Development of a CO2 gas analyzer for monitoring soil CO2 concentrations

Measurement of soil CO₂ concentrations is important for investigating the dynamics and diffusion of CO₂ in soil. In this study, we developed a small CO₂ analyzer for measuring in situ-soil CO₂ concentrations. The CO₂ analyzer consists of a module containing an infrared CO₂ gas sensor, a temperature sensor, and a relative humidity sensor. These sensors are installed in a protective box with an air vent, which is suitable for burying in the soil. The output response time of the CO₂ analyzer was 349 s, as evaluated from the phase lag after input of known CO₂ concentrations. This response time is short enough to measure soil CO₂ concentrations, because variations in concentration are slower than the response time of the analyzer. In a field test, we used the CO₂ analyzer to measure soil CO₂ concentrations at five depths (0–50 cm) over 2.5 months. While the CO₂ concentration generally increased with depth, the amplitude of the variation in CO₂ concentration decreased with depth. The phase lag of the variations in soil CO₂ concentration also increased with depth, as did soil temperature. The tests confirm that the CO₂ analyzer is applicable to continuous monitoring of soil CO₂ concentrations.     

Mapping a diploid wheat abscisic acid 8′-hydroxylase homologue in the seed dormancy QTL region on chromosome 5A<Superscript>m</Superscript>

In Arabidopsis, two genes of abscisic acid (ABA) 8′-hydroxylase (cytochrome P450 (CYP) 707A1 and A2) have been found to play important roles in seed dormancy through the regulation of ABA content in seeds. In order to examine the role of wheat ABA 8′-hydroxylase gene in seed dormancy, a diploid wheat ABA 8′-hydroxylase gene was cloned that showed high similarity to a barley ABA8′-hydroxylase gene (HvABA8′OH-2), and the cloned gene was designated as TmABA8′OH-2. Using recombinant inbred lines derived from a cross between diploid wheat Triticum boeoticum L. (Tb) and Triticum monococcum L. (Tm), TmABA8′OH-2 has been mapped to near the centromeric region of the long arm of chromosome 5A^m, where the major seed dormancy QTL has been previously found. Comparison of the deduced amino acid sequences of TmABA8′OH-2 between Tb and Tm revealed five amino acid residue substitutions. These amino acid residues have distinctly different characteristics, and one of the substitutions occurs in the highly conserved amino acid residues in CYP707A family, indicating that these substitutions may have effects on the enzyme activities. Moreover, hexaploid wheat TmABA8′OH-2 homologue revealed that the level of its expression during seed development peaks at mid-maturation stage. This resembles the expression pattern of the Arabidopsis CYP707A1, which was shown to control seed dormancy. These results imply a possibility that TmABA8′OH-2 might be involved in seed dormancy, and associated with the QTL on chromosome 5A^m.     

Numerical assessments of the impacts of climate change on regional groundwater systems in a paddy-dominated alluvial fan

Quantitative assessment of the impacts of climate change on groundwater levels is important for sustainable groundwater use. This study examined the Tedori River alluvial fan in Ishikawa Prefecture, Japan, where paddy fields occupy 45 % of the total area. A regional groundwater flow model simulated future groundwater levels in response to 38 climate change projections generated for each of three GCMs, using three GHG emission scenarios with the ELPIS-JP datasets. The numerical groundwater flow model consisted of a 1-D unsaturated water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Variable parameters consisted of daily air temperature, precipitation, humidity, solar radiation, and wind speed, which influence groundwater through infiltration, evapotranspiration, snowfall, and snowmelt. Groundwater levels had both decreasing and increasing trends, depending on climate change. There were more decreasing than increasing trends, and the maximum groundwater drawdown during 2010–2090 was ~1 m. Groundwater level was most sensitive to change in rate of precipitation during the non-irrigation period. Variations of relatively low-intensity precipitation days, when daily precipitation was <10 mm, had an effect on groundwater level. These results contribute to development of adaptive and sustainable groundwater managements (e.g. land use management and pumping strategies) in the future.     

Promotion of initial swim bladder inflation and effect of initial inflation failure on skeletal malformation in cultured seven‐band grouper Hyporthodus septemfasciatus (Thunberg)

The effects of the removal of the oily surface film on initial swim bladder inflation and survival in cultured seven‐band grouper Hyporthodus septemfasciatus were investigated during the larval stage. Additionally, the relationship between swim bladder inflation failure and malformations in later stages was examined. To explore promotion conditions for inflation, duplicate experiments were conducted under three different water surface conditions: removal of the oily surface film (ROF group), covering the water surface with an oil film (COF group), and sealing the water surface with liquid paraffin (SLP group). Larval swim bladder inflation was first observed 14 days after hatching (DAH) in the ROF group; thereafter, swim bladder inflation rates increased to 11.1% and 38.7% until the end of the experiments. This indicates that initial swim bladder inflation occurs at the pre‐flexion stage in larval development. Conversely, bladder inflation was rarely observed in the COF or SLP groups, indicating the promotional effect of surface film removal on larval swim bladder inflation and suggesting that gulping atmospheric air is necessary for initial inflation. Although larval water surface death occurred frequently in the ROF group, no significant difference existed in any group between the survival rates at 10 DAH and at the end of the experiment. The incidence rate of spinal curvature and deformation of the centra was significantly higher in individuals without initial swim bladder inflation, and these malformations mainly occurred in the caudal vertebra. Therefore, the removal of the oily surface film promotes initial swim bladder inflation and reduces larval malformations.     

The dynamic state of the ionome in roots,nodules, and shoots of soybean under different nitrogen status and at different growth stages

The relative distribution of 22 mineral elements in the roots, nodules and shoots of the soybean (Glycine max L. Merr. cv. Tsurumusume) at R1 (beginning of the flowering stage) and R7 (beginning of the mature stage) was investigated in response to ammonium and manure N treatment. Plants receiving only atmospheric nitrogen served as the negative control. The addition of ammonium sulfate to the soil caused soil acidification, induced Al and Mn toxicities, and significantly reduced the biomass production in roots and nodules. Ca, Mg, Fe, Mn, Cu, and Zn concentrations were significantly higher in shoots, and those of Mo and Co higher in nodules. The addition of manure to the soil significantly enhanced the levels of Sr, Ba, Cr, and Cd in shoots, whereas the concentration of Cs was decreased at R7. Moreover, when the soybean developed from R1 to R7, the levels of essential elements in nodules decreased, whereas those of nonessential elements increased, irrespective of the nitrogen source. Furthermore, the variation in the concentrations of many elements was not consistent for nodules and roots when soybean developed from R1 to R7. The variation of Mn, Zn, B, and Al concentrations was independent of N treatments. However, Ca, Fe, Cu, Mo, and Se levels were affected strongly by N treatments. This study is the first to document the dynamic variation of the soybean ionome in nodules, roots, and shoots from vegetative to reproductive stage of soybean.     

用城市规划方法来建造一个儿童化城市——对中国和日本几个不同居住区儿童游戏活动的调查研究( Ⅰ)(英文)

在城市规划的发展过程中,从儿童游戏空间的角度来审视城市,是最近才开始的研究课题．在未来的城市范围内,保存和发展儿童游戏空间尤为重要．我们称之为城市中的游戏场地．城市的发展容易造成游戏场地的消失．本文将首先对北京市（ 中华人民共和国） 和东京（ 日本国） 的四个地区进行比较．在此基础上,对城市化进程中,与游戏有关的儿童年龄结构进行分析,得出一些与环境有关的主题     

Multiresolutional image analysis of wood and other materials

The gloss of wood is a unique texture compared to that of other materials. To express it quantitatively, two digital-image analyses were performed. One method was multiresolutional contrast analysis, which was the new method developed in this study. The other method was fractal image analysis. Twenty-four specimens, including solid woods, wood-plastic composites (WPCs), printed grains, and granites, were prepared. Digital images of specimens were obtained in five sizes and in two illuminant directions (perpendicular and parallel to the grain). The multiresolutional contrast values of perpendicular illuminated images were calculated and compared among specimens. The result of this quantitative analysis was that the gloss of wood was characterized by bright spots in a relatively small area. Using fractal analysis, the fractal dimension of a digital image was used as an index of brightness changes, not for expressing the self-similarity. These indices showed results similar to those of the multiresolutional contrast analysis.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society in Kochi, April 1997