587 research outputs found
聴覚末梢系の機能モデルの提案－聴神経の位相固定性及びスパイク生成機構のモデル化－
No full text聴神経の発火特性を忠実に模擬可能な聴覚末梢系モデルを提案し，中枢神経系モデルの入力段としての提案モデルの有用性を示す。従来の中耳から内有毛細胞までのモデルと新規に提案するパルス列を出力する聴神経モデルを統合し，末梢系モデルを構築する。また，本末梢系モデルには，モデル出力の発火率と位相同期発火レベルを独立に制御可能な仕組みを導入する。モデル出力と生理データとを比較し，トーンバースト刺激に対するネコ聴神経の広範囲の特徴周波数に渡る発火率表現及び位相固定性と，個々の聴神経の周波数応答，発火位相，発火時間間隔，発火確率，二音抑圧に関する性質を，モデルが模擬可能であることを示す
蝸牛神経核細胞の機能モデルの提案 : 前腹側核細胞の応答特性
No full text蝸牛神経核腹側核(VCN)細胞の神経発火機構について機能モデル化を行い, 前腹側核細胞の多様な電気生理学的応答を神経発火レベルで容易に模擬可能なパラメータ数の少ない機能モデルを提案する。AVCNの電気生理学的応答に基づいて, BlackburnとSachs(1989)により詳細な条件で分類された, primary-like型(2通り), primary-like-with-notch型(1通り), sustained-chopper型(2通り), transient-chopper型(2通り), onset型(3通り)の全5種類10通りの応答型と, それぞれの応答型の発火遅延特性と位相固定性を, 提案モデルが, そのパラメータ調整により定量的に模擬可能であることを確認し, VCNの機能解明への応用可能性を示す
蝸牛神経核背側核細胞の周波数応答特性に関する神経回路モデルの提案 : トーンバースト刺激に対する応答
No full text本論文では,蝸牛神経核背側核(DCN)細胞が示す,聴覚末梢では見られない複雑な周波数応答パターン(IV型)を模擬可能な神経回路モデルを提案する。蝸牛神経核腹側核,背側核において広範囲に観察される側方抑制のみを仮定した単純な神経回路モデルを,末梢系モデルと単一神経細胞モデルを用いて構築する。モデルを用いたシミュレーションの結果,生理学的実験から得られたIV型応答とその時間応答パターンを,提案モデルにより再現できることが分かった。この結果は,DCNで観察されるIV型応答は,単純な周波数応答パターン(II,III型)を生み出す神経回路と同様に,単純な神経回路により生じている可能性を示している
下丘細胞の時間応答特性に関する計算モデルの提案
No full text中脳に位置する下丘中心核(Icc)において観察される複雑かつ多様な時間応答パターンの模擬が可能な計算モデルを提案する。Iccに関する生理学的,解剖学的実験報告に基づき,下位の神経核細胞(蝸牛神経核腹側核,又は外側毛帯核腹側核)からIcc細胞への興奮性入力とそれよりも時間的に遅れた抑制性入力という単純な神経回路により,計算モデルを構成する。モデルを用いたシミュレーションの結果,本計算モデルは,生理学的応答特性に基づいて詳細に分類されたIcc細胞の時間応答パターン,すなわち,chopper,pauser, sustained,onset,on-sustained型,及びそのサブタイプ全10種類を再現できることが分かった。この結果は,Iccにおいて観察される時間応答パターンは複雑かつ多様であっても,それを生じさせる神経回路は単純であるという可能性を示している
蝸牛神経核腹側核細胞モデルの振幅変調音に対する応答特性
No full text短音バーストに対して多様な時間応答パターンを示す蝸牛神経核腹側核(VCN)細胞は,音声に見られるような振幅変調に対して特徴的な応答を示す。VCN細胞の振幅変調(AM)音に対する応答特性を聴覚モデルを用いて神経発火レベルで模擬し,その発生メカニズムについて検討する。モデルによる検討結果から,以下の2点が示された。(1)AMの変調周波数に対するVCN細胞の発火の位相同期限界は,その細胞の純音に対する発火の位相固定限界と入力となる聴神経の変調周波数に対する位相同期発火限界に影響される。(2)短音バーストに対して規則的な時間間隔で発火するchopper型応答細胞の変調周波数に対するバンドパス型の位相同期性は,VCN細胞の不応期に起因する
Integration of read-across and artificial neural network-based QSAR models for predicting systemic toxicity: A case study for valproic acid
No full text博士(医学) 乙第3091号(主論文の要旨、要約、審査結果の要旨、本文)，著者名:Tomoka HISAKI, Maki AIBA née KANEKO, Morihiko HIROTA, Masato MATSUOKAt, Hirokazu KOUZUKI，タイトル:Integration of read-across and artificial neural network-based QSAR models for predicting systemic toxicity: A case study for valproic acid，掲載誌:The Journal of Toxicological Sciences(0388-1350)，巻・頁・年:45巻2号 p.95～108(2020)，著作権関連情報:© 2020 The Japanese Society of Toxicology.，DOI:10.2131/jts.45.95
Correction to: Comparison of glycyrrhizin content in 25 major kinds of Kampo extracts containing Glycyrrhizae Radix used clinically in Japan
No full textThe article Comparison of glycyrrhizin content in 25 major kinds of Kampo extracts containing Glycyrrhizae Radix used clinically in Japan, written by Mitsuhiko Nose, Momoka Tada, Rika Kojima, Kumiko Nagata, Shinsuke Hisaka, Sayaka Masada, Masato Homma and Takashi Hakamatsuka, was originally published Online First without open access. After publication in volume 71, issue 4, page 711–722 the author decided to opt for Open Choice and to make the article an open access publication. Therefore, the copyright of the article has been changed to © The Author(s) 2018 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.</jats:p
“Masato de Yuca” and “Chicha de Siete Semillas” Two Traditional Vegetable Fermented Beverages from Peru as Source for the Isolation of Potential Probiotic Bacteria
No full textOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by the Ibero-American Programme on Science and Technology for Development (CYTED), grant number 917PTE0537. The Spanish team was funded by the “Agencia Estatal de Investigación” and the “Fondo Europeo de Desarrollo Regional” (AEI/FEDER, UE), grant number PCIN2017-075″. The Peruvian team was funded by the National Council of Science and Technology and Innovation of Peru through its execution unit National Fund for Scientific, Technological and Technological Innovation (CONCYTEC/FONDECYT), grant No. 001–2017.In this work, two Peruvian beverages “Masato de Yuca,” typical of the Amazonian communities made from cassava (Manihot esculenta), and “Chicha de Siete Semillas,” made from different cereal, pseudo-cereal, and legume flours, were explored for the isolation of lactic acid bacteria after obtaining the permission of local authorities following Nagoya protocol. From an initial number of 33 isolates, 16 strains with different RAPD- and REP-PCR genetic profiles were obtained. In Chicha, all strains were Lactiplantibacillus plantarum (formerly Lactobacillus plantarum), whereas in Masato, in addition to this species, Limosilactobacillus fermentum (formerly Lactobacillus fermentum), Pediococcus acidilactici, and Weissella confusa were also identified. Correlation analysis carried out with their carbohydrate fermentation patterns and enzymatic profiles allowed a clustering of the lactobacilli separated from the other genera. Finally, the 16 strains were submitted to a static in vitro digestion (INFOGEST model) that simulated the gastrointestinal transit. Besides, their ability to adhere to the human epithelial intestinal cell line HT29 was also determined. Following both procedures, the best probiotic candidate was Lac. plantarum Ch13, a robust strain able to better face the challenging conditions of the gastrointestinal tract and showing higher adhesion ability to the intestinal epithelium in comparison with the commercial probiotic strain 299v. In order to characterize its benefit for human health, this Ch13 strain will be deeply studied in further works. © 2021, The Author(s).Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
An Experimental Study of Fibre SuspensionFlows in Pipes using Nuclear MagneticResonance Imaging
No full textThis study deals with fibre suspension flows through cylindrical pipes. Thepresent work aims at measurements of opaque flows, which are common inindustries. Nuclear magnetic resonance imaging (NMRI) and ultrasound velocimetryprofiling (UVP) were employed as non-invasive and optic-independenttools to measure the velocity profiles. As a first experiment, a paper-pulp suspensionflow through a sudden contraction and expansion was investigated.The results show the NMRI technique can be used to measure the stronglyunsteady flow such as separated regions though the MR signal is attenuateddue to the turbulence in the flow. The flow loop had however an insufficientinlet length which caused asymmetric profiles at the test section. As a secondexperiment, a flow loop which provided fully developed flows at the test sectionwas designed. After that, the velocity profiles of rayon-fibre and micro-spheresuspension flows were measured by the NMRI and the UVP independently.In principle, these two techniques measure the different velocities of the fibresuspensionflows, i.e. the velocity of the water and the fibre. In dilute suspensionflows, where the velocities of the two phases were assumed to be thesame, the velocity profiles were in good agreement. This shows the validityof the two measurement techniques. However, it should be pointed out thatthere is a limitation of the current UVP method for highly concentrated flows.The velocity profiles obtained by the UVP at high concentrations seems notto represent physics while the NMRI is not affected by the concentrations. Itis argued that the advances of the NMRI for the measurement of the highlyconcentrated flows
Financing small and medium sized enterprises for sustainable development : a view from the Asia-Pacific region
No full textMacroeconomic Policy and Development Division, working paper series.This discussion paper was prepared for ESCAP by Nick Freeman, Independent Economic Development Consultant.
The author gratefully acknowledges the contributions made by Masato Abe, Sailendra Narain, Michael Troilo and J. S. Juneja
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