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  • 1
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interactions between HIV-1 and CMV may be important in the pathogenesis of AIDS. We have studied whether active CMV infection alters the cell tropism of HIV-1 in dually-infected individuals. Urines from HIV-seropositive individuals excreting CMV were compared to urines from CMV non-excretors. Sixty-six urines from HIV-seropositive individuals were tested. Infectious HIV-1 was not detected in any of the concentrated urines tested. The urines were filtered, concentrated, DNase-treated and cultured on HIV-1 non-permissive human forestin fibroblasts. HIV-1 DNA was detected by PCR withpol gene primers in 5 of 39 MRHF cell cultures inoculated with CMV culture positive urine (p=0.037). HIV-1 DNA was not detected by PCR in uninfected fibroblasts, in fibroblasts inoculated with CMV uninfected urine from 27 HIV-seropositive patients or in fibroblasts cultured with 9 CMV culture positive urines from 16 HIV-seronegative renal transplant recipients. Supernatant fluid from an HIV-1 PCR-positive culture was passaged onto another fibroblast monolayer, and these cells were negative for HIV-1 DNA. Direct inoculation of fibroblasts with HIV-1 did not yield evidence of infection by PCR. CMV infection may facilitate HIV-1 DNA entry into ordinarily non-permissive cells.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-601X
    Keywords: 21.60 ; 23.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Reliable calculations of nuclear matrix elements are a prerequisite for the determination of the effective neutrino mass and other particle physics parameters from neutrinoless double beta decay. Here, the operator expansion method is improved by including Coulomb, tensor and central interactions simultaneously. Furthermore, the formalism of the OEM is extended to those matrix elements necessary to extract the right-handed parameters 〈λ 〉 and 〈η 〉 from 0νββ decay. OEM includes the dependence of the nuclear matrix elements on the intermediate states implicitly and can therefore be understood as a step beyond the closure approximation. Numerical studies are carried out for the isotope76Ge combining the OEM expressions with ground-state wave functions calculated within a proton-neutron quasiparticle Random Phase Approximation (pn-QRPA) model. The influence and relative importance of central, tensor and Coulomb interactions is investigated. Within the OEM, contributions from the Coulomb force are found to be negligible in 0νββ decay, while the tensor force leads to a moderate change of the results, of the order of (10–30)%, giving a better agreement between sets of calculations which employ different NN-interactions. Generally, results of the OEM+QRPA calculation are similar to previous calculations of 0νββ decay matrix elements, indicating that 0νββ decay is not sensitive to model approximations and might therefore be more accurately calculated than the strongly suppressed 2νββ decay matrix elements.
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  • 3
    ISSN: 1434-601X
    Keywords: PACS:95.35 Dark Matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: We examine the limitations of the data analysis scheme for annual modulations as a signature of WIMP direct detection. The consequences for existing and planned experiments are pointed out. These include determinations of optimum recoil energy regions to be analyzed for modulations and the minimum target mass needed to detect them. Calculations for 23Na, nat. Ge, and 129Xe as example nuclei have been performed.
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  • 4
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Correlations between electron density and temperature fluctuations have been measured in the core plasma of W7-AS. The simultaneous use of transmitting and receiving antennas of a heterodyne reflectometer by a crossed sightline ECE correlation radiometer enables the cross-correlation analysis of the reflectometer phase signal and ECE radiation temperature signals in overlapping plasma volumes. Correlations have been found in the spectral range 25–100 kHz, indicating an in-phase correlation between electron density and temperature fluctuations. © 1999 American Institute of Physics.
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  • 5
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A broadband heterodyne reflectometer operating in the frequency range 75–110 GHz in extraordinary mode polarization, is used at the W7-AS stellarator for density profile and density fluctuation studies. The system allows for broadband operation and permits unambiguous determination of the phase delay independent of the amplitude fluctuations in the reflected beam. The system uses two different gauss beam optics for both signal launch and detection with a slim beam waist of about 2 cm at the relevant plasma location. An amplitude modulation system has been incorporated operating at 133 MHz modulation frequency sharing with the phase sensitive system the main oscillators, antennas, and the receiver front end. AM detection is accomplished in the IF part by synchronous detection after recovery of the carrier by narrowband filtering. Time delay measurements can be done simultaneously with the carrier phase determination. The main purpose of the diagnostic in AM mode is fast edge density profile monitoring, conventional carrier phase detection is used for density fluctuation measurements and planned correlation studies. The agreement between the WKB approximation and the 1 D full wave numerical solutions for the W7-AS parameters and geometry guarantees the good localization of the measurements and permits the estimation of density fluctuation level from the measured phase fluctuations. Density fluctuation studies have been carried out in NBI and ECRH (L- and H-mode) plasmas. Fluctuation levels and spectral characteristics have been analyzed. In addition 2D effects possibly due to rotating turbulent structures have been observed. © 1995 American Institute of Physics.
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  • 6
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A broadband heterodyne reflectometer operating in the frequency range 75–110 GHz in extraordinary mode polarization is used at the W7-AS stellarator for both fast density profile determination and density fluctuation studies. The probing signal is amplitude modulated at a frequency 133 MHz using the envelope phase for profile evaluation and the carrier phase to determine the fluctuation information simultaneously. Separate Gaussian beam optics for final signal launch and detection permits a beam waist of about 2 cm at the reflecting layer in the plasma. Amplitude modulated detection is accomplished in the intermediate frequency part by synchronous detection after recovery of the carrier by narrow-band filtering. Voltage controlled solid state oscillators followed by active frequency multiplication allow to scan the full frequency band within less than 1 ms. For typical W7-AS operation the accessible density range is 1×1019 to 6×1019 m−3 for on axis magnetic field of 2.5 T and 4.5×1019 to 10×1019 m−3 for 1.25 T, respectively. The probed radial positions range between 0.2〈r/a〈1.1 depending on plasma conditions (a≈17 cm). © 1996 American Institute of Physics.
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  • 7
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Westerville, Ohio : American Ceramics Society
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Real and imaginary permittivity (ɛ′ and ɛ″, respectively) values were determined on mullite-silicon carbide whisker (mullite-SiCw) composites, mullite-ZrO2 composites, and spinel-SiCw composites, in the frequency range of 2-18 GHz, using a 14 mm coaxial air-line measurement system. Depending on the frequency, the addition of 30 vol% of SiCw to mullite increases ɛ′ from 6.6-6.9 to 16-22 and increases ɛ′ from 0 to 16-22. The addition of 32 vol% of SiCw to spinel increases ɛ′ from 7.5-7.8 to 37-44 and increases ɛ″ from 0 to 13-20. The addition of 21 vol% of ZrO2 to mullite increases ɛ″ to ∼9 but does not change ɛ″. Real and imaginary permeability values were 1 and 0, which are within experimental error.
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  • 9
    ISSN: 1435-1463
    Keywords: Equilibrium in parkinsonism ; balance and parkinsonism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lower extremity strength and joint range of motion, body sway, and electromyography responses have all been determined to be factors in balance control of healthy older individuals. The purpose of this study was to identify variables which effect balance control (equilibrium scores) of persons with Parkinsonism, and examine their relationships and predictive abilities. The composite equilibrium score from the sensory organization protocol of the Equitest was used as the dependent variable for the regression analysis. The independent variables included: 1) strategy score; 2) path sway during voluntary body displacement; 3) percent peak torque of knee flexion relative to that of knee extension (%PTKFKE); 4) peak torque of inversion of the ankle at (PTINV); 5) dorsiflexion ROM; and 6) medium loop latency (EMG). The model produced a significant overall relationship accounting for 88% of the variability in equilibrium scores. Positive and significant coefficients indicated a predicted increase in the equilibrium composite score with increases in the strategy score, PTINV and %PTKFKE. These results suggest that postural control of persons with Parkinsonism can be strongly predicted by these three variables.
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  • 10
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A maximum entropy approach has been applied to the tomographic inversion of the line integrated measurements of radiation power flux by a multichannel bolometer system. This method was applied to an H-mode discharge in the W7-AS stellarator, with increasing radiation from the plasma core after the transition being observed. Also, a neutral beam injection discharge was investigated, and the time evolution of a marfe was documented. This method has also been applied to the preliminary design of a multicamera system for full tomographic reconstruction in the W7-X stellarator. In addition, measurements with wire mesh shielded metal foil bolometers have been carried out and the shielding of these bolometers from microwaves produced by the 140 GHz gyrotrons used for electron cyclotron heating has been demonstrated. © 1997 American Institute of Physics.
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