著者

Kazuhiro SUZUKI Akiko IKEDA Kaori ADACHI Daniel DUNKLEY Etsuko NIU Takenori KATO Shinobu MORI Noriyuki FUJII

出版者

The Japan Academy

雑誌

Proceedings of the Japan Academy, Series B (ISSN:03862208)

巻号頁・発行日

vol.78, no.5, pp.111-116, 2002 (Released:2006-10-17)

参考文献数

15

被引用文献数

1

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The Kamimura River, an upper tributary of the Yahagi River, flows through steep valleys in the mountainous Kamiyahagi area of Gifu Prefecture. The Tokai Gou flood of September 11-12, 2000 destroyed embankments along the river, and exposed sedimentary layers at Umi that are typical of a lacustrine depositional setting. This confirms the existence of a paleo-lake from which the name Umi originated. The lake was formed as the result of a huge landslide that dammed up the Kamimura River. To determine when the landslide occurred, radiocarbon (14C) ages of trees buried in lacustrine sediments were determined using accelerator mass spectrometry (AMS). The 14C ages are 300±25, 340±25, 345±25 and 380±25 BP for the outermost rings of tree trunks, which include bark, and a single age of 620±25 BP. Calibrated ages of (1637), (1520, 1590, 1624), (1517, 1597, 1619) and (1482) cal AD within a range of 1455-1643 cal AD are consistent with a landslide triggered by the Tensho Earthquake of January 18, 1586, which had an estimated magnitude of 8.2-8.3 and an epicenter in Ise Bay.

著者

Kazuhiro Suzuki Mamoru Adachi

出版者

GEOCHEMICAL SOCIETY OF JAPAN

雑誌

GEOCHEMICAL JOURNAL (ISSN:00167002)

巻号頁・発行日

vol.25, no.5, pp.357-376, 1991 (Released:2008-04-08)

参考文献数

42

被引用文献数

145 260

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Precise electron microprobe analysis makes it possible to determine the Th, U and Pb concentrations in an area less than 5 μm across in a single grain of monazite, zircon or xenotime; the detection limit of PbO at 2σ confidence level is 0.005–0.008 wt.% and the relative error is 3% for 0.2 wt.% concentration level. The subgrain analyses of monazite are plotted on the coordinates of PbO and ThO2* (ThO2 plus the equivalent of UO2), and those of zircon and xenotime on the coordinates of PbO and UO2* (UO2 plus the equivalent of ThO2). Data points are arrayed linearly and enable us to define an isochron which passes through the origin. The chemical Th-U-total Pb isochron ages coincide well with mineral and whole-rock ages isotopically determined for the same samples. The chemical Th-U-total Pb isochron method was applied to the age determination of monazite, zircon and xenotime from the Tsubonosawa paragneiss and the host Hikami granite in the South Kitakami terrane of Northeast Japan. The chemical ages show that (1) the sedimentation of the gneiss-protolith occurred soon after the emplacement of 500 Ma granitoids in the source region, where the 500 Ma granitoids were widespread together with Precambrian rocks possibly dated back to as old as Archean (3080 ± 180 Ma), (2) the gneiss-protolith was metamorphosed to the amphibolite facies grade about 430 ± 10 Ma ago, and (3) the gneiss was affected by multiple thermal events of 350, 260, 180 and 100 Ma. The 350 Ma event corresponds to the intrusion of the Hikami granite, and the 100 Ma one to the intrusion of the Cretaceous Kesengawa granite. The 260 and 180 Ma events may correspond in age to the main metamorphic event and subsequent igneous activity in the Hida terrane, central Japan. The chemical Th-U-total Pb isochron age in terms of the precise microprobe analysis of low-level Th, U and Pb will open a new vista on the Paleozoic-Mesozoic tectonics of the Japanese Islands.

著者

Kazuhiko Kotani Yoshitaka Sekine Shizukiyo Ishikawa Imoh Z. Ikpot Kazuhiro Suzuki Alan T. Remaley

出版者

日本疫学会

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20130006, (Released:2013-08-27)

参考文献数

35

被引用文献数

10 36

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Prostate cancer is a common disease in modern, developed societies and has a high incidence and mortality. High-density lipoprotein cholesterol (HDL-C) has recently received much attention as a possible risk marker of prostate cancer development and prognosis. In the present article, we summarized findings from epidemiologic studies of the association between HDL-C and prostate cancer. Low HDL-C level was found to be a risk and prognostic factor of prostate cancer in several epidemiologic studies, although the overall linkage between HDL and prostate cancer has not been definitively established. The mechanisms for this association remain uncertain; however, limited data from experimental studies imply a possible role of HDL in the pathophysiology of prostate cancer. More epidemiologic research, in combination with experimental studies, is needed in this field.