<sod >Gambia's authoritarian leader Yahya Jammeh is expected to concede defeat in the country's presidential elections, the electoral commission has said, bringing an end to his 22-year rule of the small west African state.< eod>< sod > Gambia's authoritarian leader Yahya Jammeh has suffered a shock defeat in the country's presidential elections, the electoral commission has said, bringing an end to his 22-year rule of the small west African state.< eod>