  We discuss the properties of the effective dipolar interaction for two
particles tightly confined along a one-dimensional tube, stressing the
emergence of a single dipolar-induced resonance in a regime for which two
classical dipoles would just repel each other. We present a toy-model potential
reproducing the main features of the effective interaction: a non-zero-range
repulsive potential competing with an attractive contact term. The existence of
a single resonance is confirmed analytically. The toy model is than generalized
to investigate the interplay between dipolar and contact interaction, giving an
intuitive interpretation of the resonance mechanism.
