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  • 1
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 1763-1765 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We show that incoherently coupled soliton pairs are possible in biased photorefractive crystals, under steady-state conditions. These solitons can propagate in bright-bright, dark-dark, as well as in bright-dark configurations. Such soliton pairs can be established provided that the carrier beams share the same polarization, wavelength, and are mutually incoherent. Relevant examples are provided where the photorefractive crystal is of the strontium barium niobate type. The characteristics and stability properties of these soliton states are also discussed in detail. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Entomology 24 (1979), S. 255-278 
    ISSN: 0066-4170
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Materialart: Digitale Medien
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  • 3
    ISSN: 1365-2826
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The neurochemical mechanisms that link caudal hindbrain glucoprivic-‘sensitive’ neurones with the forebrain gonadotrophin-releasing hormone (GnRH)-pituitary luteinizing hormone (LH) axis remain unclear. Available studies indicate that the amino acid neurotransmitter, γ-aminobutyric acid (GABA), inhibits reproductive neuroendocrine function, and that caudal fourth ventricular administration of the glucose antimetabolite, 5-thioglucose (5TG), enhances GABA turnover within discrete septopreoptic structures that regulate LH secretion. The current experiments utilized the selective GABAA and GABAB receptor antagonists, bicuculline and phaclofen, as pharmacological tools to investigate whether one or both receptor subtypes function within neural pathways that suppress GnRH neuronal transcriptional activation and LH release during central glucose deficiency. During the ascending phase of the afternoon LH surge, groups of steroid-primed, ovariectomized female Sprague-Dawley rats were pretreated by lateral ventricular administration of bicuculline, phaclofen, or vehicle only, before fourth ventricular injection of 5TG or vehicle. The data indicate that, 2 h after 5TG treatment, Fos immunoexpression by rostral preoptic GnRH neurones and plasma LH levels were diminished relative to the vehicle-treated controls, and that inhibitory effects of 5TG on these parameters were attenuated by pretreatment with bicuculline, but not phaclofen. These results demonstrate that central GABAA, but not GABAB receptor stimulation during hindbrain glucoprivation, is required for maximal inhibition of reproductive neuroendocrine function by this metabolic challenge. The current studies thus reinforce the view that central GABAergic neurotransmission mediates regulatory effects of central glucoprivic signalling on the GnRH-pituitary LH axis.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    Clinical and experimental dermatology 26 (2001), S. 0 
    ISSN: 1365-2230
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: CD40 is a member of the tumour necrosis factor (TNF) cell surface receptor family. It plays an important role in T-cell dependent B-cell functions and in dendritic cell development. It has also been identified as a cell surface receptor on endothelial cells. In this manuscript, we report that human dermal microvascular endothelial cells (HDMEC) express cell surface CD40 and that the expression of CD40 is increased by the proinflammatory cytokines TNF-α and interferon (IFN)-γ. Additionally, we demonstrate that engagement of HDMEC CD40 with its recombinant CD40 ligand augments the induction of E-selectin, but not of intercellular or vascular cell adhesion molecules on the surface of HDMEC. Furthermore, we show that IFNγ stimulation of HDMEC results in increased binding of Jurkat leucocytes to HDMEC by a CD40–CD154 dependent pathway. This study thus provides evidence that CD40 expression in HDMEC is regulated by proinflammatory cytokines, and that CD40 functions as an important mediator of cutaneous inflammation.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 36 (1980), S. 779-784 
    ISSN: 1600-5724
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Bright-field lattice images of three syntactically coalesced polytypes of SiC were taken with a view to deriving structural information. A high-period structure 400H is found to consist of seven unit cells of 150R and one unit cell of 150RA. The 150R structure is built up of ten 15R unit cells; consecutive 15R subunits in obverse and reverse orientation give rise to sudden changes in contrast in the image. Complete structure determination of 150R and 150RA is thus possible. The structures were confirmed by comparing the calculated and observed X-ray intensities. An imaging code was established which helped in the structure determination of the 400H polytype.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Applied physics 43 (1987), S. 53-60 
    ISSN: 1432-0630
    Schlagwort(e): 72.15 ; 79.20
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract A calculation has been carried out for the drift velocity of electrons in the highfield region under the condition of impact ionization in III–V semiconductor compounds. The energy-balance equation of the one-electron model has been solved considering alloy scattering and carrier-carrier interaction, in addition to optical phonon and ionization scattering. Fairly good agreement is obtained for GaAs with the available experimental and Monte-Carlo results. Graphs for the high-field drift velocity has also been plotted for Ga1−x InxAs (x = 0.53) at different ratios of ionization mean-free path and optical phonon mean-free path. The plot of high-field drift velocity versus ionization rate reveals that the high-field drift velocity strongly depends on the ionization rate of carriers, and vice versa.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Applied physics 43 (1987), S. 105-109 
    ISSN: 1432-0630
    Schlagwort(e): 72.15 ; 79.20
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract Theoretical calculations are presented for the ionization rate of electrons in III–V ternary semiconductor compounds considering alloy scattering and carrier-carrier interaction, in addition to optical phonon scattering and ionization scattering. However, alloy scattering is found to be a weak interaction. Fairly good agreement is obtained for Ga1−x In x As withx=0.14 and 0.53 with the experimental results and for Ga0.5 Al0.5 As with the existing theoretical result which used an indirect method. The alloy scattering potential has been taken in the form of energy band-gap difference. The calculations can be used for any ternary semi-conductor.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Communications in mathematical physics 72 (1980), S. 1-13 
    ISSN: 1432-0916
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Physik
    Notizen: Abstract It is shown, with some restrictions, that on-shell two-cluster partial-wave scattering amplitudes for atomic systems whose particles interact via two-body Coulomb potentials have analytic continuations in the complex energy plane below the physical part of the real axis. The result is proved only for energies lower than any three (or more) cluster threshold. Poles of the amplitudes can occur only at discrete eigenvalues of the rotated Hamiltonian which may be reached by continuation along the same path. The method of proof uses analyticity related to a generalized scaling transformation and the boost transformation.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 174-178 
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pyralidae ; Maruca testulalis ; Pod borer ; Development ; Nutritional suitability ; Host plant ; Crotalaria ; Vigna unguiculata
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les possibilités de développement larvaire de Maruca testulalis sur les fleurs de huit espèces végétales ont été examinées en laboratoire. La comparaison a porté sur Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. mucronata, C. amazonas, Cajanus cajan et l'hôte principal de cette chenille, Vigna unguiculata. En tenant compte de la mortalité larvaire et des indices de croissance (G.I.), ces plantes ont été divisées en trois catégories principales: 1 celles provoquant une mortalité larvaire de 0–30% et ayant des G.I. ≥60%, constituent les plantes hôtes convenables (Vigna unguiculata seule); 2 les plantes qui provoquent une mortalité larvaire de 30≤50% et ont des G.I. de 30 à 60% de la plante hôte principale (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata; 3 les plantes qui causent 50–100% de mortalité larvaire et dont les G.I. sont inférieurs à 30% de la plante hôte principale (Crotalaria retusa, C. juncea, C. misereniensis). Les résultats déjà publiés sur les choix du lieu de ponte des femelles et l'utilisation de C. juncea comme plante piège, sont discutés à la lumière de ces données nouvelles.
    Notizen: Abstract Flowers of eight plant species were evaluated under laboratory conditions for their suitability as larval growth media for the cowpea pod borer, Maruca testulalis. The plants tested were Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. amazonas, Cajanus cajan and the principal host of the borer, Vigna unguiculata (cowpea), was included for comparison. Based on the data obtained on larval mortality and growth indices (GI) the plants were divided into 3 categories namely: I: Those causing 0–30% mortality and having GI value ≥60% form suitable host plants. This group only included V. unguiculata. — II: Those plant species causing 30≤50% larval mortality and having GI value 30%≤60% of the principal host plant (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata). This group of species is marginally suitable as hosts. — III: Plants causing 50–100% larval mortality and having GI value ≤30% of principal host plant (C. retusa, C. juncea and C. misereniensis). Previously published data on the oviposition preference of the adult moth are discussed in the light of the present findings and the use of C. juncea as a possible trap crop.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 47 (1988), S. 195-199 
    ISSN: 1570-7458
    Schlagwort(e): Vigna vexillata ; resistance ; pod-sucking bug ; Clavigralla tomentosicollis ; Coreidae ; Hemiptera ; Cowpea ; Vigna unguiculata ; pod hairs ; pod wall
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Deux variétés de Vigna vexillata se sont avérées plus résistantes aux infestations et dégâts causés par la punaise des cosses Clavigralla tomentosicollis (Stål.) (Hemiptera: Coreidae) que les variétés de Vigna unguiculata, tant en champ (condition de libre choix) qu'en serre (sans choix possible). Les trichomes des cosses de V. vexillata sont en partie responsables de cette résistance. Cependant d'autres facteurs de la cosses ou des fèves sont impliqués dan la résistance. Comme la paroi de la cosse de V. vexillata n'offre pas plus de résistance mécanique que celle de V. unguiculata, les études futures se porteront sur les caractéristiques biochimiques des cosses et des fèves de V. vexillata.
    Notizen: Abstract Two varieties of Vigna vexillata Benth proved more highly resistant, both under field (free-choice) and screenhouse (no-choice) conditions, to infestation and damage by the pod-sucking bug Clavigralla tomentosicollis (Stål.) (Hemiptera: Coreidae) than cowpea (Vigna unguiculata Walp.) varieties. Trichomes on the pod of V. vexillata partly accounted for the resistance. However, other factors in the pod or seeds are involved in the resistance. Because the pod wall of V. vexillata is not tougher than that of cowpeas, biochemical characteristics of pods and seeds of V. vexillata will be further investigated.
    Materialart: Digitale Medien
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