Photo by Daniel.Techie{TaiShan~4 Ever} @ 127.0.0.1 As part of its ongoing efforts to breed a new panda cub, the National Zoo artificially inseminated Mei Xiang back in January (but only after they let Tian Tian have a go at doing it the old fashioned way). Today zoo officials say they have detected a rise in Mei’s progestagen levels, which means we’re now just 40 to 50 days away from discovering whether it worked. At…