251 research outputs found

    Music Information Technology and Professional Stakeholder Audiences: Mind the Adoption Gap

    Get PDF
    The academic discipline focusing on the processing and organization of digital music information, commonly known as Music Information Retrieval (MIR), has multidisciplinary roots and interests. Thus, MIR technologies have the potential to have impact across disciplinary boundaries and to enhance the handling of music information in many different user communities. However, in practice, many MIR research agenda items appear to have a hard time leaving the lab in order to be widely adopted by their intended audiences. On one hand, this is because the MIR field still is relatively young, and technologies therefore need to mature. On the other hand, there may be deeper, more fundamental challenges with regard to the user audience. In this contribution, we discuss MIR technology adoption issues that were experienced with professional music stakeholders in audio mixing, performance, musicology and sales industry. Many of these stakeholders have mindsets and priorities that differ considerably from those of most MIR academics, influencing their reception of new MIR technology. We mention the major observed differences and their backgrounds, and argue that these are essential to be taken into account to allow for truly successful cross-disciplinary collaboration and technology adoption in MIR

    Cold Gas in Cluster Cores

    Full text link
    I review the literature's census of the cold gas in clusters of galaxies. Cold gas here is defined as the gas that is cooler than X-ray emitting temperatures (~10^7 K) and is not in stars. I present new Spitzer IRAC and MIPS observations of Abell 2597 (PI: Sparks) that reveal significant amounts of warm dust and star formation at the level of 5 solar masses per year. This rate is inconsistent with the mass cooling rate of 20 +/- 5 solar masses per year inferred from a FUSE [OVI] detection.Comment: 10 pages, conference proceeding

    Optical emission line nebulae in galaxy cluster cores 1: the morphological, kinematic and spectral properties of the sample

    Get PDF
    We present an Integral Field Unit survey of 73 galaxy clusters and groups with the VIsible Multi Object Spectrograph on the Very Large Telescope. We exploit the data to determine the H α gas dynamics on kpc scales to study the feedback processes occurring within the dense cluster cores. We determine the kinematic state of the ionized gas and show that the majority of systems (∼2/3) have relatively ordered velocity fields on kpc scales that are similar to the kinematics of rotating discs and are decoupled from the stellar kinematics of the brightest cluster galaxy. The majority of the H α flux (>50 per cent) is typically associated with these ordered kinematics and most systems show relatively simple morphologies suggesting they have not been disturbed by a recent merger or interaction. Approximately 20 per cent of the sample (13/73) have disturbed morphologies which can typically be attributed to active galactic nuclei activity disrupting the gas. Only one system shows any evidence of an interaction with another cluster member. A spectral analysis of the gas suggests that the ionization of the gas within cluster cores is dominated by non-stellar processes, possibly originating from the intracluster medium itself

    Nuclear Spin-Isospin Correlations, Parity Violation, and the fπf_\pi Problem

    Get PDF
    The strong interaction effects of isospin- and spin-dependent nucleon-nucleon correlations observed in many-body calculations are interpreted in terms of a one-pion exchange mechanism. Including such effects in computations of nuclear parity violating effects leads to enhancements of about 10%. A larger effect arises from the one-boson exchange nature of the parity non-conserving nucleon- nucleon interaction, which depends on both weak and strong meson-nucleon coupling constants. Using values of the latter that are constrained by nucleon-nucleon phase shifts leads to enhancements of parity violation by factors close to two. Thus much of previously noticed discrepancies between weak coupling constants extracted from different experiments can be removed.Comment: 8 pages 2 figures there should have been two figures in v

    Proapoptotic BH3-only proteins trigger membrane integration of prosurvival Bcl-w and neutralize its activity

    Get PDF
    Prosurvival Bcl-2–like proteins, like Bcl-w, are thought to function on organelles such as the mitochondrion and to be targeted to them by their hydrophobic COOH-terminal domain. We unexpectedly found, however, that the membrane association of Bcl-w was enhanced during apoptosis. In healthy cells, Bcl-w was loosely attached to the mitochondrial membrane, but it was converted into an integral membrane protein by cytotoxic signals that induce binding of BH3-only proteins, such as Bim, or by the addition of BH3 peptides to lysates. As the structure of Bcl-w has revealed that its COOH-terminal domain occupies the hydrophobic groove where BH3 ligands bind, displacement of that domain by a BH3 ligand would displace the hydrophobic COOH-terminal residues, allowing their insertion into the membrane. To determine whether BH3 ligation is sufficient to induce the enhanced membrane affinity, or to render Bcl-w proapoptotic, we mimicked their complex by tethering the Bim BH3 domain to the NH2 terminus of Bcl-w. The chimera indeed bound avidly to membranes, in a fashion requiring the COOH-terminal domain, but neither promoted nor inhibited apoptosis. These results suggest that ligation of a proapoptotic BH3-only protein alters the conformation of Bcl-w, enhances membrane association, and neutralizes its survival function

    Magnetic polarons in weakly doped high-Tc superconductors

    Full text link
    We consider a spin Hamiltonian describing dd-dd exchange interactions between localized spins dd of a finite antiferromagnet as well as pp-dd interactions between a conducting hole (pp) and localized spins. The spin Hamiltonian is solved numerically with use of Lanczos method of diagonalization. We conclude that pp-dd exchange interaction leads to localization of magnetic polarons. Quantum fluctuations of the antiferromagnet strengthen this effect and make the formation of polarons localized in one site possible even for weak pp-dd coupling. Total energy calculations, including the kinetic energy, do not change essentially the phase diagram of magnetic polarons formation. For parameters reasonable for high-TcT_c superconductors either a polaron localized on one lattice cell or a small ferron can form. For reasonable values of the dielectric function and pp-dd coupling, the contributions of magnetic and phonon terms in the formation of a polaron in weakly doped high-TcT_c materials are comparable.Comment: revised, revtex-4, 12 pages 8 eps figure

    Recent glitches detected in the Crab pulsar

    Full text link
    From 2000 to 2010, monitoring of radio emission from the Crab pulsar at Xinjiang Observatory detected a total of nine glitches. The occurrence of glitches appears to be a random process as described by previous researches. A persistent change in pulse frequency and pulse frequency derivative after each glitch was found. There is no obvious correlation between glitch sizes and the time since last glitch. For these glitches Δνp\Delta\nu_{p} and Δν˙p\Delta\dot{\nu}_{p} span two orders of magnitude. The pulsar suffered the largest frequency jump ever seen on MJD 53067.1. The size of the glitch is ∼\sim 6.8 ×10−6\times 10^{-6} Hz, ∼\sim 3.5 times that of the glitch occured in 1989 glitch, with a very large permanent changes in frequency and pulse frequency derivative and followed by a decay with time constant ∼\sim 21 days. The braking index presents significant changes. We attribute this variation to a varying particle wind strength which may be caused by glitch activities. We discuss the properties of detected glitches in Crab pulsar and compare them with glitches in the Vela pulsar.Comment: Accepted for publication in Astrophysics & Space Scienc

    HST imaging of the dusty filaments and nucleus swirl in NGC4696 at the centre of the Centaurus Cluster

    Get PDF
    Narrow-band HST imaging has resolved the detailed internal structure of the 10 kpc diameter H α+[N II] emission line nebulosity in NGC4696, the central galaxy in the nearby Centaurus cluster, showing that the dusty, molecular, filaments have a width of about 60 pc. Optical morphology and velocity measurements indicate that the filaments are dragged out by the bubbling action of the radio source as part of the active galactic nucleus feedback cycle. Using the drag force we find that the magnetic field in the filaments is in approximate pressure equipartition with the hot gas. The filamentary nature of the cold gas continues inwards, swirling around and within the Bondi accretion radius of the central black hole, revealing the magnetic nature of the gas flows in massive elliptical galaxies. HST imaging resolves the magnetic, dusty, molecular filaments at the centre of the Centaurus cluster to a swirl around and within the Bondi radius

    Inflation Physics from the Cosmic Microwave Background and Large Scale Structure

    Get PDF
    Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of CMB and large-scale structure (LSS) experiments are poised to test the leading paradigm for these earliest moments---the theory of cosmic inflation---and to detect the imprints of the inflationary epoch, thereby dramatically increasing our understanding of fundamental physics and the early universe. A future CMB experiment with sufficient angular resolution and frequency coverage that surveys at least 1 of the sky to a depth of 1 uK-arcmin can deliver a constraint on the tensor-to-scalar ratio that will either result in a 5-sigma measurement of the energy scale of inflation or rule out all large-field inflation models, even in the presence of foregrounds and the gravitational lensing B-mode signal. LSS experiments, particularly spectroscopic surveys such as the Dark Energy Spectroscopic Instrument, will complement the CMB effort by improving current constraints on running of the spectral index by up to a factor of four, improving constraints on curvature by a factor of ten, and providing non-Gaussianity constraints that are competitive with the current CMB bounds
    • …
    corecore