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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 67 (1984), S. 135-142 
    ISSN: 1432-2242
    Keywords: Chromosome transmission ; Pearl millet ; Trisomic series ; Trivalent frequency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Transmission rates of extra chromosomes found in the full set of trisomics of pearl millet (Pennisetum americanum) (2n = 14) were estimated by examining the progeny of selfed trisomics and the progeny of trisomics crossed to disomics. When the trisomics were selfed, ‘dark green’ and ‘tiny’ had the highest transmission rate (23.8% and 23.3%, respectively) and ‘pseudonormal’ the lowest (13.8%). Other trisomics had an intermediate rate of transmission. When the trisomics were used as females in crosses with disomics, both ‘dark green’ and ‘tiny’ again had the highest transmission rate and ‘pseudonormal’ the lowest. When the trisomics were used as males in crosses to disomics, no trisomic was transmitted to the progeny except for ‘spindle’, and this occurred with a very low frequency (2.0%). A variation in transmission rate was observed from plant to plant and season to season for the same trisomic type. A study of the transmission rate of the extra chromosomes indicated that the following factors were probably contributing to the lower rate of transmission: small- or light-weight seeds tended to have a higher proportion of trisomics than heavier seeds; lighter seeds had a lower percentage germination; a positive and significant correlation was noticed between trivalent frequency and transmission rate. Plants with reduced vigour produced a higher frequency of trisomics. Though trisomics involving longer extra chromosomes showed a high degree of pollen and ovule sterility, they were highly transmissible. This has resulted in a close relationship between gametic sterility and transmission rate of extra chromosome.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2242
    Keywords: Tertiary trisomic ; Pentavalents ; Pearl millet ; Transmission of trisomics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Nineteen tertiary trisomics were isolated from some translocation heterozygotes and interchange trisomics of pearl millet. Cytological analysis of these trisomics indicates that chromosome association of trivalents, univalents and pentavalents were frequent in all the trisomics. But their ratio varied from one trisomic to the next. Other associations were relatively infrequent. The relative frequencies of 6 pentavalent configurations observed in different trisomics were studied and their probable association with mode of fertility and transmission rates have been discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 1-13 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The major decomposition pathway involved in the fragmentation of derivatives of the title ring systems was the loss of RCN from the five-membered ring, except when this ring had a 3-amino,3-hydroxyl or 3-mercapto substituent. In these cases, the exocyclic substituent and at least one nitrogen atom from the five-membered ring were lost.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrazolo[1,5-a]pyridine undergoes fragmentation upon electron-impact by loss of HCN or C2H2N·. In the 2,3-dimethyl derivative loss of HCN and CH3CN were both observed from the [M - 1]+ ion and, in the 3-methyl-2-phenyl derivative, loss of PhCN occurred from the corresponding [M - 1]+ ion. Loss of methyl and phenyl radicals was also observed. In 3-acetyl-2-methyl and 3-benzoyl-2-phenyl derivatives, characteristic losses of the CH3CO· and PhCO· groups were noted. The introduction of a 7-methyl substituent into the six-membered ring had little effect on the fragmentation pattern.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 555-564 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of acid catalyzed decomposition of peroxodisulfate, (S2O82-) in aqueous perchlorate medium involves the hydrolysis of the species H2S2O8 and HS2O8- and the homolysis of the species H2S2O8, HS2O8- and S2O82- at the O—O bond. The overall rate law when 1.4M 〉 [HClO4] 〉 0.1M is \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{ - d[{\rm S}_{\rm 2}{\rm O}_8^{2 - }]}}{{dt}}\, = \,k_0 [{\rm S}_{\rm 2}{\rm O}_8^{2 - }]\, + \,k' [{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]\, + \,k{''}[{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]^2 $$\end{document}The constants k′ and k″ contain the hydrolysis and homolysis rate constants of HS2O8- and H2S2O8, respectively. With added Ag(I), the acid catalyzed and Ag(I) catalyzed reactions take place independently. Ag(I) catalyzed decomposition appears to involve the species AgS2O8- (aq).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 199-207 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Results on the oxidation of N3- by Br2 in neutral and acid media are presented. The rate of the reaction is found to be proportional to [N3-] and [Br2]. The gaseous product of oxidation is found to be pure nitrogen. The stoichiometry of the reaction is \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Br}_2 + 2{\rm N}_{\rm 3}^ - \to 2{\rm Br}^ - + 3{\rm N}_{\rm 2} {\rm ([N}_{\rm 3}^ -]) 〉 [{\rm Br}_2] $$\end{document} The reaction shows a positive salt effect. It is found that the addition of Br- stabilizes the complex BrN3, which decomposes into Br- and N2: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm Br}_2 + {\rm N}_{\rm 3}^ - \rightleftharpoons {\rm BrN}_{\rm 3} + {\rm Br}^ - } \\ {{\rm BrN}_3 + {\rm N}_{\rm 3}^ - \to {\rm Br}^ - + 3{\rm N}_{\rm 2} } \\ \end{array} $$\end{document} The spectroscopic measurements also support the kinetic observation. The equilibrium constant K, the rate constants and the thermodynamic parameters were calculated. It is observed that H+ ion inhibits the reaction. The mechanism is discussed in terms of the kinetic results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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