Elisa Barron-Iracheta (Barron) appeals following her jury-trial conviction and sentence for possession with intent to distribute less than 50 kilograms of marijuana and a related conspiracy court. She contends that the Government improperly adduced and commented at trial on evidence of her silence and calm demeanor manifested prior to her being advised of her rights under Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966). Barron did not object at trial, and she fails to show that there was any plain or obvious error that affected her substantial rights with regard to the evidence or the Government’s comment upon it. See United States v. Garcia-Flores, 246 F.3d 451, 457 (5th Cir. 2001); see also Fletcher v. Weir, 455 U.S. 603, 606-07, 102 S.Ct. 1309, 71 L.Ed.2d 490 (1982); United States v. Musquiz, 45 F.3d 927, 930 (5th Cir. 1995).

Barron asserts that 21 U.S.C. § 841 is unconstitutional in light of Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000). Barron concedes that her claim is foreclosed by United States v. Slaughter, 238 F.3d 580 (5th Cir. 2000). She raises the issue only to preserve it for Supreme Court review.

Barron’s conviction and sentence are AFFIRMED.