Alexandra Tabas is an actress who portrays Nadine of the science expedition. She was uncredited in "The Little Prince" and "This Place Is Death", however her character's name was revealed through dialog in "This Place Is Death".
Although the character of Nadine was never credited in the ABC Medianet press release for her introduction in "The Little Prince", there was a promotional still released by ABC Medianet showing all six science team expedition members and Jin here, which credited the actors portraying the other five team members and Daniel Dae Kim as well as one "Alexandra Tobas" (sic). Since the only two previously uncredited team members are a man and a woman, Tabas was presumed to be the actress depicting the woman.
The actress was finally officially credited when she appeared in the Fifth Season HMV Bonus DVD featurette for "This Place Is Death".