Chandra Observations of A Galactic Supernova Remnant Vela Jr.: A New Sample of Thin Filaments Emitting Synchrotron X-Rays

A galactic supernova remnant (SNR) Vela Jr. (RX J0852.0$-$4622, G266.6$-$1.2) shows sharp filamentary structure on the north-western edge of the remnant in the hard X-ray band. The filaments are so smooth and located on the most outer side of the remnant. We measured the averaged scale width of the filaments ($w_u$ and $w_d$) with excellent spatial resolution of {\it Chandra}, which are in the order of the size of the point spread function of {\it Chandra} on the upstream side and 49.5 (36.0--88.8) arcsec on the downstream side, respectively. The spectra of the filaments are very hard and have no line-like structure, and were well reproduced with an absorbed power-law model with $\Gamma =$2.67 (2.55--2.77), or a {\tt SRCUT} model with $\nu_{rolloff}$ = 4.3 (3.4--5.3)$\times 10^{16}$ Hz under the assumption of $p=0.3$. These results imply that the hard X-rays are synchrotron radiation emitted by accelerated electrons, as mentioned previously. Using a correlation between a function ${\cal B} \equiv \nu_{rolloff}/w_d^2$ and the SNR age, we estimated the distance and the age of Vela Jr.: the estimated distance and age are 0.33 (0.26--0.50) kpc and 660 (420--1400) years, respectively. These results are consistent with previous reports, implying that ${\cal B}$--age relation may be a useful tool to estimate the distance and the age of synchrotron X-ray emitting SNRs.Comment: 19 pages, 8 figures, ApJ, in pres

キョウトフ フクチヤマシ ホウゲン ニ オケル テヤ ケイゴ ノ ウンヨウ ニ ツイテ

本稿では、京都府福知山市方言におけるテヤ敬語について、中年層女性の家族・親族内での会話を調査することで、以下のような運用ルールを提示した。A群：第三者待遇において（A）：話し手にとって話題の人物が家族でない場合はテヤ敬語を使用する。（A-2）：（A）が適用されないとき、話し手よりも話題の人物が年上の場合テヤ敬語を使用する。（A-3）：（A-2）が適用されないとき、基本的にテヤ敬語は使用しない。（A-3´）：（A-2）が適用されないとき、基本的にはテヤ敬語を使用しないが、話題の人物が聞き手よりも年上の場合はテヤ敬語を使用することがある。B群：対者待遇において（B）：話し手にとって聞き手（=話題の人物）が家族である場合はテヤ敬語を使用しない。（B-2）：（B）が適用されないとき、話し手よりも聞き手（=話題の人物）が年上の場合テヤ敬語を使用する。（B-3）：（B-2）が適用されないとき、聞き手（=話題の人物）が話し手と非常に親しい場合はテヤ敬語を使用しない。（B-4）：（B-3）が適用されないとき、テヤ敬語を使用する

Thermal and Non-thermal X-Rays from the LMC Super Bubble 30 Dor C

We report on the discovery of thermal and non-thermal X-rays from the shells of the super bubble (SB) 30 Dor C in the Large Magellanic Cloud (LMC). The X-ray morphology is a nearly circular shell with a radius of about 40 pc, which is bright on the northern and western sides. The spectra of the shells are different from region to region. The southern shell shows clear emission lines, and is well fitted with a model of a thin-thermal plasma (kT = 0.21keV) in non-equilibrium ionization (NEI) plus a power-law component. This thermal plasma is located inside of the H alpha emission, which is the outer edge of the shell of the SB. The northern and western sides of the SB are dim in H alpha emission, but are bright in non-thermal (power-law) X-rays with a photon index of 2.1-2.9. The non-thermal X-ray shell traces the outer boundary of the radio shell. These features of thin-thermal and non-thermal X-rays are similar to those of SN 1006, a prototype of synchrotron X-ray shell, but the non-thermal component of 30 Dor C is about ten-times brighter than that of SN 1006. 30 Dor C is the first candidate of an extragalactic SB, in which energetic electrons are accelerating in the shell. The age is much older than that of SN 1006, and hence the particle acceleration time in this SB may be longer than those in normal shell-like SNRs. We found point-like sources associated with some of tight star clusters. The X-ray luminosity and spectrum are consistent with those of young clusters of massive stars. Point-like sources with non-thermal spectra are also found in the SB. These may be background objects (AGNs) or stellar remnants (neutron stars or black holes).Comment: 11 pages, 6 figures, Accepted for publication in ApJ, the paper with full resolution images in http://www-cr.scphys.kyoto-u.ac.jp/member/bamba/Paper/30DorC.pd

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

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

「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

Association of <it>Bordetella </it>dermonecrotic toxin with the extracellular matrix

Abstract Background Bordetella dermonecrotic toxin (DNT) causes the turbinate atrophy in swine atrophic rhinitis, caused by a Bordetella bronchiseptica infection of pigs, by inhibiting osteoblastic differentiation. The toxin is not actively secreted from the bacteria, and is presumed to be present in only small amounts in infected areas. How such small amounts can affect target tissues is unknown. Results Fluorescence microscopy revealed that DNT associated with a fibrillar structure developed on cultured cells. A cellular component cross-linked with DNT conjugated with a cross-linker was identified as fibronectin by mass spectrometry. Colocalization of the fibronectin network on the cells with DNT was also observed by fluorescence microscope. Several lines of evidence suggested that DNT interacts with fibronectin not directly, but through another cellular component that remains to be identified. The colocalization was observed in not only DNT-sensitive cells but also insensitive cells, indicating that the fibronectin network neither serves as a receptor for the toxin nor is involved in the intoxicating procedures. The fibronectin network-associated toxin was easily liberated when the concentration of toxin in the local environment decreased, and was still active. Conclusions Components in the extracellular matrix are known to regulate activities of various growth factors by binding and liberating them in response to alterations in the extracellular environment. Similarly, the fibronectin-based extracellular matrix may function as a temporary storage system for DNT, enabling small amounts of the toxin to efficiently affect target tissues or cells.</p