For the first time, a Nigerian president admitted he lost the election and prepared to hand over power peacefully to his opponent. There are lessons there for much of Africa.

The opposition candidate won the presidential election in Nigeria .. and the sitting president acknowledged defeat. It's the first time power has changed hands peacefully and democratically in Nigeria -- which has Africa's biggest population and biggest economy. The new man -- a former army general -- has official corruption and the Islamist militants of Boko Haram in his sights.

Also in this podcast: Iran and the West pull off the deal some people thought could never happen, over Iran's nuclear programme -- though there are still plenty of details to fill in; so-called Islamic State attacks a big refugee camp on the outskirts of Damascus; why some cows in India are having their photograph taken; and the British general election campaign in one minute (and a bit).