苯醚甲环唑在猕猴桃中的残留动态及安全性评价

为摸清猕猴桃中有毒有害物质的残留动态,确保出口产品质量安全符合主要贸易国官方要求,本文采用气相色谱-质谱法,测定施药后不同时期苯醚甲环唑在猕猴桃果实中的残留量,并依据残留消解动态,按照欧盟和日本食品安全卫生标准,对10%苯醚甲环唑水分散粒剂的使用安全性进行评价。结果表明,苯醚甲环唑在猕猴桃中的残留量随着时间的推移逐渐下降,动态曲线符合一级动力学方程C_t=0.5359e^-0.184t,半衰期为3.767 d,属易消解农药;按照欧盟和日本猕猴桃农药最大残留限量要求,10%苯醚甲环唑水分散粒剂按照推荐剂量单次施药,10天后采摘食用是安全的。     

价格支持政策对我国不同粮食作物播种面积变化的影响差异

［目的］文章评估了价格支持政策对不同粮食作物播种面积变化的平均效应与动态效应，并测度多种价格支持政策的交叉政策弹性。［方法］基于1998—2016年实施粮食价格支持政策省份面板数据，设立对照组，利用倾向得分匹配—双重差分方法（PSM DID）评估价格支持政策平均效应与动态效应，并构建粮食作物供给反应（Nerlove）模型测度价格支持政策的交叉政策弹性。［结果］（1）价格支持政策对水稻、小麦、玉米播种面积增加具有不同程度的推动作用，按大小依次为玉米>水稻>小麦，对大豆播种面积变化影响不显著； （2）价格支持政策持续时间越长，对水稻、玉米播种面积增加的推动作用越大，对小麦播种面积增加的推动作用较为稳定； （3）小麦、玉米播种面积变化主要来自自身价格支持政策，水稻播种面积变化除了受到自身价格支持政策影响外，还受到其他作物政策影响，大豆播种面积变化对玉米临储政策反应敏感，对自身价格支持政策反应不敏感。［结论］在制定粮食政策时既要区分政策及其持续性对不同粮食播种面积变化的影响差异，又要注意在同一地区实施多种粮食政策时，可能对不同作物产生交叉影响。     

When food regimes become hegemonic: Agrarian India through a Gramscian lens

The concept of food regimes, as developed by Friedmann and McMichael, has proven useful in analysing how systems of food production, distribution, and consumption are linked to cycles of global capital accumulation and identifying the contradictions and conflicts that underlie them. A question that food regime analysis is relatively less able to address, however, is how food regimes become established and endure with the apparent acquiescence of those who are the victims of their contradictions and inequities. In this paper, I argue that a deeper engagement with Gramsci's theory of hegemony may help to address this lacuna in food regime analysis. To illustrate my case, I draw on studies of rural India from the colonial period to the present day, highlighting the ways in which the hegemonic mechanisms of consent and coercion have been crucial to the consolidation of each of the three food regimes identified by Friedmann and McMichael.     

阐述如何加强道路桥梁施工监理

通常,道路桥梁的施工难度较高,其中涵盖的内容较多,如技术管理、预算管理、成本控制等。这些因素使道路桥梁的施工变得更为困难,施工的复杂性和综合性更加突出。在桥梁的施工过程中,存在着许多风险,所以需要做好施工监理工作,从而最大限度地保障施工过程中不会出现任何故障和问题。因此,加强道路桥梁施工监理至关重要。论文从道路桥梁施工的角度,探究和分析如何做好相关的监理工作。     

Creating a safe haven during the crisis: How organizations can achieve deep compliance with COVID-19 safety measures in the hospitality industry

The COVID-19 health crisis has engendered a set of additional health and safety regulations and procedures (e.g. social distancing) to the hospitality industry. The purpose of this paper is to explore in-depth how organizations can facilitate employees’ deep compliance with these procedures. Employing an instrumental case-study approach, we collected multi-level interview data and archival data in a small-medium sized restaurant in China. The findings reveal that employees’ deep compliance with safety procedures includes a four-stage psychological process, and this process is underpinned by both management safety practices and organizational crisis strategies. As the hospitality industry starts to exit lockdown and ramp up operations, this study offers theoretical and practical insights on how organizations in hospitality can protect the health and safety of their employees and the broader community.     

Dose safety motivation mediate the effect of psychological contract of safety on flight attendants' safety performance outcomes?: A social exchange perspective

This study proposes and tests a conceptual model that investigates the mediating effect of safety motivation linking psychological contract of safety (PCS) as manifested by employer obligations of safety and employee obligations of safety to safety violations and safety creative performance (SCP). Data were collected from a sample of flight attendants with two weeks time lag in Iran. Underpinned by social exchange theory, the results of structural equation modeling revealed that safety motivation fully mediates the simultaneous effects of PCS indicators on safety violations and SCP. Specifically, indicators of PCS jointly enhance safety motivation. In turn, safety motivation reduces safety violations, while enhancing SCP. Theoretical and practical implications evoked from the results advance existing knowledge of organizationally social interactions in promoting safety and the motivational mechanism through which PCS predicts employees' safety performance outcomes.     

畜牧产业结构变动对我国粮食安全的影响分析

［目的］改革开放40多年来，我国畜牧产业结构不断调整和优化，其生产供给结构与消费需求结构的变动与我国粮食安全问题息息相关。［方法］文章基于改革开放40多年来畜牧产业发展历程，从供给与需求两个维度分析我国畜牧产业结构变动的特征，并进一步探究畜牧产业结构变动与我国粮食安全间的作用机理，最后运用灰色关联度分析法实证其关联影响度。［结果］我国畜牧产业结构由耗粮型为主向节粮型转变，畜产品供给结构趋于合理，但不同区域间存在较大差异； 我国居民对畜产品消费需求量增加，但城乡居民畜产品消费结构及变动存在一定差异性； 畜牧产业结构变动与粮食安全有重要联系，畜牧业发展同保障国家粮食安全并不矛盾，畜牧产业结构变动主要通过耕地、基于口粮替代的食物需求结构变化及饲料粮需求3个方面作用于粮食安全； 具体来看，粮食播种面积、耗粮型畜产品比重和耗粮型畜产品饲料转化率对粮食安全水平的关联影响较大，节粮型畜产品比重与节粮型畜产品饲料转化率对粮食安全水平的关联影响小于耗粮型畜产品的影响。［结论］不断提高不同畜产品的饲料转化率，加大非粮型饲料资源开发利用度，推广非粮饲料应用技术，加快畜牧产业转型升级，满足消费者需求和保障国家粮食安全。     

Application of evidential reasoning approach and OWA operator weights in road safety evaluation considering the best and worst practice frontiers

Data envelopment analysis (DEA) has recently become relatively popular with road safety experts. Therefore, various decision-making units (DMUs), such as EU countries, have been assessed in terms of road safety performance (RSP). However, the DEA has been criticized because it evaluates DMUs based only on the concept of self-assessment, and, therefore does not provide a unique ranking for DMUs. Therefore, cross efficiency method (CEM) was developed to overcome this shortcoming. Peer-evaluations in addition to self-evaluation have made the CEM to be recognized as an effective method for ranking DMUs. The traditional CEM is based only on the standard CCR (Charnes, Cooper and Rhodes) model, and it evaluates DMUs according to their position relative to the best practice frontier while neglecting the worst practice frontier. However, the DMUs can also be assessed based on their position relative to the worst practice frontier. In this regard, the present study aims to provide a double-frontier CEM for assessing RSP by taking into account the best and worst frontiers simultaneously. For this purpose, the cross efficiency and cross anti-efficiency matrices are generated.Even though a weighted average method (WAM) is most frequently used for cross efficiency aggregation, the decision maker's (DM) preference structure may not be reflected. For this reason, the present study mainly focuses on the evidential reasoning approach (ERA), as a nonlinear aggregation method, rather than the linear WAM. Equal weights are often used for cross efficiency aggregation; consequently, the effect of the DM's subjective judgments in obtaining the overall efficiency is ignored. In this respect, the minimax entropy approach (MEA) and the maximum disparity approach (MMDA) are applied for determining the ordered weighted averaging (OWA) operator weights for cross efficiency aggregation. The weighted cross efficiencies and cross anti-efficiencies are then aggregated using the ERA. Finally, the proposed method, called DF-CEM-ERA, is used to evaluate the RSP of EU countries as well as Serbian police departments (PDs).     

Policies for managing peak stock of food grains for effective distribution: A case of the Indian food program

The Indian food program has encountered a significant shortfall in storage due to slow expansion of storage facilities in comparison with procurement. The open storage of food grains results in substantial loss and deterioration of quality. While increasing storage capacity is a viable but costly and time consuming option, the adoption of policies for peak storage reduction would go a long way towards effective food grains management. On this background, this study proposes policy adoption for peak storage reduction for effective inventory management. A dynamic simulation model was built by replicating the complex flow process and incorporating the process variability for finding the bottleneck and significant factors. It was found that steep wheat procurement is the critical bottleneck factor for peak storage requirements. Two practical and straightforward, yet effective policies are proposed from the few existing strategies for peak storage reduction owing to the constraints associated with the food program. With the actual data of the food program, reduction in peak stock was estimated for the recommended policies, including the operational cost saving in storage. The practical implications of these policies within the system were also discussed. Through peak reduction, the use of open storage can be significantly reduced, and this leads to better food grains management for effective food distribution.     

Preventing motor vehicle crash injuries and deaths: science vs. folklore lessons from history

Abstract

Not long after the beginnings of motorization in the early 1900s, deaths and injuries from motor vehicle crashes became a problem in a number of high-income-countries (HIC)s, especially the United States. With the biggest problem the US led early efforts to address this issue, and for six decades these efforts were based on folklore (ie a body of widely held but false or unsubstantiated beliefs). They were not evaluated, but clearly were unsuccessful as crash deaths and injuries continued to rise. It was not until the 1970s that a broader range of countermeasures began to be adopted and was scientifically evaluated, and as a result, crash deaths and injuries declined. This history has important lessons today for many low-and-middle-income countries that have growing numbers of motor vehicle crash deaths and injuries, many of which are pedestrians and motorcyclists. This is because there continue to be advocates for many of the failed approaches (especially educational) that dominated the early efforts in HICs.