Scientific Reports最新文献

Acoustic communication plays an important role in fish ecology and behaviour. Understanding how acoustic signals vary across species and populations is central to questions of sexual selection, population divergence, and environmental modulation of communication. Yet many fish calls remain unattributed to species or behaviour, limiting their integration into broader ecological studies and monitoring. We deployed portable audio-video arrays at two coral reef systems to study the courtship calls of two sympatric damselfishes, Dascyllus aruanus and D. reticulatus. Arrays integrated four hydrophones with a video camera, enabling automated detection of pulse trains, 3D localisation, motion classification, and behavioural observations. We found interspecific differences and strong population-level divergence in call structure, with site effects often exceeding species effects. This suggests that local thermal conditions may influence the performance of sound production, potentially constraining communication under marine heatwaves. Our study shows that integrating small audio-video arrays with behavioural validation not only provides a tool for monitoring but also reveals how socially mediated courtship signals vary within and between species across broad spatial scales. This dual perspective strengthens the role of fish bioacoustics in ecological and conservation frameworks.

Supercritical fluids are characterized by unique thermodynamic properties. One of these properties is the existence of two-component dynamics that is associated with distinct low-frequency and high-frequency vibrational responses of the fluid. However, the origin of this behavior remains unknown. By combining inelastic X-ray scattering and molecular dynamics simulations, we show that this behavior can be connected to density heterogeneities arising from molecular clusters. Analyses of measurements and molecular trajectories suggest that the two-component dynamics emerges due to distinct momentum fluctuations of clustered and unbound molecules. This connection between clusters and two-component dynamics highlights the importance of molecular-structural heterogeneities in supercritical fluids, colloids, and condensed-matter systems.

In this study, we aimed to investigate the mechanisms underlying oligohydramnios in foetal growth restriction (FGR), focusing on the contribution of renal structural and functional abnormalities. A guinea pig model of maternal nutrient restriction (MNR) was established to induce FGR. Pregnant guinea pigs were divided into control and MNR groups. Foetuses were classified as appropriate for gestational age (AGA) or FGR based on body weight. Amniotic fluid and foetal kidneys were collected at gestational days 60-61. Amniotic fluid biomarkers were measured. Histopathology was performed to evaluate renal morphology. MNR resulted in a 25% reduction in foetal body and placental weights and a 50% reduction in amniotic fluid volume compared with AGA controls. Histological analyses revealed renal injury in FGR foetuses, characterised by podocyte foot process effacement, endothelial damage, and disruption of the tubular basement membrane. These structural abnormalities indicate impaired glomerular filtration and defective tubular reabsorption. Amniotic fluid concentrations of albumin, cystatin C, and liver-type fatty acid-binding protein were higher in FGR than in controls, reflecting glomerular leakage and tubular oxidative stress. These findings are consistent with reduced foetal urine production and development of oligohydramnios. They indicate that oligohydramnios in MNR-induced FGR is associated with compromised renal integrity.