Variation in agonistic encounters in a dominance hierarchy of freely interacting red-spotted masu salmon (Oncorhynchus masou ishikawai)   总被引：1，自引：0，他引：1  

S. Nakano 《Ecology of Freshwater Fish》1994,3(4):153-158

Abstract– Agonistic behaviour and dominance relationships in red-spotted masu salmon, Oncorhynchus masou ishikawai , were observed in a mountain stream pool. A linear, size-structured dominance hierarchy was recognized among individuals, body weight being a more important determinant of dominance status than fish length. Immigrant fish interacted more frequently with residents of similar body size than with larger or smaller fish during the early period following immigration. Thereafter, frequency of interactions rapidly decreased. When a fish was attacked, it reacted in a variety of ways in close accordance with its opponent's dominance rank: responses were to simply flee, flee with lateral display, revolt by performing a counter display or ignore the aggression. Such behavioural modification seems to be established during the successive agonistic encounters, in particular, early encounter periods when frequent interactions took place.  相似文献   

Chondrulelike objects in short-period comet 81P/Wild 2   总被引：1，自引：0，他引：1  

Nakamura T  Noguchi T  Tsuchiyama A  Ushikubo T  Kita NT  Valley JW  Zolensky ME  Kakazu Y  Sakamoto K  Mashio E  Uesugi K  Nakano T 《Science (New York, N.Y.)》2008,321(5896):1664-1667

The Stardust spacecraft returned cometary samples that contain crystalline material, but the origin of the material is not yet well understood. We found four crystalline particles from comet 81P/Wild 2 that were apparently formed by flash-melting at a high temperature and are texturally, mineralogically, and compositionally similar to chondrules. Chondrules are submillimeter particles that dominate chondrites and are believed to have formed in the inner solar nebula. The comet particles show oxygen isotope compositions similar to chondrules in carbonaceous chondrites that compose the middle-to-outer asteroid belt. The presence of the chondrulelike objects in the comet suggests that chondrules have been transported out to the cold outer solar nebula and spread widely over the early solar system.  相似文献   

Antibody formation: stimulation by polyadenylic and polycytidylic acids     

Braun W  Nakano M 《Science (New York, N.Y.)》1967,157(3790):819-821

Complexes of polyadenylic and polyuridylic acids, or of polycytidylic acid and methylated bovine serum albumin, enhance the early rate of increase in numbers of antibody-forming spleen cells in mice immunized with sheep red blood cells or other particulate antigens. Polyadenylic and polycytidylic acids, respectively, appear to be the source of the critical stimulators which, as demonstrated by others in bacteria, may act by influencing nucleotide kinase activity. The stimulated antibody response, but not the normal response, is antagonized by kinetin riboside and by an adenosine derivative occurring in sRNA.  相似文献