809 research outputs found
Virological rebound in human immunodeficiency virus-infected patients with or without residual viraemia: results from an extended follow-up
AbstractHuman immunodeficiency virus (HIV) -infected patients with HIV RNA loads of < 50 copies/mL were followed-up for a median (interquartile range) of 30.8 (11.7–32.9) months to study the effect of residual viraemia (RV) on virological rebound (VR). At baseline, 446 (60.3%) patients had undetectable HIV RNA (group A) and 293 (39.7%) had RV (1–49 HIV RNA copies/mL, group B) by kinetic PCR. VR occurred in 4 (0.9%) patients in group A and in 12 (4.1%) patients in group B (p 0.007). Time to VR was shorter among patients of group B (Log-rank test: p 0.003). However, the proportion of VR was extremely low also among patients with RV
A Peculiar Family of Jupiter Trojans: the Eurybates
The Eurybates family is a compact core inside the Menelaus clan, located in
the L4 swarm of Jupiter Trojans. Fornasier et al. (2007) found that this family
exhibits a peculiar abundance of spectrally flat objects, similar to
Chiron-like Centaurs and C-type main belt asteroids. On the basis of the
visible spectra available in literature, Eurybates family's members seemed to
be good candidates for having on their surfaces water/water ice or aqueous
altered materials. To improve our knowledge of the surface composition of this
peculiar family, we carried out an observational campaign at the Telescopio
Nazionale Galileo (TNG), obtaining near-infrared spectra of 7 members. Our data
show a surprisingly absence of any spectral feature referable to the presence
of water, ices or aqueous altered materials on the surface of the observed
objects. Models of the surface composition are attempted, evidencing that
amorphous carbon seems to dominate the surface composition of the observed
bodies and some amount of silicates (olivine) could be present.Comment: 23 pages, 2 figures, paper accepted for publication in Icaru
Visible spectroscopy in the neighborhood of 2003 EL61
Context: The recent discovery of a group of trans-neptunian objects (TNOs) in
a narrow region of the orbital parameter space and with surfaces composed of
almost pure water ice, being 2003 EL61 its largest member, promises new and
interesting results about the formation and evolution of the trans-neptunian
belt (TNb) and the outer Solar System.
Aims: The aim of this paper is to obtain information of the surface
properties of two members of this group ((24835) 1995 SM55, (120178) 2003 OP32)
and three potential members (2003 UZ117, (120347) 2004 SB60 and 2005 UQ513) and
to use that in order to confirm or reject their association.
Methods: We obtained visible spectra of five TNOs using the 3.58m Telescopio
Nazionale Galileo at the ''Roque de los Muchachos Observatory'' (La Palma,
Spain)
Results: The spectra of the five TNOs are featureless within the
uncertainties and with colors from slightly blue to red (-2<
S'<18%/0.1microns). No signatures of any absorption are found.
Conclusions: We confirm the association of 1995 SM55 and 2003 OP32 with the
group of 2003 EL61 as their spectra are almost identical to that of 2003 EL61.
Only one of the three candidates, 2003 UZ117, can be considered as a possible
member of the EL61-group, as its visible spectrum is compatible with a spectrum
of a surface composed of almost pure water ice and no complex organics. The
other two, 2004 SB60 and 2005 UQ513 are red and must be considered as
interlopers.Comment: 5 pages, 2 figure
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Stability Analysis of Neuro-Adaptive SMC-Based Current Sharing Technique for Multiphase Converters in Battery Charging Applications
Dasabuvir and Ombitasvir/Paritaprevir/Ritonavir with or without Ribavirin in Patients with HIV-HCV Coinfection. Real Life Interim Analysis of an Italian Multicentre Compassionate Use Program
Background and Aims: An HCV cure is now possible in a large proportion of HIV-HCV patient. We present real life results of a compassionate use program promoted by SIMIT (Infectious and Tropical Diseases Italian Society) of Dasabuvir and Ombitasvir/Paritaprevir/Ritonavir ± Ribavirin for 12 weeks in 213 HIV-HCV genotype 1 patients. Data on efficacy and tolerability of this strategy in HIV patients have been reported until now only in 43 non cirrhotic HIV subjects
Spectrophotometric investigation of Phobos with the Rosetta OSIRIS-NAC camera and implications for its collisional capture
TheMartian satellite Phobos has been observed on 2007 February 24 and 25, during the pre- and post-Mars closest approach (CA) of the ESA Rosetta spacecraftMars swing-by. The goal of the observations was the determination of the surface composition of different areas of Phobos, in order to obtain new clues regarding its nature and origin. Near-ultraviolet, visible and near-infrared (263.5-992.0 nm) images of Phobos's surface were acquired using the Narrow Angle Camera of the OSIRIS instrument onboard Rosetta. The six multi-wavelength sets of observations allowed a spectrophotometric characterization of different areas of the satellite, belonging respectively to the leading and trailing hemisphere of the anti-Mars hemisphere, and also of a section of its sub-Mars hemisphere. The pre-CA spectrophotometric data obtained with a phase angle of 19° have a spectral trend consistent within the error bars with those of unresolved/disc-integrated measurements present in the literature. In addition, we detect an absorption band centred at 950 nm, which is consistent with the presence of pyroxene. The post-CA observations cover from NUV to NIR a portion of the surface (0° to 43°E of longitude) never studied before. The reflectance measured on our data does not fit with the previous spectrophotometry above 650 nm. This difference can be due to two reasons. First, the OSIRIS observed area in this observation phase is completely different with respect to the other local specific spectra and hence the spectrum may be different. Secondly, due to the totally different observation geometry (the phase angle ranges from 137° to 140°), the differences of spectral slope can be due to phase reddening. The comparison of our reflectance spectra, both pre-and post-CA, with those of D-type asteroids shows that the spectra of Phobos are all redder than the mean D-type spectrum, but within the spectral dispersion of other D-types. To complement this result, we performed an investigation of the conditions needed to collisionally capture Phobos in a way similar to that proposed for the irregular satellites of the giant planets. Once put in the context of the current understanding of the evolution of the early Solar system, the coupled observational and dynamical results we obtained strongly argue for an early capture of Phobos, likely immediately after the formation of Mars. © 2012 The Authors
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