Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 78 , Issue 7
Showing 1-9 articles out of 9 articles from the selected issue
  • Tadashi OKUYAMA, Morifumi FUJITA
    2002 Volume 78 Issue 7 Pages 167-172
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Molecular chirality of 4-methylcyclohexylidenemethyl iodonium salt is used to probe the chirality of intermediate state of the reaction. A possible achiral intermediate, primary vinyl cation is excluded for the reactions of the iodonium salt under any reaction conditions employed, while achiral 5-methyl-cycloheptyne, formed via rearranged cation, is involved in the reaction with sulfonate. The reaction is extended to generation of some small ring cycloalkynes. Vinylic SN2 mechanisms are also proposed.
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  • Qinghua HUANG
    2002 Volume 78 Issue 7 Pages 173-178
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    A model considering the compensation of piezoelectric effect and the dislocation theory of fault is developed to investigate theoretically the generation of co-seismic electric signals. Charges are assumed to be induced by the stress changes associated with earthquakes. The stressinduced charges are quantified by the charge density as a function of the polarization, which can be calculated using a piezoelectric model and an analytical solution of seismic stress. The theoretical charge distribution around the Nojima fault, which moved at the 1995 Kobe earthquake (M=7.2), was obtained. The co-seismic electric field consistent with that observed at the Kobe earthquake was estimated as the field due to the charges, which compensated the piezoelectric charges.
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  • Toshiya TANBO, Toshiyasu NAGAO, Hideo SAKAI
    2002 Volume 78 Issue 7 Pages 179-184
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Observation of geoelectric potential difference has been conducted since 1997 at Ohtawa station (Kamioka Town, Gifu Prefecture). The data quality is generally excellent because of small artificial electric noises. However, spiky strong changes of geoelectric potential are observed. Occurrences of these changes are clearly correlated with the DC driven train schedules of Tateyama Railway, of which closest distance from Ohtawa station is about 16km. These geoelectric potential changes were used to study the local electrical resistivity of the ground and it's time variation. Our analysis has shown a seasonal variation of apparent resistivity. Although still uncertain, there is also an indication that the standard deviation of the geoelectrical potential changes may be related to the local seismic activity.
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  • Tatsuro MATSUMOTO, Tamio NISHIDA
    2002 Volume 78 Issue 7 Pages 185-189
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    An ammonoid genus Mrhiliceras Kennedy and Wright, 1985, is revised to be based on the“inflated forms”as represented by the holotype of its type species Mammites lapparenti Pervinquière, 1907. How are the“compressed forms”of Kennedy and Wright, 1985 should be treated is a problem to be examined further. In this paper we describe an example of M. lapparenti from the basal part of the Cenomanian (Cretaceous) sequence of strata in the Soeushinai area, northwest Hokkaido. It is somewhat larger than the previously reported specimens and represents a full grown shell of a mature stage.
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  • Tetsuya YOKOYAMA, EIZO NAKAMURA, Katsura KOBAYASHI, Takeshi KURITANI
    2002 Volume 78 Issue 7 Pages 190-195
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    We present 238U-230Th-226Ra systematics in lavas from Miyakejima volcano, Izu arc, Japan, together with major element, trace element and Sr-Nd-Pb isotopic compositions, to estimate the timescale of magmatic processes beneath an island arc. 238U-230Th-226Ra disequilibria observed in Miyakejima lavas with large excesses of 238U and 226Ra to 230Th imply metasomatism of depleted mantle by fluid related processes. Our data reveal that fluid components released from the slab ascend rapidly through the mantle wedge (>50m/yr), and that individual stages of subaerial volcanism are induced by flushing of different fluid batches to the mantle wedge with a periodicity of 1-13kyr. This indicates that arc magmatism is controlled by pulsed release of fluid from the slab occurring on such a small timescale, which might be related to the occurrence of earthquakes in the subducting slab.
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  • Sarata Kumar SAHOO, Shinzo KIMURA, Yoshito WATANABE, Kunio SHIRAISHI, ...
    2002 Volume 78 Issue 7 Pages 196-200
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Uranium affected by criticality accident which occurred at the JCO in Japan was chemically separated and its isotopic composition was measured using a thermal ionisation mass spectrometer. Chemical separation of uranium was carried out by anion exchange resin and UTEVA extraction chromatography. Radioactive dis-equilibrium of 234U/238U and enrichment of 235U/238U were noticed in some soil samples. Presence of 236U produced by the accident was detected in the samples examined.
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  • Yoshiaki ARATA, Hiroshi FUJITA, Yue-Chang ZHANG
    2002 Volume 78 Issue 7 Pages 201-204
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Embedded nano-Pd particles of 5nm in size instantly absorb abundant D-atoms more than 250% in the atomic ratio against Pd-atoms at room temperature when they are kept in D2 gas pressurized to less than 10atm. In such ultrahigh densities, 2-4 D-atoms can be coagulated inside each octahedral space of Pd lattice(pycnodeuterium-lump). When a stimulation energy such as latticequake causing by ultrasonic wave was supplied to these highly deuterated Pd particles, intense deuterium nuclear fusion (“solid fusion”) was generated there and both excess heat and 4He gas were abundantly produced. Naturally, these facts can not be realized at all in bulk Pd. The results show that the nuclear fusion occurs without any hazardous rays in pycnodeuterium-lumps coagulated locally inside the each cell of the host metal lattice. These unit cells correspond to minimum unit of the solid fusion reactor as a“Lattice Reactor”.
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  • Naoki AMANO, Yoshiaki MINEZAKI, Masashi SUZUKI
    2002 Volume 78 Issue 7 Pages 205-210
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Using the draft sequence of human chromosome 22, blocks with a minimum length of 2K, in which combinations of bases are ordered to degrees higher than the rest, have been mathematically identified. Approximately 400 blocks are characterized with significantly low entropy values for combining 4-9 nucleotides each of the 4 types. These blocks span -3.5K bases on average, and altogether occupy 2.0-2.5% of this chromosome. The draft sequence extends from the end of the centromere to the beginning of the telomere, and the occupancy by identified blocks is highest near the two ends, and decreases while shifting nearer to the center.
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  • Akihiro KUME, Hiroaki MIZUKAMI, Takashi OKADA, Yutaka HANAZONO, Kazuo ...
    2002 Volume 78 Issue 7 Pages 211-216
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    The cytokine receptor common gamma chain (γc) plays a pivotal role in transmitting multiple interleukin signals. Its gene mutations cause profound lymphoid maldevelopment, a disorder known as X-linked severe combined immunodeficiency (X-SLID). Without successful bone marrow transplantation, affected patients would die in infancy or early childhood due to severe and recurrent infections. Therefore, development of gene therapy strategies has been awaited for those without suitable marrow donors. We constructed a retrovirus vector carrying the γc and the enhanced green fluorescent protein (EGFP) genes for a preclinical study with a murine X-SCID model. After transduction of X-SCID bone marrow and infusion into myeloablated X-SCID recipients, robust lymphoid reconstitution was observed in all the examined lymphocyte subsets such as CD4+-T, CD8+-T, B and NK cells. A long-term EGFP expression was demonstrated in both lymphoid and myeloid cells, suggesting that this type of vector is useful in evaluating regimens of stem cell-directed gene therapy.
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