dr. callahan and laurie garrett, thank you. stick with us for the ebola summit. we will be joined by two senators when we return, one of whom says we need a travel ban here in the united states. [ male announcer ] some come here to build something smarter. ♪ some come here to build something stronger. others come to build something faster... something safer... something greener. something the whole world can share. people come to boeing to do many different things. but it's always about the very thing we do best. ♪ [ female announcer ] we love our smartphones. and now telcos using hp big data solutions are feeling the love, too. by offering things like on-the-spot data upgrades -- an idea that reduced overcharge complaints by 98%. no matter how fast your business needs to adapt, if hp big data solutions can keep wireless customers smiling, imagine what they can do for yours. make it matter. >>> welcome back. as i told you, dr. gabe kelen and lori garrett are with us. i'm joined by senator roy blunt and democrat bob casey of pennsylvania. senator blunt, i want to