This study aimed to determine the relationships between prenatal PM2.5 exposure and childhood growth trajectories during the first 6 years of life. A total of 47,625 pairs of mothers and children were recruited from a prospective birth cohort conducted between 2011 and 2013 in Wuhan, China, and followed for 6 years. We used the group-based trajectory models to classify the population into three trajectory groups: slow growth (n = 13,671, 28.7%), normal growth (n = 29,736, 62.4%), and rapid growth (n = 4218, 8.9%). Multinomial logistic regression models were used to determine the associations of prenatal PM2.5 exposure and childhood growth trajectories. Compared to normal growth trajectory, increased PM2.5 exposure in trimester 1, trimester 2 and the entire pregnancy showed significant associations with an increased risk of the slow growth trajectory but reduced the risk for the rapid growth trajectory, significant association of prenatal PM2.5 exposure with rapid growth trajectory was only observed in the trimester 3. Stratified analyses displayed relatively stronger associations among those mothers with maternal age over 35 years, pre-pregnancy BMI ≥ 25 kg/m2, and previous delivery experience. Prenatal exposure to PM2.5, particularly during the midpoint period of pregnancy, was more likely to have a slow growth trajectory and a lower risk of rapid growth trajectory. Maternal age, pre-pregnancy BMI, and previous delivery experience might modify these associations.

Throughout his career, John Schulenberg challenged us to understand adolescent development as the confluence of distal and proximal experiences along with critical transitions. Heeding this call, we examined whether chronic childhood peer victimization predicted adolescents\' depressive symptoms via early-emerging depression growth trajectories, continued victimization into adolescence, and stress-amplification at the middle school transition. Self-reported depressive symptoms and teacher-reported and self-reported peer victimization were obtained from 636 youth (338 girls; Mage = 7.96 years, 66.7% White, 21.7% Black, 11.6% other) in the 2nd-9th grades. Latent growth curve analyses revealed that, by 7th grade, chronic childhood peer victimization was associated with depressive symptoms only through an indirect association with peer victimization in adolescence, underscoring how interrelated historical and ongoing interpersonal stressors contribute to adolescent psychopathology.

Well-designed birth cohorts are able to estimate prevalence/distribution of various health events/outcomes, and to link early-life origins with adult health and function. The past two decades have seen a surge in the establishment of new birth cohorts and their accompanying research. We discussed distinct designs of current birth cohort studies, reviewed their achievements, and highlighted insights obtained from birth cohort studies, as well as challenges we are facing. Birth cohort studies are providing increasing opportunities to identify determining factors for short- and long-term health, yielding substantial evidence to uncover biological mechanisms of diseases and phenotypes, and providing further insights for public health. Dynamic monitoring, accurate measurements, long-term follow-ups, and collaborative efforts are warranted in new birth cohorts to elucidate the nature of life course relationships in contemporary generation.

To accurately explore the interaction mechanism between Escherichia coli and Staphylococcus aureus, we designed an ecological experiment to monoculture and co-culture E. coli and S. aureus. We co-cultured 45 strains of E. coli and S. aureus, as well as each species individually to measure growth over 36 h. We implemented a genome wide association study (GWAS) based on growth parameters (λ, R, A and s) to identify significant single nucleotide polymorphisms (SNPs) of the bacteria. Three commonly used growth regression equations, Logistic, Gompertz, and Richards, were used to fit the bacteria growth data of each strain. Then each equation\'s Akaike\'s information criterion (AIC) value was calculated as a commonly used information criterion. We used the optimal growth equation to estimate the four parameters above for strains in co-culture. By plotting the estimates for each parameter across two strains, we can visualize how growth parameters respond ecologically to environment stimuli. We verified that different genotypes of bacteria had different growth trajectories, although they were the same species. We reported 85 and 52 significant SNPs that were associated with interaction in E. coli and S. aureus, respectively. Many significant genes might play key roles in interaction, such as yjjW, dnaK, aceE, tatD, ftsA, rclR, ftsK, fepA in E. coli, and scdA, trpD, sdrD, SAOUHSC_01219 in S. aureus. Our study illustrated that there were multiple genes working together to affect bacterial interaction, and laid a solid foundation for the later study of more complex inter-bacterial interaction mechanisms.

Air pollution exposure during pregnancy has been documented to be associated with impaired fetal growth and adverse birth outcomes, but the evidence regarding the effects of air pollution on early childhood growth is still limited.
We aimed to explore the associations of exposure to air pollutants during pregnancy with childhood growth trajectories from birth to age of 6 years.
A prospective cohort study based on the administrative registration system was conducted covering 62,540 births in Wuhan, China between January 1, 2011 and December 31, 2013 and followed for 6 years. Inverse distance weighted method was used to estimate the concentrations of air pollutants exposure for pregnant women. Group-based trajectory models (GBTM) were used to identify growth patterns of children: slow growth, normal growth, and rapid growth. Multinomial logistic regression models were used to examine the associations between prenatal exposure to air pollutants and childhood growth trajectories with adjustment for maternal age, educational status, pre-pregnancy BMI, residential areas, gestational diabetes, birth type, gender of infant, and breastfeeding duration.
The mean (SD) of prenatal exposure concentrations for PM10, SO2, NO2, CO, and O3 were 107.9 (30.4), 32.8(12.6), 55.8(13.1), 1081.2(293.1), and 81.6(31.0) μg/m3 respectively. Compared with normal growth trajectory, increased PM10 and CO exposure were significantly associated with higher risk of slow growth trajectory but lower risk of rapid growth trajectory. An increase in prenatal exposure to NO2 significantly increased both the risk of slow growth trajectory and rapid growth trajectory. Increased prenatal SO2 exposure was significantly associated with rapid growth trajectory and was not associated with low growth trajectory. With O3 exposure levels increased, risk to be rapid growth trajectory decreased. Prenatal air pollutants exposure had a greater impact on childhood growth of children who were girls, and those mothers lived in rural areas and were normal weight before pregnancy.
High levels of air pollutants exposure during pregnancy were associated with the risk of being in a trajectory with the deviation of BMI gain from birth to 6 years old. These findings suggest that efforts to identify children at risk of growth deviation in early childhood should pay attention to environmental exposure during pregnancy for their mothers.