Root transcriptome reveals responses to plastic film mulching and grass cover in wine grape 'Cabernet Sauvignon' root and berry

This study was designed to investigate the influence of grass and film mulching on grape (V. vinifera) fruit quality and root transcriptome. The groundcovers (plastic film and seeds of herba portulacae and E. humifusa Willd) were set or sawn on the ground under wine grape plants ('Cabernet Sauvignon'). Test plots in the control group were treated with clean tillage. Properties of plant biochemicals under covers and grape berry quality were determined after two years. RNA-seq was analyzed for grape roots under different treatments. E. humifusa Willd cover increased plant total N and P; and film mulching increased plant total P and decreased plant total K. Herba portulacae cover decreased berry tannin and increased anthocyanin, soluble solid and titratable acid; E. humifusa Willd cover increased anthocyanin, soluble solid and titratable acid. Film mulching increased the contents of berry total phenols, soluble solid, and decreased titratable acid significantly in comparison with clean tillage. Root RNA-seq showed that there were 1, 0, and 42 differently expressed genes (DEGs) in Herba portulacae, E. humifusa Willd and film cover, compared with clean tillage, respectively. Film mulching increased the expression of root high-affinity nitrate transporter 2.1 (NRT2.1), NRT2.4 and glutamine synthetase, which associated with 'Nitrogen metabolism', and decreased the expression of root small class I/II heat shock proteins. Plastic film mulching increased grapple quality properties via activating N metabolism. Film mulching was a more excellent mulching for improving grape quality than grass cover in Ningxia, China

Revisiting the Bottom Quark Forward-Backward Asymmetry AFBA_{\rm {FB}} in Electron-Positron Collisions

The bottom quark forward-backward asymmetry $A_{\rm{FB}}$ is a key observable in electron-positron collisions at the $Z^{0}$ peak. In this paper, we employ the Principle of Maximum Conformality (PMC) to fix the $\alpha_s$-running behavior of the next-to-next-to-leading order QCD corrections to $A_{\rm{FB}}$. The resulting PMC scale for this $A_{\rm{FB}}$ is an order of magnitude smaller than the conventional choice $\mu_r=M_Z$. This scale has the physically reasonable behavior and reflects the virtuality of its QCD dynamics, which is independent to the choice of renormalization scale. Our analyses show that the effective momentum flow for the bottom quark forward-backward asymmetry should be $\mu_r\ll M_Z$ other than the conventionally suggested $\mu_r=M_Z$. Moreover, the convergence of perturbative QCD series for $A_{\rm{FB}}$ is greatly improved using the PMC. Our prediction for the bare bottom quark forward-backward asymmetry is refined to be $A^{0,b}_{\rm FB}=0.1004\pm0.0016$, which diminishes the well known tension between the experimental determination for this (pseudo) observable and the respective Standard Model fit to $2.1\sigma$.Comment: 8 pages, 2 figures, published versio

Tension estimation of hangers with shock absorber in suspension bridge using finite element method

Accurate and efficient estimation of tension in hangers is very important since hangers are the vital component of suspension bridges. But for hangers with shock absorber, the existing tension estimation methods are not suitable because they are based on a single cable model and cannot consider the effect of shock absorbers. To this end, the effect of the shock absorber is taken into account by using the degree-of-freedom condensation method, and a finite element method for tension estimation of hangers with shock absorber is proposed in this paper. Finally, the proposed method is applied in the Aizhai Bridge and Huangpu Pearl River Bridge to estimate the tension of hangers with shock absorber, the tested results show that as compared with other methods, the proposed method is a more accurate and convenient method for engineering application

Practical formula to calculate tension of vertical cable with hinged-fixed conditions based on vibration method

Vertical cables are widely used in the tied-arch bridges and suspension bridges as the vital components to transfer load. It is very important to accurately estimate the cable tensions in the cable supported bridges during both construction and in-service stages. Vibration method is the most widely used method for in-situ measurement of cable tensions. But for the cables with hinged-fixed boundary conditions, no analytical formulas can be used to describe the relationship between the frequencies and the cable tension. According to the general solution of the vibration equation and based on its numerical computational results, practical formula to calculate tensions of vertical cables by multiple natural frequencies satisfying hinged-fixed boundary conditions is proposed in this paper. The expression of the practical formula is the same as the solution derived from an axially loaded beam with simple supported ends and can use the first 10 order frequencies to calculate the cable tension conveniently and accurately. Error analysis showed that when using the fundamental frequency to estimate cable force, the estimated tension errors of the cables with its dimensionless parameter ξ≥ 2.8 are less than 2 %. It contained nearly all of the vertical cables used in bridge engineering. In addition, with multiple natural frequencies being measured, bending stiffness of the cable can be identified by using the formulas presented in this paper with an iterative method. At last, the practical formula in this paper is verified to have high precision with several numerical examples, and can be conveniently applied to field test for cable-supported bridges