On Saturday, 19 April 2014 02:52:38 PM Zbyszek Otwinowski wrote: > Why not improve "effective resolution" to include consideration of solvent > content? Due to constant packing density of proteins, it would become a > synonim (by appropriate transformation) to number of observations per > modelled atom.
Following that line of thought, perhaps reporting the observation/parameter ratio would provide a more informative number than "resolution". Of course that leads to a morass of argumentation about whether to modify it by the number and class of restraints used during refinement. Ethan > > Zbyszek Otwinowski > > > > Dear Dale, dear Kay, > > > > last year, we discussed this kind of problems (Urzhumtseva et al., 2013, > > Acta Cryst., D69, 1921-1934). > > Our approach does not tell you where to cut your data and which > > reflections to accept / reject but as soon as you have your set of > > reflections, you calculate very formally and very strictly the "effective > > resolution" of ANY diffraction data set, with ANY completeness, with ANY > > composition of measured / missed reflections. For a complete data set, > > d_effective coincides with the d_high value but is different for > > incomplete data sets. The article contains a number of examples. > > > > With this approach, the discussion of the completeness of the > > highest-resolution shell becomes irrelevant; one can simply cite the > > "effective resolution". I hope this can help. > > > > With best regards, > > > > Sacha Urzhumtsev > > > > ________________________________________ > > De : CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] de la part de Dale > > Tronrud [de...@daletronrud.com] > > Envoyé : samedi 19 avril 2014 03:20 > > À : CCP4BB@JISCMAIL.AC.UK > > Objet : Re: [ccp4bb] crystallographic confusion > > > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > > > I see no problem with saying that the model was refined against every > > spot on the detector that the data reduction program said was observed > > (and I realize there is argument about this) but declare that the > > "resolution of the model" is a number based on the traditional criteria. > > > > > > Dale Tronrud > > > Zbyszek Otwinowski > UT Southwestern Medical Center at Dallas > 5323 Harry Hines Blvd. > Dallas, TX 75390-8816 > Tel. 214-645-6385 > Fax. 214-645-6353 -- mail: Biomolecular Structure Center, K-428 Health Sciences Bldg MS 357742, University of Washington, Seattle 98195-7742