Behavioural analysis based on video recording is becoming increasingly popular within research fields such as; ecology, medicine, ecotoxicology and toxicology. However, the programs available to analyse the data, which are free of cost, user‐friendly, versatile, robust, fast and provide reliable statistics for different organisms (invertebrates, vertebrates and mammals) are significantly limited. We present an automated open‐source executable software (ToxTrac) for image‐based tracking that can simultaneously handle several organisms monitored in a laboratory environment. We compare the performance of ToxTrac with current accessible programs on the web. The main advantages of ToxTrac are as follows: (i) no specific knowledge of the geometry of the tracked bodies is needed; (ii) processing speed, ToxTrac can operate at a rate >25 frames per second in HD videos using modern computers; (iii) simultaneous tracking of multiple organisms in multiple arenas; (iv) integrated distortion correction and camera calibration; (v) robust against false positives; (vi) preservation of individual identification; (vii) useful statistics and heat maps in real scale are exported in image, text and excel formats. ToxTrac can be used for high speed tracking of insects, fish, rodents or other species, and provides useful locomotor information in animal behavior experiments. Download ToxTrac here: https://toxtrac.sourceforge.io (Current version v2.61).

Zinc is an essential micronutrient for all living organisms, required for signaling and proper function of a range of proteins involved in e.g. DNA-binding and enzymatic catalysis 1 . In prokaryotes and photosynthetic eukaryotes Zn 2+ -transporting P-type ATPases of class IB (ZntA) are crucial for cellular redistribution and detoxification of Zn 2+ and related elements 2,3 . Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2.P i ) of ZntA from Shigella sonnei, determined at 3.2 and 2.7 Å resolution, respectively. The structures reveal a similar fold as the Cu + -ATPases with an amphipathic helix at the membrane interface. A conserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular Zn 2+ ions. The E2P structure displays a wide extracellular release pathway reaching the invariant residues at the high-affinity site, including Cys392, Cys394 and Asp714. The pathway closes in the E2.P i state where Asp714 interacts with the conserved Lys693, which possibly stimulates Zn 2+ release as a built-in counter-ion, as also proposed for H + -ATPases. Indeed, transport studies in liposomes provide experimental support for ZntA activity without counter-

beta-Zn4Sb3 is an outstanding thermoelectric material mainly due to its extraordinarily low thermal conductivity, which is similar to that of glasses. Recently it was proposed that interstitial Zn atoms are responsible for this peculiar behavior. Here we report on the crystal and electronic stucture of the low-temperature polymorph alpha-Zn4Sb3. During the reversible phase transition the intricate disorder in beta-Zn4Sb3 disappears, and all Zn atoms localize completely. The electronic structure of alpha-Zn4Sb3 corresponds to that of a narrow-gap semiconductor.