Potassium channels selectively conduct K(+) ions across cellular membranes with extraordinary efficiency. Their selectivity filter exhibits four binding sites with approximately equal electron density in crystal structures with high K(+) concentrations, previously thought to reflect a superposition of alternating ion- and water-occupied states. Consequently, cotranslocation of ions with water h...

This paper investigates the output and state trajectories of a third-order digital filter with two’s complement arithmetic realized in parallel form. Although the output of the thirdorder digital filter seems to behave randomly, some regular patterns can be displayed on the plot of y (k − 1) versus y (k), where those regular patterns are similar to the second-order case. When the first-order su...

Structures of the prokaryotic K(+) channel, KcsA, highlight the role of the selectivity filter carbonyls from the GYG signature sequence in determining a highly selective pore, but channels displaying this sequence vary widely in their cation selectivity. Furthermore, variable selectivity can be found within the same channel during a process called C-type inactivation. We investigated the mecha...

Studies of myocardial motion using magnetic resonance imaging usually require multiple breath holds and several methods have been proposed in order to reduce the scan time. Rapid imaging using k-t BLAST has gained much attention with its high reduction factors and image quality. Temporal smoothing, however, may reduce the accuracy when assessing cardiac function. In the present work, a modified...

Image denoising is a critical issue in the field of digital image processing. This paper proposes a novel Salt & Pepper noise suppression by developing a Kriging Interpolation Filter (KIF) for image denoising. Gray-level images degraded with Salt & Pepper noise have been considered. A sequential search for noise detection was made using kk window size to determine nonnoisy pixels only. The non...

A Texas Instruments TMS320C30 floating point digital signal processor has been used to implement a noise canceler/self-tuning filter for extracting sinusoidal audio signals from broad-band noise. A very significant part of the work is the optimization of the tuner's performance through proper choice of relevant adaptive filter parameters as well as efficient TMS320C30 code design and implementa...

Background: In addition to gas pollutants, many chemicals and air pollutants are in the form of particulate matter. Particulate matter consists of a complex mixture of variable sized particles and physicochemical composition. These particles mainly contain minerals including Fe, Al, Ca, K, Cu, Ti, Mn, Ni, V and their size, chemical composition and concentration are important to assess ...

Ba(2+), a doubly charged analogue of K(+), specifically blocks K(+) channels by virtue of electrostatic stabilization in the permeation pathway. Ba(2+) block is used here as a tool to determine the equilibrium binding affinity for various monovalent cations at specific sites in the selectivity filter of a noninactivating mutant of KcsA. At high concentrations of external K(+), the block-time di...