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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 69 (1985), S. 437-441 
    ISSN: 1432-2242
    Keywords: Inversion karyotypes ; Relative fitness ; Heterosis in interpopulation crosses ; Coadaptation ; Drosophila ananassae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The relative viabilities of homozygous and heterozygous karyotypes were measured by making crosses between strains ofD. ananassae homozygous for ST or inverted gene orders in the second and third chromosomes. The strains utilized during the present study originated from widely separated localities in India, Kuala Lumpur and Kota Kinabaru, Malaysia and Chian Mai, Thailand. The presence of heterosis in many interpopulation crosses is evident from the results which show that the inversion heterozygotes formed by chromosomes coming from distant populations exhibit heterosis. On the other hand, heterosis is absent in two intrapopulation crosses. Thus the present results provide evidence that heterozygosis for many genes and gene complexes does produce high fitness without previous selectional coadaptation.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 18 (1988), S. 357-369 
    ISSN: 1573-3297
    Keywords: Drosophila ananassae ; selection ; high and low mating propensity ; polygenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract InDrosophila ananassae, artificial selection was carried out for high and low mating propensity for 15 generations. Response to selection was from about F5, with rapid divergence in mating frequencies in replicates of both fast and slow lines. To assess the effect of selection on the two sexes, females and males of the selected lines were tested against their respective counterparts of the control line after 15 generations. Significant differences in mating propensity were observed when selected males were tested against the control females, which suggests that males were much more affected by selection than females. After 15 generations the fast and slow lines (both replicates) were crossedinter se and mating frequencies of F1 hybrids were studied in the same way as during the selection experiment. F1 flies had a higher mating activity compared to their parental lines when males were derived from fast lines to produce hybrids. On the other hand, F1 hybrids produced by crossing slow-line males with fast-line females showed mating frequencies similar to those of the slow parental lines. These findings suggest that mating propensity inD. ananassae is under the control of polygenes. Furthermore, the significant differences in mating propensity of hybrids produced by the fast and slow males indicate the possibility of a Y-linked influence on mating propensity inD. ananassae.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 23 (1993), S. 239-243 
    ISSN: 1573-3297
    Keywords: Drosophila ananassae ; selection ; high and low pupation height ; polygenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for high and low pupation height inDrosophila ananassae was carried out for 10 generations. Response to selection resulted in rapid divergence in pupation height in replicates of both high and low lines. There was a significant difference in mean pupation height among high, low, and control lines. Regression coefficients for both high and low lines were significantly different from zero. The realized heritability over 10 generations was 45–49 for the high lines and 26–29 for the low lines. The F1 hybrids produced by making reciprocal crosses between high and low lines showed intermediate pupation height. These findings suggest that pupation height inD. ananassae is under polygenic control, with a substantial amount of additive genetic variation.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Genetica 97 (1996), S. 321-329 
    ISSN: 1573-6857
    Keywords: Drosophila ananassae ; population and behaviour genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Drosophila ananassae is a cosmopolitan and domestic species. It occupies a nuique status among the Drosophila species due to certain peculiarities in its genetic behaviour. The most unusual feature of this species is spontaneous male recombination in appreciable frequency. The present review summarises the work done on population and behaviour genetics of D. ananassae from India. Population dynamics of three cosmopolitan inversions has been studied in Indian population of D. ananassae and it is evident from the results that there is a considerable degree of genetic divergence at the level of inversion polymorphism. In general, the populations from south India show more differentiation than those from the north. These three cosmopolitan inversions, which are coextensive with the species, exhibit heterosis. Interracial hybridization does not lead to beaakdown of heterosis, which suggests that evidence for coadaptation is lacking in geographic populations of D. ananassae. Heterosis appears to be simple luxuriance rather than populational heterosis (coadaptation). Unlinked inversions occur in random associations, indicating no interchromosomal interactions. However, two inversions of the third chromosome often show strong linkage disequilibrium in laboratory populations, which is due to epistatic gene interaction and suppression of crossing-over. Genetic variations for certain allozyme polymorphism and sternoleural bristle phenotypes in Indian populations of D. ananassae have also been observed. A number of investigations have also been carried out on certain aspects of behaviour genetics of Indian D. ananassae. There is evidence for sexual isolation within D. ananassae. Significant variations in mating propensity of several isofemale strains, inversion karyotypes, the diminishing effects of certain mutations on sexual activity of males and positive response to selection for high and low mating propensity provide evidence for genetic control of sexual behaviour in D. ananassae. Males contribute more to variation and thus are more subject to intra-sexual selection than females. Evidence for rare male mating advantage has also been presented. Geographic strains of D. ananassae show variation with respect to oviposition site preference. The results of studies on pupation site preference, which is an important component of larval behaviour, suggest that larval pupation behaviour in D. ananassae is under polygenic control with a substantial amount of additive genetic variation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 13 (1975), S. 2075-2086 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetics of vinyl polymerization of acrylonitrile initiated by the redox system tartaric acid-V5+ have been investigated in aqueous sulfuric acid in the temperature range 30-40°C. The rates of polymerization and V5+ disappearance and the chain lengths of polyacrylonitrile were measured. From the results it is concluded that the polymerization reaction is initiated by an organic free radical arising from the V5+-tartaric acid reaction with termination by V5+ ions. A suitable kinetic scheme has been proposed, and the various rate and energy parameters were evaluated.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 1165-1171 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Kelen-Tüdös linear graphical method was used to determine the copolymerization parameters of some halogen-substituted (e.g., Cl, Br, I) aniline monomers. It was found during copolymerization with p-aminobenzoic acid or p-aminophenol that the reactivity of these monomers followed the order of their basic strength. The order of their basic strength. The order of their reactivity, however, was reversed if they copolymerized with sulfanilic acid (SA). This reversal has been interpreted in terms of the resonance stabilization of monomers, the nature of the acidic functional groups present in the comonomer, and the influence of electron-accepting or electron-donating groups present in the comonomers.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 10 (1972), S. 2655-2660 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nature and behavior of free radicals induced in acetylated cotton celluloses irradiated with γ-rays have been studied by electron spin resonance (ESR) spectroscopy. Dehydrogenation and deacetylation appear to be responsible for the free radicals observed from samples irradiated at 77°K. The degree of substitution enhanced the yield of acetyl radicals when the samples were irradiated at 77°K and adversely affected the overall radical concentration when irradiation was done at 300°K. In addition, the ESR spectra of samples irradiated under vacuum at 300°K were more intense than those obtained from samples irradiated in air. The nature, yield, and post-irradiation behavior of the primary radicals are discussed in the light of the ultimate chemical effects observed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With a view to assessing the role of chemical substitutions in the modification of radiation effects on cotton fibers, the induction and post-irradiation behavior of free radicals in γ-irradiated pure, mercerized, benzoylated, and allylated cottons have been investigated by ESR spectroscopy. While mercerization and allylation were found to influence both the nature and yield of radicals, benzoylation reduced only the yield. These substitutions, which have been found to protect cotton fibers against radiation damage, therefore act differently at the molecular level.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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