Solitary Waves in Massive Nonlinear S^N-Sigma Models

The solitary waves of massive (1+1)-dimensional nonlinear S^N-sigma models are unveiled. It is shown that the solitary waves in these systems are in one-to-one correspondence with the separatrix trajectories in the repulsive N-dimensional Neumann mechanical problem. There are topological (heteroclinic trajectories) and non-topological (homoclinic trajectories) kinks. The stability of some embedded sine-Gordon kinks is discussed by means of the direct estimation of the spectra of the second-order fluctuation operators around them, whereas the instability of other topological and non-topological kinks is established applying the Morse index theorem

Factorization of supersymmetric Hamiltonians in curvilinear coordinates

Planar supersymmetric quantum mechanical systems with separable spectral problem in curvilinear coordinates are analyzed in full generality. We explicitly construct the supersymmetric extension of the Euler/Pauli Hamiltonian describing the motion of a light particle in the field of two heavy fixed Coulombian centers. We shall also show how the SUSY Kepler/Coulomb problem arises in two different limits of this problem: either, the two centers collapse in one center - a problem separable in polar coordinates -, or, one of the two centers flies to infinity - to meet the Coulomb problem separable in parabolic coordinates.Comment: 13 pages. Based on the talk presented by M.A. Gonzalez Leon at the 7th International Conference on Quantum Theory and Symmetries (QTS7), August 07-13, 2011, Prague, Czech Republi

Factor analysis of linear alkylbenzene sulphonate (LAS) vertical distribution in coastal sediments of Cadiz Bay (southwest Spain)

El comportamiento del alquilbenceno lineal sulfonato (LAS) en los sistemas costeros no se conoce con precisión, y este conocimiento es aun menor si nos restringimos al compartimento sedimentario. En este trabajo se aplica un análisis factorial a los resultados obtenidos para distintas variables determinadas en tres estaciones, tanto en sedimento como en agua intersticial, con el objetivo de evaluar sus interrelaciones con el LAS. Las variables analizadas presentan dos modos principales de distribución con la profundidad en el compartimento sedimentario: lineal y/o exponencial. En casi todos los casos, el LAS se asocia a ambos modos de distribución, lo que indica que su concentración sufre una disminución con la profundidad, pero se produce de forma especialmente acusada en la capa superficial.Very little is known concerning the behaviour of linear alkylbenzene sulphonate (LAS) in coastal systems, and even less when we consider the sedimentary field only. In the present study, a factor analysis is applied to the results obtained for different variables at three stations, both in the sediment and in interstitial water, with the aim of evaluating their relationship with LAS. The variables analysed have two main types of distribution in the sedimentary area in relation to depth: linear and/or exponential. LAS is, in most cases, associated with both types of distribution, indicating that its concentration decreases with depth, especially in the surface layer.Instituto Español de Oceanografí

Hacia una educación intercultural inclusiva. El caso del alumnado inmigrante en la escuela en España

Este texto discute el aumento de la migración y de la diversidad cultural y el consiguiente desarrollo de la educación intercultural en contexto español. Esta situación plantea el gran desafío de la formación del profesorado para la promoción de la educación intercultural inclusiva y crítica. El texto se articula en torno a las aportaciones del proyecto europeo Quammelot, que desarrolla investigación, intervención, formación y buenas prácticas sobre inclusión educativa y social del alumnado inmigrante y de los Menores Extranjeros No Acompañados (MENAS), con foco específico en el sistema educativo, en las edades de12 a 18 años, y en las relaciones entre escuelas, población inmigrante y territorio. Se ofrece una revisión de la literatura sobre la inclusión del alumnado inmigrante y de los menores inmigrantes en las escuelas secundarias. Posteriormente se presenta la metodología innovadora del proyecto, describiendo el curso online dirigido al profesorado de enseñanza secundaria y otras actividades del proyecto. Finalmente, se comentan las aportaciones del proyecto sobre cooperación transnacional, innovación en la educación formal, mejora de la formación del profesorado y visibilización de las necesidades de los actores educativos sobre la inclusión y la diversidad. Palabras claves: Educación intercultural, educación secundaria, alumnado inmigrante, menores no acompañados, formación del profesorado

New scalar field models and their defect solutions

Preprint[EN] In this work we introduce new scalar field models and study the defect solutions they may engender. The investigation is based on the deformation procedure, which greatly simplify the calculations, leading us to new models together with the corresponding solutions in a simple and powerful manner. [ES] En este trabajo presentamos nuevos modelos de campo escalar y estudiar los defectos las soluciones que pueden generar. La investigación se basa en el procedimiento de deformación, que simplifican en gran medida los cálculos, nos conduce a nuevos modelos junto con las soluciones correspondientes de una manera sencilla y de gran alcance

Deformed defects for scalar fields with polynomial interactions

In this paper we use the deformation procedure introduced in former work on deformed defects to investigate several new models for real scalar field. We introduce an interesting deformation function, from which we obtain two distinct families of models, labeled by the parameters that identify the deformation function. We investigate these models, which identify a broad class of polynomial interactions. We find exact solutions describing global defects, and we study the corresponding stability very carefully.Comment: 8 pages, 5 eps figures, to appear in PR

Serum levels of caspase-cleaved cytokeratin-18 and mortality are associated in severe septic patients: Pilot study

Objective: Apoptosis is increased in sepsis. Cytokeratin 18 (CK-18), a protein of the intermediate filament group present in most epithelial and parenchymal cells, is cleaved by the action of caspases and released into the blood as caspase-cleaved CK (CCCK)-18 during apoptosis. Circulating levels of CCCK-18 have scarcely been explored in septic patients. In one study with 101 severe septic patients, the authors reported higher serum CCCK-18 levels in non-survivors than in survivors; however, the sample size was too small to demonstrate an association between serum CCCK-18 levels and early mortality and whether they could be used as a biomarker to predict outcomes in septic patients. Thus, these were the objectives of this study with a large series of patients. Methods: We performed a prospective, multicenter, observational study in six Spanish Intensive Care Units with 224 severe septic patients. Blood samples were collected at the time that severe sepsis was diagnosed to determine serum levels of CCCK-18, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-10. The end point was 30-day mortality. Results: Non-surviving patients (n = 80) showed higher serum CCCK-18 levels (P391 u/L were associated with 30-day survival (Odds ratio = 2.687; 95% confidence interval = 1.449-4.983; P = 0.002), controlling for SOFA score, serum lactic acid levels and age. Kaplan-Meier survival analysis showed that the risk of death in septic patients with serum CCCK-18 levels >391 u/L was higher than in patients with lower values (Hazard Ratio = 3.1; 95% CI = 1.96-4.84; P<0.001). Serum CCCK-18 levels were positively associated with serum levels of IL-6 and lactic acid, and with SOFA and APACHE scores. Conclusions: The major novel finding of our study, the largest cohort of septic patients providing data on circulating CCCK-18 levels, was that serum CCCK-18 levels are associated with mortality in severe septic patients