Barton Associates Inc., a mechanical, electrical, and plumbing consulting engineering firm, recently promoted Michael Rader to chief operating officer.

Rader joined the State College-based firm in 1997 as a mechanical engineer and most recently served as a business unit leader of the York office. He will continue to serve as the vice president of education. As chief operating officer, he will will oversee and coordinate activities of all branch offices and associated business unit leaders.

Crystal Duffy recently joined Geisinger-Gray’s Woods’ pediatrics department, and she will also see patients at Geisinger-Philipsburg.

Duffy received her medical degree from Philadelphia College of Osteopathic Medicine in 2010. Prior to joining Geisinger-Gray’s Woods, Duffy was a pediatrician at Margiotti & Kroll Pediatrics.

Stacy Andersen, a nephrologist at Geisinger-Scenery Park, recently passed the boards to become board certified in the subspecialty of nephrology from the American Board of Internal Medicine.

Andersen joined Geisinger in September 2011 after completing a nephrology fellowship at the University of Pittsburgh Medical Center earlier that year. A 2006 graduate of Loma Linda University School of Medicine, Andersen completed her internal medicine residency in 2009 at Hershey Medical Center.

She sees patients at Geisinger-Scenery Park, Geisinger-Philipsburg and Geisinger-Lewistown.

Keller Williams Advantage Realty Market Center, based in State College, recently hired Evanna Orsin-Butler as a real estate sales professional.