371 research outputs found
Differences in brain gray matter volume in patients with Crohn’s disease with and without abdominal pain
Increasing evidence indicates that abnormal pain processing is present in the central nervous system of patients with Crohn’s disease (CD). The purposes of this study were to assess changes in gray matter (GM) volumes in CD patients in remission and to correlate structural changes in the brain with abdominal pain. We used a 3.0 T magnetic resonance scanner to examine the GM structures in 21 CD patients with abdominal pain, 26 CD patients without abdominal pain, and 30 healthy control subjects (HCs). Voxel-based morphometric analyses were used to assess the brain GM volumes. Patients with abdominal pain exhibited higher CD activity index and lower inflammatory bowel disease questionnaire scores than those of the patients without abdominal pain. Compare to HCs and to patients without abdominal pain, patients with abdominal pain exhibited lower GM volumes in the insula and anterior cingulate cortex (ACC); whereas compare to HCs and to patients with abdominal pain, the patients without abdominal pain exhibited higher GM volumes in the hippocampal and parahippocampal cortex. The GM volumes in the insula and ACC were significantly negatively correlated with daily pain scores. These results suggest that differences exist in the brain GM volume between CD patients in remission with and without abdominal pain. The negative correlation between the GM volumes in the insula and ACC and the presence and severity of abdominal pain in CD suggests these structures are closely related to visceral pain processing
Toward Feature-Preserving Vector Field Compression
The objective of this work is to develop error-bounded lossy compression methods to preserve topological features in 2D and 3D vector fields. Specifically, we explore the preservation of critical points in piecewise linear and bilinear vector fields. We define the preservation of critical points as, without any false positive, false negative, or false type in the decompressed data, (1) keeping each critical point in its original cell and (2) retaining the type of each critical point (e.g., saddle and attracting node). The key to our method is to adapt a vertex-wise error bound for each grid point and to compress input data together with the error bound field using a modified lossy compressor. Our compression algorithm can be also embarrassingly parallelized for large data handling and in situ processing. We benchmark our method by comparing it with existing lossy compressors in terms of false positive/negative/type rates, compression ratio, and various vector field visualizations with several scientific applications
Simplifying Low-Light Image Enhancement Networks with Relative Loss Functions
Image enhancement is a common technique used to mitigate issues such as
severe noise, low brightness, low contrast, and color deviation in low-light
images. However, providing an optimal high-light image as a reference for
low-light image enhancement tasks is impossible, which makes the learning
process more difficult than other image processing tasks. As a result, although
several low-light image enhancement methods have been proposed, most of them
are either too complex or insufficient in addressing all the issues in
low-light images. In this paper, to make the learning easier in low-light image
enhancement, we introduce FLW-Net (Fast and LightWeight Network) and two
relative loss functions. Specifically, we first recognize the challenges of the
need for a large receptive field to obtain global contrast and the lack of an
absolute reference, which limits the simplification of network structures in
this task. Then, we propose an efficient global feature information extraction
component and two loss functions based on relative information to overcome
these challenges. Finally, we conducted comparative experiments to demonstrate
the effectiveness of the proposed method, and the results confirm that the
proposed method can significantly reduce the complexity of supervised low-light
image enhancement networks while improving processing effect. The code is
available at \url{https://github.com/hitzhangyu/FLW-Net}.Comment: 19 pages, 11 figure
On Equivariant Gromov--Witten Invariants of Resolved Conifold with Diagonal and Anti-Diagonal Actions
We propose two conjectural relationships between the equivariant
Gromov-Witten invariants of the resolved conifold under diagonal and
anti-diagonal actions and the Gromov-Witten invariants of , and
verify their validity in genus zero approximation. We also provide evidences to
support the validity of these relationships in genus one and genus two.Comment: 26 page
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