Effect of adding steam-exploded wood flour to thermoplastic polymer/wood composite     

Masahiro Takatani  Osamu Kato  Takashi Kitayama  Tadashi Okamoto  Mitsuhiko Tanahashi 《Journal of Wood Science》2000,46(3):210-214

The effect of steam-exploded wood flour (SE) added to wood flour/plastic composite was examined using SE from beech, Japanese cedar, and red meranti and three kinds of thermoplastic polymer: polymethylmethacrylate, polyvinyl chloride, and polystyrene. Addition of SE increased the fracture strength and water resistance of the composite board to an extent dependent on the polymer species and the composition of wood/SE/polymer. However, water resistance decreased with the increasing proportion of SE when SE meranti was added. Effects of the wood species of SE on the properties of resulting board were small. An increased moisture content of wood flour or SE (or both) increased the variation of board performance.  相似文献   

Characterization of denitrification and net N2O-reduction properties of novel aerobically N2O-reducing bacteria     

Kazuhira Yokoyama  Masanori Yumura  Tadashi Honda  Eriko Ajitomi 《Soil Science and Plant Nutrition》2016,62(3):230-239

Nitrous oxide, one of the earth-warming and ozone-destructing gases, is produced through either nitrification or denitrification depending on the O₂ availability in soil. Aerobically denitrifying bacteria express denitrification tract even under the gas phase containing O₂ at the ambient air level. The net reduction of exogenous N₂O by novel aerobically denitrifying bacteria were studied. We carried out two different isolation strategies in the primary screening. One was to select isolates of interest out of periplasmic nitrate reductase-dependent denitrifying bacteria in a eutrophic condition. The other was to use diluted nutrient agar to allow the formation of colonies of diverse bacteria. Among aerobically denitrifying bacteria, those which showed net aerobic N₂O reduction were only minor populations. As a result, eight isolates belonging to Proteobacteria were obtained from soil and cow manure. The denitrification and net N₂O reduction properties of the three representative isolates, Pseudomonas sp. CM1, Thauera sp. PM2 and Paracoccus denitrificans 96, were determined separately by the acetylene inhibition method after exposure to aerobic or low O₂ conditions, a 24 h starvation prior to the determination of the aerobic activity and inoculation to a cow manure-amended sterile soil. The phenotype inversion from net N₂O-reducing to N₂O-emitting, and vice versa, attested to the fact that activity of the N₂O-producing and -reducing steps changed in different intensities to each other. The activity values and the direction of activity changes varied among the isolates. When they were inoculated in a sterilized soil microcosm at 40% maximum water holding capacity, the denitrification and the N₂O-reducing activities were comparable with or, in some cases, facilitated more than those determined under the low-O₂ condition. It is possible that these isolates sensed the O₂ deficiency even in such a relatively dry condition. Pseudomonas sp. CM1 was unique because it lacked nitrate reducing activity and acted as a net aerobic N₂O reducer.  相似文献   

Fishery characteristics of barfin flounder Verasper moseri in southern Tohoku,the major spawning ground,after the start of large-scale stock enhancement in Hokkaido,Japan     

Toshihiro Wada  Kyoichi Kamiyama  Shinya Shimamura  Osamu Murakami  Tadashi Misaka  Masayoshi Sasaki  Takaaki Kayaba 《Fisheries Science》2014,80(6):1169-1179

Commercial landings of a rare pleuronectid flatfish, barfin flounder Verasper moseri, recovered drastically after large-scale stock enhancement in Hokkaido conducted since 2006. This study investigated commercial landings, fishing grounds, size distributions, and sex and age compositions of barfin flounder during 2007–2011 in southern Tohoku, their major spawning ground, which is over 700 km south of Hokkaido. Landings, mostly comprising stocked fish, increased drastically in southern Tohoku: from 2.0 tons in 2007 to 20.8 tons in 2010. Over 98 % of them were landed during January–April, with the peak period during February–March. Fishing logbook data of offshore bottom-trawl vessels during 2007–2010 revealed the upper continental slope off southernmost Tohoku as the main fishing ground (35°40′–36°50′N, annual weighted mean depth 267–299 m). Two size modes in the landings consisted of males (ca. 40 cm) and females (ca. 60 cm). The main age at fishery recruitment in southern Tohoku was younger for males (age 2+) than for females (ages 3+ and 4+), the result of which was that the female percentage was lowest at 1.5 % in 2009 and highest at 7.9 % in 2011. Our results showed clearly how the effectiveness of large-scale stock enhancement in Hokkaido extended to southern Tohoku in association with spawning migration of stocked barfin flounder.  相似文献   

Comparison of Effect of Brassinosteroid and Gibberellin Biosynthesis Inhibitors on Growth of Rice Seedlings     

Matusmoto Tadashi  Yamada Kazuhiro  Yoshizawa Yuko  Oh Keimei 《水稻科学》2016,23(1):51

Brassinosteroid(BR) and gibberellin(GA) are two predominant plant hormones that regulate plant cell elongation. Mutants disrupt the biosynthesis of these hormones and display different degrees of dwarf phenotypes in rice. Although the role of each plant hormone in promoting the longitudinal growth of plants has been extensively studied using genetic methods, their relationship is still poorly understood. In this study, we used two specific inhibitors targeting BR and GA biosynthesis to investigate the roles of BR and GA in growth of rice seedlings. Yucaizol, a specific inhibitor of BR biosynthesis, and Trinexapac-ethyl, a commercially available inhibitor of GA biosynthesis, were used. The effect of Yucaizol on rice seedlings indicated that Yucaizol significantly retarded stem elongation. The IC_(50) value was found to be approximately 0.8 μmol/L. Yucaizol also induced small leaf angle phenocopy in rice seedlings, similarly to BR-deficient rice, while Trinexapac-ethyl did not. When Yucaizol combined with Trinexapac-ethyl was applied to the rice plants, the mixture of these two inhibitors retarded stem elongation of rice at lower doses. Our results suggest that the use of a BR biosynthesis inhibitor combined with a GA biosynthesis inhibitor may be useful in the development of new technologies for controlling rice plant height.  相似文献   

Size selectivity of trap for male red queen crab Chionoecetes japonicus with the extended SELECT model   总被引：1，自引：0，他引：1  

Eui-Cheol Jeong  Chang-Doo Park  Seong-Wook Park  Ju-Hee Lee and  Tadashi Tokai 《Fisheries Science》2000,66(3):494-501

  相似文献   

Behavioural characteristics of loggerhead turtles (Caretta caretta) in a submerged bag net of a setnet observed in a bycatch simulation and the development of a turtle releasing device     

Maika Shiozawa  Daisuke Shiode  Junichi Okuyama  Fuxiang Hu  Tadashi Tokai 《水产资源保护:海洋与淡水生态系统》2019,29(12):2107-2115

Effect of long-term exposure to sulfides on taurine transporter gene expression in the gill of the deep-sea mussel Bathymodiolus platifrons,which harbors a methanotrophic symbiont     

Koito  Tomoko  Nakamura-Kusakabe  Ikumi  Yoshida  Takao  Maruyama  Tadashi  Omata  Tamano  Miyazaki  Nobuyuki  Inoue  Koji 《Fisheries Science》2010,76(2):381-388

Seawater around deep-sea hydrothermal vents and cold seeps contain high levels of hydrogen sulfide, which is toxic to most animals. Invertebrates inhabiting these environments have been reported to accumulate high levels of thiotaurine, a sulfur-containing amino acid. Thiotaurine is likely to play an important role in sulfide detoxification, but its functions in the detoxification process are still unknown. We cloned methane-seep mussel Bathymodiolus platifrons cDNA encoding the taurine transporter (TAUT), which transports thiotaurine and its precursors across the cell membrane. Phylogenetic analyses revealed that the predicted peptide formed a clade with the TAUTs of shallow-water mussel Mytilus galloprovincialis and the hydrothermal vent mussel Bathymodiolus septemdierum that harbors thioautotrophic bacteria. We then reared B. platifrons in the presence or absence of Na₂S and quantified TAUT mRNA using a real-time PCR system. The amount of TAUT mRNA in the gills of B. platifrons increased with rearing in the presence of Na₂S for 69 days, but no change was observed in the absence of sulfide. These results suggest that TAUT plays an important role in sulfide detoxification, even in species that do not harbor thioautotrophic bacteria. The TAUT mRNA level was variable in the mantle and low in the foot throughout the entire rearing period, regardless of the presence/absence of sulfide, suggesting that TAUT gene expression is regulated differentially in each tissue.  相似文献   

Longline hook selectivity for red tilefish Branchiostegus japonicus in the East China Sea     

Hideyuki Yamashita  Daisuke Shiode  Tadashi Tokai 《Fisheries Science》2009,75(4):863-874

The catch of red tilefish by the Japanese longline fishery in the East China Sea has steeply declined during the last two decades, and resource management is clearly required. This study presents the size selectivity of hooks for red tilefish as a method to control first capture size, based on the results of longline fishing experiments using “Tainawa-bari” hooks of several sizes: Japanese nominal sizes J#10, J#11, J#12, J#13, J#14 and J#16. On the assumption of geometrical similarity in the combination of upper jaw length u and hook width g at a given retention probability, a single master curve s(R) = exp (−14.42 + 8.85R)/(1 + exp [−14.42 + 8.85R]) was estimated in terms of relative upper jaw length to hook width, R = u/g, using the SELECT method based on a multinomial distribution. The relative upper jaw length for 50% retention is 1.63, and the selection range is 0.25. Almost all fish over 300 mm in total length were retained by a hook of size J#12, but smaller fish with less commercial value were also caught. Moreover, J#10 hooks catch fish with total lengths of >250 mm efficiently. This indicates that J#10 and J#12 hooks that are currently used are too small to optimize yield per recruit and also for resource conservation.  相似文献   

Effect of halomethyl-1,3,5-triazines on nitrification of ammonia     

Shinpei Ohki  Yuuta Kasahara  Yukiharu Sato  Ko Wakabayashi  Yoshiko Miyamoto  Johannes W Vonk 《Pest management science》1999,55(6):674-675

Nitrification inhibitory activity of halomethyl-1,3,5-triazines was determined by measuring the inhibitory activities on ammonia-oxidation to nitrate (NO₃⁻-N) in an upland soil and on ammonia-oxidation to nitrite (NO₂⁻-N) by Nitrosomonas europaea ATCC 25978 (ATCC) and Nitrosomonas sp TK 794 (TK). Within the chlorinated trimethyl-1,3,5-triazines, those bearing at least one trichloromethyl group inhibited nitrification more strongly, both in soil and in cell suspension of ATCC, than other mono- or dichlorinated methyl-1,3,5-triazines. Introduction of an amino group to 2,4,6-tris(trichloromethyl)-1,3,5-triazine gave 10- and 100-fold increases of nitrification inhibitory activity in soil and ATCC cell culture, respectively. Within the trihalomethyl-1,3,5-triazines, those having tribromomethyl group(s) exhibited rather weaker nitrification inhibition in soil than the corresponding trichloromethyl-1,3,5-triazines, although they showed a strong inhibition in cell suspension. Ammonium oxidation in ATCC was inhibited more strongly than that in TK. In QSAR studies, the optimum log P values were calculated as c 4.30. By using this value it will become possible to design highly active trichloromethyl-1,3,5-triazine nitrification inhibitors.  相似文献   

Differences in dry matter production,grain production,and photosynthetic rate in barley cultivars under long-term salinity     

Tadashi Hirasawa  Kosuke Sato  Makoto Yamaguchi  Ryohei Narita  Asuka Kodama  Shunsuke Adachi 《Plant Production Science》2017,20(3):288-299

Soil salinity is a major environmental stress causing significant loss of crop productivity. Barley (Hordeum vulgare L.) is one of the few field crops that can grow in salt-affected fields and varietal differences in productivity under salinity conditions were known. To clarify the trait most responsible for grain production under salt stress, barley cultivars that were salt tolerant (OUE812) or salt sensitive (OUC613) were grown from seedling to harvest stage in vermiculite containing various concentrations of NaCl. Dry weight of aboveground parts and grain weight decreased significantly with increasing NaCl concentration. The dry weight of the aboveground parts and grain weight decreased more significantly in OUC613 than in OUE812 for plants treated with 150 mM and 200 mM NaCl. A marked reduction in ripening percentage caused significantly decreased grain production in OUC613 as compared with OUE812. In plants treated with 200 mM NaCl, the photosynthetic rate decreased three weeks after starting the NaCl treatment, but a significant difference between cultivars in photosynthetic rate did not appear until seven weeks of NaCl treatment. OUE812 kept a higher photosynthetic rate during ripening than did OUC613 and dry matter production during the period from ripening to harvest was significantly larger in OUE812 than in OUC613. Keeping a higher photosynthetic rate might have contributed to higher grain production in OUE812. Higher ripening percentage and higher rate of photosynthesis during ripening might be target traits in breeding to improve the tolerance of barley to long-term salt stress.  相似文献