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Sample records for ryukyu islands japan

  1. New records of mosquito species for different islands of the Ryukyu Archipelago, Japan.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako; Higa, Yukiko

    2011-06-01

    During an 11-year study period (1999-2010) on the islands of the Ryukyu Archipelago, Japan, 20 mosquito species were identified. The results revealed new records of species hitherto not reported on these islands. This contribution updates the mosquito fauna of the various islands of the Ryukyu Archipelago.

  2. Paleo-tsunami and storm records inferred from coastal boulders along the Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Goto, K.; Miyagi, K.; Imamura, F.

    2012-12-01

    After the 11 March 2011 Tohoku-oki earthquake and tsunami (Mw=9.0) at off the coast of Tohoku district of Japan, re-evaluation of the occurrence of large earthquake and tsunami along the subduction zone is one of the major issues in Japan. Along the Ryukyu trench, there are no known thrust type earthquakes of magnitude greater than 8.0 in the last 300 years [Ando et al., 2009, 2012], although there is one possible exception: the AD1771 event at the southern Ryukyu Islands which is characterized by the ~30 m run-up heights. Hence, the occurrence of tsunamigenic large earthquake along the Ryukyu trench in the past and future is controversial. The lack of thousands of years geological record of past earthquake and tsunami such as the sandy tsunami deposits along the Ryukyu trench has made the discussion more difficult, because there are very few suitable places to study such deposits. On the other hand, numerous coastal boulders are reported on the fringing reefs of each island [e.g. Goto et al., 2010]. They are mostly composed of the coralline and reef rocks and are regarded as useful markers of the past large tsunamis and storm events. In fact, some of them are fossil Porites sp. and hence 14C dating is possible for determining the depositional age [e.g. Araoka et al., 2010]. Moreover, boulders of tsunami and storm wave origins at Ryukyu Islands can be differentiated because difference of the wave lengths of tsunami and storm wave are affected the clast size and spatial distributions of boulders on the wide fringing reef (~1500 m) [e.g. Goto et al., 2010]. Therefore, presence or absence of tsunami boulders at each island may provide useful information of occurrence of past large tsunamis and the causative earthquakes along the Ryukyu Trench. In this study, we show the clast size and spatial distributions of more than 2,500 boulders at 11 islands along the Ryukyu trench. Based on the geological study and hydrodynamic analyses, boulders on the reefs at the Sakishima

  3. Terrestrial gamma radiation dose rate in Ryukyu Islands, subtropical region of Japan.

    PubMed

    Furukawa, M; Kina, S; Shiroma, M; Shiroma, Y; Masuda, N; Motomura, D; Hiraoka, H; Fujioka, S; Kawakami, T; Yasuda, Y; Arakawa, K; Fukahori, K; Jyunicho, M; Ishikawa, S; Ohomoto, T; Shingaki, R; Akata, N; Zhuo, W; Tokonami, S

    2015-11-01

    In order to explain the distribution of natural radiation level in the Asia, in situ measurements of dose rate in air due to terrestrial gamma radiation have been conducted in a total of 21 islands that belong to Ryukyu Islands (Ryukyu Archipelago), subtropical rejoin of southwest Japan. Car-borne surveys have also been carried out in Okinawa-jima, the biggest island of the archipelago. Based on the results for these measurements, arithmetic mean, the maximum and the minimum of the dose rates at 1 m in height from the unpaved soil ground in the archipelago were estimated to be 47, 165 and 8 nGy h(-1), respectively. A comparative study of car-borne data obtained prior to and subsequent to the 2011 Fukushima nuclear accident, as for Okinawa-jima, indicated that the nuclear accident has no impact on the environmental radiation at the present time.

  4. The preliminary results of new submarine caldera on the west of Kume-jima island, Central Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Harigane, Y.; Ishizuka, O.; Shimoda, G.; Sato, T.

    2014-12-01

    The Ryukyu Arc occurs between the islands of Kyushu and Taiwan with approximately 1200 km in the full length. This volcanic arc is caused by subduction of the Philippine Sea plate beneath the Eurasia Plate along the Ryukyu trench, and is composed of forearc islands, chains of arc volcanoes, and a back-arc rift called Okinawa Trough. The Ryukyu Arc is commonly divided into three segments (northern, central and southern) that bounded by the Tokara Strait and the Kerama Gap, respectively (e.g., Konishi 1965; Kato et al., 1982). Sato et al. (2014) mentioned that there is no active subaerial volcano in the southwest of Iotori-shima in the Central Ryukyu Arc whereas the Northern Ryukyu Arc (i.e., the Tokara Islands) has active frontal arc volcanoes. Therefore, the existence of volcanoes and volcanotectonic history of active volcanic front in the southwestern part of the Central Ryukyu Arc are still ambiguous. Detailed geophysical and geological survey was mainly conducted using R/V Kaiyou-maru No.7 during GK12 cruise operated by the Geological Survey of Japan/National Institute of Advanced Industrial Science and Technology, Japan. As a result, we have found a new submarine volcanic caldera on the west of Kume-jima island, where located the southwestern part of Central Ryukyu Arc. Here, we present (1) the bathymetrical feature of this new submarine caldera for the first time and (2) the microstructural and petrological observations of volcanic rocks (20 volcanic samples in 13 dredge sites) sampled from the small volcanic cones of this caldera volcano. The dredged samples from the caldera consist of mainly rhyolite pumice with minor andesites, Mn oxides-crust and hydrothermally altered rocks. Andesite has plagioclase, olivine and pyroxene phenocrysts. Key words: volcanic rock, caldera, arc volcanism, active volcanic front, Kume-jima island, Ryukyu Arc

  5. The Quaternary adakite distribution of Kyushu Island, Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Yoshikawa, M.; Takemura, K.

    2011-12-01

    The Quaternary volcanoes are widely distributed in Kyusu Island, Japan. Philippine Sea plate is subducting beneath Kyushu. Clear distribution of deep seismic foci is observed below the Quaternary volcanoes in southern area, but not in northern area. Notsu et al. (1990, JVGR) examined the contribution of subduction to the magma source, and emphasized that no slab derived material is observed in northern area from Sr isotopic compositions. Volcanic activity similar to the within-plate type volcanism has been also emphasized for the magma genesis of this area (e.g. Kita et al, 2001, JVGR). However, we found adakitic rocks, which show high Sr/Y ratios and low Y concentrations (e.g. Defant and Drummond, 1990, Nature) from some Quaternary volcanoes in north Kyushu on the basis of published data (Otha et al, 1990, GANKO; Itoh, 1990, GANKO). Therefore, the magma genesis is still controversial. We studied lateral variations of Sr, Nd and Pb isotopic and trace element compositions for Quaternary volcanics from Kyushu to investigate the magma genesis. From the results, a clear variation of Sr/Y ratio, decreasing from north to south, is observed along the volcanic front. Some of the Sr/Y ratio of the most northern part of Kyusu shows the value >100. The all analyzed Pb isotope compositions show a single liner trend in 208Pb/204Pb v.s. 206Pb/204Pb diagram. The liner trend of Pb isotope ratios can be explained by the binary mixing of the Shikoku Basin basalt and tereginious sediment which might be a constituent of the subducting slab. The similar binary mixing relationships are found in Sr and Nd isotopic systematics. The isotopic characteristics of the Quaternary magma in Kyushu can be explained by the magma generation process of island arc, in spite of the lack of deep seismic foci in northern area. It is considered that high and low Sr/Y ratios suggest the contributions of partial melt in the north and aqueous fluid derived from subducting slab in the south, respectively. If

  6. Three new brackish-water thalassocypridine species (Crustacea: Ostracoda: Paracyprididae) from the Ryukyu Islands, southwestern Japan.

    PubMed

    Hiruta, Shimpei F; Kakui, Keiichi

    2016-09-21

    We describe three new species of brackish-water ostracods representing two genera in the ostracod tribe Thalassocypridini from mangrove forests in the Ryukyu Islands, subtropical southwestern Japan, and provide their barcoding sequences for the mitochondrial cytochrome c oxidase subunit I (COI) gene. Mangalocypria ryukyuensis sp. nov. was found on Okinawa Island. We also found a Mangalocypria population on Ishigaki Island that was morphologically identical to M. ryukyuensis on Okinawa, but an individual differed by 4.7% in COI sequence (K2P distance) from an individual from Okinawa. This is the first record for Japan of a species in Mangalocypria. Paracypria longiseta sp. nov., obtained from Okinawa Island, is similar to Pontoparta hartmanni. Paracypria plumosa sp. nov. from Ishigaki Island is similar to Pa. adnata described from Yakushima Island, Japan. The COI genetic distance between individuals of Pa. longiseta and Pa. plumosa was roughly as large as that between either of these species and individuals in the Mangalocypria populations. Our study underscores that genera in Thalassocypridini may not represent natural groups, and that this tribe needs taxonomic revision.

  7. A new species of Gnathia (Isopoda: Cymothoida: Gnathiidae) from Okinawajima Island, Ryukyu Archipelago, southwestern Japan.

    PubMed

    Ota, Yuzo; Tanaka, Katsuhiko; Hirose, Euichi

    2007-12-01

    Gnathia limicola sp. nov. is described from Okinawajima Island, Ryukyu Archipelago, southwestern Japan. Burrows of this species were found in a small intertidal creek bank on a muddy tidal flat near mangrove trees. Adult males differ from those of other Gnathia species in the following features: (1) fine setae cover peduncle articles 1 and 2 of antenna 1, peduncle articles 1-3 of antenna 2, and the erisma of the mandibles; (2) the ventral frontal border of the cephalon is medianly notched, and the lateral parts extend beyond the dorsal frontal border; and (3) the penes are fused into a thin rectangular blade directed posteriorly. Adult females and praniza larvae were also distinguished morphologically from other Gnathia species. Based on field and laboratory observations, the mating behavior of this species appears similar to that of Paragnathia formica (Hesse, 1862), which inhabits salt marshes in Europe and North Africa.

  8. Two new dwarfgobies of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae).

    PubMed

    Greenfield, David W; Suzuki, Toshiyuki; Shibukawa, Koichi

    2014-03-10

    Two species of dwarfgoby are described from the Ryukyu Islands, Japan. Eviota flebilis n. sp. belongs to cephalic sensory-pore system pattern 2 (lacking only IT pore), has a dorsal/anal fin-ray formula of 8/7, unbranched pectoral-fin rays, the 5th pelvic-fin ray 12.9% of the 4th, a distinctive narrow, red-orange line under the eye, and a dark vertical line at the caudal-fin base. Eviota specca n. sp. has a cephalic sensory-pore system pattern 1 (complete), has a dorsal/anal-fin formula of 8/8, the body heavily sprinkled with chromatophores, and a single dark spot on the upper pectoral-fin base.

  9. Description of female pupa and larva of Ficalbia ichiromiyagii from Iriomote Island, Ryukyu Archipelago, Japan.

    PubMed

    Higa, Yukiko; Toma, Takako; Miyagi, Ichiro

    2012-12-01

    We describe and illustrate for the 1st time the pupa and larva of adult female Ficalbia ichiromiyagii based on specimens collected from a swamp forest in Otomi, Iriomote Island, Ryukyu Archipelago, Japan. The pupa has a trumpet that is 6.25 times its breadth at halfway, with a long meatal cleft line; setae 6-I, II considerably long, usually single or bifid; median caudal seta absent; and paddle edge serrated only on the outer apical half. The larva is characterized by dark pigmentation of the head and siphon, seta I-C elongate and spiniform, usually with a short lateral spine on the inner basal side and siphon with 1 pecten spine and conspicuous seta 1-S at the base. The immature stages were found only in undisturbed jungle swamps with dense vegetation.

  10. Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) from a submarine cave, off Iejima, Ryukyu Islands, Japan.

    PubMed

    Fujimoto, Shinta

    2015-04-20

    Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) is described from the submarine cave 'Daidokutsu', off Iejima, Okinawa Islands, Ryukyu Islands, Japan. It is characterised by a cylindrical body, long primary clava and shorter lateral cirrus inserted on a common cirrophore, and simple digits of unequal lengths (without folds, peduncles, proximal pads, pretarsi, or wrinkles) that terminate in a sheathed, small, crescent-shaped claw with a minute calcar. Quisarctinae subfam. nov. is erected for this unique new genus.

  11. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  12. Mechanism of early meteoric diagenesis in carbonate dune sands, Tarama Island, Ryukyu Islands, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kumai, N.; Matsuda, H.

    2012-12-01

    Carbonate sediments are useful for the interpretation of depositional environments and environmental changes because their components and chemistry reflect depositional environments sensitively. However, primary records on their depositional environments are often modified by various types of early carbonate diagenesis immediately after their deposition. Longman (1980) pointed out that sedimentary textures and mineral compositions of carbonate sediments near a subaerial exposure surface are easily changed by dissolution and cementation associated with early meteoric diagenesis. Hudson (1977) also suggested that their primary stable carbon and oxygen isotopic compositions are altered by early meteoric diagenesis. In this way, the qualitative changes of carbonate sediments with early meteoric diagenesis are well known. On the other hand, the quantitative changes, time scale and detailed mechanisms of early meteoric diagenesis are not fully understood at present. To clarify the detailed mechanism of early meteoric diagenesis, the Upper Pleistocene carbonate dune sands in Tarama Island, the Ryukyu Islands, southwestern Japan, were analyzed. These sediments consist mainly of unconsolidated to weakly-consolidated carbonate sands, composed mainly of a variety of shallow marine bioclasts. Detailed petrographical observation and XRD and isotopic analyses were carried out. As a result of examinations of these carbonate sediments, low-Mg calcite (LMC), high-Mg calcite (HMC) and aragonite (ARG) contents of unconsolidated carbonate sands (UCS) are 20 to 47%, 0 to 44% and 33 to 54%, respectively. On the other hand, LMC, HMC and ARG contents of weakly-consolidated carbonate sands (WCS) are 64 to 95%, 0 to 18% and 5 to 18%, respectively. δ13C and δ18O values of UCS have narrow ranges of 0.51 to 1.70‰ and -1.87 to -1.46‰, respectively. On the other hand, δ13C and δ18O values of WCS have wide ranges of -4.67 to 0.62‰ and -4.82 to 2.92‰, respectively. The mineral and

  13. Two new dwarfgobies (Teleostei: Gobiidae) from the Ryukyu Islands, Japan: Eviota flavipinnata and Eviota rubrimaculata.

    PubMed

    Suzuki, Toshiyuki; Greenfield, David W; Motomura, Hiroyuki

    2015-08-28

    Two new species of Eviota from Yoron Island, the Ryukyu Islands, Japan, are described. Both species belong to the cephalic sensory-canal pore system pattern 2 (lacking only the H [IT] pore); have some pectoral-fin rays branched; have a dorsal/anal-fin formula of 9/8; no dark spot over the ural centrum; no prominent distinct dark spots on the pectoral-fin base; no postocular spots; and no strong dark spots on the caudal fin. The species share the most characters with E. afelei, E. bimaculata and E. punctulata, but differ from Eviota afelei and E. punctulata by having two versus three dark marks over the anal-fin base, and from Eviota bimaculata by lacking the two dark, prominent occipital spots present in that species. Both species differ from all other described species of Eviota in fresh coloration. Eviota flavipinnata has bright golden-yellow dorsal fins and an orange anal fin, and a fifth pelvic-fin ray that is 12% the length of the fourth ray. Eviota rubrimaculata has clear dorsal fins with red spots, large red spots on the body, and lacks the fifth pelvic-fin ray.

  14. A new species of the palaemonid shrimp genus Palaemonella Dana, 1852 (Crustacea: Decapoda: Caridea) from Okinawa Island, Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Yamada, Yusuke

    2015-06-03

    The palaemonid shrimp genus Palaemonella Dana, 1852 is currently represented by 21 formally described species worldwide, of which 17 species are known from the Indo-West Pacific. In this study, a new species, P. okunoi, is described and illustrated on the basis of two ovigerous female specimens collected from coastal waters in Okinawa Island, Ryukyu Islands, Japan, at depths of 5-30 m. The new species closely resembles P. hachijo Okuno, 1999, but the shorter rostrum, more anteriorly located postrostral teeth on the carapace, the presence of a pair of submedian teeth on the fourth thoracic sternite and the less slender pereopods distinguish P. okunoi n. sp. from P. hachijo. The discovery of the present new species raises the number of Japanese species of Palaemonella to eight. An updated key to the Indo-West Pacific species of the genus is presented.

  15. Eco-geomorphic processes that maintain a small coral reef island: Ballast Island in the Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Kayanne, Hajime; Aoki, Kenji; Suzuki, Takuya; Hongo, Chuki; Yamano, Hiroya; Ide, Yoichi; Iwatsuka, Yuudai; Takahashi, Kenya; Katayama, Hiroyuki; Sekimoto, Tsunehiro; Isobe, Masahiko

    2016-10-01

    Landform changes in Ballast Island, a small coral reef island in the Ryukyu Islands, were investigated by remote sensing analysis and a field survey. The area of the island almost doubled after a mass coral bleaching event in 1998. Coral branches generated by the mass mortality and broken by waves were delivered and stocked on a reef flat and accumulated to expand the area of the island. In 2012 high waves generated by typhoons also changed the island's topography. Overall, the island moved in the downdrift direction of the higher waves. Waves impacting both sides of the island piled up a large volume of coral gravels above the high-tide level. Eco-geomorphic processes, including a supply of calcareous materials from the corals on the same reef especially during stormy wave conditions, were key factors in maintaining the dynamic topographic features of this small coral reef island.

  16. Molecular phylogenies of figs and fig-pollinating wasps in the Ryukyu and Bonin (Ogasawara) islands, Japan.

    PubMed

    Azuma, Hiroshi; Harrison, Rhett D; Nakamura, Keiko; Su, Zhi-Hui

    2010-01-01

    The interaction between figs (Ficus, Moraceae) and fig-pollinating wasps (Chalcidoidea, Agaonidae) is one of the most specific mutualisms, and thus is a model system for studying coevolution and cospeciation. In this study we focused on figs and their associated fig-wasps found in the Ryukyu and Bonin (Ogasawara) Islands, Japan, because it has been suggested that breakdown in the specificity may occur in islands or at edge of a species' distribution. We collected 136 samples of 15 native fig species and 95 samples of 13 associated fig-wasps from all major islands in the Ryukyu Islands, including two fig species and one fig-wasp species endemic to the Bonin Islands. We performed molecular phylogenetic analyses using plastid DNA and nuclear ITS sequences for the figs and nuclear 28S rRNA and mitochondrial COI genes for the fig-wasps to investigate the interspecific phylogenies and intraspecific variation within the mutualism. Our phylogenetic analyses using multiple samples per species show the single clade of each fig (except the Bonin endemic species) and fig-pollinating wasp species. Fig species belonging to the same subgenera formed well-supported clades in both plastid and ITS trees, except for the subgenus Urostigma. Likewise, fig wasps emerging from host fig species belonging to the same subgenera formed mostly well supported clades in both 28S and COI trees. Host specificity between the figs and fig-wasps functions strictly in these islands. There was very little sequence variation within species, and that no major geographic structure was found. The two Bonin endemic species (F. boninsimae and F. nishimurae) or their common ancestor and the associated fig-wasps (Blastophaga sp.) are apparently derived from F. erecta and its associated fig-wasps (B. nipponica), respectively, and probably migrated from the Ryukyu Islands.

  17. Indoapseudes bamberi sp. nov. (Crustacea: Tanaidacea: Pagurapseudidae: Hodometricinae) from Iriomote Island, Ryukyu Islands, southwestern Japan.

    PubMed

    Kakui, Keiichi; Naruse, Tohru

    2015-08-05

    We describe Indoapseudes bamberi sp. nov., based on a specimen from Funaura Bay, Iriomote Island, Japan. This species can be distinguished from its five congeners by having the combination of the antenna with a squama and pereopods 1 and 2 with one dorsal spine on the basis. We also determined part of the nucleotide sequence for the cytochrome c oxidase subunit I (COI) gene in I. bamberi, and present a key to Indoapseudes species.

  18. New records of Pagurixus Melin, 1939 (Crustacea: Decapoda: Paguridae) from the Ryukyu Islands, southwestern Japan, with description of a new species.

    PubMed

    Osawa, Masayuki; Kawai, Takashi; Sakamaki, Takashi

    2013-01-01

    Seven hermit crab species of the pagurid genus Pagurixus Melin, 1939 are reported on the basis of material recently collected from the northern and central islands of the Ryukyu Islands, southwestern Japan. Four species are new to the hermit crab fauna of the Ryukyu Islands: P. acanthocarpus Komai & Okuno, 2009; P. fasciatus Komai & Myorin, 2005; P. formosus Komai, 2010; and P. tweediei (Forest, 1956). One species is described as new to science: P vicinus sp. nov. is closely similar to P. fasciatus in both morphology and coloration, but distinguished by the armature on the left cheliped and right second pereopod. Paguruxus carininanus Komai & Osawa, 2006 and P. pseliophorus Komai & Osawa, 2006, both previously known from the Ryukyu Islands, are here reported from new localities.

  19. A new species of the pontoniine shrimp genus Eupontonia (Crustacea: Decapoda: Caridea: Palaemonidae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Minemizu, Ryo

    2014-03-27

    A third species of the pontoniine shrimp genus Eupontonia Bruce, 1971, E. gracilipes n. sp., is described and illustrated on the basis of a single female specimen collected from shallow water of Ishigaki Island, southern Ryukyu Islands, Japan. The new species is readily distinguished from the two congeneric species, E. noctalbata Bruce, 1971 and E. oahu Bruce, 2010, by a number of morphological characters, including the presence of a distinct postrostral median ridge and of the postrostral median tooth on the carapace. It is considered to be a free-living species. The generic diagnosis of Eupontonia is slightly emended to accommodate the present new species. A key in aid of identification of species of Eupontonia is provided.

  20. Marine terraces caused by fast steady uplift and small coseismic uplift and the time-predictable model: Case of Kikai Island, Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Shikakura, Yosuke

    2014-10-01

    Kikai Island, a part of the Ryukyu Islands in southwest Japan, is rimmed by marine terraces. This island has been studied in detail because these marine terraces record the fastest crustal uplift in Japan. Geological studies of the raised Holocene reef have concluded that coseismic uplift has been generating marine terraces since 6.3 ka. Analysis of GPS data suggests that Kikai Island is steadily uplifted several mm/yr. To examine the discrepancy between geological and geodetic surveys, I numerically modeled nearshore processes and simulated the generation of marine terraces under two conditions: 1) large stepwise uplift and no steady uplift and 2) steady uplift and small stepwise uplift. As a result, the emergence time of the marine terraces is the same and the heights of the terrace cliffs are consistent with the time-predictable recurrence model for large earthquakes. This result shows the possibility of overestimate of magnitudes of the past earthquakes.

  1. Calcareous nannofossil assemblages of the upper Miocene to Pliocene Shimajiri Group on Okinawa-jima, Ryukyu Islands, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Imai, Ryo; Sato, Tokiyuki; Iryu, Yasufumi

    2017-03-01

    We investigated the calcareous nannofossil biostratigraphy and paleoceanography of the Shimajiri Group in two exploratory wells (depths, 1243 and 1800 m) drilled on southern Okinawa-jima, Ryukyu Islands, southwestern Japan. Three late Miocene to Pliocene datum planes were identified: the first occurrence of Amaurolithus spp. (7.42 Ma), the last occurrence of Discoaster quinqueramus (5.59 Ma), and the first occurrence of Ceratolithus rugosus (5.12 Ma). These datum planes were also identified in two other deep wells on southern Okinawa-jima. Nutrient levels (reconstructed from the relative abundances of small Reticulofenestra spp., and the relative abundances of Discoaster spp. plus Sphenolithus abies) suggest that deposition of the Shimajiri Group (<8.29-3.50 Ma) occurred under conditions of increasing eutrophication. The eutrophication was likely caused by shallowing of the sedimentary basin, but a stepwise shift was associated with an abrupt eutrophication event that occurred in the northwestern Pacific Ocean at 5 Ma.

  2. Spatial differences and seasonal changes of net carbonate accumulation on some coral reefs of the Ryukyu Islands, Japan.

    PubMed

    Hibino; van Woesik R

    2000-09-05

    This study sought to understand short-term spatial changes in accretion and erosion on (experimental) carbonate blocks on three coral reefs of the Ryukyu Islands, Japan. The principal objectives were to differentiate net accretion/erosion according to season, location, depth and substrate-type. At all locations the summer season showed more positive net weight changes and higher coralline algal coverage than the winter season. Windward reefs revealed higher net accretion and higher coralline algal coverage than leeward reefs. Massive (Holocene) Porites blocks showed highest net loss, followed by Pleistocene carbonate and (Holocene) Acropora blocks. High population densities of Echinometra mathaei (de Blainville) were recorded on reefs adjacent to large human populations and overall net carbonate loss significantly correlated to densities of E. mathaei type A.

  3. Two new species of ghost shrimp assigned to the genus Cheramus Spence Bate, 1888 (Crustacea: Decapoda: Axiidea: Callianassidae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Maenosono, Tadafumi; Fujita, Yoshihisa

    2014-12-17

    Two new species of the callianassid ghost shrimp are described and illustrated on the basis of specimens from the Ryukyu Islands, Japan. These are provisionally assigned to the genus Cheramus Spence Bate, 1888, and appear closest to Callianassa acutirostella Sakai, 1988, also provisionally transferred to Cheramus herewith. These three species can be differentiated by characters of the telson, third maxilliped, chelipeds and uropod. The taxonomic status of Cheramus is briefly discussed.

  4. Formation of gas discharging from Taketomi submarine hot spring off Ishigaki Island in the southern Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Toki, Tomohiro; Iwata, Daigo; Tsunogai, Urumu; Komatsu, Daisuke D.; Sano, Yuji; Takahata, Naoto; Hamasaki, Hiroshi; Ishibashi, Jun-ichiro

    2017-01-01

    Taketomi submarine hot spring lies off Ishigaki Island in the southern Ryukyu Islands and vents hot spring waters at temperatures up to 50 °C from the seafloor at a depth of 20 m. We investigated the chemical and isotopic composition of gases discharging from Taketomi hot spring. The gases were composed mainly of methane, with secondary nitrogen at higher than atmospheric concentration. Carbon and hydrogen isotope data suggest that the methane in the discharging gases was derived mainly from thermal decomposition of organic matter. Helium isotopes were enriched in 3He relative to the atmosphere, suggesting a supply of mantle-derived helium to the discharging gases. The mantle-derived gases transfer the deep-originated thermal energy to the hot spring and thermogenesis of organic matter. The hydrocarbons in the venting gas could be sourced from sedimentary rocks of the Yaeyama or Shimajiri Groups, or Yaeyama metamorphic rocks, and added to the ascending gases as they pass through those source rocks on their way to the surface. Because the Pleistocene rocks of the Ryukyu Group beneath the hot spring have been altered by the spring activity, the Taketomi hot spring began venting after the Pleistocene.

  5. A crab-hole mosquito, Ochlerotatus baisasi, feeding on mudskipper (Gobiidae: Oxudercinae) in the Ryukyu Islands, Japan.

    PubMed

    Okudo, Haruo; Toma, Takako; Sasaki, Hitoshi; Higa, Yukiko; Fujikawa, Mayumi; Miyagi, Ichiro; Okazawa, Takao

    2004-06-01

    Ochlerotatus baisasi was observed and photographed feeding on a mudskipper (Periophthalmus argentilineatus). Origin of blood meals in the stomachs of female mosquitoes collected at burrows of land crabs and mud lobsters in the mangrove forests of Oura, Okinawa, and Komi, Iriomote (the Ryukyu Islands), was determined by enzyme-linked immunosorbent assay to be from a fish source.

  6. Additional record of Rayllianassa amboinensis (de Man, 1888) from Japan, and description of a new species from Okinawa Island, Ryukyu Islands (Crustacea: Decapoda: Axiidea: Callianassidae).

    PubMed

    Komai, Tomoyuki; Fujita, Yoshihisa; Maenosono, Tadafumi

    2014-07-14

    Two species referred to the callianassid ghost shrimp genus Rayllianassa Komai & Tachikawa, 2008 are reported herewith. Additional locality records from Japan are provided for R. amboinensis (de Man, 1888), and the synonymy of Callianassa ngochoae Sakai, 1999 with R. amboinensis is discussed. It is shown that R. amboinensis is associated with sponges or alcyonacean soft corals, representing unusual habitats for callianassids. Rayllianassa rudisulcus n. sp. is described on the basis of a single ovigerous female from shallow soft sediment in Ohura Bay, Okinawa Island, Ryukyu Islands. The new species is distinguished from R. amboinensis by the absence of a dorsal oval on the carapace, the antennal peduncle being longer than the antennular peduncle, and the different shape of the third maxilliped. The status of Rayllianassa is also briefly discussed.

  7. Preliminary survey of taxonomical problems, pharmacognostical characteristics, and chloroplast DNA polymorphisms of the folk medicinal herb Artemisia campestris from the Ryukyu Islands, Japan.

    PubMed

    Minami, Motoyasu; Suzuki, Minori; Hosokawa, Keizo; Kondo, Seizo; Oka, Kenji; Shibata, Toshiro

    2010-04-01

    Artemisia campestris L. (Compositae) occurs naturally along the coastline of the Ryukyu Islands and has been traditionally used as a folk medicine for the treatment of liver and kidney disorders. The authors obtained specimens from the Ishigaki and Kume Islands of the Ryukyu Islands, Japan, and from the USA. A survey of the literature revealed that the Japanese name for A. campestris is Niitaka-yomogi or Riukiu-yomogi. Two distinct overall plant-form phenotypes were identified: an erect phenotype with long, upright, and straight main axis and assurgent branches; and a prostrate phenotype, having branches that are longer than the main axis and which grow along the ground. Except for the number of ray flowers, most of the flower head characters in the erect phenotypes were significantly larger than those in the prostrate phenotypes. In this experiment, the flower heads contained only small amounts of either capillarisin (<0.01-0.11 of the dry weight, % DW) and 6,7-dimethylesculetin (<0.01-0.30% DW), or none at all. DNA polymorphisms at two sites of the rpl16-rpl14 spacer region (nucleotide position 181-189 and 291-300 from the 5' end) revealed the existence of four different haplotypes. The number of adenines at nucleotide positions 291-300 appeared to be polymorphic within A. campestris from the Ryukyu Islands. Conversely, geographic differences between specimens from the Ryukyu Islands and USA manifested as a nine-base deletion at nucleotide positions 181-189. From a pharmacognostical context, the use of A. campestris flower heads as a substitute for Artemisiae capillaris Flos is not effective.

  8. Evolutionary Relationship between Two Firefly Species, Curtos costipennis and C. okinawanus (Coleoptera, Lampyridae), in the Ryukyu Islands of Japan Revealed by the Mitochondrial and Nuclear DNA Sequences

    PubMed Central

    Muraji, Masahiko; Arakaki, Norio; Tanizaki, Shigeo

    2012-01-01

    The phylogenetic relationship, biogeography, and evolutionary history of closely related two firefly species, Curtos costipennis and C. okinawanus, distributed in the Ryukyu Islands of Japan were examined based on nucleotide sequences of mitochondrial (2.2 kb long) and nuclear (1.1-1.2 kb long) DNAs. In these analyses, individuals were divided among three genetically distinct local groups, C. costipennis in the Amami region, C. okinawanus in the Okinawa region, and C. costipennis in the Sakishima region. Their mtDNA sequences suggested that ancestral C. costipennis population was first separated between the Central and Southern Ryukyu areas, and the northern half was then subdivided between C. costipennis in the Amami and C. okinawanus in the Okinawa. The application of the molecular evolutionary clocks of coleopteran insects indicated that their vicariance occurred 1.0–1.4 million years ago, suggesting the influence of submergence and subdivision of a paleopeninsula extending between the Ryukyu Islands and continental China through Taiwan in the early Pleistocene. PMID:22629179

  9. Evolutionary relationship between two firefly species, Curtos costipennis and C. okinawanus (Coleoptera, Lampyridae), in the Ryukyu Islands of Japan revealed by the mitochondrial and nuclear DNA sequences.

    PubMed

    Muraji, Masahiko; Arakaki, Norio; Tanizaki, Shigeo

    2012-01-01

    The phylogenetic relationship, biogeography, and evolutionary history of closely related two firefly species, Curtos costipennis and C. okinawanus, distributed in the Ryukyu Islands of Japan were examined based on nucleotide sequences of mitochondrial (2.2 kb long) and nuclear (1.1-1.2 kb long) DNAs. In these analyses, individuals were divided among three genetically distinct local groups, C. costipennis in the Amami region, C. okinawanus in the Okinawa region, and C. costipennis in the Sakishima region. Their mtDNA sequences suggested that ancestral C. costipennis population was first separated between the Central and Southern Ryukyu areas, and the northern half was then subdivided between C. costipennis in the Amami and C. okinawanus in the Okinawa. The application of the molecular evolutionary clocks of coleopteran insects indicated that their vicariance occurred 1.0-1.4 million years ago, suggesting the influence of submergence and subdivision of a paleopeninsula extending between the Ryukyu Islands and continental China through Taiwan in the early Pleistocene.

  10. New records of two species of the coral reef shrimp genus Thor Kingsley, 1878 (Crustacea: Decapoda: Thoridae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Okuno, Junji; Minemizu, Ryo

    2015-09-09

    The caridean shrimp genus Thor Kingsley, 1878 (Thoridae) is currently represented by 14 species distributed in shallow tropical to subtropical waters in the Indo-Pacific, East Pacific and West Atlantic oceans. In this study, two species of the genus are reported on the basis of material from Okinawa and Kume islands in the Ryukyu Archipelago, southern Japan. Thor leptochelus (Xu & Li, 2015) n. comb., recently described from Xisha Islands, China and originally assigned to Thinora Bruce, 1997, is transferred to Thor. Relationship of the species to three congeneric species (T. cordelli Wicksten, 1996, T. spinipes Bruce, 1983 and T. spinosus Boone, 1935) is discussed. The second is T. marguitae Bruce, 1973, representing the rediscovery since the original description and new record for Japanese waters. The four specimens of T. leptochelus were all free-living, whereas the single specimen of T. marguitae was found to be associated with a solitary fungiid coral, as previously reported.

  11. A new genus and two new species of Peltogastridae (Crustacea: Cirripedia: Rhizocephala) parasitizing hermit crabs from Okinawa Island (Ryukyu Archipelago, Japan), and their DNA-barcodes.

    PubMed

    Yoshida, Ryuta; Osawa, Masayuki; Hirose, Mamiko; Hirose, Euichi

    2011-11-01

    A new genus and two new species of Peltogastridae, Peltogaster postica sp. nov. and Ommatogaster nana gen. et sp. nov., are described from Okinawa Island, Ryukyu Islands, southwestern Japan. The two new rhizocephalans were found to be parasitic on the estuarine hermit crabs, Pagurus minutus Hess, 1865 and Diogenes leptocerus Forest, 1956, respectively. Peltogaster postica sp. nov. is allied to P. curvata Kossmann, 1874, P. paguri Rathke, 1842 , and P. reticulata Shiino, 1943 , but is distinguished by its relative length and internal and external structures of the mature externa. Ommatogaster gen. nov. is established for the present new species O. nana based on the morphologies of the visceral mass of the externa and the presence of a nauplius eye in the larvae. Partial COI sequences were obtained from the two new species and one known species, Dipterosaccus indicus Van Kampen and Boschma, 1925, to test the possible usefulness of the sequences as tags for species identification.

  12. A new genus and new species of Paguridae (Crustacea: Decapoda: Anomura) from shallow subtidal waters in Okinawa Island, the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki

    2015-02-11

    During a survey on decapod crustacean fauna of shallow coral reefs and nearby environments in Okinawa Island, Ryukyu Archipelago, Japan, four specimens of a small but distinctive undescribed species of pagurid hermit crab, which could not be referred to any known genus, were collected. The new taxon, Eutrichopagurus shirakawai n. gen., n. sp., is described and illustrated herein. The new genus is characterized by the possession of 11 pairs of deeply quadriserial phyllobranchiate gills, the third maxilliped with well-developed crista dentata and one or two accessory teeth on the ischium, the presence of unpaired left gonopore in the female, the absence of paired first pleopods in the female, and the telson with prominent tuft of setae on the lateral margin of the posterior lobes; the male is unknown at present. It appears close to Trichopagurus de Saint Laurent, 1968, but the deeply quadriserial gills immediately distinguish Eutrichopagurus from Trichopagurus. The new genus is also compared with other genera characterized by the possession of 11 pairs of quadriserial phyllobranchiate gills and the lack of paired first pleopods in females.

  13. Evaluation of genetic introgression from domesticated pigs into the Ryukyu wild boar population on Iriomote Island in Japan.

    PubMed

    Murakami, K; Yoshikawa, S; Konishi, S; Ueno, Y; Watanabe, S; Mizoguchi, Y

    2014-08-01

    We evaluated genetic introgression from domesticated pigs into the Ryukyu wild boar (RWB) population on Iriomote Island based on their genetic structure and diversity. We used a combination of mitochondrial DNA D-loop region (596 bp) polymorphisms and 23 microsatellite markers. RWBs (n = 130) were collected from 18 locations on Iriomote Island and compared with 66 reference samples of European and Asian domestic pigs. We identified six distinct haplotypes, involving 22 single nucleotide polymorphisms (including one insertion) in the RWB population. The phylogenetic tree had two branches: the RWB group and domestic lineage. Fourteen of 130 RWBs (10.8%) belonged to the European domestic lineage, including 11 RWBs from the Panari Islands, northwest of Iriomote Main Island (IMI). The heterozygosity values, total number of alleles, number of effective alleles and polymorphism information content of the RWB groups were lower than those of the European domestic groups. The RWB population on IMI had a lower heterozygous deficiency index (FIS = 0.059) than did the other populations, which indicates that this population was more inbred. There was a large genetic distance (FST = 0.560) between RWBs on IMI and the Meishan populations. Structure analysis using the 23 microsatellite markers revealed that 16 RWBs had an admixture pattern between RWB and domesticated pig breeds. These results suggest that gene flow may have occurred from domestic pigs to RWBs and demonstrate that there was low genetic variation in the IMI population.

  14. Spatial and Temporal Distribution of Water-Soluble Anions and Organic Carbons in Bulk Aerosols Collected at the Ryukyu Islands, Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Somada, Y.; Azechi, S.; Ijyu, M.; Nakaema, F.; Handa, D.; Oshiro, Y.; Miyagi, Y.; Arakaki, T.; Tanahara, A.; Furukawa, M.

    2011-12-01

    Atmospheric aerosols pose health risks to humans and change global climate. Ryukyu Islands in Japan are mainly covered with maritime air mass in summer and continental air mass for the rest of the seasons. Thus, it is possible to estimate the origins of chemical components, in particular transboundary air pollutants from East Asia. Ryukyu Islands are one of the best locations for monitoring the changes in Asia's atmosphere. This study tried to elucidate the spatial and temporal distribution of water-soluble anions and organic carbons, and chemical changes during the transportation processes. Aerosol samples were collected at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS, Sep. 2005 - Dec. 2010), Kume Island (KM, ca. 100 km from Naha), and Minami-Daitou Island (MD, ca. 350 km from Naha) from June 2008 to June 2010 on quartz filters by using identical high-volume air samplers. The sample filters were exchanged every week. The concentrations of water-soluble anions (Cl-,Br-,NO3-,NO2-,SO42-) and water-soluble organic carbon (WSOC) were determined by using ion chromatography and total organic carbon analyzer, respectively. And, concentrations of non-sea-salt SO(nss-SO42-) were calculated based on the concentrations of Na+. For the samples collected at CHAAMS, seawater component accounted for on average 56±5% of total aerosol mass. Monthly mean concentrations of nss-SO42- showed distinctive difference among the sampling sites (KM>CHAAMS>MD) during Jan. to May, suggesting that distance from Asian continent affected on its behavior. Yearly average concentrations of NO3- and nss-SO42- showed +42% and +16% increase, respectively between 2005 and 2011. Annual rate of NO3- increase was much faster than that of nss-SO42-, probably reflecting changes in lifestyles in Asian continent.

  15. Peltogasterella sensuru n. sp. (Crustacea: Cirripedia: Rhizocephala) from off Okinawa Island (Ryukyu Archipelago, Japan) with remarks on its single brood externae.

    PubMed

    Yoshida, Ryuta; Hirose, Mamiko; Hirose, Euichi

    2015-09-01

    Peltogasterella sensuru n. sp. infests Pagurixus hermit crabs inhabiting rocky shores off Okinawa Island (Ryukyu Archipelago, Japan). This species is clearly distinguishable from Peltogasterella gracilis (Boschma, 1927): the stalk emerges from the middle part of the externa in the present species and P. sulcata (Lilljeborg, 1859), while the stalk in P. gracilis emerges from the posterior end of the externae. The new species differs from P. sulcata based on the morphology of the mantle aperture. Peltogasterella sensuru n. sp. repeatedly produces single brood externae that have not been previously observed in species belonging to the suborder Kentrogonida Delage, 1884. We also determined partial sequences of the COI gene and 16S rRNA gene of the new species for use as molecular markers for species identification.

  16. Tectonic implications of Early Miocene OIB magmatism in a near-trench setting: The Outer Zone of SW Japan and the northernmost Ryukyu Islands

    NASA Astrophysics Data System (ADS)

    Kiminami, Kazuo; Imaoka, Teruyoshi; Ogura, Kazuki; Kawabata, Hiroshi; Ishizuka, Hideo; Mori, Yasushi

    2017-03-01

    The Outer Zone of the SW Japan and northernmost Ryukyu arcs was affected by intense igneous activity during the Miocene, characterized by MORB-like basalts, alkaline basalts, and S-type (with subordinate I-type) felsic to intermediate volcano-plutonic complexes. These igneous rocks are inferred to be the products of near-trench magmatism. Early Miocene (∼18 Ma) alkaline basalt dikes from the Shingu-Otoyo area in central northern Shikoku, and an alkaline lamprophyre dike from Tanegashima, one of the northernmost Ryukyu Islands, pre-date the Middle Miocene felsic to intermediate igneous rocks. The basalts and lamprophyre have compositions of basanite, basalt, trachybasalt and phonotephrite. They are characterized by elevated large-ion lithophile elements (LILEs; e.g., Sr, Ba, and Th) and high concentrations of high-field strength elements (HFSEs; e.g., TiO2, Nb, and Zr). The geochemical signatures of the basalts and lamprophyre suggest an ocean island basalt-type (OIB-type) mantle source. The occurrence of alkaline basalts and lamprophyre with OIB-type, intraplate geochemical signatures in a near-trench setting is unusual with regard to plate tectonic processes. We propose that trench-ward motion of the overriding plate during the period around the Early Miocene resulted in a shallowly dipping slab, and interplate coupling between the subducting Philippine Sea Plate (PSP) and the overlying crust beneath most of the Outer Zone in the western part of SW Japan and the northernmost Ryukyu Islands. The OIB-type magmatism in the near-trench environment is most plausibly explained by the upwelling of asthenospheric material from beneath the subducting slab, which migrated through fractures and/or tears in the slab. We envisage two possible scenarios for the formation of these fractures or tears: (1) the shallowing dip angle of the subducted PSP resulted in concave-upwards flexure of the slab, generating fractures in the flexed region; and (2) differential motion within

  17. The genus Hatschekia (Copepoda: Hatschekiidae) from pufferfishes (Tetraodontiformes: Tetraodontidae) off the Ryukyu Islands, Japan, with descriptions of four new species and a redescription of H. pholas.

    PubMed

    Uyeno, Daisuke; Nagasawa, Kazuya

    2013-02-01

    Four new species of the genus Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) are described based on female specimens collected from pufferfishes (Tetraodontiformes: Tetraodontidae) caught in coastal waters off the Ryukyu Islands, Japan: H. longiabdominalis sp. n. on Arothron hispidus (Linnaeus), H. geniculata sp. n. on A. hispidus (type host) and A. stellatus (Bloch et Schneider), H. ellipsocorpa sp. n. on A. mappa (Lesson), and H. boonah sp. n. on A. nigropunctatus (Bloch et Schneider) (type host) and A. meleagris (Schneider). Hatschekia longiabdominalis sp. n. and H. boonah sp. n. differ from all other congeners by sharing an unusual, projected abdomen and a fusiform trunk with posterior lobes; these two species are differentiated from each other by the shape of the dorsal chitinous frame on the cephalothorax. Hatschekia geniculata sp. n. can be distinguished by the combination of the following morphological characters: a rhomboidal cephalothorax with a pair of lateral conical protrusions, a cylindrical trunk with posterior lobes and a bent abdomen with a dorsal protrusion. Hatschekia ellipsocorpa sp. n. resembles H. pholas (Wilson, 1906) but can be distinguished from the latter by the possession of one distal and one inner setae on the terminal endopodal segment of legs 1 and 2. Hatschekiapholas is also redescribed based on female specimens from the tetraodontid A. stellatus. At present, 44 nominal species of the genus have been reported from Japan, including four new species described in this paper; 38 of them have been described originally from Japan.

  18. Dental variation of Ryukyu islanders: a comparative study among Ryukyu, Ainu, and other Asian populations.

    PubMed

    Higa, Takako; Hanihara, Tsunehiko; Sunakawa, Hajime; Ishida, Hajime

    2003-01-01

    The presence or absence of 24 nonmetric dental traits was examined to investigate the inter- and intraregional variation of Ryukyu Islanders. We compared the dentition of the Kadena sample from the central district of Okinawa Island in the Ryukyu Island chain to those of samples from Nakijin from the northern district of the same Okinawa Island, Tokunoshima, another island of the Ryukyu Island chain, main-island Japanese in Kagoshima and Tokyo, Hokkaido Ainu, Atayal in Taiwan, and Pashtuns and Tajiks in Afghanistan. Many traits of the Ryukyu Islanders were found to be close to those of the main-island Japanese; however, several were intermediate between those of the main-island Japanese and the Ainu or Atayal. The intraregional variation in the Ryukyu Islanders was comparable to that in the main-island Japanese. This result supports the influence of a complex gene flow to the Ryukyu Islanders, as suggested by some genetic studies. Among the populations compared here, that closest to the Ainu was the population of Tokunoshima.

  19. Sex pheromones of five olethreutine species (Lepidoptera: Tortricidae) associated with the seedlings and fruits of mangrove plants in the Ryukyu Islands, Japan: identification and field evaluation.

    PubMed

    Vang, Le Van; Inomata, Shin-Ichi; Kinjo, Masakatsu; Komai, Furumi; Andoi, Tetsu

    2005-04-01

    The sex pheromones of three Cryptophlebia, one Centroxena, and one Eucosma species (Lepidoptera: Olethreutinae) inhabiting mangroves in the Ryukyu Islands, Japan, were studied with coupled gas chromatography-electroantennographic detection, and GC-mass spectrometry (GC-MS). The larvae of each Cryptophlebia species are specifically associated with viviparous seedlings from one of three mangrove Rhizophoraceae plants. Whereas three EAG-active alcohol components, (Z)-8-dodecen-1-ol, (E)-8-dodecen1-ol, and dodecan-1-ol, in a ratio of 100:12:4, were identified from the pheromone gland extract of female of C. horii (host: Bruguiera gymnorrhiza), two other sibling species produced the corresponding acetates, i.e., (Z)-8-dodecenyl acetate, (E)-8-dodecenyl acetate, and dodecyl acetate, in a 100:2:3 ratio from Cryptophlebia palustris (host: Rhizophora stylosa in Iriomote-jima Island) and in a 100:7:13 ratio from C. amamiana (host: Kandelia candel in Amami-oshima Island). The double bond positions of the monounsaturated components were confirmed by GC-MS analyses of their adducts with dimethyl disulfide. On the other hand, the larvae of Centroxena sp. feed on fruits of Sonneratia alba, another mangrove plant in the Sonneratiaceae, and the extract of the female pheromone glands contained (8E,10E)-dodecadienyl acetate and dodecyl acetate in a ratio of 100:5. The double bond position of the diunsaturated compound was confirmed by GC-MS analysis of its adduct with 4-methyl-1,2,4-triazoline-3,5-dione. (E)-9-Dodecenyl acetate w sively identified in the pheromone gland extract of Eucosma coniogramma females reared from seedlings of B. gymnorrhiza. Although the roles of minor components have not been revealed by field tests, synthetic lures baited with the main pheromone component of each species successfully attracted the target males, confirming that the sex pheromone is one of the most important factors for their reproductive isolation.

  20. A new cave-dwelling species of the alpheid shrimp genus Salmoneus Holthuis, 1955 (Crustacea: Decapoda: Caridea) from the Ryukyu Islands, southern Japan.

    PubMed

    Komai, Tomoyuki; Yamada, Yusuke; Yunokawa, Kyo

    2015-10-09

    A new species of the alpheid shrimp genus Salmoneus Holthuis, 1955, S. antricola n. sp., is described and illustrated on the basis of a single ovigerous specimen from an aphotic marine cave at a depth of 12 m, off Ie Island, Okinawa Islands, the Ryukyu Archipelago. It is morphologically similar to five species presently referred to the S. jarli (Holthuis, 1951) species group: S. erasimorum Dworschak, Anker & Abed-Navandi, 2000, S. komaii Anker, 2011, S. paulayi Anker, 2011, S. poupini Anker, 2011, and S. sketi Fransen, 1991. However, the minor cheliped with an elongate carpus being subequal to the chela, the lack of teeth on the cutting edges of the minor cheliped fingers, and the very slender third to fifth pereopods are obvious characters that distinguish S. antricola n. sp. from all of its presumed close relatives. Among the 50 species of Salmoneus, only S. sketi and the present new species are known from marine caves.

  1. A new subtidal species of the genus Petrolisthes Stimpson, 1858 (Crustacea: Decapoda: Porcellanidae) from Okinawa, with an account of species of the genus known from the Ryukyu Islands, southwestern Japan.

    PubMed

    Osawa, Masayuki; Uyeno, Daisuke

    2013-01-01

    A new porcellanid crab, Petrolisthes uruma sp. nov., is described based on a single specimen collected from Okinawajima Island in the Ryukyus, southwestern Japan. The unique holotype was collected from a subtidal depth of 10 m, though vast majority of the genus occur in intertidal to shallow subtidal zone. The new species is morphologically closest to P. noluccensis (De Man, 1888), but is distinguished by the weaker striation on the carapace, the proportionally longer carpus of the cheliped, the number of the anterior marginal teeth of the carpus of the cheliped, and the meri of the second and third pereopods each with a much stronger spine at the lateroventral distal angle. A brief note on species of Petrolisthes presently known from the Ryukyu Islands is given.

  2. Two new species of Dracoderes (Kinorhyncha: Dracoderidae) from the Ryukyu Islands, Japan, with a molecular phylogeny of the genus.

    PubMed

    Yamasaki, Hiroshi

    2015-06-30

    Two new species, Dracoderes snufkini sp. nov. and Dracoderes toyoshioae sp. nov., are described from Okinawa, southern Japan. Diagnostic characters of D. snufkini include: lateroventral tubules on segments 2 and 5; a thick, plump middorsal spine on segments 2 and 9; thick plump paradorsal spines on segments 3-8, alternately laterally displaced; and a ventral primary pectinate fringe on segment 1, with long, wide conspicuous tips. Diagnostic characters of Dracoderes toyoshioae include: a middorsal subcuticular structure on segment 1; paradorsal subcuticular structures on segments 2-9, alternately laterally displaced; paradorsal acicular spines arising from subcuticular structures, at least on segment 5; ventrolateral acicular spines on segment 1; lateral accessory tubules on segment 2; lateral accessory subcuticular structures on segments 2-7; lateroventral tubules on segment 5; and lateroventral subcuticular structures on segments 2-10. Molecular phylogenetic analyses based on 18S rRNA, 28S rRNA and mitochondrial COI sequences indicate that D. abei and D. nidhug are more closely related to one another than either is to D. snufkini or D. toyoshioae.

  3. Divergence and long-distance overseas dispersals of island populations of the Ryukyu five-lined skink, Plestiodon marginatus (Scincidae: Squamata), in the Ryukyu Archipelago, Japan, as revealed by mitochondrial DNA phylogeography.

    PubMed

    Kurita, Kazuki; Hikida, Tsutomu

    2014-04-01

    We assessed the historical biogeography of the Ryukyu five-lined skink, Plestiodon marginatus, and related species (P. stimpsonii and P. elegans). Our specific aims were to reveal the origin, tim- ing, and route of the colonization to three volcanic islands in the northern Tokara Group of the northern Ryukyus: Kuchinoshima, Nakanoshima, and Suwanosejima. We conducted phylogenetic analyses and divergence time estimation using a partial sequence of the mitochondrial cytochrome b gene for P. marginatus collected from across its whole range (the northern and central Ryukyus), and for P. stimpsonii (from the Yaeyama Group of the southern Ryukyus) and P. elegans (from Taiwan). Our results suggest three major clades (A, B, and C). Clades A and B consist of P. marginatus, excluding the Kuchinoshima population, and Clade C consisted of the Kuchinoshima population, P. stimpsonii, and P. elegans. These clades are estimated to have diverged during the Late Miocene to the Late Pliocene. Among the three examined northern Tokara populations, the Kuchinoshima population was shown to be a sister group of P. stimpsonii. The two other populations from Nakanoshima and Suwanosejima Islands were closely related to P. marginatus from the northern part of the Okinawa Group and that from Kodakarajima Island in the southern Tokara Group, respectively. These populations are estimated to have diverged from their respective related spe cies in various ages of the Early to Late Pleistocene, suggesting that they colonized the islands by independent overseas dispersals of approximately 50-850 km via the Kuroshio Current. Taxonomic implications for P. marginatus are also discussed.

  4. Three-Dimensional Seismic Attenuation Structure in the Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Komatsu, M.; Takenaka, H.

    2015-12-01

    Tomographic studies have been conducted to retrieve 3D seismic attenuation structure around Japan Arc since 1980s. However, in the Ryukyu Arc, 3D attenuation structures has never been estimated. It is important to estimate the 3D attenuation structure in this region, since there are highly active volcanos and seismicity between the Okinawa Trough and the Ryukyu Trench. In this study, we estimate 3D seismic attenuation structure in the Ryukyu Arc. We use seismic waveform data recorded by seismic observation networks of NIED, JMA and Kagoshima University, from 2004/06 to 2014/05. We select seismic events of more than 4,500. Since the Ryukyu Arc region are so wide, we separate it into three subregions: Sakishima Islands, Okinawa Islands and Amami Islands subregions. Before calculating the attenuation quantity t*, the corner frequency of the source spectrum for each event is estimated by using an omega square model. The t* is estimated from the amplitude decay rate from the source-corrected spectra. We then invert the t* data to the attenuation structure by a 3D tomographic technique using the non-negative least squares method. Our estimated attenuation structure has the remarkable features: in Sakishima Islands subregion, high attenuation zone exists beneath northern Ishigaki Island. This region corresponds to the Okinawa Trough. High attenuation zone also exists beneath Hateruma Island in upper crust. It corresponds to the accretionary prism formed by subducting Philippine Sea Plate. In Amami Islands subregion, high attenuation zone is located along volcanic front. Low attenuation zone spreads over subducting Philippine Sea slab in all subregions.Acknowledgements: We used JMA Unified Hypocenter Catalogs and seismic waveform data recorded by NIED, JMA and Kagoshima University. We also used a computer program by Zhao et al. (1992, JGR) for the tomographic analysis.

  5. Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in the Ryukyu Islands tree rat (Diplothrix legata).

    PubMed

    Okano, Tsukasa; Haga, Atsushi; Mizuno, Eriko; Onuma, Manabu; Nakaya, Yumiko; Nagamine, Takashi

    2014-04-01

    Angiostrongylus cantonensis is a zoonotic nematode with rodents serving as natural definitive hosts. We report A. cantonensis in the Ryukyu Islands tree rat (Diplothrix legata, Thomas, 1906), a native endangered species in Japan. Adult and larvae of A. cantonensis were macroscopically, histologically, and genetically detected in three tree rats collected between August 2011 and January 2012 in the Yambaru area of Okinawa Prefecture, Japan. Pathologic observations of the lungs of rats showed that infection may be lethal. We also conducted a retrospective genetic survey of helminths parasitic in lung in cryopreserved lung samples of Ryukyu Islands tree rats collected between 2007 and 2011 in the Yambaru area and found A. cantonensis DNA in one of 29 samples, which was collected in December 2010.

  6. Multiple colonizations lead to cryptic biodiversity in an island ecosystem: comparative phylogeography of anchialine shrimp species in the Ryukyu Archipelago, Japan.

    PubMed

    Weese, David A; Fujita, Yoshihisa; Santos, Scott R

    2013-09-01

    Archipelagos of the Indo-West Pacific are considered to be among the richest in the world in biodiversity, and phylogeographic studies generally support either the center of origin or the center of accumulation hypothesis to explain this pattern. To differentiate between these competing hypotheses for organisms from the Indo-West Pacific anchialine ecosystem, defined as coastal bodies of mixohaline water fluctuating with the tides but having no direct oceanic connections, we investigated the genetic variation, population structure, and evolutionary history of three caridean shrimp species (Antecaridina lauensis, Halocaridinides trigonophthalma, and Metabetaeus minutus) in the Ryukyu Archipelago, Japan. We used two mitochondrial genes--cytochrome c oxidase subunit I (COI) and large ribosomal subunit (16S-rDNA)--complemented with genetic examination of available specimens from the same or closely related species from the Indian and Pacific Oceans. In the Ryukyus, each species encompassed 2-3 divergent (9.52%-19.2% COI p-distance) lineages, each having significant population structure and varying geographic distributions. Phylogenetically, the A. lauensis and M. minutus lineages in the Ryukyus were more closely related to ones from outside the archipelago than to one another. These results, when interpreted in the context of Pacific oceanographic currents and geologic history of the Ryukyus, imply multiple colonizations of the archipelago by the three species, consistent with the center of accumulation hypothesis. While this study contributes toward understanding the biodiversity, ecology, and evolution of organisms in the Ryukyus and the Indo-West Pacific, it also has potential utility in establishing conservation strategies for anchialine fauna of the Pacific Basin in general.

  7. Tsunami hazard mitigation in tourism in the tropical and subtropical coastal areas: a case study in the Ryukyu Islands, southwest of Japan

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.

    2006-12-01

    Life and economy (including tourism) in tropical and subtropical coastal areas, such as Okinawa Prefecture (Ryukyu) are highly relying on the sea. The sea has both "gentle" side to give people healing and "dangerous" side to kill people. If we are going to utilise the sea for marine tourism such as constructing resort facilities on the oceanfront, we should know all of the sea, including the both sides of the sea: especially the nature of tsunamis. And also we islanders should issue accurate information about the sea towards outsiders, especially tourists visiting the island. We have already learned a lesson about this issue from the Sumatra tsunami in 2004. However, measures against the tsunami disaster by marine tourism industry are still inadequate in these areas. The goal of tsunami hazard mitigation for those engaged in tourism industry in tropical and subtropical coastal areas should be as follows. (1) Preparedness against tsunamis: "Be aware of the characteristics of tsunamis." "Prepare tsunamis when you feel an earthquake." "Prepare tsunamis when an earthquake takes place somewhere in the world." (2) Maintenance of an exact tsunami hazard map under quantitative analyses of the characteristics of tsunamis: "Flooding areas by tsunami attacks are dependent not only on altitude but also on amplification and inundation due to the seafloor topography near the coast and the onland topographic relief." "Tsunami damage happens repeatedly." (3) Maintenance of a tsunami disaster prevention manual and training after the manual: "Who should do what in case of tsunamis?" "How should the resort hotel employees lead the guests to the safe place?" Such a policy for disaster prevention is discussed in the class of the general education of "Ocean Sciences" in University of the Ryukyus (UR) and summer school for high school students. The students (most of them are from Okinawa Prefecture) consider, discuss and make reports about what to do in case of tsunamis as an islander

  8. Halechiniscidae (Heterotardigrada, Arthrotardigrada) of Oura Bay, Okinawajima, Ryukyu Islands, with descriptions of three new species.

    PubMed

    Fujimoto, Shinta

    2015-01-01

    Marine tardigrades of the family Halechiniscidae (Heterotardigrada: Arthrotardigrada) are reported from Oura Bay, Okinawajima, one of the Ryukyu Islands, Japan, including Dipodarctus sp., Florarctuswunai sp. n., Halechiniscuschurakaagii sp. n., Halechiniscusyanakaagii sp. n. and Styraconyx sp. The attributes distinguishing Florarctuswunai sp. n. from its congeners is a combination of two characters, the smooth dorsal cuticle and two small projections of the caudal alae caestus. Halechiniscuschurakaagii sp. n. is differentiated from its congeners by the combination of two characters, the robust cephalic cirrophores and the scapular processes with flat oval tips, while Halechiniscusyanakaagii sp. n. can be identified by the laterally protruded arched double processes with acute tips situated dorsally at the level of leg I. A list of marine tardigrades reported from the Ryukyu Islands is provided.

  9. Geographical variation in echolocation call and body size of the Okinawan least horseshoe bat, Rhinolophus pumilus (Mammalia: Rhinolophidae), on Okinawa-jima Island, Ryukyu Archipelago, Japan.

    PubMed

    Yoshino, Hajime; Matsumura, Sumiko; Kinjo, Kazumitsu; Tamura, Hisao; Ota, Hidetoshi; Izawa, Masako

    2006-08-01

    The Okinawan least horseshoe bat, Rhinolophus pumilus, is a cave-dwelling species endemic to the central and southern Ryukyus, Japan. We analyzed variation in the constant frequency (CF) of the echolocation call and in forearm length (FAL) of this species on Okinawa-jima Island on the basis of data for 479 individuals from 11 caves scattered over the island. CF values in samples from six caves, all located in the southwestern half of Okinawa-jima, were significantly higher than those in samples from five caves in the northeastern half of the island. Also, FAL was significantly greater in the latter group than in the former group, although the ranges of variation in this character substantially overlapped between the two groups. These results suggest substantial differentiation between R. pumilus populations on Okinawa-jima. The implications of our findings for the conservation of this endangered bat species are briefly discussed.

  10. New records of the squat lobster genus Munida Leach, 1820 (Crustacea: Decapoda: Anomura: Munididae) from deep-water off Okinawa Islands, Ryukyu Islands, Japan, with description of a new species.

    PubMed

    Komai, Tomoyuki; Higashiji, Takuo

    2016-05-11

    Two species of the squat lobster genus Munida Leach, 1820, M. pollioculus n. sp. and M. zebra Macpherson, 1994, are recorded from deep-waters off Okinawa Islands, the Ryukyu Islands, at depths of 1000 m and 495 m, respectively. The new species closely resembles M. clevai Macpherson, 1999 and M. microps Alcock, 1894, but it differs from the latter two in the absence of a proximal spine on the mesial margin of the cheliped dactylus and the more stout dactylus of the second pereopod. Munida zebra is first recorded from the Northwest Pacific, as well as Japanese waters, with its geographical range extended to the north from the previously known southwestern Pacific localities.

  11. Reproductive traits of the Ryukyu long-furred rat (Diplothrix legata) on Okinawa-jima Island.

    PubMed

    Okano, Tsukasa; Nakata, Katsuhi; Nakaya, Yumiko; Nagamine, Takashi; Onuma, Manabu

    2015-06-01

    The Ryukyu long-furred rat, Diplothrix legata, is a large rodent distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island, Japan. This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles. We performed theriogenological examinations of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had remarkably large preputial glands. Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were observed from September through February, and seminiferous diameter was significantly large (216 ± 27 µm, n=12) during this time in adults; testes length changed in a similar pattern. These findings indicate that the mating season may occur from September through February. Size (body length) at sexual maturity was estimated to be >560 mm in both sexes. From observation of corpora lutea and placental scars, litter size was estimated to range from 2 to 12 (average=6, n=4). These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.

  12. Intersectional gene flow between insular endemics of Ilex (Aquifoliaceae) on the Bonin Islands and the Ryukyu Islands.

    PubMed

    Setoguchi, H; Watanabe, I

    2000-06-01

    Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (cpDNA), and the sequences of internal transcribed spacer (ITS) of nuclear ribosomal DNA were examined to investigate the occurrence of gene transfer in Ilex species on the Bonin Islands and the Ryukyu Islands in Japan. A gene phylogeny for the plastid genome is in agreement with the morphologically based taxonomy, whereas the nuclear genome phylogeny clusters putatively unrelated endemics both on the Bonin and the Ryukyu Islands. Intersectional hybridization and nuclear gene flow were independently observed in insular endemics of Ilex on both sets of islands without evidence of plastid introgression. Gene flow observed in these island systems can be explained by ecological features of insular endemics, i.e., limits of distribution range or sympatric distribution in a small land area.

  13. Assessment of mycobacterial interspersed repetitive unit-QUB markers to further discriminate the Beijing genotype in a population-based study of the genetic diversity of Mycobacterium tuberculosis clinical isolates from Okinawa, Ryukyu Islands, Japan.

    PubMed

    Millet, Julie; Miyagi-Shiohira, Chika; Yamane, Nobuhisa; Sola, Christophe; Rastogi, Nalin

    2007-11-01

    The present investigation focused on genetic diversity and drug resistance of 101 Mycobacterium tuberculosis strains isolated between July 2003 and February 2005 in the Okinawa prefecture, Ryukyu Islands, Japan. A high rate of clustering (87%, eight clusters, 2 to 69 strains/cluster) was observed upon spoligotyping; most of it was due to the lower discriminatory power of this method for the Beijing lineage (n = 72; 71.3% of the isolates). The remaining diversity was limited to seven clusters (two to five isolates/cluster), with the following distribution of major lineages: ill-defined T (n = 13; 12.8%), ancestral East African-Indian (n = 6; 5.9%), Haarlem (n = 4; 4%), Latin American-Mediterranean (n = 2; 2%), X1 (n = 1; 1%), and a total absence of the central Asian clade. Three remaining strains could not be classified on the basis of their spoligotype pattern and were labeled "unknown." Subtyping with mycobacterial interspersed repetitive units (MIRUs) in association with additional QUB minisatellites was performed to discriminate among the Beijing strains. Based on an "in-house" spoligotyping/MIRU database (n = 694 Beijing strains), eight highly discriminative MIRU loci for Beijing strains were selected (loci numbered 10, 16, 23, 26, 27, 31, 39, and 40). The highest discriminatory power (h) observed in our sample (n = 72; M-26, 0.385; M-10, 0.38; M-31, 0.255; M-16, 0.238) was too low, and 73.6% of the Beijing strains from Okinawa remained clustered. Typing of Beijing strains with additional QUB loci (with the exception of "one-copy" QUB-1451) resulted in higher discriminatory powers: QUB-11b, 0.68; QUB-11a, 0.656; QUB-26, 0.644; QUB-18, 0.553; QUB-4156, 0.5; and QUB-1895, 0.453. A definitive algorithm on the use of QUB markers to subtype Beijing isolates in expanded studies would shed light on their hypervariability, which may sometimes blur recognition between epidemiologically linked Beijing isolates. The total absence of multiple drug resistance among Beijing

  14. Enhancement of Eddy Heat Transport due to the Anticyclonic Submesoscale Eddies around Ryukyu Islands near Kuroshio in East China Sea

    NASA Astrophysics Data System (ADS)

    Kamidaira, Y.; Uchiyama, Y.; Mitarai, S.; Miyazawa, Y.

    2014-12-01

    A synoptic, regional downscaling experiment of Kuroshio off Ryukyu Islands, Japan, exhibits the evident predominance of submesoscale anticyclonic eddies over cyclones in the narrow strip between Kuroshio and the islands (Uchiyama et al., 2013). In the present study, the mechanism and impacts of the anticyclone dominance are examined with a detailed oceanic downscaling model in a double nested ROMS configuration at the horizontal resolution of 3km (ROMS-L1) and 1km (ROMS-L2), forced by the assimilative JCOPE2 oceanic reanalysis and the JMA GPV-MSM atmospheric hindcast. The model results are extensively validated against a variety of data including shipboard hydrography and satellite altimetry and temperature data to show a good agreement. An alternative ROMS-L2 experiment is also conducted to examine topographic effects on the anticyclones around the Ryukyu Islands by eliminating all the island topography above z > -1000 m, while the other configurations are held unchanged. If the islands are removed, the submesoscale negative vortices on the eastern side of the Kuroshio become much weaker than those of the original case with the islands. The experiment clearly demonstrates that dominance of the negative vorticity between Kuroshio and the Ryukyu Islands is caused by enhanced lateral shear due to the concentrated Kuroshio mean current associated with appropriate formation of the eastern branch, the northward-drifting Ryuku Current, and resultant eddy shedding in the narrow channel between the continental shelf of the East China Sea and the Okinawan ridge. A diagnostic eddy heat flux analysis illustrates that the submesoscale anticyclonic eddies play a crucial role in enhancing the eddy heat transport and thus the lateral mixing between Kuroshio and the islands as compared to those in the coarser resolution models (L1 and JCOPE2), resulting in promoting regional larval and material transport from Kuroshio to the islands.

  15. Variations of short-term slow slip events along the Nankai Trough to the Ryukyu Trench, southwest Japan

    NASA Astrophysics Data System (ADS)

    Nishimura, T.

    2013-12-01

    ETSs (Episodic Tremor and Slips) occur at a depth of 30-40 km on the plate interface of the subducting Philippine Sea plate along the Nankai trough, southwest Japan (e.g., Obara, 2010). Low-frequency tremors along the Nankai Trough suddenly disappeared southwest of the Bungo Channel between Shikoku and Kyushu, which is a junction between the southwest Honshu arc along the Nankai Trough and the Ryukyu arc along the Ryukyu Trench. Any short-term SSEs (slow slip events) have never been reported southwest of the Bungo Chanel, though Mw~7 long-term SSEs repeated in the Bungo Channel every ~6 years (e.g., Ozawa et al., 2013). Here, we apply a SSE detection method using continuous GNSS data (Nishimura et al., 2013) to find out SSEs in a region along the Nankai Trough to the Ryukyu Trench. We also compare the detected SSEs with epicenters of low-frequency tremors, very-low-frequency earthquakes (VLFEs), and regular earthquakes and discuss along-trench variations on short-term SSE characteristics. Daily coordinates of ~800 GEONET GNSS stations in southwest Japan were used to detect displacements caused by short-term SSEs. We divided a whole region into three regions for spatial filtering to reduce a noise of GNSS data. We fitted a step function with a linear trend to spatial-filtered daily coordinates to detect significant displacements in a direction opposite to the relative plate motion between the Philippine Sea plate and southwest Japan. If Akaike's information criterion expressing data fits exceeds a threshold, three-dimensional displacements were inverted to estimate a rectangular fault along the plate interface. We found more than 200 probable short-term SSEs in the region over 16 years. In western Shikoku, we detected 49 Mw ~6.0 ETSs. SSEs with a similar magnitude are found at the same depth range in northeast Kyushu without tremors although the number of detected SSEs is only 10. In the further southwest region, we found several shallow SSEs at a depth of 10-40 km

  16. Situation Report--Hong Kong, Malawi, Pakistan, Panama, Philippines, Ryukyu Islands (Okinawa), Sabah, Sarawak.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in eight foreign countries are presented in these situation reports. Countries included are Hong Kong, Malawi, Pakistan, Panama, Philippines, Ryukyu Islands (Okinawa), Sabah, and Sarawak. Information is provided where appropriate and available, under two topics, general background and family planning…

  17. Phylogenetic relationships between the tideland snails Batillaria flectosiphonata in the Ryukyu Islands and B. multiformis in the Japanese Islands.

    PubMed

    Kojima, Shigeaki; Kamimura, Satomi; Kimura, Taeko; Hayashi, Ikuo; Iijima, Akiko; Furota, Toshio

    2003-11-01

    Phylogenetic relationships between two sibling species of Japanese tideland snails, namely, Batillaria multiformis from the Japanese Islands and B. flectosiphonata from the Ryukyu Islands, were analyzed on the basis of the nucleotide sequences of the mitochondrial gene for cytochrome oxidase I. Populations of B. multiformis were genetically distinct from those of B. flectosiphonata with the exception of a population from Amami-Oshima Island, which corresponded to the boundary between the distributions of these two species. Individuals with the mitochondrial gene of B. multiformis and those with the mitochondrial gene of B. flectosiphonata were collected from the same tidal flat on Amami-Oshima Island. All the snails with the mitochondrial gene of B. multiformis could be divided into two genetically distinct groups but there was no geographical structure to the distribution of these two groups. Individual populations of B. flectosiphonata in the Amami, Okinawa, Miyako and Yaeyama insular groups each consisted exclusively of a unique set of haplotypes, with the exception of a population at a northern site on Okinawajima Island, which included a few individuals with sequences related to those of individuals in the Amami insular group. All individuals from South Ryukyu formed a well-supported monophyletic group, while the monophyly of individuals from Central Ryukyu was not supported. The monophyly of B. multiformis was clearly demonstrated but there was no evidence to support that of B. flectosiphonata. Batillaria multiformis might have been derived from immigrants from the Ryukyu Islands, which became isolated and diverged genetically on the Japanese Islands.

  18. Tsunami recurrence inferred from soil deposits on Ishigaki island along the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Ando, M.; Shishikura, M.; Tu, Y.; Nakamura, M.; Arashiro, Y.

    2012-12-01

    The Ryukyu trench at the northwestern boundary of the Philippine Sea plate had no known thrust earthquakes Mw>8.0 in approximately the last 250 years. Due to this lack of associated large thrust earthquakes, an accepted common idea is that Ryukyu trench is aseismic. However, in 1771 a large tsunami struck Ishigaki islands and Miyako islands with the run-up height of up to 30-35 m. The 1771 source is suggested to be a tsunami (slow) earthquake with Mw=8.0 that occurred near the trench axis. Furthermore, very-low frequency earthquakes at shallow depths near the trench axis and slow-slip events at depths of 30km have been identified in the western Ryukyu trench. These findings suggest that the Ryukyu subduction zone has the potential to generate large thrust earthquakes. If the slip deficit has accumulated at the interface, the accumulated slip of more than 30 m would cause a large earthquake and a huge tsunami. Considering the abovementioned findings, estimate for the size and recurrence intervals of past tsunamis along the western Ryukyu trench was undertaken through excavation surveys of the Holocene deposits in Ishigaki and Miyako islands. The excavated sites are located on the lower Holocene marine terraces and implemented using a geoslicer or backhoes at 10 sites on November 2011 and June 2012. Stratigraphic and foraminiferal assemblages of tsunami sediment were compared with shallow beach sand to gain information on sediment source and depositional style. Based on the excavations, two tsunami layers were identified at 5 sites and provided estimates of sedimentation ages. The results obtained from stratigaraphic and foraminiferal analyses together with C14 dates of tsunami sediment indicated an event between 9-11th C. on Ishigaki and another or the same event occurred between 11th C. and 1771 on Miyako island. Consequently, if the 1771 earthquake is the only event that had occurred in the last 300 years over the 120 km, large earthquakes would potentially occur

  19. A revision of the genus Amamiclytus Ohbayashi from Taiwan and the Ryukyu Islands (Coleoptera, Cerambycidae).

    PubMed

    Niisato, Tatsuya; Han, Chang-do

    2011-01-01

    The clytine genus Amamiclytus Ohbayashi, 1964, from Taiwan and the Ryukyu Islands is revised. Seven species and one subspecies are recognized as follows: Amamiclytus nobuoi nobuoi Ohbayashi, 1964, (Amami Islands); Amamiclytus nobuoi akusekianus Niisato, 2005, (Tokara Islands); Amamiclytus subnitidus Holzschuh, 1984, (Taiwan); Amamiclytus setigersp. n. (Taiwan), Amamiclytus nubilussp. n. (Taiwan), Amamiclytus junisp. n. (Taiwan), Amamiclytus yulongisp. n. (Taiwan) and Amamiclytus hirtipes (Matsushita, 1940), comb. n. (Taiwan). All of them are described or redescribed and a key to species is presented. The generic features of Amamiclytus, including male and female genitalia from these taxa, are presented. The systematic position of Amamiclytus within the tribe Clytini is discussed.

  20. Genome-wide SNP analysis reveals population structure and demographic history of the ryukyu islanders in the southern part of the Japanese archipelago.

    PubMed

    Sato, Takehiro; Nakagome, Shigeki; Watanabe, Chiaki; Yamaguchi, Kyoko; Kawaguchi, Akira; Koganebuchi, Kae; Haneji, Kuniaki; Yamaguchi, Tetsutaro; Hanihara, Tsunehiko; Yamamoto, Ken; Ishida, Hajime; Mano, Shuhei; Kimura, Ryosuke; Oota, Hiroki

    2014-11-01

    The Ryukyu Islands are located to the southwest of the Japanese archipelago. Archaeological evidence has revealed the existence of prehistoric cultural differentiation between the northern Ryukyu islands of Amami and Okinawa, and the southern Ryukyu islands of Miyako and Yaeyama. To examine a genetic subdivision in the Ryukyu Islands, we conducted genome-wide single nucleotide polymorphism typing of inhabitants from the Okinawa Islands, the Miyako Islands, and the Yaeyama Islands. Principal component and cluster analyses revealed genetic differentiation among the island groups, especially between Okinawa and Miyako. No genetic affinity was observed between aboriginal Taiwanese and any of the Ryukyu populations. The genetic differentiation observed between the inhabitants of the Okinawa Islands and the Miyako Islands is likely to have arisen due to genetic drift rather than admixture with people from neighboring regions. Based on the observed genetic differences, the divergence time between the inhabitants of Okinawa and Miyako islands was dated to the Holocene. These findings suggest that the Pleistocene inhabitants, whose bones have been found on the southern Ryukyu Islands, did not make a major genetic contribution, if any, to the present-day inhabitants of the southern Ryukyu Islands.

  1. Tsunami preparedness at the resort facilities along the coast of the Ryukyu Islands - their actions against the 27 February 2010 Okinawan and Chilean tsunami warning

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.

    2010-12-01

    The economy (including tourism) in tropical and subtropical coastal areas, such as Okinawa Prefecture (Ryukyu) is highly relying on the sea. The sea has both “gentle” side to give people healing and “fierce” side to kill people. If we are going to utilise the sea for marine tourism such as constructing resort facilities on the oceanfront, we should know the whole nature of the sea, Tsunami is the typical case of the “fierce” side of the sea. We have already learned a lesson about this issue from the Sumatra tsunami in 2004. Early morning (5:31 am Japanese Standard Time = JST) on 27 February 2010, a M6.9 earthquake occurred near the coast of Okinawa Ryukyu Island Japan, and just after that Japanese Meteorological Agency (JMA) issued a tsunami warning along the coastal area of Okinawa Prefecture. About one hour later the tsunami warning was cancelled. The CMT solution of this earthquake was found to be strike-slip type with NE-SW P-axis. Therefore this did not induce a tsunami. However, in the afternoon on the same day (JST) a M8.6 earthquake occurred off the coast of Chile and soon after that a tsunami warning issued along the Pacific coastal area including Japan and Ryukyu Islands. Indeed maximum 1m tsunami hit the eastern coast of Okinawa Island on 28th February (Nakamura, 2010, personal communication). The author conducted a survey about the actions against the both tsunami after the 27 February tsunami warming to the major resort hotels along the coast of the Ryukyu Islands. A questionnaire was sent to about 20 hotels and 6 hotels replied to the questionnaire. Most of these hotels reported the regular training against tsunami attack, preparation of a disaster prevention manual, close communication with the local fire station authority, evacuation procedure towards high stories of the hotel building etc. It was “winter season” when the tsunami took place. However, if that were “summer season,” the other problem such as how they make the people

  2. Genetic differentiation within and among island populations of the endangered plant Aster miyagii (Asteraceae), an endemic to the Ryukyu Islands.

    PubMed

    Maki, M

    2001-12-01

    Genetic diversity was examined at 17 putative allozyme loci in 18 populations of the insular endemic plant Aster miyagii (Asteraceae). This species is geographically restricted to only three islands of the Ryukyu Islands and is on the federal list of threatened plants. Genetic differentiation within an island is small, suggesting that gene flow among populations on the same island is sufficiently large to prevent divergence. By contrast, genetic differentiation among islands is large, especially between Amamioshima Island and the other two islands, suggesting that gene flow between the islands is highly restricted. Two unique alleles are nearly fixed in populations on Amamioshima Island, which is the southernmost island of the three. Comparatively, genetic diversity is the smallest on Amamioshima Island. This genetic paucity on Amamioshima Island is probably a result of a population bottleneck at colonization or the small effective population size on this island. Genetic diversity at the species level of A. miyagii is larger than those of the species with a similar life history and of the congeneric widespread species, suggesting that the species has an old origin as an insular endemic species.

  3. Bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the mangrove swamps of the Ryukyu Archipelago, Japan.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako; Higa, Yukiko; Okudo, Haruo; Okazawa, Takao

    2011-09-01

    The bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the Ryukyu Archipelago, Japan, was studied in the field and in the laboratory. The studies included the natural habitat, seasonal appearance, flight activity, mating behavior, resistance of eggs to desiccation, and breeding periods of the immature stages of this species. The burrow systems made by the mud lobster Thalassina anomala were excellent as breeding and resting habitats for both the immature and adult stages of the mosquito.

  4. Description of a sexually dimorphic oribatid mite (Arachnida: Acari: Oribatida) from canopy habitats of the Ryukyu Archipelago, southwestern Japan.

    PubMed

    Karasawa, Shigenori; Behan-Pelletier, Valerie

    2007-10-01

    A new species in the monotypic genus Symbioribates, S. aokii sp. nov., is described on the basis of adult material collected from canopy habitats and wind traps in the Ryukyu Archipelago, southwestern Japan. Symbioribates aokii sp. nov. expresses different dimorphism in the octotaxic system from that of the type species, S. papuensis Aoki, 1966. The characteristics of this genus and its relationships to others of the superfamily Oripodoidea are discussed and a revised diagnosis of the family is given.

  5. Situation Report--Antigua, Dominican Republic, Grenada, Guatemala, Honduras, Philippines, Ryukyu Islands, St. Lucia, and St. Vincent.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in nine foreign countries are presented in these situation reports. Countries included are: Antigua, Dominican Republic, Grenada, Guatemala, Honduras, Philippines, Ryukyu Islands (Okinawa), St. Lucia, and St. Vincent. Information is provided under two topics, general background and family planning…

  6. Descriptions of two azooxanthellate Palythoa species (Subclass Hexacorallia, Order Zoantharia) from the Ryukyu Archipelago, southern Japan

    PubMed Central

    Irei, Yuka; Sinniger, Frederic; Reimer, James Davis

    2015-01-01

    Abstract Two new species of zoantharians (Hexacorallia, Zoantharia, Sphenopidae), Palythoa mizigama sp. n. and Palythoa umbrosa sp. n., are described from the Ryukyu Archipelago, southern Japan. Unlike almost all other known Palythoa spp., both species are azooxanthellate and inhabit low-light environments such as floors or sides of caves, crevasses, or hollows of shallow coral reefs. The two species were initially considered to be the same species from their similar habitat environments and highly similar morphological features. However, phylogenetic analyses of nuclear internal transcribed spacer (ITS) ribosomal DNA, mitochondrial 16S ribosomal DNA, and cytochrome oxidase subunit I (COI) sequences revealed that these two species have a genetically distant relationship within the genus Palythoa. Morphological characteristics, including polyp size, tentacle number, external/internal coloration, and types and sizes of cnidae were examined in this study. As a result, only tentacle coloration was found to be useful for the morphological distinction between the two species. Palythoa mizigama possesses white tentacles with black horizontal stripes while Palythoa umbrosa possesses white tentacles without any stripe patterns. Considering their distant phylogenetic relationship, it can be assumed that their unique yet similar morphological and ecological characteristics developed independently in each species as an example of parallel evolution. PMID:25685008

  7. Two new species of diplosoma (Ascidiacea: Didemnidae) bearing prokaryotic algae prochloron from Okinawajima (Ryukyu Archipelago, Japan).

    PubMed

    Oka, Atsushi T; Suetsugu, Mayu; Hirose, Euichi

    2005-03-01

    Two new species of didemnid ascidians, Diplosoma ooru sp. nov. and Diplosoma simileguwa sp. nov., are described from coral reefs on Okinawajima (Ryukyu Archipelago, Japan). These two species form green colonies, having a symbiotic association with a prokaryotic alga Prochloron sp. The former species was found at the reef edges in the subtidal zone and the latter was found in a shallow reef lagoon. In these species, the colonies are thinner and the zooids are smaller than those of any other Prochloron-bearing Diplosoma species so far described. Moreover, each of the present new species has a unique combination of stigmatic numbers: 5 stigmata in the first and third rows, 6 in the second row, and 4 in the fourth in D. ooru; 4 stigmata in the first and third rows, 5 in the second row, and 3 in the fourth in D. simileguwa. In both of the new species, the retractor muscle emerges from the underside of the thorax. Larval morphology of D. ooru is also described.

  8. Cytogeography of Ixeris nakazonei (Asteraceae, Lactuceae) in the Ryukyu Archipelago of Japan and Taiwan.

    PubMed

    Denda, Tetsuo; Yokota, Masatsugu

    2004-02-01

    The cytogeographical structures of Ixeris nakazonei, a putative hybrid between I. debilis (6x) and I. repens (2x), were investigated in the Ryukyu Archipelago and Taiwan. In the Ryukyus, I. debilis occurs on Miyakojima Island of the southern Ryukyus and northward, while I. repens occurs on all islands except for Iriomotejima and Yonagunijima Islands. I. nakazonei, comprises six polyploid cytotypes, 3x, 4x, 5x, 6x, 7x and 8x, based on x=8. Four cytotypes from 3x to 6x occur in the central Ryukyus, while four cytotypes from 5x to 8x occur in the southern Ryukyus. The higher polyploids of I. nakazonei tend to be distributed in the more southerly area. Tetraploids of I. nakazonei always co-occur with I. debilis and I. repens, supporting the hybrid origin of this cytotype. Considering the chromosome number, octoploids, which predominate in the southern Ryukyus and Taiwan, may have derived directly from hybridization between I. debilis and I. repens. Odd-numbered polyploids of I. nakazonei, 3x, 5x and 7x, are relatively rare. Their chromosome numbers indicate that triploids and heptaploids are hybrids between the tetraploid of I. nakazonei and I. repens, and between the octoploid of I. nakazonei and I. debilis, respectively. Pentaploids of I. nakazonei in the central and southern Ryukyus are, respectively, hybrids between the tetraploid of I. nakazonei and I. debilis and between the octoploid of I. nakazonei and I. repens, indicating that pentaploids of I. nakazonei have at least two independent origins.

  9. [An exploration of the training of medical talents in China for Ryukyu islands based on the Liu qiu bai wen (One Hundred Question of Ryukyu)].

    PubMed

    He, Lanping

    2014-09-01

    Ryukyu sent more than 20 batches of returned students to China for studying during the Ming and Qing Dynasties, many of whom were studying medicine. Liu qiu bai wen (One Hundred Question of Ryukyu) was the record of discussion between Cao Cunxin, a famous doctor of the Qing Dynasty, and the oversea disciples of Lü Fengyi from Ryukyu. However, it was not only a medical book, but also served as an important witness on overseas dissemination of TCM, and the fresh case of Chinese training medical talented persons for Ryukyu. Training Ryukyu medical students in the Qing Dynasty was good for the expansion of Chinese medicine in the Ryukyu, and promoted the development and social progress of the Ryukyu medicine and health, made a significant contribution to maintain the friendly relationship between the two countries.

  10. The current system east of the Ryukyu Islands as revealed by a global ocean reanalysis

    NASA Astrophysics Data System (ADS)

    Thoppil, Prasad G.; Metzger, E. Joseph; Hurlburt, Harley E.; Smedstad, Ole Martin; Ichikawa, Hiroshi

    2016-02-01

    The structure and variability of the Ryukyu Current System (RCS), which forms the western boundary current along the eastern slope of the Ryukyu Islands, are studied using results from a 32-layer, 1/12.5° global HYbrid Coordinate Ocean Model (HYCOM) and Navy Coupled Ocean Data Assimilation (NCODA) reanalysis for the period 1993-2012. It is confirmed that the reanalysis realistically reproduces salient features of the observed currents at three sections southeast of Miyakojima, Okinawa and Amami-Ohshima. The mean velocity sections show well-developed subsurface velocity maxima between 700 and 900 m. The current core southeast of Amami-Ohshima shows year-to-year variations with cyclonic (anticyclonic) circulation east of Amami-Ohshima generating weak (strong) velocity cores. Interaction of the RCS with an anticyclonic eddy often produces a two-core velocity structure, with a surface core in the upper 300 m and a deeper core near 700-900 m. The horizontal structure of the RCS at 15 m depth shows a well-developed northeastward current northeast of Okinawa, which is partly fed by the southwestward extension of the anticyclonic recirculation gyre. The RCS forms a continuous northeastward current from Miyakojima to Amami-Ohshima below 500 m with shoreward intensification. The circulation at 2000 m shows a seasonal flow reversal, which is northeastward from December to June and southwestward from August to October with July and November being the transition months. The volume transports across these three sections have respective mean values of 0.6, 6.2 and 12.4 Sv (1 Sv ≡ 106 m3 s-1) and standard deviations of 10.2, 7.1 and 11.3 Sv. They have dominant seasonal variations with the maximum in winter and spring and the minimum in summer. The interannual variation of the transport anomaly, which co-varies with the RCS core, results from westward propagating mesoscale eddies arriving from the Pacific interior.

  11. A special comment on trace metals in the viscera of turbo marmoratus, a toxic snail, on Ryukyu Island.

    PubMed

    Yamada, Masa-Oki; Fujimori, Ken; Yamada, Gen; Satoh, Hiroyasu; Tohno, Setsuko; Tohno, Yoshiyuki; Moriwake, Yumi; Azuma, Cho; Minami, Takeshi

    2003-12-01

    Trace metals in the viscera of Turbo marmoratus, a huge conical spire, in the coral reef of Ryukyu Island were analyzed. The highest amount of Zn and Fe was detectable in the midgut gland known to be polluted by saxitoxin. This intestine maintained a considerable amount of Si (higher than Ca) which fluctuated in parallel with the taurine amount. These data suggest that the viscera of the alimentary tract accumulate some metals, especially Zn and Fe.

  12. Detailed bathymetry and magnetic anomaly inthe Central Ryukyu Arc, Japan: implications for a westward shift of the volcanic front after ~2.1 Ma

    NASA Astrophysics Data System (ADS)

    Sato, T.; Oda, H.; Ishizuka, O.; Arai, K.

    2014-12-01

    Detailed bathymetry and magnetic anomalies in the southern part of the Central Ryukyu Arc reveal recent volcanic structures in a southwestward extension of the active volcanic front of the Ryukyu Arc. A line of bathymetric highs running subparallel to this recent volcanic front was observed ~20 km to the east. A set of small, sharply defined magnetic anomalies extends southward from this line of bathymetric highs to the islands Kume-jima and Aguni-jima, suggesting the former existence of an ancient volcanic front. The ages of volcanic rocks from these islands indicate that magmatic activity along the ancient volcanic front continued until at least ~2.1 Ma. The presence of magnetic anomalies between the two volcanic fronts suggests that the volcanic front has moved gradually westward. This shift can be explained by the termination of asthenospheric upwelling and/or the rapid retreat of the Ryukyu Trench after its change in subduction direction.

  13. Detailed bathymetry and magnetic anomaly in the Central Ryukyu Arc, Japan: implications for a westward shift of the volcanic front after approximately 2.1 Ma

    NASA Astrophysics Data System (ADS)

    Sato, Taichi; Oda, Hirokuni; Ishizuka, Osamu; Arai, Kohsaku

    2014-12-01

    Detailed bathymetry and magnetic anomalies in the southern part of the Central Ryukyu Arc reveal recent volcanic structures in a southwestward extension of the active volcanic front of the Ryukyu Arc. A line of bathymetric highs running subparallel to this recent volcanic front was observed approximately 20 km to the east. A set of small, sharply defined magnetic anomalies extends southward from this line of bathymetric highs to the islands Kume-jima and Aguni-jima, suggesting the former existence of an ancient volcanic front. The ages of volcanic rocks from these islands indicate that magmatic activity along the ancient volcanic front continued until at least approximately 2.1 Ma. The presence of magnetic anomalies between the two volcanic fronts suggests that the volcanic front has moved gradually westward. This shift can be explained by the termination of asthenospheric upwelling and/or the rapid retreat of the Ryukyu Trench after its change in subduction direction.

  14. Opportunities in Understanding China’s Approach to the Senkaku/Diaoyu Islands

    DTIC Science & Technology

    2014-01-01

    of the Ryukyu Island chain comprise a mere 7 square kilometers of land.4 In the context of increasingly contested sovereignty in the East China Sea...Declarations led China to be- lieve the Allied Powers would expel Japan from the Ryukyu Islands at the conclu- sion of World War II. Instead, the United...States retained administrative control and Yasukuni Shrine JFQ 75, 4th Quarter 2014 Davis 55 eventually returned the Ryukyu Islands , including the

  15. A new genus and species of hatschekiid copepod (Siphonostomatoida) from groupers (Actinopterygii: Serranidae) collected off the Ryukyu Archipelago, Japan.

    PubMed

    Uyeno, Daisuke

    2013-01-01

    A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process.

  16. American Dissertations on Foreign Education: A Bibliography with Abstracts. Volume XVII. Pacific: American Samoa, Fiji, Guam, Papua New Guinea, Ryukyu Islands, Solomon Islands, Tonga, Trust Territory of the Pacific Islands (Micronesia), Tubuai (French Polynesia), Western Samoa.

    ERIC Educational Resources Information Center

    Parker, Franklin, Ed.; Parker, Betty June, Ed.

    The editors attempt to examine and abstract all locatable doctoral dissertations completed in the United States, Canada, and some European countries that pertain to the Pacific area. Specifically, these dissertations deal with American Samoa, Fiji, Guam, Papua New Guinea, Ryukyu Islands, Solomon Islands, Tonga, Trust Territory of the Pacific…

  17. Two new genera of the pharyngodonidae (Nematoda: Oxyuroidea) found in rhacophorid frogs of the Ryukyu Archipelago, Japan.

    PubMed

    Hasegawa, Hideo

    2005-02-01

    Okinawandros goldbergi n. gen., n. sp. and Ataronema sekii n. gen., n. sp. (Nematoda: Pharyngodonidae) are described from rhacophorid frogs of the Ryukyu Archipelago, Japan. Okinawandros n. gen. resembles Batracholandros Freitas et Ibañez, 1965 and Synodontisia Petter, Vassiliades et Troncy, 1972 but is readily distinguished from the former in lacking laterally situated genital papillae and by having anteriorly directed vagina and from the latter by having operculated eggs and lacking a spicule. Ataronema n. gen. most closely resembles Parathelandros Baylis, 1930 but is readily distinguished because the posterior pair of caudal papillae is not rosette shaped and the eggs are not operculated. Morphological notes of Pharyngodon polypedatis Yamaguti, 1941 are included.

  18. Confounding effects of microbiome on the susceptibility of TNFSF15 to Crohn's disease in the Ryukyu Islands.

    PubMed

    Nakagome, Shigeki; Chinen, Hiroshi; Iraha, Atsushi; Hokama, Akira; Takeyama, Yasuaki; Sakisaka, Shotaro; Matsui, Toshiyuki; Kidd, Judith R; Kidd, Kenneth K; Said, Heba S; Suda, Wataru; Morita, Hidetoshi; Hattori, Masahira; Hanihara, Tsunehiko; Kimura, Ryosuke; Ishida, Hajime; Fujita, Jiro; Kinjo, Fukunori; Mano, Shuhei; Oota, Hiroki

    2017-04-01

    Crohn's disease (CD) involves chronic inflammation in the gastrointestinal tract due to dysregulation of the host immune response to the gut microbiome. Even though the host-microbiome interactions are likely contributors to the development of CD, a few studies have detected genetic variants that change bacterial compositions and increase CD risk. We focus on one of the well-replicated susceptible genes, tumor necrosis factor superfamily member 15 (TNFSF15), and apply statistical analyses for personal profiles of genotypes and salivary microbiota collected from CD cases and controls in the Ryukyu Islands, southernmost islands of the Japanese archipelago. Our association test confirmed the susceptibility of TNFSF15 in the Ryukyu Islands. We found that the recessive model was supported to fit the observed genotype frequency of risk alleles slightly better than the additive model, defining the genetic effect on CD if a pair of the chromosomes in an individual consists of all risk alleles. The combined analysis of haplotypes and salivary microbiome from a small set of samples showed a significant association of the genetic effect with the increase of Prevotella, which led to a significant increase of CD risk. However, the genetic effect on CD disappeared if the abundance of Prevotella was low, suggesting the genetic contribution to CD is conditionally independent given a fixed amount of Prevotella. Although our statistical power is limited due to the small sample size, these results support an idea that the genetic susceptibility of TNFSF15 to CD may be confounded, in part, by the increase of Prevotella.

  19. Catastrophic impact of typhoon waves on coral communities in the Ryukyu Islands under global warming

    NASA Astrophysics Data System (ADS)

    Hongo, Chuki; Kawamata, Hideki; Goto, Kazuhisa

    2012-06-01

    Typhoon-generated storm waves generally cause mechanical damage to coral communities on present-day reefs, and the magnitude and extent of damage is predicted to increase in the near future as a result of global warming. Therefore, a comprehensive understanding of potential future scenarios of reef ecosystems is of prime interest. This study assesses the current status of coral communities on Ibaruma reef, Ryukyu Islands, on the basis of field observations, engineering and fluid dynamic models, and calculations of wave motion, and predicts the potential effects of a super-extreme typhoon (incident wave height,H = 20 m; wave period, T = 20 s) on the reef. On the present-day reef, massive corals occur in shallow lagoons and tabular corals occur from the reef crest to the reef slope. The observed distribution of corals, which is frequently attacked by moderate (H = 10 m, T = 10 s) and extreme (H = 10 m, T = 15 s) typhoons, is consistent with the predictions of engineering models. Moreover, this study indicates that if a super-extreme typhoon attacks the reef in the near future, massive corals will survive in the shallow lagoons but tabular corals on the reef crest and reef slope will be severely impacted. The findings imply that super-extreme typhoons will cause a loss of species diversity, as the tabular corals are important reef builders and are critical to the maintenance of reef ecosystems. Consequently, reef restoration is a key approach to maintaining reef ecosystems in the wake of super-extreme typhoons.

  20. Historical Relationships among Wild Boar Populations of the Ryukyu Archipelago and Other Eurasian regions, as Inferred from Mitochondrial Cytochrome b Gene Sequences.

    PubMed

    Yoshikawa, Saka; Mimura, Makiko; Watanabe, Shin; Lin, Liang-Kong; Ota, Hidetoshi; Mizoguchi, Yasushi

    2016-10-01

    The Ryukyu wild boar (Sus scrofa riukiuanus) is an endemic, morphologically defined subspecies of the Eurasian wild boar (S. scrofa) found on five islands of the Ryukyu Archipelago (a group of small islands stretching from mainland Japan to Taiwan). Two hypothetical scenarios have been proposed regarding the origin of the current Ryukyu wild boar populations: 1) natural dispersal and 2) transportation and subsequent release by prehistoric humans. To test these two hypotheses, we compared the mitochondrial cytochrome b gene sequence (1140 base pairs) in 352 individual wild boar samples that included representatives of all five insular populations of the Ryukyu wild boar and populations of other conspecific subspecies in insular East and Southeast Asia and the Eurasian Continent. A total of 68 haplotypes were recognized, of which 12 were unique to the Ryukyu wild boar populations. The results of Bayesian phylogenetic analyses supported monophyly of the five Ryukyu populations (posterior probability value of 92), confirming the validity of the subspecies as a natural group. Coalescent analysis estimated the divergence times between the Ryukyu wild boar and the other conspecific subspecies as 144-465 thousand years ago (Kya), with a 95% HPD (highest posterior density) range of 51-837 Kya, and with no significant migration. Taking the broadly accepted date of initial human migration to the Ryukyus (no earlier than 50 Kya) into consideration, our results strongly suggest that the ancestral form of the Ryukyu wild boar first entered the Ryukyu Archipelago by natural dispersal prior to the arrival of prehistoric humans.

  1. Biology of Anopheles saperoi, an Endemic Species in Okinawajima, the Ryukyu Archipelago, Japan.

    PubMed

    Mannen, Kosuke; Toma, Takako; Minakawa, Noboru; Higa, Yukiko; Miyagi, Ichiro

    2016-03-01

    Biological studies of Anopheles saperoi were conducted using larval and adult mosquito collections in the northern part of Okinawajima of the Ryukyu Archipelago from June 2009 to July 2010. Anopheles saperoi was the most collected species in the northern Okinawajima, except Motobu Peninsula, where it was not collected. The southern distribution of An. saperoi was Sugita Stream, Nago City. Anopheles saperoi was collected throughout the year with reproduction (gonotrophic cycle) observed year-round. Immature densities varied for Hinna and Yona streams, and were negatively affected by precipitation patterns. Human attraction activity of females varied for by study area and collection time and was positively affected by temperature, but negatively by heavy rainfall. The greatest female human attraction activity was observed during 3:00-5:00 p.m., with peak at twilight. Parity rates varied from 23.1% to 83.3% throughout the year.

  2. Colonization and biology of the frog-feeding mosquito Uranotaeinia macfarlanei in the Ryukyu Archipelago.

    PubMed

    Miyagi, Ichiro; Toma, Takako; Tamashiro, Mikako; Higa, Yukiko; Kinjyo, Takako; Takara, Tomio

    2010-03-01

    A colony of Uranotaenia macfarlanei, a frog-feeding mosquito, was established in the laboratory. We report the bionomics of the species, as studied in the laboratory colony and in the field on Ryukyu Island, Japan. These include mating activity, feeding and resting habits, manner of oviposition, and egg, larval, and pupal periods.

  3. Morphological and genetic diversity of Briareum (Anthozoa: Octocorallia) from the Ryukyu Archipelago, Japan.

    PubMed

    Miyazaki, Yu; Reimer, James Davis

    2014-10-01

    The primary problem hindering the study of octocorals is the disordered situation regarding their taxonomy, chiefly caused by insufficient knowledge of valid morphological taxonomic characters. Briareum is an octocoral genus found in the Atlantic and Pacific in shallow tropical and subtropical waters, and occurs in both encrusting and branching colony forms. Their simple morphology and morphological plasticity have hindered taxonomic understanding of this genus. In this study three morphologically distinct types (= type-1, -2, and -3) of Briareum from the Ryukyu Archipelago and their genetic diversity were examined. Colony, anthostele morphology, and sclerite length were examined for each type. Four molecular markers (mitochondrial cytochrome c oxidase subunit 1, mitochondrial mismatch repair gene, nuclear 18S ribosomal DNA, internal transcribed spacer 2 (ITS2)) were used to evaluate molecular phylogenetic status of these variations. Although one morphological type ("deep" small colonies, = type-3) showed small differences in nuclear ITS2 sequences compared to the other two types, the remaining types had identical sequences for all molecular markers examined. The results suggest extremely low genetic diversity despite highly variable morphology of Briareum species in Okinawa. Nevertheless, considering the distribution patterns and discontinuous morphology of type-3 compared to the other two morphotypes, genetic isolation of type-3 is plausible. In Briareum, small variances in nuclear ITS2 sequences of type-3 may have much more importance than in molecular phylogenies of other octocorals. Further phylogenetic investigations and comparison with Briareum specimens from other regions are necessary to conclusively taxonomically identify the three types.

  4. A multiplex PCR-based molecular identification of five morphologically related, medically important subgenus Stegomyia mosquitoes from the genus Aedes (Diptera: Culicidae) found in the Ryukyu Archipelago, Japan.

    PubMed

    Higa, Yukiko; Toma, Takako; Tsuda, Yoshio; Miyagi, Ichiro

    2010-09-01

    Internal transcribed spacer regions of ribosomal DNA were sequenced, and new species-specific primers were designed to simplify the molecular identification of five morphologically related subgenus Stegomyia mosquito species--Aedes aegypti, Ae. albopictus, Ae. riversi, Ae. flavopictus, and Ae. daitensis--found in the Ryukyu Archipelago, Japan. Each newly designed primer was able to amplify a species-specific fragment with a different size. Conditions for multiplex PCR were optimized to identify all five species in a single PCR. This method is a convenient tool for entomological field surveys, particularly in arbovirus endemic/epidemic areas where some of these species coexist.

  5. Growth inhibitory activities of crude extracts obtained from herbal plants in the Ryukyu Islands on several human colon carcinoma cell lines.

    PubMed

    Kaneshiro, Tatsuya; Suzui, Masumi; Takamatsu, Reika; Murakami, Akira; Ohigashi, Hajime; Fujino, Tetsuya; Yoshimi, Naoki

    2005-01-01

    There is increasing interest in the use of herbs for the treatment of human diseases including cancer. Therefore, the purpose of this study was to determine whether crude extracts obtained from 44 herbal plants in the Ryukyu Islands might contain components capable of inhibiting the growth of a variety of human colon carcinoma cell lines. Leaves, roots and other parts of the plants were extracted with chloroform, and the crude extracts were dissolved in dimethylsulfoxide and used for the experiments. Extracts of Hemerocallis fulva, Ipomoea batatas, Curcuma longa, and Nasturium officinale caused marked dose-dependent growth inhibition, with IC(50) values in the range of 10-80 mug/ml. With the HCT116 cell line, the extracts of Hemerocallis fulva and Ipomoea batatas induced G1 cell cycle arrest after 48 h of treatment. In addition, we found that extracts of Curcuma longa, and Nasturium officinale induced apoptosis in these cells after 48 h of treatment. The present studies are the first systematic examination of the growth inhibitory effects of crude extracts obtained from herbal plants in the Ryukyu Islands. The findings provide evidence that several plants in the Ryukyu Islands contain components that may have anticancer activity.

  6. Pilot experiments in the control of bancroftian filariasis in Japan and Ryukyu*

    PubMed Central

    Sasa, Manabu

    1963-01-01

    In this paper the author reviews the literature on the distribution and epidemiology of filariasis in Japan and discusses the extensive programme of research on the disease that is at present being carried out there. As part of this programme, comparative pilot experiments were started in 1958, in several areas of differing filariasis endemicity, with the object of determining the most effective and economical methods for preventing and treating the disease. The results so far obtained from these pilot experiments, which are still in progress, suggest that a close approach to the eradication of filariasis from the endemic areas could be reached through the administration of diethylcarbamazine at a suitable dosage to microfilaria carriers and the simultaneous application of control measures against the vector mosquitos. PMID:13986607

  7. Survey of the antibody against japanese encephalitis virus in Ryukyu wild boars (Sus scrofa riukiuanus) in Okinawa, Japan.

    PubMed

    Nidaira, Minoru; Taira, Katsuya; Itokazu, Kiyomasa; Kudaka, Jun; Nakamura, Masaji; Ohno, Atsusi; Takasaki, Tomohiko

    2007-09-01

    Serum specimens were collected from 99 wild boars in the Northern area of the main Okinawa Island and from 27 wild boars on Iriomote Island in Okinawa Prefecture from 1997 to 2005. Sera were tested for Japanese encephalitis virus (JEV) antibody by hemagglutination inhibition assay and IgG enzyme-linked immunosorbent assay. Sixty-four samples (64.6%) in the Northern area and 1 sample (3.7%) from Iriomote Island were positive for the JEV antibody. The difference in seroprevalence between the Northern area and Iriomote Island was statistically significant (P < 0.01, chi2 test). This difference may be due to the lack of a pig farm on Iriomote Island, whereas wild boars in the Northern area may be infected with JEV, amplified on pig farms. It is likely that there has recently been an increase in the number of wild boars living close to humans in certain areas of Japan. This in turn increases the possibility that wild boars are infected with JEV, which is amplified on pig farms, and these infected animals may play a role in carrying JEV to other regions of the country.

  8. Genetic variation and gene flow of broadcast spawning and planula brooding coral, Goniastrea aspera (Scleractinia) in the Ryukyu Archipelago, southern Japan.

    PubMed

    Nishikawa, Akira; Sakai, Kazuhiko

    2003-08-01

    The scleractinian coral Goniastrea aspera (Verrill) undergoes both broadcast spawning and planulae brooding in the Ryukyu Archipelago of southern Japan. Genetic variation and gene flow in G. aspera were studied using allozyme electrophoresis. We tested the hypothesis that gene flow is determined by the competency period of the planulae. We also assessed the relative contributions of sexual and asexual reproduction to recruitment. For the five staining systems surveyed, G. aspera encoded five polymorphic loci and one monomorphic locus. The genotype frequencies in each population significantly differed from the expected Hardy-Weinberg equilibrium (HWE), indicating that the local populations of G. aspera are not fully panmictic. The high ratio of the observed number of genotypes to the number of individuals (0.90 +/- 0.07, mean NG:N +/- SD) and the observed to expected genotypic diversity (0.84 +/- 0.11, mean GO:GE +/- SD) suggested that each population is likely maintained by sexual reproduction. The genetic differentiation (FST) and value of average number of migrants per generation (Nem) among and within regions ranged from 0.025 to 0.104 and 2.2 to 9.6, respectively. Comparisons with other species demonstrated that larva survival rates also influence gene flow. In addition, gene flow on distant reefs by planulae originating from spawning might prevent divergence by planulae originating from brooding for short-distant dispersal among and within populations of G. aspera in the Ryukyu Archipelago.

  9. Distant Mt. Fuji, Island of Honshu Japan

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This distant view of Mt. Fuji, on the main home island of Honshu, Japan (34.0N, 139.0E) was taken from about 450 miles to the south. Evan at that great distance, the majestic and inspiring Mt. Fuji is still plainly visible and easily recognized as a world renowned symbol of Japan. The snow capped extinct volcano lies just a few miles south of Tokyo.

  10. Fundamental structure model of island arcs and subducted plates in and around Japan

    NASA Astrophysics Data System (ADS)

    Iwasaki, T.; Sato, H.; Ishiyama, T.; Shinohara, M.; Hashima, A.

    2015-12-01

    The eastern margin of the Asian continent is a well-known subduction zone, where the Pacific (PAC) and Philippine Sea (PHS) plates are being subducted. In this region, several island arcs (Kuril, Northeast Japan, Southwest Japan, Izu-Bonin and Ryukyu arcs) meet one another to form a very complicated tectonic environment. At 2014, we started to construct fundamental structure models for island arcs and subducted plates in and around Japan. Our research is composed of 6 items of (1) topography, (2) plate geometry, (3) fault models, (4) the Moho and brittle-ductile transition zone, (5) the lithosphere-asthenosphere boundary, and (6) petrological/rheological models. Such information is basic but inevitably important in qualitative understanding not only for short-term crustal activities in the subduction zone (particularly caused by megathrust earthquakes) but also for long-term cumulative deformation of the arcs as a result of strong plate-arc/arc-arc interactions. This paper is the first presentation of our research, mainly presenting the results of items (1) and (2). The area of our modelling is 12o-54o N and 118o-164o E to cover almost the entire part of Japanese Islands together with Kuril, Ryukyu and Izu-Bonin trenches. The topography model was constructed from the 500-m mesh data provided from GSJ, JODC, GINA and Alaska University. Plate geometry models are being constructed through the two steps. In the first step, we modelled very smooth plate boundaries of the Pacific and Philippine Sea plates in our whole model area using 42,000 earthquake data from JMA, USGS and ISC. For 7,800 cross sections taken with several directions to the trench axes, 2D plate boundaries were defined by fitting to the earthquake distribution (the Wadati-Benioff zone), from which we obtained equi-depth points of the plate boundary. These equi-depth points were then approximated by spline interpolation technique to eliminate shorter wave length undulation (<50-100 km). The obtained

  11. The radiolarian evidence for the accretion of the Fu-saki Formation with the inferred oceanic plate stratigraphy: A case of weakly-metamorphosed accretionary complex in Ishigaki Jima, southern Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Nakae, Satoshi

    2013-09-01

    The island of Ishigaki Jima, located in the western part of the southern Ryukyu Arc, Japan, is underlain by a basement comprising the Tumuru and Fu-saki formations. The former is a pelitic glaucophane schist with a metamorphic age of 220-190 Ma, and the latter is a weakly metamorphosed accretionary complex, composed mainly of chert, mudstone and sandstone with minor amounts of limestone and mafic rocks. The Fu-saki Formation was weakly metamorphosed at ∼140 Ma. Latest Carboniferous-Early Jurassic microfossils have been obtained from the limestones, cherts and siliceous mudstones of this formation, but no fossils have been collected from the phyllitic mudstones. The radiolarian fauna of the phyllitic mudstones described herein indicates a late Pliensbachian-early Toarcian (Early Jurassic) age. This result, when combined with existing data, enables the reconstruction of an oceanic plate stratigraphy, showing a succession of (in ascending order) Upper Carboniferous-Triassic cherts, Sinemurian-lower Pliensbachian siliceous mudstones and upper Pliensbachian-lower Toarcian phyllitic mudstones and sandstones. The radiolarians from the phyllitic mudstones are important in constraining the timing of the accretion of the Fu-saki Formation to the base of the Tumuru Formation.

  12. Description of a new genus and a new species of gaeticine crab (Crustacea: Brachyura: Varunidae) from the Ryukyu Islands, and a review of Acmaeopleura Stimpson, 1858, and Sestrostoma Davie & N.K. Ng, 2007.

    PubMed

    Naruse, Tohru

    2015-02-27

    Acmaeopleura parvula Stimpson, 1858, the type species of the varunid Acmaeopleura Stimpson, 1858, is redescribed, and a neotype is designated. Examination of all three species of the gaeticine Sestrostoma Davie & N.K. Ng, 2007, revealed that, although the diagnostic characters of Sestrostoma proposed by the previous study are variable and mostly overlap with those of Acmaeopleura, they can still be distinguished from each other by the characters of the carapace, the thoracic sternite 2, the third maxillipeds, and the ambulatory legs. The subfamilial position of Acmaeopleura was assessed by comparing it with all gaeticine genera. Gaetice Gistel, 1848, the type genus of the subfamily, has a very characteristic structure of the third maxilliped and the anterior sternal plate, which are partially shared with Gopkittisak Naruse & Clark, 2009, Brankocleistostoma Števčić, 2011, Sestrostoma and Acmaeopleura in different combinations. The generic diagnostic characters of these four genera are unique among Varunidae and they are tentatively placed in Gaeticinae. A new genus and new species, which is allied to Sestrostoma but clearly distinguishable from all varunine genera, is described from Iriomote Island, Ryukyu Islands, Japan.

  13. Submerged karst landforms observed by multibeam bathymetric survey in Nagura Bay, Ishigaki Island, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kan, Hironobu; Urata, Kensaku; Nagao, Masayuki; Hori, Nobuyuki; Fujita, Kazuhiko; Yokoyama, Yusuke; Nakashima, Yosuke; Ohashi, Tomoya; Goto, Kazuhisa; Suzuki, Atsushi

    2015-01-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the southern Ryukyu Islands, Japan. The coastal seafloor at depths shallower than ~ 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of Quaternary sea-level lowstands. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. Although these submerged karst landforms are covered by thick postglacial reef and reef sediments, their shapes and sizes are distinct from those associated with coral reef geomorphology. The submerged landscape of Nagura Bay likely formed during multiple glacial and interglacial periods. According to our bathymetric results and the aerial photographs of the coastal area, this submerged karst landscape appears to have developed throughout Nagura Bay (i.e., over an area of approximately 6 × 5 km) and represents the largest submerged karst in Japan.

  14. A new sponge-inhabiting Loxosomella (Entoprocta: Loxosomatidae) from Okinawa Island, Japan, with special focus on foot structure.

    PubMed

    Iseto, Tohru; Sugiyama, Nagisa; Hirose, Euichi

    2008-11-01

    Abstract A new solitary entoproct, Loxosomella plakorticola sp. nov., was found on a sponge, Plakortis sp., on a coral reef slope on the western coast of Okinawa Island, Ryukyu Archipelago, Japan. This species has a medium-sized body (up to about 1.2 mm), slender proportion (the stalk is 0.83-1.76 times longer than the calyx), a slug-like foot with a foot gland and foot groove, and 14 to 18 tentacles. Small black pigment granules are visible only in the living stage in the calyx, stalk, and buds. This is the first report of a commensal loxosomatid from the Ryukyu Archipelago and the second species inhabiting sponges reported from Japan. Detailed morphological observations indicate that this species attaches to sponges by narrowing the foot groove; the sponge surface is pinched in the deepest part of the groove, which is free of the cuticle layer but covered by microvilli of epidermal cells. The accessory cells lining the foot groove have long been believed to be gland cells, but they are not gland cells in ultrastructure, at least in this species.

  15. A new sexannulate species of Orobdella (Hirudinida, Arhynchobdellida, Orobdellidae) from Yakushima Island, Japan

    PubMed Central

    Nakano, Takafumi

    2012-01-01

    Abstract A new sexannulate species of the genus Orobdella Oka, 1895, Orobdella mononoke sp. n., is described on the basis of five specimens collected from Yakushima Island, Japan. Orobdella mononoke sp. n. differs from other sexannulate Orobdella species in its possessing the following combination of characters: dorsal surface bicolor in life, I–XIII, XXVII and caudal sucker grayish purple, XIV–XXVI amber, male gonopore at XI c11/c12, female gonopore at XIII b2, 8 + 1/2 between gonopores, tubular but bulbous at junction with crop gastroporal duct, epididymides in XV–XIX, and atrial cornua ovate. Phylogenetic analyses using nuclear 18S rDNA and histone H3, and mitochondrial COI, tRNACys, tRNAMet, 12S rDNA, tRNAVal and 16S rDNA markers show that Orobdella mononoke sp. n. is closely related to Orobdella esulcata Nakano, 2010 from Kyushu, Japan, and two species, Orobdella dolichopharynx Nakano, 2011 and Orobdella shimadae Nakano, 2011, from the Ryukyu Archipelago, Japan. PMID:22539913

  16. A Crustal Structure Study of the Southern Ryukyu Subduction Zone by Using the Aftershock Data

    NASA Astrophysics Data System (ADS)

    Cho, Y.; Lin, J.; Lee, C.

    2011-12-01

    The region along the Ryukyu subduction zone is known as a tsunami disaster zone. The biggest tsunami (85 m) of Japan history was recorded in the Ishigaki Island, Ryukyu, in 1771. The paleo-tsunami events show that it has a frequency of about 150 years. This thread makes the Ryukyu subduction zone as a concerned field for the earthquake studies. However, due to the long distance from the east coast of Taiwan, this is an area out of the effective earthquake detection zone from the Central Weather Bureau network. A main shock of M = 6.9 occurred near the Ishigaki Island in 2009 August 17. After this event, we quickly deployed the OBS and found many aftershocks with the magnitude greater than 5.0. The main shock was 240 km, NE direction from the Hualien city, Taiwan. If a tsunami occurred, it took only less than 15 minutes to arrive the coast. From the recorded data, we picked the P- and S-wave using the 1-D module (iasp91). There were 1500 recorded events during those time range, and most of the earthquakes were located around the Nanao Basin. Based on this, we study the southern Ryukyu subduction zone structure by using the results from focal mechanism solution. From the earthquake relocation it shows that two main groups of aftershocks. They tend in northwest - southeast with a left-lateral strike-slip fault. The left-lateral strike-slip fault is the main structures that link with the splay faults at the southern Ryukyu Trench. The stability and extension of the splay faults are one of the major concerns for the occurrence of mega earthquake. More than 500-km long of the splay fault, such as that in the Indonesia, Chile and Japan subduction zones, has attacked by mega earthquakes in the recent years. The second group of those aftershocks was located in the Gagua Ridge near the Ryukyu Trench. This group may represent the ridge structure relate to the Taitung canyon fault. The front of Ryukyu Trench was being as a locked subduction zone where it is easily to

  17. Photosymbiotic ascidians from Pari Island (Thousand Islands, Indonesia).

    PubMed

    Hirose, Euichi; Iskandar, Budhi Hascaryo; Wardiatno, Yusli

    2014-01-01

    Photosymbiotic ascidian fauna were surveyed in the subtidal zone off Pari Island in the Thousand Islands (Java Sea, Indonesia). Nine species were recorded: Didemnum molle, Trididemnum miniatum, Lissoclinum patella, L. punctatum, L. timorense, Diplosoma gumavirens, D. simile, D. simileguwa, and D. virens. All of these species have been previously recorded in the Ryukyu Archipelago, Japan. Diplosoma gumavirens and D. simileguwa were originally described from the Ryukyu Archipelago in 2009 and 2005, respectively, and all of the observed species are potentially widely distributed in Indo-West Pacific coral reefs.

  18. Photosymbiotic ascidians from Pari Island (Thousand Islands, Indonesia)

    PubMed Central

    Hirose, Euichi; Iskandar, Budhi Hascaryo; Wardiatno, Yusli

    2014-01-01

    Abstract Photosymbiotic ascidian fauna were surveyed in the subtidal zone off Pari Island in the Thousand Islands (Java Sea, Indonesia). Nine species were recorded: Didemnum molle, Trididemnum miniatum, Lissoclinum patella, L. punctatum, L. timorense, Diplosoma gumavirens, D. simile, D. simileguwa, and D. virens. All of these species have been previously recorded in the Ryukyu Archipelago, Japan. Diplosoma gumavirens and D. simileguwa were originally described from the Ryukyu Archipelago in 2009 and 2005, respectively, and all of the observed species are potentially widely distributed in Indo–West Pacific coral reefs. PMID:25061385

  19. Loxocorone, a new genus of the family loxosomatidae (Entoprocta: Solitaria), with descriptions of two new Loxomitra (sensu stricto) and a new Loxocorone from Okinawa, the Ryukyu Archipelago, Japan.

    PubMed

    Iseto, Tohru

    2002-03-01

    The type species of Loxomitra Nielsen, 1964, L. kefersteinii (Claparède, 1867), has following characters: A) the buds have a pair of terminal wings at the base of the stalk, and B) the liberated buds crawl on the substratum by attaching the two terminal wings to the substratum and twisting the whole body. By contrast, some other members of the genus have following characters: A') the buds lack the terminal wings but have a foot with foot groove, and B') the liberated buds glide over the substratum using the foot with foot groove. I thus propose to divide Loxomitra (sensu lato) into two genera- Loxomitra (sensu stricto) characterized by A) and B), and Loxocorone gen. nov. by A') and B'). I also describe two new Loxomitra (sensu stricto), L. mizugamaensis sp. nov., and L. tetraorganon sp. nov., and one new Loxocorone, L. allax sp. nov. from the Ryukyu Archipelago, Japan. All of the currently recognized species of the Loxomitra (sensu lato) are reviewed to specify their generic allocations in response to the above change.

  20. Activity of Small Repeating Earthquakes along Izu-Bonin and Ryukyu Trenches

    NASA Astrophysics Data System (ADS)

    Hibino, K.; Matsuzawa, T.; Uchida, N.; Nakamura, W.; Matsushima, T.

    2014-12-01

    There are several subduction systems near the Japanese islands. The 2011 Mw9.0 Tohoku-oki megathrust earthquake occurred at the NE Japan (Tohoku) subduction zone. We have revealed a complementary relation between the slip areas for huge earthquakes and small repeating earthquakes (REs) in Tohoku. Investigations of REs in these subduction zones and the comparison with Tohoku area are important for revealing generation mechanism of megathrust earthquakes. Our target areas are Izu-Bonin and Ryukyu subduction zones, which appear to generate no large interplate earthquake. To investigate coupling of plate boundary in these regions, we estimated spatial distribution of slip rate by using REs. We use seismograms from the High Sensitivity Seismograph Network (Hi-net), Full Range Seismograph Network of Japan (F-net), and permanent seismic stations of Japan Meteorological Agency (JMA), Tohoku University, University of Tokyo, and Kagoshima University from 8 May 2003 (Izu-Bonin) and 14 July 2005 (Ryukyu) to 31 December 2012 to detect REs along the two trenches, by using similarity of seismograms. We mainly follow the procedure adopted in Uchida and Matsuzawa (2013) that studied REs in Tohoku area to compare our results with the REs in Tohoku. We find that the RE distribution along the Ryukyu trench shows two bands parallel to the trench axis. This feature is similar to the pattern in Tohoku where relatively large earthquakes occur between the bands. Along the Izu-Bonin trench, on the other hand, we find much fewer REs than in Tohoku or Ryukyu subduction zones and only one along-trench RE band, which corresponds to the area where the subducting Pacific plate contacts with the crust of the Philippine Sea plate. We also estimate average slip rate and coupling coefficient by using an empirical relationship between seismic moment and slip for REs (Nadeau and Johnson, 1998) and relative plate motion model. As a result, we find interplate slip rate in the deeper band is higher than

  1. Submerged Humid Tropical Karst Landforms Observed By High-Resolution Multibeam Survey in Nagura Bay, Ishigaki Island, Southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kan, H.; Urata, K.; Nagao, M.; Hori, N.; Fujita, K.; Yokoyama, Y.; Nakashima, Y.; Ohashi, T.; Goto, K.; Suzuki, A.

    2014-12-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the South Ryukyu Islands, Japan. This is the first description of submerged humid tropical karst using multibeam bathymetry. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results with a grid size of 1 m over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. We assume that Nagura Bay was a large karst basin in which older limestone remained submerged, thus preventing corrosion and the accumulation of reef sediments during periods of submersion, whereas the limestone outcropping on land was corroded during multiple interglacial and glacial periods. Based on our bathymetric result together with aerial photographs of the coastal area, we conclude that the submerged karst landscape has likely developed throughout the whole of Nagura Bay, covering an area of ~6 × 5 km. Accordingly, this area hosts the largest submerged karst in Japan. We also observed abundant coral communities during our SCUBA observations. The present marine conditions of Nagura Bay are characterized by low energy (calm sea) and low irradiance owing to the terrestrial influence. Such conditions have been emphasized by the presence of large undulating landforms, which cause decreases in wave intensity and irradiance with depth. These characteristics have acted to establish unique conditions compared to other coral reef areas in the Ryukyu Islands. It may play an important role in supporting the regional coral reef ecosystem.

  2. Two new species in the Echinoderes coulli group (Echinoderidae, Cyclorhagida, Kinorhyncha) from the Ryukyu Islands, Japan.

    PubMed

    Yamasaki, Hiroshi; Fujimoto, Shinta

    2014-01-01

    Two new species belonging to the Echinoderes coulli group are described with their external morphologies and sequences of nuclear 18S rRNA and 28S rRNA genes, and mitochondrial COI gene. The first species, Echinoderes komatsui sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 8, laterodorsal tubules on segment 10, inverted triangle or wide oval shaped large sieve plates, lateral terminal accessory spines in female, and short tips of ventral pectinate fringe on segment 10. The second species, Echinoderes hwiizaa sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 7-9, midlateral tubules on segment 8, laterodorsal tubules on segment 10, large narrow oval shaped sieve plates on segment 9, and thick, short and blunt lateral terminal spines about 10-15% of trunk length. The diagnostic characters and key to species of E. coulli group are provided as well.

  3. Two new species in the Echinoderes coulli group (Echinoderidae, Cyclorhagida, Kinorhyncha) from the Ryukyu Islands, Japan

    PubMed Central

    Yamasaki, Hiroshi; Fujimoto, Shinta

    2014-01-01

    Abstract Two new species belonging to the Echinoderes coulli group are described with their external morphologies and sequences of nuclear 18S rRNA and 28S rRNA genes, and mitochondrial COI gene. The first species, Echinoderes komatsui sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 8, laterodorsal tubules on segment 10, inverted triangle or wide oval shaped large sieve plates, lateral terminal accessory spines in female, and short tips of ventral pectinate fringe on segment 10. The second species, Echinoderes hwiizaa sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 7–9, midlateral tubules on segment 8, laterodorsal tubules on segment 10, large narrow oval shaped sieve plates on segment 9, and thick, short and blunt lateral terminal spines about 10–15% of trunk length. The diagnostic characters and key to species of E. coulli group are provided as well. PMID:24624018

  4. Phylogeography of the Ryukyu robin (Erithacus komadori): population subdivision in land-bridge islands in relation to the shift in migratory habit.

    PubMed

    Seki, Shin-Ichi; Sakanashi, Masahiko; Kawaji, Noritomo; Kotaka, Nobuhiko

    2007-01-01

    We analysed the mitochondrial control region sequences of 150 Ryukyu robins (Erithacus komadori) from five migratory and three sedentary populations. E. komadori is endemic to the subtropical Asian islands, is well differentiated among populations in morphology and migratory behaviour within its narrow habitat range, and is ideal for examining the effects of altered migratory habits on population differentiation. Maximum-likelihood analysis among the haplotypes resulted in the generation of a single tree in which two phylogenetic clades corresponding to the two subspecies were evident. Within the northern lineage, three distinctive subgroups of populations (one migratory and two sedentary groups) were observed by population genetic analysis. The migration-related wing morphology and molecular data were then compared among groups. The wing shape of the northern lineage was significantly more pointed than that of the southern sedentary lineage, and they were exclusively discriminated from each other. The difference was not so apparent between the sedentary and migratory groups within the northern lineage, suggesting that the present northern subspecies is primarily a migratory lineage. The different migratory behaviours of the robin played an apparent role in maintaining the genetic structure at two different levels--one between the southern and northern lineages and the other between the sedentary and migratory groups within the northern lineage. While gene flow had long been maintained among the islands occupied by migratory individuals, migrants have been unable to contribute to the gene pool of the sedentary populations despite passing through the breeding range of such populations twice each year.

  5. Helium and methane sources and fluxes of shallow submarine hydrothermal plumes near the Tokara Islands, Southern Japan

    PubMed Central

    Wen, Hsin-Yi; Sano, Yuji; Takahata, Naoto; Tomonaga, Yama; Ishida, Akizumi; Tanaka, Kentaro; Kagoshima, Takanori; Shirai, Kotaro; Ishibashi, Jun-ichiro; Yokose, Hisayoshi; Tsunogai, Urumu; Yang, Tsanyao F.

    2016-01-01

    Shallow submarine volcanoes have been newly discovered near the Tokara Islands, which are situated at the volcanic front of the northern Ryukyu Arc in southern Japan. Here, we report for the first time the volatile geochemistry of shallow hydrothermal plumes, which were sampled using a CTD-RMS system after analyzing water column images collected by multi-beam echo sounder surveys. These surveys were performed during the research cruise KS-14-10 of the R/V Shinsei Maru in a region stretching from the Wakamiko Crater to the Tokara Islands. The 3He flux and methane flux in the investigated area are estimated to be (0.99–2.6) × 104 atoms/cm2/sec and 6–60 t/yr, respectively. The methane in the region of the Tokara Islands is a mix between abiotic methane similar to that found in the East Pacific Rise and thermogenic one. Methane at the Wakamiko Crater is of abiotic origin but affected by isotopic fractionation through rapid microbial oxidation. The helium isotopes suggest the presence of subduction-type mantle helium at the Wakamiko Crater, while a larger crustal component is found close to the Tokara Islands. This suggests that the Tokara Islands submarine volcanoes are a key feature of the transition zone between the volcanic front and the spreading back-arc basin. PMID:27671524

  6. Helium and methane sources and fluxes of shallow submarine hydrothermal plumes near the Tokara Islands, Southern Japan

    NASA Astrophysics Data System (ADS)

    Wen, Hsin-Yi; Sano, Yuji; Takahata, Naoto; Tomonaga, Yama; Ishida, Akizumi; Tanaka, Kentaro; Kagoshima, Takanori; Shirai, Kotaro; Ishibashi, Jun-Ichiro; Yokose, Hisayoshi; Tsunogai, Urumu; Yang, Tsanyao F.

    2016-09-01

    Shallow submarine volcanoes have been newly discovered near the Tokara Islands, which are situated at the volcanic front of the northern Ryukyu Arc in southern Japan. Here, we report for the first time the volatile geochemistry of shallow hydrothermal plumes, which were sampled using a CTD-RMS system after analyzing water column images collected by multi-beam echo sounder surveys. These surveys were performed during the research cruise KS-14-10 of the R/V Shinsei Maru in a region stretching from the Wakamiko Crater to the Tokara Islands. The 3He flux and methane flux in the investigated area are estimated to be (0.99–2.6) × 104 atoms/cm2/sec and 6–60 t/yr, respectively. The methane in the region of the Tokara Islands is a mix between abiotic methane similar to that found in the East Pacific Rise and thermogenic one. Methane at the Wakamiko Crater is of abiotic origin but affected by isotopic fractionation through rapid microbial oxidation. The helium isotopes suggest the presence of subduction-type mantle helium at the Wakamiko Crater, while a larger crustal component is found close to the Tokara Islands. This suggests that the Tokara Islands submarine volcanoes are a key feature of the transition zone between the volcanic front and the spreading back-arc basin.

  7. Helium and methane sources and fluxes of shallow submarine hydrothermal plumes near the Tokara Islands, Southern Japan.

    PubMed

    Wen, Hsin-Yi; Sano, Yuji; Takahata, Naoto; Tomonaga, Yama; Ishida, Akizumi; Tanaka, Kentaro; Kagoshima, Takanori; Shirai, Kotaro; Ishibashi, Jun-Ichiro; Yokose, Hisayoshi; Tsunogai, Urumu; Yang, Tsanyao F

    2016-09-27

    Shallow submarine volcanoes have been newly discovered near the Tokara Islands, which are situated at the volcanic front of the northern Ryukyu Arc in southern Japan. Here, we report for the first time the volatile geochemistry of shallow hydrothermal plumes, which were sampled using a CTD-RMS system after analyzing water column images collected by multi-beam echo sounder surveys. These surveys were performed during the research cruise KS-14-10 of the R/V Shinsei Maru in a region stretching from the Wakamiko Crater to the Tokara Islands. The (3)He flux and methane flux in the investigated area are estimated to be (0.99-2.6) × 10(4) atoms/cm(2)/sec and 6-60 t/yr, respectively. The methane in the region of the Tokara Islands is a mix between abiotic methane similar to that found in the East Pacific Rise and thermogenic one. Methane at the Wakamiko Crater is of abiotic origin but affected by isotopic fractionation through rapid microbial oxidation. The helium isotopes suggest the presence of subduction-type mantle helium at the Wakamiko Crater, while a larger crustal component is found close to the Tokara Islands. This suggests that the Tokara Islands submarine volcanoes are a key feature of the transition zone between the volcanic front and the spreading back-arc basin.

  8. The Melithaeidae (Cnidaria: Octocorallia) of the Ryukyu Archipelago: molecular and morphological examinations.

    PubMed

    Aguilar-Hurtado, Catalina; Nonaka, Masanori; Reimer, James D

    2012-07-01

    The family Melithaeidae (Octocorallia: Alcyonacea) is distributed in the West Pacific, Indian Ocean and the Red Sea. They are most abundant in warmer waters but can also be found in temperate waters. At present six genera are assigned to this family (Melithaea, Mopsella, Clathraria, Acabaria, Wrightella and Asperaxis), however overlapping characteristics make this group's taxonomic identification difficult and their relationships unclear. There are only a few reports from the Ryukyu Archipelago in southern Japan of melithaeids and most other octocorals, despite the islands being an area of high octocoral diversity. To help resolve the taxonomic confusion in this family, samples from various Ryukyu Archipelago locations were collected and DNA sequences of nuclear 28S ribosomal DNA and mitochondrial cytochrome oxidase I (COI) were obtained. Additionally, SEM micrographs of the sclerites of specimens were taken to further confirm the molecular results. Three strongly supported clades were recovered from the COI and 28S rDNA analyses, corresponding to Melithaea, Acabaria, and Mopsella, and in most cases clades were clearly related with the sclerite shape reported for each genus. These results show clearly that molecular differences are present between the three genera, and also demonstrates the strong need of other molecular markers for resolving intra-generic phylogenies. Our results provide baseline data for future studies of this octocoral family, not only on taxonomy, but also with regards to their distribution in the Ryukyu Islands.

  9. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  10. Trace elements found to be variable in two coral reef species, Heliofungia actiniformis and Galaxea fascicularis, collected from the Ryukyu Islands.

    PubMed

    Yamada, G; Fujimori, K; Yamada, M; Minami, T; Tohno, S; Tohno, Y

    1998-11-01

    Biominerals and metals of intertidal corals of two species (Heliofungia actiniformis, Quoy and Gaimard; Galaxea fascicularis, Linnaeus), collected from the Iriomote Island of Ryukyu, were examined with an inductively coupled plasma atomic emission spectrometer (ICP-AES). Twelve elements were detectable in the coralline skeletons dissected radially along the growth axis. The relative content (RC) of Hg periodically fluctuated and was minimum at the hollow sites of the coralline slab of Heliofungia sp., corresponding to the cyclic growth. There were two types of elements: constant elements and variable elements along the growth axis. RCs of Ca, Mg, Al, Si, and P were nearly constant. RCs of Fe, Mn, Cu, and Ba were variable, but not as regularly changed as Hg. There were positive mass correlations of Hg to Mn, Cu and Zn, but not to Ba and Fe. In contrast, these relationships were not prominent and were likely degraded by aging in the skeleton of Galaxea sp., suggesting a different mode from that of the Heliofungia sp.

  11. Exhumation of Triassic HP-LT rocks by upright extrusional domes and overlying detachment faults, Ishigaki-jima, Ryukyu islands

    NASA Astrophysics Data System (ADS)

    Osozawa, Soichi; Wakabayashi, John

    2012-10-01

    The Tomuru Formation of Ishigaki-jima in the southernmost part of the Ryukyu arc, comprises blueschist facies subduction complex rocks metamorphosed in Triassic time. D1 structures related to subduction, blueschist facies mineral growth, and possibly early stages of exhumation, are deformed by D2 structures that appear to reflect the last stage of exhumation. D2 structures define several anticlines with parasitic overturned folds verging away from anticlinal axes. The shortening recorded by this deformation appears to reflect upward extrusion relative to flanking material. The anticlines are flanked by detachment faults with normal sense-of-shear parallel to D2 vergence. Hanging wall rocks that include the Fusaki Formation, an accretionary prism with early Cretaceous metamorphic ages, and late Eocene limestone, conglomerate, and andesitic volcanics. The Eocene strata contain metamorphic detritus derived from the Tomuru and Fusaki Formations indicating pre-late Eocene surface exposure of these units. Ultramafic rocks and gabbro blocks of the Tomuru Formation were incorporated by sedimentary sliding into the trench prior to subduction and high-pressure metamorphism rather than being emplaced as diapirs along a post-metamorphic fault as previously proposed. Geochronologic, metamorphic, and thermal considerations suggest exhumation of the Tomuru Formation to relatively shallow crustal depths prior to or concurrent with early Cretaceous metamorphism of the Fusaki Formation. Arcward-vergent thrusting may have placed the younger, and formerly structurally lower, subduction complex (Fusaki Formation) over the older one (Tomuru Formation). D2 extrusional doming began after the emplacement of the Fusaki Formation at high structural levels. The D2 transport directions are subparallel to the strike of the orogen suggesting that the upright extrusion may have occurred along a forearc strike-slip fault system. This final stage of exhumation concluded in the late Eocene with

  12. The modifying effect of Peucedanum japonicum, a herb in the Ryukyu Islands, on azoxymethane-induced colon preneoplastic lesions in male F344 rats.

    PubMed

    Morioka, Takamitsu; Suzui, Masumi; Nabandith, Viengvansay; Inamine, Morihiko; Aniya, Yoko; Nakayama, Takashi; Ichiba, Toshio; Mori, Hideki; Yoshimi, Naoki

    2004-03-18

    The modifying effect of dietary Peucedanum japonicum (PJ), which is a traditional herb in the Ryukyu Islands and is an anti-oxidant, on azoxymethane (AOM)-induced rat colon carcinogenesis was examined. Male F344 rats were divided into six groups: rats in groups 1-4 were given subcutaneous injection of AOM (20 mg/kg body weight) once a week for 2 weeks. Rats in groups 2, 3 and 4 were fed the diets containing 0.2 and 1% PJ and 0.025% chlorogenic acid, respectively. We observed modification of the preneoplastic lesions of both aberrant crypt foci (ACF) and beta-catenin accumulated crypts (BCAC) in colon carcinogenesis, microscopically and immunohistochemically. The numbers of ACF consisting of more than four aberrant crypts per rat in groups 2 (3.2+/-1.7) and 3 (3.0+/-3.2) were significantly lower than that of group 1 (10.8+/-4.9; P<0.05, respectively). The mean number of BCAC in both groups 2 (0.88+/-0.48/cm2/rat) and 3 (0.81+/-0.34/cm2/rat) was significantly lower than that in group 1 (2.13+/-0.54/cm2/rat; P < 0.0001, respectively). In addition, proliferating cell nuclear antigen labeling indices in group 2 (10.98+/-2.03) and group 3 (9.85+/-2.62) were significantly lower than that in group 1 (14.87+/-3.93; P < 0.001 and P < 0.0001, respectively). These findings indicate that PJ inhibits both ACF formation and accumulation of beta-catenin, and that PJ also reduces the cell proliferation activity, suggesting that PJ may have chemopreventive potential for colon carcinogenesis.

  13. Cryptic genetic divergence and associated morphological differentiation in the arboreal land snail Satsuma (Luchuhadra) largillierti (Camaenidae) endemic to the Ryukyu Archipelago, Japan.

    PubMed

    Kameda, Yuichi; Kawakita, Atsushi; Kato, Makoto

    2007-11-01

    Land snails are renowned model organisms in evolutionary ecology, but extensive morphological variation and lack of readily available diagnostic characters often invite taxonomic confusion among closely related species. Satsuma (Luchuhadra) largillierti is an arboreal land snail endemic to Okinawa Island, Japan, in which extensive geographic variation in shell morphology has long caused taxonomic complication. To establish robust species limits among S. largillierti and its allies, we perform molecular and morphological analyses of snails sampled from the entire range of Luchuhadra. Analyses of the mitochondrial cytochrome oxidase subunit 1 gene and nuclear ribosomal internal transcribed spacer sequences divide S. largillierti into two, reproductively isolated groups. Each of these groups includes Satsuma erabuensis and Satsuma sooi, respectively, which occur on a nearby island and were traditionally regarded as distinct species. Morphometric analysis of the genitalia further provides clear difference between the two groups, whereas differentiation in shell morphology is slight if any. These results indicate that the traditional taxonomy has overly depended on inadequate morphological difference and a priori information of island geography, which resulted in oversimplification of complex speciation history in Luchuhadra.

  14. Sub Moho boundary beneath island arc, Japan

    NASA Astrophysics Data System (ADS)

    Iidaka, T.; Igarashi, T.; Lee, C.; Iwasaki, T.; Niu, F.

    2008-12-01

    Moho is a seismic boundary discovered by Mohorovicic in 1909. It is generally considered as the boundary between Earth"fs crust and mantle, although the origin of the Moho and the definition of the crust-mantle boundary are still debated. Regardless whether it represents a phase or chemical boundary, it has been investigated world wide by seismologists since its discovery. Reflection/refraction data acquired from active sources were the main sources of the investigation. Recently, receiver function analysis provided an emerging tool for mapping this boundary below a seismic station. Since reflection/refraction data sample P- wave structure while receiver-function data are basically sensitive to S-wave velocity, a comparison of the two can provide better constraints on the composition of the lowermost crust and the uppermost mantle. In this study, we used receiver function data to determine subsurface boundaries. Receiver functions are calculated from teleseismic records of a borehole seismic network in Japan, the Hi-net, which covers the entire Japan with a 20-km station spacing. We used the multi-taper deconvolution method to generate individual receiver functions and a common-conversion-point gathering method for stacking the receiver functions. Results along several profiles where seismic refraction surveys have been conducted in the past were selected for comparison. We found remarkable difference between southwestern and central/northeastern Japan. In southwestern Japan both receiver function and refraction data yield a consistent and distinct Moho at around 35 km. In central and northeastern Japan, however, receiver function images reveal two P-to-S conversion events at approximately 30 km and 40 km, respectively. The shallow 30-km deep boundary is consistent with the refraction Moho. The deep boundary (sub-Moho) is about 10 km deeper than the refraction Moho boundary. The uppermost mantle seismic structure at central and northeastern Japan was known to be

  15. Discrepancy in the degree of population differentiation between color-morph frequencies and neutral genetic loci in the damselfly Ischnura senegalensis in Okinawa Island, Japan.

    PubMed

    Inomata, Nobuyuki; Hironaka, Kumiko; Sawada, Kouji; Kuriwada, Takashi; Yamahira, Kazunori

    2015-06-01

    Evaluation of relative contribution of natural selection and stochastic processes to population differentiation has been of great interest in evolutionary biology. In a damselfly, Ischnura senegalensis, females show color dimorphism (gynochrome vs. androchrome), and color-morph frequencies are known to greatly vary among local populations within Okinawa Island, a small island of Ryukyu Archipelago, Japan. In this study, to examine the effects of natural selection and stochastic processes on the within-island variation in color-morph frequencies, we compared the degree of population differentiation at the color-morph locus with that at a mitochondrial DNA region and ten nuclear microsatellite loci. F ST values at the neutral loci were close to zero, indicating presence of sufficient gene flow (dispersal of adult individuals) between the local populations. In contrast, F ST values at the color-morph locus were significantly different from zero. These results suggest that variation in female color-morph frequencies observed among local populations in Okinawa Island has been caused by divergent selection acting on the phenotype and/or genes tightly linked with the color locus.

  16. [Three Cases of Tsutsugamushi Disease in Miyakojima Island, Okinawa, Japan].

    PubMed

    Nakamura, Kei; Shinzato, Takashi

    2015-03-01

    Tsutsugamushi disease (Scrub thyphus) has been reported from all over Japan except the Hokkaido area. In Okinawa, only one patient was reported in 2001, who was infected outside Okinawa Prefecture. The first case infected in Okinawa was reported at Miyakojima Island in 2008. We report herein on the second case diagnosed in 2010, and the third and fourth in 2011, and all three patients were suspected to have been infected at Ikemajima Island adjacent to the island of Miyakojima. The patients recovered without any severe complications after antibiotic therapy with tetracyclines. We should take Tsutsugamushi disease into consideration in the differential diagnosis for a patient with fever, skin rash, and/or eschar even in the Okinawa area. Implementation of appropriate information and education about the disease should be carried out for local residents and tourists.

  17. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    PubMed

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  18. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan

    PubMed Central

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J.; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands. PMID:26513585

  19. Mid to late Holocene sea-surface temperature reconstruction using fossil corals from Kume Island, Ryukyu, Japan

    NASA Astrophysics Data System (ADS)

    Seki, A.; Yokoyama, Y.; Suzuki, A.; Kawakubo, Y.; Okai, T.; Miyairi, Y.; Matsuzaki, H.; Namizaki, N.; Kan, H.

    2012-12-01

    The relative warmth and stability of the Holocene was punctuated by several brief cold events. Although these cold events on a global scale are widely reported, the lack of records from regions such as the East China Sea (ECS) results in an incomplete understanding of the underlying cooling mechanism. Late Quaternary climate anomaly, at around 4.2 ka evidence found in elsewhere, is a time of such abrupt climate change, and mechanisms of this event have not been understood. Here, we present a coral-based paleo-SST (sea-surface temperature) reconstruction from the ECS to unveil Holocene variability in strength of the Kuroshio Western Boundary Current and the East Asian Monsoon (EAM). Our new data confirm that cold conditions prevailed at 3.8 cal kyr BP, and were started after 4.5 cal kyr BP. The timing of this cold event is consistent with previously reported Pulleniatina Minimum Event (PME, 4.5-3.0 ka) (e.g., Ujiié and Ujiié, 1999). While PME had not been resolved seasonality, our high-resolution data clearly indicate a different seasonal response of summer and winter SST . This result provides an important insight into the mechanism of the millennium scale cold event in the ECS, where the region affected by EAM (Seki et al., 2012).

  20. Japan.

    PubMed

    1987-02-01

    Japan is composed of 4 main islands and more than 3900 smaller islands and has 317.7 persons/square kilometer. This makes it one of the most densely populated nations in the world. Religion is an important force in the life of the Japanese and most consider themselves Buddhists. Schooling is free through junior high but 90% of Japanese students complete high school. In fact, Japan enjoys one of the highest literacy rates in the world. There are over 178 newspapers and 3500 magazines published in Japan and the number of new book titles issued each year is greater than that in the US. Since WW1, Japan expanded its influence in Asia and its holdings in the Pacific. However, as a direct result of WW2, Japan lost all of its overseas possessions and was able to retain only its own islands. Since 1952, Japan has been ruled by conservative governments which cooperate closely with the West. Great economic growth has come since the post-treaty period. Japan as a constitutional monarchy operates within the framework of a constitution which became effective in May 1947. Executive power is vested in a cabinet which includes the prime minister and the ministers of state. Japan is one of the most politically stable of the postwar democracies and the Liberal Democratic Party is representative of Japanese moderate conservatism. The economy of Japan is strong and growing. With few resources, there is only 19% of Japanese land suitable for cultivation. Its exports earn only about 19% of the country's gross national product. More than 59 million workers comprise Japan's labor force, 40% of whom are women. Japan and the US are strongly linked trading partners and after Canada, Japan is the largest trading partner of the US. Foreign policy since 1952 has fostered close cooperation with the West and Japan is vitally interested in good relations with its neighbors. Relations with the Soviet Union are not close although Japan is attempting to improve the situation. US policy is based on

  1. Multiple invasions of the Ryukyu Archipelago by Oriental frogs of the subgenus Odorrana with phylogenetic reassessment of the related subgenera of the genus Rana.

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Ota, Hidetoshi; Tanaka-Ueno, Tomoko

    2005-12-01

    The genus Rana, notably diversified in Oriental regions from China to Southeast Asia, includes a group of cascade frogs assigned to subgenera Odorrana and Eburana. Among them, R. ishikawae and the R. narina complex represent the northernmost members occurring from Taiwan to the Ryukyu Archipelago of Japan. Relationships of these frogs with the continental members, as well as the history of their invasions to islands, have been unclear. The taxonomic status of Odorrana and related genera varies among authors and no phylogenetic reassessment has been done. Using partial sequences of mitochondrial 12S and 16S rRNA genes, we estimated phylogenetic relationships among 17 species of the section Hylarana including Odorrana and Eburana, and related species from the Ryukyus, Taiwan, China, Thailand, Malaysia, and Indonesia. We estimate that (1) Odorrana is monophyletic and encompasses species of Eburana and R. hosii, which is now placed in Chalcorana, (2) the ancestor of R. ishikawae separated from other Rana in the middle to late Miocene prior to its entry to the Ryukyu Archipelago, (3) the ancestor of the R. narina complex later diversified in continental Asia, and invaded the Ryukyu Archipelago through Taiwan, (4) the R. narina complex attained its current distribution within the Ryukyus through niche segregations, and (5) vicariance of R. hosii between Malay Peninsula and Borneo occurred much later than the divergence events in the R. narina complex. Current subgeneric classification of Rana, at least of Southeast Asian members, requires full reassessment in the light of phylogenetic relationships.

  2. Exceptional minute sex-specific region in the X0 mammal, Ryukyu spiny rat.

    PubMed

    Kobayashi, Tsuyoshi; Yamada, Fumio; Hashimoto, Takuma; Abe, Shintaro; Matsuda, Yoichi; Kuroiwa, Asato

    2007-01-01

    The Ryukyu spiny rats (genus Tokudaia) inhabit only three islands in the Nansei Shoto archipelago in Japan, and have the variations of karyotype among the islands. The chromosome number of T. osimensis in Amami-Oshima Island is 2n = 25, and T. tokunoshimensis in Tokunoshima Island is 2n = 45, and the two species have X0 sex chromosome constitution with no cytogenetically visible Y chromosome in both sexes. We constructed the standard ideograms for these species at the 100 and 200 band levels. Comparing the banding patterns between these species, it was suggested that at least 10 times the number of Robertsonian fusions occurred in T. osimensis chromosomes. However, no karyotypic differences were observed between sexes in each species. To detect the sex-specific chromosomal region of these X0 species we applied the comparative genomic hybridization (CGH) method. Although the male- and female-derived gains and losses were detected in several chromosome regions, all of them were located in the heterochromatic and/or telomeric regions. This result suggested that the differences detected by CGH might be caused by the polymorphism on the copy numbers of repeated sequences in the heterochromatic and telomeric regions. Our result indicated that the sex-specific region, where the key to sex determination lies, is very minute in X0 species of Tokudaia.

  3. Magma Genesis of Sakurajima, the Quaternary post- Aira caldera volcano, southern Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Suzuki, J.; Yoshikawa, M.; Kobayashi, T.; Miki, D.; Takemura, K.

    2012-12-01

    Sakurajima volcano is the Quaternary post-caldera volcano of Aira caldera, which was caused by the eruption of huge amount of silicic pyroclastics, situated on Ryukyu arc, southern Kyushu Island, Japan. This volcano is quite active, so it can be considered that the preparation of next caldera-forming eruption with huge amount of silicic magma is proceeding. It is, therefore, expected that the investigation of magma genesis of Sakurajima volcano give us information for the mechanism generating huge amount of silicic magma, which cause the caldera formation. We analyzed major and trace elements with Sr, Nd and Pb isotopic compositions of volcanic rocks from Sakurajima volcano. We sampled (ol) - opx - cpx - pl andesite and dacite from almost all the volcanic units defined by Fukuyama and Ono (1981). In addition to Sakurajima samples, we also studied basaltic rocks erupted at pre-caldera stage of the Aira caldera to estimate the primary magma of Sakurajima volcano. Major and trace element variations generally show linear trends on the Harker diagrams, with the exception of P2O5 and TiO2. Based on the trend of P2O5 vs.SiO2, we divided studied samples low-P (P2O5 < 0.15 wt. %) and high-P (P2O5 > 0.15 wt. %) groups and these groups also display two distinct trends on TiO2-SiO2 diagram. The composition of trace elements shows typical island arc character as depletion of Nb and enrichments of Rb, K and Pb, suggesting addition of aqueous fluids to the mantle wedge. The Zr and Nb concentrations make a liner trend (Zr/Nb = 27) and this trend across from tend of MORB (Zr/Nb = 35) to that of crustal materials (Zr/Nb=17). The Sr, Nd and Pb isotopic compositions broadly plot to on the mixing curve connecting MORB-type mantle and sediments of the Philippine Sea Plate, indicating that the primary magma was generated by partial melting of MORB-type mantle wedge, which was hydrated with fluids derived from the subducted Philippine Sea sediments. But we found that our data plot apart

  4. Numerical analysis of the paleotsunami sizes through simulation of a large coralline boulder movement at Ishigaki Island, Japan

    NASA Astrophysics Data System (ADS)

    Hisamatsu, A.; Goto, K.; Imamura, F.

    2013-12-01

    Sakishima Islands (southern Ryukyu Islands), Japan, have been frequently affected by large tsunamis through the historical ages. The AD1771 Meiwa tsunami was an extreme event and the run-up height was ~30 m in maximum. The source model of the AD1771 Meiwa tsunami is still controversial: (1) earthquake plus landslide, (2) tsunami earthquake, and (3) splay fault models. The islands were also affected by the prehistoric tsunamis according to the geological evidence. For example, numerous coral boulders that were transported by paleotsunamis, including AD1771 event, were reported at the islands. The corals that constitute the boulders had once lived in the coral reefs fringing the islands and died when they were cast ashore to the land. Therefore, it is possible to estimate the timing of their deposition by using radiocarbon dating technique. In fact, the radiocarbon dating of Porites tsunami boulders at Sakishima Islands indicates that tsunamis had occurred repeatedly within a 150-400 years interval. However, the sizes of each tsunami are still uncertain. Hence, an important question has remained: whether there were any tsunami(s) in the past that were equivalent or larger in size comparing with the AD1771 Meiwa tsunami. In this study, we numerically investigated the transportation of a very large paleotsunami boulder at the southeastern part of Ishigaki Island, one of Sakishima Islands, using a boulder transport model in order to evaluate the sizes of paleotsunamis prior to the AD1771 event. The boulder that we used is called 'tsunami ufu-ishi' and it is the largest coralline boulder (>500 t) in Ishigaki Island. It is deposited approx. 100 m from the shoreline and 10 m in elevation. It was probably transported from the coral reef by the tsunami around 2000 years ago according to the radiocarbon dating. However, it is not necessarily that the boulder reached its present position due to one tsunami event 2000 years ago. In fact, according to the paleomagnetic analysis

  5. Distinct Phylogeographic Structures of Wild Radish (Raphanus sativus L. var. raphanistroides Makino) in Japan

    PubMed Central

    Han, Qingxiang; Higashi, Hiroyuki; Mitsui, Yuki; Setoguchi, Hiroaki

    2015-01-01

    Coastal plants with simple linear distribution ranges along coastlines provide a suitable system for improving our understanding of patterns of intra-specific distributional history and genetic variation. Due to the combination of high seed longevity and high dispersibility of seeds via seawater, we hypothesized that wild radish would poorly represent phylogeographic structure at the local scale. On the other hand, we also hypothesized that wild radish populations might be geographically differentiated, as has been exhibited by their considerable phenotypic variations along the islands of Japan. We conducted nuclear DNA microsatellite loci and chloroplast DNA haplotype analyses for 486 samples and 144 samples, respectively, from 18 populations to investigate the phylogeographic structure of wild radish in Japan. Cluster analysis supported the existence of differential genetic structures between the Ryukyu Islands and mainland Japan populations. A significant strong pattern of isolation by distance and significant evidence of a recent bottleneck were detected. The chloroplast marker analysis resulted in the generation of eight haplotypes, of which two haplotypes (A and B) were broadly distributed in most wild radish populations. High levels of variation in microsatellite loci were identified, whereas cpDNA displayed low levels of genetic diversity within populations. Our results indicate that the Kuroshio Current would have contributed to the sculpting of the phylogeographic structure by shaping genetic gaps between isolated populations. In addition, the Tokara Strait would have created a geographic barrier between the Ryukyu Islands and mainland Japan. Finally, extant habitat disturbances (coastal erosion), migration patterns (linear expansion), and geographic characteristics (small islands and sea currents) have influenced the expansion and historical population dynamics of wild radish. Our study is the first to record the robust phylogeographic structure in wild

  6. Distinct Phylogeographic Structures of Wild Radish (Raphanus sativus L. var. raphanistroides Makino) in Japan.

    PubMed

    Han, Qingxiang; Higashi, Hiroyuki; Mitsui, Yuki; Setoguchi, Hiroaki

    2015-01-01

    Coastal plants with simple linear distribution ranges along coastlines provide a suitable system for improving our understanding of patterns of intra-specific distributional history and genetic variation. Due to the combination of high seed longevity and high dispersibility of seeds via seawater, we hypothesized that wild radish would poorly represent phylogeographic structure at the local scale. On the other hand, we also hypothesized that wild radish populations might be geographically differentiated, as has been exhibited by their considerable phenotypic variations along the islands of Japan. We conducted nuclear DNA microsatellite loci and chloroplast DNA haplotype analyses for 486 samples and 144 samples, respectively, from 18 populations to investigate the phylogeographic structure of wild radish in Japan. Cluster analysis supported the existence of differential genetic structures between the Ryukyu Islands and mainland Japan populations. A significant strong pattern of isolation by distance and significant evidence of a recent bottleneck were detected. The chloroplast marker analysis resulted in the generation of eight haplotypes, of which two haplotypes (A and B) were broadly distributed in most wild radish populations. High levels of variation in microsatellite loci were identified, whereas cpDNA displayed low levels of genetic diversity within populations. Our results indicate that the Kuroshio Current would have contributed to the sculpting of the phylogeographic structure by shaping genetic gaps between isolated populations. In addition, the Tokara Strait would have created a geographic barrier between the Ryukyu Islands and mainland Japan. Finally, extant habitat disturbances (coastal erosion), migration patterns (linear expansion), and geographic characteristics (small islands and sea currents) have influenced the expansion and historical population dynamics of wild radish. Our study is the first to record the robust phylogeographic structure in wild

  7. Forearc deformation and megasplay fault system of the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Hsu, S.; Yeh, Y.; Sibuet, J.; Tsai, C.; Doo, W.

    2011-12-01

    A great tsunami caused by a subduction earthquake had struck south Ryukyu islands and killed ~12000 people in 1771. Here we report the existence of a megasplay fault system along the south Ryukyu forearc. Analyses of deep multi-channel seismic reflection profiles indicate that the megasplay fault system is rising from the summit of a ~1 km high mount sitting on a ~5° landward dipping subducted plate interface. The fault system has accumulated large strain as evidenced by the active and widespread normal faults in the inner wedge. The along-trench length of the megasplay fault system is estimated to be ~450 km. The origin of this south Ryukyu megasplay fault system is linked to the subduction of elevated ridges parallel to the fracture zones. In contrast, no similar splay fault system is found in the west of 125. 5°E where the oblique subduction has produced shear zones along the south Ryukyu forearc. We infer that the megasplay fault system is responsible for the 1771 south Ryukyu tsunami. Likewise, after a quiescence of ~240 years, a near-future great earthquake and tsunami is anticipated as the extensional feature is strongly widespread over the south Ryukyu forearc.

  8. Multivariate analysis of mandible in the Ryukyu wild pig (Sus scrofa riukiuanus).

    PubMed

    Endo, H; Kurohmaru, M; Hayashi, Y; Ohsako, S; Matsumoto, M; Nishinakagawa, H; Yamamoto, H; Kurosawa, Y; Tanaka, K

    1998-06-01

    We measured adult mandibles of Ryukyu wild pig (Sus scrofa riukiuanus) from Tokunoshima Island and compared the osteometrical data with those from six Nansei Islands. The mandibles in Tokunoshima Island were larger than those from Amami-Oshima and Okinawa Islands in some measurements. We concluded that the size cline was not statistically recognized among populations. In the principal component analysis, the size cline was also denied, and the separation could be made among island populations in female. It is suggested that the populations in Tokunoshima and Okinawa Islands may be different from those in Amami-Oshima, Kakeroma, Ishigaki and Iriomote Islands in skull proportion.

  9. Mosquito Species Composition and Plasmodium vivax Infection Rates on Baengnyeong-do (Island), Republic of Korea

    DTIC Science & Technology

    2011-09-01

    mosquitoes of Japan (including the Ryukyu Archipelago and the Ogasawara Islands ) and Korea (Diptera: Culicidae). Con­ trib Am Entomol Inst 1979; 16: 1­987...north, other species are frequently more common [4,12] and may play a greater role in malaria transmission. Baengnyeong­do is a 45.8 km2 island ...located near the North­ ern Limit Line (Fig. 1). This island is the westernmost point of the ROK, and is 16 km from the DPRK coast. As such, ento­

  10. Souther portion of Island of Kyushu, Japan, as seen from the Apollo 7

    NASA Technical Reports Server (NTRS)

    1968-01-01

    City of Kagoshima and Kagoshima Bay area of the southern portion of the island of Kyushu, Japan, as seen from the Apollo 7 spacecraft during its 9th revolution of the earth. Photographed from an altitude of 125 nautical miles, at ground elapsed time of 12 hours and 10 minutes.

  11. Holocene reef associated carbonate sediments and their Pleistocene counterparts, Miyako Islands, Ryukyus, southwest of Japan

    SciTech Connect

    Tsuji, Yoshihiro; Tsuneo Yamamura; Toshio Kodato; Hisao Sunouchi; Tomoya Yuki

    1988-02-01

    Holocene carbonate sedimentary facies distribution, from sea level to shelf slope about 1,000 m in depth, and its relationship to bathymetry, off Miyako Island, Ryukyus, southwest of Japan were clarified by surveys with sidescan sonar, sparker, uniboom, sea-bottom camera, and sediment sampler.

  12. Verrucostoma, a new genus in the Bionectriaceae from the Bonin Islands, Japan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verrucostoma freycinetiae gen. et sp. nov. collected on dead leaves of Freycinetia boninensis (Pandanaceae) in Hahajima, Bonin (Ogasawara) Islands, Tokyo, Japan, is described and illustrated. The new genus is characterized by having pale orange perithecia with protuberances around the perithecial ap...

  13. Mysidella hoshinoi, a new species from Izu-Oshima Island, Japan (Crustacea, Mysidae, Mysidellinae)

    PubMed Central

    Shimomura, Michitaka

    2016-01-01

    Abstract A new mysid, Mysidella hoshinoi sp. n. is described from Izu-Oshima Island, Sagami Sea, central Japan. This species differs from its congeners in having a posterodorsal finger-like papilla on the eyestalk, five peculiar spines terminating in plumed seta on outer margin of carpopropodus of endopod of first thoracopod, and uropodal endopod bearing 27 spines on inner margin. PMID:27853405

  14. Subterranean electrical structure of Kozu-shima volcanic island, Japan.

    PubMed

    Orihara, Yoshiaki; Kamogawa, Masashi; Takeuchi, Akihiro; Fukase, Hiroaki; Nagao, Toshiyasu

    2010-01-01

    Following the electric current injection experiment carried out in 2009, a VLF-MT (Very Low Frequency Magnetotelluric) survey has been conducted in Kozu-shima Island to obtain further information on the subterranean electrical structure that might help understanding the results of our monitoring of geoelectric potentials. A number of VAN-type pre-seismic geoelectric potential anomalies were observed in 1997-2000, even showing a remarkable "Selectivity". However, similar pre-seismic anomalies were not observed during the Izu-Island volcano-seismic swarm 2000. All these observations would require extremely high degree of heterogeneity in the subterranean electrical structure of the volcanic island and its possible time changes. Several correlations between the results of this survey and the volcanic geology of the island and ground water distribution were found. Further investigation is needed for a complete explanation of the observed phenomena.

  15. Cockroach fauna in the Ogasawara Chain Islands of Japan and analysis of their habitats.

    PubMed

    Komatsu, Noriyuki; Kishimoto, Toshio; Uchida, Akihiko; Ooi, Hong-Kean

    2013-03-01

    A survey of cockroach fauna was carried out on the 3 inhabited islands of the Ogasawara chain island of Japan, namely, Chichijima island, Hahajima island and Iwo island. Seven species, namely, Periplaneta americana (Linnaeus, 1758), Periplaneta australasiae (Fabricius, 1775), Blattella lituricollis (Walker, 1868), Onychostylus vilis (Brunner von Wattenwyl, 1865), Supella longipalpa (Fabricius, 1798), Pycnoscelus surinamensis (Linnaeus, 1758) and Opisthoplatia orientalis (Burmeister, 1838), were collected on Chichijima island. Four species, namely, P. americana, P. australasiae, O. vilis and P. surinamensis were collected on Hahajima island and 6 species, namely, P. americana, P. australasiae, B. lituricollis, O. vilis, P. surinamensis and Neostylopyga rhombifolia were collected on Iwo island. This is the first record of N. rhombifolia and Onychostylus orientalis on the Ogasawara chain islands. Our study increases the recorded taxon of cockroaches on the Ogasawara from 3 families, 5 genera 10 species to 4 families, 7 genera, 12 species. A list of the cockroach species on Ogasawara islands reported to date as well as a key for their identification is also presented. Periplaneta americana and P. australasiae, being the dominant species, together with S. longipalpa, were collected mostly in the indoor environment, indicating their preference for this habitat. Pycnoscelus surinamensis, which is considered as an outdoor insect has been found in semi-household environments such as greenhouse and shed, indicating their new adaptation to the changing environment.

  16. Comparative chromosome painting map between two Ryukyu spiny rat species, Tokudaia osimensis and Tokudaia tokunoshimensis (Muridae, Rodentia).

    PubMed

    Nakamura, Taro; Kuroiwa, Asato; Nishida-Umehara, Chizuko; Matsubara, Kazumi; Yamada, Fumio; Matsuda, Yoichi

    2007-01-01

    Ryukyu spiny rats (genus Tokudaia) are indigenous species that are confined to three islands of the Nansei Shoto archipelago, Amami-Oshima, Tokunoshima and Okinawa-jima, Japan. Tokudaia tokunoshimensis from Tokunoshima Island and Tokudaia osimensis from Amami-Oshima Island are closely related taxonomically, although their karyotypes are quite different: the diploid chromosome numbers and sex chromosome constitution are 2n=45, X0/X0 for T. tokunoshimensis and 2n=25, X0/X0 for T. osimensis. We conducted comparative chromosome painting with chromosome-specific DNA probes of the laboratory mouse (Mus musculus) to molecularly examine the chromosome homology between T. tokunoshimensis and T. osimensis, and deduced a possible ancestral karyotype of Tokudaia species and the process of evolutionary chromosome rearrangements. The proposed ancestral karyotype with the diploid number of 2n=48, XX/XY was similar to the karyotype of T. tokunoshimensis, and the karyotype of T. osimensis would then have been established through at least 14 chromosomal changes, mainly centric fusion and tandem fusion, from the ancestral karyotype. The close karyological relationship between the ancestral karyotypes of Tokudaia and Apodemus also suggests that the chromosomal evolution in the Tokudaia-Apodemus lineage has been very slow and has accelerated only recently in the branch leading to T. osimensis.

  17. Blood meal identification and feeding habits of uranotaenia species collected in the ryukyu archipelago.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako

    2014-09-01

    To know the blood meal in the stomach of Uranotaenia species, blood-fed mosquitoes were collected by 4 methods at different sites in the mountain forest of 3 islands, Amamioshima, Okinawajima, and Iriomotejima in the Ryukyu Archipelago, Japan from 2005 to 2012. One hundred twenty-four blood-fed Uranotaenia mosquitoes of 7 species (Ur. jacksoni, nivipleura, ohamai, yaeyamana, annandalei, lateralis, and macfarlanei) were collected. The collection rates are 0.26, 0.6, 0.31, and 0.66 by black light trap, black light blue with dry ice trap, frog call trap, and sweeping net, respectively. The blood meals of 107 females (86.3%) were successfully identified by a polymerase chain reaction-based method. All Uranotaenia species fed on cold-blooded animals, especially amphibians (99.1%), and notably on frogs. They would feed readily on available frogs in a given region having no close connection with the breeding (calling) season of each frog. They also fed on reptiles (0.9%), but not on warm-blooded animals.

  18. A mega-splay fault system and tsunami hazard in the southern Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Hsu, Shu-Kun; Yeh, Yi-Ching; Sibuet, Jean-Claude; Doo, Wen-Bin; Tsai, Ching-Hui

    2013-01-01

    In April 1771, a subduction earthquake generated a great tsunami that struck the south Ryukyu islands and killed ˜12,000 people, whereas its mechanism is still enigmatic (Nakata and Kawana, 1995; Nakamura, 2006; Matsumoto et al., 2009). In this paper, we show its probable source on a mega-splay fault system existing along the southern Ryukyu forearc. Analyses of deep multi-channel seismic reflection profiles indicate that the mega-splay fault system is rising from the summit of a ˜1 km high ridge situated at a ˜5° landward dipping plate interface. An outer ridge marks the seafloor outcrop of the splay fault system and separates the landward inner wedge and the oceanward outer wedge. The inner wedge is uplifting and exhibits widespread normal faulting while the outer wedge shows folded structures. The mega-splay fault system is parallel to the Ryukyu Trench east of 125.5°E and is estimated to be ˜450 km long. The origin of this south Ryukyu mega-splay fault system is ascribed to a resistant subduction of the elevated transverse ridges associated with the subducting portion of the trench-parallel Luzon-Okinawa Fracture Zone. In contrast, no similar splay fault is found west of 125.5°E where the oblique subduction has produced large shear zones along the south Ryukyu forearc. We infer that a thrust earthquake linked to the mega-splay fault system is responsible for the south Ryukyu tsunami. However, another possible scenario of generating a large tsunami affecting the south Ryukyu islands is that the subducted ridge in the western end of the mega-splay fault system nucleated a large earthquake and simultaneously triggered the ˜100 km long E-W trending strike-slip fault west of 125.5°E and induced a southward-dipping tsunami-genic subsidence. In any case, after a quiescence of ˜241 yr, a large earthquake and tsunami is anticipated in the south Ryukyu forearc in the near future.

  19. Detailed analysis of Japanese population substructure with a focus on the southwest islands of Japan.

    PubMed

    Nishiyama, Takeshi; Kishino, Hirohisa; Suzuki, Sadao; Ando, Ryosuke; Niimura, Hideshi; Uemura, Hirokazu; Horita, Mikako; Ohnaka, Keizo; Kuriyama, Nagato; Mikami, Haruo; Takashima, Naoyuki; Mastuo, Keitaro; Guang, Yin; Wakai, Kenji; Hamajima, Nobuyuki; Tanaka, Hideo

    2012-01-01

    Uncovering population structure is important for properly conducting association studies and for examining the demographic history of a population. Here, we examined the Japanese population substructure using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC), which covers all but the northern region of Japan. Using 222 autosomal loci from 4502 subjects, we investigated population substructure by estimating F(ST) among populations, testing population differentiation, and performing principal component analysis (PCA) and correspondence analysis (CA). All analyses revealed a low but significant differentiation between the Amami Islanders and the mainland Japanese population. Furthermore, we examined the genetic differentiation between the mainland population, Amami Islanders and Okinawa Islanders using six loci included in both the Pan-Asian SNP (PASNP) consortium data and the J-MICC data. This analysis revealed that the Amami and Okinawa Islanders were differentiated from the mainland population. In conclusion, we revealed a low but significant level of genetic differentiation between the mainland population and populations in or to the south of the Amami Islands, although genetic variation between both populations might be clinal. Therefore, the possibility of population stratification must be considered when enrolling the islander population of this area, such as in the J-MICC study.

  20. Laboratory experiments and observations of cyclonic and anticyclonic eddies impinging on an island

    NASA Astrophysics Data System (ADS)

    Andres, Magdalena; Cenedese, Claudia

    2013-02-01

    experiments are conducted to investigate the interactions of self-propagating barotropic cyclones and baroclinic anticyclones with an island. Results are interpreted in the context of observations around Okinawa Island, Japan, where ubiquitous arrivals of cyclones and anticyclones on the southeastern side of the island influence the flow around it, thereby impacting both the Ryukyu Current's and the Kuroshio's transport. In the laboratory, baroclinic anticyclones generate a buoyant current that flows clockwise around an island whereas barotropic cyclones generate a counterclockwise current. In both cases, the interaction is governed by conservation of circulation Γ around the island, which establishes a balance between the dissipation along the island in contact with the eddy and the dissipation along the island in contact with the generated current. Laboratory results and scaling analysis suggest that the interaction between an anticyclone (cyclone) and Okinawa Island should result in an instantaneous increase (decrease) of the Ryukyu Current transport and a delayed increase (decrease) of the Kuroshio transport. The estimated delays are in good agreement with those obtained with field measurements suggesting that the dynamics at play in the laboratory may be relevant for the flow around Okinawa Island.

  1. The 1768 and 1791 Okinawa tsunamis in the Ryukyu Trench region

    NASA Astrophysics Data System (ADS)

    Nakamura, M.

    2013-12-01

    Risk of the great earthquakes and tsunamis has been assumed to be low in the Ryukyu Trench because the interplate coupling is weak and great interplate earthquakes (> M8.0) had not been recorded historically for about 300 years. However, recent study revealed that the 1771 Yaeyama earthquake (M8.5 from tsunami heights distribution) at south Ryukyu Trench and the 1911 Kikaijima earthquake (M 8.0) at north-central Ryukyu Trench were the interplate earthquakes. We need re-examine the great historical earthquakes in the Ryukyu Trench. Two historical tsunamis which occurred on 1768 and 1791 in the Okinawa Island were documented in the old document 'Kyuyo' (formal chronicles of Ryukyu). I investigated the source fault model of two tsunami events using numerical simulations of tsunami and earthquake shaking, and showed that their events would be the interplate earthquakes. One earthquake occurred at noon of July 22th, 1768. The rock-walls of castle, grave of royal family were collapsed by the earthquake shaking around Naha, Okinawa Island. After the shaking, tsunami arrived Naha port and Zamami Island, which is west of Okinawa Island. Recorded tsunami heights were about 1 m at Naha port. Nine houses and rice fields were damaged by the inundation of the tsunami in the Zamami Island. Estimated tsunami heights were 4 and 5 m in the villages of the Zamami Island. The numerical modeling of tsunami and the estimation of earthquake shaking using empirical formula were employed, and the fault parameters of the 1768 earthquake were estimated. The faults were set to Okinawa Trough (M7.5 normal faults), southwest of Okinawa island (M7.5 normal faults), southwest of Okinawa island (M7.5 reverse fault), and Ryukyu Trench (M8.0 thrust faults). The computed tsunami heights and intensities of the ground shaking of the M7.5 reverse fault near the Zamami Island and the M8.0 interplate earthquake models are consistent with to the recorded ones. Another tsunami was also recorded in the

  2. Chikungunya Fever in Japan Imported from the Caribbean Islands.

    PubMed

    Imai, Kazuo; Nakayama, Eri; Maeda, Takuya; Mikita, Kei; Kobayashi, Yukiko; Mitarai, Aoi; Honma, Yasuko; Miyake, Satoru; Kaku, Koki; Miyahira, Yasushi; Kawana, Akihiko

    2016-01-01

    A 53-year-old Japanese woman who was working as a volunteer in the Commonwealth of Dominica in the Caribbean islands presented with a high-grade fever and severe incapacitating generalized arthralgia. The Asian genotype of the chikungunya virus was confirmed using reverse transcription-PCR and serology, based on the presence of a specific neutralization titer and immunoglobulin M antibodies. She was diagnosed with post-chikungunya chronic arthritis based on persistence of her polyarthritis for 3 months and the presence of rheumatoid factor, immunoglobulin G-rheumatoid factor, and matrix metalloproteinase-3. Chikungunya virus should be considered as a causative pathogen in travelers returning from Caribbean islands. Clinicians should consider chikungunya fever in the differential diagnosis of patients who complain of chronic arthritis and have a history of travel to an endemic area.

  3. Contamination status and spatial distribution of organochlorine compounds in fishes from Nansei Islands, Japan.

    PubMed

    Malarvannan, Govindan; Takahashi, Shin; Ikemoto, Tokutaka; Isobe, Tomohiko; Kunisue, Tatsuya; Sudaryanto, Agus; Miyagi, Toshihiko; Nakamura, Masaru; Yasumura, Shigeki; Tanabe, Shinsuke

    2011-01-01

    Two species of fishes (n=52; tilapia and mullet) from industrialized and urbanized areas of Okinawa Island (Manko-Noha river, Hija river and Shikaza river) and from a remote area of Ishigaki Island (Anparu mudflat), Japan were collected between August 2005 and July 2006, and analyzed for five organochlorine compounds (OCs), viz., DDTs, PCBs, CHLs, HCHs and HCB. Concentrations and the contamination patterns of OCs in fishes varied between locations. Considerable residue levels of OCs, especially CHLs and DDTs were found in both fishes from the main Okinawa Island. These levels were relatively higher than the reported values for seafood from Japanese coasts, indicating that even now pollution sources of these contaminants still exist in this region. On the other hand, lower concentrations of OCs were detected in fishes from Ishigaki Island waters than those of other Japanese coastal waters, suggesting that this region is less contaminated by OC contaminants.

  4. Millennial-scale variability in vegetation records from the East Asian Islands: Taiwan, Japan and Sakhalin

    NASA Astrophysics Data System (ADS)

    Takahara, Hikaru; Igarashi, Yaeko; Hayashi, Ryoma; Kumon, Fujio; Liew, Ping-Mei; Yamamoto, Masanobu; Kawai, Sayuri; Oba, Tadamichi; Irino, Tomohisa

    2010-10-01

    High-resolution pollen records from Taiwan, Japan and Sakhalin document regional vegetation changes during Dansgaard-Oeschger (D-O) cycles during the last glacial. During the period from the cold phase (GS 18/19) to warm phase (D-O 19), the biome shift from temperate conifer forest to cold/cool conifer forest in Japan and from subtropical forest to temperate deciduous/conifer forest in Taiwan. The vegetation in D-O 17, cool mixed forest in central Japan, temperate deciduous broadleaf forest in western Japan and subtropical forest in Taiwan, indicates warm condition but not wet in all area. These vegetation changes lead to biome shift from MIS (Marine Isotope Stage) 4 to MIS 3. The abundance of Cryptomeria japonica and Fagus crenata in D-O 12 and D-O 8 indicates wet conditions brought by the strong summer monsoon through the Islands and high snowfall brought by the inflow of the Tsushima Warm Current into the Sea of Japan. The registration of other D-O warming events in MIS 3, although reflected by shifts in the abundance of key species, is not sufficient to produce changes in biomes. Development of cold deciduous forest in HS (Heinrich events) 1 in Sakhalin, Hokkaido and central Japan was conspicuous and was much larger than that in YD. Vegetation response in YD was small scale and within the same biome in the East Asian Islands. In D-O 1 at the termination of the last glacial, the same taxa that developed in the early Holocene, cold evergreen needleleaf trees in northern region, temperate deciduous broadleaf trees in central and western Japan, and warm-temperate evergreen trees in Taiwan, increased.

  5. Melon fly, Bactrocera cucurbitae (Diptera: Tephritidae), infestation in host fruits in the Southwestern Islands of Japan before the initiation of Island-wide population suppression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern...

  6. Mosquito biosurveillance on Kyushu Island, Japan, with emphasis on Anopheles Hyrcanus Group and related species (Diptera: culicidae).

    PubMed

    Rueda, Leopoldo M; Pagac, Benedict; Iwakami, Masashiro; Spring, Alexandra R; Motoki, Mayasa T; Pecor, James E; Higa, Yukiko; Futami, Kyoko; Imanishi, Nozomi; Long, Lewis S; Debboun, Mustapha

    2014-01-01

    This report includes the distribution records of the Anopheles (Anopheles) Hyrcanus Group and associated species in Kyushu Island, Japan, based on our field collections from various localities of 4 prefectures (Fukuoka, Kumamoto, Nagasaki, Saga), primarily from 2002-2013. The status of common and potential mosquito vectors, particularly Anopheles species, in Japan are noted.

  7. The variations of long time period slow slip events along the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Tu, Y. T.; Heki, K.

    2014-12-01

    Slow slip events (SSEs) are a type of slow earthquakes that can be observed with Global Positioning System (GPS) networks in the world. Those events are detected on intensely coupled plate boundaries such as Cascadia subduction zone (Dragert et al., 2001), western North America, Mexico (Kostoglodov et al., 2003), Alaska (Ohta et al., 2007) and Tokai and Boso areas (Ozawa et al., 2002, 2003), central Japan and are considered to have relations to large subduction thrust earthquakes. However, in southwestern Ryukyu trench where most of researchers believe that it should be a decoupled plate boundary, SSEs recur regularly and are located at a patch that is as deep as 20 to 40 km (Heki and Kataoka, 2008). For comprehending the characteristics and time variations of SSEs in this area, the GEONET GPS data of 16 years are used in this study. During 1997 to 2014, more than thirty SSEs are identified near Hateruma Island, Ryukyu. The average recurrence interval is calculated to be 6.3 months and release seismic moment is Mw 6.6 on average. However, the values of recurrence interval are not invariable. From 1997 to 2002, interval period of SSEs is 7.5 months, but during 2002 to 2008, the interval period decreases suddenly to 5.5 months. After 2008, the value restores to 7.2 months again. Furthermore, the slip amount of SSEs in this area varies with time. From 1997 to 2002, the slip is 9.5 cm/year; and during 2002 to 2008, the value slightly increases to 10.5 cm/year. However, in 2008 to 2013, the slip drops to 6.6 cm/year, but accord to the trend of cumulative slip, the slip value would increase in 2014. Considering these data, we find the slip values increase conspicuously in 2002 and 2013. Coincidentally, one Mw 7.1 thrust earthquake occurred in 2002 and earthquake swarm activity started in the Okinawa trough approximately 50km north of the SSE patch. In 2013, another earthquake swarm activity occurred in nearly the same area as the 2002 activity. This suggests that the

  8. A new strikingly-colored species of the genus Galathea Fabricius, 1793 (Crustacea: Decapoda: Anomura: Galatheidae) from the Ryukyu Islands, Japan.

    PubMed

    Osawa, Masayuki

    2015-11-06

    A new shallow-water squat lobster, Galathea ryuguu, is described on the basis of material obtained from a colony of unidentified sea fan of the genus Muricella Verrill, 1868. The new species is most closely allied to G. squamea Baba, 1979, but is distinguished by the ornamentation and armature of the carapace, third maxilliped, and ambulatory legs.

  9. A Revision of the Adult and Larval Mosquitoes of Japan (Including the Ryukyu Archipelago and the Ogasawara Islands) and Korea (Diptera: Culicidae)

    DTIC Science & Technology

    1979-01-01

    countries, due to the potential of this vector dis- persing to nonendemic geographical areas by the growing traffic between the Central and South Americas...principal vector of this disease from the available epidemiological and biologi- cal data (Mitamura 1933; Yamada 1934a, b, c), and later, this was...fossal and lateral areas, this varying according to direction of light ; apical and lateroapical tufts of long narrow erect white scales present; disk

  10. Cheilopallene ogasawarensis, a New Species of Shallow-Water Pycnogonid (Arthropoda: Pycnogonida) from the Ogasawara (Bonin) Islands, Japan, Northwest Pacific.

    PubMed

    Nakamura, Koichiro; Akiyama, Tadashi

    2015-08-05

    A new species of pycnogonid recorded from the shallow waters of Ogasawara (Bonin) Island, Japan, Cheilopallene ogasawarensis n. sp. is described, illustrated and compared with similar species. Cheilopallene ogasawarensis is only the third pycnogonid species recorded from these islands. Morphological characters clearly distinguish the new species from its geographically closest congener C. nodulosa Hong and Kim, 1987, also recorded from Japanese waters.

  11. Ribosomal DNA haplotype distribution of Bursaphelenchus xylophilus in Kyushu and Okinawa islands, Japan

    PubMed Central

    Nose, Mine; Miyahara, Fumihiko; Ohira, Mineko; Matsunaga, Koji; Tobase, Masashi; Koyama, Takao; Yoshimoto, Kikuo

    2009-01-01

    Ribosomal DNA region sequences (partial 18S, 28S and complete ITS1, 5.8S, and ITS2) of the pinewood nematode (Bursaphelenchus xylophilus) were obtained from DNA extracted directly from wood pieces collected from wilted pine trees throughout the Kyushu and Okinawa islands, Japan. Either a 2569bp or 2573bp sequence was obtained from 88 of 143 samples. Together with the 45 rDNA sequences of pinewood nematode isolates previously reported, there were eight single nucleotide polymorphisms and two indels of two bases. Based on these mutations, nine haplotypes were estimated. The haplotype frequencies differed among regions in Kyushu island (northwest, northeast and center, southeast, and southwest), and the distribution was consistent with the invasion and spreading routes of the pinewood nematode previously estimated from past records of pine wilt and wood importation. There was no significant difference in haplotype frequencies among the collection sites on Okinawa island. PMID:22736814

  12. The Role of Philippine Sea Plate to the Genesis of Quaternary Magmas of Northern Kyushu Island, Japan, Inferred from Along-Arc Geochemical Variations

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Yoshikawa, M.; Itoh, J.; Ujike, O.; Miyoshi, M.; Takemura, K.

    2013-12-01

    Quaternary volcanoes on Kyushu Island comprise volcanoes Himeshima, Futagoyama, Yufu-Tsurumi, Kuju, Aso, Kirishima and Sakurajima from north to south alongstrike the volcanic front. Adakitic lavas are observed from Yufu-Tsurumi and Kuju volcanoes in northern Kyushu (Kita et al., 2001; Sugimoto et al., 2007), whereas no Quaternary adakites were observed at Aso (e.g., Hunter, 1998) and the volcanoes south of Aso along the entire Ryukyu arc. Sugimoto et al. (2007) suggested that the trace element and Sr, Nd, and Pb isotopic compositions of adakitic magmas from Yufu-Tsurumi volcano indicate derivation of the magmas by partial melting of the subducting PSP. In contrast, Zellmer et al. (2012) suggested that these adakites may have formed by fractional crystallization of mantle-derived mafic magmas within the garnet stability field in the crust. The Honshu-Kyushu arc transition is a particular favorable setting to address these controversial models for the origin of the adakitic lavas, because of the potential relationship between the PSP materials and the alongstrike variation of the lava chemistry. The Palau-Kyushu ridge divides the oceanic crust of the PSP into northeastern and southwestern segments with ages of 26-15 (Shikoku Basin) and 60-40 Ma (West Philippine Basin), respectively (Mahony et al., 2011). Although there are no clear plate images beneath northern Kyushu, the northern extension of the Palau-Kyushu ridge potentially corresponds to the boundary between the SW Japan and Ryukyu arcs. If adakite genesis was related to the subducted slab rather than the overlying crust, then the spatial distribution of Quaternary adakites should correlate with the age of the subducted PSP. In order to test such correlation and elucidate the petrogenesis of the northern Kyushu adakites, we compiled major and trace elements and Sr-Nd-Pb isotope ratios from volcanoes along the arc front that includes the transition from adakitic to non-adakitic arc volcanism. Comprehensive

  13. Superconducting gravimeter observation for identifying slow slip events at Ryukyu Trench

    NASA Astrophysics Data System (ADS)

    Imanishi, Y.; Nawa, K.; Tamura, Y.; Ikeda, H.; Miyaji, T.; Tanaka, Y.

    2012-12-01

    Analysis of the data from the dense GPS network of Japan (GEONET) revealed quasi-periodic occurrences of long-term slow slip events at the Ryukyu Trench (Heki and Kataoka, 2008). The recurrence period of the events is about half a year, much shorter than typically found in other regions where slow slips are known to take place. Therefore, this region provides an interesting field for investigating the nature of slow slip events. In February 2012, we started gravity observation using a superconducting gravimeter (SG) at the VERA Ishigakijima Station, National Astronomical Observatory of Japan. The Ishigakijima island is located slightly east off the presumed fault area of the slow slip events. Our purpose is to detect gravity changes associated with the slow slip events by making full use of the high resolution of the SG. Of particular interest is the possible effect of water on the slow slip events, which might be identified from gravity observations. In addition to the SG, we installed an FG5 absolute gravimeter at the Iriomotejima island, located about 10 km west of the Ishigakijima island. The SG used in this study (serial number CT36) is the one which was in operation at the Inuyama Seismological Observatory, Nagoya University for about ten years. Before moving it to Ishigakijima, we made a thorough examination of the instruments. Because we found a serious problem in transferring liquid helium because of the ice inside, we warmed up the Dewar to initialize it. This not only solved the ice problem but also resulted in a significant decrease of the heater power for the gravity sensor. As of this writing, we have about six months worth of data from the SG. The condition of the gravimeter is good except for the first month when temperature control was unstable. Because of the ground vibrations caused by the movement of the 20-m VLBI antenna (about 30 m apart from the SG), the noise level is significantly enhanced compared with other domestic SG stations. Also we

  14. Science education in Elementary school by using of "Geopark", Oki Islands, Japan

    NASA Astrophysics Data System (ADS)

    Oku, S.; Matsumoto, I.

    2012-12-01

    The Oki islands are located at Japan sea coast side of southwest Japan and belonging to Shimane Prefecture. And there is rich Nature which is consist of mainly alkaline volcanic rocks and metamorphic rocks. Aiming at authorization "Geopark" authorization of Oki Islands, Geologist, Biologist, and residents of Oki Islands are doing investigation and advertisement. Promotion of the science education which utilized the precious Nature, or environmental education is very important in the viewpoint of the science literacy which can protect a Nature and the earth. In this presentation, we mainly propose activity at an elementary school about how to advance the science education by using of this precious Nature. Children learn about the geology which constitutes the ground, and its petro-genesis in the Science of the sixth grade of elementary school. The viewpoint of having been formed by volcano, Earthquake, etc, in long global time is important for the precious and beautiful geology which constitutes the ground. It is at the same time important for a global change to teach also about often doing serious damage to human beings or a living thing with an Earthquake, a volcano, tsunami, etc. That is, we can push (teaching beautiful geology and a precious living thing using "Geopark"), and can learn about the blessing and disaster of a Nature. Moreover, teaching materials and teaching tools like a local textbook or a signboard with which a teacher and a resident can teach them to a child are required.

  15. Lecanorchis tabugawaensis (Orchidaceae, Vanilloideae), a new mycoheterotrophic plant from Yakushima Island, Japan.

    PubMed

    Suetsugu, Kenji; Fukunaga, Hirokazu

    2016-01-01

    A new species, Lecanorchis tabugawaensis Suetsugu & Fukunaga, sp. nov. from Yakushima Island, Kagoshima Prefecture, Japan, is described and illustrated. Lecanorchis tabugawaensis is similar to Lecanorchis taiwaniana, but it is easily distinguished by the straight column, the glabrous status of the base of the column, the almost entire and narrow labellum morphology, the shorter part of the column fused with the labellum and the glabrous status of the apical part of the adaxial labellum surface. The new species appears to be restricted to two locations, each consisting of only dozens of mature individuals, and is assessed as Critically Endangered [CR D1] according to IUCN Red List Categories and Criteria.

  16. Cobitis takenoi sp. n. (Cypriniformes, Cobitidae): a new spined loach from Honshu Island, Japan

    PubMed Central

    Nakajima, Jun

    2016-01-01

    Abstract A new species of spined loach, Cobitis takenoi sp. n., is described based on the holotype and ten paratypes collected from Tango District, Honshu Island, Japan. The new species is distinguished by a combination of the following character states: 1) the lamina circularis at the base of the pectoral fin in adult male having a simple roundish plate form; 2) a narrowing of the upper segments of the first branched ray of the pectoral fin; 3) a short maxillary barbel whose length equals diameter of the eye; 4) 14 prepelvic myotomes, and 5) L3 and L5 well developed, forming longitudinal obvious stripes in males during the spawning season. PMID:27103876

  17. Lecanorchis tabugawaensis (Orchidaceae, Vanilloideae), a new mycoheterotrophic plant from Yakushima Island, Japan

    PubMed Central

    Suetsugu, Kenji; Fukunaga, Hirokazu

    2016-01-01

    Abstract A new species, Lecanorchis tabugawaensis Suetsugu & Fukunaga, sp. nov. from Yakushima Island, Kagoshima Prefecture, Japan, is described and illustrated. Lecanorchis tabugawaensis is similar to Lecanorchis taiwaniana, but it is easily distinguished by the straight column, the glabrous status of the base of the column, the almost entire and narrow labellum morphology, the shorter part of the column fused with the labellum and the glabrous status of the apical part of the adaxial labellum surface. The new species appears to be restricted to two locations, each consisting of only dozens of mature individuals, and is assessed as Critically Endangered [CR D1] according to IUCN Red List Categories and Criteria. PMID:27872560

  18. Epstein-Barr virus (EBV)-related oral squamous cell carcinoma in Okinawa, a subtropical island, in southern Japan--simultaneously infected with human papillomavirus (HPV).

    PubMed

    Higa, Mayumi; Kinjo, Takao; Kamiyama, Kazuya; Chinen, Katsuni; Iwamasa, Teruo; Arasaki, Akira; Sunakawa, Hajime

    2003-06-01

    Up to now, many authors have reported on the EBV infection and its carcinogenic importance in undifferentiated nasopharyngeal carcinoma (WHO classification, type III), but the infection of the virus in well differentiated oral squamous cell carcinoma has not been well described. We introduce the EBV-related well differentiated oral squamous cell carcinomas in Okinawa, a subtropical island in the southernmost part of Japan. This study aimed to clarify the pathogenesis of this malignancy in this area by carrying out analysis of the histology and the Epstein-Barr (EBV) and human papillomavirus (HPV) infection. In the Department of Oral Surgery, Ryukyu University Hospital Okinawa, 188 cases of oral malignant tumours were encountered from 1996 to 2000. The histopathological examination and the sequence analysis of LMP-1 carboxy terminal region and EBNA2 region of EBV were carried out, as were the analysis of virus subtypes, A and B, BamHI-F and f, and C and D. Additionally, HPV infection in the squamous cell carcinomas were demonstrated using E6 and E7 region primer sets by PCR method. In Okinawa, 94% (177/188) of the cases were squamous cell carcinomas. A surprisingly large number of EBV (72%) and HPV (78%) infections in the oral squamous cell carcinomas were demonstrated. EBV type B virus infection was found in 36% of EBV-related oral squamous cell carcinoma in Okinawa, but in only 2-5% of the mainland cases. In both regions the incidence of the BamHI- f variant infection was very low. The infected virus in 79 out of 80 (39 Okinawan and 41 mainland) cases was BamHI- F type. In Okinawa, the numbers of C and D variants were almost equal, whereas in the mainland the D variant was rare. Further, a 30 bp deletion in LMP-1 gene was frequently demonstrated in Okinawan and mainland cases of type A virus, but not in type B virus. Lastly, single nucleotide mutations in EBNA2 region of type A virus when compared with B95-8 strain were demonstrated in Okinawan cases. The

  19. Seismic structure of subducted Philippine Sea plate beneath the southern Ryukyu arc by receiver function and local earthquakes tomography

    NASA Astrophysics Data System (ADS)

    Nakamura, M.

    2012-12-01

    Seismic coupling of the Ryukyu subduction zone is assumed to be weak from the lack of historical interplate large earthquakes. However, recent investigation of repeating slow slip events (Heki & Kataoka, 2008), shallow low frequency earthquakes (Ando et al., 2012), and source of 1771 Yaeyama mega-tsunami (Nakamura, 2009), showed that the interplate coupling is not weak in the south of Ryukyu Trench. The biannually repeating SSEs (Mw=6.5) occur at the depth of 20-40 km on the upper interface of the subducted Philippine Sea plate beneath Yaeyama region, where earthquake swarm occurred on 1991 and 1992. To reveal the relation among the crustal structure, earthquake swarms, and occurrence of slow slip events (SSE), local earthquake tomography and receiver function (RF) analysis was computed in the southwestern Ryukyu arc. A tomographic inversion was used to determine P and S wave structures beneath Iriomote Island in the southwestern Ryukyu region for comparison with the locations of the SSE. The seismic tomography (Thurber & Eberhart-Phillips, 1999) was employed. The P- and S- wave arrival time data picked manually by Japan Meteorological Agency (JMA) are used. The 6750 earthquakes from January 2000 to July 2012 were used. For the calculation of the receiver function, the 212 earthquakes whose magnitudes are over 6.0 and epicentral distances are between 30 and 90 degrees were selected. The teleseicmic waveforms observed at two short-period seismometers of the JMA, and one broadband seismometer of F-net of National Research Institute for Earth Science and Disaster Prevention were used. The water level method (the water level is 0.01) is applied to original waveforms. Assuming that each later phase in a RF is the wave converted from P to S at a depth, I transformed the time domain RF into the depth domain one along each ray path in a reference velocity model. The JMA2001 velocity model is used in this study. The results of tomography show that the low Vp and high Vp

  20. Description of a new brown frog from Tsushima Island, Japan (Anura: Ranidae: Rana).

    PubMed

    Matsui, Masafumi

    2014-09-01

    Because all available evidence from allozymes, mtDNA sequences, and artificial hybridization suggests presence of high genetic differentiation between populations of East Asian brown frogs currently assigned to Rana dybowskii Günther, 1876, I compared morphological characters between specimens from Tsushima Island of Japan and Maritime territory of Russia. The population from Tsushima is slightly, but significantly different from R. dybowskii from Russia, including the holotype. I therefore consider the Tsushima population to be specifically distinct, and describe it as a new species R. uenoi. The new species also occurs in the Korean Peninsula and adjacent islands, but the distributional relationships with R. dybowskii are unclear, as detailed distribution in northern Korea is lacking.

  1. Japan.

    ERIC Educational Resources Information Center

    Geiger, Rita; And Others

    The document offers practical and motivating techniques for studying Japan. Dedicated to promoting global awareness, separate sections discuss Japan's geography, history, culture, education, government, economics, energy, transportation, and communication. Each section presents a topical overview; suggested classroom activities; and easily…

  2. Heterogeneous stress state of island arc crust in northeastern Japan affected by hot mantle fingers

    NASA Astrophysics Data System (ADS)

    Shibazaki, Bunichiro; Okada, Tomomi; Muto, Jun; Matsumoto, Takumi; Yoshida, Takeyoshi; Yoshida, Keisuke

    2016-04-01

    By considering a thermal structure based on dense geothermal observations, we model the stress state of the crust beneath the northeastern Japan island arc under a compressional tectonic regime using a finite element method with viscoelasticity and elastoplasticity. We consider a three-layer structure (upper crust, lower crust, and uppermost mantle) to define flow properties. Numerical results show that the brittle-viscous transition becomes shallower beneath the Ou Backbone Range compared with areas near the margins of the Pacific Ocean and the Japan Sea. Moreover, several elongate regions with a shallow brittle-viscous transition are oriented transverse to the arc, and these regions correspond to hot fingers (i.e., high-temperature regions in the mantle wedge). The stress level is low in these regions due to viscous deformation. Areas of seismicity roughly correspond to zones of stress accumulation where many intraplate earthquakes occur. Our model produces regions with high uplift rates that largely coincide with regions of high elevation (e.g., the Ou Backbone Range). The stress state, fault development, and uplift around the Ou Backbone Range can all be explained by our model. The results also suggest the existence of low-viscosity regions corresponding to hot fingers in the island arc crust. These low-viscosity regions have possibly affected viscous relaxation processes following the 2011 Tohoku-oki earthquake.

  3. JAMSTEC multibeam surveys and submersible dives around the Hawaiian Islands: a collaborative Japan-USA exploration of Hawaii's deep seafloor

    USGS Publications Warehouse

    Robinson, Joel E.; Eakins, Barry W.; Kanamatsu, Toshiya; Naka, Jiro; Takahashi, Eiichi; Satake, Kenji; Smith, John R.; Clague, David A.; Yokose, Hisayoshi

    2006-01-01

    This database release, USGS Data Series 171, contains data collected during four Japan-USA collaborative cruises that characterize the seafloor around the Hawaiian Islands. The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) sponsored cruises in 1998, 1999, 2001, and 2002, to build a greater understanding of the deep marine geology around the Hawaiian Islands. During these cruises, scientists surveyed over 600,000 square kilometers of the seafloor with a hull-mounted multibeam seafloor-mapping sonar system (SEA BEAM® 2112), observed the seafloor and collected samples using robotic and manned submersible dives, collected dredge and piston-core samples, and performed single-channel seismic surveys.

  4. Chronological trends in trace metals recorded by a tree bark pocket in Yakushima Island, Japan.

    PubMed

    Bellis, David J; Satake, Kenichi; Kagawa, Akira

    2005-04-01

    Bark included within the trunk of a 200-year-old Japanese cedar tree harvested in Yakushima Island, Japan, a World Natural Heritage Site located 150 km south of mainland Japan and 800 km east of Shanghai, China, was analysed for trace metals by ICP-MS providing a chronology of atmospheric pollution. The concentration of V, As and Pb in decadal sections of the bark pocket increased 30 to 50 fold from 1900-09 to 1960-69, indicating increased atmospheric deposition of these metals. The trend coincided with the establishment and expansion of heavy industries in Kyushu, Japan, resulting in locally high levels of air pollution. V, As and Pb subsequently declined, reflecting lower industrial emissions following air pollution control legislation from the late 1960's and decline in heavy industries. Ni, Cu and Zn showed a relatively small, 7 to 10 fold increase over time. Lead isotope ratios in the bark pockets shifted from about 0.84 to 0.86 for 207Pb/206Pb and from 2.04 to 2.10 for 208Pb/206Pb, showing that the origin of atmospheric lead changed over time from coal to more diverse sources.

  5. Spatial variation of attenuation factor in subduction zone of Philippine Sea slab around Kyushu Island Japan

    NASA Astrophysics Data System (ADS)

    Parithusta, Rizkita; Matsumoto, Satoshi; Shimizu, Hiroshi

    2010-05-01

    Kyushu Island, in south-western part of Japan is characterized by subduction from Philippine Sea Slab and Eurasian Plate (Amurian); volcanic front seen in islands arcs runs through the central part of Kyushu Island. In Kyushu, shallow and intermediate-depth earthquakes occur robustly through a depth of about 200 km. We estimated attenuation structure beneath Southern Part of Japan, at subduction zone of Philippine Sea Slab by applying modified coda normalization method (Eq.1) proposed by Parithusta, et.al. (2008*). The method estimates relative source spectra by taking spectral ratio in coda waves between two events at first. From a lot of the spectral data, those can be estimated with higher stability through singular value decomposition. After that, the relative source effect between event pair can be eliminated by the solution from ratios between direct wave spectra for many event pairs. We confirmed the estimation of source factor by assessment with empirical method, the result show that estimates of source factor almost satisfy empirical relation between magnitude and energy relation. The attenuation factor can be obtained from a relation below; ( ) Edij(tij,?-)- -1 dn = ln Edi'j(ti'j,?) = - ?Q(?) (tij - ti'j)+ const.... (1) Where: Ed denotes Direct S-wave power spectrum and Q is attenuation factor at target area; t is lapse time from origin time. Subscript i,jdenote identification number for event and station, respectively. Q-1 factor can be estimated from decay with ?tii'j(= tij - ti'j). By using this method, we obtained frequency dependent Q-1 value with smaller estimation error than previous study carried by Matsumoto et.al (2007). We used waveform data from earthquakes occurred in Philippine Sea Slab, recorded by Hi-net and Kyushu University seismic networks. Window length adopted here is 2.5 seconds for taking spectrum. The results shows the Q-1 values around Bungo-Suido area, northern part of Kyushu. Q-1 values are plotted in seven depth ranges as a

  6. Assessment of the Chile 2010 and Japan 2011 Tsunami Events in the Galapagos Islands

    NASA Astrophysics Data System (ADS)

    Renteria, Willington; Lynett, Patrick

    2015-04-01

    The object of this study is to present an analysis of measurements and observations from the Chile 2010 and Japan 2011 tsunamis, in order to understand the particular response of the Galápagos Islands to the occurrence of these extreme events. There was very limited data measured in the Galápagos during the tsunami events, other than a high-frequency and continuous record of each event logged at the two tidal gauge stations. With this data, a wavelet analysis is performed with the aim of discriminating different patterns in wave periods along the record of observation and to recognize the frequency response of the islands to an incoming tsunami. During both events, a clear and persistent signal is found in the period range of ten to twelve minutes for Baltra tide gauge, and in the range of seventeen to twenty minutes for Santa Cruz tide gauge. Both of these persistent signals are speculated to be a shelf resonant mode particular to the Galápagos Islands and the Galápagos Platform.

  7. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-04-01

    Based on absolute geostrophic velocity calculated from repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured at the same sections from 1964 to 2011, we obtained temporally averaged nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over a section) through 4 sections along the Kuroshio path from the East China Sea (sections PN and TK) to south of Japan (sections ASUKA and 137E). In addition, we examined section OK east of the Ryukyu Islands in order to understand the contribution of Ryukyu Current to the Kuroshio nutrient transport south of Japan. The mean nitrate flux shows a subsurface maximum core with a value of 10, 10, 11, 11, and 6 mol m-2 s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of subsurface maximum core changes among five sections and is approximately 400, 500, 500, 400, and 800 m at sections PN, TK, ASUKA, 137E, and OK respectively. The mean downstream nitrate transport is 199.3, 176.3, 909.2, 1385.5, and 341.2 kmol m-1 at sections PN, TK, ASUKA, 137E, and OK respectively. The nutrient transports at these sections suggest the presence of Kuroshio nutrient stream from its upstream region to downstream. The deep current structure of Ryukyu Current (section OK) makes it contribute more nitrate transport than the Kuroshio in the East China Sea (section TK) to the Kuroshio south of Japan. In addition, the positive difference between the downstream nitrate transport through section ASUKA and the sum of nitrate transports through sections TK and OK, as well as the positive difference of downstream nitrate transport between sections 137E and ASUKA, suggest that the Kuroshio recirculation significantly intensifies the downstream (eastward) nitrate transport by the Kuroshio.

  8. A new species of Jesogammarus from the Iki Island, Japan (Crustacea, Amphipoda, Anisogammaridae)

    PubMed Central

    Tomikawa, Ko

    2015-01-01

    Abstract A new species of anisogammarid amphipod, Jesogammarus (Jesogammarus) ikiensis sp. n., is described from freshwaters in the Iki Island, Nagasaki Prefecture, Japan, based on results of morphological and molecular analyses. The new species is distinguished from all members of the genus by the combination of small number of setae on dorsal margins of pleonites 1–3, short and small number of setae on posterior margins of peduncular articles of antennae, mandibular article 1 without setae, well developed posterior lobes of accessory lobes of coxal gills on gnathopod 2 and pereopods 3–5, and pectinate setae on palmar margin of female gnathopod 2. A key to all the species of Jesogammarus is provided. PMID:26692798

  9. LEPTOSPIROSIS AFTER RECREATIONAL EXPOSURE TO WATER IN THE YAEYAMA ISLANDS, JAPAN

    PubMed Central

    NARITA, MASASHI; FUJITANI, SHIGEKI; HAAKE, DAVID A.; PATERSON, DAVID L.

    2009-01-01

    Leptospirosis is a global zoonotic disease with a variety of clinical manifestations. We report an outbreak of leptospirosis in the Yaeyama Islands, Japan, in the summer of 1999 associated with heavy rainfall. Fourteen people were diagnosed with leptospirosis and required hospitalization. All cases were found to have exposure to contaminated soil or water. A history of recreational activities involving water sports was more frequent (71%) than occupational risk factors related to agriculture or construction (29%). Fever was the primary symptom in all cases, followed by chills (93%), headache (86%), myalgias (57%) and conjunctival suffusion (57%). All cases were successfully treated with antimicrobial therapy except one patient who improved spontaneously. Jarisch-Herxheimer reactions were seen in six cases (43%). The increasing incidence of leptospirosis related to recreational sports is an important public health problem in resort areas. A high-index of suspicion, early treatment, and prevention are crucial in this latently endemic area. PMID:16222003

  10. Japan.

    ERIC Educational Resources Information Center

    Jones, Savannah C.

    Materials for a secondary level, interdisciplinary social studies course on Japan are divided into introductory information, 14 classroom units, and study and evaluation materials. Introductory material includes lists of objectives and skills, an outline of Japanese history, and an explanation of Japan's name and flag. The units cover the…

  11. Japan

    ERIC Educational Resources Information Center

    Hawkins, John N.

    1986-01-01

    Analyzes the intergroup relations in Japanese society and Japan's educational system. Challenges the view that Japan is a homogeneous society by presenting the various forms of discrimination against Koreans, Ainu, and the burakumin. Suggests that despite ostracism and isolation, groups can affect public policy and achieve social advancement. (SA)

  12. Factors Affecting Groundwater Chemistry in Abandoned Terraced Paddy Fields on Sado Island, Japan

    NASA Astrophysics Data System (ADS)

    Oyanagi, Nobuhiro; Nakata, Makoto; Matsuyama, Keiko; Tsujii, Norie; Tsuchida, Takeyoshi

    The factors affecting the groundwater level and chemistry in abandoned terraced paddy fields on Sado Island, Japan, were investigated. Seasonal changes of the groundwater level in site A, which is on the bottom of the slope, was slight throughout the year compared with that in site B, which is on the middle part of the gentle slope. EC, pH, and some components involved in mineral weathering (Na+, Ca2+ and alkalinity) in the groundwater from site A were higher than those from site B. These results showed that the infiltrating water from the upper part of the slope was the main source of the groundwater in site A. On the other hand, the impact of sea salt components (Na+ and Cl-) was evident in site B, because the concentration of these components increased during winter. Groundwater chemistry was also affected by other factors such as the dilution of groundwater caused by rainfall, sulfur redox, and nutrient uptake by vegetation. The effects of each factor on groundwater chemistry differed between sites because the topography of the two adjacent sites was different. The characteristics of water environment, such as the groundwater level and chemistry, should be considered in the management of abandoned terraced paddy fields on Sado Island.

  13. Holocene reef associated carbonate sediments and their Pleistocene counterparts, Miyako Islands, Ryukyus, southwest of Japan

    SciTech Connect

    Tsuji, Y.; Yamamura, T.; Kodato, T.; Sunouchi, H.

    1988-01-01

    Holocene carbonate sedimentary facies distribution, from sea level to shelf slope about 1,000 m in depth, and its relationship to bathymeltry, off Miyako Island, Ryukyus, southwest of Japan were clarified by surveys with sidescan sonar, sparker, uniboom, sea-bottom camera, and sediment sampler. Six facies were recognized using the acoustic data, sample analytical data, and sea-bottom photographs. These are as follows: (A) Reef facies: made mainly of autochthonous hermatypic corals and encrusting algae, 0-60 m deep. (B) Inter-reef muddy facies: consists of very fine sand-size carbonate fraction and line mud, 20-60 m deep surrounded area be reefal relief and islands. (C) Inter-reef and near-reef sandy facies: characterized by tests of shallow benthic foraminifera Calcarina and Marginopora, and Halimeda fragments, 0-90 m deep. (D) Rhodolith and large foraminiferal gravelly shelf facies: contains pebble to cobble-size rhodolith and/and foraminifera Cycloclypeus and Operculina, 60-200 m deep. (E) Bryozoan sandy shelf facies: rich in byrozoan fragments, 80-200 m deep. (F) Shelf slope pelagic foraminiferal facies: dominated by pelagic foraminifera and pteropod molluscan tests, deeper than 200 m. Counterparts of these facies in emerged Pleistocene limestone sequences have been recognized in outcrops and core samples. The results of the marine survey on Holocene deposits made it easy to interpret the Pleistocene depositional environments and sea level changes.

  14. Inelastic strain rate in the seismogenic layer of Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Matsumoto, Satoshi; Nishimura, Takuya; Ohkura, Takahiro

    2016-12-01

    Seismic activity is associated with crustal stress relaxation, creating inelastic strain in a medium due to faulting. Inelastic strain affects the stress field around a weak body and causes stress concentration around the body, because the body itself has already released stress. Therefore, the understanding of inelastic deformation is important as it generates earthquakes. We investigated average inelastic strain in a spatial bin of Kyushu Island, Japan, and obtained the inelastic strain rate distribution associated with crustal earthquakes, based on the analysis of fault plane solutions and seismic moments. Large inelastic strains (>10-7 year-1) were found in the Beppu-Shimabara area, located in the center of Kyushu Island. The strain rate tensor was similar to that of the stress tensor except the absolute value in the area, implying that the inelastic strain was controlled by the stress field. The 2016 Kumamoto earthquake sequence (maximum magnitude 7.3) occurred in the Beppu-Shimabara area, with the major earthquakes located around the high inelastic strain rate area. Inelastic strain in the volume released the stress. In addition, the inelastic strain created an increment of stress around the volume. This indicates that the spatial heterogeneity of inelastic strain might concentrate stress.[Figure not available: see fulltext.

  15. ASTER-SRTM Perspective of Mount Oyama Volcano, Miyake-Jima Island, Japan

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Mount Oyama is a 820-meter-high (2,700 feet) volcano on the island of Miyake-Jima, Japan. In late June 2000, a series of earthquakes alerted scientists to possible volcanic activity. On June 27, authorities evacuated 2,600 people, and on July 8 the volcano began erupting and erupted five times over that week. The dark gray blanket covering green vegetation in the image is the ash deposited by prevailing northeasterly winds between July 8 and 17. This island is about 180 kilometers (110 miles) south of Tokyo and is part of the Izu chain of volcanic islands that runs south from the main Japanese island of Honshu. Miyake-Jima is home to 3,800 people. The previous major eruptions of Mount Oyama occurred in 1983 and 1962, when lava flows destroyed hundreds of houses. An earlier eruption in 1940 killed 11 people.

    This image is a perspective view created by combining image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA's Terra satellite with an elevation model from the Shuttle Radar Topography Mission (SRTM). Vertical relief is exaggerated, and the image includes cosmetic adjustments to clouds and image color to enhance clarity of terrain features.

    The ASTER instrument is a cooperative project between NASA, JPL, and the Japanese Ministry of International Trade and Industry.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the

  16. A model for population dynamics of the mimetic butterfly Papilio polytes in the Sakishima Islands, Japan.

    PubMed

    Sekimura, Toshio; Fujihashi, Yuta; Takeuchi, Yasuhiro

    2014-11-21

    We present a mathematical model for population dynamics of the mimetic swallowtail butterfly Papilio polytes in the Sakishima Islands, Japan. The model includes four major variables, that is, population densities of three kinds of butterflies (two female forms f. cyrus, f. polytes and the unpalatable butterfly Pachliopta aristolochiae) and their predator. It is well-known that the non-mimic f. cyrus resembles and attracts the male most, and the mimic f. polytes mimics the model butterfly P. aristolochiae. Based on experimental evidence, we assume that two forms f. cyrus and f. polytes interact under intraspecific competition for resources including the male, and the growth rate of f. cyrus is higher than that of f. polytes. We further assume that both the benefit of mimicry for the mimic f. polytes and the cost for the model are dependent on their relative frequencies, i.e. the motality of the mimic by predation decreases with increase in frequency of the model, while the motality of the model increases as the frequency of the mimic increases. Taking the density-dependent effect through carrying capacity into account, we set up a model system consisting of three ordinary differential equations (ODEs), analyze it mathematically and provide computer simulations that confirm the analytical results. Our results reproduce field records on population dynamics of P. polytes in the Miyako-jima Island. They also explain the positive dependence of the relative abundance (RA) of the mimic on the advantage index (AI) of the mimicry in the Sakishima Islands defined in Section 2.

  17. Infaunal zoogeography and intergeneric character blending: The case of Metaniphargus shiroi sp. nov. (Crustacea: Amphipoda: Hadziidae), from interstitial beach water on Akajima Island, the Kerama Islands, Southwestern Japan.

    PubMed

    Vonk, Ronald; Gable, Michael

    2014-07-01

    A survey of biogenic coralline sands in the littoral fringe of a tropical island in Japan brought a new amphipod species to light. This species represents the first record of the subterranean genus Metaniphargus from the West Pacific. The majority of the species in this genus occur in the Caribbean, but a report from Hawaii and now from Japan defies the endemic Caribbean status it kept for so long. Metaniphargus shiroi sp. nov. is described, and morphological comparisons are made with closely resembling species from Hawaii and the Cayman Islands (genus Metaniphargus), and the Great Barrier Reef and California (genus Dulzura). Involvement of non-congeners in the comparisons is necessary as character overlap is abundant. These comparisons suggest that the presence of form-related body types in the shallow marine interstitial realm is circumtropical and follows habitat suitability rather than sudden dispersal or vicariance events.

  18. First record of Plethus Hagen (Trichoptera, Hydroptilidae) from Japan, with description of a species.

    PubMed

    Ito, Tomiko; Saito, Rie

    2016-08-23

    The tropical and subtropical caddisfly genus Plethus Hagen (Hydroptilidae) is recorded from Japan for the first time. The species, Plethus ukalegon Malicky and Chantaramongkol 2007, originally described from Taiwan, is redescribed based on material from Iriomote-jima and Ishigaki-jima, southern Ryukyu Islands, the southernmost region of Japan. Female and immature stages are newly described and compared with Indonesian congeners. The early instar larva was associated with the adult through mitochondrial DNA sequence comparisons, and is described in the genus Plethus for the first time. Larvae live in fast-flowing waters such as hygropetric zones, rapid streams, and waterfalls. Final instar larvae make flattened cases of silk that they attach tightly on smooth rock surfaces.

  19. Philippine Sea Slab and South-Ryukyu Arc Sliver Accommodation of Arc-Continent Collision East of Taiwan

    NASA Astrophysics Data System (ADS)

    Lallemand, S.; Theunissen, T.; Font, Y.; Schnurle, P.; Lee, C.; Liu, C.

    2011-12-01

    The southern termination of the Ryukyu arc-trench system underwent a complex polyphased and extremely rapid tectonic evolution during the last 5 to 8 My. At first, the relative motion of the Philippine Sea plate (PSP) has changed about 5 My ago from a northward to a northwestward motion relative to Eurasia. Secondly, the Ryukyu trench has propagated from east to west during the same time period resulting in a tectonic inversion along the former passive margin of the South China Sea into the active margin of the S-Ryukyu trench. Thirdly, the convergence rate along the neo-formed S-Ryukyu trench dramatically increased from 8 to 13 cm/yr since at least 2 My when the Southern Okinawa Trough (SOT) started to rift. At the same time, the oceanic subduction of the South China Sea beneath the northern Manila arc progressively evolved into a continental subduction of the Chinese platform at the origin of the Taiwan orogen. The timing of these various kinematic and tectonic events should have been recorded in the deformed sedimentary basins and fold-and-thrust belts in the region. Unfortunately, a large part is now below the sea-level and no or a few age constraints are available. The recent joint project between Taiwan-USA & France (TAIGER & ACTS) gave us the opportunity to considerably increase the resolution of the seismic imagery around the island and especially in the most highly deformed area east of Taiwan along the S-Ryukyu forearc. We already knew that the seismic activity focussed in this region but we ignored how the converging plates deformed. We can now argue that the PSP strongly deforms in the vicinity of its deep interaction with the root of the Taiwan orogen. The north-dipping PSP slab buckles and tears along two diverging directions with a down-faulted part subducting beneath the SOT.

  20. [Aneurysmal subarachnoid hemorrhage in the Yaeyama Islands, Japan, from 1989 to 2002].

    PubMed

    Izumihara, Akifumi; Shimoji, Takashi; Uesugi, Masashi; Fujisawa, Hirosuke; Suzuko, Michiyasu; Ie, Tomoji

    2007-10-01

    The aim of this study was to analyze epidemiological and clinical data of patients with aneurysmal subarachnoid hemorrhage (SAH) in the Yaeyama islands, an isolated subtropical region of Japan. A total of 94 patients (31 men and 63 women, mean age 57.3 years) were diagnosed as having non-traumatic SAH during a 13-year period from 1989 to 2002. The age-and sex-adjusted annual incidence rate of SAH was 17.4 per 100,000 population. The incidence of SAH was the highest in August. Seventy-nine patients were hospitalized within 24 hours after onset of SAH. Seventeen patients were transferred by helicopter. The Hunt and Kosnik grade was I in 29 patients (30.9%). The CT Fisher group was 3 in 42 patients (44.7%). Ruptured aneurysm was detected in 78 patients (saccular type in 70 patients, small size in 49 patients, and internal carotid artery in 28 patients). Rebleeding occurred in 20 patients (21.3%). Symptomatic vasospasm occurred in 26 patients (27.7%). Acute and chronic hydrocephalus occurred in 25 (26.6%) and 22 (23.4%) patients respectively. A total of 120 neurosurgical operations were performed in 70 patients (operation for ruptured aneurysm in 62, early operation in 39). A total of 42 operative complications occurred in 29 patients. Fifty-one patients (54.3%) had a good outcome. The number of full-time neurosurgeons did not influence the performance of neurosurgical operation and outcome. In conclusion, epidemiologically, the high incidence of SAH in August is unusual. Patients with aneurysmal SAH in the Yaeyama islands have common clinical characteristics and undergo standard neurosurgical treatment.

  1. Wintertime urban heat island modified by global climate change over Japan

    NASA Astrophysics Data System (ADS)

    Hara, M.

    2015-12-01

    Urban thermal environment change, especially, surface air temperature (SAT) rise in metropolitan areas, is one of the major recent issues in urban areas. The urban thermal environmental change affects not only human health such as heat stroke, but also increasing infectious disease due to spreading out virus vectors habitat and increase of industry and house energy consumption. The SAT rise is mostly caused by global climate change and urban heat island (hereafter UHI) by urbanization. The population in Tokyo metropolitan area is over 30 millions and the Tokyo metropolitan area is one of the biggest megacities in the world. The temperature rise due to urbanization seems comparable to the global climate change in the major megacities. It is important to project how the urbanization and the global climate change affect to the future change of urban thermal environment to plan the adaptation and mitigation policy. To predict future SAT change in urban scale, we should estimate future UHI modified by the global climate change. This study investigates change in UHI intensity (UHII) of major metropolitan areas in Japan by effects of the global climate change. We performed a series of climate simulations. Present climate simulations with and without urban process are conducted for ten seasons using a high-resolution numerical climate model, the Weather Research and Forecasting (WRF) model. Future climate projections with and without urban process are also conducted. The future projections are performed using the pseudo global warming method, assuming 2050s' initial and boundary conditions estimated by a GCM under the RCP scenario. Simulation results indicated that UHII would be enhanced more than 30% in Tokyo during the night due to the global climate change. The enhancement of urban heat island is mostly caused by change of lower atmospheric stability.

  2. Macrogenomic evidence for the origin of the black fly Simulium suzukii (Diptera: Simuliidae) on Okinawa Island, Japan.

    PubMed

    Adler, Peter H; Huang, Yao-Te; Reeves, Will K; Kim, Sam Kyu; Otsuka, Yasushi; Takaoka, Hiroyuki

    2013-01-01

    To determine the geographic origin of the black fly Simulium suzukii on Okinawa Island, Japan, macrogenomic profiles derived from its polytene chromosomes were compared with those of mainland and other insular populations of S. suzukii and of the isomorphic Simulium tani species complex. The Okinawan population is a chromosomally unique cytoform, designated 'D,' which is essentially monomorphic and differs by about 27 fixed rearrangements from the chromosomal standard sequence for the subgenus Simulium and by two fixed differences from its nearest known relative, representing the type of S. suzukii, on the main islands of Japan. Chromosomal band sequences revealed two additional, sympatric cytoforms of S. suzukii, designated 'A' and 'B,' each with species status, in Korea, and a third cytoform, designated 'C,' on Hokkaido, Japan. A new cytoform, 'K,' of S. tani from Malaysia, representing the type of S. tani, is more closely related to cytoforms in Thailand, as are populations from Taiwan previously treated as S. suzukii but more closely aligned with S. tani and newly recognized as cytoform 'L' of the latter nominal species. Rooting of chromosomal band sequences by outgroup comparisons allowed directionality of chromosomal rearrangements to be established, enabling phylogenetic inference of cytoforms. Of 41 macrogenomic rearrangements discovered in the five new cytoforms, four provide evidence for a stepwise origin of the Okinawan population from populations characteristic of the main islands of Japan. The macrogenomic approach applied to black flies on Okinawa Island illustrates its potential utility in defining source areas for other species of flies including those that might pose medical and veterinary risks.

  3. Endogenous growth of a Miocene submarine dacite cryptodome, Rebun Island, Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Goto, Yoshihiko; McPhie, Jocelyn

    1998-09-01

    Momo-iwa, Rebun Island, Hokkaido, Japan, is a dacite cryptodome 200-300 m across and 190 m high. The dome is inferred to have intruded wet, poorly consolidated sediment in a shallow marine environment. The internal structure of the dome is concentric, with a massive core, banded rim, and narrow brecciated border, all of which are composed of compositionally uniform feldspar-phyric dacite. Boundaries between each of the zones are distinct but gradational. The massive core consists of homogeneous coherent (unfractured) dacite and is characterized by radial columnar joints 60-200 cm across. The banded rim encircles the massive core and is 40 m wide. It is characterized by large-scale flow banding parallel to the dome surface. The flow banding comprises alternating partly crystalline and more glassy bands 80-150 cm thick. The outermost brecciated border is up to 80 cm thick, and consists of in situ breccia and blocky peperite. The in situ breccia comprises polyhedral dacite clasts 5-20 cm across and a cogenetic granular matrix. The blocky peperite consists of polyhedral dacite clasts 0.5-2 cm across separated by the host sediment (mudstone). The internal structures of the dome suggest endogenous growth involving a continuous magma supply during a single intrusive phase and simple expansion from the interior. Although much larger, the internal structures of Momo-iwa closely resemble those of lobes in subaqueous felsic lobe-hyaloclastite lavas.

  4. Diversity of Aulacidae (Hymenoptera: Evanioidea) in the oceanic Ogasawara Islands (Japan), with description of a new species from Anijima Island.

    PubMed

    Watanabe, Kyohei; Konishi, Kazuhiko; Turrisi, Giuseppe Fabrizio

    2013-11-12

    In the context of the biodiversity conservation of the oceanic Ogasawara Islands, the parasitoid species of Aulacidae are reviewed. We examined material from eight islands with or without invasion of the introduced lizard Anolis carolinensis (Voigt 1832) (green anoles): two species of Pristaulacus Kieffer 1900, P. boninensis Konishi, 1989, and P. anijimensis sp. nov., are recognized. The former species is widely distributed in the islands, whereas the latter species is found from a single island only, Anijima Island. Although this island appears to be currently well preserved, the recent introduction of green anoles will probably affect the conservation status of many species, including the endemic P. anijimensis sp. nov. A description of the new species, detailed drawings and descriptions of genitalia of both recognized species, an updated key to Japanese Aulacidae, and a brief discussion on the conservation aspects of Aulacidae in the Ogasawara Islands are provided.

  5. Structural evolution of the Nojima fault (Awaji Island, Japan) revisited from the GSJ drill hole at Hirabayashi

    NASA Astrophysics Data System (ADS)

    Boullier, Anne-Marie; Fujimoto, Koichiro; Ito, Hisao; Ohtani, Tomoyuki; Keulen, Nynke; Fabbri, Olivier; Amitrano, David; Dubois, Michel; Pezard, Philippe

    2004-12-01

    Following the Hyogoken Nanbu earthquake (January 17, 1995, Mw=7.2), three drillholes were sunk through the Nojima Fault (Awaji Island, Japan). Textural and petrographic studies of the Geological Survey of Japan (GSJ) drill cores allow recognition of two deformation episodes. The first one is older than the deposition of the Middle to Late Eocene Kobe Group, corresponds to a left-lateral movement on the Nojima fault and is expressed by pseudotachylytes, kinking of biotite crystals in the low-strain rocks and an intense laumontite hydrothermal alteration. The second one displaces the basal unconformity of the Kobe group, corresponds to a right-lateral reverse displacement and is expressed at least by carbonate-filled hydraulic fractures and thin gouge zones. Different important deformation mechanisms are recorded by the fault rocks, but questions relating to the attribution of deformation and alteration features to one or other deformation episodes remain unresolved.

  6. Neostygarctus lovedeluxe n. sp. from the Miyako Islands, Japan: the first record of Neostygarctidae (Heterotardigrada: Arthrotardigrada) from the Pacific.

    PubMed

    Fujimoto, Shinta; Miyazaki, Katsumi

    2013-05-01

    A new species of the previously monospecific marine tardigrade family Neostygarctidae is described. Neostygarctus lovedeluxe n. sp. was found from a submarine cave in Miyako Islands, Japan. This is the first record of Neostygarctidae from the Pacific. The new species is easily distinguished from the previously known N. acanthophorus by its number of dorsal spines, as N. lovedeluxe has two spines each on the three dorsal body plates in contrast to one in N. acanthophorus. Furthermore the morphology of the two clawed juvenile is reported for the first time in Neostygarctidae, providing new insights into the common sequence in some ontogenic traits.

  7. Stable isotope compositions and water contents of boninite series volcanic rocks from Chichi-jima, Bonin Islands, Japan

    USGS Publications Warehouse

    Dobson, P.F.; O'Neil, J.R.

    1987-01-01

    Measurements of stable isotope compositions and water contents of boninite series volcanic rocks from the island of Chichi-jima, Bonin Islands, Japan, confirm that a large amount (1.6-2.4 wt.%) of primary water was present in these unusual magmas. An enrichment of 0.6??? in 18O during differentiation is explained by crystallization of 18O-depleted mafic phases. Silicic glasses have elevated ??18O values and relatively low ??D values indicating that they were modified by low-temperature alteration and hydration processes. Mafic glasses, on the other hand, have for the most part retained their primary isotopic signatures since Eocene time. Primary ??D values of -53 for boninite glasses are higher than those of MORB and suggest that the water was derived from subducted oceanic lithosphere. ?? 1987.

  8. Salmonella infection in green anoles (Anolis carolinensis), an invasive alien species on Chichi Island of the Ogasawara archipelago in Japan.

    PubMed

    Sumiyama, Daisuke; Izumiya, Hidemasa; Kanazawa, Tomoko; Murata, Koichi

    2014-03-01

    We investigated the presence of Salmonella in the green anole (Anolis carolinensis), an invasive alien species on Chichi Island, Japan. Samples were also collected from feral goats and public toilets on the island to examine infectious routes. Salmonellae were isolated from 27.1% of 199 samples; 32.6% of 141 cloacal samples from anoles, 62.5% of 8 intestinal samples from anole carcasses, 16.7% of 12 fecal samples from goats and 2.6% of 38 toilet bowl swabs. The serotype of most isolates was Salmonella Oranienburg (94.4% of 54). Although we did not confirm the infection pathways, our results indicated that green anoles are a risk factor as a source of Salmonella for public health. It is important to consider endemic pathogens that may be amplified by alien species within their introduced areas.

  9. On the prevalence of Asiatic cholera in Okinawa, 1879 and "Ryukyu-kiko" Written by Hironobu Tsuchiya.

    PubMed

    Fukase, Y

    1999-09-01

    The greatest prevalence of Asiatic cholera since the adoption of modern statistics was in 1879. Especially in Okinawa Prefecture, its morbidity rate was the largest in Japan in that year. Dr. Hironobu Tsuchiya, who was appointed as an official of the Department of Inner Affairs, wrote "Ryukyu-kiko" as a private memorandum. He wrote more about the situation of administrative confusion than he did about the condition of Asiatic cholera. This paper also mentions the brief sketch of Tsuchiya's life and the description of the manufacturing methods, effectiveness and use of chemical drugs which are contained in his "Sinyaku-shoko".

  10. Population structures of the red fox (Vulpes vulpes) on the Hokkaido Island, Japan, revealed by microsatellite analysis.

    PubMed

    Oishi, Takuya; Uraguchi, Kohji; Takahashi, Kenichi; Masuda, Ryuichi

    2011-01-01

    In order to examine the population structures of the red fox (Vulpes vulpes) on the Hokkaido Island in Japan, we conducted analysis on 250 foxes from all over the island for 12 microsatellite loci. Assignment tests using the genotype data set showed that they were divided into 6 subpopulations. Of the 6, one was geographically isolated in the southern region and considered definitive subpopulation, whereas the other 5 were not. The slight differences among the latter 5 subpopulations were explained by the high adaptability and long dispersal of the red fox on the Hokkaido Island. Although there are few ecological data to explain the genetic differentiation of the southern population, we have proposed some hypotheses from the present ecological and geohistorical viewpoints. One convincing reason from the ecological viewpoint is the restriction of gene flow to southern Hokkaido from other areas due to geographical isolation resulting from the land shape. The other explanation is the geohistorical division of southern Hokkaido from other regions on the island during the last interglacial age, resulting in the isolation of the fox population.

  11. Paleomagnetism of Harutagawa formation in the Hohi Volcanic Zone in northeastern part of Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Kudou, T.; Shibuya, H.

    2008-12-01

    The Beppu-Shimabara graben in the Hohi Volcanic Zone (HVZ) in northeastern part of Kyushu Island, Japan is thought to be a volcano-tectonic depression. Volcanic stratigraphy and age studies of the area have unraveled the late Pliocene structural formation history of HVZ (e.g. Kamata, 1994, Kido, 2007). The age and sedimentation rate of lacustrine deposits in HVZ is one of the keys for interpreting the temporal relation between the formation of Beppu-Shimabara graben and the huge pyroclastic flows appeared in the area. We study the magnetostratigraphy of the Harutagawa formation, which is one of those lacustrine deposits. The formation is dominated by conglomerates and mad stones to siltstones, in the lower and upper parts, respectively, but bares many tuff layers all over the formation. Fission track ages of two tuff layers, one is from lower part and the other is from upper part of Harutagawa formation, are determined as 3.86 ± 0.77Ma and 3.6 ± 0.2Ma, respectively (Kido, 2007). Samples for paleomagnetic analyses have been collected at 28 sites in several continuous outcrop of the Harutagawa formation. The sites are set to be spaced equally in the stratigraphy. Samples were collected by a portable electric motor drill. A few pilot specimens from each site are subjected to progressive thermal and alternating field (AF) demagnetization. However, AF demagnetization is not effective. All remaining specimens are, therefore, submitted to the progressive thermal demagnetization. The samples have mean magnetic intensity of 1.7 × 10- 4A/m and 7.7 × 10-5A/m before and after demagnetization, respectively. Samples from 6 sites have no stable component or are thought to be completely remagnetized by the present magnetic field. As the result, 22 sites are determined their polarities; 8 were reversed and 14 were normal. The normal polarity sites were correlative to Sidufjall, Nunivak and Cochiti subchrons in the Gilbert reversed polarity chron. This correlation indicates that

  12. Neural network analysis for geological interpretation of tomographic images beneath the Japan Islands

    NASA Astrophysics Data System (ADS)

    Kuwatani, T.; Toriumi, M.

    2009-12-01

    Recent advances in methodologies of geophysical observations, such as seismic tomography, seismic reflection method and geomagnetic method, provide us a large amount and a wide variety of data for physical properties of a crust and upper mantle (e.g. Matsubara et al. (2008)). However, it has still been difficult to specify a rock type and its physical conditions, mainly because (1) available data usually have a lot of error and uncertainty, and (2) physical properties of rocks are greatly affected by fluid and microstructures. The objective interpretation and quantitative evaluation for lithology and fluid-related structure require the statistical analyses of integrated geophysical and geological data. Self-Organizing Maps (SOMs) are unsupervised artificial neural networks that map the input space into clusters in a topological form whose organization is related to trends in the input data (Kohonen 2001). SOMs are powerful neural network techniques to classify and interpret multiattribute data sets. Results of SOM classifications can be represented as 2D images, called feature maps which illustrate the complexity and interrelationships among input data sets. Recently, some works have used SOM in order to interpret multidimensional, non-linear, and highly noised geophysical data for purposes of geological prediction (e.g. Klose 2006; Tselentis et al. 2007; Bauer et al. 2008). This paper describes the application of SOM to the 3D velocity structure beneath the whole Japan islands (e.g. Matsubara et al. 2008). From the obtained feature maps, we can specify the lithology and qualitatively evaluate the effect of fluid-related structures. Moreover, re-projection of feature maps onto the 3D velocity structures resulted in detailed images of the structures within the plates. The Pacific plate and the Philippine Sea plate subducting beneath the Eurasian plate can be imaged more clearly than the original P- and S-wave velocity structures. In order to understand more precise

  13. Long-Range Transport of Perchlorate Observed in the Atmospheric Aerosols Collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Arakaki, T.; Tanahara, A.; Oomori, T.; Miyagi, T.; Kadena, H.; Ishizaki, T.; Nakama, F.

    2007-12-01

    The study of perchlorate has become quite active in the U.S. in the last several years. Perchlorate has been recognized as a new environmental pollutant and it attracted much attention quickly in the world. The health concern about perchlorate stems from the fact that it displaces iodide in the thyroid gland, while iodine-containing thyroid hormones are essential for proper neural development from the fetal stage through the first years of life. In this study, we determined the concentrations of perchlorate ion present in the atmospheric aerosols collected in Okinawa Island, Japan. We then examined the relationships between the perchlorate concentrations and the environmental parameters and the climatic conditions peculiar to Okinawa. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS). Each sampling duration was one week. The quartz filters with aerosols were stirred with Milli-Q pure water for three hours before perchlorate ion was extracted. The extracted perchlorate ion concentrations were determined by ion chromatography (ICS-2000, DIONEX). The mean perchlorate concentration for the samples collected at CHAAMS was 1.83 ng/m3, and the minimum was 0.18 ng/m3. The samples collected during November 21-27, 2005, January 23-30, 2006 and April 24-01, 2006 had highest perchlorate concentrations. For these three samples, we performed back trajectory analysis, and found that the air mass for the three samples arrived from the Asian continent. A relatively strong correlation (r2 = 0.55) was found between perchlorate and nss-sulfate concentrations for the CHAAMS samples. Furthermore, we analyzed perchlorate in the soils and the fertilizers used for sugar cane farming around the CHAAMS area. The Milli-Q extract of the soil and the fertilizers did not contain any detectable levels of perchlorate ions. Therefore, it was suggested that perchlorate found in the atmospheric

  14. Influence of Land Development on Holocene Porites Coral Calcification at Nagura Bay, Ishigaki Island, Japan

    PubMed Central

    Sowa, Kohki; Watanabe, Tsuyoshi; Kan, Hironobu; Yamano, Hiroya

    2014-01-01

    To evaluate the relationships between coral calcification, thermal stress, and sedimentation and eutrophication linked to human impact (hereafter referred to as “land development”) by river discharge, we analyzed growth characteristics in the context of a paleoenvironment that was reconstructed from geochemical signals in modern and fossil (1.2 cal kyr BP and 3.5 cal kyr BP, respectively) massive Porites corals from Nagura Bay (“Nagura”) and from modern Porites corals from the estuary of the Todoroki River, Shiraho Reef (“Todoroki”). Both sites are on Ishigaki Island, Japan, and Nagura is located approximately 12 km west of Todoroki. At Nagura, the individual corals provide time windows of 13 (modern), 10 (1.2 cal kyr BP), and 38 yr in length (3.5 cal kyr BP). Here, we present the coral annual calcification for Nagura and Todoroki, and (bi) monthly resolved records of Sr/Ca (a proxy of sea surface temperature (SST)) and Ba/Ca (a proxy of sedimentation and nutrients related to land development) for Nagura. At Nagura, the winter SST was cooler by 2.8°C in the 1.2 cal kyr BP, and the annual and winter SSTs in the 3.5 cal kyr BP were cooler by 2.6°C and 4.6°C, respectively. The annual periodicity of Ba/Ca in modern coral is linked to river discharge and is associated with land development including sugar cane cultivation. Modern coral calcification also has declined with SST warming and increasing Ba/Ca peaks in winter. However, calcification of fossil corals does not appear to have been influenced by variations in Sr/Ca and Ba/Ca. Modern coral growth characteristics at Nagura and Todoroki indicate that coral growth is both spatially and temporally influenced by river discharge and land development. At Nagura, our findings suggest that land development induces negative thermal sensitivity for calcification in winter due to sugar cane harvest, which is a specifically modern phenomenon. PMID:24586393

  15. Japan unified hIgh-resolution relocated catalog for earthquakes (JUICE): Crustal seismicity beneath the Japanese Islands

    NASA Astrophysics Data System (ADS)

    Yano, Tomoko E.; Takeda, Tetsuya; Matsubara, Makoto; Shiomi, Katsuhiko

    2017-04-01

    We have generated a high-resolution catalog called the ;Japan Unified hIgh-resolution relocated Catalog for Earthquakes; (JUICE), which can be used to evaluate the geometry and seismogenic depth of active faults in Japan. We relocated > 1.1 million hypocenters from the NIED Hi-net catalog for events which occurred between January 2001 and December 2012, to a depth of 40 km. We apply a relative hypocenter determination method to the data in each grid square, in which entire Japan is divided into 1257 grid squares to parallelize the relocation procedure. We used a double-difference method, incorporating cross-correlating differential times as well as catalog differential times. This allows us to resolve, in detail, a seismicity distribution for the entire Japanese Islands. We estimated location uncertainty by a statistical resampling method, using Jackknife samples, and show that the uncertainty can be within 0.37 km in the horizontal and 0.85 km in the vertical direction with a 90% confidence interval for areas with good station coverage. Our seismogenic depth estimate agrees with the lower limit of the hypocenter distribution for a recent earthquake on the Kamishiro fault (2014, Mj 6.7), which suggests that the new catalog should be useful for estimating the size of future earthquakes for inland active faults.

  16. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island, Sea of East Japan, Based on Chloroplast Genome Sequencing.

    PubMed

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  17. Melon Fly, Bactrocera cucurbitae (Diptera: Tephritidae), Infestation in Host Fruits in the Southwestern Islands of Japan Before the Initiation of Island-wide Population Suppression, as Recorded in Publications of Japanese Public Institutions

    PubMed Central

    McQuate, Grant T.; Teruya, Tadashi

    2015-01-01

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here. Bactrocera cucurbitae infestation was documented in 24 plant taxa of four plant families (Caricaceae, Cucurbitaceae, Moraceae, and Solanaceae), with the following four new hosts identified: Ficus erecta Thunb., F. pumila L. (Moraceae), Solanum erianthum D. Don (Solanaceae), and Zehneria liukiuensis Jeffrey ex Walker (Cucurbitaceae). PMID:26816487

  18. Melon Fly, Bactrocera cucurbitae (Diptera: Tephritidae), Infestation in Host Fruits in the Southwestern Islands of Japan Before the Initiation of Island-wide Population Suppression, as Recorded in Publications of Japanese Public Institutions.

    PubMed

    McQuate, Grant T; Teruya, Tadashi

    2015-01-01

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here. Bactrocera cucurbitae infestation was documented in 24 plant taxa of four plant families (Caricaceae, Cucurbitaceae, Moraceae, and Solanaceae), with the following four new hosts identified: Ficus erecta Thunb., F. pumila L. (Moraceae), Solanum erianthum D. Don (Solanaceae), and Zehneria liukiuensis Jeffrey ex Walker (Cucurbitaceae).

  19. Paragonimus westermani and some rare intestinal trematodes recovered from raccoon dogs (Nyctereutes procyonoides viverrinus) introduced recently on Yakushima Island, Japan.

    PubMed

    Sato, Hiroshi; Suzuki, Kazuo; Osanai, Arihiro; Aoki, Masanari

    2006-07-01

    Helminth parasites were collected from 9 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Japan. The former carnivore was introduced to this World Natural Heritage Area presumably within the last two decades, expanding its population thence, although detailed process(es) of the introduction is unknown. The collected trematodes from raccoon dogs included the triploid form of Paragonimus westermani, Brachylaima tokudai, Maritrema eroliae, and Pseudocryptotropa sp. Simultaneously, Paragonimus ohirai was found in one weasel killed by a traffic accident. Although the triploid form of P. westermani and P. ohirai are known to be distributed in some river-mouth areas of Yakushima Island based on previous surveys on crab hosts, natural infection was detected for the first time in wild final hosts. Particularly, the raccoon dog infected with P. westermani was caught in a mountainous area, distant from human residence or river-mouth areas. Although it is possible that the infected raccoon dog moved from a river-mouth area endemic with P. westermani after infection, the alternative scenario remains to be pursued; the endemic area of this zoonosis is expanding along with the recent expansion of raccoon dogs or feral cats (Felis catus), that became prevalent recently on this island including the mountainous areas. Maritrema eroliae taking a variety of shorebirds as its natural final hosts, and a minute trematode, Pseudocryptotropa sp., taking unknown natural final host(s) were recorded for the first time in raccoon dogs.

  20. Pempheris ufuagari sp. nov., a new species in the genus Pempheris (Perciformes, Pempheridae) from the oceanic islands of Japan.

    PubMed

    Koeda, Keita; Yoshino, Tetsuo; Tachihara, Katsunori

    2013-01-29

    Pempheris ufuagari sp. nov. is described based on 10 specimens, 143.9-196.8 mm in standard length, collected from Mi-nami Daito Island and Ogasawara Islands, which are oceanic islands of Japan. Pempheris ufuagari is characterized by a distinct black spot on the pectoral fin base, a bright yellow dorsal and caudal fin, and a blackish band on the outer margin of the anal fin. Pempheris oualensis also has a large body and a distinct black spot on the pectoral fin base, and forms mixed schools with P. ufuagari, but can be distinguished by the different fin coloration (dorsal and caudal fin brown or pale; no blackish band on anal fin margin), and the presence of a villiform tooth band extending outside the lips. Although P. otaitensis, which is found in French Polynesia and Samoa, has similar coloration as P. ufuagari, the latter has lower scale counts than those of the former species: pored lateral-line scales 62-71 (vs. 70-79); scale rows above lateral line 6 1/2-7 1/2 (vs. 8 1/2); predorsal scales 37-43 (vs. 44-48).

  1. Spatial and temporal variations of chemicals in the TSP aerosols simultaneously collected at three islands in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Arakaki, Takemitsu; Azechi, Sotaro; Somada, Yuka; Ijyu, Moriaki; Nakaema, Fumiya; Hitomi, Yuya; Handa, Daishi; Oshiro, Yoshito; Miyagi, Youichi; Tsuhako, Ai; Murayama, Hitomi; Higaonna, Yumi; Tanahara, Akira; Itoh, Akihide; Fukushima, Soko; Higashi, Kazuaki; Henza, Yui; Nishikawa, Rin; Shinjo, Hibiki; Wang, Hongyan

    2014-11-01

    East Asia's rapid economic growth has led to concerns about the emission of air pollutants. We collected total suspended particle (TSP) aerosol samples simultaneously at three islands in Okinawa, Japan, which are downwind of East Asia, during the Asian dust season, to examine the spatial and temporal variations and chemical transformations of major chemicals in the aerosols. Weekly samples were collected from July 2008 to June 2010, and the concentrations of water-soluble cations, anions, and organic carbon (WSOC) were determined (n = 303). Spatial distribution analysis showed that monthly mean concentrations of non-sea-salt (nss)-SO42- in the spring (Asian dust season) decreased with increasing distance from Asia, while the trend for NO3- was less evident, suggesting that chemical transformation affected the long-range transport of certain chemicals. Temporal variation analysis showed that concentrations of nss-SO42-, NO3-, and WSOC during the spring were about 2.0, 2.4, and 1.8 times those in the summer (cleaner air mass from the Pacific Ocean), respectively. This study demonstrated that air pollutants were transported from the Asian continent to the Okinawa islands and affected the air quality in the region. There may also be impacts on ecosystems, because increased concentrations of particulate NO3- could increase nutrient levels around the Okinawa islands.

  2. Underground dams for irrigation supplies in coastal limestone aquifer, Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.; Nakano, T.; Nawa, N.

    2011-12-01

    The use of underground dams to store water in regions with arid or tropical climates is a method that has received considerable attention in the last few decades. And now, for the tropical and subtropical islands that are highly vulnerable to climate change underground dams have been attracting attention again as a method of groundwater management. Okinawa Prefecture is Japan's southernmost prefecture, which consists of hundreds of islands in a chain over 1,000 km long, called the Ryukyu Islands which extend southwest from Kyushu to Taiwan. The national irrigation project of the Ryukyu Islands has been carried out, and several underground dams have been constructed. The Komesu and Giiza underground dams are first full scale underground dam facilities constructed for irrigation in Japan. The Komesu underground dam is a salt-water proof type. It prevents salt-water intrusion and provides storage fresh-water for irrigation in coastal limestone aquifer. Giiza underground dam is a dam up type for storage of fresh-water. These groundwater reservoirs are located in the coastal region of southern part of Okinawa (main island), where Ryukyu limestone is extensively distributed. We studied the behaviour of groundwater flow, saltwater intrusion and nitrate nitrogen (NO3-N) in groundwater in this region by using observation data of groundwater and springs through long term (from 1993 to 2010) monitoring. And, a groundwater flow and salt-water intrusion analysis have been conducted with three dimensional numerical model applied to these dam reservoir areas. The MODFLOW-NWT with SWI code and PEST was used to simulate the complex groundwater flow patterns. Through the comparison with simulation and observed data, it was concluded that the cut off wall of underground dams effectively stores the groundwater and prevents the salt-water intrusion in the reservoir areas. The observed groundwater levels at the reservoir areas were almost reproduced by the numerical model, but there

  3. Post-bomb coral Δ14C record from Iki Island, Japan: possible evidence of oceanographic conditions on the northern East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Mitsuguchi, Takehiro; Hirota, Masashi; Group, Paleo Labo AMS Dating; Yamazaki, Atsuko; Watanabe, Tsuyoshi; Yamano, Hiroya

    2016-10-01

    In this study, a sea-surface water Δ14C record of AD 1966-2000 (i.e., after the atmospheric nuclear-bomb testing period of the mid-1950s to early 1960s) was reconstructed from a coral sample collected from Iki Island, western Japan. The island is located in the Tsushima Strait where the Tsushima Current flows from the East China Sea (ECS) continental shelf into the Sea of Japan, indicating a strong influence of the ECS shelf water on the island. It is widely accepted that the Tsushima Current originates in the area between the ECS shelf break and the Nansei Islands further offshore as a branch of the Kuroshio Current, although another possible origin is the Taiwan-Tsushima Current System. The Δ14C record from Iki Island shows the following evidence of a response to the atmospheric nuclear testing: (1) an increase from ~55‰ in 1966 to ~133‰ in 1970, (2) a plateau ranging between ~123 and ~142‰ during the 1970s to the late 1980s, and (3) a gradual decrease from ~115‰ in 1990 to ~83‰ in 2000. Comparison of this record with coral Δ14C records from the Nansei Islands (Okinawa Island, Ishigaki Island and Kikai Island), located ~160-280 km off the ECS shelf break and little influenced by the shelf water, suggests that the surface-water Δ14C around Iki Island was ~30-45‰ lower than that of the Nansei Islands from the mid-1960s to late 1970s, and that the Δ14C difference between Iki Island and the Nansei Islands decreased from the end of the 1970s to ~0-15‰ in the mid-1980s to 2000. The lower Δ14C around Iki Island can be explained as follows: (1) in contrast to the Nansei Islands area, the ECS shelf area is a vertically mixed, highly concentrated carbon reservoir significantly connected to subsurface and deeper waters outside the shelf area, strongly suggesting that the surface-water Δ14C of the shelf area (perhaps excepting very shallow innermost shelf areas) was significantly less sensitive to the atmospheric nuclear-bomb 14C spike than that of the

  4. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago

    PubMed Central

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  5. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

    PubMed

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-12-10

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history.

  6. Distribution of trace metals in the Pacific Oyster, Crassostrea gigas, and crabs from the east coast of Kyushu Island, Japan

    SciTech Connect

    Szefer, P.; Frelek, K.; Geldon, J.

    1997-01-01

    Oysters are known to be exceptional accumulators of Zn and Cu, and their tissue concentrations appear to reflect contamination of metals. According to Lauenstein and Dolvin, oysters clearly have a greater affinity for Ag, Cu and Zn than do mussels, while mussels have greater affinity for Cr and Pb. Oysters have been considered to be potential bioindicators for monitoring metallic pollution in marine environments. Extensive investigations of oysters from the east coast of Kyushu Island, Japan, have been performed. The aim of the study was to examine spatial differences in metal concentrations in soft tissues of the Pacific oyster (Crassostrea gigas) and whole bodies (soft tissues with shells) of the crabs Goetice depressa and Leptodius exaratus inhabiting the Japanese coastal region of the Pacific. 18 refs., 3 figs.

  7. [Toxin profiles in fish implicated in ciguatera fish poisoning in Amami and Kakeroma Islands, Kagoshima Prefecture, Japan].

    PubMed

    Yogi, Kentaro; Oshiro, Naomasa; Matsuda, Seiko; Sakugawa, Satsuki; Matsuo, Toshiaki; Yasumoto, Takeshi

    2013-01-01

    Ciguatoxins (CTXs) responsible for ciguatera fish poisoning (CFP) in Amami Islands, Kagoshima, Japan in 2008 were determined by LC-MS/MS analysis. Ciguatoxin-1B (CTX1B), 54-deoxyCTX1B, and 52-epi-54-deoxyCTX1B were detected in Variola louti and Lutjanus monostigma. The toxin profile distinctly differed from that of a CFP-related fish from Miyazaki, which mainly contained ciguatoxin-3C type toxins. Toxin profiles were species-specific, as observed in fish from Okinawa. The LC-MS/MS and mouse bioassay (MBA) methods produced comparable data, though 54-deoxyCTX1B was not taken into consideration owing to the lack of toxicity data. To improve assessment, toxicity data for this compound are needed. A reef fish caught on the same occasion and judged nontoxic by MBA (<0.025 MU/g) was found to contain low levels of CTX, indicating a potential risk for CFP.

  8. Specific accumulation of arsenic compounds in green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Ishigaki Island, Japan.

    PubMed

    Agusa, Tetsuro; Takagi, Kozue; Kubota, Reiji; Anan, Yasumi; Iwata, Hisato; Tanabe, Shinsuke

    2008-05-01

    Concentrations of total arsenic (As) and individual compounds were determined in green and hawksbill turtles from Ishigaki Island, Japan. In both species, total As concentrations were highest in muscle among the tissues. Arsenobetaine was a major compound in most tissues of both turtles. High concentrations of trimethylarsine oxide were detected in hawksbill turtles. A significant negative correlation between standard carapace length (SCL), an indicator of age, and total As levels in green turtles was found. In contrast, the levels increased with SCL of hawksbill turtles. Shifts in feeding habitats with growth may account for such a growth-dependent accumulation of As. Although concentrations of As in marine sponges, the major food of hawksbill turtles are not high compared to those in algae eaten by green turtles, As concentrations in hawksbill turtles were higher than those in green turtles, indicating that hawksbill turtles may have a specific accumulation mechanism for As.

  9. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-10-01

    Based on absolute geostrophic velocity, which was calculated using repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured in the same areas from 1964 to 2009, we obtained the temporally averaged nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over one section) of four sections across the Kuroshio from the East China Sea (sections PN and TK) to an area south of Japan (sections ASUKA and 137E). In addition, we examined section OK east of the Ryukyu Islands in order to understand how the Ryukyu Current contributes to the transport of nutrients by the Kuroshio south of Japan. The mean nitrate flux shows a subsurface maximum core with values of 9.6, 10.6, 11.2, 10.5, and 5.7 mol m-2 s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of the subsurface maximum core changes among these five sections and is approximately 400, 500, 500, 400, and 800 m at sections PN, TK, ASUKA, 137E, and OK, respectively. The mean downstream nitrate transport is 204.8, 165.8, 879.3, 1230.4, and 338.6 kmol s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The transport of nutrients in these sections suggests the presence of the Kuroshio nutrient stream from its upstream to downstream regions. The deep current structure of the Ryukyu Current (section OK) contributes to the same order of nitrate transport as does the Kuroshio from the East China Sea (section TK) to the area south of Japan; however, the former only has one-fifth the volume transport of the latter. A budget calculation suggests that the downstream increase of transported nitrate along the Kuroshio is mainly caused by the recirculation of nitrate into the Kuroshio. This conclusion, however, depends on water depth. In the upper layers (< 26.5σθ), the downstream change of nitrate concentration along the Kuroshio and that from the recirculation of nitrate has a significant contribution to the downstream

  10. Gravity changes observed during the long-term slow slip events at the Ryukyu Trench in May 2012 and December 2012

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Imanishi, Y.; Okubo, S.; Nawa, K.; Ikeda, H.; Miyaji, T.; Kazama, T.; Okamura, S.; Miyazaki, T.; Nakamura, M.

    2013-12-01

    Long-term slow-slip events (SSEs) have been observed in many plate-boundary zones along the circum-Pacific seismic belt. Previous studies have revealed that high-pressure fluids supplied from the subducted oceanic plate can generate SSEs. SSEs in different areas have different recurrence intervals. In general, the tectonic stress accumulation rates and the frictional properties on the plate boundaries control the intervals. Therefore, their differences are considered to cause the differences in the intervals. However, variations in fluid pressure will also change the intervals, because they affect the effective normal stress. Variations in fluid pressure are predicted by the earthquake-cycle model based on the fault valve behavior of Sibson (1992). So far, variations in fluid pressure associated with SSEs have not been detected by field observations. If a massive fluid pressure change occurred, gravity change could be observed since the corresponding density redistribution in the underground occurred. In the Tokai district in Japan, the SSE occurred during the years from 2000 to around 2006, and gravity changes in 2004-2009 that could be explained by a fluid pressure variation were detected (Tanaka et al., 2010). However, the quality of the data was not good due to the lower temporal resolution of the campaign data and the observation period did not cover the whole cycle of the SSE. So, a clear evidence of fluid-pressure change has not been obtained yet. In this study, we conduct a continuous gravity measurement using two absolute gravimeters and a superconducting gravimeter in Ishigakijima and Iriomotejima Islands at the Ryukyu Trench where SSEs have occurred twice a year (Heki and Kataoka, 2008) to observe a transient gravity change during the whole cycle of an SSE. In this presentation, we report gravity changes during the two slow slip events that occurred in May 2012 and December 2012.

  11. Observation of coral reefs on Ishigaki Island, Japan, using Landsat TM images and aerial photographs

    SciTech Connect

    Matsunaga, Tsuneo; Kayanne, Hajime

    1997-06-01

    Ishigaki Island is located at the southwestern end of Japanese Islands and famous for its fringing coral reefs. More than twenty LANDSAT TM images in twelve years and aerial photographs taken on 1977 and 1994 were used to survey two shallow reefs on this island, Shiraho and Kabira. Intensive field surveys were also conducted in 1995. All satellite images of Shiraho were geometrically corrected and overlaid to construct a multi-date satellite data set. The effects of solar elevation and tide on satellite imagery were studied with this data set. The comparison of aerial and satellite images indicated that significant changes occurred between 1977 and 1984 in Kabira: rapid formation in the western part and decrease in the eastern part of dark patches. The field surveys revealed that newly formed dark patches in the west contain young corals. These results suggest that remote sensing is useful for not only mapping but also monitoring of shallow coral reefs.

  12. Proposal for Japanese encephalitis surveillance using captured invasive mongooses under an eradication project on Okinawa Island, Japan.

    PubMed

    Saito, Mika; Nakata, Katsushi; Nishijima, Taku; Yamashita, Katsuhiro; Saito, Anna; Ogura, Go

    2009-06-01

    A project to eradicate invasive small Asian mongooses (Herpestes javanicus) is underway to conserve the unique ecosystem of Okinawa Island, Japan. In the present study, we tried to elucidate whether the mongoose is a host of Japanese encephalitis virus (JEV) and to evaluate the reliability of surveillance of Japanese encephalitis (JE) using this species. Culex tritaeniorhynchus, the main vector mosquito of JEV, feeds on the mongoose. Eighty-five (35.4%) of 240 wild small Asian mongooses captured between 2001 and 2005 had neutralizing antibodies against more than one of four JEV strains. Prevalence rates of JEV antibodies tended to increase with body weight and length of the animals. One of three sentinel mongooses showed a temporal change in antibody titer. These results indicate that the small Asian mongooses on Okinawa Island are sensitive to JEV. From the antibody titers and the locations of capture, the JEV active area was clarified. We propose that surveillance of JE using mongooses captured under the eradication program is reliable.

  13. Accumulation of Hg and other heavy metals in the Javan mongoose (Herpestes javanicus) captured on Amamioshima Island, Japan.

    PubMed

    Horai, Sawako; Minagawa, Mikiko; Ozaki, Hirokazu; Watanabe, Izumi; Takeda, Yasuo; Yamada, Katsushi; Ando, Tetsuo; Akiba, Suminori; Abe, Shintaro; Kuno, Katsuji

    2006-10-01

    Concentrations of 22 elements (Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, total Hg (T-Hg), Pb) and organic Hg (O-Hg) were examined in the liver, kidney and brain of the Javan mongoose (Herpestes javanicus) and in liver of the Amami rabbit (Pentalagus furnessi) from Amamioshima Island in Japan. Relatively high levels of T-Hg levels (from 1.75 to 55.5 microg g-1 wet wt.) were found in the Javan mongoose. As for a comparison of hepatic T-Hg concentrations between the two areas, there was no significant difference between the Javan mongoose in Amamioshima and those in the Okinawa islands. In addition, T-Hg levels in the livers of the Amami rabbit were the same as in the livers of other herbivorous mammals. Taken together, it suggested that T-Hg accumulation in the livers of the Javan mongoose was not affected by the environment but by a specific physiological mechanism. The comparison of Hg and other heavy metal accumulations between terrestrial mammals (13 species, 61 individuals) including the Javan mongoose and marine mammals (18 species, 508 individuals) were also discussed.

  14. Assessing tsunami-induced groundwater salinization and its temporal change: a numerical modelling study on the Niijima Island, Japan

    NASA Astrophysics Data System (ADS)

    Liu, Jiaqi; Tokunaga, Tomochika

    2016-04-01

    Groundwater is vulnerable to many natural hazards, including tsunami. As reported after the 2004 Indian Ocean earthquake and the 2011 Great East Japan earthquake, the generated massive tsunami inundations resulted in unexpected groundwater salinization in coastal areas. Water supply was strongly disturbed due to the significantly elevated salinity in groundwater. Supplying fresh water is one of the prioritized concerns in the immediate aftermath of disaster, and during long-term post-disaster reconstruction as well. The aim of this study is to assess the impact of tsunami on coastal groundwater system and provide guidelines on managing water resources in post-tsunami period. We selected the study area as the Niijima Island, a tsunami-prone area in Japan, which is under the risk of being attacked by a devastated tsunami with its wave height up to 30 m. A three-dimension (3-D) numerical model of the groundwater system on the Niijima Island was developed by using the simulation code FEFLOW which can handle both density- dependent groundwater flow and saturated-unsaturated flow processes. The model was justified by the measured water table data obtained from the field work in July, 2015. By using this model, we investigated saltwater intrusion and aquifer recovery process under different tsunami scenarios. Modelling results showed that saltwater could fully saturate the vadose zone and come into contact with groundwater table in just 10 mins. The 0.6 km2 of inundation area introduced salt mass equivalent to approximately 9×104 t of NaCl into the vadose zone. After the retreat of tsunami waves, the remained saltwater in vadose zone continuously intruded into the groundwater and dramatically salinized the aquifer up to about 10,000 mg/L. In the worst tsunami scenario, it took more than 10 years for the polluted aquifer to be entirely recovered by natural rainfall. Given that the groundwater is the only freshwater source on the Niijima Island, we can provide suggestions

  15. Vertical distribution of precipitation particles in Baiu frontal stratiform intense rainfall around Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Oue, M.; Ohigashi, T.; Tsuboki, K.; Nakakita, E.

    2015-06-01

    The vertical distribution of precipitation particles in an intensely precipitating stratiform cloud associated with the Baiu front around Okinawa Island was observed. X-band polarimetric radar, disdrometer, and hydrometeor videosonde data were used to examine the precipitation processes. The cloud top was approximately 12 km above sea level, as convection was depressed while stratiform regions developed near Okinawa Island. In the rain region below 3 km, the mean median volume diameter of the raindrop size distribution (DSD) estimated from the radar variables was 1.55 mm, and the mean normalized intercept parameter was 104.12 mm-1 m-3 with a mean radar reflectivity of 40.5 dBZe. The DSD indicates that the stratiform precipitation was characterized by higher number concentrations of smaller drops than observed previously in convective cells in a Baiu frontal convective precipitation region around Okinawa Island. The DSD also suggests the presence of larger raindrops than in convective cells embedded in a Baiu frontal stratiform precipitation region around Okinawa Island. In the ice region at 5-6 km, just above the melting layer and 6 km below the cloud top, the differential reflectivity and specific differential phase showed positive values, and videosonde measurements revealed that the number concentration of column-, plate-, and capped-column-like crystals (maximum dimensions of ≥0.1 mm) was 112 L-1. The high number concentration of these crystals contributed to the intense stratiform rainfall associated with the Baiu front.

  16. Preseismic anomalous telluric current signals observed in Kozu-shima Island, Japan.

    PubMed

    Orihara, Yoshiaki; Kamogawa, Masashi; Nagao, Toshiyasu; Uyeda, Seiya

    2012-11-20

    Monitoring of telluric current, which is practically a synonym for geoelectric potential difference, was conducted on Kozu-shima Island about 170 km south of Tokyo from May 14, 1997 to June 25, 2000. During the monitoring period, 19 anomalous telluric current changes (ATCs) were observed. Their possible correlation with nearby earthquakes was statistically examined by assuming various lead times for different ranges of magnitude and focal distance. The best correlation may be obtained for earthquakes with a magnitude greater than 3.0 occurring within 20 km of focal distance. There were 23 such earthquakes, of which 11 were preceded by ATCs within 30 d. Of these 11 earthquakes, preceding ATCs of 5 and 6 were positive and negative polarities of telluric current, respectively. Their epicenters were spatially well clustered in the east and west of the island. These facts were clearly beyond those expected by chance and led to a simple speculative model.

  17. Current status of tropical fruit breeding and genetics for three tropical fruit species cultivated in Japan: pineapple, mango, and papaya

    PubMed Central

    Ogata, Tatsushi; Yamanaka, Shinsuke; Shoda, Moriyuki; Urasaki, Naoya; Yamamoto, Toshiya

    2016-01-01

    Tropical fruit crops are predominantly produced in tropical and subtropical developing countries, but some are now grown in southern Japan. Pineapple (Ananas comosus), mango (Mangifera indica) and papaya (Carica papaya) are major tropical fruits cultivated in Japan. Modern, well-organized breeding systems have not yet been developed for most tropical fruit species. Most parts of Japan are in the temperate climate zone, but some southern areas such as the Ryukyu Islands, which stretch from Kyushu to Taiwan, are at the northern limits for tropical fruit production without artificial heating. In this review, we describe the current status of tropical fruit breeding, genetics, genomics, and biotechnology of three main tropical fruits (pineapple, mango, and papaya) that are cultivated and consumed in Japan. More than ten new elite cultivars of pineapple have been released with improved fruit quality and suitability for consumption as fresh fruit. New challenges and perspectives for obtaining high fruit quality are discussed in the context of breeding programs for pineapple. PMID:27069392

  18. Three new species of Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on Abalistes filamentosus (Pisces: Tetraodontiformes: Balistidae) from off Okinawa, Japan.

    PubMed

    Uyeno, Daisuke; Nagasawa, Kazuya

    2009-11-01

    Three new species of the copepod genus Hatschekia Poche, 1902, H. lima n. sp., H. cylindrus n. sp. and H. sunaoi n. sp., are described from the gill filaments of a triggerfish, Abalistes filamentosus Matsuura & Yoshino, caught off the Ryukyu Islands, Okinawa, Japan. These new species share an unusual morphological character, i.e. four stout posterior spines on the intercoxal sclerites of legs 1 and 2. H. lima n. sp. differs from its congeners in having a robust inner lobe on the maxillule and leg 3 with a swollen basal lobe. H. cylindrus n. sp. is distinguishable from its congeners by having a cephalothorax fused to the trunk and a double-semicircular chitinous frame. H. sunaoi n. sp. is characterised by leg 3 with a swollen basal lobe and an oval cephalothorax.

  19. Osteological and genetic analysis of the extinct Ezo wolf (Canis lupus hattai) from Hokkaido Island, Japan.

    PubMed

    Ishiguro, Naotaka; Inoshima, Yasuo; Shigehara, Nobuo; Ichikawa, Hideo; Kato, Masaru

    2010-04-01

    The Ezo wolf (Canis lupus hattai Kishida, 1931 ) is an extinct subspecies that inhabited Hokkaido in Japan until the middle of the Meiji Period. Because there are very few preserved skeletons, no osteological and/or genetic analyses of the Ezo wolf have been conducted. In this study, 20 cranial and eight mandibular characters were measured on Ezo wolf skeletons, and mitochondrial DNA (mtDNA) was analyzed to assess genetic relationships between the Ezo wolf and other wolf lineages, including the Japanese wolf on Honshu. The morphological study showed that the Ezo wolf is larger than the Japanese wolf and similar in size to the grey wolf of the Asian and American Continents. MtDNA control sequences (751 bp) from two Ezo wolves were identical to those from the Canadian grey wolf. The morphological and genetic characters indicate that the ancestor of the Ezo wolf was genetically related to that of the grey wolf in Canada.

  20. Mosquito biodiversity patterns around urban environments in South-central okinawa island, Japan.

    PubMed

    Hoshi, Tomonori; Imanishi, Nozomi; Higa, Yukiko; Chaves, Luis Fernando

    2014-12-01

    Okinawa is the largest, most urbanized, and densely populated island in the Ryukyus Archipelago, where mosquito species diversity has been thoroughly studied. However, the south-central Okinawa mosquito fauna has been relatively poorly studied. Here, we present results from a mosquito faunal survey in urban environments of Nishihara city, south-central Okinawa. Mosquitoes were sampled biweekly, from April 2007 to March 2008, at 3 different environments: a forest preserve, an animal farm, and a water reservoir. We employed 4 mosquito collection methods: 1) oviposition traps; 2) light traps; 3) sweep nets; and 4) larval surveys of tree holes, leaf axils, and artificial water containers. We collected a total of 568 adults and 10,270 larvae belonging to 6 genera and 13 species, including 6 species of medical importance: Aedes albopictus, Armigeres subalbatus, Anopheles Hyrcanus group, Culex bitaeniorhynchus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus. Mosquito species composition was similar to data from previous studies in Okinawa Island. The flattening of the species accumulation curve suggests that our diversity sampling was exhaustive with light and oviposition traps, as well as the coincidence between the species richness we found in the field and estimates from the Chao2 index, a theoretical estimator of species richness based on species abundance. This study highlights the importance of combining several sampling techniques to properly characterize regional mosquito fauna and to monitor changes in the presence of mosquito species.

  1. Characterization of early microbial communities on volcanic deposits along a vegetation gradient on the island of Miyake, Japan.

    PubMed

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species.

  2. Entamoeba marina n. sp.; a New Species of Entamoeba Isolated from Tidal Flat Sediment of Iriomote Island, Okinawa, Japan.

    PubMed

    Shiratori, Takashi; Ishida, Ken-Ichiro

    2016-05-01

    The genus Entamoeba includes anaerobic lobose amoebae, most of which are parasites of various vertebrates and invertebrates. We report a new Entamoeba species, E. marina n. sp. that was isolated from a sample of tidal flat sediment collected at Iriomote Island, Okinawa, Japan. Trophozoites of E. marina were 12.8-32.1 μm in length and 6.8-15.9 μm in width, whereas the cysts were 8.9-15.8 μm in diam. and contained four nuclei. The E. marina cells contained a rounded nucleus with a small centric karyosome and uniformly arranged peripheral chromatin. Although E. marina is morphologically indistinguishable from other tetranucleated cyst-forming Entamoeba species, E. marina can be distinguished from them based on the combination of molecular phylogenetic analyses using SSU rDNA gene and the difference of collection sites. Therefore, we propose E. marina as a new species of the genus Entamoeba.

  3. Characterization of Early Microbial Communities on Volcanic Deposits along a Vegetation Gradient on the Island of Miyake, Japan

    PubMed Central

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

  4. Sedimentary processes associated with sand and boulder deposits formed by the 2011 Tohoku-oki tsunami at Sabusawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Goto, Kazuhisa; Sugawara, Daisuke; Ikema, Satoko; Miyagi, Toyohiko

    2012-12-01

    This paper reports on the sedimentary processes of sand and boulder deposition at Sabusawa Island, Japan as a result of the 2011 Tohoku-oki tsunami. Boulders were composed of tuffaceous rocks and sourced from an earthquake-triggered slope failure as well as concrete fragments of seawall. They were scattered over the ground surface and did not form boulder ridges, although there was some local imbrication. The boulders were deposited on top of a sand layer indicating that the latter, possibly deposited from bed load, covered the ground surface first. This sand layer probably reduced friction allowing boulders to be transported more easily than might be expected across a hard ground with a high bottom friction. Sand deposits showed landward thinning and fining features, while the boulders showed a landward coarsening (tuffaceous boulders) or a landward fining (concrete boulders), indicating that large clasts were not necessarily scattered randomly but rather might have a clast size gradient with distance inland. These features are explained by the local topographic setting that constrained the directions of incoming and returning tsunami flows. Some clasts at the inland extent of the boulder field were covered by an upward fining sand layer. This feature suggests that the boulders were deposited prior to the suspended sands, with the latter subsequently laid down before the water level dropped below the top of the boulders. Such modern investigations of the sedimentary features of various sizes of grains and clasts immediately after a tsunami provide invaluable data for the reconstruction of inundation processes.

  5. Geographic genetic structure in two laticaudine sea kraits, Laticauda laticaudata and Laticauda semifasciata (Serpentes: Elapidae), in the Ryukyu-Taiwan region as inferred from mitochondrial cytochrome b sequences.

    PubMed

    Tandavanitj, Nontivich; Ota, Hidetoshi; Cheng, Yuan-Cheng; Toda, Mamoru

    2013-08-01

    The Ryukyu-Taiwan region is an island arch with intervening waters of varying distances and depths. This study examines the geographic genetic structure of two sympatric sea kraits, Laticauda laticaudata and L. semifasciata, in the region, to infer factors affecting the extent of dispersal and other biogeographical traits of these amphibious reptiles. Sequence analyses of the mitochondrial cytochrome b gene revealed four and 16 haplotypes for L. laticaudata (136 individuals) and L. semifasciata (177 individuals), respectively. For both species, population pairwise F ST analyses revealed significant genetic differentiations among islands and island groups, which are separated by deep straits, suggesting that deep waters serve as obstacles for dispersal in both species. Significant genetic differentiation was detected even among islands of the same basin in L. laticaudata, but not in L. semifasciata, and the isolation by distance analyses revealed no significant correlation between geographic and genetic distances in the former species. These results further suggest that L. laticaudata has stronger site fidelity or degree of philopatry than L. semifasciata. Based on the geographic genetic patterns, the historical biogeography of the two species in the Ryukyu-Taiwan region is also discussed.

  6. Newly found submerged reefs on the Miyako-Sone platform, Ryukyu Arc, northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Arai, K.; Matsuda, H.; Sasaki, K.; Machiyama, H.; Inoue, T.; Iryu, Y.

    2013-12-01

    Bathymetric mapping and observations of the seafloor using a remotely operated vehicle were carried out on the top of the Miyako-Sone submarine platform, northeast of Miyako-jima, Ryukyu Islands, northwestern Pacific. The high-resolution bathymetric map provides a detailed geomorphology and spatial distribution of submerged reefs and terraces on the platform. Our observations show that a submerged reef occurs at a water depth of ca. 55 m as a barrier reef that are up to 500 m across (from east to west) and 1,000 m lonng (from north to south) with a prominent ridge structure (reef crest). The submerged reef deepens westward from the crest along which spurs and grooves are well developed. A shallow lagoon extends on the east of the crest. Submersible observations confirm that the submerged reef now serves a hard substrate on which soft corals and algae grow. Terraces form at a water depth of ca. 110 m around a submerged reef on the northwestern Miyako-Sone platform. Submersible observations show the terrace surface is extensivbely covered with modern rhodoliths and living larger benthic foraminifers. Well-preserved coral-reef topography likely indicates limited sediment transportion from Miyako-jima and Okinwa-jima islands to the Miyako-Sone submarine platform. We plan to provide chronological constraint by direct sampling from the submerged reef and terraces, which enable to delineate a global deglacial sea-level history especially during early deglacial times in the northwestern Pacific.

  7. Tectonics and petroleum potential of sedimentary basins in the Bering, Okhotsk, Japan seas, and island arcs

    SciTech Connect

    Levin, L.E. )

    1993-09-01

    In this vast region located in the northwestern part of the Pacific rim, basins of two main genetic types possess petroleum potential. These two types are represented by basins of the recent active margin and basins of the transitional zone between analogs of the passive margin and the recent active margin. For basins of the active margin, the mean density of potential resources is estimated at 5000 MT/km[sup 2] or more. The total area of these basins is 324,000 km[sup 2] among which 120,000 km[sup 2] are in the Russian sector. Ultimate resources of hydrocarbons are estimated at 1.62 billing MT of oil equivalent. Basins of the zone, transitional from analogs of the passive margin to the recent active margin, are characterized by a number of factors favorable for petroleum occurrence. One of the important factors is the presence of rift trough and foredeeps that are potential sites for zones of oil and gas accumulation. The age of the rifts varies from the late Cretaceous through the Oligocene-Miocene in the Olyutorsky and Litke basins, to the Neogene in the Okhotsk Sea and Tatar-Japan basins. Only a small area of the rifts has been proven to contain zones of oil and gas accumulation. Based on the structural characteristics, the rifts are subdivided into oil-gas bearing, potentially oil-gas bearing, and nonprospective for hydrocarbon exploration. Potential hydrocarbon resources of basins of this type are estimated to be not less than 15.12 billion MT of oil equivalent including 9.2 billion MT in the Russian sector. New large zones of oil and gas accumulation are expected to be found both on the shallow shelf and in some deep-water basins such as in the Aleutian and Kuril basins.

  8. Characteristics of atmospheric aerosols containing heavy metals measured on Fukue Island, Japan

    NASA Astrophysics Data System (ADS)

    Hidemori, Takehiro; Nakayama, Tomoki; Matsumi, Yutaka; Kinugawa, Takashi; Yabushita, Akihiro; Ohashi, Masafumi; Miyoshi, Takao; Irei, Satoshi; Takami, Akinori; Kaneyasu, Naoki; Yoshino, Ayako; Suzuki, Ryota; Yumoto, Yayoi; Hatakeyama, Shiro

    2014-11-01

    To investigate transport and chemical compositions of fine aerosols in the East Asian region, aerosol chemical components and their mixing states were measured at Fukue Island in the spring of 2010. Off-line chemical analyses using an ion chromatographic analyzer and an inductively coupled plasma-mass spectrometer for the aerosols sampled by a high volume sampler have also been conducted. The mixing state and temporal variation of number concentrations of the particles containing lead (Pb) and vanadium (V) were studied by using a laser ionization single-particle aerosol mass spectrometer (LISPA-MS). The temporal variation of number concentrations of particles containing Pb measured by the LISPA-MS is well consistent with those obtained by the chemical analysis of the aerosols sampled by the high volume sampler. The Pb-containing particles were classified into four types from the statistical analysis on the basis of the single-particle mass spectra with assists of laboratory experiments. It is estimated that 52% of observed particles containing Pb were originated from coal combustion. The concentration-weighted trajectory (CWT) analysis suggests that these particles are mainly transported from China continent. The V-containing particles were classified into three types. The 41% of V-containing particles were internally mixed with sea salt and the result of CWT analysis suggests that the potentially anthropogenic V-containing particles possibility emitted from ships are mixing with sea salt in the region that is highly loaded with sea salt in the Pacific Ocean.

  9. Properties of GPS noise at Japan islands before and after Tohoku mega-earthquake.

    PubMed

    Lyubushin, Alexey; Yakovlev, Pavel

    2014-01-01

    The field of 3-components GPS signals is analyzed for the network of 1203 stations at the Japanese islands from January 30 up to March 26, 2011. This time interval includes just over 40 days of observation before the Tohoku mega-earthquake on March 11, 2011 (M = 9.0) and nearly 16 days of observation following this event. The signals from each station are three-component time series with time step 30 minutes. We study the statistical properties of the random fluctuations of GPS signals before and after the seismic catastrophe after transition to increments. The values of wavelet-based spectral index for GPS noise components for each station were estimated separately for pieces of records before and after seismic event. The maps of the noise spectral index are constructed as the values for grid size of 50 × 50 nodes covering the region under study, based on information from 10 stations closest to each node. These maps clearly extract the region of future seismic catastrophe by relatively high noise spectral index. The using of principal components method distinguished this spatial anomaly more explicitly. These results support the hypothesis that statistical properties of random fluctuations of geophysical fields carry important information about earthquake preparation.

  10. On the Fourth Diadema Species (Diadema-sp) from Japan

    PubMed Central

    Chow, Seinen; Kajigaya, Yoshikazu; Kurogi, Hiroaki; Niwa, Kentaro; Shibuno, Takuro; Nanami, Atsushi; Kiyomoto, Setuo

    2014-01-01

    Four long-spined sea urchin species in the genus Diadema are known to occur around the Japanese Archipelago. Three species (D. savignyi, D. setosum, and D. paucispinum) are widely distributed in the Indo-Pacific Ocean. The fourth species was detected by DNA analysis among samples originally collected as D. savignyi or D. setosum in Japan and the Marshall Islands and tentatively designated as Diadema -sp, remaining an undescribed species. We analyzed nucleotide sequences of the cytochrome oxidase I (COI) gene in the “D. savignyi-like” samples, and found all 17 individuals collected in the mainland of Japan (Sagami Bay and Kyushu) to be Diadema-sp, but all nine in the Ryukyu Archipelago (Okinawa and Ishigaki Islands) to be D. savignyi, with large nucleotide sequence difference between them (11.0%±1.7 SE). Diadema-sp and D. savignyi shared Y-shaped blue lines of iridophores along the interambulacrals, but individuals of Diadema-sp typically exhibited a conspicuous white streak at the fork of the Y-shaped blue iridophore lines, while this feature was absent in D. savignyi. Also, the central axis of the Y-shaped blue lines of iridophores was approximately twice as long as the V-component in D. savignyi whereas it was of similar length in Diadema-sp. Two parallel lines were observed to constitute the central axis of the Y-shaped blue lines in both species, but these were considerably narrower in Diadema-sp. Despite marked morphological and genetic differences, it appears that Diadema-sp has been mis-identified as D. savignyi for more than half a century. PMID:25054386

  11. Modelling of wave propagation and attenuation in the Osaka sedimentary basin, western Japan, during the 2013 Awaji Island earthquake

    NASA Astrophysics Data System (ADS)

    Asano, Kimiyuki; Sekiguchi, Haruko; Iwata, Tomotaka; Yoshimi, Masayuki; Hayashida, Takumi; Saomoto, Hidetaka; Horikawa, Haruo

    2016-03-01

    On 2013 April 13, an inland earthquake of Mw 5.8 occurred in Awaji Island, which forms the western boundary of the Osaka sedimentary basin in western Japan. The strong ground motion data were collected from more than 100 stations within the basin and it was found that in the Osaka Plain, the pseudo velocity response spectra at a period of around 6.5 s were significantly larger than at other stations of similar epicentral distance outside the basin. The ground motion lasted longer than 3 min in the Osaka Plain where its bedrock depth spatially varies from approximately 1 to 2 km. We modelled long-period (higher than 2 s) ground motions excited by this earthquake, using the finite difference method assuming a point source, to validate the present velocity structure model and to obtain better constraint of the attenuation factor of the sedimentary part of the basin. The effect of attenuation in the simulation was included in the form of Q(f) = Q0(f/f0), where Q0 at a reference frequency f0 was given by a function of the S-wave velocity, Q0 = αVS. We searched for appropriate Q0 values by changing α for a fixed value of f0 = 0.2 Hz. It was found that values of α from 0.2 to 0.5 fitted the observations reasonably well, but that the value of α = 0.3 performed best. Good agreement between the observed and simulated velocity waveforms was obtained for most stations within the Osaka Basin in terms of both amplitude and ground motion duration. However, underestimation of the pseudo velocity response spectra in the period range of 5-7 s was recognized in the central part of the Osaka Plain, which was caused by the inadequate modelling of later phases or wave packets in this period range observed approximately 2 min after the direct S-wave arrival. We analysed this observed later phase and concluded that it was a Love wave originating from the direction of the east coast of Awaji Island.

  12. Nagoya, Ise Bay, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This view of Nagoya, Ise Bay and nearby Kyoto, on the main island of Honshu, Japan (35.0N, 137.0E) combines in a single photo both the political, cultural and educational centers of early Japan as well as one of the main educational and business centers of modern Japan. Besides being a business, cultural and educational center, Nagoya is near the geographic center of the Japanese home islands.

  13. Dioxins and related compounds in albatrosses from the Torishima Island, Japan: accumulation features by growth stage and toxicological implications.

    PubMed

    Kunisue, Tatsuya; Nakanishi, Shigeyuki; Oka, Nariko; Sato, Fumio; Tsurumi, Miyako; Tanabe, Shinsuke

    2006-11-15

    Concentrations of dioxins and related compounds (DRCs), such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs), were determined in eggs, nestlings, and adults of black-footed albatross (BfA; Diomedea nigripes) and short-tailed albatross (StA; Diomedea albatrus) collected from the Torishima Island in Japan during 2002, which is one of their breeding grounds. Observed DRC concentrations, especially PCDFs and non-ortho Co-PCBs, in eggs of BfA and StA were relatively higher than those in other oceanic, coastal, and inland wild birds reported recently and were comparable to those in a pooled BfA egg from Midway Atoll in 1993, implying continuous input of these contaminants into open ocean and possible albatross-specific exposure. Concentrations of PCDDs except 12378-P5CDD and high-chlorinated PCDFs in 3-month-old BfA nestling were lowerthan those in 1-month-old nestling, indicating their developmental dilution. On the other hand, higher levels of T4-H6CDFs and Co-PCBs, especially low-chlorinated congeners such as 2378-T4CDF and T4CB77, were found in 3-month-old BfA nestling, suggesting specific exposure to these contaminants, possibly due to their higher transportability than high-chlorinated congeners. Estimated biomagnification factors of almost all the congeners in adults were apparently greater than those in nestlings, except 2378-T4CDF, T4CB77, and H7-O8-CDD/Fs. This could be due to preferential metabolism of 2378-T4CDF and T4CB77 and lower uptake efficiency of high-chlorinated congeners through the gastrointestinal tract in adults. Toxic equivalents in BfA and StA eggs estimated using WHO-avian toxic equivalency factors exceeded some toxicity thresholds for avian embryos, indicating possible adverse effects of DRCs to albatross embryos.

  14. Source Mechanism of May 30, 2015 Bonin Islands, Japan Deep Earthquake (Mw7.8) Estimated by Broadband Waveform Modeling

    NASA Astrophysics Data System (ADS)

    Tsuboi, S.; Nakamura, T.; Miyoshi, T.

    2015-12-01

    May 30, 2015 Bonin Islands, Japan earthquake (Mw 7.8, depth 679.9km GCMT) was one of the deepest earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 60 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. We use the velocity structure model IASP91 to calculate the wavefield near source and stations. We assume that the fault is squared with the length 50 km. We obtain source rupture model for both nodal planes with high dip angle (74 degree) and low dip angle (26 degree) and compare the synthetic seismograms with the observations to determine which source rupture model would explain the observations better. We calculate broadband synthetic seismograms with these source propagation models using the spectral-element method (Komatitsch & Tromp, 2001). We use new Earth Simulator system in JAMSTEC to compute synthetic seismograms using the spectral-element method. The simulations are performed on 7,776 processors, which require 1,944 nodes of the Earth Simulator. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 3.8 seconds and longer requires about 5 hours of CPU time. Comparisons of the synthetic waveforms with the observation at teleseismic stations show that the arrival time of pP wave calculated for depth 679km matches well with the observation, which demonstrates that the earthquake really happened below the 660 km discontinuity. In our present forward simulations, the source rupture model with the low-angle fault dipping is likely to better explain the observations.

  15. Rhyolite lava fracturing and degassing induced spherulitic growth of Sawajiriwan and Sanukayama lavas in Kozushima Island, Japan

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Uno, K.; Kanamaru, T.

    2015-12-01

    Sawajiriwan and Sanukayama rhyolite lavas are distributed along west and east coasts of Kozushima Island, Japan, respectively (Taniguchi, 1977). They were erupted in about 40,000-50,000 years ago (Yokoyama et al., 2004). The both lavas are characterized by alignment of spherulites as well as previous works (Seaman et al., 2009; Clay et al., 2013). Seaman et al. (2009) attributed the spherulite alignment to the contrasting water concentration and concluded that the heterogeneity of water contents has already achieved within the magma chamber. In this study, we propose that development of the spherulite alignment is significantly related to the fracturing within the lavas. In Sawajiriwan lava, the distal part is well exposed and shows ramp structure and reverse faults with ductile-deformed fault planes. The both structures were formed within consistent compressional stress deduced from their geometry. Discrepancy of the structure would be attributed to the strain rate variation within the advancing lava. The spherulite alignment is characteristically developed along the planes. This indicates that the fractures acted as degassing pathway, and the part achieved large undercooling. The fault planes would be healed and deformed after decreasing strain rate, and spherulites were eventually grown along the planes. In Sanukayama lava, the ductile-deformed cataclastic faults are often developed as well as Sawajiriwan lava. The cataclasite is composed of porphyroclasts and nano- and micro-scale fine particles such as microlite and crystalline fragments. Microscopic observation clearly showed that the fine particles are released from the fault margin into the surrounding melt and are aligned along the flow line. Spherulites typically nucleated on the aligned fine particles, and consequently spherulite alignment was developed. We concluded from the lavas that development of the spherulite alignment is significantly related to the fracturing within the lavas.

  16. A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus

    PubMed Central

    Vonk, Ronald; Hoeksema, Bert W.; Jaume, Damià

    2011-01-01

    Abstract Psammogammarus wallacei sp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided. PMID:21998551

  17. A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus.

    PubMed

    Vonk, Ronald; Hoeksema, Bert W; Jaume, Damià

    2011-01-01

    Psammogammarus wallaceisp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided.

  18. An investigation for population maintenance mechanism in a miniature garden: genetic connectivity or independence of small islet populations of the Ryukyu five-lined skink.

    PubMed

    Kurita, Kazuki; Hikida, Tsutomu; Toda, Mamoru

    2014-01-01

    The Ryukyu five-lined skink (Plestiodon marginatus) is an island lizard that is even found in tiny islets with less than half a hectare of habitat area. We hypothesized that the island populations are maintained under frequent gene flow among the islands or independent of each other. To test our hypotheses, we investigated genetic structure of 21 populations from 11 land-bridge islands that were connected during the latest glacial age, and 4 isolated islands. Analyses using mitochondrial cytochrome b gene sequence (n = 67) and 10 microsatellite loci (n = 235) revealed moderate to high levels of genetic differentiation, existence of many private alleles/haplotypes in most islands, little contemporary migration, a positive correlation between genetic variability and island area, and a negative correlation between relatedness and island area. These evidences suggest a strong effect of independent genetic drift as opposed to gene flow, favoring the isolation hypothesis even in tiny islet populations. Isolation-by-distance effect was demonstrated and it became more prominent when the 4 isolated islands were excluded, suggesting that the pattern is a remnant of the land-bridge age. In a few island populations, however, the possibility of occasional overwater dispersals was partially supported and therefore could not be ruled out.

  19. Mantle flow field in the southern Ryukyu subduction system

    NASA Astrophysics Data System (ADS)

    Lin, S.; Kuo, B.

    2012-12-01

    The Okinawa trough in the Ryukyu subduction system is the only active back arc basin formed within a continental lithosphere. Recent shear-wave splitting measurements show variable fast directions along the trough suggesting complex three-dimensional flow field in the mantle wedge. In this study we use numerical subduction models to explore the effects of plate thickness variations caused by non-uniform lithospheric stretching on the dynamics in the southern Ryukyu subduction system. We calculate orientations of infinite strain axes as a proxy for olivine lattice preferred orientations and orientations of seismic anisotropy. Our models demonstrate that flow patterns may vary significantly with depth near the plate edge as a result of the along-arc variations in lithospheric thickness. The model results show that the toroidal circulation around the lateral slab edge predominates at greater depths. The thick neighboring lithosphere acts as an effective barrier of the lateral mass exchanges in the shallow portion of the mantle wedge. The wedge material is drawn in horizontally toward the plate edge from the central region of the subduction zone induced by pressure gradients, opposite to the inwards lateral flow at greater depths. Model predictions for the lattice preferred orientations of olivine aggregates agree reasonably well with the observed shear-wave splitting patterns. The results suggest that the depth-varying flow field near the subduction zone edge and the westward flow components in the shallow portion of the mantle wedge may contribute to complex patterns of seismic anisotropy and arc isotopic systematics.

  20. Seismic structure related to the Philippine Sea plate subduction beneath the southwestern Nansei-Shoto (Ryukyu) Trench

    NASA Astrophysics Data System (ADS)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.

    2013-12-01

    The northwestern part of the Philippine Sea plate (PSP) is subducting beneath the Nansei-Shoto (Ryukyu) Trench. Earthquakes larger than M8 have not been recorded instrumentally in the southwestern part of the Ryukyu Trench. However, there was a large tsunami killed around 12,000 people in 1771 and the position of the source area has not been established. The direction of the PSP subduction is almost perpendicular to the Ryukyu Trench to the northeast of 126.5 E and changes to oblique to the southwest. Seismicity varies along the trench axis and lower seismicity seems to correspond to the free-air gravity anomaly high region in the forearc at around 126 E. On the other hand, the Okinawa-Luzon fracture zone extending from southwest to northeast on the PSP subducts beneath Ryukyu Trench to the northeast of 126 E and seems to relate to the high gravity anomaly. We carried out seismic experiments to elucidate these inhomogeneous crustal structures along the southwestern part of the trench and provide valuable information on potential source areas for large earthquakes and/or tsunamis. We conducted five seismic lines across southwestern Ryukyu Trench region. Multichannel reflection seismic (MCS) data using 240 ch. and 3000 m long hydrophone streamer were collected for airgun shots at an interval of 50 m. We also deployed ocean bottom seismographs (OBSs) as a receiver at an average interval of 5 km along each line. A tri-gun cluster with a volume of 1,050 (350 * 3) cubic inches (17.2 liters) was used for the reflection surveys and a non-tuned airgun array with a volume of 6,000 (1500 * 4) cubic inches (98 liters) was shot at an interval of 200 m (90 sec) for the wide-angle seismic survey. Depth conversion from the MCS time section was carried out using the refraction results. In this paper, we present the seismic structure related to the PSP subduction in the forearc region of the Nansei-Shoto island arc. The subducting Okinawa-Luzon fracture zone was able to be clearly

  1. Sanfilippo type B syndrome: five patients with an R565P homozygous mutation in the alpha-N-acetylglucosaminidase gene from the Okinawa islands in Japan.

    PubMed

    Chinen, Yasutsugu; Tohma, Takaya; Izumikawa, Yoshinori; Uehara, Hiroyuki; Ohta, Takao

    2005-01-01

    Sanfilippo type B syndrome (mucopolysaccharidosis type IIIB; MPS IIIB) is an autosomal recessive lysosomal storage disorder that is caused by defective alpha- N-acetylglucosaminidase (NAGLU). We performed NAGLU gene analysis in five patients with MPS IIIB whose respective parents from the Okinawa islands in Japan were not apparently consanguineous. We found a missense mutation (R565P) in all five patients (all homozygotes). We screened this mutation in 200 healthy subjects and found one heterozygote (none of the subjects were related to the patients). These results suggest that there may be a founder effect that results in the accumulation of R565P mutation in this area.

  2. Phosphorus and iron cycles during early diagenesis of Lake Kai-ike sediments, Kami-koshiki Island, southwest Japan

    NASA Astrophysics Data System (ADS)

    Iida, H.; Yamaguchi, K. E.; Oguri, K.

    2014-12-01

    A meromictic Lake Kai-ike is located on the northeastern margin of Kami-koshiki island, Japan. Permanent density stratification develops due to seawater infiltration through a gravel bar separating the lake from the ocean. The oxygenated surface water overlays a stagnant, saline, and anoxic deep water containing hydrogen sulfide. Purple sulfur bacteria (Chromatium sp.) inhabit the chemocline at 4.5m depth. At the lake bottom, green sulfur bacteria form microbial mat-like structures (Nakajima et al., 2003; Environ. Microbiol.). Such environment can be treated as a model for the past anoxic ocean, such as during Cretaceous OAEs (Oguri et al., 2003; Frontier Res. on Earth Evol.). A 25 cm-long KAI4 sediment core (Yamaguchi et al., 2010; Palaeo3) was used for two sequential extraction methods. SEDEX method (Ruttenberg, 1992; Limnol. Oceanogr.) was used for partitioning phosphorus-bearing species into Pabs (absorbed), PFe (Fe-bound), Pauth (authigenic), Pdet (detrital), and Porg (organic). Iron-bearing species were also divided into FeHCl (HCl-soluble), Fecarb (carbonate), Feox (oxide), Femag (magnetite), and Feresi (residue), following the method of Poulton et al. (2005; Chem. Geol.). At the uppermost part of KAI4 core, Porg was the most abundant P-bearing species (~90% of total P). The Porg content sharply decreased with increasing depth to 5cm. The second most abundant species was PFe; however, PFe and Feox contents remained constant throughout the whole depth. At sediment surface in present-day oxygenated ocean, Fe3+-(oxy)hydroxides trap phosphate diffusing from deeper-anoxic sediment, and the phosphate concentration in pore water becomes high enough to precipitate authigenic apatite (Slomp et al., 1996; J. Mar. Res.). In case of Lake Kai-ike, however, the amount of Fe3+-(oxy)hydroxides was small relative to that of Porg (PFe/Porg = ~0.1). We suggest that the excess phosphate not adsorbed on Fe3+-(oxy)hydroxides was diffused out to the overlying water mass, and the

  3. Characterization of Heavy Metal Contents in the Bulk Atmospheric Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan by X-ray fluorescence spectrometric method (XRF)

    NASA Astrophysics Data System (ADS)

    Oshiro, Y.; ITOH, A.; Azechi, S.; Somada, Y.; Handa, D.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    We studied heavy metal contents of atmospheric aerosols using an X-ray fluorescence spectrometric method (XRF). The XRF method enables us to analyze heavy metal contents of bulk aerosols rapidly without any chemical pretreatments. We used an energy dispersive X-ray fluorescence spectrometer that is compact and portable. We prepared several different amounts of standard reference materials (NIES No.28) of Japanese National Institute of Environmental Studies on quartz filters for calibration curves. Then, we evaluated quantitative responses of XRF method by comparing with the metal contents determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after acid-digestion. Good linear relationships between X-ray intensity and amount of aerosol on filter were seen in the following 10 metals; Al, K, Ti, V, Fe, Ni, Rb, Ba, Pb and As. We then used XRF method to determine heavy metal contents in authentic atmospheric aerosols collected in Okinawa islands, Japan. Okinawa islands, consisting of many small islands, are situated east of Asian continent, and its location in Asian is well suited for studying long-range transport of air pollutants. Also, in Okinawa islands, maritime air mass prevails during summer, while Asian continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air mass which has been affected by anthropogenic activities such as industries and automobiles. Therefore, Okinawa region is suitable area for studying impacts of air pollutants from East Asia. We simultaneously collected bulk aerosol samples by using identical high-volume air samplers at 3 islands; Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS). We report and discuss spatial and temporal distribution of heavy metals

  4. Japan: Shikoku Island

    Atmospheric Science Data Center

    2016-08-24

    ... U.S. National Oceanographic and Atmospheric Administration (NOAA) Research Vessel Ron Brown and the National Science Foundation ... For more about ACE-Asia, visit  http://saga.pmel.noaa.gov/Field/aceasia/ . MISR was built and is managed by NASA's Jet ...

  5. Novel Genetic Variants of Anaplasma phagocytophilum, Anaplasma bovis, Anaplasma centrale, and a Novel Ehrlichia sp. in Wild Deer and Ticks on Two Major Islands in Japan

    PubMed Central

    Kawahara, Makoto; Rikihisa, Yasuko; Lin, Quan; Isogai, Emiko; Tahara, Kenji; Itagaki, Asao; Hiramitsu, Yoshimichi; Tajima, Tomoko

    2006-01-01

    Wild deer are one of the important natural reservoir hosts of several species of Ehrlichia and Anaplasma that cause human ehrlichiosis or anaplasmosis in the United States and Europe. The primary aim of the present study was to determine whether and what species of Ehrlichia and Anaplasma naturally infect deer in Japan. Blood samples obtained from wild deer on two major Japanese islands, Hokkaido and Honshu, were tested for the presence of Ehrlichia and Anaplasma by PCR assays and sequencing of the 16S rRNA genes, major outer membrane protein p44 genes, and groESL. DNA representing four species and two genera of Ehrlichia and Anaplasma was identified in 33 of 126 wild deer (26%). DNA sequence analysis revealed novel strains of Anaplasma phagocytophilum, a novel Ehrlichia sp., Anaplasma centrale, and Anaplasma bovis in the blood samples from deer. None of these have been found previously in deer. The new Ehrlichia sp., A. bovis, and A. centrale were also detected in Hemaphysalis longicornis ticks from Honshu Island. These results suggest that enzootic cycles of Ehrlichia and Anaplasma species distinct from those found in the United States or Europe have been established in wild deer and ticks in Japan. PMID:16461655

  6. Petrology of Early Miocene volcanic rocks from Okushiri Island, Japan: geochemical characteristics of lithospheric mantle beneath the back-arc side of the NE Japan arc.

    NASA Astrophysics Data System (ADS)

    Sato, M.; Shuto, K.; Ishimoto, H.; Yagi, M.; Takazawa, E.

    2004-12-01

    The Sr and Nd isotopic studies on Tertiary to Quaternary basaltic rocks of the NE Japan arc have shown that isotopic characteristics of basaltic rocks found on the back-arc side of the NE Japan arc changed drastically from an undepleted isotopic signature (initial 87Sr/86Sr (SrI)=0.7040-0.7060 and initial 143Nd/144Nd (NdI)=0.51260-0.51284) to a depleted isotopic signature (SrI=0.7030-0.7040 and NdI=0.70284-0.51308) at around 15 Ma (Shuto et., 2004). This feature may have resulted from changes around 15 Ma in the isotopic compositions of the magma source beneath the back-arc side in the NE Japan arc due to the thinning of the undepleted subcontinental lithospheric mantle by upwelling of depleted asthenospheric mantle material during the opening of Japan Sea. Based on major and trace element data as well as SrI and NdI values for Early Miocene basaltic rocks from the back-arc side of the NE Japan arc, we examined geochemical characterization of the magma source (lithospheric mantle) for these basaltic rocks. Early Miocene (23-18 Ma) basalts and associated more felsic volcanic rocks form seven volcanic fields (Okushiri Is., Matsumae Pen., Fukaura, Oga Pen., Honjo, Atsumi and Sado Is.) delineating a 500 km-long array in the back-arc side of the NE Japan arc. In terms of major, trace element and Nd isotopic compositions, two groups of Early Miocene basalts can be distinguished. Group 1 is composed of tholeiitic basalts and alkali basalts, and is characterized by high TiO2 contents (1.5-2.5 %) and high (La/Yb)n ratios (>5.5), and high Zr/Y ratios (>6). These samples show the chondrite-normalized LREE-enriched patterns and have NdI values ranging from 0.51259 to 0.51282. Group 2 is composed of tholeiitic basalts, and is different from Group 1 by lower TiO2 contents (<1.5 %), lower (La/Yb)n ratios (<5) and lower Zr/Y ratios (<5.5). These samples show modelately LREE-enriched patterns and have NdI values ranging from 0.51250 to 0.51278. In contrast, Middle Miocene (after 15

  7. Coseismic deformation due to the 2011 Tohoku earthquake: influence of 3-D plate structure around Japan

    NASA Astrophysics Data System (ADS)

    Hashima, A.; Freed, A. M.; Becker, T. W.; Sato, H.; Okaya, D. A.; Suito, H.; Hatanaka, Y.; Matsubara, M.; Takeda, T.; Ishiyama, T.; Iwasaki, T.

    2013-12-01

    Beneath the Japan islands, the Pacific plate descends from the east and the Philippine sea plate descends from the south, causing interaction of two slabs at depth. The 2011 M9 Tohoku earthquake in northern Japan had a source region with a length of ~500 km and a width of ~200 km and forced broad lithospheric and mantle regions in the region to deform. Here, we investigate the effects of slab geometry and 3D heterogeneity on the inversion of inferred coseismic slip and the resulting broad coseismic deformation throughout the region. We construct a 3-D finite element model (FEM) to generate Green's functions for use in a coseismic inversion study that allows considering the influence of complex slab geometry as well as heterogeneities in elastic structure on inferred slip. We utilize the large, land-based Japan GPS array as well as seafloor geodetic constraints in the inversion. We are particularly interested in how coseismic seafloor constraints influence inversion results. Our FEM considers a region of 4500 km x 4900 km x 670 km, incorporating the Pacific and the Philippine sea slabs by interpolating models for the Tohoku region and the Nankai trough, as well as the Kuril, Ryukyu and Izu-Bonin arcs. The model region is divided into about 500,000 tetrahedral elements with average dimension ranging from 20-100 km. We also test the role of gravity on coseismic results, with initial results suggesting that gravitational loading is not an important factor because of the shallow dip of the upper Pacific slab.Our long-term objective is to study the influence of the Tohoku earthquake on evolution of stresses throughout Japan due to both coseismic and postseismic processes, the latter including afterslip and viscoelastic relaxation. An accurate accounting of coseismic slip is very important to such an endeavor.

  8. Phylogeography, Interaction Patterns and the Evolution of Host Choice in Drosophila-Parasitoid Systems in Ryukyu Archipelago and Taiwan.

    PubMed

    Novković, Biljana; Kimura, Masahito T

    2015-01-01

    Island biotas provide a great opportunity to study not only the phylogeographic patterns of a group of species, but also to explore the differentiation in their coevolutionary interactions. Drosophila and their parasitoids are exemplary systems for studying complex interaction patterns. However, there is a lack of studies combining interaction-based and molecular marker-based methods. We applied an integrated approach combining phylogeography, interaction, and host-choice behavior studies, with the aim to understand how coevolutionary interactions evolve in Drosophila-parasitoid island populations. The study focused on the three most abundant Drosophila species in Ryukyu archipelago and Taiwan: D. albomicans, D. bipectinata, and D. takahashii, and the Drosophila-parasitoid Leptopilina ryukyuensis. We determined mitochondrial COI haplotypes for samples representing five island populations of Drosophila and four island populations of L. ryukyuensis. We additionally sequenced parts of the autosomal Gpdh for Drosophila samples, and the ITS2 for parasitoid samples. Phylogenetic and coalescent analyses were used to test for demographic events and to place them in a temporal framework. Geographical differences in Drosophila-parasitoid interactions were studied in host-acceptance, host-suitability, and host-choice experiments. All four species showed species-specific phylogeographic patterns. A general trend of the haplotype diversity increasing towards the south was observed. D. albomicans showed very high COI haplotype diversity, and had the most phylogeographically structured populations, with differentiation into the northern and the southern population-group, divided by the Kerama gap. Differentiation in host suitability was observed only between highly structured populations of D. albomicans, possibly facilitated by restricted gene flow. Differentiation in host-acceptance in D. takahashii, and host-acceptance and host-choice in L. ryukyuensis was found, despite there

  9. Atmospheric mercury concentrations at two sites in the Kyushu Islands, Japan, and evidence of long-range transport from East Asia

    NASA Astrophysics Data System (ADS)

    Marumoto, Kohji; Hayashi, Masahiko; Takami, Akinori

    2015-09-01

    Continuous monitoring of atmospheric gaseous mercury at Fukuoka and Minamata in the Kyushu Islands, western Japan, was carried out from June 2012 to May 2013 to investigate the influence of long-range transport of mercury in the Asian region. Speciation data at Fukuoka indicated that approximately 99% of the atmospheric mercury was in the gaseous elemental form. The average concentration of gaseous elemental mercury (GEM) at Fukuoka was slightly higher than that of total gaseous mercury (TGM) at Minamata. Synchronous pollution events of higher concentrations of both GEM at Fukuoka and TGM at Minamata were frequently observed from late fall to early spring. We infer that these events occurred due to long-range transport of mercury rather than local, domestic emission sources because the two sites are far apart (about 150 km), and local sources would be unlikely to synchronously influence concentrations at both sites over such a long distance. The results of backward trajectory analyses indicated that these events occurred when air masses came from the Asian continent. In addition, the pollution events were often the result of cold fronts or migratory anticyclones that passed over the Kyushu Islands, often accompanied by descending cool and heavy air currents. Thus, these results indicate that, under specific climate conditions, higher concentrations of atmospheric mercury are transported to the Kyushu Islands from the Asian continent, and are evident in ground-based observations there.

  10. Seasonally resolved sea surface temperature variability over the past 435 years in the northwestern Pacific recorded in Porites coral in Kikai Island, Southern Japan

    NASA Astrophysics Data System (ADS)

    Kawakubo, Y.; Yokoyama, Y.; Suzuki, A.; Alibert, C.; Kinsley, L.; Eggins, S. M.

    2011-12-01

    The Little Ice Age (LIA) is the most recent climate anomaly. According to the hemispheric scale surface temperature reconstructions based on the proxy records in various places, LIA is characterized by the cooling period between 1400 and 1850. However, since these proxy records mainly depend on the terrestrial records in mid to high latitude in the northern hemisphere and the marine records are limited, there is still no consensus concerning its spatial pattern, timing and cause. In June 2009, we obtained a 435-year-long modern core from a coral reef in Kikai Island, Japan. The island is located on the eastern boundary of the East China Sea in the northwestern Pacific. This modern coral core can date back to the LIA. Thus, to better understand the LIA, we reconstructed seasonally resolved sea surface temperature (SST) over the past 435 years in the northwestern Pacific, where it is a lack of records during LIA, based on Sr/Ca ratio in coral skeleton in Kikai Island. We analyzed the skeletal elements using laser ablation inductively coupled plasma mass spectorometry (LA-ICP-MS). This is a very powerful tool to handle long-term records since it requires a relatively brief experimental time compared with the analysis using isotope dilution or thermal ionazation ICP-MS. Our SST reconstruction in Kikai Island during LIA showed cooler period before 1700 and a bit warmer period between 1700 and 1850 compared with the average after the LIA. Based on these results, we discuss the paleoceanographic conditions in the northwestern Pacific during the LIA.

  11. High-resolution MIRU-VNTRs typing reveals the unique nature of Mycobacterium tuberculosis Beijing genotype in Okinawa, Japan.

    PubMed

    Millet, Julie; Miyagi-Shiohira, Chika; Yamane, Nobuhisa; Mokrousov, Igor; Rastogi, Nalin

    2012-06-01

    Mycobacterium tuberculosis Beijing lineage is highly prevalent in Japan. The aim of the present study was to describe the population structure of the Beijing lineage in this country based on 12-, 15-, and 21-loci MIRU-VNTR genotyping schemes. The MIRU-VNTR patterns of Beijing strains from Okinawa, Ryukyu Islands were compared to those recently published from the Osaka-Kobe megalopolis of the main island of Japan, Honshu (Wada et al., 2009). We also compared proportions of "modern/typical" vs. "ancient/atypical" Beijing strains as defined by structure of the NTF locus. Contrarily to the 12-loci Minimum Spanning Tree (MST), the 15- and 21-loci trees allowed the distinction of two groups of strains in Okinawa. A 12-loci MIRU-VNTR pattern (223325173533) corresponding to MIRU international type MIT17 was identified as the most prevalent Beijing genotype in Japan. In the SITVIT2 database, this pattern was found to be disseminated worldwide and corresponded to the most widely distributed Beijing profile in East Asia and former USSR countries. A comparison of 15- and 21-loci MIRU-VNTR patterns showed that two loci (QUB-4156 and Mtub21) were most polymorphic in our study, and could be potential candidates to distinguish between NTF locus based subclassification of Beijing strains. High-resolution VNTR typing using 15- and 21-loci underlined an evolutionarily distinct "ancient/atypical" subpopulation of the Beijing genotype in Okinawa as well as a subgroup of strains closely related to "modern/typical" Beijing strains observed in Osaka/Kobe.

  12. Low-temperature thermochronometric data from the Japanese Islands and preliminary report on (U-Th)/He ages across NE Japan Arc

    NASA Astrophysics Data System (ADS)

    Tagami, T.; Sueoka, S.; Kohn, B. P.; Fukuda, S.

    2015-12-01

    A paradox of the deformation pattern in the NE Japan Arc is that the short-term (<102 years) deformation observed by geodetic techniques and the long-term (>104 years) deformation estimated from geomorphic and geologic evidence are different in both rate and/or direction. It has been proposed that elastic deformation released by a megathrust earthquake along the Japanese Trench, could resolve this paradox. However, co-seismic and post-seismic deformation associated with the 2011 Tohoku-oki earthquake (Mw9.0) has not compensated for the misfit. To understand the physical properties of the crust and mechanism of strain accumulation and release in the NE Japan Arc, more careful and detailed comparisons of deformation using various timescales and methods may provide a fundamental clue. For estimating long-term vertical deformation rates of NE Japan Arc, we performed 1) a compilation of previous low-temperature thermochronometric data in the Japanese Islands and 2) apatite and zircon (U-Th)/He (AHe and ZHe) thermochronometric analyses on the late Cretaceous and Paleogene granitoids across the NE Japan Arc. Both the previous fission-track (FT) and newly obtained AHe ages indicate an obvious contrast in cooling/denudation histories between the fore-arc and back-arc sides of the NE Japan Arc. FT ages of 100-46 Ma and AHe ages of 59-50 Ma in the Abukuma Mountains in the fore-arc side indicate relatively slow cooling/denudation and a stable tectonic setting during the Cenozoic. On the other hand, younger apatite FT ages of 6.1 and 4.6 Ma and AHe ages of 11-1.5 Ma in the Ou Backbone range, Iide-Asahi Mountains, and Echigo Mountains in the back-arc side may reflect rapid cooling/denudation since the latest Miocene or late Pliocene. ZHe ages in the back-arc side range between 54-11 Ma, which is generally consistent with their coexisting AHe ages considering the difference in their closure temperatures.

  13. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan

    PubMed Central

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    Abstract A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus. PMID:27551219

  14. Mercury and other trace metals (Ag, Cr, Co, and Ni) in soft tissue and byssus of Mytilus edulis from the east coast of Kyushu Island, Japan.

    PubMed

    Szefer, P; Ikuta, K; Frelek, K; Zdrojewska, I; Nabrzyski, M

    1999-05-19

    Concentrations of Hg and other metals such as Ag, Cr, Co and Ni in soft tissues and byssi of the blue mussel (Mytilus edulis) from three sites along the east coast of Kyushu Island, Japan, were determined by a cold-vapor technique. Large inter-regional differences in metal concentrations in both soft tissues and byssi were observed. The tissue concentrations of Hg were significantly greater in M. edulis from the most contaminated locations (Saganoseki) compared to those from a non-industrialized area (Urashiro). It is evident that, compared to the soft tissue, byssus is a more sensitive biomonitor for Hg, Cr, Co and Ni. From the data obtained in the present study evidently results that the soft tissue and especially byssi of M. edulis appear to be good bioindicators for identification of coastal areas exposed to Hg contaminants.

  15. Trial of Multidisciplinary Observation at an Expandable Sub-Marine Cabled Station “Off-Hatsushima Island Observatory” in Sagami Bay, Japan

    PubMed Central

    Kasaya, Takafumi; Mitsuzawa, Kyohiko; Goto, Tada-nori; Iwase, Ryoichi; Sayanagi, Keizo; Araki, Eiichiro; Asakawa, Kenichi; Mikada, Hitoshi; Watanabe, Tomoki; Takahashi, Ichiro; Nagao, Toshiyasu

    2009-01-01

    Sagami Bay is an active tectonic area in Japan. In 1993, a real-time deep sea floor observatory was deployed at 1,175 m depth about 7 km off Hatsushima Island, Sagami Bay to monitor seismic activities and other geophysical phenomena. Video cameras monitored biological activities associated with tectonic activities. The observation system was renovated completely in 2000. An ocean bottom electromagnetic meter (OBEM), an ocean bottom differential pressure gauge (DPG) system, and an ocean bottom gravity meter (OBG) were installed January 2005; operations began in February of that year. An earthquake (M5.4) in April 2006, generated a submarine landslide that reached the Hatsushima Observatory, moving some sensors. The video camera took movies of mudflows; OBEM and other sensors detected distinctive changes occurring with the mudflow. Although the DPG and OBG were recovered in January 2008, the OBEM continues to obtain data. PMID:22291563

  16. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan.

    PubMed

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus.

  17. Trial of multidisciplinary observation at an expandable sub-marine cabled station "off-hatsushima island observatory" in sagami bay, Japan.

    PubMed

    Kasaya, Takafumi; Mitsuzawa, Kyohiko; Goto, Tada-Nori; Iwase, Ryoichi; Sayanagi, Keizo; Araki, Eiichiro; Asakawa, Kenichi; Mikada, Hitoshi; Watanabe, Tomoki; Takahashi, Ichiro; Nagao, Toshiyasu

    2009-01-01

    Sagami Bay is an active tectonic area in Japan. In 1993, a real-time deep sea floor observatory was deployed at 1,175 m depth about 7 km off Hatsushima Island, Sagami Bay to monitor seismic activities and other geophysical phenomena. Video cameras monitored biological activities associated with tectonic activities. The observation system was renovated completely in 2000. An ocean bottom electromagnetic meter (OBEM), an ocean bottom differential pressure gauge (DPG) system, and an ocean bottom gravity meter (OBG) were installed January 2005; operations began in February of that year. An earthquake (M5.4) in April 2006, generated a submarine landslide that reached the Hatsushima Observatory, moving some sensors. The video camera took movies of mudflows; OBEM and other sensors detected distinctive changes occurring with the mudflow. Although the DPG and OBG were recovered in January 2008, the OBEM continues to obtain data.

  18. Thickness and Lower Limit Seismogenic Layer within the Crust beneath Japanese Islands on the Japan Sea Side

    NASA Astrophysics Data System (ADS)

    Matsubara, M.; Sato, H.

    2015-12-01

    1. Introduction I investigate the depth of the seismogenic layer in order to estimate the lower limit of the seismogenic fault plane since this depth is related to the size of the earthquake caused by the active fault. I have indexes D10 and D90 as the upper and lower limits of the seismogenic layer defined as the depth above which 10 % and 90 % of the whole crustal earthquakes occurred from the surface, respectively. The difference between the D10 and D90 is the thickness of the seismogenic layer. 2. Data and method The NIED Hi-net has a catalog of hypocenters determined with one-dimensional velocity (1D) structure (Ukawa et al., 1984) and I estimated the D10 and D90 with this catalog at first. I construct the system to relocate the hypocenters from 2001 to 2013 with magnitude greater than 1.5 on the Japan Sea side shallower than 50 km depth with the three-dimensional velocity (3D) structure (Matsubara and Obara, 2011) obtained by seismic tomography. I estimate the D10 and D90 from the hypocenter catalog with 3D structure. 3. Result Many earthquakes shallower than 5 km with 1D structure are relocated to deeper with 3D structure and the earthquakes deeper than 15 km are relocated to about 5 km shallower. With 3D structure D10 deepens and D90 shallows from 1D structure. D90 beneath the northern Honshu is deeper than the other area and D90 beneath the Japan Sea is much deeper than the inland area. The thickness of the seismogenic layer beneath the Japan Sea is also thick from 8-16 km. D90 on the Japan Sea side of the southwestern Japan on the west side of the Itoigawa Shizuoka Tectonic Line is very shallow as 11-16 km and the thickness of the seismogenic layer is also thin as 2-7 km. 4. Discussion Omuralieva et al. (2012) relocated the JMA unified hypocenters with 3D structure and estimated shallower D90 than that from the JMA catalog. Very deep D90 beneath the northern Hokkaido and northern Honshu is consistent with our result. 5. Conclusion Using 3D velocity

  19. Asymmetric seasonal march from autumn to the next spring in East Asia (Toward interdisciplinary education on the climate systems and the "seasonal feeling" such as around the Japan Islands area)

    NASA Astrophysics Data System (ADS)

    Kato, Kuranoshin; Kato, Haruko; Sato, Sari; Akagi, Rikako; Haga, Yuichi; Miyake, Shoji

    2014-05-01

    There are many steps of seasonal transitions in East Asia, greatly influenced by the considerable phase differences of seasonal cycle among the Asian monsoon subsystems, resulting in the variety of "seasonal feeling" around the Japan Islands. For example, the "wintertime pressure pattern" begins to prevail already from November due to the seasonal development of the Siberian Air mass and the Siberian High, although the air temperature around the Japan Islands is still rather higher than in midwinter. On the other hand, since the southward retreat of the warm moist air mass in the western Pacific area delays rather greatly to the advances of those northern systems. Thus it would be interesting to re-examine the whole seasonal cycle around the Japan Islands at the view point of how the phase differences among seasonal marches of the Asian monsoon subsystems affect the variety of the seasonal cycle there, together with their effects on the "seasonal feeling". As such, the present study will examine the asymmetric seasonal march from autumn to the next spring through midwinter around the Japan Islands as an interesting example, and will also report the joint activity with music, and so on, toward the development of an interdisciplinary study plan on such topics for the students in junior high school, high school and the faculty of education of the university. The wintertime weather pattern, i.e., precipitation in the Japan Sea side and clear day in the Pacific side of the Japan Islands, prevails from early November to early March, reflected by the seasonal cycle of the Siberian Air Mass and the Siberian High. However, the air temperature shows the minimum from late January to early February around the Japan Islands. In other words, although the dominant weather patterns around November and in early March are nearly the same as each other, air temperature is still lower in early March (early spring). In spite of that, the solar radiation is rather stronger in early

  20. Two new species of photosymbiotic ascidians of the genus Diplosoma from the Ryukyu Archipelago, with partial sequences of the COI gene.

    PubMed

    Hirose, Euichi; Oka, Atsushi T; Hirose, Mamiko

    2009-05-01

    Two new species of Diplosoma are described from coral reefs in the Ryukyu Archipelago, Japan: D. watanabei sp. nov. and D. gumavirens sp. nov. Colonies of both species are green due to algal symbionts of Prochloron, which are distributed in the common cloacal cavity. Both species are characterized by the point of emergence of the retractor muscle and a unique combination of stigma numbers among the four rows of the branchial sac. There are three adhesive papillae in the embryos of D. watanabei, as in most ascidian embryos and larvae, whereas the pre-hatching embryos of D. gumavirens sp. nov. posses 12-16 adhesive papillae. Partial sequences of the cytochrome c oxidase subunit I (COI) gene discriminated the new species from each other and from congeners.

  1. Trace element accumulation in short-tailed albatrosses (Diomedea albatrus) and black-footed albatrosses (Diomedea nigripes) from Torishima Island, Japan

    NASA Astrophysics Data System (ADS)

    Shinsuke, T.; Tokutaka, I.; Takashi, K.; Miyako, T.; Fumio, S.; Nariko, O.

    2003-05-01

    Concentrations of 19 trace elements (V, Cr, Mn, Co, Cu, Zn, Ga, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Hg, Tl, and Pb) were determined in liver, kidney, muscle, feather and stomach content of short-tailed albatross and feather of black-footed albatross from Torishima Island, Japan. For most of the elements, concentrations in liver and kidney were higher than those in muscle and feather, whereas concentrations of Ga, Sr and Ba were highest in feather of short-taled albatross. Metal concentrations in tissues of short-tailed albatross were within the range of those reported for albatrosses from other locations. Concentrations of Cr, Mn, Hg and Pb were relatively low in the tissues of short-tailed albatross, indicating less contamination by those metals in this species of Torishima Island. No significant differences were observed in metal concentrations in feather between short-tailed albatross and black-footed albatross. To our knowledge, this is the first report on the trace element accumulation in tissues of short-tailed albatross.

  2. Photochemical Formation of Fe(II) and Peroxides in Coastal Seawater Collected around Okinawa Island, Japan - Impact of Red Soil Pollution

    NASA Astrophysics Data System (ADS)

    Okada, K.; Nakajima, H.; Higuchi, T.; Fujimura, H.; Arakaki, T.; Taira, H.

    2003-12-01

    In a study to elucidate the impacts of red soil pollution on the oxidizing power of seawater, photochemical formation of Fe(II) and peroxides was studied in seawaters collected around Okinawa Island, Japan. The northern part of Okinawa Island suffers from red soil pollution which is caused mainly by land development such as pineapple farming and the construction of recreational facilities. We studied photochemical formation of peroxides and Fe(II) in the same seawater samples because the reaction between HOOH and Fe(II) forms hydroxyl radical (OH radical), the most potent environmental oxidant. Photochemical formation of Fe(II) was fast and reached steady-state in 30 minutes of simulated sunlight illumination and the steady-state Fe(II) concentrations were about 80% of total iron concentrations. Photochemical formation of peroxides was relatively slow and formation kinetics varied, depending on the initial peroxide concentrations. Because photochemical formation of peroxides was faster and total iron concentrations in the red soil polluted seawater were higher, red soil polluted seawater is expected to have greater oxidizing power than seawater that is not polluted with red soil.

  3. Evaluation of Mn and Fe in coral skeletons ( Porites spp.) as proxies for sediment loading and reconstruction of 50 yrs of land use on Ishigaki Island, Japan

    NASA Astrophysics Data System (ADS)

    Inoue, Mayuri; Ishikawa, Daisaku; Miyaji, Tsuzumi; Yamazaki, Atsuko; Suzuki, Atsushi; Yamano, Hiroya; Kawahata, Hodaka; Watanabe, Tsuyoshi

    2014-06-01

    Manganese (Mn) and iron (Fe) concentrations were measured in coral skeletons ( Porites spp.) collected from the Todoroki River on Ishigaki Island, Japan, to reconstruct the history of land use in the river catchment area. We prepared (1) five bulk samples to investigate the present spatial distribution and (2) micro-samples from two long cores to study the temporal variability of sediment loading from the Todoroki River. The existing state of the elements Mn and Fe in bulk coral skeleton samples was examined by a chemical cleaning experiment. The results of the experiment suggested that Fe was not incorporated into the crystal lattice of the coral skeleton but that Mn was incorporated, as previously reported. The bulk sample data, with and without chemical cleaning, indicated that the spatial distribution of both elements in corals collected along a sampling line from the river mouth toward the reef crest was complex and most likely reflected salinity changes and the amount of suspended particulate matter. The temporal variation of Mn and Fe, in particular the variation of baseline/background levels, mainly reflected the history of land development on Ishigaki Island. In addition, Mn showed clear seasonal variability that appeared to be controlled by a combination of temperature, primary productivity, and precipitation. The results of the present study suggest that Mn may be a useful proxy for river discharge or biological activity depending on local marine conditions, if the specific behavior of Mn at the coral growth site is known.

  4. Spatial variations of the Kuroshio nutrient stream from the East China Sea to South of Japan

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-Hua; Guo, Xinyu; Long, Yu; Li, Bo

    2013-04-01

    Based on velocity calculated from hydrographic data obtained from 39 cruises during from 2000 to 2009 and nitrate concentration data observed from 1964 to 2011, we calculated nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over a section) through 5 sections along the Kuroshio path from the East China Sea (Sections PN and TK) to south of Japan (Sections ASUKA and 137E). In addition, Section OK east of the Ryukyu Islands was also examined. The nitrate flux showed a subsurface maximum core with a value of 9, 10, 6, 11 and 11 mol/m^2/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The depth of subsurface maximum core changes at five sections and was about 400, 500, 800, 500, and 400 m at Sections PN, TK, OK, ASUKA, 137E, respectively. The eastward nitrate transport was 171, 167, 351, 942, 1444 k mol/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The difference between nitrate transport through Section ASUKA and the sum of transports through Sections TK and OK, as well as the difference of nitrate transport between Sections ASUKA and 137E, suggest that the Kuroshio recirculation south of Shikoku can significantly intensify the eastward nitrate transport by the Kuroshio and therefore play an important role in the nitrate transport in the Kuroshio region.

  5. Prehistoric introduction of domestic pigs onto the Okinawa Islands: ancient mitochondrial DNA evidence.

    PubMed

    Watanobe, Takuma; Ishiguro, Naotaka; Nakano, Masuo; Takamiya, Hiroto; Matsui, Akira; Hongo, Hitomi

    2002-08-01

    Ancient DNAs of Sus scrofa specimens excavated from archaeological sites on the Okinawa islands were examined to clarify the genetic relationships among prehistoric Sus scrofa, modern wild boars and domestic pigs inhabiting the Ryukyu archipelago, the Japanese islands, and the Asian continent. We extracted remain DNA from 161 bone specimens excavated from 12 archaeological sites on the Okinawa islands and successfully amplified mitochondrial DNA control region fragments from 33 of 161 specimens. Pairwise difference between prehistoric and modern S. scrofa nucleotide sequences showed that haplotypes of the East Asian domestic pig lineage were found from archaeological specimens together with Ryukyu wild boars native to the Ryukyu archipelago. Phylogenetic analysis of 14 ancient sequences (11 haplotypes; 574 bp) indicated that S. scrofa specimens from two Yayoi-Heian sites (Kitahara and Ara shellmiddens) and two Recent Times sites (Wakuta Kiln and Kiyuna sites) are grouped with modern East Asian domestic pigs. Sus scrofa specimens from Shimizu shellmidden (Yayoi-Heian Period) were very closely related to modern Sus scrofa riukiuanus but had a unique nucleotide insertion, indicating that the population is genetically distinct from the lineage of modern Ryukyu wild boars. This genetic evidence suggests that domestic pigs from the Asian continent were introduced to the Okinawa islands in the early Yayoi-Heian period (1700-2000 BP), or earlier.

  6. Middle Precambrian detrital monazite and zircon from the hida gneiss on Oki-Dogo Island, Japan: their origin and implications for the correlation of basement gneiss of Southwest Japan and Korea

    NASA Astrophysics Data System (ADS)

    Suzuki, Kazuhiro; Adachi, Mamoru

    1994-08-01

    Monazite and zircon from seven paragneiss samples of the upper amphibolite facies grade from Oki-Dogo Island in the Hida terrane, western Japan, were analyzed for Th, U and Pb on an electron microprobe. Most monazite grains are chronologically unzoned and give unequivocal CHIME (chemical Th-U-total Pb isochron) ages of 250 Ma, but some grains show a distinct core-overgrowth relationship. The cores retain evidence of pre-250 Ma ages and are interpreted to be of detrital origin, suggesting that monazite can be more immune to diagenetic and low-grade metamorphic decompositions than had been thought previously. Zircon grains, rounded to nearly euhedral, give CHIME ages ranging from 3000 to 350 Ma. Of particular interest are several rounded 3000 Ma recycled zircons which perhaps originated from an Archean terrain in the Sino-Korean craton. The youngest age of detrital zircons constrains that the gneiss protolith deposited after the 350 Ma event. The CHIME monazite and zircon ages for the paragneisses from Oki-Dogo Island, and from the main part of the Hida terrane, reveal that the gneisses formed from Permo-Carboniferous clastic sediments during a single metamorphism at ca. 250 Ma. The results are in marked contrast to the current view that (1) the Hida gneiss is a polymetamorphosed Precambrian complex; (2) the central part ('Hida gneiss' region) and the eastern marginal part (Unazuki schist' region) of the Hida terrane are correlative with the Precambrian Kyonggi massif and the Paleozoic Okchon zone in the Korean Peninsula, respectively. Instead, we consider that the Okchon zone alone can be correlatable with the Paleozoic Hida terrane.

  7. A new species of sesarmid crab of the genus Chiromantes (Crustacea: Decapoda: Brachyura) from the Ogasawara Islands, Japan.

    PubMed

    Komai, Tomoyuki; Ng, Peter K L

    2013-01-01

    A new species of sesarmid crab, Chiromantes magnus, is described from the Ogasawara (Bonin) Is., Japan. The new species was previously confused with C. dehaani (H. Milne Edwards, 1853). The different carapace shape, proportionally longer ambulatory legs, large adult size and the distinct live coloration distinguish the new species from its two closest congeners, C. dehaani and C. neglectus (De Man, 1887). Available information indicates that C. magnus n. sp. is endemic to the Ogasawara Is.; there is no evidence of the occurrence of the true C. dehaani in the Ogasawara Is.

  8. An extended magnetic viscous relaxation dating for calibrating an older age: an example of tsunamigenic coral boulders in Ishigaki Island, Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Nakamura, N.; Goto, K.; Kumagai, Y.; Minoura, K.; Nagahama, H.

    2015-12-01

    A key to the understanding of past tsunami events is the ability to accurately date them. Analysis of past tsunami sediments is one of the most important tools for past tsunami reconstruction. A typical example of such tsunami sediment is tsunamigenic boulders. In Ishigaki Island, Japan, coral boulders that had been transported by tsunamis were distributed on the beach and land areas. Although the historical occurrences of several huge tsunamis were estimated based on large numbers of radiocarbon dating for coral boulders, radiocarbon dating can not determine a multiple rotational history by multiple tsunamis. A viscous remanet magnetization (VRM) dating method can be used to date any geological event that results in significant movements of a rock. Sato et al. (2014) applied VRM dating for comparing the radiocarbon age of these boulders. If a magnetic-mineral bearing rock is moved or re-oriented, the magnetism of the smaller magnetic grains re-aligns to the direction of the ambient magnetic field with time. This phenomenon is well known as Néel's (1949, 1955) single-domain (SD) relaxation theory. Pullaiah et al. (1975) derived a time-temperature (t-T relation) relation by assuming Néel's (1949, 1955) theory of magnetite. In principle, an experimental combination of short relaxation time and high temperature for removing VRM can determine the unknown relaxation time (tsunami age) at room temperature. We have been applied t-T relation to the coral boulders on Ishigaki Island, but their estimated ages showed older than radiocarbon dating. The longer relaxation time means that the observed magnetic relaxation is slower than the original Néel's theory. Such slow relaxation has been described by a stretched exponential function. The stretched exponential law provided a reasonable fit to the published experimental data. Thus, in this study, we revisit Néel's theory to provide a new t-T relation based on stretched exponential function.

  9. Spatial and temporal behavior and acute ecotoxicological effects of Tributyltin (TBT) on coral reef and adjacent ecosystems around Okinawa Island, Japan.

    NASA Astrophysics Data System (ADS)

    Sheikh, M. A.; Higuchi, T.; Imo, T. S.; Fujimura, H.; Oomori, T.

    2007-12-01

    Spatial and temporal behavior of the tributyl tin (TBT) were investigated in the coastal areas around Okinawa Island, Japan. A seasonal monitoring study was conducted between February and October 2006. The effects of TBT on the carbon metabolisms (net production and calcification) on the intact coral-alga association Galaxea fascicularis were also investigated. Mean concentration of TBT (2.45 ng/L) found in the Manko estuary waters have exceeded some international permissible targets of waters quality guideline for TBT (1ng/L). The sediments in Manko estuary sediments can be considered lightly contaminated (0-20 ng/g dw) and Okukubi estuary as uncontaminated (below 3ng/g dw) with TBT. The seasonal concentration pattern of TBT at the Manko estuary was autumn > spring > summer > winter. The acute ecotoxicological results show that the photosynthesis rate and calcification rate were significantly reduced by 78 % and 72 % relative to the control (ANOVA, p<0.001) when corals were exposed to 5000 ng/LTBT, respectively. No significant effects (ANOVA, p>0.05) were observed when corals were exposed to 1000 ng/LTBT. The present study reports the occurrence and continuous input of TBT in the coastal areas around Okinawa Island, even 16 years after legal restriction of TBT usage in coastal waters was implemented by the Japanese Environmental Authorities. However, the nominal sensitive concentration of TBT that causes alteration of carbon metabolisms of coral within 96 hrs exposure are much higher than those recently found in the coral reef waters and adjacent ecosystems.

  10. Deformation and gravity changes at Izu islands, Japan, prior to, during, and after the 2000 caldera collapse at Miyake-jima volcano

    NASA Astrophysics Data System (ADS)

    Furuya, M.; Okubo, S.; Kimata, F.

    2006-12-01

    Eruptive and caldera-forming activity at Miyakejima volcano, Japan, was accompanied by more than 40 days of seismic swarms, including more than five M6 (or greater) earthquakes, and significant crustal deformation in nearby islands. Here we review ground deformation and gravity changes at Miyakejima and other nearby islands prior to, during, and after the 2000 caldera collapse episode at Miyakejima. While ground displacements observed at Izu-islands can be basically predicted from the Philippine Sea Plate motion in a global perspective, Miyakejima was undergoing inflation if examined locally within the island before the 2000 unrest. It is also known that a couple of leveling benchmarks inside the previous caldera were secularly subsiding [Miyazaki, 1990]. Using JERS1's InSAR data, Furuya~[2004] also confirmed this. Was the localized subsidence before 2000 a precursor for the caldera collapse? We will argue that this is probably not the case. After the beginning of the earthquake swarm on 26 June 2000, significant ground displacements were recorded at Miyakejima both in the permanent GPS stations [e.g., Nishimura et al. 2001] and tiltmeters by the NIED [Ukawa et al. 2001]. Using both FG5 absolute gravimeter and LaCoste-Romberg G-type gravimeters, high precision gravity survey has been repeatedly carried out by ERI, University of Tokyo. Furuya et al~[2003a] showed spatial-temporal gravity changes from the beginning stage to early 2001. Notably, they detected a gravity decrease of as much as 145 μgals (1 μgal=10^{-8} m/s2) at the summit area 2 days prior to the collapse, and interpreted as reflecting the formation of a large void beneath the volcano. Correcting for the effect of topography change due to the collapse, subsequent gravity change data suggested an effective density decrease until the middle August 2000, followed by a significant density increase toward at least November 2000. Those spatial and temporal gravity changes were associated with the explosive

  11. Complete genotyping in conservation genetics, a case study of a critically endangered shrub, Stachyurus macrocarpus var. prunifolius (Stachyuraceae) in the Ogasawara Islands, Japan.

    PubMed

    Kaneko, Shingo; Abe, Tetsuto; Isagi, Yuji

    2013-09-01

    More than 3,000 species are listed as critically endangered worldwide, and various conservation measures such as habitat restoration, assisted reproduction and establishment of ex situ populations would be required to prevent their extinction. We determined the genotype of all 15 known wild clumps using nuclear microsatellite markers for Stachyurus macrocarpus var. prunifolius, a critically endangered shrub endemic to the Ogasawara (Bonin) Islands of Japan. In addition, the seedlings propagated from seeds taken from one wild clumps were genotyped. The results of complete genotyping showed that both wild and nursery populations had population-specific alleles. Two alleles were detected only in the nursery population, indicating the existence of undiscovered mature individuals in the wild. Four alleles were found only in the wild and were detected in two geographically isolated clumps, and this finding may propose that re-introduction and transplantation between different sites requires sensitive handling in terms of the conservation of evolutionary significant units. These results show that complete genotyping can provide essential genetic and ecological information for effective management of endangered species.

  12. Analysis of Early Bacterial Communities on Volcanic Deposits on the Island of Miyake (Miyake-jima), Japan: a 6-year Study at a Fixed Site

    PubMed Central

    Fujimura, Reiko; Sato, Yoshinori; Nishizawa, Tomoyasu; Nanba, Kenji; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2012-01-01

    Microbial colonization on new terrestrial substrates represents the initiation of new soil ecosystem formation. In this study, we analyzed early bacterial communities growing on volcanic ash deposits derived from the 2000 Mount Oyama eruption on the island of Miyake (Miyake-jima), Japan. A site was established in an unvegetated area near the summit and investigated over a 6-year period from 2003 to 2009. Collected samples were acidic (pH 3.0–3.6), did not utilize any organic substrates in ECO microplate assays (Biolog), and harbored around 106 cells (g dry weight)−1 of autotrophic Fe(II) oxidizers by most-probable-number (MPN) counts. Acidithiobacillus ferrooxidans, Acidithiobacillus ferrivorans, and the Leptospirillum groups I, II and III were found to be abundant in the deposits by clone library analysis of bacterial 16S rRNA genes. The numerical dominance of Acidithiobacillus ferrooxidans was also supported by analysis of the gene coding for the large subunit of the form I ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). Comparing the 16S rRNA gene clone libraries from samples differing in age, shifts in Fe(II)-oxidizing populations seemed to occur with deposit aging. The detection of known 16S rRNA gene sequences from Fe(III)-reducing acidophiles promoted us to propose the acidity-driven iron cycle for the early microbial ecosystem on the deposit. PMID:22075623

  13. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    SciTech Connect

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-15

    Radioactive fission product {sup 131}I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, {sup 134}Cs and {sup 137}Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m{sup -3} in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of {sup 134}Cs and {sup 137}Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m{sup -3}) variation of stable cesium ({sup 133}Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  14. Comparative phylogeny and historical perspectives on population genetics of the Pacific hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas), inferred from feeding populations in the Yaeyama Islands, Japan.

    PubMed

    Nishizawa, Hideaki; Okuyama, Junichi; Kobayashi, Masato; Abe, Osamu; Arai, Nobuaki

    2010-01-01

    Mitochondrial DNA sequence polymorphisms and patterns of genetic diversity represent the genealogy and relative impacts of historical, geographic, and demographic events on populations. In this study, historical patterns of population dynamics and differentiation in hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) in the Pacific were estimated from feeding populations in the Yaeyama Islands, Japan. Phylogenetic relationships of the haplotypes indicated that hawksbill and green turtles in the Pacific probably underwent very similar patterns and processes of population dynamics over the last million years, with population subdivision during the early Pleistocene and population expansion after the last glacial maximum. These significant contemporary historical events were suggested to have been caused by climatic and sea-level fluctuations. On the other hand, comparing our results to long-term population dynamics in the Atlantic, population subdivisions during the early Pleistocene were specific to Pacific hawksbill and green turtles. Therefore, regional differences in historical population dynamics are suggested. Despite limited sampling locations, these results are the first step in estimating the historical trends in Pacific sea turtles by using phylogenetics and population genetics.

  15. Continuous measurement of CO2 flux through the snowpack in a dwarf bamboo ecosystem on Rishiri Island, Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Zhu, Chunmao; Nakayama, Momoko; Yoshikawa Inoue, Hisayuki

    2014-09-01

    To investigate the dynamics and environmental drivers of CO2 flux through the winter snowpack in a dwarf bamboo ecosystem (Hokkaido, northeast Japan), we constructed an automated sampling system to measured CO2 concentrations at five different levels in the snowpack, from the base to the upper snow surface. Using a gas diffusion approach, we estimated an average apparent soil CO2 flux of 0.26 μmol m-2 s-1 during the snow season (December-April); temporally, the CO2 flux increased until mid-snow season, but showed no clear trend thereafter; late-season snow-melting events resulted in rapid decreases in apparent CO2 flux values. Air temperature and subnivean CO2 flux exhibited a positive linear relationship. After eliminating the effects of wind pumping, we estimated the actual soil CO2 flux (0.41 μmol m-2 s-1) to be 54% larger than the apparent flux. This study provides new constraints on snow-season carbon emissions in a dwarf bamboo ecosystem in northeast Asia.

  16. In situ stress magnitudes at the toe of the Nankai Trough Accretionary Prism, offshore Shikoku Island, Japan

    NASA Astrophysics Data System (ADS)

    Huffman, K. A.; Saffer, D. M.

    2016-02-01

    Quantifying the orientation and magnitude of tectonic stresses is essential toward understanding deformation and faulting in subduction zones. However, constraints on in situ horizontal stress magnitudes (Shmin and SHmax) are rare. We estimate Shmin and SHmax at Ocean Drilling Program Site 808 at the toe of the Nankai accretionary prism offshore Japan, using coupled constraints from (1) the width of wellbore breakouts together with estimates of rock strength and a model describing stress redistribution at the borehole wall and (2) limits on regional differential stress defined by failure on preexisting faults. Our analysis extends from 175 to 915 m below seafloor (mbsf) and spans the active frontal thrust. For an upper bound on rock unconfined compressive strength (UCS) and assuming hydrostatic formation pore pressure, Shmin and SHmax (referenced to the seafloor) increase from 6.5 MPa at 175 mbsf to 17.4 MPa at 915 mbsf, with the stress state gradually transitioning from a thrust or strike-slip faulting regime above 800 mbsf to a normal faulting regime below. For cases with higher formation pore pressure, horizontal stresses are slightly lower but follow a similar pattern. We show that estimated Shmin and SHmax are strongly dependent on UCS, breakout width, and friction coefficient, all of which are characterized by uncertainty. Our results suggest that the prism is near thrust failure in the upper ~300 mbsf, but far from failure below. This may be reconciled with active thrusting if thrust faults are locally weaker than the surrounding rock or if SHmax fluctuates during the seismic cycle.

  17. Is heterostyly rare on oceanic islands?

    PubMed Central

    Watanabe, Kenta; Sugawara, Takashi

    2015-01-01

    Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands. PMID:26199401

  18. Is heterostyly rare on oceanic islands?

    PubMed

    Watanabe, Kenta; Sugawara, Takashi

    2015-07-21

    Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands.

  19. Giant Subaqueous Pyroclastic-Flow Deposits Revealed: Sedimentological Revision of the Holocene Outcrops of Izu-Oshima Island, Japan

    NASA Astrophysics Data System (ADS)

    Hemmi, R.; Yoshida, S.; Nemoto, Y.; Kotake, N.

    2010-12-01

    The early-to-middle Holocene outcrops of Izu-Oshima island, 100 km SSW of Tokyo, comprise sand- to gravel-size pyroclasts, and exhibit undulating layered structures, with each wavelet typically measuring 5-10 m high. These outcrops were traditionally interpreted as exemplary subaerial "ash-fall" deposits in volcanology textbooks (e.g. Schmincke 2006). Our detailed sedimentological analyses, however, have revealed that it is of pyroclastic density-current origin, the majority of which formed in shallow-marine settings. The present study focuses on the outcrops along the western coast of the Island, where the three-dimensional architecture of the outcrops is superbly exposed, and the existing archaeological framework provides a reliable chronostratigraphic control. The outcrops contain abundant compound bedforms, where small bedforms (dunes/antidunes) occur within the larger bedforms. The compound bedforms exhibit four-fold hierarchy (ranks 1 to 4), and bedforms for each scale display dominantly upstream-accreting geometry. The largest scale (Rank 1) of these bedforms show wavy parallel-bedding geometry (each wavelet typically measuring 5-10 m high and 50-100 m wide). We interpreted the large-scale architecture as sediment waves (gigantic antidunes) similar to the one reported from the shallow-marine deposits associated with AD 79 Mt. Vesuvius eruptions (Milia et al. 2008). Moreover, we have identified crustacean burrows and other trace fossils indicative of a nearshore shallow-marine environment. The pervasive occurrence of these fossils throughout the outcrops and abundant water-escape structures also suggests their subaqueous origin. On the other hand, evidence of subaerial deposition (e.g., paleosols and rootlets) or subaerial reworking (e.g., lahar) is absent, except for some spots on several regional unconformities that divide 10’s-m-thick sediment-wave deposits. On some of these unconformities, ribbon- to fan-shaped lava and/or ancient human-dwelling sites

  20. Paleoclimate Reconstruction during the 17th to 18th Century Using Fossil Coral Tsunami Boulders from Ishigaki Island, the Ryukyus, Japan

    NASA Astrophysics Data System (ADS)

    Tsuzuki, K.; Yokoyama, Y.; Seki, A.; Kawakubo, Y.; Araoka, D.; Suzuki, A.

    2014-12-01

    Little Ice Age (LIA) which lasted during approximately 1450 to 1850 (e.g. Grove, 1988) is known as naturally occurring climate fluctuation, so knowing LIA in detail is necessary to improve climate models. Instrumental records can only extend back to about 100 years in many areas, thus paleoclimate records are reconstructed using proxies in tree rings, sediments and so force. However there are differences in reconstructed timings and magnitudes of LIA occurred in each area (Overpack et al., 1997), and most of the records are based mainly on terrestrial proxies such as tree ring records, whereas only limited numbers of marine records are available (Mann et al., 2008). Coral skeletal climatology is a useful tool to reconstruct marine paleoclimate records in tropics and subtropics. Hermatypic corals, Porites spp. have aragonite skeletons and they have annual bands, which are suitable to reconstruct high-resolution paleoclimate in seasonal scale by measuring chemical compositions. Skeletal Sr/Ca ratio in Porites spp. has been widely used as a reliable proxy of SST (Sea Surface Temperature). However, corals grow for approximately several decades to 200 years, hence it is difficult to reconstruct LIA paleoclimate using living corals. Cobb et al. (2003) used fossil corals casted on shore by storms to reconstruct millennial scale paleoclimate. There are fossil coral boulders in the eastern coast of Ishigaki Island, Ryukyus, Japan. These fossil coral boulders were casted on shore by paleo Tsunami events, thus they are called "Tsunami boulders" (Araoka et al., 2010). Fossil corals used by Cobb et al. have 30-90-year records while some large Tsunami boulders have multi-centennial continuous records. In this study, we reconstruct paleo SST using the Tsunami boulder from Ishigaki Island. The boulder has 185 years of annual banding. U-series dating shows the boulder was moved on shore at Meiwa earthquake in 1771. We measure Sr/Ca ratio using LA-HR-ICPMS (Laser Ablation High

  1. Long-term observations of black carbon mass concentrations at Fukue Island, western Japan, during 2009-2015: constraining wet removal rates and emission strengths from East Asia

    NASA Astrophysics Data System (ADS)

    Kanaya, Yugo; Pan, Xiaole; Miyakawa, Takuma; Komazaki, Yuichi; Taketani, Fumikazu; Uno, Itsushi; Kondo, Yutaka

    2016-08-01

    Long-term (2009-2015) observations of atmospheric black carbon (BC) mass concentrations were performed using a continuous soot-monitoring system (COSMOS) at Fukue Island, western Japan, to provide information on wet removal rate constraints and the emission strengths of important source regions in East Asia (China and others). The annual average mass concentration was 0.36 µg m-3, with distinct seasonality; high concentrations were recorded during autumn, winter, and spring and were caused by Asian continental outflows, which reached Fukue Island in 6-46 h. The observed data were categorized into two classes, i.e., with and without a wet removal effect, using the accumulated precipitation along a backward trajectory (APT) for the last 3 days as an index. Statistical analysis of the observed ΔBC / ΔCO ratios was performed to obtain information on the emission ratios (from data with zero APT only) and wet removal rates (including data with nonzero APTs). The estimated emission ratios (5.2-6.9 ng m-3 ppb-1) varied over the six air mass origin areas; the higher ratios for south-central East China (30-35° N) than for north-central East China (35-40° N) indicated the relative importance of domestic emissions and/or biomass burning sectors. The significantly higher BC / CO emission ratios adopted in the bottom-up Regional Emission inventory in Asia (REAS) version 2 (8.3-23 ng m-3 ppb-1) over central East China and Korea needed to be reduced at least by factors of 1.3 and 2.8 for central East China and Korea, respectively, but the ratio for Japan was reasonable. The wintertime enhancement of the BC emission from China, predicted by REAS2, was verified for air masses from south-central East China but not for those from north-central East China. Wet removal of BC was clearly identified as a decrease in the ΔBC / ΔCO ratio against APT. The transport efficiency (TE), defined as the ratio of the ΔBC / ΔCO ratio with precipitation to that without precipitation, was

  2. A pilot study of tele-anaesthesia by virtual private network between an island hospital and a mainland hospital in Japan.

    PubMed

    Miyashita, Tetsuya; Mizuno, Yusuke; Sugawara, Yo; Nagamine, Yusuka; Koyama, Yukihide; Miyazaki, Tomoyuki; Uchimoto, Kazuhiro; Iketani, Yasuhiro; Tojo, Kentaro; Goto, Takahisa

    2015-03-01

    We studied the use of tele-anaesthesia between Sado General Hospital (SGH) located on Sado Island and Yokohama City University Hospital (YCUH) located in mainland Japan. The two sites were connected via a virtual private network (VPN). We investigated the relationship between the bandwidth of the VPN and both the frame rate and the delay time of the tele-anaesthesia monitoring system. The tool used for communication between the two hospitals was free videoconferencing software (FaceTime), which can be used over Wi-Fi connections. We also investigated the accuracy of the commands given during teleanaesthesia: any commands from the anaesthetist at the YCUH that were not carried out for any reason, were recorded in the anaesthetic records at the SGH. The original frame rate and data rate at the SGH were 5 fps and approximately 18 Mbit/s, respectively. The frame rate at the transmission speeds of 1, 5 and 20 Mbit/s was 0.6, 1.6 and 5.0 fps, respectively. The corresponding delay time was 12.2, 4.9 and 0.7 s. Twenty-five adult patients were enrolled in the study and tele-anaesthesia was performed. The total duration of anaesthesia was 37 hours. All 888 anaesthetic commands were completed. There were 7 FaceTime disconnections, which lasted for 10 min altogether. Because no commands needed to be given during the FaceTime disconnection, the telephone was not used. The anaesthesia assistance system might form part of the solution to medical resource shortages.

  3. Distribution and association of trace metals in soft tissue and byssus of Mytilus edulis from the east coast of Kyushu Island, Japan.

    PubMed

    Szefer, P; Ikuta, K; Kushiyama, S; Szefer, K; Frelek, K; Geldon, J

    1997-02-01

    Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co Ni, Mn, andFe in soft tissues and byssi of blue mussel (Mytilus edulis) fromthree sites along the east coast of Kyushu Island, Japan, were determined byAAS method. Large inter-regional differences in metal concentrations in bothsoft tissues and byssi (Cu, Cd, and Pb and Cu, Pb, Co, Ni, Mn, and Fe,respectively) were recorded. Highly significant correlations (p< 0.01) were observed between tissue and byssal concentrations of Pb,Cu, Zn, and Mn. The tissue concentrations of Cu, Cd, and Pb were two ordersof magnitude greater in Mytilus edulis from expected to be themost contaminated locations compared to those from a nonindustrialized area. Intercomparison of the present study data with those published previouslyindicates that the soft tissue and especially byssus are useful in detectingsome areas of some metallic contaminants. The high concentrations of Cd, andespecially Pb and Cu, in Saganoseki mussels and moderately elevatedconcentrations of these metals in Akamizu mussels may be attributed to theanthropogenic emissions from a metallic refinery and an artificial fiberfactory, respectively. It is evident that, compared to the soft tissue, theincrease of Cu levels relative to Zn levels in the byssi of M.edulis are eight times higher, with a slope b (Cu/Zn) of 7.5 for byssusand 0.93 for soft tissue. This suggests that byssus, as compared to softtissue, is a more sensitive bioindicator for Cu. From the data obtained, thesoft tissue and especially byssi of M. edulis appear to be goodbioindicators for identification of coastal areas exposed to metalliccontaminants.

  4. Subcellular distribution and potential detoxification mechanisms of mercury in the liver of the Javan mongoose (Herpestes javanicus) in Amamioshima Island, Japan.

    PubMed

    Horai, Sawako; Furukawa, Tatsuhiko; Ando, Tetsuo; Akiba, Suminori; Takeda, Yasuo; Yamada, Katsushi; Kuno, Katsuji; Abe, Shintaro; Watanabe, Izumi

    2008-06-01

    In a previous study, we showed that Hg accumulated to high levels in the liver of the Javan mongoose (Herpestes javanicus), a terrestrial mammal that lives on Amamioshima Island, Japan. This suggests a sophisticated mechanism of hepatic Hg detoxication. Assay of the subcellular localization of Hg and the expression of protective enzymes provides important clues for elucidating the mechanism of Hg detoxication. In the present study, the concentrations of 11 elements (Mg, Cr, Mn, Fe, Cu, Zn, Se, Rb, Cd, total Hg [T-Hg] and organic Hg [O-Hg], and Pb) were determined in the liver and in five liver subcellular fractions (plasma membrane, mitochondria, nuclei, microsome, and cytosol) of this species. As the T-Hg level increased, T-Hg markedly distributed to the plasma membrane. The T-Hg levels in all subcellular fractions correlated with Se levels. Although the T-Hg level in the microsomal fraction was relatively low, the ratio of O-Hg to T-Hg was significantly lower in the microsomes than in the other fractions. Significant positive correlations were found between the level of glutathione-S-transferase-pi, a marker of oxidative stress, and the O-Hg and T-Hg levels, but the correlation was better with O-Hg than with T-Hg. Western blot analysis of thioredoxin reductase 2 (TrxR2), a protein involved in protecting cells from mitochondrial oxidative stress, showed that the level of TrxR2 correlated with that of T-Hg. High TrxR2 levels may be one mechanism by which the Javan mongoose attenuates the toxicity of the high Hg levels present in the liver.

  5. Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan.

    PubMed

    Nakano, Takanori; Yokoo, Yoriko; Okumura, Masao; Jean, Seo-Ryong; Satake, Kenichi

    2012-11-01

    To elucidate the influence of airborne materials on the ecosystem of Japan's Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO(3) contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct (87)Sr/(86)Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81 % for Na, 83 % for Mg, 36 % for K, 32 % for Ca, and 33 % for Sr. The Sr value was comparable to the 28 % estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have (87)Sr/(86)Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China's loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima's ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils.

  6. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench

    NASA Astrophysics Data System (ADS)

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-07-01

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15-18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface.

  7. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench.

    PubMed

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-07-22

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15-18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface.

  8. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench

    PubMed Central

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-01-01

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15–18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface. PMID:27447546

  9. Okinawa, Japan: Geologic Battleground

    NASA Astrophysics Data System (ADS)

    Waymack, S. W.; Carrington, M. P.; Harpp, K. S.

    2005-12-01

    One of our main goals as instructors, particularly in introductory courses, is to impart students with an appreciation of how geology has influenced the course of human events. Despite the apparent accessibility of such topics, communicating this in a lively, relevant, and effective way often proves difficult. We use a series of historical events, the Pacific island hopping campaign of WWII, to engage students in an active, guided inquiry exercise to explore how terrain and the underlying geology of an area can shape historical events. Teams of students are assigned the role of planning either the defense or occupation of Okinawa Island, in the Ryukyu arc, in a theoretical version of the 1945 conflict. Students are given a package of information, including geologic and topographic maps, a list of military resources available to them at the time, and some historical background. Students also have access to "reconnaissance" images, 360o digital panoramas of the landscape of Okinawa, keyed to their maps. Each team has a week to plan their strategies and carry out additional research, which they subsequently bring to the table in the form of a written battle plan. With an instructor as arbiter, teams alternate drawing their maneuvers on a map of the island, to which the other team then responds. This continues one move at a time, until the instructor declares a victor. Throughout the exercise, the instructor guides students through analysis of each strategic decision in light of the island's structure and topography, with an emphasis on the appropriate interpretation of the maps. Students soon realize that an understanding of the island's terrain literally meant the difference between life and death for civilians and military participants alike in 1945. The karst landscape of Okinawa posed unique obstacles to both the Japanese and the American forces, including difficult landing sites, networks of natural caves, and sequences of hills aligned perpendicular to the

  10. Variability of the Kuroshio in the East China Sea, and its Relationship to the Ryukyu Current

    DTIC Science & Technology

    2016-06-07

    2000: Vertical structure and transport on a transect across the North Atlantic Current near 42°N: timeseries and mean. Journal of Geophysical Research ...Marine-Earth Science and Technology, Institute of Observational Research for Global Change (JAMSTEC) have determined the varying Ryukyu Current ...measurements, Journal of Geophysical Research , 107(C9), 3121, doi:10.1029/2001JC000795. James, C., M. Wimbush and H. Ichikawa, 1999. Kuroshio

  11. Improving the seismic imaging in the southern Ryukyu subduction system by using multiple attenuation methods

    NASA Astrophysics Data System (ADS)

    Lyu, Ci-Jhu; Kuo-Chen, Hao; McIntosh, Kirk; Wu, Francis; Liu, Char-Shine

    2015-04-01

    The southern Ryukyu subduction system is at the boundary where the Philippine sea plate subducts northwestward beneath the Eurasian plate near the Taiwan orogen. In previous studies, the boundary where the PSP subducts northward beneath the EP have no clear answers due to a lack of high-resolution crustal-scale geophysical constraints. We want to know the Moho boundary. We analyze in this study the dynamics of SRA system with TAIGER program of 2009, multi-channel marine seismic reflection (MGL0906_23, MGL0906_28, MGL0906_26A, MGL0906_13, MGL0906_18N). Data area covers about 30,000 km2. Shots are spaced every 50 m, hydrophones are spaced every 12.5 m, and CDP spacing is 6.25 m. Recording length is 15 s. Signal of the source is low frequencies (20Hz~60Hz), which can penetrate the shallow sediments and reflex signal of the deep crust. Because multiple can affect the deep structure signals. Therefore, we use a variety of methods to remove multiple effects, and increase Moho signals. In this study, we use four ways to remove the multiple. (1) Increases CDP spacing. (2)Deconvolution. (3) Surface Related Multiple Elimination (SRME). (4)Radon Transform multiple attenuation. From the TAIGER marine reflection data. The shallow structure are Huatung Basin, Yeyama Accretionary Prism, Forearc Basin and Ryukyu Arc (from south to north), respectively. We discover a lot of transform fault zone, and account these stress related with shear zone of Ryukyu subduction system. The deep structure, the crust of PSP velocity is about 5~7 km/s, the PSP Moho velocity is 7.5 km/s. In multichannel reflection seismic, the PSP Moho deep is about 15~20 km under the seabed. Keywords: multiple; Moho boundary; subduction zone; southern Ryukyu Arc (SRA)

  12. Tetrodotoxin and Its Analogues in the Pufferfish Arothron hispidus and A. nigropunctatus from the Solomon Islands: A Comparison of Their Toxin Profiles with the Same Species from Okinawa, Japan.

    PubMed

    Puilingi, Clyde Gorapava; Kudo, Yuta; Cho, Yuko; Konoki, Keiichi; Yotsu-Yamashita, Mari

    2015-08-26

    Pufferfish poisoning has not been well documented in the South Pacific, although fish and other seafood are sources of protein in these island nations. In this study, tetrodotoxin (TTX) and its analogues in each organ of the pufferfish Arothron hispidus and A. nigropunctatus collected in the Solomon Islands were investigated using high resolution LC-MS. The toxin profiles of the same two species of pufferfish from Okinawa, Japan were also examined for comparison. TTXs concentrations were higher in the skin of both species from both regions, and relatively lower in the liver, ovary, testis, stomach, intestine, and flesh. Due to higher TTX concentrations (51.0 and 28.7 µg/g at highest) detected in the skin of the two species from the Solomon Islands (saxitoxin was <0.02 µg/g), these species should be banned from consumption. Similar results were obtained from fish collected in Okinawa, Japan: TTX in the skin of A. hispidus and A. nigropunctatus were 12.7 and 255 µg/g, respectively, at highest, and saxitoxin was also detected in the skin (2.80 µg/g at highest) and ovary of A. hispidus. TTX, 5,6,11-trideoxyTTX (with its 4-epi form), and its anhydro forms were the most abundant, and 11-oxoTTX was commonly detected in the skin.

  13. Tetrodotoxin and Its Analogues in the Pufferfish Arothron hispidus and A. nigropunctatus from the Solomon Islands: A Comparison of Their Toxin Profiles with the Same Species from Okinawa, Japan

    PubMed Central

    Gorapava Puilingi, Clyde; Kudo, Yuta; Cho, Yuko; Konoki, Keiichi; Yotsu-Yamashita, Mari

    2015-01-01

    Pufferfish poisoning has not been well documented in the South Pacific, although fish and other seafood are sources of protein in these island nations. In this study, tetrodotoxin (TTX) and its analogues in each organ of the pufferfish Arothron hispidus and A. nigropunctatus collected in the Solomon Islands were investigated using high resolution LC-MS. The toxin profiles of the same two species of pufferfish from Okinawa, Japan were also examined for comparison. TTXs concentrations were higher in the skin of both species from both regions, and relatively lower in the liver, ovary, testis, stomach, intestine, and flesh. Due to higher TTX concentrations (51.0 and 28.7 µg/g at highest) detected in the skin of the two species from the Solomon Islands (saxitoxin was <0.02 µg/g), these species should be banned from consumption. Similar results were obtained from fish collected in Okinawa, Japan: TTX in the skin of A. hispidus and A. nigropunctatus were 12.7 and 255 µg/g, respectively, at highest, and saxitoxin was also detected in the skin (2.80 µg/g at highest) and ovary of A. hispidus. TTX, 5,6,11-trideoxyTTX (with its 4-epi form), and its anhydro forms were the most abundant, and 11-oxoTTX was commonly detected in the skin. PMID:26343722

  14. Rapid sedimentation of iron oxyhydroxides in an active hydrothermal shallow semi-enclosed bay at Satsuma Iwo-Jima Island, Kagoshima, Japan

    NASA Astrophysics Data System (ADS)

    Kiyokawa, Shoichi; Ueshiba, Takuya

    2015-04-01

    Hydrothermal activity is common in the fishing port of Nagahama Bay, a small semi-enclosed bay located on the southwest coast of Satsuma Iwo-Jima Island (38 km south of Kyushu Island, Japan). The bay contains red-brown iron oxyhydroxides and thick deposits of sediment. In this work, the high concentration and sedimentation rates of oxyhydroxide in this bay were studied and the sedimentary history was reconstructed. Since dredging work in 1998, a thickness of 1.0-1.5 m of iron oxyhydroxide-rich sediments has accumulated on the floor of the bay. To estimate the volume of iron oxyhydroxide sediments and the amount discharged from hydrothermal vents, sediment traps were operated for several years and 13 sedimentary core samples were collected to reconstruct the 10-year sedimentary history of Nagahama Bay. To confirm the timing of sedimentary events, the core data were compared with meteorological records obtained on the island, and the ages of characteristic key beds were thus identified. The sedimentation rate of iron oxyhydroxide mud was calculated, after correcting for sediment input from other sources. The sediments in the 13 cores from Nagahama Bay consist mainly of iron oxyhydroxide mud, three thick tephra beds, and a topmost thick sandy mud bed. Heavy rainfall events in 2000, 2001, 2002, and 2004-2005 coincide with tephra beds, which were reworked from Iwo-Dake ash deposits to form tephra-rich sediment. Strong typhoon events with gigantic waves transported outer-ocean-floor sediments and supplied quartz, cristobalite, tridymite, and albite sands to Nagahama Bay. These materials were redeposited together with bay sediments as the sandy mud bed. Based on the results from the sediment traps and cores, it is estimated that the iron oxyhydroxide mud accumulated in the bay at the relatively rapid rate of 33.3 cm/year (from traps) and 2.8-4.9 cm/year (from cores). The pore water contents within the sediment trap and core sediments are 73%-82% and 47%-67%, respectively

  15. A new species of fiddler crab from the Ogasawara (Bonin) Islands, Japan, separated from the widely-distributed sister species Uca (Paraleptuca) crassipes (White, 1847) (Crustacea: Decapoda: Brachyura: Ocypodidae).

    PubMed

    Shih, Hsi-Te; Komai, Tomoyuki; Liu, Min-Yun

    2013-12-10

    A new species of fiddler crab (Brachyura: Ocypodidae), Uca boninensis sp. nov., is described from the Ogasawara (Bonin) Islands, Japan. The new species has previously been identified with the widely distributed U. crassipes (White, 1847), from which it differs by having a slightly differently shaped carapace, and relatively stouter male first gonopods (G1). The recognition of the new species is also supported by differences in the mitochondrial cytochrome oxidase I (COI) and control region (CR) genes. U. boninensis sp. nov., appears to be endemic to the Ogasawara Islands, and as the only known population is small, urgent conservation measures are needed for its protection. Our study brings the total number of the Japanese fiddler crab species to 12.

  16. JPRS Report. Science & Technology: Japan

    DTIC Science & Technology

    2007-11-02

    fight was conducted as the Japan-U.S. final battle at sea off the Mariana Islands on 19 and 20 June 1944. There were 450 Japanese Zero fighters...the Pacific Ocean Plate and the rest by the eastern part of the Philippine Sea Plate when they slipped under the Japanese islands (Japan proper...will break and peel off and attach to the wall on the side of the main island , but for the most part is assumed to sink deep into the mantle in the

  17. An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.

    PubMed

    Igawa, Takeshi; Sugawara, Hirotaka; Tado, Miyuki; Nishitani, Takuma; Kurabayashi, Atsushi; Islam, Mohammed Mafizul; Oumi, Shohei; Katsuren, Seiki; Fujii, Tamotsu; Sumida, Masayuki

    2013-07-31

    Anderson's crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis.

  18. Intraplate volcanism influenced by distal subduction tectonics at Jeju Island, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Brenna, Marco; Cronin, Shane J.; Kereszturi, Gábor; Sohn, Young Kwan; Smith, Ian E. M.; Wijbrans, Jan

    2015-01-01

    The drivers behind the inception of, and the variable, pulsatory eruption rates at distributed intraplate volcanic fields are not well understood. Such broad areas of monogenetic volcanism cover vast areas of the world and are often heavily populated. Reliable models to unravel their behaviour require robust spatio-temporal frameworks within the fields, but an analysis of the potential proximal and distal regional volcano-tectonic processes is also needed. Jeju Island (Republic of Korea) is a volcanic field that has been extensively drilled and dated. It is also located near one of the world's best-studied tectonic plate boundaries: the subduction zone in southwestern Japan, which generates the Ryukyu and SW Japan arcs. A new set of 40Ar/39Ar ages collected from cores penetrating the entire Jeju eruptive pile, along with geochemical information, is used to construct a temporal and volumetric model for the volcano's growth. The overall pattern indicates inception of volcanism at ~1.7 Ma, with an initial 1.2 Myr of low-rate activity, followed by over an order of magnitude rise over the last 0.5 Myr. The magma flux at Jeju correlates well with increased extension rates in the arc/backarc region. In particular, we infer that the increased trenchward mantle flow, caused by the greater rollback of the Philippine Sea Plate, activated pre-existing shear weaknesses in the mantle beneath Jeju, resulting in mantle upwelling and decompression melting that caused a change in compositions and an increase in eruption rates at Jeju. Thus, the volcanic activity of an intraplate field system can be modulated by regional subduction processes occurring more than 650 km away. This model may explain the frequent observation of pulsatory behaviour seen in many monogenetic volcanic fields worldwide that lie within 1,000 km of subduction zones.

  19. Detection and location of shallow very low frequency earthquakes along the Nankai trough and the Ryukyu trench

    NASA Astrophysics Data System (ADS)

    Asano, Y.; Matsuzawa, T.; Obara, K.

    2013-12-01

    We have investigated spatiotemporal distribution of shallow very low frequency earthquakes (VLFEs) along the Nankai trough and the Ryukyu trench. Three component seismograms recorded at broadband stations of the NIED F-net were analyzed by using waveform-correlation and back-projection techniques after processing a band-pass filter (0.02 to 0.05 Hz). Here we used known VLFEs and regular interplate earthquakes near the trench axis as template events. Time series of cross-correlation function (CC) at each station was calculated from continuous waveform data and triggered seismograms of template events with a length of 180 s. Assuming surface wave propagation with a velocity of 3.8 km/s, CCs are back-propagated onto possible origin times and horizontal locations. We obtained VLFE epicenters by performing a grid search in time and space domains with spacing of 1 s and 0.025 degrees, respectively, to maximize the averaged CCs from all stations. At first, we choose grid points with averaged CCs larger than 0.5. If these grid points have similar origin times within 180 s, we assume that these grid points reflect a same event and choose the VLFE candidate having the largest averaged CC. If some grid points are detected in the same time window from different template events, we choose the VLFE candidate with the largest averaged CC from grid points located within 100 km from the template event. VLFEs were finally identified by removing regular earthquakes listed in the JMA catalogue from all candidates. As a result of the analysis for data from October, 2009 to February, 2010, two episodes of VLFE activity were detected. One episode was located east of the M6.8 interplate earthquake which occurred on October 30, 2009 along the Ryukyu trench. The VLFE seismicity was quite active just after the M6.8 earthquake and had been smoothly decreasing with the elapsed time. Such time dependent seismicity may be related to the post-seismic slip following the M6.8 earthquake. Another

  20. Deep Structure of the Fold-and-Thrust Belt in the Tenpoku Area, Northern Hokkaido Island, Japan, Revealed by Reprocessing of Seismic Reflection Data From the 1990 MITI Geophysical Explorations.

    NASA Astrophysics Data System (ADS)

    Yokokura, T.; Miyazaki, T.; Kano, N.

    2005-12-01

    The Tenpoku area, the northern part of Hokkaido island, Japan, is believed to have hydrocarbon potential in the thick Cretaceous-Tertiary sediments. Ministry of International Trade and Industry (MITI, present Ministry of Economy, Trade and Industry) and some private companies have conducted many geological and geophysical explorations and test drillings in this area. These surveys have revealed that some anticlines (e.g. Horonobe and Toyotomi anticlines) and faults (e.g. Ohmagari and Horonobe faults) exist in the mountainous area and that a large sedimentary basin extends from the west of the mountainous area to the Japan Sea. The area shows a fold-and-thrust belt structure of west vergence. There is an active Sarobetsu flexural zone in the eastern end of the sedimentary basin. The flexural zone is believed to have become active since the middle Pliocene. In this way, overall geological structure down to around 5km in depth is well known, while there is few information about the deeper part. Japan National Oil Corporation (present Japan Oil, Gas and Metals National Corporation (JOGMEC)) conducted seismic reflection surveys in this area in 1990 on consignment from MITI. Part of the seismic reflection data was acquired by using dynamite and has long two-way traveltime of 18sec. As the seismic data may provide us deeper information on this fold-and-thrust belt, we tried to reprocess the data with permission by JOGMEC. As a result, we found that two low-angle east-dipping thrusts extend to around 10km in depth, which are related to the Ohmagari fault and Sarobetsu flexural zone. Beneath these thrusts, some other east-dipping thrusts also exist which may be related to micro-earthquake activity of this area.

  1. Tight species cohesion among sympatric insular wild gingers (Asarum spp. Aristolochiaceae) on continental islands: Highly differentiated floral characteristics versus undifferentiated genotypes.

    PubMed

    Matsuda, Junshi; Maeda, Yoshiyuki; Nagasawa, Junichi; Setoguchi, Hiroaki

    2017-01-01

    The Amami Island group of the Ryukyu Archipelago, Japan, harbors extensive species diversity of Asarum in a small landmass. The fine-scale population genetic structure and diversity of nine insular endemic Asarum species were examined using nuclear DNA microsatellite loci and ITS sequences. High population genetic diversity (HS = 0.45-0.79) was estimated based on the microsatellites, implying outcrossing of Asarum species within populations accompanied by inbreeding. Bayesian clustering analyses revealed that species were divided into three robust genetic clusters and that the species within each cluster had a homogeneous genetic structure, indicating incomplete lineage sorting. This conclusion was supported by an ITS phylogeny. The degree of genetic differentiation among species was very low both within and between clusters (FST = 0.096-0.193, and 0.096-0.266, respectively). Although species can be crossed artificially to produce fertile hybrids, our results indicate that there is very little evidence of hybridization or introgression occurring among species in the wild, even within stands composed of multiple sympatric species. The highly differentiated floral morphology of the studied species is likely to impose reproductive isolation between them and maintain their integrity in the wild. A lack of genetic differentiation between sympatric species suggests that speciation within this group occurred rapidly and recently.

  2. Tight species cohesion among sympatric insular wild gingers (Asarum spp. Aristolochiaceae) on continental islands: Highly differentiated floral characteristics versus undifferentiated genotypes

    PubMed Central

    Matsuda, Junshi; Maeda, Yoshiyuki; Nagasawa, Junichi

    2017-01-01

    The Amami Island group of the Ryukyu Archipelago, Japan, harbors extensive species diversity of Asarum in a small landmass. The fine-scale population genetic structure and diversity of nine insular endemic Asarum species were examined using nuclear DNA microsatellite loci and ITS sequences. High population genetic diversity (HS = 0.45–0.79) was estimated based on the microsatellites, implying outcrossing of Asarum species within populations accompanied by inbreeding. Bayesian clustering analyses revealed that species were divided into three robust genetic clusters and that the species within each cluster had a homogeneous genetic structure, indicating incomplete lineage sorting. This conclusion was supported by an ITS phylogeny. The degree of genetic differentiation among species was very low both within and between clusters (FST = 0.096–0.193, and 0.096–0.266, respectively). Although species can be crossed artificially to produce fertile hybrids, our results indicate that there is very little evidence of hybridization or introgression occurring among species in the wild, even within stands composed of multiple sympatric species. The highly differentiated floral morphology of the studied species is likely to impose reproductive isolation between them and maintain their integrity in the wild. A lack of genetic differentiation between sympatric species suggests that speciation within this group occurred rapidly and recently. PMID:28301540

  3. The influence of the Kuril Islands on the penetration of tsunamis into the Sea of Okhotsk (on the example of the Japan tsunami on March 11, 2011)

    NASA Astrophysics Data System (ADS)

    Kostenko, I. S.; Kurkin, A. A.; Pelinovsky, E. N.; Yalciner, A.

    2016-01-01

    The features of the propagation of the tsunami of March 11, 2011 in the northeastern Pacific have been studied with the aim of revealing the degree of influence of the Kuril Islands on the penetration of the tsunami in the Sea of Okhotsk. For this, a series of computational experiments have been performed within the shallow water theory using bathymetry (1) with and (2) without the Kuril Islands. The wave heights calculated have been analyzed, and the tsunami's magnitude and intensity in the Sea of Okhotsk have been estimated. The computational experiments performed allow assessment of a decrease in the tsunami intensity while passing the Kuril Islands.

  4. Origin of Japanese White-Eyes and Brown-Eared Bulbuls on the Volcano Islands.

    PubMed

    Sugita, Norimasa; Kawakami, Kazuto; Nishiumi, Isao

    2016-04-01

    The Ogasawara Archipelago comprises two groups of oceanic islands: the Bonin Islands, formed in the Paleogene, and the Volcano Islands, formed in the Quaternary. These groups are located within a moderate distance (ca. 160-270 km) of one another; thus, most land bird species are not distinguished as different subspecies. Two land birds, however, show unusual distribution. The Japanese white-eyes Zosterops japonicus originally inhabited only the Volcano Islands, but has been introduced to the Bonin Islands. The brown-eared bulbuls Hypsipetes amaurotis are distributed as a different subspecies. We investigated their genetic differences and divergences in the Ogasawara Archipelago using mitochondria DNA. The Volcano population of white-eyes had four endemic haplotypes that were divergent from one another, except for the Bonin population, which shared three haplotypes with the Volcano, Izu, and Ryukyu Islands and did not have any endemic haplotype. This is the first genetic suggestion that the Bonin population is a hybrid of introduced populations. With respect to bulbuls, the Volcano and Bonin Islands each had a single endemic haplotype. The Volcano haplotype is closest to a haplotype shared with Izu, the Japanese mainland, Daito and Ryukyu, whereas the Bonin haplotype is closest to one endemic to the south Ryukyu Islands. This indicates that the sources of the two bulbul populations can be geologically and temporally distinguished. The populations of the two species in the Ogasawara Archipelago are irreplaceable, owing to their genetic differences and should be regarded as evolutionarily significant units. In order to prevent introgression between the two populations, we must restrict interisland transfers.

  5. Oblique Convergence Tectonics in Northern Taiwan-Ryukyu Area:Insights from Sandbox Modeling

    NASA Astrophysics Data System (ADS)

    Li, Z.; Lu, C. Y.

    2015-12-01

    Taiwan located on the boundary between Eurasian Plate and Philippine Sea Plate and as a results of convergence of these two plates. The specific process of Taiwan orogeny is a hot issue for many years. Sandbox modeling is a way to simulate the mountain building process. The previous studies of 3D sandbox modeling in Taiwan are more concentrated on the effect of basement high and arc-continent collision but few noted the effect of opening of Okinawa Trough. This 3D experiment aims at the structure of northern Taiwan, adds a sandpaper machine which could move in experiment that simulate the opening of Okinawa Trough, and tries to explain the tectonic evolution in northern Taiwan. Result of experimental modeling proves that: (1) the Ryukyu Arc is pulled apart and moving southward as the opening of Okinawa Trough, (2) direction of Ryukyu Arc changed between southern part and middle-northern part due to the opening of Okinawa Trough, (3) Ilan Plain subsidence caused by the opening of Okinawa Trough.

  6. Hg, Zn and Cu levels in the muscle and liver of tiger sharks (Galeocerdo cuvier) from the coast of Ishigaki Island, Japan: relationship between metal concentrations and body length.

    PubMed

    Endo, Tetsuya; Hisamichi, Yohsuke; Haraguchi, Koichi; Kato, Yoshihisa; Ohta, Chiho; Koga, Nobuyuki

    2008-10-01

    We analyzed Hg, Zn and Cu concentrations in the liver and muscle of tiger sharks (Galeocerdo cuvier) from the coast of Ishigaki Island, Japan. The Hg concentration in the muscle increased proportionally with body length in the tiger sharks, whereas that in the liver increased rapidly after maturity (defined by a length of over 2.7 m). Muscle Hg levels were higher than liver concentrations in immature sharks, with the inverse trend observed in mature sharks. Notably, the Zn and Cu concentrations in the liver tended to decrease with increasing body length. This rapid increase in hepatic Hg concentration concurrent with the onset of maturity in sharks may result from the continuous intake of Hg via food and the slower growth of mature sharks. The high concentrations of the essential metals Zn and Cu in immature sharks may be explained by the physiological demands related to rapid growth.

  7. AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

    NASA Astrophysics Data System (ADS)

    Okuno, Mitsuru; Nakamura, Toshio; Geshi, Nobuo; Kimura, Katsuhiko; Saito-Kokubu, Yoko; Kobayashi, Tetsuo

    2013-01-01

    Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained 14C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

  8. A novel cluster of mariner-like elements belonging to mellifera subfamily from spiders and insects: implications of recent horizontal transfer on the South-West Islands of Japan.

    PubMed

    Yamada, Kaori; Kawanishi, Yuichi; Yamada, Akinori; Tokuda, Gaku; Gurung, Raj Deep; Sasaki, Takeshi; Nakajima, Yumiko; Maekawa, Hideaki

    2014-04-01

    Mariner-like elements (MLEs) have been isolated from various eukaryotic genomes and they are divided into 15 subfamilies, including main five subfamilies: mauritiana, cecropia, mellifera/capitata, irritans, and elegans/briggsae. In the present study, MLEs belonging to mellifera subfamily were isolated from various spiders and insects (Hymenoptera and Lepidoptera) inhabiting the South-West Islands of Japan and neighboring regions. MLEs isolated from 15 different species formed a distinct novel cluster in mellifera subfamily. MLEs obtained from three different species [i.e., the bee Amegilla senahai subflavescens (Amsmar1), the wasp Campsomeris sp. (Casmar1), and the swallowtail butterfly Pachliopta aristolochiae (Paamar1)] contained an intact open reading frame that encoded a putative transposase. These transposases exhibited high similarity of 97.9% among themselves. In case of Casmar1, the presence of an intact ORF was found in high frequencies (i.e., 11 out of 12 clones). In addition, these transposases also showed the presence of a terminal inverted repeat-binding motif, DD(34)D and two highly conserved amino acid motifs, (W/L)(I/L)PHQL and YSP(D/N)L(A/S)P. These two motifs differed from previously known motifs, WVPHEL and YSPDLAP. MLEs isolated from these three different species may have been inserted into their genomes by horizontal transfer. Furthermore, the presence of an intact ORF suggests that they are still active in habitats along these isolated islands.

  9. Interdisciplinary approaches to better understand the past tsunamis -Case study of the 1771 Meiwa Tsunami, Japan-

    NASA Astrophysics Data System (ADS)

    Goto, K.

    2012-12-01

    It is important to know frequency and magnitude of past tsunamis over hundred to thousand years to better understand the risk from low-frequency large tsunamis. Historical documents, archeological evidence, and sediments laid down by tsunamis in coastal environments are useful for understanding the past tsunamis. Among them, tsunami geology has become a subject of great interest since the March 11, 2011 Tohoku-oki tsunami, Japan. This is because the 2011 tsunami was suspected as a recurrence of the AD869 Jogan tsunami, which was well known based on the geological and historical evidence. Our newly acquired geological data on the 2011 tsunami however, suggest that previous estimates of the Jogan tsunami have probably been underestimated [Goto et al., 2011]. This suggests that more interdisciplinary research is needed to better understand the historical and prehistoric tsunamis. As an example of the interdisciplinary research to better understand the past tsunami, here I review the studies of the AD1771 Meiwa Tsunami and its predecessors that struck the southern Ryukyu Islands, Japan. Reliable historical documents suggest run-up heights of up to 30 m for this tsunami [e.g. Goto et al., 2010], which are well supported by the archeological evidence as well as local traditions. Moreover, the displacement of specific coral boulders by the tsunami is also described in detail. Geological studies and numerical modeling of the boulder transport by the tsunami further revealed that many coral boulders of several hundred tons were deposited by the tsunami [e.g. Goto et al., 2010]. Based on such researches, the source model for the tsunami was estimated by the high-resolution numerical modeling, although it remains still controversial. Our study suggests that all available historical, geological, and archaeological data should be collected to better estimate the historical and prehistoric tsunami source model. The field evidences are still increasing for the 1771 Meiwa Tsunami

  10. Japan Report.

    DTIC Science & Technology

    1987-02-03

    10503« JPRS-JAR-87-001 3 FEBRUARY 1987 Japan Report 19980629 058 FBIS FOREIGN BROADCAST INFORMATION SERVICE BTIO QUALITY INSPECTED 6... JAPAN REPORT CONTENTS POLITICAL AND SOCIOLOGICAL Impact of Miyazawa’s Appointment as Finance Minister (Kenzo Uchida, et al.; ZAIKAI TEMBO, Oct 86...Direct U.S. Investment Discussed (Akio Morita, et? al.; KEIDANREN GEPPO, Sep 86) 30 Japan -PRC Trade Expansion Council Officially Inaugurated

  11. Japan Report.

    DTIC Science & Technology

    1985-04-30

    172068 JPRS-JAR-85-0 1 0 3 0 April 198 5 Japan Report 19980722 116 »TIC QUALITY SfSPECTED 3 FBIS FOREIGN BROADCAST INFORMATION SERVICE...85-010 30 April 19 85 JAPAN REPORT CONTENTS POLITICAL AND SOCIOLOGICAL Break Up of Tanaka-Nakasone Alliance Anticipated (Taro Maki; SEKAI, Jan 85...minister. It became "When I was prime minister, Japan was isolated in international society," and although at the U.S.- Japan summit talks President Reagan

  12. Japan Report.

    DTIC Science & Technology

    2007-11-02

    034079 JPRS-JAR-85-005 1 9 February 1 985 Japan Report A Appro-mi for pwMe \\ɘ!fc W [OTIC QUALITY IfSPIS CTED 9 FBIS FOREIGN...Virginia 22201. JPRS-JAR-85-005 19 February 1985 JAPAN REPORT CONTENTS POLITICAL AND SOCIOLOGICAL ’Crisis-Management Set-Up’ Critiqued (Koichiro...Output Jumps 11.2 Percent in 1984 (KYODO, 29 Jan 85) 43 Japan , U.S. Aircraft Makers To Cooperate (KYODO, 25 Jan 85) 45 Japan Seeks End to Auto

  13. Japan Report.

    DTIC Science & Technology

    1985-05-09

    expenditure . He said that he hoped for greater effort on Japan’s part in regard to the defense of Japan itself and its periphery. This means he clearly set...Forces into real combat forces and their unification with U.S. Forces. They dealt with the mounting defense expenditure , which is also connected with...governments of Japan and the United States on "guidelines for Japan -U.S. cooperation on defense " in 1978. Throughout 1984, even Prime Minister Nakasone

  14. Species-specific responses of corals to bleaching events on anthropogenically turbid reefs on Okinawa Island, Japan, over a 15-year period (1995-2009).

    PubMed

    Hongo, Chuki; Yamano, Hiroya

    2013-01-01

    Coral bleaching, triggered by elevated sea-surface temperatures (SSTs) has caused a decline in coral cover and changes in the abundances of corals on reefs worldwide. Coral decline can be exacerbated by the effects of local stressors like turbidity, yet some reefs with a natural history of turbidity can support healthy and resilient coral communities. However, little is known about responses of coral communities to bleaching events on anthropogenically turbid reefs as a result of recent (post World War II) terrestrial runoff. Analysis of region-scale coral cover and species abundance at 17-20 sites on the turbid reefs of Okinawa Island (total of 79 species, 30 genera, and 13 families) from 1995 to 2009 indicates that coral cover decreased drastically, from 24.4% to 7.5% (1.1%/year), subsequent to bleaching events in 1998 and 2001. This dramatic decrease in coral cover corresponded to the demise of Acropora species (e.g., A. digitifera) by 2009, when Acropora had mostly disappeared from turbid reefs on Okinawa Island. In contrast, Merulinidae species (e.g., Dipsastraea pallida/speciosa/favus) and Porites species (e.g., P. lutea/australiensis), which are characterized by tolerance to thermal stress, survived on turbid reefs of Okinawa Island throughout the period. Our results suggest that high turbidity, influenced by recent terrestrial runoff, could have caused a reduction in resilience of Acropora species to severe thermal stress events, because the corals could not have adapted to a relatively recent decline in water quality. The coral reef ecosystems of Okinawa Island will be severely impoverished if Acropora species fail to recover.

  15. Diatoms from Lake Kushu: A pilot study to test the potential of a Late Quaternary palaeoenvironmental archive from Rebun Island (Hokkaido Region, Japan)

    NASA Astrophysics Data System (ADS)

    Schmidt, Mareike; Tarasov, Pavel E.; Hoelzmann, Philipp; Meyer, Hanno; Leipe, Christian

    2016-05-01

    Rebun Island is a key research area for the Baikal-Hokkaido Archaeology Project to better understand the dynamics of the Neolithic hunter-gatherers in the NW Pacific region. Hence, the ca. 19.5 m sediment core RK12 spanning the last ca. 16.6 cal. kyr BP was obtained from Lake Kushu. Our aim is to test its potential as a high-resolution multi-proxy archive. Here, we used diatoms to investigate the modern ecosystem of Lake Kushu and its surrounding area on Rebun Island and of Hime-numa Pond on Rishiri Island and selected core samples for comparison. Modern diatom and stable isotope analyses show well-mixed freshwater bodies with eutrophic, alkaline conditions. The fossil diatom and geochemical sediment analyses display three phases that represent major changes in the lake development: (i) a marshy phase (ca. 16.6-10 cal. kyr BP); (ii) a brackish water lagoon phase (ca. 10-6.6 cal. kyr BP); and (iii) a freshwater lake phase (since ca. 6.6 cal. kyr BP). This shows the major role of the post-glacial climate amelioration, global sea-level rise and marine transgression in the development of this landscape. Further analyses will provide a palaeolimnological record at (sub-)decadal resolution that will facilitate the interpretation of the hunter-gatherer dynamics.

  16. Elucidation of Environmental Fate of Artificial Sweetener, Aspartame by Determining Bimolecular Rate Constants with Hydroxyl Radical at Various pH and Temperature Conditions and Reaction By-Products Presentation type:Poster Section:Ocean Sciences Session:General Contribution Authors:Takashi Teraji (1) Takemitsu Arakaki (2) AGU# 10173629 (1) Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru Nishihara-cho, Okinawa, 903-0123, Japan (a4269bj@yahoo.co.jp), (2) Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru Nishihara-cho, Okinawa, 903-0123, Japan (arakakit@sci.u-ryukyu.ac.jp)

    NASA Astrophysics Data System (ADS)

    Teraji, T.; Arakaki, T.

    2011-12-01

    Use of artificial sweeteners in drinks and food has been rapidly increasing because of their non-calorie nature. In Japan, aspartame, acesulfame K and sucralose are among the most widely used artificial sweeteners. Because the artificial sweeteners are not metabolized in human bodies, they are directly excreted into the environment without chemical transformations. We initiated a study to better understand the fate of artificial sweeteners in the marine environment. In particular, we focused on the fate of aspartame by determining its bimolecular rate constants with hydroxyl radicals at various pH and temperature conditions and reaction by-products. The hydroxyl radical (OH), the most potent reactive oxygen species, reacts with various compounds and determines the environmental oxidation capacity and the life-time of many compounds. The steady-state OH concentration and the reaction rate constants between the compound and OH are used to estimate the life-time of the compound. In this study, we determine the bimolecular rate constants between aspartame and OH at various pH and temperature conditions using a competition kinetics technique. We use hydrogen peroxide as a photochemical source of OH. Bimolecular rate constant we obtained so far was (2.6±1.2)×109 M-1 s-1 at pH = 3.0. Little effect was seen by changing the temperatures between 15 and 40 °C. Activation energy (Ea) was calculated to be -1.0 kJ mol-1 at pH = 3.0, which could be regarded as zero. We will report reaction rate constants at different pHs and reaction by-products which will be analyzed by GC-MS. We will further discuss the fate of aspartame in the coastal environment.

  17. Application of Satellite Geodesy in Analyzing the Accelerated Movement of the Back-arc Rifting in the Izu Bonin Islands, Japan

    NASA Astrophysics Data System (ADS)

    Arisa, D.; Heki, K.

    2014-12-01

    The Izu-Bonin islands lies along the convergent boundary between the subducting Pacific plate (PA) and the overriding Philippine Sea plate (PH) in the western Pacific. Nishimura (2011) found that the back-arc rifting goes on behind the Izu arc by studying the horizontal velocities of GNSS stations on the Izu islands. Here we show that this rifting has accelerated in 2004 using GNSS data at Aogashima, Hachijoujima, and Mikurajima stations. The back-arc rifting behind the Izu islands can be seen as the increasing distance between stations in the Izu-Bonin islands and stations located in the stable part of PH. We found that their movement showed clear acceleration around the third quarter of 2004. Obtaining the Euler vector of the PH is necessary to analyzed the movement of each stations relative to the other stations on the same plate. The analyzing of GPS timeseries leads us to one initial conclusion that some accelerated movement started to occur in the third quarter of 2004. This event was closely related to the earthquake on May 29, 2004 in Nankai Trough and September 5, 2004 earthquake near the triple junction of Sagami Trough. The analyzing process help us to understand that this accelerated movement was not the afterslip of any of these earthquakes, but it was triggering these area to move faster and further than it was. We first rule out the best possible cause by constraining the onset time of the accelerated movement, and correlating it with the earthquakes. May 29, 2004 earthquake (M6.5) at the PA-PH boundary clearly lacked the jump which should mark the onset of the eastward slow movement. Moreover, additional velocity vectors do not converge to the epicenter, and onset time that minimizes the post-fit residual is significantly later than May. We therefore conclude that accelerated movement started in 2004 was not due to the afterslip of interplate earthquake in May 29. On the next step we found that the onset time coincides with the occurrence of

  18. Update Japan.

    ERIC Educational Resources Information Center

    Hoopes, Aaron

    This book is a guide intended for persons planning on relocating to Japan. Following a chapter on background information, 13 additional chapters lead the reader step-by-step through the relocation process. These chapters include: before leaving, on arrival, language, culture, doing business in Japan, household pointers and everyday life, schools…

  19. Residence time of submarine fresh groundwater discharge in Hachijo Island, Japan: Application of dating tracers of Tritium, CFCs and SF6

    NASA Astrophysics Data System (ADS)

    MOGI, K.; Asai, K.

    2013-12-01

    Hachijo is a volcanic Island in the Western Pacific Ring of Fire. Submarine fresh groundwater discharge (SGD) distribute around the coastal area of Hachijo Island. In this study, we estimate the residence time of the SGD using the multi age tracer method, to understand the mechanism of SGD. Water samples were collected from 1 SGD, 5 mountain springs and 6 costal wells, and were measured in Tritium, CFCs and SF6 concentrations. All water samples contain detectable tritium, indicating that these waters are mainly recharged at post-bomb period. CFC-12 and SF6 concentration of water samples show wide variations from 163 to 247 pg/kg and from 1.06 to 2.61 fmol/kg, respectively. The SF6-based apparent ages for the mountain springs and shallow well were estimated at less than 6 years, and ranged from 12 to 20 years in the deep wells. Estimated SF6 age of the SGD (13 years) coincide with the age of the deep wells, suggesting that the SGD play a role of outlet of deep groundwater.

  20. Rearming Japan

    DTIC Science & Technology

    2007-11-02

    roughly ~’ Ibid., pp. 14-16, 27-30. 12 3.5 percent of their GDP towards defense while Japan spends slightly over 1 percent. Yet, when compared with...runs up huge trade surpluses in its commerce with the United States and Western Europe. Conversely, Japan spends just slightly over one percent of...its GNP on defense indicating to many in the U.S. and Western Europe that Japan is enjoying a free ride and waxing rich under American military

  1. Non-destructive monitoring of trace element levels in short-tailed albatrosses (Phoebastria albatrus) and black-footed albatrosses (Phoebastria nigripes) from Torishima Island, Japan using eggs and blood.

    PubMed

    Ikemoto, Tokutaka; Kunito, Takashi; Tanabe, Shinsuke; Tsurumi, Miyako; Sato, Fumio; Oka, Nariko

    2005-01-01

    Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Hg, Tl and Pb) were determined in abandoned eggs of short-tailed albatrosses and abandoned eggs and blood of black-footed albatrosses from Torishima Island, Japan in 2002. Mercury concentration was highest among the toxic elements in egg content of both the two species. In some egg contents of black-footed albatrosses, Hg concentrations were higher than the threshold level that may cause decreased hatchability and aberrant nesting behavior in some avian species. Concentrations of Cd in egg content and Ba in egg content and shell increased with an increase in egg breadth/length ratio, whereas Hg in egg content showed an opposite trend in black-footed albatrosses. Since egg breadth/length ratio is known to increase with the age of mother bird, this result may imply that concentrations of these elements in eggs vary with age of mother bird. In blood of black-footed albatross chicks, concentration of Hg was highest among the toxic elements and the Hg concentration showed an increase in the later growth stages. In contrast, concentration of Sr in blood decreased with growth stage. Since the behaviour of Sr is similar to that of Ca in animals, it is conceivable that Sr was used along with Ca for the formation of bone.

  2. Rifting Process and Geomorphic Development of the Okinawa Tough, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Arai, K.; Inoue, T.; Matsumoto, D.

    2012-12-01

    The Ryukyu Island Arc extends from Kyushu to Taiwan, a distance of 1,200 km, along the Ryukyu Trench where the Philippine Sea Plate is subducting beneath the Eurasian Plate. The Okinawa Trough, a back arc basin has formed behind the Ryukyu Island Arc in late Pliocene to early Pleistocene. The research cruises of GH11 (from 14 July to 15 August, 2011) and GH12 (from 20 to 30 July, 2012) were carried out around the Okinawa Trough. More than 3,600 miles multi channel high-resolution seismic profiles were acquired during these cruises by the GI-gun (Generator 250 cu inch and Injector 105 cu. inch) systems with 16ch digital streamer cable. As a result, two unconformities and three depositional sequence divided by the unconformities are recognized in the trough. The lower and the midlle sequence are tilted and blocked by many normal faults, on the other hand the upper one is not tilted and shows the pattern of onlap fill. From this result, the upper sequence started to deposit after start of the rifting. Additionally, internal reflection of the upper sequence shows the cyclic activities of the rifting. The position of the rifting axis was revealed based on dip of the normal faults. As a result, rifting axis shows echelon arrangement and the displacement of the faults are varied with the segment of the arrangement. The location of the segment boundaries is correlated with geometrical boundary of the adjacent slope. Steep slope with incised valley is distributed in southwestern part where the displacement of the normal fault is large, on the other hand, gentle slope without incised valley is distributed in northeastern part where the displacement is small. This difference of the displacement strongly controls the geometry of the adjacent slope.

  3. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

    PubMed Central

    Nagaya, Takayoshi; Walker, Andrew M.; Wookey, James; Wallis, Simon R.; Ishii, Kazuhiko; Kendall, J. -Michael

    2016-01-01

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed. PMID:27436676

  4. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone.

    PubMed

    Nagaya, Takayoshi; Walker, Andrew M; Wookey, James; Wallis, Simon R; Ishii, Kazuhiko; Kendall, J-Michael

    2016-07-20

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed.

  5. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Nagaya, Takayoshi; Walker, Andrew M.; Wookey, James; Wallis, Simon R.; Ishii, Kazuhiko; Kendall, J.-Michael

    2016-07-01

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed.

  6. A model for the termination of the Ryukyu subduction zone against Taiwan: A junction of collision, subduction/separation, and subduction boundaries

    USGS Publications Warehouse

    Wu, F.T.; Liang, W.-T.; Lee, J.-C.; Benz, H.; Villasenor, A.

    2009-01-01

    The NW moving Philippine Sea plate (PSP) collides with the Eurasian plate (EUP) in the vicinity of Taiwan, and at the same time, it subducts toward the north along SW Ryukyu. The Ryukyu subduction zone terminates against eastern Taiwan. While the Ryukyu Trench is a linear bathym??trie low about 100 km east of Taiwan, closer to Taiwan, it cannot be clearly identified bathymetrically owing to the deformation related to the collision, making the location of the intersection of the Ryukyu with Taiwan difficult to decipher. We propose a model for this complex of boundaries on the basis of seismicity and 3-D velocity structures. In this model the intersection is placed at the latitude of about 23.7??N, placing the northern part of the Coastal Range on EUP. As PSP gets deeper along the subduction zone it collides with EUP on the Taiwan side only where they are in direct contact. Thus, the Eurasian plate on the Taiwan side is being pushed and compressed by the NW moving Philippine Sea plate, at increasing depth toward the north. Offshore of northeastern Taiwan the wedge-shaped EUP on top of the Ryukyu subducting plate is connected to the EUP on the Ryukyu side and coupled to the NW moving PSP by friction at the plate interface. The two sides of the EUP above the western end of the subduction zone are not subjected to the same forces, and a difference in motions can be expected. The deformation of Taiwan as revealed by continuous GPS measurements, geodetic movement along the east coast of Taiwan, and the formation of the Hoping Basin can be understood in terms of the proposed model. Copyright 2009 by the American Geophysical Union.

  7. Prevalence of Blastocystis hominis and Strongyloides stercoralis infection in Okinawa, Japan.

    PubMed

    Hirata, Tetsuo; Nakamura, Hiroshi; Kinjo, Nagisa; Hokama, Akira; Kinjo, Fukunori; Yamane, Nobuhisa; Fujita, Jiro

    2007-11-01

    This study was conducted to clarify the prevalence of Blastocystis hominis and Strongyloides stercoralis infection in Ryukyu University Hospital, Okinawa, Japan, between January 2004 and November 2006. Stool samples collected from 3,292 patients were examined by the direct smear method, formalin-ether sedimentation method, and agar plate culture method. The prevalence rate of B. hominis and S. stercoralis infection was 1.0 and 3.4%, respectively. The prevalence rate of B. hominis infection in patients aged >80 years old was significantly higher than that in patients <80 years old (P < 0.001). The prevalence rate of S. stercoralis infection was significantly higher in patients with B. hominis infection compared with those without (P < 0.001). This study demonstrated a prevalence rate for B. hominis and S. stercoralis infection and an association between B. hominis and S. stercoralis infection in Okinawa, Japan.

  8. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan.

    PubMed

    de Queiroz, Alexya Cunha; Sakai, Yoichi; Vallinoto, Marcelo; Barros, Breno

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects.

  9. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan

    PubMed Central

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects. PMID:27547571

  10. Shallow repeating slow-slip-events along the convergent block boundary in northern Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Heki, K.; Kimura, T.

    2015-12-01

    The Japanese Islands are divided into several crustal blocks [e.g. Loveless and Meade, 2010 JGR]. In the Northern Hokkaido, the boundary between the Amurian and the North American Plates run north-south between 44.0N and 45.4N. The east-west block convergence is considered to be as fast as ~1 cm/year there, but few large earthquakes are known to have occurred along this boundary. Recently, a slow slip event (SSE) is reported to have occurred in a segment at ~45.0N over a 4 months period from 2012 summer to the early 2013 [Ohzono et al., 2014 GJI]. The maximum surface movements was about 15 mm, and the moment magnitude of the SSE would not exceed 6.0 (fault slip is estimated as 10 cm). This suggests that plate convergence takes place as episodic SSEs in this block boundary. In this research, we looked for signatures of repeating SSEs along this block boundary using continuous GNSS data of the dense array GEONET in Japan. In order to detect faint signatures of SSEs in the coordinate time series, we adopted the method using AIC (Akaike's Information Criterion) similar to Nishimura et al. [2013 JGR] and Nishimura [2014 PEPS]. As a result, we were able to find numbers of SSE signals in various segments along the boundary. The detected SSEs are all fairly small, and surface movements did not exceed a few millimeters (except the 2012-2013 SSE reported in Ohzono et al. [2014]). We also searched earthquakes that may have triggered these SSEs. Although the 2012 SSE seems to have been triggered by a deep earthquake beneath Sakhalin on Aug. 14, 2012, no clear triggering earthquakes were identified for other SSEs. SSEs in subduction zones are known to recur fairly regularly, e.g. biannually repeating SSE in the SW part of the Ryukyu Arc [Heki and Kataoka, 2008 JGR]. However, shallow SSEs along the block boundary in the northern Hokkaido did not show such regular occurrences. We plan to confirm these SSE occurrences by comparing GNSS data with the Hi-Net tiltmeter records.

  11. Japan Report.

    DTIC Science & Technology

    2007-11-02

    apprehensions of Europe and America that China would become closely related with Japan alone and that Japan might monopolize the Chinese market . As a...out of the 300 billion yen, 100 billion yen is supplier’s credit from concerted action by the Ex-Im Bank and the Open Market Bank, 130 billion yen is...to launch production in the U.S. in the belief that Japanese automakers will have to continue some form of export restraints for the American market

  12. Heat Islands

    EPA Pesticide Factsheets

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  13. Japan: Tsunami

    Atmospheric Science Data Center

    2013-04-16

    ... tsunami triggered by the March 11, 2011, magnitude 8.9 earthquake centered off Japan's northeastern coast about 130 kilometers (82 ... inland from the eastern shoreline is visible in the post-earthquake image. The white sand beaches visible in the pre-earthquake view are ...

  14. Effects of Isolation by Continental Islands in the Seto Inland Sea, Japan, on Genetic Diversity of the Large Japanese Field Mouse, Apodemus speciosus (Rodentia: Muridae), Inferred from the Mitochondrial Dloop Region.

    PubMed

    Sato, Jun J; Tasaka, Yurina; Tasaka, Ryoya; Gunji, Kentaro; Yamamoto, Yuya; Takada, Yasushi; Uematsu, Yasushi; Sakai, Eiichi; Tateishi, Takashi; Yamaguchi, Yasunori

    2017-04-01

    To study the effects of post-glacial isolation by islands on population genetic diversity and differentiation of the large Japanese field mouse, Apodemus speciosus, we examined partial nucleotide sequences of the mitochondrial Dloop region (ca. 300 bp) in 231 individuals collected from islands in the Seto Inland Sea and adjacent regions on Honshu and Shikoku Islands in the western part of the Japanese archipelago. Molecular phylogenetic and network analyses showed that haplotypes in each island tended to form monophyletic groups, while those in Honshu and Shikoku (the major Japanese islands) showed scattered relationships and were connected with island haplotypes. These observations suggest that a set of Honshu and Shikoku haplotypes became the ancestral lineages of the island population. No gene flow was detected among island populations, indicating that independent evolution occurred on each island, without the influence of human activities, since the establishment of the islands in the Holocene. Population genetic diversities on each island were lower than those on Honshu and Shikoku. Comparison between genetic diversity and island area size showed positive correlations and supported the suggestion that genetic drift is a major factor that shaped the current haplotype constitution of the islands in the Seto Inland Sea.

  15. Japan: Land of the Rising Sun. A Twelve Day Unit of Study for Fourth Grade Students.

    ERIC Educational Resources Information Center

    Craycraft, Kenneth; Winters, Norm

    This unit of study on Japan contains the following content areas: Unit Focus/Motivation; Islands of Japan; Living on an Island; Buildings; Economics; Transportation; and Culminating Activities. The objectives of the unit include knowledge, skills, and attitudes. Suggested activities for each of the content areas are offered and explained to assist…

  16. Genetic diversity and differentiation of the Ryukyu endemic frog Babina holsti as revealed by mitochondrial DNA.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Nakata, Katsushi

    2014-02-01

    We surveyed the genetic diversity and genetic differentiation of an endangered frog, Babina holsti, endemic to Okinawajima and Tokashikijima Islands of the Ryukyus, to elucidate its divergence history and obtain basic data for its conservation. Genetic differentiation between the two island lineages is moderate (3.1% p-distance in the cyt b gene). This result suggests that the two island lineages have been isolated between the late Pliocene and the middle Pleistocene and have never migrated between the current northern part of Okinawajima and Tokashikijima Islands, which were once connected in the late Pleistocene glacial age. On Okinawajima Island, the southernmost sample was constituted by a unique haplotype, without considerable genetic distance from haplotypes detected from northern samples. This unique haplotype composition in the southernmost sample would have resulted from the restricted gene flow between the southernmost population and the other populations in Okinawajima Island. Furthermore, the absence of genetic diversity within the southernmost sample indicates that this population has recently experienced population size reduction, possibly by predation pressure from an introduced mongoose, which is more abundant in the southern part than in the northern part of the island. Lower genetic diversity in the Tokashikijima sample implies a small effective population size for mitochondrial DNA (mtDNA) in B. holsti on the island. Immediate conservation measures should be taken for the populations from the southernmost range in Okinawajima and Tokashikijima.

  17. Japan Report.

    DTIC Science & Technology

    2007-11-02

    for fear of dying from the cold. Temperatures in the region fell below zero at night. The rubber boat landed ashore near Terpeniya peninsula on the...Natsume will meet Defense Minister Zhang Aiping and senior officers of the People’s Liberation Army ( PLA ). He will also visit PLA units in Tianjin...Agency sources said. China, which wants to modernize PLA armament, may ask about buying advanced Japanese military technology. However, Japan cannot

  18. Japan Report

    DTIC Science & Technology

    2007-11-02

    Japan Socialist Party General Secretary Tsuruo Yamaguchi: "The Deceptiveness of Breaking Through the Defense - Spending Limit of 1 Percent of GNP...Agency Budget Proposal 22 Defense Facilities Administration Agency Budget Proposal 41 Breaking of Defense - Spending Limit Criticized (Tsuruo...such as the high yen and decline in the price of oil. (1) Total Amount Fiscal 1987 defense related expenditures are 3,517.4 billion yen, an

  19. Japan Report

    DTIC Science & Technology

    1985-03-18

    the government should reduce expenditures for military hardware if it is difficult to hold defense spending within 1 percent of the GNP. Noting... expenditure , as well as a greater contribution to Pacific defense . According to Prior, a conservative parliamentarian and former secretary of state for...Northern Ireland, with Britain’s experience in Asia, it should join with Japan to help the United States with its Asian defense . Japanese Chairman

  20. Cenozoic rift tectonics of the Japan Sea

    SciTech Connect

    Kimura, K.

    1988-08-01

    The Japan Sea is one of the back-arc basins in trench-arc systems bordering the western Pacific. Recent paleomagnetic works suggest the Japan Sea opened during early to middle Miocene. Radiometric and microfossil ages of the Cenozoic onland sequences in the Japanese Islands elucidate the rift tectonics of the Japan Sea. The rifting history is summarized as follows: nonmarine volcanic formations of prerift stage before 50 Ma, rift-onset unconformity at 40 Ma, nonmarine volcanic formations of synrift stage 20-33 Ma, breakup unconformity 19 Ma showing the opening of the Japan Sea, marine volcanic and sedimentary formations of synrift stage 14.5-18 Ma, beginning of regional subsidence 14.5 Ma corresponding to the end of the Japan Sea opening, marine sedimentary formations of postdrift stage after 14.5 Ma. Rifting is not limited to the synrift stage but is continued to the syndrift stage. Rifting led to a horst-and-graben structure. Thus, the Cenozoic onland sequences in the Japanese Islands are suited for a study of rift tectonics because the sequences were subaerially exposed by the late Miocene-Holocene island-arc tectonics. Rift tectonics cannot be studied as easily in most Atlantic-type passive margins.

  1. Progress in infant health in Okinawa, Japan.

    PubMed

    Hokama, Tomiko; Binns, Colin

    2012-07-01

    The infant mortality rate (IMR) and neonatal mortality rate (NMR) defined as the number of infant and newborn deaths per 1000 live births, respectively, are widely accepted as population indicators of the level of perinatal and postnatal health. Since the end of World War II, Japan has made substantial progress in reducing its IMR and NMR. This resulted from improving living standards and the provision of universal maternal and child health care (MCH) services. Okinawa, the island prefecture that is the furthest from mainland Japan, had the third highest IMR and the highest low-birth-weight rate (LBW) among all prefectures when its statistics were integrated into Japan in 1973. Even though the LBW rate in Okinawa has remained higher than the all-Japan average, Okinawa has shown a considerable improvement in IMR and NMR. The aim is to review the trends in IMR, NMR, and LBW in Japan and Okinawa and to discuss sociodemographic trends, economics, and the provision of health care services. The IMR and NMR in Okinawa decreased during that time from 14.8 to 2.4 and from 7.5 to 0.8, respectively. The LBW rate decreased until the mid-1980s, but since then it has increased to 11.5 (Okinawa) and 9.6 (Japan) in 2009. Okinawa's public health and primary health care model for infants has been very successful and may be applicable to child health in island nations of the Asia-Pacific region.

  2. Measuring the Flow Through the Kerama Gap

    DTIC Science & Technology

    2012-09-30

    Jae-Hun Park Graduate School of Oceanography University of Rhode Island Narragansett, RI 02882-1197 Phone: 401-874-6515 & 401-874-6610 Fax...The principal flows in and out of the East China Sea (ECS) are through channels penetrating the Ryukyu Ridge (Figure 1). Since ~20 Sv of Kuroshio...Figure 1. The Ryukyu ridgeline, from Taiwan (on the left) to Kyushu, Japan (on the right). The Kerama Gap at Distance = 600 km from

  3. Japan Report.

    DTIC Science & Technology

    2007-11-02

    Nakasone expressed Japan’s "understanding" of SDI or the so-called "Star Wars" project in a new year summit in Los Angeles with President Ronald Reagan... project and arms con- trol issues could, be discussed during the Bonn summit of seven industrialized countries in May. CSO: 4100/229 11 JPRS-JAR-85...are projected to fall 1.08 million tons to 5.3 million tons, and exports to Southeast Asia also be 740,000 tons to 16.9 million tons, the

  4. Ryukyuan Culture.

    ERIC Educational Resources Information Center

    Trafton, Terry

    The Ryukyu Islands of Japan, of which Okinawa is the best known, possess a lengthy history and a sophisticated cultural background, an exploration of which helps to shed light on this area and on mainland Japan. This document is an exposition of Ryukuan culture. Divided into eight sections, the areas covered include: (1) Historical perspective;…

  5. Revisiting the Metaphor of the Island: Challenging "World Culture" from an Island Misunderstood

    ERIC Educational Resources Information Center

    Rappleye, Jeremy

    2015-01-01

    This article revisits the newly "discovered" island that world culture theorists have repeatedly utilised to explain their theoretical stance, conceptual preferences and methodological approach. Yet, it seeks to (re)connect world culture with the real world by replacing their imagined atoll with a real one--the island-nation of Japan. In…

  6. Shallow very low frequency earthquakes off the Pacific coast of Tohoku, Japan

    NASA Astrophysics Data System (ADS)

    Matsuzawa, T.; Asano, Y.; Obara, K.

    2012-12-01

    Activities of shallow very low frequency earthquakes (VLFEs) have been reported around the trench axis of the off-Tokachi region, and the Nankai and the Ryukyu subduction zone around the Japan Islands (e.g., Obara and Ito, 2005; Asano et al., 2008; Ando et al., 2012). In NIED, epicenters of seismic sources including VLFEs are routinely located by an array analysis technique using Hi-net high-sensitivity accelerometers (Asano et al., 2008). Some of the epicenters are also located off the Pacific coast of Tohoku, Japan. However, these events are not fully examined, as most of these sources have been thought to arise from regular earthquakes and microseisms, and the number of events is much smaller than those in the previously reported region. In this study, we aim to detect VLFEs in the off-Tohoku region with a waveform correlation analysis. We examined waveforms of the events detected by the array analysis in the off-Tohoku region. Some of events are very similar to pre-known shallow VLFEs, which are dominant around the frequency of 0.05 Hz and have no clear signals in the high frequency band (above 1 Hz). We successfully estimated CMT solutions of some of these events, using F-net broadband seismometers and Hi-net high-sensitivity accelerometers. The result shows that these events are reverse-fault-type Mw~3.5 earthquakes, and located around the depth of the subducting plate interface. As a typical dominant frequency of regular earthquakes with similar magnitude and close hypocenter is several Hz, these events are considered as shallow VLFEs. To reveal the activity of the off-Tohoku VLFEs, other VLFEs were detected by a waveform correlation analysis using a template event. We selected two VLFEs as template events in the central and southern off-Tohoku region. Averaged cross correlation values for template events were calculated using broadband seismograms at surrounding F-net stations which are bandpass-filtered between 0.02 to 0.1 Hz. Finally, we visually checked

  7. American Influence on Okinawan Culture before 1972.

    ERIC Educational Resources Information Center

    Trafton, Terry

    The Ryukyu Islands form a chain stretching from the southernmost point of mainland Japan to the northern tip of Taiwan. The largest and most important of these islands is Okinawa. This paper documents the influence of other nations and cultures upon the Okinawan culture, and focuses upon U.S. cultural influence. In the mid-nineteenth century,…

  8. Winds over Japan.

    NASA Astrophysics Data System (ADS)

    Plumley, William J.

    1994-01-01

    Before World War II, weather forecasters had little knowledge of upper-air wind patterns above 20000 feet. Data were seldom avai able at these heights, and the need was not great because commercial aircraft seldom flew at these altitudes. The war in the Pacific changed all that. Wind forecasts for 30000 feet plus became urgent to support the XXI Bomber Command in its bombing mission over Japan.The U.S. Army Air Force Pacific Ocean Area (AAFPOA) placed a Weather Central in the Marianas Islands in 1944 (Saipan in 1944 and Guam in 1945) to provide forecasting support for this mission. A forecasting procedure was put into operation that combined the elements known as "single-station forecasting" and an advanced procedure that used "altirmeter corrections" to analyze upper-airdata and make prognoses. Upper-air charts were drawn for constant pressure surfaces rather than constant height surfaces. The constant pressure surfaces were tied together by means of the atmospheric temperature field represented by specific temperature anomalies between pressure surfaces. Wind forecasts over the Marianas-Japan route made use of space cross sections that provided the data to forecast winds at each 5000-ft level to 35000 ft along the mission flight path. The new procedures allowed the forecaster to construct internally consistent meteorological charts in three dimensions in regions of sparse data.Army air force pilots and their crews from the Marianas were among the first to experience the extreme wind conditions now known as the "jet stream". Air force forecasters demonstrated that, with experience, such winds could reasonably be forecast under difficult operational conditions.

  9. Canary Islands

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This easterly looking view shows the seven major volcanic islands of the Canary Island chain (28.0N, 16.5W) and offers a unique view of the islands that have become a frequent vacation spot for Europeans. The northwest coastline of Africa, (Morocco and Western Sahara), is visible in the background. Frequently, these islands create an impact on local weather (cloud formations) and ocean currents (island wakes) as seen in this photo.

  10. A Rearmed Japan: Implications.

    DTIC Science & Technology

    1980-06-01

    Japan started its initial rearmament effort. Japan’s defense expenditures have fluctuated from near 3% of GNP to as low...Klein, Donald W. " Japan 1979: The Second Oil Crisis’ Asian Survey, January 1980. Lee, William T. "Soviet Defense Expenditures in an Era of SALT." United...relationship to the options Japan can take. In very general terms, Japan has two options: to solely rely on the D.S.-Japanese Mutual Defense Treaty for

  11. 1976 Annual Typhoon Report

    DTIC Science & Technology

    1995-01-01

    Squadron, Yokota AS, Japan with assistance from the Naval Weather Facility, Yokosuka, Japan and computer support from Fleet Weather Central, Pearl...Republic of the Philippines, the Republic of China, Hong Kong, Japan (including the Ryukyu Islands), Korea, and Guam. 3. AIRCRAFT RECONNAISSANCE EVALUATION...JTWC’S area of responsibility is accomplished in the western North Pacific by direct-readout tactical sites at: Clark AB, Phili pines; Kadena AB, Japan

  12. Unmasking Rana okinavana Boettger, 1895 from the Ryukyus, Japan (Amphibia: Anura: Ranidae).

    PubMed

    Matsui, Masafumi

    2007-02-01

    Examination of the lectotype and a paralectotype of Rana okinavana Boettger, 1895 revealed that the species is not a brown frog of the subgenus Rana, occurring in the middle group of the Ryukyu Archipelago, but is identical with a frog of the subgenus Nidirana from the southern group of the Archipelago and Taiwan, now called R. psaltes Kuramoto, 1985. The type locality of R. okinavana given in the original description, Okinawa of the middle Ryukyus, is highly doubtful and should be somewhere in the Yaeyama Islands of the southern Ryukyus. The name R. psaltes is relegated to a subjective junior synonym of R. okinavana Boettger, 1895, while the brown frog of the subgenus Rana from the northern Ryukyus requires a replacement name.

  13. Intraspecific variations in carbon-isotope and oxygen-isotope compositions of a brachiopod Basiliola lucida collected off Okinawa-jima, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Takayanagi, Hideko; Asami, Ryuji; Abe, Osamu; Miyajima, Toshihiro; Kitagawa, Hiroyuki; Sasaki, Keiichi; Iryu, Yasufumi

    2013-08-01

    This study presents intraspecific variations in carbon-isotope (δ13C) and oxygen-isotope (δ18O) compositions of nine specimens of a subtropical brachiopod, Basiliola lucida, collected west of Okinawa-jima, Ryukyu Islands, southwestern Japan. The δ13C values of samples collected along the maximum growth axis (ontogenetic samples) from two modern and seven older (pre-1945 cal AD) shells show no seasonal changes. The modern shells, which were collected from comparable depths, have similar δ13C values that fall within the range of calcite precipitated in isotopic equilibrium with ambient seawater (equilibrium calcite) (δ13CEC values), and their mean δ13C values are ˜1.1-1.6‰ less than those from the older shells. This decrease in δ13C values is similar in magnitude to the decreases in atmospheric CO2 and the oceanic dissolved inorganic carbon at the sea surface in recent years (13C Suess effect), suggesting that the effect can even be detected at water depths of 200-300 m in the subtropical northwestern Pacific Ocean. The δ18O values fluctuate within a narrow range (0.26-0.41‰) with no seasonal changes, and they exhibit small (0.14-0.51‰) offsets from those of equilibrium calcite (δ18OEC values). A statistically significant negative linear relationship is established between seawater temperature and mean δ18O values of the nine shells, but the slope (-0.31‰/°C) is steeper than those of equilibrium calcite (-0.23‰/°C) and other calcareous organisms (-0.15‰ to -0.26‰/°C). The cross-plots of the δ13C and δ18O values suggest that the degree of the vital effect varies among individuals in this species. The δ13C and δ18O values of B. lucida are potentially useful for reconstructing the δ13C and δ18O evolution of ancient oceans, because both values show small intraspecific variations, the former is identical to the δ13CEC values, and the latter shows small within-shell variations and small, nearly constant offsets from the δ18OEC values.

  14. Recent earthquake prediction research in Japan.

    PubMed

    Mogi, K

    1986-07-18

    Japan has experienced many major earthquake disasters in the past. Early in this century research began that was aimed at predicting the occurrence of earthquakes, and in 1965 an earthquake prediction program was started as a national project. In 1978 a program for constant monitoring and assessment was formally inaugurated with the goal of forecasting the major earthquake that is expected to occur in the near future in the Tokai district of central Honshu Island. The issue of predicting the anticipated Tokai earthquake is discussed in this article as well as the results of research on major recent earthquakes in Japan-the Izu earthquakes (1978 and 1980) and the Japan Sea earthquake (1983).

  15. Introductory Overview of Stone Heritages in Japan

    NASA Astrophysics Data System (ADS)

    Kato, Hirokazu; Oikawa, Teruki; Fujita, Masayo; Yokoyama, Shunji

    2013-04-01

    As one contribution to 'Global Heritage Stone Resources' (GHSR), some stone heritages in Japan, which are nominated in the interim list, are briefly introduced. The geology of Japanese Islands where are the one of the most active areas in the history of the Earth, is very complicated. Therefore Japanese Islands consist of various kinds of minerals and rocks. Some of them were used to make stone implements and accessories. Japanese people also used to the best possible advantage to built tombstone, gate, pavement ,and the basement and wall of the large building such as temples, shrines, castles and modern buildings. 1. Stone Heritages of Pre-historical age: In the late Pleistocene and the early Holocene, ancient Japanese used obsidian cooled rapidly from rhyolitic magma.to make small implements and accessories. For example, Shirataki, Hokkaido (north island) is the largest place producing obsidian in Japan where Paleolithic people made arrowhead, knives and so on. Another example, Jade yielded in Itoigawa City, Japan Sea coast of central Japan, was made in the metamorphic rock about five hundred million years ago. Itoigawa area is only one place where jade is abundantly produced in Japan. Ancient people had been already collected and processed to ornaments although it is very hard and traded in wide area more than several thousand years ago. 2. Stone Heritages of Historical age: 2.1 Archaeological remains: In the Kofun (old mound) period (250 to 538 AD), stone burial chambers were used for old mounds to preserve against the putrefaction and to protect from the theft. For example, Ishibutai Kofun ("ishi" means "stone" and "butai" means "stage") in Nara old capital city, southwest Japan, is the largest known megalithic structure made of granite in Japan. 2.2 Stone walls of some typical castles Stones used is because of not only the rich reserves of rocks but also restriction of transportation. Osaka (second biggest city) castle, are composed of Cretaceous granite

  16. Academic Libraries in Japan

    ERIC Educational Resources Information Center

    Cullen, Rowena; Nagata, Haruki

    2008-01-01

    Academic libraries in Japan are well resourced by international standards, and support Japan's internationally recognized research capability well, but there are also ways in which they reflect Japan's strong bureaucratic culture. Recent changes to the status of national university libraries have seen a new interest in customer service, and…

  17. The U.S. Imperative on the Senkaku/Diaoyu Territorial Dispute

    DTIC Science & Technology

    2013-03-01

    Moreover, Beijing intends to control its near seas out to its first island chain, which include the East China Sea’s Ryukyu Islands .27 Until 2005...Senkaku Islands . Washington has held a neutral stance on the Chinese-Japanese territorial dispute since 1971 upon its ratification of the Okinawa...demonstrate its control over the islands . Japan is responding with increasing aggression. The dispute threatens to escalate to a military crisis

  18. Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA.

    PubMed

    Yamaji, Takuya; Ishikawa, Tadashi; Nomura, Masashi

    2016-01-01

    The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNA(ser)), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups--Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus.

  19. Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA

    PubMed Central

    Yamaji, Takuya; Ishikawa, Tadashi; Nomura, Masashi

    2016-01-01

    The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNAser), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups—Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus. PMID:26798143

  20. Phylogeny and Differentiation of Wide-Ranging Ryukyu Kajika Frog Buergeria japonica (Amphibia: Rhacophoridae): Geographic Genetic Pattern Not Simply Explained by Vicariance Through Strait Formation.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Eto, Koshiro; Ota, Hidetoshi

    2015-06-01

    To investigate geographic genetic structures and taxonomic relationships among isolated populations of Buergeria japonica, occurring very widely in various habitats of the Ryukyu Archipelago and Taiwan, we conducted phylogenetic and demographic analyses among individuals from various localities, representing their entire distributional ranges. Buergeria japonica is genetically greatly differentiated and comprises three major clades (the Southern Taiwan [ST] clade, the Northern Taiwan + Southern Ryukyu [NT/SR] clade, and the Central + Northern Ryukyu [CR/NR] clade), each of which seems to represent independent species. The first divergence in the species is estimated to have occurred in the middle to late Miocene in areas of current Taiwan, then eastern periphery of the Asian continent. Split of the ST and the remaining clades, and subsequent divergence between the NT/SR and the CR/NR clades in the latter, indicate consecutive south to north vicariant diversifications. However, these vicariances are not always associated with formation of significant barriers such as deep straits. Less but still prominently diverged subclades (the Amami + Tokara [AM/TK] and the Okinawa [ON] subclades) in the CR/NR clade were recognized in spite of the absence of an intervening deep strait. Contrariwise, individuals from Amami and Tokara Groups formed the AM/TK subclade in spite of the presence of the intervening Tokara Gap (a long-standing deep tectonic strait). Furthermore, in the AM/TK subclade, low but definite genetic divergence was found between the Northern Amami + Tokara (NAM/TK) lineage and the Southern Amami (SAM) lineage. Estimated divergence time and gene flow rate within the NAM/TK lineage indicate that this species reached northern Tokara from the south by overseas dispersal over the Tokara Gap long after its formation, but not by more recent artificial transportation. This overseas dispersal would have been facilitated by its more frequent occurrence around coastal

  1. Can GRACE detect winter snows in Japan?

    NASA Astrophysics Data System (ADS)

    Heki, Kosuke

    2010-05-01

    Current spatial resolution of the GRACE (Gravity Recovery and Climate Experiment) satellites is 300-400 km, and so its hydrological applications have been limited to continents and large islands. The Japanese Islands have width slightly smaller than this spatial resolution, but are known to show large amplitude seasonal changes in surface masses due mainly to winter snow. Such loads are responsible for seasonal crustal deformation observed with GEONET, a dense array of GPS (Global Positioning System) receivers in Japan (Heki, 2001). There is also a dense network of surface meteorological sensors for, e.g. snow depths, atmospheric pressures, etc. Heki (2004) showed that combined effects of surface loads, i.e. snow (predominant), atmosphere, soil moisture, dam impoundment, can explain seasonal crustal deformation observed by GPS to a large extent. The total weight of the winter snow in the Japanese Islands in its peak season may reach ~50 Gt. This is comparable to the annual loss of mountain glaciers in the Asian high mountains (Matsuo & Heki, 2010), and is above the detection level of GRACE. In this study, I use GRACE Level-2 Release-4 data from CSR, Univ. Texas, up to 2009 November, and evaluated seasonal changes in surface loads in and around the Japanese Islands. After applying a 350 km Gaussian filter and a de-striping filter, the peak-to-peak change of the water depth becomes ~4 cm in northern Japan. The maximum value is achieved in February-March. The region of large winter load spans from Hokkaido, Japan, to northeastern Honshu, which roughly coincides with the region of deep snow in Japan. Next I compiled snow depth data from surface meteorological observations, and converted them to loads using time-dependent snow density due to compaction. By applying the same spatial filter as the GRACE data, its spatial pattern becomes similar to the GRACE results. The present study suggests that GRACE is capable of detecting seasonal mass changes in an island arc not

  2. An Evaluation of the Numazu Operating Area and Kagoshima Harbor, Japan, as Typhoon Havens

    DTIC Science & Technology

    1975-12-01

    TYPE OF REPORT & PERIOD COVERED An Evaluation of the Numazu Operating Area and Kagoshima Harbor, Japan as Typhoon Havens «. PERFORMINO ORG. REPORT...HARBOR, JAPAN AS TYPHOON HAVENS by DECEMBER 1975 NAVAL ENVIRONMENTAL PREDICTION RESEARCH FACIUTY MONTEREY, CALIFORNIA 93940 Qualified requestors...TROPICAL CYCLONES 10 2.4 INTENSITY 13 3. JAPAN 14 3.1 JAPANESE ISLANDS 14 3.2 HONSHU 14 4. NUMAZU OPERATING AREA -- GENERAL DESCRIPTION .... 17

  3. Radar Image, Hokkaido, Japan

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The southeast part of the island of Hokkaido, Japan, is an area dominated by volcanoes and volcanic caldera. The active Usu Volcano is at the lower right edge of the circular Lake Toya-Ko and near the center of the image. The prominent cone above and to the left of the lake is Yotei Volcano with its summit crater. The city of Sapporo lies at the base of the mountains at the top of the image and the town of Yoichi -- the hometown of SRTM astronaut Mamoru Mohri -- is at the upper left edge. The bay of Uchiura-Wan takes up the lower center of the image. In this image, color represents elevation, from blue at the lowest elevations to white at the highest. The radar image has been overlaid to provide more details of the terrain. Due to a processing problem, an island in the center of this crater lake is missing and will be properly placed when further SRTM swaths are processed. The horizontal banding in this image is a processing artifact that will be removed when the navigation information collected by SRTM is fully calibrated. This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 100 by 150 kilometers

  4. Galapagos Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  5. Strawberry Species of Iturup and Sakhalin Islands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A plant collecting expedition to Iturup (known in Japan as Etorofu) and Sakhalin Islands, Sakhalin Territory, Russian Federation, occurred between 21 July and 12 September 2003. Strawberries, Fragaria L., were observed and collected. Japanese and Russian flora have described two diploid (2n = 2x = ...

  6. Intraspecific variation of flower colour and its distribution within a sea lavender, Limonium wrightii (Plumbaginaceae), in the northwestern Pacific Islands.

    PubMed

    Matsumura, Shun-ichi; Yokoyama, Jun; Tateishi, Yoichi; Maki, Masayuki

    2006-11-01

    Differentiation of flower colour is thought to be one of the most important factors promoting plant speciation. We describe the intraspecific variation of flower colour and its distribution in Limonium wrightii. We conducted a survey on 36 islands in the northwestern Pacific and discriminated six morphs of flower colour variation. Two flower colour morphs, pink and yellow, were most frequently observed, and their geographical distributions were basically allopatric. These two morphs were in contact in a narrow zone on Okinoerabu Island, located in the middle region of the Ryukyu Archipelago. In addition, orange, white, and ivory flower morphs were also found in this zone. The geographical distribution of pink and yellow morphs showed a "leapfrog" pattern; the distribution of pink flowers was divided into two areas, intercalated by the distribution of the yellow flower morph. The orange morph may have resulted from hybridization between the pink and yellow flower morphs.

  7. A new species of photosymbiotic ascidian from the Ryukyu Archipelago, Japan, with remarks on the stability of stigma number in photosymbiotic Diplosoma species.

    PubMed

    Hirose, Euichi; Oka, Atsushi T

    2008-12-01

    Diplosoma variostigmatum sp. nov. is a photosymbiotic ascidian in the family Didemnidae. This species is characterized by the unique pattern of its stigma number, which is often variable within the same zooid, as well as within the same colony. The total number of stigmata per half branchial sac varies from 22 (five, six, six, and five stigmata from the top to bottom rows) to 27 (seven, seven, seven, and six). In contrast, the stigma patterns are constant in D. ooru, D. simile, D. simileguwa, and D. virens. Thus, the stigma number and its stability (or variability) seem to be important as characters for the taxonomy of the photosymbiotic Diplosoma species.

  8. DNA markers indicate low genetic diversity and high genetic divergence in the landlocked freshwater goby, Rhinogobius sp. YB, in the Ryukyu Archipelago, Japan.

    PubMed

    Ohara, Kenichi; Takagi, Motohiro; Hashimoto, Miho; Miyazaki, Kazunori; Hirashima, Kentaro

    2008-04-01

    Genetic diversity and genetic divergence were investigated in the landlocked goby Rhinogobius sp. YB by analysis of seven microsatellite DNA loci and the mtDNA control region sequence, and were compared with those of the closely related amphidromous species Rhinogobius sp. DA. Samples of Rhinogobius sp. YB and Rhinogobius sp. DA were collected from seven and four rivers, respectively. All pairwise Fst tests based on microsatellite DNA showed significant genetic differences, except for one pair of populations of Rhinogobius sp. DA (P<0.00064, alpha=78). The average Nei's genetic distance was 0.616 in Rhinogobius sp. YB and 0.394 in Rhinogobius sp. DA. Forty-two haplotypes were detected in both species, and almost all Rhinogobius sp. YB populations included different haplotypes. The means of allelic richness, Ho, and He in Rhinogobius sp. YB (2.057, 0.149, and 0.156, respectively) were significantly lower than in Rhinogobius sp. DA (4.868, 0.366, and 0.403, respectively; P<0.05). The high genetic divergence and low genetic diversity in Rhinogobius sp. YB may have resulted from repeated colonizations of rivers by different founders. Efforts to conserve genetic resources should take these evolutionarily significant units (ESU) of Rhinogobius sp. YB into account. The genetic markers used in this study provide simple and highly informative indicators for Rhinogobius sp. YB population management.

  9. Seismology in Ryukyu arc, Japan reveals the distribution and orientation of serpentine minerals suggesting convection and low viscosity of forearc mantle

    NASA Astrophysics Data System (ADS)

    Nagaya, T.; Walker, A.; Wookey, J. M.; Kendall, M.; Wallis, S.

    2014-12-01

    Refining available estimates of the amount, distribution and alignment of serpentinite in the forearc wedge is needed to develop a better understanding of the seismic anisotropy, strength and fluid transport in this region. Mantle dominantly consists of olivine. However, petrological studies and thermal modeling of convergent margins predict that olivine will be replaced by hydrous mineral phases in fluid-rich and relatively cold forearc mantle. The dominant hydrous mineral will be antigorite. Lower seismic velocities (Vp < ~8 km/s and Vs < ~4 km/s) and higher Vp/Vs values (> ~1.8) of serpentine minerals than those of olivine are commonly used as to detect the distribution of antigorite and estimate its proportion compared to olivine. However, antigorite is highly anisotropic and this anisotropy can disguise the presence of antigorite in seismic tomography; the apparent Vp/Vs ratio of antigorite can vary from 1.2-3.4 (Vp = 5.6-8.9 km/s and Vs = 2.5-5.1 km/s) depending on the propagation path of the seismic wave relative to the crystal orientation. Here, we take advantage of this anisotropy and perform an analysis of seismic anisotropy that takes into account ray path measured above the forearc mantle of the Rykuyu arc subduction zone. The measured shear wave splitting delay time above this subduction zone is very large, suggesting the presence of aligned antigorite. Comparing the results of modeling to observed shear wave splitting for both local-S and teleseismic SKS phases, we conclude that the mantle wedge consists of 65 % antigorite and that the antigorite must be aligned along the subducting slab in the deepest part of the wedge but aligned vertically at intermediate depths. This distribution of different orientations strongly suggests the presence of convective mantle flow in the forearc mantle. Physical modeling of the dynamics of the mantle wedge shows that a bulk long-term viscosity of less than 1019 Pa s is required to maintain this large-scale flow. This analysis reveals the presence of otherwise invisible antigorite bearing domains, allows an estimate of the volume percent of serpentinite in the forearc mantle to be made and indicates the pattern of large scale induced flow in this domain.

  10. Akpatok Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

  11. Intra-Cultural Variation in Child Care Practices in Japan

    ERIC Educational Resources Information Center

    Toyama, Noriko

    2016-01-01

    This study, comprising three sub-studies, aims to examine how child-rearing practices vary according to different social circumstances in Japan. By comparing teacher-child interaction at mealtimes in day care centres both on an isolated small island located in Okinawa prefecture, Tarama, and in a large industrialised city, Tokyo, the following was…

  12. Shallow earthquake swarms in southern Ryukyu area: manifestation of dynamics of fluid and/or magma plumbing system revealed by teleseismic and regional datasets

    NASA Astrophysics Data System (ADS)

    Špičák, Aleš; Vaněk, Jiří

    2016-06-01

    Earthquake swarm occurrence beneath volcanic domains is one of the indicators of current magmatic activity in the Earth's crust. Repeated occurrence of teleseismically recorded earthquake swarms has been observed in the lithospheric wedge of the southern Ryukyu area above the subducting slab of the Philippine Sea Plate. The swarms were analyzed using the EHB, ISC and JMA catalogs of hypocenter parameters. The swarm earthquakes are shallow (1-60 km), in the body-wave magnitude range up to 5.8. The swarms are distributed beneath the seafloor, parallel to the Ryukyu Trench along a belt connecting active subaerial volcanoes Io-Torishima north-east and Kueishantao west of the investigated area. Epicentral zones of the swarms often coincide with distinct elevations at the seafloor—seamounts and seamount ranges. The top of the subducting slab reaches a depth of about 100 km beneath the zones of earthquake swarm occurrence, which is an average depth of a slab beneath volcanoes in general. The repeated occurrence of relatively strong, teleseismically recorded earthquake swarms thus probably reflects fluid and/or magma migration in the plumbing system of the volcanic arc and points to brittle character of the lithospheric wedge at respective depths. In addition to the factual results, this study documents the high accuracy of hypocenter parameter determinations published by the International Seismological Centre and the usefulness of the EHB relocation procedure.

  13. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  14. Seismicity of the Earth 1900-2007, Japan and Vicinity

    USGS Publications Warehouse

    Rhea, Susan; Tarr, Arthur C.; Hayes, Gavin P.; Villaseñor, Antonio; Benz, Harley

    2010-01-01

    This map shows details of Japan and vicinity not visible in an earlier publication, U.S. Geological Survey Scientific Investigations Map 3064. Japan and its island possessions lie across four major tectonic plates: Pacific plate, North America plate; Eurasia plate; and Philippine Sea plate. The Pacific plate is subducted into the mantle, beneath Hokkaido and northern Honshu, along the eastern margin of the Okhotsk microplate, a proposed subdivision of the North America plate (Bird, 2003). Farther south, the pacific plate is subducted beneath volcanic islands along the eastern margin of the Philippine Sea plate. This 2,200 km-long zone of subduction of the Pacific plate is responsible for the creation of the deep offshore Ogasawara and Japan trenches as well as parallel chains of islands and volcanoes, typical of the Circumpacific island arcs. Similarly, the Philippine Sea plate is itself subducting under the Eurasia plate along a zone, extending from Taiwan to southern Honshu, that comprises the Ryuku Islands and the Nansei-Shonto trench.

  15. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth.

    PubMed

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed.

  16. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth

    PubMed Central

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed. PMID:26859569

  17. Japan's High Schools.

    ERIC Educational Resources Information Center

    Rohlen, Thomas P.

    The author, an anthropologist, spent 14 months (1974-75) in the industrial port city of Kobe (Japan) observing a cross section of urban high schools, including Japan's most elite private school and a night vocational school plagued by absenteeism and delinquency. He reports on the character of the institutions and of the experience via…

  18. Rehabilitation in Japan, 1988.

    ERIC Educational Resources Information Center

    Japanese Society for Rehabilitation of the Disabled, Tokyo.

    The scope of Japan's rehabilitation services for persons with disabilities is reviewed and discussed from the perspective of social and demographic change in that country. An introductory chapter on the current situation in Japan looks at characteristics of the land, the people, the government, industry and the economy, and the culture. The second…

  19. Current status of atopic dermatitis in Japan

    PubMed Central

    Chiba, Takahito; Takeuchi, Satoshi

    2011-01-01

    Atopic dermatitis (AD) is a common, chronic or chronically relapsing, severely pruritic, eczematous skin disease. AD is the second most frequently observed skin disease in dermatology clinics in Japan. Prevalence of childhood AD is 12-13% in mainland Japan; however, it is only half that (about 6%) in children from Ishigaki Island, Okinawa. Topical steroids and tacrolimus are the mainstay of treatment. However, the adverse effects and emotional fear of long-term use of topical steroids have induced a "topical steroid phobia" in patients throughout the world. Undertreatment can exacerbate facial/periocular lesions and lead to the development of atopic cataract and retinal detachment due to repeated scratching/rubbing/patting. Overcoming topical steroid phobia is a key issue for the successful treatment of AD through education, understanding and cooperation of patients and their guardians. PMID:22053299

  20. Volcano-Hydrothermal Systems of the Central and Northern Kuril Island Arc - a Review

    NASA Astrophysics Data System (ADS)

    Kalacheva, E.; Taran, Y.; Voloshina, E.; Ptashinsky, L.

    2015-12-01

    More than 20 active volcanoes with historical eruptions are known on 17 islands composing the Central and Northern part of the Kurilian Arc. Six islands - Paramushir, Shiashkotan, Rasshua, Ushishir, Ketoy and Simushir - are characterized by hydrothermal activity, complementary to the fumarolic activity in their craters. There are several types of volcano-hydrothermal systems on the islands. At Paramushir, Shiashkotan and Ketoy the thermal manifestations are acidic to ultra-acidic water discharges associated with hydrothermal aquifers inside volcano edifices and formed as the result of the absorption of magmatic gases by ground waters. A closest known analogue of such activity is Satsuma-Iwojima volcano-island at the Ryukyu Arc. Another type of hydrothermal activity are wide spread coastal hot springs (Shiashkotan, Rasshua), situated as a rule within tide zones and formed by mixing of the heated seawater with cold groundwater or, in opposite, by mixing of the steam- or conductively heated groundwater with seawater. This type of thermal manifestation is similar to that reported for other volcanic islands of the world (Satsuma Iwojima, Monserrat, Ischia, Socorro). Ushishir volcano-hydrothermal system is formed by the absorption of magmatic gases by seawater. Only Ketoy Island hosts a permanent acidic crater lake. At Ebeko volcano (Paramushir) rapidly disappearing small acidic lakes (formed after phreatic eruptions) have been reported. The main hydrothermal manifestation of Simushir is the Zavaritsky caldera lake with numerous coastal thermal springs and weak steam vents. The last time measured temperatures of fumaroles at the islands are: >500ºC at Pallas Peak (Ketoy), 480ºC at Kuntamintar volcano (Shiashkotan), variable and fast changing temperatures from 120º C to 500ºC at Ebeko volcano (Paramushir), 150ºC in the Rasshua crater, and > 300ºC in the Chirpoy crater (Black Brothers islands). The magmatic and rock-forming solute output by the Kurilian volcano

  1. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... each summer since 1999, researchers from NASA's Haughton-Mars Project and the Mars Society reside at this "polar desert" location to study the geologic and ...

  2. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... deepest ocean trench. Anatahan had no known historical eruptions until May 2003. The evacuation of the island's residents in 1990 was ... earthquake swarm that suggested the possibility of impending volcanic activity. The Micronesian Megapode is an endangered species of ...

  3. IMPACTS OF DIOXIN EMISSIONS FROM THE SHINKAMPO INCINERATOR TO THE U.S. NAVAL AIR FACILITY AT ATSUGI, JAPAN

    EPA Science Inventory

    The United States Naval Air Facility at Atsugi, Japan (NAF Atsugi) is located in the Kanto Plain area on the island of Honshu, Japan. Directly to the south of the facility, in the Tade River Valley, was the Shinkampo Incinerator Complex (SIC). The Incinerator is no longer in op...

  4. Groundwater contamination in Japan

    NASA Astrophysics Data System (ADS)

    Tase, Norio

    1992-07-01

    Problems on groundwater contamination in Japan are briefly summarized in this paper. Although normal physical conditions in Japan restrict the possibilities of groundwater contamination, human activities are threatening groundwater resources. A survey by the Environment Agency of Japan showed nationwide spreading of organic substances, such as trichloroethylene as well as nitrogen compounds. Synthetic detergents have also been detected even in rural areas and in deep confined aquifers, although their concentrations are not as high. Public awareness of agrichemical or pesticides abuse, especially from golf courses, is apparent. Other problems such as nitrate-nitrogen, leachate from landfills, and the leaking of underground storage tanks are also discussed.

  5. Microelectronics in Japan

    NASA Technical Reports Server (NTRS)

    Boulton, William R.

    1995-01-01

    The purpose of this JTEC study is to evaluate Japan's electronic manufacturing and packaging capabilities within the context of global economic competition. To carry out this study, the JTEC panel evaluated the framework of the Japanese consumer electronics industry and various technological and organizational factors that are likely to determine who will win and lose in the marketplace. This study begins with a brief overview of the electronics industry, especially as it operates in Japan today. Succeeding chapters examine the electronics infrastructure in Japan and take an in-depth look at the central issues of product development in order to identify those parameters that will determine future directions for electronic packaging technologies.

  6. Thermal modeling of the SW Ryukyu forearc (Taiwan): Implications for the seismogenic zone and the age of the subducting Philippine Sea Plate (Huatung Basin)

    NASA Astrophysics Data System (ADS)

    Gutscher, M.-A.; Klingelhoefer, F.; Theunissen, T.; Spakman, W.; Berthet, T.; Wang, T. K.; Lee, C.-S.

    2016-12-01

    Subduction mega-thrust earthquakes in the SW Ryukyu trench pose a seismic and tsunami hazard. One of the objectives of this study is to estimate the downdip width of the seismogenic zone using numerical modeling to determine the temperature distribution along the plate interface. However, this approach depends strongly on the thermal parameters of the subducting slab. While the Philippine Sea plate (PSP) subducting beneath the central and eastern Ryukyu arc is of Eocene age (35-50 Ma), its age west of the Gagua Ridge is uncertain, with proposed ages ranging from Lower Cretaceous (140 Ma) to Upper Eocene (35 Ma). Since the sparse available heat flow data are insufficient to resolve this debate, both end-member hypotheses are tested as input parameters. We examined two transects at 122.5°E and 123.5°E on either side of the N-S trending, 4-km high, Gagua Ridge. The shallow forearc geometry is obtained from wide-angle seismic data. The deep slab geometry was obtained from hypocenter distribution and tomography. For an Eocene slab age, we obtain a 100 km and 110 km wide seismogenic zone (between the 150 °C and 350 °C isotherms) west and east of Gagua Ridge, respectively. This is in good agreement with the observed distribution of hypocenters. Using a Cretaceous slab west of Gagua Ridge predicts a deep seismogenic zone (25 km-60 km depth), inconsistent with observed thrust earthquakes. Tomographic images at 122.5°E and 123.5°E show a similar slab thickness of 70-80 km suggesting that the oceanic lithosphere has a young (Eocene) thermal age. The westernmost PSP (Huatung Basin) may have been thermally rejuvenated by mantle convection near the slab corner. The tectonic history since 6 Ma (transition from subduction to collision beneath Taiwan) may have also perturbed the thermal structure.

  7. GPM Arrives in Japan

    NASA Video Gallery

    An international satellite that will set a new standard for global precipitation measurements from space has completed a 7,300-mile journey from the United States to Japan, where it now will underg...

  8. Signs of continental rifting in the southwestern Japanese Island Arc

    NASA Astrophysics Data System (ADS)

    Chernysheva, E. A.; Eroshenko, D. V.

    2016-03-01

    The southwestern margin of the Japan Arc evolved in the geodynamic regime of continental rifting during the Miocene-Pleistocene. This has been verified by broad manifestations of metasomatosis of mantle peridotites that underlie the lithosphere of the Japan Islands and by episodes of deep magmatism (kimberlites and melilitites) in the region. The high enrichment of deep melts in incompatible rare and rare earth elements is partially preserved in melts of regional basalts from smaller depths. In contrast, spreading basalts of the Sea of Japan and subduction basalts from the Nankai trench at the boundary with the Philippine Plate are extremely depleted in rare elements.

  9. Japanese population structure, based on SNP genotypes from 7003 individuals compared to other ethnic groups: effects on population-based association studies.

    PubMed

    Yamaguchi-Kabata, Yumi; Nakazono, Kazuyuki; Takahashi, Atsushi; Saito, Susumu; Hosono, Naoya; Kubo, Michiaki; Nakamura, Yusuke; Kamatani, Naoyuki

    2008-10-01

    Because population stratification can cause spurious associations in case-control studies, understanding the population structure is important. Here, we examined Japanese population structure by "Eigenanalysis," using the genotypes for 140,387 SNPs in 7003 Japanese individuals, along with 60 European, 60 African, and 90 East-Asian individuals, in the HapMap project. Most Japanese individuals fell into two main clusters, Hondo and Ryukyu; the Hondo cluster includes most of the individuals from the main islands in Japan, and the Ryukyu cluster includes most of the individuals from Okinawa. The SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were found in the HLA region in chromosome 6. The nonsynonymous SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were the Val/Ala polymorphism (rs3827760) in the EDAR gene, associated with hair thickness, and the Gly/Ala polymorphism (rs17822931) in the ABCC11 gene, associated with ear-wax type. Genetic differentiation was observed, even among different regions in Honshu Island, the largest island of Japan. Simulation studies showed that the inclusion of different proportions of individuals from different regions of Japan in case and control groups can lead to an inflated rate of false-positive results when the sample sizes are large.

  10. [Increase of poisoning by tropical mushrooms in Japan in recent years].

    PubMed

    Yokoyama, Kazumasa; Gonmori, Kunio

    2009-09-01

    A tropical poisonous mushroom, Chlorophyllum molybdites, invaded into Japan in recent years, and distributed in south-eastern and central part of Japan including 27 Prefectures in 2009; Gunma, Tochigi, Saitama, Ibaraki, Tokyo (including Bonin Islands), Chiba, Shizuoka, Ishikawa, Aichi, Mie, Shiga, Kyoto, Nara, Osaka, Wakayama, Hyogo, Tottori, Okayama, Hiroshima, Yamaguchi, Kagawa, Tokushima, Kochi, Ohita, Kumamoto, Kagoshima and Okinawa. Poisoning by this fungus has increased recently (Table 2). Topics on distribution and poisoning by Russula subnigricans and Podostroma cornu-damae briefly discussed.

  11. A new insight on magma generation environment beneath Jeju (Cheju) volcanic island

    NASA Astrophysics Data System (ADS)

    Shin, Y.; CHOI, K.; Koh, J.; Yun, S.; Nakamura, E.; Na, S.

    2011-12-01

    We present a Moho undulation model from gravity inversion that gives a new insight on the magma generation environment beneath Jeju (Cheju) volcanic island, Korea. The island is an intra-plate volcanic island located behind Ryukyu Trench, the collisional boundary between Eurasian plate and Philippine plate. Jeju island is a symmetrical shield volcano of oval shape (74 km by 32 km) whose peak is Hallasan (Mt. Halla: 1950m). The landform, which is closely related to the volcanism, can be divided topographically into the lava plateau, the shield-shaped Halla volcanic edifice and the monogenetic cinder cones, which numbers over 365. The basement rock mainly consists of Precambrian gneiss, Mesozoic granite and volcanic rocks. Unconsolidated sedimentary rock is found between basement rock and lava. The lava plateau is composed of voluminous basaltic lava flows, which extend to the coast region with a gentle slope. Based on volcanic stratigraphy, paleontology and geochronology, the Jeju basalts range from the early Pleistocene to Holocene in age. The mean density of the island is estimated to be very low, 2390 kg/cubic cm from gravity data analysis, which reflects the abundant unconsolidated pyroclastic sediments below the surface lava. The mean Moho depth is estimated to be 29.5 km from power spectral density of gravity anomaly, which means it has continental crust. It is noticeable that the gravity inversion indicates the island is developed above and along a swelled-up belt (ridge), several hundred meters higher than the surrounding area. The structure is also shows positive correlation with high magnetic anomaly distribution that could indicate existence of volcanic rocks. We interpret the Moho structure has a key to the magma generation: 1) the high gravity anomaly belt is formed by folding/buckling process under compressional environment, 2) it causes decrease of pressure beneath the lithosphere along the belt, and 3) it accelerates melting of basaltic magma in

  12. Black brant from Alaska staging and wintering in Japan

    USGS Publications Warehouse

    Derksen, Dirk V.; Bollinger, K.S.; Ward, David H.; Sedinger, J.S.; Miyabayashi, Y.

    1996-01-01

    Black brant (Branta bernicla nigricans) nest in colonies in arctic Canada, Alaska, and Russia (Derksen and Ward 1993, Sedinger et al. 1993). Virtually the entire population stages in fall at Izembek Lagoon near the tip of the Alaska Peninsula (Bellrose 1976) before southward migration (Dau 1992) to winter habitats in British Columbia, Washington, Oregon, California, and Baja California (Subcommittee on Black Brant 1992). A small number of black brant winter in Japan, Korea, and China (Owen 1980). In Japan 3,000–5,000 brant of unknown origin stop over in fall, and a declining population (<1,000) of birds winter here, primarily in the northern islands (Brazil 1991, Miyabayashi et al. 1994). Here, we report sightings of brant in Japan that were marked in Alaska and propose a migration route based on historical and recent observations and weather patterns.

  13. Space robotics in Japan

    NASA Astrophysics Data System (ADS)

    Whittaker, William; Lowrie, James W.; McCain, Harry; Bejczy, Antal; Sheridan, Tom; Kanade, Takeo; Allen, Peter

    1994-03-01

    Japan has been one of the most successful countries in the world in the realm of terrestrial robot applications. The panel found that Japan has in place a broad base of robotics research and development, ranging from components to working systems for manufacturing, construction, and human service industries. From this base, Japan looks to the use of robotics in space applications and has funded work in space robotics since the mid-1980's. The Japanese are focusing on a clear image of what they hope to achieve through three objectives for the 1990's: developing long-reach manipulation for tending experiments on Space Station Freedom, capturing satellites using a free-flying manipulator, and surveying part of the moon with a mobile robot. This focus and a sound robotics infrastructure is enabling the young Japanese space program to develop relevant systems for extraterrestrial robotics applications.

  14. Psychology in Japan.

    PubMed

    Imada, Hiroshi; Tanaka-Matsumi, Junko

    2016-06-01

    The purpose of this article is to provide information about Japan and its psychology in advance of the 31st International Congress of Psychology (ICP), to be held in Yokohama, Japan, in 2016. The article begins with the introduction of the Japanese Psychological Association (JPA), the hosting organization of the ICP 2016, and the Japanese Union of Psychological Associations consisting of 51 associations/societies, of which the JPA is a member. This is followed by a brief description of a history of psychology of Japan, with emphasis on the variation in our approach to psychology in three different periods, that is, the pre- and post-Pacific War periods, and the post-1960 period. Next, the international contributions of Japanese psychology/psychologists are discussed from the point of view of their visibility. Education and training in psychology in Japanese universities is discussed with a final positive remark about the long-awaited enactment of the Accredited Psychologist Law in September, 2015.

  15. Space robotics in Japan

    NASA Technical Reports Server (NTRS)

    Whittaker, William; Lowrie, James W.; Mccain, Harry; Bejczy, Antal; Sheridan, Tom; Kanade, Takeo; Allen, Peter

    1994-01-01

    Japan has been one of the most successful countries in the world in the realm of terrestrial robot applications. The panel found that Japan has in place a broad base of robotics research and development, ranging from components to working systems for manufacturing, construction, and human service industries. From this base, Japan looks to the use of robotics in space applications and has funded work in space robotics since the mid-1980's. The Japanese are focusing on a clear image of what they hope to achieve through three objectives for the 1990's: developing long-reach manipulation for tending experiments on Space Station Freedom, capturing satellites using a free-flying manipulator, and surveying part of the moon with a mobile robot. This focus and a sound robotics infrastructure is enabling the young Japanese space program to develop relevant systems for extraterrestrial robotics applications.

  16. Cultural Astronomy in Japan

    NASA Astrophysics Data System (ADS)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  17. A morphological review of the Cuora flavomarginata complex (Testudines: Geoemydidae)

    USGS Publications Warehouse

    Ernst, C.H.; Laemmerzahl, A.F.; Lovich, J.E.

    2008-01-01

    A reevaluation of the morphometric and color pattern differences within the Asiatic box turtle, Cuora flavomarginata sensu latu, was conducted in view of determining the taxonomic position of the three currently recognized subspecies: C. f. flavomarginata (Taiwan), C. f. sinensis (southern mainland China), and C. f. evelynae (Ryukyu Islands, Japan). Recent analyses indicate that the allopatric population of C. f. evelynae is the most divergent of the three taxa and shares little possibility for gene exchange with the other two populations. In contrast, the populations of C. f. flavomarginata and C. f. sinensis share many characters. We recommend the recognition of the Ryukyu population as a full species, C. evelynae.

  18. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  19. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  20. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Japan wax. 186.1555 Section 186.1555 Food and....1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a... succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan), and R. trichocarpa (China,...

  1. Globalization and Education in Japan

    ERIC Educational Resources Information Center

    Ohkura, Kentaro; Shibata, Masako

    2009-01-01

    In this paper, the authors contend that globalization in Japan is the gradual process in which Japan's positioning of "self" within international relations, which had formerly been dominated by the West, has changed. Accordingly, Japan's relationships with the West and the rest of the world, for example, Asia, have also been reviewed and…

  2. The influence of Ryukyu subduction on magma genesis in the Northern Taiwan Volcanic Zone and Middle Okinawa Trough - Evidence from boron isotopes

    NASA Astrophysics Data System (ADS)

    Pi, Ju-Lien; You, Chen-Feng; Wang, Kuo-Lung

    2016-09-01

    Boron (B) is an excellent geochemical tracer for investigating crustal recycling processes at convergent margins, due to its high fluid mobility under high P-T conditions, distinct elemental abundances and isotopic compositions in the mantle wedge and subducting slabs. The Northern Taiwan Volcanic Zone (NTVZ), wherein the nature of magma genesis has long been a topic of debate, is located at the rear side of the Okinawa Trough (OT), an atypical back-arc rift in the Ryukyu subduction system. In this study, B and B isotopes (δ11B) were measured in 19 volcanic rocks collected from the NTVZ and the middle Okinawa Trough (MOT) to assess the influence of the Ryukyu subduction system on magma genesis. The B concentrations in the MOT and NTVZ volcanic rocks are 5.8 to 13.6 mg/L and 2.2 to 48.6 mg/L, respectively. The large B abundances variation in the NTVZ was caused mainly by variable degrees of partial melting. The Nb/B and δ11B in the MOT have small ranges of 0.5 to 0.6 and - 2.7‰ to 0.2‰, respectively, whereas they range widely from 0.4 to 2.5 and from - 8.6‰ to 2.4‰, respectively in the NTVZ. These Nb/B values suggest that the magma contains a smaller subduction component than that normally observed in arcs, although this component is still more substantial than in a typical back-arc setting. The δ11B results indicate insignificant influence of the subducting Philippine Sea Plate at 2.6 Ma, but it becomes more substantial later in the NTVZ. The mixing proportions of sediment derived fluids in onshore volcanoes in the NTVZ imply a rather heterogeneous mantle wedge near the plate boundary, most likely due to either a heterogeneous source of slab derived fluids or more complicated mantle flow. A substantial B flux from the subducting slab in the incipient back-arc rifting in the MOT and NTVZ may reflect characteristics of a cold, steep and fast subducting slab, which may be capable of carrying volatiles efficiently into greater depth in subduction zones. The

  3. Advanced composites in Japan

    NASA Technical Reports Server (NTRS)

    Diefendorf, R. Judd; Hillig, William G.; Grisaffe, Salvatore J.; Pipes, R. Byron; Perepezko, John H.; Sheehan, James E.

    1994-01-01

    The JTEC Panel on Advanced Composites surveyed the status and future directions of Japanese high-performance ceramic and carbon fibers and their composites in metal, intermetallic, ceramic, and carbon matrices. Because of a strong carbon and fiber industry, Japan is the leader in carbon fiber technology. Japan has initiated an oxidation-resistant carbon/carbon composite program. With its outstanding technical base in carbon technology, Japan should be able to match present technology in the U.S. and introduce lower-cost manufacturing methods. However, the panel did not see any innovative approaches to oxidation protection. Ceramic and especially intermetallic matrix composites were not yet receiving much attention at the time of the panel's visit. There was a high level of monolithic ceramic research and development activity. High temperature monolithic intermetallic research was just starting, but notable products in titanium aluminides had already appeared. Matrixless ceramic composites was one novel approach noted. Technologies for high temperature composites fabrication existed, but large numbers of panels or parts had not been produced. The Japanese have selected aerospace as an important future industry. Because materials are an enabling technology for a strong aerospace industry, Japan initiated an ambitious long-term program to develop high temperature composites. Although just starting, its progress should be closely monitored in the U.S.

  4. Sapovirus in water, Japan.

    PubMed

    Hansman, Grant S; Sano, Daisuke; Ueki, You; Imai, Takahiro; Oka, Tomoichiro; Katayama, Kazuhiko; Takeda, Naokazu; Omura, Tatsuo

    2007-01-01

    Sapoviruses are etiologic agents of human gastroenteritis. We detected sapovirus in untreated wastewater, treated wastewater, and a river in Japan. A total of 7 of 69 water samples were positive by reverse transcription-PCR. Phylogenetic analysis of the viral capsid gene grouped these strains into 4 genetic clusters.

  5. Political Corruption in Japan.

    ERIC Educational Resources Information Center

    Reed, Steven R.; And Others

    1996-01-01

    Provides an overview of political corruption and its place in Japanese culture and society. Discusses recent scandals and efforts at political reform. These efforts are moving Japan from a "boss-patronage" system to a "civic-culture." Includes a table of post-war Japanese prime ministers and corruption scandals. (MJP)

  6. Japan's builders study platforms

    SciTech Connect

    Burke, R.G.

    1984-07-05

    This paper discusses the developing role of Japan as a major supplier of offshore drilling and production equipment. Different firms are discussed along with their capacity. The marketing areas, work experience, and plans for designs are also included. There is special attention payed on the potential for developing Arctic platforms.

  7. Nuclear Power in Japan.

    ERIC Educational Resources Information Center

    Powell, John W.

    1983-01-01

    Energy consumption in Japan has grown at a faster rate than in any other major industrial country. To maintain continued prosperity, the government has embarked on a crash program for nuclear power. Current progress and issues/reactions to the plan are discussed. (JN)

  8. Teaching Unit: Japan.

    ERIC Educational Resources Information Center

    Evans, Dina

    The cultural diversity of Japan can provide a rewarding learning experience for children of all grade levels. This teaching unit includes resources and ideas for the study of Japanese society, art, folklore, and poetry. Included among the instructional objectives are: (1) children will compare U.S. lifestyles with Japanese lifestyles by reading…

  9. The Graying of Japan.

    ERIC Educational Resources Information Center

    Martin, Linda G.

    1989-01-01

    Japan's rapidly aging population has become a top policy issue, especially as the increasing costs of pensions and medical care are debated. With the highest life expectancy on earth, the Japanese potentially face long periods of retirement, as well as the possibility of long periods of disability. Although family support of the elderly is thought…

  10. Japan's electronic packaging technologies

    NASA Technical Reports Server (NTRS)

    Tummala, Rao R.; Pecht, Michael

    1995-01-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  11. Japan's electronic packaging technologies

    NASA Astrophysics Data System (ADS)

    Tummala, Rao R.; Pecht, Michael

    1995-02-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  12. Photovoltaics in Japan

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1985-01-01

    Report surveys status of research and development on photovoltaics in Japan. Report based on literature searches, private communications, and visits by author to Japanese facilities. Included in survey are Sunshine Project, national program to develop energy sources; industrial development at private firms; and work at academic institutions.

  13. Teacher Education in Japan.

    ERIC Educational Resources Information Center

    Shimahara, Nobuo

    A discussion is presented on the education of Japanese teachers, their roles in the schools, and proposed reforms in their education. In describing the pre-World War II background of teacher education in Japan, three ideological forces are discussed: Western thought that impacted upon early Meiji reforms, Confucianism, and nationalism. Western…

  14. Japan Report, Science and Technology

    DTIC Science & Technology

    2007-11-02

    Commuter Market (AEROSPACE JAPAN-WEEKLY, 3 Nov 86) MHI Fostering MU-300 Sales to ASDF for FC-X (AEROSPACE JAPAN-WEEKLY, 3 Nov 86) Next Japan Air...Available (AEROSPACE JAPAN-WEEKLY, 10 Nov 86) 22 Briefs GD Implies Twin-Engined F-16 for FS-X 23 ASDF To Modernize C-l Transport 23 SH-60J To Be...the National Land Agency. /13046 CSO: 4307/008 AEROSPACE SCIENCES MHI FOSTERING MU-300 SALES TO ASDF FOR FC-X Tokyo AEROSPACE JAPAN

  15. Occurrence of human respiratory syncytial virus in summer in Japan.

    PubMed

    Shobugawa, Y; Takeuchi, T; Hibino, A; Hassan, M R; Yagami, R; Kondo, H; Odagiri, T; Saito, R

    2017-01-01

    In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007-2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.

  16. 2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan

    NASA Astrophysics Data System (ADS)

    Ando, Y.; Ogi, M.; Tachibana, Y.

    2013-12-01

    On Japan, wintertime cold wave has social, economic, psychological and political impacts because of the lack of atomic power stations in the era of post Fukushima world. The colder winter is the more electricity is needed. Wintertime weather of Japan and its prediction has come under the world spotlight. The winter of 2012/13 in Japan was abnormally cold, and such a cold winter has persisted for 3 years. Wintertime climate of Japan is governed by some dominant modes of the large-scale atmospheric circulations. Yasunaka and Hanawa (2008) demonstrated that the two dominant modes - Arctic Oscillation (AO) and Western Pacific (WP) pattern - account for about 65% of the interannual variation of the wintertime mean surface air temperature of Japan. A negative AO brings about cold winter in Japan. In addition, a negative WP also brings about cold winter in Japan. Looking back to the winter of 2012/13, both the negative AO and negative WP continued from October through December. If the previous studies were correct, it would have been extremely very cold from October through December. In fact, in December, in accordance with previous studies, it was colder than normal. Contrary to the expectation, in October and November, it was, however, warmer than normal. This discrepancy signifies that an additional hidden circumstance that heats Japan overwhelms these large-scale atmospheric circulations that cool Japan. In this study, we therefore seek an additional cause of wintertime climate of Japan particularly focusing 2012 as well as the AO and WP. We found that anomalously warm oceanic temperature surrounding Japan overwhelmed influences of the AO or WP. Unlike the inland climate, the island climate can be strongly influenced by surrounding ocean temperature, suggesting that large-scale atmospheric patterns alone do not determine the climate of islands. (a) Time series of a 5-day running mean AO index (blue) as defined by Ogi et al., (2004), who called it the SVNAM index. For

  17. Native fruit tree genetic resources in Japan

    PubMed Central

    Iketani, Hiroyuki

    2016-01-01

    The diversity of climate, from subarctic to subtropical, and the complex geological history of Japan have produced a rich biodiversity. The flora includes several hundred species of native woody plants with edible fleshy fruits or nuts. People have eaten them from prehistoric times until about a half century ago. In Hokkaidō and the Ryūkyū Islands nut species had an important role in the diet, but fleshy fruits were also eaten until recently. Only Castanea crenata and a few minor species became domesticated as edible fruit trees in pre-modern times. Recently, Vitis coignetiae, Lonicera caerulea, Akebia quinata, Akebia trifoliata, Stauntonia hexaphylla, and Actinidia arguta have entered small-scale cultivation. The conservation of the germplasm of many of these native species, both in situ and ex situ, is precarious. PMID:27069393

  18. DPAL activities in Japan

    NASA Astrophysics Data System (ADS)

    Endo, Masamori; Wani, Fumio

    2015-02-01

    Activities on diode pumped alkali laser (DPAL) in Japan is reviewed. We have started alkali laser works in 2011, and currently, we are the only players in Japan. Our interests are application oriented, and it is not only defense but also industrial. DPAL is a good candidate as a source of remote laser machining, thanks to its scalability and extremely good beam quality. We are studying on scientific and engineering problems of Cs DPAL with a small-scale apparatus. A commercial diode laser with volume Bragg grating outcoupler is used to pump the gain cell longitudinally. A 6.5 W continuous-wave output with optical to optical efficiency of 56% (based on the absorbed power) has been achieved. Numerical simulation codes are developed to understand the physics of DPAL and to help future developments.

  19. Water reuse in Japan.

    PubMed

    Ogoshi, M; Suzuki, Y; Asano, T

    2001-01-01

    Even though Japan has mean annual precipitation of 1,714 mm and hundreds of dams and reservoirs constructed, frequent and severe droughts have occurred in wide regions of the country. Because of rapid economic growth and concentrations of population in urban areas, water demands in large cities have stressed reliability of water supply systems and necessitated the development of new water resources with considerable economic and environmental costs. To alleviate these situations, wastewater reclamation and reuse have been implemented widely in major cities. This paper summarizes the current status of water reuse in Japan and discusses dominant uses of reclaimed water, emphasizing non-potable urban applications such as toilet flushing, industrial reuse, and environmental water.

  20. Scientific ballooning in Japan

    NASA Astrophysics Data System (ADS)

    Makino, Fumiyoshi

    Activities in scientific ballooning in Japan during 1998-1999 are reported. The total number of scientific balloons flown in Japan in 1998 and 1999 was sixteen, eight flights in each year. The scientific objectives were observations of high energy cosmic electrons, air samplings at various altitudes, monitoring of atmospheric ozone density, Galactic infrared observations, and test flights of new type balloons. Balloon expeditions were conducted in Antarctica by the National Institute of Polar Research, in Russia, in Canada and in India in collaboration with foreign countries' institutes to investigate cosmic rays, Galactic infrared radiation, and Earth's atmosphere. There were three flights in Antarctica, four flights in Russia, three flights in Canada and two flights in India. Four test balloons were flown for balloon technology, which included pumpkin-type super-pressure balloon and a balloon made with ultra-thin polyethylene film of 3.4 μm thickness.

  1. Japan Report, No. 184.

    DTIC Science & Technology

    1983-11-10

    Iraw war escalated further. Speaking at a press conference, Tokio Nagayama, president of Petroleum As- sociation of Japan and also president of...figures were 41.0 percent and 31.8 percent respectively. This tendency is stronger among blue -collar 31 workers than white-collar workers. It would...respectively.) Furthermore, in a great majority of the workshop groups, whether it be blue collar or white collar jobs, a large number of

  2. Island Formation: Constructing a Coral Island

    ERIC Educational Resources Information Center

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  3. Terrorism in Japan.

    PubMed

    Asai, Yasufumi; Arnold, Jeffrey L

    2003-01-01

    Although the 1995 Tokyo subway sarin attack probably was the most widely reported terrorist event in Japan to date (5,500 injured, 12 dead), the country has suffered numerous other large terrorism-related events in recent decades, including bombings of the headquarters of Mitsubishi Heavy Industries in Tokyo in 1974 (207 injured, 8 dead), the Hokkaido Prefectural Government office building in Sapporo in 1976 (80 injured, 2 dead), and the Yosakoi-Soran Festival in Sapporo in 2000 (10 injured, none dead). Japan also has experienced two other mass-casualty terrorist events involving chemical releases, including the 1994 Matsumoto sarin attack (600 injured, 7 dead) and the 1998 Wakayama arsenic incident (67 injured, 4 dead). Until 1995, emergency management in Japan focused on planning and preparedness at the local level for the frequent disasters caused by natural events. Since that time, substantial progress has been made in advancing emergency planning and preparedness for terrorism-related events, including the designation of disaster centers in each prefecture, the implementation of several education and training programs for nuclear, biological, and chemical terrorism, and the establishment of a national Anti terrorism Office within the Ministry of Health, Labor, and Welfare.

  4. The genus Platytenerus Miyatake, 1985 (Coleoptera: Cleridae: Neorthopleurinae), with description of a new species from Japan.

    PubMed

    Murakami, Hiroyuki

    2015-03-23

    The genus Platytenerus Miyatake, 1985 (Coleoptera: Cleridae) is redescribed and classified into the subfamily Neorthopleurinae Opitz, 2009. A phylogenetic tree is supplementally provided for Platytenerus based on twenty morphological and two geographical characters. A new species of the genus, Platytenerus iriomotensis sp. n. is described from Iriomote Island, Okinawa, Japan.

  5. Proceedings of US-Japan heliotron-stellarator workshop: Volume 4

    SciTech Connect

    Not Available

    1987-01-01

    This paper is the fourth of four volumes on the US-Japan Heliotron-Stellarator workshop. It contains talks on the following: Compact torsatron studies; Low aspect ratio torsatron design; Optimized small stellarator designs; Currents in ATF; Computations of 3-D equilibria with islands; and Magnetic surface mapping studies. (LSP)

  6. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  7. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  8. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  9. Japan-Russia Pediatric Society.

    PubMed

    Nihei, K; Thunemathu, Y; Kobayashi, N

    1993-12-01

    In March 1990, medical interchange between Japan and the Soviet Union began with a letter from the local health bureau of Khabarovsk. We visited Khabarovsk three times and Kamchatka once, and saw many hospitals and patients. Russian doctors of pediatrics visited Japan. Medical information was exchanged and discussed. The Japan-Russia Pediatric Society was established to perform interchange of medical information, technology and staff such as doctors, nurses and technicians between Japan and Russia, especially the Far East district of Russia. The Society meeting has been held three times: Tokyo (1991), Khabarovsk (1992) and Niigata (1993). It is necessary to continue the interchange between the two countries.

  10. Astrogeodetic geoid of Japan

    NASA Technical Reports Server (NTRS)

    Ganeko, Y.

    1976-01-01

    Three kinds of astrogeodetic geoid maps for Japan are presented: one referred to the global (18, 18) geoid of the 1973 Smithsonian Standard Earth (III) (SE III), referred to the best-fitting ellipsoid of SE III, and one referred to the reference ellipsoid of the Tokyo datum. Interpolations of the deflection of the vertical are carried out by a least squares estimation method. The geoid height differences obtained are compared with solutions of satellite-derived station positions. Good agreement is found in a comparison with Doppler tracking stations.

  11. Numerical earthquake model of the 20 April 2015 southern Ryukyu subduction zone M6.4 event and its impact on seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Lee, Shiann-Jong

    2015-10-01

    The M6.4 earthquake that took place on the 20 April 2015 off the shore of eastern Taiwan was the largest event in the vicinity of Taiwan during 2015. The mainshock was located in the southern Ryukyu subduction zone, which is the interface between the Philippine Sea Plate and the Eurasian Plate. People in Taipei experienced strong ground shaking for more than 40 s, even though the epicenter was located more than 150 km away. In order to understand the origin of ground motions from this earthquake and how it caused such strong shaking in Taipei, a numerical earthquake model is analyzed, including models of source rupture and wave propagation. First, a joint source inversion was performed using teleseismic body wave and local ground motion data. Source inversion results show that a large slip occurred near the hypocenter, which rapidly released seismic energy in the first 2 s. Then, the rupture propagated toward the shallow fault plane. A large amount of seismic energy was released during this rupture stage that slipped for more than 8 s before the end of the rupture. The estimated stress drop is 2.48 MPa, which is consistent with values for subduction zone earthquakes. Forward simulation using this inverted source rupture model and a 3D seismic velocity model based on the spectral-element method was then performed. Results indicate that the strong ground motion in Taipei resulted from two factors: (1) the Taipei basin amplification effect and (2) the specific source radiation pattern. The results of this numerical earthquake model imply that future subduction zone events that occur in offshore eastern Taiwan are likely to cause relatively strong ground shaking in northern Taiwan, especially in the Taipei metropolitan area.

  12. Numerical earthquake model of the 20 April 2015 southern Ryukyu subduction zone M6.4 event and its impact on seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Lee, S. J.

    2015-12-01

    The M6.4 earthquake that took place on the 20th April 2015 off the shore of eastern Taiwan was the largest event that occurred in the vicinity of Taiwan during 2015. The mainshock located in the southern Ryukyu subduction zone, which is the interface between the Philippine Sea Plate and the Eurasian Plate. People in Taipei experienced strong ground shaking for more than 40 s, even though the epicenter was located more than 150 km away. In order to understand the origin of this earthquake and how it caused such strong shaking in Taipei, a numerical earthquake model is analyzed, including models of source rupture and wave propagation. First, a joint source inversion is performed using teleseismic body wave and local ground motion data. Source inversion results show that a large slip occurred near the hypocenter, which rapidly released seismic energy in the first 2 s. Then, the rupture propagated toward the shallow fault plane. A large amount of seismic energy was released during this rupture stage that slipped for more than 8 s before the end of the rupture. The estimated stress drop is 2.48 MPa, which is consistent with values for subduction zone earthquakes. Forward simulation using this inverted source rupture model based on the spectral-element method is then performed. Results indicate that the strong ground motion in Taipei resulted from two factors: (1) the Taipei basin amplification effect and (2) the specific source radiation pattern. The results of this numerical earthquake model imply that future subduction zone events that occur in offshore eastern Taiwan are likely to cause relatively strong ground shaking in northern Taiwan, especially in the Taipei metropolitan area.

  13. 69 FR 61403 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2004-10-18

    ... COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION... on polychloroprene rubber from Japan. SUMMARY: The Commission hereby gives notice that it will...)) to determine whether revocation of the antidumping finding on polychloroprene rubber from Japan...

  14. Transition of the Taiwan-Ryukyu collision-subduction process as revealed by ocean-bottom seismometer observations

    NASA Astrophysics Data System (ADS)

    Chin, Shao-Jinn; Lin, Jing-Yi; Chen, Yen-Fu; Wu, Wen-Nan; Liang, Chin-Wei

    2016-10-01

    Located at the arc-continental collision region between the Eurasian (EP) and Philippine Sea Plates (PSP), Taiwan is usually considered to have a complex tectonic environment, particularly along the eastern coast of the island. To gain a better understanding of the geological evolution of the east Taiwan area, the data from 8 Ocean Bottom Seismometers (OBS) acquired during the Across Taiwan Strait Explosion Experiment in 2012 and 14 inland seismic stations were used to determine a more detailed and accurate distribution of marine earthquakes. Based on the 333 relocated earthquakes and available geophysical data, we suggest two main tectonic boundaries for eastern Taiwan. South of 23.25°N, the homogeneous distribution of earthquakes in the crustal portion for both the inland and offshore areas suggests an ongoing collisional process. North of this location, between approximately 23.25°N and 23.8°N, the abrupt increasing of seismicity depth infers that the underthrusted arc/fore-arc material is deforming due to the collisional compression at depth. In this segment, the subsidence of the arc/fore-arc area determines the transition from collision to subduction. North of 23.8°N, the northwestern dipping PSP is well illustrated by the seismicity both onshore and offshore, indicating a dominant subduction process.

  15. Constraints on the Moho in Japan and Kamchatka

    NASA Astrophysics Data System (ADS)

    Iwasaki, Takaya; Levin, Vadim; Nikulin, Alex; Iidaka, Takashi

    2013-12-01

    This review collects and systematizes in one place a variety of results which offer constraints on the depth and the nature of the Moho beneath the Kamchatka peninsula and the islands of Japan. We also include studies of the Izu-Bonin volcanic arc. All results have already been published separately in a variety of venues, and the primary goal of the present review is to describe them in the same language and in comparable terms. For both regions we include studies using artificial and natural seismic sources, such as refraction and reflection profiling, detection and interpretation of converted-mode body waves (receiver functions), surface wave dispersion studies (in Kamchatka) and tomographic imaging (in Japan). The amount of work done in Japan is significantly larger than in Kamchatka, and resulting constraints on the properties of the crust and the uppermost mantle are more detailed. Japan and Kamchatka display a number of similarities in their crustal structure, most notably the average crustal thickness in excess of 30 km (typical of continental regions), and the generally gradational nature of the crust-mantle transition where volcanic arcs are presently active.

  16. Seroprevalence of tularemia in wild bears and hares in Japan.

    PubMed

    Hotta, A; Tanabayashi, K; Yamamoto, Y; Fujita, O; Uda, A; Mizoguchi, T; Yamada, A

    2012-03-01

    Tularemia is a zoonotic disease caused by Francisella tularensis. The distribution of the pathogen in Japan has not been studied well. In this study, seroprevalence of tularemia among wild black bears and hares in Japan was determined. Blood samples collected from 431 Japanese black bears (Ursus thibetanus japonicus) and 293 Japanese hares (Lepus brachurus) between 1998 and 2009 were examined for antibodies against F. tularensis by micro-agglutination test (MA) or enzyme-linked immunosorbent assay. By subsequent confirmatory tests using western blot (WB) and indirect immunofluorescence assay (IFA), eight sera from Japanese black bears were definitely shown to be seropositive. All of these eight bears were residents of the northeastern part of main-island of Japan, where human tularemia had been reported. On the other hand, no seropositive Japanese hares were found. These results suggest that Japanese black bears can serve as sentinel for tularemia surveillance and may help understand the distribution of F. tularensis throughout the country. This is the first report on detection of antibody to F. tularensis in black bears of Japan.

  17. Strong Quake Strikes Japan

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-03-01

    As Eos was about to go to press, a powerful earthquake with a preliminary estimated magnitude of 8.9 shook the northeast coast of Japan on 11 March at 05:46:23 UTC. It is the largest known earthquake along the Japan Trench subduction zone since 869 A.D. or earlier, Brian Atwater, geologist with the U.S. Geological Survey (USGS), told Eos. The quake's magnitude would place it fifth in terms of any earthquake magnitude worldwide since at least 1900, according to information from the USGS Earthquake Hazards Program. The amount of energy released in the quake—which occurred 130 kilometers east of Sendai, Honshu, at a depth of 24.4 kilometers—was equivalent to the energy from 30 earthquakes the size of the 1906 quake in San Francisco, Calif., according to David Applegate, USGS senior science advisor for earthquake and geologic hazards. He said the economic losses from the shaking are estimated to be in the tens of billions of dollars.

  18. Nutrition trends in Japan.

    PubMed

    Matsumura, Y

    2001-01-01

    The National Nutrition Survey (NNS) in Japan has been undertaken annually since 1946. It was originally intended to provide information on the food and nutrient intake of the Japanese people, with a view to acquiring emergency food supplies from other countries when food shortages caused malnutrition in many Japanese. The food balance sheet (FBS) has been drawn up since 1949 to show the food supply available to the Japanese people. The trends and figures shown by both approaches were similar until the mid-1970s. Since then, however, the disparity between the food supply and the intake of foods and nutrients has been getting larger. National food security means that a country has enough food for everyone. This does not mean, however, that every family has enough food, because the food may not be evenly distributed. In fact, marginal deficiencies in iron and calcium are thought to still exist and there is considerable variation among households in energy intake. In Japan, nutrition and diet are now considered to play important roles in the emerging problems of obesity, diabetes mellitus, hypertension etc., because of excessive energy intake and deficiency or excessive intake of certain nutrients.

  19. Higher Education Studies in Japan

    ERIC Educational Resources Information Center

    Kaneko, Motohisa

    2010-01-01

    The rapid development of higher education in the postwar period has given rise to various problems, and higher education studies in Japan have developed in response to them. What have been the major issues, and how did academic research respond to them, in postwar Japan? This article delineates an outline of higher education studies in general,…

  20. Teaching Elementary Students about Japan

    ERIC Educational Resources Information Center

    Fitzhugh, William P.

    This paper presents a study unit on Japan for elementary students which can be adapted for any level. Lessons include: (1) "Video Traveling Activities To Accompany Students on Their Journey to Japan"; (2) "Travel Brochure"; (3) "Discovering Culture by Using a Realia Kit"; (4) "Comparative Geography Using the Five…

  1. [Buddhist mummies in Japan].

    PubMed

    Morimoto, I

    1993-08-01

    The mummy of priest Kochi (preserved at Saishoji Temple, Teradomari, Niigata Pref.) has become famous, since it appeared in the book "Snow Country Tales" written by Bokushi Suzuki in 1841 (Fig. 1). In a country of high humidity, such as Japan, the belief that mummification could not, and did not, exist would not be altogether unfounded, but rather more a matter of common sense. There are two dozen Buddhist mummies in this country. It was not known until 1961 that a reliable source of artificial mummification has existed in Japan. The Japanese Buddhist mummies, apart from those of the Fujiwara family, a powerful clan of northeast Japan in the 12th century, dated mostly from the 17th to the 19th century as given in Table 1. Three principal types of mummification described by Vreeland, Jr. and Cockburn (1980) could be identified in the Japanese Buddhist mummies: type I, natural mummification; type II, intentional natural; and type III, artificial. Matsumoto (1990) classified the mummies into four groups, based on their ideological backgrounds: group A, mummies of the priests having faith in the Amitabha (the Supreme Buddha presiding over the Pure Land in the West); group B, sokushin-butsu mummies of the priests belonging to the Shingon sect of Japanese Buddhism founded by Kukai (Kobo-daishi); group C, nyujo mummies of the priests having faith in the Maitreya (the Buddha presiding over the Pure Land in the North, or the Buddha of the future); and group D, other mummies. These mummies of groups A, B, C and D are respectively listed in Table 2. Previous papers have shown that the mummies of the groups A, C and D belonged to the mummification of type I (natural mummification) or type II (intentional natural), whereas those of only the group B were of type III (artificial). The mummies of groups A to D were given as follows. a) Mummies of group A. The four mummies of the Fujiwara family in the Amitabha faith (preserved at Chusonji Temple, Hiraizumi, Iwate Pref.), which

  2. Vaccine chronicle in Japan.

    PubMed

    Nakayama, Tetsuo

    2013-10-01

    The concept of immunization was started in Japan in 1849 when Jenner's cowpox vaccine seed was introduced, and the current immunization law was stipulated in 1948. There have been two turning points for amendments to the immunization law: the compensation remedy for vaccine-associated adverse events in 1976, and the concept of private vaccination in 1994. In 1992, the regional Court of Tokyo, not the Supreme Court, decided the governmental responsibility on vaccine-associated adverse events, which caused the stagnation of vaccine development. In 2010, many universal vaccines became available as the recommended vaccines, but several vaccines, including mumps, zoster, hepatitis B, and rota vaccines, are still voluntary vaccines, not universal routine applications. In this report, immunization strategies and vaccine development are reviewed for each vaccine item and future vaccine concerns are discussed.

  3. Japan (country/area statements).

    PubMed

    1985-09-01

    Japan, a country generally successful in solving population problems, now faces the problem of an aging population. It must provide welfare for its aged population and give them a role in society. Recognizing the vital importance to economic and social development of population problems in developing countries, Japan has cooperated through bilateral and multilateral channels in assisting various projects of developing countries concerned about population problems. As for bilateral aid, Japan extends technical cooperation to Economic and Social Commission for Asia and the Pacific (ESCAP) region countries by providing them with experts, by conducting surveys, by giving equipment, and by organizing training courses, particularly in the field of family planning. Japan also cooperates with some of the developing countries of the ESCAP region by providing them with financial assistance in the form of multilateral cooperation. Japan makes a cash contribution the the UN Fund for Population Activities (UNFPA) as the biggest donor country. In fiscal year 1984, the Japanese contribution to UNFPA totaled $US 40.1 million; the contribution will amount of $US 42.9 million in 1985. Aware of the importance of human resource development in the field of population, Japan has organized annual group training courses for the developing countries, namely: the Seminar on Family Planning Administration for Senior Officers; the Seminar on Community-Based Family Planning Strategy; and the Seminar on Health Aspects of Family Planning. Japan generally supports the work of ESCAP with regard to training in the field of population.

  4. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  5. Use of microbial analysis to evaluate denitrification in the karstic aquifer of Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.

    2014-12-01

    Denitrification, a microbial process in the nitrogen cycle, is a facultative respiratory pathway in which nitrate (NO3-), nitrite (NO2-), nitric oxide (NO), and nitrous oxide (N2O), successively, are reduced to nitrogen gas (N2). This study explores the use of microbial analysis to evaluate the processes involved in nitrate attenuation in groundwater. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) is used to identify denitrifiers based only on their 16SrRNA gene sequences, and Real-Time PCR analysis is used to quantify nitrite reducing genes (nirK and nirS), this suggest that a new methods for detecting denitrification activity by comparing the gene dosage that has been detected by RT-PCR and the value of the δ15NNO3- and δ18ONO3-. This study focuses on a zone of significant NO3- attenuation occurring at underground dam catchment area in the karstic Ryukyu limestone aquifer, which is located southern part of Okinawa, Japan. As a result of microbial analysis, the bacteria were detected at all observation points which have been reported to have denitrification ability. And it has been confirmed that the bacteria has a gene nirS which is related to denitrification. In addition, many bacteria related to denitrification have been extracted from suspended solids more than from groundwater in the aquifer. And, the correlation was high between nirK /nirS gene dosage that has been detected by RT-PCR and the value of the δ15N and δ18O; therefore, this study demonstrates the effectiveness of using Real-Time PCR analysis for providing insights into the processes affecting nitrate attenuation in ground water.

  6. Canary Island Archipelago

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This nearly vertical view of the Canary Archipelago (28.5N, 16.5W) shows five of the seven islands: Grand Canary, Tenerife, Gomera, Hierro and La Palma. The largest island in view is Tenerife. Island cloud wakes evident in this photo are the result of southerly winds giving rise to cloud banks on the lee side especially on Tenerife which has the highest volcanic peaks. Island water wakes and internal waves are also evident but not as apparent.

  7. Falkland Islands, UK

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view of the Falkland Islands (52.0S, 58.5W) was taken with a dual camera mount. Compare this scene with STS048-109-043 to analyze the unique properties of each film type. Seldom seen cloud free, the Falkland Islands lie off the southern coast of Argentina. The cold Falklands Ocean Current keeps the islands chilly, ideal for sheep herding and fishing, the two main industries. Colonies of seals and penguins also thrive on the islands.

  8. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  9. Multiple personality disorder in Japan.

    PubMed

    Fujii, Y; Suzuki, K; Sato, T; Murakami, Y; Takahashi, T

    1998-06-01

    The aim of this study was to determine whether the features of multiple personality disorder (MPD) in Japan are similar to those in North America, although a wide disparity exists in the prevalence of MPD between the two areas. In order to describe the features of MPD in Japan, we obtained clinical data from MPD case reports, including two of our own cases, published in Japanese academic journals and compared it with the data from other countries. The cases in Japan differed significantly from those in North America in the mean number of personalities and prevalence of sexual and/or physical abuse.

  10. Avifauna: Turnover on Islands.

    PubMed

    Mayr, E

    1965-12-17

    The percentage of endemic species of birds on islands increases with island area at a double logarithmic rate. This relation is apparently due to extinction, which is more rapid the smaller the island. The turnover resulting from extinction and replacement appears to be far more rapid than hitherto suspected.

  11. Diomede Islands, Bering Straight

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations.

    The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  12. Paleomagnetism of Tertiary rocks from the OGA Peninsula and the rotation of northeast Japan

    NASA Astrophysics Data System (ADS)

    Tosha, Toshiyuki; Hamano, Yozo

    1988-06-01

    We have made a paleomagnetic study of Tertiary rocks from the Oga Peninsula, northern Honshu Island. Volcanic and sedimentary rocks were sampled from 26 sites in the peninsula. The ages of the rocks range from 62 Ma to the present. The results indicate a counterclockwise rotation of Northeast Japan with respect to eastern Asia around a pole at 58°N, 149°E, between about 22 Ma and 15 Ma. The amount of the rotation is about 20°. Before the rotation, Northeast Japan was situated along the east coast of the Asian continent.

  13. The Southern Kurile Islands: Shrouded in Eternal Fog

    DTIC Science & Technology

    2012-03-22

    September 1945. The dispute is only between two nations, has not erupted into armed conflict, and does not have ethnic or religious dimensions...defense alliance and strong economic ties with Japan and security interests in Northeast Asia. A three island compromise solution is the most likely...September 1945. The dispute is only between two nations, has not erupted into armed conflict, and does not have ethnic or religious dimensions. However

  14. Japan Report, Science and Technology.

    DTIC Science & Technology

    2007-11-02

    include water temperature, water quality, ocean currents, sea ice, wave conditions, coastal conditions, and marine resources. Environmental polution ... air , and food supplies (procured in Japan) to the station for use by its crew. It is also a real possibility that Japan’s data relay satellite (DRTS...the pressurized unit via a mechanical manipulator and an air lock to permit the exchange of equipment and samples and the assembly of space

  15. JPRS Report, Science & Technology, Japan

    DTIC Science & Technology

    2007-11-02

    said. The arrangement opens the way for Japan to participate in the U.S. space station project , the Japanese negotiators said. Canada and the...European Space Agency have also been asked by U.S. President Ronald Reagan to participate in the project . Reagan emphasized the planned space station...provision, understood to mean permission for the Pentagon to use the station caused Japan to have reservations about the project , and there was a

  16. JPRS Report, Science & Technology, Japan.

    DTIC Science & Technology

    2007-11-02

    to perform our international role, as well as to contribute to the space development of Japan in the future. 2. The epoch- making contents of this...our social duty to become involved in this as an aircraft manufacturer. At the same time, we will also contribute to space utilization in the...of commercial communications satellites are also planned in Japan starting next year. Private corporations are making efforts such as our

  17. Layered anisotropy within the crust and lithospheric mantle beneath the Sea of Japan

    NASA Astrophysics Data System (ADS)

    Legendre, C. P.; Zhao, L.; Deschamps, F.; Chen, Q.-F.

    2016-10-01

    Continental rifting during the Oligocene to mid-Miocene caused the opening of the Sea of Japan and the separation between the Japanese Islands and the Eurasian Plate. The tectonic evolution in the Sea of Japan is important for understanding the evolution of back-arc regions in active convergent margins. Here, we use data from the seismic stations surrounding the Sea of Japan to map the Rayleigh-wave azimuthal anisotropy in the crust and lithospheric mantle beneath the Sea of Japan. We explore the variations of Rayleigh-wave phase-velocity beneath the Sea of Japan in a broad period range (30-80 s). Rayleigh-wave dispersion curves are measured by the two-station technique for a total of 231 interstation paths using vertical-component broad-band waveforms at 22 seismic stations around the Sea of Japan from 1411 global earthquakes. The resulting maps of Rayleigh-wave phase velocity and azimuthal anisotropy allow the examination of azimuthal anisotropy at specific periods. They exhibit several regions with different isotropic and anisotropic patterns: the Japan Basin displays fast velocities at shorter periods (30 and 40 s) with NNE-SSW anisotropy, whereas at 60 s and longer, the velocities become slow even if the anisotropy remains NE-SW; the East China Sea shows fast velocities at all periods (30-80 s) with constant NW-SE anisotropy. Trench-normal anisotropy beneath the Japanese Islands is found at short periods (30-40 s) and become trench-parallel at periods of 60 s and longer. Overall, our model resolves two layers of anisotropy, the shallowest and deepest layers being potentially related to frozen deformation due to recent geodynamic events, and asthenospheric flow, respectively.

  18. High definition systems in Japan

    NASA Technical Reports Server (NTRS)

    Elkus, Richard J., Jr.; Cohen, Robert B.; Dayton, Birney D.; Messerschmitt, David G.; Schreiber, William F.; Tannas, Lawrence E., Jr.; Shelton, Duane

    1991-01-01

    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems.

  19. Plate tectonics and crustal deformation around the Japanese Islands

    NASA Technical Reports Server (NTRS)

    Hashimoto, Manabu; Jackson, David D.

    1993-01-01

    We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

  20. [Canine histoplasmosis in Japan].

    PubMed

    Sano, Ayako; Miyaji, Makoto

    2003-01-01

    Histoplasmosis is a fungal infection caused by Histoplasma capsulatum and is distributed a worldwide. Although the disease has been treated as an imported mycosis, some autochthonous human, 1 equine and 4 canine cases suggested that the disease is endemic. Histoplasmosis is classified depending on the variety of causative agent. Histoplasmosis farciminosi known as pseudofarcy, is manifested only in Perissodactyla where it invades lymph nodes and lymph ducts, and is recognized by isolation from horses. Historically, Japan was one of the endemic areas of pseudofarcy before World War II, and more than 20,000 cases were recorded in horses used by the military. Interestingly, Japanese canine histoplasmosis uniformly showed skin ulcers and granulomatous lesions on the skin without pulmonary or gastrointestinal involvement, both of which were very similar to pseudofarcy. It was diagnosed as histoplasmosis by the detection of internal transcribed spacer legions of rRNA gene of H. capsulatum from paraffin embedded tissue samples. Furthermore, the fungal isolate from the human case with no history of going abroad or immigrating was identified as H. capsulatum var. farciminosum by a gene sequence. These facts indicated that pseudofarcy is not only an infectious disease in horses, but also a zoonotic fungal infection. Japanese autochthonous canine histoplasmosis might be a heteroecism of pseudofarcy because of its likeness to the human case, the similarity of clinical manifestations and the historical background at this stage.

  1. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

  2. Women's health in Japan.

    PubMed

    1994-08-01

    In Japan, the Women's Center in Osaka operates a women's health information hotline for 3 days/month. An analysis of 730 calls to the Centre during 1990-1992 shows that abortion and contraception are not major concerns. (Safe abortion is accessible. Oral contraceptives are banned. Condoms and the rhythm method are the most common family planning methods.) The bulk of the calls (22.6%) centered around menstruation, followed by reproductive diseases (21.5%), menopause (7%), and infertility (7%). Irregular menstruation, no menstruation, and painful periods made up most menstruation concerns. These cases tended not to be serious, which explains why physicians were not interested in them, resulting in client dissatisfaction. Physicians are usually concerned about menstruation only as it pertains to desire for pregnancy. Mothers who call the hotline with questions about their daughters' menstruation ask about menstruation as it relates to fertility. Clearly, woman's role is to bear children. Physicians prescribe medication to women with concerns about infertility but women have difficulty asking their physicians any questions about the medication. Women concerned about infertility do not consider other options such as alternative treatments, adoption, or not bearing children. Once fertility has diminished, physicians are no longer interested in women. Women with questions about menopause who do not get the information from their physician or respectful attention from their physician call the hotline. Most menopause- related complaints revolve around symptoms.

  3. Global update: Japan.

    PubMed

    Sipp, Doug

    2011-11-01

    Japan continues to be a major player in stem cell biology and related fields, boasting multiple world-class programs in a broad spectrum of stem cell studies, a permissive regulatory framework, an active society for regenerative medicine and a growing industry involvement. The most noted work in recent years has of course originated in the laboratory of Shinya Yamanaka, with the first report of induced pluripotent stem cells (iPS cells) in 2006, and numerous technical advancements since, which prompted the government to establish a Center for iPS Cell Research and Application in 2010 (see below). Additional concentrations of stem cell research excellence can be found in Tokyo, Osaka, Kobe and Kumamoto. In 2011, Yoshiki Sasai's laboratory in the RIKEN Center for Developmental Biology, Kobe, achieved another remarkable result in inducing optic cup-like structures from embryonic stem cells using 4D tissue culture techniques, building on previous work in which the group had generated stratified cerebral cortex-like tissue from embryonic stem cells in vitro.

  4. Ainu as a Heritage Language of Japan: History, Current State and Future of Ainu Language Policy and Education

    ERIC Educational Resources Information Center

    Teeter, Jennifer Louise; Okazaki, Takayuki

    2011-01-01

    Ainu is the heritage language of the indigenous people of present-day southern Sakhalin, the Kurile Islands, present-day Hokkaido, and northeastern Honshu (mainland Japan). The UNESCO Interactive Atlas of the World's Languages in Danger (2009) considered the Ainu language critically endangered with only 15 speakers remaining. This article…

  5. 77 FR 73057 - Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-ISG-2012-05; Performance of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... . SUPPLEMENTARY INFORMATION: Background Information On March 11, 2011, a magnitude 9.0 earthquake struck off the coast of the Japanese island of Honshu. The earthquake resulted in a large tsunami, estimated to have... earthquake and tsunami produced widespread devastation across northeastern Japan and significantly...

  6. FBIS report. Science and technology: Japan, January 28, 1997

    SciTech Connect

    1997-01-28

    ;Partial Contents: Japan: AIST`s Frontier Carbon Technology Research Project Under Way; Japan: Sumitomo Electric Develops Aluminum Nitride Substrate; Japan: NASDA To Develop Small, High Performance, Low Cost Satellite; Japan to Haive Rocket Launch Cost; Japan: Combined-Cycle Technology for Higher Thermal Efficiency Using Various Fuels; Japan: S&T Corporation Develops Carbon Thin Film Solar Cell; Japan: Atomic Energy Commission of Japan Suports Using ITER for Japan`s Experimental Reactor; Japan: NO New Nuclear Power Plant Construction in Sight; and Japan: Mitsubishi Electric Executive on Guided Missile Development.

  7. Back-arc Mantle Evolution inferred from Peridotite Xenotlishs from the Japan Sea

    NASA Astrophysics Data System (ADS)

    Morishita, T.; Ichiyama, Y.; Tamura, A.; Arai, S.

    2014-12-01

    Peridotite xenoliths are recovered in basaltic to andesitic lavas from several localities in the Japan Sea, a Miocene back-arc basin of the Western Pacific region. These peridotites are classified into two groups: two-pyroxene peridotitess and dunite-wehrlite groups. Although slight chemical modifications are observed in these peridotite samples, two-pyroxene peridotite group has retained their original residual mantle geochemical signatures left after partial melting. The dunite-wehrlite group is, on the other hand, probably formed by extensive interaction of the two-pyroxene peridotite group. We examined trace element characteristics of clinopyroxene in these xenoliths. Light REE-depleted clinopyroxenes that are usually interpreted as a simple residual mantle after anhydrous partial melting are similar to those of abyssal peridotite recovered from mid-ocean ridges and back-arc basins. Other samples show LREE-enriched patterns that are residues after influx melting caused by hydrous melt/supercritical fluids released from the subducted slab at high pressure conditions. The geotectonic and geochemical variations of the peridotite xenoliths from the Japan Sea (Shirabeshi Seamount, Seifu Seamount and Oshima-Oshima Island) suggest that the mantle beneath the Japan Sea are suffered from hydrous to anhydrous melting as the Japan Sea forms. This is consistent with the geochemical and isotopic results from Miocene basaltic rocks formed during opening of the Japan Sea (Sato et al., Jour. Petrol., 2013). The Japan Sea peridotite xenoliths also shed lights on the origin of ophiolites.

  8. FBIS report. Science and technology: Japan, April 10, 1996

    SciTech Connect

    1996-04-10

    ;Partial Contents: Biotechnology (Japan: Japan`s RITE Introduces Biotech Projects, Japan: Pharmacia Biotech Develops Detection Method for Point Mutation); Energy (Japan: New Catalyst for Synthesis Gas Reduces Energy Needs, Japan: Major Company Activities for Promotion of Wind Power Generation, Japan: Waste Power Generation System in Saitama Draws Much Attention); Environment (Japan: AIST`s NIMC To Develop Efficient Decomposition Method for Waste Using Super-Critial Water, Japan: Kyoei Co. Develops High Temperature Fusion Furnace for Industrial Waste Treatment, Japan: Air Dry Cleaning for Recycling Chemically Contaminated Plastic Sheets); Microelectronics (Japan: Toshiba Corp. DEC To jointly Develop LSI for ATM); Science and Technology Policy (Japan`s MITI To Begin Electronic Commerce Experiment Project); Technology Transfer (Japan: Nissho Iwai Delivers Cleaner Plant to Russia`s Energiya, Japan: Energy Agency Transfers Coal Fired Power Generation Technology to Indonesia); Telecommunications (Japan`s MPT Releases Study Report on Advanced Information Technologies).

  9. Mt. Fuji, Japan

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] Click on image to view the movie

    The nearly perfectly conical profile of Fuji soars 3,776 meters (12,388 feet) above sea level on southern Honshu, near Tokyo. The highest mountain in Japan, Fuji is the country's most familiar symbol. The summit of this graceful, dormant volcano is broken by a crater 610 meters (2,000 feet) in diameter. The crater is ringed by eight jagged peaks. The five Fuji Lakes lie on the northern slopes of the mountain, all formed in the wake of lava flows. Mirrored in the still waters of Kawaguchi-ko, the most beautiful of the five lakes, is a reflection of Fuji. Part of Fuji-Hakone-Izu National Park, Fuji last erupted for a two-month period starting in November 1707, covering Tokyo, some 100 kilometers (60 miles) away, with a layer of ash. According to legend, Fuji arose from the plain during a single night in 286 BC. Geologically, the mountain is much older than this.

    Considered sacred by many, Fuji is surrounded by temples and shrines. Thousands of pilgrims climb the mountain each year as part of their religious practice, hoping to reach the summit by dawn to watch the sunrise. This animated fly-by was created by draping visible and near infrared image data over a digital topography model, created from ASTER's stereo bands. The spatial resolution of both the image and topography is 15 m. The image is centered at 35.3 degrees north latitude, 138.7 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  10. Proton therapy in Japan

    SciTech Connect

    Tsunemoto, H.; Morita, S.; Ishikawa, T.; Furukawa, S.; Kawachi, K.; Kanai, T.; Ohara, H.; Kitagawa, T.; Inada, T.

    1985-01-01

    There are two facilities for clinical trials with protons in Japan: the National Institute of Radiological Sciences (NIRS), Chiba, and the Particle Radiation Medical Science Center (PARMS), University of Tsukuba. At the National Institute of Radiological Sciences, patient treatment with the 70 MeV proton beam began in November 1979, and 29 patients were treated through December 1984. Of 11 patients who received protons only, 9 have had local control of the tumor. Two of the 9 patients, suffering from recurrent tumor after radical photon beam irradiation, developed complications after proton treatment. In the patients treated with photons or neutrons followed by proton boost, tumors were controlled in 12 of 18 patients (66.6%), and no complications were observed in this series. Malignant melanoma could not be controlled with the proton beam. A spot-beam-scanning system for protons has been effectively used in the clinical trials to minimize the dose to the normal tissues and to concentrate the dose in the target volume. At the Particle Radiation Medical Science Center, University of Tsukuba, treatment with a vertical 250 MeV proton beam was begun in April 1983, and 22 patients were treated through February 1984. Local control of the tumor was observed in 14 of 22 patients (63.6%), whereas there was no local control in the treatment of glioblastoma multiforme. There have been no severe complications in patients treated at PARMS. The results suggest that local control of tumors will be better with proton beams than with photon beams, whereas additional modalities are required to manage radioresistant tumors.

  11. Levels and distribution of polybrominated diphenyl ethers and organochlorine compounds in sea turtles from Japan.

    PubMed

    Malarvannan, Govindan; Takahashi, Shin; Isobe, Tomohiko; Kunisue, Tatsuya; Sudaryanto, Agus; Miyagi, Toshihiko; Nakamura, Masaru; Yasumura, Shigeki; Tanabe, Shinsuke

    2011-01-01

    Three species of sea turtles (green, hawksbill and loggerhead turtles) stranded along the coasts or caught (by-catch) around Ishigaki Island and Kochi, Japan were collected between 1998 and 2006 and analyzed for six organohalogen compounds viz., PBDEs, PCBs, DDTs, CHLs, HCHs and HCB. The present study is the first and foremost to report the occurrence of organohalogen compounds in the sea turtles from Japan. Among the compounds analyzed, concentrations of PCBs, DDTs and CHLs were the highest in all the turtle samples. PBDEs were ubiquitously present in all the turtle species. Comparing with the other two species, concentrations of organohalogens in green turtle were relatively low and decreasing trend in the concentrations were noted with increasing carapace length. Concentrations of OCs in sea turtles from the coasts of Ishigaki Island and Kochi were relatively low as compared to those from other locations in the world.

  12. 10Be concentrations of Red soils in Southwest Japan and its possibility of dating

    NASA Astrophysics Data System (ADS)

    Maejima, Y.; Matsuzaki, H.; Nakano, C.

    2004-08-01

    10Be concentrations of six Red soils distributed in Southwest Japan ranged from 0.8 × 108 to 2.7 × 109 atoms g-1, and minimum absolute ages were estimated by inventory of meteoric 10Be. The results are follows: Red soils on Toyota derived from granite (⩽25 ka), Kashii derived from Tertiary shale (⩽24 ka), Akiyoshidai derived from limestone (⩽110 ka), Okinawa Island derived from Kunigami gravel bed (⩽9 ka) and Ogasawara Island derived from agglomerate and Boninite (⩽22 and ⩽7 ka) were obtained, respectively. Soil age except with Akiyoshidai indicated younger age. It suggested that the loss of 10Be from the soil was caused by leaching of 10Be or by soil erosion, and 10Be is susceptible to leaching out from these Red soils under the humid climate condition such as Southwest Japan.

  13. Psychotropic dose equivalence in Japan.

    PubMed

    Inada, Toshiya; Inagaki, Ataru

    2015-08-01

    Psychotropic dose equivalence is an important concept when estimating the approximate psychotropic doses patients receive, and deciding on the approximate titration dose when switching from one psychotropic agent to another. It is also useful from a research viewpoint when defining and extracting specific subgroups of subjects. Unification of various agents into a single standard agent facilitates easier analytical comparisons. On the basis of differences in psychopharmacological prescription features, those of available psychotropic agents and their approved doses, and racial differences between Japan and other countries, psychotropic dose equivalency tables designed specifically for Japanese patients have been widely used in Japan since 1998. Here we introduce dose equivalency tables for: (i) antipsychotics; (ii) antiparkinsonian agents; (iii) antidepressants; and (iv) anxiolytics, sedatives and hypnotics available in Japan. Equivalent doses for the therapeutic effects of individual psychotropic compounds were determined principally on the basis of randomized controlled trials conducted in Japan and consensus among dose equivalency tables reported previously by psychopharmacological experts. As these tables are intended to merely suggest approximate standard values, physicians should use them with discretion. Updated information of psychotropic dose equivalence in Japan is available at http://www.jsprs.org/en/equivalence.tables/. [Correction added on 8 July 2015, after first online publication: A link to the updated information has been added.].

  14. Middle Jurassic radiolarian fauna from Rotti Island, Indonesia

    NASA Astrophysics Data System (ADS)

    Sashida, K.; Munasri; Adachi, S.; Kamata, Y.

    1999-08-01

    A well-preserved Middle Jurassic radiolarian fauna was discriminated from calcareous shale of the Wai Luli Formation on Rotti Island, Indonesia. This fauna is characterized by the presence of Tricolocapsa plicarum, Tricolocapsa ? fusiformis, Stichocapsa japonica, S. convexa, Cyrtocapsa mastoidea, Protunuma turbo, Transhsuum maxwelli, Eucyrtidiellum sp., Archaeodictyomitra sp. A. and others. These radiolarians represent the T. plicarum Assemblage reported from Bajocian and early Bathonian (Middle Jurassic) sequences in Japan and southeastern Europe. Based on accumulated micropaleontological evidence in Timor Island contributed by the present authors, Rotti Island was probably positioned within a warm water current system originating in the low latitude Tethyan realm through the Middle Jurassic. Fifteen species belonging to seven genera are systematically investigated. Among them, Tricolocapsa multispinosa and Tricolocapsa matsuokai are described as new.

  15. U.S. Military Aviation Mishaps In Japan and Okinawan Political Controversy

    DTIC Science & Technology

    2015-12-01

    accidents routinely create political controversy in Okinawa, but some incidents draw more attention or ridicule than others. This study evaluates the...military aviation mishaps in Japan. Such accidents routinely create political controversy in Okinawa, but some incidents draw more attention or ridicule...late 1990s.18 Although the U.S. Air Force’s Kadena is the largest military installation on the island, it draws considerably less political attention

  16. Designation of a neotype and redescription of Hesione reticulata von Marenzeller, 1879 from Japan (Annelida, Hesionidae)

    PubMed Central

    Jimi, Naoto; Salazar-Vallejo, Sergio I.; Kajihara, Hiroshi

    2017-01-01

    Abstract The hesionid polychaete Hesione reticulata von Marenzeller, 1879 was described from Enoshima Island, Japan and has been recorded also from the Red Sea. Depending on researchers, it has been regarded as either a distinct species or synonymous with older established ones. The type specimen has been lost. In order to clarify its taxonomic status, Hesione reticulata is herein redescribed, illustrated, and a neotype is proposed based on recent material collected near the type locality. The diagnostic features include the presence of several dorsal, discontinuous longitudinal bands, interrupted by pale segmental spots; prostomium with tiny antennae; a tuberculated dorsal integument; acicular lobes double; and neurochaetal blades with guards approaching the distal tooth. The dorsal color pattern in life enables a clear distinction from similar species such as Hesione intertexta Grube, 1878 amongst others. Mitochondrial COI barcoding sequences are deposited in the DNA Data Bank of Japan. A key to Hesione species from Japan is also included. PMID:28331407

  17. Ober's Island, One of the Review Islands on Rainy Lake, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  18. Molecular epidemiological study of mumps epidemics of 2015 in Okinawa, Japan.

    PubMed

    Kuba, Yumani; Kyan, Hisako; Arakaki, Eri; Takara, Taketoshi; Kato, Takashi; Okano, Sho; Oshiro, Yuko; Kudaka, Jun; Kidokoro, Minoru

    2016-12-22

    In Okinawa Prefecture in Japan, although major mumps epidemics have occurred every 4-5 years, no laboratory diagnoses have been conducted. The mumps epidemic spread in Okinawa from October 2014, and we collected clinical materials from 31 mumps patients in 4 areas (Hokubu, Nanbu, Miyako and Yaeyama) from July to December 2015 for virus isolation and RT-PCR, whose positive ratios were 52% and 87%, respectively. The phylogenetic analyses showed that all isolates were classified into genotype G, most of which, except for 1, consisted of two subgenotypes, Ge (55.6%) and Gw (40.7%), which have been prominent in Japan recently. One isolate was classified into another lineage, which was first detected in Japan, and was similar to the Hong Kong isolate in 2014. Remarkably, the geographic distributions of the two major lineages were separated, namely, the Ge viruses were isolated from the main island of Okinawa, and the Yaeyama Islands, while the Gw isolates were mainly detected from the Miyako Islands. These results suggest that Ge and Gw mumps viruses mainly caused the mumps epidemics of 2015 in Okinawa, and they spread independently in separate regions. This is the first report describing the molecular epidemiological studies of mumps epidemics in Okinawa Prefecture.

  19. JPRS Report, Science & Technology, Japan

    DTIC Science & Technology

    1987-10-27

    WEEKLY, 27 Jul 87) 38 ASDF Selects HH-60J for New SAR Helicopter (AEROSPACE JAPAN-WEEKLY, 10 Aug 87) 39 ASDF Briefed on BAe 125-800 Flight...be mounted in pylons of the P-3C to attack enemies. /13046 CSO: 4307/038 38 DEFENSE INDUSTRIES ASDF SELECTS HH-60J FOR NEW SAR HELICOPTER Tokyo...AEROSPACE JAPAN-WEEKLY in English 10 Aug 87 p 1 [Text] The Air self-Defense Force ( ASDF ) has selected the Sikorsky HH-60J for its new

  20. The educational system in Japan

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1986-01-01

    The rapid economic growth of Japan since World War II has resulted in Japan becoming a reference point for developing nations and the West. This remarkable growth results from a combination of factors, one of which has been unyielding attention to education in order to cultivate the human talent necessary to provide the productivity for economic growth. The Japanese education system emphasizes quality of instruction and rewards hard work. Some of the principles of the system are outlined together with a summary of the content of the curriculum, the quantity and quality of instruction, and the influence of culture and environment.

  1. 75 FR 57980 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION... whether revocation of the antidumping duty finding on polychloroprene rubber from Japan would be likely...

  2. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...), and R. trichocarpa (China, Indo-China, India, and Japan). Japan wax is soluble in hot alcohol, benzene, and naphtha, and insoluble in water and in cold alcohol. (b) In accordance with paragraph (b)(1)...

  3. 70 FR 2656 - Drafting Machines From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2005-01-14

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Drafting Machines From Japan AGENCY: United States International Trade Commission. ACTION... determine whether revocation of the antidumping duty order on drafting machines from Japan would be...

  4. Is Japan a military threat to Asia?

    SciTech Connect

    Halloran, R.

    1994-11-01

    The foreign minister of Japan, Yohei Kono, stood in the UN General Assembly in September and sought to reassure delegates that Japan would not again employ military power in the international area. {open_quotes}Japan does not, nor will it, resort to the use of force prohibited by its constitution,{close_quotes} Kono said, {open_quotes}Japan will remain resolutely a nation of peace.{close_quotes}

  5. Free Resources for Teaching about Japan. Revised Edition.

    ERIC Educational Resources Information Center

    Wojtan, Linda S.

    A collection of sources of information about Japan and resource materials available for teaching about Japan are included in this document. Part one, "Who and Where" lists names and addresses from a variety of sources including the Embassy and Consulates General of Japan, the Japan Foundation, Japan Trade Centers (Japan External Trade…

  6. Island Natural Science School.

    ERIC Educational Resources Information Center

    Toronto Board of Education (Ontario).

    Prepared for students in grade six attending the Island Natural Science School, Toronto, Ontario, Canada, this booklet offers information and suggests activities in the areas of ecology, conservation, natural resources, and outdoor recreation. Introductory material describes island lore, its formation and significant features, followed by units of…

  7. Bouvet Island near Antarctica

    Atmospheric Science Data Center

    2013-04-16

    ... an obstacle to the westerly winds, and wake patterns in the cloud layers are visible downstream of the island's location. In the lower left ... the lower right image, the island is partially obscured by cumulus clouds, and a spiral cloud pattern associated with an atmospheric ...

  8. Back to Treasure Island

    ERIC Educational Resources Information Center

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  9. Marine and Island Ecology.

    ERIC Educational Resources Information Center

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  10. Teaching about Japan: Lessons and Resources.

    ERIC Educational Resources Information Center

    Bernson, Mary Hammond, Ed.; Wojtan, Linda S., Ed.

    This document is a revised and updated version of two publications: "Modern Japan: An Idea Book for K-12 Teachers" and "Resources for Teaching About Japan." These lesson plans were developed by teachers who participated in a summer institute on Japan, sponsored by the East Asia Resource Center at the Jackson School of…

  11. Some Aspects of Higher Education in Japan

    ERIC Educational Resources Information Center

    Teichler, Ulrich

    1972-01-01

    Contemporary Japanese higher education is reviewed, taking into account German influences especially. Three main objectives of post-war reforms are discussed along with the entrance examination system in Japan. Available from: Japan Cultural Society, 101018, Shirokane-dai, Minato-ku, Tokyo, Japan. (LBH)

  12. Preparing Teachers for Japan's Classrooms. Fastback 394.

    ERIC Educational Resources Information Center

    Beauchamp, Edward R.

    This volume reviews the development of teacher education in Japan from 1868 to the present. The first section examines teacher education in Japan from 1868 to 1945, covering the development of normal schools; the Tokyo Normal School, Japan's first modern teacher education institute, founded in 1872; conservative reaction during the 1880s and the…

  13. Legislative Basis of Pedagogical Education in Japan

    ERIC Educational Resources Information Center

    Kuchai, Tetiana

    2014-01-01

    Legal framework policy of Japan in the field of education has been analyzed. The problem of influence of legislative materials on the development of education in Japan, its legislative support has been considered. It has been defined that directive materials affect the development of education system in Japan. Legislation policy of the country is…

  14. 75 FR 38119 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty finding on polychloroprene rubber from Japan... antidumping duty finding on polychloroprene rubber from Japan would be likely to lead to continuation...

  15. The US Occupation and Japan's New Democracy

    ERIC Educational Resources Information Center

    Kumano, Ruriko

    2007-01-01

    During the US Occupation of Japan (1945-1952), a victorious America attempted to reform Japanese education by replacing Japan's tradition system of values with one that promoted American democratic values. The United States had considered the source of Japan's militarism to lie in the selfless loyalty and love of country that many older Japanese…

  16. Education and Youth Employment in Japan.

    ERIC Educational Resources Information Center

    Kato, Hidetoshi

    The education/employment situation of young people in Japan is examined as part of a project to broaden perspectives on social, educational, and employment issues in contemporary societies. Youth problems in Japan stem from the incredibly rapid industrialization and social change that have taken place in Japan since World War II. In spite of this…

  17. 69 FR 78474 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2004-12-30

    ... COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION... Japan. SUMMARY: The Commission hereby gives notice of the scheduling of a full review pursuant to... revocation of the antidumping duty order on polychloroprene rubber from Japan would be likely to lead...

  18. 59 FR- Unshu Oranges From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    1994-03-21

    ... Japan AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Final rule. SUMMARY: We are amending the regulations governing the importation and interstate movement of Unshu oranges from Japan by... pv. citri (Hasse) Dye. The strain of citrus canker that occurs in Japan infects the twigs,...

  19. 63 FR 41279 - Acrylic Sheet From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    1998-08-03

    ... COMMISSION Acrylic Sheet From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on acrylic sheet from Japan. SUMMARY: The... order on acrylic sheet from Japan would be likely to lead to continuation or recurrence of...

  20. 70 FR 8822 - Outboard Engines From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2005-02-23

    ... COMMISSION Outboard Engines From Japan Determination On the basis of the record \\1\\ developed in the subject... the United States is not materially retarded, by reason of imports from Japan of outboard engines and... notification of a preliminary determination by Commerce that imports of outboard engines from Japan were...