Some caveats about the evolution of the N/O abundance and the star
  formation history
  We carefully analyze how the abundance of Nitrogen over Oxygen evolves when
dependent on metallicity stellar yields with a primary component of N
proceeding from AGBs stars are used. We show the results obtained with a
chemical evolution models grid, calculated with variable star formation
efficiencies, which produce different star formation histories. Finally we see
how the N/O abundance is related on the evolutionary history.
