Three-dimensional singularities of a thin plasma slab

The three-dimensional (3D) nonlinear development of the interchange-like (Rayleigh-Taylor) instability of a thin slab of plasma exhibits interesting features with respect to its two-dimensional (2D) limit investigated by Bulanov, Pegoraro, and Sakai [Phys. Rev. E 59, 2292 (1999)]. We show that, contrary to the 2D case, the 3D evolution equations remain nonlinear when Lagrangian variables are adopted. Explicit solutions are found by the use of a generalized hodograph transformation. Both compression and rarefaction singularities are formed. Local solutions in the neighborhood of the singular points have a generic 2D character.

Magnetic field energy dissipation due to particle trapping in a force-free configuration of collisionless pair plasmas

It is shown by using a two-dimensional, fully relativistic, electromagnetic particle-in-cell simulation code that a force-free magnetic configuration in collisionless, electron-positron (pair) plasmas becomes unstable against current-driven Buneman instability and subsequently there occurs a strong magnetic field energy dissipation associated with collisionless magnetic reconnection, which can be driven by particle trapping due to two-dimensional electric potentials remaining in the nonlinear stage of the initial current-driven Buneman instability. About 43% of the initial magnetic field energy dissipates and is transformed to plasma heating as well as high-energy particle production. The energy spectrum in the high-energy region is given by an exponential type with two temperatures. We also show the simulation results for the electron-ion plasma to compare the effect of the mass ratio of the electron and proton.

Magnetic flux generation and wave emissions during coalescence of magnetic islands in pair plasmas

It is shown by using a two-dimensional fully relativistic electromagnetic particle-in-cell code that the tearing instability in a current sheet of pair plasmas is caused by Landau resonances of both electrons and positrons. Strong magnetic flux can be generated during coalescence of magnetic islands in the nonlinear phase of the tearing instability. The magnetic flux produced in an O-type magnetic island is caused by the counterstreaming instability found by Kazimura et al. [Astrophys. J. Lett. 498, L183 (1998); J. Phys. Soc. Jpn. 67, 1079 (1998)]. It is also shown that charge separation with a quadrupole-like structure is generated from the localized strong magnetic flux. During the decay of the quadrupole-like charge structure as well as the magnetic flux, there appear wave emissions with high-frequency electromagnetic waves and Alfvén waves as well as Langmuir waves.

Leustroduscin B, a new cytokine inducer derived from an actinomycetes, induces thrombocytosis in mice

Leustroduscin B (LSN-B), a novel colony-stimulating factor (CSF) inducer produced by an actinomycetes, has previously been shown to induce CSF production in bone marrow stromal cells. To determine the biological activity of LSN-B on hematopoiesis in vivo, LSN-B was administered intraperitoneally to mice every day for three to six days. Peripheral platelet counts were markedly elevated on days 4 through 6 compared with the control mice injected with vehicle. Serum II/6 levels were low (0.8 ng/ml) or virtually undetectable in the drug treated groups. This cytokine profile suggests that LSN-B induction of thrombocytosis is mechanistically distinct from other cytokine inducers such as IL-1 or FK-565.