Genome-wide identification of WRKY gene family and expression analysis under abiotic stresses in Andrographis paniculata

Andrographis paniculata(A.paniculata)is a Chinese herbal medicine that clears away heat,reduces inflammation,protects the liver,and promotes choleretics.The WRKYs of A.paniculata are still not well characterized,although many WRKYs have been identified in various plant species.In the present study,59 A.paniculata WRKY(ApWRKY)genes were identified and renamed on the basis of their respective chromosome distribution.These ApWRKYs were divided into three groups via phylogenetic analysis according to their WRKY domains and combined with WRKY of Arabidopsis.The 59 identified ApWRKY transcription factors were nonuniformity distributed on 23 chromosomes of A.paniculata.From the structural analysis of the conserved motifs,different ApWRKYs structures showed different biological functions,and the ApWRKY transcription factor had certain species-specificity in the evolutionary process.The expression patterns of the 41 ApWRKYs were examined through quantitative real-time PCR(qRT-PCR)in various tissues and under abiotic stresses(salt).The results showed that most of the ApWRKY had different reactions to salt treatment.In addition,the content of the four main secondary metabolites in A.paniculata leaves was determined under salt stress.The results show that under a low concentration of salt treatment,the synthesis of andrographolide can be improved.

Optimization of the key position parameters for tractor steering wheel based on a driver’s arm muscle load analysis

Steering wheel is the most frequently used manual device in tractors,whose position directly affects the handling comfort of the driver and fatigue degree of the arm muscles.In this study,the biomechanical modelling software AnyBody was used for an inverse kinetics analysis of the rotation process of tractor steering wheel,calculate the muscle activation degree of the driver’s arm and compare it with the calculated results of surface EMG tests to verify the reliability of the biomechanical model.Based on the biomechanical model,the effects of three position parameters(steering wheel inclination,front-back distance,and upper-lower height)on the activation degree of the driver’s arm muscles were evaluated.The results demonstrated that steering wheel inclination has the most significant effect on the degree of muscle activation,followed by the upper-lower height and then front-back distance.Considering the interaction among factors,a regression orthogonal test was designed,and the test results revealed that the minimum muscle activation(1.2887)can be obtained with the steering wheel inclination of 31°,front-back distance of 431 mm and upper-lower height of 375 mm.The findings can provide a reference for optimizing the structure and position parameters of tractor steering wheels.

Mercury distribution and bioaccumulation up the soil-plant-grasshopper-spider food chain in Huludao City, China

The purpose of this study is to investigate total mercury （THg） distribution and its bioaccumulation up the soil-plant-grasshopperspider in the Huludao City, which is polluted seriously by chlor-alkali and zinc smelting industry in Northeast of China. Results indicated that average THg concentrations in soil, plant leaves, grasshopper Locusta migratoria manilensis and Acrida chinensis, and spider were 0.151, 0.119, 0.167 and 0.134 mg/kg, respectively. THg spatial distribution suggested that most of mercury came from the chlor-alkali plant and the two zinc smelteries. The highest mercury concentration was found in the wings among different grasshoppers’ organs. Although spiders are the predatory, THg concentrations in their bodies were not high, and only on the same level as in grasshoppers, which might be due to spiders’ special living habits. In the light of the mercury transportation at every stage of the soil-plant-grasshopper-spider food chain, the bioaccumulation factors were 0.03, 0.79–1.11 and 0.80–1.13 respectively. It suggested that mercury biomagnification up terrestrial food chains was not so large and obvious as it was in the aquatic food chain.

优化算法的复杂度分析

优化算法的收敛性分析是优化中很重要的一个领域,然而收敛性并不足以作为比较不同算法效率的标准,因此需要另外一套衡量优化问题难易程度以及优化算法效率高低的理论,这套理论被称为优化算法的复杂度分析理论.本文共分为5个部分.第1节介绍复杂度分析的背景和理论框架,给出复杂度分析的定义、方法和例子,并总结本文中的复杂度结论.第2节介绍光滑优化问题的复杂度分析,给出不同优化问题的复杂度上界和下界,并给出加速梯度法收敛性分析的框架.第3节介绍非光滑优化问题的复杂度上界,介绍次梯度法、重心法、椭球法和近似点梯度法的复杂度分析.第4节介绍条件梯度法的复杂度分析,介绍条件梯度法的复杂度上界和下界,以及加速条件梯度法的框架.第5节介绍随机优化算法的复杂度分析,比较随机优化算法在凸和非凸问题下收敛的置信水平和复杂度.

Comfort evaluation and position parameter optimization of the steering wheel in agricultural machinery based on a three-level evaluation index system

The aim of this study is to evaluate the comfort and optimize the position parameters of steering wheel.Taking the H point of driver as the reference point,three position parameters of steering wheel were determined,which were used as experimental factors.A comprehensive evaluation index system of the comfort was established.The comfort range and optimal levels of three parameters were determined by a single factor test,based on which a response surface optimization and validation test was carried out.The optimization and validation test results show that the expected comprehensive score of the comfort is 0.864,and the average relative error between the predicted and the measured value is 4.18%,indicating that the optimization results are reliable.The findings can provide reference for the comfort optimization design of steering wheel in agricultural devices.

Single-cell genomics： An overview

The newly developed next-generation sequencing platforms, in combination with gcnome-scale amplification methods, provide a powerful tool to study genomics from a single cell. This mini-review summarizes the technologies of single cell genomics and their applications in several areas of biomedical research including stem cells, cancer biology and reproductive medicine. Particularly, it highlights recent advances in single cell exome sequencing, RNA-seq, and genome sequencing. The application of these powerful techniques will shed new light on the fundamental principles of gene transcription and genome organization at single-cell level and improve our understanding of cellular heterogeneity and diversity in multicellular organisms