The founder of medical testing startup Theranos, Elizabeth Holmes, has been painted as both a villain and an underdog on the first day of her fraud trial in California. She is accused of deceiving patients and investors with claims about technology that could screen for medical conditions with a few drops of blood. Holmes denies the charges. Also today, Treasury Secretary Janet Yellen has warned US political leaders to raise the country's borrowing limit or risk the government running out of cash next month.