N. O. Santos

Nonadiabatic gravitational collapse

The junction conditions of a collapsing nonadiabatic charged body producing radiation are studied. The interior spacetime is modelled by a magnetohydrodynamic fluid undergoing dissipation in the form of a radial heat flow. The fluid is considered shear-free, giving rise to the slowest possible collapse, as shown by Raychaudhuris (1957) equation. The exterior spacetime is described by the Reissner-Nordstrom-Vaidya metric, which represents a spherically symmetric electric field and a radial flow of unpolarized radiation. The generalization of the dynamical equations for spherical collapse proposed by Misner and Sharp (1964) and Bekenstein (1971) is presented, and the evolution of its horizons is considered. 24 references.

Friedmann-like collapsing radiating sphere

The model of a collapsing body proposed by Kolassis et al. (1988) is further studied. Consideration is given to the collapse of a spherical body with a mass of 1.3 solar masses. Equations are solved in the weak flow approximation. There is a nonzero fluid pressure and, during the collapse, the pressure gradient becomes positive; this further increases the instability of the object. 6 refs.

Clinical features of adolescents with deliberate self-harm: A case control study in Lisbon, Portugal

Deliberate self-harm (DSH) among adolescents is a high-risk condition for suicide. The aim of the present study is to describe the characteristic clinical features of adolescents with DSH according to our local context (Lisbon, Portugal), using easily available information from clinical settings. A case control study was constructed from a sample of 100 adolescents (aged 12 to 21 years). The sample was divided into two groups: adolescents with and without DSH. Case files were examined and data was completed by clinical interviews. Demographic, psychosocial, and psychopathological data were assessed and compared. Ninety-eight subjects completed the protocol. The DSH group was associated with the following: suicidal ideation or suicidal behavior as consultation motive, emergency room referral, previous follow-up attempts, suicidal ideation, psychosocial difficulties, or lack of therapeutic goals. There was a nonsignificant trend towards diagnosis of depression in the DSH group. These results reflect our clinical practice with adolescents and add data about teenagers who self-harm to the literature. Prevention and early recognition of DSH (and frequently associated depression) in adolescents are essential and could be life-saving measures. An integrated approach, which takes into account psychosocial difficulties, family dysfunction, and negative expectations, seems to be of great importance.