44 research outputs found

    A concept of hazardous NEO detection and impact warning system

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    In 2013, the well-known Chelyabinsk meteor entered the Earth's atmosphere over Chelyabinsk, Russia. It is estimated that the meteor exploded at altitude near 30 km[2], which damaged thousands of buildings and injured a thousand of residents[3–4]. The estimated size of the meteor is approximately 20 m[2]. Because the meteor approached to Earth from Sun direction, no ground-based observatories could not detect until the impact. Considering such situations, the paper proposes a concept to detect Chelyabinsk-class small Near-Earth Objects. The concept addresses a “last-minute” warning system of NEO impact, in the same manner of “Tsunami” warning. To achieve the mission objective, two locations are assumed for the space telescope installation point i.e., Sun-Earth Lagrange point 1, SEL1 and Artificial Equilibrium Point, AEP. SEL1 is one of the natural equilibrium points, on the other hand, AEP is artificially equilibrated point by Sun and Earth gravity, centrifugal force and low-thrust acceleration. The magnitude of the acceleration to keep AEP is sufficiently small near 1 au radius orbit around the Sun i.e., the order of μm/s2 which can be achieved by solar sail. Through some cases of numerical simulations considering the size of NEOs and detector capability, this paper will show the feasibility of the proposed concept

    Brown adipose tissue dysfunction promotes heart failure via a trimethylamine N-oxide-dependent mechanism.

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    Low body temperature predicts a poor outcome in patients with heart failure, but the underlying pathological mechanisms and implications are largely unknown. Brown adipose tissue (BAT) was initially characterised as a thermogenic organ, and recent studies have suggested it plays a crucial role in maintaining systemic metabolic health. While these reports suggest a potential link between BAT and heart failure, the potential role of BAT dysfunction in heart failure has not been investigated. Here, we demonstrate that alteration of BAT function contributes to development of heart failure through disorientation in choline metabolism. Thoracic aortic constriction (TAC) or myocardial infarction (MI) reduced the thermogenic capacity of BAT in mice, leading to significant reduction of body temperature with cold exposure. BAT became hypoxic with TAC or MI, and hypoxic stress induced apoptosis of brown adipocytes. Enhancement of BAT function improved thermogenesis and cardiac function in TAC mice. Conversely, systolic function was impaired in a mouse model of genetic BAT dysfunction, in association with a low survival rate after TAC. Metabolomic analysis showed that reduced BAT thermogenesis was associated with elevation of plasma trimethylamine N-oxide (TMAO) levels. Administration of TMAO to mice led to significant reduction of phosphocreatine and ATP levels in cardiac tissue via suppression of mitochondrial complex IV activity. Genetic or pharmacological inhibition of flavin-containing monooxygenase reduced the plasma TMAO level in mice, and improved cardiac dysfunction in animals with left ventricular pressure overload. In patients with dilated cardiomyopathy, body temperature was low along with elevation of plasma choline and TMAO levels. These results suggest that maintenance of BAT homeostasis and reducing TMAO production could be potential next-generation therapies for heart failure.We thank Kaori Yoshida, Keiko Uchiyama, Satomi Kawai, Naomi Hatanaka, Yoko Sawaguchi, Runa Washio, Takako Ichihashi, Nanako Koike, Keiko Uchiyama, Masaaki Nameta (Niigata University), Kaori Igarashi, Kaori Saitoh, Keiko Endo, Hiroko Maki, Ayano Ueno, Maki Ohishi, Sanae Yamanaka, Noriko Kagata (Keio University) for their excellent technical assistance, C. Ronald Kahn (Joslin Diabetes Center and Harvard Medical School) for providing the BAT cell line, Evan Rosen (Harvard Medical School) for providing us Ucp-Cre mice, Kosuke Morikawa (Kyoto University), Tomitake Tsukihara (University of Hyogo) and Shinya Yoshikawa (University of Hyogo) for their professional opinions and suggestions. Tis work was supported by a Grant-in-Aid for Scientifc Research (A) (20H00533) from MEXT, AMED under Grant Numbers JP20ek0210114, and AMED-CREST under Grant Number JP20gm1110012, and Moonshot Research and Development Program (21zf0127003s0201), MEXT Supported Program for the Strategic Research Foundation at Private Universities Japan, Private University Research Branding Project, and Leading Initiative for Excellent Young Researchers, and grants from the Takeda Medical Research Foundation, the Vehicle Racing Commemorative Foundation, Ono Medical Research Foundation, and the Suzuken Memorial Foundation (to T.M.). Support was also provided by a Grants-in-Aid for Young Scientists (Start-up) (26893080), and grants from the Uehara Memorial Foundation, Kowa Life Science Foundation, Manpei Suzuki Diabetes Foundation, SENSHIN Medical Research Foundation, ONO Medical Research Foundation, Tsukada Grant for Niigata University Medical Research, Te Nakajima Foundation, SUZUKEN memorial foundation, HOKUTO Corporation, Mochida Memorial Foundation for Medical & Pharmaceutical Research, Grants-in-Aid for Encouragement of Young Scientists (A) (16H06244), Daiichi Sankyo Foundation of Life Science, AMED Project for Elucidating and Controlling Mechanisms of Aging and Longevity under Grant Number JP17gm5010002, JP18gm5010002, JP19gm5010002, JP20gm5010002, JP21gm5010002, Astellas Foundation for Research on Metabolic Disorders, Research grant from Naito Foundation, Te Japan Geriatrics Society (to I.S.); by a Grant-in-Aid for Scientifc Research (C) (19K08974), Yujin Memorial Grant, Sakakibara Memorial Research Grant from Te Japan Research Promotion Society for Cardiovascular Diseases, TERUMO Life Science Foundation, Kanae Foundation (to Y.Y.), JST ERATO (JPMJER1902), AMED-CREST (JP20gm1010009), the Takeda Science Foundation, the Food Science Institute Foundation (to S.F.), and by a grant from Bourbon (to T.M., I.S. and Y.Y.).S

    総合的な視点に基づいた児童英語指導法に関する研究 : 英語を専科としない学生による積極的かつ専門的アプローチをめざして

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    The concern of this paper is to clarify a joint research project conducted in 2005 at Toyo Eiwa University, whose purpose was mainly to explore ways to instruct Toyo Eiwa students to teach English to children in a significant and effective way. In 2002, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) introduced in the nation\u27s public elementary schools the "Period of Integrated Study," in which they could conduct English-related activities for the purpose of promoting international understanding. In the following year, the MEXT established an Action Plan to "Cultivate Japanese with English Abilities," one of whose focuses is to support and enhance English conversation activities in elementary schools. Therefore, teaching English to children, both preschoolers and schoolchildren, have been attracting much attention of teachers and educators, not to mention the parents. Such being the case, several faculty members with different academic backgrounds set up a joint research project in order to investigate into good ways for our students to contribute to meeting the needs of the society; even though they do not major in English, they can support those teachers in kindergarten and elementary school as undergraduates, and will be able to do so in the future at different stages of their life. The joint research actually aimed at serving a double purpose; for the faculty to search for a didactics of training especially Toyo Eiwa students to teach English to small children in various approaches, and for these students to receive training in teaching English to children with heightening their awareness of the meaning of international understanding. We have made full use of the research results in an elective English course, "Children and English," which was first introduced in our curriculum in 2005, by taking turns to interact with the students as instructors as well as co-learners

    Gate Drive Circuit Suitable for a GaN Gate Injection Transistor

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    A GaN gate injection transistor (GIT) has great potential as a power semiconductor device. However, a GaN GIT has a diode characteristic at the gate-source, and a corresponding gate drive circuit is thus required. Several studies in the literature have proposed the gate drive circuits with the speed-up capacitors, but adding these capacitors complicates the gate drive circuit, and increases both the drive and reverse conduction losses. Moreover, driving a GaN GIT with such gate drive circuits becomes more susceptible to the false turn-on. In this paper, a gate drive circuit suitable for a GaN GIT without a speed-up capacitor is proposed. This type can provide the high-speed switching, and exhibit the low gate drive loss and reverse conduction loss. The proposed circuit also has high immunity against the false turn-on and stable gate-source voltage before and after startup. The drive loss of the proposed type is calculated and its validity is confirmed experimentally. Furthermore, the drive loss of the proposed type is compared with the conventional circuits. The result shows that the drive loss of the proposed type is improved by up to 50 %, compared with the conventional type. Finally, the proposed type is experimentally tested to drive a buck converter at the switching frequency of 150 kHz. The entire loss of the converter can be reduced by up to 9.2% at 250 W, compared with the conventional type

    Effect of freezing on cytochrome c oxidase cytochemistry in cells in monolayer culture.

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