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111.
An arctic river was fertilized continuously through the ice-free season with phosphoric acid beginning in 1983. The epilithic
diatom community increased in biomass in the first two years in response to the added limiting nutrient (Peterson et al., 1983). The diatom community switched from one dominated by Hannea arcus to one dominated by species of Achnanthes and Cymbella. The immediate responses to the P-addition were decreases in both
the Shannon diversity and evenness indices. By the second year, the community diversity increased downriver reaching maximal
species richness (110–127 spp). In 1985–1987, the epilithic algal biomass decreased an order of magnitude with both whole-river
PO4 (1985, 1987) and PO4 + NH4 addition (1986). In the 5th summer of fertilization, the reduction in biomass was clearly caused by a numerical increase
of grazing, refugia-building chironomids (Orthocladiinae, primarily) (Gibeau, 1991; Gibeau, Miller, Hershey, in prep.). We
assume the algal biomass reduction in the 3rd and 4th years was similarly caused by grazers with a two year time lag in the
numerical response of these monovoltine species. The evenness of the community increased in 1986 as if it might have been
grazed; however the number of immigrants was reduced. The community became dominated by Eunotia, Cymbella and Achnanthes,
species either fast growing or more prostrate, as the erect species of Hannea Diatoma, and Fragillaria declined. A detrended
correspondence analysis of the temporal and spatial diatom samples in species space (186 spp.) showed that the largest variation
in the community was between years and less variation was associated with river fertilization.
Samples from bioassay tubes run by Peterson et al. (1983) in the Kuparuk River showed P and N + P limitation as found in the river in 1983–84. Like the river samples, the
largest change in the diatom community occurred between 15 and 25 day samples, more than that induced by fertilization. Diatoms
sampled from all treatments taken at day 25 were more similar to one another than those sampled at day 15. Diatoms colonizing
glass slides used in the bioassay tubes were dominated by Achnanthes linearis and Cymbella minuta. Of the 84 species found in bioassays, 26 species were present in all river samples for 4 years. Differences in the communities
discriminated by multivariate methods were cause by changes in rare species and abundance patterns of common species. 相似文献
112.
113.
Kazuhiro Nakamura Yasuhiro Goto Naoko Yoshie Yoshio Inoue 《International journal of biological macromolecules》1992,14(6):321-325
It was found that an optically active copolyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), denoted as P(3HB-co-3HV), is synthesized by Alcaligenes eutrophus H16 from several amino acids under various fermentation conditions. The optimum condition for the biosynthesis from one amino acid, threonine, was investigated and its biosynthetic pathway was discussed on the basis of the relation between the fermentation condition and the co-monomer composition of the produced polyesters. 相似文献
114.
Autocatalytic processing of procathepsin E to cathepsin E and their structural differences 总被引:1,自引:0,他引:1
S B Athauda T Takahashi T Kageyama K Takahashi 《Biochemical and biophysical research communications》1991,175(1):152-158
The processing of human gastric procathepsin E to its mature form, cathepsin E, was studied at pH 3.5. The results revealed the autocatalytic and apparently one-step conversion of procathepsin E to cathepsin E within 10 min of incubation at 14 degrees C under the conditions used. Analyses of the amino acid sequences of both procathepsin E and cathepsin E showed that cleavage occurred at the Met36-Ile37 bond to produce the mature form, cathepsin E. The NH2-terminal amino acid sequence of procathepsin E thus determined was identical with that predicted from the cDNA sequence by Azuma et al. except that the NH2-terminal glutamine residue in the latter was converted into a pyroglutamic acid residue in the former and that the glycine residue at position 2 in the latter sequence was deleted in the former. On the other hand, the NH2-terminal amino acid sequence of cathepsin E was identical with that reported previously by us. 相似文献
115.
Structural evidence for two isozymic forms and the carbohydrate attachment site of human gastric cathepsin E 总被引:1,自引:0,他引:1
S B Athauda O Matsuzaki T Kageyama K Takahashi 《Biochemical and biophysical research communications》1990,168(2):878-885
The amino acid sequences in the NH2-terminal region and some other parts of human gastric cathepsin E were investigated. The NH2-terminal sequencing revealed that the cathepsin E preparation which had been activated at pH 4.0 contained one major and one minor isozymes in an approximate molar ratio of 3:1. The NH2-terminal sequence of the former was very similar to but partly different from that predicted from cDNA sequencing by Azuma et al., whereas the latter had an NH2-terminal sequence identical with the predicted sequence. These results provide structural evidence for the presence of at least two isozymic forms in human gastric cathepsin E. In addition, the site of carbohydrate attachment was elucidated by isolation and analysis of a glycopeptide fraction from an enzymatic digest of cathepsin E. A single carbohydrate chain was deduced to be attached to the asparagine residue at position 34 in the major isozyme and to the corresponding asparagine residue in the minor isozyme. 相似文献
116.
Clinical anatomy of the blood spaces and blood vessels surrounding the siphon of the internal carotid artery 总被引:9,自引:0,他引:9
The anterior blood space of the cavernous sinus is situated anterolateral to the carotid siphon in 70%, anterior to it in 15%, and lateral to it in 15%. Its height, depth, and mediolateral breadth were measured. The mean distance between the carotid siphon and the skin at the supraorbital foramen was measured with 63 (52.4-71.4) mm. The drainage of the orbital veins was studied and described as well as the area of origin and first course of the ophthalmic artery and its clinical importance. 相似文献
117.
Kenzo Yokozeki Shigeru Yamanaka Koichi Takinami Yoshio Hirose Atsuo Tanaka Kenji Sonomoto Saburo Fukui 《Applied microbiology and biotechnology》1982,14(1):1-5
Summary Lipase from Rhizopus delemar was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymers or by binding to various types of porous silica beads. The immobilized lipase preparations thus obtained were examined for their activity in converting olive oil to an interesterified fat (cacao butter-like fat), whose oleic acid moieties at 1- and 3-positions were replaced with stearic acid moieties, in the reaction solvent n-hexane. Although all of the immobilized preparations exhibited some activity, lipase adsorbed on Celite and then entrapped with a hydrophobic photo-crosslinkable resin prepolymer showed the highest activity, about 75% of that of lipase simply adsorbed onto Celite. Entrapment markedly enhanced the operational stability of lipase.Dedicated to Professor H. Holzer, Freiburg University, on his 60th birthday (June 13, 1981) 相似文献
118.
Seasonal and areal features of the lagoonal environment in Lake Nakanoumi,a shallow coastal lagoon in Japan 总被引:1,自引:1,他引:0
Lake Nakanoumi is a shallow coastal lagoon connected with the Japan Sea by a narrow channel. Over the past decade, land reclamation resulted in a 33% reduction of the lagoon's surface area. The remaining water basin of Lake Nakanoumi is scheduled to be artificially freshened to supply irrigation water for the newly reclaimed lands. This paper deals with the seasonal and areal features of the lagoonal environment prior to the beginning of the artificial desalinization. 相似文献
119.
Masaharu Konishi Yoshio Mori Kentaro Hirai 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1982,229(2)
A gas—liquid chromatographic method for the simultaneous determination of triazolobenzophenone [2′,5-dichloro-2-(3-glycylaminomethyl-5-methyl-4H-1,2,4-triazol-4-yl)-benzophenone, TB] and its major blood metabolite, triazolam, 8-chloro-6-(o-chlorophenyl)-1-methyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine (TZ), in monkey plasma was developed. Decomposition of TB was observed during gas—liquid chromatography. In alkaline medium, TB in plasma was submitted to ring closure reaction to yield triazolo-aminoquinoline, [4-amino-7-chloro-5-(2-chlorophenyl)-1-methyl-4H-s-triazolo[4,3-a]quinoline (TAQ), while TZ remained unaffected, and TAQ and TZ in the benzene extract were assayed by gas—liquid chromatography using an electron-capture detector. The concentration ranges studied were from 5 to 40 ng of TB per 0.5 ml of plasma and from 2 to 20 ng of TZ per 0.5 ml of plasma. This method could be applied to the determination of the plasma levels of TB and TZ in monkeys following intravenous administration of a single 0.2 mg/kg dose of TB. 相似文献
120.
Rapid effects of indole-3-acetic acid (IAA) on the mechanical properties of cell wall, and sugar compositions, intrinsic viscosity and molecular weight distribution of cell wall polysaccharides were investigated with excised epicotyl segments of Vigna angularis Ohwi et Ohashi cv. Takara.
- 1 IAA caused cell wall loosening as studied by stress-relaxation analysis within 15 min after the IAA application.
- 2 IAA stimulated the decrease in the content of arabinose and galactose in the hemicellulose 1 h after its application. The amounts of other component sugars in the cell wall polysaccharides remained constant during the IAA-induced segment growth.
- 3 The intrinsic viscocity of the pectin increased as early as 30 min after the IAA application. This effect was not prevented when elongation growth of the segment was osmotically suppressed by 0.15 M mannitol.
- 4 Gel permeation chromatography of the pectin on a Sepharose 4 B column demonstrated that IAA caused increase in the mass-average molecular weight of the pectin. Analysis of the sugar compositions of the pectin eluted from the Sepharose 4 B column indicated that IAA increased the molecular weight of the polysaccharides composed of uronic acid, galactose, rhamnose and arabinose. This effect became apparent within 30 min after the IAA application. Furthermore, IAA increased the molecular weight of the pectin when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.
- 5 Hemicellulose of the cell wall chromatographed on a Sepharose CL-4 B column. Analysis of the neutral sugar compositions and the iodine staining property (specific for xyloglucans) of the polysaccharide solution eluted from the column indicated that the hemicellulose consisted of xyloglucans, arabinogalactans and polysaccharides composed of xylose and/or mannose. IAA caused a decrease in the arabinogalactan content and depolymerization of xyloglucans. These IAA effects became apparent within 30 min after the IAA application. These changes occurred even when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.