Whether obama , when he does eventually engage , can successfully elucidate an israel-palestine policy that is substantively different from that of bush-cheney is wholly uncertain at present .
But even as he spares no pains to elucidate the harm caused by both national socialism and stalinism , he understates the extent to which their history was a fateful encounter .
Although the study did not elucidate exactly how sleep affects growth - the authors theorized that changes in hormonal signals during sleep may boost the secretion of growth hormones - it adds to the evidence that sleep carries important biological functions .