Investigating the role of the Itoigawa-Shizuoka tectonic line towards the evolution of the Northern Fossa Magna rift basin

AbstractThe Itoigawa-Shizuoka tectonic line (ISTL) fault system is considered to have one of the highest probabilities for a major inland earthquake occurrence in the whole of Japan. It is a complex fault system with the dip directions of the local fault segments changing from north to south between an east-dipping low-angle thrust fault, a strike slip fault and a west-dipping thrust fault. The tectonic relations between the different parts of the fault system and the surrounding geological units are yet to be fully explained. This study aims to reveal the juncture of the northern and central parts of the ISTL and investigate its contribution towards the shaping of the Northern Fossa Magna rift basin. We conducted 3 deployments of 1 or 2 linear arrays of seismic stations across the central and northern ISTL regions and observed local micro-earthquakes for a period of 3 years. Each deployment recorded continuous waveform data for approximately 3 months. Using arrival times of 1193 local earthquakes, we jointly determined earthquake locations and a 3D velocity model, applying the tomography method. We were able to image the regional crustal structures from the surface to a depth of 20km with a spatial resolution of 5km. Subsequently, we used the obtained 3D velocity model to relocate the background local seismicity from 2003 to 2009. The juncture of the northern and central parts of the ISTL was well constrained by our results. The depth extension of the northern parts of the ISTL fault segments follows the bottom of the Miocene Northern Fossa Magna rift basin (NFM) and forms an east-dipping low-angle fault. In contrast, the central parts of the ISTL fault segments are estimated to lie along the eastern boundary of the Matsumoto basin forming an oblique strike slip fault (Fig. 1)

Tsunami run-up heights of the 2003 Tokachi-oki earthquake

Tsunami height survey was conducted immediately after the 2003 Tokachi-oki earthquake. Results of the survey show that the largest tsunami height was 4 m to the east of Cape Erimo, around Bansei-onsen, and locally at Mabiro. The results also show that the tsunami height distribution of the 2003 Tokachi-oki earthquake is clearly different from that of the 1952 Tokachi-oki earthquake, suggesting the different source areas of the 1952 and 2003 Tokachioki earthquakes. Numerical simulation of tsunami is carried out using the slip distribution estimated by Yamanaka and Kikuchi (2003). The overall pattern of the observed tsunami height distribution along the coast is explained by the computed ones although the observed tsunami heights are slightly smaller. Large later phase observed at the tide gauge in Urakawa is the edge wave propagating from Cape Erimo along the west coast of the Hidaka area.The 2003 Tokachi-oki earthquak

キョウクウ センパ ニヨル ノウキョウ ガッペイ オ ミトメタ セイジュクガタ ジュウカク キケイシュ ノ 1レイ

症例は16 歳女性,咳嗽,発熱,左前胸部痛を主訴に来院.胸部CT にて内部不均一な径7 cm の前縦隔腫瘍及び左舌区・下葉の完全無気肺を確認,また,MRI にて前縦隔腫瘍内に脂肪組織と同一の吸収域を認め,成熟型奇形腫穿破による膿胸と診断.膿胸に対し胸腔内繊維素溶解療法,ドレナージ及び抗生剤にて加療,膿胸改善を確認した上で,前縦隔腫瘍摘出術施行,病理にて嚢胞性成熟型奇形腫と診断した.病理組織にて膵類似の腺組織を確認,穿破の原因として,腫瘍内膵酵素の存在が考えられた.成熟型縦隔奇形腫は穿破により重篤な合併症発生の危険性があり,また経過中悪性転化する可能性もあることから,早期の外科治療が重要と考えられた.A 16-year-old female visited our hospital, complaining ofcough, fever, and left precordial pain. Chest computed tomographyshowed a heterogeneous anterior mediastinal tumormeasuring 7 cm in diameter and complete atelectasis inthe lingula and lower lobe of the left lung. Magnetic resonanceimaging also showed an area of intensity identical tothat of adipose tissue in the anterior mediastinal tumor.Thus, empyema due to rupture of a mature teratoma wasdiagnosed. The empyema was treated with intra-pleural fibrinolytictherapy, drainage, and antibiotics. After confirmingresolution of the empyema, we resected the anteriormediastinal tumor and pathologically diagnosed it as cysticmature teratoma. Histopathological examination showedglandular tissue resembling the pancreas, suggesting thatthe rupture had been caused by pancreatic enzymes in thetumor. Mediastinal mature teratoma carries a risk of seriouscomplications developing due to rupture and the possibilityof malignant transformation during the diseasecourse. Thus, early surgical treatment is important

A pristine record of outer Solar System materials from asteroid Ryugu’s returned sample

Volatile and organic-rich C-type asteroids may have been one of the main sources of Earth’s water. Our best insight into their chemistry is currently provided by carbonaceous chondritic meteorites, but the meteorite record is biased: only the strongest types survive atmospheric entry and are then modified by interaction with the terrestrial environment. Here we present the results of a detailed bulk and microanalytical study of pristine Ryugu particles, brought to Earth by the Hayabusa2 spacecraft. Ryugu particles display a close compositional match with the chemically unfractionated, but aqueously altered, CI (Ivuna-type) chondrites, which are widely used as a proxy for the bulk Solar System composition. The sample shows an intricate spatial relationship between aliphatic-rich organics and phyllosilicates and indicates maximum temperatures of ~30 °C during aqueous alteration. We find that heavy hydrogen and nitrogen abundances are consistent with an outer Solar System origin. Ryugu particles are the most uncontaminated and unfractionated extraterrestrial materials studied so far, and provide the best available match to the bulk Solar System composition

A common developmental plan for neocortical gene-expressing neurons in the pallium of the domestic chicken gallus gallus domesticus and the Chinese softshell turtle pelodiscus sinensis

The six-layered neocortex is a unique characteristic of mammals and likely provides the neural basis of their sophisticated cognitive abilities. Although all mammalian species share the layered structure of the neocortex, the sauropsids exhibit an entirely different cytoarchitecture of the corresponding pallial region. Our previous gene expression study revealed that the chicken pallium possesses neural subtypes that express orthologs of layer-specific genes of the mammalian neocortex. To understand the evolutionary steps leading toward animal group-specific neuronal arrangements in the pallium in the course of amniote diversification, we examined expression patterns of the same orthologs and a few additional genes in the pallial development of the Chinese softshell turtle Pelodiscus sinensis, and compared these patterns to those of the chicken. Our analyses highlighted similarities in neuronal arrangements between the two species; the mammalian layer 5 marker orthologs are expressed in the medial domain and the layer 2/3 marker orthologs are expressed in the lateral domain in the pallia of both species. We hypothesize that the mediolateral arrangement of the neocortical layer-specific gene-expressing neurons originated in their common ancestor and is conserved among all sauropsid groups, whereas the neuronal arrangement within the pallium could have highly diversified independently in the mammalian lineage. © 2014 Suzuki and Hirata.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The Temporal Sequence of the Mammalian Neocortical Neurogenetic Program Drives Mediolateral Pattern in the Chick Pallium

SummaryThe six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-specific neuron subtypes do exist in the chick pallium. Deep- and upper-layer neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-specific neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.Video Abstrac