Generation of field-aligned current in the auroral zone

Generation of a magnetic field-aligned current in the auroral zone connecting the magnetospheric and ionospheric plasmas has been studied by means of a three dimensional particle simulation model. The model is of a magnetostatic variety appropriate for a low beta plasma in which the high frequency transverse displacement current has been eliminated. The simulation model is highly elongated along the magnetic field lines in order to model a highly elongated flux tube in the auroral zone. An enhanced field-aligned current was generated by injection of a magnetospheric plasma across the auroral zone magnetic field at the center of the model. Such a plasma injection may correspond to a plasmoid injection at the geomagnetic tail associated with magnetic reconnection during a substorm or a transverse plasma flow along the low latitude magnetopause boundary layer. The results of the simulations show that the field-aligned current can be enhanced over the thermal current by a factor of 5 - 10 via such injection. Associated with the enhanced current are the electrostatic ion cyclotron waves and shear Alfven waves excited in the auroral zone

Particle simulation of auroral double layers

Work on the simulation of auroral double layers (DLs) with realistic particle-in-cell models is presented. An early model simulated weak DLs formed in a self-consistent circuit but under conditions subject to the ion-acoustic instability. Recent work has focused on strong DLs formed when currentless jets are injected into a dipole magnetic field

Exploring Galaxy Evolution from Infrared Number Counts and Cosmic Infrared Background

Recently reported infrared (IR) galaxy number counts and cosmic infrared background (CIRB) all suggest that galaxies have experienced a strong evolution sometime in their lifetime. We statistically estimate the galaxy evolution history from these data. We find that an order of magnitude increase of the far-infrared (FIR) luminosity at redshift z = 0.5 - 1.0 is necessary to reproduce the very high CIRB intensity at 140 um reported by Hauser et al. (1998). z \sim 0.75 and decreases to, even at most, a factor of 10 toward z \sim 5, though many variants are allowed within these constraints. This evolution history also satisfies the constraints from the galaxy number counts obtained by IRAS, ISO and, roughly, SCUBA. The rapid evolution of the comoving IR luminosity density required from the CIRB well reproduces the very steep slope of galaxy number counts obtained by ISO. We also estimate the cosmic star formation history (SFH) from the obtained FIR luminosity density, considering the effect of the metal enrichment in galaxies. The derived SFH increases steeply with redshift in 0 0.75. This is consistent with the SFH estimated from the reported ultraviolet luminosity density. In addition, we present the performance of the Japanese ASTRO-F FIR galaxy survey. We show the expected number counts in the survey. We also evaluate how large a sky area is necessary to derive a secure information of galaxy evolution up to z \sim 1 from the survey, and find that at least 50 - 300 deg^2 is required.Comment: 18 pages LaTeX, PASJ in press. Abstract abridge

カンジダ特異的IgG(4)抗体と気管支喘息

Serum levels of Candida-specific IgG(4) antibodies were examined in 66 patients with bronchial asthma, relating to patient age and asthma severity. 1. The levels of Candida-specific IgG(4) antibodies were the highest in patients with 60+years of age, compared to the levels in cases with 0-39 and 40-59 years of age. 2. In cases with 40-59 years of age, the levels of Candida-specific IgG(4) were significantly higher in cases with long-term steroid therapy (severe intractable asthma) than in cases without steroid regimen. The results suggest that increased levels of Candida-specific IgG(4) were observed in relation to patient age and asthma severity.66例の気管支喘息症例を対象に，血清中カンジダ特異的lgG(4)抗体を測定し，その血中レベルと年齢および喘息の重症度との関連について検討を加えた。1．血清カンジダ特異的IgG(4)値は，0～39才，40～59才の年齢層にくらべ，60才以上の年齢層において高く，年齢によりその値が変動することが 示唆された。2．40～59才の年齢層では，血清カンジダ特異的IgG(4)は，ステロイド非使用例にくらべ，ステロイド依存性重症難治性喘息症例で有意の高値を示し，この年齢層では，カンジダ特異的IgG(4)抗体がその発症病態に関連している可能性が示唆された。以上，カンジダ特異的IgG(4)抗体の上昇は，高年齢層の症例（60才以上）では全般的に，また40～59才の年齢層で重症型喘息症例において観察されることが明らかにされた

ステロイド依存性重症難治性喘息に対する複合温泉療法の作用機序

Effects of complex spa therapy, which comprises swimming training in a hot spring pool, inhalation of iodine salt solution and fango therapy, were analyzed in patients with steroid-dependent intractable asthma (SDIA) by comparison between the subjects with and without efficacy of the therapy. 1. The complex spa therapy was effective in the patients with lower levels of FEV(1.0%) and % PEFR. 2. The complex spa therapy was not always effective in the patients with a low value of % V(25), which represents depressed airflow in the small airways. 3. The efficacy of the complex spa therapy was found in the patients showing a low value of % V(25) accompanied by BAL neutrophilia, but not found in those without increased proportion (more than 10% ) of neutrophils in BAL fluid. The results reveal that the complex spa therapy is effective in patients with SDIA showing low values of FEV(1.0%) and % PEFR, and in those with a low value of % V(25) and BAL neutrophilia.ステロイド依存性重症難治性喘息を対象に,温泉プール水泳訓練,ヨードゾル吸入療法.鉱泥湿布療法からなる複合温泉療法の臨床効果の解析を行った。1.複合温泉療法は,FEV(1.0%)および% PEFR値の低い症例により有効であった｡2.複合温泉療法は､細気管支領域の換気障害を示すと考えられる% V(25)値が低い症例に対して,必ずしも有効ではなかった｡3.複合温泉療法の効果は,BAL液中好中球増多(10%以上)が見られ､かつ% V(25)値が低い症例により有効であったが､同様に% V(25)値が低くても,BAL液中に好中球増多 が見られない症例に対しては,有効ではなかった｡以上の結果より,複合温泉療法はFEV(1.0%)や% PEFR値の低く,またBAL液中好中球増多が見られ,かつ% V(25)値が低いようなステロイド依存性重症難治性喘息に対して有効性が高いことが示唆された

Temperature and Density in the Foot Points of the Molecular Loops in the Galactic Center; Analysis of Multi-J Transitions of 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0)

Fukui et al. (2006) discovered two molecular loops in the Galactic center and argued that the foot points of the molecular loops, two bright spots at both loops ends, represent the gas accumulated by the falling motion along the loops, subsequent to magnetic flotation by the Parker instability. We have carried out sensitive CO observations of the foot points toward l=356 deg at a few pc resolution in the six rotational transitions of CO; 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0). The high resolution image of 12CO (J=3-2) has revealed the detailed distribution of the high excitation gas including U shapes, the outer boundary of which shows sharp intensity jumps accompanying strong velocity gradients. An analysis of the multi-J CO transitions shows that the temperature is in a range from 30-100 K and density is around 10^3-10^4 cm^-3, confirming that the foot points have high temperature and density although there is no prominent radiative heating source such as high mass stars in or around the loops. We argue that the high temperature is likely due to the shock heating under C-shock condition caused by the magnetic flotation. We made a comparison of the gas distribution with theoretical numerical simulations and note that the U shape is consistent with numerical simulations. We also find that the region of highest temperature of ~100 K or higher inside the U shape corresponds to the spur having an upward flow, additionally heated up either by magnetic reconnection or bouncing in the interaction with the narrow neck at the bottom of the U shape. We note these new findings further reinforce the magnetic floatation interpretation.Comment: 40 pages, 23 figures, accepted by PASJ on Vol.62 No.

An isomorphous replacement method for efficient de novo phasing for serial femtosecond crystallography.

SACLAのX線自由電子レーザーを用いた新規タンパク質立体構造決定に世界で初めて成功. 京都大学プレスリリース. 2015-09-14.Serial femtosecond crystallography (SFX) with X-ray free electron lasers (XFELs) holds great potential for structure determination of challenging proteins that are not amenable to producing large well diffracting crystals. Efficient de novo phasing methods are highly demanding and as such most SFX structures have been determined by molecular replacement methods. Here we employed single isomorphous replacement with anomalous scattering (SIRAS) for phasing and demonstrate successful application to SFX de novo phasing. Only about 20,000 patterns in total were needed for SIRAS phasing while single wavelength anomalous dispersion (SAD) phasing was unsuccessful with more than 80,000 patterns of derivative crystals. We employed high energy X-rays from SACLA (12.6 keV) to take advantage of the large anomalous enhancement near the LIII absorption edge of Hg, which is one of the most widely used heavy atoms for phasing in conventional protein crystallography. Hard XFEL is of benefit for de novo phasing in the use of routinely used heavy atoms and high resolution data collection

Faint 6.7um Galaxies and their Contributions to the Stellar Mass Density in the Universe

We discuss the nature of faint 6.7um galaxies detected with the mid-infrared camera ISOCAM on board the Infrared Space Observatory (ISO). The 23 hour integration on the Hawaii Deep Field SSA13 has provided a sample of 65 sources down to 6uJy at 6.7um. For 57 sources, optical or near-infrared counterparts were found with a statistical method. All four Chandra sources, three SCUBA sources, and one VLA/FIRST source in this field were detected at 6.7um with high significance. Using their optical to mid-infrared colors, we divided the 6.7um sample into three categories: low redshift galaxies with past histories of rapid star formation, high redshift ancestors of these, and other star forming galaxies. Rapidly star forming systems at high redshifts dominate the faintest end. Spectroscopically calibrated photometric redshifts were derived from fits to a limited set of template SEDs. They show a high redshift tail in their distribution with faint (1. The 6.7um galaxies tend to have brighter K magnitudes and redder I-K colors than the blue dwarf population at intermediate redshifts. Stellar masses of the 6.7um galaxies were estimated from their rest-frame near-infrared luminosities. Massive galaxies (M_star~10e11M_sun) were found in the redshift range of z=0.2-3. Epoch dependent stellar mass functions indicate a decline of massive galaxies' comoving space densities with redshift. Even with such a decrease, the contributions of the 6.7um galaxies to the stellar mass density in the universe are found to be comparable to those expected from UV bright galaxies detected in deep optical surveys.Comment: 31 pages, 15 figures, AJ (accepted), a version with color figures at http://www.ioa.s.u-tokyo.ac.jp/~ysato/pub/3/p3c-ysato.ps.g

THE NEUTRAL INTERSTELLAR GAS TOWARD SNR W44: CANDIDATES FOR TARGET PROTONS IN HADRONIC γ-RAY PRODUCTION IN A MIDDLE-AGED SUPERNOVA REMNANT

We present an analysis of the interstellar medium (ISM) toward the γ-ray supernova remnant (SNR) W44. We used NANTEN2 12CO(J = 2-1) and 12CO(J = 1-0) data and Arecibo H I data in order to identify the molecular and atomic gas in the SNR. We confirmed that the molecular gas is located in the SNR shell with a primary peak toward the eastern edge of the shell. We newly identified high-excitation molecular gas along the eastern shell of the SNR in addition to the high-excitation broad gas previously observed inside the shell; the line intensity ratio between the 12CO(J = 2-1) and 12CO(J = 1-0) transitions in these regions is greater than ~1.0, suggesting a kinetic temperature of 30 K or higher, which is most likely due to heating by shock interaction. By comparing the ISM with γ-rays, we find that target protons of hadronic origin are dominated by molecular protons of average density around 200 cm–3, where the possible contribution of atomic protons is 10% or less. This average density is consistent with the recent discovery of the low-energy γ-rays suppressed in 50 MeV-10 GeV as observed with AGILE and Fermi. The γ-ray spectrum differs from place to place in the SNR, suggesting that the cosmic-ray (CR) proton spectrum significantly changes within the middle-aged SNR perhaps due to the energy-dependent escape of CR protons from the acceleration site. We finally derive a total CR proton energy of ~1049 erg, consistent with the SN origin of the majority of the CRs in the Galaxy