We report the result of the HST snapshot survey of BL Lac host galaxies. Almost 100 sources with redshift ranging from 0.05 to 1.2 were observed. Virtually all source at z

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The excitation of p-modes seems to be produced by turbulence in the convection zone (see, e.g., Kumar, 1997 and the references therein). Low-degree p-mode allowed a study of the energy distribution of the p-mode oscillations, concluding that it is of Boltzmann type (Elsworth et al., 1995; Chaplin et al., 1997). Moreover, these authors suggest that

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I report on a critical analysis of the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This mechanism relies upon electroweak symmetry restoration in a region around cosmic strings, where sphalerons would be unsuppressed. I discuss the various problems this scenario has to face, presenting a careful computation

The influence of the environment on the processes that regulate the history of star formation and the chemical enrichment in galaxies is a key ingredient for the study of galaxy evolution. New evidence has accumulated reinforcing the idea that galaxies located in high density environments, such as groups or clusters, may exhibit different levels of