Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Prospective randomized multicentre phase III study of liver perfusion with HTK solution compared with UW OR celsior solutions in the setting of liver transplantation

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Aspectos neurocirúrgicos dos osteomas fronto-etmoidais: relato de 6 casos e revisão da literatura

São relatados seis casos de osteomas fronto-etmoidais que provocaram complicações intracranianas ou orbitárias. Os casos são divididos em dois grupos, dependendo dos sintomas observados, desde deformações cranio-faciais e exoftalmo até complicações mais graves como rinorréas, meningites, pneumocéfalos e mucoceles. Uma revisão da literatura mostra a importância destas lesões na patologia neurocirúrgica como causa de meningites recidivantes, rinorréas espontâneas e pneumocéfalos não traumáticos. Uma análise crítica das técnicas cirúrgicas propostas mostra que, por meio de craniotomia frontal, é possível obter resultado bom, tanto estético como funcional