Modified thermoelectric figure of merit estimated from enhanced mobility of [100] oriented beta-FeSi<Subscript>2</Subscript> thin film

The modification of thermoelectric figure of merit was estimated from enhanced mobility of [100] oriented beta-FeSi₂ film. beta-FeSi₂ on Si(001) substrate was prepared by molecular beam epitaxy method using an Fe source. The crystallographic orientation of beta-FeSi₂ film on Si(001) substrate was characterized by using X-ray diffraction. Using scanning electron microscopy, surface morphology and film thickness of samples were observed and estimated, respectively. The mobility of beta-FeS₂ film on Si(001) substrate were also characterized by Hall measurement at room temperature. A part of the enhancement of figure of merit was evaluated as the functions of mobility and crystallographic orientation of samples.     

Group feature extraction based on matrix factorization from long-range office-logging data

To increase the productivity of knowledge workers, it is necessary to manage their organization so that they are motivated to collaborate with each other for their synergy. However, it is difficult for managers to grasp the explicit interactions of workers in the organization all the time. Owing to advanced communications technology, and the reduced size and improved capabilities of computers, we are able to record group behaviors as logging data in the office. The aim of this study is to extract features of group behavior from long-range office-logging data. We apply principal component analysis to the data matrix whose element is the mean travel velocity calculated from an individual’s trajectory per day. The results demonstrate the feasibility of our approach, since nontrivial informative group features can be extracted.     

A circular beam spot and low threshold current laser diode withreverse-v-shape layer

A laser with a reverse-V-shape layer exhibits a circular beam spot and low threshold current. The beam aspect ratio of the reverse-V-shape laser is clarified to be insensitive to reverse-V-shape width. The reverse-V-shape layer consists of a strained active layer and a passive guide layer, which leads to a low threshold current. The reverse-V-shape laser is attractive as an optical source for optical-communication and information systems     

Kink and power saturation of 660-nm AlGaInP laser diodes

We analyze kink and power saturation phenomena of high power 660-nm laser diodes for DVD-R/RW experimentally. Power-current (P-I) and voltage-current (V-I) characteristics of laser diodes with different cavity lengths were measured. Using these results and thermal resistances, temperature rises caused by self-heating (/spl Delta/T) and the dependence of slope efficiencies on the temperature rise (Se-/spl Delta/T) were calculated. The slope efficiencies decreased linearly with /spl Delta/T and their gradients showed the same value regardless of the cavity length, while they had no systematic dependence on the current. The kinks occurred at the same /spl Delta/T of 30/spl deg/C regardless of the cavity length, while they occurred at different currents. These results indicate that the temperature rise caused by the self-heating is a key parameter for the kink and the saturation power. A method is proposed to calculate the kink and the saturation power using the gradient (Se-/spl Delta/T) and the kink temperature.     

Properties of mixed chlorophyll a-glycolipid monolayers

Surface pressure, ellipsometric and surface potential-area isotherms have been measured to investigate the properties of chlorophyll a-digalactosyldiacyglycerol (Chl a-DGDG) and Chl a-sulfoquinovosyldiacylglycerol (SQDG) monolayers at the nitrogen-water interface. The surface pressure-area isotherms of Chla-DGDG exhibit a pronounced negative deviation with respect to ideality, whereas ellipsometric and surface potential isotherms of the mixed monolayers fall between those of the pure components. Hydrophilic interactions have been ruled out on the basis of the additivity law followed by the surface dipole moment of the mixed monolayers. The observed deviation exhibited by the π-A isotherms is interpreted in terms of an intermolecular cavity effect.     

1.5%-/spl Delta/ athermal arrayed-waveguide grating multi/demultiplexer with very low loss groove design

We describe a compact 1.5%-/spl Delta/ athermal silica-based 100-GHz-spacing 16-channel arrayed-waveguide grating (AWG) multi/demultiplexer with a modified groove design for a very low excess loss. We propose new approaches for modifying the shape of the grooves and the arrayed waveguides and optimize the shape modifications for 1.5%-/spl Delta/ waveguides. By employing this modified groove design, we greatly reduced the groove excess loss from 1.9 to 0.4 dB in the 1.5%-/spl Delta/ athermal AWG.     

Synthesis of silica-coated rhodium nanoparticles in reversed micellar solution

Silica (SiO₂)-coated rhodium (Rh) nanoparticles were prepared using a water-in-oil microemulsion of polyoxyethylene (15) cetyl ether, cyclohexane and water. SiO₂-coated Rh nanoparticles were obtained by hydrolyzing metal alkoxide (tetraethylorthosilicate, TEOS) in the solution containing Rh complex nanoparticles followed by thermal and reduction treatments. In the SiO₂-coated Rh nanoparticle, a Rh particle with an average diameter of 4.1 nm was located nearly at the center of each spherical SiO₂ particle. The SiO₂ layer was approximately 15 nm thick. Since the Rh particle was wholly surrounded by SiO₂, the Rh particle of the SiO₂-coated Rh nanoparticle exhibited an extremely high thermal stability. Furthermore, the porous structure of the SiO₂ layer could be controlled by the hydrolysis conditions of TEOS.     

Relationship between Expression of Onco-Related miRNAs and the Endoscopic Appearance of Colorectal Tumors

Accumulating data indicates that certain microRNAs (miRNAs or miRs) are differently expressed in samples of tumors and paired non-tumorous samples taken from the same patients with colorectal tumors. We examined the expression of onco-related miRNAs in 131 sporadic exophytic adenomas or early cancers and in 52 sporadic flat elevated adenomas or early cancers to clarify the relationship between the expression of the miRNAs and the endoscopic morphological appearance of the colorectal tumors. The expression levels of miR-143, -145, and -34a were significantly reduced in most of the exophytic tumors compared with those in the flat elevated ones. In type 2 cancers, the miRNA expression profile was very similar to that of the exophytic tumors. The expression levels of miR-7 and -21 were significantly up-regulated in some flat elevated adenomas compared with those in exophytic adenomas. In contrast, in most of the miR-143 and -145 down-regulated cases of the adenoma-carcinoma sequence and in some of the de novo types of carcinoma, the up-regulation of oncogenic miR-7 and/or -21 contributed to the triggering mechanism leading to the carcinogenetic process. These findings indicated that the expression of onco-related miRNA was associated with the morphological appearance of colorectal tumors.     

Structural Analysis of the Complex between Penta-EF-Hand ALG-2 Protein and Sec31A Peptide Reveals a Novel Target Recognition Mechanism of ALG-2

ALG-2, a 22-kDa penta-EF-hand protein, is involved in cell death, signal transduction, membrane trafficking, etc., by interacting with various proteins in mammalian cells in a Ca²⁺-dependent manner. Most known ALG-2-interacting proteins contain proline-rich regions in which either PPYPXnYP (type 1 motif) or PXPGF (type 2 motif) is commonly found. Previous X-ray crystal structural analysis of the complex between ALG-2 and an ALIX peptide revealed that the peptide binds to the two hydrophobic pockets. In the present study, we resolved the crystal structure of the complex between ALG-2 and a peptide of Sec31A (outer shell component of coat complex II, COPII; containing the type 2 motif) and found that the peptide binds to the third hydrophobic pocket (Pocket 3). While amino acid substitution of Phe⁸⁵, a Pocket 3 residue, with Ala abrogated the interaction with Sec31A, it did not affect the interaction with ALIX. On the other hand, amino acid substitution of Tyr¹⁸⁰, a Pocket 1 residue, with Ala caused loss of binding to ALIX, but maintained binding to Sec31A. We conclude that ALG-2 recognizes two types of motifs at different hydrophobic surfaces. Furthermore, based on the results of serial mutational analysis of the ALG-2-binding sites in Sec31A, the type 2 motif was newly defined.     

A hybrid approach to keyframe extraction from motion capture data using curve simplification and principal component analysis

In this paper, we propose a novel method to extract keyframes from motion capture data. A hybrid approach, which combines a curve‐simplification algorithm with an initialization procedure including principal component analysis, is adopted. The developed method automatically extracts an appropriate number of keyframes at high speed without performance degradation. Experimental results prove the effectiveness of the present method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.