399 research outputs found

    Break in the Mean and Persistence of Inflation: A Sectoral Analysis of French CPI

    Full text link
    This paper uses disaggregated CPI time series to show that a break in the mean of French inflation occurred in the mid-eighties and that the 1983 monetary policy shift mostly accounted for it. CPI average yearly growth declined from nearly 11% before the break date (May 1985) to 2.1% after. No other break in the 1973-2004 sample period can be found. Controlling for this mean break, both aggregate and sectoral inflation persistence are stable and low, with the unit root lying far in the tail of the persistence estimates. However, persistence differs dramatically across sectors. Finally, the duration between two price changes (at the firm level) appears positively related with inflation persistence (at the aggregate level)

    The Pricing Behaviour of Firms in the Euro Area: New Survey Evidence

    Full text link

    Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy

    Full text link
    Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide new insights to understand the evolution of galaxies, measuring the evolution of the cosmic star formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected new phenomena. This review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.Comment: To be published in Nature Astronomy 18 Sept 201

    Surgery and postoperative radiotherapy a valid treatment for advanced oropharyngeal carcinoma

    Get PDF
    Since 1992 we have prospectively included all head and neck cancer patients in our health region in a departmental based register. Our hospital takes care of all head and neck cancer patients in our health region consisting of approximately 1 million people. In 1997, we evaluated the results of the treatment of oropharyngeal cancer in the 1992–1997 period. On the basis of this evaluation, we changed our treatment policy for tonsillar and base of tongue carcinoma. We first changed the treatment for the lesions with worst prognosis, i.e., those with T3–T4 carcinomas, from radiotherapy only, to radical surgery and postoperative radiotherapy. We have since that time increasingly also operated the smaller oropharyngeal carcinomas. The 2 years’ overall survival and disease-specific survival for all patients diagnosed in the 1992–1997 period was 56 and 63%, respectively. The results from a similar group of patients in the 6 years’ period from 2000 to 2005, after the change in treatment, have increased to 83 and 88%. When we looked at the subgroup of patients in the 2000–2005 period treated with surgery and postoperative radiotherapy, 45 out of 69 patients (65%) presenting with an oropharyngeal cancer were fit for operation. With radical surgery and postoperative radiation therapy, the 2 years overall survival is now 91%. The 2-year disease-specific survival is 96% and the locoregional control is 98%. This is a marked improvement as compared to radiotherapy alone and definitely competitive with modern radiochemotherapy

    Selective disruption of the DNA polymerase III α–β complex by the umuD gene products

    Get PDF
    DNA polymerase III (DNA pol III) efficiently replicates the Escherichia coli genome, but it cannot bypass DNA damage. Instead, translesion synthesis (TLS) DNA polymerases are employed to replicate past damaged DNA; however, the exchange of replicative for TLS polymerases is not understood. The umuD gene products, which are up-regulated during the SOS response, were previously shown to bind to the α, β and ε subunits of DNA pol III. Full-length UmuD inhibits DNA replication and prevents mutagenic TLS, while the cleaved form UmuD′ facilitates mutagenesis. We show that α possesses two UmuD binding sites: at the N-terminus (residues 1–280) and the C-terminus (residues 956–975). The C-terminal site favors UmuD over UmuD′. We also find that UmuD, but not UmuD′, disrupts the α–β complex. We propose that the interaction between α and UmuD contributes to the transition between replicative and TLS polymerases by removing α from the β clamp

    Affine term structure models : a time-changed approach with perfect fit to market curves

    Full text link
    We address the so-called calibration problem which consists of fitting in a tractable way a given model to a specified term structure like, e.g., yield or default probability curves. Time-homogeneous jump-diffusions like Vasicek or Cox-Ingersoll-Ross (possibly coupled with compounded Poisson jumps, JCIR), are tractable processes but have limited flexibility; they fail to replicate actual market curves. The deterministic shift extension of the latter (Hull-White or JCIR++) is a simple but yet efficient solution that is widely used by both academics and practitioners. However, the shift approach is often not appropriate when positivity is required, which is a common constraint when dealing with credit spreads or default intensities. In this paper, we tackle this problem by adopting a time change approach. On the top of providing an elegant solution to the calibration problem under positivity constraint, our model features additional interesting properties in terms of implied volatilities. It is compared to the shift extension on various credit risk applications such as credit default swap, credit default swaption and credit valuation adjustment under wrong-way risk. The time change approach is able to generate much larger volatility and covariance effects under the positivity constraint. Our model offers an appealing alternative to the shift in such cases.Comment: 44 pages, figures and table

    Foundations of Black Hole Accretion Disk Theory

    Get PDF
    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).Comment: 91 pages, 23 figures, final published version available at http://www.livingreviews.org/lrr-2013-
    corecore