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461.
Emiliano Cristiani Paolo Frasca Benedetto Piccoli 《Journal of mathematical biology》2011,62(4):569-588
This paper proposes an agent-based model which reproduces different structures of animal groups. The shape and structure of
the group is the effect of simple interaction rules among individuals: each animal deploys itself depending on the position
of a limited number of close group mates. The proposed model is shown to produce clustered formations, as well as lines and
V-like formations. The key factors which trigger the onset of different patterns are argued to be the relative strength of
attraction and repulsion forces and, most important, the anisotropy in their application. 相似文献
462.
463.
Héctor Romero Emiliano Pereira Hugo Naya Héctor Musto 《Journal of molecular evolution》2009,69(2):203-206
One of the historic debates in molecular evolution concerns the strong variation in the genomic guanine–cytosine (GC) content of prokaryotes, which ranges from approximately 20–75%: Is this factor selectively neutral, or is it the result of natural selection? In a previous article published by our group, we showed that inside well-defined taxonomic groups of prokaryotes, strictly aerobic organisms tend to display higher genomic GC levels than strictly anaerobic species. In the present study, we examined the GC content of fragments of DNA obtained from microbial communities along a well-defined environmental gradient: a 4,000-m vertical profile in the North Pacific subtropical gyre. The patterns of GC distribution might be associated with oxygen concentrations in the seawater column. These results give further support to the link between a physiologic trait (aerobic respiration) and genomic GC content. 相似文献