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The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
A modification of the scanning X-ray topographic camera, is reported. The specimen and photoplate are traversed back and forth independently in two directions rather than in the same direction as in the case of Lang’s camera. The distortions of the photographs caused by geometrical arrangement can be eliminated through this construction so as to have a one-to-one correspondence. Examples of reflection photographs as well as transmission photographs are shown. Some of them are compared with those taken using Lang’s camera. The dislocation images in the reflection photographs show a good one-to-one correspondence to those in the transmission photographs. The broadening of the dislocation images in the traversing direction is discussed. The present camera is especially useful for the studies of lattice defects in the thick specimens because the reflection photographs can be easily taken.
The Fuji Imaging Plate (IP) is a 2-dimensional detector in which a latent X-ray image is stored as a distribution of color centers on a photostimulable phosphor (BaFBr:Eu2+) screen. It has a large effective area, wide dynamic range and high sensitivity. Thus it has been widely used not only in medical but also in scientific and industrial fields. Particularly in X-ray structure analysis, mainly of proteins, it has been used extensively and achieved good results.
On the other hand, few applications have been reported in the field except for structure analysis, in spite of the superior performance of the IP which will give significant advantages in various measurements which have been done using an X-ray film such as electric device and fiber specimen.
Therefore we report here the basic performance of R-AXIS II(Rigaku Automated X-Ray Imaging System II), an IP reader made by Rigaku, and some applications of X-ray diffraction measurements using IP.
Soon after Von Laue's experiment of X-ray diffraction in 1912, a similar experiment was conducted in Japan by Prof. Terada at University of Tokyo. He made direct observation of Laue spots from rock-sault on a fluorescent screen. In 1914, Prof. Nishikawa also at University of Tokyo photographed Laue spots of spinel. The X-ray generator employed was one designed for medical use. The first X-ray diffractometer in Japan was fabricated in the 1920s at the Institute of Physical and Chemical Research, It was designed with reference to Bragg's spectrometer using an ionization chamber as the X-ray detector.
In 1932, X-ray generators and cameras were manufactured by Rigaku Denki Mfg., the predecessor of the present Rigaku Corporation, Shimazu Mfg. and some other few companies. X-ray tubes at the time were Coolidge type demountable tubes.
For time-resolved diffraction studies under high temperature and/or high pressure, we designed a new diffractometer incorporating a curved position sensitive detector and tested the rapid intensity measurement and the resolution of the angular dispersive diffraction. The diffraction profiles were compared with those from energy dispersive diffraction. Rapid intensity collection has been carried out with a CAMAC module. A curved position sensitive detector with a 120° working angular region was installed on the off-centered four circle diffractometer. Only a few seconds were needed to obtain a whole powder diffraction because of the extremely high counting efficiency due to the streamer mode.
Time-resolved observations of the dehydration reactions of Mg(OH)2 and Ca(OH)2, have been undertaken by angular dispersive and energy dispersive x-ray powder diffraction at high temperature. The in situ observations of the dehydration process provide kinetic information, such as the reaction rate, the apparent activation energy and the dehydration mechanism.
In modern technology, thin-layered materials with layer thickness in nanometer ranges have been utilized for various advanced components such as integrated circuits, magnetic heads and disks, X-ray mirrors and coated window glasses. For the analysis of such materials, powerful probes, fluorescence(TXRF)1), diffraction(TXRD) 2-4) and reflectivity(GIXR) 5-7), formed by X-rays in conjunction with total reflection phenomena can provide important information on element composition, crystalline structure, layer thickness, electron density and interfacial roughness.
This paper reexamines the Serendipity Theorem of Samuelson (1975) from the stability viewpoint, and shows that, for the Cobb–Douglas preference and CES technology, the most-golden golden-rule lifetime state being stable depends on parameter values. In some situations, the Serendipity Theorem fails to hold despite the fact that steady-state welfare is maximized at the population growth rate, since the steady state is unstable. Through numerical simulations, a more general case of CES preference and CES technology is also examined, and we discuss the realistic relevance of our results. We present the policy implication of our result, that is, in some cases, the steady state with the highest utility is unstable, and thus a policy that aims to achieve the social optima by manipulating the population growth rate may lead to worse outcomes.
We aimed to examine missing data in FFQ and to assess the effects on estimating dietary intake by comparing between multiple imputation and zero imputation.
We used data from the Okazaki Japan Multi-Institutional Collaborative Cohort (J-MICC) study. A self-administered questionnaire including an FFQ was implemented at baseline (FFQ1) and 5-year follow-up (FFQ2). Missing values in FFQ2 were replaced by corresponding FFQ1 values, multiple imputation and zero imputation.
A methodological sub-study of the Okazaki J-MICC study.
Of a total of 7585 men and women aged 35–79 years at baseline, we analysed data for 5120 participants who answered all items in FFQ1 and at least 50% of items in FFQ2.
Among 5120 participants, the proportion of missing data was 3·7%. The increasing number of missing food items in FFQ2 varied with personal characteristics. Missing food items not eaten often in FFQ2 were likely to represent zero intake in FFQ1. Most food items showed that the observed proportion of zero intake was likely to be similar to the probability that the missing value is zero intake. Compared with FFQ1 values, multiple imputation had smaller differences of total energy and nutrient estimates, except for alcohol, than zero imputation.
Our results indicate that missing values due to zero intake, namely missing not at random, in FFQ can be predicted reasonably well from observed data. Multiple imputation performed better than zero imputation for most nutrients and may be applied to FFQ data when missing is low.
Clinical trials show that protein supplement increases infant size in malnourished populations; however, epidemiological studies in high-income countries have reported mixed results. Although these findings suggest a non-linear relationship between maternal macronutrient intake and fetal growth, this relationship has not been closely examined. We assessed the association between maternal protein intake and fetal growth among 91 637 Japanese women with singletons in a nation-wide cohort study using validated FFQ. The respondents answered the FFQ twice, once during early pregnancy (FFQ1; 16·3 (sd 6·0) weeks), and second during mid-pregnancy (FFQ2, 28·1 (sd 4·1) weeks). Daily energy intake and percentage energy from protein, fats and carbohydrates were 7477 (sd 2577) kJ and 13·5 (sd 2·0), 29·5 (sd 6·5) and 55·3 (sd 7·8) %, respectively, for FFQ1, and 7184 (sd 2506) kJ and 13·6 (sd 2·1), 29·8 (sd 6·6) and 55·3 (sd 7·9) %, respectively, for FFQ2. The average birth weight was 3028 (sd 406) g, and 6350 infants (6·9 %) were small for gestational age (SGA). In both phases of the survey, birth weight was highest and the risk of SGA was lowest when the percentage energy from protein was 12 %, regardless of whether isoenergetic replacement was with fat or carbohydrates. Furthermore, when protein density in the maternal diet was held constant, birth weight was highest when 25 % of energy intake came from fat and 61 % came from carbohydrates during early pregnancy. We found maternal protein intake to have an inverse U-curve relationship with fetal growth. Our results strongly suggest that the effect of protein on birth weight is non-linear, and that a balanced diet fulfilling the minimum requirement for all macronutrients was ideal for avoiding fetal growth restriction.
The piezoelectric properties of lead-free ferroelectric materials have been dramatically improved over the past two decades. For some limited applications, their properties have reached the same levels or have even surpassed the properties of the benchmark lead-based material Pb(Zr,Ti)O3 (PZT). Initial commercial lead-free products, including powders, ceramic components, films, and devices (e.g., ultrasonic cleaner, knocking sensor), are now available on the market. Several prototype devices, such as inkjet printheads, ultrasonic motors, angular sensors, and energy harvesters, have been developed. Their overall performance is still inferior to that of PZT-based devices; however, these prototypes and products point the way for future applications. Here, we provide an overview of recent industrial developments in the field and discuss the main advantages and disadvantages of lead-free piezoceramics for individual applications.