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Violet seed propulsion inspires robot design

Comparative analysis of seed biomechanics reveals principles that can guide soft robot technology

Patterns of viral prevalence and load show independent circulation of some honey bee viruses in wild bees

Big Ebola outbreak puts research spotlight on little-known virus

The Bundibugyo virus only emerged twice before. Now, scientists see a chance to get to know it better

Correction: Performance-driven switched reluctance motor drive using multiport cascaded converter and advanced direct torque control scheme

Author Correction: Hidden states and dynamics of fractional fillings in twisted MoTe2 bilayers

Protein-templated synthesis of dinucleotide repeat DNA by an antiphage reverse transcriptase

Defense-associated reverse transcriptases (DRTs) are widespread bacterial antiphage systems that use unconventional mechanisms of polynucleotide synthesis. We show that DRT3, which comprises two distinct RTs (Drt3a and Drt3b) and a noncoding RNA (ncRNA), synthesizes alternating poly(GT/AC) double-stranded DNA. Cryo–electron microscopy structures at 2.6-angstrom resolution reveal a D3-symmetric 6:6:6 complex of Drt3a, Drt3b, and ncRNA. Drt3a produces the poly(GT) strand using a conserved ACACAC template within the ncRNA. Notably, Drt3b synthesizes a complementary, protein-primed poly(AC) strand in the complete absence of a nucleic acid template, using conserved active site residues specific to Drt3b to enforce precise base alternation. These findings expand the functional landscape of nucleic acid polymerases, revealing a protein-templated mechanism for sequence-specific DNA synthesis.

Daily briefing: The brain builds a sentence neuron by neuron

Human serum albumin profiling by top-down analysis enables multi-class liver fibrosis staging: a cross-platform validation study

Direct development of stem tetrapods across the fin-to-limb transition

Modern amphibians are characterized by an aquatic larval stage that ends abruptly with a period of widespread tissue remodeling (metamorphosis) upon transition to terrestrial adulthood. A transient larval stage ending in gradual metamorphosis is often assumed for the earliest digited tetrapods, but direct evidence of this larval stage is lacking. Exceptionally preserved stem tetrapod hatchlings show that a transient larval stage was absent in tetrapods both before and after the fin-to-limb transition; instead we identified soft- and hard-tissue evidence of direct development, falsifying hypotheses of an ancestral origin of metamorphosis or of a gradual larval-postlarval transition serving as a template for lissamphibian metamorphosis. We argue that a transient larval period culminating in metamorphosis originated near or within the tetrapod crown group as part of a broader suite of traits associated with terrestrialization.

Decoupling pitch and angle of attack with a variable-incidence wing extends quadrotor flight endurance

Abstract The aerodynamic efficiency of conventional lifting-wing quadrotors is severely constrained by the rigid coupling between fuselage pitch attitude and wing angle of attack (AoA), which prevents the vehicle from maintaining optimal lift-to-drag performance across varying flight speeds. This study presents a novel variable-incidence lifting-wing quadrotor that effectively decouples fuselage attitude from wing aerodynamics. The proposed mechanism incorporates a 143 g lightweight lifting wing and a dual-actuator drive system, with a total structural mass penalty of only 209 g. High-fidelity Computational Fluid Dynamics (CFD) simulations, reveal that the variable-incidence strategy alleviates detrimental rotor-wing interference. Specifically, a fuselage pitch of − 20° combined with a wing AoA of 10°–12° reestablishes a strong suction peak on the wing’s upper surface, maximizing passive lift. Systematic flight experiments validate the decoupling control strategy, demonstrating that the prototype achieves a maximum normalized power-saving ratio of 42.98% at 10 m/s relative to hover. Furthermore, even when accounting for the 209 g structural weight penalty, the design provides a net 13.22% efficiency improvement over the fixed-incidence concept of the original RflyLW. Leveraging these aerodynamic enhancements, predictive analyses indicate that the UAV can achieve an extended maximum flight endurance of 46.8 min and a practical range of 28.1 km. These results, showing high consistency between numerical predictions and experimental data, offer a robust and highly efficient solution for extending the endurance of UAVs in energy-constrained environments.

Hour of the wolf

Wolves have made a spectacular comeback in Europe. But attacks on livestock and humans have caused a heated debate about the limits of coexistence

An in situ non-contact 3D microscopic measurement system for temporal bone anatomy based on stereo imaging

ScS-triggered slip on megathrust interfaces after the 2011 <i>M</i> _W 9.0 Tohoku-Oki earthquake

We report an extraordinary observation of ground motion in Japan after the moment magnitude ( M W ) 9.0 2011 Tohoku-Oki earthquake attributed to a multiplate-interface slip event triggered by shear wave that traveled to the Earth’s core and back. The megathrust earthquake generated a strong ScS phase with a peak-to-peak amplitude exceeding 1 centimeter in Japan. Superposed on this waveform, an eastward steplike displacement of up to 5 to 6 millimeters was recorded in Global Navigation Satellite System (GNSS) data throughout Japan. This likely originated from slip on the megathrust interfaces triggered by the nearly simultaneous arrival of the ScS wave across Japan. Such an ScS triggering is a previously unrecognized source of seismic hazard, which can potentially (re)activate the mainshock area and the broader surrounding megathrust interfaces.

The context of new media art for photography generation based on diffusion models

Decoupling of global metabolic flux and proteome partitioning in bacteria

Bacteria regulate homeostatic growth by adjusting proteome composition. In Escherichia coli , this coordination is mediated by guanosine tetraphosphate and pentaphosphate, collectively termed (p)ppGpp, which couple amino acid supply with ribsosome production. We identified a distinct architecture in Bacillus subtilis , in which guanosine triphosphate (GTP), not (p)ppGpp, controls proteome allocation. Translational inhibition resulted in GTP depletion and suppressed amino acid biosynthesis through feedback inhibition without altering ribosome abundance, establishing a regulated decoupling between total amino acid flux and proteome composition, with flux deviating from proteome-based predictions. By artificially adjusting GTP concentrations, we recoupled flux and proteome, restoring growth to maximal amounts. The regulated suboptimality enables a trade-off to balance growth and stress resilience. Similar GTP-based strategies were present in other Firmicute species, indicating possible evolutionary conservation. Proteome composition and metabolic flux have distinct regulatory layers in some bacteria.

Development of a portable device for the detection of anti-PEG antibodies in human plasma

AI finds legal loopholes, even when not asked

Models repeatedly discovered ways to exploit regulations, and current safeguards largely failed to stop them

Correction: Exploitation of phage Carin-5’s own DNA polymerase to sequence its T-hypermodified genome

Lamprey 3D single-cell transcriptomics reveals ancestral and specialized features of the vertebrate brain

The lamprey occupies a pivotal position for elucidating vertebrate brain evolution. Using spatial transcriptomics and single-nucleus RNA sequencing, we generated a three-dimensional molecular atlas of the lamprey brain, identifying 209 distinct cell clusters across 14 regions. Cross-species comparisons revealed broad conservation of regional spatial architecture, defining an ancestral organizational blueprint. Within this conserved framework, however, marked lineage-specific divergence emerged. We observed extensive neuronal specialization across vertebrate lineages, accompanied by regulatory shifts associated with spatial reorganization and functional diversification of neuronal populations. Additionally, our results suggest that a cerebellum-like architecture predates the jawed vertebrate cerebellum. Together, these findings identified constraints on neural organization and detected cellular innovations driving evolutionary diversification.

These ‘master’ proteins protect us from deadly mutations — and could inspire new drugs