Hi 

I'd have a look at the CC(1/2) in the high resolution bin - it's 0.851 (in the 
column 2.10 - 2.16), so there is plenty of self-agreement in that range. 

Also Mean(I/sd(I)) is 2.8 in the high resolution bin, which means you have (on 
average) significantly strong reflections to at least 2.1Å, so you can happily 
integrate that far.

R(meas) in the high resolution bin is acceptable at 0.44 (but Rmeas is not a 
good criterion for a cut-off, as has been discussed ad nauseam on this BB, so 
if you are going to look at it, only use it to confirm what CC(1/2) and I/sd(I) 
have already told you, i.e. you can safely process to higher resolution than 
2.1Å ).

Then I'd look at the image and see that the corners go to about 1.89Å (or a bit 
better) , so I'd integrate into the corners rather than use the "inscribed 
circle" (which is the default in iMosflm) - I notice you have already set your 
resolution limit on that image to about 1.87Å.

Don't worry about the presence of ice rings - you can exclude them in either 
integration or in scaling (with an otherwise good dataset like this I would 
exclude them in scaling unless including them in integration had caused 
problems).

Any modern refinement program should be able to weight your (weak) high 
resolution reflections properly so I wouldn't apply a manual resolution cut-off 
subsequently with these data.

I would actually have been inclined to collect (and process) the data to higher 
resolution (smaller crystal to detector distance) since the data may well be 
usable beyond your current detector limits, and it doesn't look like you have 
overlaps.

HTH & Merry Christmas!

On 22 Dec 2014, at 12:20, sreetama das wrote:

> Dear all,
>              I have a synchrotron data which has low outer shell and overall 
> completeness (table below). The dataset has ice rings (picture of frame 
> attached).
> If it reduce the higher resolution limit during scaling (aimless), the 
> completeness increases, but the <I/sig(I)> in outermost shell also increases. 
> Besides, this would also involve throwing away of high resolution data.
> In these circumstances, what criteria should be looked at to determine to 
> what resolution the data should be used during processing? 
> thanks and regards,
> sreetama
> Overall InnerShell OuterShell
> Low resolution limit                       47.75     47.75      2.16
> High resolution limit                       2.10      8.91      2.10
> 
> Rmerge  (within I+/I-)                     0.058     0.029     0.338
> Rmerge  (all I+ and I-)                    0.062     0.031     0.370
> Rmeas (within I+/I-)                       0.068     0.034     0.441
> Rmeas (all I+ & I-)                        0.068     0.035     0.447
> Rpim (within I+/I-)                        0.035     0.018     0.280
> Rpim (all I+ & I-)                         0.027     0.014     0.242
> Rmerge in top intensity bin                0.043        -         - 
> Total number of observations               67721      1193      1985
> Total number unique                        10915       189       709
> Mean((I)/sd(I))                             18.4      35.1       2.8
> Mn(I) half-set correlation CC(1/2)         0.993     0.998     0.851
> Completeness                                89.8      99.6      73.5
> Multiplicity                                 6.2       6.3       2.8
> 
> Anomalous completeness                      84.5      99.6      49.7
> Anomalous multiplicity                       3.1       3.8       1.7
> DelAnom correlation between half-sets     -0.012     0.304     0.008
> Mid-Slope of Anom Normal Probability       0.945       -         -  
> 
> Estimates of resolution limits: overall
>    from half-dataset correlation CC(1/2) >  0.50: limit =  2.10A  == maximum 
> resolution
>    from Mn(I/sd) >  2.00:                         limit =  2.10A  == maximum 
> resolution
> 
> 
> 
> ICE RINGS:
> 
> Possible Ice Rings
> 
> Ice Ring Summary:
> reso mean_I mean_Sigma Estimated_I Zscore Completeness Ave_Completeness
> 3.89 19320.73 417.47 17504.43 4.35 0.76 1.00
> 3.67 16354.48 395.80 12788.36 9.01 0.71 1.00
> 3.44 12035.71 301.90 12214.14 -0.59 0.68 1.00
> 2.66 2358.33 143.37 2288.63 0.49 0.56 1.00
> 2.24 42046.24 1430.20 656.36 28.94 0.34 0.68
> 
> 
> <frame.png>

Harry
--
Dr Harry Powell, MRC Laboratory of Molecular Biology, Francis Crick Avenue, 
Cambridge Biomedical Campus, Cambridge CB2 0QH
Chairman of International Union of Crystallography Commission on 
Crystallographic Computing
Chairman of European Crystallographic Association SIG9 (Crystallographic 
Computing) 










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