Sierra was released on $11,500 bail. There was no immediate indication if she had a lawyer.
The victim suffered a cut over his eye, but the spokeswoman gave no further information.
Sierra, of Tampa, was one of the hit show's top 10 contestants in 2005.
A final ovation
Mstislav Rostropovich, the celebrated cellist and champion of human rights, was buried yesterday in Moscow to the applause of hundreds of mourners, an echo of the ovations he received during his life.
Several thousand teary admirers of his musical talent and ebullient personality flocked to a morning service in the soaring, gold-domed Cathedral of Christ the Savior, which was blown up by Communists in 1931 and which Rostropovich helped rebuild after the Soviet collapse.
After the ceremony, Rostropovich's coffin was transported to the Novodevichy Cemetery, where his teachers Dmitry Shostakovich and Sergei Prokofiev are also buried.
After the casket was lowered, Rostropovich's widow, the Bolshoi Opera soprano Galina Vishnevskaya, his daughters Olga and Yelena and family friends sprinkled the casket with earth.
Disturbia fended off a weak batch of newcomers to remain No. 1 for the third straight weekend with $9.1 million, raising its total to $52.2 million, according to studio estimates yesterday.
Disney's The Invisible turned in the best performance among the debuts, taking in $7.6 million to open at No. 2.
Paramount's Next, starring Nicolas Cage, premiered at No. 3 with $7.2 million. Lionsgate's The Condemned, with wrestler Stone Cold Steve Austin, debuted in ninth place with $4 million. Yari Film Group's comedy Kickin' It Old Skool, starring Jamie Kennedy, opened at No. 11 with $2.8 million.
Rounding out the Top 10 were Fracture ($7.1 million) at No. 4; Blades of Glory ($5.2 million) at No. 5; Meet the Robinsons ($4.84 million) at No. 6; Hot Fuzz ($4.8 million) at No.7; Vacancy ($4.2 million) at No. 8; and Are We Done Yet? ($3.4 million) finishing 10th.
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