Ivermectin for COVID-19 in Peru: 14-fold reduction in nationwide excess deaths, p=.002 for effect by state, then 13-fold increase after ivermectin use restricted

Introduction. On May 8, 2020, Peru’s Ministry of Health approved ivermectin (IVM), a drug of Nobel Prize-honored distinction, for inpatient and outpatient treatment of COVID-19. As IVM treatments proceeded in that nation of 33 million residents, excess deaths decreased 14-fold over four months through December 1, 2020, consistent with clinical benefits of IVM for COVID-19 found in several RCTs. But after IVM use was sharply restricted under a new president, excess deaths then increased 13-fold. Methods. To evaluate possible IVM treatment effects suggested by these aggregate trends, excess deaths were analyzed by state for ages ≥ 60 in Peru’s 25 states. To identify potential confounding factors, Google mobility data, population densities, SARS-CoV-2 genetic variations and seropositivity rates were also examined.Results. The 25 states of Peru were grouped by extent of IVM distributions: maximal (mass IVM distributions through operation MOT, a broadside effort led by the army); medium (locally managed IVM distributions); and minimal (restrictive policies in one state, Lima). The mean reduction in excess deaths 30 days after peak deaths was 74% for the maximal IVM distribution group, 53% for the medium group and 25% for Lima. Reduction of excess deaths is correlated with extent of IVM distribution by state with a p value of 0.002 using the Kendall τb test, well below the confidence threshold of 0.05 for an established clinical effect.Conclusion. Mass treatments with IVM, a drug safely used in 3.7 billion doses worldwide since 1987, most likely caused the 14-fold reductions in excess deaths in Peru, prior to their 13-fold increase under reversed IVM policy. This strongly suggests that IVM treatments can likewise effectively complement immunizations to help eradicate COVID-19. The indicated biological mechanism of IVM, competitive binding with SARS-CoV-2 spike protein, is likely non-epitope specific, possibly yielding full efficacy against emerging viral mutant strains.

Evaluation of Waste Blends with Sewage Sludge as a Potential Material Input for Pyrolysis

In line with the requirements of the circular economy, the European Union’s waste management legislative changes also concern the treatment of sewage sludge. Although sewage sludge production cannot be prevented, its quantities may be reduced by the synergetic effect of energy recovery via choosing a proper technology. Sewage sludge is difficult to apply as fuel alone, because of its high moisture and ash content. However, its energy use will be increased by adding suitable waste materials (different types of plastics, waste tires and paper rejects). Most recently, the thermal utilization of sewage sludge via incineration or pyrolysis has grown in importance. This article describes the fuel parameters of particular waste materials and of their blends with sewage sludge in connection with laboratory-scale thermal decomposition in an inert atmosphere, for their potential use in a semi-pilot plant pyrolysis unit. For pyrolytic application, the results of thermogravimetric analysis are needed in order to know the maximal temperature of thermal decomposition in an inert atmosphere, maximal mass losses, and weight loss rates. The samples of different thermoplastics mixed with sewage sludge, and low-density polyethylene blends with sewage sludge, had the lowest residual masses (70–74%) and the highest weight loss rates (11–19%/min). On the other hand, the blend of polyester rejects from tire processing, paper rejects and sewage sludge had the second highest residual mass (60%) and the lowest weight loss rate (3%/min).

Estimating compressibility from maximal-mass compact star observations

We investigated recent observation data of pulsar masses of PSR J0740+6620, PSR J0348+0432, and PSR J1614−2230 based on the extended σ-ω model. We assumed that these pulsars are maximal mass compact star, which suggest that the core approximation can be applied. Using the linear relations between the microscopic and macroscopic parameters of neutron stars suggested by this model, we estimated the values of the nucleon Landau mass and nuclear compressibility mL=776.0−84.9+38.5 MeV and K=242.7−28.0+57.2 MeV, respectively.

Stellar structure of quark stars in a modified Starobinsky gravity

We propose a form of gravity–matter interaction given by $$\omega RT$$ωRT in the framework of f(R, T) gravity and examine the effect of such interaction in spherically symmetric compact stars. Treating the gravity–matter coupling as a perturbative term on the background of Starobinsky gravity, we develop a perturbation theory for equilibrium configurations. For illustration, we take the case of quark stars and explore their various stellar properties. We find that the gravity–matter coupling causes an increase in the stable maximal mass which is relevant for recent observations on binary pulsars.

MGD Dirac Stars

The method of geometric deformation (MGD) is here employed to study compact stellar configurations, which are solutions of the effective Einstein–Dirac coupled field equations on fluid branes. Non-linear, self-interacting, fermionic fields are then employed to derive MGD Dirac stars, whose properties are analyzed and discussed. The MGD Dirac star maximal mass is shown to increase as a specific function of the spinor self-interaction coupling constant, in a realistic model involving the most strict phenomenological current bounds for the brane tension.

Disappearance of the extended main sequence turn-off in intermediate age clusters as a consequence of magnetic braking

Context. Extended main sequence turn-offs are features commonly found in the colour-magnitude diagrams of young and intermediate age (less than about 2 Gyr) massive star clusters, where the main sequence turn-off is broader than can be explained by photometric uncertainties, crowding, or binarity. Rotation is suspected to be the cause of this feature, by accumulating fast rotating stars, strongly affected by gravity darkening and rotation-induced mixing, near the main sequence turn-off. This scenario successfully reproduces the tight relation between the age and the actual extent in luminosity of the extended main sequence turn-off of observed clusters. Aims. Below a given mass (dependent on the metallicity), stars are efficiently braked early on the main sequence due to the interaction of stellar winds and the surface magnetic field, making their tracks converge towards those of non-rotating tracks in the Hertzsprung-Russell diagram. When these stars are located at the turn-off of a cluster, their slow rotation causes the extended main sequence turn-off feature to disappear. We investigate the maximal mass for which this braking occurs at different metallicities, and determine the age above which no extended main sequence turn-off is expected in clusters. Methods. We used two sets of stellar models (computed with two different stellar evolution codes: STAREVOL and the Geneva stellar evolution code) including the effects of rotation and magnetic braking, at three different metallicities. We implemented them in the SYCLIST toolbox to compute isochrones and then determined the extent of the extended main sequence turn-off at different ages. Results. Our models predict that the extended main sequence turn-off phenomenon disappears at ages older than about 2 Gyr. There is a trend with the metallicity, the age at which the disappearance occurs becoming older at higher metallicity. These results are robust between the two codes used in this work, despite some differences in the input physics and in particular in the detailed description of rotation-induced internal processes and of angular momentum extraction by stellar winds. Conclusions. Comparing our results with clusters in the Large Magellanic Cloud and Galaxy shows a very good fit to the observations. This strengthens the rotation scenario to explain the cause of the extended main sequence turn-off phenomenon.