A new algorithm for computing branching rules and Clebsch-Gordan coefficients of unitary representations of compact groups

A numerical algorithm that computes the decomposition of any finite-dimen\-sio\-nal unitary reducible representation of a compact Lie group is presented. The algorithm, which does not rely on an algebraic insight on the group structure, is inspired by quantum mechanical notions. After generating two adapted states (these objects will be conveniently defined in {\bf Def.\,II.1}) and after appropriate algebraic manipulations, the algorithm returns the block matrix structure of the representation in terms of its irreducible components. It also provides an adapted orthonormal basis. The algorithm can be used to compute the Clebsch--Gordan coefficients of the tensor product of irreducible representations of a given compact Lie group. The performance of the algorithm is tested on various examples: the decomposition of the regular representation of two finite groups and the computation of Clebsch--Gordan coefficients of two examples of tensor products of representations of $SU(2)$.Comment: Updated paper. arXiv admin note: text overlap with arXiv:1512.0824

Using the Delphi Method and its use in communication research and education

Se analizan las posibilidades que la metodología Delphi ofrece para la investigación educativa y de la comunicación al mismo tiempo se ofrece algunas referencias históricas, se presentan cuáles son sus características fundamentales, las posibilidades y limitaciones que tiene su aplicación, las diferentes versiones existentes para su incorporación en los procesos de evaluación en investigación, y las fases operativas para su aplicación. También se estudia una de las problemáticas fundamentales que presenta esta técnica y que se refiere al proceso de selección de los expertos, respecto al cual se ofrecen algunas sugerencias y aportaciones para su una correcta identificación. Al mismo tiempo se presenta una de las estrategias más novedosas que últimamente se están utilizado para la selección de los informadores: el denominado “coeficiente de conocimiento experto”.The possibilities that the Delphi methodology provides for educational research and communication at the same time provides some historical references are analyzed, presented what their fundamental characteristics, possibilities and limitations of their application, the different existing versions for incorporation in research assessment processes, and operational phases for implementation. We also study one of the fundamental problems with this technique and refers to the process of selection of experts, for which some suggestions and inputs for correct identification is. At the same time one of the most innovative strategies that are ultimately used for the selection of informants is presented: the "coefficient of expertise.

Joint degrees in cooperative e-learning environments

En los modelos educativos tradicionales es común observar el desarrollo de convenios de cooperación entre diversas organizaciones para la realización de titulaciones conjuntas, en los cuales, cada organización aporta a su contraparte recursos de aprendizaje, docentes y/o estudiantes, buscando el logro de las competencias educativas con esfuerzos comunes. En la sociedad del conocimiento, las tecnologías de la información y de las comunicaciones (TIC) aportan ventajas competitivas que facilitan los espacios de cooperación para el desarrollo de titulaciones conjuntas; sin embargo, se observa que existen limitaciones de índole tecnológica, que dificultan la realización de estos espacios de cooperación. El presente trabajo analiza los ambientes cooperativos para la realización de titulaciones conjuntas, describiendo factores adversos que inhiben estos espacios y propone alternativas de solución a la problemática observada.In traditional education models, we can frequently observe the development of cooperation agreements between diverse organisations for the undertaking of joint degrees, whereby each organisation provides its counterpart with learning resources, faculty and/or students in order to achieve educational competences through joint efforts. In the knowledge society, Information and Communication Technologies (ITC) provide competitive advantages that facilitate areas of cooperation for the development of joint degrees. However, technological limitations exist that hinder the creation of such areas of cooperation. This work analyses the cooperative environs for the undertaking of joint degrees and describes adverse factors that inhibit such areas, as well as proposing alternative solutions to the problems observed

On the Distributional Fourier Duality and Its Applications

AbstractSampling theorems for bandlimited functions or distributions are obtained by exploiting the topological isomorphism between the space E′(R) of distributions of compact support on R and the Paley–Wiener spacePWof entire functions satisfying an estimate of the form |f(z)|≤A(1+|z|)NeB|Imz|for some constantsA,B,N≥0. We obtain sampling theorems forfinPWby expanding its Fourier transformTin a series converging in the topology of E′(R) and whose coefficients are samples taken fromf. By Fourier duality, we obtain a sampling theorem forfin the spacePW. These sampling expansions converge, in fact, uniformly on compact sets of C, since convergence in the topology ofPWimplies uniform convergence on compact sets of C. This procedure allows us to recover previous sampling theorems in a unified way. We also present further expansions of Paley–Wiener functions obtained by expanding their Fourier transform as a series involving Legendre or Hermite polynomials

El síndrome de iris flácido. Estudio de cambios oculares inducidos por tamsulosina

Texto en español y resumen en inglésEl síndrome de iris flácido descrito en el año 2005 se ha relacionado con el consumo de tamsulosina. Tras estudiar 830 cirugías de catarata llevadas a cabo en el Hospital del Henares, determinamos que el consumo de tamsulosina en nuestro medio se asocia a un aumento importante de "complicaciones menores" durante la cirugía de catarata. Por ello este fármaco no modifica de forma importante el pronóstico "funcional" de la cirugía. Podría existir asimismo un efecto aditivo entre el consumo de este fármaco y la diabetes mellitus, que contraindica su utilización en estos pacientes.Se llevo a cabo una encuesta a los especialistas de urología de la Comunidad de Madrid, que demostró que los urólogos tienen un buen conocimiento de este síndrome, pero desconocen el carácter en parte irreversible de los cambios inducidos por su consumo.Tras seguir dos cohortes de pacientes que iniciaban y cesaban el tratamiento con tamsulosina se demostró que el inicio del tratamiento produce una reducción del diámetro pupilar y esta reducción es máxima en respuesta a fenilefrina. Asimismo en un estudio trasversal en el que se compararon consumidores y no consumidores de tamsulosina, este midriático demostró tener una buena sensibilidad y especificidad para detectar el consumo de este fármaco, si bien el bajo valor predictivo positivo, hace que este test no resulte útil en la práctica clínica. Puesto que la hendidura palpebral fue similar en ambos grupos, es probable que el receptor alfa-1A adrenérgico no se exprese en el músculo de Müller. No se demostró que la tamsulosina influya sobre la cuantificación del defecto pupilar aferente relativo. Palabras clave: tamsulosina, síndrome de iris flácido, cirugía de catarata, complicaciones quirúrgicas

La crisis de reproducibilidad de la ciencia y la necesidad de publicar los resultados negativos.

pre-print245 K

Laser pointer maculopathy. A new public health problem?

pre-print186 K

Perturbation theory for Hamiltonian matrices and the distance to bounded-realness

Motivated by the analysis of passive control systems, we undertake a detailed perturbation analysis of Hamiltonian matrices that have eigenvalues on the imaginary axis. We construct minimal Hamiltonian perturbations that move and coalesce eigenvalues of opposite sign characteristic to form multiple eigenvalues with mixed sign characteristics, which are then moved from the imaginary axis to specific locations in the complex plane by small Hamiltonian perturbations. We also present a numerical method to compute upper bounds for the minimal perturbations that move all eigenvalues of a given Hamiltonian matrix outside a vertical strip along the imaginary axis

Maculopatía por puntero láser. ¿Un nuevo problema de salud pública?

Available online 13 October 2016, publicado en papel n enero de 2017Depto. de Optometría y VisiónSección Deptal. de Óptica (Óptica)Fac. de Óptica y OptometríaTRUEpu

Open-globe-injury: A single center Spanish retrospective 5-year cohort study.

Purpose: To review and analyze the epidemiological profile, clinical characteristics and visual outcomes in patients attended for traumatic open globe injury (OGI) at our hospital over a 5-year period. Design: Retrospective chart review study. Methods: Retrospective analysis of all patients attended at Fundación Jiménez Díaz University Hospital for OGI between 2011 and 2015. Data from 104 patients including demographics, ocular examination, medical and surgical treatment, visual outcomes, and complications were analyzed. Results: Most patients were male (79.8%) and the median age at the time of injury was 41 years (interquartile range 31.5–58 years). Work-related accidents represent more than half of the cases and their main mechanism was penetrating trauma or foreign body. This type of accident had good prognosis (median final visual acuity in decimal scale 0.8; interquartile range 0.4–1). Falls were the second most common cause of OGI, predominantly affecting senior women (50%), with a high incidence of ocular rupture (50%) and associating a poor visual prognosis (median final visual acuity 0.01; interquartile range 0–0.5). There was a strong correlation (0.75; p < 0.001) between ocular trauma score (OTS) and final best corrected visual acuity. Conclusions: Two different patterns of OGI were identified in our sample. Work-related trauma in young males was the most common form of OGI and was associated with good prognosis. However, falls in senior women were associated with poor prognosis.pre-print484 K