A novel role for RhoA GTPase in the regulation of airway smooth muscle contraction

Recent studies have demonstrated a novel molecular mechanism for the regulation of airway smooth muscle (ASM) contraction by RhoA GTPase. In ASM tissues, both myosin light chain (MLC) phosphorylation and actin polymerization are required for active tension generation. RhoA inactivation dramatically suppresses agonist-induced tension development and completely inhibits agonist-induced actin polymerization, but only slightly reduces MLC phosphorylation. The inhibition of MLC phosphatase does not reverse the effects of RhoA inactivation on contraction or actin polymerization. Thus, RhoA regulates ASM contraction through its effects on actin polymerization rather than MLC phosphorylation. Contractile stimulation of ASM induces the recruitment and assembly of paxillin, vinculin, and focal adhesion kinase (FAK) into membrane adhesion complexes (adhesomes) that regulate actin polymerization by catalyzing the activation of cdc42 GTPase by the G-protein-coupled receptor kinase-interacting target (GIT) - p21-activated kinase (PAK) - PAK-interacting exchange factor (PIX) complex. Cdc42 is a necessary and specific activator of the actin filament nucleation activator, N-WASp. The recruitment and activation of paxillin, vinculin, and FAK is prevented by RhoA inactivation, thus preventing cdc42 and N-WASp activation. We conclude that RhoA regulates ASM contraction by catalyzing the assembly and activation of membrane adhesome signaling modules that regulate actin polymerization, and that the RhoA-mediated assembly of adhesome complexes is a fundamental step in the signal transduction process in response to a contractile agonist

Effects of post-anneal conditions on the dielectric properties of CaCu3Ti4O12 thin films prepared on Pt/Ti/SiO2/Si substrates

High-dielectric-constant CaCu3Ti4O12 (CCTO) thin films were prepared on Pt/Ti/SiO2/Si(100) substrates by pulsed-laser deposition. The 480 nm thick polycrystalline films have preferred orientation and show obvious crystallization on the surface. The temperature-dependence of dielectric constant and loss of the Pt/CCTO/Pt capacitors is comparable with that of epitaxial CCTO films grown on oxides substrates. We found that the dielectric properties are very sensitive to the post-annealing atmosphere and temperature. Post-annealing in nitrogen atmosphere produces larger low-frequency dielectric relaxation as the annealing temperature increases, while annealing in oxygen atmosphere at high temperature suppresses the relaxation but lowers the dielectric constant. Such results are attributed to the presence of insulating grain boundary barrier layers.Comment: 10 pages, 3 figure

Transcriptome and Comparative Gene Expression Analysis of Sogatella furcifera (Horváth) in Response to Southern Rice Black-Streaked Dwarf Virus

BACKGROUND: The white backed planthopper (WBPH), Sogatella furcifera (Horváth), causes great damage to many crops by direct feeding or transmitting plant viruses. Southern rice black-streaked dwarf virus (SRBSDV), transmitted by WBPH, has become a great threat to rice production in East Asia. METHODOLOGY/PRINCIPAL FINDINGS: By de novo transcriptome assembling and massive parallel pyrosequencing, we constructed two transcriptomes of WBPH and profiled the alternation of gene expression in response to SRBSDV infection in transcriptional level. Over 25 million reads of high-quality DNA sequences and 81388 different unigenes were generated using Illumina technology from both viruliferous and non-viruliferous WBPH. WBPH has a very similar gene ontological distribution to other two closely related rice planthoppers, Nilaparvata lugens and Laodelphax striatellus. 7291 microsatellite loci were also predicted which could be useful for further evolutionary analysis. Furthermore, comparative analysis of the two transcriptomes generated from viruliferous and non-viruliferous WBPH provided a list of candidate transcripts that potentially were elicited as a response to viral infection. Pathway analyses of a subset of these transcripts indicated that SRBSDV infection may perturb primary metabolism and the ubiquitin-proteasome pathways. In addition, 5.5% (181 out of 3315) of the genes in cell cytoskeleton organization pathway showed obvious changes. Our data also demonstrated that SRBSDV infection activated the immunity regulatory systems of WBPH, such as RNA interference, autophagy and antimicrobial peptide production. CONCLUSIONS/SIGNIFICANCE: We employed massively parallel pyrosequencing to collect ESTs from viruliferous and non-viruliferous samples of WBPH. 81388 different unigenes have been obtained. We for the first time described the direct effects of a Reoviridae family plant virus on global gene expression profiles of its insect vector using high-throughput sequencing. Our study will provide a road map for future investigations of the fascinating interactions between Reoviridae viruses and their insect vectors, and provide new strategies for crop protection

Disentangled Representation Learning

Disentangled Representation Learning (DRL) aims to learn a model capable of identifying and disentangling the underlying factors hidden in the observable data in representation form. The process of separating underlying factors of variation into variables with semantic meaning benefits in learning explainable representations of data, which imitates the meaningful understanding process of humans when observing an object or relation. As a general learning strategy, DRL has demonstrated its power in improving the model explainability, controlability, robustness, as well as generalization capacity in a wide range of scenarios such as computer vision, natural language processing, data mining etc. In this article, we comprehensively review DRL from various aspects including motivations, definitions, methodologies, evaluations, applications and model designs. We discuss works on DRL based on two well-recognized definitions, i.e., Intuitive Definition and Group Theory Definition. We further categorize the methodologies for DRL into four groups, i.e., Traditional Statistical Approaches, Variational Auto-encoder Based Approaches, Generative Adversarial Networks Based Approaches, Hierarchical Approaches and Other Approaches. We also analyze principles to design different DRL models that may benefit different tasks in practical applications. Finally, we point out challenges in DRL as well as potential research directions deserving future investigations. We believe this work may provide insights for promoting the DRL research in the community.Comment: 22 pages,9 figure

Indium Phosphide Bismide

Indium phosphide bismide is a new member to the dilute bismide family. Since the first synthesis by molecular beam epitaxy (MBE) in 2013, it has cut a figure for its abnormal properties comparing with other dilute bismides. Bismuth (Bi) incorporation is always a difficulty for epitaxial growth of dilute. In this chapter, it shows how to regulate MBE growth parameters and their influence on Bi incorporation in InP1−xBix. Structural, electronic and optical properties are systematically reviewed. Thermal annealing to study Bi thermal stability and its effect on physical properties is performed. InP1−xBix shows strong and broad photoluminescence at room temperature, which is a potential candidate for fabricating super-luminescence diodes applied for enhancing spatial resolution in optical coherence tomography. Quaternary phosphide bismide, including InGaPBi and InAlPBi, is briefly introduced in this chapter