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Dear Blaine Mooers,
I don't think that you avoid Fourier ripples with this method. You
may, however, increase the noise level so that the Fourier ripples
drown in the noise.
You don't really generate a low resolution data set by truncation for
that very reason. Crystals that only diffract to 3.5A, say, usually do
this because of a high degree of disorder with leeds to more noise.
Of course you could add noise to the sigma-values, but this is merely
cosmetics.
There are repositories for frames (JCSG?), where you might want to get
real data that diffract to the desired resolution, reprocess and then
carry out the phasing experiments.
Best,
Tim
On 02/13/2014 03:54 PM, Mooers, Blaine H.M. (HSC) wrote:
> For some simulated phasing experiments, I want to create a lower
> resolution diffraction data set by truncating a high resolution
> data set. I would like to avoid Fourier ripples due to the
> truncation of the high resolution data by downscaling the data
> such that <I/sigma>=2.0 in the highest resolution shell of the
> truncated data. What is the best way to do this?
>
> Blaine Mooers Assistant Professor Department of Biochemistry and
> Molecular Biology University of Oklahoma Health Sciences Center
> S.L. Young Biomedical Research Center Rm. 466
>
> Shipping address: 975 NE 10th Street, BRC 466 Oklahoma City, OK
> 73104-5419
>
> Letter address: P.O. Box 26901, BRC 466 Oklahoma City, OK 73190
>
>
> office: (405) 271-8300 lab: (405) 271-8313 fax: (405) 271-3910
> e-mail: [log in to unmask]
>
> Faculty webpage:
> http://www.oumedicine.com/department-of-biochemistry-and-molecular-biology/faculty/blaine-mooers-ph-d-
>
> X-ray lab webpage:
> http://www.oumedicine.com/department-of-biochemistry-and-molecular-biology/department-facilities/macromolecular-crystallography-laboratory
>
> Small Angle Scattering webpage:
> http://www.oumedicine.com/docs/default-source/ad-biochemistry-workfiles/small-angle-scattering-links.html?sfvrsn=0
>
>
- --
- --
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
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