In Sudan and South Sudan, questions of nationality
Hundreds of thousands stranded after Sudan, South Sudan split
US troops synch hi-tech and nomad intel in Kony hunt
The troops provide intelligence, help coordinate hunt
S.Sudan says to quit border zone, seeks end to clashes
Sudanese leader declares emergency in some border areas
S. Sudan says 21 dead in clash with Sudanese-backed militia
Khartoum and Juba accuse each other of supporting rebel militia to destabilise their opponents, and each denies the other's charges