From: Tom Laue <Tom.Laue@unh.edu>
  To  : rasmb@alpha.bbri.org
  Date: Mon, 20 Mar 2000 16:21:01 -0500

Sednterp update

Dear RASMBers,
  While working on the update to Sednterp, John Philo found an error in the
original code from my lab. In particular, the temperature correction of the
density for heavy isotopes was wrong: the melting point of the isotope was
used instead of the temperature of maximum density in the calculations. 
  Some quick testing by John indicates that the miscalculation for pure D2O
would produce errors of ~.003 in rho. This error, in turn, propogates to a
~1.1% error in the mass estimate for a protein with a vbar = 0.73 ml/g. 
  To give you a better idea of the level of imprecision, here are values
John calculated for pure D20 at different temperatures:

T	old code	new code	CRC(Kell data, not formula)
5	1.10601	1.10564	1.10562
10	1.10569	1.10601	1.10599
20	1.10392	1.10537	1.10534
30	1.10091	1.10325	1.10323
40	1.09689	1.09997	1.09996

  There are two ways to update Sednterp with this problem patched. The new
full install is the file sdtr0002.exe (1.8 MB). Since only the program
executable is changed, there is also a file sdnupdat.exe (220 KB) which
updates versions 1.01-1.04 to 1.05. The update-only file does not have a
true installation utility; when the self-extracting archive is run you must
supply the correct folder location for the previous SEDNTERP installation
(usually c:\sednterp) and the archive will overwrite the older program file.
  Both the full update and the patches are available from either John
Philo's site or the RASMB ftp site:
http://www.jphilo.mailway.com/download.htm
ftp://alpha.bbri.org/rasmb/spin/ms_dos/sednterp-philo/
  If you do a full re-install, you must be careful not to overwrite your own
databases (make a backup of SEDNTERP.MDB and PHYCONST.MDB just in case, and
answer YES that you want to preserve your existing databases when you get
the prompts).
  My apologies to everyone for allowing this error, and my thanks to John
Philo for finding and fixing it.
Tom
--------------------------------------------
Tom Laue
Professor and Director of the Center to Advance Molecular Interaction Science
University of New Hampshire
Biochemistry and Molecular Biology
Rudman-379
46 College Rd.
Durham, NH 03824-3544

Phone: 603-862-2459
FAX:   603-862-4013
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