115 research outputs found
Scalable Semidefinite Relaxation for Maximum A Posterior Estimation
Maximum a posteriori (MAP) inference over discrete Markov random fields is a
fundamental task spanning a wide spectrum of real-world applications, which is
known to be NP-hard for general graphs. In this paper, we propose a novel
semidefinite relaxation formulation (referred to as SDR) to estimate the MAP
assignment. Algorithmically, we develop an accelerated variant of the
alternating direction method of multipliers (referred to as SDPAD-LR) that can
effectively exploit the special structure of the new relaxation. Encouragingly,
the proposed procedure allows solving SDR for large-scale problems, e.g.,
problems on a grid graph comprising hundreds of thousands of variables with
multiple states per node. Compared with prior SDP solvers, SDPAD-LR is capable
of attaining comparable accuracy while exhibiting remarkably improved
scalability, in contrast to the commonly held belief that semidefinite
relaxation can only been applied on small-scale MRF problems. We have evaluated
the performance of SDR on various benchmark datasets including OPENGM2 and PIC
in terms of both the quality of the solutions and computation time.
Experimental results demonstrate that for a broad class of problems, SDPAD-LR
outperforms state-of-the-art algorithms in producing better MAP assignment in
an efficient manner.Comment: accepted to International Conference on Machine Learning (ICML 2014
Multi-View Representation is What You Need for Point-Cloud Pre-Training
A promising direction for pre-training 3D point clouds is to leverage the
massive amount of data in 2D, whereas the domain gap between 2D and 3D creates
a fundamental challenge. This paper proposes a novel approach to point-cloud
pre-training that learns 3D representations by leveraging pre-trained 2D
networks. Different from the popular practice of predicting 2D features first
and then obtaining 3D features through dimensionality lifting, our approach
directly uses a 3D network for feature extraction. We train the 3D feature
extraction network with the help of the novel 2D knowledge transfer loss, which
enforces the 2D projections of the 3D feature to be consistent with the output
of pre-trained 2D networks. To prevent the feature from discarding 3D signals,
we introduce the multi-view consistency loss that additionally encourages the
projected 2D feature representations to capture pixel-wise correspondences
across different views. Such correspondences induce 3D geometry and effectively
retain 3D features in the projected 2D features. Experimental results
demonstrate that our pre-trained model can be successfully transferred to
various downstream tasks, including 3D shape classification, part segmentation,
3D object detection, and semantic segmentation, achieving state-of-the-art
performance.Comment: 14 pages, 6 figure
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An Aquaporin 3-Notch1 Axis in Keratinocyte Differentiation and Inflammation
Aquaporin 3 (AQP3) is an aquaglyceroporin which transports water, glycerol and small solutes across the plasma membrane. Its functions are not limited to fluid transport but also involve the regulation of cell proliferation, migration, skin hydration, wound healing and tumorigenesis. While AQP3 has been reported to play an important role in keratinocyte proliferation, its role in differentiation remains controversial. Our study demonstrated that the expression of AQP3 was regulated during differentiation and that it participated in keratinocyte differentiation control. We further revealed that AQP3 was a transcriptional target of Notch signaling, a critical pathway regulating keratinocyte differentiation and tumor suppression, and it regulated differentiation through a reciprocal negative feedback loop with Notch1. When the expression level of AQP3 was elevated, impaired barrier integrity and increased pro-inflammatory cytokine production ensued, mimicking the pathological conditions in Notch deficient mice and in atopic dermatitis. Dysregulation of AQP3 and Notch receptors has been reported in several skin diseases, including skin cancer. Our discovery of the novel AQP3-Notch1 axis may provide insight into epidermal homeostasis control and possible translational applications, including its potential use as a biomarker for molecular diagnosis in environmental studies
Forest biomass resources and utilization in China
Under the context of climate change, persistent high oil prices and rapidly growing dependence on imported oil prompt China to pay much more attention to biofuels that provide environmental benefits besides fuel. China has rich biodiversity with 30 thousand high plant species and 154 kinds of energy trees could produce seeds containing more than 40% of oil, with total production of the seeds totaling 5 million t, and 200 x109 t of biomass production per year, which is equal to 2 x 109 t of petroleum. There are over 2000 types of wild and cultivated firewood plants in the country. So far there is 4 million ha raising oil-bearing trees planted on some land in different regions. Another 57 million ha of waste land are available and suitable for planting trees for the production of forest bioenergy. On part of these lands, the central government plans to cultivate a total of 13 million ha of high-grade bioenergy forests by 2020. This will yield 6 million tons of diesel that would be enough to fuel power plants with a combined capacity of 11 GW each year. Moreover, forest biomass plantations potentially offer many direct and indirect environmental benefits. In view of climate change their globally significant environmental benefits may result from using forest biomass for energy rather than fossil fuels.Key words: Biomass energy, China, forest biomass resources
Neural Volumetric Mesh Generator
Deep generative models have shown success in generating 3D shapes with
different representations. In this work, we propose Neural Volumetric Mesh
Generator(NVMG) which can generate novel and high-quality volumetric meshes.
Unlike the previous 3D generative model for point cloud, voxel, and implicit
surface, the volumetric mesh representation is a ready-to-use representation in
industry with details on both the surface and interior. Generating this such
highly-structured data thus brings a significant challenge. We first propose a
diffusion-based generative model to tackle this problem by generating voxelized
shapes with close-to-reality outlines and structures. We can simply obtain a
tetrahedral mesh as a template with the voxelized shape. Further, we use a
voxel-conditional neural network to predict the smooth implicit surface
conditioned on the voxels, and progressively project the tetrahedral mesh to
the predicted surface under regularizations. The regularization terms are
carefully designed so that they can (1) get rid of the defects like flipping
and high distortion; (2) force the regularity of the interior and surface
structure during the deformation procedure for a high-quality final mesh. As
shown in the experiments, our pipeline can generate high-quality artifact-free
volumetric and surface meshes from random noise or a reference image without
any post-processing. Compared with the state-of-the-art voxel-to-mesh
deformation method, we show more robustness and better performance when taking
generated voxels as input
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Increased gene copy number of DEFA1/DEFA3 worsens sepsis by inducing endothelial pyroptosis.
Sepsis claims an estimated 30 million episodes and 6 million deaths per year, and treatment options are rather limited. Human neutrophil peptides 1-3 (HNP1-3) are the most abundant neutrophil granule proteins but their neutrophil content varies because of unusually extensive gene copy number polymorphism. A genetic association study found that increased copy number of the HNP-encoding gene DEFA1/DEFA3 is a risk factor for organ dysfunction during sepsis development. However, direct experimental evidence demonstrating that these risk alleles are pathogenic for sepsis is lacking because the genes are present only in some primates and humans. Here, we generate DEFA1/DEFA3 transgenic mice with neutrophil-specific expression of the peptides. We show that mice with high copy number of DEFA1/DEFA3 genes have more severe sepsis-related vital organ damage and mortality than mice with low copy number of DEFA1/DEFA3 or wild-type mice, resulting from more severe endothelial barrier dysfunction and endothelial cell pyroptosis after sepsis challenge. Mechanistically, HNP-1 induces endothelial cell pyroptosis via P2X7 receptor-mediating canonical caspase-1 activation in a NLRP3 inflammasome-dependent manner. Based on these findings, we engineered a monoclonal antibody against HNP-1 to block the interaction with P2X7 and found that the blocking antibody protected mice carrying high copy number of DEFA1/DEFA3 from lethal sepsis. We thus demonstrate that DEFA1/DEFA3 copy number variation strongly modulates sepsis development in vivo and explore a paradigm for the precision treatment of sepsis tailored by individual genetic information
Point Defects and Localized Excitons in 2D WSe2
Identifying the point defects in 2D materials is important for many
applications. Recent studies have proposed that W vacancies are the predominant
point defect in 2D WSe2, in contrast to theoretical studies, which predict that
chalcogen vacancies are the most likely intrinsic point defects in transition
metal dichalcogenide semiconductors. We show using first principles
calculations, scanning tunneling microscopy (STM) and scanning transmission
electron microscopy experiments, that W vacancies are not present in our
CVD-grown 2D WSe2. We predict that O-passivated Se vacancies (O_Se) and O
interstitials (Oins) are present in 2D WSe2, because of facile O2 dissociation
at Se vacancies, or due to the presence of WO3 precursors in CVD growth. These
defects give STM images in good agreement with experiment. The optical
properties of point defects in 2D WSe2 are important because single photon
emission (SPE) from 2D WSe2 has been observed experimentally. While strain
gradients funnel the exciton in real space, point defects are necessary for the
localization of the exciton at length scales that enable photons to be emitted
one at a time. Using state-of-the-art GW-Bethe-Salpeter-equation calculations,
we predict that only Oins defects give localized excitons within the energy
range of SPE in previous experiments, making them a likely source of previously
observed SPE. No other point defects (O_Se, Se vacancies, W vacancies and Se_W
antisites) give localized excitons in the same energy range. Our predictions
suggest ways to realize SPE in related 2D materials and point experimentalists
toward other energy ranges for SPE in 2D WSe2
Cloth2Tex: A Customized Cloth Texture Generation Pipeline for 3D Virtual Try-On
Fabricating and designing 3D garments has become extremely demanding with the
increasing need for synthesizing realistic dressed persons for a variety of
applications, e.g. 3D virtual try-on, digitalization of 2D clothes into 3D
apparel, and cloth animation. It thus necessitates a simple and straightforward
pipeline to obtain high-quality texture from simple input, such as 2D reference
images. Since traditional warping-based texture generation methods require a
significant number of control points to be manually selected for each type of
garment, which can be a time-consuming and tedious process. We propose a novel
method, called Cloth2Tex, which eliminates the human burden in this process.
Cloth2Tex is a self-supervised method that generates texture maps with
reasonable layout and structural consistency. Another key feature of Cloth2Tex
is that it can be used to support high-fidelity texture inpainting. This is
done by combining Cloth2Tex with a prevailing latent diffusion model. We
evaluate our approach both qualitatively and quantitatively and demonstrate
that Cloth2Tex can generate high-quality texture maps and achieve the best
visual effects in comparison to other methods. Project page:
tomguluson92.github.io/projects/cloth2tex/Comment: 15 pages, 15 figure
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