56 research outputs found
Biodiversity management of organic orchard enhances both ecological and economic profitability
Effects of ozone pollution on yield and quality of winter wheat under flixweed competition
The concentration of ozone (O-3) is believed to continually increase due to anthrogenic activity, which might affect severely the growth and grain quality of winter wheat (Triticum aestivum). Flixweed (Descurainia sophia) is one of the most troublesome annual dicot weeds in wheat fields. As a vigourous competitor, the presence of flixweed in wheat field is a major factor to reduce wheat production. However, few studies have investigated the effects of ozone on wheat growth and yield under competition with flixweed. In the present study, physiological and ecological responses of wheat to O-3 stress with different density of flixweed competition were reported. Chlorophyll concentration and leaf area were reduced by elevated O-3. Gas exchange of wheat was suppressed by both elevated O-3 and the presence of flixweed. Moreover, exposure of wheat to elevated O-3 induced accumulation of Proline due to the up-regulation of pyrroline-5-carboxylate synthetase at transcriptional level, suggesting that Proline may confer tolerance to oxidative stress induced by O-3 pollution. Finally, elevated O-3 had significant adverse impacts on wheat above-ground biomass, grain yield and harvest index, and these impacts were intensified by the presence of flixweed. Exposure of wheat to elevated O-3 led to a significant increase in crude protein concentration of grain, while decreases in mineral element concentrations of grain were observed. Our findings indicate that effects of ozone and flixweed competition on winter wheat should be considered for the future breeding and cultivation. (C) 2015 Elsevier B.V. All rights reserved
Effects of ozone pollution on yield and quality of winter wheat under flixweed competition
The concentration of ozone (O-3) is believed to continually increase due to anthrogenic activity, which might affect severely the growth and grain quality of winter wheat (Triticum aestivum). Flixweed (Descurainia sophia) is one of the most troublesome annual dicot weeds in wheat fields. As a vigourous competitor, the presence of flixweed in wheat field is a major factor to reduce wheat production. However, few studies have investigated the effects of ozone on wheat growth and yield under competition with flixweed. In the present study, physiological and ecological responses of wheat to O-3 stress with different density of flixweed competition were reported. Chlorophyll concentration and leaf area were reduced by elevated O-3. Gas exchange of wheat was suppressed by both elevated O-3 and the presence of flixweed. Moreover, exposure of wheat to elevated O-3 induced accumulation of Proline due to the up-regulation of pyrroline-5-carboxylate synthetase at transcriptional level, suggesting that Proline may confer tolerance to oxidative stress induced by O-3 pollution. Finally, elevated O-3 had significant adverse impacts on wheat above-ground biomass, grain yield and harvest index, and these impacts were intensified by the presence of flixweed. Exposure of wheat to elevated O-3 led to a significant increase in crude protein concentration of grain, while decreases in mineral element concentrations of grain were observed. Our findings indicate that effects of ozone and flixweed competition on winter wheat should be considered for the future breeding and cultivation. (C) 2015 Elsevier B.V. All rights reserved
Organic management enhances both ecological and economic profitability of apple orchard: A case study in Shandong Peninsula
Huge amount usage of synthetic fertilizers, herbicides, pesticides and growth hormones in orchards has resulted in some negative impacts on environment and biodiversity. Organic management has been regarded as an alternative solution for both agricultural sustainability and human health maintenance. However, debates also exist on whether organic management can increase apple yield and economic benefits. We here reported a case study on the effect of organic management on apple yield, economic benefits, fruit quality and soil physicochemical properties in an apple production area of Shandong Peninsula, China. The results demonstrated that apple yield in organic management treatment significantly increased by 30 % than that of conventional management (P < 0.05). Economically, organic management achieved an increased annual net output by 504 %. Compared to conventional management, organic management significantly increased phosphorus, potassium, total soluble sugar, titratable acidity and Vitamin C in apples, by 2.9 %, 19.3 %, 8.5 %, 23.4 % and 34.7 % respectively (P < 0.05). For soil physicochemical properties, organic management enhanced soil pH, soil organic carbon and the total nitrogen, phosphorus and potassium. Besides, decrease in soil bulk density was also observed in organic management. Our study demonstrated that organic management without chemical pollution increased apple yield and enhanced economic benefits
Different Subcomponents of Executive Functioning Predict Different Growth Parameters in Mathematics: Evidence From a 4-Year Longitudinal Study With Chinese Children
Executive functioning (EF), an umbrella term used to represent cognitive skills engaged in goal-directed behaviors, has been found to be a unique predictor of mathematics performance. However, very few studies have examined how the three core EF subcomponents (inhibition, shifting, and working memory) predict the growth parameters (intercept and slope) in mathematics skills and even fewer studies have been conducted in a non-Western country. Thus, the purpose of this study was to examine how inhibition, shifting, and working memory predict the growth parameters in arithmetic accuracy and fluency in a group of Chinese children (n = 179) followed from Grade 2 (mean age = 97.89 months) to Grade 5 (mean age = 133.43 months). In Grade 2, children were assessed on measures of nonverbal IQ, number sense, speed of processing, inhibition, shifting, and working memory. In addition, in Grades 2–5, they were assessed on arithmetic accuracy and fluency. Results of structural equation modeling showed that nonverbal IQ, speed of processing, and number sense predicted the intercept in arithmetic accuracy, while working memory was the only EF subcomponent to predict the slope (rate of growth) in arithmetic accuracy. In turn, number sense, speed of processing, inhibition, and shifting were significant predictors of the intercept in arithmetic fluency. None of the EF subcomponents predicted the slope in arithmetic fluency. Our findings reinforce those of previous studies in North America and Europe showing that EF contributes to mathematics performance over and above other key predictors of mathematics, and suggest that different EF subcomponents may predict different growth parameters in mathematics
Digital Technology-and-Services-Driven Sustainable Transformation of Agriculture: Cases of China and the EU
China’s sustainable development goals and carbon neutrality targets cannot be achieved without revolutionary transitions of the agricultural sector. The rapid development of digital technologies is believed to play a huge role in this revolution. The ongoing prevention and control of COVID-19 has greatly boosted the penetration of digital technology services in all areas of society, and sustainable transformation driven by digital technologies and services is rapidly becoming an area of innovation and research. Studies have shown that the rapid advancement of digitalization is also accompanied by a series of new governance challenges and problems: (1) unclear strategic orientation and inadequate policy and regulatory responses; (2) various stakeholders have not formed a sustainable community of interest; (3) information explosion is accompanied by information fragmentation and digital divide between countries and populations within countries. Meanwhile, current research has focused more on the role of digital services in urban governance and industrial development and lacks systematic research on its role in sustainable agricultural and rural development. To address the realities faced by different stakeholders in the process of digital transformation of agriculture, this paper aims to propose an inclusive analytical framework based on the meta-governance theory to identify and analyze the demand, supply, actor networks, and incentives in the digital technology-and-services-driven sustainable agricultural transformation, starting from the goals and connotations of sustainable agricultural and rural transformation and the interactions among different stakeholders in governing information flows. This analytical framework is further applied to analyze the cases of China and the EU. Although China and the EU represent different development phases and policy contexts, the framework is valid for capturing the characteristics of information flows and actor networks along the flows. It is concluded that a common information platform based on the stakeholder network would benefit all stakeholders, help reach common framing of issues, and maintain a dynamic exchange of information. Depending on the country context, different types of stakeholders may play different roles in creating, supervising, and maintaining such platforms. Digital infrastructures/products as hardware and farmers digital capacity as ‘software’ are the two wings for digital sustainable transformation. Innovative incentives from different countries may inspire each other. In any case, farmers’ actual farming behavior changes should be an important criterion for evaluating the effects and effectiveness of digital transition governance
An Adaptive Proportional Plus Damping Control for Teleoperation Systems with Asymmetric Time-Varying Communication Delays
Communication delay is an important factor affecting the stability and performance of telerobotic systems. In this paper, a new adaptive proportional damping controller is proposed to improve the stability and performance of the system in the presence of the cases such as asymmetric communication delay, unknown gravity torque, friction torque, and other disturbance torques. The proposed proportional damping control method combines the RBF neural network and adaptive control strategy to compensate for the unknown torque. The stability and robustness of the system are enhanced by adding error-damping items, operator force, and environmental force items. The Lyapunov–Krasovskii functional is employed to analyze and prove the exponential stability and signal boundedness of the closed-loop system. The simulation results verify the correctness of the proposed method, and the comparison with the results of other control methods shows the effectiveness of the designed control strategy
Controllability robustness against cascading failure for complex logistic network based on dynamic cascading failure model
Inspired by the empirical dynamic characteristics of the load of real logistics network, we propose a dynamic cascading failure model against cascading failure, which is more suitable for complex logistics network by adding dynamic factors based on the nonlinear load-capacity model under initial residual capacity load-redistribution strategy. The simulation is executed on the complex logistics network model and the results show that the controllability robustness and economy after cascading failure based on the dynamic cascading failure model is feasible and effective. It can effectively reduce the logistics cost and enhance controllability robustness against cascading failure by adjusting the network cost e and capacity parameter γ, so as to balance the controllability robustness and economy for the complex logistics network.Ministry of Education (MOE)Published versionThis work was supported in part by the National Natural Science Foundation of China under Grant U1664257, in part by the International Cooperation Project of Science and Technology Department of Jilin Province under Grant 20200801042GH, and in part by the Singapore Ministry of Education (MOE) AcRF Tier 2 under Grant MOE2016-T2-1-044
- …