When he first saw a map of malaria's range, Mann says it was as if the scales had fallen from my eyes. That range extends almost precisely to the Mason-Dixon Line, along which the American Civil War broke out in 1861, between the slave-holding states of the South and the Union soldiers of the North.
Opened yogurt will typically stay at peak quality for 5 to 7 days after opening, but will generally remain safe to consume for at least 1 to 2 weeks after the sell by date on the package, provided it has been properly stored- discard entire package if any sign of mold appears.
Yogurt is preserved by its acidity which inhibits the growth of putrefactive or pathogenic bacteria. With lids intact, yogurt will keep at least a month or two in the refrigerator. After that time, especially if your refrigerator is on the warm side, a layer of non-pathogenic white mold may form on the top.