Ames is a city located in the central part of the U.S. state of Iowa in Story County, and approximately 30 miles (48 km) north of Des Moines. It is the principal city of the Ames, Iowa Metropolitan Statistical Area which encompasses all of Story County, and which, when combined with the Boone, Iowa Micropolitan Statistical Area, comprises the larger Ames-Boone Combined Statistical Area. As of the 2000 Census, the city population was 50,731. While Ames is the largest city in Story County, the county seat is in Nevada which is 8 miles (13 km) east of Ames. Ames is the home of Iowa State University of Science and Technology (ISU), a public research institution with leading Agriculture, Design, Engineering, and Veterinary Medicine colleges. ISU is the nation's first designated land-grant university, and the birthplace of the Atanasoff-Berry Computer, the world's first electronic digital computer. Ames is one of two national sites for the Animal and Plant Health and Inspection Service (APHIS) which is provided by the National Veterinary Services Laboratories (NVSL). Ames is also the home of the National Animal Disease Center (NADC). NADC is the largest federal animal disease center in the U.S. , conducting research aimed at solving animal health and food safety problems faced by livestock producers and the public. Ames has the headquarters for the Iowa Department of Transportation. It is the site of the Ames Straw Poll, an important straw poll in the Republican party presidential nomination process as well as the first in the nation Democratic and Republican caucuses (see Politics, below). The city is featured in the bestselling book The Girls from Ames written by Wall Street Journal columnist Jeffrey Zaslow. It examines the lives and friendships of several young girls who grew up in Ames and have moved on with their adult lives but still remain close.