How have courts treated the exclusion of expert testimony in a sexual assault case?

We review the exclusion of expert testimony for an abuse of discretion, see United States v. Croft, 124 F.3d 1109, 1120 n.3 (9th Cir. 1997), and observe none here. The district court acted within its discretion in concluding that the testimony would not have been helpful to the jury in the resolution of Sayakhom's guilt. See United States v. Hoac, 990 F.2d 1099, 1103 (9th Cir. 1993) (exclusion of testimony by expert on Chinese culture not abuse of discretion where expert's knowl- edge of defendant was limited and testimony would not have helped the jury); United States v. Rubio-Villareal, 927 F.2d 1495, 1502 (9th Cir. 1991), amended on other grounds by 967 F.2d 294 (9th Cir. 1992) (denial of defense request to admit expert testimony on Mexican culture not abuse of discretion). We affirm the denial of Sayakhom's motion to allow the expert testimony.