A reassessment of trends and rural-urban/regional differences in the total fertility rate in China, 2000-2020: analyses of the 2020 national census data.

The decline in the total fertility rate (TFR) is a key driver of population change and has important implications for population health and social development. However, China's TFR has been a considerable controversy due to a lack of high-quality data. Therefore, this study used the 2020 national population census of China (NPCC) data and reverse survival method to reassess temporal trends in the TFRs and to reexamine rural-urban differences and regional variations in TFRs from 2000 to 2020 in China. Overall, there were significant gaps between the estimated and reported TFRs before 2020, and the estimated TFRs based on the 2020 NPCC data remained higher than the reported TFRs from government statistics. Although TFRs rebounded shortly in the years after the two-child policy, they have shown a wavelike decline since 2010. Additionally, the estimated TFRs fluctuated below 1.5 children per woman in urban areas compared to above 1.8 in rural areas, but the rural-urban differences continued to decrease. Regarding geographic regional variations, the estimated TFRs in all regions displayed a declining trend during 2010-2020, especially in rural areas. Large decreases of over 25% in TFRs occurred in the north, east, central, and northwest regions. In addition to changing the birth policy, the government and society should adopt comprehensive strategies, including reducing the costs of marriage, childbearing, and child education, as well as promoting work-family balance, to encourage and increase fertility levels.

Artemisiaqingheensis (Asteraceae, Anthemideae), a new species from Xinjiang, China.

Artemisiaqingheensis (Asteraceae, Anthemideae), a new species from Qinghe County, Xinjiang, China, is described and illustrated. We investigated its phylogenetic position and relationships with 35 other species of Artemisia using whole chloroplast DNA sequence data. The molecular phylogenetic results and morphological evidence (multi-layered involucral bracts and homogamous capitula with bisexual flowers) showed that the new species belongs to ArtemisiasubgenusSeriphidium. A diagnostic table and discussion of morphological characters are provided to distinguish the new species from A.amoena, A.gracilescens, A.lessingiana and A.terrae-albae.

Comparative analysis of complete Artemisia subgenus Seriphidium (Asteraceae: Anthemideae) chloroplast genomes: insights into structural divergence and phylogenetic relationships.

BACKGROUND: Artemisia subg. Seriphidium, one of the most species-diverse groups within Artemisia, grows mainly in arid or semi-arid regions in temperate climates. Some members have considerable medicinal, ecological, and economic value. Previous studies on this subgenus have been limited by a dearth of genetic information and inadequate sampling, hampering our understanding of their phylogenetics and evolutionary history. We therefore sequenced and compared the chloroplast genomes of this subgenus, and evaluated their phylogenetic relationships. RESULTS: We newly sequenced 18 chloroplast genomes of 16 subg. Seriphidium species and compared them with one previously published taxon. The chloroplast genomes, at 150,586-151,256 bp in length, comprised 133 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and one pseudogene, with GC content of 37.40-37.46%. Comparative analysis showed that genomic structures and gene order were relatively conserved, with only some variation in IR borders. A total of 2203 repeats (1385 SSRs and 818 LDRs) and 8 highly variable loci (trnK - rps16, trnE - ropB, trnT, ndhC - trnV, ndhF, rpl32 - trnL, ndhG - ndhI and ycf1) were detected in subg. Seriphidium chloroplast genomes. Phylogenetic analysis of the whole chloroplast genomes based on maximum likelihood and Bayesian inference analyses resolved subg. Seriphidium as polyphyletic, and segregated into two main clades, with the monospecific sect. Minchunensa embedded within sect. Seriphidium, suggesting that the whole chloroplast genomes can be used as molecular markers to infer the interspecific relationship of subg. Seriphidium taxa. CONCLUSION: Our findings reveal inconsistencies between the molecular phylogeny and traditional taxonomy of the subg. Seriphidium and provide new insights into the evolutionary development of this complex taxon. Meanwhile, the whole chloroplast genomes with sufficiently polymorphic can be used as superbarcodes to resolve interspecific relationships in subg. Seriphidium.

Longitudinal associations between traditional and cyberbullying victimization and depressive symptoms among young Chinese: A mediation analysis.

BACKGROUND: The impacts of bullying victimization on psychological health are long-lasting. However, the longitudinal mediating processes of the association between being bullied (traditionally and in a cyber context) and depressive symptoms of Chinese youth remain underexplored, including across the sexes. OBJECTIVE: This study investigated the longitudinal association between bullying victimization and depressive symptoms, including the mediating effects of physical health, healthy lifestyles, sleep quality, and academic achievements. Different pathways from traditional bullying and cyberbullying victimization regarding depressive symptoms were also explored, with a comparison across the sexes. PARTICIPANTS AND SETTING: Data were obtained from the China Education Panel Survey, and ninth graders aged approximately 15 years constituted the baseline cohort. METHODS: The baseline data and longitudinal data at two- and five-year follow-ups, respectively, were evaluated to estimate structural equation models. RESULTS: Baseline traditional bullying and cyberbullying victimization significantly predicted subsequent depressive symptoms at both follow-ups (P < 0.001). Being bullied also predicted worse healthy lifestyles, poorer sleep quality, and lower academic achievements (P < 0.05), all significantly correlated with the development of depressive symptoms (P < 0.001) regarding both bullying victimizations. Physical health was the mediator of the traditional bullying victimization-depressive symptoms linkage (P < 0.05). Female victims have a relatively higher risk of depression versus male victims, with different mediating pathways from victimization to depressive symptoms. CONCLUSIONS: Our findings strengthen the evidence of a longitudinal association between bullying victimization and depressive symptoms, provide new explanations for mechanisms of mediation, and highlight the importance of long-term comprehensive mental health interventions for victims of bullying.

The complete chloroplast genome of an endangered plant Artemisia borotalensis (Asteraceae) and phylogenetic analysis.

Artemisia borotalensis Poljakov is an endemic and endangered herb in China. In this study, we sequenced and analyzed the complete chloroplast genome of this species. Sequencing revealed the genome to be 151,179 bp in length, containing a large single copy region (82,862 bp), a small single copy region (18,377 bp), and a pair of inverted repeat regions (24,970 bp each). Our analyses demonstrated that it contained 133 genes, including 87 protein-coding genes, 37 transfer RNA genes, eight ribosomal RNA genes, and one pseudogene (ycf1). Furthermore, we found the genome to have an overall GC content of 37.4%. A phylogenetic analysis indicated that A. borotalensis and A. maritima clustered together as sister group to A. annua and A. fukudo clade.

Internet access, support, usage divides, and depressive symptoms among older adults in China: A nationally representative cross-sectional study.

OBJECTIVE: This study examines the associations between multiple sub-dimensions of the digital divide, including Internet access, support, usage divides, and depressive symptoms among older adults as well as the potential moderating effects of rural/urban status on these associations in China. METHODS: Data were obtained from the 2018 China Longitudinal Aging Social Survey, which provided a nationally representative sample of 11,418 participants aged 60 years and older. Multivariate linear regression models were used to analyze the associations between digital divide and depressive symptoms. The moderating role of rural/urban status was tested based on the interaction terms. RESULTS: After controlling for the covariates, access to Internet devices, support for Internet use from family, and using the Internet for communication, entertainment, or as instruments, were found to be significantly associated with a lower level of depressive symptoms (P < 0.05), and compared with no access to the Internet, accessing and using the Internet was significantly related to decreased depressive risks (P < 0.001), whereas access to the Internet with non-use was not statistically significant. Additionally, the associations between multidimensional aspects of the digital divide and depressive symptoms were moderated by rural/urban status, with these associations being significantly stronger among rural older adults (P < 0.05). CONCLUSIONS: This study highlights the importance of assessing the associations between digital divide and depressive symptoms from the multidimensional perspectives of access, support, and usage. Policy interventions targeting various aspects of the digital divide should be implemented to ensure active Internet engagement among older adults, especially those living in rural areas.

Chemical composition and phytotoxic activity of the essential oil of Artemisia sieversiana growing in Xinjiang, China.

The chemical profile and phytotoxic activity of the essential oil extracted from Artemisia sieversiana was investigated. In total 17 compounds were identified by GC/MS, representing 99.17% of the entire oil, among which α-thujone (64.46%) and eucalyptol (10.15%) were the most abundant constituents. The major components, their mixture as well as the essential oil exhibited significant phytotoxic activity against Amaranthus retroflexus, Medicago sativa, Poa annua and Pennisetum alopecuroides, with their IC50 values ranged from 1.55 ∼ 6.21 mg/mL (α-thujone), 1.42 ∼ 17.81 mg/mL (eucalyptol), 0.23 ∼ 1.05 mg/mL (the mixture), and 1.89 ∼ 4.69 mg/mL (the essential oil) on the four tested species. The mixture of the major constituents exerted more potent effect compared with each individual compound, indicating the possible involvement of synergistic effect of these two compounds.