Tissue engineering has been developed with the ultimate aim of manufacturing human organs, but success has been limited to only thin tissues and tissues with no significant structures. In order to construct more complicated tissues, we have developed a three-dimensional (3D) fabrication technology in which 3D structures are directly built up by layer-by-layer printing with living cells and several tissue components. We developed a custom-made inkjet printer specially designed for this purpose. Recently, this printer was improved, and the on-demand printing mode was developed and installed to fabricate further complicated structures. As a result of this version, 3D layer-by-layer printing based on complicated image data has become possible, and several 2D and 3D structures with more complexity than before were successfully fabricated. The effectiveness of the on-demand printing mode in the fabrication of complicated 3D tissue structures was confirmed. As complicated 3D structures are essential for biofunctional tissues, inkjet 3D biofabrication has great potential for engineering complicated bio-functional tissues.

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The purpose of this study, which comprised 2 experiments, was to investigate cognitive effects on odor perception. An odor was presented using an olfactometer. In Experiment 1 ("continuous" presentation), anethole, an odor unfamiliar to most Japanese individuals, was presented continuously for 1 session (20 min), whereas in Experiment 2 ("intermittent" presentation), odor stimuli were presented 60 times for a short duration (0.2 s) over 4 sessions (24 min, including 9 min of intersession intervals), in which odor duration, temperature, and humidity were strictly controlled and the odor in the nostril was removed immediately after presentation. In each session, participants were asked to continuously evaluate odor intensity. In both Experiments 1 and 2, the participants were informed that the odor was either healthy (healthy-description group) or hazardous (hazardous-description group) prior to the session. The results show that in Experiment 2 (intermittent presentation), the hazardous-description group perceived the odor as more intense than did the healthy-description group, especially during the last 2 sessions. In Experiment 1 (continuous presentation), however, no significant difference in perceived intensity was present between the 2 groups. This study demonstrates the effect of cognitive state on perceived intensity by developing an experimental setting wherein the peripheral adaptation process was reduced and central olfactory processes were emphasized.

We analyzed the food source of riparian spiders in a middle reach of the Chikuma River, Japan, by using stable isotope ratios of carbon and nitrogen. The carbon and nitrogen isotope ratios of attached algae were higher than those of terrestrial plants, reflecting a large carbon isotope fractionation in terrestrial plants and a difference in nitrogen sources. The carbon isotope ratios of terrestrial insects were similar to those of the terrestrial plants, and the ratios of aquatic insects were scattered between those of the terrestrial plants and the attached algae. The carbon and nitrogen isotope ratios of spiders were intermediate between those of the terrestrial and aquatic insects. The two-source mixing model using the carbon isotope ratio showed that the web-building spiders utilized both the terrestrial and aquatic insects, with large contribution by the aquatic insects (54% on average with a maximum of 92% among spider's taxa collected in each zone), in the riparian area in a middle reach of the Chikuma River. The large contribution of the aquatic insects was often observed for the spiders collected near river channel ( < 5 m) and for the horizontal web-building spiders collected across the riparian area. The relative contribution of the aquatic insects might be related with food availability (distance from river channel) and spider's food preference reflected in their web types (horizontal vs. vertical). Our results showed that organic materials produced in the river channel, in the riparian area, and in the terrestrial area surrounding the riparian area were mixed at the carnivorous trophic level of riparian spiders.

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