Salmonellosis in finishing pigs in Spain: prevalence, antimicrobial agent susceptibilities, and risk factor analysis

A herd-based survey of Salmonella in pigs was carried in a major pig producing region of Spain. Mesenteric lymph nodes were collected from the carcasses of 25 pigs from each of 80 herds at time of slaughter. Salmonella spp. were isolated from 31% of animals and 94% of herds. Within-herd prevalence ranged from 4 to 88%, with the prevalence in most herds being greater than 10%. A large diversity of Salmonella serotypes was found, with Typhimurium, 4,[5],12:i:-, and Rissen being the most prevalent. Two or more serotypes coexisted in 73% of the herds. Salmonella Typhimurium was present in 68% of the herds. Most (82%) of the Salmonella isolates belonged to serogroups targeted by enzyme-linked immunosorbent assay tests for pig salmonellosis. Resistance to at least one antimicrobial agent was detected in 73% of the strains, and one or more resistant strains were recovered from pigs in 93% of the herds. Antimicrobial agent resistance (AR) was more frequent among the most prevalent than it was among the rarer serotypes. Twenty-five multi-AR patterns were found. Resistance to three or more families of antimicrobial agents was found in 75% of AR strains. The finding that many of the herds yielded isolates of several multi-AR patterns indicates that Salmonella infections were acquired from multiple sources. High prevalence of Salmonella in herds was associated with lack of rodent control programs, herds from farms with only finishing pigs, herds managed by more than one full-time worker, herds for which the source of drinking water was not a city supply, and relatively long fattening times.     

接触式油挡在透平机上的应用

中原大化集团有限公司透平机将原来的梳齿式油挡改造为接触式油挡后,彻底解决了透平机漏油及油中含水的问题,保证了机组的安全稳定运行。     

适度现代性的建筑诠释——以本溪博物馆建筑创作为例

该文以本溪博物馆建筑创作为契机,分别从主题、环境、文脉及空间四个方面切入,提出在适度契合本溪人文环境的同时创造可识别性,在适度延续周边城市肌理和场地形态的同时营造丰富性,在适度体验内部空间的同时塑造鲜明性,进而诠释一种适度的现代性。     

基于AMESim与ADAMS联合仿真技术的减摇鳍液压系统仿真研究

为了对机、电、液一体化减摇鳍液压系统准确仿真,提出了基于AMESim与ADAMS联合仿真技术的建模与仿真方法,运用ADAMS软件建立机械系统多体动力学模型,采用AMESim软件对液压系统与控制系统建模,完成较准确的系统模型,并分析了减摇鳍液压系统的动态特性,将获得的数据与实测数据进行比较,证明联合仿真与传统仿真方式相比结果更准确.     

A study of job shop standard setup time quota

For the multi-item and small lot size production mode and single machine job shop scheduling sequence independent setup time, many setup times are difficult to estimate accurately, which influences the ability to achieve accurate production cycles and costs of products. The survey shows that the length of the setup time depends on the level of employee’s knowledge. Therefore, a method for determining the standard setup time quota based on the level of employees’ knowledge is proposed. First, an evaluation index system for the level of employee’s knowledge is built; the level of employee’s knowledge is estimated by the masses and experts fuzzy comprehension evaluation and entropy method. Second, the range and definition of the level of employees’ knowledge index are developed. Third, the relational model of the employee’s knowledge level and the level of employees’ knowledge index is constructed through the least squares method. Finally, an example application is presented to verify the feasibility and effectiveness of the proposed model.     

超固体润滑及其在微机械电子系统中的应用前景

介绍了超固体润滑的概念 ,综述了超固体润滑的研究现状和近年来的研究成果 ,通过对微机械电子系统摩擦学问题的讨论 ,分析了超固体润滑在微机械电子系统中应用的前景 ,阐述了超固体润滑技术在微机械电子系统中应用的发展趋势     

无毒和低毒防污涂料的研究进展及存在问题

防污涂料作为一个有效解决海生物污损的方法,在船舶、海洋水下设施上得到广泛应用。随着环保意识的增强以及各种相关规定的制订,各国开始竞相研制开发新型无毒和低毒防污涂料。本文在介绍无毒和低毒防污剂、防污涂料的种类、研究现状、应用效果的基础上,论述了从防污剂的筛选到防污涂料实船实验的一系列研制过程以及研制过程中存在的问题,并对未来的发展方向进行了展望。     

螺旋输砂器模型试验相似设计及数值模拟

以HS210混砂车螺旋输砂器为原型,根据Bockinghamπ定理,参照实际的结构和工作参数,采用量纲分析法完成1∶2、1∶5的试验模型相似设计,并运用Fluent流体分析软件对原型及试验模型出砂口流量进行数值模拟。将模拟结果与相似准则的计算结果进行对比分析可知,模拟值比相似理论计算值偏高,但其误差均不超过22%,在一定程度上能够反映原型机的实际工作情况,证明对HS210螺旋输砂器模型试验的相似设计是可行的。     

Latent communities of digital publications: The role of editors,followers, and advertisers

This research explores how digital publications may be turned into something more than just a meeting point for people who are seeking information and may become a latent community. The paper proposes that the network of editors, followers, and advertisers of digital publications determine the user sense of community towards the publication. While the pattern of connections among editors and followers reinforces the sense of community, advertisers act as intruders who weaken the feasibility of building a community. Data were collected from followers of digital publications. The dynamics of the sense of community is described as a process in which informational value and identification are essential to nurturing readers’ soft or hard commitment. Findings indicate that the strong ties between editors and followers as well as the diversity positively impacts on informational value and identification, whereas advertising intrusiveness diminishes the informational value.     

Scalable and flexible wireless distributed architecture for intelligent video surveillance systems

Multimedia Tools and Applications - This paper presents a novel distributed intelligent video surveillance architecture based on Wireless Multimedia Sensor Networks (WMSNs). This architecture is...