Aims. We discuss whether the process of winding-up the magnetic field by differential rotation in a newborn quark-star can cause an energy emission rate high enough and lasting sufficiently long to explain long gamma ray bursts. Methods. Within the magneto-hydrodynamics, we study the torsional oscillations and the extraction of energy from a newborn , hot, differentially rotating quark-star. Re...

With the diffusion approximation, we study the cascade and damping of Alfvén-cyclotron fluctuations in solar plasmas numerically. Motivated by wavewave couplings and nonlinear effects, we test several forms of the diffusion tensor. For a general locally anisotropic and inhomogeneous diffusion tensor in the wave vector space, the turbulence spectrum in the inertial range can be fitted with power...

Most of the sungrazing comets observed by LASCO at SOHO belong to the Kreutz group of comets and follow trajectories that are tightly clumped in space. Statistical analysis of 9 years of SOHO observations suggests that the true apparition rate of these comets is as high as one every other day. Practically all these comets break up before perihelion passage. Their material is dissociated and ion...

PURPOSE Serotonin, a neurotransmitter known to be involved in nociceptor sensitization, is present in human tears. The purpose of this study was to correlate tear serotonin levels, as a marker of nociceptor sensitization, to facets of dry eye (DE), including symptoms and signs. DESIGN Cross-sectional study. PARTICIPANTS A total of 62 patients with normal eyelid and corneal anatomy were pros...

Aims. We report a multi-wavelength analysis of the prompt emission and early afterglow of GRB 051111 and discuss its properties in the context of current fireball models. Methods. The detection of GRB 051111 by the Burst Alert Telescope on-board Swift triggered early BVRi' observations with the 2-m robotic Faulkes Telescope North in Hawaii, as well as X-ray observations with the Swift X-Ray Tel...

The Antarctic Slope Front (ASF) modulates ventilation of the abyssal ocean via the export of dense Antarctic Bottom Water (AABW) and constrains shoreward transport of warm Circumpolar Deep Water (CDW) toward marine-terminating glaciers. Along certain stretches of the continental shelf, particularly where AABW is exported, density surfaces connect the shelf waters to the middepth Circumpolar Dee...

[1] We examined the spatial and temporal variations of upwelling off northeast Taiwan, using a fine-resolution numerical model with realistic bathymetry. The zonally running shelf break in the area deflects the Kuroshio seaward and produces upwelling on its onshelf edge. The upwelling, in turn, manifests a cold dome or a cyclonic eddy. In depths below 150 m or so, the upwelling and hence the cy...

The kinetic evolution of the Orszag–Tang vortex is studied using collisionless hybrid simulations. In magnetohydrodynamics MHD this configuration leads rapidly to broadband turbulence. At large length scales, the evolution of the hybrid simulations is very similar to MHD, with magnetic power spectra displaying scaling similar to a Kolmogorov scaling of 5/3. At small scales, differences from MHD...

[1] Influence of winter pre-conditioning of Arctic sea ice due to atmospheric forcing associated with the North Atlantic Oscillation (NAO) on the reduction in summer sea ice extent is studied. It is found that winter sea ice is about 50 cm thinner in high-NAO index years than in low-NAO index years in the Eurasian coastal region mainly due to stronger wind-driven ice export. The thinner wintert...

The environments of supernova explosion are often inhomogeneous and there may be jumps in their density structure. We have developed a semi-analytic model under the thin-shell approximation for supernova remnants that evolve crossing a density jump in the ambient medium. The generic evolutionary relations are presented for the blast wave after impacting on a cavity wall, which may be produced b...