18,995 research outputs found
Influence of rotational instability on the polarization structure of SrTiO3
The k-space polarization structure and its strain response in SrTiO3 with
rotational instability are studied using a combination of first-principles
density functional calculations, modern theory of polarization, and analytic
Wannier-function formulation. (1) As one outcome of this study, we rigorously
prove-both numerically and analytically-that folding effect exists in
polarization structure. (2) After eliminating the folding effect, we find that
the polarization structure for SrTiO3 with rotational instability is still
considerably different from that for non-rotational SrTiO3, revealing that
polarization structure is sensitive to structure distortion of oxygen-octahedra
rotation and promises to be an effective tool for studying material properties.
(3) Furthermore, from polarization structure we determine the microscopic
Wannier-function interactions in SrTiO3. These interactions are found to vary
significantly with and without oxygen-octahedra rotation.Comment: 25 pages, 7 figure
Feature Selective Networks for Object Detection
Objects for detection usually have distinct characteristics in different
sub-regions and different aspect ratios. However, in prevalent two-stage object
detection methods, Region-of-Interest (RoI) features are extracted by RoI
pooling with little emphasis on these translation-variant feature components.
We present feature selective networks to reform the feature representations of
RoIs by exploiting their disparities among sub-regions and aspect ratios. Our
network produces the sub-region attention bank and aspect ratio attention bank
for the whole image. The RoI-based sub-region attention map and aspect ratio
attention map are selectively pooled from the banks, and then used to refine
the original RoI features for RoI classification. Equipped with a light-weight
detection subnetwork, our network gets a consistent boost in detection
performance based on general ConvNet backbones (ResNet-101, GoogLeNet and
VGG-16). Without bells and whistles, our detectors equipped with ResNet-101
achieve more than 3% mAP improvement compared to counterparts on PASCAL VOC
2007, PASCAL VOC 2012 and MS COCO datasets
Galectin-12 in Cellular Differentiation, Apoptosis and Polarization.
Galectin-12 is a member of a family of mammalian lectins characterized by their affinity for β-galactosides and consensus amino acid sequences. The protein structure consists of a single polypeptide chain containing two carbohydrate-recognition domains joined by a linker region. Galectin-12 is predominantly expressed in adipose tissue, but is also detected in macrophages and other leukocytes. Downregulation of galectin-12 in mouse 3T3-L1 cells impairs their differentiation into adipocytes. Conversely, overexpression of galectin-12 in vitro induces cell cycle arrest in G1 and apoptosis. Upregulation of galectin-12 and initiation of G1 cell cycle arrest are associated with driving pre-adipocytes toward terminal differentiation. Galectin-12 deficiency increases insulin sensitivity and glucose tolerance in obese animals. Galectin-12 inhibits macrophage polarization to the M2 population, enhancing inflammation and decreasing insulin sensitivity in adipocytes. Galectin-12 also affects myeloid differentiation, which is associated with chemotherapy resistance. In addition to highlighting the above-mentioned aspects, this review also discusses the potential clinical applications of modulating the function of galectin-12
- …