Science
11 NOV 2022
VOLUME 378 | ISSUE 6620
RESEARCH ARTICLES
1.Subnational implications from climate and air pollution policies in India’s electricity sector
下载原文
First Author:
Shayak Sengupta①
Corresponding Author:
Ines M.l.Azevedo②
Affiliations:
Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA, USA.①
Department of Energy Resources Engineering, Woods Institute for the Environment, and Precourt Energy Institute, Stanford University, Stanford, CA, USA.②
Abstract:
Emissions of greenhouse gases and air pollutants in India are important contributors to climate change and health damages. This study estimates current emissions from India’s electricity sector and simulates the state-level implications of climate change and air pollution policies. We find that (i) a carbon tax results in little short-term emissions reductions because there is not enough dispatchable lower emission spare capacity to substitute coal; (ii) moving toward regional dispatch markets rather than state-level dispatch decisions will not lead to emissions reductions; (iii) policies that have modest emissions effects at the national level nonetheless have disparate state-level emissions impacts; and (iv) pricing or incentive mechanisms tied to production or consumption will result in markedly different costs to states.
2.Seventy years of tunas, billfishes, and sharks as sentinels of global ocean health下载原文
First / Corresponding Author:
Maria Jose Juan-Jorda
Affiliations:
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA). Herrera Kaia, Portualdea z/g, 20110 Pasaia, Gipuzkoa, Spain.
Abstract:
Fishing activity is closely monitored to an increasing degree, but its effects on biodiversity have not received such attention. Using iconic and well-studied fish species such as tunas, billfishes, and sharks, we calculate a continuous Red List Index of yearly changes in extinction risk over 70 years to track progress toward global sustainability and biodiversity targets. We show that this well-established biodiversity indicator is highly sensitive and responsive to fishing mortality. After ~58 years of increasing risk of extinction, effective fisheries management has shifted the biodiversity loss curve for tunas and billfishes, whereas the curve continues to worsen for sharks, which are highly undermanaged. While populations of highly valuable commercial species are being rebuilt, the next management challenge is to halt and reverse the harm afflicted by these same fisheries to broad oceanic biodiversity.
3.Enhanced T cell effector activity by targeting the Mediator kinase module下载原文
First Author:
Katherine A. Freitas①
Corresponding Author:
Crystal L. Mackall②
Affiliations:
Immunology Graduate Program, Stanford University School of Medicine, Stanford, CA, USA.①
Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA.①②
Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA.②
Division of Pediatric Hematology/Oncology and Division of Stem Cell Transplantation and Regenerative Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.②
Division of Blood and Marrow Transplantation and Cell Therapy, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.②
Abstract:
T cells are the major arm of the immune system responsible for controlling and regressing cancers. To identify genes limiting T cell function, we conducted genome-wide CRISPR knockout screens in human chimeric antigen receptor (CAR) T cells. Top hits were MED12 and CCNC, components of the Mediator kinase module. Targeted MED12 deletion enhanced antitumor activity and sustained the effector phenotype in CAR- and T cell receptor–engineered T cells, and inhibition of CDK8/19 kinase activity increased expansion of nonengineered T cells. MED12-deficient T cells manifested increased core Meditator chromatin occupancy at transcriptionally active enhancers—most notably for STAT and AP-1 transcription factors—and increased IL2RA expression and interleukin-2 sensitivity. These results implicate Mediator in T cell effector programming and identify the kinase module as a target for enhancing potency of antitumor T cell responses.
4.Imprinted antibody responses against SARS-CoV-2 Omicron sublineages下载原文
First Author:
Young-Jun Park①
Corresponding Author:
Davide Corti②
Affiliations:
Department of Biochemistry, University of Washington, Seattle, WA, USA.①
Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.①
Humabs Biomed SA, Subsidiary of Vir Biotechnology, Bellinzona, Switzerland.②
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant–neutralizing antibody that is a strong candidate for clinical development.
5.Structures of a mobile intron retroelement poised to attack its structured DNA target下载原文
First Author:
Kevin Chung①
Corresponding Author:
Anna Marie Pyle②
Affiliations:
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA.①
Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.②
Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.②
Abstract:
Group II introns are ribozymes that catalyze their self-excision and function as retroelements that invade DNA. As retrotransposons, group II introns form ribonucleoprotein (RNP) complexes that roam the genome, integrating by reversal of forward splicing. Here we show that retrotransposition is achieved by a tertiary complex between a structurally elaborate ribozyme, its protein mobility factor, and a structured DNA substrate. We solved cryo–electron microscopy structures of an intact group IIC intron-maturase retroelement that was poised for integration into a DNA stem-loop motif. By visualizing the RNP before and after DNA targeting, we show that it is primed for attack and fits perfectly with its DNA target. This study reveals design principles of a prototypical retroelement and reinforces the hypothesis that group II introns are ancient elements of genetic diversification.
REVIEWS
6.The discovery and scientific potential of fast radio bursts下载原文
First / Corresponding Authors:
Matthew Bailes
Affiliations:
Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
Abstract:
Fast radio bursts (FRBs) are millisecond-time-scale bursts of coherent radio emission that are luminous enough to be detectable at cosmological distances. In this Review, I describe the discovery of FRBs, subsequent advances in understanding them, and future prospects. Thousands of potentially observable FRBs reach Earth every day, which likely originate from highly magnetic and/or rapidly rotating neutron stars in the distant Universe. Some FRBs repeat, with this subclass often occurring in highly magnetic environments. Two repeating FRBs exhibit cyclic activity windows, consistent with an orbital period. One nearby FRB was emitted by a Galactic magnetar during an x-ray outburst. The host galaxies of some FRBs have been located, providing information about the host environments and the total baryonic content of the Universe.
REPORTS
7.A limit on variations in the fine-structure constant from spectra of nearby Sun-like stars下载原文
First / Corresponding Author:
Michael T. Murphy
Affiliation:
Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
Abstract:
The fine structure constant α sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines depend on α but are subject to systematic effects owing to astrophysical processes in stellar atmospheres. We measured precise line wavelengths from observations of 17 stars, selected to have almost identical atmospheric properties to those of the Sun (solar twins), which reduces those systematic effects. We found that α varies by ≲50 parts per billion within 50 parsecs from Earth. Combining the results from all 17 stars provides an empirical local reference for stellar measurements of α, with an ensemble precision of 12 parts per billion.
8.Universal assembly of liquid metal particles in polymers enables elastic printed circuit board下载原文
First Author:
Wonbeom Lee①
Corresponding Author:
Jiheong Kang②
Affiliations:
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.①②
Abstract:
An elastic printed circuit board (E-PCB) is a conductive framework used for the facile assembly of system-level stretchable electronics. E-PCBs require elastic conductors that have high conductivity, high stretchability, tough adhesion to various components, and imperceptible resistance changes even under large strain. We present a liquid metal particle network (LMPNet) assembled by applying an acoustic field to a solid-state insulating liquid metal particle composite as the elastic conductor. The LMPNet conductor satisfies all the aforementioned requirements and enables the fabrication of a multilayered high-density E-PCB, in which numerous electronic components are intimately integrated to create highly stretchable skin electronics. Furthermore, we could generate the LMPNet in various polymer matrices, including hydrogels, self-healing elastomers, and photoresists, thus showing their potential for use in soft electronics.
9.Hydraulic failure as a primary driver of xylem network evolution in early vascular plants下载原文
First Author:
Martin Bouda①
Corresponding Author:
Craig R. Broderson②
Affiliations:
Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia.①
Yale School of the Environment, New Haven, CT, USA.②
Abstract:
The earliest vascular plants had stems with a central cylindrical strand of water-conducting xylem, which rapidly diversified into more complex shapes. This diversification is understood to coincide with increases in plant body size and branching; however, no selection pressure favoring xylem strand-shape complexity is known. We show that incremental changes in xylem network organization that diverge from the cylindrical ancestral form lead to progressively greater drought resistance by reducing the risk of hydraulic failure. As xylem strand complexity increases, independent pathways for embolism spread become fewer and increasingly concentrated in more centrally located conduits, thus limiting the systemic spread of embolism during drought. Selection by drought may thus explain observed trajectories of xylem strand evolution in the fossil record and the diversity of extant forms.
10.Polarized x-rays from a magnetar下载原文
First / Corresponding Author:
Roberto Taverna
Affiliation:
Department of Physics and Astronomy, University of Padova, I-35131 Padova, Italy.
Abstract:
Magnetars are neutron stars with ultrastrong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observed polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer and found a linear polarization degree of 13.5 ± 0.8% averaged over the 2– to 8–kilo–electron volt band. The polarization changes with energy: The degree is 15.0 ± 1.0% at 2 to 4 kilo–electron volts, drops below the instrumental sensitivity ~4 to 5 kilo–electron volts, and rises to 35.2 ± 7.1% at 5.5 to 8 kilo–electron volts. The polarization angle also changes by 90° at ~4 to 5 kilo–electron volts. These results are consistent with a model in which thermal radiation from the magnetar surface is reprocessed by scattering off charged particles in the magnetosphere.
11.Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1下载原文
First / Corresponding Author:
Henric Krawczynski
Affiliation:
Department of Physics and McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA.
Abstract:
A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto a black hole, which heats the gas sufficiently to emit x-rays. We report a polarimetric observation of the XRB Cygnus X-1 using the Imaging X-ray Polarimetry Explorer. The electric field position angle aligns with the outflowing jet, indicating that the jet is launched from the inner x-ray–emitting region. The polarization degree is 4.01 ± 0.20% at 2 to 8 kiloelectronvolts, implying that the accretion disk is viewed closer to edge-on than the binary orbit. These observations reveal that hot x-ray–emitting plasma is spatially extended in a plane perpendicular to, not parallel to, the jet axis.
12. Intensification of subhourly heavy rainfall下载原文
First / Corresponding Author:
Hooman Ayat
Affiliations:
Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia.
ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, New South Wales, Australia.
Abstract:
Short-duration rainfall extremes can cause flash flooding with associated impacts. Previous studies of climate impacts on extreme precipitation have focused mainly on daily rain totals. Subdaily extremes are often generated in small areas that can be missed by gauge networks or satellites and are not resolved by climate models. Here, we show a robust positive trend of at least 20% per decade in subhourly extreme rainfall near Sydney, Australia, over 20 years, despite no evidence of trends at hourly or daily scales. This trend is seen consistently in storms tracked using multiple independent ground radars, is consistent with rain-gauge data, and does not appear to be associated with known natural variations. This finding suggests that subhourly rainfall extremes may be increasing substantially faster than those on more widely reported time scales.
13.Inhibiting creep in nanograined alloys with stable grain boundary networks下载原文
First Author:
B.B.Zhang①
Corresponding Author:
X.Y.Li ②
Affiliations:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China. ①②
Abstract:
Creep, the time-dependent deformation of materials stressed below the yield strength, is responsible for a great number of component failures at high temperatures. Because grain boundaries (GBs) in materials usually facilitate diffusional processes in creep, eliminating GBs is a primary approach to resisting high-temperature creep in metals, such as in single-crystal superalloy turbo blades. We report a different strategy to inhibiting creep by use of stable GB networks. Plastic deformation triggered structural relaxation of high-density GBs in nanograined single-phased nickel-cobalt-chromium alloys, forming networks of stable GBs interlocked with abundant twin boundaries. The stable GB networks effectively inhibit diffusional creep processes at high temperatures. We obtained an unprecedented creep resistance, with creep rates of ~10–7 per second under gigapascal stress at 700°C (~61% melting point), outperforming that of conventional superalloys.
14.TPP1 promoter mutations cooperate with TERT promoter mutations to lengthen telomeres in melanoma下载原文
First Author:
Pattra Chun-on①
Corresponding Author:
Carol W. Greider②
Affiliations:
Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, Division of Pulmonary, Allergy, and Critical Care Medicine, Pittsburgh, PA, USA.①
Environmental and Occupational Health Department, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.①
Faculty of Medicine and Public Health, Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand.①
UC Santa Cruz Genomics Institute, University of California, Santa Cruz, CA, USA.②
Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA, USA.②
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.②
Abstract:
Overcoming replicative senescence is an essential step during oncogenesis, and the reactivation of TERT through promoter mutations is a common mechanism. TERT promoter mutations are acquired in about 75% of melanomas but are not sufficient to maintain telomeres, suggesting that additional mutations are required. We identified a cluster of variants in the promoter of ACD encoding the shelterin component TPP1. ACD promoter variants are present in about 5% of cutaneous melanoma and co-occur with TERT promoter mutations. The two most common somatic variants create or modify binding sites for E-twenty-six (ETS) transcription factors, similar to mutations in the TERT promoter. The variants increase the expression of TPP1 and function together with TERT to synergistically lengthen telomeres. Our findings suggest that TPP1 promoter variants collaborate with TERT activation to enhance telomere maintenance and immortalization in melanoma.