Recent results from NA57 on strangeness production in p-A and Pb-Pb   collisions at 40 and 158 A GeV/c
  The production of hyperons in Pb-Pb and p-Be interaction at 40 $A$ GeV/$c$\ beam momentum has been measured by the NA57 experiment. Strange particle enhancements at 40 $A$ GeV/$c$ are presented and compared to those measured at 158 $A$ GeV/$c$. Their transverse mass spectra have been studied in the framework of the blast-wave model. The multiplicity of charged particles as a function of the energy is also discussed. 
T. Virgili (for the NA57 collaboration)