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The number of tests performed is an important surveillance indicator. We illustrate this point using HIV surveillance data, focusing on Tokyo and Okinawa, two prefectures with high HIV notification rates in Japan. Restricting to data reported from local public health centres and affiliate centres where testing data are accessible, we assessed HIV surveillance data during 2007–2014, based on the annual HIV notification rate (per 100 000 population), HIV testing rate (per 100 000 population) and proportion testing HIV-positive (positivity). Nationally, testing activity and positivity showed an inverse relationship; in 2008, the testing rate peaked, but positivity was lowest. While notification rates were higher for Tokyo (median = 0.98, range = 0.89–1.33) than Okinawa (median = 0.61, range = 0.42–1.09), Okinawa had slightly higher testing rates (median = 187, range = 158–274) relative to Tokyo (median = 172, range = 163–210). Positivity was substantially lower in Okinawa (median = 0.34%, range = 0.24–0.45%) compared with Tokyo (median = 0.57%, range = 0.46–0.67%). Relative to the national testing rate (median = 85, range = 80–115) and positivity (median = 0.34%, range = 0.28–0.36%), Tokyo had higher positivity, despite more testing. In 2014 in Okinawa, all three indicators increased, providing a strong reason to be concerned as positivity increased despite more testing. Together with other information, accounting for testing and positivity improve interpretation of surveillance data to guide public health assessments.
The large scatter in Lyman-α opacity at z > 5.3 has been an ongoing mystery, prompting a flurry of numerical models. A uniform ultra-violet background has been ruled out at those redshifts, but it is unclear whether any proposed models produce sufficient inhomogeneities. In this paper we provide an update on the measurement which first highlighted the issue: Lyman-α effective optical depth along high-z quasar lines of sight. We nearly triple on the previous sample size in such a study thanks to the cooperation of the DES-VHS, SHELLQs, and SDSS collaborations as well as new reductions and spectra. We find that a uniform UVB model is ruled out at 5.1 < z < 5.3, as well as higher redshifts, which is perplexing. We provide the first such measurements at z ∼ 6. None of the numerical models we confronted to this data could reproduce the observed scatter.
A CCD detector has been developed for photometry and image detection with the 60cm reflector at Kagoshima Space Center. The structure and the manipulation of the instrument were simpified by the use of Peltier devices for cooling the CCD in order to eliminate thermal noise. A micro-computer system is used to control the instrument and process the data. A test observing run has demonstrated that a photometric sensitivity of 20th magnitude in the W band(3800-7000 Å) can be achieved in a 3600sec exposure.
The Fukushima Daiichi and Daini Nuclear Power Plant workers experienced multiple stressors as both victims and onsite workers after the 2011 Great East Japan Earthquake and subsequent nuclear accidents. Previous studies found that disaster-related exposures, including discrimination/slurs, were associated with their mental health. Their long-term impact has yet to be investigated.
A total of 968 plant workers (Daiichi, n = 571; Daini, n = 397) completed self-written questionnaires 2–3 months (time 1) and 14–15 months (time 2) after the disaster (response rate 55.0%). Sociodemographics, disaster-related experiences, and peritraumatic distress were assessed at time 1. At time 1 and time 2, general psychological distress (GPD) and post-traumatic stress response (PTSR) were measured, respectively, using the K6 scale and Impact of Event Scale Revised. We examined multivariate covariates of time 2 GPD and PTSR, adjusting for autocorrelations in the hierarchical multiple regression analyses.
Higher GPD at time 2 was predicted by higher GPD at time 1 (β = 0.491, p < 0.001) and discrimination/slurs experiences at time 1 (β = 0.065, p = 0.025, adjusted R2 = 0.24). Higher PTSR at time 2 was predicted with higher PTSR at time 1 (β = 0.548, p < 0.001), higher age (β = 0.085, p = 0.005), and discrimination/slurs experiences at time 1 (β = 0.079, p = 0.003, adjusted R2 = 0.36).
Higher GPD at time 2 was predicted by higher GPD and discrimination/slurs experience at time 1. Higher PTSR at time 2 was predicted by higher PTSR, higher age, and discrimination/slurs experience at time 1.
We report investigation of the iron Kα line in a long (100 ks) ASCA observation of NGC 4151. This observation offers unprecedented good statistics; however, the situation is complicated by the fact that the absorption in NGC 4151 is complex and therefore it is difficult to deconvolve a broad iron line from the power law strongly curved by the absorption. Preliminary spectral fitting with a dual absorber model, using updated abundances and response matrices, and also allowing for iron overabundance, revealed significant spectral residuals around 5 keV which could be modeled with a broad Gaussian. This profile resembles the line characteristic of emission from a relativistic accretion disk; however, that model fit the spectra poorly. Since the energy of the narrow core is nearly 6.4 keV, the orientation of the accretion disk should be nearly face-on, because if the inclination were higher, the blue horn should be shifted to higher energies. If the orientation is face-on, there should be no emission blueward of 6.4 keV; however, a small blue wing as well as a long red wing are present in the residuals.
The first-ever high energy (~ 1-30 keV) X-ray spectra of three z ~ 2 radio-quiet quasars (RQQs) are presented. If confirmed, the most interesting result is the marginal, but consistent, evidence for FeKα emission lines in at least two of the sources. Further ASCA observations of high-z RQQs are needed for firm conclusions.
Here we present a very short review of the ASCA observation campaign of the enigmatic galactic jet system SS433. The campaign started in 1994 just after the launch, and ended in 1996. Various phases of the 162.5-day precession and 13-day orbital motion were sampled. With ASCA, the Doppler-shifted pairs from various ion species from Si to Ni were resolved for the first time (Kotani et al. 1994). The Doppler-shift parameters were determined with an accuracy comparable to optical spectroscopy (Kawai 1995). No velocity gradient was found between the X-ray emission region of the jet and the optical. The distance between them was constrained to be less than 1015 cm. Line intensity ratios of Fe XXVI/Fe XXV give the base temperature of the jet to be 20 keV (Kotani et al. 1996). The variation of the apparent base temperature of the jet can be explained in terms of the partial occultation of the jet by a precessing accretion disk (Kotani et al. 1997a). From the variation, the disk radius and the disk height in unit of the X-ray jet length were estimated to be 0.23 ± 0.10 and 0.0232 ± 0.0049, respectively. (These are an improved version of the values in Kotani et al. (1997a).) SS433 is also known as an eclipsing binary. Because the emission from each jet with ASCA, it is possible to know how much of which jet is occulted by the companion star during an eclipse. Relative size of the companion star gives Roche lobe size and thus mass ratio MX/MC = 0.22+0.09-0.16 (Kotani 1997b). With the help of Doppler modulation, compact star mass is constrained. However, the values of Doppler modulation reported from optical observations largely scatters. D'Odorico et al. (1991) reported 112 km s−1 and this gives MX = 0.68+0.43-0.53 M⊙, i.e., a white dwarf, while Fabrika and Bychkova (1990) reported 175 km s−1, which gives 2.6+1.6-2.0 M⊙. (This error includes systematic errors of the X-ray data, and will be reduced in future analysis.) On the other hand, the absolute size of the system were determined with a satisfactory precision. For example, the X-ray jet length was determined to be 2×1013 cm, ten times larger than previous estimations (Kotani et al. 1997c). Other physical parameters of the jet can be derived from the X-ray jet length. Mass outflow rate and the kinetic luminosity of both jet were determined to be 8 × 10−6 M⊙ yr−1 and 1.6 × 1040 erg s−1 (Kotani et al. 1997d), implicating a highly super critical accretion. Most of these values are first precise measurements and/or “radical” revisions of previous estimations. The new picture of SS433 drawn here is far stormy and highly energetic.
SS 433 has been observed with ASCA for three years since the launch in 1993. The excellent energy resolution of ASCA revealed the Doppler-shifted emission lines from the both jets, though it had been generally accepted that the X-ray emitting region of the receding jet is hidden behind the accretion disk. Thus the estimation on the properties of the X-ray jet, such as length, temperature, and mass outflow rate, should be revised in accordance with the ASCA data. Modeling the jet as a radiating ballistic plasma, we determined these quantities. It is also tried to determine the mass of the system from a data covering an eclipse.
We propose an X-ray all sky monitor for Japanese Experimental Module (JEM) on the space station. Considering practical circumstances, we show as a case study that the all sky monitor with slit hole cameras is most promising for monitoring the short-term and long-term X-ray transients. We call this all sky monitor as MAXI (Monitor of All-sky X-ray Image). Position determination of gamma-ray bursts could be achieved with accuracy less than one degree observing the X-ray component of the burst. Weak X-ray sources such as active galactic nuclei could be also monitored with time resolution less than one day. The X-ray all sky monitor will work to discover X-ray novae and transient phenomena and give us the alarm for further detailed observations. The obtained data will be also used for archival study.
The High Energy Transient Explorer 2 is a small scientific satellite designed to detect and localize gamma-ray bursts (GRBs). The coordinates of GRBs detected by HETE-2 will be distributed to interested ground-based observers within seconds of burst detection, thereby allowing detailed observations of the initial phases of GRBs. HETE-2 was launched successfully on October 9, 2000. The GRB positions will start to be delivered after a few months of the complete testing and calibration of the spacecraft system and the science instruments.
The Collaboration of Australia and Nippon for a GAmma Ray Observatory in the Outback operates two large telescopes at Woomera (South Australia), which detect the Čerenkov light images produced in the atmosphere by electronpositron cascades initiated by very high energy (~1 TeV or 1012 eV) gamma rays. These gamma rays arise from a different mechanism than at EGRET energies: inverse Compton (IC) emission from relativistic electrons.
The spoke-like images are recorded by a multi-pixel camera which facilitates the rejection of the large numbers of oblique and ragged cosmic ray images. A field of view ~3.5° is required. The Australian team operates a triple 4 m diameter mirror telescope, BIGRAT, with a 37 photomultiplier tube camera and energy threshold 600 GeV. The Japanese operate a single, highly accurate 3.8 m diameter f/1 telescope and high resolution 256 photomultipler tube camera. In 1998 a new 7 m telescope is planned for Woomera with a design threshold ~;200GeV.
Cosmic X-rays were observed with three sets of proportional counters covering the energy range between 0.15 and 20 keV. The detector born on a spinning rocket scanned a celestial region in which the galactic latitude bII changed from 30° to −55° across the galactic plane in the Cygnus-Cassiopeia region. The spectrum of Cyg XR-2 thus obtained is represented by a thermal bremsstrahlung of temperature 3.4 keV modified by the interstellar absorption for the hydrogen column density of 3 × 1021 cm−2. The diffuse component showed an interstellar absorption effect, which was however found much weaker than one would expect if the diffuse component were due entirely to be of extragalactic origin. The spectrum obtained in the highest latitude region is represented approximately by a power law E−1.8 but shows a possible trough at about 1 keV.
The wurtzite structure In1−x−yGaxAlyN quaternary system is studied with respect to the unstable region in mixing. The composition in the unstable region is calculated from the free energy of mixing by using the strictly regular solution model. The interaction parameter used in this calculation is obtained by using the delta-lattice-parameter method. Here, the proportionality constant connecting the lattice constants and the band-gap energy is determined by fitting the calculation to the composition data obtained experimentally from InGaN grown by metallorganic vapor phase epitaxy. From this calculation, the ternary alloys of InAlN, InGaN and GaAlN are predicted to always, sometimes, and hardly ever, respectively, have an unstable mixing region. The essential mismatch in thermal equilibrium between the strictly regular solution approximation and the growth conditions in MOVPE is removed by using a fitting calculation and experimental data. Also, the mismatch between the zinc-blende structure and the wurtzite structure is corrected. As a result, this prediction of the phase separation in In1−x−yGaxAlyN becomes more reliable.
Monitor of All-sky X-ray Image (MAXI) on board International Space Station is capable of
observing gamma-ray bursts (GRBs) and sending notices of GRBs or other transient events,
using real time connection to the ground. MAXI observed 32 GRBs or short X-ray transients
as of the end of September 2012. Among them, eleven events were simultaneously detected by
other satellites. The observed rate of the MAXI GRBs is about one event per month. This
rate is comparable to a past observation with larger effective area and larger field of
view. The fact indicates that MAXI has better sensitivity to observe GRBs because of low
background. The distribution of the spectral hardness of MAXI GRBs is similar to the
results of a past instrument, which is sensitive to similar energy range.
Interfaces between two kind of substrate, a bulk silicon wafer and a laser-recrystallized Silicon-On-Insulator (SOI), and its thermally grown oxide have been studied. High resolution transmission electron microscopy (HRTEM) of cross sectional specimen shows that the roughness at the interface is atomically flat and nearly uniform for the bulk single crystal silicon and silicon oxide, while being nonuniform and rough as much as 20 nm height for the recrystallized silicon and silicon oxide interface. Consideration of interface between recrystallized silicon and silicon oxide, and the oxide surface above, the observed roughness at the interface is due to original grain boundaries of polycrystalline silicon which was used as the material for the laser recrystallized silicon formation. It is also discussed HRTEM of the interface between polycrystalline silicon and silicon oxide.
Correlation between defects and electrical conduction in surface conductive layers of CVD diamond films has been studied using electron spin resonance ( ESR ) and two points probe technique methods. The ESR analysis revealed the presence of Pac-center with spin density of 1020 spins/cm3. The Pac-center is composed from two ESR signals: ESR signal from carbon dangling bond with carbon atom neighbors and ESR signal from carbon dangling bond associated with nearest neighbor hole ( hole associated Pac-center ). The hole associated Pac-center is an electrically active defect.
Phase-change memory is promising because it has a simple structure and has scalability that originates from its unique operating mechanism. However, the programming current should be reduced in accordance with the scaling of cell size [1,2]. We previously reported PCM (Phase Change Memory) cells that operate under 1.5-V/100-μA writing pulses [3, 4]. This PCM had a cell structure composed of 180-nm-W (tungsten) bottom contact to an O-GST (Oxygen-doped GeSbTe) film. Its low-power characteristic is suitable for 0.13-μm generation embedded applications. In the present study, we introduced a new W/O-GST/TaO/W cell structure and found further decrease of programming current the improved stability in the fabrication process. We analyzed the mechanism by which oxygen in GST and the additional TaO layer reduce the power consumption during SET/RESET operations.
We investigate the metallicity of the narrow line regions (NLRs) of high-z radio galaxies (HzRGs), using new deep optical spectra of 9 HzRGs obtained with FORS2 on VLT and data from the literature. To estimate the metallicity of NLRs we focus on the Civ/Heii and Ciii]/Civ flux ratios. Based on comparison between the observed emission-line flux ratios and the prediction of our photoionization model calculations, we find no significant metallicity evolution in NLRs of HzRGs, up to z ~ 4. We discuss the possibility that massive galaxies had almost completed the major epoch of the star formation in the very high-z universe (z > 5).
Chemical properties of AGNs and their redshift evolution are of interest to understand the star-formation history of AGN host galaxies and the co-evolution between galaxies and supermassive black holes (SMBHs). One important observational clue on this issue is a tight correlation between the AGN luminosity and the metallicity of the broad-line region. Surprisingly this relation shows no redshift evolution, even up to z ~ 6. This correlation is attributable mainly to the positive correlation between metallicity and SMBH mass, rather than to the relation between metallicity and Eddington ratio. A significant positive correlation between the metallicity and the AGN luminosity is also seen in narrow-line regions, not only in broad-line regions. Possible implications of these results on the galaxy–SMBH co-evolution are briefly mentioned.