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31.
Estimation of the size of freshwater ciliate populations by a sub-sampling technique 总被引:4,自引:4,他引:0
Paolo Madoni 《Hydrobiologia》1984,111(3):201-206
A technique is described for the estimation of the size of ciliate populations based on replicated counts. Sample drops were
taken by automatic pipettes of different volume from activated sludge and from a small oligotrophic stream. Specific aims
were: 1) the estimation of the number of species; 2) the estimation of the number of individual in each species; 3) the selection
of a suitable sub-sample size and number of replicates. For each volume the cumulative increase in species taken in successive
sub-samples was determined. For each species the minimum permissible sub-sample volume and the number of replicates required
for an allowable error of 10% and 25% were determined. Lastly, the relationship between the mean number of individuals counted
for each species and the relative coefficient of variation was visualized. 相似文献
32.
Dion tomasellii sp. nov. occurs with an interrupted distribution from Guerrero to central Sonora. It is characterized by falcate to subfalcate leaflets. The populations from Sonora and northern Sinaloa are segregated asD. tomasellii var.sonorense on the basis of their narrower and glaucous leaflets. 相似文献
33.
Giorgio M. Hanozet Barbara Giordana Paolo Parenti Andrea Guerritore 《The Journal of membrane biology》1984,81(3):233-240
Summary In brush border membrane vesicles from the midgut ofPhilosamia cynthia larvae (Lepidoptera) thel- andd-alanine uptake is dependent on a potassium gradient and on transmembrane electrical potential difference. Each isomer inhibits the uptake of the other form: inhibition ofl-alanine uptake byd-alanine is competitive, whereas inhibition ofd-alanine uptake byl-alanine is noncompetitive. Transstimulation experiments as well as the different pattern of specificity to cations suggest the existence of two transport systems. Kinetic parameters for the two transporters have been calculated both when Kout>Kin and Kout=Kin.d-alanine is actively transported also by the whole midgut, but it is not metabolized by the intestinal tissue. 相似文献
34.
J Granados D V Cramer J B Caputo D Marcus C A Alper 《Journal of immunology (Baltimore, Md. : 1950)》1984,133(1):405-407
The complement protein C6 has been shown to be genetically polymorphic in the rat. Isoelectric focusing of plasma samples from 19 inbred strains demonstrated two electrophoretically distinguishable migration patterns, each consisting of three bands. Breeding studies with the use of the BN and DA strains showed that the C6 patterns were inherited in a manner consistent with the co-dominant autosomal expression of two alleles (C6 A and C6 B). The distribution of the C6 alleles in a backcross mating was compared with eight independently segregating marker genes: RT1.A, RT2, Gdc -1, Igk-1, Hbb, Svp-1, Fh-1, and Es-6. There was no detectable linkage between C6 and any of these eight loci. 相似文献
35.
G Scala G Caputo M Corona G Colella 《Bollettino della Società italiana di biologia sperimentale》1983,59(4):439-443
The structural and histological characteristics of the limiting layer between the cortex and medulla of the bursa of Fabricius in the duck are described in relation to different functional moments of the organ. On E.M. study the limiting layer, in duck having 30 days of age, is constituted of reticular-epithelial cells palisades in shape with many cytoplasmics extension. Lymphatic migration occur in interstitial spaces. 相似文献
36.
The isomerization of poly-L -proline in different solvents has been studied by NMR spectroscopy. Different resonance signals for the CHα protons have been obtained for the two different helical conformations of thus compound, namely form I and form II. 相似文献
37.
38.
39.
The effect of tryptophan on the biosynthesis of proline has been investigated. Cells of Daucus carota grown in B5 medium supplemented with 5×10–4M tryptophan acquired the ability to grow in the presence of inhibitory concentrations of azetidine-2-carboxylic acid, an analog of proline. When trp was added to carrot cell cultures at sub-growth inhibiting concentrations, overproduction of intracellular free proline was observed. An increase was also observed for lys, his, ala, leu and phe. Likewise, the addition of asparagine, glutamic acid and phenylalanine to the medium stimulated the intracellular increase of free proline and other amino acids.Abbreviations A2CA
azetidine-2-carboxylic acid
- 2,4-D
2,4-dichlorophenoxyacetic acid
- 5MT
5-methyltryptophan
- P5C
pyrroline-5-carboxylic acid
- f.wt.
fresh weight
- d.wt.
dry weight 相似文献
40.
Analyses of wheat/rye addition lines by Southern blotting confirmed the presence of sequences related to theSec 1, Sec 2, andSec 3 loci on chromosomes 1R and 2R. Comparison of the 1R and 2R addition lines allowed the identification of -secalin genes atSec 1 andSec 2, respectively, while -secalin and -secalin genes atSec 1 were discriminated by comparative hybridization with three probes: -secalin, total -secalin, and 3 -secalin. The high molecular weight (HMW) secalin genes atSec 3 were identified using a homologous HMW subunit probe from wheat. Gene copy numbers were estimated as about 40–60 for -secalins, 5–10 for -secalins, and 2 for HMW secalins. Comparison of individual plants of cv. Gazelle showed a high degree of polymorphism, particularly for sequences related to -secalins and HMW secalins. 相似文献