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Dr. J. J. Waters M. E. Ferguson-Smith N. Carter J. L. Alexander S. V. Hodgson 《黑龙江环境通报》1990,10(10):677-681
Prenatal diagnosis, by amniocentesis, revealed mosaicism with respect to a bisatellited, apparently dicentric, DA/DAPI positive, de novo marker. The following cell lines were observed in decreasing order of frequency: 46,XX > 48.XX, + mar, + mar » 47,XX, + mar. The pregnancy was terminated and post-mortem examination revealed an apparently normal fetus. Cytogenetic studies of fetal and placental tissues revealed approximately the same level of mosaicism together with the unusual copy number ratio seen in the amniotic fluid cultures. Non-disjunction at the first post-zygotic mitotic division giving rise to a mosaic: 46,XX/ 48,XX, + mar, + mar followed by subsequent mitotic instability of the marker could account for the unusual copy number ratio. 相似文献
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Jolyon J. Faria John R. G. Dyer Romain O. Clément Iain D. Couzin Natalie Holt Ashley J. W. Ward Dean Waters Jens Krause 《Behavioral ecology and sociobiology》2010,64(8):1211-1218
Collective animal behaviour has attracted much attention recently, but cause-and-effect within interaction sequences has often
been difficult to establish. To tackle this problem, we constructed a robotic fish (‘Robofish’) with which three-spined sticklebacks
(Gasterosteus aculeatus L.) interact. Robofish is a computer-controlled replica stickleback that can be programmed to move around a tank. First,
we demonstrated the functioning of the method: that the sticklebacks interacted with Robofish. We examined two types of interaction:
recruitment and leadership. We found that Robofish could recruit a single fish from a refuge and could initiate a turn in
singletons and in groups of ten, i.e. act as a leader. We also showed that the influence of Robofish diminished after the
first 30 min that fish spent in a new environment. Second, using this method, we investigated the effects of metric and topological
inter-individual distance on the influence that Robofish had on the orientation of fish in a shoal of ten. We found that inter-individual
interactions during this turn were predominantly mediated by topological, rather than metric, distance. Finally, we discussed
the potential of this novel method and the importance of our findings for the study of collective animal behaviour. 相似文献