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Tokyo, Japan

Rikkyo University , also known as Saint Paul's University, is a private university, located in Ikebukuro, Tokyo.A leading liberal arts teaching and research institution, Rikkyo is the largest Anglican Christian affiliated university in Japan and is a member of the "Big Six" grouping of prominent private universities in Tokyo. The university is known for its supportive and student focused approach to academic study; encouraging all enrolled students to challenge themselves and discover their own innate potential in their chosen field of study. A philosophy symbolized by the motto "academy of freedom" ; urging students to reject preconceived limitations and to broaden their knowledge and appreciation of the essence of all things through advanced study. Wikipedia.

Irie M.,Rikkyo University | Fukaminato T.,Hokkaido University | Matsuda K.,Kyoto University | Kobatake S.,Osaka City University
Chemical Reviews | Year: 2014

Chemical bond rearrangement during the phototransformation induces electronic as well as geometrical structure changes of the molecules. The molecular structure changes can be applied to various photonic devices. The electronic structure changes can be applied to optical memory media and various photoswitching devices. On the other hand, the geometrical structure changes can be applied to light-driven actuators and others. The photochromic diarylethene was serendipitously discovered during the course of study on photoresponsive polymers a quarter of a century ago. Various types of polymers having photoisomerizable chromophores, such as spiropyran, azobenzene, or stilbene, in the side or main chains, have been prepared in an attempt to change their conformation by photoirradiation. Source

Individuals of many avian and mammalian species produce antipredator calls when they encounter a predator. These calls often vary in acoustic structure depending on the type or level of predation risk, thereby eliciting the appropriate escape responses in conspecifics. Such complexity in communication may also be advantageous in situations in which animals recruit other individuals to mob predators because different risks may sometimes require different mobbing responses. I tested this idea in Japanese great tits, Parus major minor, which produce acoustically distinct mobbing calls for two different nest predators: 'chicka' calls for jungle crows, Corvus macrorhynchos, and 'jar' calls for Japanese rat snakes, Elaphe climacophora. A playback experiment revealed that adult great tits responded to different mobbing calls with qualitatively different behaviours: they scanned the horizon in response to 'chicka' calls and gazed towards the ground in response to 'jar' calls. These two responses help adults search for and detect the corresponding predators since crows fly to the nest and snakes approach from the ground. This study demonstrates that the mobbing calls of Japanese great tits transmit referential information about predator types and elicit the appropriate predator-searching behaviours in adults. © 2012 The Association for the Study of Animal Behaviour. Source

Takahashi D.,Rikkyo University
Journal of High Energy Physics | Year: 2011

We construct a boundary state for a class of analytic solutions in the Witten's open string field theory. The result is consistent with the property of the zero limit of a propagator's length, which was claimed in [19]. And we show that our boundary state becomes expected one for the perturbative vacuum solution and the tachyon vacuum solution. We also comment on possible presence of multi-brane solutions and ghost brane solutions from our boundary state. © 2011 SISSA. Source

Irie M.,Rikkyo University
Photochemical and Photobiological Sciences | Year: 2010

Photochromism is characterized as a reversible colour change of a chemical species upon photoirradiation. Although vast numbers of photochromic molecules have been so far synthesized, molecules which exhibit thermally irreversible photochromic reactivity are limited within a few families of compounds. Among the thermally irreversible photochromic molecules, diarylethene derivatives are the most promising candidates for applications to opto-electronic devices because of their fatigue resistance, high sensitivity and rapid response. In this review, characteristic photochromic performances of the derivatives, detection and analysis of the photochromic reactions at a single-molecule level and application of the single-crystalline photochromism to molecular machinery will be described. © 2010 The Royal Society of Chemistry and Owner Societies. Source

Tsujioka T.,Osaka Kyoiku University | Irie M.,Rikkyo University
Journal of Photochemistry and Photobiology C: Photochemistry Reviews | Year: 2010

Recent progress in electrical properties of photochromic molecules is reviewed. A typical application of the properties is current switching based on the changes in ionization potential or carrier mobility induced by the photoisomerization of photochromic molecules. Carrier injection-type molecular memories have also attracted wide interest because they are a promising candidate for organic semiconductor devices in the field of organic electronics. Various new applications are proposed using photo-induced electrical, as well as optical, property changes of photochromic molecules. © 2010 Elsevier B.V. All rights reserved. Source

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