29 research outputs found

    Discovery of Triassic microfaunas at Mae-Sot, NW Thailand (Preliminary report)

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    The Middle and Late Triassic radiolarian faunas were extracted from a vitric tuff rich laminated bedded-chert in the Mae-Sot and Umphang areas of NW Thailand. The radiolarian faunas from the bedded-chert succession are characterized by Triassocampe postdeweveri (Early Ladinian), Pachus multinodosus (Early Norian), Sarla natividadensis (Middle Norian) and Canoptum rhaeticum (Norian-Rhaetian), individually. The Triassic chert-sequence is overlain by the ‘Jurassic base-conglomerate’, an ill-sorted breccia in a reddish-silt matrix. The limestone and chert clasts in the conglomerate yield Early - Late Triassic conodonts and Middle - Late Triassic radiolarians, respectively. Chert clasts in the conglomerate yield among others Norian - Rhaetian radiolarians like Pachus multinodosus and Canoptum rhaeticum, while Early - Late Triassic conodonts as Platyvillosus costatus, Cratognathodus cf. cuspidatus, Metapolygnathus polygnathiformis, M. carpathicus, Ancyrogondolella quadrata and A. spatulata are found in limestone clasts. The silici-pelagic origin of the clasts suggests the presence of an ocean before the end Triassic orogeny along the Mae Sariang Zone that amalgamated the parts of the Shan-Thai block. This first finding of Late Triassic (Norian - Rhaetian) radiolarians from bedded-cherts, next to the Middle Triassic and older radiolarian faunas, adds another element to the reconstruction of the sequence now comprised in the Mae Sariang Zone, W of the Nan-Uttaradit Suture. The occurrence of Triassic limestone, as that of the Chaiburi Formation in the Phatthalung area of the Mae Sariang Zone or the Kodiang Limestone in the ‘Western zones’, may elucidate the question about the provenance of the Triassic conodont-bearing limestone clasts in the Jurassic base-conglomerate that seals the Mae-Sariang Zone. The newly dated Triassic sequence is further sealed by the continental-shelf deposits of the Toarcian - early Bajocian Hua Fai Group

    Application of Single Prolonged Stress Induces Post-traumatic Stress Disorder-like Characteristics in Mice

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    We tried to clarify the applicability of a single prolonged stress (SPS) protocol as post-traumatic stress disorder (PTSD) model in mice. To investigate PTSD pathophysiology, we conducted hypothalamo-pituitary-adrenal (HPA) negative feedback testing at 1, 4, 8 and 12 weeks after the SPS by administrating a dexamethasone (DEX) suppression test. The SPS induced over-suppression of the HPA system by DEX treatment at 8 and 12 weeks. To investigate PTSD-like behavioral characteristics, we subjected mice to testing in a light/dark box (to assess anxiety), a Y-maze (working memory), a cliff avoidance (visual cognition), and an open field (locomotor activity) at 1, 4, 8 and 12 weeks after the SPS. In the light/dark box test, the SPS-applied mice spent significantly less time in the light box at 8 or 12 weeks. In the cliff avoidance test, the SPS-applied mice spent significantly less time in the open area at 1 week. However, in both the Y-maze test and the open field test, SPS-applied mice tended toward slight decreases in a time-dependent manner until 12 weeks. Therefore, SPS-applied mice may thus be useful for assessing characteristics relevant to PTSD that coincide with changes in the HPA axis

    Expression of osteonectin in articular cartilage of osteoarthritic knees

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    The expression of osteonectin (ON) in osteoarthritic articular cartilage was investigated by enzyme immunohistochemistry and colloidal gold immunoelectron microscopy. A total of 96 specimens from 9 knees of 8 patients with osteoarthritis (OA) were examined. In OA cartilage, ON-positive cells varied in distribution and were not seen in all the specimens obtained from the same patient. However, in over half of the specimens (56 of 96), especially in the specimens of Mankin's grades from 4 to 9, which corresponds to relatively early stages of OA, ON was expressed in the cartilage above the calcified layer. On the other hand, ON was detected only in the calcified layer below the tidemark in normal articular cartilage. In addition, colloidal gold immunoelectron microscopy revealed ON in chondrocytes and matrix vesicles (MVs). These findings suggest that ON acts through MVs in the early stages of OA as a significant pathogenetic factor involved in intracartilage calcification, which is known to have a close relationship to the progression of OA.</p

    Marbles from Tokushima Prefecture, used in the National Diet Building : Part 1: locality and geological framework

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    The quarries of marbles for the construction of the National Diet Building (Nagata-cho, Chiyodaku, Tokyo) were identified in Tokushima Prefecture. The geological setting and microfossil age of the marbles were studied. Seven brands, "Akebono", "Kito-ishi ", "Hototogisu", "Kamo-sarasa", "Awayuki ", "Kotajima" and "Shin-awayuki" were used in the House of Councilors and the Central part of the building. The "Akebono", used for the wall along the Councilor's Second Stairway, is Silurian limestone from the Hiakari-yama lenticular body of the Kurosegawa Tectonic Zone in the Koyama-daira area (Kisawa Village). The "Kito-ishi" from the Misago-yama area (Kisawa Village), used for the fireplace in the reception room of the Vice-president of the House of Councilors, is the limestone and greenstone breccia intercalated in the Upper Carboniferous alternation of chert and pelagic limestone in the Permian accretion terrene (Masaki Belt of the Kurosegawa Terrane). The "Hototogisu", used for the well-ornamented entrance gate of the Emperor's room "Gokyujo", is the Upper Triassic dolimitic limestone in the Late Jurassic-earliest Cretaceous accretion mélange of the South Chichibu Terrane (Tsunomine Subbelt) from the Arida area (Asebi-cho, Anan City). The "Kamo-sarasa", used for the inside wall of the central entrance of the building, is the Upper Triassic limestone with some green reticulation in Late Jurassic-earliest Cretaceous accretion mélange of the South Chichibu Terrane (Tsunomine Subbelt) from the Oji area (Kuwano-cho, Anan City). The "Awayuki", used for the lower part of the wall along the square in front of the Emperor's room, and the lower part of the wall around the assembly hall of the House of Councilors, presumed to be a kind of "Kamo-sarasa", is proved to be the Upper Triassic Megalodon limestone with hexacoral-bearing dark limestone blocks in the accretion mélange of the South Chichibu Terrane (Tsunomine Subbelt) from the Kurogo area (Kamo-cho, Anan City). The "Kotajima", used for the lower part of the wall along the passage of the second floor, and the wall along the "Kisha Kaidan" stairway, is proved to be the Upper Triassic limestone with reticulation of black cleavages in Late Jurassic-earliest Cretaceous accretion mélange of the South Chichibu Terrane (Tsunomine Subbelt) from the Higashibun area (Tsunomine-cho, Anan City). The "Shin-awayuki", used for the mosaic on the floor of the Central Hall and the lower part of the wall along the passage of the southern central part of the first floor, is the Upper Carboniferous limestone in Jurassic accretion mélange of the South Chichibu Belt (Hosono Subbelt) from the Izeki area (Takarada-cho, Anan City)
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