Observing classical nucleation theory at work by monitoring phase transitions with molecular precision.

It is widely accepted that many phase transitions do not follow nucleation pathways as envisaged by the classical nucleation theory. Many substances can traverse intermediate states before arriving at the stable phase. The apparent ubiquity of multi-step nucleation has made the inverse question relevant: does multistep nucleation always dominate single-step pathways? Here we provide an explicit example of the classical nucleation mechanism for a system known to exhibit the characteristics of multi-step nucleation. Molecular resolution atomic force microscopy imaging of the two-dimensional nucleation of the protein glucose isomerase demonstrates that the interior of subcritical clusters is in the same state as the crystalline bulk phase. Our data show that despite having all the characteristics typically associated with rich phase behaviour, glucose isomerase 2D crystals are formed classically. These observations illustrate the resurfacing importance of the classical nucleation theory by re-validating some of the key assumptions that have been recently questioned

Hitting all Maximal Independent Sets of a Bipartite Graph

We prove that given a bipartite graph G with vertex set V and an integer k, deciding whether there exists a subset of V of size k hitting all maximal independent sets of G is complete for the class Sigma_2^P.Comment: v3: minor chang

Dificultades del profesorado en Educación Física de educación secundaria ante el alumno con discapacidad

En este estudio se pretende determinar las dificultades y problemas que tienen actualmente los profesores de Educación Secundaria en la especialidad de Educación Física, ante la variedad de alumnos con discapacidad que pueden existir en sus clases. Se trata sin duda de uno de los temas más delicados en la educación. Para ello se estudió la zona norte de Madrid tomando una muestra de 30 profesores. Los instrumentos de obtención de información fue un cuestionario de 25 preguntas pasado a todos los profesores, así como la formación de un grupo de discusión. Los resultados evidencian la buena disposición del colectivo docente para integrarlos de la manera más correcta, pero por el contrario se encuentran ante falta de recursos, tantos materiales, humanos y formativos. La poca coordinación entre departamentos, el número excesivo de alumnos o la falta de respaldo por parte de la administración desemboca en muchos casos en una falta de motivación que repercute en una peor calidad de enseñanza

Assertion-based Analysis via Slicing with ABETS

[EN] We present ABETS, an assertion-based, dynamic analyzer that helps diagnose errors in Maude programs. ABETS uses slicing to automatically create reduced versions of both a run's execution trace and executed program, reduced versions in which any information that is not relevant to the bug currently being diagnosed is removed. In addition, ABETS employs runtime assertion checking to automate the identification of bugs so that whenever an assertion is violated, the system automatically infers accurate slicing criteria from the failure. We summarize the main services provided by ABETS, which also include a novel assertionbased facility for program repair that generates suitable program fixes when a state invariant is violated. Finally, we provide an experimental evaluation that shows the performance and effectiveness of the system.This work has been partially supported by the EU (FEDER) and Spanish MINECO grant TIN2015-69175-C4-1-R, and by Generalitat Valenciana PROMETEOII/2015/013. J. Sapina was supported by FPI-UPV grant SP2013-0083.Alpuente Frasnedo, M.; Frechina, F.; Sapiña Sanchis, J.; Ballis, D. (2016). Assertion-based Analysis via Slicing with ABETS. Theory and Practice of Logic Programming. 16(5):515-532. https://doi.org/10.1017/S1471068416000375S51553216