The Excitement of Multiple Noradrenergic Cell Groups in the Rat Brain Related to Hyperbaric Oxygen Seizure

The mechanism of oxygen toxicity for central nervous system and hyperbaric oxygen (HBO) seizure has not been clarified. Noradrenergic cells in the brain may contribute to HBO seizure. In this study, we defined the activation of noradrenergic cells during HBO exposure by c-fos immunohistochemistry. Electroencephalogram electrodes were pre-implanted in all animals under general anesthesia. In HBO seizure animals, HBO was induced with 5 atm of 100% oxygen until manifestation of general tonic convulsion. HBO non-seizure animals were exposed to 25 min of HBO. Control animals were put in the chamber for 120 min without pressurization. All animals were processed for c-fos immunohistochemical staining. All animals in the HBO seizure group showed electrical discharge on EEG. In the immunohistochemistry, c-fos was increased in the A1, A2 and A6 cells of the HBO seizure group, and in the A2 and A6 cells of the HBO non-seizure group, yet was extremely low in all three cell types in the control group. These results suggest the participation of noradrenaline in HBO seizure, which can be explained by the early excitement of A1 cells due to their higher sensitivity to high blood pressure, hyperoxia, or by the post-seizure activation of all noradrenergic cells

Oki-Dozen Dike Swarm: Effect of the Regional Stress Field on Volcano-Tectonic Orientations

This article presents new field, geochronological, and geochemical data for the Late Miocene Oki-dozen dike swarm (ODS), southwest Japan. This swarm is part of a volcanic suite comprising mafic and silicic dikes, sills, and pyroclastic cones from which we obtained structural measurements at a various genetic orders and scales. The mafic magmas generated three dike swarms with dikes oriented to NW-SE, N-S, and NE-SW. In comparison, the silicic intrusions do not have a preferred orientation but instead appear to radiate from the center of the volcanic suite. Comparison of the maximum thickness of 37 dikes with SiO2 content (wt%) yielded a critical thickness (T cr ) value of T cr = 0.2 × (SiO2 − 40). These data indicate that the orientations of dikes were controlled by the magnitude of dike tip pressure and magma overpressure, both of which positively correlate with SiO2 concentrations. The silicic units yield estimated pressures (up to 15–60 MPa) that are large enough to have counteracted the regional stress field, whereas the mafic dike swarm only yielded lower pressures. This result suggests that comparative analysis at a range of scales is essential for the accurate determination on the tectonic stress field by igneous rocks

Monoclonal antibody to galactosylceramide: discrimination of structural difference in the ceramide moiety

AbstractA mouse monoclonal antibody (mAb) was developed against monohexaosylceramide. This mAb differentially reacted on thin-layer chromatograms with 3 types of galactosylceramide (GalCer) obtained from bovine brain. Structural analysis of the 3 glycolipids revealed that they consisted of the same galactose and sphingosine but of apparently different fatty acids. Among the 3 GalCers, the mAb reacted with two GalCers which contained α-hydroxy fatty acids, but not with GalCer composed of nonhydroxy fatty acids. These findings suggest not only that the mAb discriminated the fatty acid composition in the ceramide moiety of GalCer, but also that the ceramide structure defines the immunological epitope as it is known to do for the carbohydrate moiety of glycosphingolipid

Photopolarimetric Monitoring of Blazars in the Optical and Near-Infrared Bands with the Kanata Telescope. I. Correlations between Flux, Color, and Polarization

We report on the correlation between the flux, color and polarization variations on time scales of days--months in blazars, and discuss their universal aspects. We performed monitoring of 42 blazars in the optical and near-infrared bands from 2008 to 2010 using TRISPEC attached to the "Kanata" 1.5-m telescope. We found that 28 blazars exhibited "bluer-when-brighter" trends in their whole or a part of time-series data sets. This corresponds to 88% of objects that were observed for >10 days. Thus, our observation unambiguously confirmed that the "bluer-when-brighter" trend is common in the emission from blazar jets. This trend was apparently generated by a variation component with a constant and relatively blue color and an underlying red component. Prominent short-term flares on time scales of days--weeks tended to exhibit a spectral hysteresis; their rising phases were bluer than their decay phases around the flare maxima. In contrast to the strong flux--color correlation, the correlation of the flux and polarization degree was relatively weak; only 10 objects showed significant positive correlations. Rotations of polarization were detected only in three objects: PKS 1510-089, 3C 454.3, and PKS 1749+096, and possibly in S5 0716+714. We also investigated the dependence of the degree of variability on the luminosity and the synchrotron peak frequency, \nu_peak. As a result, we found that lower luminosity and higher \nu_peak objects had smaller variations in their amplitudes both in the flux, color, and polarization degree. Our observation suggests the presence of several distinct emitting sources, which have different variation time-scales, colors, and polarizations. We propose that the energy injection by, for example, internal shocks in relativistic shells is a major factor for blazar variations on time scales of both days and months.Comment: 39 pages, accepted for publication in PAS

Spontaneous complete necrosis of hepatocellular carcinoma caused by feeding vessel occlusion outside the tumour capsule

A 64-year-old man began treatment for chronic hepatitis C with peg-interferon and ribavirin. His hepatitis C virus ribonucleic acid (HCV-RNA) results turned negative. Just after the treatment, a computed tomography (CT) scan revealed a hypovascular mass in the segment 8. We performed a right hemihepatectomy as HCC. Upon macroscopic examination, the tumour was yellow and firm with a fibrous capsule. A wedge-shaped necrotic area was located at the top of an artery and a portal vein of segment 8. Necrosis was observed not only in the tumour but in the adjacent parenchyma. A histopathological examination showed that the tumour had been completely replaced by necrosis. This tumour was surrounded by capillary vessels and fed by several thick arteries, but organized thrombi were not detected. No viable cells were found. The histopathological diagnosis was a spontaneous complete necrosis of HCC caused by the occlusion of feeding vessels outside the capsule

Early Spectroscopy of the 2010 Outburst of U Scorpii

We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at $t_{\rm d}=$0.37--0.44~d, where $t_{\rm d}$ denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At $t_{\rm d}\sim 0.4$~d the H$\alpha$ line consists of a blue-shifted ($-5000$ km s$^{-1}$) narrow absorption component and a wide emission component having triple peaks, a blue ($\sim -3000$ km s$^{-1}$), a central ($\sim 0$ km s$^{-1}$) and a red ($\sim +3000$ km s$^{-1}$) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At $t_{\rm d}=1.4$~d the H$\alpha$ line has a nearly flat-topped profile with weak blue and red peaks at $\sim \pm 3000$ km s$^{-1}$. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after $t_{\rm d}=9$ d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter

Projective Coordinates and Projective Space Limit

The "projective lightcone limit" has been proposed as an alternative holographic dual of an AdS space. It is a new type of group contraction for a coset G/H preserving the isometry group G but changing H. In contrast to the usual group contraction, which changes G preserving the spacetime dimension, it reduces the dimensions of the spacetime on which G is realized. The obtained space is a projective space on which the isometry is realized as a linear fractional transformation. We generalize and apply this limiting procedure to the "Hopf reduction" and obtain (n-1)-dimensional complex projective space from (2n-1)-dimensional sphere preserving SU(n) symmetry.Comment: 16 pages, v2: modified the section 2.1 clarifying the difference from IW contraction, added notes & references, version to appear in Nuclear Physics

Five-body resonances of 8He using the complex scaling method

The 0+ states of 8He are studied in a five-body 4He+n+n+n+n cluster model. Many-body resonances are treated on the correct boundary condition as Gamow states using the complex scaling method. The 0+_2 state of 8He is predicted as a five-body resonance in the excitation energy of 6.3 MeV with a width of 3.2 MeV, which mainly has a (p_{3/2})^2(p_{1/2})^2 configuration. In this state, number of the 0+ neuron pair shows almost two, which is different from the ground state having a large amount of the 2+ pair component. The monopole transition of 8He from the ground state into the five-body unbound states is also evaluated. It is found that the 7He+n component mostly exhausts the strength, while the 0+_2 contribution is negligible. The final states are dominated by 6He+n+n, not 4He+n+n+n+n. The results indicate the sequential breakup process of 8He to 7He+n to 6He+n+n by the monopole excitation.Comment: 6 pages, 6 figures, table I is updated for the experimental value