> Rmeas is always higher than Rmerge, so if my Rmerg is high I don't like
Rmeas either.
But that makes perfect sense now per Tim: the linear Rmerge gives for small
N (lower redundancy) always lower values and rises with redundancy to
approach Rmeas/rim for high redundancy.
> I like the idea just to look at the I/sigI and include more data.
Lucky me to suggest to use all your present data for refinement... ;-)
BR
Maia
Tim Gruene wrote:
> Hello Maia,
>
> Rmerge is obsolete, so the reviewers had a good point to make you
> publish Rmeas instead. Rmeas should replace Rmerge in my opinion.
>
> The data statistics you sent show a mulltiplicity of about 20! Did you
> check your data for radiation damage? That might explain why your
> Rmeas is so utterly high while your I/sigI is still above 2 (You
> should not cut your data but include
> more!)
>
> What do the statistics look like if you process just about enough
> frames so that you get a reasonable mulltiplicity, 3-4, say?
>
> Cheers, Tim
>
> On Thu, Mar 03, 2011 at 10:57:37AM -0700, Maia Cherney wrote:
>
>> I see, there is no consensus about my data. Some people say 2.4A,
>> other say all. Well, I chose 2.3 A. My rule was to be a little bit
>> below Rmerg 100%. At 2.3A Rmerg was 98.7% Actually, I have published
>> my paper in JMB. Yes, reviewers did not like that and even made me
>> give Rrim and Rpim etc.
>>
>> Maia
>>
>>
>>
>> Bernhard Rupp (Hofkristallrat a.D.) wrote:
>>
>>> First of all I would ask a XDS expert for that because I don't know
>>> exactly what stats the XDS program reports (shame on me, ok) nor
>>> what the quality of your error model is, or what you want to use the
>>> data for (I guess refinement - see Eleanor's response for that, and use
all data).
>>>
>>> There is one point I'd like to make re cutoff: If one gets greedy
>>> and collects too much noise in high resolution shells (like way
>>> below <I/sigI> =
>>> 0.8 or so) the scaling/integration may suffer from an overabundance
>>> of nonsense data, and here I believe it makes sense to select a
>>> higher cutoff (like what exactly?) and reprocess the data. Maybe one
>>> of our data collection specialist should comment on that.
>>>
>>> BR
>>>
>>> -----Original Message-----
>>> From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf
>>> Of Maia Cherney
>>> Sent: Thursday, March 03, 2011 9:13 AM
>>> To: [log in to unmask]
>>> Subject: Re: [ccp4bb] I/sigmaI of >3.0 rule
>>>
>>> I have to resend my statistics.
>>>
>>> Maia Cherney wrote:
>>>
>>>> Dear Bernhard
>>>>
>>>> I am wondering where I should cut my data off. Here is the
>>>> statistics from XDS processing.
>>>>
>>>> Maia
>>>>
>>>>
>>>>> On 11-03-03 04:29 AM, Roberto Battistutta wrote:
>>>>>
>>>>>> Dear all,
>>>>>> I got a reviewer comment that indicate the "need to refine the
>>>>>> structures
>>>>>>
>>>>> at an appropriate resolution (I/sigmaI of>3.0), and re-submit the
>>>>> revised coordinate files to the PDB for validation.". In the
>>>>> manuscript I present some crystal structures determined by
>>>>> molecular replacement using the same protein in a different space
>>>>> group as search model. Does anyone know the origin or the
>>>>> theoretical basis of this "I/sigmaI>3.0" rule for an appropriate
>>>>> resolution?
>>>>>
>>>>>> Thanks,
>>>>>> Bye,
>>>>>> Roberto.
>>>>>>
>>>>>>
>>>>>> Roberto Battistutta
>>>>>> Associate Professor
>>>>>> Department of Chemistry
>>>>>> University of Padua
>>>>>> via Marzolo 1, 35131 Padova - ITALY tel. +39.049.8275265/67 fax.
>>>>>> +39.049.8275239 [log in to unmask]
>>>>>> www.chimica.unipd.it/roberto.battistutta/
>>>>>> VIMM (Venetian Institute of Molecular Medicine) via Orus 2,
>>>>>> 35129 Padova - ITALY tel. +39.049.7923236 fax
>>>>>> +39.049.7923250 www.vimm.it
>>>>>>
>>>>>>
>>>
>
>
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