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  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 30 (1989), S. 2714-2720 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Some physically realizable positive discrete series representations of the noncompact orthosymplectic superalgebra Osp(4/2,R) are considered. The decomposition of these Osp(4/2,R) representations on reduction to Sp(2,R)×SO(4) is studied in detail, and the corresponding state vectors are explicitly constructed by acting with the generators on a general lowest weight state. Some examples are given to illustrate these results for particular single-particle spaces.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 29 (1988), S. 1634-1639 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Coherent states for the harmonic oscillator representations of the noncompact supergroup Osp(1/2N,R) are introduced and the invariant integration measure is calculated by studying transformation properties of supercoset variables. The generalized Bogoliubov transformation for mixed systems of bosons and fermions is also obtained. An example for the simple harmonic oscillator is given.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 30 (1989), S. 274-279 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: An analysis of the coherent states for the noncompact supergroup Osp(2/2N,R) is presented. In contrast to Osp(1/2N,R), both typical and atypical representations have to be considered. The measure of integration, in general, for Osp(2/2N,R) coherent states is calculated; it is then used to construct the decomposition of unity for the special case of Osp(2/2,R). It is found, however, that the typical and atypical representations of Osp(2/2,R) have to be treated separately. It is verified that the coherent states for Osp(2/2,R) are "closest to classical'' in the sense of Perelomov.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 41 (1985), S. 1821-1825 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1988), S. 621-626 
    ISSN: 1432-0533
    Keywords: Angiomatosis ; Meningo-cerebral ; Congenital ; Necrotizing encepholopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Various observations of diffuse meningocerebral angiomatoses, which cannot be satisfactorily classified with the common phakomatoses, have been reported. They may occur at any age, with familial accumulation or sporadically. Divry and van Bogaert were the first to draw attention to such conditions in adults, where meningo-cerebral angiomatoses seemed to be combined with sudanophilic leukodystrophy. However, subsequently the latter was considered to be due to hypoxic damage to the white matter. In other observations, the severe damage to the grey matter was more evidently of hypoxic origin. Observations on two newborn individuals, sporadic examples of diffuse meningo-cerebral angiomatosis and with severe necrotic changes in the grey and white matter, are reported and discussed. Published reports on the various age-related forms are summarized and a general designation is suggested, which includes the various observations under a general heading. A parallel will be drawn between the meningo-cerebral angiomatosis and Foix-Alajouanin's disease.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-0533
    Keywords: Thromboangiitis obliterans ; Dementia ; Cortical synaptophysin expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The generalized form of von Winiwarter-Buerger's disease (WBD) occasionally involves the brain. However, pure cerebral forms of the disease were also described by Spatz and Lindenberg (“Spatz-Lindenberg's disease”, SLD). Both, the type I, which involves the large basal arteries, and the type II, which results in a sickle-shaped granular atrophy of the cerebral cortex, are often accompanied by (“vascular”) dementia, which Lindenberg and Spatz mainly attributed to the bilateral involvement of the second frontal gyrus by granular atrophy. Recently, synaptic deprivation of the cortical gray matter has been shown to occur in the dementia of Alzheimer type (DAT) and other neurodegenerative disorders. In DAT, the synaptic loss highly correlated with the degree of the mental impairment. We wanted to examine whether similar changes also occurred in dementia of vascular origin, for which SLD, although infrequent, is a typical example. In fact, we found that in three cases of typical SLD type II the synaptophysin immunoreactivity of the cortical neuropil in areas without overt infarcts or scar formation was as much reduced as in Alzheimer's disease. Although it must be taken into account that in the present cases the synapse loss might, at least in part, be due to secondary (Wallerian) degeneration as a result of the neuronal loss in the “watershed” regions of the arterial blood supply, it cannot be excluded that a decline of cortical synaptic contacts in areas without necroses or scars may occur as a primary event, contributing to the pathogenesis of the dementia. Final conclusions can only be expected from investigations into further cases of cerebro-vascular disorders with and without dementia.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0533
    Keywords: Neurofibromatosis 2 ; Bilateral acoustic neurofibromatosis ; Ghal hamartomas ; Immunohistochemistry ; S-100 protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bilateral acoustic neurofibromatosis (neurofibromatosis 2, NF2) accounts for less than 10% of all cases of neurofibromatosis and manifests itself with bilateral acoustic schwannomas, multiple schwannomas of spinal nerve roots, meningiomas, glial tumors and hamartomatous CNS lesions. We have observed dysplastic foci of immature neuroectodermal cells in the cerebral cortex and basal ganglia of six patients afflicted with neurofibromatosis 2, ranging from occasional clusters of immature, dysplastic cells to numerous, confluent lesions. These cells, although often polymorphic and multinuclear did not show mitotic acitivity or a tendency for neoplastic transformation. To determine the histogenesis of these foci, extensive immunocytochemical reactions were carried out with antibodies to a variety of glial, neuronal and nonneural cell lineages. With the exception of S-100 protein, no immunoreactivity was detectable. S-100 was consistently expressed in these foci, irrespective of their size, location, and degree of polymorphism. On the basis of cytological appearance, distribution and immunoreactivity we tentatively designate these foci as glial micro-hamartomas. Although we did not systematically analyze the CNS of patients with von Recklinghausen neurofibromatosis (neurofibromatosis 1, NF1), the present study strongly suggests that these micro-hamartomas constitute a morphological hallmark of bilateral acoustic neurofibromatosis (NF2).
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0942-0940
    Keywords: Iodine-125 implantation ; Stereotactic interstitial irradiation ; inoperable cerebral gliomas ; cerebral radiation necrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Late radiation necroses constitute a hazard in low dose rate interstitial irradiation for inoperable gliomas. An incidence of 40% (8/20 patients) was found after permanent implantation of Iodine-125 seeds. This finding may even underestimate the real frequency, because follow-up of unaffected patients was shorter than in patients with radiation necrosis. The necrotic reactions caused a transient mass effect, which lead to a significant deterioration of performance scores. Further manifestations of late delayed radiation damage were observed in two patients. The occurrence of radiation necrosis was correlated with total radiation dose, amount of implanted radioactivity, and with velocity of tumour shrinkage. A mechanism underlying the development of radiation necrosis is proposed: A rapid shrinkage of tumour after interstitial Iodine-125 implantation may cause a significant irradiation of surrounding brain tissue, which was initially lying outside the target volume. Since most patients affected by radiation necrosis were children or adolescents, the risk of radiation damage should be minimized. This could probably be achieved either by reduction of irradiation dose, or by using temporary implants of Iodine-125.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 52 (1991), S. 223-233 
    ISSN: 1432-0630
    Keywords: 44.25 ; 44.60+f ; 47.25.Q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The temperature oscillation accompanying the photoacoustic effect generates a periodic variation of the vapor pressure of a liquid. The propagation of the oscillating concentration of the vapor in the inert cell gas (air) is described by a mass diffusion wave on which a convective motion of the gas is superposed. The diffusion wave characterized by the diffusion coefficient of the cell gas alone can be measured by the Mirage effect, whereas a microphone detects the total mass flux including the convective flux, which increases with temperature. On approaching the boiling temperature, the convective flow will govern the oscillating transport of mass. The photoacoustic signal is determined directly from the flux of heat and mass at the boundary between liquid and gas using the Gauss' divergence theorem. We have found that the temperature behaviour of the amplitude and phase angle of the photoacoustic signal depends on the length of the gas column in the cell. The contribution of thermal expansion to the photoacoustic signal is considered using the composite piston model. The results of the calculations agree fairly well with the experimental data.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 10 (1985), S. 103-110 
    ISSN: 1432-0983
    Keywords: Yeast taxonomy ; DNA homologies ; Southern analysis ; Glycolytic gene probes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genePDC1 ofSaccharomyces cerevisiae coding for pyruvate decarboxylase (E.C. 4.1.1.1.) was used as a hybridization probe to detect gene sequence homologies in different strains ofSaccharomyces cerevisiae and in other yeast species. Additionally six other genes coding for glycolytic enzymes as well as the genesURA3 of the pyrimidine synthetic andTRP1 of the tryptophan synthetic pathways were used. A restriction polymorphism for the BamH1 fragments carrying thePDC1 gene was evident within the speciesSaccharomyces cerevisiae. All strains definitely declared asSaccharomyces cerevisiae showed the same restriction patterns. Hybridizations of different intensities were observed only with species in the familySaccharomycetaceae. Hybridizations with different genes showed different degrees of conservation for certain DNA sequences.
    Type of Medium: Electronic Resource
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