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Preparations derived from plants were the original therapeutic interventions used by man to control diseases (including parasites), both within humans and livestock. Development of herbal products depended upon local botanical flora with the result that different remedies tended to develop in different parts of the world. Nevertheless, in some instances, the same or related plants were used over wide geographic regions, which also was the result of communication and/or the importation of plant material of high repute. Thus, the Nordic countries have an ancient, rich and diverse history of plant derived anthelmintic medications for human and animal use. Although some of the more commonly used herbal de-wormers were derived from imported plants, or their products, many are from endemic plants or those that thrive in the Scandinavian environment. With the advent of the modern chemotherapeutic era, and the discovery, development and marketing of a seemingly unlimited variety of highly efficacious, safe synthetic chemicals with very wide spectra of activities, herbal remedies virtually disappeared from the consciousness--at least in the Western world. This attitude is now rapidly changing. There is a widespread resurgence in natural product medication, driven by major threats posed by multi-resistant pest, or disease, organisms and the diminishing public perceptions that synthetic chemicals are the panacea to health and disease control. This review attempts to provide a comprehensive account of the depth of historical Nordic information available on herbal de-wormers, with emphasis on livestock and to provide some insights on potentially rewarding areas of "re-discovery" and scientific evaluation in this field.  相似文献   
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为了探索烟叶生产过程中各机械的性能及工作效率,2013年在福建省建阳市莒口镇河坝新村开展了烟叶生产全程机械化作业试点研究。结果表明,起垄环节,碎土率方面邵武华友履带式起垄机表现最好(89.9%),沟底积土方面松溪永顺表现最好;覆膜环节,各测试机型表现中等,在效率方面优于人工覆膜;移栽环节,漏栽率上江苏久泰移栽机高于江苏井关移栽机;培土环节,漳州南冠培土机操作简便,掉头灵活,单人操作,单行双侧作业,深受烟农喜爱;拔杆环节,龙岩诚德拔杆机单人操作,操作简便,动力较足,拔杆顺畅,拔杆带土较少,效果较好,适应性较强。  相似文献   
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The influence was investigated of irradiance on blackcurrant cv Baldwin shoot proliferation and subsequent rooting in vitro. Shoots were cultured under a range of irradiance levels between 0.9 and 28.4 Wm-2 and the rate of proliferation expressed as shoot doubling times (td), was lowest at 0.9 Wm-2 (td = 59.5 d) and rose to a maximum at 18.5 Wm-2 (td =14.8 d). Rooting was influenced by the light level during the proliferation stage of culture as higher light levels increased the time of root emergence. The shoot dry weight at the end of the rooting period was positively correlated with the light level during proliferation and negatively correlated with the time of root emergence.  相似文献   
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The addition of sugar beet to soils as a source of C led to an increase in the availability of easily utilizable C (glucose), which in turn markedly increased numbers of soil bacteria and of the yeast Williopsis californica. Nitrification, P solubilization, urea hydrolysis (and the subsequent nitrification of liberated NH inf4 sup+ ) were stimulated by this amendment. The stimulation of nitrification may have been a result of increased heterotrophic nitrification. In contrast, the concentration of sulphate in So-amended soils declined following amendment, presumably as the result of enhanced S immobilization. Activity of the enzymes amylase, aryl sulphatase, invertase, phosphatase, dehydrogenase, and urease were all stimulated by the sugar beet amendment. These results suggest that sugar beet amendment could be used to increase the rate of release of plant-available ions from fertilizers such as insoluble phosphates. Problems may arise, however, from a subsequent increase in nitrification and reduced sulphate availability.  相似文献   
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Field application of six fungicides at twice the normal rate resulted in increases in bacterial and fungal numbers after 28 days. Members of the fungal genera Gliocladium. Penicillium and Trichoderma predominated. Fungicides when applied at the field rate decreased the concentration of NO3? -N in soils. while the level of exchangeable NH4+ -N, K, Mn and Na were generally increased. Addition of the fungicides to soil incubated in the laboratory consistently increased exchangeable Mn and K, and occasionally increased exchangeable Cu, Na and Zn. The results are discussed in relation to the microbial changes which occur, and in relation to soil fertility.  相似文献   
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OBJECTIVE: To identify risk factors associated with the spread of low pathogenicity H7N2 avian influenza (AI) virus among commercial poultry farms in western Virginia during an outbreak in 2002. DESIGN: Case-control study. PROCEDURE: Questionnaires were used to collect information about farm characteristics, biosecurity measures, and husbandry practices on 151 infected premises (128 turkey and 23 chicken farms) and 199 noninfected premises (167 turkey and 32 chicken farms). RESULTS: The most significant risk factor for AI infection was disposal of dead birds by rendering (odds ratio [OR], 73). In addition, age > or = 10 weeks (OR for birds aged 10 to 19 weeks, 4.9; OR for birds aged > or = 20 weeks, 4.3) was a significant risk factor regardless of poultry species involved. Other significant risk factors included use of nonfamily caretakers and the presence of mammalian wildlife on the farm. Factors that were not significantly associated with infection included use of various routine biosecurity measures, food and litter sources, types of domestic animals on the premises, and presence of wild birds on the premises. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that an important factor contributing to rapid early spread of AI virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off-farm. Because of the highly infectious nature of AI virus and the devastating economic impact of outbreaks, poultry farmers should consider carcass disposal techniques that do not require off-farm movement, such as burial, composting, or incineration.  相似文献   
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