganized and several minor corrections mad

La educación en la Santa Fe colonial /

Durante la época de la Colonia, la universidad jugó un papel clave dentro de la jerarquizada y segregacionista sociedad de la época. El acceso a ella fue privilegio exclusivo de la “República de españoles americanos”, particularmente de los españoles pobres y los hijos de funcionarios reales de distintas posiciones jerárquicas. Para estos dos sectores de la población neogranadina, la universidad funcionó como un mecanismo para mantener y elevar su status social y económico: el acceso a un saber determinado –particularmente Teología o Derecho–, significaba poder; el uso del latín, lengua en que se expresaban y circulaban tales saberes, constituía un elemento de diferenciación y prestigio; la pertenencia a una institución universitaria implicaba, entonces, una serie de preeminencias y privilegios sociales y laborales; pero además, la universidad funcionó como un mecanismo de defensa contra la amenaza que significó para el sector minoritario de la sociedad, la extensión que la pobreza alcanzó, particularmente durante el siglo xvii, y contra el mestizaje y sus consecuencias, que amenazaban derruir privilegios ejercidos durante mucho tiempoSegunda edició

El proyecto Bogotá : apuntes sobre la extensión de la tecnología educativa y el modelo curricular en el distrito /

Dividido en cuatro apartados el autor aborda algunos elementos sobre las formas como la tecnología educativa circuló en las prácticas e instituciones del Distrito Capital. En un primer momento se explica la crisis mundial de la educación, que establecía una relación estrecha entre desarrollo-educación-economía.Segunda edició

Censo de dendrobates truncatus (anura, dendrobatidae) en la reserva forestal protectora serranía de coraza, montes de maría, sucre, colombia

Mediante la aplicación del transecto lineal (BURNHAM et al., 1980), iniciando desde la Estación Primates, municipio de Colosó, Sucre, Colombia, del 5 al 7 febrero de 2010, en un recorrido de 1000 m hacia el Norte del Arroyo Sereno, entre las coordenadas 9°31´51´´N, 75°20´59´´O y 9°32´18´´N, 75°20´42´´O, con un ancho de banda de 10 m en promedio (Fig. 1), se detectaron a simple vista 65 individuos de D. truncatus divididos, así: maduros 42 e inmaduros 23. La determinación de madurez en el campo fue comparativamente evidenciada por tamaño corporal, vocalizaciones, comportamiento reproductivo y defensa territorial (SILVERSTONE, 1975; CADWELL, 1996)

Desenvolvimento de estacas de Alfavaca (Ocimum gratissimum L.) em direfentes substratos.

O objetivo deste estudo foi avaliar o efeito de diferentes proporções de areia, terra e composto orgânico no crescimento de raízes e parte aérea de estacas de alfavaca, de modo a identificar o substrato que proporciona as melhores condições de pegamento das estacas e desenvolvimento das mudas.bitstream/CPAP-2010/57271/1/COT75.pd

An analytical solution for the settlement of stone columns beneath rigid footings

This paper presents a new approximate solution to study the settlement of rigid footings resting on a soft soil improved with groups of stone columns. The solution development is fully analytical, but finite element analyses are used to verify the validity of some assumptions, such as a simplified geometric model, load distribution with depth and boundary conditions. Groups of stone columns are converted to equivalent single columns with the same cross-sectional area. So, the problem becomes axially symmetric. Soft soil is assumed as linear elastic but plastic strains are considered in the column using the Mohr-Coulomb yield criterion and a non-associated flow rule, with a constant dilatancy angle. Soil profile is divided into independent horizontal slices and equilibrium of stresses and compatibility of deformations are imposed in the vertical and horizontal directions. The solution is presented in a closed form and may be easily implemented in a spreadsheet. Comparisons of the proposed solution with numerical analyses show a good agreement for the whole range of common values, which confirms the validity of the solution and its hypotheses. The solution also compares well with a small scale laboratory test available in literature

Session D7: Fishway with Two Entrance Locations: Understanding its importance for Iberian Barbel

Abstract In recent years, in the Iberian Peninsula, many fish passes have been built and improved. To ensure the proper operation of these, it is essential to carry out an evaluation and subsequent monitoring, considering both biologic and hydraulic aspects. We analyze the performance of Iberian barbel –Luciobarbus bocagei (Steindachner, 1864)– in a technical fishway: pool and weir, with bottom orifice. It is located in the Josefina hydropower plant (Duero River, Valladolid, Spain). Fish ladder has two fish entrances: one in the turbine outlet channel and another in the natural river course. Both the most relevant hydraulic values (flow, velocity, volumetric energy dissipation) and biological parameters (movement pattern, attraction, entry and passage) were measured. Biological assessment was conducted in the spawning season using PIT tag technology. The main influence on upstream movement was river discharge. There were no preferences between path selection; and ascent success and transit time were similar between two entrances.. Results highlight the importance of two access points for improve entrance and decrease migration delay