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Many investigations have made contributions to an understanding of energy flow through large mammals in East African ecosystems. This paper lists references to such works and compiles them according to their application to various segments as they appear in an energy-flow model. The first part indicates papers on pasture utilization, value of foodstuffs, animal numbers and distribution, population dynamics and secondary production. The second part assembles references dealing with individual animal species, stratifying them according to the subjects of ecology, food habits and nutrient utilization, population dynamics and growth. 相似文献
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R. U. Ahmad 《Journal of Zoology》1970,160(3):371-375
Chromatic adaptation of the Paradise fish, Macropodus opercularis L., to illuminated backgrounds ranging from "white" to "black" shows that the pigment is most readily dispersed in the deepest-lying melanophores and least readily in the uppermost layers. 相似文献
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Activation of S6 kinase in cultured vascular smooth muscle cells by submitogenic levels of thrombospondin 总被引:2,自引:0,他引:2
T Scott-Burden T J Resink U Baur M Bürgin F R Bühler 《Biochemical and biophysical research communications》1988,150(1):278-286
Purified human platelet thrombospondin was shown to activate S6 kinase in cultured vascular smooth muscle cells in a dose- (1-9 micrograms/ml) and time-dependent manner. Down regulation of epidermal growth factor and somatomedin C receptors by prior treatment of cells with their respective growth factors did not reduce this effect. Kinase activation by thrombospondin was only marginally reduced in the presence of platelet-derived growth factor specific antibody at levels that totally inhibited platelet-derived growth factor (5 ng/ml) induced activation. Additionally, thrombospondin elicits a rapid dose-dependent phosphoinositide turnover response analogous to that of platelet-derived growth factor, epidermal growth factor and somatomedin C. Prior treatment of cells with phorbol ester for 48 hrs in serum-free culture medium resulted in a small enhancement of S6 kinase activation by thrombospondin and the above mentioned growth factors but a complete loss in the ability of phorbol ester to activate this enzyme. These findings with cultured smooth muscle cells suggest a growth factor-like role for thrombospondin. 相似文献