Scrambling to secure much-needed funding, the Public Broadcasting Service began its spring pledge drive Monday with the debut broadcast of Nova: Boobs A-Bouncin'. 'We at PBS are proud to present this latest installment in our award-winning science series,' PBS spokesperson David Brennan said of the two-hour special devoted to the science of breast mobility. 'As you'll see, Boobs A-Bouncin' covers all the ups-and-downs, side-to-sides, and other various jiggling patterns associated with the physics of breasts in motion. Please enjoy this episode, and please, please call the number at the bottom of your screen to donate.' Faced with a similar budget shortfall, NPR announced last week that it had retooled its popular show Fresh Air so that Terry Gross would now conduct all her interviews from a Sybian. 