Comment on Why is the DNA Transition First Order? and Griffiths   Singularities in Unbinding of Strongly Disordered Polymers
  The papers [1,2] consider unbinding of a disordered heteropolymer. They find the first order phase transition [1] when disorder is strong (i.e. the ratio v of the binding energies is large; in DNA v is~1.1) and the Griffiths singularity, i.e. infinite order transition, otherwise [2]. The problem is important, since many physical phenomena map onto the same model (see refs. in [1, 2]). Drastic non-universality in the strength of disorder is unanticipated. Unfortunately, both titles are misleading: they claim the results which are proven for homopolymers only. 
Mark Ya. Azbel