In a big turnaround from the message last year, attendees at the Unified Wine & Grape Symposium in Sacramento heard a mostly upbeat presentation at the yearly wine trade show. Unified, by far the largest trade show in America for wineries, winemakers and growers, is jointly sponsored by the California Association of Winegrape Growers and the American Society of Enology and Viticulture. It attracted about 12,000 people from the wine industry and 600 exhibitors to its expanded concurrent trade show.