109 research outputs found

    Triangle Cylinder Wake Analysis Based on Wavelet and POD Techniques

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    AbstractThe turbulent structure behind a two-dimensional symmetric triangle cylinder is measured by PIV experiment at Reynolds number of 14440. To reveal the possibly existed flow phenomena that buried in the mean flow, one dimensional orthogonal wavelet and POD analyses are employed to decompose the fluctuating velocity field into different wavelet components and modes. The features of reconstructed flow fields are analyzed in terms of fluctuating energy, time frequency distribution and length scale. It is found that the first two wavelet components and POD modes can give representations to the most energetic large scale structures, contributing about 77% and 73% to the total fluctuating energy respectively. Comparing with the first two wavelet components, the first two POD modes are more appropriate to represent the Karman like vortical structures. The time-frequency and length scale characteristics of wavelet components suggest that frequency behavior can reflect the spatial related length scale and the wavelet analysis can be used to extract turbulent structures of different scales

    Recent topics of infrared effective lattice QCD

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    Three topics concerning infrared effective lattice QCD are discussed. (1)Perfect lattice action of infrared SU(3) QCD and perfect operators for the static potential are analytically given when we assume two-point monopole interactions alone. The assumption seems to be justified from numerical analyses of pure SU(3) QCD in maximally abelian gauge. (2)Gauge invariance of monopole dominance can be proved theoretically if the gauge invariance of abelian dominance is proved. The gauge invariance of monopole condensation leads us to confinement of abelian neutral but color octet states after abelian projection. (3)A stochastic gauge fixing method is developed to study the gauge dependence of the Abelian projection, which interpolates between the maximally abelian (MA) gauge and no gauge fixing. Abelian dominance for the heavy quark potential holds even in the gauge which is far from Maximally Abelian one.Comment: LATTICE99(Poster),3 pages, LaTeX with 4 eps figure

    Long-term EEJ variations by using the improved EE-index

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    In 2008, International Center for Space Weather Science and Education, Kyushu University (ICSWSE) proposed the EE-index, which is an index to monitor the equatorial geomagnetic phenomena. EE-index has been improved with the development of the MAGnetic Data Acquisition System and the Circum-pan Pacific Magnetometer Network (MAGDAS/CPMN) and the enormous archive of MAGDAS/CPMN data over 10 years since the initial article. Using the improved EE-index, we examined the solar cycle variation of equatorial electrojet (EEJ) by the time series analysis for EUEL (one part of EE-index) at Ancon in Peru and the solar activity from September 18, 1998 to March 31, 2015. We found that the long-term variation of daily EEJ peak intensity has a trend similar to that of F10.7 (the solar activity). The power spectrum of the daily EEJ peak has clearly two dominant peaks throughout the analysis interval: 14.5 days and 180 days (semi-annual). The solar cycle variation of daily EEJ peak correlates well with that of F10.7 (the correlation coefficient 0.99). We conclude that the daily EEJ peak intensity is roughly determined as the summation of the long-period trend of the solar activity resulting from the solar cycle and day-to-day variations caused by various sources such as lunar tides, geometric effects, magnetospheric phenomena and atmospheric phenomena. This work presents the primary evidence for solar cycle variations of EEJ on the long-term study of the EE-index.2015 UN/Japan Workshop on Space Weather, 2-6 March 2015, Fukuoka, Japa

    Genomic characterization of biliary tract cancers identifies driver genes and predisposing mutations

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    Background & Aims Biliary tract cancers (BTCs) are clinically and pathologically heterogeneous and respond poorly to treatment. Genomic profiling can offer a clearer understanding of their carcinogenesis, classification and treatment strategy. We performed large-scale genome sequencing analyses on BTCs to investigate their somatic and germline driver events and characterize their genomic landscape. Methods We analyzed 412 BTC samples from Japanese and Italian populations, 107 by whole-exome sequencing (WES), 39 by whole-genome sequencing (WGS), and a further 266 samples by targeted sequencing. The subtypes were 136 intrahepatic cholangiocarcinomas (ICCs), 101 distal cholangiocarcinomas (DCCs), 109 peri-hilar type cholangiocarcinomas (PHCs), and 66 gallbladder or cystic duct cancers (GBCs/CDCs). We identified somatic alterations and searched for driver genes in BTCs, finding pathogenic germline variants of cancer-predisposing genes. We predicted cell-of-origin for BTCs by combining somatic mutation patterns and epigenetic features. Results We identified 32 significantly and commonly mutated genes including TP53 , KRAS , SMAD4 , NF1 , ARID1A , PBRM1 , and ATR , some of which negatively affected patient prognosis. A novel deletion of MUC17 at 7q22.1 affected patient prognosis. Cell-of-origin predictions using WGS and epigenetic features suggest hepatocyte-origin of hepatitis-related ICCs. Deleterious germline mutations of cancer-predisposing genes such as BRCA1 , BRCA2 , RAD51D , MLH1 , or MSH2 were detected in 11% (16/146) of BTC patients. Conclusions BTCs have distinct genetic features including somatic events and germline predisposition. These findings could be useful to establish treatment and diagnostic strategies for BTCs based on genetic information. Lay summary We here analyzed genomic features of 412 BTC samples from Japanese and Italian populations. A total of 32 significantly and commonly mutated genes were identified, some of which negatively affected patient prognosis, including a novel deletion of MUC17 at 7q22.1 . Cell-of-origin predictions using WGS and epigenetic features suggest hepatocyte-origin of hepatitis-related ICCs. Deleterious germline mutations of cancer-predisposing genes were detected in 11% of patients with BTC. BTCs have distinct genetic features including somatic events and germline predisposition

    Sequence-specific error profile of Illumina sequencers

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    We identified the sequence-specific starting positions of consecutive miscalls in the mapping of reads obtained from the Illumina Genome Analyser (GA). Detailed analysis of the miscall pattern indicated that the underlying mechanism involves sequence-specific interference of the base elongation process during sequencing. The two major sequence patterns that trigger this sequence-specific error (SSE) are: (i) inverted repeats and (ii) GGC sequences. We speculate that these sequences favor dephasing by inhibiting single-base elongation, by: (i) folding single-stranded DNA and (ii) altering enzyme preference. This phenomenon is a major cause of sequence coverage variability and of the unfavorable bias observed for population-targeted methods such as RNA-seq and ChIP-seq. Moreover, SSE is a potential cause of false single-nucleotide polymorphism (SNP) calls and also significantly hinders de novo assembly. This article highlights the importance of recognizing SSE and its underlying mechanisms in the hope of enhancing the potential usefulness of the Illumina sequencers

    Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection

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    新型コロナウイルス排出と粘膜抗体の関係を解明 --呼吸器ウイルスのヒト間伝播を制御・予防する第一歩--. 京都大学プレスリリース. 2023-12-25.Articles: Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection. 京都大学プレスリリース. 2023-12-25.Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics

    EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies

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    We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of 0.0150.195 Z0.015-0.195~Z_\odot and low stellar masses of 104108 M10^4-10^8~M_\odot in the local universe. We conduct deep optical integral-field spectroscopy (IFS) for the low-mass EMPGs with the medium high resolution (R=7500R=7500) grism of the 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate Hα\alpha emission of the EMPGs. Exploiting the resolution high enough for the low-mass galaxies, we derive gas dynamics with the Hα\alpha lines by the fitting of 3-dimensional disk models. We obtain an average maximum rotation velocity (vrotv_\mathrm{rot}) of 15±3 km s115\pm3~\mathrm{km~s^{-1}} and an average intrinsic velocity dispersion (σ0\sigma_0) of 27±10 km s127\pm10~\mathrm{km~s^{-1}} for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have vrot/σ0<1v_\mathrm{rot}/\sigma_0<1 suggesting dispersion dominated systems. There is a clear decreasing trend of vrot/σ0v_\mathrm{rot}/\sigma_0 with the decreasing stellar mass and metallicity. We derive the gas mass fraction (fgasf_\mathrm{gas}) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These vrot/σ0v_\mathrm{rot}/\sigma_0 and fgasf_\mathrm{gas} trends should be compared with young high-zz galaxies observed by the forthcoming JWST IFS programs to understand the physical origins of the EMPGs in the local universe.Comment: 18 pages, 9 figures, accepted for publication in Ap

    EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?

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    We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities (0.0160.098 Z0.016-0.098\ Z_{\odot}) and low stellar masses (104.7107.6M10^{4.7}-10^{7.6} M_{\odot}). Taking deep medium-high resolution (R7500R\sim7500) integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with Hα\alpha emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed Hα\alpha flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities (vrotv_{\rm rot}) of 5--23 km s1^{-1} smaller than the velocity dispersions (σ0\sigma_{0}) of 17--31 km s1^{-1}, indicating dispersion-dominated (vrot/σ0=0.290.80<1v_{\rm rot}/\sigma_{0}=0.29-0.80<1) systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of fgas0.91.0f_{\rm gas}\simeq 0.9-1.0. Comparing our results with other Hα\alpha kinematics studies, we find that vrot/σ0v_{\rm rot}/\sigma_{0} decreases and fgasf_{\rm gas} increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high-zz (z7z\sim 7) forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at z7z\sim 7.Comment: Submitted to ApJ; After revisio

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
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