Blue stragglers are anomalously luminous core hydrogen-burning stars formed through mass-transfer in binary/triple systems and stellar collisions. Their physical and evolutionary properties are largely unknown and unconstrained. Here we analyze 320 high-resolution spectra of blue stragglers collected in eight galactic globular clusters with different structural characteristics and show evidence that the fraction of fast rotating blue stragglers (with rotational velocities larger than 40 km/s) increases for decreasing central density of the host system.
View Article and Find Full Text PDFObjective: Nasal administration of Streptococcus salivarius 24SMB and Streptococcus oralis 89a has been proposed to reduce the risk of new episodes of adenoiditis, tonsillitis and acute rhinosinusitis in children.
Patients And Methods: We enrolled 202 children with a recent diagnosis of recurrent upper respiratory tract infection. All the patients were treated twice daily for 7 days each month for 3 consecutive months with a nasal spray whose active agents were two specific bacterial strains: Streptococcus salivarius 24SMB and Streptococcus oralis 89a.
Acta Otorhinolaryngol Ital
February 2018
Schwannomas are rare benign tumours that arise from Schwann cells. The most known and studied is the intracranial vestibular schwannoma, even if it is not the most frequent. More often schwannomas arise from peripheral sensitive nerves, and the vagous is most involved among the cranial nerves.
View Article and Find Full Text PDFHorizontal branch stars belong to an advanced stage in the evolution of the oldest stellar galactic population, occurring either as field halo stars or grouped in globular clusters. The discovery of multiple populations in clusters that were previously believed to have single populations gave rise to the currently accepted theory that the hottest horizontal branch members (the 'blue hook' stars, which had late helium-core flash ignition, followed by deep mixing) are the progeny of a helium-rich 'second generation' of stars. It is not known why such a supposedly rare event (a late flash followed by mixing) is so common that the blue hook of ω Centauri contains approximately 30 per cent of the horizontal branch stars in the cluster, or why the blue hook luminosity range in this massive cluster cannot be reproduced by models.
View Article and Find Full Text PDFJ Neurol Surg B Skull Base
February 2012
In this study we evaluate the postoperative facial nerve function after vestibular schwannoma (VS) surgery and analyze the factors that cause it. We included 97 consecutive patients undergoing surgical excision of sporadic unilateral VS. Patient and tumor characteristics, surgical approaches, facial nerve function, extent of tumor removal, perioperative complications are all analyzed through standardized systems.
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