((a)) ** .—** Except as otherwise provided in this chapter, this chapter shall take effect on .
((b)) ** .—** Sections 411(d), 412(c), 413(c), 414(c), 415(c), 416(c), 421(d), 425(d), 431(c), 431(d), 452(a), and 454(a) shall take effect on the date of enactment of this Act.