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Previous studies have fully discussed the relationship between family socioeconomic status (SES) and achievement, but few of them regarded urban–rural differences as the moderating factor, which is an essential issue in urban–rural educational equalization in terms of educational outcomes. This study discusses the urban–rural heterogeneous effect of family SES on achievement and manifests the mediating role of education-related cultural factors. Based on the China Education Panel Survey data of 18,672 junior high school students, this study found the following: (1) family SES had a weaker positive effect among rural children than among urban children; (2) the urban–rural heterogeneous effect could be mediated by education-related cultural factors, i.e., learning environments and beliefs; and (3) in this regard, contemporary China is experiencing cultural reproduction rather than a cultural mobility mode. In Conclusion, although the urban–rural achievement gap will be maintained or even expanded in China, improving rural children's learning environments and beliefs opens up the possibility of alleviating disadvantages in achievement resulting from family socioeconomic disadvantages. Therefore, narrowing down the urban–rural achievement gap from a cultural perspective provides policy implications for educational development in rural areas. [ABSTRACT FROM AUTHOR]

Positive relationships between structural diversity and forest productivity have been documented in controlled experiments and early secondary forests, however, negative relationships have also been observed in late successional forests. The mechanisms causing observed relationships between structural diversity and productivity are not well‐established, but complementarity among crowns and asymmetric competition have been suggested.We used LiDAR and repeated census data to examine the relationship between canopy structural diversity and productivity in nine 1‐ha subtropical forest plots along a disturbance gradient in southeastern China. We quantified the relative importance of community composition, species diversity, canopy structural diversity, leaf area index (LAI) and disturbance regime on productivity using piecewise structural equation modelling. We also tested how vertical leaf area distribution affected productivity.Contrary to many prior observations, we found a negative relationship between canopy structural diversity and forest productivity. The negative effect may stem from asymmetric competition between overstorey and understorey leaves, leading to a lower leaf area efficiency (i.e. wood production per leaf area). Asymmetric competition was suggested by a negative relationship between understorey leaf area and total productivity. Changes in community composition over the disturbance gradient, but not species diversity, had a significant effect on productivity.Synthesis. Our study suggests that leaf area and canopy structural diversity have contrasting effects on productivity in this subtropical forest, and this needs to be considered when estimating rates of carbon sequestration in secondary forests. The negative effect of asymmetric competition on productivity is comparable to that of the shift in species composition over succession, highlighting the role of canopy structural diversity in shaping forest productivity. [ABSTRACT FROM AUTHOR]

Aims. To compare the clinical features of endometrial polyps (EPs) between patients with endometriosis (EM) (EM group) and without EM (non-EM group). Methods and Results. Seventy-six cases in the EM group and 133 cases in the non-EM group underwent laparotomy or hysteroscopy and laparoscopy; later, it was confirmed that the results by pathology from July 2002 to April 2008 in the Department of Gynecology and Obstetrics at the First Affiliated Hospital of Sun Yat-sen University. The recurrence of EPs was followed up after the surgery until 2013. The following parameters were assessed: age, gravidity, parity, infertility, and menstrual cycle changes, as well as polyps diameters, locations, number, association with the revised American Fertility Society (r-AFS) classification, and their recurrence. On review, 76 EPs cases of EM group histologically resembled EPs but the majority of EPs with EM occurred in primary infertility cases and in fewer pregnancy rate women who had stable and smaller EPs without association with the AFS stage. The recurrence rate of EPs in EM group was higher than that in non-EM group. Conclusion. It is important to identify whether infertile patients with EM are also having EPs. Removing any coexisting EPs via hysteroscopy would be clinically helpful in treating endometriosis-related infertility in these patients. [ABSTRACT FROM AUTHOR]

Background: Maternal body mass index is linked to short- and long-term unfavorable health outcomes both for child and mother. We conducted a systematic review and meta-analysis of population-based cohort studies to evaluate maternal BMI and the risk of harmful neonatal outcomes in China.Methods: Six databases identified 2454 articles; 46 met the inclusion criteria for this study. The dichotomous data on maternal BMI and harmful neonatal outcomes were extracted. Pooled statistics (odds ratios, ORs) were derived from Stata/SE, ver. 12.0. Sensitivity analyses assessed the robustness of the results. Meta-regression and subgroup meta-analyses explored heterogeneity.Results: The meta-analysis revealed that compared with normal BMI, high maternal BMI is associated with fetal overgrowth, defined as macrosomia ≥4000 g (OR 1.91, 95% CI 1.75-2.09); birth weight ≥ 90% for gestational age (OR 1.88, 95% CI 1.64-2.15); and increased risk of premature birth (OR 1.38, 95% CI 1.25-2.52) and neonatal asphyxia (OR 1.74, 95% CI 1.39-2.17). Maternal underweight increased the risk of low birth weight (OR 1.61, 95% CI 1.33-1.93) and small for gestational age (OR 1.75, 95% CI 1.51-2.02).Conclusions: Raised as well as low pre-pregnancy BMI is associated with adverse neonatal outcomes. Management of weight during pregnancy might help reduce their adverse neonatal outcomes in future intervention studies or programmes. [ABSTRACT FROM AUTHOR]

Novel H7N9 influenza virus transmitted from birds to human and, since March 2013, it has caused five epidemic waves in China. Although the evolution of H7N9 viruses has been investigated, the evolutionary changes associated with codon usage are still unclear. Herein, the codon usage pattern of two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), was studied to understand the evolutionary changes in relation to host, epidemic wave, and pathogenicity. Both genes displayed a low codon usage bias, with HA higher than NA. The codon usage was driven by mutation pressure and natural selection, although the main contributing factor was natural selection. Additionally, the codon adaptation index (CAI) and deoptimization (RCDI) illustrated the strong adaptability of H7N9 to Gallus gallus. Similarity index (SiD) analysis showed that Homo sapiens posed a stronger selection pressure than Gallus gallus. Thus, we assume that this may be related to the gradual adaptability of the virus to human. In addition, the host strong selection pressure was validated based on CpG dinucleotide content. In conclusion, this study analyzed the usage of codons of two genes of H7N9 and expanded our understanding of H7N9 host specificity. This aids into the development of control measures against H7N9 influenza virus. [ABSTRACT FROM AUTHOR]