Hybrid Galerkin numerical modelling of elastodynamics and compressible Navier–Stokes couplings: applications to seismo-gravito acoustic waves

We introduce a hybrid Galerkin modelling tool for the nonlinear acoustic and gravity wave propagation in planetary atmospheres coupled through topography to a solid medium. We rely on a 2-D spectral-element technique to model linear visco-elastic solid media and couple it to a discontinuous Galerkin method for the atmosphere modelled by the fully nonlinear Navier–Stokes equations. Significant benefits of such a method are, first, its versatility because it handles both acoustic and gravity waves in the same simulation, second, it enables one to observe nonlinear effects as convection or wave-breaking and, finally, it allows one to study the impact of ground-atmosphere coupling for waves propagating from seismic sources. Simulations are performed for 2-D isothermal atmosphere models with complex wind and viscosity profiles. We validate the computations by comparing them to finite-difference solutions, already validated in a previous paper. Specific benchmark validation cases are considered for both acoustic and gravity waves subject to viscosity variations, wind duct and nonlinear wave breaking. We apply this tool to study acoustic and gravity waves generated by a strong seismic source and its nonlinear breaking in the upper atmosphere

Deep cultural ancestry and human development indicators across nation states

How historical connections, events and cultural proximity can influence human development is being increasingly recognized. One aspect of history that has only recently begun to be examined is deep cultural ancestry, i.e. the vertical relationships of descent between cultures, which can be represented by a phylogenetic tree of descent. Here, we test whether deep cultural ancestry predicts the United Nations Human Development Index (HDI) for 44 Eurasian countries, using language ancestry as a proxy for cultural relatedness and controlling for three additional factors—geographical proximity, religion and former communism. While cultural ancestry alone predicts HDI and its subcomponents (income, health and education indices), when geographical proximity is included only income and health indices remain significant and the effect is small. When communism and religion variables are included, cultural ancestry is no longer a significant predictor; communism significantly negatively predicts HDI, income and health indices, and Muslim percentage of the population significantly negatively predicts education index, although the latter result may not be robust. These findings indicate that geographical proximity and recent cultural history—especially communism—are more important than deep cultural factors in current human development and suggest the efficacy of modern policy initiatives is not tightly constrained by cultural ancestry.</jats:p

Finite-Difference Modeling of Acoustic and Gravity Wave Propagation in Mars Atmosphere: Application to Infrasounds Emitted by Meteor Impacts

The propagation of acoustic and gravity waves in planetary atmospheres is strongly dependent on both wind conditions and attenuation properties. This study presents a finite-difference modeling tool tailored for acoustic-gravity wave applications that takes into account the effect of background winds, attenuation phenomena (including relaxation effects specific to carbon dioxide atmospheres) and wave amplification by exponential density decrease with height. The simulation tool is implemented in 2D Cartesian coordinates and first validated by comparison with analytical solutions for benchmark problems. It is then applied to surface explosions simulating meteor impacts on Mars in various Martian atmospheric conditions inferred from global climate models. The acoustic wave travel times are validated by comparison with 2D ray tracing in a windy atmosphere. Our simulations predict that acoustic waves generated by impacts can refract back to the surface on wind ducts at high altitude. In addition, due to the strong nighttime near-surface temperature gradient on Mars, the acoustic waves are trapped in a waveguide close to the surface, which allows a night-side detection of impacts at large distances in Mars plains. Such theoretical predictions are directly applicable to future measurements by the INSIGHT NASA Discovery mission

Infected breast milk associated with late-onset and recurrent group B streptococcal infection in neonatal twins: a genetic analysis

The original publication is available at www.springerlink.comInternational audienceAsymptomatic excretion of group B streptococcus (GBS) in breast milk may be an underrecognized cause of neonatal and recurrent infection. We report the case of late-onset and recurrent infection in newborn twins resulting from ingestion of maternal breast milk infected with GBS. Genetic analysis of isolates is equally presented

Magnetically Guided Laser Surgery for the Treatment of Twin-to-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome (TTTS) is a severe disorder that often leads to the death of monochorionic twin fetuses, if left untreated. Current prenatal interventions to treat the condition involve the use of rigid fetoscopes for targeted laser coagulation of the vascular anastomoses. These tools are limited in their area of operation, making treatment challenging, especially in cases with anterior placentation. Herein, a robotic platform to perform this task using remote magnetic navigation is proposed. In contrast to rigid tools, the presented custom magnetic fetoscope is highly flexible, dexterous, and has considerable advantages, including safety and precision. A visual servoing algorithm that allows the surgeon to navigate in the uterus with submillimeter precision is introduced. The system has been validated on ex vivo human placentas in a setting that mimics the real intraoperative conditions

Pharmacological hypothesis: A recombinant probiotic for taming bacterial β-glucuronidase in drug-induced enteropathy

Advances in pharmacomicrobiomics have shed light on the pathophysiology of drug-induced enteropathy associated with the therapeutic use of certain non-steroidal anti-inflammatory drugs, anticancer chemotherapies and immunosuppressants. The toxicity pathway results from the post-glucuronidation release and digestive accumulation of an aglycone generated in the context of intestinal dysbiosis characterized by the expansion of β-glucuronidase-expressing bacteria. The active aglycone could trigger direct or indirect inflammatory signaling on the gut epithelium. Therefore, taming bacterial β-glucuronidase (GUS) activity is a druggable target for preventing drug-induced enteropathy. In face of the limitations of antibiotic strategies that can worsen intestinal dysbiosis and impair immune functions, we hereby propose the use of a recombinant probiotic capable of mimicking repressive conditions of GUS through an inducible plasmid vector

Lack of resistance of Plasmodium falciparum to dihydroartemisinin in Uganda based on parasitogolgical and molecular assays

Artemisinin-­‐based combination therapy is now standard treatment for falciparum malaria. However, this regimen is threatened by resistance to artemisinins, manifest as delayed clearance of parasitemia after therapy, in southeast Asia. Artemisinin resistance in southeast Asia is associated with increased parasitemias in culture, compared to those in sensi0ve parasites, 72 hours a=er a 6 hour pulse with 700 nM dihydroartemisinin (DHA), and with propeller domain polymorphisms in the Plasmodium falciparum kelch (K13; PF3D7_1343700) gene Given that artemether/lumefantrine has been adopted as standard therapy for malaria within the last decade in Uganda, we characterized artemisinin sensiBvity in fresh P. falciparum isolates from Kampala using ex vivo ring-­‐stage survival and IC50 assays. We also assessed the K13 gene for polymorphisms

Lack of Artemisinin Resistance in Plasmodium falciparum in Uganda Based on Parasitological and Molecular Assays

We evaluated markers of artemisinin resistance in Plasmodium falciparum isolated in Kampala in 2014. By standard in vitro assays, all isolates were highly sensitive to dihydroartemisinin (DHA). By the ring-stage survival assay, after a 6-h DHA pulse, parasitemia was undetectable in 40 of 43 cultures at 72 h. Two of 53 isolates had nonsynonymous K13-propeller gene polymorphisms but did not have the mutations associated with resistance in Asia. Thus, we did not see evidence for artemisinin resistance in Uganda

Is Intestinal Dysbiosis-Associated With Immunosuppressive Therapy a Key Factor in the Pathophysiology of Post-Transplant Diabetes Mellitus?

Post-transplant diabetes mellitus (PTDM) is one of the most common and deleterious comorbidities after solid organ transplantation (SOT). Its incidence varies depending on the organs transplanted and can affect up to 40% of patients. Current research indicates that PTDM shares several common features with type 2 diabetes mellitus (T2DM) in non-transplant populations. However, the pathophysiology of PTDM is still poorly characterized. Therefore, ways should be sought to improve its diagnosis and therapeutic management. A clear correlation has been made between PTDM and the use of immunosuppressants. Moreover, immunosuppressants are known to induce gut microbiota alterations, also called intestinal dysbiosis. Whereas the role of intestinal dysbiosis in the development of T2DM has been well documented, little is known about its impacts on PTDM. Functional alterations associated with intestinal dysbiosis, especially defects in pathways generating physiologically active bacterial metabolites (e.g., short-chain fatty acids, trimethylamine N-oxide, indole and kynurenine) are known to favour several metabolic disorders. This publication aims at discussing the potential role of intestinal dysbiosis and dysregulation of bacterial metabolites associated with immunosuppressive therapy in the occurrence of PTDM