Monitoring of Environmental Ionizing Radiation and Radioisotopes in Okayama City and the Vicinty (II) - An estimation of the external radiation from the environmental radiation dose -

Monitoring of environmental ionizing radiation and radioisotopes in Okayama city and the vicinity was carried out from the point of view of the external radiation from the environmental radiation dose. Although the fluctuation of monthly detected radiation dose throughout the year was rather low at each observation point, the mean value of dose equivalent was varied between the place of observation. From the observation of the distribution of environmental radiation dose in Okayama city, it was assumed that its distribution was well corresponded with the distribution of igneous rocks. The concentrations of radioisotopes in various kinds of rocks corrected in Okayama city and its vicinity were determined. It became apparent that high concentrations of radioisotopes, such as (134)Cs, (40)K, (226)Ra and (228)Th, were detected in igneous rocks, such as granite, gabbro and rhyolitic tuff, although the contents in sedimentary rocks, such as pelite, schist, psammite and limestone, were rather low. This result was in good agreement with that of the distribution of radiation dose in Okayama city

Magnetic droplet nucleation with homochiral Neel domain wall

We investigate the effect of the Dzyaloshinskii Moriya interaction (DMI) on magnetic domain nucleation in a ferromagnetic thin film with perpendicular magnetic anisotropy. We propose an extended droplet model to determine the nucleation field as a function of the in-plane field. The model can explain the experimentally observed nucleation in a CoNi microstrip with the interfacial DMI. The results are also reproduced by micromagnetic simulation based on the string model. The electrical measurement method proposed in this study can be widely used to quantitatively determine the DMI energy density

Non-human primate model of amyotrophic lateral sclerosis with cytoplasmic mislocalization of TDP-43

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive motoneuron loss. Redistribution of transactive response deoxyribonucleic acid-binding protein 43 from the nucleus to the cytoplasm and the presence of cystatin C-positive Bunina bodies are considered pathological hallmarks of amyotrophic lateral sclerosis, but their significance has not been fully elucidated. Since all reported rodent transgenic models using wild-type transactive response deoxyribonucleic acid-binding protein 43 failed to recapitulate these features, we expected a species difference and aimed to make a non-human primate model of amyotrophic lateral sclerosis. We overexpressed wild-type human transactive response deoxyribonucleic acid-binding protein 43 in spinal cords of cynomolgus monkeys and rats by injecting adeno-associated virus vector into the cervical cord, and examined the phenotype using behavioural, electrophysiological, neuropathological and biochemical analyses. These monkeys developed progressive motor weakness and muscle atrophy with fasciculation in distal hand muscles first. They also showed regional cytoplasmic transactive response deoxyribonucleic acid-binding protein 43 mislocalization with loss of nuclear transactive response deoxyribonucleic acid-binding protein 43 staining in the lateral nuclear group of spinal cord innervating distal hand muscles and cystatin C-positive cytoplasmic aggregates, reminiscent of the spinal cord pathology of patients with amyotrophic lateral sclerosis. Transactive response deoxyribonucleic acid-binding protein 43 mislocalization was an early or presymptomatic event and was later associated with neuron loss. These findings suggest that the transactive response deoxyribonucleic acid-binding protein 43 mislocalization leads to α-motoneuron degeneration. Furthermore, truncation of transactive response deoxyribonucleic acid-binding protein 43 was not a prerequisite for motoneuronal degeneration, and phosphorylation of transactive response deoxyribonucleic acid-binding protein 43 occurred after degeneration had begun. In contrast, similarly prepared rat models expressed transactive response deoxyribonucleic acid-binding protein 43 only in the nucleus of motoneurons. There is thus a species difference in transactive response deoxyribonucleic acid-binding protein 43 pathology, and our monkey model recapitulates amyotrophic lateral sclerosis pathology to a greater extent than rodent models, providing a valuable tool for studying the pathogenesis of sporadic amyotrophic lateral sclerosis

Vibration isolation system with a compact damping system for power recycling mirrors of KAGRA

A vibration isolation system called the Type-Bp system used for power recycling mirrors has been developed for KAGRA, the interferometric gravitational-wave observatory in Japan. A suspension of the Type-Bp system passively isolates an optic from seismic vibration using three main pendulum stages equipped with two vertical vibration isolation systems. A compact reaction mass around each of the main stages allows for achieving sufficient damping performance with a simple feedback as well as vibration isolation ratio. Three Type-Bp systems were installed in KAGRA, and were proved to satisfy the requirements on the damping performance, and also on estimated residual displacement of the optics

KAGRA: 2.5 Generation Interferometric Gravitational Wave Detector

The recent detections of gravitational waves (GWs) reported by LIGO/Virgocollaborations have made significant impact on physics and astronomy. A globalnetwork of GW detectors will play a key role to solve the unknown nature of thesources in coordinated observations with astronomical telescopes and detectors.Here we introduce KAGRA (former name LCGT; Large-scale Cryogenic Gravitationalwave Telescope), a new GW detector with two 3-km baseline arms arranged in theshape of an "L", located inside the Mt. Ikenoyama, Kamioka, Gifu, Japan.KAGRA's design is similar to those of the second generations such as AdvancedLIGO/Virgo, but it will be operating at the cryogenic temperature with sapphiremirrors. This low temperature feature is advantageous for improving thesensitivity around 100 Hz and is considered as an important feature for thethird generation GW detector concept (e.g. Einstein Telescope of Europe orCosmic Explorer of USA). Hence, KAGRA is often called as a 2.5 generation GWdetector based on laser interferometry. The installation and commissioning ofKAGRA is underway and its cryogenic systems have been successfully tested inMay, 2018. KAGRA's first observation run is scheduled in late 2019, aiming tojoin the third observation run (O3) of the advanced LIGO/Virgo network. In thiswork, we describe a brief history of KAGRA and highlights of main feature. Wealso discuss the prospects of GW observation with KAGRA in the era of O3. Whenoperating along with the existing GW detectors, KAGRA will be helpful to locatea GW source more accurately and to determine the source parameters with higherprecision, providing information for follow-up observations of a GW triggercandidate

A content analysis of Japanese cancer documentaries across 25 years

We analysed Japanese television documentaries to (1) assess how cancer and the difficulties of patients with cancer were portrayed in documentaries on major Japanese national broadcasting networks and (2) evaluate changes in quality of life in Japan’s history of medicine as depicted in these documentaries to identify any trends. We analysed television documentaries aired from 1965 to 2015 on two major national broadcasting networks in Japan. Sixteen programmes on 24 patients with cancer aged 23–85 years were broadcast. The most common difficulty depicted was patient’s disease and care (n = 17). After 2006, more survivors discussed ongoing problems during cancer treatment. Over time, the proportion of programmes dealing with survivorship increased

Switchable giant nonreciprocal frequency shift of propagating spin waves in synthetic antiferromagnets

スピン波の巨大な非相反性の制御に成功 --人工反強磁性体を用いたスピン波デバイスの実現に向けて--. 京都大学プレスリリース. 2020-04-30.The nonreciprocity of propagating spin waves, i.e., the difference in amplitude and/or frequency depending on the propagation direction, is essential for the realization of spin wave–based logic circuits. However, the nonreciprocal frequency shifts demonstrated so far are not large enough for applications because they originate from interfacial effects. In addition, switching of the spin wave nonreciprocity in the electrical way remains a challenging issue. Here, we show a switchable giant nonreciprocal frequency shift of propagating spin waves in interlayer exchange–coupled synthetic antiferromagnets. The observed frequency shift is attributed to large asymmetric spin wave dispersion caused by a mutual dipolar interaction between two magnetic layers. Furthermore, we find that the sign of the frequency shift depends on relative configuration of two magnetizations, based on which we demonstrate an electrical switching of the nonreciprocity. Our findings provide a route for switchable and highly nonreciprocal spin wave–based applications