Oh dear.
You definitely cannot de-twin a dataset by mergeing it with a
non-twinned dataset! And if the twin fraction of your synchrotron set
is much greater than 0.3 then it is unlikely that you will be able to
use the anomalous differences to solve the phase problem.
If I were you, I would focus on the non-twinned crystal system. You CAN
average anomalous differences across different crystals, provided they
are reasonably isomorphous. http://dx.doi.org/10.1107/S0907444910046573
And I should add the caveat that twinning is equivalent to
"non-isomorphism" until after you have solved the structure because it
dramatically changes the intensity you have available for any given hkl
index.
-James Holton
MAD Scientist
On 1/19/2012 8:20 AM, arka chakraborty wrote:
Hi all,
Thanks for providing multiple solutions to my problem. Prof . Tim
Gruene and Prof. James Holton provided some nice solutions. However
since the data are collected from different crystals, I am not sure
whether I can do MAD phasing. My aim is to merge the two data-sets to
circumvent the problem posed by the fact that the synchroton data is
twinned. So maybe merging the data sets will provide better phases
from SAD phasing? My main concern was how to do scaling adjustments
before using the data-sets together.
Thanking you,
Regards,
ARKO
On Thu, Jan 19, 2012 at 1:46 AM, Soisson, Stephen M
<stephen_sois...@merck.com <mailto:stephen_sois...@merck.com>> wrote:
But if we were to follow that convention we would have been stuck
with Multi-wavelength Resonant Diffraction Experimental Results,
or, quite simply, MuRDER.
-----Original Message-----
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK
<mailto:CCP4BB@JISCMAIL.AC.UK>] On Behalf Of Jacob Keller
Sent: Wednesday, January 18, 2012 3:13 PM
To: CCP4BB@JISCMAIL.AC.UK <mailto:CCP4BB@JISCMAIL.AC.UK>
Subject: Re: [ccp4bb] Merging data collected at two different
wavelength
This begs the question* whether you want the lemmings to understand
you. One theory of language, gotten more or less from Strunk and
White's Elements of Style, is that the most important feature of
language is its transparency to the underlying thoughts. Bad language
breaks the transparency, reminds you that you are reading and not
simply thinking the thoughts of the author, who should also usually be
invisible. Bad writing calls attention to itself and to the author,
whereas good writing guides the thoughts of the reader unnoticeably.
For Strunk and White, it seems that all rules of writing follow this
principle, and it seems to be the right way to think about language.
So, conventions, even when somewhat inaccurate, are important in that
they are often more transparent, and the reader does not get stuck on
them.
Anyway, a case in point of lemmings is that once Wayne Hendrickson
himself suggested that the term anomalous be decommissioned in favor
of "resonant." I don't hear any non-lemmings jumping on that
bandwagon...
JPK
*Is this the right use of "beg the question?"
On Wed, Jan 18, 2012 at 1:57 PM, Phoebe Rice <pr...@uchicago.edu
<mailto:pr...@uchicago.edu>> wrote:
>>
>>> Can I be dogmatic about this ?
>>
>>I wish you could, but I don't think so, because even though those
>>sources call it that, others don't. I agree with your thinking, but
>>usage is usage.
>
> And 10,000 lemmings can't be wrong?
--
*******************************************
Jacob Pearson Keller
Northwestern University
Medical Scientist Training Program
email: j-kell...@northwestern.edu <mailto:j-kell...@northwestern.edu>
*******************************************
Notice: This e-mail message, together with any attachments, contains
information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station,
New Jersey, USA 08889), and/or its affiliates Direct contact
information
for affiliates is available at
http://www.merck.com/contact/contacts.html) that may be confidential,
proprietary copyrighted and/or legally privileged. It is intended
solely
for the use of the individual or entity named on this message. If
you are
not the intended recipient, and have received this message in error,
please notify us immediately by reply e-mail and then delete it from
your system.
--
/ARKA CHAKRABORTY/
/CAS in Crystallography and Biophysics/
/University of Madras/
/Chennai,India/
