Distortion of the outer boundary of the closed region in the Tsyganenko magnetic field model

Using the Tsyganenko magnetic field model (TSYGANENKO, Planet. Space Sci., 37, 5, 1989) we make an attempt to determine the outer boundary of the closed region when the interplanetary magnetic field (IMF) is southward. As a simple magnetic field model including the effect of IMF B_z<0, the B_z component of a constant value of minus a few nanoTeslas is added to the magnetic field in the Tsyganenko model with low K_p values. In this paper, if the magnetic field strength, B, is not less than 2 nT in the whole range of a field line (namely the minimum B along a field line is greater than 2 nT), this field line is judged to be "firmly" closed. The firmly closed field lines are thought to be definitely closed as long as the fluctuation amplitude of B_z (around its average level) in the interplanetary (solar wind) magnetic field is less than 2 nT. The outer boundary of the firmly closed region is then constituted by field lines with the minimum B of 2 nT. This boundary is found to be close to (just inside of) the open-closed boundary, which can be determined with accuracy of 0.01° in latitude of the foot point of a field line. It is found that a circle with the center at a latitude of about 85° on the midnight meridian can be fitted to the outer boundary of the firmly closed region, as it is projected to the ionosphere. Interestingly this circle coincides with a typical auroral circle; the auroral circles are those delineating the poleward boundary of the quiet auroral belt, which were earlier identified from the statistical analysis of satellites\u27 auroral images by MENG et al. (J. Geophys. Res., 82, 164, 1977). Importantly we find that the outer boundary of the firmly closed region is "distorted" on the nightside in the sense that the ionospheric projection of the average magnetic drift velocity of a plasma with isotropic pressure is not parallel to the boundary; more specifically, that of an isotropic ion fluid has an equatorward component on the duskside boundary and a poleward one on the dawnside boundary, respectively. This kind of the boundary distortion may be one of the possible causes of the generation of the nightside region 1 field-aligned current, which has been first suggested by HRUSKA (J. Geophys. Res., 91, 371, 1986) and recently, further studied by YAMAMOTO and INOUE (Proc. NIPR Symp. Upper Atmos. Phys., 11, 106, 1998)

Plasma and synovial fluid microRNAs as potential biomarkers of rheumatoid arthritis and osteoarthritis

[Introduction]: MicroRNAs (miRNAs), endogenous small noncoding RNAs regulating the activities of target mRNAs and cellular processes, are present in human plasma in a stable form. In this study, we investigated whether miRNAs are also stably present in synovial fluids and whether plasma and synovial fluid miRNAs could be biomarkers of rheumatoid arthritis (RA) and osteoarthritis (OA). [Methods]: We measured concentrations of miR-16, miR-132, miR-146a, miR-155 and miR-223 in synovial fluid from patients with RA and OA, and those in plasma from RA, OA and healthy controls (HCs) by quantitative reverse transcription-polymerase chain reaction. Furthermore, miRNAs in the conditioned medium of synovial tissues, monolayer fibroblast-like synoviocytes, and mononuclear cells were examined. Correlations between miRNAs and biomarkers or disease activities of RA were statistically examined. [Results]: Synovial fluid miRNAs were present and as stable as plasma miRNAs for storage at -20°C and freeze-thawing from -20°C to 4°C. In RA and OA, synovial fluid concentrations of miR-16, miR-132, miR-146a, and miR-223 were significantly lower than their plasma concentrations, and there were no correlation between plasma and synovial fluid miRNAs. Interestingly, synovial tissues, fibroblast-like synoviocytes, and mononuclear cells secreted miRNAs in distinct patterns. The expression patterns of miRNAs in synovial fluid of OA were similar to miRNAs secreted by synovial tissues. Synovial fluid miRNAs of RA were likely to originate from synovial tissues and infiltrating cells. Plasma miR-132 of HC was significantly higher than that of RA or OA with high diagnosability. Synovial fluid concentrations of miR-16, miR-146a miR-155 and miR-223 of RA were significantly higher than those of OA. Plasma miRNAs or ratio of synovial fluid miRNAs to plasma miRNAs, including miR-16 and miR-146a, significantly correlated with tender joint counts and 28-joint Disease Activity Score. [Conclusions]: Plasma miRNAs had distinct patterns from synovial fluid miRNAs, which appeared to originate from synovial tissue. Plasma miR-132 well differentiated HCs from patients with RA or OA, while synovial fluid miRNAs differentiated RA and OA. Furthermore, plasma miRNAs correlated with the disease activities of RA. Thus, synovial fluid and plasma miRNAs have potential as diagnostic biomarkers for RA and OA and as a tool for the analysis of their pathogenesis

The large helical device vertical neutron camera operating in the MHz counting rate range

In the currently performed neutral beam (NB) -heated deuterium plasma experiments, neutrons are mainly produced by a beam-plasma reaction. Therefore, time-resolved measurement of the neutron emission profile can enhance the understanding of the classical and/or anomalous transport of beam ions. To measure radial neutron emission profiles as a function of time, the vertical neutron camera (VNC) capable of operation with a counting rate in the MHz range was newly installed on the Large Helical Device (LHD). This is the world’s first neutron camera for stellarator/heliotron devices. The VNC consists of a multichannel collimator, eleven fast-neutron detectors, and the digital-signal-processing-based data acquisition system (DAQ). The multichannel collimator having little cross talk was made from hematite-doped heavy concrete, which has a high shielding performance against both neutrons and gamma-rays. A stilbene crystal coupled with a photomultiplier having high-gain-stability in the high-count rate regime was utilized as a fast-neutron scintillation detector because it has a high neutron-gamma discrimination capability at high count rates. The DAQ system equipped with a field programmable logic controller was developed to obtain the waveform acquired with a 1 GHz sampling rate and the shaping parameter of each pulse simultaneously at up to 106 cps (counts per second). Neutron emission profiles were successfully obtained in the first deuterium campaign of LHD in 2017. The neutron emission profile was measured in tangentially co-injected NB-heated plasma with different magnetic axes (Rax). The neutron counts became larger in the inward-shifted configuration, which was consistent with the total neutron rate measured by the neutron flux monitor. The radial peak position of the line-integrated neutron profile which changed according to Rax showed that the VNC worked successfully as designed. The VNC demonstrated the expected performance conducive to extending energetic-particle physics studies in LHD

High abundance ratio of 13^{13}CO to C18^{18}O toward photon-dominated regions in the Orion-A giant molecular cloud

Aims. We derive physical properties such as the optical depths and the column densities of $^{13}$CO and C$^{18}$O to investigate the relationship between the far ultraviolet (FUV) radiation and the abundance ratios between $^{13}$CO and C$^{18}$O. Method. We have carried out wide-field (0.4 deg$^2$) observations with an angular resolution of 25.8 arcsec ($\sim$ 0.05 pc) in $^{13}$CO ($J$=1--0) and C$^{18}$O ($J$=1--0) toward the Orion-A giant molecular cloud using the Nobeyama 45 m telescope in the on-the-fly mode. Results. Overall distributions and velocity structures of the $^{13}$CO and C$^{18}$O emissions are similar to those of the $^{12}$CO ($J$=1--0) emission. The optical depths of the $^{13}$CO and C18O emission lines are estimated to be 0.05 $<$ $\tau_{\rm ^{13}CO}$ $<$ 1.54 and 0.01 $<$ $\tau_{\rm C^{18}O}$ $<$ 0.18, respectively. The column densities of the $^{13}$CO and C$^{18}$O emission lines are estimated to be 0.2 $\times$ 10$^{16}$ $<$ $N_{\rm ^{13}CO}$ $<$ 3.7 $\times$ 10$^{17}$ cm$^{-2}$ and 0.4 $\times$ 10$^{15}$ $<$ $N_{\rm C^{18}O}$ $<$ 3.5 $\times$ 10$^{16}$ cm$^{-2}$, respectively. The abundance ratios between $^{13}$CO and C$^{18}$O, $X_{\rm ^{13}CO}$/$X_{\rm C^{18}O}$, are found to be 5.7 - 33.0. The mean value of $X_{\rm ^{13}CO}$/$X_{\rm C^{18}O}$ in the nearly edge-on photon-dominated regions is found to be 16.47 $\pm$ 0.10, which is a third larger than that the solar system value of 5.5. The mean value of $X_{\rm ^{13}CO}$/$X_{\rm C^{18}O}$ in the other regions is found to be 12.29 $\pm$ 0.02. The difference of the abundance ratio is most likely due to the selective FUV photodissociation of C$^{18}$O.Comment: 11 pages, 9 figures, Accepted to A&

Effect of Thermal Neutrons on Fusion Power Measurement using the Micro-Fission Chamber in ITER

Abstract A Micro-fission Chamber (MFC) provides time-resolved measurements of global neutron source strength and fusion power in ITER. The MFC is a pencil-sized gas counter containing the fissile material, 235 U. MFCs will be installed behind blanket modules at upper and lower outboard positions due to interface considerations with other equipment and the vacuum vessel. Measurements of the neutron source strength could be affected by cooling water in branch pipes, which will be installed near the MFC. The effect of the branch pipes upon the MFC is assessed by neutron transport calculation using MCNP 5. Results indicate a significant increase in the MFC response rate (up to ~ 40% higher) due to the branch pipe. The increase in the MFC response is caused by the slowing down of the neutrons due to the cooling water in the branch pipes. The effect of the thermal neutrons on the MFC response is especially significant. One possible solution to reduce the effect is to cover the MFC with a material that absorbs thermal neutrons such as cadmium. The ways in which the absorbent material may affect MFC response is analyzed through neutron transport calculation. Results indicate that the increase in the MFC response can be reduced to &lt; 10 % through cadmium coating

Oral Treatment with Extract of Agaricus blazei Murill Enhanced Th1 Response through Intestinal Epithelial Cells and Suppressed OVA-Sensitized Allergy in Mice

To clarify the mechanism of the antiallergic activity of Agaricus blazei Murill extract (ABME), the present paper used an in vivo allergy model and an in vitro intestinal gut model. During OVA sensitization, the serum IgE levels decreased significantly in ABME group. Interleukin (IL)-4 and -5 produced from OVA-restimulated splenocytes was significantly decreased, and anti-CD3ε/CD28 antibody treatment also reduced IL-10, -4, and -5 production and increased IFN-γ production in ABME group. These results suggest that oral administration of ABME improves Th1/Th2 balance. Moreover, a coculture system constructed of Caco-2 cells and splenocytes from OT-II mice or RAW 264.7 cells indicated that the significant increases in IFN-γ production by ABME treatment. Therefore, it was concluded that the antiallergic activity of ABME was due to the activation of macrophages by epithelial cells and the promotion of the differentiation of naïve T cells into Th1 cells in the immune