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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 Zn-bearing beaverite of Sato et al. (2008) has been named ‘beaverite-(Zn)’ in accordance with the alunite supergroup nomenclature of Bayliss et al. (2010), and data for the mineral have been approved by the IMA-CNMNC. Beaverite-(Zn) occurs as a dark-brown secondary mineral in the hydrothermal Cu-Zn-Pb ore deposit of the Mikawa mine, Niigata Prefecture, Japan. Electron microprobe analysis gave an empirical formula of Pb0.95(Fe1.88Al0.10)(Zn0.83Cu0.03)(SO4)2[(OH)5.36O0.38] on the basis of S = 2. The Rietyeld analysis (Sato et al, 2008) indicated it to be trigonal, R3̄m, a = 7.3028(2), c = 17.0517(4) Å, V = 787.56(4) Å3.
IAU Commission 28 (IAU C28: Galaxies) was founded in the late 1930s at which time it had only a small membership (see the historical notes by Sadler et al. 2007). When C28 ended its existence in 2015 there were well over 1000 members on its books. The membership had grown to the point where the effort to keep track of active participants had become a major task. During the C28s tenure 27 IAU Symposia have been devoted to galaxies, the third highest number (Mickaelian 2014)
We have been monitoring the flux density of Sagittarius A* (Sgr A*) at 22 GHz since DOY=42 (11 Feb. 2013) with a sub-array of the Japanese VLBI Network in order to search the increase of 22-GHz emission from Sgr A* induced by the interaction of the G2 cloud with the accretion disk. The flux densities observed until DOY=322 (18 Nov. 2013) are consistent with the previously observed values before the approaching of the cloud. We have detected no large flare during this period.
The membership of Commission 28 is so large, and the spread of research interests so broad, that the research highlights presented here of necessity represent just a small subset of the work carried out over the past three years. Progress in the area of galaxy evolution continues to be particularly rapid, driven by both the availability of new multi-wavelength survey data and the development of increasingly sophisticated simulations to model the complex behaviour of stars and gas (e.g. Agertz et al. 2011; Guo et al. 2011; Keres et al. 2009; Schaye et al. 2010).
An induced mutant of rice, designated M41, resistant to several races of bacterial leaf blight, obtained after irradiation with thermal neutrons, was crossed with the original variety, Harebare. Test crosses revealed that the resistance of M41 to the Japanese races I, II, III and IV is controlled by a single recessive gene, considered to be different from four previously identified dominant resistance genes of japonica-type varieties and from three recessive genes in indica-type varieties for resistance to Philippine races. The gene in M41 was tentatively designated xa-nm(t).
Recent direct-drive implosion experiments on the GEKKO XII laser with plastic hollow shell targets demonstrated compressed densities of ∼600 g/cm3 (∼600 times liquid density) at a temperature of ∼0.3 keV. The highly compressed core plasmas are indicated to be strongly coupled (average Coulomb energy/thermal energy ≈5) and partially degenerate (thermal energy/Fermi energy ≈0.3). The diagnostic method based on the secondary nuclear fusion reactions is presented to prove the electron degeneracy in the highly compressed core plasma. The yield ratio of the secondary DT neutrons to the primary DD neutrons in such highly compressed core plasmas was calculated with inclusion of the strong Coulomb-coupling effects, the varied degrees of the electron degeneracy, and the electronic shielding effects. It was found in our calculations that there is a significant dependence of the yield ratio on the compressed core density. For the plastic targets at the electron temperature of ∼0.3 keV, the yield ratio increases from 9 × 10−4 to 8 × 10−3 for densities from 10 to 1000 g/cm3. The preliminary experiments using deuterated plastic hollow shell targets suggested that the enhancement of the yield ratio provided evidence of the electron degeneracy.
Direct-drive implosion experiments on the GEKKO XII laser (9 kJ, 0.5 μm, 2 ns) with deuterium and tritium (DT) exchanged plastic hollow shell targets demonstrated fuel areal densities (ρR) of ˜0.1 g/cm2 and fuel densities of ˜600 times liquid density at fuel temperatures of ˜0.3 keV. (The density and ρR values refer only to DT and do not include carbons in the plastic targets.) These values are to be compared with thermonuclear ignition conditions, i.e., fuel densities of 500–1000 times liquid density, fuel areal densities greater than 0.3 g/cm2, and fuel temperatures greater than 5 keV. The irradiation nonuniformity in these experiments was significantly reduced to a level of <5% in root mean square by introducing random-phase plates. The target irregularity was controlled to a 1% level. The fuel ρR was directly measured with the neutron activation of Si, which was originally compounded in the plastic targets. The fuel densities were estimated from the ρR values using the mass conservation relation, where the ablated mass was separately measured using the time-dependent X-ray emission from multilayer targets. Although the observed densities were in agreement with one-dimensional calculation results with convergence ratios of 25–30, the observed neutron yields were significantly lower than those of the calculations. This suggests the implosion uniformity is not sufficient to create a hot spark in which most neutrons should be generated.
The conventional implosion scheme for high gain and high density compression depends upon the piston action of an accelerated heavy pusher. However, the contact surface between the pusher and the fuel layer is very unstable in the stagnation phase. In this paper, the laser pulse tailoring and the scaling laws for pellet gain, fuel ρR, etc. are discussed under the condition of very weak piston action of the pusher. The scaling laws indicate that the fuel will be ignited by 100 kJ, 0·35 μm wavelength laser irradiation.
In the last few years, systematic studies on radiation hydrodynamics in the X-ray confining cavity and a fuel capsule have attained remarkable progress. This makes it possible to analyze quantitatively the energy transfer processes from laser to the fusion capsule and find uniform irradiation conditions of the fusion capsule driven by thermal X rays. As a result, reproducible and stable implosions were achieved. Throughout implosion experiments with the Gekko XII blue laser system (351 nm, kJ, 0.8 ns), good agreement of implosion has been obtained between the experiment and numerical simulations, assuming perfectly spherical symmetry, up to a radial convergence ratio of 15. Described are particularly the issues of (1) energy transfer processes from laser to a fuel capsule and conditions for uniform irradiation, (2) properties of the X-ray propagation through aluminum heated by X-ray radiation, and (3) dependence of the convergence ratio of Ri/Rf (where Ri and Rf are the initial and final radii) of the capsule on the initial fill pressure of D–T gas and its influence on the core parameters and fusion products to evaluate implosion sphericity.
The recent progress of laser fusion research has been remarkable in obtaining the high density of more than 100 times solid density (Nakai et al. 1988) and high temperature plasma producing thermonuclear neutrons of 1013 per shot (pellet gain of 0·2%) (Yamanaka et al. 1986a) and in the understanding of the implosion physics. The data bases of the laser fusion are rapidly being accumulated and the technologies for the advanced experiments have been developed, both of which enable us to proceed toward the fusion ignition experiment and the achievement of the breakeven conditions.
In order to enhance the coupling efficiency, a low Z ablator is generally used for ICF targets. The ablator thickness is appropriately chosen so it is burned out by the end of a laser pulse. Then all of the implosion kinetic energy is contained in the DT fuel. However, a small amount of preheating degrades the compression in a hollow shell, DT fueled target implosion. In this paper, we investigate the preheating level of the fuel shell by Fokker–Planck simulations of the electron heat transport.
From the analysis, it is found that a thick surface layer of a laser irradiated low-Z target is preheated by Maxwellian tail electrons which have a long mean free path. Hence, we propose that the target be precompressed by a tailored pulse, in order to increase the shell ρΔR at the laser peak.
Plasmas with long life times (∼20 ns) are generated in a cavity target by intense CO2 laser pulses (2 × 1014W/cm2). The plasma life depends on the configuration of irradiation and target, which may infer thermal conduction inhibition by the laser-generated magnetic field. The experimental results agree with those of computer simulations with magnetic inhibition of thermal conduction.
Recent progress in research on Light Ion Beams-Inertial Confinement Fusion (LIB-ICF) at ILE, Osaka University is summarized. We report on pulsed power compression using PEOS, a super high voltage source, on diode physics, on beam trajectory control for focusing, on beam-target interactions and on a conceptual reactor design (Rokko I) in this article.
Emissions from the rear side of the targets were temporally resolved by irradiating an ultraviolet (UV) laser on Al and Au thin targets. A difference was clearly observed between the above two targets. Given the fact that absorbed laser energy is converted with a very high efficiency to soft x-rays in a high Z plasma, a characteristic emission peak only observed for Au targets was attributed to the effect of soft x-ray energy transport. The ablation pressures estimated from the emissions indicate that the pressure scaling for Au is close to the one by x-ray radiation rather than by a UV laser. With soft x-ray irradiation, energy transport in A1 foils was also studied. An ablation pressure was estimated by the shock speed.
Light ion beams for the energy drive for inertial confinement fusion (ICF) research have been studied on a super high voltage generation system (SHVS) using an inductive voltage adder system. A simple analysis implied the capability of the output voltage of several tens of MV. This system has a feasibility of acceleration of ions heavier than proton. The two-stage charge stripping ion diode is considered a SHVS diode. This diode reduces the size of the induction adder module and extends the possible power range in operation. We have constructed a prototype SHVS, which consists of eight stages of induction cavities (4MV, 40kA, 100ns) powered by a Reiden IV pulse power machine. The first ion diode experiments on the induction adder were performed with the beam extraction type ion diode (Br applied magnetic field). The injection plasma ion source was used to control the diode impedance and then the diode voltage. The time delay of ion current turn-on was reduced from 15–20 ns to less than 5 ns by this ion source.
The wavelength scalings of soft X-ray and hot electron generation efficiencies were studied using 1·05, 0·53, 0·35 and 0·26 μm lasers. A coupling efficiency from absorbed laser energy to compressed fuel core of 4.5% was obtained by using the GEKKO XII green laser.