RESUMEN
Ultra-reliable low-latency communication (URLLC) is one of the three usage scenarios anticipated for 5G, which plays an important role in advanced applications of vehicle-to-everything (V2X) communications. In this paper, the Stackelberg game-based power allocation problem was investigated in V2X communications underlaying cellular networks. Assuming that the macro-cellular base station (MBS) sets the interference prices to protect itself from the V2X users (VUEs), the Stackelberg game was adopted to analyze the interaction between MBS and VUEs, where the former acts as a leader and the latter act as followers. For MBS, we aimed at maximizing its utility from interference revenue while considering the cost of interference. Meanwhile, the VUEs aimed at maximizing their utilities per unit power consumption. We analyzed the Stackelberg model and obtained the optimal prices for MBS and optimal transmit powers for VUEs. Simulation results demonstrated the superiority of the proposed Stackelberg game-based power allocation scheme in comparison with the traditional power allocation strategy. Meanwhile, the proposed scheme achieved a better trade-off between economic profit and power consumption.
RESUMEN
Sequence analysis of the Nocardia essential secretory protein SecA1 gene (secA1) for species identification of 120 American Type Culture Collection (ATCC) and clinical isolates of Nocardia (16 species) was studied in comparison with 5'-end 606-bp 16S rRNA gene sequencing. Species determination by both methods was concordant for all 10 ATCC strains. secA1 gene sequencing provided the same species identification as 16S rRNA gene analysis for 94/110 (85.5%) clinical isolates. However, 40 (42.6%) isolates had sequences with <99.0% similarity to archived secA1 sequences for the species, including 29 Nocardia cyriacigeorgica (96.6 to 98.9% similarity) and 4 Nocardia veterana (91.5 to 98.9% similarity) strains. Discrepant species identification was obtained for 16 (14.5%) clinical isolates, including 13/23 Nocardia nova strains (identified as various Nocardia species by secA1 sequencing) and 1 isolate each of Nocardia abscessus (identified as Nocardia asiatica), Nocardia elegans (Nocardia africana), and Nocardia transvalensis (Nocardia blacklockiae); both secA1 gene sequence analysis and deduced amino acid sequence analysis determined the species to be different from those assigned by 16S rRNA gene sequencing. The secA1 locus showed high sequence diversity (66 sequence or genetic types versus 40 16S rRNA gene sequence types), which was highest for N. nova (14 secA1 sequence types), followed by Nocardia farcinica and N. veterana (n = 7 each); there was only a single sequence type among eight Nocardia paucivorans strains. The secA1 locus has potential for species identification as an adjunct to 16S rRNA gene sequencing but requires additional deduced amino acid sequence analysis. It may be a suitable marker for phylogenetic/subtyping studies.