A multidimensional account of democratic legitimacy: how to make robust decisions in a non-idealized deliberative context

This paper analyses the possibility of granting legitimacy to democratic decisionmaking procedures in a context of deep pluralism. We defend a multidimensional account according to which a legitimate system needs to grant, on the one hand, that citizens should be included on an equal footing and acknowledged as reflexive political agents rather than mere beneficiaries of policies, and, on the other hand, that their decisions have an epistemic quality. While Estlund\u2019s account of imperfect epistemic proceduralism might seem to embody a dualistic conception of democratic legitimacy, we point out that it is not able to recognize citizens as reflexive political agents and is grounded in an idealized model of the circumstances of deliberation. To overcome these ambiguities, we develop an account of democratic legitimacy according to which disagreement is the proper expression of citizens\u2019 reflexive agency and the attribution of epistemic authority does not stem from a major expertise or specific ability, but it comes through the public confrontation among disagreeing agents. Consequently, the epistemic value of deliberation should be derived from the reasons-giving process rather than from the reference to the alleged quality of its outcomes. In this way, we demonstrate the validity of the multidimensional perspective of legitimacy, yet abstain from introducing any outcome-oriented criterion. Finally, we argue that this account of legitimacy is well suited for modeling deliberative democracy as a decision-making procedure that respects the agency of every citizen and grants her opportunity to influence public choices

Discovery of extreme particle acceleration in the microquasar Cygnus X-3

The study of relativistic particle acceleration is a major topic of high-energy astrophysics. It is well known that massive black holes in active galaxies can release a substantial fraction of their accretion power into energetic particles, producing gamma-rays and relativistic jets. Galactic microquasars (hosting a compact star of 1-10 solar masses which accretes matter from a binary companion) also produce relativistic jets. However, no direct evidence of particle acceleration above GeV energies has ever been obtained in microquasar ejections, leaving open the issue of the occurrence and timing of extreme matter energization during jet formation. Here we report the detection of transient gamma-ray emission above 100 MeV from the microquasar Cygnus X-3, an exceptional X-ray binary which sporadically produces powerful radio jets. Four gamma-ray flares (each lasting 1-2 days) were detected by the AGILE satellite simultaneously with special spectral states of Cygnus X-3 during the period mid-2007/mid-2009. Our observations show that very efficient particle acceleration and gamma-ray propagation out of the inner disk of a microquasar usually occur a few days before major relativistic jet ejections. Flaring particle energies can be thousands of times larger than previously detected maximum values (with Lorentz factors of 105 and 102 for electrons and protons, respectively). We show that the transitional nature of gamma-ray flares and particle acceleration above GeV energies in Cygnus X-3 is clearly linked to special radio/X-ray states preceding strong radio flares. Thus gamma-rays provide unique insight into the nature of physical processes in microquasars.Comment: 29 pages (including Supplementary Information), 8 figures, 2 tables version submitted to Nature on August 7, 2009 (accepted version available at http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature08578.pdf

ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents

Abstract Objectives To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents. Methods The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach's statistics were used to rate levels of agreement and internal reliability of the consensus. Results Three Delphi rounds were conducted and 76 statements composed on MR technique (n=17), clinical application of liver-specific contrast agents in benign, focal liver lesions (n=7), malignant liver lesions in non-cirrhotic (n=9) and in cirrhotic patients (n=18), diffuse and vascular liver diseases (n=12), and bile ducts (n=13). The overall mean score of agreement was 4.84 (SD ±0.17 with liver specific contrast agents in the study of liver diseases. Key points • Liver-specific contrast agents are recommended in MRI of the liver. • The hepatobiliary phase improves the detection and characterization of hepatocellular lesions. • Liver-specific contrast agents can improve the detection of HCC