RESUMEN
At a distance of 1.295 parsecs, the red dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890 or simply Proxima) is the Sun's closest stellar neighbour and one of the best-studied low-mass stars. It has an effective temperature of only around 3,050 kelvin, a luminosity of 0.15 per cent of that of the Sun, a measured radius of 14 per cent of the radius of the Sun and a mass of about 12 per cent of the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is about 83 days (ref. 3) and its quiescent activity levels and X-ray luminosity are comparable to those of the Sun. Here we report observations that reveal the presence of a small planet with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units. Its equilibrium temperature is within the range where water could be liquid on its surface.
Asunto(s)
Planetas , Estrellas Celestiales , Medio Ambiente Extraterrestre/química , Rotación , Temperatura , Agua/análisis , Agua/químicaRESUMEN
Se ha planteado que el manejo del niño con antecedentes familiares de atopia que no ha presentado asma, debe incluir medidas de Prevención Primaria que lo puedan proteger de desarrollar esta condición. En los estudios realizados a este respecto, se ha evaluado la influencia de factores dietéticos, ambientales e infecciosos que pudieran tener impacto en la historia natural de la enfermedad. En este artículo se evalúa la evidencia disponible acerca de cada intervención, a fin de dar al médico Pediatra y de Atención Primaria herramientas para hacer recomendaciones apropiadas para los padres.
It has been suggested that the management of children at risk for developing asthma should include Primary Prevention measures in order to protect them against the development of this condition. In the published studies to date, the influence of dietary, environmental, and infectious factors involved has been assessed. In this article, we review the available evidence on each intervention, and give some tools to the Pediatrician and Primary Care Physician to make appropriate recommendations for parents.