Unprecedented trial aims to protect people exposed to Ebola in the DRC and Uganda.Unprecedented trial aims to protect people exposed to Ebola in the DRC and Uganda.
Supermassive black holes and their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties. Determining the evolution of these correlations requires precise...Supermassive black holes and their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties. Determining the evolution of these correlations requires precise measurements of the masses of distant black holes. We observed the gravitationally lensed quiescent galaxy MRG-M0138 at redshift 1.95 using James Webb Space Telescope integral field spectroscopy to spatially resolve the kinematics of stars within the black hole's sphere of influence. By using a foreground lens model and fitting stellar dynamical models, we determined the mass of its inactive black hole to be [Formula: see text] solar masses. Comparing this measurement to local galaxies, we found that [Formula: see text] is higher than expected given the galaxy's bulge mass but consistent with the correlation of [Formula: see text] with stellar velocity dispersion.
DNA study reveals hidden biodiversity off Brazil-and raises alarm over oil exploration.DNA study reveals hidden biodiversity off Brazil-and raises alarm over oil exploration.
Human cooperation is fundamental to solving collective challenges, yet its individual drivers remain insufficiently understood. Using globally representative data from an incentivized two-player cooperation experiment co...Human cooperation is fundamental to solving collective challenges, yet its individual drivers remain insufficiently understood. Using globally representative data from an incentivized two-player cooperation experiment conducted in 125 countries ( = 101,123 individuals), we assess the extent of human cooperation and study its individual determinants. Across the globe, about two-thirds of people choose to cooperate. The decision to cooperate is significantly shaped by cooperation beliefs, injunctive norms, and preferences. Effect sizes of these determinants vary across countries, a variation that is systematically associated with historical and cultural markers. Globally, people underestimate others' willingness to cooperate-humans are more cooperative than they believe. A simple information treatment reduces misperceptions and causally increases cooperation.
As capabilities of artificial intelligence (AI) advance rapidly, human understanding of these systems is increasingly falling behind. Several trends are converging to make AI systems harder to understand just as they bec...As capabilities of artificial intelligence (AI) advance rapidly, human understanding of these systems is increasingly falling behind. Several trends are converging to make AI systems harder to understand just as they become more consequential. Without deliberate countervailing efforts, the window for building AI systems that we can meaningfully understand and guide may close beyond recovery.
National governments and multilateral institutions face difficult challenges reconciling biodiversity, climate, and economic development goals. We integrated spatial biophysical and economic data with optimization method...National governments and multilateral institutions face difficult challenges reconciling biodiversity, climate, and economic development goals. We integrated spatial biophysical and economic data with optimization methods to develop sustainable landscape efficiency frontiers that show maximally feasible combinations of biodiversity conservation, land-based climate mitigation, and net economic value from agricultural crops, livestock, and forestry production. We applied this approach in 146 countries and found large potential gains in biodiversity, climate, and economic development from improved land use and land management. Summing national-level results shows the potential to increase climate mitigation by more than 200 billion metric tons of CO equivalents (>20% increase) or net economic value by more than US$350 billion (>80% increase), without loss in other objectives.
How does remote work affect isolation and mental health? We drew on five nationally representative surveys of American workers ( = 588,322) conducted from 2011 to 2024, omitting the peak pandemic years of 2020-2021. Our...How does remote work affect isolation and mental health? We drew on five nationally representative surveys of American workers ( = 588,322) conducted from 2011 to 2024, omitting the peak pandemic years of 2020-2021. Our difference-in-differences approach compared changes in mental health among people in remotable jobs-who experienced a large and persistent rise in remote work since COVID-19-to people in nonremotable jobs, where remote work increased far less. We found that remote work increases time spent alone, worsens mental well-being across multiple measures, and increases the use of mental health services and prescriptions. These effects were concentrated among individuals living alone. We estimate that the rise of remote work explains about a third of the increase in isolation and mental distress between 2011-2019 and 2022-2024.
Liu S, Tian Y, Wen Y
… +20 more, Bai S, Qin B, Shi H, Su L, Feng X, Liu R, Gao D, Jin Y, Hu Y, Gao T, Liu D, Li Y, Zhu Y, Han S, Xing L, Wang S, Gao X, Chen Y, Qin Y, Zhao LD
Thermoelectric cooling is pivotal for solid-state thermal management, yet large-scale deployment is hindered by the scarcity and cost of tellurium in commercial bismuth telluride devices. We developed a tellurium-free th...Thermoelectric cooling is pivotal for solid-state thermal management, yet large-scale deployment is hindered by the scarcity and cost of tellurium in commercial bismuth telluride devices. We developed a tellurium-free thermoelectric cooler based on all lead selenide (PbSe), in which an ultralow-dopant chromium (Cr) grid allows the engineering of defects and donors to optimize carrier transport to match the performance of the n-type and p-type legs. We fabricated high-performance n-type (PbSe + 0.005Cr) and p-type (PbSe + 0.001Cr) crystals with synergistically matched properties. The device exhibits exceptional performance with lower power consumption and higher cooling capacity, achieving a cooling density of approximately 6 watts per square centimeter, a peak coefficient of performance of approximately 21, and a maximum temperature difference of approximately 53 kelvin at a 363-kelvin hot-side temperature. These findings establish PbSe as a highly effective, sustainable alternative for large-scale cooling applications.
Global mangrove forests have disappeared rapidly because of deforestation but have also regrown through natural regeneration and restoration. Yet their long-term trends in extent and canopy cover remain poorly quantified...Global mangrove forests have disappeared rapidly because of deforestation but have also regrown through natural regeneration and restoration. Yet their long-term trends in extent and canopy cover remain poorly quantified. By developing a global dataset of annual mangrove extent and canopy cover, we show that losses (long-term conversion) and degradation (canopy thinning) have both reduced since the 1980s and have been largely offset by regeneration and seaward expansion in the past decade. Consequently, global mangrove extent has shifted from net loss to net gain since around 2010 and changed only marginally from the 1980s to 2023 (-0.5% ± 1.4%). Beyond changes in extent, persistent mangroves exhibited sustained canopy accumulation. Our findings reveal the underestimated resilience of a highly threatened ecosystem, demonstrate early conservation effectiveness, and highlight halting deforestation as a priority for achieving conservation targets through natural regrowth.
Atomically thin nanotubes of semiconducting transition metal dichalcogenides offer a platform for exploring quantum phenomena at the one-dimensional limit and for realizing nanoscale transistor channels. However, convent...Atomically thin nanotubes of semiconducting transition metal dichalcogenides offer a platform for exploring quantum phenomena at the one-dimensional limit and for realizing nanoscale transistor channels. However, conventional syntheses produce only large-diameter (>10 nm), multiwalled tubes with uncontrolled chiralities. We report the synthesis of single-walled molybdenum disulfide (MoS) nanotubes with diameters approaching 1 nm, achieved through spatially confined reactions inside boron nitride (BN) nanotubes. The confined geometry stabilizes otherwise inaccessible, highly strained MoS nanotubes, yielding structurally well-defined armchair configurations. Their bandgaps shrink systematically with decreasing diameter, in accordance with long-standing theoretical predictions. The insulating BN sheath simultaneously provides an intrinsic gate-all-around architecture, thereby promising access to truly nanoscale transistor channels.
Strengthened US oversight of dual-use research may face growing jurisdictional limits while imposing costs on domestic science.Strengthened US oversight of dual-use research may face growing jurisdictional limits while imposing costs on domestic science.
Problem-solving using novel solutions without explicit training is often considered a hallmark of cognitive flexibility. We investigated whether bumble bees () could solve a novel object manipulation task spontaneously....Problem-solving using novel solutions without explicit training is often considered a hallmark of cognitive flexibility. We investigated whether bumble bees () could solve a novel object manipulation task spontaneously. Bees trained to associate a blue ring ("flower") on the floor with a reward successfully moved a ball underneath a flower relocated to the ceiling to reach the flower. In control experiments in which the flower was out of sight when ball movement began and remained hidden during transport, bees still succeeded in the task. These results suggest that these were goal-directed actions rather than reinforcement-based associations driven by perceptual feedback. Our findings provide evidence that bumble bees can exhibit spontaneous problem-solving, challenging the notion that such advanced cognitive abilities are exclusive to large-brained vertebrates.
Recent surges in wildfire emissions have exacerbated surface ozone pollution in the United States. Using deep learning, we developed a gapless daily surface ozone dataset at 1-kilometer resolution for 2003-2024. This dat...Recent surges in wildfire emissions have exacerbated surface ozone pollution in the United States. Using deep learning, we developed a gapless daily surface ozone dataset at 1-kilometer resolution for 2003-2024. This dataset revealed a reversal in national policy-relevant ozone trends that had gone undetected by the sparse monitoring network: from -0.65 parts per billion (ppb) per year (2003-2015) to +0.13 ppb per year (2015-2024). The reversal was primarily driven by increasing wildfire emissions, offsetting 3.9 years of mitigation progress. Premature deaths from fire-sourced ozone have increased by 318 deaths per year since 2013, with post-2013 mortality 46% higher than pre-2013 mortality. During 2022-2024, wildfire emissions exposed 43 million people to nonattainment conditions, effectively preventing a 4-ppb tightening of the ozone standard. These results underscore the growing challenges of sustaining air quality progress as wildfires intensify under climate change.
Qin Y, Ren P, Hu J
… +17 more, Pradhan S, Vuong TH, He X, Alluhaibi L, Rockstroh N, Monti S, Barcaro G, Jaworski A, Kuśtrowski P, Rabeah J, Hohenberger D, Bagnich S, Köhler A, Breu J, Vilé G, Beller M, Das S
Oxidative cleavage of carbon-carbon double bonds often requires hazardous reagents and demanding conditions. In this study, we report a photocatalytic oxidative cleavage of alkenes using benign carbon dioxide (CO) as an...Oxidative cleavage of carbon-carbon double bonds often requires hazardous reagents and demanding conditions. In this study, we report a photocatalytic oxidative cleavage of alkenes using benign carbon dioxide (CO) as an oxygen donor, producing ketones or carboxylic acids at atmospheric pressure and room temperature. A robust iron-based heterogeneous photocatalyst facilitates oxygen transfer to form an epoxide intermediate that subsequently undergoes ring opening and carbon-carbon bond cleavage to yield the oxidative products with high selectivity. Comprehensive mechanistic studies combine time-resolved spectroscopy, isotope labeling, and in situ spectroscopic analyses with advanced quantum mechanical simulations. These results uncover fundamental principles of oxygen transfer from CO under photocatalytic conditions, offering a sustainable platform for light-driven oxidative transformations.
Remote work has substantially increased social isolation, with measurable consequences for mental health.Remote work has substantially increased social isolation, with measurable consequences for mental health.
Plants and animals respond to pathogen attack by mounting innate immune responses that require intracellular nucleotide-binding leucine-rich repeat (NLR) proteins. These immune receptors detect pathogen infection by sens...Plants and animals respond to pathogen attack by mounting innate immune responses that require intracellular nucleotide-binding leucine-rich repeat (NLR) proteins. These immune receptors detect pathogen infection by sensing virulence effector proteins. However, how receptors evolve new recognition specificities remains poorly understood. We found that the plant NLR MLA3 (Mildew locus a 3) has evolved to recognize a pathogen effector by acting as a molecular mimic of an effector virulence target, thereby triggering an immune response. By introducing the mimic's binding interface into the wheat stem rust resistance protein SR50, we bioengineered a chimeric receptor with dual recognition activities that conferred resistance to two major cereal pathogens in barley transgenic lines. These results demonstrate that molecular mimicry by immune receptors can be harnessed to engineer multiple disease resistance.
Gases released from satellites could slash the threat of severe space weather.Gases released from satellites could slash the threat of severe space weather.