Gas-phase turbulence in a bubbling gas–solid fluidised bed is modelled using the data from particle-resolved direct numerical simulations. The subgrid particle-induced turbulent kinetic energy (TKE) is modelled as a function of filter width, filtered solid volume fraction, particle Reynolds number and filtered gas-phase strain rate tensor. Within the volume-filtered framework, we demonstrate that the fluid Reynolds stress models originally developed for a homogeneous system remain applicable to the inhomogeneous fluidised bed, provided that the inhomogeneous drag and particle-induced TKE models are used for the dissipation rate interfacial term. An algebraic model for the anisotropy of gas-phase velocity variance is developed by simplifying the proposed Reynolds stress equation model, which incorporates the effects from both filtered slip velocity and filtered fluid strain rate. The new models are shown to agree well with the direct numerical simulation data of clustered particle settling systems, indicating good applicability of our models for various clustered particle-laden flows.

This study compares turbulent channel flows over elastic walls with those over rough walls, to explore the role of the dynamic change of shape of the wall in turbulence. The comparison is made meaningful by generating rough walls from instantaneous configurations of elastic cases. The aim of this comparison is to individually understand the role of fluid–structure interaction effects and the role of wall shape/undulations in determining the overall physics of flow near elastic walls. With an increase in the compliance of the wall, qualitatively similar trends for many of the effects produced by a rough wall are also seen in the elastic wall. However, specific features can be observed for the elastic-wall cases only, arising from the mutual interaction between the solid and fluid, leading to a further increase in drag. To understand them, we look at the turbulent structures, which exhibit clear differences across the various configurations: roughness induces only a slight reduction of streamwise coherency, resulting in a situation qualitatively similar to what is found in classical turbulent channel flows, whereas elasticity causes the emergence of a novel dominant spanwise coherency. Additionally, we explored the effect of vertical disturbances on elastic-wall dynamics by comparing with permeable walls having similar (average) wall-normal velocity fluctuations at the interface. The permeable walls were found to have minimal similarities to elastic walls. Overall, we can state that the wall motion caused by the complex fluid–structure interaction contributes significantly to the flow and must be considered when modelling it. In particular, we highlight the emergence of strong wall-normal fluctuations near the wall, which result in strong ejection events, an attribute not observed for rigid walls.

It is widely believed that high inflation reduces the popularity of incumbents, and contributed to poor incumbent performance in recent elections in the United States and elsewhere. Existing research shows that voters’ inflation perceptions are associated with their evaluations of incumbent parties, but these observational studies cannot eliminate the possibility that the causal relationship runs the other way, where opposition to incumbent governments causes individuals to report higher price increases. To help overcome this inferential challenge, this study draws on a pre-registered experiment embedded in a nationally representative survey fielded just days before the 2024 US Presidential election. We find that priming Americans to think about inflation reduced support for the incumbent party. This effect is most pronounced among Independents and Democrats. These findings suggest that inflation likely contributed to the Democrats’ 2024 electoral defeat, and provide novel evidence that inflation has a causal effect on support for incumbent parties.

The locomotion of microorganisms in complex fluids at low Reynolds numbers has been widely studied by ignoring fluid inertia. Here, we combine the asymptotic analysis and numerical simulations to explore the effect of fluid inertia on the dynamic mechanism of microorganisms swimming through viscoelastic fluids using Taylor’s swimming sheet model, undergoing small-amplitude undulations. Surprisingly, fluid inertia can enhance the speed and efficiency of the infinite-length sheet in viscoelastic fluids at finite Reynolds numbers, in stark contrast to the previous results found in Newtonian fluids. Moreover, speed and efficiency slightly exceed those Newtonian values at the small Weissenberg number due to a passive inertial response of the sheet. We associate this with the magnitude of the hydrodynamic force increasing at finite Reynolds numbers. These insights contribute to a deeper understanding of the inertial effect on the locomotion of microorganisms through complex fluids.

Twin children are more likely to die than singletons. This is an additional burden in sub-Saharan African (SSA) countries, as child mortality levels are already higher than anywhere else. This article provides estimates of under-5 mortality rates (U5MRs) for twins and singletons in SSA from 1986 to 2016. It describes the geographical variations and changes over time. It also describes the variation of twins’ excess mortality according to age from 0 to 5 years. Additionally, it analyzes the factors associated with twins’ excess mortality. We used data from 156 national surveys from 42 countries. We estimated U5MRs for twins and single children and built a Cox model to analyze factors associated with excess mortality among twins. Although child mortality has declined on the continent, twins’ excess mortality remains very high. U5MRs are, on average, 3 times higher among twins than singletons. The Cox model shows that all other things being equal, the adjusted hazard ratio of under-5 mortality (U5M) is 3.2 (2.9−3.3; p < .001) times higher among twins than singletons. The main factors associated with excess mortality risks among twins are biomedical and nutritional features, such as low birth weight, non-use of cesarean section delivery, and lack of breastfeeding. Health policy makers in SSA should be aware of the vulnerability of twins, and interventions to prevent their early deaths should be considered.

Turbulence accounts for most of the energy losses associated with the pumping of fluids in pipes. Pulsatile drivings can reduce the drag and energy consumption required to supply a desired mass flux, when compared with steady driving. However, not all pulsation waveforms yield reductions. Here, we compute drag- and energy-optimal driving waveforms using direct numerical simulations and a gradient-free black-box optimisation framework. Specifically, we show that Bayesian optimisation is vastly superior to ordinary gradient-based methods in terms of computational efficiency and robustness, due to its ability to deal with noisy objective functions, as they naturally arise from the finite-time averaging of turbulent flows. We identify optimal waveforms for three Reynolds numbers and two Womersley numbers. At a Reynolds number of $8600$ and a Womersley number of 10, optimal waveforms reduce total energy consumption by 22 % and drag by 37 %. These reductions are rooted in the suppression of turbulence prior to the acceleration phase, the resulting delay in turbulence onset, and the radial localisation of turbulent kinetic energy and production towards the pipe centre. Our results pinpoint that the predominant, steady operation mode of pumping fluids through pipes is far from optimal.

With the introduction of tetflupyrolimet as the first herbicide with a novel site of action in the last three decades, screening for herbicide resistance before commercialization has become integral to ensure successful applications. In the mid-southern United States, tetflupyrolimet is anticipated to be used as a preemergence (PRE) herbicide for barnyardgrass control but does exhibit postemergence (POST) herbicidal activity. In 2020, 45 Echinochloa crus-galli (barnyardgrass) accessions were collected from rice-producing areas in Arkansas and were screened in the greenhouse to tetflupyrolimet at 134 g ai ha-1 PRE and POST at the 2- to 3-leaf growth stage on a silt loam soil. A field experiment was conducted where tetflupyrolimet was applied alone at 134 g ai ha-1 or with clomazone at 336 g ai ha-1, to a susceptible barnyardgrass standard and four other accessions with confirmed resistance to florpyrauxifen-benzyl, imazethapyr, propanil, and quinclorac at the spiking, 1-, 2-, 3-, and 4-leaf stages. For the PRE screening, the percent visible control ranged from 88% to 99%, with some accessions differing in sensitivity to tetflupyrolimet. Percent mortality ranged from 47% to 90% at the PRE timing. Visible control and mortality ranged from 63% to 88% and 7% to 65%, respectively, from a POST application, suggesting there is differential sensitivity and that foliar applications may not be as effective as soil applications. In the field experiment, barnyardgrass accession did not influence POST biomass production and was impacted more by the growth stage at application, although the difference was frequently numerical. In general, applying tetflupyrolimet alone or with clomazone to ≥3 leaf grass compromised performance. Tetflupyrolimet will be better optimized as a soil-applied herbicide in mid-southern U.S. rice culture.

Extreme precipitation events are projected to increase both in frequency and intensity due to climate change. High-resolution climate projections are essential to effectively model the convective phenomena responsible for severe precipitation and to plan any adaptation and mitigation action. Existing numerical methods struggle with either insufficient accuracy in capturing the evolution of convective dynamical systems, due to the low resolution, or are limited by the excessive computational demands required to achieve kilometre-scale resolution. To fill this gap, we propose a novel deep learning regional climate model (RCM) emulator called graph neural networks for climate downscaling (GNN4CD) to estimate high-resolution precipitation. The emulator is innovative in architecture and training strategy, using graph neural networks (GNNs) to learn the downscaling function through a novel hybrid imperfect framework. GNN4CD is initially trained to perform reanalysis to observation downscaling and then used for RCM emulation during the inference phase. The emulator is able to estimate precipitation at very high resolution both in space ($ 3 $km) and time ($ 1 $h), starting from lower-resolution atmospheric data ($ \sim 25 $km). Leveraging the flexibility of GNNs, we tested its spatial transferability in regions unseen during training. The model trained on northern Italy effectively reproduces the precipitation distribution, seasonal diurnal cycles, and spatial patterns of extreme percentiles across all of Italy. When used as an RCM emulator for the historical, mid-century, and end-of-century time slices, GNN4CD shows the remarkable ability to capture the shifts in precipitation distribution, especially in the tail, where changes are most pronounced.

Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) is a significant pest of wheat, Triticum aestivum Linnaeus (Poaceae), in Canada. Monitoring currently relies on labour-intensive counts of ovipositing females. Although traps baited with S. mosellana pheromone are used as decision support tools in the United Kingdom, in Canada, they are considered reliable only to indicate adult activity. Recent findings show that variability in pheromone release from commercial lures affects the number of midges captured and limits the reliability of pheromone monitoring. Here, two lure types and two trap types were compared for their ability to attract and retain S. mosellana males. We then compared the number of males captured in pheromone traps with the information provided by other monitoring tools, including emergence traps, soil cores, and ovipositing female counts. Jackson traps with Trécé rubber septa lures captured the most midges. The number of males captured in pheromone-baited traps was not related to overwintering, ovipositing, or emerging populations, suggesting that pheromone traps may not accurately reflect S. mosellana populations under field conditions. Variability in extracted pheromone amount between lures, regional climate, and Canada’s vast wheat-growing area may limit the development of an effective pheromone-based decision support tool for this region. Nevertheless, refinement of lure formulation, standardisation of trapping protocols, and integration of complementary monitoring approaches may enhance trap reliability and support a stronger monitoring system.

While scholars of deliberative democracy have long conceded that good deliberation requires careful facilitation, little attention has been paid to the effects of different facilitation methods. This paper has three aims. First, it establishes the importance of facilitation. Second, it argues that facilitation may not be enough to counteract the imbalances in power and influence within deliberation. As such, this paper introduces two games that can be utilized in concert with facilitation: deliberative worth exercises and simulated representation. The former pushes participants to remain aware of their behavior patterns within deliberation by asking them to choose the best deliberator at the end of each round of deliberation; the latter enables empathy and perspective-taking by partnering participants and asking them to represent one another’s viewpoints for a portion of deliberation as if they were their own. Third, using proof-of-concept experiments, this paper demonstrates the efficacy of these games.

Pelmatozoa is an informal grouping of filter-feeding echinoderms including crinoids, paracrinoids, rhombiferans, and eocrinoids that possess a theca, an erect stalk, and feeding appendages. Although crinoids were major constituents of marine communities with high diversity and abundance throughout the Paleozoic, most other pelmatozoans had relatively low species diversity and/or short temporal durations. It has been proposed that these different diversification trajectories could have resulted from crinoids outcompeting other filter-feeding pelmatozoans during the early Paleozoic, although this hypothesis involving niche overlap has never been formally tested. Here, we tested this hypothesis using the incredibly diverse pelmatozoan fauna of the Late Ordovician (Sandbian) Bromide Formation of Oklahoma, which preserves a rich, ecologically complex fauna that developed as a result of the Great Ordovician Biodiversification Event. We developed a framework to quantitatively characterize pelmatozoan feeding ecology using multivariate analysis of ecomorphological traits and explored niche space occupation and potential competition between crinoids, rhombiferans, paracrinoids, eocrinoids, and diploporans from the Bromide fauna. Results revealed key ecological factors controlling niche differentiation and showed that crinoids, paracrinoids, and rhombiferans occupy nonoverlapping regions of niche space, indicating competition between groups was unlikely. Although the competition hypothesis was not supported, narrow niche space occupation suggests that paracrinoids and rhombiferans were more ecologically limited than crinoids, which might have played a role in their differential diversification dynamics. These results elucidate both the nature of interactions between pelmatozoan taxa and the potential mechanisms driving their evolutionary trajectories, as well as the complexity of ecological communities that arose during the Ordovician radiation.