Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age

<p>Abstract</p> <p>Background</p> <p>The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA) derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far.</p> <p>Results</p> <p>Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C) and the West Eurasian haplogroups (H and K), whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals.</p> <p>Conclusion</p> <p>Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin.</p

Whole-genome sequencing of <em>Oryza brachyantha</em> reveals mechanisms underlying <em>Oryza</em> genome evolution

The wild species of the genus Oryza contain a largely untapped reservoir of agronomically important genes for rice improvement. Here we report the 261-Mb de novo assembled genome sequence of Oryza brachyantha. Low activity of long-terminal repeat retrotransposons and massive internal deletions of ancient long-terminal repeat elements lead to the compact genome of Oryza brachyantha. We model 32,038 protein-coding genes in the Oryza brachyantha genome, of which only 70% are located in collinear positions in comparison with the rice genome. Analysing breakpoints of non-collinear genes suggests that double-strand break repair through non-homologous end joining has an important role in gene movement and erosion of collinearity in the Oryza genomes. Transition of euchromatin to heterochromatin in the rice genome is accompanied by segmental and tandem duplications, further expanded by transposable element insertions. The high-quality reference genome sequence of Oryza brachyantha provides an important resource for functional and evolutionary studies in the genus Oryza

Innovative measurement, trade-off-synergy relationship and influencing factors for agricultural net carbon emissions and effective supply of agricultural products in China

Sensitive zone of global climate change has been formed in China, and it has become a hot topic how can agriculture ensure food security and the supply of important agricultural products while achieving the “Dual Carbon” goal in the country. Based on such background, this paper uses the IPCC carbon emission calculation method, environmental input-output model and economic-water-carbon coefficient method to measure agricultural net carbon emissions, adopts bivariate spatial auto-correlation analysis and SYS-GMM to explore separately the relationship between agricultural net carbon emissions and effective supply of agricultural products, as well as the carbon reduction effect, growth effect and reasonable range of green technology innovation. The results show that: (1) China's agricultural net carbon emissions reveal a spatial distribution of “higher in the east than in the west than in the center” and a temporal characteristic of increasing year by year; China's effective supply of agricultural products shows an increasing trend and a spatial distribution of “higher in the east than in the center than in the west” in 2006–2012 and “higher in the east than in the west than in the center” in 2013–2020. (2) In 2006, 2010, 2015 and 2020, the number of provinces that belong to low-low agglomeration trade-off zone, low-high agglomeration synergy zone, non-significant zone, high-low agglomeration non-trade-off-synergy zone and high-high agglomeration trade-off zone averagely accounted for 12.500 %, 30.000 %, 26.667 %, 9.167 % and 21.667 % of the totality, respectively. (3) The carbon reduction and production growth effects of green technology innovation both show an inverted “U-shape”, and green technology innovation is conducive to both reducing agricultural net carbon emissions and improving supply of agricultural products when it is within a reasonable range of greater than 0.930. (4) Green technology innovation not only has significant spatial and temporal heterogeneity impact, but also exhibits a differential effect on productive agricultural carbon emissions, agricultural trade carbon emissions, agricultural carbon sinks, total output of agricultural products and agricultural net imports in international trade. Therefore, it is proposed that China should establish and improve green technology innovation incubation platforms, guide all participants to ensure the investment and application of green technology products within a reasonable range, formulate and implement regional differential policies and plan in accordance with local conditions, drive ultimately coordinated promotion of agricultural carbon emission reduction and product supply guarantee and lay an important foundation for achieving high-quality economic development and efficient ecological protection

Antibacterial Activities of Poly(amidoamine) Dendrimers Terminated with Amino and Poly(ethylene glycol) Groups

Poly(amidoamine) (PAMAM) dendrimer derivatives have been investigated for their biological applications, especially for delivery of drugs, including antimicrobial drugs to eukaryotic cells, but their effects on bacterial cells are largely unexplored. Herein we report that amino-terminated PAMAM dendrimers are highly toxic to the common Gram-negative pathogen Pseudomonas aeruginosa. The concentration that kills 50% of the bacteria (EC50) was in the range of ∼0.9−1.5 μg/mL for the generation 5, amino-terminated dendrimers with or without partial (43%) coating of poly(ethylene glycol) (PEG). These EC50 values were lower than that (∼1.9−2.8 μg/mL) for LL-37, a potent antimicrobial peptide expressed in a variety of epithelia. On the contrary, the dendrimers were far less toxic (EC50 > 21 μg/mL) to the Gram-positive pathogen Staphylococcus aureus than LL-37 (EC50 = ∼1.9 μg/mL). In agreement with the previous studies on other cell types, the dendrimers were not cytotoxic to human corneal epithelial cells at the concentrations that were toxic to P. aeruginosa. Our findings indicate that amino-terminated PAMAM dendrimers and their partially PEG-coated derivatives possess attractive antimicrobial properties, particularly against Gram-negative bacteria, thus expanding the potential biological application of the dendrimers