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1.
Knowledge on transport and deposition of fine particulate organic matter (FPOM) from reservoir dams is increasingly required
for habitat management and restoration of dam tailwater ecosystems. Variations in the transport distance of FPOM, however,
have never been studied well, particularly in relation to channel morphology, due to channel size restrictions of artificial
tracers such as corn pollen when applied to larger river channels. This study aims to show the relations between FPOM retention
efficiency and channel morphology in dam tailwaters using lentic plankters as tracers. We estimated the mean transport distance,
S
p, by calculating downstream reduction ratios of lentic tracer plankters and calculated the deposition velocity, v
dep. Suspended FPOM samples were collected in tailwaters of two river channels below reservoir dams and two artificial canals
below Lake Biwa in the Yodo River system. The longest S
p (19.2 km) and the shortest one (2.2 km) were recorded in the deep canal and shallow canal, respectively, showing a positive
correlation with channel hydraulic radius. The values of v
dep were 4.7–6.4 times higher in river channels than in artificial canals. These results indicate that increasing complexity
of bed morphology can minimize S
p, whereas bed degradation and armored bed materials may lead to increased S
p. Advantages of lentic plankters as tracers for estimating distance ranges of reservoir dam impact on river ecosystems are
also discussed. 相似文献
2.
3.
A respiration-deficient (RD) mutant was isolated from the petite-negative, salt-tolerant yeast Zygosaccharomyces rouxii. One strain among sixteen glycerol-non-utilizing mutants exhibited vigorous liberation of CO2 but no uptake of O2. Furthermore, this strain lacked cytochrome aa3 and had a reduced level of cytochrome b. The few mitochondria found in cells of this strain contained few or no cristae. Salt tolerance and intracellular accumulation of glycerol by the RD strain were almost equal to that of the wild-type strain in media containing NaCl up to 2.5 M. In media with more than 3 M NaCl, the growth of the RD mutant was retarded and the intracellular accumulation of glycerol was depressed in spite of ample production. 相似文献
4.
Toshifumi Nakao Ichiro Yamato Yasuhiro Anraku 《Molecular & general genetics : MGG》1987,208(1-2):70-75
5.
A method for determination of the redox level of plastoquinoneA in spinach chloroplasts is described. Plastoquinone A andits reduced form plastoquinol A were extracted from chloroplastson a sample-preparation cartridge (SEP-PAK C18 Cartridge, WatersAssoc. Inc.) with a mixture of ethanol and diethyl ether ( 1: 1, vv). Extracts were separated by reversed-phase high-performanceliquid chromatography and examined with an electrochemical detectorequipped with dual electrodes. Plastoquinone A was determinedby its reductive current on one electrode, and plastoquinolA by its oxidative current on the other electrode. This method was applied to the determination of the redox potentialof plastoquinone A in chloroplasts. The midpoint potential atpH 7.8 of plastoquinone A was +20 mV with an n number of 2. (Received March 30, 1987; Accepted August 3, 1987) 相似文献
6.
Yuichi Fujita Yasuhiro Takahashi Takayuki Kohchi Haruo Ozeki Kanji Ohyama Hiroshi Matsubara 《Plant molecular biology》1989,13(5):551-561
The frxC gene, one of the unidentified open reading frames present in liverwort chloroplast DNA, shows significant homology with the nifH genes coding for the Fe protein, a component of the nitrogenase complex (Ohyama et al., 1986, Nature 322: 572–574). A truncated form of the frxC gene was designed to be over-expressed in Escherichia coli and an antibody against this protein was prepared using the purified product as an antigen. This antibody reacted with a protein in the soluble fraction of liverwort chloroplasts, which had an apparent molecular weight of 31 000, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, in good agreement with a putative molecular weight of 31945 deduced from the DNA sequence of the frxC gene. In a competitive inhibition experiment, the antigenicity of this protein was indicated to be similar to that of the over-expressed protein in E. coli. Therefore, we concluded that the frxC gene was expressed in liverwort chloroplasts and that its product existed in a soluble form. The molecular weight of the frxC protein was approximately 67 000, as estimated by gel filtration chromatography, indicating that the frxC protein may exist as a dimer of two identical polypeptides analogous to the Fe protein of nitrogenase. The results obtained from affinity chromatography supported the possibility that the frxC protein, which possesses a ATP-binding sequence in its N-terminal region that is conserved among various other ATP-binding proteins, has the ability to bind ATP. 相似文献
7.
Mutagenesis of human granulocyte colony stimulating factor 总被引:9,自引:0,他引:9
T Kuga Y Komatsu M Yamasaki S Sekine H Miyaji T Nishi M Sato Y Yokoo M Asano M Okabe 《Biochemical and biophysical research communications》1989,159(1):103-111
To define the structure-function relationship, we have made a number of mutants of human granulocyte colony-stimulating factor (hG-CSF) by in vitro mutagenesis. The results indicate that most of the mutations located in the internal and C-terminal regions of the molecule abolished the activity, whereas the mutants without N-terminal 4, 5, 7, or 11 amino acids retained the activity. N-terminal amino acids were also altered by cassette mutagenesis using a synthetic oligonucleotide mixture. Among them, KW2228, in which Thr-1, Leu-3, Gly-4, Pro-5 and Cys-17 were respectively substituted with Ala, Thr, Tyr, Arg and Ser, showed more potent granulopoietic activity than that of intact hG-CSF both in vitro and in vivo. 相似文献
8.
Ichiro Yamato Hiro Nakamura Hiroshi Murakami Yasuhiro Anraku 《FEMS microbiology letters》1988,56(1):21-27
Abstract The cybB gene on a plasmid encoding cytochrome b 561 in Escherichia coli was disrupted by insertion of Kmrl determinant DNA. The cromosomal cybB gene was replaced by the inactivated cybB gene on the plasmid by homologous recombination using λ phage lysogenization and heat-induction. The replacement was confirmed by Southern and Western blotting analyses. Deficiency on the cybB gene product did not affect the growth properties of the cells, and the oxidase activities of the cells dependent on various substrates were similar to those of the parental strain. Cytochrome b 561 is concluded to be expressed in E. coli , but may not play a major role in cell growth. In the genetic map of E. coli , the cybB gene was determined by conjugational and transductional crosses to be at 31 min between trg and terC . 相似文献
9.
Hiro Nakamura Hiroshi Murakami Ichiro Yamato Yasuhiro Anraku 《Molecular & general genetics : MGG》1988,212(1):1-5
Summary The complete nucleotide sequence of the Escherichia coli cybB gene for diheme cytochrome b
561 and its flanking region was determined. The cybB gene comprises 525 nucleotides and encodes a 175 amino acid polypeptide with a molecular weight of 20160. From its deduced amino acid sequence, cytochrome b
561 is predicted to be very hydrophobic (polarity 33.7%) and to have three membrane spanning regions. Histidines, canonical ligand residues for protohemes, are localized in these regions, and the heme pockets are thought to be in the cytoplasmic membrane. No significant homology of the primary structure of cytochrome b
561 with those of other bacterial b-type cytochromes was observed. 相似文献
10.
Role of Chitinase and Chitin Oligosaccharides in Lignification Response of Cultured Carrot Cells Treated with Mycelial Walls 总被引:3,自引:0,他引:3
Chitinase activity was induced in cultured carrot cells by incubationwith mycelial walls of a fungus, Chaetomium globosum. Both intra-and extracellular chitinases were resolved into four componentsby gel filtration chromatography. The extracellular enzymesliberated soluble oligosaccharides of different sizes from insolublechitin, suggesting that these carrot chitinases are endo-hydrolases.The solubilized chitinase digests obtained from insoluble mycelialwalls of C. globosum and chitin were fractionated by gel filtrationchromatography, and the elicitor activity of each fraction forthe accumulation of phenolic acids in cultured carrot cellswas determined. In both solubilized fragments of fungal wallsand of chitin, elicitor-active oligosaccharides were distributedin many fractions, however, potent activity for inducing phenolicacid synthesis was observed in the high molecular weight fractions. (Received October 5, 1987; Accepted February 12, 1988) 相似文献