computer science - If a paper or software is released to the public, can the university still file a patent?

It is my understanding that patents can be invalidated if there is prior art to the technique at hand; DJB has a piece that would suggest that this way authors can inadvertently invalidate their own patents, if not being careful with information disclosure.

http://cr.yp.to/patents/us/4200770.html

Diffie disclosed the idea of public-key cryptography at a conference in June 1976. Diffie and Hellman also distributed preprints of their ``New Directions in Cryptography'' paper, which disclosed the Diffie-Hellman system, at that conference and by mail. For example, Mike Matyas received a copy in August 1976. The patent was filed in September 1977.

Under United States case law, a document has been published if it ``has been disseminated or otherwise made available to the extent that persons interested and ordinarily skilled in the subject matter or art, exercising reasonable diligence, can locate it.'' A patent is automatically invalid if the patented invention was published more than a year before the patent's filing date.

It appears, therefore, that the Diffie-Hellman-Merkle patent was invalid. In the subsequent court case MIT v. Fortia, another patent was invalidated for the same reason: the inventor handed out six copies of a preprint at a conference fourteen months before applying for the patent.

How does this work in the general case? Is it important that in both examples a whole year has passed between the publishing and the patent application?

Is it necessary for a significant amount of time to pass between the publishing of a paper, and the patent application, for the patent to be subsequently declared invalid?

Specifically, if one's university explicitly claims that it has no interest in one's copyrighted work (whether books, articles or software), and no interest in any part of any revenue from such copyrights, but that patent revenue sharing and disclosure to the university of the patentable ideas is mandatory (IU), can one get around of any future claims for patents by simply releasing everything open-source and publishing all pre-prints before the university's patent office can get their hand on any of the research?