Abstract:
In this paper we study the structure of the manifold of solitary waves in some deformations of SO(2) symmetric two-component scalar field theoretical models in two-dimensional Minkowski space. The deformation is chosen in order to make the analogous mechanical system Hamilton-Jacobi separable in polar coordinates and displays a singularity at the origin of the internal plane. The existence of the singularity confers interesting and intriguing properties to the solitary waves or kink solutions.

Abstract:
In this paper we describe the structure of a class of two-component scalar field models in a (1+1) Minkowskian space-time which generalize the well-known Montonen-Sarker-Trullinger-Bishop -hence MSTB- model. This class includes all the field models whose static field equations are equivalent to the Newton equations of two-dimensional type I Liouville mechanical systems with a discrete set of instability points. We offer a systematic procedure to characterize these models and to identify the solitary wave or kink solutions as homoclinic or heteroclinic trajectories in the analogous mechanical system. This procedure is applied to a one-parametric family of generalized MSTB models with a degree-eight polynomial as potential energy density.

Abstract:
We discuss time evolution of some solitary waves described in the first part of this work. The adiabatic motion of the non-linear non-dispersive waves composed of three lumps is interpreted as three-body low energy scattering of these particle-like kinks.

Abstract:
We study the structure of the manifold of solitary waves in a particular three-component scalar field theoretical model in two-dimensional Minkowski space. These solitary waves involve one, two, three, four, six or seven lumps of energy.

Abstract:
It is shown how a integrable mechanical system provides all the localized static solutions of a deformation of the linear O(N)-sigma model in two space-time dimensions. The proof is based on the Hamilton-Jacobi separability of the mechanical analogue system that follows when time-independent field configurations are being considered. In particular, we describe the properties of the different kinds of kinks in such a way that a hierarchical structure of solitary wave manifolds emerges for distinct N.

Abstract:
In this paper we describe the moduli space of kinks in a class of systems of two coupled real scalar fields in (1+1) Minkowskian space-time. The main feature of the class is the spontaneous breaking of a discrete symmetry of (real) Ginzburg-Landau type that guarantees the existence of kink topological defects.

Abstract:
The kinks of the (1+1)-dimensional Wess-Zumino model with polynomic superpotential are investigated and shown to be related to real algebraic curves.

Abstract:
We identify the kinks of a deformed O(3) linear Sigma model as the solutions of a set of first-order systems of equations; the above model is a generalization of the MSTB model with a three-component scalar field. Taking into account certain kink energy sum rules we show that the variety of kinks has the structure of a moduli space that can be compactified in a fairly natural way. The generic kinks, however, are unstable and Morse Theory provides the framework for the analysis of kink stability.

Abstract:
Background: sixty percent of patients with irritable bowel disease (IBS) are hypersensitive to rectal distension. It is uncertain to what extend the identification of this abnormality has an impact in the clinical outcome. Objective: to evaluate if rectal hypersensitivity is associated with a different clinical outcome, prognosis and use of medical resources. Material and methods: patients with IBS (Rome II criteria) who underwent a rectal distension study at least one year before were eligible if they have not been included in any research protocol since then. We reviewed how many times in the last year they came to emergency room, underwent an endoscopy, and consulted a gastroenterologist or other medical physician for any reason. Also, a telephone interview was done by a gastroenterology fellow using a structured questionnaire to evaluate the frequency and severity of their symptoms in the last year and last month. Results: a total of 52 patients were eligible and 38 were included. Forteen were not included because inability to made a phone contact or did not consent to phone interview. Twenty six patients were hypersensitive and 12 normosensitive. Both groups had similar symptoms (frequency and severity) but hypersensitive patients visited less to the gastroenterologist (1.2 ± 0.2 vs. 2.9 ± 0.6 times yearly, p < 0.01). Conclusion: identification of rectal hypersensitivity to distension is associated to less consultation to gastroenterologist, although severity and frequency of symptoms are not modified. Finding of an objective explanation of the symptoms seems to help patients to understand their disease, leading to a decrease in resources' use. Introducción: el 60% de los pacientes con SII tienen hipersensibilidad a la distensión rectal. Se desconoce si la identificación de esta alteración puede modificar su evolución. Objetivo: evaluar si la hipersensibilidad a la distensión rectal se asocia con un diferente pronóstico respecto a la presentación de síntomas y la utilización de recursos sanitarios en pacientes con SII. Material y métodos: se incluyeron pacientes con SII según criterios de Roma II, que habían sido sometidos a un estudio de distensión rectal. Se recogieron datos de los registros informáticos sobre asistencia a consultas especializadas, realización de endoscopias, asistencia a urgencias e ingresos hospitalarios. Además, se realizó entrevista telefónica en la que se interrogó acerca de la existencia de síntomas a lo largo del último a o y último mes (características, duración y severidad). Resultados: se evaluaron 38 pacientes, 26 con