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Natural rubber is an important national strategic and industrial raw material. The leaf anthracnose of rubber trees caused by the Colletotrichum species is one of the important factors restricting the yields of natural rubber. In this study, we isolated and identified strain Bacillus velezensis SF334, which exhibited significant antagonistic activity against both C. australisinense and C. siamense, the dominant species of Colletotrichum causing rubber tree leaf anthracnose in the Hainan province of China, from a pool of 223 bacterial strains. The cell suspensions of SF334 had a significant prevention effect for the leaf anthracnose of rubber trees, with an efficacy of 79.67% against C. siamense and 71.8% against C. australisinense. We demonstrated that SF334 can lead to the lysis of C. australisinense and C. siamense mycelia by causing mycelial expansion, resulting in mycelial rupture and subsequent death. B. velezensis SF334 also harbors some plant probiotic traits, such as secreting siderophore, protease, cellulase, pectinase, and the auxin of indole-3-acetic acid (IAA), and it has broad-spectrum antifungal activity against some important plant pathogenic fungi. The genome combined with comparative genomic analyses indicated that SF334 possesses most genes of the central metabolic and gene clusters of secondary metabolites in B. velezensis strains. To our knowledge, this is the first time a Bacillus velezensis strain has been reported as a promising biocontrol agent against the leaf anthracnose of rubber trees caused by C. siamense and C. australisinense. The results suggest that B. velezensis could be a potential candidate agent for the leaf anthracnose of rubber trees. [ABSTRACT FROM AUTHOR]

Abstract: In our geometric modeling, the inner layer of competent rock units in a detachment fold is approximated by several quadratic Bézier curves, which are joined together according to some geometrical rules, whereas the outer layers are calculated from the inner layer by parallel folding mechanism. In this model, an ideal fold is determined by three parameters: w, half of the distance between the locations of the fold''s two limbs where their dips are measured, θ 1 and θ 2, the dip angles of its two limbs. Two more parameters, respectively the axial lift-up ratio (u) and the limb elongation (E) may be used to change the ideal fold shape, if necessary. In kinematic modeling, downward deflection in the two synclines flanking an anticline is assumed to maintain constant area during folding. Both mathematical derivation and numerical simulation show that the reduction of the balanced area (A r) is directly proportional to the downward deflection angle (φ), and there is an approximate linear relationship between the detachment depth and the downward deflection angle. Based on this relationship, an iterative method is used to find the approximate value of φ. Furthermore, syn-folding growth strata can be modeled through calculating the velocity field above a detachment fold during folding. The method is applied to three seismic interpretation cross-sections of detachment folds respectively in Tarim Basin (western China), Zagros fold-belt (Iran) and Niger delta (western Africa). Variations of φ with the development of the detachment folds indicate the transfer of rock materials between the synclinal and anticlinal areas of the folds. [Copyright &y& Elsevier]

• R. pseudoacacia increased the fine particles and reduced coarse particles content. • R. pseudoacacia significantly reduced D 0 , D 1 , D 2 but increased Δα and Δf. • R. pseudoacacia suppress the coarsening and deterioration of the surface. The soil particle size distribution (PSD) is a fundamental physical property that can affect soil nutrients, soil structure characterization and soil hydraulic properties. However, the effect of plant expansion on soil PSD is not clear. Therefore, in this study, fractal theory was applied to quantitatively describe the PSD. On Mount Tai, artificial afforestation with Robinia pseudoacacia is helpful in restoring ecosystems and improving soil quality. However, clonal spread allows R. pseudoacacia to easily escape cultivation, leading to the formation of mixed forests. Therefore, exploring the effect of R. pseudoacacia expansion on soil PSD is important. The results show that 1) R. pseudoacacia expansion increased the clay and silt contents and reduced the sand content; 2) R. pseudoacacia expansion significantly reduced the capacity dimension, entropy dimension, and correlation dimension and increased the width and asymmetry of the singularity spectra but was unrelated to the entropy dimension/capacity dimension; and 3) the capacity dimension was significantly positively correlated with the sand content and significantly negatively correlated with the silt and clay contents, but the asymmetry of the soil PSD was inconsistent with the capacity dimension. In summary, R. pseudoacacia can reduce the heterogeneity of the PSD by increasing the distribution range and density of the PSD. Our results provide important insight into the effect of plant expansion on soil PSD. [ABSTRACT FROM AUTHOR]

Abstract: The greatest source of rock dust on rock roadway heading face is the roadheader. Overexposure to respirable rock dust can be a serious health hazard to roadheader operators and other workers. One of the rock roadways, named North Belt Main Entry (NBME), belonging to the underground coal mine Zhuxianzhuang, located in east China, is being driven by the EBZ318H roadheader. The cross-section of the roadway is 15.84m2, and the heading face has a high concentration of respirable rock dust. This paper presents a study of rock roadheader dust control by foam, taking into account the dust generation characteristics. A new foam preparation system and application method has been proposed and the dust suppression effect of foam has been assessed by dust concentration measurements taken at two points next to the roadheader operator in the previously mentioned underground coal mine. The results have shown that the foam dramatically reduced the rock dust concentrations. The roadheader operator’s respirable dust exposures were lowed from 540.2mg/m3 to 84.3mg/m3, and the dust suppression efficiency reached 84.4% on the NBME heading face. In addition, the visibility and environment of the heading face was significantly improved. It is concluded that the foam showed a significant improvement on the rock dust capture efficiency, and avoided the main deficiencies of conventional water sprays. [Copyright &y& Elsevier]