12,813 research outputs found
Interferon gamma upregulates frataxin and corrects the functional deficits in a Friedreich ataxia model
No full textCopyright © The Author 2012. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.Friedreich's ataxia (FRDA) is the most common hereditary ataxia, affecting ∼3 in 100 000 individuals in Caucasian populations. It is caused by intronic GAA repeat expansions that hinder the expression of the FXN gene, resulting in defective levels of the mitochondrial protein frataxin. Sensory neurons in dorsal root ganglia (DRG) are particularly damaged by frataxin deficiency. There is no specific therapy for FRDA. Here, we show that frataxin levels can be upregulated by interferon gamma (IFNγ) in a variety of cell types, including primary cells derived from FRDA patients. IFNγ appears to act largely through a transcriptional mechanism on the FXN gene. Importantly, in vivo treatment with IFNγ increases frataxin expression in DRG neurons, prevents their pathological changes and ameliorates the sensorimotor performance in FRDA mice. These results disclose new roles for IFNγ in cellular metabolism and have direct implications for the treatment of FRDA.AtaxiaUK, National Ataxia Foundation, USA, Friedreich Ataxia Research Alliance
(FARA), USA and Telethon-Italy, FARA, GoFAR, the Wellcome
Trust, the EU FP7 and the Fondazione Telethon
High angular resolution millimeter observations of circumstellar disks
No full textIn this lecture, we review the properties of protoplanetary disks as derived from high angular resolution observations at millimeter wavelengths. We discuss how the combination of several different high angular resolution techniques allow us to probe different regions of the disk around young stellar objects and to derive the properties of the dust when combined with sophisticated disk models. The picture that emerges is that the dust in circumstellar disks surrounding pre-main sequence stars is in many cases significantly evolved compared to the dust in molecular clouds and the interstellar medium. It is however still difficult to derive a consistent picture and timeline for dust evolution in disks as the observations are still limited to small samples of objects. We also review the evidence for and properties of disks around high-mass young stellar objects and the implications on their formation mechanisms. The study of massive YSOs is complicated by their short lifetimes and larger average distances. In most cases high angular resolution data at millimeter wavelengths are the only method to probe the structure of disks in these objects. We provide a summary of the characteristics of available high angular resolution millimeter and submillimeter observatories. We also describe the characteristics of the ALMA observatory being constructed in the Chilean Andes. ALMA is going to be the world leading observatory at millimeter wavelengths in the coming decades, the project is now in its main construction phase with early science activities envisaged for 2010 and full science operations for 2012
Report on the Workshop ''ALMA Community Days: Towards Early Science''
No full textALMA is rapidly approaching Early Science operations, and is scheduled to start the first observing projects for the astronomical community in the autumn of 2011. The Call for Proposals for ALMA Early Science Cycle 0 was published on 30 March, inviting the community to submit observing proposals by the deadline of 30 June 2011. Held just after the Call for Proposals was issued, the ALMA Community Days were designed to optimally prepare the European ALMA Community for Cycle 0 proposal submission. The workshop included a broad range of scientific and technical presentations as well as hands-on software tutorials for the ALMA simulators and the Observing Tool
Synecology of Quercus suber communities in S-Europe along geographical and ecological gradients.European Vegetation Survey, March 2005,Roma
No full textEdaphic characteristics of Quercus suber woods in Latium.
No full textIn this paper the results are reported of a soil survey done in selected sites of Latium under the most significant Quercus suber woods (Cytiso-Quercetum suberis Testi, Pignatti and Lucattini 1994) previously studied from a phytosociological point of view. After describing the dominant soil type of each area, physical-chemical characteristics have been analysed in order to point out the significance of edaphic factors in the distribution and floristic composition of the Quercus suber coenoses. Bioclimatic, structural and edaphic features of this vegetation showed a great convergence; among all the parameters examined, AWC resulted to be the most effective one in conditioning the mesophilous character of Quercus suber coenoses growing in Latium. In this respect this type of vegetation shows rather strong affinities with mixed Quercus cerris woods, both in the floristic composition and in the edaphic requirements, as already suggested in the most recent phytosociological studies
Temperaments of young stars : rapid mass accretion rate changes in T Tauri and Herbig Ae stars
No full textFunding: JSV would like to thank the UK Science and Technologies Facility Council (STFC) and the Northern Ireland Department of Culture Arts and Leisure (DCAL) for financial support. AS and TR would like to thank the Science Foundation of Ireland (SFI) for their support under grant numbers 11/RFP/AST/3331 and 10/RFP/AST2780.Variability in emission lines is a characteristic feature in young stars and can be used as a tool to study the physics of the accretion process. Here, we present a study of Hα variability in 15 T Tauri and Herbig Ae stars (K7 - B2) over a wide range of time windows, from minutes, to hours, to days, and years. We assess the variability using linewidth measurements and the time series of line profiles. All objects show gradual, slow profile changes on time-scales of days. In addition, in three cases there is evidence for rapid variations in Hα with typical time-scales of 10 min, which occurs in 10 per cent of the total covered observing time. The mean accretion rate changes, inferred from the line fluxes, are 0.01–0.07 dex for time-scales of <1 h, 0.04–0.4 dex for time-scales of days, and 0.13–0.52 dex for time-scales of years. In Costigan et al., we derived an upper limit finding that the intermediate (days) variability dominated over longer (years) variability. Here, our new results, based on much higher cadence observations, also provide a lower limit to accretion rate variability on similar time-scales (days), thereby constraining the accretion rate variability physics in a much more definitive way. A plausible explanation for the gradual variations over days is an asymmetric accretion flow resulting in a rotational modulation of the accretion-related emission, although other interpretations are possible as well. In conjunction with our previous work, we find that the time-scales and the extent of the variability is similar for objects ranging in mass from ∼0.1 to ∼5 M⊙. This confirms that a single mode of accretion is at work from T Tauri to Herbig Ae stars – across a wide range of stellar masses.Peer reviewe
"Prospective comparative trial of bone marrow transplantation and postremission chemotherapy for childhood acute myelogenous leucemia"
No full textPURPOSE: This study was conducted to assess the comparative values of allogeneic bone marrow transplantation (BMT) and autologous bone marrow transplantation (ABMT) with sequential postremission chemotherapy (SPC) in children with acute myelogenous leukemia (AML) in first remission.
PATIENTS AND METHODS: From March 1987 to March 1990, 161 assessable patients younger than 15 years of age with newly diagnosed AML were treated uniformly with two courses of daunorubicin and standard-dose cytarabine. After initial consolidation with a course of daunorubicin, cytarabine, and thioguanine (DAT), patients in complete remission (CR) were randomized to receive either ABMT or SPC, except for those with an HLA-matched sibling who were assigned to undergo BMT. SPC consisted of three additional courses of DAT, followed by three pairs of drugs administered sequentially for a total of six cycles.
RESULTS: Overall, 127 of 161 patients attained CR (79%). The estimated probabilities of survival and event-free survival (EFS) at 5 years for all patients were 42% and 25%, respectively (median follow-up, 28 months). For the 127 complete responders, the 5-year probability of disease-free survival (DFS) was 31%, with a cumulative risk of relapse of 64%. For the purpose of this study, all complete responders were evaluated for analysis of disease outcome according to the intent-to-treat principle, regardless of whether they actually received the intended therapy. The 5-year DFS was 51% for the BMT group (n = 24), significantly higher (P = .03) than that observed for the other cohorts: 21% for ABMT (n = 35), 27% for SPC (n = 37), and 34% for a group of 31 nonrandomized (NR) patients. Bone marrow relapse was the most frequent cause of postremission failure in all therapeutic subgroups, including the BMT cohort, in which no deaths attributable to the toxicity of the procedure were recorded
A study of the Galactic star forming region IRAS 02593+6016/S 201 in infrared and radio wavelengths
No full textWe present infrared and radio continuum observations of the S 201 star forming region. A massive star cluster is seen, which contains different classes of young stellar objects. The near-infrared colour-colour and colour-magnitude diagrams are studied to determine the nature of these sources. We have discovered knots of molecular hydrogen emission at 2.122 μm in the central region of S 201. These knots are clearly seen along the diffuse emission to the north-west and are probably obscured Herbig-Haro objects. High sensitivity and high resolution radio continuum images from GMRT observations at 610 and 1280 MHz show an arc-shaped structure due to the interaction between the HII region and the adjacent molecular cloud. The ionization front at the interface between the HII region and the molecular cloud is clearly seen comparing the radio, molecular hydrogen and Brγ images. The emission from the carriers of Unidentified Infrared Bands in the mid-infrared 6-9 μm (possibly due to PAHs) as extracted from the Midcourse Space Experiment survey (at 8, 12, 14 and 21 μm) is compared with the radio emission. The HIRES processed IRAS maps at 12, 25, 60 and 100 μm have also been used for comparison. The spatial distribution of the temperature and the optical depth of the warm dust component around the S 201 region has been generated from the mid-infrared images
La quadratura del cerchio
No full textNel volume sono pubblicati tutti i disegni del concorso, inoltre vi è un testo esplicativo dei disegni e una riflessione del presidente della giuria prof. Portoghesi sul gruppo L. Ribichini, M. Testi, F. Arina, vincitore di uno dei premi del concorso
- …
