Hong, Could you send out the following URL for people to get next week's reading for MBJC? Thanks. Jan Next week's reading: http://www.amath.washington.edu/~medlock/dengue.pdf http://www.amath.washington.edu/~medlock/dengue.ps I had some trouble with the pdf (acrobat4 seems to work but acrobat3 doesn't work well) so there's a postscript version too.