Hi all,
I definitely agree that depositing unfiltered half maps should be
mandatory. However, descriptions of masks in papers are likely to be
incomplete or ambiguous. The simplest solution would be to also deposit
any masks used in postprocessing. The EMDB already allows this. This would
make recalculating the global FSC fairly straightforward (and could even
be done as part of the deposition validation checks?). For completeness,
MTF files may also need to be deposited/or associated with the entry.
Best wishes,
Alan
> Hi,
>
> I've also noticed significantly higher FSC resolution estimates with
> cryosparc vs relion, which do not seem realistic upon inspection. (IE: a
> 4A relion postprocessed map looks much different than a 4A cryosparc map).
> Has anyone noticed as well? How are you handling?
>
> Best,
> Jillian
>
> Sent from my iPhone
>
>> On May 26, 2017, at 8:47 PM, Oliver Clarke <[log in to unmask]> wrote:
>>
>> Hi all,
>>
>> Ive seen several high-impact cryoEM structures recently with "headline"
>> global FSC resolutions that do not seem plausible based on inspection of
>> the map.
>>
>> In each case, the resolution was based on results out of
>> relion_postprocess, but no details were given about mask calculation or
>> the volume of the mask compared to the model, and only the final map was
>> deposited, not the half maps (so checking workings was not possible).
>>
>> I think that at a bare minimum, reporting either the volume of the mask
>> compared to the volume of the map at the suggested contour level, or
>> simply displaying an overlay of the mask on the model, should be
>> mandatory (as should deposition of unfiltered half maps to facilitate
>> recalculation of the FSC).
>>
>> Without knowledge of the mask, the FSC is meaningless, particularly if
>> the author has chosen to use relion_postprocess as a "black box", and
>> has chosen to automatically generate a mask based on an initial
>> threshold without subsequently inspecting it.
>>
>> (There have also been a couple of structures using the pymol 'carve'
>> option in extremely misleading ways without disclosing its use or the
>> map contour level, but that is a rant for another day!)
>>
>> Thoughts/debate welcome! :)
>>
>> Cheers
>>
>> Oli
>
|