Piecewise Omnigenous Stellarators.

In omnigenous magnetic fields, charged particles are perfectly confined in the absence of collisions and turbulence. For this reason, the magnetic configuration is optimized to be close to omnigenity in any candidate for a stellarator fusion reactor. However, approaching omnigenity imposes severe constraints on the spatial variation of the magnetic field.

Reduction or Enhancement of Stellarator Turbulence by Impurities.

A systematic study of the impact of impurities on the turbulent heat fluxes is presented for the stellarator Wendelstein 7-X (W7-X) and, for comparison, the Large Helical Device and ITER. By means of nonlinear multispecies gyrokinetic simulations, it is shown that impurities, depending on the sign of their density gradient, can significantly enhance or reduce turbulent ion heat losses. For the relevant scenario of turbulence reduction, an optimal impurity concentration that minimizes the ion heat diffusivity emerges as a universal feature.

Highs and Lows in Calicivirus Reverse Genetics.

In virology, the term reverse genetics refers to a set of methodologies in which changes are introduced into the viral genome and their effects on the generation of infectious viral progeny and their phenotypic features are assessed. Reverse genetics emerged thanks to advances in recombinant DNA technology, which made the isolation, cloning, and modification of genes through mutagenesis possible. Most virus reverse genetics studies depend on our capacity to rescue an infectious wild-type virus progeny from cell cultures transfected with an "infectious clone".

The chaperone ClpC participates in sporulation, motility, biofilm, and toxin production of Clostridioides difficile.

Objectives: Clostridioides difficile is a nosocomial pathogen that is associated with the use of antibiotics. One of the most worrying aspects of C. difficile infection is its ability to resist antimicrobial therapies, owing to spore formation.

Delimiting conditions under which natural organic matter can control Fe speciation and size in freshwaters.

Pollutant and nutrient mobility in natural waters is typically controlled by sorption onto the high surface area of colloidal particles, most of which may form by precipitation of Fe(III)(hydr)oxides. Therefore, prediction of the speciation and size of Fe is critical to managing water quality. Prediction from pH and dissolved oxygen (D.