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Journal of Pest Science - Over the past three decades, highly increased whitefly (Bemisia tabaci) populations have been observed on the staple food crop cassava in eastern Africa and associated...  相似文献   
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Etorphine and xylazine were found to be a safe and reliable drug combination for the immobilization of Père David's deer, whether excited or unexcited. Excited deer had a longer preimmobilization period, when compared with unexcited deer at comparable dosages. Generally, the acid-base status of Père David's deer during immobilization was not seriously altered. Deer that had been excited and exercised experienced mild respiratory problems; the unexcited, relatively calm deer experienced minimal acidosis. Significantly high pH and PO2 and significantly lower PCO2 and bicarbonate values were found in the excited deer, when compared with the unexcited deer. Rapid physiologic changes occurred after the intravenous administration of the antagonist, diprenorphine.  相似文献   
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Blood volume determinations were performed in 5 anesthetized gopher snakes (Pituophis melanoleucus catenifer) by means of a 51Cr-labeled red blood cell (RBC) method. The mean blood volume was 52.8 ml/kg of body weight (+/- 6.21 SE). Previous blood volume measurements have not been reported for this species. The RBC survival rate was estimated to be greater than 660 days. The RBC survival rate is long, but it cannot be determined accurately by this method.  相似文献   
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The principal molecular determinant of virulence of Newcastle disease virus (NDV) is the amino acid sequence at the fusion cleavage activation site. To extend the understanding of the role of the fusion cleavage activation site in NDV virulence, the pathogenesis in chickens of a lentogenic LaSota isolate and two infectious clones, NDFL and NDFLtag, were compared. NDFL is an infectious clone of a lentogenic NDV strain (LaSota E13-1), and NDFLtag is the infectious clone with the fusion cleavage site sequence mutated to the virulent motif. NDFL and NDFLtag were described by Peeters et al. The viruses were inoculated intraconjunctivally into groups of 4-wk-old white leghorn chickens and compared in a pathogenesis study for determination of disease causation (clinical signs of disease, gross lesions, histology, virus isolation, and serology) and viral distribution (presence of viral nucleoprotein and mRNA was detected by immunohistochemistry and in situ hybridization, respectively). The modification of the fusion cleavage activation site to the virulent motif in the infectious clone only slightly increased disease severity and viral distribution in the pathogenesis assessment, even though dramatically increased pathogenicity of NDFLtag was confirmed by standard pathogenicity index tests. The result, that the mutated fusion cleavage site of NDV-NDFLtag had only a small influence on pathogenesis in chickens compared to either E13-1 or NDFL, suggests that the pathogenic effects of NDV are not dependent on the fusion cleavage site alone.  相似文献   
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OBJECTIVE: To assess the iodine status of long-term refugees dependent on international food aid and humanitarian assistance. DESIGN: A series of cross-sectional two-stage cluster or systematic random sample surveys which assessed urinary iodine excretion and the prevalence of visible goitre. Salt samples were also collected and tested for iodine content by titration. SETTING: Six refugee camps in East, North and Southern Africa. SUBJECTS: Male and female adolescents aged 10-19 years. MAIN RESULTS: The median urinary iodine concentration (UIC) ranged from 254 to 1200 microg l(-1) and in five of the camps exceeded the recommended maximum limit of 300 microg l(-1), indicating excessive iodine intake. Visible goitre was assessed in four surveys where it ranged from 0.0 to 7.1%. The camp with the highest UIC also had the highest prevalence of visible goitre. The iodine concentrations in 11 salt samples from three camps were measured by titration and six of these exceeded the production-level concentration of 20 to 40 ppm recommended by the World Health Organization (WHO), but were all less than 100 ppm. CONCLUSIONS: Excessive consumption of iodine is occurring in most of the surveyed populations. Urgent revision of the level of salt iodisation is required to meet current WHO recommendations. However, the full cause of excessive iodine excretion remains unknown and further investigation is required urgently to identify the cause, assess any health impact and identify remedial action.  相似文献   
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Nutritionists, dietitians and food manufacturers have advocated an increased consumption of whole grain foods. In some countries, this message is supported by governmental guidelines and health claims that can be used on whole grain foods. The bulk of evidence to support these messages comes from observational studies; in some cases, cohort studies with follow‐up. Although these data are powerful indicators of the relationship between whole grain intake and improved health, they do not demonstrate causality. Nevertheless, it is difficult to argue against the evidence, particularly for the benefit of whole grains in reducing the risk of cardiovascular diseases. Repeated meta‐analyses show that CVD risk is reduced by ≈30% when comparing the lowest whole grain consumers with the highest whole grain consumers. It is argued that to help explain the benefits of whole grain and, in particular, to inform the development of health claims for whole grain foods, intervention studies are needed to link observational data with mechanistic explanations. Until recently, the number of whole grain intervention studies has been very small and most have been conducted in at‐risk populations and with small numbers of subjects. Data from larger studies are gradually appearing and, in some cases, the results support the observational data but in others they do not. This report compares observational data with data from intervention studies to reconcile these differences and make recommendations for future research.  相似文献   
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The total value of agricultural production in the Ukraine amounts to $30 billion, equivalent to 30% of the Gross Domestic Product (GDP). The annual cost of pesticide inputs is estimated to be $200–225 million. Herbicides and insecticides account for approximately 50% and 30% of pesticide use, respectively. The government has introduced a National Programme for the development of agricultural production over the next five to eight years. The programme envisages an expansion in agricultural production and pesticide use and a continuation of the move towards a free‐market economy. Improvements in crop yield and quality will benefit both the individual grower and the national economy. In the transition to the free‐market economy, growers require a clear understanding of present pesticide technology and crop production systems. A major change of attitude is required by all those people involved in providing and using pesticides to ensure that they are used both economically and safely. To address this issue, a Regional Academic Programme (REAP), involving Writtle College and Bila Tserkva State Agrarian University, has been initiated. © 2000 Society of Chemical Industry  相似文献   
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