A big birthday celebration is planned for Sunday afternoon -- and you're invited!!  The Community Foundation of North Louisiana officially turns 50 Sunday, so the Shreveport Regional Arts Council is hosting a big birthday bash at Artspace in the 700 block of Texas.  The celebration coincides with the opening of a new exhibit at Artspace.  "On the Shoulders of Giants" focuses on the impact of philanthropy in the community.  The celebration starts at 2:00 Sunday afternoon and goes until 5:00.