Time-dependent toroidal compactification proposals and the Bianchi type I model: classical and quantum solutions

In this work we construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. This approach is applied to anisotropic cosmological Bianchi type I model for which we study the classical coupling of the anisotropic scale factors with the two real scalar moduli produced by the compactification process. Under this approach, we present an isotropization mechanism for the Bianchi I cosmological model through the analysis of the ratio between the anisotropic parameters and the volume of the Universe which in general keeps constant or runs into zero for late times. We also find that the presence of extra dimensions in this model can accelerate the isotropization process depending on the momenta moduli values. Finally, we present some solutions to the corresponding Wheeler-DeWitt (WDW) equation in the context of Standard Quantum Cosmology.Comment: LaTeX source, 16 pages, Modified title and additional references. Advances in High Energy Physics, 201

Paisaje Vegetal y Espectro Ecológico de dos Municipios Navarros (España)

Tomando como referencia el trabajo de BRAUN BLANQUET y 0. DE BOLOS (1957) sobre el Valle del Ebro, se ha realizado un estudio del paisaje vegetal de Marcilla y Milagro, municipios situados en la Ribera de Navarra. Hemos reconocido comunidades vegetales pertenecientes a 14 clases fitosociológicas. Expresamos nuestros resultados mediante dos perfiles fitotopográficos y un espectro ecológico

Type-2 Fuzzy Entropy-Sets

The final goal of this study is to adapt the concept of fuzzy entropy of De Luca and Termini to deal with Type-2 Fuzzy Sets. We denote this concept Type-2 Fuzzy Entropy-Set. However, the construction of the notion of entropy measure on an infinite set, such us [0, 1], is not effortless. For this reason, we first introduce the concept of quasi-entropy of a Fuzzy Set on the universe [0, 1]. Furthermore, whenever the membership function of the considered Fuzzy Set in the universe [0, 1] is continuous, we prove that the quasi-entropy of that set is a fuzzy entropy in the sense of De Luca y Termini. Finally, we present an illustrative example where we use Type-2 Fuzzy Entropy-Sets instead of fuzzy entropies in a classical fuzzy algorithm

Fracturas de cadera y diáfisis femoral ipsilaterales

Se aportan 10 casos de fracturas de cadera y diáfisis femoral ipsilaterales tratados quirúrgicamente de forma diferida con un tiempo medio de demora de 12 días (rango: 3 a 22 días). Nueve fracturas diafisarias fueron tratadas con placa AO de fémur, y una, donde la fractura de cadera asociada pasó inicialmente inadvertida, mediante un clavo de Küntscher. Las fracturas de cadera se fijaron con tornillos de esponjosa (8 casos) o clavo-placa de Richards (2 casos). En todos los pacientes se inició un programa de rehabilitación precoz. El seguimiento medio ha sido de 31 meses (rango: 12 a 84 meses). Todas las fracturas consolidaron. Las complicaciones fueron un caso de acortamiento femoral y otro de artrosis coxofemoral post-traumá- tica. En nuestra experiencia, la fijación de la fractura diafisaria con placa AO, combinada con tornillos de esponjosa o clavo-placa de Richards para la síntesis de la fractura de cadera, proporciona resultados satisfactoriosWe review 10 cases of ipsilateral hip and femoral shaft fractures. Operative treatment was performed in all cases, with an average delay of 12 days (range: 3 to 22 days). Nine femoral shaft fractures were stabilizated with an AO plate, and one, where the associated hip fracture was initially missed, with a Küntscher rod. Hip fractures were fixed with cancellous screws (8 cases) or Richards compression screw (2 cases). An early rehabilitation program was carried out in all patients. The average follow-up was 31 months (range: 12 to 84 months). All fractures healed. Complications were a case of femoral shortening an a case of post-traumatic hip osteoarthritis. In our study, the combination of AO plate for the shaft fracture with cancellous screws or Richards compression screw for the hip fracture provides good results

Spiked oscillators: exact solution

A procedure to obtain the eigenenergies and eigenfunctions of a quantum spiked oscillator is presented. The originality of the method lies in an adequate use of asymptotic expansions of Wronskians of algebraic solutions of the Schroedinger equation. The procedure is applied to three familiar examples of spiked oscillators

Luxación tibio astragalina posteromedial sin fractura de maleolos: a propósito de un caso

Se describe un caso de luxación tibioastragalina posteromedial abierta sin fractura asociada de maleolos, en un paciente de 28 años. A los dos años del desbridamiento quirúrgico, reducción manual y reparación capsuloligamentosa, el paciente estaba libre de dolor y presentaba una función semejante a la del tobillo contralateral. Se revisa la literatura sobre el tema y se discuten los factores etiopatológicos, complicaciones y principios de tratamiento

Artritis séptica de rodilla por Streptococcus agalactiae: presentación de un caso y revisión de la literatura

Se describe un caso de artritis séptica de rodilla en un paciente diabético de 69 años. En el momento de la presentación se hallaba sometido a curas locales de una úlcera crónica en el mismo miembro y a antibioterapia oral inespecífica por supuesta infección urinaria. En el cultivo del líquido sinovial se identificó un Streptococcus agalactiae (Estreptococo del grupo B). La infección no remitió con antibioterapia intravenosa electiva e irrigación-aspiración articular repetidas, requiriendo desbridamiento quirúrgico y sinovectomía. A pesar de instaurarse un programa de rehabilitación intensiva la rodilla evolucionó a la rigidez. Se revisa la literatura al respecto, destacando la asociación de artritis por estreptococos del grupo B con pacientes diabéticos portadores de úlceras cutáneas crónicas, así como la potencial gravedad de estas infecciones.This report describes a case of knee septic arthritis in a 69-year-old diabetic patient. At the time of admission he was receiving local treatment for a chronic skin ulcer in the same extremity and inespecific oral antibiotherapy because of an urinary tract infection. Synovial fluid cultures showed a Streptococcus agalactiae (group B streptococcus). The infection had no response to specific parenteral antibiotherapy and repeated joint irrigations-aspirations, and therefore surgical desbridement and synovectomy was required. Despite of an intensive rehabilitation program, the affected knee developed ankylosis. In a review of literature, it is remarkable the association between group B streptococcal arthritis and chronic skin ulcers in diabetic patients and the potential severity of these infections

A field expansions method for scattering by periodic multilayered media

The interaction of acoustic and electromagnetic waves with periodic structures plays an important role in a wide range of problems of scientific and technological interest. This contribution focuses upon the robust and high-order numerical simulation of a model for the interaction of pressure waves generated within the earth incident upon layers of sediment near the surface. Herein described is a boundary perturbation method for the numerical simulation of scattering returns from irregularly shaped periodic layered media. The method requires only the discretization of the layer interfaces (so that the number of unknowns is an order of magnitude smaller than finite difference and finite element simulations), while it avoids not only the need for specialized quadrature rules but also the dense linear systems characteristic of boundary integral/element methods. The approach is a generalization to multiple layers of Bruno and Reitich’s “Method of Field Expansions” for dielectric structures with two layers. By simply considering the entire structure simultaneously, rather than solving in individual layers separately, the full field can be recovered in time proportional to the number of interfaces. As with the original field expansions method, this approach is extremely efficient and spectrally accurate

A report on the nonlinear squeezed states and their non-classical properties of a generalized isotonic oscillator

We construct nonlinear squeezed states of a generalized isotonic oscillator potential. We demonstrate the non-existence of dual counterpart of nonlinear squeezed states in this system. We investigate statistical properties exhibited by the squeezed states, in particular Mandel's parameter, second-order correlation function, photon number distributions and parameter $A_3$ in detail. We also examine the quadrature and amplitude-squared squeezing effects. Finally, we derive expression for the $s$-parameterized quasi-probability distribution function of these states. All these information about the system are new to the literature.Comment: Accepted for publication in J. Phys. A: Math. Theo