An American Airlines Boeing 737-800 plane takes off from Los Angeles International airport.Mike Blake | ReutersCheck out the companies making headlines after the bell:Shares of American Airlines dipped 1.65% during extended trading after authorities in Miami forcibly removed a man on a flight to Newark, New Jersey earlier Monday. The man reportedly ran past a gate agent onto the plane.Qiagen shares tanked 8% after the company announced that CEO and Chairman Peer M. Schatz will step down after leading the company for 27 years. Senior Vice President Thierry Bernard will act as interim CEO and work in tandem with CFO Roland Sackers, while Schatz will remain as a “special advisor” during the transition, the company announced in a press release.The biotechnology company additionally lowered its sales outlook due to weaker business in China in its preliminary third-quarter earnings. Qiagen expects total net sales to grow by 3% at constant exchange rates, compared to the 4% to 5% growth it had forecast. The company also announced a strategic collaboration with Illumina, and a pre-tax restructuring charge of about $260 million to $265 million, which amounts to about $1.14 to $1.15 per share after taxes.Shares of Ambarella plummeted as much as 12% after one of its Chinese customers Hikvision was blacklisted by the U.S. Commerce Department, along with 27 other China-based entities. The chip-maker did not disclose how much of its revenue comes from Hikvision, although made note of ongoing trade tensions with China in its latest quarterly earnings.Discovery shares rose 2% after digital publisher Group Nine Media agreed to acquire women-focused publisher Pop Sugar in an all-stock deal at reportedly more than $300 million. Discovery is a major backer of Group Nine, most recently leading a $50 million funding round for the publisher in September. Discovery invested $100 million into Group Nine in 2016.