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Fine three-dimensional (3D) reconstruction of real forest scenes can provide a reference for forestry digitization and forestry resource management applications. Airborne LiDAR technology can provide valuable data for large-area forest scene reconstruction. This paper proposes a 3D reconstruction method for complex forest scenes with trees, shrubs, and grass, based on airborne LiDAR point clouds. First, forest vertical distribution characteristics are used to segment tree, shrub, and ground–grass points from an airborne LiDAR point cloud. For ground–grass points, a ground–grass grid model is constructed. For tree points, a method based on hierarchical canopy point fitting is proposed to construct a trunk model, and a crown model is constructed with the 3D α-shape algorithm. For shrub points, a shrub model is directly constructed based on the 3D α-shape algorithm. Finally, tree, shrub, and ground–grass models are spatially combined to achieve the reconstruction of real forest scenes. Taking six forest plots located in Hebei, Yunnan, and Guangxi provinces in China and Baden-Württemberg in Germany as study areas, experimental results show that the accuracy of individual tree segmentation reaches 87.32%, the accuracy of shrub segmentation reaches 60.00%, the height accuracy of the grass model is evaluated with an RMSE < 0.15 m, the volume accuracy of shrub and tree models is assessed with R2 > 0.848 and R2 > 0.904, respectively. Furthermore, we compared the model constructed in this study with simplified point cloud and voxel models. The results demonstrate that the proposed modeling approach can meet the demand for the high-accuracy and lightweight modeling of large-area forest scenes. [ABSTRACT FROM AUTHOR]

As global climate change continues, drought episodes have become increasingly frequent. Studying plant stress tolerance is urgently needed to ensure food security. The common ice plant is one of the model halophyte plants for plant stress biology research. This study aimed to investigate the functions of a newly discovered transcription factor, Homeobox 7 (HB7), from the ice plant in response to drought stress. An efficient Agrobacterium-mediated transformation method was established in the ice plant, where ectopic McHB7 expression may be sustained for four weeks. The McHB7 overexpression (OE) plants displayed drought tolerance, and the activities of redox enzymes and chlorophyll content in the OE plants were higher than the wild type. Quantitative proteomics revealed 1910 and 495 proteins significantly changed in the OE leaves compared to the wild type under the control and drought conditions, respectively. Most increased proteins were involved in the tricarboxylic acid cycle, photosynthesis, glycolysis, pyruvate metabolism, and oxidative phosphorylation pathways. Some were found to participate in abscisic acid signaling or response. Furthermore, the abscisic acid levels increased in the OE compared with the wild type. McHB7 was revealed to bind to the promoter motifs of Early Responsive to Dehydration genes and abscisic acid-responsive genes, and protein–protein interaction analysis revealed candidate proteins responsive to stresses and hormones (e.g., abscisic acid). To conclude, McHB7 may contribute to enhance plant drought tolerance through abscisic acid signaling. [ABSTRACT FROM AUTHOR]

To study the transformation and release of fuel K, the combustion of corn stalk and wheat straw were performed in a reactor with a fixed bed between 400–1000°C. Measurements of weight and elemental composition, chemical fractionation analysis, and low‐temperature ashing coupled with X‐ray diffraction (XRD) analysis were conducted on biomass and residual samples. The effects of biomass species, temperature and duration time of combustion, oxygen concentration, and pretreatment of water washing were evaluated. The results show that compared with wheat straw, corn stalk has a lower K release, which is much more sensitive to the combustion temperature than to the oxygen concentration. The inorganic potassium occurs as KClO3 and KClO4 in wheat straw and KCl and KClO4 in corn stalk. K2SO4 appears through sulphation of KCl as combustion happens at 800°C or above. When the combustion temperature reached 900°C for corn stalk and 1000°C for wheat straw, some KCl changed into K2Si2O5, which contains insoluble K. K2Ca(SO4)2 appears as corn stalk and wheat straw are burnt at 1000 and 900°C, respectively. Along with the proceeding of wheat straw combustion, more ion‐exchangeable and water‐soluble K transform to the insoluble K with the increasing temperature. The pretreatment of water washing removes nearly all the water‐soluble K from the corn stalk and significantly decreases the K release from 3.26–0.27 mg g−1 in quantity and from 26.74%–14.84% in ratio at 1000°C, respectively. [ABSTRACT FROM AUTHOR]

The low‐low temperature electrostatic precipitator (LLT‐ESP) has been applied in many power plants to improve the emission performance. In this study, a number of fix‐bed experiments were conducted, which simulated the operation condition of LLT‐ESP. The effect of chemical composition on the adsorption characteristics of ash samples and the agglomeration after adsorption were studied. The results show that the agglomeration of ash particles occurs in three forms, including agglomeration among small particles, adhesion of loose pellets to large particles, and agglomeration among large particles. The capacity of ash particles to adsorb sulphuric acid is less affected by the increase of added amounts of NaCl or KCl. At the same time, the added amount of NaCl or KCl also has little effect on the agglomeration degree of ash particles. The addition of MgO, CaO, Fe2O3, Na2CO3, or K2CO3 from 0% to 13.3%, 22.4%, 23.9%, 18.4%, or 14.2%, promotes the adsorption of sulphuric acid by ash particles from 1.95 mg g−1 to 7.33, 7.71, 6.72, 5.1, or 5.44 mg g−1 (based on sulphur content), respectively, thereby promoting the agglomeration between ash particles. As the addition amount increases, the agglomeration phenomenon among particles becomes more conspicuous. The form of agglomeration changes from agglomeration among small particles to agglomeration among large particles. In addition, the addition of MgO or CaO has great influence on the adsorption and agglomeration. [ABSTRACT FROM AUTHOR]

Uncontrolled metastasis significantly contributes to high lethality of patients suffering from ovarian cancer. To date, the detailed molecular mechanisms which account for ovarian tumor cell spreading and metastasis remain largely unknown. In a recent study, we have demonstrated that aberrantly high expression of the non-receptor tyrosine kinase FER is responsible for ovarian tumor cell metastasis both in vitro and in vivo. Mechanistically, we indentified Hepatocyte Growth Factor Receptor HGFR/MET as a novel substrate of FER, and through which the kinase FER modulates ovarian cancer cell motility and invasiveness in a ligand-independent manner. We also observed aberrantly high expression of PAK1 kinase in cancer cells, and RNAi-mediated knockdown of FER kinase inactivated the RAC1-PAK1 signaling pathway and decreased metastatic potential of CAOV4 ovarian cancer cells. Overall, our study revealed a previously uncharacterized, pro-metastatic role of the kinase FER in ovarian cancer through the MET-RAC1-PAK1 pathway. Further efforts are essential to investigating beneficial outcomes towards targeting the RAC1-PAK1 signaling pathway in reducing metastatic burden of this deadly disease. [ABSTRACT FROM AUTHOR]