Robust Downlink Power Control in Wireless Cellular Systems

<p>A serious shortcoming of current downlink power control methods is that their performance may be severely degraded when the downlink channel information is known imprecisely at the transmitter. In this paper, a computationally and implementationally simple centralized downlink power control method is proposed for cellular wireless communication systems using code division multiple access (CDMA) or space division multiple access (SDMA). Our method provides a substantially improved robustness against imperfect knowledge of the wireless channel by means of maintaining the required quality of service for the worst-case channel uncertainty. In the SDMA case, the proposed technique can be straightforwardly combined with any of the existing transmit beamforming methods. Simulation results validate substantial robustness improvements achieved by our approach.</p

Evaluation of ERAP1 gene single nucleotide polymorphisms in immunomodulation of pro-inflammatory and anti-inflammatory cytokines profile in ankylosing spondylitis.

BACKGROUND: Ankylosing spondylitis (AS) is a prototype of chronic inflammatory arthritis termed seronegative spondyloarthropathies that typically affects the joints. Among the non-Human leukocyte antigen (HLA) loci, the strongest association has been observed with Endoplasmic reticulum aminopeptidase 1 (ERAP1) gene single nucleotide polymorphisms (SNPs). Moreover, the effect of ERAP1 gene SNPs on the pro-inflammatory and anti-inflammatory cytokines in AS disease has still been poorly elucidated. In this study, we aimed to determine the association of ERAP1 gene SNPs (rs30187 and rs2287987) with AS risk as well as their effect on the mRNA expression of pro-inflammatory and anti-inflammatory cytokines, with emphasis on the immunoregulation of the IL-17/IL-23 pathway, in an Iranian population. METHODS: We performed Single specific primer (SSP)-PCR for genotyping of 160 AS patients and 160 healthy controls. After isolation of peripheral blood mononuclear cells (PBMCs), total RNA of PBMCs was isolated, complementary DNA (cDNA) was synthesized, and quantitative analyses of mRNA expression of cytokines were performed by Real-time PCR for 40 HLA-B27 positive AS patients and 40 healthy individuals as controls. RESULTS: It was seen that T allele of rs30187 (OR = 1.54, 95% CI = 1.07-2.22, P = 0.017) and C allele of rs2287987 (OR 1.50, 95% CI 1.05-2.14, P = 0.024) were associated with the risk of AS. Both of these alleles were associated more strongly in the HLA-B27 positive AS patients. There was a significant overexpression of mRNAs of pro-inflammatory (IL-17A, IL-17F, IL-23, TNF-α and IFN-γ), while downregulation of anti-inflammatory cytokines (IL-10 and TGF-β) in PBMCs from 40 HLA-B27 positive AS patients in comparison to controls. AS patients with rs30187 SNP TT genotype expressed mRNA of IL-17A, IL-17F, and IL-23 significantly higher than patents with CT and CC genotypes for this SNP. CONCLUSIONS: This study represented the association of ERAP1 gene rs30187 and rs2287987 polymorphism with the risk of AS. Additionally, it appears that rs30187 polymorphism may be involved in the immunomodulation of the IL-17/IL-23 pathway in the AS disease

Reinfection risk of novel coronavirus (CoVID-19): A systematic ‎review of current evidence

International audienceThere is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients