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Escherichia coli O26:K60, with genetic attributes consistent with a potentially human enterohaemorrhagic E. coli was isolated from the faeces of an eight-month-old heifer with dysentery. Attaching and effacing lesions were identified in the colon of a similarly affected heifer examined postmortem, and shown to be associated with E. coli O26 by specific immunolabelling.  相似文献   
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It has been reported previously that the major resistance mechanism to pyrethroid insecticides by the cotton bollworm Helicoverpa armigera (Hübner) in Australia is a consequence of overproduction of esterase isoenzymes. This paper reports structure-activity relationships that support such a view, based on in vivo bioassays conducted with a range of pyrethroid structures containing a variety of acid and alcohol moieties and the correlation with in vitro esterase inhibition assays against the same structures, and identifies the critical regions of the molecule with regard to esterase inhibition, and hence resistance. The implications of this work in terms of possible resistance management are evaluated and discussed.  相似文献   
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The compositions at which amorphous ethanol-maltose-water mixtures exhibit liquid-liquid separation have been determined in the temperature range from 20 to 80 degrees C. At water contents below approximately 20% w/w two phases were observed, with the maltose-rich phase slightly richer in water. Partition coefficients of organic nonelectrolytes ranging in hydrophobicity from 1, 2-ethanediol and 1,2-propanediol to benzyl alcohol and propyl acetate have been measured for octanol/sorbitol, benzyl alcohol/sorbitol, and 1-butanol/sorbitol mixtures. Linear correlations were found between the log partition coefficients in the various solvent systems. Replacing water with sorbitol results in more organic partitioning into the octanol. Replacing octanol with benzyl alcohol or 1-butanol also results in more organic partitioning into the hydrophobic phase. The results establish a relationship with partition coefficients for octanol/water mixtures, which are well studied experimentally and for which predictive approaches exist. The implications of these results for flavor retention and encapsulation are discussed.  相似文献   
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The effects of water content and temperature variation on the release of flavor components into the headspace over flavors, encapsulated by an extrusion process, in low water content carbohydrate matrixes is studied. The largest amounts of release occurred when the matrix was above its glass transition temperature, whether this was due to increased water content or elevated temperature. Under these conditions up to 70% of the sucrose in the matrix crystallized over a period of 10 days, as quantified using Fourier transform Raman spectroscopy. Smaller amounts of headspace release occurred when the water content of the encapsulated flavor system was decreased from 3. 5 to 3.1% w/w. Small amounts of release occurred from the "as prepared" materials, which were associated with the presence of small amounts of unencapsulated flavor oil with direct access to the headspace. It was concluded that release due to matrix permeability was relatively slow as compared with the above mechanisms.  相似文献   
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OBJECTIVE: To evaluate the impact and appropriateness of programmes for the management and treatment of severe malnutrition in emergency situations. DESIGN: A central unified database was set up with all data and statistics provided by nutritional centres (NC) active in Burundi. SETTING: The paper describes the case of Burundi as an example of the response of the humanitarian community to nutritional crisis. SUBJECTS: Since 1999, more than one million (1,054,210) severely malnourished patients were treated in NC established in Burundi. RESULTS: Peaks of beneficiaries were registered in 2000 and 2001; the admission rate started to decrease in 2002. In 2004, twenty therapeutic feeding centres (TFC) and 224 supplementary feeding centres (SFC) were active for the treatment of 127,420 beneficiaries. Nutritional programmes were present in every province with a coverage rate of 55%. The most convincing impact of the nutritional programme in Burundi was the reduction of mortality rate in children under 5 years of age; an impact on the prevalence of acute malnutrition could not be demonstrated. Children under 5 years old accounted for 62% of beneficiaries in TFC and 76% in SFC. TFC performance indicators fulfilled the minimum standards in disaster response; the performance of SFC was not so optimal with a low recovery rate (69% v. >80%) and a high non-respondent rate (16% v. <5%). With the combination of coverage and cure rate, the programme met 44% of the assessed needs in 2004. CONCLUSIONS: In Burundi the stabilisation of security conditions permitted a combination of humanitarian responses ranging from emergency activities to strengthening of community-based initiatives that could correct the coverage and impact limitations.  相似文献   
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可追溯体系信息管理的挑战及展望   总被引:1,自引:0,他引:1  
一个可追溯体系的实施需要采集大量的数据.这个体系的本质依赖于其目的、范围和预期结果.正如OIE规则中的描述,这些应该通过咨询兽医主管机关和相关的企业和团体来进行明确定义.在设计这个体系时,基于信息管理的主要研究在于如何采集、确认和整理数据,保存多长时间和采取何种安全措施.根据法律框架,不同国家之间的数据获取也不尽相同.  相似文献   
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