Relationship between antibiotic residues and occurrence of resistant bacteria in Nile tilapia (Oreochromisniloticus) cultured in cage-farm

The aim of this study was to investigate the relationship between antibiotic residues found in the muscle of cage-farm-raised Nile tilapia (Oreochromisniloticus), the occurrence of resistant bacteria, and the sanitary practices adopted by farmers in Ilha Solteira reservoir, Brazil. Nine fish (three small fish, 40–200 g; three medium-sized fish, 200–500 g; and three large fish, 500–800 g) were collected from four cage farms every three months from April 2013 to January 2014. Ten antibiotic residues were determined using liquid chromatography-mass spectrometry, and bacteria were isolated and tested for antibiotic resistance to determine the multiple antibiotic resistance (MAR) index. Only three antibiotics (oxytetracycline, tetracycline, and florfenicol) were detected in the muscle of Nile tilapia, and their residues were the highest in small fish; however, the MAR index was higher in large fish. In addition, a direct positive relationship between the MAR index and the concentration of antibiotic residues in Nile tilapia was found. Overall, the adoption of prophylactic management practices improved the sanitary status of cage farms, reducing bacterial infections and hampering the development of antibiotic-resistant bacteria.     

Towards urban food sovereignty: the trials and tribulations of community-based aquaponics enterprises in Milwaukee and Melbourne

Community-based urban aquaponics enterprises represent a new model for how to blend local agency with scientific innovation to deliver food sovereignty (FS) in cities, re-engaging and giving urban communities more control over their food production and distribution. Little is known, however, about the factors and outcomes that determine the success or failure of these enterprises. This paper explores stakeholder experiences of building community-based urban aquaponics enterprises to understand the internal and external factors that impact on their success or failure. We draw upon existing FS, social enterprise and aquaponics literature, to identify factors in the related area of community-based urban agriculture. For exploring these factors, we use a comparative case study methodology for two cases in Milwaukee and Melbourne, conducting in-depth interviews with key stakeholders, exploring their relative contexts, objectives and structure. Based on these findings, we highlight the challenges and suggest relevant indicators for establishing an urban aquaponics enterprise.     

环境税的企业绿色投资效应研究——基于面板分位数回归的实证研究

企业绿色投资有助于我国企业建立良好的社会声誉,实现企业的可持续发展。本文试图从环境税的角度,探讨环境税对企业绿色投资的边际效应是正向还是负向?环境税对企业绿色投资效应是否具有异质性?本文运用我国重污染行业上市公司的2008-2013年的经验数据,用分位数回归的研究方法对环境税的企业绿色投资效应进行了研究。分位数回归方法相比普通最小二乘法回归,分位数能够更全面的描述自变量对于因变量的变化范围以及条件分布形状的影响;分位数回归方法与最小二乘法使用残差平方和为最小化的目标函数相比,不易受到极端值的影响,估计结果更为稳健。研究发现:环境税对企业绿色投资的边际效应为正向并具有异质性,表现在:1从平衡面板的固定效应模型估计结果来看,环境税对企业绿色投资投资额的影响是正向的,换句话说,在其他因素不变的情况下,随着环境税额的不断提高,企业绿色投资额也会随之提高;2从面板分位数回归的估计结果来看,环境税对企业绿色投资的边际效应为正向并具有异质性,即低分位企业的环境税绿色投资效应为正,但并不显著;高分位企业的环境税绿色投资效应为正,但呈递减趋势;中间分位企业的环境税绿色投资效应为正,并呈递增趋势。本文研究结果的启示是:1环境税的出台具有积极的意义;2环境税的相关法律制定要注意因企业制宜,考虑企业承担能力的同时兼顾效率和公平。本文研究结果为环境税的出台提供了证据支持、为完善环境税的设计提供了经验证据。     

发电企业技术监督工作要点解析

为了适应大量新技术应用,加强技术监督工作,搞好安全生产,国电集团公司下发系列技术监督规章制度,对各发电企业的技术监督工作进行了准确定位,提出了许多具体要求。根据参与制定国电集团公司系列技术监督规章制度的讨论、研究以及从事多年的综合技术监督管理经验,介绍了国电集团公司所属发电企业搞好技术监督工作要点,对发电企业搞好技术监督工作提供了参考。     

Antibiotic resistance and genetic diversity of Escherichia coli isolates from traditional and integrated aquaculture in South China

This study investigated antibiotic resistance profiles including antibiotic resistance frequencies, resistance genes and resistance patterns in Escherichia coli strains isolated from traditional and integrated aquaculture systems in South China by using antibiotic susceptibility testing and real time polymerase chain reaction (PCR) technique. The E. coli isolates were found to be resistant to at least one antibiotic among 12 antibiotics. Higher resistance frequencies to ampicillin, sulfamethoxazole, trimethoprime, streptomycin and tetracycline were found compared to the rest antibiotics. Among the 10 tetracycline resistance genes detected in the resistant isolates, the most prevalent tetracycline resistance genes were tetA, tetW and tetB with the frequency of 69.7%, 63.5% and 21.9%, respectively. Three sulfonamide resistance genes were detected in these resistant isolates, with their detection frequencies in the following order: sul2 (55.3%) > sul3 (28.2%) > sul1 (6.2%). Four resistance genes mainly encoding extended-spectrum β-lactamases (ESBLs) were detected in these resistant isolates, with the detection frequencies of blaTEM (28.4%) > blaOXA (9.7%) > blaCTX (9.3%) > blaCARB (5.2%) > blaSHV (0.0%). It was found that the integrated aquaculture system exhibited generally higher prevalence of antibiotic resistance than the traditional aquaculture system. An integrated aquaculture system could facilitate development of bacterial resistance and spread of the antibiotic resistance genes, and consequently become an important reservoir of resistance genes.     

建立环境管理体系与中小企业可持续发展

分析我国中小企业在当前国际市场环境下建立ISO1 4 0 0 1管理体系的必要性 ;提出中小企业建立环境管理体系的步骤 ;阐述了实施环境管理体系与中小企业可持续发展的关系 ;为中小企业进行环境管理体系建立实施提供参考。     

VOCs快速检测在某化工企业搬迁遗留污染场地调查中的应用

以天津市某化工企业搬迁遗留污染场地为例,采用VOCs快速检测法辅助现场钻孔取样,以初步判断土壤污染深度,同时将现场样品送实验室检测。试验表明,VOCs快速检测法与实验室检测法结果基本一致。将452个样品测定结果做比对,结果表明实验室检测数据VOCs加和值与快速检测法现场检测数据存在显著相关,R2为0.803 7。污染物主要集中于场地5 m~9 m的粉土层中。其中,13种VOCs检出,4种VOCs超过《场地土壤环境风险评价筛选值》(DB11/T 811—2011)商业用地筛选值。     

How can social enterprises contribute to sustainable pro-poor tourism development?

“Tourism-Assisting the Poor” has been an important approach in anti-poverty strategy. Studies suggest that the conventional tourism model fails to generate benefits for the poor and to some extent enlarges the gap between the poor and the rich, which subsequently causes more social problems. Pro-poor tourism (PPT) is regarded as an alternative model. Precisely targeted assistance to the poor is the key to initiating this model, while the institutional change and implementation mechanism are essential to run it successfully and sustainably. Social entrepreneurship focusing on social values while adopting modern business philosophy has been introduced recently as an instrument in helping disadvantage population. This paper takes the Smangus community in Taiwan as an example to explore the role of social entrepreneurship and social enterprises in PPT development. It also discusses their implications for the anti-poverty practice in other regions including ethnic areas in China.     

中国煤炭企业绩效管理滞后对安全生产的影响研究

在分析中国煤矿事故频发现状和绩效管理滞后问题的基础上,重点探讨绩效管理滞后对煤炭企业安全生产的影响程度和渠道,并提出改进煤炭企业绩效管理的对策。研究表明:煤层条件复杂、安全投入不足、超负荷率高、员工素质低以及绩效管理滞后是煤矿事故频发的主要原因;绩效管理存在管理体系不完备、管理目标单一、绩效考核不规范、安全绩效考核缺位等问题;绩效管理滞后影响安全生产的程度为10.54%;绩效管理滞后是通过人才流失、员工不满、考核简单、协同作业和团队救助精神缺失等渠道影响安全生产的;要通过构建多重化目标、规范绩效考核工作、完善安全责任考核和培植协同作业以及团队救助理念来强化绩效管理。     

高效氧化吸收液治理炼油企业恶臭的研究

采用动态配气法配置硫化氢恶臭气体,筛选出一种价廉易得、吸收氧化效果好的吸收液,考察了影响处理效果的因素:漂白粉投加量、进气浓度、进气流量、温度、吸收时间对去除效果的影响,并对实验结果进行了分析。结果表明:在室温25℃、0～5391mg/m3硫化氢浓度范围、3h吸收时间的条件下,漂白粉对硫化氢去除率在92%以上。此法能在较长时间、较大浓度范围内保持较好的去除效果,适于工业化放大。