著者
Eizo NAKAMURA Katsura KOBAYASHI Ryoji TANAKA Tak KUNIHIRO Hiroshi KITAGAWA Christian POTISZIL Tsutomu OTA Chie SAKAGUCHI Masahiro YAMANAKA Dilan M. RATNAYAKE Havishk TRIPATHI Rahul KUMAR Maya-Liliana AVRAMESCU Hidehisa TSUCHIDA Yusuke YACHI Hitoshi MIURA Masanao ABE Ryota FUKAI Shizuho FURUYA Kentaro HATAKEDA Tasuku HAYASHI Yuya HITOMI Kazuya KUMAGAI Akiko MIYAZAKI Aiko NAKATO Masahiro NISHIMURA Tatsuaki OKADA Hiromichi SOEJIMA Seiji SUGITA Ayako SUZUKI Tomohiro USUI Toru YADA Daiki YAMAMOTO Kasumi YOGATA Miwa YOSHITAKE Masahiko ARAKAWA Atsushi FUJII Masahiko HAYAKAWA Naoyuki HIRATA Naru HIRATA Rie HONDA Chikatoshi HONDA Satoshi HOSODA Yu-ichi IIJIMA Hitoshi IKEDA Masateru ISHIGURO Yoshiaki ISHIHARA Takahiro IWATA Kosuke KAWAHARA Shota KIKUCHI Kohei KITAZATO Koji MATSUMOTO Moe MATSUOKA Tatsuhiro MICHIKAMI Yuya MIMASU Akira MIURA Tomokatsu MOROTA Satoru NAKAZAWA Noriyuki NAMIKI Hirotomo NODA Rina NOGUCHI Naoko OGAWA Kazunori OGAWA Chisato OKAMOTO Go ONO Masanobu OZAKI Takanao SAIKI Naoya SAKATANI Hirotaka SAWADA Hiroki SENSHU Yuri SHIMAKI Kei SHIRAI Yuto TAKEI Hiroshi TAKEUCHI Satoshi TANAKA Eri TATSUMI Fuyuto TERUI Ryudo TSUKIZAKI Koji WADA Manabu YAMADA Tetsuya YAMADA Yukio YAMAMOTO Hajime YANO Yasuhiro YOKOTA Keisuke YOSHIHARA Makoto YOSHIKAWA Kent YOSHIKAWA Masaki FUJIMOTO Sei-ichiro WATANABE Yuichi TSUDA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.98, no.6, pp.227-282, 2022-06-10 (Released:2022-06-10)
参考文献数
245
被引用文献数
90

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation.
著者
Hirokazu KAWAGISHI
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.99, no.7, pp.191-197, 2023-07-31 (Released:2023-07-31)
参考文献数
18

The mushroom, Pleurocybella porrigens, is widely consumed in Japan; however, in autumn 2004, acute encephalopathy due to ingestion of the mushroom in a large group of patients was reported in Japan. We have continued working on the mushroom to clarify the mechanisms underlying the acute encephalopathy that occurred due to its consumption. The data collected to date have shown that three compounds, pleurocybelline (PC), a Pleurocybella porrigens lectin (PPL), and pleurocybellaziridine (PA), in the mushroom are potentially responsible for the onset of the disease; PC that exhibit lethal activity in mice and PPL formed a complex, and the complex of the two components exhibited proteolytic activity and disrupted the blood-brain barrier. Although PA was not isolated directly from the mushroom, the existence of this compound in the mushroom was predicted. The compound was chemically synthesized and its endogeneity in the mushroom was demonstrated. Furthermore, PA exhibited toxicity to oligodendrocytes.
著者
Ryugo S. HAYANO Masaharu TSUBOKURA Makoto MIYAZAKI Akihiko OZAKI Yuki SHIMADA Toshiyuki KAMBE Tsuyoshi NEMOTO Tomoyoshi OIKAWA Yukio KANAZAWA Masahiko NIHEI Yu SAKUMA Hiroaki SHIMMURA Junichi AKIYAMA Michio TOKIWA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.91, no.8, pp.440-446, 2015-10-09 (Released:2015-10-09)
参考文献数
14
被引用文献数
18 28

BABYSCAN, a whole-body counter (WBC) for small children was developed in 2013, and units have been installed at three hospitals in Fukushima Prefecture. Between December, 2013 and March, 2015, 2707 children between the ages of 0 and 11 have been scanned, and none had detectable levels of radioactive cesium. The minimum detectable activities (MDAs) for 137Cs were ≤3.5 Bq kg−1 for ages 0–1, decreasing to ≤2 Bq kg−1 for ages 10–11. Including the 134Cs contribution, these translate to a maximum committed effective dose of ∼16 µSv y−1 even for newborn babies, and therefore the internal exposure risks can be considered negligibly small.Analysis of the questionnaire filled out by the parents of the scanned children regarding their families’ food and water consumption revealed that the majority of children residing in the town of Miharu regularly consume local or home-grown rice and vegetables, while in Minamisoma, a majority avoid tap water and produce from Fukushima. The data show, however, no correlation between consumption of locally produced food and water and the children’s body burdens.
著者
Ryugo S. HAYANO Masaharu TSUBOKURA Makoto MIYAZAKI Hideo SATOU Katsumi SATO Shin MASAKI Yu SAKUMA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.89, no.4, pp.157-163, 2013-04-11 (Released:2013-04-11)
参考文献数
14
被引用文献数
85 102

The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the 137Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data.(Communicated by Toshimitsu YAMAZAKI, M.J.A.)
著者
Ryugo S. HAYANO Masaharu TSUBOKURA Makoto MIYAZAKI Hideo SATOU Katsumi SATO Shin MASAKI Yu SAKUMA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.91, no.3, pp.92-98, 2015-03-11 (Released:2015-03-11)
参考文献数
17
被引用文献数
4 7

Comprehensive whole-body counter surveys of Miharu-town school children have been conducted for four consecutive years, in 2011–2014. This represents the only long-term sampling-bias-free study of its type conducted after the Fukushima Dai-ichi accident. For the first time in 2014, a new device called the Babyscan, which has a low 134/137Cs MDA of <50 Bq/body, was used to screen the children shorter than 130 cm. No child in this group was found to have detectable level of radiocesium. Using the MDAs, upper limits of daily intake of radiocesium were estimated for each child. For those screened with the Babyscan, the upper intake limits were found to be ≲1 Bq/day for 137Cs. Analysis of a questionnaire filled out by the children’s parents regarding their food and water consumption shows that the majority of Miharu children regularly consume local and/or home-grown rice and vegetables. This however does not increase the body burden.
著者
Andy CRUMP Satoshi OMURA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.87, no.2, pp.13-28, 2011-02-10 (Released:2011-02-10)
参考文献数
68
被引用文献数
115 238

Discovered in the late-1970s, the pioneering drug ivermectin, a dihydro derivative of avermectin—originating solely from a single microorganism isolated at the Kitasato Intitute, Tokyo, Japan from Japanese soil—has had an immeasurably beneficial impact in improving the lives and welfare of billions of people throughout the world. Originally introduced as a veterinary drug, it kills a wide range of internal and external parasites in commercial livestock and companion animals. It was quickly discovered to be ideal in combating two of the world’s most devastating and disfiguring diseases which have plagued the world’s poor throughout the tropics for centuries. It is now being used free-of-charge as the sole tool in campaigns to eliminate both diseases globally. It has also been used to successfully overcome several other human diseases and new uses for it are continually being found. This paper looks in depth at the events surrounding ivermectin’s passage from being a huge success in Animal Health into its widespread use in humans, a development which has led many to describe it as a “wonder” drug.(Contributed by Satoshi OMURA, M.J.A.)
著者
Ryugo S. HAYANO Ryutaro ADACHI
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.89, no.5, pp.196-199, 2013-05-10 (Released:2013-05-10)
参考文献数
8
被引用文献数
12 27

The first objective data showing the geographical locations of people in Fukushima after the Fukushima Dai-ichi nuclear power plant accident, obtained by an analysis of GPS (Global Positioning System)-enabled mobile phone logs, are presented. The method of estimation is explained, and the flow of people into and out of the 20 km evacuation zone during the accident is visualized.(Communicated by Toshimitsu YAMAZAKI, M.J.A.)
著者
Shun-ichi TANAKA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.88, no.9, pp.471-484, 2012-11-09 (Released:2012-11-09)
参考文献数
15
被引用文献数
24 54

The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety of NPSs, as well as radiation protection of residents under the emergency involving the accident. The materials of the current paper are those released by governmental agencies, academic societies, interim reports of committees under the government, and others.(Communicated by Toshimitsu YAMAZAKI, M.J.A.)
著者
築島 裕
出版者
The Japan Academy
雑誌
日本學士院紀要 (ISSN:03880036)
巻号頁・発行日
vol.51, no.3, pp.227-251, 1997 (Released:2007-06-22)
被引用文献数
1

“Kata-Kana”character is a kind of phonetic characters for the Japanese language transformed from the Chinese character.The scientific study on the history of“Kata-Kana”characters was originated by Dr. Tohru Ohya from the beginning of the 20th century. He was the first scholar who took notice of the“Kunten”materials of the Heian-period as very important and useful manuscripts to research the history of the Japanese language. These“Kunten”materials have been kept in several old traditional temples, and offers many reliable proofs on the invention of“Kata-Kana” characters. After Ohya, Professors Shinkichi Hashimoto, Masaji Kasuga, M. J. A, and Norio Nakada have had the outstanding achievements in this field. However, many problems are left unsolved. The facts philologically proved for the present are as follows.“Kata-Kana”characters were devised in the early 9th century by the Buddhist scholars (especially studying at Todaiji (東大寺) Temple), in order to express the Japanese reading of the Chinese sentences.The scholars had to write down the Japanese reading in the narrow space between the lines of the Chinese sentences, listening their teacher's lecture. “Kata-Kana”characters were formed by abbreviating the strokes of Chinese characters, leaving the first strokes or the final strokes of them, for the purpose of saving these time and labour.In the first period of inventing“Kata-Kana”characters, many different forms were used at the same time with“Mannyou-Gana”, and“Hira-Gana” characters which was made from the cursive style of the Chinese characters, but, in the phase of reading Chinese sentences,“Kata-Kana”characters had taken more simplified forms and had been standardized in the society by 12th Century.The current forms of“Kata-Kana”characters today have been officially settled in 1900 by the Japanese government.“Kata-Kana”characters were made from Chinese characters which had been used especially as“Mannyo-Gana”in the ancient Japan. Accordingly, the explanation that“Kata-Kana”サ (sa) was abbreviated from 薩 or 奘 is not right, because these Chinese characters had never been used as“Mannyo-Gana”. This theory may be revised to be from 散.As these characters were made for the purpose of quick writing, the origin is not formal style but simplified style. レ (re) and ネ (ne) are not from 禮 (rei) and 禰 (nei), but from simplified style 礼 andi 祢. ヱ (we, e) is not from 慧 (we) but from the beginning part of curved strokes of 惠 (we).Beside these facts, the origins of the“Kata-Kana”characters used in the present time are often misunderstood generally. For example,“Kata-Kana”character タ (ta) is explained as to be formed from the beginning strokes of Chinese character 多 (ta), but it is not right. It is from its last stroke, according to the ancient form 多. ロ (ro) was not from 呂, but from 〓 which was the old form of this character.“Kata-Kana”characters have kept essentially a phonetic and practical factor through their history. They have never had an aesthetic factor, different from“Hira-Gana”characters.“Kata-Kana”characters have made historical change by reason of practical usage, although some unique and curious forms used exceptionally in some sects of Buddhism and Confusiasm in the Heian period had been bequeathed to the after ages.
著者
Eizo NAKAMURA Akio MAKISHIMA Kyoko HAGINO Kazunori OKABE
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.85, no.7, pp.229-239, 2009 (Released:2009-07-31)
参考文献数
58
被引用文献数
14 22

While exposure to fibers and particles has been proposed to be associated with several different lung malignancies including mesothelioma, the mechanism for the carcinogenesis is not fully understood. Along with mineralogical observation, we have analyzed forty-four major and trace elements in extracted asbestos bodies (fibers and proteins attached to them) with coexisting fiber-free ferruginous protein bodies from extirpative lungs of individuals with malignant mesothelioma. These observations together with patients’ characteristics suggest that inhaled iron-rich asbestos fibers and dust particles, and excess iron deposited by continuous cigarette smoking would induce ferruginous protein body formation resulting in ferritin aggregates in lung tissue. Chemical analysis of ferruginous protein bodies extracted from lung tissues reveals anomalously high concentrations of radioactive radium, reaching millions of times higher concentration than that of seawater. Continuous and prolonged internal exposure to hotspot ionizing radiation from radium and its daughter nuclides could cause strong and frequent DNA damage in lung tissue, initiate different types of tumour cells, including malignant mesothelioma cells, and may cause cancers.(Communicated by Takashi SUGIMURA, M.J.A.)
著者
Yousuke FURUTA Takashi KOMENO Takaaki NAKAMURA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.93, no.7, pp.449-463, 2017-08-02 (Released:2017-08-02)
参考文献数
61
被引用文献数
423 750

Favipiravir (T-705; 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) is an anti-viral agent that selectively and potently inhibits the RNA-dependent RNA polymerase (RdRp) of RNA viruses. Favipiravir was discovered through screening chemical library for anti-viral activity against the influenza virus by Toyama Chemical Co., Ltd. Favipiravir undergoes an intracellular phosphoribosylation to be an active form, favipiravir-RTP (favipiravir ribofuranosyl-5′-triphosphate), which is recognized as a substrate by RdRp, and inhibits the RNA polymerase activity. Since the catalytic domain of RdRp is conserved among various types of RNA viruses, this mechanism of action underpins a broader spectrum of anti-viral activities of favipiravir. Favipiravir is effective against a wide range of types and subtypes of influenza viruses, including strains resistant to existing anti-influenza drugs. Of note is that favipiravir shows anti-viral activities against other RNA viruses such as arenaviruses, bunyaviruses and filoviruses, all of which are known to cause fatal hemorrhagic fever. These unique anti-viral profiles will make favipiravir a potentially promising drug for specifically untreatable RNA viral infections.
著者
宮澤 健一
出版者
The Japan Academy
雑誌
日本學士院紀要 (ISSN:03880036)
巻号頁・発行日
vol.60, no.2, pp.87-115, 2006 (Released:2007-06-22)
被引用文献数
1

With Japan's quicker-than-expected declining birth rate and aging population, the scale of activities in its medical, care and welfare sectors exceeds those of education and research, which are also components of Japan's public domain. This is bringing new issues into questions, including policy-related ones. In providing answers, it will be necessary to investigate the state of the medical, care and welfare sectors, while also taking a look from a wider perspective at the influence and function of these sectors as they interact within the wider economy and society. In elucidating this situation, I use as a tool input-output, or inter-industry, analysis, while attempting to widen its scope.
著者
Shogo NISHIYAMA Tomohiro KARA Brian THORSBRO Hiromi SAIDA Yohsuke TAKAMORI Masaaki TAKAHASHI Takayuki OHGAMI Kohei ICHIKAWA Rainer SCHÖDEL
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
pp.pjab.100.007, (Released:2023-12-01)

The tremendous tidal force that is linked to the supermassive black hole (SMBH) at the center of our galaxy is expected to strongly subdue star formation in its vicinity. Stars within 1'' from the SMBH thus likely formed further from the SMBH and migrated to their current positions. In this study, spectroscopic observations of the star S0-6/S10, one of the closest (projected distance from the SMBH of ≈0''.3) late-type stars were conducted. Using metal absorption lines in the spectra of S0-6, the radial velocity of S0-6 from 2014 to 2021 was measured, and a marginal acceleration was detected, which indicated that S0-6 is close to the SMBH. The S0-6 spectra were employed to determine its stellar parameters including temperature, chemical abundances ([M/H], [Fe/H], [α/Fe], [Ca/Fe], [Mg/Fe], [Ti/Fe]), and age. As suggested by the results of this study, S0-6 is very old (≳10 Gyr) and has an origin different from that of stars born in the central pc region.
著者
Yoshiyuki SAKAKI
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.95, no.8, pp.441-458, 2019-10-11 (Released:2019-10-11)
参考文献数
43
被引用文献数
2 2

The Human Genome Project (HGP) is one of the most important international achievements in life sciences, to which Japanese scientists made remarkable contributions. In the early 1980s, Akiyoshi Wada pioneered the first project for the automation of DNA sequencing technology. Ken-ichi Matsubara exhibited exceptional leadership to launch the comprehensive human genome program in Japan. Hideki Kambara made a major contribution by developing a key device for high-speed DNA sequencers, which enabled scientists to construct human genome draft sequences. The RIKEN team led by Yoshiyuki Sakaki (the author) played remarkable roles in the draft sequencing and completion of chromosomes 21, 18, and 11. Additionally, the Keio University team led by Nobuyoshi Shimizu made noteworthy contributions to the completion of chromosomes 22, 21, and 8. In April 2003, the Japanese team joined the international consortium in declaring the completion of the human genome sequence. Consistent with the HGP mandate, Japan has successfully developed a wide range of ambitious genomic sciences.
著者
Tomoko M. NAKANISHI
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.94, no.1, pp.20-34, 2018-01-11 (Released:2018-01-11)
参考文献数
42
被引用文献数
3

Immediately after the Fukushima nuclear power plant accident, a team of 40–50 researchers at the Graduate School of Agricultural and Life Sciences at the University of Tokyo began to analyze the behavior of radioactive materials in the fallout regions. The fallout has remained in situ and become strongly adsorbed within the soil over time. 137Cs was found to bind strongly to the fine clay, weathered biotite, and organic matter in the soil; therefore, it has not mobilized from mountainous regions, even after heavy rainfall. In farmland, the quantity of 137Cs in the soil absorbed by crop plants was small. The downward migration of 137Cs in soil is now estimated at 1–2 mm/year. The intake of 137Cs by trees occurred through the bark and not from the roots. This report summarizes the findings of research across a wide variety of agricultural specialties.
著者
Kiwamu NISHIDA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.93, no.7, pp.423-448, 2017-08-02 (Released:2017-08-02)
参考文献数
183
被引用文献数
63

The ambient seismic wave field, also known as ambient noise, is excited by oceanic gravity waves primarily. This can be categorized as seismic hum (1–20 mHz), primary microseisms (0.02–0.1 Hz), and secondary microseisms (0.1–1 Hz). Below 20 mHz, pressure fluctuations of ocean infragravity waves reach the abyssal floor. Topographic coupling between seismic waves and ocean infragravity waves at the abyssal floor can explain the observed shear traction sources. Below 5 mHz, atmospheric disturbances may also contribute to this excitation. Excitation of primary microseisms can be attributed to topographic coupling between ocean swell and seismic waves on subtle undulation of continental shelves. Excitation of secondary microseisms can be attributed to non-linear forcing by standing ocean swell at the sea surface in both pelagic and coastal regions. Recent developments in source location based on body-wave microseisms enable us to estimate forcing quantitatively. For a comprehensive understanding, we must consider the solid Earth, the ocean, and the atmosphere as a coupled system.
著者
Masaharu TSUBOKURA Yuko NABESHIMA Michio MURAKAMI Tsuyoshi NEMOTO Toshiyuki KAMBE Saori NONAKA Yuki SHIMADA Yurie KOBASHI Akihiko OZAKI Tomoyoshi OIKAWA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.96, no.2, pp.70-78, 2020-02-10 (Released:2020-02-10)
参考文献数
31
被引用文献数
13

Responding to the radiation-related concerns of parents/guardians with infants/small children is an important public health issue for regional recovery after radioactive contamination. This study summarizes the results of a systematic internal contamination screening of infants/small children, aged 0–6 years, using BABYSCAN and individual counselling sessions with physicians about radiation concerns from 2014 to 2018 in Minamisoma City. Of 3,114 participants, no one was found to have internal contamination with radioactive caesium with a detection limit of 50 Bq/body. The questionnaire survey showed a decreasing trend of concerns about food contamination and playing outside as possible causes of internal contamination over time. Because people’s concerns were diverse in counselling sessions, individual responses are required. This study showed that examinations using BABYSCAN provide an opportunity for direct dialogue between the parents/guardians of infants/small children and experts. This can be considered a model case for risk communication conducted by the local government after a radioactive contamination incident.