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ABSTRACT A mechanized direct seeding of rice with less labor and water usage, has been widely adopted. However, this approach requires varieties that exhibit uniform seedling emergence. Mesocotyl elongation (ME) offers the main drive of fast emergence of rice seedlings from soils; nevertheless, its genetic basis remains unknown. Here, we identify a major rice quantitative trait locus Mesocotyl Elongation1 (qME1), an allele of the Green Revolution gene Semi‐Dwarf1 (SD1), encoding GA20‐oxidase for gibberellin (GA) biosynthesis. ME1 expression is strongly induced by soil depth and ethylene. When rice grains are direct‐seeded in soils, the ethylene core signaling factor OsEIL1 directly promotes ME1 transcription, accelerating bioactive GA biosynthesis. The GAs further degrade the DELLA protein SLENDER RICE 1 (SLR1), alleviating its inhibition of rice PHYTOCHROME‐INTERACTING FACTOR‐LIKE13 (OsPIL13) to activate the downstream expansion gene OsEXPA4 and ultimately promote rice seedling ME and emergence. The ancient traits of long mesocotyl and strong emergence ability in wild rice and landrace were gradually lost in company with the Green Revolution dwarf breeding process, and an elite ME1‐R allele (D349H) is found in some modern Geng varieties (long mesocotyl lengths) in northern China, which can be used in the direct seeding and dwarf breeding of Geng varieties. Furthermore, the ectopic and high expression of ME1 driven by mesocotyl‐specific promoters resulted in rice plants that could be direct‐seeded without obvious plant architecture or yield penalties. Collectively, we reveal the molecular mechanism of rice ME, and provide useful information for breeding new Green Revolution varieties with long mesocotyl suitable for direct‐seeding practice. [ABSTRACT FROM AUTHOR]

Hydroxygenkwanin (HGK) has an anticancer effect in a variety of tumors, but its role in osteosarcoma has not been explored. The purpose of the present study was to investigate the therapeutic effect of HGK on osteosarcoma and its specific molecular mechanism. Osteosarcoma cells (MG-63 and U2OS) treated with various concentrations of HGK were assigned to the treatment group. MTT, clone formation, wound healing and Transwell assays were performed to assess the viability, proliferation, migration, and invasion of MG-63 and U2OS cells. RT-qPCR was conducted to quantify the expression levels of of microRNA (miR)-320a and SRY-box transcription factor 9 (SOX9) in MG-63 and U2OS cells. The binding sites of miR-320a and SOX9 were predicted by starBase database, and verified using the dual-luciferase reporter assay. The expression levels of SOX9 and EMT-related proteins (N-cadherin, E-cadherin and vimentin) were detected by western blot analysis. HGK inhibited cell proliferation, migration, invasion, but promoted the expression of miR-320a in MG-63 and U2OS cells. Downregulation of miR-320a reversed the effects of HGK on proliferation, migration and invasion of MG-63 and U2OS cells, while upregulation of miR-320a had the opposite effect. HGK inhibited the expression of SOX9 by promoting the expression of miR-320a. Upregulation of SOX9 could partially reverse miR-320a-induced migration and invasion of MG-63 and U2OS cells. In addition, upregulation of miR-320a promoted E-cadherin expression and inhibited the expression of N-cadherin and vimentin, and the effect of miR-320a was also reversed by SOX9. In conclusion, HGK inhibited proliferation, migration and invasion of MG-63 and U2OS cells through the miR-320a/SOX9 axis. [ABSTRACT FROM AUTHOR]

The average symbol error probability (ASEP) and outage probability (OP) performance of mobile-to-mobile (M2M) senor networks employing transmit antenna selection (TAS) and selection combining (SC) over N-Nakagami fading channels are investigated in this paper. Based on the moment generating function (MGF) approach, the exact ASEP expressions are derived for several modulation schemes. The exact closed-form OP expressions are also presented. Then, the ASEP and OP performance under different conditions are evaluated through numerical simulations to confirm the accuracy of the analysis. The simulation results show that the number of antennas, the fading coefficient, and the number of cascaded components have an important influence on the ASEP and OP performance. [ABSTRACT FROM AUTHOR]

In order to study the mixing effect of natural gas calorific value control process, this study establishes the pipeline models for the mixing of the natural gas with different calorific value, meshing for the pipeline models, and caries out the numerical simulation on the natural gas mixing for one branch pipe and one manifold by using ANSYS Fluent 16.0 software. Based on the distribution characteristics of the velocity Held and the components Held in pipeline after natural gas mixing, the effect of natural gas mixing is compared and analyzed. In addition, the effect of natural gas mixing is evaluated by analyzing the percentage of the gas components at different pipe diameter positions after natural gas mixing. The numerical results show that for the branch pipe nixing flow, the mixing effect is not as good as that of the manifold because of the low-speed stagnation area at the mixing corner. For the branch pipe mixing flow, the mixing is relatively sufficient and the gas components are relatively inform at the distance of 15D=3 000 mm from the mixing center. However, with the development of flow in the downstream, the mixing is still in progress. For the mixing flow of the manifold, the direction of fluid flow is changed due to the existence of the manifold, which aggravates the mixing of natural gas flow. Therefore, the mixing effect is better. At the outlet of the manifold, that is, the inlet of the branch pipe, the gas components have reached a relatively uniform state. [ABSTRACT FROM AUTHOR]

Vehicular communication is an emergent technology with promising future, which can promote the development of mobile vehicular networks. Due to the broadcast nature of wireless channels, vehicular user mobility, and the diversity of vehicular network structures, the physical layer security issue of the mobile vehicular networks is a major concern. In this paper, the physical layer security performance of the mobile vehicular networks over N-Nakagami fading channels is investigated. Exact closed-form expressions for the probability of strictly positive secrecy capacity (SPSC), secrecy outage probability (SOP), and average secrecy capacity (ASC) are derived. Monte-Carlo simulation is used to verify the secrecy performance under different conditions. We further investigate the relationship between secrecy performance and the system parameters. [ABSTRACT FROM AUTHOR]