> 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 Rmerge is obsolete, so the reviewers had a good point to make you 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:CCP4BB@JISCMAIL.AC.UK] On Behalf 
>>> Of Maia Cherney
>>> Sent: Thursday, March 03, 2011 9:13 AM
>>> To: CCP4BB@JISCMAIL.AC.UK
>>> 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 roberto.battistu...@unipd.it 
>>>>>> 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
>>>>>>
>>>>>>             
>>>       
>
>   

Reply via email to