1,456 research outputs found

    An empirical test for cellular automaton models of traffic flow

    Full text link
    Based on a detailed microscopic test scenario motivated by recent empirical studies of single-vehicle data, several cellular automaton models for traffic flow are compared. We find three levels of agreement with the empirical data: 1) models that do not reproduce even qualitatively the most important empirical observations, 2) models that are on a macroscopic level in reasonable agreement with the empirics, and 3) models that reproduce the empirical data on a microscopic level as well. Our results are not only relevant for applications, but also shed new light on the relevant interactions in traffic flow.Comment: 28 pages, 36 figures, accepted for publication in PR

    IACHEC CROSS-CALIBRATION OF CHANDRA, NuSTAR, SWIFT, SUZAKU, XMM-NEWTON WITH 3C 273 ANDPKS 2155-304

    Get PDF
    On behalf of the International Astronomical Consortium for High Energy Calibration, we present results from the cross-calibration campaigns in 2012 on 3C 273 and in 2013 on PKS 2155-304 between the then active X-ray observatories Chandra, NuSTAR, Suzaku, Swift, and XMM-Newton. We compare measured fluxes between instrument pairs in two energy bands, 1–5 keV and 3–7 keV, and calculate an average cross-normalization constant for each energy range. We review known cross-calibration features and provide a series of tables and figures to be used for evaluating cross-normalization constants obtained from other observations with the above mentioned observatories.United States. National Aeronautics and Space Administration (Smithsonian Astrophysical Observatory. Contract SV3-73016)United States. National Aeronautics and Space Administration. (Grant NNX09AE58G

    A role for accessory genes rI.-1 and rI.1 in the regulation of lysis inhibition by bacteriophage T4

    Get PDF
    Lysis inhibition (LIN) is a known feature of the T-even family of bacteriophages. Despite its historical role in the development of modern molecular genetics, many aspects of this phenomenon remain mostly unexplained. The key element of LIN is an interaction between two phage-encoded proteins, the T holin and the RI antiholin. This interaction is stabilized by RIII. In this report, we demonstrate the results of genetic experiments which suggest a synergistic action of two accessory proteins of bacteriophage T4, RI.-1, and RI.1 with RIII in the regulation of LIN

    Variations of Hadron Masses and Matter Properties in Dense Nuclear Matter

    Get PDF
    Using a self-consistent quark model for nuclear matter we investigate variations of the masses of the non-strange vector mesons, the hyperons and the nucleon in dense nuclear matter (up to four times the normal nuclear density). We find that the changes in the hadron masses can be described in terms of the value of the scalar mean-field in matter. The model is then used to calculate the density dependence of the quark condensate in-medium, which turns out to be well approximated by a linear function of the nuclear density. Some relations among the hadron properties and the in-medium quark condensate are discussed.Comment: 22 pages, University of Adelaide preperint ADP-94-20/T160, submitted to Physical Review

    Losing the media battle, waging the policy war: The pharmaceutical industry’s response to the access to medicines crisis in the Global South

    Get PDF
    This article sheds new light on the pharmaceutical industry’s response to the public relations crisis generated by the global civil society campaign for access to HIV/AIDS medicines since the early 2000s – one of the most contentious policy areas of global trade and health governance. Drawing on interviews with industry insiders, the article explores the industry’s communicative agency in both the media sphere and key sites of power, with a focus on the European Union (EU) policy sphere. The analysis shows that the industry has focused primarily on maintaining access to policymakers and sustaining elite consensus around the existing global intellectual property rights regime through political communication activities that largely bypass mediated public arenas – from strategically promoting its corporate social responsibility (CSR) programmes and mobilizing third-party endorsement to direct lobbying. The article concludes by reflecting on the implications of the findings for critical investigations of the interplay between media and political power in relation to global economic governance

    Raman gain from waveguides inscribed in KGd(WO₄)₂ by high repetition rate femtosecond laser

    No full text
    We report the formation of waveguides in Raman-active KGd(WO₄)₂ with a focused, high repetition rate femtosecond laser. Parallel guiding regions, formed to either side of the laser-induced damage track, supported TE and TM modes that coupled efficiently to optical fiber at telecom wavelengths. Micro-Raman spectroscopy of the guiding regions revealed the preservation of the characteristic 768 and 901cm¯¹ Raman mode intensities. Raman gain with 6% efficiency was demonstrated for the 768cm¯¹ Raman line by pumping the waveguide with an infrared 80ps source, the first time Raman gain has been reported in laser formed waveguides

    Theory of Circle Maps and the Problem of One-Dimensional Optical Resonator with a Periodically Moving Wall

    Full text link
    We consider the electromagnetic field in a cavity with a periodically oscillating perfectly reflecting boundary and show that the mathematical theory of circle maps leads to several physical predictions. Notably, well-known results in the theory of circle maps (which we review briefly) imply that there are intervals of parameters where the waves in the cavity get concentrated in wave packets whose energy grows exponentially. Even if these intervals are dense for typical motions of the reflecting boundary, in the complement there is a positive measure set of parameters where the energy remains bounded.Comment: 34 pages LaTeX (revtex) with eps figures, PACS: 02.30.Jr, 42.15.-i, 42.60.Da, 42.65.Y
    corecore