On $\kappa$-reducibility of pseudovarieties of the form $\bf V*\bf D$
  This paper deals with the reducibility property of semidirect products of the form $\bf V*\bf D$ relatively to graph equation systems, where $\bf D$ denotes the pseudovariety of definite semigroups. We show that, if the pseudovariety $\bf V$ is reducible with respect to the canonical signature $\kappa$ consisting of the multiplication and the $(\omega-1)$-power, then $\bf V*\bf D$ is also reducible with respect to $\kappa$. 
Jos\'e Carlos Costa, Concei\c{c}\~ao Nogueira and M. Lurdes Teixeira
math.GR