53 research outputs found
Time correlation functions and Fisher zeros for q-deformed Bose gas
The time-dependent correlation functions of q-deformed Bose gas are studied.
We find relation of zeros of the correlation functions with the Fisher zeros of
partition function of the system. Complex temperature appears as a result of
q-deformation and evolution of correlation function. A particular case of
q-deformed Bose particles on two levels is examined and zeros of correlation
functions and Fisher zeros of partition function are analyzed
Focusing in Multiwell Potentials: Applications to Ion Channels
We investigate out of equilibrium stationary distributions induced by a
stochastic dichotomous noise on double and multi-well models for ion channels.
Ion-channel dynamics is analyzed both through over-damped Langevin equations
and master equations. As a consequence of the external stochastic noise, we
prove a non trivial focusing effect, namely the probability distribution is
concentrated only on one state of the multi-well model. We also show that this
focusing effect, which occurs at physiological conditions, cannot be predicted
by a simple master equation approach.Comment: 8 pages, 7 figure
Translocation of a polymer chain driven by a dichotomous noise
We consider the translocation of a one-dimensional polymer through a pore
channel helped by a motor driven by a dichotomous noise with time exponential
correlation. We are interested in the study of the translocation time, mean
velocity and stall force of the system as a function of the mean driving
frequency. We find a monotonous translocation time, in contrast with the mean
velocity which shows a pronounced maximum at a given frequency. Interestingly,
the stall force shows a nonmonotonic behavior with the presence of a minimum.
The influence of the spring elastic constant to the mean translocation times
and velocities is also presented.Comment: 11 pages, 7 figure
A Novel Frequency Analysis Method for Assessing Kir2.1 and Nav1.5 Currents
Voltage clamping is an important tool for measuring individual currents from an electrically active cell. However, it is difficult to isolate individual currents without pharmacological or voltage inhibition. Herein, we present a technique that involves inserting a noise function into a standard voltage step protocol, which allows one to characterize the unique frequency response of an ion channel at different step potentials. Specifically, we compute the fast Fourier transform for a family of current traces at different step potentials for the inward rectifying potassium channel, Kir2.1, and the channel encoding the cardiac fast sodium current, Nav1.5. Each individual frequency magnitude, as a function of voltage step, is correlated to the peak current produced by each channel. The correlation coefficient vs. frequency relationship reveals that these two channels are associated with some unique frequencies with high absolute correlation. The individual IV relationship can then be recreated using only the unique frequencies with magnitudes of high absolute correlation. Thus, this study demonstrates that ion channels may exhibit unique frequency responses
The Plant Root as an Osmo-diffusive Converter of Free Energy
Abstract. This work focuses on the maize root as a one-membrane osmo-diffusive converter of free energy. Energy expenditures of the root on water transport by radial route as well as on xylem water uptake, occurring according to the prin ciple of osmotic root pressure, are analyzed. The so-called practical method of osmo-diffusive energy conversio
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