Neotenic reproductives influence worker caste differentiation in the termite Reticulitermes speratus (Isoptera; Rhinotermitidae)

Division of labor among castes in social insect colonies increases ergonomic efficiency and colony-level fitness, and has played a key role in the ecological success of social insects. Knowledge of the factors that regulate castes is important for understanding adaptive social organization. Our previous study on the termite Reticulitermes speratus demonstrated that the presence of a pair of nymphoid reproductives during development affected offspring caste ratios. In the present study, we investigated further the influence of individual neotenics on offspring caste ratios. Parthenogenetically-produced offspring were reared in worker-tended experimental colonies with the addition of different forms (nymphoid or ergatoid) and numbers of neotenics, and compared the caste ratios of the offspring between the different experimental treatments. We found that all offspring in worker-only tended colonies became nymphs, while a proportion of offspring in colonies with a single neotenic (with the exception of male ergatoids) differentiated into workers. These results show offspring caste ratios are influenced by the presence of single female ergatoids, single female and male nymphoids, while they remain unaffected by the presence of male ergatoids

Real-time atomic-resolution imaging of crystal growth process in water by phase modulation atomic force microscopy at one frame per second

Recent advancement in dynamic-mode atomic force microscopy (AFM) has enabled its operation in liquid with atomic-scale resolution. However, its imaging speed has often been too slow to visualize atomic-scale dynamic processes. Here, we propose a method for making a significant improvement in the operation speed of dynamic-mode AFM. In this method, we use a wideband and low-latency phase detector with an improved algorithm for the signal complexification. We demonstrate atomic-scale imaging of a calcite crystal growth process in water at one frame per second. The significant improvement in the imaging speed should enable various studies on unexplored atomic-scale interfacial processes. © 2013 AIP Publishing LLC

第8章 携帯電話対応コメントカードシステムを活用した多人数講義における授業コミュニケーションの改善(第I部 平成14年度、15年度の研究課題,フレキシブル・ラーニングのための学習支援と評価(II),メディアFDとフレキシブル・ラーニング支援の研究開発)

受講者が所持している携帯電話(i-mode,J-Sky,EZWeb)やPDAに対応したコメントカードシステムを開発した。大学での多人数講義において、教官が課題テーマの提示や発問をし、受講者が各自の携帯電話からコメントカードシステムの携帯電話サイトに接続し、課題に対する自分の意見や質問を送信できるシステムである。受講者からの回答や質問をテーマやキーワードを元に整理し、リアルタイムで大講義室の液晶プロジェクタに映し出すデータベース機能を有している。受講者から携帯電話を通して書き込まれた意見や質問等のコメントを講義者が本システムを活用し、検索・抽出して講義中に取り上げながら、講義を展開していくアプローチを行った。その結果、多人数講義においても、テーマに対する各受講者の活発な意見や質問等の書き込みがあり、ディスカッションが活性化するとともに、授業コミュニケーションの改善が図れた。また、携帯電話対応の本システムのユーザーインタフェースや有用性に関しても利用者から高い評価を得た

Note: High-speed Z tip scanner with screw cantilever holding mechanism for atomic-resolution atomic force microscopy in liquid

High-speed atomic force microscopy has attracted much attention due to its unique capability of visualizing nanoscale dynamic processes at a solid/liquid interface. However, its usability and resolution have yet to be improved. As one of the solutions for this issue, here we present a design of a high-speed Z-tip scanner with screw holding mechanism. We perform detailed comparison between designs with different actuator size and screw arrangement by finite element analysis. Based on the design giving the best performance, we have developed a Z tip scanner and measured its performance. The measured frequency response of the scanner shows a flat response up to ∼10 kHz. This high frequency response allows us to achieve wideband tip-sample distance regulation. We demonstrate the applicability of the scanner to high-speed atomic-resolution imaging by visualizing atomic-scale calcite crystal dissolution process in water at 2 s/frame