1,407 research outputs found

    List of microplankton in Uranouchi Inlet, Kochi, Japan during the summer of 1997

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    Ninety-nine species of microplankton excluding crustaceans are listed from Uranouchi Inlet, Kochi, Japan, during the summer of 1997. The list comprises 33 new records from Uranouchi Inlet

    Scandium 45 in meteoritic irons

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    This report presents the results of determinations of cosmogenic ^Sc and light noble gases in iron meteorites. Sc and REE were simultaneously determined using radiochemical neutron activation method. This method is sensitive enough for detection of as little as lower than 10^gSc/g, compared to the level of cosmic ray effects in irons which are usually in the range of 10^-10^gSc/g. The lowest concentration found in irons was 2×10^gSc/g in the Campo del Cielo and similar contents were observed in the Gibeon, DRP-78008 (and Brenham-metal). Even at these low levels, Sc seems mostly attributable to cosmic ray production. The Sc content in irons is best compared with cosmogenic ^4He. The ratio of Sc to ^4He, approximately 1×10^gSc/1×10^cc ^4He, or an average atomic ratio of 1 : 19±3,was observed independent of shielding. Technical aspects of metal phase separation from ordinary chondrites were studied. In one Peace River metal sample, 0.9 ppbSc was found. This number corresponds to 0.01% of the stone phase in the metal. This level of contamination seems still higher than the cosmogenic level of 0.2 ppbSc expected in the metal phase of this meteorite

    Acanthamoeba containing endosymbiotic chlamydia isolated from hospital environments and its potential role in inflammatory exacerbation

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    Background: Environmental chlamydiae belonging to the Parachlamydiaceae are obligate intracellular bacteria that infect Acanthamoeba, a free-living amoeba, and are a risk for hospital-acquired pneumonia. However, whether amoebae harboring environmental chlamydiae actually survive in hospital environments is unknown. We therefore isolated living amoebae with symbiotic chlamydiae from hospital environments. Results: One hundred smear samples were collected from Hokkaido University Hospital, Sapporo, Japan; 50 in winter (February to March, 2012) and 50 in summer (August, 2012), and used for the study. Acanthamoebae were isolated from the smear samples, and endosymbiotic chlamydial traits were assessed by infectivity, cytokine induction, and draft genomic analysis. From these, 23 amoebae were enriched on agar plates spread with heatkilled Escherichia coli. Amoeba prevalence was greater in the summer-collected samples (15/30, 50%) than those of the winter season (8/30, 26.7%), possibly indicating a seasonal variation (p = 0.096). Morphological assessment of cysts revealed 21 amoebae (21/23, 91%) to be Acanthamoeba, and cultures in PYG medium were established for 11 of these amoebae. Three amoebae contained environmental chlamydiae; however, only one amoeba (Acanthamoeba T4) with an environmental chlamydia (Protochlamydia W-9) was shown the infectious ability to Acanthamoeba C3 (reference amoebae). While Protochlamydia W-9 could infect C3 amoeba, it failed to replicate in immortal human epithelial, although exposure of HEp-2 cells to living bacteria induced the proinflammatory cytokine, IL-8. Comparative genome analysis with KEGG revealed similar genomic features compared with other Protochlamydia genomes (UWE25 and R18), except for a lack of genes encoding the type IV secretion system. Interestingly, resistance genes associated with several antibiotics and toxic compounds were dentified. Conclusion: These findings are the first demonstration of the distribution in a hospital of a living Acanthamoeba carrying an endosymbiotic chlamydial pathogen

    ON A HOMOLOGY OF FOLIATIONS DEFINED BY NON-SINGULAR MORSE-SMALE FLOWS

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    We propose a denition of a homology of a one-dimensional oriented foliation dened by a non-singular Morse-Smale flow. We also show the calculation of the homology of such a foliation which is naturally associated with a Seifert bration.departmental bulletin pape

    On a homology of foliations defined by non-singular Morse-Smale flows

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    We propose a definition of a homology of a one-dimensional foliation defined by a non-singular Morse-Smale flow. We also show the calculation of the homology of such a foliation which is naturally associated with Seifert fibration

    Physics and Applications of Laser Diode Chaos

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    An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

    Turnover of Focal Adhesions and Cancer Cell Migration

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    Cells are usually surrounded by the extracellular matrix (ECM), and adhesion of the cells to the ECM is a key step in their migration through tissues. Integrins are important receptors for the ECM and form structures called focal adhesions (FAs). Formation and disassembly of FAs are regulated dynamically during cell migration. Adhesion to the ECM has been studied mainly using cells cultured on an ECM-coated substratum, where the rate of cell migration is determined by the turnover of FAs. However, the molecular events underlying the disassembly of FAs are less well understood. We have recently identified both a new regulator of this disassembly process and its interaction partners. Here, we summarize our understanding of FA disassembly by focusing on the proteins implicated in this process

    Stable carbon and oxygen isotope signatures of mantle-derived calcite in Aitutaki lherzolite xenolith: Implications for organic carbon cycle in the oceanic mantle

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    海洋マントルの有機炭素検出 --南太平洋アイツタキ島マントル捕獲岩からのアプローチ-- .京都大学プレスリリース. 2024-08-07.Carbon isotope data is desired to be increased to promote the understanding of carbon cycle throughout in the Earth. Diamond is a key carbonaceous tool to study deep carbon cycle, but most diamond occurrences are limited from kimberlite pipes in the continental region. Recently, micron-sized diamonds have been discovered from the oceanic region and investigated to understand deep carbon cycle in the oceanic mantle. However, some fundamental cautions have been issued on the oceanic diamonds because some of them could be of artificial origin. Hence, alternative oceanic mantle-derived carbonaceous material is needed to increase oceanic carbon isotope data. We report micron-sized calcite vein in a lherzolite xenolith hosted by enriched mantle I (EM1)-type olivine nephelinite from Aitutaki Island, Cook Islands in the southern Pacific. With employing various techniques to determine carbon and oxygen isotope compositions from sub-micrograms of calcite, we demonstrate that carbonaceous fluid originated from EM1-type mantle source exhibited organic carbon signature based on its light carbon isotope composition along with petrographic characteristics of the calcite vein. The oceanic mantle hosts organic carbon in places due to the recycling of surface materials

    Comparative Study of 5-Day and 10-Day Cefditoren Pivoxil Treatments for Recurrent Group A β-Hemolytic Streptococcus pharyngitis in Children

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    Efficacy of short-course therapy with cephalosporins for treatment of group A β-hemolytic streptococcus (GABHS) pharyngitis is still controversial. Subjects were 226 children with a history of at least one episode of GABHS pharyngitis. Recurrence within the follow-up period (3 weeks after initiation of therapy) occurred in 7 of the 77 children in the 5-day treatment group and in 1 of the 149 children in the 10-day treatment group; the incidence of recurrence being significantly higher in the 5-day treatment group. Bacteriologic treatment failure (GABHS isolation without overt pharyngitis) at follow-up culture was observed in 7 of the 77 children in the 5-day treatment group and 17 of the 149 children in the 10-day treatment group. There was no statistical difference between the two groups. A 5-day course of oral cephalosporins is not always recommended for treatment of GABHS pharyngitis in children who have repeated episodes of pharyngitis
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