Exact analytic solutions for nonlinear waves in cold plasmas

Large amplitude plasma oscillations are studied in a cold electron plasma. Using Lagrangian variables, a new class of exact analytical solutions is found. It turns out that the electric field amplitude is limited either by wave breaking or by the condition that the electron density always has to stay positive. The range of possible amplitudes is determined analytically

Mapping Methods Visualizing Visual Novelsâ Cultural Production in Japan

This research report presents mapping methods visualizing Visual Novelsâ cultural production in Japan. Three mapping of the East section of Ikebukuro city in Tokyo are presented in order to unravel the urban environment surrounding the production of Visual Novels for â girlsâ (Otome and Boyâ s Love games). The imbrications of a typology of Visual Novel and their paraphernalia, with cartographies of the urban infrastructures and events sustaining Visual Novelâ s paraphernalia circulation therefore invites to question of the definition of a â game environmentâ as the emergence of a urban cultural network emerging from the circulation of game paraphernalia

A new electromagnetic wave in a pair plasma

A new nonlinear electromagnetic wave mode in a plasma is reported. Its existence depends on the interaction of an intense circularly polarized electromagnetic wave with a plasma, where quantum electrodynamical photon--photon scattering is taken into account. As an illustration, we consider a pair plasma and show that the new mode can be significant in astrophysical settings and in the next generation laser-plasma systems.Comment: 3 page

PEMBELAJARAN BAHASA INDONESIA DAN PENDIDIKAN BERKARAKTER

We reconsider the nonlinear resonant interaction between three electrostatic waves in a magnetized plasma. The general coupling coefficients derived from kinetic theory are reduced here to the low-frequency limit. The main contribution to the coupling coefficient we find in this way agrees with the coefficient recently presented in Annales Geophysicae. But we also deduce another contribution which sometimes can be important, and which qualitatively agrees with that of an even more recent paper. We have thus demonstrated how results derived from fluid theory can be improved and generalized by means of kinetic theory. Possible extensions of our results are outlined

Retromer in Synaptic Function and Pathology

The retromer complex mediates export of select transmembrane proteins from endosomes to the trans-Golgi network (TGN) or to the plasma membrane. Dysfunction of retromer has been linked with slowly progressing neurodegenerative disorders, including Alzheimer’s and Parkinson’s disease (AD and PD). As these disorders affect synapses it is of key importance to clarify the function of retromer-dependent protein trafficking pathways in pre- and postsynaptic compartments. Here we discuss recent insights into the roles of retromer in the trafficking of synaptic vesicle proteins, neurotransmitter receptors and other synaptic proteins. We also consider evidence that implies synapses as sites of early pathology in neurodegenerative disorders, pointing to a possible role of synaptic retromer dysfunction in the initiation of disease

Light bullets and optical collapse in vacuum

In quantum electrodynamics, photon--photon scattering can be the result of the exchange of virtual electron--positron pairs. Effectively, this gives rise to self-interaction terms in Maxwell's equations, similar to the nonlinearities due to polarization in nonlinear optics. These self-interaction terms vanish in the limit of parallel propagating waves. However if the modes generated in bounded regions are used, there will be a non-zero total effect. We show that stationary two-dimensional light bullets can form in guiding structures, due to the balancing effect of quantum electrodynamical vacuum nonlinearities on dispersion and diffraction. These light bullets are unstable and exhibit the possibility of self-focusing collapse. The consequences of our results are also discussed.Comment: 7 pages, to appear in Phys. Lett.