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  • Hymenoptera  (2)
  • Bronchopulmonary dysplasia  (1)
  • EnterotoxigenicEscherichia coli  (1)
Materialart
Erscheinungszeitraum
  • 1
    ISSN: 1570-7458
    Schlagwort(e): Hymenoptera ; Symphyta ; Diprionidae ; sawfly ; pest insect ; semiochemical ; chemical communication ; diprionol ; 3,7-dimethyl-2-pentadecanol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae), is a widespread and economically important forest insect. The sex pheromone communication system of this species has been previously investigated in North America, Japan and Europe, with the acetate or propionate of the alcohol (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) shown to be the main pheromone component. In some locations, male attraction either increased or decreased by the addition of the (2S,3R,7R)-diprionyl acetate isomer. However, these studies were made with different batches of synthetic pheromones, with different types of traps and according to different procedures, so the observed differences might not reflect true geographic variation. Here we investigate the geographic pattern of male sawfly response by using identical chemicals, traps and experimental procedures at eight field sites ranging from Japan in the east to Canada in the west. We found an increased inhibitory effect of the (2S,3R,7R)-isomer from Japan and Siberia to Europe. At the eastern sites, increasing amounts of the (2S,3R,7R)-isomer up to and equal to the amount of the (2S,3S,7S )-isomer, did not influence the trap catch, whereas at sites in Europe, as little as 1% of the (2S,3R,7R)-isomer almost completely inhibited the attraction. The response of the North American population was intermediate. The only site in which the (2S,3R,7R)-isomer was essential for the attraction of males was in Siberia. A similar pattern was found for the (2S,3R,7S)-isomer. Both the acetate and the propionate form of the (2S,3S,7S)-isomer were attractive by themselves in Japan, Europe and North America, and neither the (2S,3R,7S)-isomer nor the (2S,3R,7R)-isomer alone were attractive, in the acetate or propionate form. We discuss the significance of our findings for the development of more efficient monitoring schemes and for the causes of population divergence and speciation in the European pine sawfly.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1572-8889
    Schlagwort(e): Hymenoptera ; Athalia rosae ; egg deposition behavior ; mating ; eye color mutation ; primary sex ratio
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The egg deposition behavior of the turnip sawfly, Athalia rosae (Hymenoptera: Symphyta), is described. Both unmated and mated females lay eggs individually inside of fresh young leaves of cruciferous plants. During an oviposition event, females exhibit a distinct pause in abdominal contractions just before the actual egg deposition act. Unmated females show a longer pause (11.31 s on average) than mated females (4.38 s on overall average). By employing an eye color mutation, the sex of the eggs laid by females was ascertained. Females mated once lay mostly fertilized (diploid female) eggs initially but begin to lay a considerable number of unfertilized (haploid male) eggs later in life. The laying of an unfertilized egg is associated with a longer pause (6.98 s on average) than the laying of a fertilized egg (3.76 s on average). These results are in contrast to previous reports on apocritan Hymenoptera, where the presence of a pause or a longer pause during oviposition was associated with the deposition of fertilized eggs rather than unfertilized eggs. The possibility that mated Athalia rosae females control fertilization and its implications for sex allocation strategies are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-1076
    Schlagwort(e): Respiratory distress syndrome ; Surfactant replacement ; Bronchopulmonary dysplasia ; Intraventricular haemorrhage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We conducted a prospective, randomized, controlled trial comparing the efficacy of two doses of a reconstituted bovine surfactant (Surfactant TA) in premature infants requiring mechanical ventilation shortly after birth for respiratory distress syndrome. Forty-six infants weighing 1000–1499 g were randomized into two groups: a low-dose group (23 infants given a single dose of 60 mg surfactant lipid/kg) and a high-dose group (23 infants given a single dose of 120 mg/kg). The mean (SD) age at which surfactant was given was 5.5 (±1.2) h in the low-dose group and 6.0 (±1.5) h in the high dose group. Both treatments improved oxygenation (increased arterial-alvcolar PO2 ratio) with decreased mean airway pressure, the high-dose surfactant having a more beneficial effect in prolonging the response. Infants in the high-dose group had significantly less (P〈0.05) incidence of both intraventricular haemorrhage and bronchopulmonary dysplasia. This prospective trial documents that a greater benefit can be obtained by increasing the dose of surfactant (120 mg/kg) beyond 60 mg/kg in the treatment of premature infants with severe respiratory distress syndrome (RDS).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1573-7284
    Schlagwort(e): EnterotoxigenicEscherichia coli ; Yibrio cholerae ; LT ; CT
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract It was examined where a protease purified from Vibrio cholerae might nick the heat-labile enterotoxin (LT) A subunit from enterotoxigenicEscherichia coli. LT was digested by the protease and contained a fragment which had the same mobility on SDS-PAGE as that of the Al fragment of LT digested by trypsin. The biological activity of LT by this protease was also identical to that of LT by trypsin. The amino acid sequence of the N-terminus of the A2-like fragment was Thr-Ser-Thr-Gly, which corresponded to the sequence from 193 to 196 of the A subunit. These data suggest that this protease, like trypsin, nicks arginine at position 192 from the N-terminus of the A subunit and that the biological activation of LT by this protease is similar to that by trypsin.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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