Transverse response potentials

There are several major classes of Ca channels (1) receptor-operated Ca channels in plasma membranes (2) ligand-gated Ca " channels in intracellular membranes and (3) voltage-dependent Ca channels that are usually found in plasma membranes or the invaginations of the plasma membrane that are known as transverse tubule membranes. Receptor-dependent or receptor-operated Ca channels (ROCCs) are primarily opened in response to activation of their associated receptors and, by definition, exhibit a certain amount of selectivity for Ca " over other cations. Several potentially different types of ROCCs have been characterized including ATP-sensitive channels in smooth muscle [1], mitogen and IP3-sensitive... 

In this chapter, dielectric response of only isotropic medium is considered. However, in a local-order scale, such a medium is actually anisotropic. The anisotropy is characterized by a local axially symmetric potential. Spatial motion of a dipole in such a potential can be represented as a superposition of oscillations (librations) in a symmetry-axis plane and of a dipole s precession about this axis. In our theory this anisotropy is revealed as follows. The spectral function presents a linear combination of the transverse (K ) and the longitudinal (K ) spectral functions, which are found, respectively, for the parallel and the transverse orientations of the potential symmetry axis with... 

If the angle (3 is much less than 1, then, in accord with Figs. 7 and 9, the most part of the rotators move freely under effect of a constant potential U0, since their trajectories do not intersect the conical cavity. A small part of the rotators moves along a trajectory of the type 1 shown in Fig. 10. However, at d > (3—that is, in the most part of such a trajectory—they are affected by the same constant potential U0- Therefore, for this second group of the particles the law of motion is also rather close to the law of free rotation. For the latter the dielectric response is described by Eq. (77). We shall represent this formula as a particular case of the general expression (51), in which the contributions to the spectral function due to longitudinal A) and transverse KL components are determined, respectively, by the first and second terms under summation sign. Free rotators present a medium isotropic in a local-order scale. Therefore, we set = K . Then the second term... 

A being the value of the vector potential at the n-th layer. This results in a (small) diamagnetic susceptibility, j(, which is however strongly H-dependent in a manner similar to the superconducting case. The response of an exciton-paired p-n junction to the transverse field (V) is insulating, provided that V satisfies condition... 

If the magnitude of the center point deflection of the film wq increases to values on the order of film thickness h, then the potential arises for generation of significant membrane stress in the film due to transverse deflection (in addition to any residual membrane stress which may be present in the film prior to deflection). As in the case of film buckling, the von Karman plate theory provides a useful and effective framework for describing response with center point deflection wq of magnitude equal to several times the film thickness. In the present case, the von Karman equations reduce to the pair of ordinary differential equations... 

The simulations were continued until the sample had extended by about 50-100% of its original length. Extensions beyond about 100% were not possible without violating the truncation radius criterion for the site-site potential due to the contraction in the transverse direction. The primary information which results from these tension experiments is the response of the h matrix, defining the size and shape of the primary cell, and that of the measured pressure tensor, P. These together allow us to elucidate the stress versus strain behavior. 

The components of the directional potentials are azimuthal and polar rotational potentials which determine the conformation of molecular chains, ie, valence angles, and cause their intrinsic stiffness. They are responsible for transverse bending modes which are combined with torsional modes. 

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