Masateru Ito

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A calcium-aluminum-rich inclusion (CAI) from the Allende meteorite was analyzed and found to contain melilite crystals with extreme oxygen-isotope composition (approximately 5 percent oxygen-16 enrichment relative to terrestrial oxygen-16). Some of the melilite is also anomalously enriched in oxygen-16 compared with oxygen isotopes measured in other CAIs.(More)
Many apparently achiral organic molecules on Earth may be chiral because of random substitution of the 1.11% naturally abundant 13C for 12C in an enantiotopic moiety within the structure. However, chirality from this source is experimentally difficult to discern because of the very small difference between 13C and 12C. We have demonstrated that this small(More)
In a previous study, Ito (1990) who used a rapid two-element force-production task, found that the simple reaction time (RT) to initiate the second element was shorter when a sequence was made up of homogeneous elements than when a sequence was made up of heterogeneous elements. The purpose of the present study was to replicate and extend the earlier(More)
The present study was conducted to test the hypothesis that response programming occurs when movements are only imagined. 12 subjects were required to react and produce the sequence of same or different force by squeezing a handle as quickly and accurately as possible after the two reaction signals which were separated by the interstimulus interval of 1(More)
The present study tested the hypothesis that the repetition effect occurs during response programming. The choice reaction-time to initiate the second of two responses was examined when two consecutive responses were the same or different in their kinematics and force characteristics and repeated for two different stimuli. 12 subjects were required to react(More)
Two experiments were conducted to examine the effects of number and similarity of sequenced elements on simple reaction time (RT). In Exp. 1, subjects were required to initiate and execute sequences of one to three homogeneous or heterogeneous force elements by squeezing the handle as quickly and accurately as possible. Simple RTs and premotor times(More)
The present study examined whether varying magnitude of force required to perform an isometric response influences fractionated reaction time in simple and choice conditions and whether reaction time and premotor time to initiate the response are shorter when force is selected freely by the subject than when it is selected by the experimenter. 20 subjects(More)
The purpose of this study was to examine whether the similarity of R1 and R2 is a moderating variable in the psychological refractoriness effect. 10 subjects were required to react and produce the sequence of two homogeneous or heterogeneous peak forces as soon as possible after Stimulus 1 and 2 separated by variable interstimulus intervals. The(More)
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