Washington Ochieng, reader in geomatics and transport telematics at Imperial College London, says that returning to his homeland of Kenya is not an option. The technology and funding he needs for his research mean that he must remain "absent without leave".
Ochieng left Kenya after gaining an engineering degree at the University of Nairobi. As a postgraduate at Nottingham University, he began researching satellite navigation systems - and has never looked back. He says that his case is not unusual.
"Most African students would normally opt for postgraduate training in the West," Ochieng explains. "It's not because of the quality of the instruction, but there are more research facilities and you get better exposure to the wider world. Ideally, I'd like to go back. But there is no way I'd get the funding and facilities to do my research over there. Positions tend to be mainly in teaching, and there is no research in technology or engineering."
Since Ochieng left in the 1980s, the political situation in Kenya has worsened. Not only is there corruption in government, but he believes it is rife in universities. Despite a younger generation pressing for better conditions and transparency, pay is also an issue. Before Ochieng quit Kenya, an academic salary just about covered the cost of living. Now, he says, academics have to take second jobs.
But Ochieng retains a strong attachment to the country of his birth. He works on projects to exchange computers with Kenyan universities and to enable Kenyan students to study in the UK. He works in a research field that transcends boundaries, he says: "I don't see what benefit I could be to Kenya if I was in situ ."