Science

最新文章

• The EPA's shaken foundation AI翻译
  作者：Frey, H. Christopher
  作者单位：North Carolina State University
• The phylogenetic position of the Yunxian cranium elucidates the origin of Homo longi and the Denisovans AI翻译
  作者：Feng, Xiaobo; Yin, Qiyu; Gao, Feng; Lu, Dan; Fang, Qin; Feng, Yilu; Huang, Xuchu; Tan, Chen; Zhou, Hanwen; Li, Qiang; Zhang, Chi; Stringer, Chris; Ni, Xijun
  作者单位：Shanxi University; Hubei Polytechnic University; Hanjiang Normal University; Hanjiang Normal University; Chinese Academy of Sciences; Institute of Vertebrate Paleontology & Paleoanthropology, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; China University of Geosciences; Natural History Museum London; Fudan University
  摘要：Diverse forms of Homo coexisted during the Middle Pleistocene. Whether these fossil humans represent different species or clades is debated. The similar to 1-million-year-old Yunxian 2 fossil from China is important for understanding the cladogenesis of Homo and the origin of Homo sapiens. In this study, we restored and reconstructed the distorted Yunxian 2 cranium using recently introduced technology. The results show that this cranium displays mosaic primitive and derived features. Morphomet...
• By-product recovery from US metal mines could reduce import reliance for critical minerals AI翻译
  作者：Holley, Elizabeth A.; Hadden, Karlie M.; Hammerling, Dorit; Eggert, Rod; Spiller, D. Erik; Nelson, Priscilla P.
  作者单位：Colorado School of Mines; Colorado School of Mines; Colorado School of Mines; Colorado School of Mines
  摘要：The United States (US) has sufficient geological endowment in active metal mines to reduce the nation's dependence on critical mineral imports. Demand is increasing for cobalt, nickel, rare earth elements, tellurium, germanium, and other materials used in energy production, semiconductors, and defense. This study uses a statistical evaluation of new geochemical datasets to quantify the critical minerals that are mined annually in US ores but go unrecovered. Ninety percent recovery of by-produc...
• The cosmic time machine on Long Island winds down AI翻译
  作者：Cho, Adrian
• Ethicists flirt with AI for reviewing human research AI翻译
  作者：Zhao, Celina
• Deazaguanylation is a nucleobase-protein conjugation required for type IV CBASS immunity AI翻译
  作者：Wassarman, Douglas R.; Pfaff, Patrick; Paulo, Joao A.; Gygi, Steven P.; Shokat, Kevan M.; Kranzusch, Philip J.
  作者单位：Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; University of California System; University of California San Francisco; University of California System; University of California San Francisco; Howard Hughes Medical Institute; Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute
  摘要：7-Deazapurines are nucleobase analogs essential for nucleic acid modifications in nearly all cellular life. In this study, we discovered a role for 7-deazapurines in protein modification within type IV cyclic oligonucleotide-based antiviral signaling system (CBASS) antiphage defense and defined functions for CBASS ancillary proteins Cap9 and Cap10 in nucleobase-protein conjugation. A structure of Cap10 revealed a transfer RNA transglycosylase family enzyme remodeled to bind a partner cGAS/DncV...
• Crustal stresses and damage evolve throughout the seismic cycle of the Ridgecrest fault zone AI翻译
  作者：Bryan, Jared; Frank, William B.; Audet, Pascal
  作者单位：Massachusetts Institute of Technology (MIT); University of Ottawa
  摘要：Earthquakes abruptly release tectonic stress that builds slowly over time through the coupled evolution of faults and the surrounding crust. Seismic wavespeeds track crustal deformation and stress changes, but typical monitoring methods are most sensitive to shallow depths. Using receiver functions, we tracked rupture-zone wavespeed and anisotropy changes throughout the crust during the 2019 Ridgecrest earthquake sequence. Shallow coseismic wavespeed reductions recovered within months, whereas...
• Categorical and semantic perception of the meaning of call types in zebra finches AI翻译
  作者：Elie, Julie E.; de Witasse-Thezy, Aude; Thomas, Logan; Malit, Ben; Theunissen, Frederic E.
  作者单位：University of California System; University of California Berkeley; Universite Claude Bernard Lyon 1; Ecole Normale Superieure de Lyon (ENS de LYON); University of California System; University of California Berkeley; University of California System; University of California Berkeley
  摘要：Vocal communication in social animals involves the production and perception of various calls that ethologists categorize into call types based on their acoustical structure and behavioral context. Whether these categories indicate distinct meanings for the animals remains unknown. The zebra finch, a gregarious songbird, uses similar to 11 call types that are known to communicate hunger, danger, or social conflict and to establish social contact and bonding. Using auditory discrimination tasks...
• Climate rather than overgrazing explains most rangeland primary productivity change in Mongolia AI翻译
  作者：Purevjav, Avralt-Od; Avirmed, Tumenkhusel; Wilcox, Steven W.; Barrett, Christopher B.
  作者单位：The World Bank; Stanford University; Utah System of Higher Education; Utah State University; Cornell University; Cornell University
  摘要：Rangelands are Earth's dominant land type, supporting the livelihoods of more than 2 billion people. Concerns about rangeland degradation typically focus on overgrazing. But climate change may be a greater culprit. Using spatially disaggregated, nationwide data from Mongolia, from 1984 to 2024, we exploited seasonal variation in grazing locations to quasi-experimentally estimate the causal effects of livestock herd size, weather, and climate change on rangeland primary productivity. At interan...
• Stereo-reversed E2 unlocks Z-selective C-H functionalization AI翻译
  作者：Verardi, Peter J.; Ryutov, Elizabeth A.; Mukherjee, Poulami; Lalisse, Remy; Targos, Karina; Inagaki, Tetsuya; Kelly, Megan; Guzei, Ilia A.; Schreier, Marcel; Gutierrez, Osvaldo; Wickens, Zachary K.
  作者单位：University of Wisconsin System; University of Wisconsin Madison; University of California System; University of California Los Angeles; University of Osaka; University of Wisconsin System; University of Wisconsin Madison
  摘要：The stereoselective functionalization of C-H bonds represents a central challenge in modern organic synthesis. Despite decades of innovation in C-H activation chemistry, methods for Z-selective functionalization of alkenes have eluded synthetic practitioners. Terminal alkenes present the biggest challenge for Z-selectivity as they require selective cleavage of the more hindered of two otherwise virtually identical C-H bonds. Herein, we describe the transformation of alkenes into transient 1,2-...