去除效价的土霉素药渣亚慢性毒性试验

用小鼠对去除效价的土霉素药渣进行亚慢性毒性试验,探讨在处理土霉素药渣过程中是否产生有毒物质。结果表明,饲喂处理后药渣的小鼠与饲喂原药渣的小鼠各脏器系数没有显著差异(P0.05),证明经过处理的药渣不仅与原药渣的各项指标相同,而且使残留效价大幅度降低。     

动物产品药物残留的危害及其控制对策

动物产品药物残留不但影响人身健康,还会导致细菌耐药性增强及危害生态环境,已成为国际社会关注的公共卫生问题。文章概述了兽药残留的危害性,提出加大对兽药、饲料和饲料添加剂生产企业的监管力度,从源头保障动物产品质量安全;加大对非法生产和使用禁用药物、添加剂企业的处罚力度;加强对动物、动物产品药物残留的检测,严禁不合格产品进入市场;加快企业诚信体系建设,增强全社会的食品安全诚信意识;开发新的兽药残留检测方法及技术,并在基层中推广应用;推广绿色畜产品生产技术,扶持绿色畜牧业发展;加大对抗生素替代品的投入和研发力度,以绿色兽药和添加剂替代有较高残留量的抗生素或化学合成药物;加大宣传力度,提高人们的安全意识等对策,以促进我国养殖业的健康发展。     

陕甘宁地区气候变化空间结构

根据陕甘宁地区35年来(1971-2005),39个测站的气象资料,运用线性回归法,聚类分析法,5年滑动平均法等方法,利用地理信息系统ARCGIS软件,分析该地区的气候变化趋势,比较该地区39个县的气候变化空间结构特点以及致灾效应。结果表明:陕甘宁地区暖干化趋势明显;全区有6个增温中心(定边靖边,神木,正宁,西峰,延安和同心)和4个干旱中心(延长宜川,甘泉富县,吴堡,和子长);气候变化导致该地区原本恶化的生态环境更加恶劣,灾害出现的频率增加,持续的时间延长,强度增大,最后导致人们的生活更加的贫困。     

化学农药对蜜蜂的急性毒性测定方法与危害评价

蜜蜂独特的生物学特性决定了它对化学农药的危害十分敏感,因此,精确地测定化学农药对蜜蜂的毒性和评价化学农药对蜜蜂的危害,对保护蜜蜂等非靶标生物和新农药的开发与推广都具有重要作用.在众多测定化学农药对蜜蜂的毒性方法中,急性毒性的测定是最主要的手段,是评价化学农药对蜜蜂危害的基础.从急性经口毒性和急性触杀毒性两方面综述了化学农药对蜜蜂的急性毒性测定方法和危害评价体系.     

四川省兴文县地质灾害特征及影响因素分析

四川省兴文县地质灾害发育频繁,在对全县地质灾害发育、分布特征调查基础上,对地质灾害的影响因素进行分析,得出较长时间的降雨和境内矿产开发是兴文县地质灾害的主要诱发因素,从而为兴文县地质灾害防治与区划提供了科学依据和参考。     

玉米丝黑穗病的发生条件与防治措施

玉米丝黑穗病是一种全球性的病害,大多数玉米产区都有不同程度的发生,属绝产性病害,植株一旦得病,几乎颗粒无收。70年代后期,玉米丝黑穗病的大面积发生,逐渐成为限制我国玉米单产和总产提高的制约因素,经我国几代农业科学工作者的努力,对玉米丝黑穗病的症状、病原菌、侵染途径、侵染条件、侵染规律,抗病遗传规律等都进行了大量研究。本文介绍了玉米丝黑穗病的发病症状、病菌来源、侵染途径、侵染条件、生理小种等特性,并提出轮作倒茬、选用抗病品种、抗病弱的品种正确包衣种衣剂、药剂拌土、促进出苗、加强田间管理等相应的防治措施。     

Cloning and Sequencing of cnf1 from Escherichia coli Incriminated in Mink and Bovine Colibacillosis

Colibacillosis is responsible for significant losses to the mink and cattle industries. Previous work in our laboratory and by others has suggested that possession of cnf1, the gene encoding cytotoxic necrotizing factor (CNF1), may contribute to the virulence of isolates of E. coli from mink and cattle. The cnf1 gene from E. coli isolated from a mink with colisepticaemia and a bovid with scours was amplified and cloned as a 3.5 kb fragment, and the fragment was sequenced. The cnf1 sequences from the mink and bovine isolates of E. coli were compared to each other and to cnf1 sequences of E. coli from urinary tract and diarrhoea-associated infections of humans. The difference was only 7 nucleotides between the cnf1 sequences of the mink and bovine isolates of E. coli, which translated into 7 differences in amino acids. The cnf1 sequence of the mink isolate of E. coli had 15 nucleotide differences from the cnf1 sequences of the human isolate of E. coli (GenBank X70670), which translated into 11 differences in amino acids between these proteins. The cnf1 sequence of the bovine isolate of E. coli had 14 nucleotide differences from the cnf1 sequence of the human isolate of E. coli (GenBank X70670), which translated into 10 differences in amino acids between these proteins. The highly conserved sequences of the amino acids of CNF1 proteins make them a promising target for detection and control of the CNF1-producing E. coli involved in disease among various host species.     

土壤中氯的累积状况及其对作物的营养作用及毒害作用

本文系统的阐述了土壤中氯的来源、含量及分布状况,以及氯对植株的生理功能的影响、植株中氯的分布和累积对其生理生长的影响及其反应出的毒害症状,为安全利用含氯微咸水和含氯肥料提供理论参考。     

畜禽生产无害化处理措施

我国畜牧业快速发展,生产规模不断扩大,畜禽生产中的粪污、剩料、生产用水、病死畜如果处理不当,会对环境造成污染,携带病原菌的污染物会直接污染生产生活用水,造成动物疾病传播,土壤水源污染,最终威胁人的健康。为提高人们对动物生产中污染物危害的认识程度和处理意识,该文就污染物的危害和处理技术进行分析。     

Chapter 2. Characteristics of the Study Area,Data Utilized,and Modeling Approach

Summary

A wildfire hazard and risk model was developed in a week-long workshop to test the feasibility of using existing resource data and combined expert assessment to help address the increasing concern over wildfires in the Western United States. The goal was to utilize readily-available resource data, translated into a GIS format, to develop and illustrate relative hazard and risk assessments in a format that would be useful to decision makers. This paper discusses the characteristics of the study area, the data that were assembled, and the methods utilized. The results of the hazard and risk assessments are discussed in the papers that follow.