Coordinated motion of cell monolayers during epithelial wound healing and tissue morphogenesis involves mechanical stress generation. Here we propose a model for the dynamics of epithelial expansion that couples mechanical deformations in the tissue to contractile activity and polarization in the cells. A new ingredient of our model is a feedback between local strain, polarization, and contract...

Solitary water waves are long nonlinear waves that can propagate steadily over long distances. They were first observed by Russell in 1837 in a now famous report [26] on his observations of a solitary wave propagating along a Scottish canal, and on his subsequent experiments. Some forty years later theoretical work by Boussinesq [8] and Rayleigh [25] established an analytical model. Then in 189...

Propagating wave segments are stabilized to a constant size and shape by applying negative feedback from the measured wave area to the excitability of the medium. The locus of steady-state wave size as a function of excitability defines the perturbation threshold for the initiation of spiral waves. This locus also defines the excitability boundary for spiral wave behavior in active media.

High cadence Transition Region and Coronal Explorer (TRACE) observations show that outward propagating intensity disturbances are a common feature in large, quiescent coronal loops, close to active regions. An overview is given of measured parameters of such longitudinal oscillations in coronal loops. The observed oscillations are interpreted as propagating slow magnetoacoustic waves and are un...

Significant work in the past few decades has lead to a well developed understanding of seismic wave propagation in fractured media. However, previous research has focused on fractures within rock as opposed to fractures at the surface of a rock. A theoretical and experimental study was performed to examine seismic wave propagation along a fracture at the surface, i.e., along the intersection of...

Previous studies in non-human primates (NHPs) have shown that beta oscillations (15-30 Hz) of local field potentials (LFPs) in the arm/hand areas of primary motor cortex (MI) propagate as traveling waves across the cortex. These waves exhibited two stereotypical features across animals and tasks: (1) The waves propagated in two dominant modal directions roughly 180° apart, and (2) their propaga...

The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves. The existence of Alfvén waves far from the Sun has been known since the 1970s, and recently the presence of ubiquitous Alfvénic waves throughout the solar atmosphere has been confirm...

Special features of surface gravity waves in deep fluid flow with constant vertical shear of velocity is studied. It is found that the mean flow velocity shear leads to non-trivial modification of surface gravity wave modes dispersive characteristics. Moreover, the shear induces generation of surface gravity waves by internal vortex mode perturbations. The performed analytical and numerical stu...

A rarefaction wave for system of viscous conservation laws induces strong coupling of waves pertaining to different characteristic fields. For the characteristic field pertaining to the rarefaction wave, there are the nonlinear hyperbolic, linear in time, and the parabolic, sub-linear in time, dissipations. We study the quantitative properties of the waves propagating around the rarefaction wav...

A rarefaction wave for system of viscous conservation laws induces strong coupling of waves pertaining to different characteristic fields. For the characteristic field pertaining to the rarefaction wave, there are the nonlinear hyperbolic, linear in time, and the parabolic, sub-linear in time, dissipations. We study the quantitative properties of the waves propagating around the rarefaction wav...