アフリカにおける気候・陸域生態系の変化による火災起源ブラックカーボン放出の時空間変動性

Tohoku University山崎剛課

Evaluation of the Roller Arrangements for the Ball-Dribbling Mechanisms Adopted by RoboCup Teams

The middle-size league soccer competition is an important RoboCup event designed to promote advancements in Artificial Intelligence (AI) and robotics. In recent years, soccer robots using a dribbling mechanism, through which the ball is controlled using two driving rollers, have been adopted by teams worldwide. A survey conducted during the 2017 World Cup in Nagoya revealed that the teams determined their roller arrangements heuristically without the use of a formal mathematical process. In this study, we focus on sphere slip speed to develop a mathematical model for sphere rotational motion, allowing for slip. Using this framework, we derived the relationship between the sphere slip and mobile speeds and evaluated the roller arrangements used by the participating teams

Can Superflares Occur on Our Sun?

Recent observations of solar type stars with the Kepler satellite by Maehara et al. have revealed the existence of superflares (with energy of 10^33 - 10^35 erg) on Sun-like stars, which are similar to our Sun in their surface temperature (5600 K - 6000 K) and slow rotation (rotational period > 10 days). From the statistical analysis of these superflares, it was found that superflares with energy 10^34 erg occur once in 800 years and superflares with 10^35 erg occur once in 5000 years on Sun-like stars. In this paper, we examine whether superflares with energy of 10^33 - 10^35 erg could occur on the present Sun through the use of simple order-of-magnitude estimates based on current ideas relating to the mechanisms of the solar dynamo.Comment: Accepted by Publ. Astron. Soc. Japan on Dec. 6, 2012 (to be published on PASJ vol. 65, No. 3, (2013) June 25

Isolation and characterization of cancer stem cells derived from human glioblastoma

Cancer stem cell (CSC) is considered as a cause of cancer recurrence and metastasis. Simultaneously CSCs are responsible for the heterogeneous population in tumor tissues due to their differentiation potential. However, the characterizations of CSCs are still not enough and cancer stem cell lines widely available is desired to be established for the advancement of cancer research. In this study, we tried to isolate and characterize stem like cells from human glioblastoma cell line U-251MG cells. U-251MG P1 cells, which was previously condensed in the presence of hyaluronic acid as CD44 positive population were subjected to single cell isolation procedure. Although 5 clones were isolated, only one clone exhibited high expression of CD44, Nanog, OCT3/4 and SOX2, and named U-251MGSC1. The sphere forming ability of U-251MGSC1 cell was significantly higher than the parental U-251MG cells. Tumorigenicity of U-251MG-SC1 cells were higher than that of U-251MG cells. U-251MGSC1 cells exhibited higher expression of CD44, SOX2, Nestin and A2B5 than U-251MG cells in vitro and in vivo. The expression of GFAP and NF-M was enhanced when the cells were treated with the conditioned medium of U-251MG cells indicating the potential of differentiation. Sphere forming ability was more efficient than that of U-251MG cells and was enhanced in the presence of hyaluronic acid, which enhanced the cell growth as well. U-251MGSC1 cells exhibited rapid growth tumor in nude mice and efficient metastatic ability in transmembrane assay when compared with U-251MG cells. As the result, we concluded U-251MGSC1 cell was a glioblastoma CSC line derived from the parental U-251MG cells. U-251MGSC1 cells will be a good tool to develop effective therapeutic agents against CSCs and to elucidate the properties of glioma derived CSCs and the mechanism of tumor development in brain

IGF-1 Induction by Acylated Steryl β-Glucosides Found in a Pre-Germinated Brown Rice Diet Reduces Oxidative Stress in Streptozotocin-Induced Diabetes

BACKGROUND: The pathology of diabetic neuropathy involves oxidative stress on pancreatic β-cells, and is related to decreased levels of Insulin-like growth factor 1 (IGF-1). Acylated steryl β-glucoside (PR-ASG) found in pre-germiated brown rice is a bioactive substance exhibiting properties that enhance activity of homocysteine-thiolactonase (HTase), reducing oxidative stress in diabetic neuropathy. The biological importance of PR-ASG in pancreatic β-cells remains unknown. Here we examined the effects of PR-ASG on IGF-1 and glucose metabolism in β-cells exposed to oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, a pre-germinated brown rice (PR)-diet was tested in streptozotocin (STZ)-induced diabetic rats. Compared with diabetic rats fed control diets, the PR-diet fed rats showed an improvement of serum metabolic and neurophysiological parameters. In addition, IGF-1 levels were found to be increased in the serum, liver, and pancreas of diabetic rats fed the PR-diet. The increased IGF-1 level in the pancreas led us to hypothesize that PR-ASG is protective for islet β-cells against the extensive injury of advanced or severe diabetes. Thus we examined PR-ASG to determine whether it showed anti-apoptotic, pro-proliferative effects on the insulin-secreting β-cells line, INS-1; and additionally, whether PR-ASG stimulated IGF-1 autocrine secretion/IGF-1-dependent glucose metabolism. We have demonstrated for the first time that PR-ASG increases IGF-1 production and secretion from pancreatic β-cells. CONCLUSION/SIGNIFICANCE: These findings suggest that PR-ASG may affect pancreatic β-cells through the activation of an IGF-1-dependent mechanism in the diabetic condition. Thus, intake of pre-germinated brown rice may have a beneficial effect in the treatment of diabetes, in particular diabetic neuropathy

チイキ ホケン ニオケル ナイゾウ シボウ ショウコウグン キケン インシ ホユウシャ ニ タイスル ホスウケイ オヨビ インサツブツ オ モチイタ ケンコウ キョウシツ ノ ジッシ

本研究は, 健康教育を目的とした健康教室において, 歩数計の貸与, 運動および栄養に関する健康情報を掲載した印刷物を配布し, 5ケ月間(2008年10月から2009年3月)の介入を行った。対象は, 京都市南部の精華町在住の40-74歳の特定健診における腹囲, 血糖, 脂質, 血圧のリスクに1つでも該当する者(総数694名, 男性313名, 女性381名)のうち, 本研究に参加意思のあった52名(男性23名, 女性29名)であった。介入前後の評価指標は, 歩数, 身体組成および血圧を用いた。その結果, 介入期間中に有意な歩数の増減は認められなかった。しかし, 介入開始時の1日平均歩数が7,500歩未満または以上で介入期間中の歩数増加量を検討すると, 終了時には7,500歩未満群が約1,200歩/日増加した。本研究により, 健康教室, 歩数計および印刷物による介入は, 身体活動量の低い者の身体活動量を増加させることが示唆された