ヒナハゼ ハ トウキョウワン オクブ デ サンラン スル

東京湾が分布の北限となっているヒナハゼが東京湾の奥部で産卵していることを、2017 年5 月22 日から8 月25 日にかけて、東京海洋大学品川キャンパスの繋船場に設置した人工巣を使って明らかにした。調査期間中に4 日（5 月22 日と8 月4、9、25 日）、人工巣のカキ殻に卵が産みつけられていることを確認した。6 月14 日には、水槽に収容した3個体（雌2 個体と雄1 個体）が産卵し、雄が卵を守っていた。産卵を確認してすぐの卵の長径と短径の平均±標準偏差（SD）は1.46±0.025 mm と0.45±0.008 mm（個体数7）であった。形はいわゆる“こん棒状”で、細くなった方の先端に付着糸があり、反対側のやや太い方では先端部が少しくびれていた。卵を確認して4 日目に仔魚が孵化したことを確認した。孵化後1 日目の仔魚の平均体長±SD は1.95±0.168 mm（4 個体）であった。孵化後4 日目にはすべての仔魚が斃死した。The spawning of marble goby Redigobius bikolanus, of which northern limit of the distribution is Tokyo Bay, was confirmed at the innermost Tokyo Bay by using artificial nests set up from 22 May to 25 August 2017 at the mooring berth called as a pond in Shinagawa Campus, Tokyo University of Marine Science and Technology. During the period, egg-masses spawned on oyster shells in artificial nests were recognized in four days, 22 May and 4,9 and 25 August. A spawning was confirmed in 14 June in an aquarium, in which three individuals of a pair and one female collected from the artificial nest in 9 and 13 June, respectively, had been reared. The mean±SD of the size of eggs was 1.46±0.025 mm in the major axis and 0.45±0.008 mm in the minor axis (7 individuals). Larvae hatched out in four days after the recognition of spawning, the size measured in the following day being 1.95±0.168 mm in body length (4 individuals). All the larvae died four days after the recognition of hatching.石川新・河野博: 東京海洋大学魚類学研究室河野博: 東京海洋大学学術研究院海洋環境科学部

Bright X-ray flares from the BL Lac object Mrk 421, detected with MAXI in 2010 January and February

Strong X-ray flares from the blazar Mrk 421 were detected in 2010 January and February through the 7 month monitoring with the MAXI GSC. The maximum 2 -- 10 keV flux in the January and February flares was measured as 120 +- 10 mCrab and 164 +- 17 mCrab respectively; the latter is the highest among those reported from the object. A comparison of the MAXI and Swift BAT data suggests a convex X-ray spectrum with an approximated photon index of about 2. This spectrum is consistent with a picture that MAXI is observing near the synchrotron peak frequency. The source exhibited a spectral variation during these flares, slightly different from those in the previous observations, in which the positive correlation between the flux and hardness was widely reported. By equating the halving decay timescale in the January flare, $t_{\rm d} \sim 2.5 \times 10^{4}$ s, to the synchrotron cooling time, the magnetic field was evaluated as B = 0.045 G $(\delta/10)^{-1/3}$, where $\delta$ is the jet beaming factor. Assuming that the light crossing time of the emission region is shorter than the doubling rise time, $t_{\rm r} \lesssim 2 \times 10^{4}$ s, the region size was roughly estimated as $R < 6 \times 10^{15}$ cm $(\delta/10)$. These are consistent with the values previously reported. For the February flare, the rise time, $t_{\rm r} < 1.3 \times 10^{5}$ s, gives a loose upper limit on the size as $R < 4 \times 10^{16}$ cm $(\delta/10)$, although the longer decay time $t_{\rm d} \sim 1.4 \times 10^{5}$ s, indicates B = 0.015 G $(\delta/10)^{-1/3}$, which is weaker than the previous results. This could be reconciled by invoking a scenario that this flare is a superposition of unresolved events with a shorter timescale.Comment: 14 pages, 4 figures, accepted for PASJ (Vol. 62 No. 6

MAXI GSC observations of a spectral state transition in the black hole candidate XTE J1752-223

We present the first results on the black hole candidate XTE J1752-223 from the Gas Slit Camera (GSC) on-board the Monitor of All-sky X-ray Image (MAXI) on the International Space Station. Including the onset of the outburst reported by the Proportional Counter Array on-board the Rossi X-ray Timing Explorer on 2009 October 23, the MAXI/GSC has been monitoring this source approximately 10 times per day with a high sensitivity in the 2-20 keV band. XTE J1752-223 was initially in the low/hard state during the first 3 months. An anti-correlated behavior between the 2-4 keV and 4-20 keV bands were observed around January 20, 2010, indicating that the source exhibited the spectral transition to the high/soft state. A transient radio jet may have been ejected when the source was in the intermediate state where the spectrum was roughly explained by a power-law with a photon index of 2.5-3.0. The unusually long period in the initial low/hard state implies a slow variation in the mass accretion rate, and the dramatic soft X-ray increase may be explained by a sudden appearance of the accretion disk component with a relatively low innermost temperature (0.4-0.7 keV). Such a low temperature might suggest that the maximum accretion rate was just above the critical gas evaporation rate required for the state transition.Comment: Publication of Astronomical Society of Japan Vol.62, No.5 (2010) [in print

Gastric mucosal levels of prostaglandins and leukotrienes in patients with gastric ulcer after treatment with rabeprazole in comparison to treatment with ranitidine

AIM : Prostaglandins (PGs) and leukotrienes (LTs) are major factors involved in the defense of the gastric mucosa against ulcer formation. However, little is still known about the gastromucosa-protecting action of proton pump inhibitors (PPIs) and histamine H2 receptor antagonists (H2 blockers) in patients with gastric ulcer. We therefore examined the effectiveness of a PPI in protecting the gastric mucosa. METHODS : We compared the PGE2 and LTB4 levels and the expression levels of cyclooxygenase (COX)-1 and COX-2 mRNA in the gastric mucosa in gastric ulcer patients between the group treated for 8 weeks with a PPI, rabeprazole (PPI group ; n=5), and the group treated for 8 weeks with an H2 blocker, ranitidine (H2 blocker group ; n=6), as well as in nonulcer subjects (control group ; n=5). RESULTS : The mucosal levels of PGE2 and COX-2 mRNA expression were significantly lower in the ulcer patients than those in the nonulcer patients, whereas the LTB4 level was significantly higher in the ulcer patients than that in the nonulcer patients, and it was also significantly lower in the ulcerated mucosa than that in the nonulcerated mucosa. The PPI group had a significantly increased PGE2 and decreased LTB4 levels in comparison to the H2 blocker group during the ulcer-healing stage. The COX-1 mRNA expression showed no difference among the PPI and H2 blocker groups or between before and after the treatment. However, the COX-2 mRNA expression increased in the PPI group more than that in the H2 blocker group during the ulcer-healing stage. CONCLUSION : These findings demonstrated the significant gastric-mucosa-protecting effect of PPI by increasing the PGE2 production and reducing the LTB4 production

A Large X-ray Flare from a Single Weak-lined T Tauri Star TWA-7 Detected with MAXI GSC

We present a large X-ray flare from a nearby weak-lined T Tauri star TWA-7 detected with the Gas Slit Camera (GSC) on the Monitor of All-sky X-ray Image (MAXI). The GSC captured X-ray flaring from TWA-7 with a flux of $3\times10^{-9}$ ergs cm$^{-2}$ s$^{-1}$ in 2--20 keV band during the scan transit starting at UT 2010-09-07 18:24:30.The estimated X-ray luminosity at the scan in the energy band is 3$\times10^{32}$ ergs s$^{-1}$,indicating that the event is among the largest X-ray flares fromT Tauri stars.Since MAXI GSC monitors a target only during a scan transit of about a minute per 92 min orbital cycle, the luminosity at the flare peak might have been higher than that detected. At the scan transit, we observed a high X-ray-to-bolometric luminosity ratio, log $L_{\rm X}/L_{\rm bol}$ = $-0.1^{+0.2}_{-0.3}$; i.e., the X-ray luminosity is comparable to the bolometric luminosity. Since TWA-7 has neither an accreting disk nor a binary companion, the observed event implies that none of those are essential to generate such big flares in T Tauri stars.Comment: 4 pages, 2 figures, 1 table accepted for publication in PAS

Concomitant administration of radiation with eribulin improves the survival of mice harboring intracerebral glioblastoma

Glioblastoma is the most common and devastating type of malignant brain tumor. We recently found that eribulin suppresses glioma growth in vitro and in vivo and that eribulin is efficiently transferred into mouse brain tumors at a high concentration. Eribulin is a non‐taxane microtubule inhibitor approved for breast cancer and liposarcoma. Cells arrested in M‐phase by chemotherapeutic agents such as microtubule inhibitors are highly sensitive to radiation‐induced DNA damage. Several recent case reports have demonstrated the clinical benefits of eribulin combined with radiation therapy for metastatic brain tumors. In this study, we investigated the efficacy of a combined eribulin and radiation treatment on human glioblastoma cells. The glioblastoma cell lines U87MG, U251MG and U118MG, and SJ28 cells, a patient‐derived sphere culture cell line, were used to determine the radiosensitizing effect of eribulin using western blotting, flow cytometry and clonogenic assay. Subcutaneous and intracerebral glioma xenografts were generated in mice to assess the efficacy of the combined treatment. The combination of eribulin and radiation enhanced DNA damage in vitro. The clonogenic assay of U87MG demonstrated the radiosensitizing effect of eribulin. The concomitant eribulin and radiation treatment significantly prolonged the survival of mice harboring intracerebral glioma xenografts compared with eribulin or radiation alone (P < .0001). In addition, maintenance administration of eribulin after the concomitant treatment further controlled brain tumor growth. Aberrant microvasculature was decreased in these tumors. Concomitant treatment with eribulin and radiation followed by maintenance administration of eribulin may serve as a novel therapeutic strategy for glioblastomas

ギョルイ コッカク ヒョウホン オ モチイタ ESD ノ レイ アユ ノ チギョ ノ ハ オ カンサツ シテ セイタイ ト ノ カンケイ オ シロウ

本研究は、透明骨格二重染色標本を海洋環境教育や理科教育を含めたESD（Education for Sustainable Development：持続的発展教育）で利活用できることを実証する事例の第三弾である。ここでは、アユ仔魚の透明標本の歯を観察することで、形態と生態を理解しようと試み、その有効性を事前と事後のアンケートにもとづいて調査した。対象としたのは、5 つのイベントに参加した16 歳から80 歳の男性29 名、女性31 名、計60 名である。プログラムは、アユの生活史、顕微鏡の使い方、透明標本の基礎知識、主題1（体長20mm 前後の個体の歯の探索）、および主題2（体長30mm 前後の個体の歯の観察）の順に進めた。プログラムの前には参加者は全員アユの仔魚に歯が生えていることを知らなかった。しかし、事後のアンケートによると、内翼状骨や基舌骨、基鰓骨などの歯を観察し、これらの歯で動物プランクトンを摂餌することを理解したと判断できた。This study is the third round in a project to utilize double stained fish transparent specimens for ESD (Education for Sustainable Development) including science, marine and environmental education. In this round, fish transparent specimens were applied to a study of the relationships between morphology and ecology through the observation of teeth in ayu Plecoglossus altivelis altivelis larvae, and its effectiveness was investigated by the preand post-intervention questionnaire. The research examined 60 participants in five learning interventions, the age ranging from 16 to 80 with a mean of 37.1 years old and the sex ratio being 31 females and 29 males. The program was composed of the followings: the life history of ayu, which is a diadromous fish migrating between the river and the sea; how to use the microscope; the basic knowledge of bones; main observation 1, searching teeth of ca. 20 mm in body length (BL) specimens; and main observation 2, searching and observing teeth of ca. 30mm BL specimens.Although no participants recognized the presence of teeth in ayu larvae in the pre-intervention questionnaire, all of them would observe the teeth on bones such as the endopterygoid, basihyal, basibranchial, dentary and upper and lower pharyngeals and understand that the larvae would seize zooplankton during their marine life by using these teeth.河野博: 東京海洋大学学術研究院海洋環境科学部門河野博・デイビッド エリック アンマリサン・石川 新・新城遥己・小野寺暁・手良村知功: 東京海洋大学魚類学研究