Coherent pi0 photoproduction on nuclei

The coherent nuclear ¼0 photoproduction reaction is sensitive to the nuclear matter form factor i.e. the distribution of matter within the nucleus. Accurate measurements of the nuclear matter distribution as charaterised by the r.m.s. radius are important for applications to nuclear theories, neutron stars, atomic parity non-conservation and heavy ion collisions. This thesis presents the results from a new experiment to measure coherent ¼0 photoproduction on 208Pb, 40Ca, 16O and 12C. The ultimate goal of the research programme is to make a high precision measurement of the nature of the neutron skin of 208Pb. The first major step in this direction is to achieve an accurate data set of coherent pion photoproduction which is presented in this thesis. The experiment was performed in the A2 hall of the MAMI electron accelerator facility at the InstitÄut fur Kernphysik, Mainz, Germany. An 883 MeV beam of electrons was directed on to a 10¹m nickel radiator producing a Bremsstrahlung photon beam which was then 'tagged' with a resolution of 2 MeV using the Glasgow Photon Tagging Spectrometer. The photon beam was incident on one of the 4 experimental targets inducing the reaction A(°,¼0)A. The neutral ¼0s were then detected via their two photon decay in the newly installed 4¼ Crystal Ball and TAPS detector systems. The results from all four targets are presented as differential and total cross sections covering the energy range E°=(135-300) MeV and covering the full 180± of the pion polar angle. Comparisons have been made with previous data and with the latest theoretical calculations of Dreschel et. al. which employ detailed pion optical potentials in describing the pion-nucleus final state interaction. It is concluded that the 208Pb cross sections show good agreement with the calculations indicating that the pion-nucleus FSI distortions are well accounted for by the model. A pleasing reduction in statistical and systematic uncertainties from previous measurements is also observed. While the 208Pb cross sections are finalised it is suggested that the 12C and 16O data would benefit from a further analysis utilising the coincident detection of nuclear decay photons to isolate incoherent events and allow a more detailed comparison with theory. A first comparison of the theoretical model with the new high quality data gives first indications of a neutron skin on 208Pb. A future scheme for the full detailed extraction of the matter distribution from the new data set is also suggested

Accuracy and feasibility of an android-based digital assessment tool for post stroke visual disorders - The StrokeVision App

Background: Visual impairment affects up to 70% of stroke survivors. We designed an app (StrokeVision) to facilitate screening for common post stroke visual issues (acuity, visual fields and visual inattention). We sought to describe the test-time, feasibility, acceptability and accuracy of our app based digital visual assessments against a) current methods used for bedside screening, and b) gold standard measures. Methods: Patients were prospectively recruited from acute stroke settings. Index tests were app based assessments of fields and inattention performed by a trained researcher. We compared against usual clinical screening practice of visual fields to confrontation including inattention assessment (simultaneous stimuli). We also compared app to gold standard assessments of formal kinetic perimetry (Goldman or Octopus Visual Field Assessment); and pencil and paper based tests of inattention (Albert’s, Star Cancellation, and Line Bisection). Results of inattention and field tests were adjudicated by a specialist Neuro-Ophthalmologist. All assessors were masked to each other’s results. Participants and assessors graded acceptability using a bespoke scale that ranged from 0 (completely unacceptable) to 10 (perfect acceptability). Results: Of 48 stroke survivors recruited, the complete battery of index and reference tests for fields was successfully completed in 45. Similar acceptability scores were observed for app-based (assessor median score 10 [IQR:9-10]; patient 9 [IQR:8-10]) and traditional bedside testing (assessor 10 [IQR:9-10; patient 10 [IQR:9-10]). Median test time was longer for app-based testing (combined time-to-completion of all digital tests 420 seconds [IQR:390-588]) when compared with conventional bedside testing (70 seconds, [IQR:40-70]) but shorter than gold standard testing (1260 seconds, [IQR:1005-1620]). Compared with gold standard assessments, usual screening practice demonstrated 79% sensitivity and 82% specificity for detection of a stroke-related field defect. This compares with 79% sensitivity and 88% specificity for StrokeVision digital assessment. Conclusion: StrokeVision shows promise as a screening tool for visual complications in the acute phase of stroke. The app is at least as good as usual screening and offers other functionality that may make it attractive for use in acute stroke

Nipype: a flexible, lightweight and extensible neuroimaging data processing framework in Python. 0.13.1

0.13.1 (May 20, 2017) FIX: Make release compatible with conda-forge build process (https://github.com/nipy/nipype/pull/2017) ENH: Update some minimum versions in compliance with Debian Jessie (https://github.com/nipy/nipype/pull/2017) ENH: Circle builds use cached docker layers (https://github.com/nipy/nipype/pull/2017) ENH: Base docker to use FS6 and ANTS 2.2.0 (https://github.com/nipy/nipype/pull/2024) FIX: Mailmap and contributor acknowledgment (https://github.com/nipy/nipype/pull/2017) FIX: Preserve node properties in sub nodes of MapNode (https://github.com/nipy/nipype/pull/2019) FIX: Fix interfaces 3DUnifize, ICA_AROMA, BinaryMaths, RegAverage, BBRegister, AffineInitializer (https://github.com/nipy/nipype/pull/2025, https://github.com/nipy/nipype/pull/2027, https://github.com/nipy/nipype/pull/2036, https://github.com/nipy/nipype/pull/2037, https://github.com/nipy/nipype/pull/2031, https://github.com/nipy/nipype/pull/2010) ENH: Add Anisotropic Power interface (https://github.com/nipy/nipype/pull/2039) FIX: Bayesian estimation in SPM (https://github.com/nipy/nipype/pull/2030) 0.13.0 (May 11, 2017) ENH: Multi-stage recon-all directives (https://github.com/nipy/nipype/pull/1991) FIX: FEAT "folder does not exist" error (https://github.com/nipy/nipype/pull/2000) ENH: Niftyfit interfaces (https://github.com/nipy/nipype/pull/1910) FIX: Define ANTSPATH for BrainExtraction automatically (https://github.com/nipy/nipype/pull/1986) ENH: New trait for imaging files (https://github.com/nipy/nipype/pull/1949) ENH: Niftyseg interfaces (https://github.com/nipy/nipype/pull/1911) ENH: Niftyreg interfaces (https://github.com/nipy/nipype/pull/1913) MRG: Allow more support for CLI (https://github.com/nipy/nipype/pull/1908) ENH: 3dQwarpPlusMinus interface (https://github.com/nipy/nipype/pull/1974) FIX: PY3.6 support (https://github.com/nipy/nipype/pull/1977) FIX: PY3 and stream fixes for MRTrix2TrackVis (https://github.com/nipy/nipype/pull/1804) ENH: More mask options for CompCor interfaces (https://github.com/nipy/nipype/pull/1968 + https://github.com/nipy/nipype/pull/1992) ENH: Additional TOPUP outputs (https://github.com/nipy/nipype/pull/1976) ENH: Additional Eddy flags (https://github.com/nipy/nipype/pull/1967) ENH: ReconAll handlers for less common cases (https://github.com/nipy/nipype/pull/1966) ENH: FreeSurferSource now finds graymid/midthickness surfs (https://github.com/nipy/nipype/pull/1972) ENH: Additional fslmaths dimensional reduction operations (https://github.com/nipy/nipype/pull/1956) ENH: More options for RobustFOV interface (https://github.com/nipy/nipype/pull/1923) ENH: Add MRIsCombine to FreeSurfer utils (https://github.com/nipy/nipype/pull/1948) FIX: Level1Design EV parameter substitution (https://github.com/nipy/nipype/pull/1953) FIX: Dcm2niix outputs can be uncompressed (https://github.com/nipy/nipype/pull/1951) FIX: Ensure build fails in Circle when tests fail (https://github.com/nipy/nipype/pull/1981) ENH: Add interface to antsAffineInitializer (https://github.com/nipy/nipype/pull/1980) ENH: AFNI motion parameter support for FrameWiseDisplacement (https://github.com/nipy/nipype/pull/1840) ENH: Add ANTs KellyKapowski interface (https://github.com/nipy/nipype/pull/1845) FIX: AFNI interface bug setting OMP_NUM_THREADS to 1 (https://github.com/nipy/nipype/pull/1728) FIX: Select Eddy run command at runtime (https://github.com/nipy/nipype/pull/1871) FIX: Increase FLIRT's flexibility with apply_xfm (https://github.com/nipy/nipype/pull/1875) DOC: Update FSL preprocess docstrings (https://github.com/nipy/nipype/pull/1881) ENH: Support GIFTI outputs in SampleToSurface (https://github.com/nipy/nipype/pull/1886) FIX: Configparser differences between PY2 and PY3 (https://github.com/nipy/nipype/pull/1890) ENH: Add mris_expand interface (https://github.com/nipy/nipype/pull/1893) FIX: Split over-eager globs in FreeSurferSource (https://github.com/nipy/nipype/pull/1894) FIX: Store undefined by default so that xor checks don't trip (https://github.com/nipy/nipype/pull/1903) FIX: Gantt chart generator PY3 compatibility (https://github.com/nipy/nipype/pull/1907) FIX: Add DOF and --fsl-dof options to BBRegister (https://github.com/nipy/nipype/pull/1917) ENH: Auto-derive input_names in Function (https://github.com/nipy/nipype/pull/1918) FIX: Minor fixes for NonSteadyStateDetector (https://github.com/nipy/nipype/pull/1926) DOC: Add duecredit references for AFNI and FSL (https://github.com/nipy/nipype/pull/1930) ENH: Added zenodo (https://zenodo.org/) file (https://github.com/nipy/nipype/pull/1924) ENH: Disable symlinks on CIFS filesystems (https://github.com/nipy/nipype/pull/1941) ENH: Sphinx extension to plot workflows (https://github.com/nipy/nipype/pull/1896) ENH: Added non-steady state detector for EPI data (https://github.com/nipy/nipype/pull/1839) ENH: Enable new BBRegister init options for FSv6+ (https://github.com/nipy/nipype/pull/1811) REF: Splits nipype.interfaces.utility into base, csv, and wrappers (https://github.com/nipy/nipype/pull/1828) FIX: Makespec now runs with nipype in current directory (https://github.com/nipy/nipype/pull/1813) FIX: Flexible nifti opening with mmap if Numpy < 1.12.0 (https://github.com/nipy/nipype/pull/1796 + https://github.com/nipy/nipype/pull/1831) ENH: DVARS includes intensity normalization feature - turned on by default (https://github.com/nipy/nipype/pull/1827) FIX: DVARS is correctly using sum of squares instead of standard deviation (https://github.com/nipy/nipype/pull/1827) ENH: Refactoring of nipype.interfaces.utility (https://github.com/nipy/nipype/pull/1828) FIX: CircleCI were failing silently. Some fixes to tests (https://github.com/nipy/nipype/pull/1833) FIX: Issues in Docker image permissions, and docker documentation (https://github.com/nipy/nipype/pull/1825) ENH: Revised all Dockerfiles and automated deployment to Docker Hub from CircleCI (https://github.com/nipy/nipype/pull/1815) ENH: Update ReconAll interface for FreeSurfer v6.0.0 (https://github.com/nipy/nipype/pull/1790) FIX: Cast DVARS float outputs to avoid memmap error (https://github.com/nipy/nipype/pull/1777) FIX: FSL FNIRT intensity mapping files (https://github.com/nipy/nipype/pull/1799) ENH: Additional outputs generated by FSL EDDY (https://github.com/nipy/nipype/pull/1793) TST: Parallelize CircleCI build across 4 containers (https://github.com/nipy/nipype/pull/1769) 0.13.0-rc1 (January 4, 2017) FIX: Compatibility with traits 4.6 (https://github.com/nipy/nipype/pull/1770) FIX: Multiproc deadlock (https://github.com/nipy/nipype/pull/1756) TST: Replace nose and unittest with pytest (https://github.com/nipy/nipype/pull/1722, https://github.com/nipy/nipype/pull/1751) FIX: Semaphore capture using MultiProc plugin (https://github.com/nipy/nipype/pull/1689) REF: Refactor AFNI interfaces (https://github.com/nipy/nipype/pull/1678, https://github.com/nipy/nipype/pull/1680) ENH: Move nipype commands to group command using click (https://github.com/nipy/nipype/pull/1608) FIX: AFNI Retroicor interface fixes (https://github.com/nipy/nipype/pull/1669) FIX: Minor errors after migration to setuptools (https://github.com/nipy/nipype/pull/1671) ENH: Add AFNI 3dNote interface (https://github.com/nipy/nipype/pull/1637) ENH: Abandon distutils, only use setuptools (https://github.com/nipy/nipype/pull/1627) FIX: Minor bugfixes related to unicode literals (https://github.com/nipy/nipype/pull/1656) TST: Automatic retries in travis (https://github.com/nipy/nipype/pull/1659/files) ENH: Add signal extraction interface (https://github.com/nipy/nipype/pull/1647) ENH: Add a DVARS calculation interface (https://github.com/nipy/nipype/pull/1606) ENH: New interface to b0calc of FSL-POSSUM (https://github.com/nipy/nipype/pull/1399) ENH: Add CompCor (https://github.com/nipy/nipype/pull/1599) ENH: Add duecredit entries (https://github.com/nipy/nipype/pull/1466) FIX: Python 3 compatibility fixes (https://github.com/nipy/nipype/pull/1572) REF: Improved PEP8 compliance for fsl interfaces (https://github.com/nipy/nipype/pull/1597) REF: Improved PEP8 compliance for spm interfaces (https://github.com/nipy/nipype/pull/1593) TST: Replaced coveralls with codecov (https://github.com/nipy/nipype/pull/1609) ENH: More BrainSuite interfaces (https://github.com/nipy/nipype/pull/1554) ENH: Convenient load/save of interface inputs (https://github.com/nipy/nipype/pull/1591) ENH: Add a Framewise Displacement calculation interface (https://github.com/nipy/nipype/pull/1604) FIX: Use builtins open and unicode literals for py3 compatibility (https://github.com/nipy/nipype/pull/1572) TST: reduce the size of docker images & use tags for images (https://github.com/nipy/nipype/pull/1564) ENH: Implement missing inputs/outputs in FSL AvScale (https://github.com/nipy/nipype/pull/1563) FIX: Fix symlink test in copyfile (https://github.com/nipy/nipype/pull/1570, https://github.com/nipy/nipype/pull/1586) ENH: Added support for custom job submission check in SLURM (https://github.com/nipy/nipype/pull/1582) ENH: Added ANTs interface CreateJacobianDeterminantImage; replaces deprecated JacobianDeterminant (https://github.com/nipy/nipype/pull/1654