Natalia Sats, director of the Moscow Opera and Ballet Theater for Children since it opened in 1965, died Dec. 18.She was 90. Sats, the daughter of Russian composer Ilya Sats, was among the millions of people swept up in the purges and repressions of Josef Stalin. She was arrested in 1937 and incarcerated for five years. She went on to found the first theater for children in Kazakhstan and won international recognition for her work with children in Moscow. She was awarded many top Soviet honors, including the Hero of Socialist Labor.