著者
Hiroshi Takagi Akihiko Ito Heon-Sook Kim Shamil Maksyutov Makoto Saito Tsuneo Matsunaga
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
pp.2021-037, (Released:2021-10-13)
被引用文献数
2

Numerous wetlands, including the world's two largest contiguous wetlands, lie along the free-flowing Paraná and Paraguay Rivers that travel the length of subtropical South America (SSA) region. These wetlands are floodplains that are inundated with rising river water in flood events; their morphology and area are highly changeable with flooding extent. The long-term variability of methane emission from this wetland hotspot and its sensitivity to meteorological conditions are not well known. We herein explore this unknown using space-based estimates of methane flux for SSA region between 2009 and 2015 along with data of water balance. We find that methane emission from this region coherently varies with precipitation and inundation areal extent.
著者
Hiromitsu Kanno Hiroshi Matsuyama
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
vol.17, pp.170-176, 2021 (Released:2021-10-05)
参考文献数
34

In the Western North Pacific, there is little meteorological data available for the 19th century. We found historical documents at Chichi-jima in the Ogasawara (Bonin) Islands that report routine meteorological observations and weather conditions before 1906. In 1906, Japan Meteorological Agency began observations at Ohmura in the northwestern part of the island. The Home Ministry in Japan conducted the observations until 1906 at Ohgiura, the central part of Chichi-jima, which is 3 km away from Ohmura. We analyzed precipitation data at Ohgiura and Ohmura from 1975 to 2020 and found that the former is systematically greater than the latter. Therefore, we corrected pre-1906 precipitation at Ohgiura to ensure correlation with post-1906 precipitation at Ohmura. No discontinuous changes in the data were found around 1906. A previous study reported that annual precipitation at Ohmura for 1907-1944 was higher than that after World War II. We found that in some years from 1882 to 1906, the precipitation was less than that for 1907-1944, which agrees with the reported higher atmospheric pressure around Chichi-jima before 1906. Our study suggests that the trend of decreasing precipitation at Chichi-jima in the 20th century is not monotonous but a part of longer-scale temporal variations.
著者
Hiromitsu Kanno Hiroshi Matsuyama
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
pp.2021-030, (Released:2021-09-01)

In the Western North Pacific, there is little meteorological data available for the 19th century. We found historical documents at Chichi-jima in the Ogasawara (Bonin) Islands that report routine meteorological observations and weather conditions before 1906. In 1906, Japan Meteorological Agency began observations at Ohmura in the northwestern part of the island. The Home Ministry in Japan conducted the observations until 1906 at Ohgiura, the central part of Chichi-jima, which is 3 km away from Ohmura. We analyzed precipitation data at Ohgiura and Ohmura from 1975 to 2020 and found that the former is systematically greater than the latter. Therefore, we corrected pre-1906 precipitation at Ohgiura to ensure correlation with post-1906 precipitation at Ohmura. No discontinuous changes in the data were found around 1906. A previous study reported that annual precipitation at Ohmura for 1907-1944 was higher than that after World War II. We found that in some years from 1882 to 1906, the precipitation was less than that for 1907-1944, which agrees with the reported higher atmospheric pressure around Chichi-jima before 1906. Our study suggests that the trend of decreasing precipitation at Chichi-jima in the 20th century is not monotonous but a part of longer-scale temporal variations.
著者
Takeshi Horinouchi Yu Kosaka Hiroshi Nakamigawa Hisashi Nakamura Norihisa Fujikawa Yukari N. Takayabu
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
vol.17B, no.Special_Edition, pp.1-8, 2021 (Released:2021-06-01)
参考文献数
30
被引用文献数
14

A prolonged heavy rainfall event occurred in Kyushu in early July 2020. Its large-scale environmental factors are investigated with observational and reanalysis data. Seven-day precipitation and moisture flux convergence around Kyushu were the greatest among the last 30 years. This pronounced convergence was maintained by nearly steady moisture influx, and the persistent upper-level trough to the northwest enhanced the ratio of moisture convergence to the influx. The magnitude of instantaneous moisture flux, however, was not particularly large among those along the subtropical jet axis or the Meiyu-Baiu rainband. What made this event unique is the persistence of the moisture flux peak anchored around Kyushu under the influence of the Silk-Road teleconnection. In June 2020, three upper-level troughs, whose easternmost one corresponding to the aforementioned trough, tend to form along the subtropical Asian jet. This wave train was persistent in the month and lasted until mid-July, 2020. Our analysis suggests that, prior to the rainfall event, the Silk-Road teleconnection was intensified through an interaction with a wave train at subpolar latitudes, which involves nonlinear processes including trough cut-off.
著者
Ryota Ishiyama Hiroshi L. Tanaka
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
vol.17, pp.120-124, 2021 (Released:2021-06-26)
参考文献数
23
被引用文献数
1

In this study, we conducted a domain-integrated vorticity budget analysis to quantitatively understand the developing mechanism of the Arctic Cyclone (AC) in August 2016 (AC16). The results showed that the vorticity enhancement of the AC16 was dominated by the horizontal flux convergence of vorticity at all layers with a maximum near the tropopause. The enhancement near the tropopause was characterized not only by the horizontal supply but also by the vertical transport of vorticity. In the boundary layer within the AC16, the convergence of horizontal winds and the corresponding divergence of vertical winds occurred. In addition, during the merging process, updrafts were dominant in the troposphere due to the structure of the mid-latitude cyclone. These structures caused the upward transport of vorticity to the tropopause, which is considered as an important internal process of the AC16. However, time-averaged vorticity budget during the developing stage indicated that the vertical flux term and the divergence term compensate with each other. As a result, it was concluded that the AC is excited and maintained by the merging of the vortices associated with the migrating mid-latitude cyclone and polar vortex.
著者
Hiroshi Okada Keiji Yoshioka
出版者
The Japanese Society of Internal Medicine
雑誌
Internal Medicine (ISSN:09182918)
巻号頁・発行日
vol.49, no.19, pp.2113-2116, 2010 (Released:2010-10-01)
参考文献数
6
被引用文献数
7 9

A 73-year-old woman was admitted to our hospital because of persistent fever, headache and fatigue for several weeks. On admission, she was diagnosed as having meningitis due to Mycobacterium intracellulare (M. intracellulare) detected in her cerebrospinal fluid (CSF) by polymerase chain reaction. Even though anti-tuberculous therapy improved her CSF findings, her condition was not restored. Brain MRI showed multifocal and asymmetrical increases in T2 signals involving white matter and cortical gray-white junction of cerebral hemispheres, cerebellum and brainstem. Based on the progression of clinical symptoms and radiological features, we diagnosed her illness as acute disseminated encephalomyelitis (ADEM) associated with meningitis due to M. intracellulare. Steroid therapy dramatically improved her condition. This is the first report of ADEM following meningitis due to M. intracellulare in a non-immunocompromized host.
著者
Takeshi Horinouchi Yu Kosaka Hiroshi Nakamigawa Hisashi Nakamura Norihisa Fujikawa Yukari N. Takayabu
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
pp.2021-019, (Released:2021-04-28)
被引用文献数
14

A prolonged heavy rainfall event occurred in Kyushu in early July 2020. Its large-scale environmental factors are investigated with observational and reanalysis data. Seven-day precipitation and moisture flux convergence around Kyushu were the greatest among the last 30 years. This pronounced convergence was maintained by nearly steady moisture influx, and the persistent upper-level trough to the northwest enhanced the ratio of moisture convergence to the influx. The magnitude of instantaneous moisture flux, however, was not particularly large among those along the subtropical jet axis or the Meiyu-Baiu rainband. What made this event unique is the persistence of the moisture flux peak anchored around Kyushu under the influence of the Silk-Road teleconnection. In June 2020, three upper-level troughs, whose easternmost one corresponding to the aforementioned trough, tend to form along the subtropical Asian jet. This wave train was persistent in the month and lasted until mid-July, 2020. Our analysis suggests that, prior to the rainfall event, the Silk-Road teleconnection was intensified through an interaction with a wave train at subpolar latitudes, which involves nonlinear processes including trough cut-off.
著者
Maki Fukuda Tsuyoshi Ohta Hiroshi Okabayashi Noritaka Masahira Toshiki Matsuoka Kenji Okada Takaya Tsuno Shota Nishimoto Yusuke Ueba
出版者
The Japanese Society for Neuroendovascular Therapy
雑誌
Journal of Neuroendovascular Therapy (ISSN:18824072)
巻号頁・発行日
vol.14, no.4, pp.151-156, 2020 (Released:2020-04-20)
参考文献数
8
被引用文献数
1 1

Objective: The objective of this study was to evaluate the reproducibility of three-dimensional (3D) images of the aortic arch reconstructed using a novel image processing algorithm for non-enhanced computed tomography (CT) images of the cervicothorax and abdomen obtained before emergency endovascular surgery.Case Presentations: In all, 46 patients who underwent acute mechanical thrombectomy between January and December 2018 were examined. The anatomical variations of the aortic arch were reproduced in all cases; however, the reproduction of the carotid arteries was difficult.Conclusion: Our novel 3D analysis system enables obtaining information on the aortic arch easily from plain CT data that may be useful in acute endovascular treatment.
著者
Tetsuya TAKAHASHI Michitaka KATO Kengo OBATA Ryo KOZU Toru FUJIMOTO Koji YAMASHITA Morihide ANDO Yusuke KAWAI Noriaki KOJIMA Hiroshi KOMATSU Kensuke NAKAMURA Yuhei YAMASHITA Shane PATMAN Akemi UTSUNOMIYA Osamu NISHIDA
出版者
Japanese Society of Physical Therapy
雑誌
Physical Therapy Research (ISSN:21898448)
巻号頁・発行日
pp.E10060, (Released:2020-11-25)
参考文献数
22
被引用文献数
7

Objective: Early mobilization and rehabilitation has become common and expectations for physical therapists working in intensive care units have increased in Japan. The objective of this study was to establish consensus-based minimum clinical practice standards for physical therapists working in intensive care units in Japan. It also aimed to make an international comparison of minimum clinical practice standards in this area. Methods: In total, 54 experienced physical therapists gave informed consent and participated in this study. A modified Delphi method with questionnaires was used over three rounds. Participants rated 272 items as "essential/unknown/non-essential". Consensus was considered to be reached on items that over 70% of physical therapists rated as "essential" to clinical practice in the intensive care unit. Results: Of the 272 items in the first round, 188 were deemed essential. In round 2, 11 of the 62 items that failed to reach consensus in round 1 were additionally deemed essential. No item was added to the "essential" consensus in round 3. In total, 199 items were therefore deemed essential as a minimum standard of clinical practice. Participants agreed that 42 items were not essential and failed to reach agreement on 31 others. Identified 199 items were different from those in the UK and Australia due to national laws, cultural and historical backgrounds. Conclusions: This is the first study to develop a consensus-based minimum clinical practice standard for physical therapists working in intensive care units in Japan.
著者
Natsuki UENO Shoichi KOYAMA Hiroshi SARUWATARI
出版者
The Institute of Electronics, Information and Communication Engineers
雑誌
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)
巻号頁・発行日
pp.2021EAP1004, (Released:2021-02-25)

We propose a useful formulation for ill-posed inverse problems in Hilbert spaces with nonlinear clipping effects. Ill-posed inverse problems are often formulated as optimization problems, and nonlinear clipping effects may cause nonconvexity or nondifferentiability of the objective functions in the case of commonly used regularized least squares. To overcome these difficulties, we present a tractable formulation in which the objective function is convex and differentiable with respect to optimization variables, on the basis of the Bregman divergence associated with the primitive function of the clipping function. By using this formulation in combination with the representer theorem, we need only to deal with a finite-dimensional, convex, and differentiable optimization problem, which can be solved by well-established algorithms. We also show two practical examples of inverse problems where our theory can be applied, estimation of band-limited signals and time-harmonic acoustic fields, and evaluate the validity of our theory by numerical simulations.
著者
Hidemasa Nakaminami Hinako Kawasaki Shunsuke Takadama Hiroshi Kaneko Yoshiko Suzuki Hiroshi Maruyama Norihisa Noguchi
出版者
National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee
雑誌
Japanese Journal of Infectious Diseases (ISSN:13446304)
巻号頁・発行日
vol.74, no.1, pp.82-84, 2021-01-29 (Released:2021-01-22)
参考文献数
15
被引用文献数
8

In the last decade, methicillin-resistant Staphylococcus aureus (MRSA) has been identified in livestock animals, such as swine, poultry, and veal calves, and has been termed livestock-associated MRSA (LA-MRSA). LA-MRSA sequence type (ST) 398 strains can effectively infect and colonize humans, with subsequent human-to-human transmission in both community and hospital settings. Unlike other countries, LA-MRSA had not been reported in Japanese patients until 2019. However, we recently reported a case of intractable arthritis caused by an LA-MRSA CC398 (ST1232) clone, which is a single-locus variant of ST398, in a patient in Tokyo, Japan, with no animal contact (Nakaminami H, et al. Emerg Infect Dis. 2020; 26: 795-7.). Uniquely, the strain was positive for Panton-Valentine leukocidin. Here, we report the second such case in Japan. To prevent the dissemination of LA-MRSA in the Japanese community, the prevalence of the CC398 MRSA clone should be closely monitored in the future.
著者
Sachiko Bandai Ken Okamura Megumi Fujikawa Kaori Sato Hiroshi Ikenoue Takanari Kitazono
出版者
The Japan Endocrine Society
雑誌
Endocrine Journal (ISSN:09188959)
巻号頁・発行日
vol.66, no.6, pp.535-545, 2019 (Released:2019-06-28)
参考文献数
46
被引用文献数
2 33

Since there have been few reports on the long-term prognosis of Graves’ hyperthyroidism, the prognosis of 549 Graves’ hyperthyroidism patients initially treated with thionamide and followed for >8 (range: 8.6–36.4) years was studied, evaluating the change in the TSH binding inhibitor immunoglobulin activity (TBII). The distribution of the time required for the first disappearance of TBII was normal after logarithmic conversion, and the mean ± 2 SD was 1.5 (0.3–8.1) years. TBII became negative once within 5 years in 78.9% of patients. However, TBII re-elevation was observed in 47.8% of this group (fluctuating type). Remission was observed in 88.9% of the non-fluctuating type (smooth remission) and 37.2% of the fluctuating type patients. TBII remained positive for >5 years in 21.1% (smoldering type) of patients, with remission observed in only 19.8% of patients. Final remission was observed in 301 (54.8%) patients; the median time to remission was 6.8 (interquartile range: 4.0–10.9) years. A longer time until normalization of TBII and higher final thyroid weight were associated with a poor prognosis. Spontaneous hypothyroidism was observed in 6.0% of patients, independent of the TBII change. Our findings suggest that remission of Graves’ hyperthyroidism mostly occurred after 4–11 years treatment. While predicting the prognosis before therapy was difficult, the clinical course may suggest a better prognosis if TBII disappears within five years without TBII fluctuation or enlargement of the goiter. Patients may safely wait more than five years to undergo ablative therapy if they hope to avoid permanent hypothyroidism.
著者
Junya KOGUCHI Shinnosuke TAKAMICHI Masanori MORISE Hiroshi SARUWATARI Shigeki SAGAYAMA
出版者
The Institute of Electronics, Information and Communication Engineers
雑誌
IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)
巻号頁・発行日
vol.E103-D, no.12, pp.2673-2681, 2020-12-01
被引用文献数
2

We propose a speech analysis-synthesis and deep neural network (DNN)-based text-to-speech (TTS) synthesis framework using Gaussian mixture model (GMM)-based approximation of full-band spectral envelopes. GMMs have excellent properties as acoustic features in statistic parametric speech synthesis. Each Gaussian function of a GMM fits the local resonance of the spectrum. The GMM retains the fine spectral envelope and achieve high controllability of the structure. However, since conventional speech analysis methods (i.e., GMM parameter estimation) have been formulated for a narrow-band speech, they degrade the quality of synthetic speech. Moreover, a DNN-based TTS synthesis method using GMM-based approximation has not been formulated in spite of its excellent expressive ability. Therefore, we employ peak-picking-based initialization for full-band speech analysis to provide better initialization for iterative estimation of the GMM parameters. We introduce not only prediction error of GMM parameters but also reconstruction error of the spectral envelopes as objective criteria for training DNN. Furthermore, we propose a method for multi-task learning based on minimizing these errors simultaneously. We also propose a post-filter based on variance scaling of the GMM for our framework to enhance synthetic speech. Experimental results from evaluating our framework indicated that 1) the initialization method of our framework outperformed the conventional one in the quality of analysis-synthesized speech; 2) introducing the reconstruction error in DNN training significantly improved the synthetic speech; 3) our variance-scaling-based post-filter further improved the synthetic speech.
著者
Hiroshi G. Takahashi Takuya Yamazaki
出版者
Meteorological Society of Japan
雑誌
SOLA (ISSN:13496476)
巻号頁・発行日
vol.16, pp.206-211, 2020 (Released:2020-11-04)
参考文献数
15
被引用文献数
2

This study investigated the impact of sea surface temperature (SST) on a snowfall event of late January 2018 on Kanto, Honshu, Japan, associated with an extratropical cyclone (south-coast cyclone) along the Pacific side, during the Kuroshio large meandering period by a regional atmospheric model. We addressed SST impacts on the snowfall event under almost the same synoptic-scale conditions, such as extratropical cyclone, in a framework of lateral boundary forcing. We conducted control experiments (KLM) with SST of the Kuroshio large meandering, and sensitivity experiments (NKLM) prescribed non-Kuroshio large meandering SSTs. Observational results showed that SST anomalies south of Tokai, and east of northern Kanto and Tohoku could be candidates to modify a snowfall event. As simulated results, timings of snowfall and precipitation associated with the extratropical cyclone was reproduced. Unlike what has been suggested, the SST impact south of Tokai on snowfall was not clear. However, the SST east of northern Kanto and Tohoku showed a significant impact. This impact was explained by southward advection of modified air-mass from east of northern Kanto and Tohoku. Additional sensitivity experiments supported this result. This study implies the importance of the SST anomaly east of northern Kanto and Tohoku for snowfall in Tokyo.
著者
YAMAJI Moeka TAKAHASHI Hiroshi G. KUBOTA Takuji OKI Riko HAMADA Atsushi TAKAYABU Yukari N.
出版者
Meteorological Society of Japan
雑誌
気象集誌. 第2輯 (ISSN:00261165)
巻号頁・発行日
pp.2020-038, (Released:2020-05-27)
被引用文献数
18

This study investigates the global drop size distribution (DSD) of rainfall and its relationship to large-scale precipitation characteristics using the Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) Core Observatory. This study focuses on seasonal variations in the dominant precipitation systems regarding variations in DSD. A mass-weighted mean diameter (Dm), which is estimated based on the dual-frequency information derived from the GPM/DPR, is statistically analyzed as a typical parameter of the DSD. Values of the annual mean Dm, in general, are larger over land than over the oceans, and the relationship between Dm and precipitation rate (R) is not a simple one-to-one relationship. Furthermore, Dm exhibits statistically significant seasonal variations, specifically over the northwest Pacific Ocean, whereas R shows insignificant variations, indicating the variations in R cannot explain the distinct seasonal changes in Dm. Focusing on the seasonal variation in Dm over the northwest Pacific Ocean, the results indicate that the variation in Dm is related to the seasonal change in the dominant precipitation systems. In the summer over the northwest Pacific Ocean, Dm is related to the organized precipitation systems associated with the Baiu front over the mid-latitudes and tropical disturbances over the subtropical region, with relatively higher precipitation top heights, composed of both stratiform and convective precipitations. Contrary to the summer, larger Dm over the mid-latitudes in winter is related to extratropical frontal systems with ice particles in the upper layers, which consists of more stratiform precipitation in the storm track region. The smaller Dm over the subtropical northwest Pacific Ocean in winter is associated with shallow convective precipitation systems with trade-wind cumulus clouds and cumulus congestus under the subtropical high.
著者
Mikito Hayakawa Yuji Matsumaru Nobuyuki Sakai Hiroshi Yamagami Koji Iihara Kuniaki Ogasawara Hidenori Oishi Yasushi Ito Kenji Sugiu Shinichi Yoshimura for the STrategy of Optimal carotid revascularization for high-risk Patients of Cerebral Hyperperfusion Syndrome (STOP CHS) study group
出版者
The Japanese Society for Neuroendovascular Therapy
雑誌
Journal of Neuroendovascular Therapy (ISSN:18824072)
巻号頁・発行日
pp.oa.2017-0009, (Released:2017-03-27)
参考文献数
30
被引用文献数
5

Objective: Cerebral hyperperfusion syndrome (CHS) including intracranial hemorrhage (ICH) is a serious complication after carotid artery stenting (CAS). Therefore, neurointerventionalists in Japan commonly stratify the risk for CHS preprocedurally in CAS candidates using various imaging tests that are available, and sometimes performed preventive methods against CHS, such as staged angioplasty (SAP), undersized-balloon angioplasty followed by delayed CAS. In the current study, we used a nationwide questionnaire survey to clarify the current status of the periprocedural management against CHS and the 30-day outcomes of patients with a high risk of CHS after undergoing CAS or endovascular carotid revascularization procedures, such as SAP or stand-alone angioplasty. This study specifically analyzed the data for the periprocedural management against CHS.Materials and Methods: Between June and August 2014, questionnaires were emailed to all of the neurointerventional specialists certified by the Japanese Society for Neuroendovascular Therapy (JSNET). If two or more specialist physicians belonged to an institute, a representative physician of the institute answered the questionnaire. This study focused on 14 items of the questionnaire that were directed at examining the preprocedural imaging tests done to evaluate the risk of CHS, the periprocedural management strategies used to prevent CHS, and the postprocedural imaging tests to detect hyperperfusion phenomenon, among others.Results: Replies were obtained from 154 institutes which represented 336 JSNET-certified neurointerventional specialists. Preprocedural imaging tests done to evaluate the risk of CHS were performed in 144 institutes (93.5%), with single-photon emission CT (SPECT) the most used modality in 88.2% of the institutes. Acetazolamide challenge was performed in 114 (89.8%) of 127 institutes that used preprocedural SPECT evaluation. Of the institutes performing preprocedural CHS-risk evaluation, general anesthesia was administered during the procedure in 44.4%, periprocedural edaravone (a free radical scavenging agent) was used in 52.1%, and periprocedural strict blood pressure control was performed in 91.7%. Postprocedural intravenous anticoagulation therapy was not used for patients with a high risk of CHS in 63.2%. Postprocedural imaging tests to detect hyperperfusion phenomenon were undertaken in 99.3% of the institutes performing preprocedural CHS-risk evaluation. The leading imaging modality, SPECT, was used in 78.3%. SAP was attempted or performed in 27.1% of the institutes.Conclusion: The present study demonstrated that Japanese practitioners attempt to prevent CHS after carotid endovascular revascularization procedures. Most Japanese neurointerventionalists preprocedurally evaluated the risk of CHS in CAS candidates primarily using SPECT with acetazolamide challenge. The penetration rate for SAP was 27.1% of the institutes.