[OS X TeX] Inter-section spacing

[jmm]

Can someone tell me if there is a straightforward way to manipulate  
the amount of vertical spacing before a section header in a typical  
document class. (In my current case, amsart.)  I need to squeeze out a  
bit of white space for a 5-page, double-spaced proposal that requires  
9 different sections.  (That's a lot of space devoted to the section  
headers!)

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Jeffrey MacKie Mason
http://www-personal.umich.edu/~jmm/
Arthur W. Burks Collegiate Professor of
         Information and Computer Science
Professor or Economics and Public Policy