AS CHIEF executive of Barclays, Antony Jenkins will have encountered the top dogs of the world’s major financial institutions. None of them, apparently, exercise leadership in as impressive a way as Sr Mary Owens, who runs the Nyumbani orphanage in Kenya for orphaned or abandoned children infected with HIV.Jenkins, who was brought up a Catholic, explained on BBC Radio 4’s Today programme that he took his senior team at the bank to meet the Loreto sister. The banker was guest editing the programme on New Year’s Eve and had decided to focus on the theme of leadership.Sr Mary, 74, told us: “I don’t know why he chose me [as a model of a leader]. I think he was touched by the fact we do our work with limited resources.”The Loreto sister, who went as a missio