Sr Isotopic Signature in Plant-Derived Ca in Rain     

Takanori Nakano  Seo-Ryong Jeon  Junko Shindo  Tamon Fumoto  Naoki Okada  Jun Shimada 《Water, air, and soil pollution》2001,130(1-4):769-774

The ⁸⁷Sr/⁸⁶Sr ratios in rain at three sites in Japan were about 0.706 to 0.712, whereas those at one site in central Korea were higher (0.711 to 0.716), reflecting the difference in geology between the two countries. Because the ⁸⁷Sr/⁸⁶Sr ratios of exchangeable sites in soil minerals are indistinguishable from those of associated plants, aerosol Sr originating from both can be grouped together as plant-derived Sr. Spatial and temporal variations in ⁸⁷Sr/⁸⁶Sr and Sr/Ca ratios in the rain suggest the presence of plant-derived Sr and Ca in addition to Sr and Ca derived from sea-salt, acid-soluble aeolian carbonate from China, and cement-derived carbonate. However, systematic data on the ⁸⁷Sr/⁸⁶Sr ratios and elemental concentrations of soils, plants, fly-ash, and road dust are required to put reliable constraints on the provenance of atmospheric Ca.  相似文献   

Impact of nutrient enrichment in a waterchestnut ecosystem at Takahama-iri Bay of Lake Kasumigaura,Japan     

Hideo Nakano  Humitake Seki 《Water, air, and soil pollution》1981,15(2):215-227

The waterchestnut ecosystem of Lake Kasumigaura is at the climax stage of eutrophication. Organic debris in the ecosystem showed highly dynamic fluctuations throughout the year. This was chiefly attributed to high viable fractions of organic matter in the hypereutrophic water. The stability of steady-state equilibrium of organic debris was found to be maintained even in such a dynamic ecosystem, likely due to the precedence of heterotrophic processes over autotrophic processes. Using a mathematical model approximated by in situ data, the turnover time of organic solutes was analyzed to be between four and six months through these active heterotrophic processes.  相似文献   

Alanine racemase activity in the microalga <Emphasis Type="Italic">thalassiosira</Emphasis> sp.     

Takehiko?Yokoyama  Yumiko?Tanaka  Minoru?Sato  Nobuhiro?Kan-No  Toshiki?Nakano  Toshiyasu?Yamaguchi  Eizoh?NagahisaEmail author 《Fisheries Science》2005,71(4):924-930

ABSTRACT:   In this paper, the authors report the detection of alanine racemase activity in the marine diatom Thalassiosira sp. Since the Thalassiosira sp. was cultured under germ-free conditions, it appeared that D-alanine was not derived from bacteria but was produced through catalysis by algal alanine racemase. The rate of conversion of L-alanine to D-alanine was approximately the same as that for the reverse reaction, and the enzyme catalyzed the equilibration of the D- and L-forms. The crude enzyme preparation obtained from the cells at the stationary phase of the growth cycle had an optimal pH of approximately 9.5. The Lineweaver–Burk analysis showed that the K _m for D- and L-alanine was 16.5 mM and 29.4 mM, respectively. It appears that the enzyme is highly specific for D- or L-alanine because it does not catalyze the racemization of other amino acids. In addition, after gel filtration, the enzyme did not require exogenous pyridoxal 5'-phosphate (PLP) for its activity, however, the effects of several chemicals suggest that the enzyme may be PLP-dependent. The enzyme is more similar to that found in invertebrates when compared with that found in bacteria. This is the first report on the occurrence of alanine racemase activity in the microalga Thalassiosira sp.  相似文献   

农产品品质无损检测技术应用研究     

陈红光  张云鹤  敖长林  中野和宏  王健 《农机化研究》2011,(9)

研究目标是开发一种用可见光和近红外光谱(Vis/NIR)检测农产品的非破坏性测定方法。用波长范围为310～1 100nm的可见/近红外分光仪得到枣的光谱测量数据,用于测定交互作用下的枣的内部可溶性固体含量和基于反射系数的枣的表面缺陷;用多元线性回归校准模型来预测可溶性固体含量,校正判别分析判断大枣有或没有表面缺陷。  相似文献   

Chromosome doubling of Lychnis spp. by in vitro spindle toxin treatment of nodal segments     

Takahiro Nonaka  Eriko Oka  Megumi Asano  Sachiko Kuwayama  Hiromu Tasaki  Dong-Sheng Han  Toshinari Godo  Masaru Nakano 《Scientia Horticulturae》2011

Lychnis (Caryophyllaceae) consists of about 30 species distributed throughout the temperate regions of the Northern Hemisphere, from East Asia to Europe. Many Lychnis spp. have high ornamental value and cultivated as pot or garden plants. In the present study, in vitro chromosome doubling of several Lychnis spp. was examined in order to widen their variability in horticultural traits. Initially effect of various spindle toxin treatments [100, 500 or 1000 mg l⁻¹ colchicine (COL), 10, 20 or 50 mg l⁻¹ oryzalin (ORY), or 1, 5, 10 mg l⁻¹ amiprophos-methyl (APM)] of nodal segments of a triploid genotype of L. senno (3x) was investigated on survival of nodal segments and chromosome doubling in nodal segment-derived plantlets. Significantly higher percentage (75.0%) of surviving segments after spindle toxin treatment was obtained in 10 mg l⁻¹ ORY treatment. Flow cytometry (FCM) analysis of leaf tissues showed that 9.4–13.8% of plantlets, which were derived from 10 to 20 mg l⁻¹ ORY, or 5 mg l⁻¹ APM treatments, were hexaploid (6x) or ploidy chimera (3x + 6x, 4x + 6x, 5x + 6x, 3x + 4x + 6x). The results obtained by FCM analysis were confirmed by chromosome observation in root tip cells. Thus 10 mg l⁻¹ ORY treatment of nodal segments is suitable for in vitro chromosome doubling of triploid L. senno. Efficient chromosome doubling was also achieved in diploid L. fulgens (2x) and L. sieboldii (2x) by treating nodal segments with 10 mg l⁻¹ ORY: 68.9–88.7% of nodal segments survived after ORY treatment, and 24.7–26.5% of plantlets derived from ORY-treated nodal segments were tetraploid (4x) or ploidy chimera (2x + 4x) in both species. These results indicate that the in vitro chromosome doubling method established for triploid L. senno may be applicable to a wide range of Lychnis spp. Tetraploid L. fulgens and L. sieboldii showed a compact plant form, and had thick stems and deep green leaves compared with the diploid mother plants. On the other hand, hexaploid L. senno showed very poor growth and died before flowering.  相似文献   

Quantification of the effect of rice paddy area changes on recharging groundwater     

Mitsumasa Anan  Kozue Yuge  Yoshisuke Nakano  Satiant Saptomo  Tomokazu Haraguchi 《Paddy and Water Environment》2007,5(1):41-47

This study quantifies the effects of paddy irrigation water on groundwater recharge. A numerical model of groundwater flow was conducted using MODFLOW in a 600 ha study site in an alluvial plain along the Chikugo River, located in southwestern Japan. To specify the surface boundary condition, data on the land use condition stored in the GIS database were transferred into a numerical model of groundwater flow. The simulated results were consistent with the observed yearly changes of groundwater level. Thus, it was appropriate to use the model to simulate the effects of paddy irrigation on groundwater. To quantify these effects, the groundwater level was simulated during the irrigation period when all farmlands in the study site were ponded. In this situation, the groundwater level was 0.5 to 1.0 m higher, the ground water storage 20% larger, and the return flow of the groundwater to the river 50% larger than in the present land use condition.  相似文献   

N-Acetyl-d-Glucosamine-Binding Lectin in Acropora tenuis Attracts Specific Symbiodiniaceae Cell Culture Strains     

Ryota Takeuchi  Mitsuru Jimbo  Fumika Tanimoto  Mariko Iijima  Hiroshi Yamashita  Go Suzuki  Saki Harii  Yoshikatsu Nakano  Ko Yasumoto  Shugo Watabe 《Marine drugs》2021,19(3)

Many corals establish symbiosis with Symbiodiniaceae cells from surrounding environments, but very few Symbiodiniaceae cells exist in the water column. Given that the N-acetyl-d-glucosamine-binding lectin ActL attracts Symbiodiniaceae cells, we hypothesized that corals must attract Symbiodiniaceae cells using ActL to acquire them. Anti-ActL antibody inhibited acquisition of Symbiodiniaceae cells, and rearing seawater for juvenile Acropora tenuis contained ActL, suggesting that juvenile A. tenuis discharge ActL to attract these cells. Among eight Symbiodiniaceae cultured strains, ActL attracted NBRC102920 (Symbiodinium tridacnidorum) most strongly followed by CS-161 (Symbiodinium tridacnidorum), CCMP2556 (Durusdinium trenchii), and CCMP1633 (Breviolum sp.); however, it did not attract GTP-A6-Sy (Symbiodinium natans), CCMP421 (Effrenium voratum), FKM0207 (Fugacium sp.), and CS-156 (Fugacium sp.). Juvenile polyps of A. tenuis acquired limited Symbiodiniaceae cell strains, and the number of acquired Symbiodiniaceae cells in a polyp also differed from each other. The number of Symbiodiniaceae cells acquired by juvenile polyps of A. tenuis was correlated with the ActL chemotactic activity. Thus, ActL could be used to attract select Symbiodiniaceae cells and help Symbiodiniaceae cell acquisition in juvenile polyps of A. tenuis, facilitating establishment of symbiosis between A. tenuis and Symbiodiniaceae cells.  相似文献   

Geochemical Comparison of Stream Water, Rain Water, and Watershed Geology in Central Korea     

Seo-Ryong Jeon  Takanori Nakano 《Water, air, and soil pollution》2001,130(1-4):739-744

A hilly to mountainous watershed in Chonju in central Korea does not receive acid rain (average pH: 6.2); however, the stream water in the granite watershed is slightly acidic (6.4–6.7) and contains a low concentration of Ca compared to the stream water in sedimentary and volcanic rock watersheds (6.8–7.6). Although the concentrations of Ca and Sr and the ⁸⁷Sr/⁸⁶Sr ratio in the stream water change in accordance with the watershed geology, the stream ⁸⁷Sr/⁸⁶Sr ratios are closer to the ⁸⁷Sr/⁸⁶Sr ratios of rain than to those of the substrate rocks, suggesting the selective but sluggish weathering of Ca-containing minerals neutralizes acid. The concentrations of trace metals (As, Cr, Cu, Mo, Ni, Pb) in the water are lower than those in rain and less dependent on the watershed geology, indicating that they originated dominantly from the atmosphere. This result is consistent with the stream water having Pb isotope ratios close to that of rain but distinct from that of the rocks. We assume that the soil pool of exchangeable ions dominantly contains atmospherically derived heavy metals, which are subsequently discharged into streams. It is likely that the poor acid-neutralizing capacity of granite makes the aquatic systems in the granite watershed in Chonju sensitive to atmospheric acidification.  相似文献   

First report of horn gall disease of Cinnamomum pseudopedunculatum caused by Laurobasidium hachijoense in the Bonin Islands,Japan     

Shibata  Saho  Ono  Tsuyoshi  Kobayashi  Yoshiko  Miyagawa  Itsuha  Mukai  Akitsugu  Ichioka  Youzou  Takenaka  Izumi  Nakano  Hideto  Hirooka  Yuuri 《Journal of General Plant Pathology》2021,87(5):322-325

Journal of General Plant Pathology - In June 2017, deer-horn-like galls covered with a whitish, powdery fungal layer were found on the trunks of Cinnamomum pseudopedunculatum (Lauraceae) in...  相似文献   

Automated analysis of fine‐root dynamics using a series of digital images     

Aiko Nakano  Hidetoshi Ikeno  Toshifumi Kimura  Hiromichi Sakamoto  Masako Dannoura  Yasuhiro Hirano  Naoki Makita  Leena Finér  Mizue Ohashi 《植物养料与土壤学杂志》2012,175(5):775-783

Information related to the growth of fine roots is important for understanding C allocation in trees and the mechanisms of C cycling in ecosystems. Observations using a camera or scanner embedded in the soil enabled us to obtain continuous images of fine‐root‐growth dynamics. However, these methods are still labor‐intensive because the image analysis has to be conducted manually. We developed an automated method for tracking movement or elongation of fine roots using a sequence of scanner images. We also show how data obtained with these methods can be used for calculating fine‐root behavior. Two A4‐size scanners were buried in a mixed forest in Japan and images were taken continuously from within the soil. We preprocessed these images by extracting the fine‐root area from the images and developed an automated calculation plug‐in we named A‐root for tracking growth movement of the tips of fine roots. A‐root and manual‐tracking results were compared using the same images. The results show the A‐root and manual‐tracking methods yielded similar levels of accuracy. The average growth rate of 17 fine roots tracked using the program was 0.16 mm h^–1. The observation of the direction of growth in fine roots showed the direction may be influenced by the original root's growth where the fine roots branched, distribution of soil particles, other roots, and the force of gravity. The A‐root analysis also suggested there may be an interaction between speed of growth and changes in direction of growing fine roots.  相似文献