Hybrid stars with the color dielectric and the MIT bag models

We study the hadron-quark phase transition in the interior of neutron stars (NS). For the hadronic sector, we use a microscopic equation of state (EOS) involving nucleons and hyperons derived within the Brueckner-Bethe-Goldstone many-body theory, with realistic two-body and three-body forces. For the description of quark matter, we employ both the MIT bag model with a density dependent bag constant, and the color dielectric model. We calculate the structure of NS interiors with the EOS comprising both phases, and we find that the NS maximum masses are never larger than 1.7 solar masses, no matter the model chosen for describing the pure quark phase.Comment: 11 pages, 5 figures, submitted to Phys. Rev.

Comparison of a double-textured prototype manual toothbrush with 3 branded products: A professional brushing study

Background: The consensus has been that there is no one superior design of manual toothbrush for plaque removal, despite, in some cases, encouraging findings from laboratory studies. The user appears the major variable and may mask differences in brush efficacy. Aims: The aim of this study was to compare 2 new double‐filament texture brushes with 3 established brands for plaque removal, under standardised conditions of professional brushing. Method: The study was a blind, randomised crossover design, balanced for residual effects. A panel of 15 subjects suspended tooth cleaning for 3 days. On day 4, plaque was scored from 6 sites per tooth before and after a 2‐min professional toothbrushing. A washout period of at least 3 days was allowed between study periods. Results: Overall plaque removal was 50% with no significant differences between brushes, a 3% absolute difference in average total mouth plaque separating brushes. However, at upper‐ and mid‐buccal sites, a not significant 8% and a significant 9% difference, respectively, in plaque removal were recorded in favour of one of the prototype brushes, and at the mid‐lingual site, there was a non‐significant 10% difference in favour of one branded brush. Other sites were cleaned similarly by all brushes except for reduced plaque removal from buccal compared to lingual surfaces and interproximal compared to mid‐surface sites. Highly significant subject differences in plaque removal were noted which may be relevant to inherent anatomical difficulties in tooth cleaning for some individuals. Period effects were not significant, supporting the consistency in brushing by the professional brusher. Conclusion: The method appeared capable of detecting small benefits of brush design. However, the benefits reported must be taken within the context of an overall lack of difference between brushes. The method could be used to set and record a minimum level of efficacy for toothbrushes