Scope out multiband gravitational-wave observations of GW190521-like binary black holes with space gravitational wave antenna B-DECIGO

The gravitational wave event, GW190521 is the most massive binary black hole merger observed by ground-based gravitational wave observatories LIGO/Virgo to date. While the observed gravitational-wave signal is mainly in the merger and ringdown phases, the inspiral gravitational-wave signal of GW190521-like binary will be more visible by space-based detectors in the low-frequency band. In addition, the ringdown gravitational-wave signal will be more loud with the next generation (3G) of ground-based detectors in the high-frequency band, displaying a great potential of the multiband gravitational wave observations. In this paper, we explore the scientific potential of multiband observations of GW190521-like binaries with milli-Hz gravitational wave observatory: LISA, deci-Hz observatory: B-DECIGO, and (next generation of) hecto-Hz observatories: aLIGO and ET. In the case of quasicircular evolution, the triple-band observation by LISA, B-DECIGO and ET will provide parameter estimation errors of the masses and spin amplitudes of component black holes at the level of order 1% -- 10%. This would allow consistency tests of general relativity in the strong-field at an unparalleled precision, particularly with the "B-DECIGO + ET" observation. In the case of eccentric evolution, the multiband signal-to-noise ratio by "B-DECIGO + ET" observation would be larger than 100 for a five year observation prior to coalescence, even with high final eccentricities.Comment: 26 pages, 2 figures, accepted versio

Variation of Rumen Bacterial Diversity in Steers after the Beginning of Grazing

Holstein heifers before or after puberty often are herded on public pastures in Japan. The herbage intake and rumen fermentation of grazing heifers that are not adapted for fresh herbage decreases due to a change of feed from stall-fed dried forage to fresh herbage. This limits their performance during the first several weeks on pasture. Thus, the feeding program such as supplementation before and after the beginning of grazing is important. An increase in ammonia concentration and a decline in fibre degradation in the rumen of a heifer (both of which occur simultaneously with low herbage intake and rumen fermentation) would be caused by the reduced capacity of various bacteria to produce peptides and degrade fibre (Oshio and Tahata 1981). This suggests that variation in rumen bacterial diversity plays an important role in herbage intake and rumen fermentation. However, less information is available on how bacterial diversity in heifers varies during the first few weeks of grazing. This information will provide the basis for designing nutritional management programs for heifers before and after the beginning of grazing. The objective of this study was to determine how herbage intake, digestibility, and rumen bacterial diversity vary in steers that have started grazing without adaptation for fresh herbage during the first 4 weeks after the beginning of grazing

日本の家畜と畜産農家から分離した mcr-1 によるコリスチン耐性大腸菌の分布状況と関連性について

Colistin is used to treat infectious diseases in humans and livestock; it has also been used as a feed additive for livestock for approximately 50 years. Since the mcr-1 plasmid-mediated colistin resistance gene was discovered in China in 2015, it has been detected worldwide, mainly in livestock. In this study, we investigated the prevalence and characteristics of mcr-mediated colistin-resistant Escherichia coli in livestock and farmers in Japan. We collected fecal samples from 295 healthy livestock (202 cattle and 93 swine) and 62 healthy farmers from 72 livestock farms (58 cattle farms and 14 swine farms) between 2013 and 2015. Twenty-eight mcr-1-harboring E. coli strains were isolated from 25 livestock (six cattle and 19 swine) and three farmers (two cattle farmers and one swine farmer). The prevalence rates of mcr-1-harboring E. coli in livestock and farmers were 8.47 and 4.84%, respectively. Of the 28 strains, the resistance genes of three were transferable via the mcr-1-coding plasmids to E. coli J53 at low frequencies (10-7-10-8). Six strains coharbored mcr-1 with CTX-M β-lactamases (CTX-M-14, CTX-M-27, or CTX-M-156). Of the isolates obtained from livestock and farmers in four farms (farms C, I, N, and P), nine strains had the same genotypical characteristics (sequence types and pulsed-field gel electrophoresis band patterns), plasmid characteristics (incompatibility group and plasmid transferability), and minimum inhibitory concentrations. Thus, the findings suggested that clonal strains could spread among livestock and farmers within farms. To our knowledge, this is the first study to detect clonal relatedness of mcr-1-mediated colistin-resistant E. coli in livestock and farmers. It is suggested that farmers are at a higher risk of acquiring mcr-1-harboring strains, calling for our attention based on the One Health concept.博士（医学）・甲第798号・令和3年9月29日Copyright © 2021 Nakano, Nakano, Nishisouzu, Suzuki, Horiuchi, Kikuchi-Ueda, Ubagai, Ono and Yano. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY https://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

日本における基質特異性拡張型β-ラクタマーゼ産生肺炎桿菌の分子遺伝学的特徴：CTX-M-15の優位性と高病原性クローンの出現

Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n=55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n=8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.博士（医学）・甲第769号・令和3年3月15日© 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

THE INCIDENCE OF PEPTIC ULCER SURGERY BEFORE AND AFTER THE INTRODUCTION OF H2-RECEPTOR ANTAGONISTS

Since the introduction of H2-receptor antagonists, the incidence of ulcer surgery has decreased markedly. Based on the number of patients who underwent ulcer surgery and upper gastrointestinal endoscopy in our hospital, the number of operations for peptic ulcer disease has decreased, although the number of peptic ulcer patients diagnosed by endoscopy has increased after the introduction of cimetidine (the first H2-receptor antagonist in Japan). The decreasing rate of surgical therapy before and after the administration of H2-receptor antagonists was 49.1%. The number of emergency operations has also decreased among ulcer patients diagnosed by endoscopy although the number of perforated and bleeding ulcer patients has increased. It is also reported that the most common operative procedure for both gastric and duodenal ulcer was distal gastrectomy reconstructed by gastroduodenostomy (Billroth Ⅰ)

奈良県の地域住民と生活環境におけるピロリ菌の蔓延実態

Background: Chronic infection with Helicobacter pylori, specifically cagA-positive strains, is associated with gastric cancer. Thus, measures to prevent H. pylori infection are required. This study was conducted to clarify the prevalence of H. pylori in the community to identify the infection source and comprehensively assess the risk of H. pylori infection. Methods: We collected 90 human faecal samples and 73 environmental samples (water, vegetable, and animal faecal samples) from the residents in an area with a high incidence of gastric cancer in Japan. Polymerase chain reaction assay was performed to detect the glmM housekeeping gene and the cagA virulence gene of H. pylori. A questionnaire survey was conducted, and the responses were analyzed statistically. Results: The glmM gene was detected in 18 of 90 (20%) faecal samples obtained from residents; among them, the cagA gene was detected in 33.3% (6/18), and in all who had undergone eradication therapy. H. pylori was not detected in environmental samples. However, contact with dogs (OR 3.89, 95% CI 1.15-13.15, P < 0.05) was associated with higher odds for glmM gene positivity in the questionnaire survey. Conclusions: The prevalence of H. pylori and cagA-positive strains among the residents was low. However, the study results suggest a correlation between recurrent infection and cagA-positive H. pylori strains. Although H. pylori genes were not detected in living environments, an association between contact with dogs and a glmM positive status was revealed. Further investigations targeting community-dwelling healthy people and their living environments would be required for H. pylori infection control.博士（医学）・甲第774号・令和3年3月15日© 2020 The Authors. Published by Elsevier Ltd on behalf of King Saud Bin Abdulaziz University for Health Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)