Since there are several sub-plots in that mammoth thread, I thought
branching out would be a good idea.
I think working out the technicalities of how to publicly archive raw
data is fairly simple compared to the bigger picture.
1. Indeed, all the required meta-data will need to be captured just
like for refined coordinates. This will be an additional burden for
the depositor, but it's clearly necessary, and I do consider it
trivial. Trivial, as in the sense of "straightforward", i.e., there
is no fundamental problem blocking progress. As mentioned, current
data processing software captures most of the pertinent information
already, although that could be improved. I am sure that the
beamlines, diffraction-system manufacturers and authors of data-
processing software can be convinced to cooperate appropriately, if
the community needs these features.
2. More tricky is the issue of a unified format for the images, which
would be very helpful. There have been attempts at creating unified
image formats, but - to my knowledge - they haven't gotten anywhere.
However, I am also convinced that such formats can be designed, and
that detector manufacturers will have no problems implementing them,
considering that their detectors may not be purchased if they don't
comply with requirements defined by the community.
3. The hardware required to store all those data, even in a highly
redundant way, is clearly trivial.
4. The biggest problem I can see in the short run is the burden on
the databank when thousands of investigators start transferring
gigabytes of images, all at the same time.
5. I think the NSA might go bonkers over that traffic, although it
certainly has enough storage space. Imagine, they let their decoders
go wild on all those images. They might actually find interesting
things in them...
So, what's the hold-up?
Best - MM
On Aug 17, 2007, at 3:23 AM, Winter, G (Graeme) wrote:
Storing all the images *is* expensive but it can be done - the JCSG do
this and make available a good chunk of their raw diffraction data.
The
cost is, however, in preparing this to make the data useful for the
person who downloads it.
If we are going to store and publish the raw experimental measurements
(e.g. the images) which I think would be spectacular, we will also
need
to define a minimum amount of metadata which should be supplied with
this to allow a reasonable chance of reproduction of the results. This
is clearly not trivial, but there is probably enough information in
the
harvest and log files from e.g. CCP4, HKL2000, Phenix to allow this.
The real problem will be in getting people to dig out that tape / dvd
with the images on, prepare the required metadata and "deposit" this
information somewhere. Actually storing it is a smaller challenge,
though this is a long way from being trivial.
On an aside - firewire disks are indeed a very cheap way of storing
the
data. There is a good reason why they are much cheaper than the
equivalent RAID array. They fail. Ever lost 500GB of data in one go?
Ouch. ;o)
Just MHO.
Cheers,
Graeme
-----Original Message-----
From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of
Phil Evans
Sent: 16 August 2007 15:13
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] The importance of USING our validation tools
What do you count as raw data? Rawest are the images - everything
beyond
that is modellling - but archiving images is _expensive_!
Unmerged intensities are probably more manageable
Phil
On 16 Aug 2007, at 15:05, Ashley Buckle wrote:
Dear Randy
These are very valid points, and I'm so glad you've taken the
important step of initiating this. For now I'd like to respond to one
of them, as it concerns something I and colleagues in Australia are
doing:
The more information that is available, the easier it will be to
detect fabrication (because it is harder to make up more information
convincingly). For instance, if the diffraction data are deposited,
we can check for consistency with the known properties of real
macromolecular crystals, e.g. that they contain disordered solvent
and not vacuum. As Tassos Perrakis has discovered, there are
characteristic ways in which the standard deviations depend on the
intensities and the resolution. If unmerged data are deposited,
there
will probably be evidence of radiation damage, weak effects from
intrinsic anomalous scatterers, etc. Raw images are probably even
harder to simulate convincingly.
After the recent Science retractions we realised that its about time
raw data was made available. So, we have set about creating the
necessary IT and software to do this for our diffraction data, and
are
encouraging Australian colleagues to do the same. We are about a week
away from launching a web-accessible repository for our recently
published (eg deposited in PDB) data, and this should coincide
with an
upcoming publication describing a new structure from our labs. The
aim
is that publication occurs simultaneously with release in PDB as well
as raw diffraction data on our website.
We hope to house as much of our data as possible, as well as data
from
other Australian labs, but obviously the potential dataset will be
huge, so we are trying to develop, and make available freely to the
community, software tools that allow others to easily setup their own
repositories. After brief discussion with PDB the plan is that PDB
include links from coordinates/SF's to the raw data using a simple
handle that can be incorporated into a URL. We would hope that we
can
convince the journals that raw data must be made available at the
time
of publication, in the same way as coordinates and structure factors.
Of course, we realise that there will be many hurdles along the way
but we are convinced that simply making the raw data available
ASAP is
a 'good thing'.
We are happy to share more details of our IT plans with the CCP4BB,
such that they can be improved, and look forward to hearing feedback
cheers
------------------------------------------------------------------------
--------
Mischa Machius, PhD
Associate Professor
UT Southwestern Medical Center at Dallas
5323 Harry Hines Blvd.; ND10.214A
Dallas, TX 75390-8816; U.S.A.
Tel: +1 214 645 6381
Fax: +1 214 645 6353
