  We summarise measurements of the COSY-11 collaboration concerning the
excitation functions of the near threshold pseudoscalar meson production in the
proton-proton interaction. The results are discussed in the context of the
meson-nucleon and hyperon-nucleon interactions. We conclude that the
$\eta$-proton interaction is significantly stronger than the eta'-proton
interaction. Similarly, we found that the hyperon Lambda interacts with the
nucleon considerably stronger than the hyperon Sigma, and that the interaction
of (K-)-proton is much stronger than this of the (K+)-proton.

Nuclear Experiment