[要旨]損傷菌の菌数測定には培養法が用いられることが多いが、細胞計測法のFlow cytometry (FCM) では、生菌、死菌、および損傷菌の迅速評価が可能である。本研究では、Listeria monocytogenesの代替株であるL.innocua (毒素陰性株)の薬剤損傷菌数測定について、培養法のThin agar layer (TAL)法とFCM法の比較 を行った。有効塩素謹度0～6ppmの強酸性電解水で処理したとき、TAL法では1ppmおよび2ppmの強酸性電解水処理において、選択培地よりもTAL培地で0.6log菌数が多く検出され、それぞれ59%および67%の損傷薗が生残したことが示唆された。 一方FCM法では、生菌を染色する膜透過型DNA染色剤 (thiazole orange:TO) と、死菌を染色する膜非透過型DNA染色剤 (propidium iodide:PI) での二重染色の結果、TOとPIの両方に染色された損傷菌の割合は、有効塩素濃度 1～3ppmでそれぞれ59%～78%となった。薬剤損傷L. innocuaの回復においては、TAL法では2時間後には損傷菌が未検出となったが、FCM法では4時間後まで損傷菌が生残していた。この結果より回復期の薬剤損傷菌の検出においては、二つの方法で違いがあることが示された。[Abstract]Culture-based methods are often used for the enumeration of sublethally injured bacteria,while flow cytometry(FCM)can provide rapid quantitation of live,dead,and injured bacteria. In this study,the culutur-based thin agar layer(TAL)method was compared with a FCM assay to enumerate chlorine-injured Listeria.innocua,a surrogate for L.monocytogenes.Bacteria were injured by mixing them with diluted electrolyed water containing 0 to 6 ppm available chlorine. In the TAL method,counts of L.innocua exposed to 1 to 2 ppm available chlorine were 0.6log higher on the TAL medium than on the selective medium than on the selective medium,indicating that 59 to 67% of the viable cells were injured by a chlorine level of 1 to 2 ppm.In comparison,the available chlorine level of 1 to 3 ppm caused sublethal injury ranging from 59 to 78% as determined by the FCM assay based on the quantitation of staned cells with both permeant DNA dye (thiazole orange:TO)and impermeant DNA dye (propidium iodide:PI),relative to live and dead cells that were stained only with TO and PI,respectively.With regard to recovery of chlorine-injured L.innocua after treatment with electrolyzed water,injured cells were inactivated after two hours when enumerated with the TAL method,whereas injured cells remained injured for four hours after the treatment as determined by the FCM assay.This result indicated a difference in the detection of chlorine-injured L.innocua between the two methods during the recovery period of injuredv cells.

[要旨] 従事すべき作業とは関係の無い考え事に注意が奪われている状態では, 覚醒水準とは無関係に判断や応答といった認知パフォーマンスが低下するため, 判断ミスなどのヒューマンエラーによる事故をもたらす危険性が高くなるが, 作業者がそうした状態に陥っていることを客観的に評価することは極めて困難である. 本研究では, 課題とは無関係な考え事をしている状態を課題非依存性思考状態と定義し, このような課題非依存性思考状態が, 認知パフォーマンスに与える影響の客観的な評価を目的として, あらかじめ提示された8桁の数字の記憶を維持しつつ, 同時に課せられた視覚探索課題を遂行する際の, 目標探索時間や前頭前野外側部の近赤外線スペクトロスコピー(Near-Infrared Spectroscopy: NIRS)信号を解析した. 実験の結果, 複数の視覚属性の組み合わせにより定義された視対象の中から唯一の特徴を持った目標を探索する場合においてのみ, 課題非依存性思考の有無により目標探索時間が影響されることが示された.また, この条件においてはNIRS信号から推定された前頭前野外側部の賦活度が高まることも示唆された.これらのことから, 課題非依存性思考によって前頭前野の情報処理リソースが消費されることが示唆され, こうした状況下では, 認知タスクのパフォーマンスが影響を受ける可能性が示された. [Abstract] Working with stimulus-independent thoughts(SITs) often causes the decline of cognitive performances, such as judgments of signals or response times to certain tasks. It might lead to fatal accidents called "human errors" independently of arousal level. The detection and prediction of these errors is extremely difficult, and the measurement technology of inattentiveness has not yet been established. In this study, we investigate the effect of SITs on the performance of visual search tasks. SITs are the streams of thoughts that are unrelated to immediate situations. The subjects memorized the numeral of eight digits as an SIT while carrying out visual search tasks. The reaction time and the near-infrared spectroscopy signals from the lateral prefrontal cortex(PFC) were analyzed to evaluate the effect of SITs objectively. As a result, the average reaction time for searching targets from distracters only in terms of their feature conjunctions increased when having SITs during the tasks. Also, the SITs in these tasks enhance the activity of the lateral PFC. These results suggest that the SITs occupy the resource of attention and it might affect the performances of certain cognitive tasks under these conditions.【注記】本研究は, 近畿大学生物理工学部戦略的研究NO.11-Ⅰ-3 2012, および, JSPS科研費24560534の助成を受けた.

Patients who have difficulty moving their muscles freely require support for various situations that occur in everyday life. A controllable robot arm without using muscles may make the patient's quality of life improve. By using a brain-computer interface (BCI), control of the robot arm is possible by thought alone. Therefore, we have constructed several robot arms with an ultrasonic range finder and a web camera for BCI system. By utilizing these devices, collisions between the robot arm and the user could be avoided and control could be partially automated. The distance is very important information in the system. In the present work, an acoustic distance measurement (ADM) device was used. It consists of equipment with easy acquisition and does not need an electronic circuit which is in the ultrasonic range finder. It is a new device and has a possibility of simplifying the ADM device.

Since the distance to target is very important information, we have proposed an acoustic distance measurement (ADM) method using a standing wave, which is generated by interference between transmitted and reflected waves. However, the amplitude-frequency characteristics of the measuring system between the microphone and the loudspeaker are not considered, but these characteristics cannot be ignored in a real environment. To remove the effect of the measuring system, our previous methods required a 2ch microphone or two measurements with targets and without targets. This paper describes a new ADM method considering a movement of transmitting-and-receiving system composed of 1ch microphone and loudspeaker. Finally, we examine the validity and effectiveness of our method by applying it to an actual sound field.

Objectives: The aim of this paper is to develop a new algorithm to enhance the performance of EEG-based brain-computer interface (BCI). Methods: We improved our time-frequency approach of classification of motor imagery (MI) tasks for BCI applications. The approach consists of Laplacian filtering, band-pass filtering and classification by correlation of time-frequency-spatial patterns. Results and Conclusions: Through off-line analysis of data collected during a "cursor control" experiment, we evaluated the capability of our new method to reveal major features of the EEG control for enhancement of MI classification accuracy. The pilot results in a human subject are promising, with an accuracy rate of 96.1%.

Human motor imagery (MI) tasks evoke electroencephalogram (EEG) signal changes. The features of these changes appear as subject-specific temporal traces of EEG rhythmic components at specific channels located over the scalp. Accurate classification of MI tasks based upon EEG may lead to a noninvasive brain-computer interface (BCI) to decode and convey intention of human subjects. We have previously proposed two novel methods on time-frequency feature extraction, expression and classification for high-density EEG recordings (Wang and He 2004; Wang, Deng, and He, 2004). In the present study, we refined the above time-frequency-spatial approach and applied it to a one-dimensional "cursor control" BCI experiment with online feedback. Through offline analysis of the collected data, we evaluated the capability of the present refined method in comparison with the original time-frequency-spatial methods. The enhanced performance in terms of classification accuracy was found for the proposed approach, with a mean accuracy rate of 91.1% for two subjects studied.

We have developed a novel Time-Frequency approach of classification of motor imagery (MI) tasks for brain-computer interface (BCI) applications. Through off-line data analysis on data collected during a "cursor control" experiment, we evaluated the capability of our proposed method in revealing the major features of the EEG control and enhancing MI classification accuracy. The pilot results in two human subjects are promising, with a mean accuracy rate of 57.9%, suggesting the feasibility of defining a new and more reliable EEG-based BCI.

和歌山特別栽培農産物に認証された青果物を対象に、残留農薬量と微生物数を迅速検出し、それらを基にした情報を加えたトレーサビリティシステムの構築を試みた。HPを作成し、これらの情報がWebサイトで見られるように、デモとして公開した。

神経回路網における神経細胞の連絡様式の一つである相互抑制型の神経回路(以後, 相互抑制回路と書く)において, 疲労やノイズなどがない場合でも周期的または非周期的な交番バーストなどの様々な刺激ー応答パターンが現れることを示す. 更に, 刺激一応答パターンの大域的分岐図も示す.

脳波による文字入力装置(脳波キーボード)の制御に適した電極位置を調べ、その結果を報告した。

EEGベースのブレイン・コンピュータ・インターフェースにおいて、心像タスクの分類率を向上させるアルゴリズムを開発した。（英文）

複数の信号が混合された観測信号から源信号を分離する問題をブラインド分離という。その解法の一つに源信号の統計的独立性に基づく独立成分分析(ICA)がある。本研究では、著者等の提案している Hermte モーメントに基づくICA 手法を、多チャンネルの脳波(EEG)データの分離に適用する。本手法により、ノイズ成分(アーチファクト)を取り除けることが分かった。 (英文)

タスク実行時における視覚刺激のサイズが脳の活動に与える影響について述べている。（英文）

神経心理学に基づく脳機能トレーニングソフトを作成し、その評価結果を示した。

パーソナルコンピュータで使用する神経心理学テストを作成し、 その評価結果を示した。

手足や声を使わず、考えるだけで「はい」または「いいえ」を伝える意思伝達装置を作製し、その性能を評価した。その結果、意思伝達に要する時間は約12秒、4名の平均正答率は87%となった。本装置は、手や腕の動作の想像時に現れる脳波の変化を使用しているため、視覚情報を必要とせず、閉眼状態で使用可能となっている。閉眼状態で使用可能な意思伝達装置は少ないため、筋萎縮性側索硬化症等の方々のための意思伝達手段の選択肢を増やすことが期待できる。