4,289 research outputs found

    Statement of Arnold E. Perl Before the Commission on the Future of Worker-Management Relations

    Get PDF
    Testimony_Perl_081094.pdf: 191 downloads, before Oct. 1, 2020

    Corrections to Fermi's Golden Rule in ϕ→KKˉ\phi \to K\bar{K} Decays

    Full text link
    We analyze the decays ϕ→KKˉ\phi \to K\bar{K} utilizing a formulation of transition rates which explicitly exhibits corrections to Fermi's Golden Rule. These corrections arise in systems in which the phase space and/or matrix element varies rapidly with energy, as happens in ϕ→KKˉ\phi \to K\bar{K}, which is just above threshold. We show that the theoretical corrections resolve a puzzling 5σ5\sigma discrepancy between theory and experiment for the branching ratio R=Γ(ϕ→K+K−)/Γ(ϕ→K0Kˉ0)R = \Gamma (\phi \to K^+K^-)/\Gamma(\phi \to K^0\bar{K}^0)

    Search for Free Fractional Electric Charge Elementary Particles

    Get PDF
    We have carried out a direct search in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied - about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71×10−224.71\times10^{-22} particles per nucleon with 95% confidence.Comment: 10 pages,LaTeX, 4 PS figures, submitted to PR

    The Dreyfus Affair and Contemporary Anti-Semitism

    Get PDF

    Multiple-access phased array antenna simulator for a digital beam forming system investigation

    Get PDF
    Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design, and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities

    Causalgia, pathological pain, and adrenergic receptors

    Get PDF
    Control of expression of molecular receptors for chemical messengers and modulation of these receptors’ activity are now established as ways to alter cellular reaction. This paper extends these mechanisms to the arena of pathological pain by presenting the hypothesis that increased expression of α-adrenergic receptors in primary afferent neurons is part of the etiology of pain in classical causalgia. It is argued that partial denervation by lesion of peripheral nerve or by tissue destruction induces a change in peripheral nociceptors, making them excitable by sympathetic activity and adrenergic substances. This excitation is mediated by α-adrenergic receptors and has a time course reminiscent of experimental denervation supersensitivity. The change in neuronal phenotype is demonstrable after lesions of mixed nerves or of the sympathetic postganglionic supply. Similar partial denervations also produce a substantial increase in the number of dorsal root ganglion neurons evidencing the presence of α-adrenergic receptors. The hypothesis proposes the increased presence of α-adrenergic receptors in primary afferent neurons to result from an altered gene expression triggered by cytokines/growth factors produced by disconnection of peripheral nerve fibers from their cell bodies. These additional adrenergic receptors are suggested to make nociceptors and other primary afferent neurons excitable by local or circulating norepinephrine and epinephrine. For central pathways, the adrenergic excitation would be equivalent to that produced by noxious events and would consequently evoke pain. In support, evidence is cited for a form of denervation supersensitivity in causalgia and for increased expression of human α-adrenergic receptors after loss of sympathetic activity

    The INSIDEOUT framework provides precise signatures of the balance of intrinsic and extrinsic dynamics in brain states

    Get PDF
    Finding precise signatures of different brain states is a central, unsolved question in neuroscience. We reformulated the problem to quantify the 'inside out' balance of intrinsic and extrinsic brain dynamics in brain states. The difference in brain state can be described as differences in the detailed causal interactions found in the underlying intrinsic brain dynamics. We used a thermodynamics framework to quantify the breaking of the detailed balance captured by the level of asymmetry in temporal processing, i.e. the arrow of time. Specifically, the temporal asymmetry was computed by the time-shifted correlation matrices for the forward and reversed time series, reflecting the level of non-reversibility/non-equilibrium. We found precise, distinguishing signatures in terms of the reversibility and hierarchy of large-scale dynamics in three radically different brain states (awake, deep sleep and anaesthesia) in electrocorticography data from non-human primates. Significantly lower levels of reversibility were found in deep sleep and anaesthesia compared to wakefulness. Non-wakeful states also showed a flatter hierarchy, reflecting the diversity of the reversibility across the brain. Overall, this provides signatures of the breaking of detailed balance in different brain states, perhaps reflecting levels of conscious awareness
    • …
    corecore