Joe biden promises to lead america out of what he calls its season of darkness as he formally accepts the Democratic Party president ial nomination. Hello and welcome if you re watching in the uk or around the world 7 and stay with us for the latest news and analysis from here and across the globe. The mystery over the condition of leading russian opposition activist Alexei Navalny has deepened. The fierce and outspoken critic of president putin collapsed while on a flight to moscow and is now in a coma in hospital. His supporters claim he was poisoned via a substance added to his tea but one of the doctors in charge of his care has this morning said that so far no traces of poison have been in his system. Mr navalnys aides have insisted he be transferred to germany for treatment, but the russian hospital chief says hes too ill to be moved. The hopsital say they have a diagnosis, which they have yet to reveal. They gave this update a little earlier. Translation today, from the tests we