Genome-wide identification, phylogenetic and expression analysis of the heat shock transcription factor family in bread wheat (Triticum aestivum L.)

BackgroundEnvironmental toxicity from non-essential heavy metals such as cadmium (Cd), which is released from human activities and other environmental causes, is rapidly increasing. Wheat can accumulate high levels of Cd in edible tissues, which poses a major hazard to human health. It has been reported that heat shock transcription factor A 4a (HsfA4a) of wheat and rice conferred Cd tolerance by upregulating metallothionein gene expression. However, genome-wide identification, classification, and comparative analysis of the Hsf family in wheat is lacking. Further, because of the promising role of Hsf genes in Cd tolerance, there is need for an understanding of the expression of this family and their functions on wheat under Cd stress. Therefore, here we identify the wheat TaHsf family and to begin to understand the molecular mechanisms mediated by the Hsf family under Cd stress.ResultsWe first identified 78 putative Hsf homologs using the latest available wheat genome information, of which 38 belonged to class A, 16 to class B and 24 to class C subfamily. Then, we determined chromosome localizations, gene structures, conserved protein motifs, and phylogenetic relationships of these TaHsfs. Using RNA sequencing data over the course of development, we surveyed expression profiles of these TaHsfs during development and under different abiotic stresses to characterise the regulatory network of this family. Finally, we selected 13 TaHsf genes for expression level verification under Cd stress using qRT-PCR.ConclusionsTo our knowledge, this is the first report of the genome organization, evolutionary features and expression profiles of the wheat Hsf gene family. This work therefore lays the foundation for targeted functional analysis of wheat Hsf genes, and contributes to a better understanding of the roles and regulatory mechanism of wheat Hsfs under Cd stress

The genome-wide impact of cadmium on microRNA and mRNA expression in contrasting Cd responsive wheat genotypes

© 2019 The Author(s). Background: Heavy metal ATPases (HMAs) are responsible for Cd translocation and play a primary role in Cd detoxification in various plant species. However, the characteristics of HMAs and the regulatory mechanisms between HMAs and microRNAs in wheat (Triticum aestivum L) remain unknown. Results: By comparative microRNA and transcriptome analysis, a total three known and 19 novel differentially expressed microRNAs (DEMs) and 1561 differentially expressed genes (DEGs) were found in L17 after Cd treatment. In H17, by contrast, 12 known and 57 novel DEMs, and only 297 Cd-induced DEGs were found. Functional enrichments of DEMs and DEGs indicate how genotype-specific biological processes responded to Cd stress. Processes found to be involved in microRNAs-associated Cd response include: ubiquitin mediated proteolysis, tyrosine metabolism, and carbon fixation pathways and thiamine metabolism. For the mRNA response, categories including terpenoid backbone biosynthesis and phenylalanine metabolism, and photosynthesis - antenna proteins and ABC transporters were enriched. Moreover, we identified 32 TaHMA genes in wheat. Phylogenetic trees, chromosomal locations, conserved motifs and expression levels in different tissues and roots under Cd stress are presented. Finally, we infer a microRNA-TaHMAs expression network, indicating that miRNAs can regulate TaHMAs. Conclusion: Our findings suggest that microRNAs play important role in wheat under Cd stress through regulation of targets such as TaHMA2;1. Identification of these targets will be useful for screening and breeding low-Cd accumulation wheat lines

Mechanism of intercalation and deintercalation of lithium ions in graphene nanosheets

Graphene nanosheets (GNSs) were synthesized by reducing exfoliated graphite oxides. Their structure, surface morphology and lithium storage mechanism were characterized and investigated systematically using X-ray diffraction, atomic force microscopy, scanning electron microscopy, charge-discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. It was found that the GNSs, which were obtained via chemical synthesis, were primarily less than 10 graphene layers. The GNS electrodes, which were fabricated from the reduced GNSs, exhibited an enhanced reversible lithium storage capacity and good cyclic stability when serving as anodes in lithium-ion batteries. Also, the first-cycle irreversible capacities of the system were relatively high, because of the formation of a solid electrolyte interphase film on the surface of the GNS electrode and the spontaneous stacking of GNSs during the first lithiation. The electrochemical impedance spectroscopy results suggest that the solid electrolyte interphase film on the GNS electrode during first lithiation were primarily formed at potentials between 0.95 and 0.7 V. Also, the symmetry factor of the charge transfer was measured to be 0.446.Fundamental Research Funds for the Central Universities[2010LKHX03, 2010QNB04, 2010QNB05]; China University of Mining Technology[ON090237

Thermo-physiological comfort properties of different woven fabrics used in sportswear for outdoor activities

In this study, the thermo-physiological wear comfort is mainly characterized by the thermal and water vapor resistance performance of the woven fabrics used as sportswear for outdoor activities. The commonly used twill woven fabric with different thicknesses, weight, and density are selected for the experimental analysis, and it finds that fabric weight and thickness have crucial effects on the thermal resistance, and the water vapor resistance depends linearly on density and thickness. The present study gives an optimal design of sportswear for outdoor activities with low thermal and water vapor resistance

Facial Expression Recognition Based on Discrete Separable Shearlet Transform and Feature Selection

In this paper, a novel approach to facial expression recognition based on the discrete separable shearlet transform (DSST) and normalized mutual information feature selection is proposed. The approach can be divided into five steps. First, all test and training images are preprocessed. Second, DSST is applied to the preprocessed facial expression images, and all the transformation coefficients are obtained as the original feature set. Third, an improved normalized mutual information feature selection is proposed to find the optimal feature subset of the original feature set, thus we can retain the key classification information of the original data. Fourth, the feature extraction and selection of the feature space is reduced by employing linear discriminant analysis. Finally, a support vector machine is used to recognize the expressions. In this study, experimental verification was carried out on four open facial expression databases. The results show that this method can not only improve the recognition rate of facial expressions, but also significantly reduce the computational complexity and improve the system efficiency

Level and Contamination Assessment of Environmentally Sensitive Elements in Smaller than 100 μm Street Dust Particles from Xining, China

Concentrations of the environmentally sensitive elements (ESEs) As, Co, Cu, Mn, Ni, Pb, V and Zn in smaller than 100 μm street dust particles from Xining were measured using X-ray fluorescence spectrometry and their contamination levels were assessed based on enrichment factor (EF), geoaccumulation index (Igeo) and pollution load index (PLI). The concentrations of As, Co, Cu, Mn, Ni, Pb, V and Zn in smaller than 100 μm street dust particles from Xining are 0.1–0.8, 2.7–10.9, 0.7–5.2, 0.3–1.1, 0.6–2.5, 1.2–11.1, 0.7–1.3 and 0.4–2.9 times the background values of Qinghai soil, respectively. The calculated EF and Igeo values reveal the order Co > Pb > Cu > Zn > V > Ni > Mn > As. The EF and Igeo values of Co, Cu, Pb and Zn are higher indicating that there is considerable pollution by these elements in smaller than 100 μm street dust particles, especially for Co. The EF and Igeo of Mn, Ni and V are lower and the assessment results indicate an absence of distinct Mn, Ni and V pollution in the studied samples. The mean value of PLIsite is 1.14, indicating a slightly pollution in the whole city of Xining. The order of PLIarea for the five tested districts is Center District (CD) > East District (ED) > West District (WD) > North District (ND) > South District (SD), showing that ESEs pollution in the South District is the lightest while it is the highest in the Central District

Kernel Negative ε Dragging Linear Regression for Pattern Classification

Linear regression (LR) and its variants have been widely used for classification problems. However, they usually predefine a strict binary label matrix which has no freedom to fit the samples. In addition, they cannot deal with complex real-world applications such as the case of face recognition where samples may not be linearly separable owing to varying poses, expressions, and illumination conditions. Therefore, in this paper, we propose the kernel negative ε dragging linear regression (KNDLR) method for robust classification on noised and nonlinear data. First, a technique called negative ε dragging is introduced for relaxing class labels and is integrated into the LR model for classification to properly treat the class margin of conventional linear regressions for obtaining robust result. Then, the data is implicitly mapped into a high dimensional kernel space by using the nonlinear mapping determined by a kernel function to make the data more linearly separable. Finally, our obtained KNDLR method is able to partially alleviate the problem of overfitting and can perform classification well for noised and deformable data. Experimental results show that the KNDLR classification algorithm obtains greater generalization performance and leads to better robust classification decision

Calendar aging mechanism of NCM811/graphite-SiOx pouch cells at different temperatures

Considering that a personal car spends about 95% of its life in parking mode, calendar aging can have a significant impact on battery life. High temperature storage is a common method for rapid evaluation of battery calendar life. In order to obtain reliable results of high temperature accelerated aging test, it is necessary to study the aging mechanism of battery stored at different temperature conditions. In this paper, the calendar aging experiment of graphite-SiOx/NCM811 pouch cells were carried out within the temperature range of 25-55℃. The differential curve analysis and post-mortem analysis were used to explore the aging mechanism. The results show that the calendar aging of pouch cells is mainly caused by the loss of lithium inventory and the loss of cathode active materials. When cells store at higher temperature, the loss of lithium inventory and the loss of cathode active materials increase, while the loss of anode active materials remains relatively unchanged. Based on various test results, it can be inferred that the parasitic reactions on the surface of electrode lead to the loss of lithium inventory and the increase of SEI. With the increase of storage temperature, this side reaction continues and consumes more lithium inventory. It is worth mentioning that when storage at 55℃, the microcracking develops and even breaks some of the secondary particles of cathode materials. Therefore, the pouch cells suffer severe loss of cathode active materials, which makes it inappropriate to accelerate the aging of batteries at such high temperature