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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 37 (1990), S. 273-293 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Kreuzungsexperimente mit 5 verschiedenen nestkopulierenden Arten der sozialparasitisch lebenden GattungEpimyrma erwiesen sich als außerordentlich erfolgreich. Von 76 kreuzbegatteten Epimyrma-♀ ♀ (verschiedene Kombinationen) produzierten 37 ♀ ♀ 841 hybrid-♀ ♀, 22 hybrid- und 1 Intermorphe. ♀ ♀ der F1-generation wurden mit Hilfe morphologischer und elektrophoretischer Untersuchungen als Hybriden identifiziert. In keiner der Kreuzungen war die Begattungshäufigkeit innerhalb der F1-Generation reduziert. 57 begattete Hybrid-♀ ♀ aus 6 verschiedenen Kreuzungskombinationen produzierten 894 ♀ ♀, 43 und 10 Intermorphe. In der F2-Generation (hier sind die ♂ ♂ Hybriden) ist die Kopulationsaktivität und — häufigkeit stark reduziert. Die untersuchtenEpimyrma-Arten unterscheiden sich in ihrem ♀/ -VerHÄltnis und in der Larvalentwicklung (“rapid brood” / Brut überwintert vor der Verpuppung). Bezüglich der Brutproduktion kreuzbegatteter ♀ ♀ ist ein Einfluß des väterlichen Genoms nur in Einzelfällen nicht auszuschließen. Der Einfluß des Weibchens, bzw. des mütterlichen Genoms, auf die Kastendetermination überwiegt offensichtlich, Veränderungen in dem ♀/ -VerHÄltnis treten daher verstärkt in der Nachkommenschaft der Hybrid-♀ ♀ (F2-Generationen) auf. Das väterliche Genom übt höchstwahrscheinlich keinen Einfluß auf die Larvalentwicklung aus, weder in der F1-Generation noch in der F2-Ceneration.
    Notes: Summary Cross-breeding experiments with 5 intranidal mating species of the social parasitic ant genusEpimyrma turned out to be extraordinarily successful. Out of 76 cross-mated Epimyrma-♀ ♀ (various combinations) 37 ♀ ♀ produced 841 hybrid-♀ ♀, 22 hubrid- and 1 intermorph. ♀ ♀ produced by cross-mated ♀ ♀ were proved as hybrids by morphological and electrophoretical studies. In each cross combination examined within the F1-generation mating activity is not reduced. 57 mated hybrid-♀ ♀ of 6 various crosses produced 894 ♀ ♀, 43 and 10 intermorphs. In the F2-generation (here the ♂ ♂ were hybrids), however, mating activity and mating success strongly declines. ♀/ -ratio and larval development (“rapid brood” / brood hibernates before pupation) of the species examined differ. With regard to the brood production of cross-mated ♀ ♀ only in single cases an influence of the male's genome cannot be excluded. The influence of the ♀, respectively the female's genome, on caste determination obviously dominates. Modifications in the ♀/ -ratrio therefore are more likely in the brood production of hybrid-♀ ♀ (F2-generation). An influence of the male's genome on larval development never was observed, neither in the F1-generation nor in the F2-generation,
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European radiology 7 (1997), S. 77-81 
    ISSN: 1432-1084
    Keywords: Key words: Computed tomography ; Image quality ; Radiation dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Radiation exposure to the patient during CT is relatively high, and it is therefore important to optimize the dose so that it is as low as possible but still consistent with required diagnostic image quality. There is no established method for measuring diagnostic image quality; therefore, a set of image quality criteria which must be fulfilled for optimal image quality was defined for the retroperitoneal space and the mediastinum. The use of these criteria for assessment of image quality was tested based on 113 retroperitoneal and 68 mediastinal examinations performed in seven different CT units. All the criteria, except one, were found to be usable for measuring diagnostic image quality. The fulfilment of criteria was related to the radiation dose given in the different departments. By examination of the retroperitoneal space the effective dose varied between 5.1 and 20.0 mSv (milli Sievert), and there was a slight correlation between dose and high percent of “yes” score for the image quality criteria. For examination of the mediastinum the dose range was 4.4–26.5 mSv, and there was no significant increment of image quality at high doses. The great variation of dose at different CT units was due partly to differences regarding the examination procedure, especially the number of slices and the mAs (milli ampere second), but inherent dose variation between different scanners also played a part.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 633 (1991), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 633 (1991), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Studies in Educational Evaluation 1 (1975), S. 95-108 
    ISSN: 0191-491X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Education
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 2 (1990), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We have investigated the influence of platelet-derived growth factor (PDGF) in peripheral nervous system gliogenesis using two types of Schwann cell cultures. Short-term Schwann cell cultures grow very slowly, but when maintained in culture for several months the division rate of some cells increases, and cell lines can be established. We show that Schwann cells in both short- and long-term culture possess PDGF receptors and synthesize DNA in response to PDGF. Competitive binding experiments show that Schwann cells express mainly PDGF β-receptors and respond better to PDGF-BB than to PDGF-AA. Conditioned media from short-and long-term Schwann cell cultures contain PDGF-like mitogenic activity, and anti-PDGF immunoglobin partially inhibits DNA synthesis in long-term Schwann cell cultures. Antibody neutralization experiments and Northern blot analyses both indicate that the predominant PDGF isoform in these cultures is PDGF-BB. PDGF-like activity is also detected in extracts of rat sciatic nerve. Taken together, these results suggest that PDGF-BB may stimulate Schwann cell proliferation in an autocrine manner during normal development.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. Reliable and precise lifetimes of excited states in 154 Gd and 156 Dy were measured using the recoil distance Doppler shift (RDDS) technique. Excited states of 154 Gd were populated via Coulomb excitation with a 32 S beam at 110 MeV delivered by the FN tandem accelerator at the University of Cologne. For 156 Dy a coincidence plunger experiment was performed at the Laboratori Nazionali di Legnaro with the GASP spectrometer and the Cologne coincidence plunger apparatus using the reaction 124 Sn(36 S,4n)156 Dy at a beam energy of 155 MeV. Shape changes previously suggested to appear in the ground-state band (gsb) of 156 Dy and in the s-band above the first band crossing were not supported by the transition probabilities determined in this work. The measured transition probabilities of 156 Dy and 154 Gd as well as the corresponding energy spectra are compared with the predictions of the recently proposed X(5) model and in the case of 156 Dy also with an IBA fit.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1434-601X
    Keywords: PACS:21.10.Re Collective levels – 27.60+j 90 ≤ A ≤ 149
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: Excited states of the nucleus ν123Xe have been investigated with the fusion–evaporation-reaction ν110Pd(ν18O,5n)ν123Xe at 86 MeV beam energy, using the compton-suppressed Nordball-multidetector-system at the Niels-Bohr-Institute in Risø, Denmark. The level scheme of ν123Xe was extended up to a level of tentative 53/2+ħ. Four excited bands of 3-quasiparticle-character were observed. Analyzing the directional correlation information, we could assign spin- and parity-values to all observed bands in ν123Xe. The observed band structures fit well into systematics of the neighboring nuclei ν125Xe and ν127Xe.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1434-601X
    Keywords: PACS:21.10.Hw Spin, parity and isobaric spin – 23.20.Gq Multipole mixing ratios – 25.70.Gh Compound nucleus – 27.60.+j 90 ≤ A ≤ 149
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The high-spin states of 147Tb have been studied with regard to their spins. The data were obtained by in-beam γ-ray spectroscopy using the reaction 120Sn(31P,4n)147Tb at 152 MeV performed at the Osiris spectrometer in Berlin. We obtained multipole mixing ratios for 60 transitions, and level spins up to 67/2ħ are introduced.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 16 (1960), S. 205-206 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Die Änderung der Dunkelempfindlichkeit gegenüber monochromatischem Licht wird am Froschauge nach Helladaptation an 5 × 105 Trolands elektroretinographisch bestimmt. Von der 10. Minute bis zu einer Stunde nimmt die Empfindlichkeit für Rot (652 mµ) um das 2,4fache ab, während jene für Blau (435 mµ) in der gleichen Zeit um das 25fache zunimmt. Da der Abfall der Rotempfindlichkeit zeitlich mit dem Beginn der zweiten Phase der Dunkeladaptation übereinstimmt, wird auf eine Depression der Zapfenerregung durch die Aktivität der Stäbchen geschlossen.
    Type of Medium: Electronic Resource
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