Decoupled, Linear, and Energy Stable Finite Element Method for the Cahn-Hilliard-Navier-Stokes-Darcy Phase Field Model

In this paper, we consider the numerical approximation for a phase field model of the coupled two-phase free flow and two-phase porous media flow. This model consists of Cahn—Hilliard—Navier—Stokes equations in the free flow region and Cahn—Hilliard—Darcy equations in the porous media region that are coupled by seven interface conditions. The coupled system is decoupled based on the interface conditions and the solution values on the interface from the previous time step. A fully discretized scheme with finite elements for the spatial discretization is developed to solve the decoupled system. In order to deal with the difficulties arising from the interface conditions, the decoupled scheme needs to be constructed appropriately for the interface terms, and a modified discrete energy is introduced with an interface component. Furthermore, the scheme is linearized and energy stable. Hence, at each time step one need only solve a linear elliptic system for each of the two decoupled equations. Stability of the model and the proposed method is rigorously proved. Numerical experiments are presented to illustrate the features of the proposed numerical method and verify the theoretical conclusions. © 2018 Society for Industrial and Applied Mathematics

Seasonal variations and feedback from microplastics and cadmium on soil organisms in agricultural fields

Plastic film mulching is an important agricultural technology that plays a critical role in increasing crop yield and maintaining soil moisture. However, long-term coverage and untimely recovery lead to a large amount of plastic residues in soils. This decomposes into smaller plastics over time, which can reduce sowing quality, destroy the soil structure, and have adverse effects on soil organisms. In this study, the seasonal variations and correlations of microplastics and cadmium (Cd) in Wuxi farmland soils of Taihu Lake, China, were investigated in the spring and winter. The microplastics were mainly in the form of films, fibers, and debris and were mainly transparent and black in color. Microplastic abundance reached 890 particles/kg soil, with the majority of microplastics (>72.5%) being 0–500 μm. Polyethylene microplastics were the main polymers, accounting for >54.65%. In addition, the abundance of soil microplastics in the winter was significantly correlated with Cd, indicating that microplastics and heavy metals present a risk of coexposure to soil organisms. Furthermore, the response of in situ earthworms to microplastic–Cd pollution revealed that microplastics can be used as a vector to transfer heavy metals in the soil environment and may accumulate in the bodies of soil organisms. Multiomics techniques demonstrated bacterial community structure dysbiosis and metabolic changes of in situ earthworms under microplastic heavy metal-contaminated soils. The abundance of microplastics in earthworm casts and intestines was higher than that in the soil samples. These results reveal the potential risks from microplastics entering the soil environment and heavy metal pollution in soil ecosystems.publishedVersio

Hesperidin inhibits the epithelial to mesenchymal transition induced by transforming growth factor-β1 in A549 cells through Smad signaling in the cytoplasm

Hesperidin, a natural compound, suppresses the epithelial-to-mesenchymal transition through the TGF-β1/ Smad signaling pathway. However, studies on the detailed effects and mechanisms of hesperidin are rare. The present study showed that, for A549 alveolar epithelial cells, the anti-proliferative effects of hesperidin occurred in a dose-dependent manner, with an IC50= 216.8 μM at 48 h. TGF-β1 was used to activate the Smad signaling pathway and induce the epithelial to mesenchymal transition in cells. Treatment with hesperidin or SB431542 was used for antagonism of Smad pathway activation. Hesperidin inhibited the increase in ɑ-SMA and Col1ɑ-1 and the decrease in E-cadherin in a dose-dependent manner from concentration of 20 μM to 60 μM, as assessed by both ELISA and Western blotting assays; however, there was no significant effect on cellular morphological alterations. Moreover, the Western blotting assay showed that, in the cytoplasm, hesperidin and SB431542 had no significant effect on the protein expression of Smad 2, 3, 4, or 7 as well as 2/3. However, 60 μM hesperidin and SB431542 significantly decreased p-Smad2/3 protein expression. From the above results, it is concluded that hesperidin can partly inhibit the epithelial to mesenchymal transition in human alveolar epithelial cells; the effect accounts for the blockage of the phosphorylation of Smad2/3 in the cytoplasm rather than a change in Smad protein production in the cytoplasm

WS-Snapshot: An effective algorithm for wide-field and large-scale imaging

The Square Kilometre Array (SKA) is the largest radio interferometer under construction in the world. The high accuracy, wide-field and large size imaging significantly challenge the construction of the Science Data Processor (SDP) of SKA. We propose a hybrid imaging method based on improved W-Stacking and snapshots. The w range is reduced by fitting the snapshot $uv$ plane, thus effectively enhancing the performance of the improved W-Stacking algorithm. We present a detailed implementation of WS-Snapshot. With full-scale SKA1-LOW simulations, we present the imaging performance and imaging quality results for different parameter cases. The results show that the WS-Snapshot method enables more efficient distributed processing and significantly reduces the computational time overhead within an acceptable accuracy range, which would be crucial for subsequent SKA science studies.Comment: 10 pages, 10 figures, 6 tables, accepted by MNRA

Identifying Functional Genes Influencing Gossypium hirsutum Fiber Quality

Fiber quality is an important economic index and a major breeding goal in cotton, but direct phenotypic selection is often hindered due to environmental influences and linkage with yield traits. A genome-wide association study (GWAS) is a powerful tool to identify genes associated with phenotypic traits. In this study, we identified fiber quality genes in upland cotton (Gossypium hirsutum L.) using GWAS based on a high-density CottonSNP80K array and multiple environment tests. A total of 30 and 23 significant single nucleotide polymorphisms (SNPs) associated with five fiber quality traits were identified across the 408 cotton accessions in six environments and the best linear unbiased predictions, respectively. Among these SNPs, seven loci were the same, and 128 candidate genes were predicted in a 1-Mb region (±500 kb of the peak SNP). Furthermore, two major genome regions (GR1 and GR2) associated with multiple fiber qualities in multiple environments on chromosomes A07 and A13 were identified, and within them, 22 candidate genes were annotated. Of these, 11 genes were expressed [log2(1 + FPKM)>1] in the fiber development stages (5, 10, 20, and 25 dpa) using RNA-Seq. This study provides fundamental insight relevant to identification of genes associated with fiber quality and will accelerate future efforts toward improving fiber quality of upland cotton

Correction:Structural and Functional Insights into an Archaeal Lipid Synthase

(Cell Reports 33, 108294-1–9.e1–e4; October 20, 2020) In the originally published version of this article, the supplemental information file containing Figures S1–S7 and Table S1 was inadvertently removed. The complete supplemental information file is now included with the paper online. The production team regrets this error