AfricaLink on Air - 03 June 2015: 0405 UTCTo play this audio please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoCaldwell, Mark06/03/2015June 3, 2015Nigeria's new president Muhammadu Buhari leaves for a trip to Niger and Chad+++South Sudan expels UN humanitarian coordinator Toby Lanzer+++World Economic Forum on Africa begins in Cape Town, South Africahttps://p.dw.com/p/1FatdAdvertisement