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Volume 75, Issue 7
Displaying 1-9 of 9 articles from this issue
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Vertical distribution of heat source in the island arc crustMakiko MUKAI, Tohru YAMAGUCHI, Kazuhisa KOMURA, Muneyoshi FURUMOTO, To ...1999 Volume 75 Issue 7 Pages 181-185
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSTerrestrial heat flow is the sum of the radioactive heat generated in the crust and the heat flow from the mantle. If we can evaluate the radioactive heat generation in the crust more precisely, we can better estimate the heat flow from the mantle and the thermal state in the earth crust. In this study, the authors measured the contents of radioactive elements in rocks of Kohistan volcanic arc, Pakistan and Ichinomegata, northeast Japan. We conclude that low density rocks (ρ_??_2.9) systematically contain much more radioactive elements leading to high heat generation compared with high density rocks (ρ_??_3.0). In the next step, the vertical distribution of radioactive heat generation in the crust was estimated, and the heat generation of the lower crust in the two areas was found to be much lower than previously considered. It means, if the surface heat flow is the same, the estimated temperature at 30km depth is about 80°C higher than previous estimates. This temperature change may strongly affect the seismic activity at the depth.View full abstractDownload PDF (740K) -
Masashi KAMOGAWA, Yoshi-Hiko OHTSUKI1999 Volume 75 Issue 7 Pages 186-189
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSA theory is proposed to explain how the electromagnetic waves are created from the epicenter of large earthquakes. By the increase of strong stress in the rock, exo-electrons are excited and emitted, and bulk plasmon can be produced. They propagate to the earth surface, and transform into electromagnetic waves. Simple order-estimation shows that the electromagnetic waves of the frequency range 10MHz-1 GHz may be observed. Some characteristics of observed earthquake related electromagnetic waves may be interpreted by our plasmon model.View full abstractDownload PDF (1563K) -
Haruo TANAKA, Masashi KAMOGAWA, Yoshi-Hiko OHTSUKI1999 Volume 75 Issue 7 Pages 190-194
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSWe study the interaction between electromagnetic waves and bulk excitation modes of planar-bound electrons (bulk plasmons), excited by lightning or seismic activity, employing the electromagnetic hydrodynamics. By calculating the transition probability in the first order perturbation theory, it is shown that bulk plasmons are transformed into electromagnetic waves with the assistance of surface roughness.View full abstractDownload PDF (779K) -
Masayoshi OKUBO, Tsuyoshi YAMASHITA, Eriko ISE1999 Volume 75 Issue 7 Pages 195-200
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSIn a previous article, micron-sized, monodispersed, anomalous highly styrene-“adsorbed”particles having“snowman”shape were prepared by the dynamic swelling method (DSM) with tightly cross- linked polystyrene (PS)/poly(divinylbenzene) (PDVB) (PS/PDVB=1/10, w/w) composite particles. In this article, the thermodynamic background of DSM for the preparation of such monomer-adsorbed particles was discussed.View full abstractDownload PDF (1310K) -
Sakae SUDA, Hiroshi UYAMA, Shiro KOBAYASHI1999 Volume 75 Issue 7 Pages 201-206
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSSynthesis of aliphatic polyesters was performed by dehydration polycondensation in water using lipase as catalyst. Effects of the lipase origin and reaction parameters on the polymer yield and molecular weight have been systematically investigated in the combination of sebacic acid and 1, 8-octanediol. In the polymerization of α, ω-dicarboxylic acid and glycol, the polymerization behavior greatly depended on the chain length of the monomers. The polymer was obtained in good yields from 1, 10-decanediol, whereas no polymer formation was observed in using 1, 6-hexanediol. Oxyacids were also enzymatically polymerized in water to give the corresponding polyesters. The terminal structure was analyzed by NMR and MALDI-TOF mass spectroscopies. The reason of the dehydration polymerization in water was speculated.View full abstractDownload PDF (823K) -
Tsuyoshi MATSUMURA, Masashi AOKI, Atsushi NAGANO, Yukiko K. HAYASHI, C ...1999 Volume 75 Issue 7 Pages 207-212
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSMiyoshi myopathy (MM) is an autosomal recessive distal muscular dystrophy first described by Miyoshi in 1967. MM is caused by mutations of a dysferlin gene (DYSF) at chromosome 2p13. We identified 8 novel mutations and 3 polymorphisms in the DYSF among seven unrelated Japanese families. The mutations in our MM occurred throughout the DYSF and showed no mutational hot spot. Expression of dysferlin at the plasma membrane of skeletal muscle was deficient in all the patients studied. In two families, we found two distinct clinical phenotypes (distal and proximal dominancies) within a family. This is the first report of DYSF mutations and dysferlin deficiency in Japanese patients with MM. Our findings suggest, (1) the specific deficiency of dysferlin at the plasma membrane of skeletal muscle in MM, (2) the ethnic difference in DYSF mutations and (3) the presence of possible genetic or environmental modification factors which influence the clinical variability of MM.View full abstractDownload PDF (2356K) -
Tsuyoshi KAWASHIMA, Yoshihiro YAMAMOTO, Hironori ARAMAKI, Tatsuo NUNOS ...1999 Volume 75 Issue 7 Pages 213-218
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSThe complete genomic DNA sequence of the aero/anaero-facultative archaebacterium, Thermoplasma volcanium GSS1, has been determined. A number of DNA fragments were cloned by using the λ, cosmid, and BAC systems, and sequenced. The remaining 30 gaps were bridged by DNA fragments constructed using the polymerase chain reaction. The repetition in sequencing the same base positions was 13.1±7.5 fold. The alignment of the DNA fragments and the completeness of the genomic sequence were confirmed by the consistency of the genomic sequence with the lengths and partial sequences of a second set of DNA fragments that altogether covered 88% of the genome. The number of bases found in the genomic sequence is 1, 584, 799, with a G/C content of 39.9%. The combination of the four types of bases in the new genomic sequence is compared with those in known genomic sequences of similar sizes.View full abstractDownload PDF (3206K) -
Miro SMRIGA, Ji CHEN, Jun-Tian ZHANG, Takao NARUI, Shoji SHIBATA, Eiko ...1999 Volume 75 Issue 7 Pages 219-223
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSThe acute effects of isolichenan, a homologous α-glucan (1-3)(1-4) (3:2) isolated from lichen Cetrariella islandica, on the hippocampal synaptic plasticity were investigated in rats in vivo. Isolichenan (1mg /kg, intravenous treatment) significantly enhanced short-term potentiation evoked by a subthreshold tetanus, without any effect on the basal synaptic excitability (no tetanus stimulation). No effects on a supra-threshold tetanus-evoked potentiation were found. Isolichenan did not influence learning behaviors of intact mice in passive-avoidance tests and of intact rats in the Morris water maze test. When the learning ability of mice was impaired by 30% ethanol pre-treatment, isolichenan (>100mg/kg, oral treatment) significantly improved memory acquisition in passive-avoidance tests. Similarly, isolichenan (100 mg/kg, oral treatment) repaired memory-impairment induced by β-amyloid peptide (fraction 25-35) in the Morris water maze test in rats. These results suggest positive effects of isolichenan on spatial memory formation in rodents.View full abstractDownload PDF (720K) -
Kazuhiro IMAI, Makoto TSUNODA, Kazuko TAKEZAWA, Kazuto MITSUHASHI, Tom ...1999 Volume 75 Issue 7 Pages 224-227
Published: 1999
Released on J-STAGE: October 17, 2006
JOURNAL FREE ACCESSWe have previously demonstrated that the release of plasma norepinephrine (NE) in response to blood pressure reduction induced by calcium antagonist was substantially decreased in spontaneously hypertensive rats (SHR), as compared to the age-matched normotensive Wistar Kyoto (WKY) rats. Here we examined extraneuronal methylation of NE to normetanephrine (NMN) by catechol-O-methyltransferase (COMT). In the face of an acute hypotension by benidipine, the ratio of the increase of NMN to the increase of NE in plasma was lower in SHR than in WKY rat. The finding suggests that the extraneuronal inactivation of the released NE is blunted in SHR, namely, COMT is deactivated in this hypertensive rats. To define the role of NE methylation in hypertension, S-adenosyl-L-methionine (SAMe; 1.0mg/kg, iv.), a coenzyme of COMT, was administered to SHR. The treatment induced a greater antihypertensive effect, along with a greater decrease of NE and a larger increase of NMN in SHR. The data suggest that SAMe may be used as a possible remedy for hypertension.View full abstractDownload PDF (520K)
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