<Table> James Madison University <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Motto </Th> <Td> Knowledge is Liberty </Td> </Tr> <Tr> <Th> Type </Th> <Td> Public </Td> </Tr> <Tr> <Th> Established </Th> <Td> 1908 </Td> </Tr> <Tr> <Th> Academic affiliations </Th> <Td> SURA, SCHEV </Td> </Tr> <Tr> <Th> Endowment </Th> <Td> $80.0 million (2016) </Td> </Tr> <Tr> <Th> Budget </Th> <Td> $549 million (2017) </Td> </Tr> <Tr> <Th> President </Th> <Td> Jonathan R. Alger </Td> </Tr> <Tr> <Th> Academic staff </Th> <Td> 1,375 </Td> </Tr> <Tr> <Th> Students </Th> <Td> 22,667 </Td> </Tr> <Tr> <Th> Undergraduates </Th> <Td> 20,779 </Td> </Tr> <Tr> <Th> Postgraduates </Th> <Td> 1,888 </Td> </Tr> <Tr> <Th> Location </Th> <Td> Harrisonburg, Virginia, U.S. </Td> </Tr> <Tr> <Th> Campus </Th> <Td> Small city, 721 acres (2.92 km) </Td> </Tr> <Tr> <Th> Colors </Th> <Td> Purple and Gold </Td> </Tr> <Tr> <Th> Nickname </Th> <Td> Dukes </Td> </Tr> <Tr> <Th> Sporting affiliations </Th> <Td> NCAA Division I--CAA </Td> </Tr> <Tr> <Th> Mascot </Th> <Td> Duke Dog </Td> </Tr> <Tr> <Th> Website </Th> <Td> www.jmu.edu </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> </Table> <Tr> <Th> Motto </Th> <Td> Knowledge is Liberty </Td> </Tr>

What is the mascot of james madison university