Classroom Presenter: Enhancing Interactive Education with Digital Ink

Classroom Presenter is a Tablet PC-based interaction system that supports the sharing of digital ink on slides between instructors and students. Initial deployments show that using the technology can achieve a wide range of educational goals and foster a more participatory classroom environment.     

The dynamic effects and compensation of load transitions in robotic systems

The problem of a robot handling a payload typically involves pre-load, load, and post-load stages, and payload transitions between these stages. Although considerable work has focused on the control of robots carrying payloads, few consider the problem of load transitions—one of the most important effects on system performance. This article studies these transitions and presents a compensation method. It is shown that load transitions lead to abrupt (jump) parameters and uncertain transition times in the robot/payload model. A control strategy is proposed that takes the load transitions into account and guarantees the stable path tracking of robots in the face of these transitions. The effectiveness of the proposed control strategy is verified via simulation. © 1994 John Wiley & Sons, Inc.     

Argon I Lines Produced in a Hollow Cathode Source, 332 nm to 5865 nm

We report precision measurements by Fourier transform spectroscopy of the vacuum wavenumber, line width, and relative signal strength of 928 lines in the Ar I spectrum. Wavelength in air and classification of the transition are supplied for each line. A comparison of our results with other precision measurements illustrates the sensitivity of Ar I wavelengths to conditions in the light source.     

Emotional responding following experimental manipulation of facial electromyographic activity.

Thirty female subjects were instructed to imagine three positive affective scenes and three negative affective scenes. During the initial imagination of each scene, the subject was told simply to imagine the situation. The subject then imagined the situation again and was instructed to enhance the muscle tension in one of two muscle groups (the zygomatic muscles for positive scenes and the corrugator muscle for negative scenes). The subject then imagined the scene a third time and was instructed to suppress the muscle tension in the same muscle group. Feedback was available during practice trials and during the enhancement and suppression trials of the experiment. Continuous monitoring of both zygomatic and corrugator electromyogram (EMG) during the study indicated that subjects were successful in altering muscle tension in accord with the experimental instructions, and videotapes of subjects' faces indicated no overt changes in facial responding during imagination of the scenes. Subjects' ratings of emotional responding during each scene indicated that subjects experienced less enjoyment and more distress during positive affective trials in which they suppressed zygomatic EMG activity. The results are discussed in terms of the facial feedback hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endothelial selectins and vascular cell adhesion molecule-1 promote hematopoietic progenitor homing to bone marrow

The adhesive mechanisms allowing hematopoietic progenitor cells (HPC) homing to the bone marrow (BM) after BM transplantation are poorly understood. We investigated the role of endothelial selectins and vascular cell adhesion molecule-1 (VCAM-1) in this process. Lethally irradiated recipient mice deficient in both P-and E-selectins (P/E-/-), reconstituted with minimal numbers (相似文献   

cDNA sequence and gene locus of the human retinal phosphoinositide-specific phospholipase-C beta 4 (PLCB4)

Defects in the Drosophila norpA (no receptor potential A) gene encoding a phosphoinositide-specific phospholipase C (PLC) block invertebrate phototransduction and lead to retinal degeneration. The mammalian homolog, PLCB4, is expressed in rat brain, bovine cerebellum, and the bovine retina in several splice variants. To determine a possible role of PLCB4 gene defects in human disease, we isolated several overlapping cDNA clones from a human retina library. The composite cDNA sequence predicts a human PLC beta 4 polypeptide of 1022 amino acid residues (MW 117,000). This PLC beta 4 variant lacks a 165-amino-acid N-terminal domain characteristic for the rat brain isoforms, but has a distinct putative exon 1 unique for human and bovine retina isoforms. A PLC beta 4 monospecific antibody detected a major (130 kDa) and a minor (160 kDa) isoform in retina homogenates. Somatic cell hybrids and deletion panels were used to localize the PCLB4 gene to the short arm of chromosome 20. The gene was further sublocalized to 20p12 by fluorescence in situ hybridization.