Unifying the roll waves.

Free surface flows down a slope occur in various real-life scenarios, such as civil engineering, industry, and natural hazards. Unstable waves can develop at the free surface when inertia is sufficiently strong, indicated by the Reynolds number exceeding a critical value. Although this instability has been investigated for specific fluids with different rheologies, a common framework is still lacking to facilitate comparison among the various models.

Phages reconstitute NAD to counter bacterial immunity.

Bacteria defend against phage infection through a variety of antiphage defence systems. Many defence systems were recently shown to deplete cellular nicotinamide adenine dinucleotide (NAD) in response to infection, by cleaving NAD into ADP-ribose (ADPR) and nicotinamide. It was demonstrated that NAD depletion during infection deprives the phage of this essential molecule and impedes phage replication.

Cassette recombination dynamics within chromosomal integrons are regulated by toxin-antitoxin systems.

Integrons are adaptive bacterial devices that rearrange promoter-less gene cassettes into variable ordered arrays under stress conditions, thereby sampling combinatorial phenotypic diversity. Chromosomal integrons often carry hundreds of silent gene cassettes, with integrase-mediated recombination leading to rampant DNA excision and integration, posing a potential threat to genome integrity. How this activity is regulated and controlled, particularly through selective pressures, to maintain such large cassette arrays is unknown.