Browse Articles
Discover research articles across all indexed journals
Inside a mosquito factory
Complete biosynthesis of salicylic acid from phenylalanine in plants
Abstract Salicylic acid (SA) is a pivotal phytohormone for plant responses to biotic and abiotic stresses. Plants have evolved two pathways to produce SA: the isochorismate synthase and phenylalanine ammonia lyase (PAL) pathways1. Whereas the isochorismate synthase pathway has been fully identified2–4, the PAL pathway remains incomplete. Here we report the full characterization of the PAL pathway for SA biosynthesis via functional analysis of rice (Oryza sativa) SA-DEFICIENT GENE 1 (OSD1) to OSD4. The cinnamoyl-coenzyme A (CoA) ligase OSD1 catalyses the conversion of trans-cinnamic acid to cinnamoyl-CoA, which is subsequently transformed to benzoyl-CoA via the β-oxidative pathway in peroxisomes. The resulting benzoyl-CoA is further converted to benzyl benzoate by the peroxisomal benzoyltransferase OSD2. Benzyl benzoate is subsequently hydroxylated to benzyl salicylate by the endoplasmic reticulum membrane-resident cytochrome P450 OSD3, which is ultimately hydrolysed to salicylic acid by the cytoplasmic carboxylesterase OSD4. Evolutionary analyses reveal that the PAL pathway was first assembled before the divergence of gymnosperms and has been conserved in most seed plants. Activation of the PAL pathway in rice significantly enhances salicylic acid levels and plant immunity. Completion of the PAL pathway provides critical insights into the primary salicylic acid biosynthetic pathway across plant species and offers a precise target for modulating crop immunity.
Ultra-processed foods — it’s time for an improved definition
Training of physical neural networks
Missing steps uncovered in a pathway plants use to produce the defence molecule salicylic acid
How academics and ‘big tech’ can learn from one another
Three-step biosynthesis of salicylic acid from benzoyl-CoA in plants
Nanobody therapy rescues behavioural deficits of NMDA receptor hypofunction
Are ultra-processed foods really so unhealthy? What the science says
Brain-wide representations of prior information in mouse decision-making
Abstract The neural representations of prior information about the state of the world are poorly understood 1 . Here, to investigate them, we examined brain-wide Neuropixels recordings and widefield calcium imaging collected by the International Brain Laboratory. Mice were trained to indicate the location of a visual grating stimulus, which appeared on the left or right with a prior probability alternating between 0.2 and 0.8 in blocks of variable length. We found that mice estimate this prior probability and thereby improve their decision accuracy. Furthermore, we report that this subjective prior is encoded in at least 20% to 30% of brain regions that, notably, span all levels of processing, from early sensory areas (the lateral geniculate nucleus and primary visual cortex) to motor regions (secondary and primary motor cortex and gigantocellular reticular nucleus) and high-level cortical regions (the dorsal anterior cingulate area and ventrolateral orbitofrontal cortex). This widespread representation of the prior is consistent with a neural model of Bayesian inference involving loops between areas, as opposed to a model in which the prior is incorporated only in decision-making areas. This study offers a brain-wide perspective on prior encoding at cellular resolution, underscoring the importance of using large-scale recordings on a single standardized task.
Adaptive and context-aware volumetric printing
Abstract We introduce Generative, Adaptive, Context-Aware 3D Printing (GRACE), a new approach combining 3D imaging, computer vision and parametric modelling to create tailored, context-aware geometries using volumetric additive manufacturing. GRACE rapidly and automatically generates complex structures capable of conforming directly around features ranging from cellular to macroscopic scales with minimal user intervention. Here we demonstrate its versatility in applications ranging from synthetic objects to biofabrication, including adaptive vascular-like geometries around cell-laden bioinks, resulting in improved functionality. GRACE also enables precise alignment of sequential prints, as well as the detection and overprinting of opaque surfaces through shadow correction. Compatible with various printing modalities1–4, GRACE transcends traditional additive manufacturing limitations in automating overprinting and adapting the printed designs to the content of the printable material. This opens new possibilities in tissue engineering and regenerative medicine.
Seismic detection of a 600-km solid inner core in Mars
Abstract For rocky planets, the presence of a solid inner core has notable implications on the composition and thermal evolution of the core and on the magnetic history of the planet 1–3 . On Mars, geophysical observations have confirmed that the core is at least partially liquid 4–7 , but it is unknown whether any part of the core is solid. Here we present an analysis of seismic data acquired by the InSight mission, demonstrating that Mars has a solid inner core. We identify two seismic phases, the deep core-transiting phase, PKKP, and the inner core boundary reflecting phase, PKiKP, indicative of the inner core. Our inversions constrain the radius of the Martian inner core to about 613 ± 67 km, with a compressional velocity jump of around 30% across the inner core boundary, supported by additional inner-core-related seismic phases. These properties imply a concentration of distinct light elements in the inner core, segregated from the outer core through core crystallization. This finding provides an anchor point for understanding the thermal and chemical state of Mars. Moreover, the relationship between inner core formation and the Martian magnetic field evolution could provide insights into dynamo generation across planetary bodies.
AI for Latin inscriptions supplies missing text and predicts date and location
Publisher Correction: Liquid–liquid interfacial tension stabilized Li-metal batteries
Marsquakes indicate that the inner core of the red planet is solid, not liquid
Contextualizing ancient texts with generative neural networks
A brain-wide map of neural activity during complex behaviour
Abstract A key challenge in neuroscience is understanding how neurons in hundreds of interconnected brain regions integrate sensory inputs with previous expectations to initiate movements and make decisions 1 . It is difficult to meet this challenge if different laboratories apply different analyses to different recordings in different regions during different behaviours. Here we report a comprehensive set of recordings from 621,733 neurons recorded with 699 Neuropixels probes across 139 mice in 12 laboratories. The data were obtained from mice performing a decision-making task with sensory, motor and cognitive components. The probes covered 279 brain areas in the left forebrain and midbrain and the right hindbrain and cerebellum. We provide an initial appraisal of this brain-wide map and assess how neural activity encodes key task variables. Representations of visual stimuli transiently appeared in classical visual areas after stimulus onset and then spread to ramp-like activity in a collection of midbrain and hindbrain regions that also encoded choices. Neural responses correlated with impending motor action almost everywhere in the brain. Responses to reward delivery and consumption were also widespread. This publicly available dataset represents a resource for understanding how computations distributed across and within brain areas drive behaviour.