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61.
62.
Reiji Fujimaki Akiyuki Kawasaki Yoshikazu Fujii Nobuhiro Kaneko 《Journal of Forest Research》2008,13(6):380-385
The water chemistry of 51 headwater streams was studied in the Tanzawa Mountains, western fringe of Southern Kanto Plain,
Japan. The relationships to soil N processes and catchment topography were also evaluated using a geographic information system
with fine-scale map data. The average concentration of total dissolved N was 0.74 mg-N L−1, of which 95% consisted of NO3
−-N. Stream N concentrations were not different among bedrock geologies and among vegetations of the catchments. Stream NO3
−-N marginally correlated to soil nitrification. Stream NO3
−-N also tended to be high in areas with steep and south-facing slopes. These results imply that N transport from Tanzawa forest
ecosystems is related to hydrological and biological processes associated with catchment topography.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
63.
64.
Takeshi Ohta Yasufumi Toriniwa Naruhiko Ryumon Nobuhiro Inaba Tadaaki Hirao Saori Yamanaka Takayuki Maeno Wakako Sakakibara Morio Sumikawa Kaoru Chiba Akiko Nakamura Katsuhiro Miyajima Fatchiyah Fatchiyah Takahisa Yamada 《Animal Science Journal》2017,88(1):149-155
The onset and progression of type II diabetes is closely related to environmental factors, in particular dietary habit. Moreover, the environmental exposures very early in life can influence the risk for development of type II diabetes later in life. In this study, we investigated pathophysiological changes in the pups of maternal Spontaneously Diabetic Torii (SDT) rats that were fed a high‐fat diet (HFD) throughout gestation and lactation. Maternal SDT rats were continued on HFD for 5 weeks, from day 8 of gestation to day 21 after birth, and biological analyses of the pups were performed from 2 to 22 weeks of age. Results of serum lipid levels in pups from dams fed HFD were higher than pups from dams fed a standard diet, and the onset of diabetes was significantly accelerated in pups from dams fed HFD. In pathological analyses, pups from dams fed HFD showed increases in liver weight and vacuolation of hepatic cells at 2 weeks of age. In conclusion, the metabolic disorder of lipids and glucose in SDT rats is closely related to the nutritional condition of dams during the periods of gestation and lactation. 相似文献
65.
Nobuhiro Tanaka 《Rice》2011,5(1):1-6
Plant hormone gibberellin (GA) promotes juvenile-adult phase change in higher plants. To confirm the functions of GA in rice, I used dwarf mutant d18-dy. d18-dy is a loss-of-function allele of D18, which encodes GA3ox2. d18-dy mutant exhibited long juvenile phase in morphological traits such as the size of the shoot apical meristem (SAM), shape of leaf blades, presence or absence of midribs and node–internode differentiation in stem. In contrast, expression patterns of juvenile-adult phase change markers miR156 and miR172 were similar between wild type and d18-dy. In addition, d18-dy mutation and GA did not affect expression levels of downstream genes of miR156. GA does not function upstream of miR156 in juvenile-adult phase change. 相似文献
66.
67.
Taizo Nakamori Satoshi Yoshida Yoshihisa Kubota Tadaaki Ban-nai Nobuhiro Kaneko Makiko Hasegawa Ryosaku Itoh 《European Journal of Soil Biology》2008,44(3):266-270
Knowing whether test species used for single-species toxicity tests are representative of other species provides valuable information because contaminant effects are often extrapolated to the community level based on these tests. To evaluate how representative the sensitivity of the standard test collembolan species Folsomia candida is for Collembola, we devised toxicity tests using the collembolan species Onychiurus yodai and Sinella umesaoi, which exhibit life-forms different from F. candida. Sensitivity to cadmium (Cd) was compared between F. candida and the novel test species. The 50% effective concentrations for reproduction were 154.7, 72.2 and 40.9 mg Cd/kg dry soil for O. yodai, F. candida and S. umesaoi, respectively. Thus, the reproductive sensitivity of F. candida to Cd was between that of the other two species. Increasing reproductive sensitivity to Cd corresponded to increasing activity levels and a more surface-dwelling life-form. Our data may facilitate the generalisation of effect data for F. candida to other species. 相似文献
68.
Tomoyoshi Yoshinaga Nobuyuki Tsutsumi Kathryn Ann Hall Kazuo Ogawa 《Fisheries Science》2009,75(5):1167-1176
In the mid-1990s, Neoheterobothrium hirame suddenly appeared as a new species in olive flounder Paralichthys olivaceus in Japanese coastal waters. Anemia caused by the parasite has prevailed in wild and cultured populations of olive flounder since that time. In this study, to clarify the origin of N. hirame, two Neoheterobothrium species, namely unidentified Neoheterobothrium species (tentatively abbreviated as Neoheterobothrium sp. PL) and N. affine, were collected from Paralichthys lethostigma and Paralichthys dentatus, respectively, off the east coast of North America and compared with N. hirame collected in Japan. No substantial differences were detected in the morphology and DNA sequences of ITS1-5.8S rRNA-ITS2 and mitochondrial cytochrome oxidase subunit I (mt COI) regions between N. hirame and Neoheterobothrium sp. PL. On the other hand, the congeneric N. affine was clearly distinguished from both N. hirame and Neoheterobothrium sp. PL in its longer isthmus and the DNA sequences in ITS1 and mt COI. The absence of differences between N. hirame and Neoheterobothrium sp. PL and the clear difference between both of these and N. affine indicate that N. hirame is conspecific with Neoheterobothrium sp. PL infecting P. lethostigma and that N. hirame was recently introduced from North America to Japan. 相似文献
69.
C4 plants show higher photosynthetic capacity and productivity than C3 plants owing to a CO2-concentrating mechanism in leaves, which reduces photorespiration. However, which traits regulate the photosynthetic capacity of C4 plants remains unclear. We investigated structural, biochemical, and physiological traits associated with photosynthesis and resource use efficiency in 20 accessions of 12 species of Amaranthus, NAD-malic enzyme-type C4 dicots. Net photosynthetic rate (PN) ranged from 19.7 to 40.5 μmol m?2 s?1. PN was positively correlated with stomatal conductance and nitrogen and chlorophyll contents of leaves and was weakly positively correlated with specific leaf weight. PN was also positively correlated with the activity of the C3 enzyme ribulose-1,5-bisphoshate carboxylase/oxygenase, but not with the activities of the C4 enzymes phosphoenolpyruvate carboxylase and NAD-malic enzyme. Structural traits of leaves (stomatal density, guard cell length, leaf thickness, interveinal distance, sizes of mesophyll and bundle sheath cells and the area ratio between these cells) were not significantly correlated with PN. These data suggest that some of the biochemical and physiological traits are involved in interspecific PN variation, whereas structural traits are not directly involved. Photosynthetic nitrogen use efficiency ranged between 260 and 458 μmol mol?1 N s?1. Photosynthetic water use efficiency ranged between 5.6 and 10.4 mmol mol?1. When these data were compared with previously published data of C4 grasses, it is suggested that common mechanisms may determine the variations in resource use efficiency in grasses and this dicot group. 相似文献
70.
Kyoko Kinoshita Sayaka Tamaki Miho Yoshioka Sarawut Srithonguthai Tadao Kunihiro Daigo hama Kouichi Ohwada Hiroaki Tsutsumi 《Fisheries Science》2008,74(1):77-87
ABSTRACT: For bioremediation of organically enriched sediment deposited below fish farms, the extremely high potential for population growth of a deposit-feeding polychaete, Capitella sp. I, in the organically enriched sediment, and the effect on decomposition of organic matter in the sediment, were examined. A mass-culturing technique was conducted for this species. Bioremediation experiments were conducted on the organically enriched sediment in a fish farm in Kusuura Bay, Japan in 2003–2006. Approximately 1.7 million individuals of the worms were placed on the sediment below one net pen in December 2003, 9.3 million individuals in November 2004, and 2.2 million individuals in November 2005. After the worms were spread on the sediment, they rapidly increased in number and reached the highest densities of approximately 134 000 inds/m2 in February 2004, 527 000 inds/m2 in March 2005 and 103 000 inds/m2 in January 2006. In the process of rapid population growth, the decomposition of the organic matter of the sediment was enhanced markedly. Our results demonstrate that the promotion of population growth by spreading cultured colonies of Capitella can enhance the decomposition rate of organic matter markedly in organically enriched sediment below fish farms. This method is promising for minimization of the negative effects of fish farms. 相似文献