Effects of tillage and maturity stage on the yield, nutritive composition, and silage fermentation quality of whole-crop wheat

Whole-crop wheat (Triticum aestivum, WCW) has a high nutritional value and digestibility. No-tillage (NT) can reduces energy and labor inputs in the agricultural production process, thus decreasing production costs. There are many studies on planting techniques of WCW at present, few being on no-tillage planting. This study aimed to compare the effects of different tillage methods and maturity stages on the yield, nutritive value, and silage fermentation quality of WCW. The experiment included two tillage methods (NT; conventional tillage, CT), two maturity stages (flowering stage; milk stage), and three years (2016-2017; 2017-2018; 2018-2019). Years had a strong influence on the yield and nutritional composition of WCW. This was mainly related to the amount of rainfall, as it affects the seedling emergence rate of wheat. Although tillage methods showed no significant effects on the yield, plant height, and stem number per plant of WCW (P > 0.05), compared to CT, the dry matter (DM) and crude protein (CP) yields of NT decreased by 0.74 t/ha and 0.13 t/ha. Tillage methods showed no significant effects on the nutritive composition of WCW (P > 0.05). The WCW at the milk stage had greater DM (5.25 t/ha) and CP (0.60 t/ha) yields than that at the flowering stage (3.19 t/ha and 0.39 t/ha) (P< 0.05). The acid detergent fiber concentration of WCW decreased by 34.5% from the flowering to the milk stage, whereas water-soluble carbohydrates concentration increased by 50.6%. The CP concentration at the milk stage was lower than that at the flowering stage (P< 0.05). The lactic acid concentration of NT (17.1 g/kg DM) silage was lower than that of CT (26.6 g/kg DM) silage (P< 0.05). The WCW silage at the milk stage had a lower NH3-N concentration (125 g/kg TN) than that at the flowering stage (169 g/kg TN) (P< 0.05). Wheat sown by NT and CT was of similar yield and nutritional value, irrespective of harvest stages. WCW harvested at the milk stage had greater yield and better nutritional composition and silage fermentation quality than that at the flowering stage. Based upon the results of the membership function analysis, no-tillage sowing of wheat was feasible and harvesting at milk stage was recommended

A note on the dynamics around the Lagrange points of the Earth-Moon system in a complete Solar System model

This paper studies the dynamics of a massless particle around the libration points of the Earth - Moon system in a full Solar System gravitational model. The study is based on the analysis of the quasi - periodic solutions around the equilibrium points. For the analysis and computation of the quasi - periodic orbits, a novel iterative algorithm is introduced which is a combination of the multiple shooti ng method and a refined Fourier analysis of the orbits computed with the multiple shooting. Using as initial seeds the libration point orbits of Circular Restricted Three Body Problem, determined by Lindstedt - Poincar é methods, the procedure is able to refi ne them in a complete Solar System model for large time - spans covering most of the relevant Sun - Earth - Moon periods. For the collinear points, the developed approach works well and reveals the strong relevance of the phase space around the equilibrium point s in both models. For the triangular points, difficulties appear and an intermediate model (bicircular model, BCM) is introduced to aid the refinement.Postprint (published version

A note on the dynamics around the L1,2 Lagrange points of the Earth-Moon system in a complete solar system model

The purpose of this paper is the study of the phase space around the collinear libration points L1 and L2 of the Earth–Moon system when the gravitational effects of the remaining bodies of the Solar System are taken into account. In the simplified model defined by the Circular Restricted Three Body Problem (CR3BP), the description of the phase space around these two points has already been done in the past, either using semi-analytical techniques1 or numerical ones.2 When using more realistic models of motion, the refinement of the different kinds of libration point orbits around both points (see G´omez et al.3) has some problems when the time interval used is large. These problems are more evident for the Earth–Moon L2 point due to a 1:2 resonance between the natural frequency of some halo orbits (!h) and the external frequency due to the perturbation of the Sun (!s); in fact !h ' 2!s for some orbits of the halo family of periodic orbits around this point. To analyse more closely this fact, Andreu4 introduced an intermediate model between the CR3BP and the restricted n-body problem, which is the so called Quasi-Bicircular Problem. It is a restricted four body problem in which the three primaries move following a “true” solution of the three body problem along orbits close to circular (the Earth and the Moon around their barycenter, and the Earth-Moon barycenter around the Sun). The description of the different types of orbits in the neighbourhood of L2 is also done in Reference 4 by means of the reduction of the Hamiltonian of the problem to the central manifold. The reduced Hamiltonian is then studied by means of Poincar´e maps at different energy levels.Postprint (published version

An Efficient Iteration Method for Toeplitz-Plus-Band Triangular Systems Generated from Fractional Ordinary Differential Equation

It is time consuming to numerically solve fractional differential equations. The fractional ordinary differential equations may produce Toeplitz-plus-band triangular systems. An efficient iteration method for Toeplitz-plus-band triangular systems is presented with OMlogM computational complexity and OM memory complexity in this paper, compared with the regular solution with OM2 computational complexity and OM2 memory complexity. M is the discrete grid points. Some methods such as matrix splitting, FFT, compress memory storage and adjustable matrix bandwidth are used in the presented solution. The experimental results show that the presented method compares well with the exact solution and is 4.25 times faster than the regular solution

Predictive Sliding Mode Control for Attitude Tracking of Hypersonic Vehicles Using Fuzzy Disturbance Observer

We propose a predictive sliding mode control (PSMC) scheme for attitude control of hypersonic vehicle (HV) with system uncertainties and external disturbances based on an improved fuzzy disturbance observer (IFDO). First, for a class of uncertain affine nonlinear systems with system uncertainties and external disturbances, we propose a predictive sliding mode control based on fuzzy disturbance observer (FDO-PSMC), which is used to estimate the composite disturbances containing system uncertainties and external disturbances. Afterward, to enhance the composite disturbances rejection performance, an improved FDO-PSMC (IFDO-PSMC) is proposed by incorporating a hyperbolic tangent function with FDO to compensate for the approximate error of FDO. Finally, considering the actuator dynamics, the proposed IFDO-PSMC is applied to attitude control system design for HV to track the guidance commands with high precision and strong robustness. Simulation results demonstrate the effectiveness and robustness of the proposed attitude control scheme

A Domain Decomposition Method for Time Fractional Reaction-Diffusion Equation

The computational complexity of one-dimensional time fractional reaction-diffusion equation is O(N2M) compared with O(NM) for classical integer reaction-diffusion equation. Parallel computing is used to overcome this challenge. Domain decomposition method (DDM) embodies large potential for parallelization of the numerical solution for fractional equations and serves as a basis for distributed, parallel computations. A domain decomposition algorithm for time fractional reaction-diffusion equation with implicit finite difference method is proposed. The domain decomposition algorithm keeps the same parallelism but needs much fewer iterations, compared with Jacobi iteration in each time step. Numerical experiments are used to verify the efficiency of the obtained algorithm

Utilizing differences in bTH tolerance between the parents of two-line hybrid rice to improve the purity of hybrid rice seed

IntroductionTwo-line hybrid rice based on Photoperiod/thermo-sensitive genic male sterile (P/TGMS) lines has been developed and applied widely in agriculture due to the freedom in making hybrid combinations, less difficulty in breeding sterile lines, and simpler procedures for breeding and producing hybrid seed. However, there are certain risks associated with hybrid seed production; if the temperature during the P/TGMS fertility-sensitive period is lower than the critical temperature, seed production will fail due to self-pollination. In a previous study, we found that the issue of insufficient purity of two-line hybrid rice seed could be initially addressed by using the difference in tolerance to β-triketone herbicides (bTHs) between the female parent and the hybrid seeds.MethodsIn this study, we further investigated the types of applicable herbicides, application methods, application time, and the effects on physiological and biochemical indexes and yield in rice.ResultsThe results showed that this method could be used for hybrid purification by soaking seeds and spraying plants with the bTH benzobicylon (BBC) at safe concentrations in the range of 37.5-112.5 mg/L, and the seeds could be soaked in BBC at a treatment rate of 75.0 mg/L for 36-55 h without significant negative effects. The safe concentration for spraying in the field is 50.0-400.0 mg/L BBC at the three-leaf stage. Unlike BBC, Mesotrione (MST) can only be sprayed to achieve hybrid purification at concentrations between 10.0 and 70.0 mg/L without affecting yield. The three methods of hybrid seed purification can reach 100% efficiency without compromising the nutritional growth and yield of hybrid rice. Moreover, transcriptome sequencing revealed that 299 up-regulated significant differentially expressed genes (DEGs) in the resistant material (Huazhan) poisoned by BBC, were mainly enriched in phenylalanine metabolism and phenylpropanoid biosynthesis pathway, it may eliminate the toxic effects of herbicides through this way.DiscussionOur study establishes a foundation for the application of the bTH seed purification strategy and the three methods provide an effective mechanism for improving the purity of two-line hybrid rice seeds

Aphrodisiac Use Associated with HIV Infection in Elderly Male Clients of Low-Cost Commercial Sex Venues in Guangxi, China: A Matched Case-Control Study

Background: Rising HIV infection rates have been observed among elderly people in Guangxi, China. Inexpensive aphrodisiacs are available for purchase in suburban and rural areas. This study aims to investigate the association between aphrodisiac use and increased HIV risk for middle-aged and elderly men in Guangxi. Methods: A matched case-control study of aphrodisiac use-associated HIV infection was performed among male subjects over 50 years old who were clients of low-cost commercial sex venues in Guangxi. The cases were defined as clients who were HIV-positive and two controls were selected for each case. The cases and the controls were matched on the visited sex venue, age (±3 years), number of years of purchasing sex (±3 years), and educational attainment. Subjects were interviewed and tested for HIV. Paired t-test or McNemar Chi-squared test were used to compare the characteristics between the cases and controls. A stepwise conditional logistic regression was used to identify risk factors associated with HIV infection. Findings: This study enrolled 103 cases and 206 controls. Aphrodisiac use (P = 0.02, odds ratio (OR) = 1.81, 95% CI = 1.08–3.04), never using condom during commercial sex encounter (P = 0.03, odds ratio (OR) = 1.82, 95% CI = 1.08–3.07), and lacking a stable partner (P = 0.03, odds ratio (OR) = 1.76, 95% CI = 1.05–2.98) were found to be risk factors for HIV infection among the study groups. For subjects reporting aphrodisiac use, the frequency of purchasing sex was positively correlated with the frequency of aphrodisiac use (r = 0.3; p = 0.02). Conclusions: Aphrodisiac use was significantly associated with increased HIV infection risk in men over 50 years old who purchased commercial sex in the suburban and rural areas of Guangxi. Further research and interventions should address the links between aphrodisiac use, commercial sex work, condom use, and increased HIV transmission