Improvement of simple impedance tomography method in RF range for estimating moisture distribution in squared timbers     

Nobuo Sobue  Ian Woodhead 《Journal of Wood Science》2010,56(5):366-370

Improvement of the simple tomography method for estimating moisture distribution in squared timbers was conducted by using impedance measurement in the RF range at 250 kHz. The local impedance in the horizontal and vertical directions was measured during natural drying. An inverse procedure using a trial-and-error method was used to reconstitute the cross-sectional moisture distribution from the surface impedance measurement. Two essential corrections for the spatial heterogeneity of the electric field between electrodes and for the calculation error due to the algorithm of the trial-and-error method were introduced to improve the accuracy of the reconstitution of the moisture distribution. The reconstituted moisture distribution matched well that determined by the oven-dry method.  相似文献   

Characterization of spheres derived from canine mammary gland adenocarcinoma cell lines     

Michishita M  Akiyoshi R  Yoshimura H  Katsumoto T  Ichikawa H  Ohkusu-Tsukada K  Nakagawa T  Sasaki N  Takahashi K 《Research in veterinary science》2011,91(2):254-260

There is increasing evidence for the presence of cancer stem cells in several solid tumors, and these cancer stem cells have a potential role in tumor initiation, aggression, and recurrence. The stem cell-like properties of spheres derived from canine mammary tumors remain largely elusive. We attempted to induce sphere formation using four cell lines of canine mammary adenocarcinoma, and characterized the spheres derived from a CHMp line in vitro and in vivo. The CHMp-derived spheres showed predominantly CD44⁺CD24⁻ population, higher expression of stem cell-related genes, such as CD133, Notch3 and MDR, and higher resistance to doxorubicin compared with the CHMp-derived adherent cells. Xenograft transplantations in nude mice demonstrated that only 1 × 10⁴ sphere cells were sufficient for tumor formation. Use of the sphere assay on these sphere-derived tumors showed that sphere-forming cells were present in the tumors, and were maintained in serial transplantation. We propose that spheres derived from canine mammary adenocarcinoma cell lines possess a potential characteristic of cancer stem cells. Spheres derived from canine mammary tumors could be a powerful tool with which to investigate novel therapeutic drugs and to elucidate the molecular and cellular mechanisms that underlie tumorigenesis.  相似文献   

Uptake of ammonium‐nitrogen by blueberry plants     

Nobuo Sugiyama  Mikiya Hirooka 《Journal of plant nutrition》2013,36(10):1975-1981

Blueberry plants (Vaccinium ashei Reade cv. Tifblue) and Citrus natsudaidai Hayata were compared in terms of their ability to regulate the uptake of ammonium‐nitrogen (NH₄‐N). Plants of both species were grown in N‐free nutrient solutions for three days and then transferred to nutrient solutions that contained various concentrations of NH4‐N. Blueberry plants showed increases in rates of uptake of NH₄‐N 8 to 24 h after application of NH₄‐N. At concentrations of NH₄‐N above 200 (μM, uptake rates decreased to the initial value 24 h after application of NH₄‐N and then increased. By contrast, seedlings of Citrus natsudaidai showed constant rates of uptake of NH₄‐N during the experiment. These results indicate that blueberry plants are able to repress the uptake of NH₄‐N periodically when they are exposed to high concentrations of external NH₄‐N, but not seedlings of Citrus natsudaidai.  相似文献   

Cloning of the phloem-specific small heat-shock protein from leaves of rice plants     

Akari Fukuda  Yoshihisa Okada  Nobuo Suzui  Toru Fujiwara  Tadakatsu Yoneyama  Hiroaki Hayashi 《Soil Science and Plant Nutrition》2013,59(8):1255-1262

The N-terminal amino-acid sequence of a major rice phloem-sap protein, designated as RPP23, was determined. The complete amino-acid sequence of RPP23 was deduced from the corresponding rice EST- clone and contained an extra 46 amino acids at the N-terminus, that was apparently cleaved off to form mature RPP23 in sieve tubes. RPP23 shared a similarity to plant small heat-shock proteins (smHSPs), though the N-terminal region of RPP23 was distinct from that of known smHSPs. Immunocytological analyses using leaf sections showed that RPP23 was located only in the phloem regions of leaves, and was present in non-stressed plants. In mature leaves, stronger immunocytological signals were detected in sieve elements than in companion cells.  相似文献   

Aluminum oxyhydroxide polymorphs and some micromorphological characteristics in sclerotium grains     

Makiko Watanabe  Akira Genseki  Nobuo Sakagami  Yudzuru Inoue  Hiroyuki Ohta  Nobuhide Fujitake 《Soil Science and Plant Nutrition》2013,59(8):1205-1210

The presence of aluminum oxyhydroxide and its micromorphological characteristics in sclerotium grains were examined by SEM, TEM, and EDX analyses. A spherical fraction with a diameter of 100 nm, which contained C and Al as the predominant elements, was recognized as the unit particle of the matrix of sclerotium grains. The Al polymorphs and the Si spherical structures found in the ignited grains were assumed to correspond to boehmite and opaline silica particles, respectively. SEMI analysis revealed the presence of a needle ball structure inside the hollow part of sclerotium grains. The relationship between the inner structure of sclerotium and biochemical processes of the host fungi was discussed.  相似文献   

A quick incorporation of 13N into the soluble high-molecular compound in rice (Oryza sativa L.) roots by application of 13N-labeled nitrate/nitrite     

Tadakatsu Yoneyama  Nobuo Suzui  Noriko S. Ishioka  Shu Fujimaki 《Soil Science and Plant Nutrition》2013,59(4)

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Saccharides of ectomycorrhizal fungal sclerotia as sources of forest soil polysaccharides     

Yuki Sugiura  Makiko Watanabe  Yaya Nonoyama  Nobuo Sakagami  Yong Guo 《Soil Science and Plant Nutrition》2013,59(5):426-433

ABSTRACT

The neutral monosaccharide composition of forest soils differs from that of non-forest soils suggesting there is an accumulation of microbial saccharides. Ectomycorrhizal (ECM) fungi can be responsible as the fungi are typical in forest soils. We investigated neutral saccharides of ECM fungal sclerotia to determine what part it might play in the origin of forest soil polysaccarides. Sclerotial grain (SG) was collected from the O, A1 and A2 horizons of a soil of subalpine forest of Mt. Ontake, central Japan. Neutral saccharides in soil and SG were analyzed by two step hydrolysis with sulfuric acid and gas-chromatography of alditol acetate derivatives. Saccharides accounted for 6.0?16% of the SG by carbon content. The SG contained predominantly easily hydrolysable (EH)-glucose, which accounted for 75–85% of the composition depending on grain size and the soil horizon, followed by mannose (7.7?15%), galactose (2.2?4.8%) and non-easily hydrolysable (NEH)-glucose (1.7?6.1%). The SG contained all of these sugars irrespective of its size. The SG collected from the A1 and A2 horizons contained all sugar components found in that from the O horizon, except for fucose in that from A2 horizon. The monosaccharide composition of SG indicates that accumulation of ECM fungal sclerotial polysaccharides might have been responsible for enlarging the molar ratios of (galactose + mannose) /(arabinose + xylose) and EH-glucose/NEH-glucose of forest soils. The proportions of SG saccharides relative to soil saccharides were 3.6, 1.2, and 0.83% for the O, A1 and A2 horizons, respectively. These levels of the proportion are considerable as ECM fugal sclerotia are the products of a limited species among hundreds and thousands of microbial species inhabiting forest soils. The sclerotia forming ECM fungal species such as Cenococcum geophilum may be key sources of forest soil polysaccharides.  相似文献   

Effects of nitrogen and phosphorus fertilization on the ratio of activities of carbon-acquiring to nitrogen-acquiring enzymes in a primary lowland tropical rainforest in Borneo,Malaysia     

Taiki Mori  Nobuo Imai  Daiki Yokoyama  Kanehiro Kitayama 《Soil Science and Plant Nutrition》2013,59(5):554-557

ABSTRACT

Previous meta-analyses revealed that the ratio of activities of carbon (C)-acquiring enzyme to nitrogen (N)-acquiring enzymes in tropical forest ecosystems was nearly identical to those in other ecosystems, despite of the N-rich condition in tropical forests. This could be explained by microbes in tropical forest soils, which require a large amount of N to produce N-rich acid phosphatase (AP) for catalyzation of the organic form of phosphorus (P) and compensation for poor P availability in soils. Based on this idea, we hypothesized that experimental P fertilization would reduce the allocation to N-acquiring enzymes compared with that of C-acquiring enzymes, i.e. that it would increase the ratios of activities of β-1,4-glucosidase (BG) to β-1,4-acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP). We tested this hypothesis using an experimental fertilization site with factorial N (100 kg ha^?1 yr^?1) and P (50 kg ha^?1 yr^?1) addition in a primary tropical lowland forest in Bornean Malaysia, where our earlier work demonstrated that P fertilization reduced AP activity. Contrary to our hypothesis, the BG:NAG and BG:(NAG + LAP) ratios were not altered by either N or P fertilizations. This result indicated that AP production was not a reason for the maintenance of a relatively high investment in N-acquiring enzyme at our study site. Rather, NAG and LAP production was likely driven by C acquisition, rather than N acquisition, as the target substrates contained C as well as N. This idea was supported by the fact that neither the BG:NAG ratio nor the BG:(NAG + LAP) ratio was elevated by N addition. We propose that the ratios of activities of BG to NAG and LAP do not necessarily indicate the ratio of C:N acquisition, at least in our N-rich tropical forest ecosystem.  相似文献   

Effects of difference in fertilization treatments on nitrification activity in tea soils     

Masahito Hayatsu  Nobuo Kosuge 《Soil Science and Plant Nutrition》2013,59(2):373-378

Abstract

It is generally recognized that the nitrification activity in acid soils is very low. Indeed, nitrification in mineral soils has been found to be negligible at pH values below 5.0 (Dancer et al. 1973; Nyborg and Hoyt 1978). However, it was reported that autotrophic nitrification occurred in some tea soils at pH levels far below 5.0 (Walker and Wickramasinghe 1979; Hayatsu and Kosuge 1993). An acidophilic ammonia-oxidizing bacterium has been recently isolated from strongly acidic tea soils in Japan (Hayatsu 1993). On the other hand, fertilization has-been considered to be an important factor influencing nitrification in agricultural soils. For example, several studies have shown that the addition of ammoniacal fertilizer to soils can lead to the increase of the populations of Nitrosomonas (McLaren 1971; Ardakani et al. 1974). Liming of acidic soils also tends to stimulate the nitrification activity (Dancer et al. 1973; Nyborg and Hoyt 1978). Although nitrification has been studied in a wide variety of agricultural soils, there is little information available on nitrification in tea soils. The effect of fertilization on nitrification in tea soils is poorly documented.  相似文献   

Crystalline clay minerals of the soils derived from recent volcanic ashes in Hokkaido,Japan     

Nobuo Uchiyama  Jun-ichi Masui  Sadao Shoji 《Soil Science and Plant Nutrition》2013,59(4):125-132

For the past ten years much work has been carried out on clay minerals of volcanic ash soils. Most investigators have reported that allophane is dominant among clay minerals of volcanic ash soils and crystallizes to halloysite or meta-halloysite with the advance of weathering (1–8). On the other hand, UCHIYAMA, MASUI and ONIKURA (1960) found that montmorillonite predominates in the clay fraction of volcanic ash soil in Kawatabi (9). Furthermore, MASUI, SHOJI and UCHIYAMA (1966) showed that the major crystalline clay minerals of volcanic ash soils in the Tohoku district are montmorillonite, vermiculite, intergradient montmorillonite-vermiculite and chlorite (10). They also showed that these minerals increase with the advance of weathering and that kaolin minerals are minor constituents.  相似文献