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101.
Estimation of the distribution of the level of individual heterozygosity within natural populations is explored with both Monte-Carlo simulation studies and data from natural populations. Simulations indicate that heterozygosities estimated from as few as a dozen randomly chosen loci may, to some degree, reflect (r = 0.35) heterozygosity determined by 100 independent loci. The shape of the expected distribution of heterozygosity is heavily dependent upon levels of heterozygosity at the loci. Complete genetic data for 12 loci from 997 Fundulus heteroclitus are used to describe the distributions of heterozygosity for different localities, for age classes and for sexes. The distributions deviate from normality. Distributions from different localities are not different, but the distributions are heterogeneous among age classes at one of two localities and are heterogeneous between the sexes. 相似文献
102.
Distribution-free regression analysis of grouped survival data 总被引:1,自引:0,他引:1
Methods based on regression models for logarithmic hazard functions, Cox models, are given for analysis of grouped and censored survival data. By making an approximation it is possible to obtain explicitly a maximum likelihood function involving only the regression parameters. This likelihood function is a convenient analog to Cox's partial likelihood for ungrouped data. The method is applied to data from a toxicological experiment. 相似文献
103.
Cytosolic location of an endo-N-acetyl-beta-D-glucosaminidase activity in rat liver and kidney. 下载免费PDF全文
Endo-N-acetyl-beta-D-glucosaminidase activity towards an oligomannosidic type glycoamino acid substrate was found in the soluble fraction of rat liver and kidney. No evidence for a lysosomal form of the activity was found. 相似文献
104.
J. Edson Pontes James M. Pierce Jr. Byung-Kil Choe Noel R. Rose 《In vitro cellular & developmental biology. Plant》1979,15(7):469-472
Summary Studies of acid phosphates produced by cell lines MA 160 and EB 33 demonstrated immunochemically their prostatic origin. MA
160 and EB 33, rather than being HeLa contaminants, may be hybrids of prostatic epithelial and HeLa cells or true prostatic
cell lines with chromosomal changes common to all long-term cultivated cell lines.
This research was supported by NIH (Cancer) Research Grants Nos. 18748 and 16426; and Detroit General Hospital Research Corporation. 相似文献
105.
Richard N. Pierce Peter I. Jatlow 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1979,164(4):471-478
We describe a method for measuring adriamycin and its major metabolite, adriamycinol, in plasma, using reversed-phase high-performance liquid chromatography and fluorescence detection. The lower limit of detection is approximately 1 ng/ml for both compounds; within-day coefficients of variation are 3.6% and 4.4% for adriamycin and adriamycinol, respectively. A slight modification of this procedure also allows measurement of aglycone metabolites. 相似文献
106.
107.
108.
Regulatory Properties of the ADP-Glucose Pyrophosphorylase of the Blue-Green Bacterium Synechococcus 6301 下载免费PDF全文
ADP-glucose was found to be the primary sugar nucleotide used for glycogen synthesis by Synechococcus 6301. ADP-glucose pyrophosphorylase was partially purified 12-fold from this blue-green bacterium. The enzyme was activated 8- to 25-fold by glycerate 3-phosphate. Fructose 6-phosphate, fructose 1,6-bisphosphate, 5'-adenylate, and adenosine diphosphate activated the enzyme, but less than glycerate 3-phosphate. The enzyme was inhibited by inorganic phosphate. The I(0.5) of phosphate was 0.072 mm, and in the presence of 2 mm glycerate 3-phosphate, increased to 1.8 mm. The substrate saturation curves for glucose 1-phosphate and ATP were hyperbolic in both the presence and absence of glycerate 3-phosphate or phosphate. The saturation curve for MgCl(2) was sigmoidal; 2 mm glycerate 3-phosphate decreased the sigmoidicity from a Hill slope n value of 5.6 to 2.8, and increased the MgCl(2) optimum from 3 mm to 6 to 7 mm. 相似文献
109.
The carrier-mediated transport of GABA in rat brain synaptosomes was strongly and permanently inhibited byl-2,4-diaminobutyric acid (DAB). In order to discriminate between carrier-mediated and non-carrier-mediated release of [3H]GABA, synaptosomes prelabeled with 0.5 M [3H]GABA in the presence of 100 M DAB, or with 0.2 M [3H]GABA without DAB, were superfused in conditions stimulating the release of [3H]GABA. Only the release elicited by unlabeled GABA or DAB (by homo- and heteroexchange, respectively) was strongly inhibited in DAB-pretreated synaptosomes. The spontaneous release and the release induced by 56 mM KCl in the presence of CaCl2, by the ionophore A23187, by ouabain, by lack of K+, or by purified black widow spider toxin were unaffected or only barely decreased in DAB-treated synaptosomes, and therefore do not seem to be mediated by the DAB-blocked GABA carrier. 相似文献
110.
The effects of the ionophore A23187 and of ouabain on the release of [3H]GABA and [3H]norepinephrine were studied in superfused rat brain synaptosomes. Each of the two drugs moderately stimulated the spontaneous release of [3H]GABA, but greatly potentiated the release of [3H]GABA induced by unlabeled GABA. In contrast, the ionophore and norepinephrine showed an additive, but not a supraadditive, releasing effect on synaptosomal [3H]norepinephrine. Ouabain modestly and transiently potentiated the norepinephrine-induced [3H]norepinephrine release, which, however, was inhibited by the drug after a few minutes. It is suggested that in the new intrasynaptosomal ionic conditions determined by the two drugs, the stoichiometry of the basal homoexchange of GABA is changed in a direction favoring net outward transport. 相似文献