Gravitational field of a straight cosmic string in the framework of higher-derivative gravity

The gravitational properties of a straight cosmic string are studied in the linear approximation of higher-derivative gravity. These properties are shown to be very different from those found using linearized Einstein gravity: there exists a short range gravitational (anti-gravitational) force in the nonrelativistic limit; in addition, the deflection angle of a light ray moving in a plane orthogonal to the string depends on the impact parameter. © 2008 World Scientific Publishing Company.

La sostenibilidad del desarrollo en América Latina y el Caribe: desafíos y oportunidades

Incluye Bibliografía

The sustainability of development in Latin America and the Caribbean: challenges and opportunities

Includes bibliography

Evaluation of titanium implants with surface modification by laser beam. Biomechanical study in rabbit tibias

The purpose of the present study was to evaluate, using a biomechanical test, the force needed to remove implants with surface modification by laser (Nd:YAG) in comparison with implants with machined surfaces. Twenty-four rabbits received one implant with each surface treatment in the tibia, machined surface (MS) and laser-modified surface (LMS). After 4, 8 and 12 weeks of healing, the removal torque was measured by a torque gauge. The surfaces studied were analyzed according to their topography, chemical composition and roughness. The average removal torque in each period was 23.28, 24.0 and 33.85 Ncm for MS, and 33.0, 39.87 and 54.57 Ncm for LMS, respectively. The difference between the surfaces in all periods of evaluation was statistically significant (p < 0.05). Surface characterization showed that a deep and regular topography was provided by the laser conditioning, with a great quantity of oxygen ions when compared to the MS. The surface micro-topography analysis showed a statistical difference (p < 0.01) between the roughness of the LMS (R a = 1.38 ± 0.23 μm) when compared to that of the MS (R a = 0.33 ± 0.06 μm). Based on these results, it was possible to conclude that the LMS implants' physical-chemical properties increased bone-implant interaction when compared to the MS implants. © 2009 Sociedade Brasileira de Pesquisa Odontológica.

Tecnología de la información y las comunicaciones (TIC) para el fomento de las PYMES exportadoras en América Latina y Asia Oriental

Incluye Bibliografía

Servicios de agua potable y alcantarillado: lecciones de las experiencias de Alemania, Francia e Inglaterra

Incluye bibliografía

Contabilidad regulatoria, sustentabilidad financiera y gestión mancomunada: temas relevantes en servicios de agua y saneamiento

Incluye Bibliografía

Fomento de la eficiencia de las empresas estatales de agua potable y saneamiento

Incluye Bibliografía

América Latina y el Caribe hacia la Cumbre Mundial sobre el Desarrollo Sostenible

Introducción de Alicia Bárcena Ibarra

Avaliação dos efeitos do inseticida imidacloprido para abelhas sem ferrão Scaptotrigona postica Latreille, 1807 (Hymenoptera, Apidae, Meliponini): Hellen Maria Soares. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Provisional agenda

Regional Preparatory Conference of Latin America and the Caribbean for the World Conference on Sustainable Development (Johannesburg, South Africa, 2002), Rio de Janeiro, Brazil, 23 and 24 October 2001

Annotated provisional agenda

Background and Objectives of the Conference Annotations to the Agenda Regional Preparatory Conference of Latin America and the Caribbean for the World Summit on Sustainable Development (Johannesburg, South Africa, 2002) Rio de Janeiro, Brazil, 23 and 24 October 2001

Financing for sustainable development in Latin America and the Caribbean

Includes bibliography

Propuesta de plan de acción sobre la sociedad de la información de América Latina y el Caribe (eLAC2015)

Esta es la versión de la propuesta del Plan de Acción eLAC2015 acordada en la reunión preparatoria de la tercera Conferencia Ministerial sobre la Sociedad de la Información de América Latina y el Caribe, celebrada en Montevideo, los días 23 y 24 de septiembre de 2010, con los cambios editoriales introducidos por la CEPAL.