甲状腺乳头状癌术前超声及临床病理特征与侵袭性的相关性

目的探讨甲状腺乳头状癌(papillary thyroid carcinoma,PTC)术前超声及临床病理特征与侵袭性的相关性,为PTC患者手术方式选择和预后提供参考。方法回顾性分析311例PTC患者的临床特点,以病理结果为金标准,分析PTC的术前超声图像特点、临床病理特征与侵袭性表现的相关性。结果术前超声诊断颈侧区淋巴结同术后病理结果一致性较好(κ=0.554, P <0.001);术前超声诊断中央区淋巴结同术后病理结果一致性差(κ=0.006 6, P =0.863)。单因素分析显示,病灶数量、病灶大小、BRAF基因突变与甲状腺被膜侵犯相关( P <0.05);患者性别、年龄、病灶数量、病灶大小、血流、钙化、边界与淋巴结转移有相关性( P <0.05)。多因素分析显示,病灶数量、病灶大小、BRAF基因突变与被膜侵犯相关( P <0.05);患者性别、病灶大小、边界与淋巴结转移相关,差异有统计学意义( P <0.05)。结论 PTC中病灶数量、病灶大小、BRAF基因突变与被膜侵犯相关,患者性别、病灶大小、边界与淋巴结转移相关,可以为诊断提供参考。术前超声诊断PTC中央区淋巴结转移准确性差,PTC应常规清扫中央区淋巴结。

Food safety controls in different governance structures in China's vegetable and fruit industry

Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished： farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that （1） pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and （2） agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.

Are social embeddedness associated with food risk perception under media coverage?

Traceability system has received wide attention in solving food safety issues, via which food information could be tracked back to producer/farmers. Consumers need to obtain this information from producers or social networks, trust in the information,and consequently assess perceived risks, especially when food scandals are exposed to the media. In this study, we introduce the social embeddedness theory to understand how consumers’ social activities affect their risk perceptions on traceable food. Specifically, we investigate how risk perceptions are predicted by the interpersonal relationships, organizational level and social-level relationships. Results show that the interpersonal relationships were associated with lower levels of risk perceptions, while organizational and social relationships impacted consumer’s risk perceptions at middle and higher levels,respectively. Results also show that the "ripple effect" extended to effect of risk events with negative information, however,did not exist for the group exposed to positive information. Potential food safety implications have been proposed to identify for effective risk mitigation under media coverages.

Vegetable production under COVID-19 pandemic in China: An analysis based on the data of 526 households

The COVID-19 pandemic had an enormous impact on the vegetable supply chain in China.Effective evaluation of the pandemic’s influences on vegetable production is vital for policy settings to enhance the security of vegetable supply.Based on first-hand data from 526 households,we explored regional differences in different types of loss and potential factors affecting the severity farmer households suffered during the pandemic.The results underline that sales contraction and price volatility in the context of interruption of supply chain dominate the total losses during the pandemic.Such losses differ across provinces and are more substantial in provinces with stricter confinement measures.Farmer households’participation in local market and modern marketing methods helps mitigate the negative effects of the COVID-19 shock,while labor hiring and facilities adoption in production widen the losses due to the shortage in the workforce.In the future,the vegetable industry practitioners and relevant government departments should work together to coordinate the development of short and long supply chains and strengthen the stability and security of the vegetable supply chain.

Estimating the average treatment effect of adopting stress tolerant variety on rice yield in China

Climate extremes, characterized by droughts and floods, have become one of the major constraints to sustainable improvement of rice productivity. Variety choice, considered as one of the main adaptation measures, could help farmers reduce yield loss resulting from these extremes. Based on a three-year panel survey of 1 080 Chinese rice farms in major rice producing provinces, we assume Hicksian neutral technology and employ an IV regression to estimate the average treatment effect(ATE) on rice yield for adopting stress tolerant variety, and find that farmers who adopted the stress tolerant variety on average increased rice yield by 15.5% in comparison to the non-adopters.

Food safety inspection and the adoption of traceability in aquatic wholesale markets: A game-theoretic model and empirical evidence

Supply chain traceability is key to reduce food safety risks,since it allows problems to be traced to their sources. Moreover,it allows regulatory agencies to understand where risk is introduced into the supply chain,and offers a major disincentive for upstream agricultural businesses engaging in economically motivated adulteration. This paper focuses on the aquatic supply chain in China,and seeks to understand the adoption of traceability both through an analytical model,and empirical analysis based on data collected through an extensive (largest ever) field survey of Chinese aquatic wholesale markets. The field survey includes 76 managers and 753 vendors,covering all aquatic wholesale markets in Zhejiang and Hunan provinces. The analytical and empirical results suggest that the adoption of traceability among wholesale market vendors is significantly associated with inspection intensity,their individual history of food safety problems,and their risk awareness. The effect of inspection intensity on traceability adoption is stronger in markets which are privately owned than in markets with state/collective ownership. The analysis offers insights into the current state of traceability in China. More importantly,it suggests several hypothesized factors that might affect the adoption of traceability and could be leveraged by regulatory organizations to improve it.

Identification of Behavior of Voluntary Traceability and Analysis of Its Determinants: A Case Study of Hog Slaughtering and Processing Firms in Zhejiang Province,China

In recent years, the Chinese government has highlighted the importance of adopting hog safety/quality traceability, and a growing amount of research continues to entice firms to adopt traceability systems. In this study, a survey was conducted on a sample of pig slaughtering and processing firms in Zhejiang, China through personal interviews and emails. The aim of this study was to examine the determinants of firm behavior on the implementation of voluntary traceability systems with more stringent standards and controls than those of the mandatory system in China. The results revealed that motivation based on product quality improvement, capital ability and role perception （business type） had significantly positive relationships with a firm＇s voluntary traceability. Other incentives, such as operation improvement, recall risk reduction, reduced occurrence of safety issues, and technical strength were not found to be supportive in our study. This study provides an opportunity to better understand the determinants of firm behavior on voluntary traceability, particularly in light of the fact that some Chinese firms are facing the threat of criminal action for the use of illegal additives and the abuse of Clenbuterol. Policy recommendations on encouraging the implementation of pork safety voluntary traceability by hog slaughtering and processing firms are also discussed.

Are vulnerable farmers more easily influenced?Heterogeneous effects of Internet use on the adoption of integrated pest management

The Internet is believed to bring more technological dividends to vulnerable farmers during the green agriculture transformation.However,this is different from the theory of skill-biased technological change,which emphasizes that individuals with higher levels of human capital and more technological endowments benefit more.This study investigates the effects of Internet use on farmers'adoption of integrated pest management(IPM),theoretically and empirically,based on a dataset containing 1015 farmers in China's Shandong Province.By exploring the perspective of rational inattention,the reasons for the heterogeneity of the effects across farmers with different endowments,i.e.,education and land size,are analyzed.The potential endogeneity issues are addressed using the endogenous switching probit model.The results reveal that:(1)although Internet use significantly positively affects farmers'adoption of IPM,vulnerable farmers do not benefit more from it.Considerable selection bias leads to an overestimation of technological dividends for vulnerable farmers;(2)different sources of technology information lead to the difference in the degree of farmers'rational inattention toward Internet information,which plays a crucial role in the heterogeneous effect of Internet use;and(3)excessive dependence on strong-tie social network information sources entraps vulnerable farmers in information cocoons,hindering their ability to reap the benefits of Internet use fully.Therefore,it is essential to promote services geared towards elderly-oriented Internet agricultural technology information and encourage farmers with strong Internet utilization skills to share technology information with other farmers actively.