12,016 research outputs found
The contribution of lesion location to upper limb deficit after stroke
BACKGROUND: Motor deficit after stroke is related to regional anatomical damage. OBJECTIVE: To examine the influence of lesion location on upper limb motor deficit in chronic patients with stroke. METHODS: Lesion likelihood maps were created from T1-weighted structural MRI in 33 chronic patients with stroke with either purely subcortical lesions (SC, n=19) or lesions extending to any of the cortical motor areas (CM, n=14). We estimated lesion likelihood maps over the whole brain and applied multivoxel pattern analysis to seek the contribution weight of lesion likelihood to upper limb motor deficit. Among 5 brain regions of interest, the brain region with the greatest contribution to motor deficit was determined for each subgroup. RESULTS: The corticospinal tract was most likely to be damaged in both subgroups. However, while damage in the corticospinal tract was the best indicator of motor deficit in the SC patients, motor deficit in the CM patients was best explained by damage in brain areas activated during handgrip. CONCLUSIONS: Quantification of structural damage can add to models explaining motor outcome after stroke, but assessment of corticospinal tract damage alone is unlikely to be sufficient when considering patients with stroke with a wide range of lesion topography
Comment on ‘Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis’
No abstract available
Polarized light ions and spectator nucleon tagging at EIC
An Electron-Ion Collider (EIC) with suitable forward detection capabilities
would enable a unique experimental program of deep-inelastic scattering (DIS)
from polarized light nuclei (deuterium 2H, helium 3He) with spectator nucleon
tagging. Such measurements promise significant advances in several key areas of
nuclear physics and QCD: (a) neutron spin structure, by using polarized
deuterium and eliminating nuclear effects through on-shell extrapolation in the
spectator proton momentum; (b) quark/gluon structure of the bound nucleon at x
> 0.1 and the dynamical mechanisms acting on it, by measuring the spectator
momentum dependence of nuclear structure functions; (c) coherent effects in
QCD, by exploring shadowing in tagged DIS on deuterium at x << 0.1. The JLab
MEIC design (CM energy sqrt{s} = 15-50 GeV/nucleon, luminosity ~ 10^{34}
cm^{-2} s^{-1}) provides polarized deuterium beams and excellent coverage and
resolution for forward spectator tagging. We summarize the physics topics, the
detector and beam requirements for spectator tagging, and on-going R&D efforts.Comment: 6 pages, 2 figures. Prepared for proceedings of DIS 2014, XXII.
International Workshop on Deep-Inelastic Scattering and Related Subjects,
University of Warsaw, Poland, April 28 - May 2, 201
Multiferroicity in the generic easy-plane triangular lattice antiferromagnet RbFe(MoO4)2
RbFe(MoO4)2 is a quasi-two-dimensional (quasi-2D) triangular lattice
antiferromagnet (TLA) that displays a zero-field magnetically-driven
multiferroic phase with a chiral spin structure. By inelastic neutron
scattering, we determine quantitatively the spin Hamiltonian. We show that the
easy-plane anisotropy is nearly 1/3 of the dominant spin exchange, making
RbFe(MoO4)2 an excellent system for studying the physics of the model 2D
easy-plane TLA. Our measurements demonstrate magnetic-field induced
fluctuations in this material to stabilize the generic finite-field phases of
the 2D XY TLA. We further explain how Dzyaloshinskii-Moriya interactions can
generate ferroelectricity only in the zero field phase. Our conclusion is that
multiferroicity in RbFe(MoO4)2, and its absence at high fields, results from
the generic properties of the 2D XY TLA.Comment: 5 pages, 5 figures, accepted in PRB as a Rapid Communicatio
Can fully automated detection of corticospinal tract damage be used in stroke patients?
We compared manual infarct definition, which is time-consuming and open to bias, with an automated abnormal tissue detection method in measuring corticospinal tract-infarct overlap volumes in chronic stroke patients to help predict motor outcome
Spectral origin of the colossal magnetodielectric effect in multiferroic DyMn2O5
The origin of the colossal magnetodielectric effect in DyMn2O5 [1] has been
an outstanding question in multiferroics. Here, we report the activation of the
electric dipole mode at 4-5 cm-1 in an applied magnetic field which fully
accounts for the CMD effect. We examine two alternative explanations of this
mode: an electromagnon and transitions between f-electron levels of Dy3+ ions.
The experimental and theoretical evidence supports the electromagnon origin of
the CMD effect.Comment: 5 pages, 4 figures, submitted to PR
Hybrid desalination processes for beneficial use of reverse osmosis brine: Current status and future prospects
© 2018 Elsevier B.V. As water shortage has increasingly become a serious global problem, desalination using seawater reverse osmosis (SWRO) is considered as a sustainable source of potable water sources. However, a major issue on the SWRO desalination plant is the generation of brine that has potential adverse impact due to its high salt concentration. Accordingly, it is necessary to develop technologies that allow environmentally friendly and economically viable management of SWRO brines. This paper gives an overview of recent research works and technologies to treat SWRO brines for its beneficial use. The treatment processes have been classified into two different groups according to their final purpose: 1) technologies for producing fresh water and 2) technologies for recovering energy. Topics in this paper includes membrane distillation (MD), forward osmosis (FO), pressure-retarded osmosis (PRO), reverse electrodialysis (RED) as emerging tools for beneficial use of SWRO brine. In addition, a new approach to simultaneously recover water and energy from SWRO brine is introduced as a case study to provide insight into improving the sustainability of seawater desalination
Strange form factors in the context of SAMPLE, HAPPEX, and A4 experiments
The strange properties of the nucleon are investigated within the framework
of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying
the symmetry conserving SU(3) quantization. We present the form factors
, and the electric and magnetic strange form
factors incorporating pion and kaon asymptotics. The results
show a fairly good agreement with the recent experimental data from the SAMPLE
and HAPPEX collaborations. We also present predictions for future measurements
including the A4 experiment at MAMI (Mainz).Comment: 10 pages with four figures. RevTeX4 is used. Few lines are changed.
Accepted for publication in Phys.Rev.
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