Complex sentence: He remained Editor-in-chief of Focus till then the end of 2006, before becoming the publisher of Avgo Books, an imprint of Oceanida Publications that is specializing in popular science books and the organization of science & art events for a wider audience.
Split into simpler sentences: He remained Editor-in-chief of Focus till the end of 2006. Then he became the publisher of Avgo Books, an imprint of Oceanida Publications that is specializing in popular science books and the organization of science and art events for a wider audience.