> What I meant, of course, is that I/sigma=1 is legitimate choice in general.
For refinement, yes, as long as the program weights them properly, and your Rmerge is about 0.8/<I/Sig(I)> in that shell. High resolution cutoff in refinement should not be necessary as long as the program applies proper bulk solvent correction. Different for phasing, where much higher high-res cutoffs are needed to suppress dominating high delta**2 values resulting from noise difference, or in MR to suppress reflections giving rise to certain Patterson distances of less relevance (to short or too long). I say this just to impress on the beginners that cutoffs and outlier downscaling are quite different depending on the use of the data! BR -----Original Message----- From: Ed Pozharski [mailto:[email protected]] Sent: Friday, December 11, 2009 3:45 PM To: [email protected] Cc: [email protected] Subject: RE: [ccp4bb] FW: pdb-l: Retraction of 12 Structures.... Bernhard, I understand that you are referring to the 2hr0, right? There the Rmerge was unexpectedly low given the I/sigma. What I meant, of course, is that I/sigma=1 is legitimate choice in general. Ed. On Fri, 2009-12-11 at 15:33 -0800, Bernhard Rupp wrote: > There is nothing wrong per se with the cutoff level selected, but it is > the inconsistency of that level with Rmerge and the Rvalues for the > highest shell. > > BR > > -----Original Message----- > From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Ed > Pozharski > Sent: Friday, December 11, 2009 12:58 PM > To: [email protected] > Subject: Re: [ccp4bb] FW: pdb-l: Retraction of 12 Structures.... > > Not to derail the thread, but there is nothing, imho, wrong with I/s=1 > cutoff (you expect I/s=2, I assume?). R-factors will get higher, but > there are good reasons to believe that model will actually be better. > This has been discussed many times before and there is probably no > resolution, so why not just let people choose whatever resolution cutoff > they want (as long as the I/s is clearly stated)? > > Disclaimer: I always use I/s=1 cutoff (assuming that completeness is > good, of course). Compared to I/s=2 it doesn't really overstate > resolution all that much (e.g. 2.1 vs 2.2). > > On Fri, 2009-12-11 at 13:18 +0100, Silvia Onesti wrote: > > I think also the editors are sometimes to blame. > > > > I once refereed a paper and pointed out that the resolution was overstated > > (I/s(I) = 1.05 in the last resolution shell, as well as a couple of > > comments > > that clearly suggested that the density wasn't very good). The editor > > ignored my comments. > > > > Silvia > > ------------------------------------------------------------------------------------------------ > > Silvia Onesti > > > > Sincrotrone Trieste S.C.p.A. > > SS 14 - km 163,5 - AREA Science Park, 34149 Basovizza, Trieste ITALY > > > > Email: [email protected] > > Tel. +39 040 3758451 > > Mob +39 366 6878001 > > > > http://www.elettra.trieste.it/PEOPLE/index.php?n=SilviaOnesti.HomePage > > http://www.sissa.it/sbp/web_2008/research_structuralbio.html > > ------------------------------------------------------------------------------------------------ > > > > On Fri, 11 Dec 2009 10:48:41 +0100 > > Vellieux Frederic <[email protected]> wrote: > > Hi all, > > > > Like everyone else, I was appalled. > > > > My two cents worth: Nature and Science are not scientific journals in the > > strict sense of the term. They are more like magazines (I won't go all the > > way > > to say "tabloids"), and as such will do anything to publish what seems to be > > hot. And will reject very good scientific papers. So it's not a surprise > > that > > retractions affect magazines such as Science and Nature. > > > > Fred. > > -- Edwin Pozharski, PhD, Assistant Professor University of Maryland, Baltimore ---------------------------------------------- When the Way is forgotten duty and justice appear; Then knowledge and wisdom are born along with hypocrisy. When harmonious relationships dissolve then respect and devotion arise; When a nation falls to chaos then loyalty and patriotism are born. ------------------------------ / Lao Tse /
