5,718 research outputs found
Modularity Enhances the Rate of Evolution in a Rugged Fitness Landscape
Biological systems are modular, and this modularity affects the evolution of
biological systems over time and in different environments. We here develop a
theory for the dynamics of evolution in a rugged, modular fitness landscape. We
show analytically how horizontal gene transfer couples to the modularity in the
system and leads to more rapid rates of evolution at short times. The model, in
general, analytically demonstrates a selective pressure for the prevalence of
modularity in biology. We use this model to show how the evolution of the
influenza virus is affected by the modularity of the proteins that are
recognized by the human immune system. Approximately 25\% of the observed rate
of fitness increase of the virus could be ascribed to a modular viral
landscape.Comment: 45 pages; 7 figure
(Sr3La2O5)(Zn1-xMnx)2As2: A Bulk Form Diluted Magnetic Semiconductor isostructural to the "32522" Fe-based Superconductors
A new diluted magnetic semiconductor system, (Sr3La2O5)(Zn1-xMnx)2As2, has
been synthesized and characterized. 10% Mn substitution for Zn in bulk form
(Sr3La2O5)Zn2As2 results in a ferromagnetic ordering below Curie temperature,
TC ~ 40 K. (Sr3La2O5)(Zn1-xMnx)2As2 has a layered crystal structure identical
to that of 32522-type Fe based superconductors, and represents the fifth DMS
family that has a direct counterpart among the FeAs high temperature
superconductor families.Comment: Accepted for publication in EP
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