Laura Jackson awaits the day when patients like her will come to Michigan for a new chance at life. Her message to the 2010 World Stem Cell Summit meeting next week in Detroit will be: “I’m ready and prepared to be walking again.” Jackson, 21, of Livonia is one of more than 150 speakers who will talk about how stem cells could hold the promise of repairing or strengthening the body’s response to chronic disease or injury.