At the other end of the scale, war-smitten Somalia is worst, barely beaten by Congo, Chad and Sudan.The league table is the idea of Mo Ibrahim, a Sudanese-born British entrepreneur who sold his mobile-phone company, Celtel, to a Kuwait-based firm, MTC, for $3.4 billion £1.88 billion) two years ago.
MTC expanded in the other direction, from the Middle East into Africa.
Celtel, an African operator owned by MTC of Kuwait, charges no roaming fees at all to customers moving between its networks in Kenya, Tanzania and Uganda.
A team led by Claude Wischik, a professor of mental health at the University of Aberdeen, in Scotland, who also chairs a firm called TauRx Therapeutics, presented six papers to the conference describing the early success of a drug called methylthioninium chloride (MTC) in inhibiting the progression of Alzheimer's.
But that is now starting to change, and the industry is preparing for a round of consolidation as the operators start to attack each other's markets.The five big operators are MTN of South Africa, MTC of Kuwait, Egypt's Orascom, Etisalat of the United Arab Emirates (UAE) and Vodacom, an Anglo-South African firm.
These markets are dominated by big prison-services firms such as GEO, MTC and Serco, which claim that private jails are better, cheaper and more accountable in both construction and management.Developing countries are trying other variations.
Tau researchers already knew that MTC dissolves tau tangles in test tubes, and also prevents the aggregation of tau into tangles in the first place.
Might it be possible to set up a pan-African mobile operator and to do so without paying bribes?This was the genesis of Celtel, which is now one of Africa's largest mobile operators, with some 20m subscribers in 15 countries.When Mr Ibrahim sold Celtel in 2005 to MTC, a Kuwaiti operator, for $3.4 billion, it demonstrated that the continent was open for business.
In 2005 Ibrahim sold Celtel to MTC Kuwait for $3.4 billion but continued to serve as chairman of the company until 2007, when he retired from its board.
Donald Margulies's 1996 play, which MTC brings to Broadway for the first time, traces the trajectory of the women's friendship.
Full productions are not guaranteed, but Ms. Greenfield said she hoped some of the new works would run at the club's newly configured space, MTC Studio at Stage II, where the critically praised "Murder Ballad" just concluded its run.
