OBJECTIVES: To assess the intake inadequacy and food sources of zinc of people in China. DESIGN AND SUBJECTS: Diets of 68 962 subjects aged 2-101 years (urban 21 103, rural 47,859) in the 2002 China National Nutrition and Health Survey were analysed. Dietary intake was assessed using 24-hour recall for three consecutive days. Zinc intake inadequacy was calculated based on values suggested by the World Health Organization. RESULTS: The median zinc intake ranged from 4.9 mg day- 1 (urban girls, 2-3 years) to 11.9 mg day-1 (rural males, 19+ years). The zinc density of urban residents (2-3 to 19+ years) was 5.0-5.3 mg day-1 (1000 kcal)-1, significantly higher than that of their rural counterparts (4.7-4.8 mg day-1 (1000 kcal)-1). Differences in food sources of zinc from cereal grains (27.4-45.1 vs. 51.6-63.2%) and animal foods (28.4-54.8 vs. 16.8-30.6%) were found between urban and rural residents. Zinc from vegetables and fruits (8.2-13.8 vs. 9.7-12.4%) and legumes (1.3-3.3 vs. 2.5-3.4%) was comparable between urban and rural residents. The proportion of zinc intake inadequacy ranged between 2.8% (urban females, 19+ years) and 29.4% (rural lactating women). Rural residents had higher proportions of zinc intake inadequacy than their urban counterparts. Significantly higher proportions of zinc inadequacy were found in the category of phytate/zinc molar ratio >15 for both rural and urban residents. CONCLUSIONS: About 20% of rural children are at risk of inadequate zinc intake, with phytate as a potential important inhibitor. Moreover, lactating women are also considered a vulnerable group. 相似文献
BACKGROUND: Thiophanate-methyl, a member of the benzimidazole class of fungicides, is used in California to control brown rot of stone fruit caused by Monilinia fructicola (G. Wint.) Honey. The goal of this study was to develop a real-time polymerase chain reaction (PCR) assay as an efficient method to quantify the E198A allele of beta-tubulin that confers benzimidazole resistance. RESULTS: Using the real-time PCR assay, the frequency of allele E198A (FEA) in a population was determined from the quantities of DNA amplified with the E198A allele-specific primer pair HRF/HRR and the M. fructicola-specific primer pair MfF6/MfR6. The average proportions of highly resistant isolates determined with the conventional fungicide sensitivity method were within the range of average FEA values determined with the real-time PCR assay. We also determined the FEAs of M. fructicola populations sampled from 21 stone fruit orchards in California. Only one orchard showed a high FEA over 0.20, seven orchards had values between 0.01 and 0.1, and 13 orchards had values less than 0.01. CONCLUSION: The real-time PCR assay developed in this study provides a potentially useful tool to efficiently quantify benzimidazole resistance for large M. fructicola populations. 相似文献
Low winter temperatures severely stress newly arriving insect species. Adaptive evolutionary changes in cold tolerance can facilitate their establishment in new environments. Ambrosia artemisiifolia, a noxious invasive plant, occurs throughout China. Ophraella communa, a biological control agent of A. artemisiifolia, mainly occurs in southern China. However, in 2012, it established populations in Beijing (39.98°N, 115.97°E) following introduction from Laibin (23.62°N, 109.37°E), implying cold adaptation. The mechanisms underlying its rapid evolution of cold tolerance remain unknown. We investigated the levels of cryoprotectants and energy reserves in adult O. communa from two latitudes. In high-latitude insects, we found high trehalose, proline, glycerol, total sugar, and lipid levels; five potential genes (Tret1a, Tret1b, Tret1-2, P5CS, and GST), responsible for regulating cold tolerance and involved in trehalose transport, proline biosynthesis, and glutathione S-transferase activation, were highly expressed. These hybridisation changes could facilitate cold temperature adaptation. We demonstrate the genetic basis underlying rapid adaptation of cold tolerance in O. communa, explaining its extension to higher latitudes. Thus, specialist herbivores can follow host plants by adapting to new temperature environments via rapid genetic evolution.