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1.
2.
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
3.
Toshifumi Nakao Ichiro Yamato Yasuhiro Anraku 《Molecular & general genetics : MGG》1987,208(1-2):70-75
4.
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
5.
Analysis of bacterial populations in a grassland soil according to rates of development on solid media 总被引:3,自引:0,他引:3
Abstract The process of colony formation by bacteria from grassland soil sampled in April, July and September was simulated by a colony-forming curve (CFC). The CFC was a super-imposition of several component curves (cCFC) given theoretically by the first order reaction (FOR) model [3,6]. The pattern of FOR model curves was not influenced by the time of sampling and four cCFCs were always recognized during an incubation period of 160 h. It was considered that the CFC describes an inherent property of the bacterial population of the field. Bacterial isolates were obtained from colonies produced in each of four cCFCs on agar plates. Isolates corresponding to one cCFC were classified as one group. The bacterial isolates were characterized by morphological and physiological tests and subsequently clustered. Few oligotrophic bacteria were obtained among bacteria which produced visible colonies within 63 h of incubation time. On the other hand, approx. 50% of bacteria which produced v colonies after 63 h were oligotrophic bacteria. The time required for the appearance of the first colony, t r of the FOR model, was very similar in the isolates belonging to one group. A close linear relationship was observed between t r value and doubling time of isolates. 相似文献
6.
A survey of oligotrophic Lake Rara, the biggest lake in Nepal, was carried out from 1982 till 1984. Mean depth is 100 m, and
maximum depth is 167 m. The surface area covers 9.8 km2, and the lake contains 0.98 km3 volume of water.
Transparency was about 16 m, photoquantum yield decreased exponentially with depth below 5 m, and the extinction coefficient
was 8.3 × 10−2. The concentration of Chl.-a was in the range of 0.06–0.46 mg m−3, and total nitrogen was 18–30 μg 1−1. The whole water column was well oxygenated. Primary productivity was extremely low. It has more than 30 inflowing brooks
and one outlet. The water quality of the brooks changes drastically with their location. The pH, electrical conductivity,
and EDTA hardness in the waters from a landslide area were high. In the waters from a rich pine forest they were extremely
low.
The zooplankton consisted of two species of protozoa, five species of rotifers, two species of Cladocera, and two species
of Copepoda. The zooplankton density range was 6200–16200 individuals m−3. The minimum was on November 11th, 1983 and the maximum on August 19th, 1983. 相似文献
7.
8.
The Escherichia coli cytochrome b556 gene, cybA, is assignable as sdhC in the succinate dehydrogenase gene cluster 总被引:2,自引:0,他引:2
Hiroshi Murakami Kiyoshi Kita Hiroshi Oya Yasuhiro Anraku 《FEMS microbiology letters》1985,30(3):307-311
Abstract The cytochrome b556 -deficient mutant Escherichia coli K12 strain TK3D11 [7] could not grow with succinate as the sole carbon source, but could grow well on dl -lactate. This finding suggested that cytochrome b556 is primarily responsible for oxidative metabolism and utilization of succinate. 24 Amino acid residues at the amino-terminal of purified cytochrome b556 were determined. This sequence coincided completely with amino acid residues 4 to 27, predicted from the DNA sequence of the sdhC gene, one of the unassigned open reading frames of the sdh gene cluster recently reported by Wood et al. [16]. Based on these and other results, we concluded that cybA , the gene for cytochrome b556 , is assignable as sdhC . 相似文献
9.
Transformation of L cells with virus thymidine kinase genes introduced by red cell-mediated microinjection 总被引:2,自引:0,他引:2
Takashi Iino Mitsuru Furusawa Iwao Furusawa Masuo Obinata 《Experimental cell research》1983,148(2):475-480
Fusion of red cell ghosts containing foreign materials with cells results in the introduction of the materials into the cells (red cell-mediated microinjection). Until now, 'two-step dialysis' has mainly been used for trapping proteins in the ghosts. Large-sized materials such as DNA, however, are rarely trapped in the ghosts, since the holes in the red cell membrane caused by osmotic shock are too small for such materials to pass through. In this study, we improved the trapping technique. Some of the Hind III fragments of lambda phage DNA as well as proteins could be trapped in the ghosts when the mixture of these materials and red cells were frozen at -80 degrees C for a short period followed by quick thawing. Red cell-mediated microinjection using ghosts containing plasmid pBR322 linked with a Herpes simplex viral thymidine kinase (tk) gene brought about transformation of tk-defective L cells, the efficiency of transformation was 1 out of 20 000-60 000 cells fused with the ghosts. 相似文献
10.
Takahashi Yasuhiro; Hase Toshiharu; Wada Keishiro; Matsubara Hiroshi 《Plant & cell physiology》1983,24(2):189-198
An antibody for ferredoxin was used to investigate the developmentof ferredoxin during the greening of spinach cotyledons. Ferredoxinwas present in 8-day-old etiolated cotyledons and increasedwith illumination, which means that the synthesis of ferredoxinwas both light dependent and independent. The ferredoxin purified from etiolated cotyledons, greeningcotyledons, and mature leaves was a mixture of two chemicallydistinct molecular species; ferredoxin I and II. The relativecontents of these two species varied with the stage of developmentand the conditions used. Ferredoxin I was identical with that isolated previously asvalidated by its amino acid sequence [Matsubara and Sasaki (1968)J. Biol. Chem. 243: 1732]. The complete amino acid sequenceof the second component, ferredoxin II, was determined as well.It was composed of 97 amino acid residues and differed fromferredoxin I by 25 residues. (Received October 16, 1982; Accepted December 14, 1982) 相似文献