Objectives To investigate relationship between iron deficiency of different degrees and physical performance and habitual activity of migrant schoolchildren at the age of 11-14 years. Methods Ninety one randomly selec...Objectives To investigate relationship between iron deficiency of different degrees and physical performance and habitual activity of migrant schoolchildren at the age of 11-14 years. Methods Ninety one randomly selected schoolchildren were divided into three groups according to their iron status. Iron status including hemoglobin （Hb）, serum ferritin （SF）, serum iron （SI） and sTfR was determined. Physical performance tests included maximum oxygen consumption （VO2max） and maximum work time. Energy expenditure （EE） and daily physical activity were estimated by recording 24-h heart rate （HR）. Dietary intake was assessed with frequency questionnaires, and physical activity level was estimated with frequency and physical activity questionnaires. Results Severe iron deficiency （IDA） impaired the aerobic capacity and habitual physical activity. When fat-free mass （FFM） was considered, VO2max （VO2max/FFM） was significantly lower in the iron-marginal group than in the iron-adequate groups among girls （P=0.02）, but such a deference was not found among boys （P=0.28）. Aerobic activity and EE at leisure were significantly lower in the severe iron deficient group than in the marginal iron deficient and iron adequate groups. Net HR at leisure time was correlated with lib, log SF, body weight, and FFM （P〈0.05）. Conclusion The functional effect of iron deficiency on physical performance and habitual physical activity rely on the degree of current iron deficiency. Severe iron deficiency significantly impairs both aerobic capacity and habitual physical activity. Iron-marginal deficiency impairs VO2max/FFM in girls, rather than in boys.展开更多
A population of migrant workers have appearing during the process of China’s urbanization,and is an important part of the society that cannot be ignored.In the process of integration into cities,the equal development...A population of migrant workers have appearing during the process of China’s urbanization,and is an important part of the society that cannot be ignored.In the process of integration into cities,the equal development between the rights and obligations of migrant workers is gaining attention.Especially,the issure of schooling of their children has garnered a lot of attention.All problems resulting from schooling of their children are rooted in the asynchronization between system changes and social development.Systematic barriers have become the crux of schooling problem of migrant workers’children.展开更多
In the course of the large-scale migration to the cities of China＇s rural labor force over the past twenty years, most migrant workers have left their children behind in their hometown, though some children do follow...In the course of the large-scale migration to the cities of China＇s rural labor force over the past twenty years, most migrant workers have left their children behind in their hometown, though some children do follow their parents to the city. The issue of the upbringing and education of these children, whether ＂left behind＂ or ＂migrating,＂ has always been a major concern of society and the academic world. This article aims to understand the factors affecting whether these children ＂stay behind＂ in their hometown or ＂flow＂ to the city through analysis of the child-rearing and education patterns reflected in survey information on over 3,000 migrant workers in the Pearl River Delta in 2006. We find that, after controlling for individual and family factors, regional differences in migrant workers＇ origins remains an important factor influencing whether children ＂stay behind＂ or ＂migrate.＂ The causes and mechanisms behind the existence of ＂regional barriers＂ is an issue worth further exploration.展开更多
基金funded by the Global Alliance for Improved Nutrition, NFA-CHN-FE-2003-01-00
文摘Objectives To investigate relationship between iron deficiency of different degrees and physical performance and habitual activity of migrant schoolchildren at the age of 11-14 years. Methods Ninety one randomly selected schoolchildren were divided into three groups according to their iron status. Iron status including hemoglobin （Hb）, serum ferritin （SF）, serum iron （SI） and sTfR was determined. Physical performance tests included maximum oxygen consumption （VO2max） and maximum work time. Energy expenditure （EE） and daily physical activity were estimated by recording 24-h heart rate （HR）. Dietary intake was assessed with frequency questionnaires, and physical activity level was estimated with frequency and physical activity questionnaires. Results Severe iron deficiency （IDA） impaired the aerobic capacity and habitual physical activity. When fat-free mass （FFM） was considered, VO2max （VO2max/FFM） was significantly lower in the iron-marginal group than in the iron-adequate groups among girls （P=0.02）, but such a deference was not found among boys （P=0.28）. Aerobic activity and EE at leisure were significantly lower in the severe iron deficient group than in the marginal iron deficient and iron adequate groups. Net HR at leisure time was correlated with lib, log SF, body weight, and FFM （P〈0.05）. Conclusion The functional effect of iron deficiency on physical performance and habitual physical activity rely on the degree of current iron deficiency. Severe iron deficiency significantly impairs both aerobic capacity and habitual physical activity. Iron-marginal deficiency impairs VO2max/FFM in girls, rather than in boys.
文摘A population of migrant workers have appearing during the process of China’s urbanization,and is an important part of the society that cannot be ignored.In the process of integration into cities,the equal development between the rights and obligations of migrant workers is gaining attention.Especially,the issure of schooling of their children has garnered a lot of attention.All problems resulting from schooling of their children are rooted in the asynchronization between system changes and social development.Systematic barriers have become the crux of schooling problem of migrant workers’children.
文摘In the course of the large-scale migration to the cities of China＇s rural labor force over the past twenty years, most migrant workers have left their children behind in their hometown, though some children do follow their parents to the city. The issue of the upbringing and education of these children, whether ＂left behind＂ or ＂migrating,＂ has always been a major concern of society and the academic world. This article aims to understand the factors affecting whether these children ＂stay behind＂ in their hometown or ＂flow＂ to the city through analysis of the child-rearing and education patterns reflected in survey information on over 3,000 migrant workers in the Pearl River Delta in 2006. We find that, after controlling for individual and family factors, regional differences in migrant workers＇ origins remains an important factor influencing whether children ＂stay behind＂ or ＂migrate.＂ The causes and mechanisms behind the existence of ＂regional barriers＂ is an issue worth further exploration.
