Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid

Induced Norm-Based Analysis for Computed Torque Control of Robot Systems

This paper is concerned with providing a new quantitative analysis method of computed torque control of robot systems by using three types of induced norm. This paper first considers design of a computed torque controller to achieve a trajectory tracking performance of a robot manipulator. Taking into account of the effects of unknown elements on the tracking performance, this paper next divides the unknown elements into model uncertainty and disturbance, and introduces various closed-loop representations of robot systems consisting of robot manipulators together with computed torque controllers and unknown elements. This paper further derives a readily applicable robust stability condition for the model uncertainty by using two types of induced norm from L-2 to L-2 and from L-infinity to L-infinity. Regarding a performance analysis for the disturbance, this paper also proposes to take the induced norm from L-2 to L-infinity, by which the relation between the maximum tracking errors caused by the disturbance and the corresponding parameters of the computed torque controllers are dealt with. Finally, this paper gives some experiments to validate the effectiveness of the performance analysis methods based on the L-infinity/L-2-induced norm.11Ysciescopu

A Near-Infrared Study of the Highly-Obscured Active Star-Forming Region W51B

We present wide-field JHKs-band photometric observations of the three compact HII regions G48.9-0.3, G49.0-0.3, and G49.2-0.3 in the active star-forming region W51B. The star clusters inside the three compact HII regions show the excess number of stars in the J-Ks histograms compared with reference fields. While the mean color excess ratio E(J-H)/E(H-Ks) of the three compact HII regions are similar to ~ 2.07, the visual extinctions toward them are somewhat different: ~ 17 mag for G48.9-0.3 and G49.0-0.3; ~ 23 mag for G49.2-0.3. Based on their sizes and brightnesses, we suggest that the age of each compact HII region is =< 2 Myr. The inferred total stellar mass, ~ 1.4 x 10^4 M_sun, of W51B makes it one of the most active star forming regions in the Galaxy with the star formation efficiency of ~ 10 %.Comment: 12 pages, 10 eps figures, uses jkas.st