Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J-band magnitude of ~7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet's short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy.
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.
Twenty-four children with infantile cerebral palsy (6 girls and 18 boys aged 3-17 years), surgically treated in the years 1993-1997, were involved in the study. Neurological-orthopaedic examinations and computer tomography (CT) of the head allowed precise diagnosis and understanding of its pathology. The group consisted of 10 patients with hemiplegia, 10 with diplegia and 4 with severe quadriplegia. In 18 children changes in the brain were largely dependent on the clinical type of paresis. In hemiparesis, unilateral changes, such as cerebral cortex atrophy with enlarged ventricles, were predominant. Diplegia cases frequently showed periventricular damage to the white matter. Brain tomography in severe quadriplegia did not always correspond to the clinical condition. CT examinations revealed no abnormalities in the brain in 6 out of 24 cases. Since the results of rehabilitation were not satisfactory, 29 surgical procedures were performed in the presented group of patients, with improved the course of therapeutic rehabilitation or nursing care in all the children.
Brain/pathology , Cerebral Palsy/diagnosis , Cerebral Palsy/rehabilitation , Adolescent , Cerebral Palsy/surgery , Child , Child, Preschool , Female , Hemiplegia/pathology , Humans , Male , Prognosis , Quadriplegia/pathology , Tomography, X-Ray Computed , Treatment Outcome
Twenty four children with Scheuermann's disease (11 girls and 13 boys) aged 9-18 years measured for bone mineral density. The total skeleton (TB BMD) and lumbar spine (L2-L4 BMD) mineral density were investigated by dual energy X-ray absorptiometry (DEXA). In nine patients with Scheuermann's disease and backache we found lower levels of TB BMD and L2-L4 BMD in comparison with reference population of Lunar database. Osteopenia in these children may be caused by decreased physical activity due to vertebral pain.
Bone Density , Scheuermann Disease/pathology , Absorptiometry, Photon , Adolescent , Back Pain/etiology , Back Pain/pathology , Body Height , Body Weight , Bone Diseases, Metabolic/etiology , Bone and Bones/pathology , Child , Databases as Topic , Female , Humans , Lumbar Vertebrae/pathology , Male , Motor Activity/physiology , Puberty , Scheuermann Disease/complications , Scheuermann Disease/physiopathology
