Context. Finding the sources responsible for the hydrogen reionization is one of the most pressing issues in observational cosmology. Bright QSOs are known to ionize their surrounding neighborhood, but they are too few to ensure the required HI ionizing background. A significant contribution by faint AGNs, however, could solve the problem, as recently advocated on the basis of a relatively large space density of faint active nuclei at z > 4. Aims. This work is part of a long term project aimed at measuring the Lyman Continuum escape fraction for a large sample of AGNs at z ∼ 4 down to an absolute magnitude of M 1450 ∼ −23. We have carried out an exploratory spectroscopic program to measure the HI ionizing emission of 16 faint AGNs spanning a broad U − I color interval, with I ∼ 21 − 23 and 3.6 < z < 4.2. These AGNs are three magnitudes fainter than the typical SDSS QSOs (M 1450 −26) which are known to ionize their surrounding IGM at z 4. Methods. We acquired deep spectra of these faint AGNs with spectrographs available at the VLT, LBT, and Magellan telescopes, i.e. FORS2, MODS1-2, and LDSS3, respectively. The emission in the Lyman Continuum region, i.e. close to 900 Å rest frame, has been detected with S/N ratio of ∼ 10 − 120 for all the 16 AGNs. The flux ratio between the 900 Å rest frame region and 930 Å provides a robust estimate of the escape fraction of HI ionizing photons. Results. We have found that the Lyman Continuum escape fraction is between 44 and 100% for all the observed faint AGNs, with a mean value of 74% at 3.6 < z < 4.2 and −25.1 M 1450 −23.3, in agreement with the value found in the literature for much brighter QSOs (M 1450 −26) at the same redshifts. The Lyman Continuum escape fraction of our faint AGNs does not show any dependence on the absolute luminosities or on the observed U − I colors of the objects. Assuming that the Lyman Continuum escape fraction remains close to ∼ 75% down to M 1450 ∼ −18, we find that the AGN population can provide between 16 and 73% (depending on the adopted luminosity function) of the whole ionizing UV background at z ∼ 4, measured through the Lyman forest. This contribution increases to 25-100% if other determinations of the ionizing UV background are adopted from the recent literature. Conclusions. Extrapolating these results to z ∼ 5 − 7, there are possible indications that bright QSOs and faint AGNs can provide a significant contribution to the Reionization of the Universe, if their space density is high at M 1450 ∼ −23.

Despite the first reports concerning benzodiazepine dependence being published in the early 1960s literature, the risk of benzodiazepine addiction is still greatly debated. The severe discomfort and life threatening complications usually experienced by long-term benzodiazepine users who suddenly interrupt benzodiazepine intake have led to the development of several detoxification protocols. A successful strategy used by our Addiction Unit is abrupt benzodiazepine cessation by administering flumazenil slow subcutaneous infusion (FLU-SSI) with an elastomeric pump. Although some studies proved the efficacy of flumazenil infusion more than 20 years ago, only a few centres in the world offer this method to their patients. This paper reports the data related to 214 subjects addicted to high doses of benzodiazepine and treated with the FLU-SSI method between 2012 and 2014. This technique is less invasive and requires less nursing intervention than intravenous infusion. Our data support FLU-SSI as a possible efficient strategy for the treatment of patients with long-term, high-dose benzodiazepine addiction, and could become a routine therapy as long as the necessary further studies on dose, duration of infusion and safety issues are carried out.

We present a detailed study of the stellar and H  structure of the dwarf irregular galaxies Sextans A and Sextans B, members of the NGC 3109 association. We use newly obtained deep (r 26.5) and wide-field g and r photometry to extend the surface brightness (SB) profiles of the two galaxies down to µ V 31.0 mag/arcsec 2 . We find that both galaxies are significantly more extended than previously traced with surface photometry, out to ∼ 4 kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the red giant branch, [Fe/H] = −1.6. The SB profiles show significant changes of slope and cannot be fitted with a single Sérsic model. Both galaxies have HI discs as massive as their respective stellar components. In both cases the H  discs display solid-body rotation with maximum amplitude of ∼50 km s −1 (albeit with significant uncertainty due to the poorly constrained inclination), implying a dynamical mass ∼10 9 M , a mass-to-light ratio∼ 25, and a dark-to-baryonic mass ratio of ∼10. The distribution of the stellar components is more extended than the gaseous disc in both galaxies. We find that the main, approximately round, stellar body of Sex A is surrounded by an elongated low-SB stellar halo that can be interpreted as a tidal tail, similar to that found in another member of the same association (Antlia). We discuss these, as well as other evidence of tidal disturbance, in the framework of a past passage of the NGC 3109 association close to the Milky Way, which has been hypothesised by several authors and is also supported by the recently discovered filamentary configuration of the association itself.

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