Chronicle of Higher Education: The National Science Foundation reports that the number of science doctorates earned by foreign students fell last year by 3.5% compared with 2008. By contrast, the total number of science doctorates rose by 1.6%. Accounting for the small decline is tricky. Last year’s graduates began their courses before the current recession but after the tougher post-9/11 visa rules were put in place. One possibility is that students are delaying graduation until job prospects in the US and, in some cases, their home countries improve.