The substrate specificity of beef heart phosphodiesterase activity and of the phosphodiesterase activity at the cell surface of the cellular slime mold Dictyostelium discoideum has been investigated by measuring the apparent Km and maximal velocity (V) of 24 derivatives of adenosine 3',5'-monophosphate (cAMP). Several analogs have increased Km values, but… (More)
We study the existence of perfect matchings in suitably chosen induced subgraphs of random biregular bipartite graphs. We prove a result similar to a classical theorem of Erd˝ os and Rényi about perfect matchings in random bipartite graphs. We also present an application to commutative graphs, a class of graphs that are featured in additive number theory.