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...

The K(+) channel-selectivity filter consists of two absolutely conserved glycine residues. Crystal structures show that the first glycine in the selectivity filter, Gly-77 in KcsA, is in a left-handed helical conformation. Although the left-handed helical conformation is not favorable for the naturally occurring L-amino acids, it is favorable for the chirally opposite D-amino acids. Here, we de...

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...

We consider a problem for storing a map that associates a key with a set of values. To store n values from the universe of size m, it requires log2 ( m n ) bits of space, which can be approximated as (1.44 + n) log2 m/n bits when n ≪ m. If we allow ε fraction of errors in outputs, we can store it with roughly n log2 1 ε bits, which matches the entropy bound. Bloom filter is a wellknown example ...

C o m m e n t a r y All known K + channels use the same molecular architecture to achieve K + selectivity. Selectivity filters, even from distantly related K + channels, appear nearly identical in atomic resolution crystal structures; remarkably, the deviation in the coordinates of K +-coordinating backbone carbonyls is less than the uncertainty in the mod-Brohawn et al., 2012). Although retain...

-Layered architecture is proposed for solving a class o f regularization problems in image processing. There are two major hurdles in the implementation of regularization filters with second or higher order smoothness constraints: ( a ) Stability: With second or higher order constraints, a direct implementation of a regularization filter necessitates negative conductance which, in turn, gives r...