3,674 research outputs found

    Be Smart to Identify the Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome

    Get PDF
    Stroke-like migraine attacks after radiation therapy (SMART) are uncommon, often occurring years or decades after brain radiation therapy. This syndrome is a diagnosis of exclusion, and only about 40 cases describing SMART have been published, each one describing a constellation of symptoms and findings. Because symptoms can arise years after initial radiation therapy, the ability of physicians to recognize SMART and rule out other possible causes of symptoms is critical for the long-term care of oncology patients who have undergone cranial radiation. Here we present the case of a 55-year-old man who experienced SMART nine years after radiation therapy and who was successfully treated with steroids

    Quasi-decadal variability of Antarctic sea ice

    Get PDF
    第3回極域科学シンポジウム/第35回極域気水圏シンポジウム 11月29日(木) 国立国語研究所 2階多目的

    Coefficient of restitution for elastic disks

    Full text link
    We calculate the coefficient of restitution, ϵ\epsilon, starting from a microscopic model of elastic disks. The theory is shown to agree with the approach of Hertz in the quasistatic limit, but predicts inelastic collisions for finite relative velocities of two approaching disks. The velocity dependence of ϵ\epsilon is calculated numerically for a wide range of velocities. The coefficient of restitution furthermore depends on the elastic constants of the material via Poisson's number. The elastic vibrations absorb kinetic energy more effectively for materials with low values of the shear modulus.Comment: 25 pages, 12 Postscript figures, LaTex2

    Gac two-component system in Pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction

    Get PDF
    Pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. To investigate the regulatory mechanism of the expression of virulence, Gac two-Component system-defective mutants, Delta gacA and Delta gacS, and a double mutant, Delta gacA Delta gacS, were generated. These mutants produced smaller amounts of N-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algT gene required for exopolysaccharide production. The ability of the mutants to cause disease symptoms in their host tobacco plant was remarkably reduced, while they retained the ability to induce hypersensitive reaction (HR) in the nonhost plants. These results indicated that the Gac two-component system of P. syringae pv. tabaci 6605 is indispensable for virulence on the host plant, but not for HR induction in the nonhost plants.</p

    Phase Changes in an Inelastic Hard Disk System with a Heat Bath under Weak Gravity for Granular Fluidization

    Full text link
    We performed numerical simulations on a two-dimensional inelastic hard disk system under gravity with a heat bath to study the dynamics of granular fluidization. Upon increasing the temperature of the heat bath, we found that three phases, namely, the condensed phase, locally fluidized phase, and granular turbulent phase, can be distinguished using the maximum packing fraction and the excitation ratio, or the ratio of the kinetic energy to the potential energy.It is shown that the system behavior in each phase is very different from that of an ordinary vibrating bed.Comment: 4 pages, including 5 figure

    Microcanonical Foundation for Systems with Power-Law Distributions

    Full text link
    Starting from microcanonical basis with the principle of equal a priori probability, it is found that, besides ordinary Boltzmann-Gibbs theory with the exponential distribution, a theory describing systems with power-law distributions can also be derived.Comment: 9 page

    Angle of Repose and Angle of Marginal Stability: Molecular Dyanmics of Granular Particles

    Full text link
    We present an implementation of realistic static friction in molecular dynamics (MD) simulations of granular particles. In our model, to break contacts between two particles, one has to apply a finite amount of force, determined by the Coulomb criterion. Using a two dimensional model, we show that piles generated by avalanches have a {\it finite} angle of repose θR\theta_R (finite slopes). Furthermore, these piles are stable under tilting by an angle smaller than a non-zero tilting angle θT\theta_T, showing that θR\theta_R is different from the angle of marginal stability θMS\theta_{MS}, which is the maximum angle of stable piles. These measured angles are compared to a theoretical approximation. We also measure θMS\theta_{MS} by continuously adding particles on the top of a stable pile.Comment: 14 pages, Plain Te

    Topological Nature of Anomalous Hall Effect in Ferromagnet

    Full text link
    The anomalous Hall effect in two-dimensional ferromagnets is discussed to be the physical realization of the parity anomaly in (2+1)D, and the band crossing points behave as the topological singularity in the Brillouin zone. This appears as the sharp peaks and the sign changes of the transverse conductance σxy\sigma_{xy} as a function of the Fermi energy and/or the magnetization. The relevance to the experiments including the three dimensional systems is also discussed.Comment: LaTeX 13 pages, 3 figure

    Electronic and magnetic excitations in the "half-stuffed" Cu--O planes of Ba2_2Cu3_3O4_4Cl2_2 measured by resonant inelastic x-ray scattering

    Full text link
    We use resonant inelastic x-ray scattering (RIXS) at the Cu L3_3 edge to measure the charge and spin excitations in the "half-stuffed" Cu--O planes of the cuprate antiferromagnet Ba2_2Cu3_3O4_4Cl2_2. The RIXS line shape reveals distinct contributions to the dddd excitations from the two structurally inequivalent Cu sites, which have different out-of-plane coordinations. The low-energy response exhibits magnetic excitations. We find a spin-wave branch whose dispersion follows the symmetry of a CuO2_2 sublattice, similar to the case of the "fully-stuffed" planes of tetragonal CuO (T-CuO). Its bandwidth is closer to that of a typical cuprate material, such as Sr2_2CuO2_2Cl2_2, than it is to that of T-CuO. We interpret this result as arising from the absence of the effective four-spin inter-sublattice interactions that act to reduce the bandwidth in T-CuO.Comment: 10 pages, 8 figure
    corecore