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Abstract Previous observational and modeling studies have suggested that moisture plays a dominant role in Madden–Julian oscillation (MJO) evolution. Using a realistic MJO simulation by incorporating the role of mesoscale stratiform heating in the Zhang–McFarlane deep convection scheme in the National Center for Atmospheric Research Community Atmosphere Model, version 5.3 (NCAR CAM5.3), this study investigates the factors responsible for the improved MJO simulation by examining moisture variations during different MJO phases. The results of column moist static energy (MSE) and moisture budgets show that during the suppressed phases of MJO, vertical advection acts to increase MSE anomalies for the development of deep convection while radiative heating and surface heat flux decrease MSE. The opposite holds true at the MJO mature phase. However, their roles largely cancel each other, leaving horizontal advection to play a major role in the low-level MSE increase during the suppressed phase of the MJO and MSE decrease after the MJO mature phase. A further analysis combining moisture and temperature budget equations is performed to demonstrate the effects of vertical advection and cloud processes within the column at each level. The vertical profiles of column-confined moisture tendency show that large-scale vertical advection induced by latent heat release and evaporation within shallow convective clouds is also important to the lower-tropospheric moistening during suppressed phases. This confirms the role of shallow convection in low-level moistening ahead of MJO deep convection. Radiative heating is vital across all MJO phases, and its warming effects keep the column humidity anomaly maintained in mature phases. None of these features are reproduced by the standard CAM5.3. 

We present a systematic analysis of cavity effects on the decay dynamics of an open magnonic system. The Purcell effect on the magnon oscillator decay is thoroughly examined for both driven and nondriven scenarios with realistic parameters and initial conditions. Analytical conditions are determined to distinguish between strong and weak coupling regimes, corresponding to oscillatory and pure decay behaviors, respectively. Additionally, our theory predicts the decay of the photon mode within the cavity-magnonic open system, demonstrating excellent agreement with existing experimental data. Our findings and methodologies provide valuable insights for advancing research in cavity magnonic quantum control, quantum information processing, and the development of magnonic quantum devices. 

Bacterial motility is essential for navigating heterogeneous environments like soil, where it plays a key role in nutrient cycling, bioremediation, and overall soil health. Despite its importance, the interplay between bacterial motility and soil microstructures—such as the effects of physical confinement and interfacial interactions—remains underexplored. In this study, we investigated the motility of Escherichia coli bacteria in aqueous micro-environments with three different natural soil samples and examined how the particle size, void fraction, and proximity to soil particles affect bacterial motility and movement patterns by quantitatively analyzing bacterial trajectories, velocities, and directional changes. We observed that bacterial velocity decreased significantly in soil micro-environments, showing a strong positive correlation with the soil particle size and a negative correlation with the void fraction of the soil samples. Additionally, bacteria in soil micro-environments showed rapid and dramatic directional changes, and the rate of directional changes of bacteria was negatively correlated with the particle size. These results were further validated with synthetic micro-environments with glass microspheres. As the density of microspheres increased, the translational velocity of bacteria decreased while the directional changes increased. This study enhances our understanding of how the soil type, porosity, and particle proximity impact bacterial movement and is expected to contribute to a better understanding of bacterial activities on soil health and management. 

Bent DNA amplifying sensors were recently developed to amplify and quantify the interactions of DNA with various salts and molecules. However, a thorough quantitative understanding of their mechanism is missing. Here, using all-atom molecular dynamics (MD) simulations, we investigate the behavior and dynamics of sharply bent DNA molecules in the absence and presence of Mg2+ ions at different concentrations. The simulations show that Mg2+ ions reduce the fluctuations of DNA strands, enhance base-pairing, and stabilize bent DNA molecules. The computational results are further verified by both melting curve experiments and ensemble FRET measurements, highlighting the mechanical instability and sensitivity of bent DNA molecules. 

Abstract Analogous of pixels to two-dimensional pictures, voxels—in the form of either small cubes or spheres—are the basic building blocks of three-dimensional objects. However, precise manipulation of viscoelastic bio-ink voxels in three-dimensional space represents a grand challenge in both soft matter science and biomanufacturing. Here, we present a voxelated bioprinting technology that enables the digital assembly of interpenetrating double-network hydrogel droplets made of polyacrylamide/alginate-based or hyaluronic acid/alginate-based polymers. The hydrogels are crosslinked via additive-free and biofriendly click reaction between a pair of stoichiometrically matched polymers carrying norbornene and tetrazine groups, respectively. We develop theoretical frameworks to describe the crosslinking kinetics and stiffness of the hydrogels, and construct a diagram-of-state to delineate their mechanical properties. Multi-channel print nozzles are developed to allow on-demand mixing of highly viscoelastic bio-inks without significantly impairing cell viability. Further, we showcase the distinctive capability of voxelated bioprinting by creating highly complex three-dimensional structures such as a hollow sphere composed of interconnected yet distinguishable hydrogel particles. Finally, we validate the cytocompatibility and in vivo stability of the printed double-network scaffolds through cell encapsulation and animal transplantation. 

Abstract Humid heat waves pose significant risks to human health and the ecosystem. Intuitively, rainfall often alleviates extreme humid heat. However, here we show that light rain often accompanies extreme humid heat, exacerbating its frequency and intensity, especially over arid and semi-arid regions compared to no rain and moderate-to-heavy rain cases. This is because light rain does not dramatically reduce solar radiation but increases near-surface humidity through enhanced surface evaporation. The water replenishment from light rain as well as a shallower planetary boundary layer is crucial for consecutive extremes where there are commonly sporadic drizzle days amidst several rain-free days. These extremes last longer than rain-free extremes. Current global climate models (GCMs) overestimate light rain. After reducing this bias in a GCM, underestimations of humid heat waves in energy-limited regions and overestimations in water-limited regions are largely alleviated. These findings underscore the underappreciated impact of light rain on extreme humid heat. 

For decades, the Rate of Change of Total Electron Content Index (ROTI) has been employed to monitor and quantify ionospheric irregularities, serving as a potential substitute for standard scintillation indices. However, to date, ROTI has not been sufficiently investigated in terms of its relationship with standard scintillation indices. This study presents a preliminarily statistical analysis of the relationship between ROTI and standard scintillation indices using GPS receivers from the Canadian High Arctic Ionospheric Network (CHAIN) over a 5-year period from 2011 to 2015. Our results show that as ROTI increases, the phase scintillation index (σ_φ) exhibits a corresponding linear increase (slope of ∼0.34), while the amplitude scintillation index (S₄) shows little to no enhancement (slope of ∼0.05). Both relationships exhibit high correlation, with coefficients of approximately 0.93 and 0.82, respectively. The differentiated responses suggest that the significant enhancement of standard phase scintillation index is fundamentally dominated by refractive effects, which is primarily driven by large-scale ionospheric structures (>Fresnel-scale probably). The feeble inflation of S₄supports the assertion. Accordingly, the linear relationship solely between ROTI and σ_φsuggests that the increase in ROTI can be used to empirically assess the contribution of refractive variations to the enhancement of σ_φat high latitudes.