3D model based tracking for omnidirectional vision: A new spherical approach

The current work addresses the problem of 3D model tracking in the context of monocular and stereo omnidirectional vision in order to estimate the camera pose. To this end, we track 3D objects modeled by line segments because the straight line feature is often used to model the environment. Indeed, we are interested in mobile robot navigation using omnidirectional vision in structured environments. In the case of omnidirectional vision, 3D straight lines are projected as conics in omnidirectional images. Under certain conditions, these conics may have singularities.In this paper, we present two contributions. We, first, propose a new spherical formulation of the pose estimation withdrawing singularities, using an object model composed of lines. The theoretical formulation and the validation on synthetic images thus show that the new formulation clearly outperforms the former image plane one. The second contribution is the extension of the spherical representation to the stereovision case. We consider in the paper a sensor which combines a camera and four mirrors. Results in various situations show the robustness to illumination changes and local mistracking. As a final result, the proposed new stereo spherical formulation allows us to localize online a robot indoor and outdoor whereas the classical formulation fails.     

Metallic Conductive Nanowires Elaborated by PVD Metal Deposition on Suspended DNA Bundles

Metallic conductive nanowires (NWs) with DNA bundle core are achieved, thanks to an original process relying on double‐stranded DNA alignment and physical vapor deposition (PVD) metallization steps involving a silicon substrate. First, bundles of DNA are suspended with a repeatable process between 2 µm high parallel electrodes with separating gaps ranging from 800 nm to 2 µm. The process consists in the drop deposition of a DNA lambda‐phage solution on the electrodes followed by a naturally evaporation step. The deposition process is controlled by the DNA concentration within the buffer solution, the drop volume, and the electrode hydrophobicity. The suspended bundles are finally metallized with various thicknesses of titanium and gold by a PVD e‐beam evaporation process. The achieved NWs have a width ranging from a few nanometers up to 100 nm. The electrical behavior of the achieved 60 and 80 nm width metallic NWs is shown to be Ohmic and their intrinsic resistance is estimated according to different geometrical models of the NW section area. For the 80 nm width NWs, a resistance of about few ohms is established, opening exploration fields for applications in microelectronics.     

Length of Dialysis Session Is More Important Than Large Kt/V in Hemodialysis

Long, slow hemodialysis (3 × 8 hours/week) has been used without significant modification in Tassin, France, for 30 years with excellent morbidity and mortality rates. A long dialysis session easily provides high Kt/V_urea and allows for good control of nutrition and correction of anemia with a limited need for erythropoietin (EPO). Control of serum phosphate and potassium is usually achieved with low-dose medication. The good survival achieved by long hemodialysis sessions is essentially due to lower cardiovascular morbidity and mortality than in short dialysis sessions. This, in turn, is mainly explained by good blood pressure (BP) control without the need for antihypertensive medication. Normotension in this setting is due to the gentle but powerful ultrafiltration provided by the long sessions, associated with a low salt diet and moderate interdialytic weight gains. These allow for adequate control of extracellular volume (dry weight) in most patients without important intradialytic morbidity. Therefore, increasing the length of the dialysis session seems to be the best way of achieving satisfactory long-term clinical results.     

Experimental Evidence for Seed Metabolic Allometry in Barrel Medic (Medicago truncatula Gaertn.)

Seed size is often considered to be an important trait for seed quality, i.e., vigour and germination performance. It is believed that seed size reflects the quantity of reserve material and thus the C and N sources available for post-germinative processes. However, mechanisms linking seed size and quality are poorly documented. In particular, specific metabolic changes when seed size varies are not well-known. To gain insight into this aspect, we examined seed size and composition across different accessions of barrel medic (Medicago truncatula Gaertn.) from the genetic core collection. We conducted multi-elemental analyses and isotope measurements, as well as exact mass GC–MS metabolomics. There was a systematic increase in N content (+0.17% N mg⁻¹) and a decrease in H content (–0.14% H mg⁻¹) with seed size, reflecting lower lipid and higher S-poor protein quantity. There was also a decrease in ²H natural abundance (δ²H), due to the lower prevalence of ²H-enriched lipid hydrogen atoms that underwent isotopic exchange with water during seed development. Metabolomics showed that seed size correlates with free amino acid and hexoses content, and anticorrelates with amino acid degradation products, disaccharides, malic acid and free fatty acids. All accessions followed the same trend, with insignificant differences in metabolic properties between them. Our results show that there is no general, proportional increase in metabolite pools with seed size. Seed size appears to be determined by metabolic balance (between sugar and amino acid degradation vs. utilisation for storage), which is in turn likely determined by phloem source metabolite delivery during seed development.     

The Endothelium and COVID-19: An Increasingly Clear Link Brief Title: Endotheliopathy in COVID-19

The endothelium has a fundamental role in the cardiovascular complications of coronavirus disease 2019 (COVID-19). Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) particularly affects endothelial cells. The virus binds to the angiotensin-converting enzyme 2 (ACE-2) receptor (present on type 2 alveolar cells, bronchial epithelial cells, and endothelial cells), and induces a cytokine storm. The cytokines tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 have particular effects on endothelial cells—leading to endothelial dysfunction, endothelial cell death, changes in tight junctions, and vascular hyperpermeability. Under normal conditions, apoptotic endothelial cells are removed into the bloodstream. During COVID-19, however, endothelial cells are detached more rapidly, and do not regenerate as effectively as usual. The loss of the endothelium on the luminal surface abolishes all of the vascular responses mediated by the endothelium and nitric oxide production in particular, which results in greater contractility. Moreover, circulating endothelial cells infected with SARS-CoV-2 act as vectors for viral dissemination by forming clusters that migrate into the circulation and reach distant organs. The cell clusters and the endothelial dysfunction might contribute to the various thromboembolic pathologies observed in COVID-19 by inducing the formation of intravascular microthrombi, as well as by triggering disseminated intravascular coagulation. Here, we review the contributions of endotheliopathy and endothelial-cell-derived extracellular vesicles to the pathogenesis of COVID-19, and discuss therapeutic strategies that target the endothelium in patients with COVID-19.     

Modified Fluoroquinolones as Antimicrobial Compounds Targeting Chlamydia trachomatis

Chlamydia trachomatis causes the most common sexually transmitted bacterial infection and trachoma, an eye infection. Untreated infections can lead to sequelae, such as infertility and ectopic pregnancy in women and blindness. We previously enhanced the antichlamydial activity of the fluoroquinolone ciprofloxacin by grafting a metal chelating moiety onto it. In the present study, we pursued this pharmacomodulation and obtained nanomolar active molecules (EC₅₀) against this pathogen. This gain in activity prompted us to evaluate the antibacterial activity of this family of molecules against other pathogenic bacteria, such as Neisseria gonorrhoeae and bacteria from the ESKAPE group. The results show that the novel molecules have selectively improved activity against C. trachomatis and demonstrate how the antichlamydial effect of fluoroquinolones can be enhanced.     

Experimenting with the partnership ability φ-index on a million computer scientists

Schubert introduced the partnership ability φ-index relying on a researcher’s number of co-authors and collaboration rate. As a Hirsch-type index, φ was expected to be consistent with Schubert–Glänzel’s model of h-index. Schubert demonstrated this relationship with the 34 awardees of the Hevesy medal in the field of nuclear and radiochemistry (r ² = 0.8484). In this paper, we upscale this study by testing the φ-index on a million researchers in computer science. We found that the Schubert–Glänzel’s model correlates with the million empirical φ values (r ² = 0.8695). In addition, machine learning through symbolic regression produces models whose accuracy does not exceed a 6.1 % gain (r ² = 0.9227). These results suggest that the Schubert–Glänzel’s model of φ-index is accurate and robust on the domain-wide bibliographic dataset of computer science.     

Physiological compliance for social gaming analysis: Cooperative versus competitive play

We report the results of an empirical study demonstrating the value of using physiological compliance as a measure of social presence during digital game playing. The physiological activity (facial EMG, electrodermal activity, cardiac activity and respiration) of 21 dyads were acquired synchronously while they were playing a digital game either cooperatively or competitively and either at home or in the laboratory. Physiological compliance was defined as the correlation between the physiological signals of the dyad members. The results of this study confirm that physiological compliance is higher in a conflicting situation than when playing cooperatively. Importantly, the results also demonstrate that physiological compliance is related to self-reported social presence. This suggests that physiological compliance is not limited to negative situations but rather increases due to rich interactions. Only minor differences in physiological compliance were observed between home play and laboratory play, suggesting the ecological validity of laboratory measures. Finally, we propose that compliance measures can be considered as objective indices of social presence in digital gaming.