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Sources of mycobacterial infections in 50 pig herds in the Czech Republic were investigated during the years 1996 to 2002. A total of 2,412 samples from the external environment (feeds, bedding ... materials, drinking water, biofilms on drinkers, scrapings from the walls, floors and pen barriers, dust, spider webs, peat, kaolin, faeces, organs of rodents, and birds, etc.) were examined. After staining by the Ziehl-Neelsen technique, acid-fast rods were detected in 3.9 % of samples and mycobacteria were cultured from 23.8 % of samples. From Mycobacterium avium complex (MAC), M. avium subsp. hominissuis (genotype IS901-, IS1245+) of serotypes 4, 6, 8, and 9 (47 % of isolates), M. a. avium (genotype IS901+, IS1245+) of serotype 2 (2.2 % of isolates) and M. intracellulare (genotype IS901-, IS1245-) of different serotypes (0.3 % of isolates) were detected most frequently. Peat given to piglets as a feed supplement was the most important source of mycobacteria (65.1 % positive of 327 examined samples); 81.2 % of them were positive for M. a. hominissuis of serotypes 4, 6, 8, and 9. High contamination levels were found in faecal samples (15.6 %) and in scrapings (18.4 %) from pens and stables. Mycobacteria were also detected in 7.9 % of various invertebrate species. več

分析我国农机经营组织模式的演替过程，对农机经营组织模式进行科学界定，为农机经营组织模式的区域适应性研究奠定理论基础。从文献和实地调研2方面入手，剖析我国农机经营组织模式的发展历程，分析现有农机经营组织模式的发展现状和存在问题，对我国农机经营组织模式进行科学界定，通过综合评价对各种组织模式的发展前景进行排序。我国农机经营组织模式的发展经历了3个阶段，与此相对应，可将我国的农机经营组织模式分为集体经营、个体经营、联合经营、合作社经营和企业经营5种模式。从组织化程度、经营管理水平、经营效益、服务水平等方面对5种经营组织模式的发展前景进行综合评价，结果表明5种模式发展前景从低到高依次为集体经营、个体经营、联合经营、合作社经营和企业经营。各地农机经营组织模式的演替进程不同，不同时期适宜发展的农机经营组织模式是动态变化的，因此各地应因时因地制宜，选择适宜的农机经营组织模式，以促进区域农机化更好、更快地发展。合作社经营组织模式和企业经营组织模式是未来农机经营组织模式的发展方向。 The study was done to analyze the succession process of China’s agricultural machinery management organization model, and to define it scientifically, to lay theoretical basis for the regional adaptability research of agricultural machinery management organization model. On the basis of literature research and field studies, we analyzed the history of China’s agricultural management organization model, development status and existing problems of the current agricultural management organization model, made a scientific definition for China’s agricultural management organization m

Previous studies have reported that tractors are responsible for high proportions of fatal and nonfatal agricultural injuries. However, many common and preventable risk factors, conditions, and ... associated costs related to tractor-related injuries have not been investigated. This case-based study used workers' compensation data to investigate tractor-related injuries. The objectives of this study were to (1) identify and describe tractor-related injuries, (2) assess medical and indemnity costs associated with tractor-related injuries, and (3) determine contributing factors associated with those injuries. Tractor-related injury claims data from Colorado workers' compensation records were analyzed for a 12-year period (1992-2004). Descriptive analyses of the costs, characteristics, and contributing factors associated with tractor-related injuries were conducted. The epidemiological agent-host-environment model was used to analyze injury event descriptions. A total of 23,484 agricultural-related injury claims were analyzed. Through an event description analysis, a total of 642 claims were identified as being tractor-related. Over 60% of tractor-related claims involved sprains/strains and contusions. A total of 21% of tractor-related claims were associated with the worker mounting or dismounting a tractor, and an additional 10% of claims were associated with the worker falling, jumping, or slipping off a tractor. Among all claims associated with tractor mounting or dismounting, 35% involved the ankle and 15% involved the knee. Nearly three-quarters of tractor-related claims were medical-only claims. The median medical claim cost was $319, and the median medical plus indemnity claim cost was $335. Claim costs associated with tractor-overturn injuries were higher than tractor-related injury claims in general. This study determined that a large percentage of tractor-related injury claims were associated with tractor mounting and dismounting. These findings are consistent with previous research and suggest the need to further investigate tractor design criteria related to mounting and dismounting. več

Physiological Effect of Vibrations on Tractor Drivers under Variable Ploughing Conditions: Mohammad Muzammil, et al. Department of Mechanical Engineering, Ergonomics Laboratory, Faculty of ... Engineering & Technology, Aligarh Muslim University, India—The vibration conditions to which tractor operators are subjected are complex and varied with multi axis translation and rotational vibration inputs to different parts of the body. Working under such conditions may lead to human fatigue and other driving related hazards. The present research was carried out to study the operators under varying conditions of vibration while driving a tractor with and without farm equipment on different fields. Test runs were conducted in wet and dry fields to determine the levels of vibration generated at different engine speeds. On the basis of this study three levels of vibration namely 2.5, 3.5 and 5.0 m/s2 were selected. Five subjects, all males, with no experience in the field of tractor driving participated in the study. The data were analyzed on the basis of three factor repeated measure kind of experimental design. The results showed that the main effects of farm equipment and the vibration level were statistically significant but the effect of field type was found to be statistically non‐significant. The results of the study call upon the ergonomists to design and develop a tractor where the driver may be relieved of vibration induced stresses. Front loading of farm equipment is recommended for improved visibility and better working posture. več