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Federated learning (FL) is an emerging machine learning method in which all participants can collaboratively train a model without sharing their raw data, thereby breaking down data silos and avoiding privacy issues caused by centralized data storage. In practical applications, client data are non-independent and identically distributed, resulting in FL requiring multiple rounds of communication to converge, which entails high communication costs. Moreover, the centralized architecture of traditional FL remains susceptible to privacy breaches, network congestion, and single-point failures. In order to solve these problems, this paper proposes an FL framework based on blockchain technology and a cluster training algorithm, called BCFL. We first improved an FL algorithm based on odd–even round cluster training, which accelerates model convergence by dividing clients into clusters and adopting serialized training within each cluster. Meanwhile, compression operations were applied to model parameters before transmission to reduce communication costs and improve communication efficiency. Then, a decentralized FL architecture was designed and developed based on blockchain and Inter-Planetary File System (IPFS), where the blockchain records the FL process and IPFS optimizes the high storage costs associated with the blockchain. The experimental results demonstrate the superiority of the framework in terms of accuracy and communication efficiency. [ABSTRACT FROM AUTHOR]

Online food delivery increases dramatically during the COVID-19 era and has grown into a global marketplace worth more than $150 billion dollars, necessitating a more effective and responsive governance system. Public-private governance systems with whistleblowing to the public are seen as an effective tool for addressing the formidable challenges of food security in modern society. Accordingly, this study aims to explore the determinants of whistleblowing intentions and to propose policy policies for the whistleblowing system to fully utilize the advantages of public-private governance systems. Through empirical research, this paper finds that employees' perceived effectiveness of government authorities, as well as their familiarity with whistleblowing systems, positively affect their intentions to blow the whistle. However, the whistleblowing intent of restaurant employees is adversely affected by the online platform's focus. The root cause lies in the employee's trust in both the government sector and corporate sector. This study thus argues that a suite of measures to promote individual trust in public-private governance systems is desired and that this is an effective means of better mitigating food safety governance challenges in terms of capacity and resources. [ABSTRACT FROM AUTHOR]

Toad venom, a dried product of secretion from Bufo bufo gargarizans Cantor or Bufo melanostictus Schneider, has had the therapeutic effects of hepatocellular carcinoma confirmed. Bufalin and cinobufagin were considered as the two most representative antitumor active components in toad venom. However, the underlying mechanisms of this antitumor effect have not been fully implemented, especially the changes in endogenous small molecules after treatment. Therefore, this study was designed to explore the intrinsic mechanism on hepatocellular carcinoma after the cotreatment of bufalin and cinobufagin based on untargeted tumor metabolomics. Ultraperformance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was performed to identify the absorbed components of toad venom in rat plasma. In vitro experiments were determined to evaluate the therapeutic effects of bufalin and cinobufagin and screen the optimal ratio between them. An in vivo HepG2 tumor-bearing nude mice model was established, and a series of pharmacodynamic indicators were determined, including the body weight of mice, tumor volume, tumor weight, and histopathological examination of tumor. Further, the entire metabolic alterations in tumor after treating with bufalin and cinobufagin were also profiled by UHPLC-MS/MS. Twenty-seven active components from toad venom were absorbed in rat plasma. We found that the cotreatment of bufalin and cinobufagin exerted significant antitumor effects both in vitro and in vivo, which were reflected in inhibiting proliferation and inducing apoptosis of HepG2 cells and thereby causing cell necrosis. After cotherapy of bufalin and cinobufagin for twenty days, compared with the normal group, fifty-six endogenous metabolites were obviously changed on HepG2 tumor-bearing nude mice. Meanwhile, the abundance of α-linolenic acid and phenethylamine after the bufalin and cinobufagin intervention was significantly upregulated, which involved phenylalanine metabolism and α-linolenic acid metabolism. Furthermore, we noticed that amino acid metabolites were also altered in HepG2 tumor after drug intervention, such as norvaline and Leu-Ala. Taken together, the cotreatment of bufalin and cinobufagin has significant antitumor effects on HepG2 tumor-bearing nude mice. Our work demonstrated that the in-depth mechanism of antitumor activity was mainly through the regulation of phenylalanine metabolism and α-Linolenic acid metabolism. [ABSTRACT FROM AUTHOR]

Promoting farmland transfer through the farmland rental market is an essential instrument to achieve the centralized scale operation of farmland in China. However, few studies have explored or verified the economies of scale after land concentration. This study uses face-to-face interviews to randomly select 395 farmers engaged in land scale management in 68 villages of 11 cities in Shandong Province. Based on these data, a production cost function model is used to measure the cost elasticity of farmland scale management and further empirically test whether farmland scale management can achieve economies of scale in actual agricultural production. The empirical results show that the development of farmland scale operation can reduce production costs and realize the economy of scale. In other words, the scale of farmland management still has the possibility of further expansion. More importantly, we find the operation cost of farmland is significantly influenced by the price of farmland transfer, fixed capital input and labor input, especially the scale operator with rich planting experience and good cultural quality is an important human capital stock, which can make significant contribution to reducing production cost and developing the positive effect of scale operation. To promote farmland scale management in China, we should pay attention to reducing the transferring cost and transaction cost of farmland by building the land transfer market trading platform, increasing the subsidies for farmland transfer and developing agricultural mechanization, which is helpful to improve agricultural productivity and realize the scale economy. This research can provide a reference for rational land scale management and land use policymaking. [ABSTRACT FROM AUTHOR]

The pig-breeding industry is one of the pillar industries of China's agriculture. Improving the green total factor productivity of pig breeding is the basis for ensuring the stable supply of pork, and is also the key to the green transformation of the pig industry. The existing studies about the green total factor productivity of pig breeding lack an analysis of regional coordination and the spillover of spatial technology efficiency at the macro level, and most studies focus on the impact of agricultural production's environment pollution and other undesirable outputs. Based on the input–output index system of the pig-breeding industry's green production, the DDF directional distance function model and the Malmquist–Luenberger (ML) productivity index were combined to measure the green total factor productivity of the pig-breeding industry. Moran's I-Theil index model was used to measure and reveal the technical efficiency differences among the dominant regions of the pig-breeding industry in China and the σ-convergence test was adopted to reveal the convergence trend of green total factor productivity. The results showed that: (1) The growth level of green total factor productivity of pig breeding in China was generally low from 2006 to 2018, and there were obvious regional and scale differences. (2) The green total factor productivity of pig breeding in each province had spatial autocorrelation; that is, there was technology spillover. From 2006 to 2018, with the advance of time, a pattern of gradual evolution from low-level equilibrium to high-level imbalance was formed. (3) Through the convergence test, the convergence trend of large and medium-scale development between different regions fluctuated, while the convergence trend of small-scale development between different regions was not obvious. Therefore, it is necessary to increase investment in technological innovation, promote the large-scale and standardized development of the pig-breeding industry, and strengthen the promotion of technology in producing areas with advantages in pig breeding. [ABSTRACT FROM AUTHOR]

Developing low-carbon agriculture has become a development goal for low-carbon economies in various countries, and consumers' awareness and willingness to pay (WTP) for low-carbon agricultural products is an important link in achieving the sustainable development of low-carbon agriculture. The theory of planned behavior is a widely used framework to explain consumers' food choices. Considering the intrinsic norms of consumers, their perceptions of low-carbon agricultural products, and shifts in consumer behavior, our study adds the influence of environmental awareness and consumer preferences to the theoretical framework of analysis. We choose the contingent valuing method (CVM) and use 532 consumer questionnaires in Shanghai to validate Chinese urban consumers' WTP for low-carbon products and its influencing factors. The findings show that Chinese urban consumers have a high overall awareness of low-carbon agricultural products and, after strengthening the conceptual information of consumers, most consumers agree that low-carbon vegetables are more conducive to ecological environment protection, quality, and safety guarantees than conventional vegetables. The existing analysis showed that some variables such as bid price, behavioral attitudes, subjective norms, and consumption preferences significantly influenced consumers' willingness to pay for low-carbon leafy greens, while the effect of the environmental awareness variable was not significant. Further research found that consumers' WTP for low-carbon leafy greens showed significant group differences across income, gender, age, and education. Therefore, to promote the consumption of low-carbon agricultural products in China, we should attach importance to the publicity and guidance of low-carbon vegetables and strengthen the certification of low-carbon vegetable products. This study can provide policy reference for reasonably regulating and subdividing China's low-carbon agricultural products market.