To examine the reciprocal relations between teacher-child relationships and children's behavior problems, the authors analyzed cross-lagged longitudinal data on teacher-child relationships and children's internalizing and externalizing problems using a structural equation modeling approach. The homeroom teachers of 105 first-year preschoolers aged 2-3 years filled in the Student-Teacher Relationship Scale and the Child Behavior Checklist/2-3, first at 3 months after the children's preschool entrance and then at the end of the first preschool year. Results showed significant cross-wave reciprocal relations between externalizing problems and teacher-child conflict and significant cross-wave relation from early internalizing problems to later teacher-child conflict. However, the cross-wave associations between internalizing and externalizing problems and teacher-child closeness were not significant.

Mangroves, as a blue carbon reservoir, provide an environment for a variety of microorganisms. Mangroves lie in special locations connecting coastal and estuarine areas and experience fluctuating conditions, which are expected to intensify with climate change, creating a need to better understand the relative roles of stochastic and deterministic processes in shaping microbial community assembly. Here, a study of microbial communities inhabiting mangrove sediments across southeastern China, spanning mangroves in six nature reserves, was conducted. We performed high-throughput DNA sequencing of these samples and compared them with data of 1,370 sediment samples collected from the Earth Microbiome Project (EMP) to compare the microbial diversity of mangroves with that of other biomes. Our results showed that prokaryotic alpha diversity in mangroves was significantly higher than that in other biomes and that microbial beta diversity generally clustered according to biome types. The core operational taxonomic units (OTUs) in mangroves were mostly assigned to Gammaproteobacteria, Deltaproteobacteria, Chloroflexi, and Euryarchaeota. The majority of beta nearest-taxon index values were higher than 2, indicating that community assembly in mangroves was better explained through a deterministic process than through a stochastic process. Mean annual precipitation (MAP) and total organic carbon (TOC) were main deterministic factors explaining variation in the microbial community. This study fills a gap in addressing the unique microbial diversity of mangrove ecosystems and their microbial community assembly mechanisms. IMPORTANCE Understanding the underlying mechanisms of microbial community assembly patterns is a vital issue in microbial ecology. Mangroves, as an important and special ecosystem, provide a unique environment for examining the relative importance of stochastic and deterministic processes. We made the first global-scale comparison and found that microbial diversity was significantly different in mangrove sediments compared to that of other biomes. Furthermore, our results suggest that a deterministic process is more important in shaping microbial community assembly in mangroves.

Plants harbors complex and variable microbial communities. Endophytic bacteria play an important function and potential role more effectively in developing sustainable systems of crop production. To examine how endophytic bacteria in sugar beet (Beta vulgaris L.) vary across both host growth period and location, PCR-based Illumina was applied to revealed the diversity and stability of endophytic bacteria in sugar beet on the north slope of Tianshan mountain, China. A total of 60.84 M effective sequences of 16S rRNA gene V3 region were obtained from sugar beet samples. These sequences revealed huge amount of operational taxonomic units (OTUs) in sugar beet, that is, 19-121 OTUs in a beet sample, at 3 % cutoff level and sequencing depth of 30,000 sequences. We identified 13 classes from the resulting 449,585 sequences. Alphaproteobacteria were the dominant class in all sugar beets, followed by Acidobacteria, Gemmatimonadetes and Actinobacteria. A marked difference in the diversity of endophytic bacteria in sugar beet for different growth periods was evident. The greatest number of OTUs was detected during rossette formation (109 OTUs) and tuber growth (146 OTUs). Endophytic bacteria diversity was reduced during seedling growth (66 OTUs) and sucrose accumulation (95 OTUs). Forty-three OTUs were common to all four periods. There were more tags of Alphaproteobacteria and Gammaproteobacteria in Shihezi than in Changji. The dynamics of endophytic bacteria communities were influenced by plant genotype and plant growth stage. To the best of our knowledge, this study is the first application of PCR-based Illumina pyrosequencing to characterize and compare multiple sugar beet samples.

Two studies examined the relationship between preschool experiences and the early academic achievement of rural Chinese children. In both Study 1 (n = 165) and Study 2 (n = 205), the school preparedness, and the literacy and mathematics attainment of first graders with different preschool experiences (kindergarten, separate pre-primary class, "sitting-in" a Grade 1 class, no preschool experience) were assessed. In Study 1, attainment was evaluated using end-of-semester examinations designed by local educational authorities; whereas in Study 2, better-constructed and identical tests were administered at the beginning and end of the academic year. Further, in Study 2, the different types of preschool programs attended by participating children were directly observed. Findings from both studies showed that children with developmentally appropriate preschool experiences (kindergartens or separate pre-primary classes) had higher school readiness scores than other children. Results from Study 2 also indicated that (i) disparities in children's school attainment were associated with the type of their preschool experience; and (ii) children from the developmentally appropriate kindergarten program showed higher mathematics and literacy achievement at the end of Grade 1 than children who merely "sat in" Grade 1 classes or had no preschool experience. Implications of the findings for the scaling up of preschool services in rural China are discussed.