大都市大震災軽減化特別プロジェクト : 地震動（強い揺れ）の予測「大都市圏地殻構造調査研究」の成果概要

A new 5-year project, named ""Regional Characterization of the Crust in Metropolitan areas for Predicting Strong Ground Motions,"" was started in 2003 to characterize sources and propagation paths in Japanese metropolitan areas; the Kanto (Tokyo) region and Kinki (Osaka) region. We conducted three subprograms, 1) Deep Seismic Exploration, 2) Deep Drilling, and 3) Characterization of Earthquake Faults and Crustal Structure, with special emphasis on the characterization of seismic sources. We summarize the purposes of the project, and present results obtained during the first 3-year period

Broadband dielectric spectroscopy of glucose aqueous solution: Analysis of the hydration state and the hydrogen bond network.

Recent studies of saccharides' peculiar anti-freezing and anti-dehydration properties point to a close association with their strong hydration capability and destructuring effect on the hydrogen bond (HB) network of bulk water. The underlying mechanisms are, however, not well understood. In this respect, examination of the complex dielectric constants of saccharide aqueous solutions, especially over a broadband frequency region, should provide interesting insights into these properties, since the dielectric responses reflect corresponding dynamics over the time scales measured. In order to do this, the complex dielectric constants of glucose solutions between 0.5 GHz and 12 THz (from the microwave to the far-infrared region) were measured. We then performed analysis procedures on this broadband spectrum by decomposing it into four Debye and two Lorentz functions, with particular attention being paid to the β relaxation (glucose tumbling), δ relaxation (rotational polarization of the hydrated water), slow relaxation (reorientation of the HB network water), fast relaxation (rotation of the non-HB water), and intermolecular stretching vibration (hindered translation of water). On the basis of this analysis, we revealed that the hydrated water surrounding the glucose molecules exhibits a mono-modal relaxational dispersion with 2-3 times slower relaxation times than unperturbed bulk water and with a hydration number of around 20. Furthermore, other species of water with distorted tetrahedral HB water structures, as well as increases in the relative proportion of non-HB water molecules which have a faster relaxation time and are not a part of the surrounding bulk water HB network, was found in the vicinity of the glucose molecules. These clearly point to the HB destructuring effect of saccharide solutes in aqueous solution. The results, as a whole, provide a detailed picture of glucose-water and water-water interactions in the vicinity of the glucose molecules at various time scales from sub-picosecond to hundreds of picoseconds

Investigating the role of the Itoigawa-Shizuoka tectonic line towards the evolution of the Northern Fossa Magna rift basin

AbstractThe Itoigawa-Shizuoka tectonic line (ISTL) fault system is considered to have one of the highest probabilities for a major inland earthquake occurrence in the whole of Japan. It is a complex fault system with the dip directions of the local fault segments changing from north to south between an east-dipping low-angle thrust fault, a strike slip fault and a west-dipping thrust fault. The tectonic relations between the different parts of the fault system and the surrounding geological units are yet to be fully explained. This study aims to reveal the juncture of the northern and central parts of the ISTL and investigate its contribution towards the shaping of the Northern Fossa Magna rift basin. We conducted 3 deployments of 1 or 2 linear arrays of seismic stations across the central and northern ISTL regions and observed local micro-earthquakes for a period of 3 years. Each deployment recorded continuous waveform data for approximately 3 months. Using arrival times of 1193 local earthquakes, we jointly determined earthquake locations and a 3D velocity model, applying the tomography method. We were able to image the regional crustal structures from the surface to a depth of 20km with a spatial resolution of 5km. Subsequently, we used the obtained 3D velocity model to relocate the background local seismicity from 2003 to 2009. The juncture of the northern and central parts of the ISTL was well constrained by our results. The depth extension of the northern parts of the ISTL fault segments follows the bottom of the Miocene Northern Fossa Magna rift basin (NFM) and forms an east-dipping low-angle fault. In contrast, the central parts of the ISTL fault segments are estimated to lie along the eastern boundary of the Matsumoto basin forming an oblique strike slip fault (Fig. 1)

Monitoring mature tomato (red stage) quality during storage using ultraviolet-induced visible fluorescence image

The potential of UV-induced fluorescence imaging was investigated as a non-destructive tool to monitor postharvest quality degradation of tomatoes harvested at the red stage and stored at 25 °C. The fluorescence images (excitation at 365 nm) were found to be a better indicator of tomato quality degradation than color images after color saturation. Tomatoes were stored at 25 °C for 9 d. The changes in color and fluorescence of tomato were evaluated by two types of images: Color and fluorescence images. A conventional colorimeter was also used for as a reference. Changes in the RGB ratio for these two types of images were opposite. In the color images, the G ratio decreased rapidly for the initial 3 or 5 d and then stabilized afterwards. On the other hand, in the fluorescence images, the G ratio increased continuously up to 9 d. Given that temperature conditions during transportation and storage of tomatoes is not always ideal, the results from this research provide the foundation for developing a postharvest monitoring system of mature tomato quality degradation

応力テンソル逆解析による本州 : 千島弧会合部の沈み込む太平洋プレート内の応力場

This study addresses the space distribution of the stress field in the Wadati-Benioff zone of Northeastern Japan and southernmost Kurile area based on homogeneous data of earthquake focal mechanisms and the inverse technique by Gephart and Forsyth (1984). The data set used consists of 785 JMA focal mechanism solutions (FMS) and 97 FMS listed in Kosuga et al. (1996) for shallow and intermediate depth earthquakes. The detailed analysis of the space distribution of orientation of P (compression) and T (extension) axes of FMS allowed the outlining of the following WBZ subvolumes for which we applied the stress inversion: three planar structures in North Honshu (NH) and the Hokkaido corner (HC) WBZ (Plane1, Plane 2, Plane 3), and upper and lower subvolumes in the Hokkaido Island (HI) WBZ. The stress field parameters are evaluated along the northeastern Japan and southern Kurile arcs for these WBZ subvolumes. The stress field in Plane 1, mainly low-angle thrust faults, is characterized by shallow dipping and close to strike normal maximum compression s1 and down dipping minimum compression σ3. Plane 2, the upper surface of the WBZ below 60-70km in NH and HC, is under slab parallel s1 and close to slab normal s3 all along NH, while in HC the minimum compression rotates counterclockwise about 30° relative to the slab normal. Plane 3, the lower surface of the WBZ, is characterized by close to slab normal s1 and close to slab parallel σ3. The stress regime in Plane 1 is of general compression everywhere but in segment HT, beneath the Hokkaido corner, where it is of general extension (Guiraud, 1989). The stress regime in Plane 2 is of general compression, and in Plane 33 of pure extension. A characteristic feature of the two WBZ subvolumes outlined beneath Hokkaido is that the upper subvolume overlies the lower one everywhere but in the southern part of the island. The orientations of the maximum and minimum compressive stresses in the upper subvolume of the Hokkaido WBZ, considered relatively to the local slab geometry, are similar to these in Plane 1 of NH and HC WBZ, i.e. close to strike normal s1 and down dipping σ3. However, the dip of the principle stresses is different 3 here s1 is steeper and s3 is shallower. The stress field in the lower WBZ subvolume beneath Hokkaido is characterized by strike aligned s3 dipping north at about 50°, s1 trends SE being strike normal beneath the southern part of the island and slab normal beneath its northern part. The orientations of P and T in the upper WBZ subvolume in central Hokkaido differ significantly from these in the upper WBZ volumes to the south and to the north but are similar to those in the lower subvolume here. The stress inversion results indicate homogeneous stress field in the upper and lower WBZ subvolumes beneath central Hokkaido. The orientation of the minimum compression here (strike aligned, trending north) is close to the orientations of s3 in the southern and northern lower parts of the HI WBZ, while the s1 is dipping steeply WSW. These stress directions, if considered kinematically, indicate that the preferred faulting occurs at plane that is almost vertical and perpendicular to the strike of the slab (the strike of the trench) with the northern wall moving down and the southern one moving up. The stress regime is of general extension in all the considered subvolumes in the HI WBZ. The results of this study clearly indicate 3-planar distribution of stresses in the WBZ beneath North Honshu and the Hokkaido corner. We outlined two subvolumes (upper and lower) in the WBZ beneath Hokkaido, which are characterized by different orientations of the principle stresses. The stress field in the upper WBZ subvolume is perturbed by a deformation zone (DZ), located beneath central Hokkaido. This DZ is perpendicular to the slab’s strike and is cutting through the slab, the stresses in the upper and lower subvolumes of it are of similar orientation. The directions of the best-fit stress model in the DZ suggest that its northern wall moves down while its southern wall moves up. One plausible explanation is that this deformation zone represents a crack or a tear cutting through the entire slab

Structural basis of Sec-independent membrane protein insertion by YidC

[プレスリリース]バイオサイエンス研究科膜分子複合機能学研究室の塚崎智也准教授らの研究グループが、タンパク質を細胞膜に組み込むメカニズムを解明しました（2014/04/17）Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively1, 2. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG3, 4, 5. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 Å resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane