Research on the Structure and Characteristics of the Overall Social Network of Professional Athletes

This study chooses Chinese athletes as the research object and constructs the overall network of its social support network and discussion network. From the micro-, meso-, and macrolevels of the social network structure, the structure and characteristics of the athlete’s overall social network are analyzed. Through research, we found that there is embeddedness, that is, the relevance, between society support networks, between society discussion networks, and between society support networks and society discussion networks. At the same time, in the athletes’ social support network and social discussion network, some athletes have no contact with other players; they have no “power” in the group as well, so it is difficult to obtain network resources. We also found that there are small-world characteristics in the social network of Chinese professional athletes. The above findings will provide a deeper understanding of the peculiarities of athlete groups and have certain practical significance for improving athletes’ daily training and life management conditions

Copper-Catalyzed <i>gem</i>-Difluoroolefination of Diazo Compounds with TMSCF₃ via C–F Bond Cleavage

A novel Cu-catalyzed <i>gem</i>-difluoroolefination of diazo compounds is described. This transformation starts from readily available TMSCF₃ and diazo compounds, via trifluoromethylation followed by C–F bond cleavage, to afford the desired 1,1-difluoroalkene products

Identification of Elite <i>R</i>-Gene Combinations against Blast Disease in <i>Geng</i> Rice Varieties

Rice blast, caused by the Magnaporthe oryzae fungus, is one of the most devastating rice diseases worldwide. Developing resistant varieties by pyramiding different blast resistance (R) genes is an effective approach to control the disease. However, due to complex interactions among R genes and crop genetic backgrounds, different R-gene combinations may have varying effects on resistance. Here, we report the identification of two core R-gene combinations that will benefit the improvement of Geng (Japonica) rice blast resistance. We first evaluated 68 Geng rice cultivars at seedling stage by challenging with 58 M. oryzae isolates. To evaluate panicle blast resistance, we inoculated 190 Geng rice cultivars at boosting stage with five groups of mixed conidial suspensions (MCSs), with each containing 5–6 isolates. More than 60% cultivars displayed moderate or lower levels of susceptibility to panicle blast against the five MCSs. Most cultivars contained two to six R genes detected by the functional markers corresponding to 18 known R genes. Through multinomial logistics regression analysis, we found that Pi-zt, Pita, Pi3/5/I, and Pikh loci contributed significantly to seedling blast resistance, and Pita, Pi3/5/i, Pia, and Pit contributed significantly to panicle blast resistance. For gene combinations, Pita+Pi3/5/i and Pita+Pia yielded more stable pyramiding effects on panicle blast resistance against all five MCSs and were designated as core R-gene combinations. Up to 51.6% Geng cultivars in the Jiangsu area contained Pita, but less than 30% harbored either Pia or Pi3/5/i, leading to less cultivars containing Pita+Pia (15.8%) or Pita+Pi3/5/i (5.8%). Only a few varieties simultaneously contained Pia and Pi3/5/i, implying the opportunity to use hybrid breeding procedures to efficiently generate varieties with either Pita+Pia or Pita+Pi3/5/i. This study provides valuable information for breeders to develop Geng rice cultivars with high resistance to blast, especially panicle blast