Quorum sensing governs bacterial communication, playing a crucial role in regulating population behaviour. We propose a mathematical model that uncovers chaotic dynamics within quorum sensing networks, highlighting challenges to predictability. The model explores interactions between autoinducers and two bacterial subtypes, revealing oscillatory dynamics in both a constant autoinducer sub-model and the full three-component model. In the latter case, we find that the complicated dynamics can be explained by the presence of homoclinic Shilnikov bifurcations. We employed a combination of normal form analysis and numerical continuation methods to analyse the system.

The present study focuses on the modification of primary amine–functionalized drugs, namely pyrimethamine and 4-amino-N-(2,3-dihydrothiazol-2-yl)benzenesulfonamide, through a condensation reaction with 2-hydroxy-1-naphthaldehyde in methanol, yielding two new organic zwitterionic compounds: (E)-1-(((4-(N-(2,3-dihydrothiazol-2-yl)sulfamoyl)phenyl)iminio)methyl)naphthalen-2-olate (DSPIN) and (E)-1-(((4-amino-5-(4-chlorophenyl)-6-ethylpyrimidin-2-yl)iminio)methyl)naphthalen-2-olate (ACPIN). The crystal structures of both compounds were confirmed as imine-based zwitterionic products by single-crystal X-ray diffraction (SC-XRD), revealing stabilization through various noncovalent interactions. Supramolecular assembly was investigated using Hirshfeld surface analysis, while void analysis was employed to predict the mechanical response of the crystals. Density Functional Theory (DFT) calculations showed good agreement with experimental structural parameters. Frontier molecular orbital (FMO) analysis indicated that the HOMO–LUMO gap of DSPIN is 0.15 eV smaller than that of ACPIN, attributed to HOMO destabilization and LUMO stabilization in DSPIN. Charge distribution analysis suggested the presence of intramolecular hydrogen bonding, as well as intermolecular hydrogen bonds, dipole–dipole, and dispersion interactions.

Temporal (race) computing schemes rely on temporal memories, where information is represented with the timing of signal edges. Standard digital circuit techniques can be used to capture the relative timing characteristics of signal edges. However, the properties of emerging device technologies could be particularly exploited for more efficient circuit implementations. Specifically, the collective dynamics of networks of memristive devices could be leveraged to facilitate time-domain computations in emerging memristive memories. To this end, this work studies the star interconnect configuration of bipolar memristive devices. Through circuit simulations using a behavioral model of voltage-controlled bipolar memristive devices, we demonstrated the suitability of such circuits in two different contexts, namely sensing and “rank-order” coding. We particularly analyzed the conditions that the employed memristive devices should meet to guarantee the expected operation of the circuit and the possible effects of device variability in the storage and the reproduction of the information in arriving signal edges. The simulation results in LTSpice validate the correct operation and confirm the promising application prospects of such simple circuit structures, which, we show, natively exist in the crossbar geometry. Therefore, the star interconnect configuration could be considered for temporal computations inside resistive memory (ReRAM) arrays.

First-ever measurements of the turbulent kinetic energy (TKE) dissipation rate in the northeastern Strait of Magellan (Segunda Angostura region), obtained in March 2019, are presented. During the microstructure measurements, the magnitude of the reversing tidal current ranged between 0.8 and 1.2 m s⁻¹. The probability distribution of the TKE dissipation rate in the water interior above the bottom boundary layer was lognormal, with a high median value of ε_MS(med) = 1.2 × 10⁻⁶ W kg⁻¹. Strong vertical shear, ranging from 1 × 10⁻² to 2 × 10⁻² s⁻¹, in the weakly stratified water interior resulted in a subcritical gradient Richardson number (Ri < 10⁻¹–10⁻²). In the bottom boundary layer (BBL), both the vertical shear and the TKE dissipation rate decreased exponentially with distance from the seafloor (ξ), leading to a turbulent regime characterized by an eddy viscosity K_M ≈ 10⁻³ m² s⁻¹. This parameter varied with time and location, while remaining independent of the vertical coordinate in the upper part of the BBL (for ξ ≳ 2 m above the bottom).