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81.
Fitness and its components in Drosophila melanogaster were estimated under the homozygous condition. All of these parameters, except for egg-to-adult viability and female fecundity, were measured under interspecific competition with D. hydei. The following results were obtained: (1) Significant genetic variation was detected in fitness, productivity, adult viability, total egg-to-adult viability and female fecundity. (2) Significant correlation was obtained between fitness and productivity (rp = 0.792 for phenotypic correlation, rg = 0.945 for genotypic correlation), between fitness and total egg-to-adult viability (rp = 0.355, rg = 0.395), and between fitness and female fecundity (rp = 0.451, rg = 0.511). (3) There was no significant correlation between total egg-to-adult viability and fecundity (rp = -0.046). The biological implications of the interrelationship between fitness and its components are discussed. 相似文献
82.
K Miyamura K Yamashita S Yamadera N Kato M Akatsuka S Yamazaki 《Japanese journal of medical science & biology》1990,43(2):51-58
Laboratory reports of isolation of echovirus serotype 18 (E18) slightly increased in the summer of 1987 followed by a sharp increase with a peak in July, 1988. A total of 1,094 isolations were reported during these two years from 39 laboratories participating in the National Epidemiological Surveillance of Infectious Agents in Japan. When compared with the previous E18 outbreaks, a higher proportion of children at two years of age or under (58.3%) and a much higher incidence of exanthem (46.4%) were remarkable. Meningitis-associated isolations were reported in 30.6%, less than half of the percentage of the previous epidemic. 相似文献
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The nature of the acid-alkaline conversion of horseradish peroxidases was studied by measuring four rate constants in reactions, E + H+ (k1) in equilibrium (k2) EH+ and E + H2O (k3) in equilibrium (k4) EH+ + OH-, where EH+ and E denote the acid and alkaline forms of the enzymes. The values of k1, (k2 + k3), and k4 were obtained by measuring the relaxation rates of the acid leads to alkaline and alkaline leads to acid conversions by means of th pH jump method with a stopped-flow apparatus. The value of k3 could also be obtained by measuring the rate of reactions between hydrogen peroxide and peroxidases at alkaline pH. The measurements were conducted with four peroxidases having different pKa values: peroxidase A )pKa = 9.3), peroxidase C (pKa = 11.1), diacetyldeuteroperoxidase A (pKa = 7.7), and diacetyldeuteroperoxidase C (pKa = 9.1). The value of k1 was about 10(10) M-1 s-1 in the reaction of the four enzymes while k4 was quite different between the enzymes. The pKa was determined by k3 and k4 for the natural peroxidases and by k1 and k2 for the diacetyldeuteroperoxidases. The mechanism of the acid-alkaline conversion was discussed in comparison with that of metmyoglobin. 相似文献
85.
Plant growth-promoting activities of alkoxycarbonylisoureas in relation to their chemical structures
Masami Ogawa Kozo Oyamada Takashi Matsui Junzo Tobitsuka Yoshio Yamazaki 《Phytochemistry》1976,15(12):1829-1835
A number of alkoxycarbonylisourea derivatives were synthesized and their plant growth-promoting activities examined by the rice (Oryza sativa) seedling test. Isourea compounds with an appropriate substituent such as a halogen atom or a methyl, ethyl or methoxy group at the para-position on a benzene ring in 1-alkoxycarbonyl-2-alkyl-3-phenylcarbamoylisoureas promoted the growth of rice seedlings and acted as a highly active gibberellic acid-synergist when used in combination with gibberellic acid. The common structural requirements of isourea derivatives applied well for a growth promoter and a gibberellic acid-synergist. 相似文献
86.
Saccharomycodes ludwigii, supposed to be petite-negative, gave rise to respiration-deficient mutants when acriflavine and ultraviolet irradiation, respectively, were applied to this yeast, strain IFO 1194. The frequency of such mutants was very low as compared with that in Saccharomyces cerevisiae and other petite-positive yeasts. Cytochrome composition was characterized by spectrophotometry at the temperature of liquid nitrogen. The respiratory mutants examined contained cytochrome c unaltered in quality and quantity. Cytochrome b was often present only in small amounts though never absent, while cytochrome a+a3 was either present or absent. The respiratory mutants could form zygotes after conjugation with a wild-type culture of opposite mating type ( vs. a). The hybridization and segregation analysis of spore tetrads showed the inheritance of respiratory mutant character to be either Mendelian or non-Mendelian and similar to that of pet (nuclear) and rho- (cytoplasmic) mutants, respectively, in Saccharomyces cerevisiae. 相似文献
87.
The stability of oxyperoxidases increased in the order meso- < proto < chlorocruoro- < diacetylperoxidases, which was an increasing order of electron-withdrawing capacities of 2,4-substituents of deuteroheme and the ratio of Δlogk1toΔpK3 was approximately 0.6 in the two series of isoenzyme preparations, horseradish peroxidases A and (B + C), where k1andpK3 represent a rate constant for conversion from an oxyperoxidase to the ferric enzyme and a measure of basicity of pyrrole nitrogen of the substituted deuterohemes, respectively. Deutero-oxyperoxidases A and (B + C) were definitely more stable than expected from the above linear relationship. The stability of peroxidase Compound I also varied with the 2,4-substituents, but it did not necessarily correlate with electron-withdrawing capacities of the substituents. Natural peroxidases formed relatively stable Compound I in both series of the isoenzymes. From these results it was concluded that the stability of oxyperoxidases was affected by the electron density at the iron atom of the enzyme while steric factors might be involved in stabilizing Compound I. 相似文献
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