General integral relations for the description of scattering states using the hyperspherical adiabatic basis

In this work we investigate 1+2 reactions within the framework of the hyperspherical adiabatic expansion method. To this aim two integral relations, derived from the Kohn variational principle, are used. A detailed derivation of these relations is shown. The expressions derived are general, not restricted to relative $s$ partial waves, and with applicability in multichannel reactions. The convergence of the ${\cal K}$-matrix in terms of the adiabatic potentials is investigated. Together with a simple model case used as a test for the method, we show results for the collision of a $^4$He atom on a \dimer dimer (only the elastic channel open), and for collisions involving a $^6$Li and two $^4$He atoms (two channels open).Comment: Accepted for publication in Physical Review

Clasificación de las anomalías vasculares (tumores y malformaciones). Características clínicas e historia natural

Vascular anomalies are divided into tumours and malformations. Haemangiomas are the most frequent amongst the former. Not normally present at birth, except in a premonitory form, they grow for 10-12 months due to hyperplasia, to subsequently undergo a progressive involution for a period that might last from ten to twelve years. They have an incidence of up to 12% in newborns; they are more common amongst girls; and are divided into superficial, deep and compound. Congenital haemangiomas and those that do not undergo involution are considered to be rare entities. Vascular malformations, with a lower incidence than haemangiomas, are always present at birth, they grow by hypertrophy and never undergo involution. According to the classification of the ISSVA, vascular malformations are divided - depending on the vessel affected - into capillary or venular (port-wine stain), venous, lymphatic, arteriovenous and combined or complex. Each of these has certain defining clinical and haemodynamic peculiarities. Within the final group are included some with a low flow, such as the Klippel-Trenaunay syndrome (venous and lymphatic venular vascular malformation associated with the muscularskeletal hypertrophy of an extremity), and others with a high flow, such as the Parkes-Weber syndrome

Variational description of continuum states in terms of integral relations

Two integral relations derived from the Kohn Variational Principle (KVP) are used for describing scattering states. In usual applications the KVP requires the explicit form of the asymptotic behavior of the scattering wave function. This is not the case when the integral relations are applied since, due to their short range nature, the only condition for the scattering wave function $\Psi$ is that it be the solution of $(H-E)\Psi=0$ in the internal region. Several examples are analyzed for the computation of phase-shifts from bound state type wave functions or, in the case of the scattering of charged particles, it is possible to obtain phase-shifts using free asymptotic conditions. As a final example we discuss the use of the integral relations in the case of the Hyperspherical Adiabatic method.Comment: 34 pages, 7 figures, accepted in Phys. Rev.

Book review: Le lapin. De la biologie à l’élevage

González-Redondo, P. (2016). Book review: Le lapin. De la biologie à l’élevage. World Rabbit Science. 24(4):333-334. doi:10.4995/wrs.2016.4675.SWORD33333424

Large eddy simulation and laboratory experiments on the decay of grid wakes in strongly stratified flows

A detailed analysis of the flow structure resulting from the combination of turbulence and internal waves is carried out and visualized by means of the Schlieren method on waves in a strongly stratified fluid at the Laboratory of the IPM in Moscow. The joint appearance of the more regular internal wave oscillations and the small-scale turbulence that is confined vertically to the Ozmidov length scale favours the use of a simple geometrical analysis to investigate their time-space span and evolution. This provides useful information on the collapse of internal wave breaking processes in the ocean and the atmosphere. The measurements were performed under a variety of linear stratifications and different grid forcing scales, combining the grid wake and velocity shear. A numerical simulation using LES on the passage of a single bar in a linearly stratified fluid medium has been compared with the experiments identifying the different influences of the environmental agents on the actual effective vertical diffusion of the wakes. The equation of state, which connects the density and salinity, is assumed to be linear, with the coefficient of the salt contraction being included into the definition of salinity or heat. The characteristic internal waves as well as the entire beam width are related to the diameter of the bar, the Richardson number and the peak-to-peak value of oscillations. The ultimate frequency of the infinitesimal periodic internal waves is limited by the maximum buoyancy frequency relating the decrease in the vertical scale with the anisotropy of the velocity turbulent r.m.s. velocity.Peer ReviewedPreprin

Alexithymia Mediates the Relationship Between Insecure Attachment and Eating Disorder Symptoms

Insecure attachment and alexithymia have traditionally been associated with eating disorders. However, research has recently started to examine the specific mechanisms by which attachment insecurity affect disordered eating. The aim of this study was therefore to investigate the hypothesis that alexithymia mediates the relationships between insecure attachment patterns and eating disorders (EDs) and to test the relative contribution of each component of alexithymia. 323 female university students and 38 anorexic patients completed questionnaires on attachment, alexithymia and ED symptoms within a structural equation modeling approach. Insecure attachment was related to alexithymia, specifically difficulty identifying feelings (DIF) and difficulty describing feelings (DDF) subscales of the Toronto Alexithymia Scale. Furthermore, alexithymia scores were associated with eating disorder symptoms. However, only DIF mediated the relationship between attachment insecurity and ED symptoms. Despite the limitations of the cross-section design, attachment and alexithymia seem to be an important focus when preventing and treating EDs

Protocolo de actuación ante hemangiomas y/o malformaciones vasculares

When facing any vascular lesion present in the first moments of life, it is necessary to determine whether one is dealing with a tumour or a vascular malformation, given the different evolution of both processes and, hence, the different treatments they require. Diagnosis is basically clinical, based on a correct anamnesis and a detailed physical exploration. The first thing is to establish whether the lesion was present at birth and has changed size significantly, which would lead one to think of a haemangioma or, on the contrary, whether it is congenital and of very slow growth, such as vascular malformations. Facing dubious lesions, it is recommendable to carry out a biopsy with immunohistochemistry for the GLUT-1 antibody, specific to haemangiomas. Amongst the image tests, the first choice is usually ecography-Doppler, which makes it possible to determine whether the lesion is of high or low flow and to distinguish whether one is dealing with a haemangioma or a vascular malformation. Depending on the type of lesion, its localisation and degree of affectation it might be necessary to carry out radiography, magnetic resonance, phlebography, angio-resonance, arteriography or lymphoscintigraphy to complete the study. In more particular cases, such as multiple haemangiomatosis, it is necessary to carry out an hepatic echography, blood concealed in faeces, gastroscopy and colonoscopy, as well a determination of thyroid hormones; and in venous or combined extensive malformations, a haemogram and coagulation tests. On the other hand, the possible repercussions on other organs make a multidisciplinary approach essential, with the participation of different specialists. Due to the wide spectrum covered by vascular anomalies, treatment must be individualised