As a result of China's one-child-per-family policy, concern has been expressed in China regarding the effect of that policy on children. One hundred and sixty-four children, aged 11-13 years, in the same grade in an elementary school in Guangzhou, China, completed the Self-Perception Profile for Children. Sociometric measures were also completed by the children and their teachers. Of the 164 children, 51 were from one-child families, while 113 had siblings. No significant differences were found on the six subscales of the Self-Perception Profile. Gender effects were noted, however. Student and teacher evaluations on the sociometric measures tended to favor the only children. The results of the study provide no support for existing stereotypes concerning only-children, one-child families in China.

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Background: Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). The species is also admired as a landscape plant with high developmental prospects and scientific research value. The A. truncatum chloroplast genome has recently been reported; however, the mitochondrial genome (mitogenome) is still unexplored.Results: We characterized the A. truncatum mitogenome, which was assembled using reads from Pacbio and Illumina sequencing platforms, and performed a comparative analysis against different species of Acer. The circular mitogenome of A. truncatum has a length of 791,052 bp, with a base composition of 27.11% A, 22.21% T, 22.79% G, and 22.89% C. The A. truncatum mitogenome contains 62 genes, including 35 protein-coding genes, 23 tRNA genes, and 4 rRNA genes. We also examined codon usage, sequence repeats, RNA editing, and selective pressure in the A. truncatum mitogenome. To determine the evolutionary and taxonomic status of A. truncatum, we conducted a phylogenetic analysis based on the mitogenomes of A. truncatum and 25 other taxa. We also analyzed gene migration from chloroplast and nuclear genomes to the mitogenome. Finally, we developed a novel NAD1 intron indel marker for distinguishing several Acer species. Conclusions: In this study, we assembled and annotated the mitogenome of A. truncatum, a woody oil-tree species producing nervonic acid. The results of our analyses provide comprehensive information on the A. truncatum mitogenome, which should facilitate evolutionary research and molecular barcoding in Acer.

With economic and cultural globalization, the trend of globalization of higher education becomes inevitable. Using the concept of competitiveness, the authors established a principal component analysis (PCA) model to examine disciplinary competitiveness in stomatology of various higher education institutions worldwide. A total of forty-four universities entered the inal list according to these calculations. Possible reasons for their selection were explored and explained at macro and micro levels. The authors further accessed various sources of data and summarized several suggestions for enhancing disciplinary competitiveness for other universities in pursuit of promoting their position in the global spectrum.H igher education is affected by both public and private pressures. On the public side, its expected outcomes include the transfer of knowledge, scientiic research, social service, and cultural inheritance. The private sector's inluence is relected in economic excludability and international competition. 1 The formation of an international market of higher education has led to opportunities for educational institutions, as well as challenges that must be faced, 2 such as 1) how to enhance mutual communication and cooperation; 2) how to adapt the content and method of teaching for international communication and development needs; and 3) how to establish good international relationships and produce direct and long-term economic beneits to their own countries. A study of disciplinary competitiveness, based on higher education internationalization, can be helpful in answering such questions.Two methods of analyzing disciplinary competitiveness appear in the literature. One is the model of example, which sets a speciic level as the example of comparison and analyzes a number of indicators accordingly. 3 The other is the ranking model, which quantitatively calculates scores of a series of indicators and ranks institutions accordingly. 4 Both models

In order to better use the discrete element method (DEM) to study the cutting and throwing process of King Grass (KG) stalk in mechanical harvesting, the DEM model and contact parameters of KG stalk were studied in this paper. By using the Multi-sphere method, the DEM model of KG stalk was established in EDEM software. Through the impact bounce test and slope sliding test, the stalk-steel coefficient of static friction, stalk-steel coefficient of restitution and stalk-stalk coefficient of restitution were calibrated as 0.372, 0.656 and 0.523, respectively. Based on the stacking test, using the response surface methodology, the optimal values of stalk-stalk coefficient of static friction, stalk-stalk coefficient of rolling friction, stalk-steel coefficient of rolling friction were calibrated as 0.393, 0.072 and 0.144, respectively. The throwing test bench of stalk was designed, and the actual and simulation throwing test were carried out. The relative error of throwing distance in bench test and simulation test under four throwing speeds was 1.15%, 7.76%, 8.88% and 10.46%, respectively. The throwing trajectory curve of the simulation test is consistent with that of the actual test, which verifies the accuracy of the DEM model and contact parameters of KG stalk.