No abstract

Protein structures define a complex network of atomic interactions in three dimensions. Direct visualization of the structure and analysis of the interaction potential energy are not straightforward approaches to pinpoint the atomic contacts that are crucial for protein function. We used the tetrameric hyperpolarization-activated cAMP-regulated (HCN) channel as a model system to study the intersubunit contacts in cAMP-dependent gating. To obtain a systematic survey of the contacts between each pair of residues, we used normal-mode analysis, a computational approach for studying protein dynamics, and constructed the covariance matrix for C-α atoms. The significant contacts revealed by covariance analysis were further investigated by means of mutagenesis and functional assays. Among the mutant channels that show phenotypes different from those of the wild-type, we focused on two mutant channels that express opposite changes in cAMP-dependent gating. Subsequent biochemical assays on isolated C-terminal fragments, including the cAMP binding domain, revealed only minimal effects on cAMP binding, suggesting the necessity of interpreting the cAMP-dependent allosteric regulation at the whole-channel level. For this purpose, we applied the patch-clamp fluorometry technique and observed correlated changes in the dynamic, state-dependent cAMP binding in the mutant channels. This study not only provides further understanding of the intersubunit contacts in allosteric coupling in the HCN channel, it also illustrates an effective strategy for delineating important atomic contacts within a structure.

The Kalman filter (KF) has been improved for a mobile robot to human tracking. The proposed algorithm combines a curve matching framework and KF to enhance prediction accuracy of target tracking. Compared to other methods using normal KF, the Curve Matched Kalman Filter (CMKF) method predicts the next movement of the human by taking into account not only his present motion characteristics, but also the previous history of target behavior patterns-the CMKF provides an algorithm that acquires the motion characteristics of a particular human and provides a computationally inexpensive framework of human-tracking system. The proposed method demonstrates an improved target tracking using a heuristic weighted mean of two methods, i.e., the curve matching framework and KF prediction. We have conducted the experimental test in an indoor environment using an infrared camera mounted on a mobile robot. Experimental results validate that the proposed CMKF increases prediction accuracy by more than 30% compared to normal KF when the characteristic patterns of target motion are repeated in the target trajectory.

Today's consumer has access to a wide variety of video sources, including traditional broadcast and packaged media sources as well as internet sources like YouTube, Hulu and iTunes. These video sources have a variety of resolutions and usually a lot of artifacts. Furthermore, they all have limited gray‐scales of 256 levels or less, resulting in contouring artifacts. On the other hand displays continue to increase in bit‐depth, size, and resolution, with 10‐bit and 12‐bit panels increasingly common and 4K×2K displays starting to enter the high‐end. This paper describes a new digital video format converter IC featuring proprietary Qdeo video processing that bridges this big “color‐gap” between video sources and video displays.

There has been a rapid increase in the number and variety of video sources that are now available to the consumer. In addition to the traditional broadcast and packaged media sources, consumers now get video from internet sources like YouTube, Google, iTunes, etc., as well as "place-shifted" video from sources like the SlingBox, etc. These new video sources are often low-resolution and full of artifacts. However, consumers expect to be able to view all of these types of video on their large-screen flat-panel TVs and obtain a consistent high image quality. Achieving this requires a new class of highly adaptive digital video format converters. This paper describes the first member of a new family of ICs that has been designed to meet this need..