Downlink channel access performance of NR-U: Impact of numerology and mini-slots on coexistence with Wi-Fi in the 5 GHz band

Coexistence between cellular systems and Wi-Fi gained the attention of the research community when LTE License Assisted Access (LAA) entered the unlicensed band. The recent introduction of NR-U as part of 5G introduces new coexistence opportunities because it implements scalable numerology (flexible subcarrier spacing and OFDM symbol lengths), and non-slot based scheduling (mini-slots), which considerably impact channel access. This paper analyzes the impact of NR-U settings on its coexistence with Wi-Fi networks and compares it with LAA operation using simulations and experiments. First, we propose a downlink channel access simulation model, which addresses the problem of the dependency and non-uniformity of transmission attempts of different nodes, as a result of the synchronization mechanism introduced by NR-U. Second, we validate the accuracy of the proposed model using FPGA-based LAA, NR-U, and Wi-Fi prototypes with over-the-air transmissions. Additionally, we show that replacing LAA with NR-U would not only allow to overcome the problem of bandwidth wastage caused by reservation signals but also, in some cases, to preserve fairness in channel access for both scheduled and random-access systems. Finally, we conclude that fair coexistence of the aforementioned systems in unlicensed bands is not guaranteed in general, and novel mechanisms are necessary for improving the sharing of resources between scheduled and contention-based technologies

Combined application of bacteriophages with a competitive exclusion culture and carvacrol with organic acids can reduce Campylobacter in primary broiler production

For reducing Campylobacter (C.) in the food production chain and thus the risk to the consumer, the combined application of different measures as a multiple-hurdle approach is currently under discussion. This is the first study to investigate possible synergistic activities in vivo, aiming at reducing intestinal C. jejuni counts by administering (i) bacteriophages (phages) in combination with a competitive exclusion (CE) product and (ii) carvacrol combined with organic acids. The combined application of the two selected phages (Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1) and the CE product significantly reduced C. jejuni loads by 1.0 log10 in cecal and colonic contents as well as in cloacal swabs at the end of the trial (33 and 34 days post hatch). The proportion of bacterial isolates showing reduced phage susceptibility ranged from 10.9% (isolates from cecal content) to 47.8% (isolates from cloacal swabs 32 days post hatch) for the Fletchervirus phage, while all tested isolates remained susceptible to the Firehammervirus phage. The use of carvacrol combined with an organic acid blend (sorbic acid, benzoic acid, propionic acid, and acetic acid) significantly reduced Campylobacter counts by 1.0 log10 in cloacal swabs on day 30 only

Weak-localization corrections to the conductivity of double quantum wells

The weak-localization contribution \delta\sigma(B) to the conductivity of a tunnel-coupled double-layer electron system is evaluated and its behavior in weak magnetic fields B perpendicular or parallel to the layers is examined. In a perpendicular field B, \delta \sigma(B) increases and remains dependent on tunneling as long as the magnetic field is smaller than \hbar/e D \tau_t, where D is the in-plane diffusion coefficient and \tau_t the interlayer tunneling time. If \tau_t is smaller than the inelastic scattering time, a parallel magnetic field also leads to a considerable increase of the concuctivity starting with a B**2 law and saturating at fields higher than \hbar/e Z (D \tau_t)**(1/2), where Z is the interlayer distance. In the limit of coherent tunneling, when \tau_t is comparable to elastic scattering time, \delta \sigma(B) differs from that of a single-layer system due to ensuing modifications of the diffusion coefficient. A possibility to probe the weak-localization effect in double-layer systems by the dependence of the conductivity on the gate-controlled level splitting is discussed.Comment: Text 18 pages in Latex/Revtex format, 4 Postscript figures. J. Phys.: CM,in pres

Performance improvement of the multicell cavity prototype for proton Linac projects

The CEA-Saclay / IPN-Orsay collaboration allowed to manufacture a multicell superconducting RF cavity prototype for proton linac. Since the first experimental results [1], obtained in a vertical cryostat and the horizontal cryostat CryHoLab, the accelerating field Eacc has been recently increased up to 19 MV/m with a quality factor Q0 = 9.109 and a limitation by quench. However some improvements are still needed, in particular to suppress the field emission above 16 MV/m

Genetic polymorphisms in the serotonin, dopamine and opioid pathways influence social attention in rhesus macaques (Macaca mulatta)

Behaviour has a significant heritable component; however, unpicking the variants of interest in the neural circuits and molecular pathways that underpin these has proven difficult. Here, we present a comprehensive analysis of the relationship between known and new candidate genes from identified pathways and key behaviours for survival in 109 adult rhesus macaques (Macaca mulatta). Eight genes involved in emotion were analysed for variation at a total of nine loci. Genetic data were then correlated with cognitive and observational measures of behaviour associated with wellbeing and survival using MCMC-based Bayesian GLMM in R, to account for relatedness within the macaque population. For four loci the variants genotyped were length polymorphisms (SLC6A4 5-hydroxytryptamine transporter length-polymorphic repeat (5-HTTLPR), SLC6A4 STin polymorphism, Tryptophan 5-hydroxylase 2 (TPH2) and Monoamine oxidase A (MAOA)) whilst for the other five (5-hydroxytryptamine receptor 2A (HTR2A), Dopamine Receptor D4 (DRD4), Oxytocin receptor (OXTR), Arginine vasopressin receptor 1A (AVPR1a), Opioid receptor mu(μ) 1 (OPRM1)) SNPs were analysed. STin genotype, DRD4 haplotype and OXTR haplotype were significantly associated with the cognitive and observational measures of behaviour associated with wellbeing and survival. Genotype for 5-HTTLPR, STin and AVPR1a, and haplotype for HTR2A, DRD4 and OXTR were significantly associated with the duration of behaviours including fear and anxiety. Understanding the biological underpinnings of individual variation in negative emotion (e.g., fear and anxiety), together with their impact on social behaviour (e.g., social attention including vigilance for threat) has application for managing primate populations in the wild and captivity, as well as potential translational application for understanding of the genetic basis of emotions in humans.Acknowledgements: We thank the staff at MRC-CFM, particularly Faye Peters and Sebastian Merritt who assisted with data collection.National Centre for the Replacement, Refinement and Reduction of Animals in Research; funder-id: http://dx.doi.org/10.13039/501100000849; Grant(s): grantNC/L000539/1Liverpool John Moores University; funder-id: http://dx.doi.org/10.13039/501100004144; Grant(s): PhD studentshi