science - US visa rules damage academic exchange with China

The story about how the US visa rules damage ties with China I heard already more than a year ago in the US, the American Chamber of Commerce told us this summer that commerce lost 30 billion US dollar for this reason, but now there is also scientific proof. Scientists Zhang Yaping and He Shigang asked for Science Magazine their academic colleagues and guess: the US visa rules do hurt academic exchanges.
"The result is lost opportunities to present new research at important international conferences or to participate in scientific collaborations. This situation even affects some of the most prominent scientists in China, such as the vice president of the Chinese Academy of Sciences (CAS) and the director of the Shanghai Institutes of Biological Sciences, CAS," they write.
An article in scidev.net (obtained through the excellent Chinese internet research mailing list) points at more information indicating also fewer foreign students in the US for what used to be a booming industry, where between 2003 and 2004 the number of Chinese students to the US dropped by one third.
"Much of what you are seeing [in this poll] is a reflection of the past," says Dennis Murphy, spokesperson for the US Department of Homeland Security in a reaction.