Earth Tool Co. — Brian Metcalf, vice president International Sales and Business Development for the Oconomowoc, Wis.-based company, has been named president and chief executive officer.

Central Life Sciences — Frank Jusich, chief operating officer for the Schaumburg, Ill.-based company, has been named president of the professional products group.

Henrico County, Va. — Randall Silber, the county's planning director, has been named deputy county manager for community development. John Vithoulkas, interim director of finance, has been named director.

Hydro International — Chris Williams, managing director for the Portland, Maine-based company, has been named chief operating officer for the European and U.S. business divisions.

Suffolk, Va. — Selena Cuffee-Glenn, deputy city manager, has been named city manager.

Mack Trucks — Dennis Slagle has been named president and chief executive officer for the Allentown, Pa.-based company. Previously, he was president of Asheville, N.C.-based Volvo Construction Equipment of North America.

CH2M HILL OMI — Elisa Speranza, vice president for the Denver-based company's water business group, has been named company president.

First Solar — Kathy Weiss has joined the Phoenix-based solar panel manufacturer as vice president for government relations. Previously, she was vice president for government affairs at Dallas-based Centex.

URS — Tom Zarges, senior executive vice president for the San Francisco-based company's Washington division, has been named president of the division.