  After reformulating the representation theory of 0-Hecke algebras in an
appropriate family of Yang-Baxter bases, we investigate certain specializations
of the Ariki-Koike algebras, obtained by setting q=0 in a suitably normalized
version of Shoji's presentation. We classify the simple and projective modules,
and describe restrictions, induction products, Cartan invariants and
decomposition matrices. This allows us to identify the Grothendieck rings of
the towers of algebras in terms of certain graded Hopf algebras known as the
Mantaci-Reutenauer descent algebras, and Poirier quasi-symmetric functions. We
also describe the Ext-quivers, and conclude with numerical tables.
