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  • 1
    Electronic Resource
    Electronic Resource
    The propagation of a radar pulse in sea water (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 1581-1590 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The propagation in sea water of an electromagnetic field in the form of a semi-infinite wave train or a radar pulse generated by an electric dipole is investigated analytically for low frequencies. The frequency-domain formula for the downward-traveling field of a horizontal electric dipole excited by a sinusoidally modulated electric-current pulse is Fourier transformed to obtain an explicit expression for the field at any distance in the time domain. Specific application is made to a wave packet of 25.5 cycles in a time duration of 1 s. The amplitude and phase velocity of the wave packet are determined together with the amplitudes of the initial and final transients. Graphs are displayed and discussed for a range of distances; these show that the amplitude of the wave packet decays more rapidly than the amplitudes of the transients. Possible application to remote sensing in the ocean is considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353216
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The universal current distribution near the end of a tubular antenna (1989)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 30 (1989), S. 2721-2729 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: An asymptotic solution for the charge density and current near the end of a linear tubular antenna is obtained by means of the Wiener–Hopf technique. It is found that, due to the charge-repulsion effect, the distributions of charge per unit length and of current within a distance of the order of the radius from the end are significantly different from the sinusoidal distributions that are the solutions from approximate theories. Furthermore, the relative distributions are independent of the length of the antenna and of the frequency of operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528505
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Role of Egr-1 in cAMP-dependent protein kinase regulation of the phenylethanolamine N-methyltransferase gene (2001)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 76 (2001), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The molecular mechanism by which cAMP activates the rat phenylethanolamine N-methyltransferase (PNMT) gene was examined by transient transfection of the wild-type rat PNMT promoter-luciferase reporter gene construct pGL3RP893 into PC12 cells. Forskolin treatment (10 μm) of the transfected cells for 3–6 h maximally induced luciferase threefold. Induction by forskolin was mimicked by the cAMP analog, 8-Br-cAMP, and prevented in PC12 cells pretreated with the protein kinase A (PKA) inhibitor H-89 or co-transfected with an expression construct for PKI, a polypeptide inhibitor of PKA. Furthermore, forskolin did not activate the PNMT promoter when the 893 bp PNMT promoter-reporter gene construct was transfected into the PKA-deficient cell line, A126. Detailed examination of the forskolin responsiveness of PNMT constructs harboring ≥ 60 bp and 〈 893 bp of PNMT promoter demonstrated that the cAMP-responsive element(s) lay between 〈 392 bp and ≥60 bp. Within this region of the promoter lies a functional binding element for Egr-1, a transcriptional activator of the PNMT gene. Forskolin treatment of PC12 cells also rapidly increased nuclear levels of Egr-1 and the catalytic subunit of PKA (PKA-C), with the rise in PKA-C preceding that of Egr-1. Mutation of the −165 bp Egr-1 site markedly decreased forskolin activation of the PNMT promoter. These findings demonstrate that the rat PNMT gene promoter can be activated via the cAMP–PKA signal transduction pathway, mediated by the immediate early gene transcription factor, Egr-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.2001.00189.x
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  • 4
    Electronic Resource
    Electronic Resource
    Backscattering of an electromagnetic missile by a metal cylinder of degree higher than two (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 15-24 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The backscattering of an electromagnetic missile from a perfectly conducting curved obstacle is investigated. The obstacle is assumed to have zero curvature just at the point of reflection of the incident pulse. The asymptotic dependence of the backscattered energy is sought, as the distance separating the obstacle from the source of the incident pulse tends to infinity. The backscattered energy is found to depend on the rate at which the energy spectral density of the current pulse at the source decays with increasing frequency, as well as on the degree of flatness of the obstacle at the point of reflection. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362769
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  • 5
    Electronic Resource
    Electronic Resource
    Erratum: "The propagation of a radar pulse in sea water'' [J. Appl. Phys. 73, 1581 (1993)] (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 3586-3587 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359613
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  • 6
    Electronic Resource
    Electronic Resource
    The complete electromagnetic field of a three-phase transmission line over the earth and its interaction with the human body (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 668-683 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electromagnetic field at all points near a high-voltage transmission line is determined in analytical form. Account is taken of the presence of the earth below the three-wire, three-phase power line. The electric and magnetic fields, the total axial current, and the current and power densities in the interior of a human body are determined when the body is standing on the ground under or near the line, is in an elevated basket under the line, or is reclining in bed near the height of the line. The fields are very weak and the current and power densities so small that thermal effects are ignorable, but not necessarily possible effects on nerve action, the functioning of cells, or on certain secretions. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360325
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  • 7
    Electronic Resource
    Electronic Resource
    Lateral electromagnetic pulses generated by a vertical dipole on the boundary between two dielectrics (1987)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 62 (1987), S. 4345-4355 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An exact solution in terms of elementary functions is obtained in the time domain for the vertical electric field Ez(ρ,t) and the transverse magnetic field Bφ(ρ,t) of a dipole located on the plane boundary z=0 between air (region 2, z〈0) and a perfect dielectric (region 1, z〉0) when the dipole is excited by a single delta-function current pulse. The vertical electric field on the boundary consists of a delta-function pulse that travels in the air with the velocity c, an oppositely directed delta-function pulse that travels in the dielectric with the smaller velocity c/ε1/2, an amplitude structure that varies in time between the two pulses, and a final static electric field due to the charges left on the dipole. The horizontal magnetic field is similar. For comparison, the vertical electric field in the equatorial plane of the same dipole in a homogeneous dielectric is also derived. The comparison indicates that the field along the boundary is a surface-wave or lateral pulse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.339067
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  • 8
    Electronic Resource
    Electronic Resource
    Protein kinase A and protein kinase C signaling pathway interaction in phenylethanolamine N-methyltransferase gene regulation (2003)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 85 (2003), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The protein kinase A (PKA) and protein kinase C (PKC) signaling pathways appear to interact in regulating phenylethanolamine N-methyltransferase (PNMT) promoter-driven gene transcription in PC12 cells. Forskolin treatment of cells transfected with the rat PNMT promoter-luciferase reporter gene construct pGL3RP893 increased promoter activity approximately two-fold whereas phorbol-12-myristate-13 acetate (PMA) treatment had no effect. However, simultaneous forskolin and PMA treatment synergistically activated the PNMT promoter approximately four-fold, suggesting that PKC stimulation requires prior induction of the PKA pathway. Consistent with this possibility the adenylate cyclase inhibitor MDL12,330A, and the PKA inhibitor H-89 prevented PNMT promoter stimulation by the combination of forskolin and PMA. PKA and PKC regulation seems to be mediated in part by Egr-1 and Sp1 through their consensus elements in the PNMT promoter. Forskolin and PMA treatment of PC12 cells increased Egr-1 protein and phosphorylated Egr-1/DNA-binding complex formation to the same extent but only increased phosphorylated Sp1/DNA binding complex formation without altering Sp1 protein levels. Mutation of the − 165 bp Egr-1 and − 48 bp Sp1 sites, respectively, attenuated and abolished combined forskolin and PMA-mediated promoter activation. PNMT promoter analysis further showed that synergistic stimulation by PKA and PKC involves DNA sequences between − 442 and − 392 bp, and potentially a GCM binding element lying within this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.2003.01728.x
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  • 9
    Electronic Resource
    Electronic Resource
    A broad-host-range vector system for cloning and translational lacZ fusion analysis
    Amsterdam : Elsevier
    Plasmid 19 (1988), S. 175-188 
    Details
    ISSN: 0147-619X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0147-619X(88)90037-6
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    Paper (German National Licenses)
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  • 10
    Electronic Resource
    Electronic Resource
    Creating the right structural fit for self-directed teams (2000)
    Bingley : Emerald
    Team performance management 6 (2000), S. 25-33 
    Details
    ISSN: 1352-7592
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Economics
    Notes: Human resources are the most important asset of any organization. Yet most organizations continue to arrange their people in work patterns that inhibit and limit their employees' participation. Many companies have tried to move away from a traditional rigid organizational structure to a more flexible one only to abandon it with few or no positive results. The difference between success and failure depends not on company size or resources, but on appropriate planning and avoidance of pitfalls. This article presents Chevron's experiences in establishing interfunctional work teams, evaluates barriers, and suggests steps for successful implementation of self-directed process teams.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/13527590010731952
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