Protection by iron salts against sporidesmin intoxication in sheep

A number of iron compounds have been shown to protect sheep against the harmful effects of the facial eczema toxin, sporidesmin. Various salts were found to be effective; the oxidation state of the metal was not important although water-solubility did appear to be a prerequisite for prophylactic activity. The effect of iron salts was additive with that of zinc, and it is suggested that the protective action of these compounds results from their ability to inhibit the absorption of copper, consistent with the previously-proposed freeradical mechanism for sporidesmin toxicity.     

Dual-purpose Guzerá cattle exhibit high dairy performance under heat stress

The present study evaluated the heat stress response pattern of dual-purpose Guzerá cattle for test-day (TD) milk yield records of first lactation and estimated genetic parameters and trends related to heat stress. A total of 31,435 TD records from 4,486 first lactations of Guzerá cows, collected between 1986 and 2012, were analysed. Two random regression models considered days in milk (DIM) and/or temperature × humidity-dependent (THI) covariate. Impacts of −0.037, −0.019 and −0.006 kg/day/THI for initial and intermediate stages of lactation were observed when considering the mean maximum daily temperature and humidity to calculate THI. Heritability estimates ranged from 0.16 to 0.35 throughout lactation and THI values, suggesting the possibility to expect gains from selection for such trait. The variable trajectory of breeding values for dual-purpose Guzerá sires in response to changes in THI values confirms that the genotype × environment interaction due to heat stress can have some effect on TD milk yield. Despite the high dairy performance of Guzerá cattle under heat stress, estimated genetic trends showed a progressive reduction in heat tolerance. Therefore, new strategies should be adopted to prevent negative impacts of heat stress over milk production in Guzerá animals in future.     

Research and Development of a Quality Control System in Construction

In the civil industry, quality is a key factor, so quality management and quality control play decisive roles in construction especially. At present, the main method of construction is quality controlling that engineers and technicians consult the standard and norm concerned, then check them one by one, and supervise the construction. It is not only inefficient but also easy to make mistake. Using computer technology in the quality control of construction will promote quality control level and improve management measures. Through the research of the quality control of construction,the system of quality control in construction is studied and developed, the structure of the software and its developed technology are expounded.     

民族旅游利益保障制度的伦理学反思——基于三大伦理学派对利益的分析

在民族旅游发展过程中,利益保障制度的缺失或是不合理已成为利益冲突频发却又不能得到合理、彻底解决的根源。全面了解三大伦理学派对利益、利益主体、利益冲突、利益协调的阐释,对于构建和调整民族旅游利益保障制度有深切意义。     

Economic evaluation of forest drainage and fertilization in northern Ontario peatlands with an investment decision model

Drainage and fertilization of an existing peatland black spruce (Picea mariana (Mill.) B.S.P.) stand and 24 possible methods of planting a clear-cut area near Cochrane, Ontario were evaluated by means of a recently developed forestry investment decision model, FIDME.Results indicate that, on the basis of the cost estimates used and assumptions made, drainage of the existing stand is the most economical treatment if it can reduce the rotation age by 30 years or more. Drainage combined with fertilization is the second best alternative if this treatment can reduce the rotation age by 40 years or more. Fertilization of the undrained site ranks a distant third, and then only if it reduces the rotation age by 10 years; otherwise, it will be uneconomical to apply.In the case of the clear-cut area, planting bare-root stock on a mechanically prepared but undrained site without weed control ranked first among the 24 alternatives considered; the same treatment, but with weed control included, ranked second. Planting containerized seedlings on a mechanically prepared but undrained site with weed control ranked third, followed by planting bare-root stock on a mechanically prepared and drained site with weed control. In contrast, planting containerized seedlings on an unprepared site and with no weed control ranked as the least cost-effective method considered.     

辽西半干旱区玉米有限补灌制度研究初探

对辽宁省西部半干旱地区对该区玉米的有限补灌制度进行了初步研究。在不同的补灌定额和补灌次数条件下对玉米的产量效应和耗水量以及水分利用效应进行了分析,通过分析表明,补灌定额与产量之间差异显著水平,耗水量与产量之间差异显著。开花期为作物需水最敏感的时期。并且补灌效果最好的是在开花期1次补灌,其次是灌浆期和拔节期2次补灌。并且以高产和节水以及水分高效利用为目地,确定出试验年降水量条件下的补灌制度为:补灌时间为开花期补灌,补灌定额为67.5 mm。     

浅析当代大学生的主观幸福感

培养当代大学生的主观幸福感是大学生心理健康教育的重要内容。本文就主观幸福感的概念、影响大学生主观幸福感的因素及培养的方法进行论述。     

关中平原小麦生育期VTCI加权估算及其与产量的相关性研究

选取关中平原冬小麦主要生育期的条件植被温度指数( VTCI)遥感干旱监测结果,运用层次分析法、因子权重排序法两种主观赋权法和主成分分析法、熵值法两种客观赋权法,分别确定加权VTCI,并与关中平原5地区冬小麦年产量建立线性回归模型,研究VTCI对冬小麦产量的影响.结果表明,两种主观赋权法确定的加权VTCI与产量之间存在着...     

规则约束下水禽养殖户饲料添加剂使用意愿与行为研究——基于TPB-NAM整合模型

饲料添加剂具有提高动物免疫功能、促进动物健康生长等诸多优势。然而,滥用饲料添加剂已经对动物、人类健康和环境构成了严重的威胁,规范使用饲料添加剂是养殖户亲环境生产行为的重要表现。基于计划行为理论(TPB)和规范激活理论(NAM)的整合框架,利用江西省、湖北省和云南省水禽养殖户微观调查数据,采用结构方程模型,从个体理性和社会理性两个维度,分析在规则约束下水禽养殖户饲料添加剂的使用意愿与行为。结果表明,受访者表现出较高的规范使用饲料添加剂意愿,均值为3.764,但实际行为偏低,均值为3.216。态度、主观规范和感知行为控制均对水禽养殖户规范使用饲料添加剂意愿产生显著正向影响,但影响效应依次减弱;结果意识正向影响责任归属,而责任归属和感知收益共同激活个人规范。意愿与个人规范对水禽养殖户规范使用饲料添加剂行为均具有显著正向影响,且意愿的影响更大,但意愿与行为之间存在悖离现象。据此,提出应采取措施提升水禽养殖户规范使用饲料添加剂的积极态度,强化水禽养殖户在生产过程中所承担的环境责任,营造规范使用饲料添加剂氛围,加大政策支持和补贴力度,加强监管与督察力度等政策建议。     

论农村职教教师备课的原则和措施

分析了农村职业教育中教师备课的重要性,论述了教师备课时要遵循科学性、艺术性和实用性等原则,并强调备课的规范化,加强教学监督,从而提高教师备课水平,提高教学质量。