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231.
Latency-dependent responses to artificial electric stimuli in 11 species of the Nilotic mormyrids were studied. In total, more than 350 poststimulus time histograms from 132 individuals were analyzed. All species studied exhibited the latency-dependent responses. Both main types of responses – phase locking and phase avoidance behavior or the preferred latency response (PLR) and preferred latency avoidance (PLA) – were found in eight species (Brevimyrus niger, Hippopotamyrus pictus, Marcusenius cyprinoides, Mormyrus kannume, M. hasselquistii, Petrocephalus bane, P. bovei and ‘Pollimyrus’ petherici), while only PLR were recorded from the remaining three species (Hyperopisus bebe, Mormyrops anguilloides and Mormyrus caschive). In eight species both types of behavior were found in fish of the same sex. In four species both types of behavior were found both in females and males. Finally, in four species both types of behavior were revealed in the same individual (in total, there were eight such individuals). In some individuals of different species the atypical responses with substantially increased latencies (compared to the typical PLR and PLA) were observed. The possible role of the phase locking and phase avoidance behavior in the mormyrid electrolocation and communication is discussed. 相似文献
232.
The juvenile specimen of Cyclopteropsis jordani from the Kara Sea was first found and described. According to the trapezoid form of the first dorsal fin, the largest length of its median rays, slightly lateral compression of the body and the number of rays in the dorsal, anal and pectoral fins, the juvenile is classified as Cyclopteropsis jordani. From one-size juvenile of Eumicrotremus derjugini it is distinguished by the complete absence of bone plaques. 相似文献
233.
Dolgoleva G. V. Ermolovich V. F. Ivanovsky A. V. Orlov A. P. 《Plasma Physics Reports》2003,29(9):764-767
Plasma Physics Reports - The feasibility is considered of igniting thermonuclear reaction during the gas-dynamic compression of a capsule filled with a gaseous DT mixture by a compact high-speed... 相似文献
234.
235.
分析克拉玛依市麻疹流行状况及预防控制措施,为消除麻疹提供依据。采用描述流行病学分析方法,对2008年克拉玛依市麻疹资料进行分析。结果显示,克拉玛依市2008年麻疹发病率为38.83/10万(138/355381),呈高度散发,较2007年有所上升。发病高峰在3~5月,发病数占全年的83.33%。年龄分布大年龄组高于小年龄组,>20岁年龄组病例占50.00%,<1岁病例占18.84%;流动人口发病占51.11%。应切实提高麻疹常规免疫接种率和做好入托、入学儿童查验预防接种证工作,加强麻疹监测,提高实验室确诊病例的比例。 相似文献
236.
Yu. M. Borisov A. I. Kozlovsky A. E. Balakirev T. B. Demidova S. Yu. Irchin V. M. Malygin N. M. Okulova S. G. Potapov A. N. Shchipanov V. N. Orlov 《Contemporary Problems of Ecology》2008,1(5):583-589
Cytogenetic analysis of the common shrew populations in the Valdai Hills revealed the presence of four distinct chromosome races (Western Dvina, Seliger, St. Petersburg, and Moscow). The geographic distribution of these races relative to the borders of the Late Valdai glaciation area is described and discussed. Five contact zones between chromosomal races were found, located directly on the ice-marginal formations of the Veps stage. Two races, Seliger and St. Petersburg, are located exclusively in the former ice sheet area. Attention is drawn to the fact that many of the races located in the last glacial area from the Valdai Hills through Scandinavia are characterized by endemic chromosomes (gi, gp, mo, or, etc.). It is concluded that the situation in the former glaciation area could favor the preservation of tundra or forest vegetation refuges and populations of some small mammal species. 相似文献
237.
238.
A. N. Fesenko N. A. Provorov Irina F. Orlova V. P. Orlov B. V. Simarov 《Plant and Soil》1995,172(2):189-198
From an analysis of 481 Rhizobium leguminosarum bv. viceae strains with 7 pea cultivars in pot and field experiments, we demonstrated that effective strains could be isolated from a rich medium-acid grey forest soil of the Oröl area (Central region of the European part of Russia) but not from a poor acid podzolic soil of the St. Petersburg area (North-West Russia). The proportion of the isolates significantly increasing N accumulation in pea plants (10.2%) is higher than that of strains increasing the shoot dry mass (4.6%) in the pot experiments. The mean values of the increase for N accumulation (33.8%) upon inoculation are also higher than for shoot mass (27.0%) in these experiments. N accumulation in the inoculated pea plants in the pot experiments was significantly correlated with seed yield and seed N accumulation in field experiments, while for shoot dry mass these correlations were either weak or not significant. Two-factor analysis of variance demonstrated that the contribution of plant cultivars to the variation of the major symbiotic efficiency parameters is higher (30.8–31.6%) and contributions of cultivar-strain specificity is lower (5.4–8.8%) than the contributions of strain genotypes (13.4–14.9%). We identified an ineffective R. leguminosarum bv. viceae strain 50 which can be used as a tester for assessing the nodulation competitiveness of the effective strains by an indirect method (analysis of dry mass and N accumulation in pea plants inoculated with the mixture of the tested effective strains and the tester strain). The relative competitive ability (RCA) determined by this method was 75.7–82.8% for strain 52 but only 10.5–13.8% for strain 250a; this difference was confirmed by a direct method (use of the streptomycin-resistant mutants). Results of screening of the diverse collection of 53 effective R. leguminosarum bv. viceae strains by the indirect method permits us to divide them into 3 groups (32 high-competitive, 10 medium-competitive and 11 low-competitive strains) but reveals no correlation between the competitiveness and symbiotic efficiency. N accumulation in the pea shoots is demonstrated to be a much more suitable criterion than the shoot mass for selection either of the highly-effective or of highly-competitive (by the indirect estimation) R. leguminosarum bv. viceae strains in the pot experiments. 相似文献
239.
The catalytic domains of murine Golgi alpha1,2-mannosidases IA and IB that
are involved in N-glycan processing were expressed as secreted proteins in
P.pastoris . Recombinant mannosidases IA and IB both required divalent
cations for activity, were inhibited by deoxymannojirimycin and
kifunensine, and exhibited similar catalytic constants using
Manalpha1,2Manalpha-O-CH3as substrate. Mannosidase IA was purified as a 50
kDa catalytically active soluble fragment and shown to be an inverting
glycosidase. Recombinant mannosidases IA and IB were used to cleave
Man9GlcNAc and the isomers produced were identified by high performance
liquid chromatography and proton-nuclear magnetic resonance spectroscopy.
Man9GlcNAc was rapidly cleaved by both enzymes to Man6GlcNAc, followed by a
much slower conversion to Man5GlcNAc. The same isomers of Man7GlcNAc and
Man6GlcNAc were produced by both enzymes but different isomers of
Man8GlcNAc were formed. When Man8GlcNAc (Man8B isomer) was used as
substrate, rapid conversion to Man5GlcNAc was observed, and the same
oligosaccharide isomer intermediates were formed by both enzymes. These
results combined with proton-nuclear magnetic resonance spectroscopy data
demonstrate that it is the terminal alpha1, 2-mannose residue missing in
the Man8B isomer that is cleaved from Man9GlcNAc at a much slower rate.
When rat liver endoplasmic reticulum membrane extracts were incubated with
Man9GlcNAc2, Man8GlcNAc2was the major product and Man8B was the major
isomer. In contrast, rat liver Golgi membranes rapidly cleaved
Man9GlcNAc2to Man6GlcNAc2and more slowly to Man5GlcNAc2. In this case all
three isomers of Man8GlcNAc2were formed as intermediates, but a distinctive
isomer, Man8A, was predominant. Antiserum to recombinant mannosidase IA
immunoprecipitated an enzyme from Golgi extracts with the same specificity
as recombinant mannosidase IA. These immunodepleted membranes were enriched
in a Man9GlcNAc2to Man8GlcNAc2- cleaving activity forming predominantly the
Man8B isomer. These results suggest that mannosidases IA and IB in Golgi
membranes prefer the Man8B isomer generated by a complementary mannosidase
that removes a single mannose from Man9GlcNAc2.
相似文献
240.
Concentrations of cefotaxime and its major active metabolite, desacetylcefotaxime, were determined in the serum and bronchial secretion of patients with chronic bronchitis aggravated after intramuscular injection of cefotaxime in a dose of 4 g once a day. Characteristic patterns of cefotaxime metabolism and high peak concentrations of desacetylcefotaxime in the serum (67.6 +/- 17.2 micrograms/ml) defined the prolonged retention of the metabolite both in the blood and bronchial secretion. The metabolite concentrations in more than half of the patients maintained within 2 micrograms/ml in the bronchial secretion by the 12th hour after the injection and in the blood serum by the 24th hour. Therefore, 4 g cefotaxime administered intramuscularly once a day provided the blood concentrations of the metabolite comparable with the MIC for the majority of the pathogens causing nosocomial infections of the respiratory tract practically within the whole period of the daily dosage. In the bronchial secretion such concentrations were attained within half of the period of the daily dosage. 相似文献