Yutaka Kobayashi

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Bacteria of the genus Wolbachia are among the most common endosymbionts in the world. In many insect species these bacteria induce a sperm-egg incompatibility between the gametes of infected males and uninfected females, commonly called unidirectional cytoplasmic incompatibility (CI). It is generally believed that unidirectional CI cannot promote speciation(More)
Fibroblast growth factor (FGF) 8, also known as androgen-induced growth factor, was originally isolated from an androgen-dependent mouse mammary Shionogi carcinoma SC-3 cell line, in which it was shown to have androgen-regulated properties. We previously demonstrated that Fgf 8 transcripts were detected in several human prostate and breast cancer cell lines(More)
Genotypic fitness landscapes are constructed by assessing the fitness of all possible combinations of a given number of mutations. In the last years, several experimental fitness landscapes have been completely resolved. As fitness landscapes are high-dimensional, simple measures of their structure are used as statistics in empirical applications. Epistasis(More)
This paper considers a dialog control strategy based on the reliability of speech recognition. The spoken dialog system using this strategy accepts an utterance of the user if the reliability is high, while it rejects the utterance and asks the user to speak again (the basic strategy), or conrms the content of the utterance if the reliability is low. The(More)
With this algorithm, the uncertainties are reduced to within 3 m. Still, comparison between the corrected TOPSAR DEMs shows an average periodic height discrepancy along the cross-track direction of about 5 m. Simulation results show that this might have been caused by multipath from an object near one of the INSAR antennas. Careful examination of the(More)
This paper proposes and analyzes mathematically an interactive strategy to recover from misrecognition of utterances including multiple information items through a short conversation with a speaker. First the speech rec-ognizer in a dialogue system recognizes an utterance and evaluates the reliability of each item contained in it. The dialogue system(More)
We model the evolution of learning in a population composed of infinitely many, finite-sized islands connected by migration. We assume that there are two discrete strategies, social and individual learning, and that the environment is spatially homogeneous but varies temporally in a periodic or stochastic manner. Using a population-genetic approximation(More)
Learning abilities are categorized into social (learning from others) and individual learning (learning on one's own). Despite the typically higher cost of individual learning, there are mechanisms that allow stable coexistence of both learning modes in a single population. In this paper, we investigate by means of mathematical modeling how the effect of(More)