-
Revista Chilena de Historia Natural 08/2007; 81:155-170.
-
[show abstract]
[hide abstract]
ABSTRACT: The electrical responses of individual hemocyanain channels in oxidized cholesterol membranes demonstrate that the voltage-dependent conductance of many-chanel membranes arises from two different mechanisms. These are the voltage-dependent redistribution of channels among several discrete single-channel conductance states themselves. The relaxation time for the discrete conductance changes is of the order of seconds nd the relaxation time of the continuous conductance changes is of the order 10(-4) seconds. As salt concentration in the bathing medium is increased, the single-channel conductance first increases lineary and then saturates. The characteristics of the saturation curves suggest that the continuous conductance changes occur at the edges of the channel and that the mean time an ion spends in the channel is 4 nanoseconds...
Journal of Membrane Biology 01/1976; 25(1-2):163-81.
-
[show abstract]
[hide abstract]
ABSTRACT: Sampling rate and frequency content determinations for optical quantities related to light propagation through turbulence are still unsettled experimental problems. Many papers about estimating properties of the optical turbulence seem to use some ad-hoc assumptions to set the sampling frequency used; without further analysis, this chosen sampling rate is assumed good enough to perform a proper measurement. On the other hand, other authors estimate the optimal sampling rate via fast Fourier transform of the data series associated to the experiment, defining a cut-off frequency with an arbitrary criterion---that may be related to an underlying model. The aim of this paper is to propose an alternative, and practical, method to estimate a proper sampling rate. By means of the discrete wavelet transform, this approach can prevent any loss of information and, at the same time, avoid oversampling. Moreover, it is independent of the statistical model imposed on the turbulence.
Optics Express 07/2013; 21(13):15230.
