454 research outputs found

    Jomon Reflections

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    A fully illustrated introduction to the archaeology of the Jomon period in Japan, this book explores the complex relationships between Jomon people and their rich natural environment. From the end of the last Ice Age 12,000 years ago to the appearance of rice agriculture around 400 BC, Jomon people subsisted by hunting, fishing and gathering; but abundant and predictable sources of wild food enabled Jomon people to live in large, relatively permanent settlements, and to develop an elaborate material culture. This book explores thematic issues in Jomon archaeology: the appearance of sedentism in the Japanese archipelago and the nature of Jomon settlements; the invention of pottery and the development and meaning of regional pottery styles; social and spiritual life; as well as the astronomical significance of causeway monuments and the conceptualisation of landscape in the Jomon period. These ideas are considered in the light of current work in the European Mesolithic and Neolithic, setting Jomon archaeology within a global context. The book draws extensively on new archaeological information from various parts of Japan, including the sites of Sannai Maruyama, Isedotai, Komankino among others. Extensive color illustrations provide a vivid demonstration of Jomon ideology and creativity

    In situ study of oxidation states of platinum nanoparticles on a polymer electrolyte fuel cell electrode by near ambient pressure hard X-ray photoelectron spectroscopy

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    We performed in situ hard X-ray photoelectron spectroscopy (HAXPES) measurements of the electronic states of platinum nanoparticles on the cathode electrocatalyst of a polymer electrolyte fuel cell (PEFC) using a near ambient pressure (NAP) HAXPES instrument having an 8 keV excitation source. We successfully observed in situ NAP-HAXPES spectra of the Pt/C cathode catalysts of PEFCs under working conditions involving water, not only for the Pt 3d states with large photoionization cross-sections in the hard X-ray regime but also for the Pt 4f states and the valence band with small photoionization cross-sections. Thus, this setup allowed in situ observation of a variety of hard PEFC systems under operating conditions. The Pt 4f spectra of the Pt/C electrocatalysts in PEFCs clearly showed peaks originating from oxidized Pt(II) at 1.4 V, which unambiguously shows that Pt(IV) species do not exist on the Pt nanoparticles even at such large positive voltages. The water oxidation reaction might take place at that potential (the standard potential of 1.23 V versus a standard hydrogen electrode) but such a reaction should not lead to a buildup of detectable Pt(IV) species. The voltage-dependent NAP-HAXPES Pt 3d spectra revealed different behaviors with increasing voltage (0.6 → 1.0 V) compared with decreasing voltage (1.0 → 0.6 V), showing a clear hysteresis. Moreover, quantitative peak-fitting analysis showed that the fraction of non-metallic Pt species matched the ratio of the surface to total Pt atoms in the nanoparticles, which suggests that Pt oxidation only takes place at the surface of the Pt nanoparticles on the PEFC cathode, and the inner Pt atoms do not participate in the reaction. In the valence band spectra, the density of electronic states near the Fermi edge reduces with decreasing particle size, indicating an increase in the electrocatalytic activity. Additionally, a change in the valence band structure due to the oxidation of platinum atoms was also observed at large positive voltages. The developed apparatus is a valuable in situ tool for the investigation of the electronic states of PEFC electrocatalysts under working conditions

    Left-right asymmetry in the level of active Nodal protein produced in the node is translated into left-right asymmetry in the lateral plate of mouse embryos

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    Left-right (L-R) asymmetry in the mouse embryo is generated in the node and is dependent on cilia-driven fluid flow, but how the initial asymmetry is transmitted from the node to the lateral plate has remained unknown. We have now identified a transcriptional enhancer (ANE) in the human LEFTY1 gene that exhibits marked L>R asymmetric activity in perinodal cells of the mouse embryo. Dissection of ANE revealed that it is activated in the perinodal cells on the left side by Nodal signaling, suggesting that Nodal activity in the node is asymmetric at a time when Nodal expression is symmetric. Phosphorylated Smad2/3 (pSmad2) indeed manifested an L-R asymmetric distribution at the node, being detected in perinodal cells preferentially on the left side. This asymmetry in pSmad2 distribution was found to be generated not by unidirectional transport of Nodal but rather as a result of LR distribution of active Nodal in the node is translated into the asymmetry in LPM. (C) 2011 Elsevier Inc. All rights reserved.CREST (Core Research for Evolutional Science and Technology) of the Japan Science and Technology Corporation; Ministry of Education, Culture, Sports, Science, and Technology of Japan; Japan Society for the Promotion of Scienceinfo:eu-repo/semantics/publishedVersio

    Probability assessment of flood and sediment disasters in Japan using the Total Runoff-Integrating Pathways model

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    AbstractTo address many of the problems faced in hydrological engineering planning, design, and management, a detailed knowledge of flood event characteristics, such as flood peak, volume, and duration is required. Flood frequency analysis often focuses on flood peak values and provides a limited assessment of flood events. To develop effective flood management and mitigation policies, estimation of the scale of potential disasters, incorporating the effects of social factors and climate conditions, is required along with quantitative measures of flood frequency. The Japanese flood risk index, the flood disaster occurrence probability (FDOP), was established based on both natural and social factors. It represents the expectation of damage in the case of a single flood occurrence, which is estimated by integrating a physical-based approach as a Total Runoff Integrating Pathways (TRIP) model with Gumbel distribution metrics. The resulting equations are used to predict potential flood damage based on gridded Japanese data for independent variables. This approach is novel in that it targets floods based on units of events instead of a long-term trend. Moreover, the FDOP can express relative potential flood risk while considering flood damage. The significance of the present study is that both the hazard parameters (which contribute directly to flood occurrence) and vulnerability parameters (which reflect conditions of the region where the flood occurred), including residential and social characteristics, were shown quantitatively to affect flood damage. This study examined the probability of flood disaster occurrence using the TRIP model for Japan (J-TRIP), a river routing scheme that provides a digital river network covering Japan. The analysis was based on floods from 1976 to 2004 associated with flood inundation and sediment disasters. Based on these results, we estimated the probability of flood damage officially reported for the whole region of Japan at a grid interval of 0.1 degrees. The relationship between the magnitude of the rain hazard expressed as the probability of exceedance and the probability of flood damage officially reported was expressed as an exponential function by equalizing the whole region of Japan based on excess probability. Moreover, the probabilities of flood damage occurrence according to social factors and changes in climate conditions were also examined. The probability of flood damage occurrence is high, especially in regions of high population density. The results also showed the effect of the dam maintenance ratio on extreme flooding and flood damage frequency. The probability of flood damage occurrence was expected to increase during extreme weather events at the end of this century. These findings provide a sound foundation for use in catchment water resources management

    Liganded Thyroid Hormone Receptor Inhibits Phorbol 12-O-Tetradecanoate-13-Acetate-Induced Enhancer Activity via Firefly Luciferase cDNA

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    Thyroid hormone receptor (TR) belongs to the nuclear hormone receptor (NHR) superfamily and regulates the transcription of its target genes in a thyroid hormone (T3)-dependent manner. While the detail of transcriptional activation by T3 (positive regulation) has been clarified, the mechanism of T3-dependent repression (negative regulation) remains to be determined. In addition to naturally occurring negative regulations typically found for the thyrotropin β gene, T3-bound TR (T3/TR) is known to cause artificial negative regulation in reporter assays with cultured cells. For example, T3/TR inhibits the transcriptional activity of the reporter plasmids harboring AP-1 site derived from pUC/pBR322-related plasmid (pUC/AP-1). Artificial negative regulation has also been suggested in the reporter assay with firefly luciferase (FFL) gene. However, identification of the DNA sequence of the FFL gene using deletion analysis was not performed because negative regulation was evaluated by measuring the enzymatic activity of FFL protein. Thus, there remains the possibility that the inhibition by T3 is mediated via a DNA sequence other than FFL cDNA, for instance, pUC/AP-1 site in plasmid backbone. To investigate the function of FFL cDNA as a transcriptional regulatory sequence, we generated pBL-FFL-CAT5 by ligating FFL cDNA in the 5' upstream region to heterologous thymidine kinase promoter in pBL-CAT5, a chloramphenicol acetyl transferase (CAT)-based reporter gene, which lacks pUC/AP-1 site. In kidney-derived CV1 and choriocarcinoma-derived JEG3 cells, pBL-FFL-CAT5, but not pBL-CAT5, was strongly activated by a protein kinase C activator, phorbol 12-O-tetradecanoate-13-acetate (TPA). TPA-induced activity of pBL-FFL-CAT5 was negatively regulated by T3/TR. Mutation of nt. 626/640 in FFL cDNA attenuated the TPA-induced activation and concomitantly abolished the T3-dependent repression. Our data demonstrate that FFL cDNA sequence mediates the TPA-induced transcriptional activity, which is inhibited by T3/TR

    Prevalence and Risk Factors for Hepatitis C Virus Infection in Mongolian Children: Findings From a Nationwide Survey

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    Although the hepatitis C virus (HCV) infection is one of the major causes of chronic hepatitis and hepatocellular carcinoma (HCC) in Mongolia, its prevalence among children and routes of transmission are largely unknown. The aim of the study was to determine the prevalence of anti-HCV antibodies and the possible risk factors for transmission among school children using representative national data. A nationwide cross-sectional survey among elementary school children was conducted in four main geographical regions and the metropolitan area of Mongolia, through multistage, stratified, random cluster sampling. Serum samples from 1,145 children (response rate, 93%; 592 boys and 553 girls; age range, 7-12 years), which represented nearly 2% of the second grade population in Mongolia, were tested for HCV antibodies with a third-generation immunoradiometric assay (IRMA). Positive samples were further evaluated by a third-generation immunoblot assay (RIBA). A standardized questionnaire concerning the socio-demographic characteristics and potential risk factors was used. Overall, seven subjects were confirmed to be anti-HCV seropositive, giving a prevalence of 0.6% (95% CI: 0.15-1.0%). The prevalence of anti-HCV increased with age. In the multivariate logistic regression analysis, adjusted for age, sex, and residence, the history of dental manipulation (odds ratio [OR] ¼ 15.4; 95% CI: 1.4-164.8) and surgery (OR ¼ 8.3; 95% CI: 1.5-45.6) were associated independently with the presence of anti-HCV. These findings suggest that contaminated equipment used in the dental and surgical manipulations probably played a predominant role in HCV transmission among Mongolian children. Strict guidelines on disinfection and sterilization procedures of medical instruments have to be introduced and should be followed to improve the control of HCV infection in Mongolia

    Investigation of cathodic reaction in SOFCs and PCFCs by using patterned thin film model electrodes

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    In recent years, fuel cells operating at relatively high temperatures, such as solid oxide fuel cells (SOFCs) using an oxide ion conducting electrolyte and proton ceramics fuel cells (PCFCs) using an proton conducting electrolyte, attract attentions as high-efficient energy-conversion devices. For further enhancements of the performance and the durability of SCFCs and PCFCs, it is essential to understand the electrode reactions. In particular, the knowledge on the dominant reaction path in the electrodes would help us to optimize the material and the microstructure of the electrode. Please click Additional Files below to see the full abstract
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