The problem of kink stability of isothermal spherical self-similar flow in newtonian gravity is revisited. Using distribution theory we first develop a general formula of perturbations, linear or non-linear, which consists of three sets of differential equations, one in each side of the sonic line and the other along it. By solving the equations along the sonic line we find explicitly the spect...

Fish sonic swimbladder muscles are the fastest muscles in vertebrates and have fibers with numerous biochemical and structural adaptations for speed. Carapid fishes produce sounds with a complex swimbladder mechanism, including skeletal components and extrinsic sonic muscle fibers with an exceptional helical myofibrillar structure. To study this system we stimulated the sonic muscles, described...

Erythropoietin reportedly has beneficial effects on the heart after myocardial infarction, but the underlying mechanisms of these effects are unknown. We here demonstrate that sonic hedgehog is a critical mediator of erythropoietin-induced cardioprotection in mice. Treatment of mice with erythropoietin inhibited left ventricular remodeling and improved cardiac function after myocardial infarcti...

Direct determination of formation shear wave travel time is impossible in "slow" formations where the shear wave velocity is lower than the borehole fluid (mud) velocity. However, the Stoneley waves in these formations are very sensitive to changes in formation shear wave properties and can be used to indirectly determine the formation shear velocity, In addition, the P wave packet is highly de...

Ventral cell fates in the central nervous system are induced by Sonic hedgehog, a homolog ofhedgehog, a secreted Drosophila protein. In the central nervous system, Sonic hedgehog has been identified as the signal inducing floor plate, motor neurons, and dopaminergic neurons. Sonic hedgehog is also involved in the induction of ventral cell type in the developing somites. ptc is a key gene in the...

Effects of finite ion temperature on the plasma flow in converging–diverging magnetic field, mirror, or equivalently, nozzle configuration are studied using a quasineutral paraxial two-fluid MHD model with isothermal electrons and warm magnetized ions. The acceleration was an emphasis role singularity at sonic point transition. It is shown that regularity defines global solution describing from...

OBJECTIVE To evaluate the impact of the creation of corneal flaps at different thicknesses on the biomechanical properties of swine corneas. METHOD Twelve swine eyes were obtained to form two groups: 100 μm flap thickness and 300 μm flap thickness. Each eye was submitted to the following examinations: raster topography to investigate corneal curvature alterations, ocular response analyzer to ...

We investigate a simple toy model of particle scattering in the flat spacetime limit an analogue-gravity model. The medium is treated as scalar field phonons that obeys Klein--Gordon equation and thus admits Lorentz symmetry with respect to ${c}_{\mathrm{s}}$, speed sound medium. from which are scattered external system does not obey sonic phonon obeys. In-universe observers who use exchange op...