A Parallel Branch and Bound Algorithm for the Maximum Labelled Clique Problem

The maximum labelled clique problem is a variant of the maximum clique problem where edges in the graph are given labels, and we are not allowed to use more than a certain number of distinct labels in a solution. We introduce a new branch-and-bound algorithm for the problem, and explain how it may be parallelised. We evaluate an implementation on a set of benchmark instances, and show that it is consistently faster than previously published results, sometimes by four or five orders of magnitude.Comment: Author-final version. Accepted to Optimization Letter

Optical realization of nonlinear quantum dynamics

In a cavity filled with a Kerr medium it is possible to generate the superposition of coherent states, i.e. Schroodinger cat states may be realized in this system. We show that such a medium may be mimicked by the propagation of a conveniently shaped Gaussian beam in a GRIN device. This is attained by introducing a second order correction to the paraxial propagation of the beam. An additional result is that a Gaussian beam propagating in GRIN media, may split into two Gaussian beams

Contribution for the teaching of natural sciences: Mapuche and school knowledge

El artículo tiene por objeto la relación con el saber, asociada a los métodos educativos para la enseñanza sobre la naturaleza en el contexto de familias y comunidades mapuches. El objetivo es aportar en la identificación de métodos educativos que han sido construidos y reconstruidos en relación con el desarrollo social, cultural, político, económico y espiritual, experimentado por las comunidades mapuches. La metodología empleada es la investigación educativa, con un enfoque cualitativo, para favorecer procesos investigativos que buscan develar las dimensiones subjetivas e intersubjetivas del conocimiento educativo que poseen los sujetos en su contexto de vida. El trabajo de campo se ha desarrollado con una muestra de sabios mapuches de La Araucanía. Los resultados del estudio se organizan en cuatro categorías: 1) Relación con el medio natural; 2) Conocimiento de seres vivos; 3) Ciclo del küyen (fases lunares); y 4) Vida saludable. Los datos permiten vincular los contenidos conceptuales, procedimentales y actitudinales que subyacen en los métodos educativos propiamente mapuche, para revelar sus racionalidades, presentes en la relación con el saber. Se aporta una base epistemológica que fundamenta la implementación de una educación sobre la enseñanza de las ciencias naturales articulada con el conocimiento mapuche. Esto permitirá contextualizar el sector de aprendizaje Ciencias Naturales, basado en un enfoque educativo intercultural, para avanzar en la configuración de un diálogo de saberes en contextos de relaciones interétnicas e interculturales.Within the context of Mapuche families and communities, this paper focuses on the relationship between knowledge and educational methods in teaching the natural sciences. It aims to identify educational methods that have been forged and re-forged in connection with the social, cultural, political, economical and spiritual development experienced by Mapuche communities. Our educational research methodology is based on a qualitative approach in order to unveil the subjective and inter-subjective dimensions that characterize the subjects' educational knowledge in their life context. Our fieldwork has been carried out from a sample of interviews conducted with Mapuche wise men (sabios) living in the Araucanía. The results of the study are divided in four categories: 1) Relationship towards the natural environment; 2) Knowledge regarding living beings; 3) Küyen cycle (phases of the Moon); and finally, 4) Healthy lifestyle. The collected data have allowed us to link different contents (conceptual, practical and attitudinal) underlying the proper Mapuche educational methods to underline their rationalities with reference to core knowledge. Thus, we want to make a case for an epistemological basis substantiating the teaching of natural sciences in relation to Mapuche knowledge. This will allow us to contextualize natural science teaching within the framework of an intercultural educational approach. By doing so, we aim to establish an intellectual dialogue in a context of interethnic and intercultural relationships.Contribution for the teaching of natural sciences: Mapuche and school knowledg