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  • Polymer and Materials Science  (5)
  • Drosophila melanogaster  (4)
  • spiroacetal  (3)
  • taxonomy  (3)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 59 (1991), S. 51-58 
    ISSN: 1570-7458
    Keywords: Overwintering ; Cold and freezing resistance ; Developmental duration ; Cold adaptation and evolution ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In temperate regions low temperatures seem to be the most restrictive factor for survival of Drosophila natural populations, which depends on the capacity of one or more developmental stages to resist unfavourable winter conditions. In this study we have attempted to answer the question of how D. melanogaster overwinters under natural temperature conditions. Only adults overwintered and no diapause was observed in any developmental stage. Thus, developmental duration becomes a decisive component with respect to overwintering potential and, therefore, the preadult stages are unlikely to overwinter. Possible evolutionary steps in adaptation to cold regions are discussed.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-041X
    Keywords: Salivary gland ; Protein synthesis ; Larval development ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Patterns of protein synthesis in the salivary glands ofDrosophila melanogaster have been studied throughout late larval and prepupal development by pulse labelling the tissues with35S-methionine. Specific changes to the pattern of proteins synthesized during development are found and the significance of these changes is discussed in view of the known changes in gene (puffing) activity which occur at the same times. We review the problem of salivary gland function in “prepupal”Drosophila.
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  • 3
    ISSN: 1573-1561
    Keywords: Enantiospecific synthesis ; enantiomers ; spiroacetal ; pheromone ; Dacus oleae ; olive fruit fly ; Diptera ; Tephritidae ; D-fructose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The synthesis of (3S,6R)-3-hydroxy-1,7-dioxaspiro[5.5]undecane (8) and its (4R)-4-hydroxy isomer (11) from (3R,4S,6R)-3,4-dihydroxy-1,7-dioxaspiro[5.5]undecane (1), obtained from D-fructose, has been accomplished by regioselective deoxygenation at C-4 and C-3, respectively, of the appropriately protected derivatives.
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  • 4
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; artificial selection ; female receptivity ; hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract A wild population ofDrosophila melanogaster was subjected to selection for high and low female receptivity. Selection was only applied in females on the basis of the mating times observed in a 30-min period. We applied a selection paradigm that allowed us to conclude that females unmated after 30 min correspond to the truncated upper tail of the distribution underlying mating times. Selection was successful, with mean mating times of about 5 min for the high lines, 35 min for the low lines, and 12 min for the control. Receptivity of the selection lines remained steady after 42 generations of relaxed selection, suggesting a lack of natural selection on receptivity in laboratory conditions. We also found a clear relationship between high or low receptivity and high or low frequency of hybridization withD. simulans males, emphasizing the role of female receptivity in maintaining isolation with its sibling speciesD. simulans.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 78 (1989), S. 243-248 
    ISSN: 1432-2242
    Keywords: Genotype × temperature interaction ; Heterosis ; Egg laying ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genotype × temperature interactions for egg laying were studied in Drosophila melanogaster using two sets of half diallel crosses: one between inbred lines of the same geographic origin, and the other between established laboratory, newly derived inbred lines from different geographic origins. The sensitivity of most genotypes to changes in temperature was adequately described as a linear regression of mean in temperature. The regression coefficients (linear sensitivities) were heterogeneous between genotypes. Hybrids were more affected by temperature variation than were inbreds. All the heterogeneity of linear sensitivities was accounted for by a linear function of the genotypic means, which strongly suggests that a scale effect is responsible for the differences in sensitivity to temperature. In contrast, no general relationship was found between standard error deviation (sensitivity to small environmental changes) and mean performance between genotypes, although hybrids tended to be less variable than inbreds. This shows that the sensitivity to environmental variation depends not only on the genotype, but also on the nature of the environmental variation. The variability within temperatures may be affected by the general homeostasis of individual genotypes, while the variability between temperatures could be the result of genes directly affecting the trait and their multiplicative interaction with the environment.
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  • 6
    ISSN: 1573-1561
    Keywords: Enantiospecific ; synthesis ; spiroacetal ; pheromone ; olive fruit fly ; d-Fructose ; Dacus oleae ; Diptera ; Tephritidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The synthesis of the title compound13 has been carried out through the preparation of its precursor, (3R,4R,5S,6R)-3,4,5-trihydroxy-1,7-dioxaspiro[5.5]undecane (6), obtained fromd-fructose using Wittig's methodology, reduction, and spiroketalation. Compound6 was transformed into13 by a Barton deoxygenation at C-5 followed by a Corey dideoxygenation at C-3,4 of the appropriately protected derivatives.
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  • 7
    ISSN: 1573-1561
    Keywords: Enantiospecific synthesis ; spiroacetal ; d-fructose ; pheromone ; Paravespula vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The synthesis of (2S,5R)-(1) and (2R,5R)-2-methyl-1,6-dioxaspiro [4.5]decane (2) from (2RS,5R,8R,9R,10S)-8,9,10-trihydroxy-2-methyl-1, 6-dioxaspiro[4.5]decane (8), obtained in five steps fromd-fructose using Wittig's methodology, reduction, and spiroketalation, has been accomplished by a Corey dideoxygenation at C-8,9, followed by a Barton deoxygenation at C-10, of the appropriately protected derivatives.
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 42 (1997), S. 271-283 
    ISSN: 0006-3525
    Keywords: poly(inosinic)-poly(cytidylic) acid ; self-modeling curve resolution ; copper(II) metal complexation ; chemometrics ; speciation ; melting behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The acid-base and copper (II) complexing properties of the heteropolynucleotide poly(inosinic)-poly(cytidylic) acid were studied by means of potentiometric, spectrophotometric, CD, and molecular fluorescence titrations in a working aqueous medium of 0.15 M ionic strength at 37°C. The study of the acid-base equilibria has proved the existence of four different species in the pH interval 2-11. Two new species are detected in the presence of copper(II) ion, at acidic and neutral pH values.Spectrophotometric, CD, melting, and fluorescence data were treated with a multivariate curve resolution procedure that allowed the determination of the number of species simultaneously present in each system [acid-base equilibria, copper(II) complexation equilibria], and the estimation of their concentration profiles and of the pure spectra for each species. From the concentration profiles an unambiguous assignment of which species are present at any pH conditions can be made. Furthermore, the knowledge of the pure uv-visible, fluorescence, and CD spectra recovered by the proposed resolution method for each species brings important structural information. When this mathematical approach was applied to the thermal denaturation data, the melting profile and the uv pure spectra for all the different species or conformations formed in the melting process, were calculated. © 1997 John Wiley & Sons, Inc. Biopoly 42: 271-283, 1997
    Additional Material: 12 Ill.
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  • 9
    ISSN: 1040-0397
    Keywords: Continuous stripping voltammetry ; Zinc ; Cadmium ; Simultaneous ; Biological samples ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A flow-injection (FI) voltammetric-stripping method for the simultaneous determination of Cd and Zn is proposed after a systematic study of the variables affecting the method. The low determination limits, 1 × 10-9 and 5 × 10-9 M (detection limits 8 × 1010- and 2 × 10-9 M for Cd and Zn, respectively), and rsd. values, 1.57 and 5.16% for Cd and Zn, respectively, allow one to apply the method to real samples (biological tissues and reference materials) with good results. No formation of intermetallic compounds was detected.
    Additional Material: 2 Ill.
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  • 10
    ISSN: 1040-0397
    Keywords: Lyophilization ; Digestion ; Flow-injection analysis ; Anodic stripping voltammetry ; Simultaneous determination ; Copper ; Lead ; Cadmium ; Zinc ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Improvements in three main aspects of the analysis of metal traces in biological tissues are proposed, namely: (a) lyophilization of the samples both to preserve them and to favor the digestion process; (b) digestion of the lyophilized tissues using an effective and fast procedure; and (c) automatic determination of the target analytes by flow-injection analysis/anodic stripping voltammetry (FIA/ASV). After optimization of these steps, the overall procedure was successfully applied to the simultaneous determination of copper, lead, cadmium, and zinc in certified reference materials (CRMs) and fresh bovine liver samples with good results. Finally, the performance of the method was validated by a statistical study using parameters of the certification campaign of the CRMs; the results obtained being within, or close to, the confidence levels of the certification campaign.
    Additional Material: 3 Ill.
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