229 research outputs found

    Sakurajima-Satsuma (Sz-S) and Noike-Yumugi (N-Ym) tephras: new tephrochronological marker beds for the last deglaciation, southern Kyushu, Japan

    Get PDF
    Two prominent tephras, Sakurajima-Satsuma (Sz-S) erupted from Sakurajima volcano and Noike-Yumugi (N-Ym) erupted from Kuchierabujima Island, provide new key marker beds for dating and synchronizing palaeoenvironmental and archaeological records in the last deglaciation in southern Japan. These tephras were identified on the basis of glass major-element compositions in two distal areas, a marine core (IMAGES MD98-2195) in the northern part of the East China Sea and on the central part of Tanegashima Island, and related their stratigraphic positions to the marine oxygen isotope-based chronology. In MD98-2195, Sz-S, 0.8 cm in thickness at 9.12 m depth and N-Ym, 3 cm in thickness at 9.30 m depth, are both white, vitric, ash-grade tephras. On Tanegashima Island, Sz-S, 10 cm in thickness and N-Ym, 3 cm in thickness, are stratigraphically constrained by well-characterised marker tephras Kikai-Akahoya (7,300 cal BP) and Aira-Tn (29,000 cal BP). Sz-S is rhyolitic and homogeneous on the basis of glass major-element compositions assayed by electron microprobe. Pumiceous glass shards predominant in distal Sz-S tephra indicate that it derived from pumice fall units that correspond to pumiceous and phreatomagmatic fine ash units constituting proximal Sz-S tephra. N-Ym is rhyolitic and glass major-element analyses reveal compositional diversity between units, suggesting that the lower and middle tephra units dispersed to the east, whereas the upper unit was dispersed north to north-west from the vent. Stratigraphically, Sz-S occurs at around the start of the late-glacial reversal (cooling) in oxygen isotope records of MD98-2195, corresponding to the end of GI-1 and the start of GS-1 in the ice-core events of NGRIP (GICC05), consistent with a terrestrial age of ˜12,800 cal BP. Based on the oxygen isotope stratigraphy, the tephra identified in the core as N-Ym at 9.30 m depth is close to the end of Greenland GI-1 and hence has an age of ˜13,000 cal BP, but on Kuchierabujima Island it has an age based on ¹⁴C assay of charcoal of c. 14,900 cal BP. Although this age discrepancy (14.9 vs 13.0 cal ka) needs resolution, the occurrence in core MD98-2195 of N-Ym shows that it is more widespread than hitherto demonstrated. The widespread distributions and key stratigraphic positions for the two marker tephras indicate that they are thus critical isochrons for precise correlation of palaeoenvironmental changes and prehistoric cultural events during the last deglaciation in southern Kyushu, and for relating such changes and events to the ice-core chronology via the marine oxygen isotope chronostratigraphy

    FACTOR ANALYSIS OF SPRINT PHASES ON THE SPEED CURVE OF THE 100M DASH

    Get PDF
    Previous studies have indicated that the speed curve of the 100m dash consists of some distinct phases which can be used to analyze an athlete's performance. The purpose of this study was to introduce a method using a portable computer as a device for the measurement of sprint time and the illustration of the speed curve, and to clarify a simple model of sprint phases on the factor structure. Based on the data of 133 participants, principal factor solution was given to the correlation matrix, and varimax rotation was applied to simplify the factorial structure of sprint phases. Finally, two factors were extracted and interpreted. It is suggested that this method is useful for measurement and evaluation in the 100m dash, and that a simple model of sprint phases may be explained by these two factors. These findings are important in predicting the ability of 100m sprinters and in considering coaching methods in terms of technique, training, strategy, etc

    Helicobacter pylori Exploits Host Membrane Phosphatidylserine for Delivery, Localization, and Pathophysiological Action of the CagA Oncoprotein

    Get PDF
    SummaryWhen delivered into gastric epithelial cells via type IV secretion, Helicobacter pylori CagA perturbs host cell signaling and thereby promotes gastric carcinogenesis. However, the mechanisms of CagA delivery, localization, and action remain poorly understood. We show that direct contact of H. pylori with epithelial cells induces externalization of the inner leaflet enriched host phospholipid, phosphatidylserine, to the outer leaflet of the host plasma membrane. CagA, which is exposed on the bacterial surface via type IV secretion, interacts with the externalized phosphatidylserine to initiate its entry into cells. CagA delivery also requires energy-dependent host cell processes distinct from known endocytic pathways. Within polarized epithelial cells, CagA is tethered to the inner leaflet of the plasma membrane through interaction with phosphatidylserine and binds the polarity-regulating host kinase PAR1/MARK to induce junctional and polarity defects. Thus, host membrane phosphatidylserine plays a key role in the delivery, localization, and pathophysiological action of CagA

    Antioxidant Activity of β-Glucan

    Get PDF
    β-Glucans extracted from barley, which mainly contains β-(1,3-1,4)-D-glucan, are used extensively as supplements and food additives due to their wide biologic activities, including a reduction in blood lipid level. In this study, the antioxidant activity of β-glucan was examined to assess potential new benefits associated with β-glucan, because oxidative stress is considered one of the primary causal factors for various diseases and aging. β-Glucan extracted from barley was found to possess significant antioxidant activity. The amount of antioxidant activity was influenced by different physiologic properties (e.g., structure and molecular size) of β-glucan, which varied depending on the source and extraction method used. The antioxidant activity of β-glucan was significantly higher than that of various polymers that are used as food additives. These results indicate that β-glucan has promise as a polymeric excipient for supplement and food additive with antioxidant and other benefits, which may contribute to enhancing health and beauty

    Natural history of Upshaw-Schulman syndrome based on ADAMTS13 gene analysis in Japan

    Get PDF
    Upshaw–Schulman syndrome (USS) is an extremely rare hereditary deficiency of ADAMTS13 activity, termed congenital TTP. The clinical signs are usually mild during childhood, often with isolated thrombocytopenia. But their symptoms become more evident when patients have infections or get pregnant. We identified 43 USS-patients in Japan, who ranged in age from early childhood to 79 years of age. Analysing the natural history of these USS patients based on ADAMTS13 gene mutations may help characterise their clinical phenotypes. Severe neonatal jaundice that requires exchange blood transfusion, a hallmark of USS, was found in 18 of 43 patients (42%). During childhood, 25 of 43 patients were correctly diagnosed with USS without gender disparity. These 25 patients were categorised as having ‘the early-onset phenotype’. Between 15 and 45 years of age, 15 were correctly diagnosed, and, interestingly, they were all female. The remaining three patients were male and were diagnosed when they were older than 45 years of age, suggesting that they were ‘the late-onset phenotype’. Two of these three males developed sudden overt TTP when they were 55 and 63 years old, respectively. These two men had two different homozygous ADAMTS13 gene mutations, p.R193W/p.R193W and p.C1024R/p.C1024R, respectively. Both of which were not discovered in the US or Western countries. In vitro expression studies showed that these two proteins were consistently secreted into the culture medium but to a lesser extent and with reduced activity compared to the wild-type protein. Our results indicate that ‘the late-onset phenotype’ of USS is formed with ethnic specificity.・The definitive version is available at " http://dx.doi.org/10.1111/j.1538-7836.2011.04341.x "・State of the Art 2011 : XXIII Congress of the International Society on Thrombosis and Haemostasis Invited Reviewhttp://dx.doi.org/10.1111/j.1538-7836.2011.04341.

    Imparting CO₂ reduction selectivity to ZnGa₂O₄ photocatalysts by crystallization from hetero nano assembly of amorphous-like metal hydroxides

    Get PDF
    Imparting an enhanced CO₂ reduction selectivity to ZnGa₂O₄ photocatalysts has been demonstrated by controlled crystallization from interdispersed nanoparticles of zinc and gallium hydroxides. The hydroxide precursor in which Zn(II) and Ga(III) are homogeneously interdispersed was prepared through an epoxide-driven sol–gel reaction. ZnGa₂O₄ obtained by a heat-treatment exhibits a higher surface basicity and an enhanced affinity for CO₂ molecules than previously-reported standard ZnGa₂O₄. The enhanced affinity for CO₂ molecules of the resultant ZnGa₂O₄ leads to highly-selective CO evolution in CO₂ photo-reduction with H₂O reductants. The present scheme is promising to achieve desirable surface chemistry on metal oxide photocatalysts

    Peritoneal keratin granuloma associated with endometrioid adenocarcinoma of the uterine corpus

    Get PDF
    We present a 69-year-old woman with a chief complaint of postmenopausal bleeding. She was diagnosed as having an endometrioid adenocarcinoma by biopsy, and underwent a total abdominal hysterectomy. At the time of surgery, granulation tissue-like nodules were found on the peritoneal serosa of the uterus. In the intraoperative cytology of peritoneal washing, atypical cells were noted. The intraoperative frozen section of the peritoneal nodule revealed granulation tissue with proliferating mesothelial cells. Microscopic examination of the permanent section showed keratin granulomas without viable adenocarcinoma cells on the serosal surface of the ovaries, fallopian tubes and broad ligaments. Postoperative chemotherapy was administered. She has been alive with no evidence of recurrence for 6 months postoperatively. It should be noted that the prognosis of cases in peritoneal keratin granuloma without viable cancer cells is favorable, and that the histological examination is essential for its diagnosis

    Acceptedfor publicationMay 19

    Get PDF
    ABSTRACT We and other investigators obtained evidence that platelets stimulate endothelin-i (ET-i) production at both message and protein levels in vascular endothelial cells (EC5),and that plate let-derived transforming growth factor-f31 (TGF-j3i) is respon sible for this stimulation. In the present study, we examined the effects of acidification or heat treatment, known to activate latent TGF-f31, on the platelet supernatant-induced Er-i pro duction in cultured porcine aortic ECs. Supematant of platelets (6.0 x 1O@ platelets/mI) aggregated by adenosine diphosphate contained large amounts of TGF-pi, but were almost in a latent form, and the proportion of active TGF-j31 in the supematant was increased markedly in the case of acidification or heat treatment. These treatments also significantly potentiated the supematant-induced stimulation of prepro Er-i mRNA expres sion and the Er-i release in ECs. Purified TGF-@i also en hanced Er-i release, dose-dependently, but the enhancement declined at the higher concentrations. Thus, powerful stimula tion of Er-i production by platelet supematant after acidifica tion or heat treatment cannot be explained only by increments in active TGF-131. The supematant-induced stimulation of Er-i synthesis was significantly inhibited by concomitant treatment of TGF-@i neutralizing antibody, but this inhibition was incom plete even at a concentration that abolished TGF-31 -induced maximal stimulation. These resutts suggest that platelet-induced stimulation and subsequent acidification and heat treatment induced potentiation on endothelial Er-i production depend closely on release and activation of TGF-@i derived from plate lets. However, when TGF-fii concentration is increased, this peptide may further stimulate Er-i production, probably through interactions with other platelet-derived substances

    Reconstruction of submarine eruption processes from FTIR volatile analysis of marine tephra: Example of Oomurodashi volcano, Japan

    Get PDF
    Tephra layers in marine sediments are widely used to correlate and date paleoclimate and paleoceanography records, and to determine spatiotemporal changes in magmatic evolution and eruption frequency. Dissolved matrix glass H2O contents of marine tephra could potentially inform understanding of eruption processes but are rarely used due to the issue of secondary hydration after deposition. Recent advancements in Fourier transform infrared spectroscopy (FTIR) volatile analysis have enabled reconstruction of original water contents of hydrated volcanic glasses. These new Fourier transform infrared spectroscopy analysis methods offer a new way to investigate tephra stored in marine sedimentary archives. We present a case study of the Od-1 tephra layer in marine sedimentary core C9010E, drilled ∼40 km south of the Boso peninsula in Japan. This tephra was erupted by the shallow silicic submarine Oomurodashi volcano in the northern Izu-Bonin arc at ∼13.5 ka. Our Fourier transform infrared spectroscopy volatile data show it has been affected by secondary hydration, with the extent of hydration controlled by grain size and porosity characteristics. Numerical modelling of low temperature hydration suggests Fourier transform infrared spectroscopy data offer an additional method for estimating eruption ages of marine tephra. OH contents, unaltered by low temperature secondary hydration, record low ambient eruptive pressures for all grain sizes and tephra types i.e., blocky and dense or pumiceous. Consideration of hydrostatic pressure gradients and past sea level at Oomurodashi shows that the majority of tephra volatile data cannot be explained by quench within a submarine eruption plume. Instead, OH contents record quench fragmentation within the shallow submarine edifice. Physical characteristics of the tephra are consistent with the formation of these tephra by explosive phreatomagmatic eruption processes. Together these OH data and tephra characteristics support the interpretation that the Od-1 tephra layer was formed by the same shallow phreatomagmatic eruption that formed the existing Oomuro Hole crater and that produced subaerial tephra deposits on nearby Izu-Oshima and Toshima islands. This study demonstrates the crucial contribution that imaging Fourier transform infrared spectroscopy analysis can make to the interpretation of degassing and eruption processes of volcanic glasses, particularly vesicular pyroclasts and/or glasses affected by secondary hydration, adding an important new dimension to marine tephra research
    corecore