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Self-incompatibility (SI) is a crucial mechanism that prevents self-fertilization and inbreeding in flowering plants. Citrus exhibits SI regulated by a polymorphic S -locus containing an S-RNase gene and multiple S -locus F-box (SLF) genes. It has been documented that S-RNase functions as the pistil S determinant, but there is no direct evidence that the SLF genes closely linked with S-RNase function as pollen S determinants in Citrus. This study assembled the genomes of two pummelo (Citrus grandis) plants, obtained three novel complete and well-annotated S -haplotypes, and isolated 36 SLF or SLF-like alleles on the S -loci. Phylogenetic analysis of 138 SLFs revealed that the SLF genes were classified into 12 types, including six types with divergent or missing alleles. Furthermore, transformation experiments verified that the conserved S6-SLF7a protein can lead to the transition of SI to self-compatibility by recognizing non-self S8-RNase in 'Mini-Citrus' plants (S 7 S 8 and S 8 S 29 , Fortunella hindsii), a model plant for citrus gene function studies. In vitro assays demonstrated interactions between SLFs of different S haplotypes and the Skp1–Cullin1–F-box subunit CgSSK1 protein. This study provides direct evidence that SLF controls the pollen function in Citrus , demonstrating its role in the 'non-self recognition' SI system. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to study the effects of different proportions of Zhangzagu straw instead of peanut vine on the growth performance, nutrients apparent digestibility, meat quality, and serum biochemical indexes of finishing sheep. Twenty-four healthy 'Du x Hu' hybrid finishing rams with the body weight of (32.73± 2.46) kg aged about three months were randomly divided into three groups, with eight replicates in each group and one sheep in each replicate. The control group only added peanut vine. In the experimental Group I, 50% Zhangzagu straw was used to replace peanut vine. In the experimental Group II, 80% Zhangzagu straw was used to replace peanut vine. The pre-feeding period was 10 days, and the formal trial period was 70 days. The results showed that compared with the control group, the average daily feed intake of Group I decreased significantly (P<0.05), and the apparent digestibility of neutral detergent fiber increased significantly (P<0.05). Compared with the control group, the L* value of flesh color in Group I significantly increased (P<0.05) and the shear force significantly decreased (P<0.05), the pH45 min value in Group II significantly increased (P<0.05) and the shear force value significantly decreased (P<0.05), while the L* value of flesh color in Group II was significantly lower than that of Group I (P<0.05). Compared with the control group, the levels of total protein (TP), alanine aminotransferase (ALT), and cholesterol (CHOL) were significantly increased in Group I (P<0.05), and the TP content in Group II increased significantly (P<0.05). The study indicates that replacing peanut vine with Zhangzagu straw has certain effects on the growth performance, nutrients apparent digestibility, meat quality, and serum biochemical indexes of finishing sheep, and 50% Zhangzagu straw instead of peanut vine has the best weight gain effect. [ABSTRACT FROM AUTHOR]

Based on linear materials, two kinds of equivalent tire models were proposed, which are single solid element structure and solid element + beam element mixed structure, taking TBR tire 11.00 R20 18 RP as the research object. The impact of different elastic modulus of each layer on the static stiffness of two equivalent models was analyzed using ANSYS. And on this basis, the parameter optimization analysis of elastic modulus of materials was carried out. Based on the optimization results, the modal property of the two equivalent models were studied, and the effective range of the equivalent models was analyzed by comparison with the experimental results. The was shown that the tire equivalent model composed of solid element + beam element mixed structure based on linear material can better simulate the static stiffness, tangential mode and axial mode of tire, but the radial mode frequency is relatively low; in the study in which only the radial property is concerned, such as in a vehicle-road coupling simulation, the radial mode frequency can be improved by reducing the density of the bundle layer, so that the equivalent model is more effective.

The anti-impact ability of shafting affects stability and security of the ship power transmission directly. Moreover, it also cannot be ignored that the rub-impact loads have influence on the torsion vibration of ship shafting. In order to solve the problem of engineering application of reliability assessment under rub-impact loads, a test rig with rubbing generator is established. By carrying out the integrative analysis, the torsional vibration characteristics, such as vibration amplitude and orbit of axle center under the rub impact load are studied. According to the rub-impact conditions obtained through numerical simulation, the experimental verification is carried out on the test rig with rubbing generator. The results show that it is not obvious the influence of rub-impact loads upon the shafting torsion vibration except in special working conditions, that can be simulated by the rubbing generator. The maximum amplitude of torsional vibration is influenced by the radial rigidity as well as the friction coefficient of rubbing body, and the degree of influence is difference under conditions of continuous rubbing and serious rubbing. By adjusting the rigidity of stern bearing, the influence of rub-impact upon shafting can be weaken, which provides a theoretical reference for the safety evaluation of ship shafting.

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