Latitudinal gradients in air density create invisible topography at sea level, affecting animal flight costs.

Regional patterns in wind underpin the low-cost migratory flyways of billions of birds and insects, but the effect of large-scale changes in temperature on flight is unknown. Flight costs should increase with rising temperatures because lift decreases as density decreases, whereas weight remains unchanged. The effects of density are well-established in the context of high-altitude movements and migration.

Role of ammonia-lyases in the synthesis of the dithiomethylamine ligand during [FeFe]-hydrogenase maturation.

The generation of an active [FeFe]-hydrogenase requires the synthesis of a complex metal center, the H-cluster, by three dedicated maturases: the radical S-adenosyl-l-methionine (SAM) enzymes HydE and HydG, and the GTPase HydF. A key step of [FeFe]-hydrogenase maturation is the synthesis of the dithiomethylamine (DTMA) bridging ligand, a process recently shown to involve the aminomethyl-lipoyl-H-protein from the glycine cleavage system, whose methylamine group originates from serine and ammonium. Here we use functional assays together with electron paramagnetic resonance and electron-nuclear double resonance spectroscopies to show that serine or aspartate together with their respective ammonia-lyase enzymes can provide the nitrogen for DTMA biosynthesis during in vitro [FeFe]-hydrogenase maturation.

Landing force reveals new form of motion-induced sound camouflage in a wild predator.

Predator-prey arms races have led to the evolution of finely tuned disguise strategies. While the theoretical benefits of predator camouflage are well established, no study has yet been able to quantify its consequences for hunting success in natural conditions. We used high-resolution movement data to quantify how barn owls () conceal their approach when using a sit-and-wait strategy.

Impact of mineral and non-mineral sources of iron and sulfur on the metalloproteome of .

Methanogens often inhabit sulfidic environments that favor the precipitation of transition metals such as iron (Fe) as metal sulfides, including mackinawite (FeS) and pyrite (FeS). These metal sulfides have historically been considered biologically unavailable. Nonetheless, methanogens are commonly cultivated with sulfide (HS) as a sulfur source, a condition that would be expected to favor metal precipitation and thus limit metal availability.