chicago from the north side, to the south side, to the west side. from oakland to johannesburg, from ho chi minh city to rio de janeiro, there a young people who are not waiting for someo else to solve big problems. instead, in the face of sometimes impossible odds, they're rolling up their sleeves and putting down stas and making a difference one neighborhood, school, community at a time. they're building health clinics in urban slums and educating gis in rural villas. they're reforming policing and challenging corruption. they're inventing new ways to cut carbon emissions and providing clean water to those who need it. they're building businses on