Upper crustal structure beneath the Ongul Island, East Antarctica

Two explosion seismic experiments were conducted in 1980 by the 21st Japanese Antarctic Research Expedition (JARE-21) to reveal the velocity structure beneath the Ongul Islands, East Antarctica. In one experiment eleven stations were established along a line of 5.2 km long at intervals of about 0.5 km on the outcrops on East and West Ongul Islands and two explosions of 100 and 80 kg were fired at the bottom of the sea. The other smaller-scale experiment was made on East Ongul Island to reveal the structure shallower than that obtained by the above-mentioned experiment. Five shots were fired and the seismic waves were observed at eight stations along two lines of 0.7 and 0.9 km long respectively. In both experiments direct waves were clearly recorded at all the stations as first arrivals. The mean apparent velocity and the mean average velocity of P-waves are 6.19±0.11 and 5.74±0.88 km/s, respectively. The obtained velocity in the ice-free area of the Ongul Islands is nearly the same as the velocities under the ice sheet in East Antarctica hitherto obtained by the research expeditions of the United States, USSR and Japan. The sedimentary layer with a velocity less than 5.5 km/s does not exist. Clear later arrivals with large amplitude were also detected at all the stations that ranged from 0.1 to 5.2 km from the shot point. The mean apparent velocity and the mean average velocity were 2.84±0.03 and 2.94±0.37 km/s, respectively. These later arrivals are presumably Rayleigh waves

Deep crustal structure along the profile between Syowa and Mizuho Stations, East Antarctica

Three big seismic explosion experiments were carried out by the 21st and 22nd Japanese Antarctic Research Expeditions in the vicinity of Syowa Station and in the northern Mizuho Plateau in East Antarctica. Twenty-seven temporal seismic observation stations were set up along a 300-km long profile from Syowa to Mizuho Stations. Explosives were fired near Syowa Station, near Mizuho Station and at the middle point of the profile. The apparent P-wave velocity in the upper crust varies from 6.0 to 6.4 km/s, suggesting a gradual increase of the P-wave velocity with depth. Apparent velocities of 6.9 km/s for P^* and 7.9 km/s for P_n were observed from the biggest shot near Syowa Station. From the analyses of travel times and an amplitude study by synthetic seismograms, the crustal structure of the northern Mizuho Plateau was determined. The depth of the Conrad and the Moho discontinuities was determined as about 30 km and 40 km, respectively. The P-wave velocity increases from 6.0 km/s on the surface to 6.4 km/s at a depth of 13 km. At the Conrad, there is no sharp velocity discontinuity. The thickness of the transition zone is 2.4 km. Comparing our results with those in Dronning Maud Land (in the vicinity of Novolazarevskaya Station of USSR), East Antarctica, velocity values are nearly the same, but the thickness of lower crust in the northern Mizuho Plateau is about a half of that in Dronning Maud Land

Reaction of Fluorine and Carbon and Properties of Their Compounds

As the compounds which react with carbon and fluorine possess extremely low surface energies, the formation of the compound on the surface of carbon electrode would cause high overpotential and finally anode effect in fluorine or aluminum cell. Their compounds having the atomic ratio of C : F＝1 : 1 are white fine powders and have the properties of good water and oil repellency and lubrication. The present paper is concerned with the reactions of fluorine and six kinds of carbon materials and with the rate determining steps of their reactions. Their properties and structures were studied by means of thermogravimetric and differential thermal analysis, IR and NMR spectra, X-ray diffraction, and the measurements of specific gravity and surface area etc. From these results, there are new compounds containing fluorine atoms between the layers of carbon, where the fluorine atoms are strongly connected to the carbon atoms with covalent bonds, and are very stable to chemicals. Their decomposition temperatures depend upon carbon materials

Modeling of the Fukushima Daiichi Nuclear Power Plant Derived Radioactive Cesium Dynamics in Grazing Grassland

The damage to the Fukushima Daiichi Nuclear Power Plant incurred following the Great East Japan Earthquake and tsunami on March 11, 2011 resulted in serious radioactive pollution of Eastern Japan. In some grasslands of this area, radioactive cesium (Cs) content of grasses exceeded the provisional safety standard for use as feed for dairy and beef cattle of 100 Bq kg–1 fresh weight, and the livestock industry has been seriously affected in numerous ways: needing to dispose of polluted forage, grazing prohibitions, declines in beef prices, suspensions of shipping beef to market, and blanket testing of beef cattle (Manabe et al., 2013). The spatial distribution of radioactive Cs in grasslands was complex in various scales (Tsuiki and Maeda, 2012a; 2012b). So it is difficult to estimate actual pollution level in grassland ecosystems. The transfer of radioactive Cs from soil to plant is affected by soil soluble potassium (K) concentration, pH, clay and organic matter contents (Absalom et al., 2001; Tsuiki et al., 2013). The radioactive Cs dynamics in soil-plantanimal system is complex and modeling is necessary to clarify the relationships. In this study, a model of radioactive Cs dynamics in Zoysia japonica Steud. dominated grazing grassland was developed to predict radioactive Cs concentration of grass and grazing cattle

Phagocytosis of Advanced Glycation End Products (AGEs) in Macrophages Induces Cell Apoptosis

Advanced glycation end products (AGEs) are the products of a series of nonenzymatic modifications of proteins by reducing sugars. AGEs play a pivotal role in development of diabetic complications and atherosclerosis. Accumulation of AGEs in a vessel wall may contribute to the development of vascular lesions. Although AGEs have a diverse range of bioactivities, the clearance process of AGEs from the extracellular space, including the incorporation of AGEs into specific cells, subcellular localization, and the fate of AGEs, remains unclear. In the present study, we examined the kinetics of the uptake of AGEs by mouse macrophage J774.1 cells in vitro and characterized the process. We demonstrated that AGEs bound to the surface of the cells and were also incorporated into the cytoplasm. The temperature- and time-dependent uptake of AGEs was saturable with AGE concentration and was inhibited by cytochalasin D but not chlorpromazine. We also observed the granule-like appearance of AGE immunoreactivity in subcellular localizations in macrophages. Higher concentrations of AGEs induced intracellular ROS and 4-HNE, which were associated with activation of the NF-κB pathway and caspase-3. These results suggest that incorporation of AGEs occurred actively by endocytosis in macrophages, leading to apoptosis of these cells through NF-κB activation