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<div class="moz-cite-prefix">On 09/12/2015 02:32, Smith Lee wrote:<br>
</div>
<blockquote
cite="mid:632225445.429713.1449624736990.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial,
Lucida Grande, sans-serif;font-size:16px">
<div id="yui_3_16_0_1_1449624487110_3472"> Dear All,</div>
<div id="yui_3_16_0_1_1449624487110_3218"><br>
</div>
<div id="yui_3_16_0_1_1449624487110_3469">Will you please
explain to me in plain language on the meaning of fourier
shell in the term "fourier shell correlation (FSC)?</div>
<div id="yui_3_16_0_1_1449624487110_3470"><br>
</div>
<div id="yui_3_16_0_1_1449624487110_3471">Smith</div>
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</blockquote>
<br>
Dear Smith<br>
<br>
The meaning of "Fourier Shell" or "Fourier Ring" in the definition
of the FSC or of the FRC respectively is clearly explained in the
first publications on the issue (see below). The "Fourier Ring", is
a circular area in 2D Fourier space with an inner radius and an
outer radius which typically has the width "1" . The "Fourier Shell"
is a spherical volume mask in Fourier space with an inner radius and
an outer radius, again with a typical width of "1". The FRC and FSC
have become <br>
the "gold standard" quality metrics for measuring reproducible
resolution in electron microscopy, but are now also used outside
the field of single-particle cryo EM (X-ray crystallography, light
microscopy, for example). If you have a problem finding these old
papers please request the PDFs from me directly. (You may also want
have a look at the Wikipedia page:
<a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Fourier_shell_correlation">https://en.wikipedia.org/wiki/Fourier_shell_correlation</a> ). <br>
<br>
Cheers,<br>
<br>
Marin<cite class="citation journal"><br>
<br>
Harauz, G.; van Heel M "Exact filters for general geometry three
dimensional reconstruction". <i>Optik</i> <b>73</b> </cite><cite
class="citation journal"><cite class="citation journal">(1986) </cite>146–156<br>
<br>
</cite><cite class="citation book">van Heel, M.; Keegstra, W.;
Schutter, W.; van Bruggen E.F.J. (1982). <i>Arthropod hemocyanin
studies by image analysis, in: Structure and Function of
Invertebrate Respiratory Proteins,EMBO Workshop 1982, E.J. Wood</i>.
<i>Life Chemistry Reports</i>. Suppl. 1. pp. 69–73. <a
href="https://en.wikipedia.org/wiki/International_Standard_Book_Number"
title="International Standard Book Number">ISBN</a> <a
href="https://en.wikipedia.org/wiki/Special:BookSources/9783718601554"
title="Special:BookSources/9783718601554">9783718601554</a></cite><cite
class="citation journal"></cite><br>
<pre class="moz-signature" cols="72">
--
================================================================
Prof Dr Ir Marin van Heel
Professor of Cryo-EM Data Processing
Leiden University
NeCEN Building Room 05.27
Einsteinweg 55
2333 CC Leiden
The Netherlands
Tel. NL: +31(0)715271424 // Mobile NL: +31(0)652736618
Skype: Marin.van.Heel
email: marin.vanheel(A_T)gmail.com
and: mvh.office(A_T)gmail.com
----------------------------------------------
Emeritus Professor of Structural Biology
Imperial College London
Faculty of Natural Sciences
Biochemistry Building (Room 512)
South Kensington Campus
London SW7 2AZ, UK
email: m.vanheel(A_T)ic.ac.uk
Tel. UK: +44(0)2075945316 //Mobile: +44(0)7941540625
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Visiting Professor at:
Laboratório Nacional de Nanotecnologia - LNNano
CNPEM/ABTLuS, Campinas, Brazil
Brazilian mobile phone +55-19-983189143
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