Modeling Nonlinear Dynamics in Continuous Time with Inductive Biases on Decay Rates and/or Frequencies

We propose a neural network-based model for nonlinear dynamics in continuous time that can impose inductive biases on decay rates and/or frequencies. Inductive biases are helpful for training neural networks especially when training data are small. The proposed model is based on the Koopman operator theory, where the decay rate and frequency information is used by restricting the eigenvalues of the Koopman operator that describe linear evolution in a Koopman space. We use neural networks to find an appropriate Koopman space, which are trained by minimizing multi-step forecasting and backcasting errors using irregularly sampled time-series data. Experiments on various time-series datasets demonstrate that the proposed method achieves higher forecasting performance given a single short training sequence than the existing methods

バナジン酸によるエンドウ培養細胞におけるフィトアレキシン生産の誘導

We previously reported that the addition of orthovanadate suppressed the defense responses of plant differentiated tissues induced by a fungal elicitor.In this report,the effect of orthovanadate on the defense response of pea cultured cells was examined.The activities of ATPase and PI metabolism in plasma membrance fraction,which was prepared from suspension-cultured cells,were inhibited in vitro by orthovanadate as well as those in plasma membrances from pea epicotyl tissues. However,orthovanadate alone induced the accumulation of a phytoalexin, pisatin in suspention-clutured cells of pea in a manner similar to CuCl2.The viability of pea suspension-cultured cells was decreased by orthovanadate as well as by CuCl2.These results indicated that orthovanadate acts as an abiotic elicitor to pea suspension-cultured cell as observed in those of red bean,peanut and Perunia hybrida.バナジン酸は、エンドウ組織に褐紋病菌エリシターの処理で誘導される一連の防御応答を抑制することが報告されている。そこで、本研究ではバナジン酸のエンドウ培養細胞に対する影響を調べた。バナジン酸は培養細胞から分離した原形質膜画分のポリホスホイノシチド代謝系関連酵素やATPaseの活性を濃度依存的に阻害した。次に、褐紋病菌エリシター、塩化銅（非生物的エリシターの一種）、およびバナジン酸のin vivoでの影響を調べたところ、いずれの単独処理においてもエンドウ培養細胞のピサチン生産を誘導した。褐紋病菌エリシターはエンドウ培養細胞の細胞死（FDAの染色性喪失）を誘導しなかったが、塩化銅、バナジン酸は明らかな毒性を示した。以上の結果とこれまでの知見に基づいて、エンドウ培養細胞に対しては非生物的エリシターとして作用するバナジン酸の作用機構を考察した

バナジン酸によるエンドウ培養細胞におけるフィトアレキシン生産の誘導

We previously reported that the addition of orthovanadate suppressed the defense responses of plant differentiated tissues induced by a fungal elicitor.In this report,the effect of orthovanadate on the defense response of pea cultured cells was examined.The activities of ATPase and PI metabolism in plasma membrance fraction,which was prepared from suspension-cultured cells,were inhibited in vitro by orthovanadate as well as those in plasma membrances from pea epicotyl tissues. However,orthovanadate alone induced the accumulation of a phytoalexin, pisatin in suspention-clutured cells of pea in a manner similar to CuCl2.The viability of pea suspension-cultured cells was decreased by orthovanadate as well as by CuCl2.These results indicated that orthovanadate acts as an abiotic elicitor to pea suspension-cultured cell as observed in those of red bean,peanut and Perunia hybrida.バナジン酸は、エンドウ組織に褐紋病菌エリシターの処理で誘導される一連の防御応答を抑制することが報告されている。そこで、本研究ではバナジン酸のエンドウ培養細胞に対する影響を調べた。バナジン酸は培養細胞から分離した原形質膜画分のポリホスホイノシチド代謝系関連酵素やATPaseの活性を濃度依存的に阻害した。次に、褐紋病菌エリシター、塩化銅（非生物的エリシターの一種）、およびバナジン酸のin vivoでの影響を調べたところ、いずれの単独処理においてもエンドウ培養細胞のピサチン生産を誘導した。褐紋病菌エリシターはエンドウ培養細胞の細胞死（FDAの染色性喪失）を誘導しなかったが、塩化銅、バナジン酸は明らかな毒性を示した。以上の結果とこれまでの知見に基づいて、エンドウ培養細胞に対しては非生物的エリシターとして作用するバナジン酸の作用機構を考察した