Dynamic max-consensus with local self-tuning

This work describes a novel control protocol for multi-agent systems to solve the dynamic max-consensus problem. In this problem, each agent has access to an external timevarying scalar signal and has the objective to estimate and track the maximum among all these signals by exploiting only local communications. The main strength of the proposed protocol is that it is able to self-tune its internal parameters in order to achieve an arbitrary small steady-state error without significantly affecting the convergence time. We employ the proposed protocol in the context of distributed graph parameter estimations, such as size, diameter, and radius, and provide simulations in the scenario of open multi-agent systems. Copyright (C) 2022 The Authors

A Sliding Mode Observer design for the Average State Estimation in Large-Scale Systems

In this letter the average state estimation problem on a large-scale system with only few gateway nodes available for measurements is solved as the design problem of a reduced-order sliding mode observer subjected to unmatched perturbations. Necessary and sufficient conditions to guarantee the exact estimation are derived. Still, even in the case such conditions are not fulfilled, the boundedness of the estimation error is proved. Finally, a criteria to minimize such bound, and a gain adaptation law to trade-off that bound and its convergence rate are provided. Neither the observer complexity nor the estimation error depend explicitly on the size of the system, thus making the approach scalable and computationally tractable. Simulations supporting the effectiveness of the proposed strategy and a comparison with other existing strategies are also provided

Prediction of intervertebral disc mechanical response to axial load using isotropic and fiber reinforced FE models

International audienc

Time Calibration of the LHCb muon System

The LHCb muon System consists of about 122,000 frontend channels. It plays a basic role in the first trigger level. The trigger requires 95% efficiency in muon tracks detection. It is then necessary to reach a system time alignment at the level of about 2 ns. This alignment must be monitored against possible fluctuations due to changes in the detector operating conditions. We describe the custom instrumentation implemented at system level for time calibration, the strategy adopted, the procedure to be followed both for system alignment and monitoring, the control program realized for this purpose. We also illustrate first results obtained during the detector commissioning in the LHCb pit

Molecular detection of virulence factors and antibiotic resistance pattern in clinical Enterococcus faecalis strains in Sardinia

In this study, the antibiotic resistance pattern and the presence of genes encoding several virulence factors in 91 Enterococcus faecalis strains isolated from different human clinical sources in Sardinia were investigated. Genotypic determination of virulence genes (gelE, esp, agg, ace, cylA,B,M,LL,LS, efaA, fsrB) was car- ried out by PCR. The production of gelatinase and haemolytic activity were also determined. Antimicrobial susceptibility tests were performed by an automated microdilution test (Vitek). The strains examined in this study contained at least one and up to as many as all virulence genes investigated. Examining the distribu- tion of these factors in the different groups of clinical strains, we found that all but one virulence determinant were detected more frequently among urinary isolates. The detection of some factors by PCR did not always correlate with its phenotypic expression. Antibiotic susceptibilities among the Enterococcus faecalis strains investigated in our study were typical for the species, with expected levels of acquired resistance. Faecal iso- lates had the highest percentage of resistance, especially to high level-gentamicin, ciprofloxacin and norfloxacin. In summary, a wide variety of genes encoding virulence factors have been detected among our clinical Enterococcus faecalis strains, and those isolated from UTI were characterized by a higher virulence potency compared with strains from other clinical sources. Silent virulence genes (cyl or gelE) were frequently detected, therefore both the genotypic and phenotypic assays seem necessary for a better characterization of the strains. Our results may serve as a basis for additional surveillance studies of infections caused by this microorganism

Exploring the fatty acid amide hydrolase and cyclooxygenase inhibitory properties of novel amide derivatives of ibuprofen

Inhibition of fatty acid amide hydrolase (FAAH) reduces the gastrointestinal damage produced by non-steroidal anti-inflammatory agents such as sulindac and indomethacin in experimental animals, suggesting that a dual-action FAAH-cyclooxygenase (COX) inhibitor could have useful therapeutic properties. Here, we have investigated 12 novel amide analogues of ibuprofen as potential dual-action FAAH/COX inhibitors. N-(3-Bromopyridin-2-yl)−2-(4-isobutylphenyl)propanamide (Ibu-AM68) was found to inhibit the hydrolysis of [3H]anandamide by rat brain homogenates by a reversible, mixed-type mechanism of inhibition with a Ki value of 0.26 µM and an α value of 4.9. At a concentration of 10 µM, the compound did not inhibit the cyclooxygenation of arachidonic acid by either ovine COX-1 or human recombinant COX-2. However, this concentration of Ibu-AM68 greatly reduced the ability of the COX-2 to catalyse the cyclooxygenation of the endocannabinoid 2-arachidonoylglycerol. It is concluded that Ibu-AM68 is a dual-acting FAAH/substrate-selective COX inhibitor

Design and pharmacological evaluation of Ibuprofen amides derivatives as dual FAAH/COX inhibitors

Fatty acid amide hydrolase (FAAH) is a serine hydrolase enzyme responsible of the hydrolytic degradation of N-acylethanolamine endocannabinoids, such as the Arachidonoylethanolamide (anandamide, AEA), which it has been shown to alleviate pain and inflammation (1). In particular, the anti-nociceptive and anti-inflammatory effects of AEA could be enhanced by the simultaneous block of FAAH and COX enzymes (2). For this reason, several studies have been carried out in order to develop new FAAH/COX inhibitors (2). In 1997 it was reported that the NSAID ibuprofen inhibited FAAH, although with a modest potency (3), and successively the first dual inibhitor, the amide derivative of ibuprofen with a 2-amino-3-methylpyridine side chain (Ibu-AM5) was reported (4). -5). Benzylamides and piperazinoamides analogs of Ibuprofen have been also designed as less potent FAAH inhibitors than Ibu-AM5 (5). Here, I discuss the computational studies and the structure–activity relationships leading to the design, of novel Ibuprofen amide derivatives with a higher inhibition potency of FAAH and COX, which represent novel powerful anti-nociceptive agents