Black holes with scalar hair in light of the Event Horizon Telescope

Searching for violations of the no-hair theorem (NHT) is a powerful way to test gravity, and more generally fundamental physics, particularly with regards to the existence of additional scalar fields. The first observation of a black hole (BH) shadow by the Event Horizon Telescope (EHT) has opened a new direct window onto tests of gravity in the strong-field regime, including probes of violations of the NHT. We consider two scenarios described by the Einstein-Maxwell equations of General Relativity and electromagnetism, to which we add a scalar field. In the first case we consider a minimally-coupled scalar field with a potential, whereas in the second case the field is conformally-coupled to curvature. In both scenarios we construct charged BH solutions, which are found to carry primary scalar hair. We then compute the shadows cast by these two BHs as a function of their electric charge and scalar hair parameter. Comparing these shadows to the shadow of M87* recently imaged by the EHT collaboration, we set constraints on the amount of scalar hair carried by these two BHs. The conformally-coupled case admits a regime for the hair parameter, compatible with EHT constraints, describing a so-called mutated Reissner-Nordstr\"{o}m BH: this solution was recently found to effectively mimic a wormhole. Our work provides novel constraints on fundamental physics, and in particular on violations of the no-hair theorem and the existence of additional scalar fields, from the shadow of M87*.Comment: 33 pages, 6 figures, 1 table, references added, version accepted for publication in JCA

Myocardial infarct-sparing effect of ischemic preconditioning abrogated in cirrhotic rat through involvement of mitochondrial permeability transition pore

Despite all studies undertaken mechanism of cirrhotic cardiomyopathy the role of cirrhosis on ischemia-reperfusion (I/R) injury and ischemic preconditioning (IPC) phenomenon hasn't been explored yet. The aim of present study is to assess the relation between cirrhosis and IPC and the mitochondrial permeability transition pore (mPTP) role in IPC cardioprotective effects in cirrhotic rats. Material and method: Rat's heart were isolated and perfused with Krebs buffer by Langendorff method. Animals were equally divided into six groups (n=6): (I) I/R; hearts were subjected to 30 min ischemia and 45 min reperfusion, (II) IPC; IPC was induced via four cycle of 5 min regional ischemia followed by 5 min of reperfusion (III) common bile duct ligated (CBDL); hearts were subjected ischemia and reperfusion in cirrhotic rats, (IV) IPC-CBDL; four cycle of 5 min regional ischemia followed by 5 min of reperfusion in cirrhotic rats (V) CSA; Cyclosporine A was added 40 min prior to main ischemia (VI) CBDL+CSA. Results: Infarct size was increased significantly in IPC-CBDL group in comparison with IPC group (p< 0.05). Addition of CSA in CBDL+CSA group significantly decreased infarct size in comparison with IPC-CBDL group (p< 0.05). Ventricular arrhythmia severity was decreased significantly in IPC group compared to IR group, whereas it was increased significantly in IPC-CBDL group compared to IPC group (p< 0.05). CSA did not decrease arrhythmia score in CBDL group. Conclusion: The results showed that the cardioprotective effects of IPC are eliminated in cirrhosis. MPTP signaling in partly involve in cirrhotic cardiomyopathy

Study of genetic polymorphism of Artemisia herba-alba from Tunisia using ISSR markers

Artemisia herba-alba is an herbaceous aromatic and therapeutic plant widely distributed in semi-arid regions of Tunisia and is potentially usable to restore degraded ecosystems. A study of genetic variation among 216 accessions was conducted using ISSR (Inter Simple Sequence Repeat) markers to assess the polymorphism at the species level. A total of 60 polymorphic loci were scored using four primers revealing a high level of genetic polymorphism among A. herba-alba accessions. Correlationanalysis revealed no direct relation between morphological traits, geographic distance and genetic distance. Correlogram analysis showed a patchy distribution of the genetic variability of A. herba-alba accessions revealing the contribution of local ecological and geographic conditions on variability

Efficient Single Photon Absorption by Optimized Superconducting Nanowire Geometries

We report on simulation results that shows optimum photon absorption by superconducting nanowires can happen at a fill-factor that is much less than 100%. We also present experimental results on high performance of our superconducting nanowire single photon detectors realized using NbTiN on oxidized silicon.Comment: \copyright 2013 IEEE. Submitted to "Numerical Simulation of Optoelectronic Devices - NUSOD 2013" on 19-April-201

Analysis of wedge penetration in clay

A variety of devices designed to penetrate soil is used in soil engineering practice to measure soil properties or to emplace instrumentation, although the mechanics of the steady state penetration process is not well understood. Consequently the two-dimensional problem of steady state wedge penetration is examined. Solutions are obtained for wedge penetration in an ideal rigid plastic medium representing a clay. It is found that the solution requires the presence of a cavity behind the wedge, and the geometry of this cavity is established. A lower limit of the soil/wedge friction coefficient is derived, above which the wedge is considered rough. The force required to push the wedge is calculated as a function of wedge point angle and is shown to reach a minimum for a rough wedge at a point angle of about 67°. For axisymmetric penetration some finite element solutions were obtained and show that cone and wedge penetration mechanisms are similar. The mechanism and patterns of flow movement past the wedge for different point angles are demonstrated. Practical implication of the results and their extension to axisymmetric cone penetration are discussed

Virus-like particle vaccinology, from bench to bedside.

Virus-like particles (VLPs) have become key tools in biology, medicine and even engineering. After their initial use to resolve viral structures at the atomic level, VLPs were rapidly harnessed to develop antiviral vaccines followed by their use as display platforms to generate any kind of vaccine. Most recently, VLPs have been employed as nanomachines to deliver pharmaceutically active products to specific sites and into specific cells in the body. Here, we focus on the use of VLPs for the development of vaccines with broad fields of indications ranging from classical vaccines against viruses to therapeutic vaccines against chronic inflammation, pain, allergy and cancer. In this review, we take a walk through time, starting with the latest developments in experimental preclinical VLP-based vaccines and ending with marketed vaccines, which earn billions of dollars every year, paving the way for the next wave of prophylactic and therapeutic vaccines already visible on the horizon

Statistics of nonlinear internal waves during the Shallow Water 2006 Experiment

Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 33 (2016): 839-846, doi:10.1175/JTECH-D-15-0221.1.During the Shallow Water Acoustic Experiment 2006 (SW06) conducted on the New Jersey continental shelf in the summer of 2006, detailed measurements of the ocean environment were made along a fixed reference track that was parallel to the continental shelf. The time-varying environment induced by nonlinear internal waves (NLIWs) was recorded by an array of moored thermistor chains and by X-band radars from the attending research vessels. Using a mapping technique, the three-dimensional (3D) temperature field for over a month of NLIW events is reconstructed and analyzed to provide a statistical summary of important NLIW parameters, such as the NLIW propagation speed, direction, and amplitude. The results in this paper can be used as a database for studying the NLIW generation, propagation, and fidelity of nonlinear internal wave models.This research was supported by the Office of Naval Research Ocean Acoustics Program (322OA) through Grants N00014-10-1-0396 and N00014-11-1-0701.2016-10-1