Earlier this year, the Institute of Transportation Engineers Journal published a paper by a group of Iranian researchers, including Mahmoud Ahmadinejad of the Iran University of Science and Technology. Yes, that Mahmoud Ahmadinejad, the former Iranian president notorious for his anti-Semitism and Holocaust denial. After a reader pointed out the coauthor’s past political identity to the journal, the editors retracted the article. “Mr. Ahmadinejad’s affiliation with the government of Iran was not identified when the article was submitted,” Jeffrey Paniati, the executive director of the engineering group, told Tablet magazine. In withdrawing the paper — about the use of smartphone GPS systems to evaluate road safety — the journal is bucking typical practice. Ahmadinejad left office in 2013, long before the retracted article was submitted and published. Retracting a paper not on its substance, but because one author has an objectionable past, is unusual to say the least.