6 research outputs found

    Political Islam and Non-Muslim Religions - A Lesson from Lessing for the Arab Transition

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    Hardly any region has recently captured the global geopolitical imagination as much as the Arab world after the so-called Arab Spring and very likely no state more so than Egypt. Finally it seemed that democracy was coming to the region, that this would spell the end of radical Islam, and of any local aspirations of creating Islamic states, and mark the beginning of a rapprochement between East and West. This article analyses and links those dynamics, with particular reference to the transition process in the wake of the so-called Arab Revolution, and gauges what may be at stake for members of non-Muslim faiths. It particularly traces the rift between theoretical Muslim discourse about Islamic tolerance towards other faiths and its implementation or the absence thereof in practice. It concludes that so far no real progress has been made and that, for the relationship to evolve, Islam needs to proceed to a state in which it sees itself as no more than an equal to other religions. The recognition of its tradition-based nature and of the consequences that flow from such a realization for the treatment of its fundamental sources, the Qur'an and the Sunna, will be addressed. To evaluate the current situation and the outlook, we shall use the example of the famous eighteenth-century German play by Gotthold Ephraim Lessing, Nathan the Wise, about the occupation of Jerusalem by Saladin

    STIR Software for Tomographic Image Reconstruction

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    <h1>Summary of changes in STIR release 5.2.0</h1> <p>This version is 100% backwards compatible with STIR 5.0 as far as usage goes. However, there are changes in the output of scatter estimation and ECAT8 normalisation, see below for more information.</p> <h2>Overall summary</h2> <p>Of course, there is also the usual code-cleanup and improvements to the documentation. See also <a href="https://github.com/UCL/STIR/milestone/6">the 5.2 milestone on GitHub</a>.</p> <p>Overall code management and assistance by Kris Thielemans (UCL and ASC). Other main contributors were Daniel Deidda (NPL) and Markus Jehl (Positrigo).</p> <h2>Patch release info</h2> <ul> <li>5.2.0 released 30/10/2023</li> </ul> <h2>Summary for end users (also to be read by developers)</h2> <h3>Bug fixes</h3> <ul> <li>Scatter estimation was setting initial activity image to 1 at set-up, effectively ignoring the initial image, aside from geometric info.</li> <li>Setting SPECTUB resolution model with STIR python or SIRF divided slope by 10 in error. The problem did not occur when set using parameter file</li> </ul> <h3>Changed functionality</h3> <ul> <li>The ECAT8 normalisation (used for the Siemens mMR) code now takes the 4th component <em>axial effects</em> into account. These normalisation factors are therefore different (even up to ~10%). This gives improved axial uniformity in the images. The use of the axial effects can be switched off by adding setting <code>use_axial_effects_factors:=0</code> to the parameter file (see an example in <code>examples/Siemens-mMR/correct_projdata_no_axial_effects.par</code>), or the class member of the same name. In addition, the Siemens normalisation header is now read (using a new class <code>InterfileNormHeaderSiemens</code>) such that hard-coded variables for the Siemens mMR have been removed. Further testing of this functionality is still required however. <a href="https://github.com/UCL/STIR/pull/1182/">PR #1182</a>.</li> <li>Interfile header parsing now correctly identifies keywords that contain a colon by checking for <code>:=</code>.</li> <li>The <code>set_up()</code> method of the ray-tracing projection matrix now skips further processing if it was already called with data of the same characteristics. This will means that any cached data will be re-used, potentially leading to a speed-up when re-using it from Python. <a href="https://github.com/UCL/STIR/pull/1281/">PR #1281</a>.</li> </ul> <h3>New functionality</h3> <ul> <li><p>The <code>Discretised Shape3D</code> shape/ROI has now an extra value <code>label index</code>. For ROIs, this allows using a single volume with multiple ROIs encoded as labels, such as output by ITKSnap and many others. When used as a shape in <code>generate_image</code>, it could be used to extract a single ROI from such a label image. <a href="https://github.com/UCL/STIR/pull/1196/">PR #1196</a>.</p> </li> <li><p>Global variables in SPECTUB have been substituted by class members, such that multiple SPECTUB projectors can be used. <a href="https://github.com/UCL/STIR/pull/1169/">PR #1169</a>.</p> </li> <li><p>Global variables in PinholeSPECTUB have been substituted by class members, such that multiple PinholeSPECTUB projectors can be used. <a href="https://github.com/UCL/STIR/pull/1212/">PR #1212</a>.</p> </li> <li><p>Scatter estimation is now smoothed in axial direction for BlocksOnCylindrical scanners. <a href="https://github.com/UCL/STIR/pull/1172/">PR #1172</a>.</p> </li> <li><p><code>InverseSSRB</code> now works for BlocksOnCylindrical after a rewrite. <a href="https://github.com/UCL/STIR/pull/1172/">PR #1172</a>. /</p> </li> <li><p>Parallelised function <code>set_fan_data_add_gaps_help</code> across segments to reduce computation time. <a href="https://github.com/UCL/STIR/pull/1168/">PR #1168</a>.</p> </li> <li><p>New utility <code>SPECT_dicom_to_interfile</code> which reads a DICOM file with SPECT projection data and extracts the data and writes one or more Interfile 3.3 headers (still somewhat preliminary). <a href="https://github.com/UCL/STIR/pull/1182/">PR #1182</a>.</p> </li> <li><p>The new <code>stir_timings</code> utility is mostly useful for developers, but you could use it to optimise the number of OpenMP threads to use for your data. <a href="https://github.com/UCL/STIR/pull/1237/">PR #1237</a>.</p> </li> <li><p>New classes <code>SegmentIndices</code>, <code>ViewgramIndices</code> and <code>SinogramIndices</code>, used by <code>ProjData</code> related classes, as opposed to having to specify all the elements directly, e.g. in C++</p> <pre><code> auto sinogram = proj_data.get_sinogram(sinogram_indices);</code></pre> <p>This makes these functions more future proof, in particular for TOF. The older functions are now deprecated. Note that as <code>Bin</code> is now derived from <code>ViewgramIndices</code>, instantations of <code>Bin</code> can now be used to specify the indices as well in most places. There is still more work to do here, mostly related to the symmetries. <a href="https://github.com/UCL/STIR/pull/1273/">PR #1273</a>.</p> </li> </ul> <h4>Python (and MATLAB)</h4> <ul> <li>Examples use <code>stir.ProjData.read_from_file</code> as opposed to <code>stir.ProjData_read_from_file</code>. The former is supported since SWIG 3.0, and the <a href="https://swig.org/Doc4.1/Python.html#Python_nn20">default from SWIG 4.1</a>.</li> <li>Addition of <code>DetectionPosition</code> and <code>DetectionPositionPair</code>.</li> <li><code>bin.time_frame_num</code> is now no longer a function in Python, but acts like a variable (as the other <code>Bin</code> members).</li> <li>Addition of <code>RadionuclideDB</code></li> </ul> <h3>New examples</h3> <ul> <li><code>examples/python/construct_projdata_demo.py</code> illustrates constructing a <code>ProjDataInMemory</code></li> </ul> <h3>Changed functionality</h3> <ul> <li>Scatter estimation was resetting the activity image to 1 before each iteration. This led to cases where the reconstructed image (and therefore the scatter estimation) did not converge, especially when using a small number of sub-iterations. Now, the reconstructed image is continuouslu updated between scatter iterations by default. This should also allow users to use less sub-iterations, therefore saving some time for the scatter estimation. The old behaviour can be re-enabled by setting <code>restart_reconstruction_every_scatter_iteration</code> to true either via a parameter file or via the <code>set_restart_reconstruction_every_scatter_iteration()</code> function. <a href="https://github.com/UCL/STIR/pull/1160/">PR #1160</a>.</li> <li>energy resolution functions and keywords have now more documentation. <code>Scanner::check_consistency</code> also checks if the energy resolution is less than 20 (as it is FWHM/reference_energy). <a href="https://github.com/UCL/STIR/pull/1149/">PR #1149</a>.</li> <li>Errors now throw <code>std::runtime_error</code> instead of <code>std::string</code>. <a href="https://github.com/UCL/STIR/pull/1131/">PR #1131</a>.</li> <li>The parameter <code>use_view_offset</code> was removed from the <code>interpolate_projdata</code> functions. View-offset is now always taken into account. <a href="https://github.com/UCL/STIR/pull/1172/">PR #1172</a>.</li> <li>The info, warning and error calls are thread safe now (which makes them slower), and the logging output in <code>distributable.cxx</code> was changed from verbosity 2 (which is the STIR default) to verbosity 3. This is to reduce the default output during iterative reconstructions. <a href="https://github.com/UCL/STIR/pull/1243/">PR #1243</a>.</li> <li>The <code>Succeeded</code> class has a new method <code>bool succeeded()</code> enabling more concise code (avoiding the need for comparing with <code>Succeeded::yes</code> which is especially verbose in Python).</li> <li>The example files for the Siemens mMR now use lower min/max thresholds for the (single) scatter scale. This gives better results, see <a href="https://github.com/UCL/STIR/issues/1163/">Issue #1163</a>. <a href="https://github.com/UCL/STIR/pull/1279/">PR #1279</a>.</li> </ul> <h3>Deprecated functionality and upcoming changes to required tool versions</h3> <ul> <li>The following functions (previously used for upsampling the scatter estimate) have been made obsolete or replaced, and will be removed in STIR version 6.0.0: <code>interpolate_axial_position</code>, <code>extend_sinogram_in_views</code> and <code>extend_segment_in_views</code></li> <li>Constructors/functions in <code>ProjData</code> related classes that explicitly use <code>axial_pos_num</code>, <code>view_num</code> etc in their arguments are now deprecated, and should be replaced by their respective versions that use <code>SegmentIndices</code>, <code>ViewgramIndices</code> or <code>SinogramIndices</code>. The former will not be compatible with TOF information that will be introduced in version 6.0.0.</li> <li>Use of the AVW library to read Analyze files will be removed in 6.0, as this has not been checked in more than 15 years. Use ITK instead.</li> <li>GE VOLPET and IE support will be removed in 6.0, as we have no files to test this, and it's obsolete anyway.</li> <li>STIR version 6.0.0 will require C++ 14 (currently we require C++ 11, but already support C++ 20) and CMake 3.14.</li> </ul> <h3>Build system and dependencies</h3> <ul> <li>CMake 3.12 is now required on Windows.</li> <li>We now use CMake's <a href="https://gitlab.kitware.com/cmake/community/-/wikis/doc/tutorials/Object-Library">OBJECT library feature</a> for the registries. This avoids re-compilation of the registries for every executable and therefore speeds-up building time. Use of STIR in an external project is not affected as long as the recommended practice was followed. This is now documented in the User's Guide. <a href="https://github.com/UCL/STIR/pull/1141/">PR #1141</a>.</li> <li>The <code>error</code> and <code>warning</code> functions are now no longer included from <code>common.h</code> and need to be included manually when used (as was already the case for <code>#include "stir/info.h"</code>). <a href="https://github.com/UCL/STIR/pull/1192/">PR #1192</a>.</li> <li>add .h and .i as dependencies for SWIG generated wrappers to make sure they get rebuild. (Currently adding all .h files, which is too much, but CMake needs a fix before we can do this properly). <a href="https://github.com/UCL/STIR/pull/1218/">PR #1218</a>.</li> </ul> <h3>Changes for developers</h3> <ul> <li>moved all functionality in <code>CListEventCylindricalScannerWithDiscreteDetectors</code> to template class <code>CListEventScannerWithDiscreteDetectors</code> (templated in <code>ProjDataInfoT</code>). This enables re-use for generic/blocksoncylindrical scanners. <a href="https://github.com/UCL/STIR/pull/1222/">PR #1222</a>.</li> <li>rewritten <code>ProjDataInMemory</code> to avoid streams, causing a speed-up of some operations, and removing a limit of total size of 2GB. <a href="https://github.com/UCL/STIR/pull/1260/">PR #1260</a>.</li> </ul> <h3>Known problems</h3> <ul> <li>See <a href="https://github.com/UCL/STIR/labels/bug">our issue tracker</a>.</li> </ul> <h3>Minor (?) bug fixes</h3> <ul> <li>Small change in scatter simulation to how non-arccorrected bins are computed. Added a check in the construction of non-arccorrected projdata that the number of tangential bins is not larger than the maximum non-arccorrected bins. <a href="https://github.com/UCL/STIR/pull/1152/">PR #1152</a>.</li> <li><code>extend_segment_in_views</code> does not handle view offsets correctly and does not work for BlocksOnCylindrical scanners <a href="https://github.com/UCL/STIR/issues/1177/">issue #1177</a>. A new function <code>extend_segment</code> was added that works for Cylindrical and BlocksOnCylindrical and allows extension in tangential and axial direction as well. <a href="https://github.com/UCL/STIR/pull/1172/">PR #1172</a>.</li> <li><code>sample_function_on_regular_grid</code> did not handle offset correctly in all places <a href="https://github.com/UCL/STIR/issues/1178/">issue #1178</a>. <a href="https://github.com/UCL/STIR/pull/1172/">PR #1172</a>.</li> <li>Ray tracing projection for BlocksOnCylindrical scanner geometries contained a bug where some bins were swapped across oblique segments <a href="https://github.com/UCL/STIR/issues/1223/">issue #1223</a>. This sometimes lead to large artifacts in reconstructions. <a href="https://github.com/UCL/STIR/pull/1231/">PR #1231</a>.</li> </ul> <h3>Documentation changes</h3> <ul> <li>Updated the STIR developers guide, which was quite out-of-date w.r.t. C++ features etc.</li> </ul> <h3>recon_test_pack changes</h3> <ul> <li>Updated headers of most images and projection data to avoid warnings.</li> </ul> <h3>Other changes to tests</h3> <ul> <li><code>test_Scanner.cxx</code> tests for energy resolution, <a href="https://github.com/UCL/STIR/pull/1149/">PR #1149</a>.</li> <li>New file <code>test_interpolate_projdata</code>, <a href="https://github.com/UCL/STIR/pull/1141/">PR #1141</a>.</li> </ul>If you use this software, please cite it using the metadata from this file
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