CMYK - the saga continues

I found a grad student in the lab next door who's a graphics whiz, and she converted my PowerPoint files to CMYK for me.  But I forgot about the need for 300dpi resolution and for reducing the size to approximately that of the final printed image, so the CMYK versions are both about twice as big as they should be and much too low in resolution (72 dpi, says the digital image analyzer thoughtfully recommended by the journal).  

Unfortunately the size discrepancy isn't large enough compensate for the resolution discrepancy.  So I've sent the PowerPoint file and jpgs and tiffs derived from it to my collaborator, hoping she can do the conversion we need.  She's sent me the other information I need for the final revisions, so maybe we can still get it all submitted before Monday.