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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 177 (1988), S. 557-569 
    ISSN: 1432-0568
    Keywords: Cerebellar graft ; Molecular layer ; GABA-immunoreaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphological organization of Purkinje cells and of molecular layer of the cerebellar cortex cocultivated intraocularly with cerebral cortex for two months was studied. It was found, that while numerous spines on the main dendritic branches of Purkinje cells in single cerebellar grafts were “vacant” and non-synaptic, dendritic spines of thick Purkinje dendrites in double grafts were covered by large presynaptic bags. The resulting complex synaptic arrangement was strikingly similar although not identical to climbing terminals in normal (“in situ”) cerebellar cortex. Three distinct types of large presynaptic climbing-fibre like terminals were distinguished: (a) bouton with dense matrix and small round synaptic vesicles, (b) with large round vesicles and (c) containing ovoid synaptic vesicles. The spines of the thin, presumably tertiary dendritic branches were contacted mostly by one parallel axon varicosity, or — as a contrast to normal conditions-by axon terminal, containing ovoid synaptic vesicles. Irrespective of the shape of synaptic vesicles in the presynaptic terminal, all spine-synapses were of asymmetric type; in contrast, synapses on the dendritic shafts were always symmetric. GABA-immunogold reaction has revealed the presence of this inhibitory transmitter in most axon terminals containing ovoid-pleomorphic vesicles within the molecular layer, including those resembling climbing fiber-terminals. This shows a plasticity of the Purkinje cell dendrites to receive non-specific, “foreign” axons in the absence of specific afferents. Also, the type of synaptic junctions, i.e. whether symmetric or asymmetric, is determined exclusively by the postsynaptic neuron and is independent of the transmitter content of the presynaptic terminal.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 177 (1988), S. 543-556 
    ISSN: 1432-0568
    Keywords: Cerebro-cerebellar transplant ; Glomerulus ultrastructure ; GABA-ergic mossy terminals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fetal cerebral cortex and cerebellar anlage from rat fetuses of 15–16 gestational day were grafted simultaneously to the anterior eye chamber of adult female albino rat recipients. Two months after transplantation the cerebellar portion of the double graft consisted of foliated cerebellar cortex surrounding a welldefined cerebellar nucleus. In the absence of pia mater or glial scar the cerebral and cerebellar grafts were observed to establish direct contact with each other. Although much thinner than in the normal cerebellum, the overall morphological organization of the granular layer in the transplant was similar to that described for “in situ” normal cerebellum, with some remarkable differences, though. In normal cerebellum all mossy terminals contain spheroid synaptic vesicles, a characteristic morphological feature of excitatory endings. In the transplant, however, although the majority of mossy terminals contained (small or large) spheroid synaptic vesicles, numerous mossy terminals were filled with ovoid, or pleomorphic synaptic vesciles, a morphological marker of inhibitory terminals. GABA-immunogold reaction, revealed, indeed, the presence of this inhibitory transmitter in mossy terminals containing ovoid synaptic vesicles. Both GABA (-) and GABA (+) mossy terminals formed asymmetric (Gray I-type) synaptic junctions with the surrounding dendritic digits of granule cells. It is suggested that GABA-ergic fibers as well as most non-GABA-ergic axons (originating either from the cerebral cortical graft, or from the cerebellar nucleus) may develop to mossy terminal-like structures as a consequence of the huge deficit in “natural” mossy fibers in this model.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0649
    Keywords: 42.65 ; 42.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that for waves incident with a polarisation in the plane of the grating the component of the electric field in the direction of propagation must be included in the calculations. Coupled differential equations for both the transverse and longitudinal components are derived for wave interaction in photorefractive BaTiO3. Analytic solutions for the electric field of the signal wave are obtained under the assumption that the pump wave is undepleted. For the parameters considered the longitudinal component is shown to be negligible.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 57 (1986), S. 2605-2608 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A simple, efficient helium-3 cryostat for Mössbauer spectroscopy based on a closed-cycle carbon sorption pump is described. An unexpected variation of the minimum available temperature as a function of measurement time is described and explained as a hydrostatic pressure effect connected to the density maximum of liquid helium-3 at 0.515 K.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bradford : Emerald
    Compel 20 (2001), S. 1002-1015 
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: This paper starts with the description of a purely mathematical model of the saturation curve and the hysteresis loop based on the fundamental similarities between the Langevin function the specified T(x) function and the sigmoid shape. The T(x) function which is composed of tangent hyperbolic and linear functions with its free parameters can describe the regular anhysteretic magnetisation curve. Developed from this function the model describes not only the regular hysteresis loop but also the biased and other minor loops like the ones produced by the interrupted and reversed magnetisation process and the open "loops" created by a piecewise monotonic magnetising field input of diminishing amplitude. The remanent magnetism as the function of the interrupted field co-ordinates is predicted by the model in this mathematical form for the first time. The model presented here is based on the principle that all processes follow the shape of the T(x) function describing the shape of the major hysteresis loop of the ferromagnetic specimen under investigation. The model is also applicable to hysteretic processes in other fields.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Bradford : Emerald
    Compel 24 (2005), S. 1180-1190 
    ISSN: 0332-1649
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: Purpose - The paper sets out to formulate the intermolecular forces leading to Barkhausen instability. In the approach the known concept of effective field is used within the framework of the T(x) model. The aim is to provide a mathematical tool to theoreticians and applied scientists in magnetism that is easier to use than those of other models. At the same time to demonstrate the easy applicability of the T(x) model to hysteretic phenomena. Design/methodology/approach - With the combination of the effective and the external field the model is applied to hysteresis loops as well as to the anhysteretic state showing in both cases the local development of unstable conditions at beyond a critical point, leading to local hysteresis loops. Findings - The paper formulates the critical conditions for the hysteretic and the anhysteretic process and calculates the susceptibility as the functions of magnetisation and the applied field. Research limitations/implications - Experimental verification will be required to prove the applicability to the various magnetic materials and to the accuracy of the model. Practical implications - The paper provides an easy mathematical and visual method to show the conditions before and after the Barkhausen instability sets in during the magnetisation process. Originality/value - The paper provides an easy mathematical tool for theoreticians and experimental scientists with a visual presentation of processes leading to Barkhausen instability and magnetic behaviour beyond that by using the T(x) model.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 125 (1984), S. 1110-1116 
    ISSN: 0006-291X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Inorganica Chimica Acta 45 (1980), S. L189-L190 
    ISSN: 0020-1693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Inorganica Chimica Acta 198-200 (1992), S. 401-405 
    ISSN: 0020-1693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 208 (1965), S. 996-997 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Recent results of Schram et al.2 can be used to show that the relative ionization cross-sections (RIGS) of saturated and unsaturated hydrocarbons are constant over the electron energy-range of 12,000 eV-600 eV and are approximately (within ±15 per cent from methane to benzene) proportional ...
    Type of Medium: Electronic Resource
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