Light propagating in the topological edge channel of an array of ring resonators is predicted to generate nested frequency combs: like a Matryoshka doll containing a set of smaller dolls, each ‘tooth’ of the comb comprises another frequency comb.

The state that forms at low temperatures in a quantum antiferromagnet on a kagome lattice has been debated for decades. Nuclear magnetic resonance has now shown the gradual emergence of entangled spin singlets in a disordered kagome antiferromagnet.

Recent advances in realizing optical frequency combs using nonlinear parametric processes in integrated photonic resonators have revolutionized on-chip optical clocks, spectroscopy and multichannel optical communications. At the same time, the introduction of topological physics in photonic systems has allowed the design of photonic devices with novel functionalities and inherent robustness against

The kagome Heisenberg antiferromagnet formed by frustrated spins arranged in a lattice of corner-sharing triangles is a prime candidate for hosting a quantum spin liquid (QSL) ground state consisting of entangled spin singlets1. However, the existence of various competing states makes a convincing theoretical prediction of the QSL ground state difficult2, calling for experimental clues from model materials

A newly arrived Russian laboratory module misfired and pushed the International Space Station 45° out of its normal orientation. The U.S. Centers for Disease Control and Prevention said fully vaccinated people should again wear masks in public, indoor spaces in areas of substantial or high coronavirus transmission. Relatives of Henrietta Lacks, whose cervical cancer cells were harvested without her

The U.S. troop withdrawal from Afghanistan is imperiling the 3-decade global quest to eradicate polio. The Taliban, which now controls large swaths of the country, has blocked house-to-house polio vaccination in areas under its reign the past 3 years, putting up to 3 million children out of reach of the campaign. The Taliban may well wrest complete control from the Afghan government—which supports

After more than 6 months in the doldrums, one of the world’s largest trials of COVID-19 treatments is finally restarting. Solidarity, a global study led by the World Health Organization, will test three new drugs in hospitalized COVID-19 patients: the cancer drug imatinib, an antibody named infliximab that is used to treat autoimmune diseases, and artesunate, an antimalarial. When Solidarity started

Experiments suggest that the frogs use internal proteins to soak up their own toxins.

Today, oxygen fuels much of life on Earth, but it wasn't always that way. Three billion years ago, this gas was scarce in the atmosphere and oceans. Knowing why oxygen became plentiful could illuminate the evolution of our planet's flora and fauna, but scientists have struggled to find an explanation satisfying to all. Now, a research team has proposed a novel link between how fast our planet spun

But a study of the publications of millions of researchers also suggests that women are less likely to continue their academic careers than their male counterparts.

Fears of backfire effects are overblown, and advice to listen and interact still stands.

Analysis reveals that strange turns of phrase may indicate foul play in science.

The United States has been ramping up efforts to protect its high technology, and one part of that strategy involves barring certain Chinese graduate students from studying in the country. Former President Donald Trump issued a proclamation that blocks visas to Chinese graduate students and postgraduate researchers with ties to an entity in China "that implements or supports China's 'military-civil

Concerns over waning immunity and SARS-CoV-2 variants have convinced some countries to deploy extra vaccine doses — but it’s not clear to scientists whether most people need them.

Should people who volunteer for genomic studies be told about unrelated disease mutations that turn up in their sequence data? The decadeslong debate about such "incidental findings," which can include genes that boost risk for cancer or heart disease, flared up again last week after bioethicists at the National Institutes of Health published a study showing many participants who at first refuse those

Following stagnating vaccination rates in the spring, nearly 20 states tried to incentivize the vaccine hesitant to get their shot with the thrill of a lottery. Although emerging studies suggest the gamble may have convinced some of those holding out, some are placing their bets on cash payouts for everyone that gets vaccinated. Experts hope the $100 incentive will change the cost-benefit analysis

In his 20s, Joseph Allen helped run his father's investigative agency and started the process to become an FBI agent. When that didn't work out, he turned to another passion—science. Allen now runs the Healthy Buildings Program at Harvard University's T.H. Chan School of Public Health, where his research has helped nail down the connections between indoor air quality and human health and cognition

To meet the needs of a growing population in a manner that is socially equitable, economically viable, and environmentally sustainable, Africa's electricity sector will require a major transformation (1). It has already undergone some important changes over the past decade. Efforts to expand access to electricity have proceeded at a slightly faster pace than anticipated 10 years ago. In parallel, the

Comparative research reveals extraordinary animal athleticism—mites lift >1000 times their body weight, mantis shrimp strike their prey with the force of a bullet, and peregrine falcons dive toward prey at 335 mph (539.13 km/hour) (1). Even human babies travel the distance of eight football fields per hour during free play (2). However, movement in the real world is not about being the strongest, fastest

HIV-1 particle assembly is driven by the Gag polyprotein precursor, which contains several structural and functional domains that engage in protein-protein, protein-lipid, and protein-RNA interactions during virion assembly. Concomitant with virus release from an infected cell, the viral protease cleaves the Gag precursor to liberate the mature Gag proteins, triggering a morphological transformation

Over the past several years, advances in RNA sequencing have led to an increased appreciation of the prevalence and function of noncoding RNAs, including long noncoding RNAs (lncRNAs). These are typically expressed in a tissue-specific manner in healthy tissues and are often dysregulated in disease, making them potential biomarkers and therapeutic targets. On page 662 of this issue, Li et al. (1) reveal

In digital computing, functions such as processing and memory require separate components wired together for electronic conduction. Neurons, the functional units equivalent to processor and memory areas, are integrated in the brain and transmit signals through ionic and neurotransmitter conduction. Inspired by the energy-efficient computation architectures from biological systems, on page 687 of this

In Inflamed, physician Rupa Marya and scholar Raj Patel use the concept of in­flammation to probe the many ills cur­rently plaguing humanity and the planet. The text moves uneasily between inflam­mation as a cause of illness, inflamma­tion as a signal that something is wrong, and inflammation as a framework for examining European and Ameri­can colonialism, which Marya and Patel consider the root cause

In the decades since the Human Genome Project was launched in 1990, genomic science has opened a dizzying array of scientific, medical, and commercial possibilities. Some of its applications have generated visible public controversy. As Harvard University political scientist Jennifer Hochschild points out in her new book, Genomic Politics, these controversies often make for strange bedfellows. 

We develop a unified framework to characterize one-shot transformations of dynamical quantum resources in terms of resource quantifiers, establishing universal conditions for exact and approximate transformations in general resource theories. Our framework encompasses all dynamical resources represented as quantum channels, including those with a specific structure—such as boxes, assemblages, and measurements—thus

Several fast-spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have become the dominant circulating strains in the COVID-19 pandemic. We report here cryo–electron microscopy structures of the full-length spike (S) trimers of the B.1.1.7 and B.1.351 variants, as well as their biochemical and antigenic properties. Amino acid substitutions in the B.1.1.7 protein increase

A novel variant of concern (VOC) named CAL.20C (B.1.427/B.1.429), which was originally detected in California, carries spike glycoprotein mutations S13I in the signal peptide, W152C in the N-terminal domain (NTD), and L452R in the receptor-binding domain (RBD). Plasma from individuals vaccinated with a Wuhan-1 isolate–based messenger RNA vaccine or from convalescent individuals exhibited neutralizing

We report de novo genome assemblies, transcriptomes, annotations, and methylomes for the 26 inbreds that serve as the founders for the maize nested association mapping population. The number of pan-genes in these diverse genomes exceeds 103,000, with approximately a third found across all genotypes. The results demonstrate that the ancient tetraploid character of maize continues to degrade by fractionation

The functional role of long noncoding RNAs (lncRNAs) in inherited metabolic disorders, including phenylketonuria (PKU), is unknown. Here, we demonstrate that the mouse lncRNA Pair and human HULC associate with phenylalanine hydroxylase (PAH). Pair-knockout mice exhibited excessive blood phenylalanine (Phe), musty odor, hypopigmentation, growth retardation, and progressive neurological symptoms including

Fully controllable ultracold atomic systems are creating opportunities for quantum sensing, yet demonstrating a quantum advantage in useful applications by harnessing entanglement remains a challenging task. Here, we realize a many-body quantum-enhanced sensor to detect displacements and electric fields using a crystal of ~150 trapped ions. The center-of-mass vibrational mode of the crystal serves

A prototypical hydroperoxyalkyl radical (•QOOH) intermediate, transiently formed in the oxidation of volatile organic compounds, was directly observed through its infrared fingerprint and energy-dependent unimolecular decay to hydroxyl radical and cyclic ether products. Direct time-domain measurements of •QOOH unimolecular dissociation rates over a wide range of energies were found to be in accord

High atomic diffusivity in metals enables substantial tuneability of their structure and properties by tailoring the diffusional processes, but this causes their customized properties to be unstable at elevated temperatures. Eliminating diffusive interfaces by fabricating single crystals or heavily alloying helps to address this issue but does not inhibit atomic diffusion at high homologous temperatures

Recent advances in nanofluidics have enabled the confinement of water down to a single molecular layer. Such monolayer electrolytes show promise in achieving bioinspired functionalities through molecular control of ion transport. However, the understanding of ion dynamics in these systems is still scarce. Here, we develop an analytical theory, backed up by molecular dynamics simulations, that predicts

Incorporating passive radiative cooling structures into personal thermal management technologies could effectively defend humans against intensifying global climate change. We show that large-scale woven metafabrics can provide high emissivity (94.5%) in the atmospheric window and high reflectivity (92.4%) in the solar spectrum because of the hierarchical-morphology design of the randomly dispersed

Arboreal animals often leap through complex canopies to travel and avoid predators. Their success at making split-second, potentially life-threatening decisions of biomechanical capability depends on their skillful use of acrobatic maneuvers and learning from past efforts. Here, we found that free-ranging fox squirrels (Sciurus niger) leaping across unfamiliar, simulated branches decided where to launch

Gag, the primary structural protein of HIV-1, is recruited to the plasma membrane for virus assembly by its matrix (MA) domain. Gag is subsequently cleaved into its component domains, causing structural maturation to repurpose the virion for cell entry. We determined the structure and arrangement of MA within immature and mature HIV-1 through cryo–electron tomography. We found that MA rearranges between

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with multiple spike mutations enable increased transmission and antibody resistance. We combined cryo–electron microscopy (cryo-EM), binding, and computational analyses to study variant spikes, including one that was involved in transmission between minks and humans, and others that originated and spread in human populations. All

In quantum-confined semiconductor nanostructures, electrons exhibit distinctive behavior compared with that in bulk solids. This enables the design of materials with tunable chemical, physical, electrical, and optical properties. Zero-dimensional semiconductor quantum dots (QDs) offer strong light absorption and bright narrowband emission across the visible and infrared wavelengths and have been engineered

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Hear the biggest stories from the world of science | 28 July 2021

Jupiter’s upper atmosphere is considerably hotter than expected from the amount of sunlight that it receives1,2,3. Processes that couple the magnetosphere to the atmosphere give rise to intense auroral emissions and enormous deposition of energy in the magnetic polar regions, so it has been presumed that redistribution of this energy could heat the rest of the planet4,5,6. Instead, most thermospheric

Macroscale analogues1,2,3 of microscopic spin systems offer direct insights into fundamental physical principles, thereby advancing our understanding of synchronization phenomena4 and informing the design of novel classes of chiral metamaterials5,6,7. Here we introduce hydrodynamic spin lattices (HSLs) of ‘walking’ droplets as a class of active spin systems with particle–wave coupling. HSLs reveal

Reproductive longevity is essential for fertility and influences healthy ageing in women1,2, but insights into its underlying biological mechanisms and treatments to preserve it are limited. Here we identify 290 genetic determinants of ovarian ageing, assessed using normal variation in age at natural menopause (ANM) in about 200,000 women of European ancestry. These common alleles were associated with

During the splicing of introns from precursor messenger RNAs (pre-mRNAs), the U2 small nuclear ribonucleoprotein (snRNP) must undergo stable integration into the spliceosomal A complex—a poorly understood, multistep process that is facilitated by the DEAD-box helicase Prp5 (refs. 1,2,3,4). During this process, the U2 small nuclear RNA (snRNA) forms an RNA duplex with the pre-mRNA branch site (the U2–BS

Key to our understanding of how electrons behave in crystalline solids is the band structure that connects the energy of electron waves to their wavenumber. Even in phases of matter with only short-range order (liquid or amorphous solid), the coherent part of electron waves still has a band structure. Theoretical models for the band structure of liquid metals were formulated more than five decades

One in four women suffers from uterine leiomyomas (ULs)—benign tumours of the uterine wall, also known as uterine fibroids—at some point in premenopausal life. ULs can cause excessive bleeding, pain and infertility1, and are a common cause of hysterectomy2. They emerge through at least three distinct genetic drivers: mutations in MED12 or FH, or genomic rearrangement of HMGA23. Here we created genome-wide

Flooding affects more people than any other environmental hazard and hinders sustainable development1,2. Investing in flood adaptation strategies may reduce the loss of life and livelihood caused by floods3. Where and how floods occur and who is exposed are changing as a result of rapid urbanization4, flood mitigation infrastructure5 and increasing settlements in floodplains6. Previous estimates of

MFSD2A is a sodium-dependent lysophosphatidylcholine symporter that is responsible for the uptake of docosahexaenoic acid into the brain1,2, which is crucial for the development and performance of the brain3. Mutations that affect MFSD2A cause microcephaly syndromes4,5. The ability of MFSD2A to transport lipid is also a key mechanism that underlies its function as an inhibitor of transcytosis to regulate

Global concern over widely documented declines in pollinators1,2,3 has led to the identification of anthropogenic stressors that, individually, are detrimental to bee populations4,5,6,7. Synergistic interactions between these stressors could substantially amplify the environmental effect of these stressors and could therefore have important implications for policy decisions that aim to improve the

The topological protection of wave transport, originally observed in the context of the quantum Hall effect in two-dimensional electron gases1, has been shown to apply broadly to a range of physical platforms, including photonics2,3,4,5, ultracold atoms in optical lattices6,7,8 and others9,10,11,12. That said, the behaviour of such systems can be very different from the electronic case, particularly