Gestational Outcomes and Birth Weight in Japanese Women at the Upper and Lower limits of the Normal BMI range

To examine the outcome of gestational blood pressure and birth weight in women with normal pre-pregnancy BMI (18.5-25 kg/m2) who are at the lower and upper limits of this range, i.e., slightly underweight or slightly overweight. Overall, 2,038 Japanese women with low -risk who had delivered during January 2014–December 2016 were classified according to their pre-pregnancy BMI: underweight (< 18.5 kg/m2), slightly underweight (18.5≤BMI<21 kg/m2), normal (21≤BMI<23 kg/m2), slightly overweight (23≤BMI<25 kg/m2) and overweight (≤ 25 kg/m2). Their blood pressure during each trimester and birth weight was evaluated. The slightly overweight group showed a significantly higher blood pressure than the underweight and slightly underweight groups. Birth weight was lower in the slightly underweight than in the slightly overweight group (p<0.01). The incidence rate of “heavy for dates” (HFD) infants was significantly higher in the slightly overweight and overweight groups than in the other groups (p<0.05 and p<0.01, respectively). Weight gain of < 7 kg significantly increased the rate of “light for dates” (LFD) infants, while a weight gain of ≥13 kg significantly increased the rate of HFD infants (p<0.05 and p<0.01, respectively). Blood pressure during pregnancy was ssociated with pre-pregnancy BMI. The birth weight of infants of low-risk pregnant women is affected by both pre-pregnancy BMI and gestational weight gain

Seismic refraction and wide-angle reflection exploration by JARE-43 on Mizuho Plateau, East Antarctica

The 43rd Japanese Antarctic Research Expedition (JARE-43) carried out seismic exploration experiments on Mizuho Plateau,East Antarctica,in the austral summer season of ,2001-2002. The exploration was composed of seven large explosions and 161seismic stations distributed along the 151 km-long seismic line.The first arrival time data are analyzed by a refraction method.It is found that the ice sheet is composed of two layers:the upper layer with P wave velocity of 2.7-2.9 km/s has thickness of 35-45 m,and the lower layer with P wave velocity of 3.7-3.9 km/s continues to the bedrock.Lateral velocity variation in the upper-most crust is revealed:P wave velocity for the upper-most crust in the southern and central parts is 6.1-6.2 km/s and that in the northern part is5.9 km/s. This result implies that the geological boundary observed along the coast in the Lu tzow-Holm Bay and Prince Olav Coast regions possibly continues to the inland area.The S wave velocity is also obtained to be roughly 3.5km/s for the whole upper-most crust.Travel time analysis of two distinct reflection phases shows two horizontal reflecting planes located at 19 and 40km depth; the latter corresponds to the Moho discontinuity

Crustal structure and growth of the Forearc region of Izu-Ogasawara arc

（独）海洋研究開発機構(JAMSTEC)では、2002年から伊豆・小笠原・マリアナ島弧において、大陸地殻の生成過程を明らかにすることを目的に構造調査を進め、現在の島弧地殻のボリュームより多くの玄武岩マグマが必要で島弧地殻を生成する過程でマフィックな島弧地殻の一部をマントル内に戻していること（Takahashi et al., 2007, 2008; Tatsumi et al., 2008）、火山フロントと背弧側の地殻の厚さ分布には相関があり過去のリフティングが検出されたこと（Kodaira et al., 2009）などがわかってきた。前弧域の地殻に関しては、厚い地殻と薄い地殻が存在すること（Takahashi et al., 2011）、地磁気異常から島弧的な構造があること（Yamazaki and Yuasa, 1998）がわかっているが、地殻構造から実証されていなかった。前弧域の地殻構造を求め、地殻進化の影響をどの程度受けているのか、前弧域の島弧成長を明らかにするために、（独）海洋研究開発機構の深海調査船「かいれい」を用いて人工地震探査を行った。 地震探査の測線は、新黒瀬からスミス海脚、第二東鳥島海丘、大町海山を通って、小笠原トラフに至る。得られた速度構造から前弧域は25km程度の地殻の厚い部分と10～15km程度の薄い部分があることが明らかになった。厚い地殻は、北緯32.5度付近、スミス海脚、第二東鳥島海丘、大町海山の下に分布する。新黒瀬側は厚い地殻を持たない。大町海山の内部には異常に厚い下部地殻が分布する。薄い地殻が分布するところでは、堆積層が厚く地殻の厚さの半分近くを占める。大町海山以外の地殻が厚く分布するところでは、P波速度6km/sの速度コンターが上に凸、7km/sの速度コンターが下に凸の形状を示す。火山フロントに沿った地殻構造では、むしろ6km/s以下の速度を持つ層が厚いことが示されている（Kodaira et al., 2007）。これは、前弧域下の島弧地殻は、火山フロント下と比較して未分化な物質を多く含むことを示唆おり、過去の掘削結果とも整合する（e.g., Taylor, 1992）。前弧海盆下の島弧地殻の分布は、地磁気異常の空間分布（Yamazaki and Yuasa, 1998）とよく合致する。新黒瀬周辺で見られる地磁気異常は、本研究から明らかになった地殻が薄く地殻全体が盛り上がっている形状と合致する。伊豆小笠原島弧の本州弧への衝突が新黒瀬の浅海部を作っているものと示唆される。SCG66-03発表要旨 / 日本地球惑星科学連合2012年大会（2012年5月20日～5月25日, 幕張メッセ国際会議場） / 日本惑星科学連合の許諾に基づき本文ファイルを掲

構造研究に基づく南海トラフ（西部）地震発生帯のプレート形状および速度構造の3次元モデル

Great interplate earthquakes have repeatedly occurred in pairs along the Nankai Trough. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture zone of the Nankai megathrust event based on the knowledge of realistic earthquake cycles and variations of magnitude, it is important to know the geometry and property of the plate boundary of the subduction seismogenic zone. To improve a physical model of the Nankai Trough seismogenic zone, the large-scale high-resolution wide-angle and reflection (MCS) seismic studies, and long-term observation have been conducted since 2008. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km per year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. This study is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. The seismic survey was conducted off the Tokai area including the onshore survey across the eastern Kii Peninsula in 2012, the final year of this project. Compiling those studies provides a three-dimensional plate geometry and velocity structure models of the western Nankai Trough at the moment. Although their reliability and resolution should be evaluated, these models can be applied to a numerical simulation to examine if the observed rupture zone of the historical event can be reproduced. We will also try to construct more fine-scale model for the entire Nankai Trough area.SSS31-P15ポスター要旨 / 日本地球惑星科学連合2013年大会（2013年5月19日～5月24日, 幕張メッセ国際会議場） / 日本惑星科学連合の許諾に基づき本文ファイルを掲載http://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr10-11/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr11-09/

Structural variation in the incoming Philippine Sea plate along the Nankai Trough

The next large-thrust earthquake along the Nankai Trough, southwest Japan is concerned to occur within this century. Nonvolcanic deep low-frequency tremors and earthquakes are observed around the down-dip limit of the coseismic rupture zone of the last Tonankai and Nankai earthquakes [Obara, 2002]. One of the causes of these low-frequency seismic phenomena is considered to be fluid generated by dehydration processes from the subducting slab. It is important to investigate structural variation in the incoming Philippine Sea plate, including its fluid content to understand the generation of the low-frequency seismic phenomena as well as large-thrust earthquakes. In 2014, we conducted the seismic refraction and reflection survey in the northern margin of the Shikoku Basin, where the Philippine Sea plate is subducting beneath the Eurasia plate at the Nankai Trough. We conducted a 360km long seismic profile about 50-60km seaward of the deformation front along the Nankai Trough. 35 OBSs were deployed along the profile with the interval of 10km. A tuned airgun array shot with a total volume of 7800 cu. in. every 200m for OBSs, and 380 cu. in. every 37.5m for a 192-channel, 1.2km-long hydrophone streamer. In the time-migrated reflection section, variation in the sedimentary layer and basement reflection can be recognized off Shikoku, which may correspond with the boundary of the plate age proposed by magnetic lineation [Okino et al., 1999]. In the southwestern part of the profile, the basement reflection is not always clear, and shows smooth structure. Comparatively in the northeastern part, basement changes in depth drastically with prominent reflection signals. In the wide-angle OBS data, PS converted waves are clearly observed over along the seismic profile. In particular, PS converted waves refracted from the uppermost mantle can be remarkably recognized in the northeastern half of the profile. We will show the structural variation of the oceanic crust of the incoming plate, which may be related to the formation of the Shikoku Basin as well as the generation of the various seismic activities including the low-frequency events, by using OBS data. This study is part of ‘Research project for compound disaster mitigation on the great earthquakes and tsunamis around the Nankai Trough region’ funded by MEXT, Japan.Poster abstract T51A-4578 presented at 2014 Fall Meeting, AGU, San Francisco, Calif., 15-19 Dec.http://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr14-05/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky14-07/

First Case of Cytokine Release Syndrome after Nivolumab for Gastric Cancer

Introduction: Cytokine release syndrome (CRS) is a potentially life-threatening systemic disease that has been observed after treatment with antibodies and adoptive T cell therapies. In this case, we observed nivolumab-induced CRS in a patient with gastric cancer. Case Presentation: A 43-year-old male with advanced gastric cancer was treated with nivolumab as a third-line chemotherapy. He had no history of allergies. Eight days after the first administration of nivolumab, fever, tachycardia, appetite loss and increases in liver and biliary enzymes were observed. Computed tomography revealed neither bile duct obstruction nor progression of liver metastases but showed that there was edema of the Gleason sheath. Histopathological analysis of the liver revealed cholestatic liver injury with CD8+ T lymphocyte and macrophage infiltration. Neither viral infection nor autoimmune disease was revealed. His symptoms were similar to those of CRS observed after T cell therapy. We diagnosed his disease as nivolumab-induced liver injury and cholangitis accompanied by CRS based on his serum cytokine levels. Discussion/Conclusion: To the best of our knowledge, this is the first report of nivolumab-induced CRS in a patient with gastric cancer

Velocity structure of the fore-arc region of the Ogasawara Ridge and distribution of horizons

小笠原海嶺はフィリピン海プレート上の島弧地殻としては、もっとも古い島弧の一つとして島弧生成時の地殻を含む地殻が分布すると知られている（例えば、Ishizsuka et al., 2006）。これらのことは、これまでに行われてきた構造探査結果からも示唆されている。海嶺を横断する調査からは、P 波速度6.4-6.6 km/s の上部地殻とP 波速度7.0-7.2 km/s の下部地殻が同定された（Takahashi et al., 2009）。しかし、海嶺軸に沿った方向の調査からは、海洋性地殻と同等の薄い地殻の分布が明らかになり、海嶺の最浅部近傍の狭いエリアに薄い地殻が存在することが明らかになっている（Kodaira et al., 2012）。しかもその厚さは、海嶺に沿った方向に大きく変化する。一方、しんかい6500 を用いた海底観察からは、boninite、fore-arc basalt、gabbro、peridotite が分布していることが明らかになっており（Ishizuka et al.,2006）、オフィオライトの構造、つまり島弧生成前の古い海洋性地殻が存在しているのではないか、と議論された。太平洋プレート上の構造との共通的な特徴が地震学的に確認できるかどうか、この層序の海嶺の前弧域直下への連続性を確認するため、2011 年に構造探査を実施した。これらの構造は島弧の初期生成の鍵になるため、IODP の掘削提案も提出された。紹介する調査は、このIODP 掘削提案の事前調査の一環として行われた。調査は（独）海洋研究開発機構の深海調査船「かいれい」を用いて行われた。マルチチャンネル反射法探査データのみならず（444channels, 25 m group interval）、海底地震計を用いた屈折法探査データも取得した。使用したエアガンは総容量7800 cu.in.のAPG ガンで、反射法探査向けには50 m、屈折法探査向けには200 m 間隔で発振した。測線長は約250 kmで、海底地震計43 台を5 km 間隔で設置した。得られた反射断面は非常に複雑な様相を呈する。少なくとも測線全体に渡って連続する反射面は見当たらない。いくつかの小海山があるが、これらの海山はなだらかな傾斜をしており、また火山フロント上の海山で見られるようなすそ野に広がる厚い堆積物も見られない。海底地震計の記録も、海底地震計直上から40?60 km の範囲でしか初動が読み取れず、複雑な速度構造が分布していることを示唆している。peridotite が広く存在していれば、8 km/s 前後の見かけ速度の走時が読み取れるはずだが、そのような部分は、測線の中央部付近の海嶺の一部に限定された。また、初動走時が不連続でジャンプするような低速度層の分布を示唆する記録も得られた。浅部の構造は深部と比較して均質であり、5.0-5.5 km/s、6.0-7.0 km/s の層が広範囲に分布している。以前の調査結果によれば、上盤側の地殻と海洋性地殻が接している場所に本発表の測線があり、部分的に上盤側のperidotite 層がこの測線直下に分布しているものと思われる。海底から約4 秒のところには、比較的明瞭な反射波が読み取れた。本発表では、トモグラフィックインバージョンによる暫定的に決定した速度構造と反射面の分布を紹介する。また、反射記録断面から上盤側の反射面と沈み込む太平洋プレート上面からの反射波を同定し、オフィオライト構造を確認するために、得られた速度構造と海洋性地殻の類似性、相違性を確認する。B21-12発表要旨, 日本地震学会2012年度秋季大会（2012年10月16日～19日, 北海道函館市

Velocity structure along the Ogasawara Ridge fore-arc region

The Ogasawara Ridge is known as one of oldest arc on the Philippine Sea Plate. This Ridge has very complex structure. According to refraction survey crossing the ridge, the ridge has a very thin granitic layer with velocity of approximately 6 km/s, an andesitic layer with a velocity of 6.4-6.6 km/s and gabbroic layer with a velocity of 7.0-7.2 km/s (Takahashi et al., 2009). On the other hand, the thin crust with a thickness less than 10 km distributes beneath the shallowest topographic peak (Kodaira et al., 2012). According to geologic studies, boninites, fore-arc basalts, gabbros and peridotites were collected by Shinkai 6500 dives on the trench slope (Ishizuka et al., 2006). The observation is expected to be helpful for subduction initiation studies because these geological sequences are similar characteristics of ophiolite. Therefore, we carried out refraction survey using ocean bottom seismographs (OBSs) along the strike of the Ogasawara Ridge to detect such geological sequences using seismic imaging technique as one of site surveys for IBM drilling. This survey was carried by using R/V “Kairei” of Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in 2011 and we collected not only OBSs data but also multi-channel reflection data (MCSs) on a seismic line with a length of 250 km. Total 43 OBSs were deployed at an interval of 5 km and the airgun shooting with a total capacity of 7800 cu.in. was 200 m interval. First arrivals on OBS records are traced to offsets of 40-60 km, and the data is generally noisy suggesting complexity of fore-arc structure. If there is peridotite layer in the hanging wall side, the refractions with apparent velocity of about 8 km/s are identified, and discontinuous jump of the first arrivals should be at far side due to subducting oceanic crust. The observed refractions, however, have apparent velocities between 6.0-7.5 km/s to far side. Refractions with an apparent velocity of 8 km/s seem to be limited in narrow area. In addition, the jump of first arrivals is also identified on some OBS records, but it is not common character for whole of the line. We introduce the tentative tomographic image obtained by using first arrivals and reflection points distribution. Although the plate boundary structure is very complex, the structure of the hanging wall is relatively homogeneous. Then, we compared the structural image obtained by this study with geologic observation.Poster abstract T51D-2620 presented at 2012 Fall Meeting, AGU, San Francisco, Calif., 3-7 Dec