31 research outputs found

    Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism

    Full text link
    We probe the two-scale factor universality hypothesis by evaluating, firstly explicitly and analytically at the one-loop order, the loop quantum corrections to the amplitude ratios for O(NN) λϕ4\lambda\phi^{4} scalar field theories with rotation symmetry-breaking in three distinct and independent methods in which the rotation symmetry-breaking mechanism is treated exactly. We show that the rotation symmetry-breaking amplitude ratios turn out to be identical in the three methods and equal to their respective rotation symmetry-breaking ones, although the amplitudes themselves, in general, depend on the method employed and on the rotation symmetry-breaking parameter. At the end, we show that all these results can be generalized, through an inductive process based on a general theorem emerging from the exact calculation, to any loop level and physically interpreted based on symmetry ideas.Comment: 17 pages, 3 figure

    Diversidade genética de bactérias isoladas de nódulos de feijão-caupi cultivado em solos sob diferentes sistemas em Juazeiro, BA.

    Get PDF
    O objetivo deste trabalho foi determinar a diversidade genética de bactérias isoladas de nódulos de feijão-caupi (Vigna unguiculata L. Walp.) em solos sob diferentes sistemas de cultivo desta leguminosa por meio do uso da técnica de IGS-RFLP

    Co-inoculation of two symbiotically efcient Bradyrhizobium strains improves cowpea development better than a single bacterium application.

    Get PDF
    The co-inoculation of Bradyrhizobium with other non-bradyrhizobial strains was already assessed on cowpea, but the co-inoculation of two Bradyrhizobium strains was not tested up to now. This study aimed to evaluate the cowpea growth, N accumulation, and Bradyrhizobium competitiveness of the elite strain B. pachyrhizi BR 3262 when co-inoculated with other efcient Bradyrhizobium from the Brazilian semiarid region. Three potted-plant experiments were carried out. In the frst assay, 35 efcient Bradyrhizobium isolates obtained from the semiarid region of Brazil were co-inoculated with the elite strains B. pachyrhizi BR 3262. The experiment was conducted in gnotobiotic conditions. The plant growth, nodulation, N nutritional variables, and nodular occupation were assessed. Under gnotobiotic and non-sterile soil conditions, ten selected bacteria plus the elite strain B. yuanmingense BR 3267 were used at the second and third experiments, respectively. The cowpea was inoculated with the 11 bacteria individually or co-inoculated with BR 3262. The plant growth and N nutritional variables were assessed. A double-layer medium spot method experiment was conducted to evaluate the interaction among the co-inoculated strains in standard and diluted YMA media. The co-inoculation treatments showed the best efciency when compared to the treatments inoculated solely with BR 3262. This strain occupied a low amount of cowpea nodules ranging from 5 to 67.5%. The treatments with lower BR 3262 nodule occupancy showed the best results for the shoot nitrogen accumulation. The culture experiment showed that four bacteria inhibited the growth of BR 3262. In contrast, seven strains from the soils of Brazilian semiarid region were benefted by the previous inoculation of this strain. In the second and third experiments, the results indicated that all 11 co-inoculated treatments were more efcient than the single inoculation, proofng the best performance of the dual inoculation of Bradyrhizobium on cowpea.Article: 4
    corecore