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This study examines the relationship between paternal height or body mass index (BMI) and birth weight of their offspring in a Japanese general population. The sample included 33,448 pregnant Japanese women and used fixed data, including maternal, paternal and infant characteristics, from the Japan Environment and Children’s Study (JECS), an ongoing nationwide birth cohort study. Relationships between paternal height or BMI and infant birth weight [i.e., small for gestational age (SGA) and large for gestational age (LGA)] were examined using a multinomial logistic regression model. Since fetal programming may be a sex-specific process, male and female infants were analyzed separately. Multivariate analysis showed that the higher the paternal height, the higher the odds of LGA and the lower the odds of SGA in both male and female infants. The effects of paternal BMI on the odds of both SGA and LGA in male infants were similar to those of paternal height; however, paternal height had a stronger impact than BMI on the odds of male LGA. In addition, paternal BMI showed no association with the odds of SGA and only a weak association with the odds of LGA in female infants. This cohort study showed that paternal height was associated with birth weight of their offspring and had stronger effects than paternal BMI, suggesting that the impact of paternal height on infant birth weight could be explained by genetic factors. The sex-dependent effect of paternal BMI on infant birth weight may be due to epigenetic effects.
The near-infrared absorption line Fe I 15648 Å, which has a Landé g-factor of 3, shows a particularly large Zeeman splitting. We regularly take full-disk polarization maps of the Sun in the Fe I 15648 Å line (as well as the He I 10830 Å line) with an infrared spectropolarimeter installed at the Solar Flare Telescope of the National Astronomical Observatory of Japan (NAOJ). It is known that weak, mostly horizontal magnetic fields are ubiquitously distributed in the quiet regions of the Sun, while the strong magnetic fields are concentrated in active regions and network boundaries. The weak horizontal field has not been sufficiently investigated due to the difficulty of such observations. The polarization maps in Fe I 15648 Å show the magnetic field strength at each pixel, regardless of the filling factor, so we can easily isolate the weak horizontal field signals from strong magnetic field ones using the Stokes V profiles of the Fe I 15648 Å line. Here we present instrumental aspects and observational results of solar near-infrared full-disk polarimetry. We highlight the weak horizontal field inferred from Fe I 15648 Å.
Asiatic black bears Ursus thibetanus are threatened in Japan but are generally considered to be nuisance animals because of the damage they cause to agriculture and property, and because they cause human casualties. We analysed media coverage of black bears in Japan to understand social discourse and potential influences on public perceptions about conservation of bears. Content analysis of a total of 348 articles in a local and a national newspaper revealed that the number of articles regarding black bears and the proportion of negative articles that describe the risks posed by bears increased concomitant with a rise in sightings of bears. Local newspapers included more articles about the risks posed by bears than national newspapers. This potentially reflects and can amplify local residents' perceptions of risk. The proportion of thematic and episodic articles was unrelated to increases in bear appearances. More extensive communications with media representatives by biologists, government officials and police are needed to enhance public knowledge of bears and lead to broader perspectives on their management.
(Na,K)NbO3 is a promising candidate for lead-free piezoelectric materials. (Na1-xKx)NbO3 films (x = 0.3–0.7) were epitaxially grown on a (100)SrTiO3 substrate via pulsed laser deposition. The effects of substrate temperature and oxygen pressure during deposition on the crystallinity of the films were examined: both parameters affected the mosaic spread of the crystallites and the formation of an impurity phase. In this study, the optimum conditions for the preparation of highly crystalline films were a substrate temperature of 800 °C and oxygen pressure of ∼60 Pa. The lattice constants parallel and perpendicular to the substrate surface responded differently to changes in x: the constant parallel to the surface increased with increasing x, while the constant perpendicular to the surface was maximized at x = 0.5. The difference in the dependence of the lattice constants could be explained by the elastic distortion of the lattice.
In order to measure precisely the polarization of Crab Nebula and Cygnus X-1, we have been developing a hard X-ray polarimeter for balloon-borne experiments called PHENEX (Polarimetry of High ENErgy X-rays). It consists of several detectors called unit counters. The unit counter has a detection efficiency of 20% and a modulation factor of 53% at 80 keV. Up to now, we have finished the installation of eight unit counters to the polarimeter, that will be launched in Spring 2009 to observe the Crab Nebula. If the polarization of this source is more than 30%, the PHENEX polarimeter will be able to measure the degree and the direction of the polarization with errors less than 10% and 10°, respectively.
X-ray astronomy has been much advanced by three observations: spectroscopy, timing, and imaging. Also in the hard X-ray region, these three observations will be realized by ASTRO-H and XEUS. However, the observation of the polarization is at the moment left out in spite of its potential usefulness. This is because of the difficulty of developing polarimeters with high sensitivity. Since the origin of the polarization is often due to nonthermal radiation processes such as synchrotron radiation, observations in the hard X-ray region are possibly more important than those in the soft X-ray region: it is expected that the degree of polarization in the hard X-ray region would be higher than that at lower energies.
We study pressure-induced structural phase transition of carbon nanotubes using the constant-pressure tight-binding molecular-dynamics simulation. The systems studied are nanotube bundles composed of (6,6) armchair nanotube and/or (7,4) chiral nanotube, which are reported to be the nanotubes relatively abundant in experimentally purified sample. We find that the nanotube bundles transforms into a new phase that consist of graphitic ribbons and diamond blocks, “graphitic nanoribbon solid”. It is also found that sp3-rich phases obtained from the armchair nanotubes possess an anisotropic network and have high hardness which is comparable to that of cubic diamond. In the case of the bundles containing chiral nanotubes, on the other hand, amorphous diamond phase is obtained. Based on the local-density approximation in the density-functional theory, we also investigate the energetics and electronic structure of some of new carbon phases obtained in the molecular-dynamics study.
We propose new measurement system for direct detection of WIMPs with directional information using nano imaging tracker (NIT) and X-ray microscope. The NIT made of fine grains of emulsion has a good spatial resolution of several tens nanometer and the X-ray microscope can work as a readout instrument for sub-micron track structure instead of ordinary optical microscope. Wolter type-I fluorescence X-ray microscope utilizing Ag-L line can be applied to this system. Crucial issues are reduction of background event due to random fog and to develop fast selection method of WIMP event candidates.
We have grown device-grade Cu(In,Ga)Se2 (CIGS) thin films using a RF-cracked Se-radical beam source. A unique combination of film properties: smooth surface, large grain size and high photovoltaic performance are shown. A competitive energy conversion efficiency of 17 % has been demonstrated from a solar cell fabricated using a CIGS absorber grown with a Se-radical source. In addition to the unique combination of film properties and high photovoltaic performance, a significant improvement in the use of Se source material in comparison with the conventional Se-evaporative sources has been demonstrated.
We investigated electric and chemical properties of metal/Y2O3 interfaces. The Pt/Y2O3 interface can be chemically activated by bias voltage, resulting in a microscopic oxidation-reduction center at interface. The oxidation-reduction of the center alternatively changed resistance of the Pt/Y2O3 system, and the alternation yield hysteresis with respect to the bias voltage, i.e. a memory effect. On the other hand, in Au/Y2O3 system, non-oxidization of Au induced ejection of O2 gas from the interface, so that there was no memory effect. Possible reactions of these metal/Y2O3 systems were proposed, and the balance between oxidation and reduction at microscopic center was concluded to be essential for the memory effect.
Dependence of band alignments at interfaces between CdS by chemical bath deposition and Cu(In1-xGax)Se2 by conventional 3-stage co-evaporation on Ga substitution ratio x from 0.2 to 1.0 has been systematically studied by means of photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). For the specimens of the In-rich CIGS, conduction band minimum (CBM) by CIGS was lower than that of CdS. Conduction band offset of them was positive about +0.3 ~ +0.4 eV. Almost flat conduction band alignment was realized at x = 0.4 ~ 0.5. On the other hand, at the interfaces over the Ga-rich CIGS, CBM of CIGS was higher than that of CdS, and CBO became negative. The present study reveals that the decrease of CBO with a rise of x presents over the wide rage of x, which results in the sign change of CBO around 0.4 ~ 0.45. In the Ga-rich interfaces, the minimum of band gap energy, which corresponded to energy spacing between CBM of CdS and valence band maximum of CIGS, was almost identical against the change of band gap energy of CIGS. Additionally, local accumulation of oxygen related impurities was observed at the Ga-rich samples, which might cause the local rise of band edges in central region of the interface.
In-situ characterization of composition, electronic structure and their depth profiles of surface of Cu(In1-xGax)Se2 (CIGS) film grown by three stage co-evaporation has been carried out by means of photoemission and inverse photoemission spectroscopy (PES/IPES), for the purpose of investigating the formation mechanism of the CIGS-side wide band-gap region adjacent to CBD-CdS/CIGS interface in cell structure. Sample-transportation in vacuum below 1 x 10-8 Torr yielded almost contamination-free feature of the CIGS surface. The as-transferred surface of Cu0.93(In0.65Ga0.35)Se2 grown at the identical condition for the high performance solar cell exhibited seriously Cu and Ga deficient composition. Chemical formula of this region was inbetween Cu : (In+Ga): Se = 1 : 3 : 5 and 1 : 5 : 8. In-situ UPS/IPES measurements CIGS showed that the as-grown surface region of the CIGS already had expanded band gap energy up to 1.4 eV and n-type character. A gradual decrease of band energy and a rise of valence band maximum as a function of depth from the original surface were observed. These results have revealed that the surface of CIGS by the three stage method already has the wide band gap, which might originate in so-called Cu-vacancy ordered phase.
For understanding the origin of the improvements of properties in the CIGS-based cells, of which the CIGS absorber has been fabricated by H2O-introduced co-evaporation [CIGS-H2O], band alignment at the interfaces between chemical bath deposited CdS and CIGS-H2O with Ga substitution ratio ~ 40 % has been studied by photoemission and inverse photoemission spectroscopy. The CdS layer over the CIGS-H2O showed an identical electronic structure with that of CdS on the conventionally grown CIGS; band gap energy of 2.3 ~ 2.4 and a location of conduction band minimum (CBM) and valence band maximum (VBM) relative to Fermi level were + 0.75 eV and -1.6 ~ -1.7 eV, respectively. In the interface region, decreases of CBM and a rise of VBM were observed. Total amount of the decrease of CBM over the interface was 0.2 ~ 0.3 eV. XPS measurements of the core-level signals over the interface showed a small upward bend bending of 0.1 ~ 0.2 eV. Consequently, the conduction band offset (CBO) and valence bad offset (VBO) at the CBD-interface over the CIGS-H2O (Ga~40%) are about +0.1, and 0.9 ~ 1.1 eV, respectively. This positive CBO is contrast with a slightly negative CBO at the interface between CBD-CdS/conventionally grown CIGS with Ga ~ 40 % measured previously. These results indicate that the H2O introduction is effective to extend the upper limit of the Ga substitution ratio where the Type-I conduction band alignment is maintained. The observed band alignments are consistent with the rise of Voc and efficiency in the CIGS-H2O based cells.
Three-dimensional magnetohydrodynamics of the Solar coronal plasma is investigated by numerical simulation, aiming to understand the mechanisms of the Solar flare onset. It is demonstrated by the simulations that the resistive tearing mode instability growing on the magnetic shear inversion layer can drive the large-scale eruption through the mutual excitation of double reconnections. It is also revealed that the instability is able to cause the magnetohydrodynamic energy relaxation, in which the typical sigmoidal structure is self-organized prior to the onset of eruption. The simulation results predict that both the formation of sigmoids and the onset of flares should occur around the electric current sheet where the magnetic shear is steeply reversed. It is consistent with the reversed-shear flare model and the vector magnetograph observations.
Direct characterization of band alignment at chemical bath deposition (CBD)-CdS/Cu0.93 (In1-xGax)Se2 has been carried out by photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). Ar ion beam etching at the condition of the low ion kinetic energy of 350 eV yields a removal of surface contamination as well as successful measurement of the intrinsic properties of each layer and the interfaces. Especially interior regions of the wide gap CIGS layers with a band gap of 1.4 ∼ 1.6 eV were successfully exposed. IPES spectra revealed that the conduction band offset (CBO) at the interface region of the wide gap CIGS with x = 0.60 and 0.75 was negative, where the conduction band minimum of CdS was lower than that of CIGS. It was also observed that the energy spacing between conduction band minimum (CBM) of CdS layer and valence band maximum (VBM) of Cu0.93(In0.25Ga0.75)Se2 layer at interface region was no wider than that of the interface over the Cu0.93(In0.60Ga0.40)Se2 layer.
Zn1-yMgyO bandgap controllable transparent conducting films were used for the wide-gap Cu(In1-xGax)Se2 thin film solar cells. Undoped Zn1-yMgyO and Al doped Zn1-yMgyO films were deposited by co-sputtering using a carousel type sputtering apparatus. Zn1-yMgyO films with Mg content y of up to 0.10 were examined. For Cu(In1-xGax)Se2 with band gap energy ˜1.38 eV, the cell performance was slightly improved by using Zn1-yMgyO and Al doped Zn1-yMgyO instead of ZnO and Al doped ZnO. An unexpected improvement of short circuit current density was observed.
A 2-dimensional Doppler coronagraph “NOGIS” (NOrikura Green-line Imaging System) at the Norikura Solar Observatory, NAOJ, is a unique imaging system that can provide both intensity and Doppler velocity of 2 MK plasma from the green coronal line emission $\lambda$5303 Å of Fe xiv. We present the first detection of a CME onset by NOGIS. The event was originally induced by a C9.1 confined flare that occurred on 2003 June 1 at an active region NOAA $\#$10365 near the limb. This flare triggered a filament eruption in AR 10365, which later evolved into a partial halo CME as well as an M6.5 flare at the same AR 10365 on 2003 June 2. The CME originated in a complex of two neighboring magnetic flux systems across the solar equator: AR 10365 and a bundle of face-on tall coronal loops. NOGIS observed i) a density enhancement in between the two flux systems in the early phase, ii) a blue-shifted bubble and jet that later appeared as (a part of) the CME, and iii) a red-shifted wave that triggered a periodic fluctuations in Doppler shifts in the face-on loops. These features are crucial to understand unsolved problems on a CME initiation (e.g., mass supply, magnetic configuration, and trigger mechanism) and on coronal loop oscillations (e.g., trigger and damping mechanisms). We stress a possibility that interaction between separatrices of the two flux systems played a key role on our event.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html
This study compares the management performance of timber production among three management systems in Nepal: private forestry, community forestry with collective management, and community forestry with centralized management. While collective management relies entirely on community labor for the whole management, centralized management uses community labor for the protection of forests and hired labor for silvicultural operations, for example weeding, pruning, and thinning. We found that collective community management is less costly for the protection of planted trees but allocates less labor for the management of trees than private management. We also found that centralized management of natural forests leads to higher revenue and profit than collective management. These findings support the hypothesis that, while collective management is more efficient than private management for the protection of trees due to effective mutual supervision, profit-seeking private management or centralized management is more efficient than collective management for silvicultural operations due to superior work incentives. This study, however, failed to compare efficiency of private and centralized management.
Low resistivity and transparent Al doped ZnMgO films were deposited on glass substrates by a pulsed laser deposition system. For up to 32 atm% of Mg content, segregation of a MgO phase was not observed. The bandgap of these films could be widened to about 4 eV with increasing Mg content. The relation between bandgap and resistivity was found to be a trade-off; i.e. the larger the bandgap, the higher the resistivity. The maximum bandgap among films with an electrical resistivity of less than 10-3 Ω cm was 3.94 eV. The average optical transmittance of these films was more than 90 % for wavelengths λ between 400 and 1100 nm. The transmittance around λ = 330 nm was still 50 %.