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    Syfy's hit show "Alphas" returns to television on Monday, July 23, and this season's sexy attraction is Summer Glau. Glau was introduced in the show's first season as the super-intelligent Skylar Adams, and will return for three second-season episodes.

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    Glau is a cult favorite among American actresses, best known for playing the role of River Tam on the sci-fi TV series "Firefly." She also had lead roles on two other short-lived shows, "Terminator: The Sarah Connor Chronicles" and "The Cape."

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    Glau was born in San Antonio, Texas and is the oldest of three girls in her family.

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    When she was a young girl, Glau received a scholarship to a ballet company and was classically trained as a ballet dancer. She auditioned for and won a role in the 2010 movie "Black Swan," but the character was cut from the film in the pre-production stages.

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    Glau is of Scots-Irish and German descent.

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    Glau auditioned for the role of the Pink Ranger on the "Power Rangers" series, but didn't get it.

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    In 2008, Glau was ranked No. 8 in Wizard magazine's "Sexiest Women on TV" list. She has also appeared on FHM's "100 Sexiest Women in the World" list in 2010 and 2011.

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    Summer Glau won two awards for her role in "Serenity" (the follow-up movie to "Firefly"): a Saturn Award and an SFX Award.

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    Summer Glau is involved in a number of charities, is an animal lover and advocate against animal cruelty, and is a fan of cooking shows and the Dallas Cowboys.

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    Next: Alison Brie is an American Beauty

    Glau is trained in multiple forms of martial arts, so this brunette beauty can also kick your butt.