Intersections of self-gravitating charged shells in a Reissner-Nordstrom field

We describe the equation of motion of two charged spherical shells with tangential pressure in the field of a central Reissner-Nordstrom (RN) source. We solve the problem of determining the motion of the two shells \textsl{after} the intersection by solving the related Einstein-Maxwell equations and by requiring a physical continuity condition on the shells velocities. We consider also four applications: post-Newtonian and ultra-relativistic approximations, a test-shell case, and the ejection mechanism of one shell. This work is a direct generalization of Barkov-Belinski-Bisnovati-Kogan paper.Comment: 21 pages, 1 figure;v3 added reference

On the semiclassical treatment of Hawking radiation

In the context of the semiclassical treatment of Hawking radiation we prove the universality of the reduced canonical momentum for the system of a massive shell self gravitating in a spherical gravitational field within the Painlev\'e family of gauges. We show that one can construct modes which are regular on the horizon both by considering as hamiltonian the exterior boundary term and by using as hamiltonian the interior boundary term. The late time expansion is given in both approaches and their time Fourier expansion computed to reproduce the self reaction correction to the Hawking spectrum.Comment: 18 pages, LaTeX, Corrected typo

Primer Acuerdo Nacional de Referentes para la Prevención de las Complicaciones y del Diagnóstico y Tratamiento de la Toxoplasmosis

El presente trabajo es un relato de experiencia de la reunión realizada en la ciudad de Alta Gracia, Córdoba, donde se llevo cabo el “1er Acuerdo Nacional de Referentes para la Prevención de las Complicaciones y del Diagnóstico y Tratamiento de la Toxoplasmosis”. Se discutieron conocimientos validados por la literatura científica como base para propuestas racionales de diagnóstico. Los objetivos del acuerdo fueron: discutir y reflexionar sobre las prácticas y diagnóstico de la Toxoplasmosis en el sistema público nacional, consensuar y proponer un algoritmo de diagnóstico para el sistema público, analizar la brecha entre el nivel de conocimiento y la aplicación de practicas y procedimientos en la población general y en los grupos de riesgo, discutir y proponer actividades destinadas a identificar el riesgo de transmisión vertical con el fin de proponer estrategias de tamizaje adecuados a la prevalencia nacional, proponer actividades para reducir la brecha conocimiento/aplicación de ese conocimiento en un marco de equidad. Los profesionales referentes acordaron la firma del Acta de Alta Gracia que contempla para la red pública de atención médica el diagnóstico de Toxoplasmosis con equidad, calidad, acceso a metodologías complejas, cooperación y asesoría técnica y disponibilidad oportuna de insumos en casos de emergencias jurisdiccionales

Subacute pericardial abscess after aortic valve replacement: a case report

BACKGROUND: Purulent pericarditis is an infectious disease, frequently caused by gram-positive bacteria, that is rarely observed in healthy individuals, and is often associated with predisposing conditions. CASE PRESENTATION: Here, we present the case of an Escherichia coli post-surgical localized purulent pericarditis complicated by transient constrictive pericarditis and its diagnostic and therapeutic management. CONCLUSIONS: Our case report focuses on the importance of imaging-guided treatment of purulent pericardial diseases, in particular on the emerging role of 18\u2009F-labelled 2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in pericardial diseases and on the management of transient constrictive pericarditis, often seen after thoracic surgery

Effect of fibre configurations on mechanical properties of flax/tannin composites.

Flax reinforced tannin-based composites have a potential to be used in vehicle applications due to the environmental advantages and good mechanical properties. In this paper, the effects of fibre configuration on mechanical properties of flax/tannin composites were investigated for nonwoven and woven fabric lay-up angles (UD, [0°, 90°]2 and [0°, +45°, 90°, -45°]2). The tannin/flax composites were prepared by compression moulding. The manufactured specimens were then characterized for quasi-static tensile properties, dynamic mechanical properties and low-energy impact performance. Failure mechanism was further investigated using microscopy and demonstrated the need for further adhesion improvements. The study shows that the UD fabric reinforced composite performs better in tensile strength and modulus whereas [0°, +45°, 90°, -45°]2 composite provides the best impact energy absorption performance

Early detection of pleuro-pulmonary tuberculosis by bedside lung ultrasound: A case report and review of literature

We present a case in which lung ultrasound (LUS) was relevant to reach an early diagnosis of lung tuberculosis and to manage the patient in the right setting. Moreover, ultrasound allowed to detect and treat massive pleural effusion through an ultrasound-guided thoracentesis

Charged membrane as a source for repulsive gravity

We demonstrate an alternative (with respect to the ones existing in literature) and more habitual for physicists derivation of exact solution of the Einstein-Maxwell equations for the motion of a charged spherical membrane with tangential tension. We stress that the physically acceptable range of parameters for which the static and stable state of the membrane producing the Reissner-Nordstrom (RN) repulsive gravity effect exists. The concrete realization of such state for the Nambu-Goto membrane is described. The point is that membrane are able to cut out the central naked singularity region and at the same time to join in appropriate way the RN repulsive region. As result we have a model of an everywhere-regular material source exhibiting a repulsive gravitational force in the vicinity of its surface: this construction gives a more sensible physical status to the RN solution in the naked singularity case.Comment: Accepted for publication in IJMPD, 17-07-2008; 16 pages, 1 figur