Screening Vector Field Modifications of General Relativity

A screening mechanism for conformal vector-tensor modifications of general relativity is proposed. The conformal factor depends on the norm of the vector field and makes the field to vanish in high dense regions, whereas drives it to a non-null value in low density environments. Such process occurs due to a spontaneous symmetry breaking mechanism and gives rise to both the screening of fifth forces as well as Lorentz violations. The cosmology and local constraints are also computed.Comment: 10 pages, 4 figures, revised version, to be published in PL

Blind multiuser equalization using a PARAFAC-subspace spproach

- Dans cet article, nous utilisons la décomposition tensorielle PARAFAC (PARAllel FACtors) en vue de développer une nouvelle approche pour l'égalisation aveugle multi-utilisateur dans le cadre des systèmes de communications sans fil. Le système considéré est basé sur l'utilisation conjointe d'un réseau d'antennes et d'un sur-échantillonnage à la réception. Nous proposons tout d'abord un modèle tridimensionnel du type PARAFAC pour le signal reçu, dont les 3 dimensions sont l'espace, le temps et le sur-échantillonnage. Ensuite, nous présentons un nouveau récepteur aveugle multi-utilisateur pour la séparation des signaux et pour l'égalisation. Le récepteur proposé combine une modélisation PARAFAC, une méthode de sous-espace et l'exploitation de la propriété d'alphabet fini des symboles transmis. Des résultats de simulations sont montrés pour illustrer la performance du récepteur aveugle proposé

Circulating miRNAs are associated with the systemic extent of atherosclerosis : novel observations for miR-27b and miR-146

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The mechanisms that regulate the systemic extent of atherosclerosis are not fully understood. We investigated whether the expression of circulating miRNAs is associated with the extent of stable atherosclerosis to a single territory or multiple territories (polyvascular) and with the severity of atherosclerosis in each territory. Ninety-four participants were prospectively recruited and divided into five age- and sex-matched groups: presenting no atherosclerosis, isolated coronary atherosclerosis, coronary and lower extremity atherosclerosis, coronary and carotid atherosclerosis, and atherosclerosis of the coronary, lower extremity, and carotid territories. The expression of six circulating miRNAs with distinct biological roles was assessed. The expression of miR-27b and miR-146 differed across groups (p < 0.05), showing a decrease in the presence of atherosclerosis, particularly in the three territories. miR-27b and miR-146 expression decreased in association with a higher severity of coronary, lower extremity, and carotid atherosclerosis. Polyvascular atherosclerosis involving the three territories was independently associated with a decreased miR-27b and miR-146 expression. Both miRNAs presented an area under the curve of ≥0.75 for predicting polyvascular atherosclerosis involving the three territories. To conclude, miR-27b and miR-146 were associated with the presence of severe polyvascular atherosclerosis and with the atherosclerosis severity in each territory. Both are potential biomarkers of severe systemic atherosclerosis.info:eu-repo/semantics/publishedVersio

Association between mir-146a and tumor necrosis factor alpha (Tnf-α) in stable coronary artery disease

Background and Objectives: Tumor necrosis factor alpha (TNF-α) is proatherogenic and associated with the risk of acute ischemic events, although the mechanisms that regulate TNF-α expression in stable coronary artery disease (SCAD) are not fully understood. We investigated whether metabolic, inflammatory, and epigenetic (microRNA (miRNA)) markers are associated with TNF-α expression in SCAD. Materials and Methods: Patients with SCAD were prospectively recruited and their metabolic and inflammatory profiles were assessed. TNF-α levels were assessed using an enzyme-linked immunosorbent assay. The relative expression of six circulating miRNAs associated with the regulation of inflammation and/or atherosclerosis was determined. Results: Of the 24 included patients with the mean age of 65 (9) years, 88% were male, and 54% were diabetic. The TNF-α levels were (median (interquartile range)) 1.0 (0.7–1.1) pg/mL. The percentage of glycosylated hemoglobin (r = 0.418, p = 0.042), serum triglyceride levels (r = 0.429, p = 0.037), and C-reactive protein levels (r = 0.407, p = 0.048) were positively correlated with TNF-α levels. Of the candidate miRNAs, miR-146a expression levels were negatively correlated with TNF-α levels (as indicated by r = 0.500, p = 0.035 for correlation between delta cycle threshold (∆Ct) miR-146a and TNF-α levels). In multivariate analysis, serum triglyceride levels and miR-146a expression levels were independently associated with TNF-α levels. miR-146 expression levels were not associated with metabolic or other inflammatory parameters and were negatively correlated with the number of coronary vessels with obstructive disease (as indicated by r = 0.556, p = 0.017 for correlation between ∆Ct miR-146a and number of diseased vessels). Conclusions: miR-146a expression levels were negatively correlated with TNF-α levels in patients with SCAD, irrespective of other metabolic or inflammatory markers, and with the severity of coronary artery disease. The results add to the knowledge on the role of miR-146a in TNF-α-based inflammation in SCAD and support future research on the potential therapeutic use of miR-146a in such a clinical scenario.publishersversionpublishe

Cigarette smoking, miR-27b downregulation, and peripheral artery disease : insights into the mechanisms of smoking toxicity

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Cigarette smoking is a risk factor for the development of peripheral artery disease (PAD), although the proatherosclerotic mediators of cigarette smoking are not entirely known. We explored whether circulating microRNAs (miRNAs) are dysregulated in cigarette smokers and associated with the presence of PAD. Ninety-four participants were recruited, including 58 individuals without and 36 with PAD, 51 never smokers, 28 prior smokers, and 15 active smokers. The relative expression of six circulating miRNAs with distinct biological roles (miR-21, miR-27b, miR-29a, miR-126, miR-146, and miR-218) was assessed. Cigarette smoking was associated with the presence of PAD in multivariate analysis. Active smokers, but not prior smokers, presented miR-27b downregulation and higher leukocyte, neutrophil, and lymphocyte counts; miR-27b expression levels were independently associated with active smoking. Considering the metabolic and/or inflammatory abnormalities induced by cigarette smoking, miR-27b was independently associated with the presence of PAD and downregulated in patients with more extensive PAD. In conclusion, the atheroprotective miR-27b was downregulated in active smokers, but not in prior smokers, and miR-27b expression was independently associated with the presence of PAD. These unreported data suggest that the proatherogenic properties of cigarette smoking are mediated by a downregulation of miR-27b, which may be attenuated by smoking cessation.info:eu-repo/semantics/publishedVersio

Tensor-Based Methods for Blind Spatial Signature Estimation in Multidimensional Sensor Arrays

The estimation of spatial signatures and spatial frequencies is crucial for several practical applications such as radar, sonar, and wireless communications. In this paper, we propose two generalized iterative estimation algorithms to the case in which a multidimensional (R-D) sensor array is used at the receiver. The first tensor-based algorithm is an R-D blind spatial signature estimator that operates in scenarios where the source’s covariance matrix is nondiagonal and unknown. The second tensor-based algorithm is formulated for the case in which the sources are uncorrelated and exploits the dual-symmetry of the covariance tensor. Additionally, a new tensor-based formulation is proposed for an L-shaped array configuration. Simulation results show that our proposed schemes outperform the state-of-the-art matrix-based and tensor-based techniques