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991.
The present study was carried out to evaluate the excretion of aflatoxin B1 residues in eggs of young laying hens fed aflatoxin B1-contaminated rations for 8 weeks. To this end, 96 twenty-week-old hens were randomly distributed into four experimental groups (24 birds per group) and given rations containing either 0 (controls), 100 micrograms, 300 micrograms or 500 micrograms aflatoxin B1/kg feed. Egg aflatoxin B1 residues were determined by thin layer chromatography; two samples per treatment per week were used for analysis. Egg production and average egg weights were not affected (p < 0.05) in the groups receiving aflatoxin B1-contaminated rations. Residues of aflatoxin B1 were detected only in the eggs of hens given 500 micrograms/kg feed, at levels that ranged from 0.05 to 0.16 microgram/kg (average: 0.10 microgram/kg). The results indicate that the feed to eggs aflatoxin B1 transmission ratio was approximately 5000:1, emphasizing the importance of controlling aflatoxin levels in rations for laying hens.  相似文献   
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The importance of short-term load forecasting has been increasing lately. With deregulation and competition, energy price forecasting has become a big business. Bus-load forecasting is essential to feed analytical methods utilized for determining energy prices. The variability and nonstationarity of loads are becoming worse, due to the dynamics of energy prices. Besides, the number of nodal loads to be predicted does not allow frequent interactions with load forecasting experts. More autonomous load predictors are needed in the new competitive scenario. This paper describes two strategies for embedding the discrete wavelet transform into neural network-based short-term load forecasting. Its main goal is to develop more robust load forecasters. Hourly load and temperature data for North American and Slovakian electric utilities have been used to test the proposed methodology.  相似文献   
995.
The aims of the study were to evaluate toxic and essential metal concentrations in meat and offal from pigs in north-west Spain to compare these with reported metal concentrations in pigs in other countries and in cattle in this region, and to relate the observed concentrations to maximum acceptable concentrations. Samples from 63 pigs aged 6 months were randomly collected at slaughter. After acid digestion, levels of metals were determined by ICP-OES and ICP-MS. As regards the toxic metals, mean concentrations in liver, kidney and muscle were 0.073, 0.308 and 0.009 mg kg-1 fresh weight for cadmium, 0.004, 0.008 and 0.003 mg kg-1 for lead, 0.013, 0.011 and 0.003 mg kg-1 for arsenic, and 0.001, 0.002 and 0.001 mg kg-1 for mercury. These concentrations can be considered low, and in general similar to those reported in similar studies in recent years. In addition, maximum admissible concentrations established by the European Union were not exceeded in any sample. As regards the essential metals, concentrations in liver, kidney and muscle were 14.9, 5.63 and 6.85 mg kg-1 for copper, 81.3, 28.9 and 42.5 mg kg-1 for zinc, 195, 51.6 and 26.5 mg kg-1 for iron; 1.17, 2.51 and 0.656 mg kg-1 for selenium, 3.32, 1.56 and 1.01 mg kg-1 for manganese, 0.023, 0.027 and 0.003 mg kg-1 for cobalt, 0.120, 0.077 and 0.131 mg kg-1 for chromium, 0.009, 0.027 and 0.026 mg kg-1 for nickel, and 1.62, 0.683 and 0.140 mg kg-1 for molybdenum. These concentrations are all within the accepted adequate-safe ranges for this animal species, and in general are in line with those previously reported in the literature.  相似文献   
996.
A survey on the scientific journals dealing with microbiology published in Europe has been carried out. Eighteen European countries publish microbiological journals with the United Kingdom. Netherlands and Germany leading in number of journals on this specialty. Most of the European journals on microbiology are published bimonthly (27%), and English is the most common language used (54%). Most of these journals (86%) are included in some database, but only 36 (25%) are indexed in the six databases studied. Out of the 146 journals registered, 71 (49%), published in 11 European countries, are included in the 1995 Journal Citation Reports (ISI, Philadelphia).  相似文献   
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This paper presents a boundary element formulation for the computation of moments and stresses at internal and boundary points of laminated composite plates. Integral equations for second transversal displacement derivatives are developed and all derivatives of the fundamental solution are computed analytically. These integral equations are used to compute moments and stresses at internal points. Stresses on the boundary are computed by a procedure that uses integral equations for the first transversal displacement derivatives, derivatives of shape functions, and constitutive relations. The obtained results are in good agreement with finite element results available in literature.  相似文献   
1000.
Objective: To test the association between self-reported unfair treatment and objective and self-reported sleep characteristics in African American and Caucasian adults. Design: Cross-sectional study of 97 African American and 113 Caucasian middle-aged adults. Main Outcome Measures: Participants completed: (a) two-night in-home, polysomnography (PSG) sleep study, (b) sleep diaries and actigraph assessments across 9 days and nights, and (c) self-report measures of sleep quality in the past month, and daytime sleepiness in the past 2 weeks. Results: Greater unfair treatment was associated with reports of poorer self-reported sleep quality and greater daytime sleepiness, shorter sleep duration, and lower sleep efficiency as measured by actigraphy and PSG, and a smaller proportion of rapid eye movement (REM) sleep. Racial/ethnic differences were few. Exploratory analyses showed that nightly worry partially mediated the associations of unfair treatment with sleep quality, daytime sleepiness, sleep efficiency (actigraphy), and proportion of REM sleep. Conclusion: Perceptions of unfair treatment are associated with sleep disturbances in both African American and Caucasian adults. Future studies are needed to identify the pathways that account for the association between unfair treatment and sleep. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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