Search

AbstractCell migration plays important roles in many biological processes, but how migrating cells orchestrate intracellular molecules and subcellular structures to regulate their speed and direction is still not clear. Here, by characterizing the intracellular diffusion and the three-dimensional lamellipodium structures of fish keratocyte cells, we observe a strong positive correlation between the intracellular diffusion and cell migration speed and, more importantly, discover a switching of cell migration modes with reversible intracellular diffusion variation and lamellipodium structure deformation. Distinct from the normal fast mode, cells migrating in the newly-found slow mode have a deformed lamellipodium with swollen-up front and thinned-down rear, reduced intracellular diffusion and compartmentalized macromolecule distribution in the lamellipodium. Furthermore, in turning cells, both lamellipodium structure and intracellular diffusion dynamics are also changed, with left-right symmetry breaking. We propose a mechanism involving the front-localized actin polymerization and increased molecular crowding in the lamellipodium to explain how cells spatiotemporally coordinate the intracellular diffusion dynamics and the lamellipodium structure in regulating their migrations.

Maoze Gao,1,* Yaohui Fang,1,* Zhangrui Liu,1 Xinpeng Xu,1,2 Hua You,1,2 Qifeng Wu1 1School of Public Health, Nanjing Medical University, Nanjing, People’s Republic of China; 2Institute of Healthy Jiangsu Development, Nanjing Medical University, Nanjing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinpeng Xu, School of Public Health, Nanjing Medical University, Nanjing, 211166, People’s Republic of China, Email xuxinpeng@njmu.edu.cnBackground: Effective healthcare utilization throughout pregnancy is essential in protecting mother and child health, but the maternal healthcare utilization and its associated factors among migrant women are still underexplored.Methods: The data came from the 2018 China Migrants Dynamic Survey. Our analysis included 6337 pregnant migrant women. Prenatal healthcare utilization comprises receiving at least 5 antenatal care (ANC) times and establishing the maternal health record within the first 12 weeks of pregnancy. Postnatal healthcare utilization refers to whether an individual received a postpartum visit and a physical health examination within 28 days and 42 days following delivery. A multivariate binary logit model was employed to investigate the factors related to maternal healthcare utilization.Results: 67.15% of the 6337 participants established health records within the first 12 weeks of pregnancy, and 88.35% received at least five ANC visits. 76.88% and 84.20% of migrant pregnant women received a postpartum visit and a health examination respectively. Age was positively correlated with receiving at least five ANC visits (OR:1.245, 95% CI: 1.038– 1.493), a postpartum visit within 28 days (OR: 1.272, 95% CI: 1.107– 1.460) and a physical examination within 42 days after delivery (OR=1.174, 95% CI: 1.002– 1.376). Education, household income, health insurance and maternal health education were positively associated with prenatal and postnatal healthcare

CONTEXT: To avoid excessive chemical-fertilizer application and improve agricultural productivity in rice, a fertilizer recommendation system called Nutrient Expert® (NE) was designed. However, the ability of NE to balance yield, profitability and environmental sustainability in rice production needs to be further evaluated, as it is still difficult for farmers to assess the proper nitrogen (N) application rate. OBJECTIVE: The objective of this study was to demonstrate the advantages of the NE system in balancing yield, profitability and N loss in rice production, and recommend proper N application rates for different cropping seasons of rice. METHODS: This study describes results from field experiments conducted in five main rice cropping provinces from 2017 to 2020 in China, to investigate any advantages of NE compared with local farmers' practice (FP), and to determine the proper N application rates for different cropping seasons of rice. RESULTS AND CONCLUSIONS: Compared with FP, NE had 12.1% lower N-fertilizer application, but increased rice grain yield by 4.3% and net profit by 7.4%, and decreased yield-scaled N loss by 20.7%. We showed how yield, profitability and N loss were affected by N balance (i.e., N applied to the field minus N removed from the field by the harvested crop biomass), and quantified relationships between N balance and N application rate, and between N output and input. Based on relationships between N balance and N application rate, we recommend N application rates in a range from 122 to 214 kg ha−1, depending on cropping seasons of rice. We demonstrated that NE can simultaneously improve yield, profitability and environmental sustainability. SIGNIFICANCE: Our study provided quantitative support for NE-based recommendations on the N application rate for smallholders farming in different rice cropping systems, and these recommendations can serve as a reference for avoiding excessive N application rate in paddy fields in other regions with