Action-angle representation of linear fluctuation in plasma is formally performed by taking the Lagrange-Hamilton theory as the basis and invoking the recent spectral technique [Hirota and Fukumoto, J. Math. Phys. 49 083101 (2008)], which is shown to be applicable equally to the magnetohydrodynamic (MHD) system and the Vlasov-Maxwell system. This formalism leads to a natural definition of the w...

We discuss the Green-Schwarz action for type IIB strings in general plane-wave backgrounds obtained as Penrose limits from any IIB supergravity solutions with vanishing background fermions. Using the honest normal-coordinate expansion in superspace, we prove that the light-cone action is necessarily quadratic in the fermionic coordinates. This proof is valid for more general pp-wave backgrounds...

The Principle of Least Action is used with a simple Lagrangian density, involving second-order derivatives of the wave function, to obtain the Schrödinger equation. A Hamiltonian density obtained from this simple Lagrangian density shows that Hamilton’s equations also give the Schrödinger equation. This simple Lagrangian density is equivalent to a standard Lagrangian density with first-order de...

Zebrafish is becoming an increasingly popular model in the field of visual neuroscience. Although the absorption spectra of its cone photopigments have been described, the cone action spectra were still unknown. In this study we report the action spectra of the four types of zebrafish cone photoreceptors, determined by measuring voltage responses upon light stimulation using whole cell patch cl...

Action potentials recorded from canine ventricular fibers displayed characteristic alterations in configuration upon abrupt change in the cycle length. After a relative prolongation of the diastolic interval, abbreviation of phase 2 and slowing of phase 3 were consistently observed, while a relative shortening of diastole was terminated by an action potential displaying prolongation of phase 2 ...

in this paper the telemac-3d model has been hired to simulate and study the high waves’ interaction with coastal structures. therefore a special arrangement of telemac-3d has been prepared in this study to simulate wave generation, coastal processes, wave set-up and overtopping over coastal structures. experimental data has been used to verify this arrangement of the model. thereafter, the mode...

Propagation failure of an action potential wave at a finite distance from its source (so-called type-II block) may cause spiral wave formation or wave breakup in the heart, phenomena that are believed to underlie lethal and nonlethal heart rhythm disorders. In this study, we develop a sufficient condition for this type of block in a homogeneous, spatially one-dimensional system. Using a topolog...

Action potential duration (APD) restitution, which relates APD to the preceding diastolic interval (DI), is a useful tool for predicting the onset of abnormal cardiac rhythms. However, it is known that different pacing protocols lead to different APD restitution curves (RCs). This phenomenon, known as APD rate dependence, is a consequence of memory in the tissue. In addition to APD restitution,...

We propose a travelling-wave perturbation method to control the spatiotemporal dynamics in a cardiac model. It is numerically demonstrated that the method can successfully suppress the wave instability (alternans in action potential duration) in the one-dimensional case and convert spiral waves and turbulent states to the normal travelling wave states in the two-dimensional case. An experimenta...

A method of intensity-dependent polarization switching is proposed. The effect is based on simultaneous action of two phase-matched second-order processes in a quadratic medium. Using analytical and numerical techniques, we demonstrate that a single linearly polarized fundamental wave, when it is propagating in such a medium, can efficiently generate a new fundamental wave of orthogonal polariz...