Sodium temperature lidar based on injection seeded Nd:YAG pulse lasers using a sum-frequency generation technique

We report on a sodium (Na) temperature lidar based on two injection seeded Nd:YAG pulse lasers using single-pass sum-frequency generation. The laser power at 589 nm is 400 mW (40 mJ per pulse at a repetition rate of 10 Hz) and the pulse width is 22 nsec FWHM. The narrowband laser tuned to the Doppler broadened Na D(2) spectrum enables us to measure the temperature of the mesopause region (80-115 km). This solid-state transportable system demonstrated high performance and capability at Syowa Station in Antarctica for 3 years and at Uji in Japan for an additional year without any major operational troubles. (C) 2011 Optical Society of AmericaArticleOPTICS EXPRESS. 19(4):3553-3561 (2011)journal articl

Sodium temperature lidar observation at Syowa Station: Summary of three-year observations and unusually high temperature in 2002

Total 223 nights (2002 hours) of temperature measurement in the mesopause region (80-105 km) was successfully done in wintertime at Syowa Station (69ºS, 39ºE) starting from 2000 through 2002. Monthly mean temperatures were calculated using nightly mean temperatures and year-to-year variation was examined. The monthly temperature of 2002 shows unusually higher (25 K and 20 K) in June and July compared with previous 2 years. Variations of individual nights showed the temperatures at 80 km, 85 km and 110 km are in good agreement among three years through the observation period. The temperature of 2002 began to increase from the middle of May and was back to normal around the end of July in the limited altitude range of 90-105 km

First mesopause temperature measurements using sodium lidar observations in the Antarctic region

The mesopause temperature structure was observed using a sodium temperature lidar system at Syowa Station (69°00\u27 S, 39°35\u27 E), beginning in February 2000. The laser transmitter was newly developed and included two injection-seeded Nd: YAG lasers. Regular observations were performed using the two-frequency technique as demonstrated by C.Y. She et al. (Geophys. Res. Lett., 17, 929, 1990), with a spatial resolution of about 1 km and a temporal resolution of 6 min. The temperature structures of the 85km to 105km region of the upper atmosphere were measured by Na D_2 Doppler profile-fitting as well as the two-frequency technique. Temperatures derived from the two techniques agreed well and were consistent with the MSIS 90 model temperature structure. Night-time temperature variations over a 15-hour period were measured in May 2000. A large temperature fluctuation with an interval of about 4 hours, and an amplitude of 60 K (probably caused by gravity waves) was observed. From the average night temperature profile, the mesopause was determined to be located at 102km, and have a temperature of 180K. These values are similar to winter values observed in the northern hemisphere

Study on variation of neutral temperature in the polar MLT region using a sodium LIDAR at Tromsø

第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月14日（月） 国立極地研究所 2階大会議

Laser-induced fluorescence imaging of plants using a liquid crystal tunable filter and charge coupled device imaging camera

ArticleReview of Scientific Instruments. 76, 106103 (2005)journal articl

A statistical study of convective and dynamic instabilities in the polar upper mesosphere above Tromsø

We have studied the convective (or static) and dynamic instabilities between 80 and 100 km above Tromsø (69.6° N, 19.2° E) using temperature and wind data of 6 min and 1 km resolutions primarily almost over a solar cycle obtained with the sodium lidar at Tromsø. First, we have calculated Brunt–Väisälä frequency (N) for 339 nights obtained from October 2010 to December 2019, and the Richardson number (Ri) for 210 nights obtained between October 2012 to December 2019. Second, using those values (N and Ri), we have calculated probabilities of the convective instability (N2<0) and the dynamic instability (0≤Ri<0.25) that can be used for proxies for evaluating the atmospheric stability. The probability of the convective instability varies from about 1% to 24% with a mean value of 9%, and that of the dynamic instability varies from 4 to 20% with a mean value of 10%. Third, we have compared these probabilities with the F10.7 index and local K-index. The probability of the convective instability shows a dependence (its correlation coefcient of 0.45) of the geomagnetic activity (local K-index) between 94 and 100 km, suggesting an auroral infuence on the atmospheric stability. The probability of the dynamic instability shows a solar cycle dependence (its correlation coefcient being 0.54). The probability of the dynamic instability shows the dependence of the 12 h wave amplitude (meridional and zonal wind components) (C.C.=0.52). The averaged potential energy of gravity waves shows decrease with height between 81 and 89 km, suggesting that dissipation of gravity waves plays an important role (at least partly) in causing the convective instability below 89 km. The probability of the convective instability at Tromsø appears to be higher than that at middle/low latitudes, while the probability of the dynamic instability is similar to that at middle/low latitudes

Sodium temperature lidar based on injection seeded Nd:YAG pulse lasers using a sum-frequency generation technique

We report on a sodium (Na) temperature lidar based on two injection seeded Nd:YAG pulse lasers using single-pass sum-frequency generation. The laser power at 589 nm is 400 mW (40 mJ per pulse at a repetition rate of 10 Hz) and the pulse width is 22 nsec FWHM. The narrowband laser tuned to the Doppler broadened Na D(2) spectrum enables us to measure the temperature of the mesopause region (80-115 km). This solid-state transportable system demonstrated high performance and capability at Syowa Station in Antarctica for 3 years and at Uji in Japan for an additional year without any major operational troubles. (C) 2011 Optical Society of AmericaArticleOPTICS EXPRESS. 19(4):3553-3561 (2011)journal articl

昭和基地高機能ライダーの機能拡張のための波長可変共鳴散乱ライダー開発の現状

第6回極域科学シンポジウム分野横断型セッション：[IM] 横断　中層大気・熱圏11月17日（火）　国立極地研究所１階交流アトリウ

Development of multi-wavelength resonance scattering lidar for the observations of the middle-and the upper-atmosphere interactions

第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月15日（火） 国立極地研究所 2階大会議室前フロ

Sequencing and Bioinformatics-Based Analyses of the microRNA Transcriptome in Hepatitis B–Related Hepatocellular Carcinoma

MicroRNAs (miRNAs) participate in crucial biological processes, and it is now evident that miRNA alterations are involved in the progression of human cancers. Recent studies on miRNA profiling performed with cloning suggest that sequencing is useful for the detection of novel miRNAs, modifications, and precise compositions and that miRNA expression levels calculated by clone count are reproducible. Here we focus on sequencing of miRNA to obtain a comprehensive profile and characterization of these transcriptomes as they relate to human liver. Sequencing using 454 sequencing and conventional cloning from 22 pair of HCC and adjacent normal liver (ANL) and 3 HCC cell lines identified reliable reads of more than 314000 miRNAs from HCC and more than 268000 from ANL for registered human miRNAs. Computational bioinformatics identified 7 novel miRNAs with high conservation, 15 novel opposite miRNAs, and 3 novel antisense miRNAs. Moreover sequencing can detect miRNA modifications including adenosine-to-inosine editing in miR-376 families. Expression profiling using clone count analysis was used to identify miRNAs that are expressed aberrantly in liver cancer including miR-122, miR-21, and miR-34a. Furthermore, sequencing-based miRNA clustering, but not individual miRNA, detects high risk patients who have high potentials for early tumor recurrence after liver surgery (P = 0.006), and which is the only significant variable among pathological and clinical and variables (P = 0,022). We believe that the combination of sequencing and bioinformatics will accelerate the discovery of novel miRNAs and biomarkers involved in human liver cancer