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With the development of urbanization, a large number of village settlements have disappeared. As important carriers of ethnic and cultural heritage, village settlements are important for the continuation of folk culture and farming spirit. Building a regional ecological security pattern helps to protect the integrity of village settlements and promote the sustainable development of the Chinese nation. In this work, the importance of ecosystem services was first obtained by using the Integrated Valuation of Ecosystem Services and Tradeoffs model (In-VEST) and the revised universal soil loss equation model (RUSLE) to evaluate the regional ecosystem services in the southeastern region of Chongqing (SRC). Then, the ecological importance evaluation results were combined with the sensory evaluation results to derive ecological conservation importance areas and identify ecological source points in their high-value areas. Finally, the ecological corridors were obtained by the minimum cumulative resistance model (MCR). The regional ecological security pattern was constructed, i.e., the triangular protection area strategy of "one screen, one belt, and three cores". The results show the following: the total area of ecological source sites larger than 20 km2 in SRC is 436.02 km2, accounting for 2.28% of the area of SRC. The largest ecological patch is 69.93 km2, accounting for 16.04% of the total area of ecological source sites. Thirteen ecological source sites were identified as follows: four in Youyang County, three in Shizhu County, three in Wulong County, and one in Pengshui County. There are 78 ecological corridors with a total length of 4832.82 km, including 32 important ecological corridors with a length of about 1544.53 km and 46 potential ecological corridors with a length of about 3288.29 km. Based on the minimum cumulative model constructed by eight resistance factors, the spatial variation of the ecological resistance surface was analyzed, showing a trend of being high in the west and central part and low in the surrounding area. There are one high-value area of the resistance surface of Wulong County Nature Reserve and one high-value area of ecological sensitivity that overlap to the extreme, and which should be given sufficient protection attention. The core protected areas consist of three mountains including the Qiyao Mountain Range, the Wuling Mountain Range, and the Wulong County Nature Reserve. The ecological security pattern in SRC based on the mode of "source–ecological corridor–ecological node" can identify important ecological function areas, providing scientific guidance for sustainable development and ecological security protection in the ethnic village settlements in China. [ABSTRACT FROM AUTHOR]

Volatile ester compounds are important contributors to the flavor of strawberry, which affect consumer preference. Here, the GC-MS results showed that volatile esters are the basic aroma components of strawberry, banana, apple, pear, and peach, and the volatile esters were significantly accumulated with the maturation of strawberry fruits. The main purpose of this study is to discuss the relationship between carboxylesterases (CXEs) and the accumulation of volatile ester components in strawberries. FaCXE2 and FaCXE3 were found to have the activity of hydrolyzing hexyl acetate, Z-3-hexenyl acetate, and E-2-hexenyl acetate to the corresponding alcohols. The enzyme kinetics results showed that FaCXE3 had the higher affinity for hexyl acetate, E-2-hexenyl acetate, and Z-3-hexenyl acetate compared with FaCXE2. The volatile esters were mainly accumulated at the maturity stages in strawberry fruits, less at the early stages, and the least during the following maturation stages. The expression of FaCXE2 gradually increased with fruit ripening and the expression level of FaCXE3 showed a decreasing trend, which suggested the complexity of the true function of CXEs. The transient expression of FaCXE2 and FaCXE3 genes in strawberry fruits resulted in a significantly decreased content of volatile esters, such as Z-3-hexenyl acetate, methyl hexanoate, methyl butyrate, and other volatile esters. Taken together, FaCXE2 and FaCXE3 are indeed involved in the regulation of the synthesis and degradation of strawberry volatile esters. [ABSTRACT FROM AUTHOR]

Icing on transmission lines might lead to ice flashovers of insulators, collapse of towers, tripping faults of transmission lines, and other accidents. Shed spacing and shed overhang of insulators are clues for evaluating the probability of ice flashover. This paper researches imageprocessing methods for the natural icing of in-service glass insulators. Calculation methods of graphical shed spacing and graphical shed overhang are proposed via recognizing the convexity defects of the contours of an icing insulator string based on the GrabCut segmentation algorithm. The experiments are carried out with image data from our climatic chamber and the China Southern Power Grid Disaster (Icing) Warning System of Transmission Lines. The results show that the graphical shed overhang of insulators show evident change due to icing. This method can recognize the most serious icing conditions where the insulator sheds are completely bridged. Also, it can detect bridging positions including the left side, right side, or both sides of the insulator strings in the images. [ABSTRACT FROM AUTHOR]

Dihydroorotate dehydrogenase (DHODH), in the de novo pyrimidine biosynthetic pathway, is the fourth enzyme of pyrimidine synthesis and is used to oxidize dihydroorotate and hence to orotat. We cloned and characterized here the dhod of silkworms, Bombyx mori. The full-length cDNA sequence of dhod is 1339 bp, including an open reading frame (ORF) of 1173 bp that encoded a 390 amino acid protein. And two domains were involved in the Dihydroorotate dehydrogenase amino acid sequence of silkworms, Bombyx mori (BmDHODH), namely a DHO_dh domain and a transmembrane domain in N-termina. The silkworm dhod is expressed throughout development and in nine tissues. Moreover, knockdown of the silkworm dhod gene reduced cell growth and proliferation through G2/M phase cell cycle arrest. Similarly, DHODH inhibitor (leflunomide) also reduced cell growth and proliferation, with a significant decrease of cyclin B and cdk2. DHODH is the fourth enzyme of pyrimidine synthesis, so we also found that leflunomide can inhibit, at least in part, the endomitotic DNA replication in silk glands cells. These findings demonstrate that downregulation of BmDHODH inhibits cell growth and proliferation in silkworm cells, and the endomitotic DNA replication in silk gland cells. [ABSTRACT FROM AUTHOR]

Flavan-3-ols and oligomeric proanthocyanidins (PAs) are the main nutritional polyphenols in green tea (Camellia sinensis), which provide numerous benefits to human health. To date, the regulatory mechanism of flavan-3-ol biosynthesis in green tea remains open to study. Herein, we report the characterization of a C. sinensis tryptophan-aspartic acid repeat protein (CsWD40) that interacts with myeloblastosis (MYB) and basic helix-loop-helix (bHLH) transcription factors (TFs) to regulate the biosynthesis of flavan-3-ols. Full length CsWD40 cDNA was cloned from leaves and was deduced to encode 342 amino acids. An in vitro yeast two-hybrid assay demonstrated that CsWD40 interacted with two bHLH TFs (CsGL3 and CsTT8) and two MYB TFs (CsAN2 and CsMYB5e). The overexpression of CsWD40 in Arabidopsis thaliana transparent testa glabra 1 (ttg1) restored normal trichome and seed coat development. Ectopic expression of CsWD40 alone in tobacco resulted in a significant increase in the anthocyanins of transgenic petals. CsWD40 was then coexpressed with CsMYB5e in tobacco plants to increase levels of both anthocyanins and PAs. Furthermore, gene expression analysis revealed that CsWD40 expression in tea plants could be induced by several abiotic stresses. Taken together, these data provide solid evidence that CsWD40 partners with bHLH and MYB TFs to form ternary WBM complexes to regulate anthocyanin, PA biosynthesis, and trichome development. [ABSTRACT FROM AUTHOR]