Yoshiaki Shibagaki

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The human immunodeficiency virus type 1 (HIV-1) vpr gene is an evolutionarily conserved gene among the primate lentiviruses HIV-1, HIV-2, and simian immunodeficiency viruses. One of the unique functions attributed to the vpr gene product is the arrest of cells in the G2 phase of the cell cycle. Here we demonstrate that Vpr interacts physically with HHR23A,(More)
The wild-type and mutant derivatives of the integrase protein of feline immunodeficiency virus (FIV) were cloned and expressed in Escherichia coli. The purified proteins were examined using various model DNA substrates for their catalytic activities: 3'-end processing, 3'-end joining, and disintegration. The reactions required the presence of either Mn2+ or(More)
Integration of retroviral DNA can occur into many sites on target DNA with a wide variation in preference. One factor known to affect target site selection is integrase, the viral protein required for the integration reaction. In this study, assays that measure the distribution and frequency of retroviral DNA integration showed that purified integrases of(More)
Time, location, and polarity of lightning discharges in wintertime thunderstorms are discussed in light of horizontal and height distribution of radar echoes observed by C-band and millimeter-wave radars. The core of the radar echoes that produced a number of positive-current cloud-to-ground discharges in a few minutes tends to be found near a comparatively(More)
This paper deals with the detection and quantification of refractivity turbulence in the troposphere from radiosonde and very high frequency (VHF) band radar data. Balloon data processing methods based on Thorpe sorting and recently developed by Wilson et al. (2010, 2011, and 2013) can be applied for a direct identification of turbulent layers from the in(More)
The effects of site diversity techniques on Kuband rain attenuation are investigated using two sets of simultaneous satellite signal observations, which have been conducted among Osaka Electro-Communication University (OECU) in Neyagawa, Kyoto University in Uji, and Shigaraki MU Observatory in Koga for about past nine years, and among the headquarters of(More)
Yasuyuki Maekawa, Koichi Sawai, Yoshiaki Shibagaki, Tomoyuki Takami, and Takeshi Hatsuda 1 Department of Telecommunication Engineering, Osaka Electro-Communication University 18-8 Hatsucho, Neyagawa, Osaka 572-8530, Japan, maekawa@maelab.osakac.ac.jp 2 Osaka Electro-Communication University, 1130-70 Kiyotaki, Shijonawate, Osaka, 572-0063 Japan 3 Hokkaido(More)
The recent satellite communications tend to use high frequency bands of more than 10 GHz, in addition to the traditional C band of 6/4 GHz. In these higher frequency bands, however, the rain attenuation of radio waves becomes one of the severe problems of satellite communications. Thus, detailed observations and statistical analyses of rain attenuation(More)
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