[World Scientific Publishing Co. Pte. Ltd. Hadron Physics 2000 - Topics on the Structure and Interaction of Hadronic Systems - The International Workshop - Caraguatatuba, São Paulo, Brazil (2000.04.10-2000.04.15)] Hadron Physics 2000 - Topics on the Structure and Interaction of Hadronic Systems - Proceedings of the International Workshop - Effects of vacuum structure on neutron star