As a critical ecological barrier in China,the Qinling Mountains see their ecological functions significantly impaired by frequent shallow landslides.However,existing research on the distribution characteristics and dr...As a critical ecological barrier in China,the Qinling Mountains see their ecological functions significantly impaired by frequent shallow landslides.However,existing research on the distribution characteristics and driving mechanisms of such landslides remains relatively limited.To address this knowledge gap,the present study integrated data analysis,field investigations,and remote sensing interpretation to construct a landslide database for the core area of the Qinling Mountains,and systematically analyzed the spatial patterns,development characteristics,and environmental driving factors of shallow landslides.The results reveal that shallow landslides are predominantly small-to-medium in scale,concentrated in regions with an altitude of 800–1000 m and a slope gradient of approximately 30°,with a distinct tendency to develop on sunny(southfacing)slopes.The occurrence frequency of these landslides exhibits a significant positive correlation with the soil moisture content of the weathered layer and the degree of groundwater enrichment in the study area.Specifically,these landslides are mainly developed in bedrock fissure water zones and karst fissure water zones with favorable water-bearing capacity,indicating that rainfall and surface hydrological processes are the key triggering factors for shallow landslides.Notably,vegetation exerts a mediating role in the"vegetation-hydrology-landslide"system:shallow landslides occur most frequently in areas with artificial or shrub-grass vegetation,peaking at a moderate coverage of 50%–60%.This peak suggests that vegetation within this range is ineffective at regulating soil moisture,while the interaction between specific vegetation types and hydrological enrichment further exacerbates landslide risk.By prioritizing the weights of vegetation and hydrological factors,we enhanced the information quantity model,which significantly improved its performance and increased the AUC value to 0.83.These findings confirm the pivotal roles of vegetation and hydrological factors,thereby providing a robust scientific basis for targeted landslide prevention and control in this region.展开更多
Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limi...Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limited.Thus,it is necessary to measure breast milk energy and macronutrient concentrations of healthy urban Chinese mothers at different lactation stages,to expand the database of milk composition of Chinese population,and to examine whether dietary or other maternal factors can affect the levels of macronutrients in breast milk.Methods Breast milk of full expression of one side breast from 436 urban Chinese lactating mothers at 5-11 days,12-30 days,31-60 days,61-120 days,and 121-240 days postpartum was obtained at 9：00 a.m.to 11：00 a.m.Total energy,lactose,protein,and fat contents were measured.24-hour dietary recall was surveyed,and maternal nutrient intakes were analyzed.Results Milk composition changed over the course of lactation and large individual variations were documented.The concentrations were 61.3 kcal/dl for total energy,7.1 g/dl for lactose,0.9 g/dl for protein,and 3.4 g/dl for fat in mature milk.Stage of lactation was a strong factor affecting milk composition.Minimal evidence was found for associations between maternal current dietary intake and milk macronutrient concentration,consistently with prior research.Maternal body mass index （BMI） was positively associated with milk fat content,to a greater extent than did dietary intake.All other maternal characteristics were not significant for milk composition.Conclusion These findings suggest that milk composition is generally weakly associated with maternal factors except for stage of lactation,and is likely to be more susceptible to long-term maternal nutritional status than short-term dietary fluctuation.展开更多
Background Optimal mineral intakes are important for infant growth and development. However, data on mineral compositions of breast milk in Chinese women are scarce, and most were acquired before 1990. The objectives ...Background Optimal mineral intakes are important for infant growth and development. However, data on mineral compositions of breast milk in Chinese women are scarce, and most were acquired before 1990. The objectives of this study were three-fold： （1） to investigate the mineral compositions of Chinese healthy mothers＇ breast milk in different lactation stages; （2） to explore correlations among mineral concentrations in breast milk; and （3） to explore the associated factors affecting mineral compositions in breast milk. Methods The inductively coupled plasma mass spectrometry （ICP-MS） was used to analyze mineral concentrations in breast-milk of 444 healthy lactating women from three cities in China. A questionnaire was used to survey socio- demographic characteristics and pregnancy history. Food intakes by lactating women were measured using both food frequency questionnaire and one cycle of 24-hour dietary recall. Results Mineral compositions of breast milk varied in different regions. Concentrations of most minerals were higher in the first one or two months of lactation, and then decreased with time, except for magnesium and iron. Inter-mineral correlations existed among several minerals. The calcium-to-phosphorus ratio was above 2：1 in each lactation stage. Women with caesarean section had higher concentration of iodine in the transitional milk （349.9 pg/kg） compared to women with natural delivery （237.5 pg/kg, P〈0.001）. Dietary mineral intakes, supplements, food intake frequencies in the recent 6 months, maternal age and maternal BMI did not show significant correlations with concentrations of milk minerals （all P 〉0.05）. Conclusions Milk minerals decreased with time, and changed most rapidly in the first one or two months of lactation. Caesarean section might affect the iodine level in transitional milk. Chin Med J 2014;127 （14）： 2643-2648展开更多
基金supported by the National Key R&D Program of China(No.2024YFF1306502)three Special Programs of the National Natural Science Foundation of China(Nos.42341101,42442045,42307220)the Basic Scientific Research Business Funds of Central Universities(Nos.300102263401,300102265501,300102264103)。
文摘As a critical ecological barrier in China,the Qinling Mountains see their ecological functions significantly impaired by frequent shallow landslides.However,existing research on the distribution characteristics and driving mechanisms of such landslides remains relatively limited.To address this knowledge gap,the present study integrated data analysis,field investigations,and remote sensing interpretation to construct a landslide database for the core area of the Qinling Mountains,and systematically analyzed the spatial patterns,development characteristics,and environmental driving factors of shallow landslides.The results reveal that shallow landslides are predominantly small-to-medium in scale,concentrated in regions with an altitude of 800–1000 m and a slope gradient of approximately 30°,with a distinct tendency to develop on sunny(southfacing)slopes.The occurrence frequency of these landslides exhibits a significant positive correlation with the soil moisture content of the weathered layer and the degree of groundwater enrichment in the study area.Specifically,these landslides are mainly developed in bedrock fissure water zones and karst fissure water zones with favorable water-bearing capacity,indicating that rainfall and surface hydrological processes are the key triggering factors for shallow landslides.Notably,vegetation exerts a mediating role in the"vegetation-hydrology-landslide"system:shallow landslides occur most frequently in areas with artificial or shrub-grass vegetation,peaking at a moderate coverage of 50%–60%.This peak suggests that vegetation within this range is ineffective at regulating soil moisture,while the interaction between specific vegetation types and hydrological enrichment further exacerbates landslide risk.By prioritizing the weights of vegetation and hydrological factors,we enhanced the information quantity model,which significantly improved its performance and increased the AUC value to 0.83.These findings confirm the pivotal roles of vegetation and hydrological factors,thereby providing a robust scientific basis for targeted landslide prevention and control in this region.
文摘Background Infancy is a critical period of growth and physiological development,in which breast milk is the best source of nutrients.Compared to western countries,research on breast milk of Chinese population are limited.Thus,it is necessary to measure breast milk energy and macronutrient concentrations of healthy urban Chinese mothers at different lactation stages,to expand the database of milk composition of Chinese population,and to examine whether dietary or other maternal factors can affect the levels of macronutrients in breast milk.Methods Breast milk of full expression of one side breast from 436 urban Chinese lactating mothers at 5-11 days,12-30 days,31-60 days,61-120 days,and 121-240 days postpartum was obtained at 9：00 a.m.to 11：00 a.m.Total energy,lactose,protein,and fat contents were measured.24-hour dietary recall was surveyed,and maternal nutrient intakes were analyzed.Results Milk composition changed over the course of lactation and large individual variations were documented.The concentrations were 61.3 kcal/dl for total energy,7.1 g/dl for lactose,0.9 g/dl for protein,and 3.4 g/dl for fat in mature milk.Stage of lactation was a strong factor affecting milk composition.Minimal evidence was found for associations between maternal current dietary intake and milk macronutrient concentration,consistently with prior research.Maternal body mass index （BMI） was positively associated with milk fat content,to a greater extent than did dietary intake.All other maternal characteristics were not significant for milk composition.Conclusion These findings suggest that milk composition is generally weakly associated with maternal factors except for stage of lactation,and is likely to be more susceptible to long-term maternal nutritional status than short-term dietary fluctuation.
文摘Background Optimal mineral intakes are important for infant growth and development. However, data on mineral compositions of breast milk in Chinese women are scarce, and most were acquired before 1990. The objectives of this study were three-fold： （1） to investigate the mineral compositions of Chinese healthy mothers＇ breast milk in different lactation stages; （2） to explore correlations among mineral concentrations in breast milk; and （3） to explore the associated factors affecting mineral compositions in breast milk. Methods The inductively coupled plasma mass spectrometry （ICP-MS） was used to analyze mineral concentrations in breast-milk of 444 healthy lactating women from three cities in China. A questionnaire was used to survey socio- demographic characteristics and pregnancy history. Food intakes by lactating women were measured using both food frequency questionnaire and one cycle of 24-hour dietary recall. Results Mineral compositions of breast milk varied in different regions. Concentrations of most minerals were higher in the first one or two months of lactation, and then decreased with time, except for magnesium and iron. Inter-mineral correlations existed among several minerals. The calcium-to-phosphorus ratio was above 2：1 in each lactation stage. Women with caesarean section had higher concentration of iodine in the transitional milk （349.9 pg/kg） compared to women with natural delivery （237.5 pg/kg, P〈0.001）. Dietary mineral intakes, supplements, food intake frequencies in the recent 6 months, maternal age and maternal BMI did not show significant correlations with concentrations of milk minerals （all P 〉0.05）. Conclusions Milk minerals decreased with time, and changed most rapidly in the first one or two months of lactation. Caesarean section might affect the iodine level in transitional milk. Chin Med J 2014;127 （14）： 2643-2648
