Abstract: 
We consider the classical geometric problem of prescribing scalar and
boundary mean curvature via conformal deformation of the metric on a
ndimensional compact Riemannian manifold. We deal with the case of
negative scalar curvature and positive boundary mean curvature. It is
known that if n=3 all the blowup points are isolated and simple. In
this work we prove that this is not true anymore in low dimensions (that
is n=4, 5, 6, 7).
In particular, we construct a solution with a clustering blowup
boundary point (i.e. nonisolated), which is nonumbilic and
minimizes the norm of the tracefree second fundamental form of the
boundary. 
