Carlos Mougan, Lauritz Morlock, Jair Aguirre, James R M Black, Jan Brauner, Simeon Campos, Sunishchal Dev, David Fernández Llorca, Alberto Franzin, Mario Fritz, Emilia Gómez, Friederike Grosse-Holz, Eloise Hamilton, Max Hasin, Jose Hernandez-Orallo, Dan Lahav, Luca Massarelli, Vasilios Mavroudis, Malcolm Murray, Patricia Paskov, Jaime Raldua, Wout Schellaert
AI evaluations should provide meaningful risk information without imposing excessive burden.
人工智能评估应提供有意义的风险信息，而不应造成过度负担。
{"title":"The science and practice of proportionality in AI risk evaluations.","authors":"Carlos Mougan, Lauritz Morlock, Jair Aguirre, James R M Black, Jan Brauner, Simeon Campos, Sunishchal Dev, David Fernández Llorca, Alberto Franzin, Mario Fritz, Emilia Gómez, Friederike Grosse-Holz, Eloise Hamilton, Max Hasin, Jose Hernandez-Orallo, Dan Lahav, Luca Massarelli, Vasilios Mavroudis, Malcolm Murray, Patricia Paskov, Jaime Raldua, Wout Schellaert","doi":"10.1126/science.aea3835","DOIUrl":"https://doi.org/10.1126/science.aea3835","url":null,"abstract":"<p><p>AI evaluations should provide meaningful risk information without imposing excessive burden.</p>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":"769-771"},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos José Saldanha Machado, Rodrigo Machado Vilani, Philip M Fearnside
{"title":"Brazil endangers global climate and health.","authors":"Carlos José Saldanha Machado, Rodrigo Machado Vilani, Philip M Fearnside","doi":"10.1126/science.aee6316","DOIUrl":"https://doi.org/10.1126/science.aee6316","url":null,"abstract":"","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":"774-775"},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andre Schwarz, Mara Mueller, Helene Will, Lea Dietrich, Stefano L. Giandomenico, Georgi Tushev, Ina Bartnik, Iskander Khusainov, Claudia M. Fusco, Erin M. Schuman
Cells down-regulate protein synthesis when stressed to conserve energy and shift resources toward repair. We found that in some mammalian cells, including neurons, stress also resulted in the formation of inactive ribosome-ribosome clusters (disomes). We used cryo–electron tomography (cryo-ET) to visualize ribosomes in situ and observed that this ribosome dimerization was mediated by a homotypic interaction of the ribosomal RNA (rRNA) expansion segment ES31Lb. ES31Lb interactions were both necessary and sufficient for disome formation and conferred a growth advantage and stress resistance to brain cells. ES31Lb is predicted to homodimerize in ~20% of chordates, including variants in both chicken and human. Cryo-ET analysis of chicken tetrasomes revealed an interaction between ES31Lb and ES9La. Thus, in animal cells, translation regulation can use a flexible component of the protein synthesis machinery—rRNA expansion segments.
{"title":"Ribosomal RNA expansion segments mediate the oligomerization of inactive animal ribosomes","authors":"Andre Schwarz, Mara Mueller, Helene Will, Lea Dietrich, Stefano L. Giandomenico, Georgi Tushev, Ina Bartnik, Iskander Khusainov, Claudia M. Fusco, Erin M. Schuman","doi":"10.1126/science.adr4287","DOIUrl":"https://doi.org/10.1126/science.adr4287","url":null,"abstract":"Cells down-regulate protein synthesis when stressed to conserve energy and shift resources toward repair. We found that in some mammalian cells, including neurons, stress also resulted in the formation of inactive ribosome-ribosome clusters (disomes). We used cryo–electron tomography (cryo-ET) to visualize ribosomes in situ and observed that this ribosome dimerization was mediated by a homotypic interaction of the ribosomal RNA (rRNA) expansion segment ES31Lb. ES31Lb interactions were both necessary and sufficient for disome formation and conferred a growth advantage and stress resistance to brain cells. ES31Lb is predicted to homodimerize in ~20% of chordates, including variants in both chicken and human. Cryo-ET analysis of chicken tetrasomes revealed an interaction between ES31Lb and ES9La. Thus, in animal cells, translation regulation can use a flexible component of the protein synthesis machinery—rRNA expansion segments.","PeriodicalId":21678,"journal":{"name":"Science","volume":"1 1","pages":""},"PeriodicalIF":56.9,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146222957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiazheng Sun, Xudong Tian, Zhenghan Zhang, Jing Liu, Lei Han, Fanrong Xu, Han Jiang, Chao Ma, Hongwei Guo, Cong Lin, Qike Jiang, Guangchao Li, Tsz Woon Benedict Lo, Haitao Song, Wei Lin, Le Xu, Jian Li
Stable extra-large pore zeolites are highly desirable for catalysis and molecular separation, but most remain microporous, limiting their effectiveness for bulky substrates. Among the few extra-large pore zeolites that exhibit mesoporosity, the pores typically form as elongated, non-circular pore aperture. we report NJU120-6, a stable silicate zeolite with an intrinsic cylindrical mesoporous system, have the currently largest 36-ring windows with a free diameter of 25.71 Ångstroms by 19.12 Ångstroms. NJU120-6 exhibits the lowest framework density of 9.39 Si atoms nm −3 and a pore volume of 0.66 cubic centimeters per grams. It remains stable up to 1173 K and can incorporate aluminum and titanium, enabling superior performance in catalytic cracking and in liquid-phase alkene oxidations of bulky molecules, respectively.
{"title":"A 36-ring zeolite with intrinsic cylindrical mesopores","authors":"Jiazheng Sun, Xudong Tian, Zhenghan Zhang, Jing Liu, Lei Han, Fanrong Xu, Han Jiang, Chao Ma, Hongwei Guo, Cong Lin, Qike Jiang, Guangchao Li, Tsz Woon Benedict Lo, Haitao Song, Wei Lin, Le Xu, Jian Li","doi":"10.1126/science.aec4882","DOIUrl":"https://doi.org/10.1126/science.aec4882","url":null,"abstract":"Stable extra-large pore zeolites are highly desirable for catalysis and molecular separation, but most remain microporous, limiting their effectiveness for bulky substrates. Among the few extra-large pore zeolites that exhibit mesoporosity, the pores typically form as elongated, non-circular pore aperture. we report NJU120-6, a stable silicate zeolite with an intrinsic cylindrical mesoporous system, have the currently largest 36-ring windows with a free diameter of 25.71 Ångstroms by 19.12 Ångstroms. NJU120-6 exhibits the lowest framework density of 9.39 Si atoms nm <jats:sup>−3</jats:sup> and a pore volume of 0.66 cubic centimeters per grams. It remains stable up to 1173 K and can incorporate aluminum and titanium, enabling superior performance in catalytic cracking and in liquid-phase alkene oxidations of bulky molecules, respectively.","PeriodicalId":21678,"journal":{"name":"Science","volume":"40 1","pages":""},"PeriodicalIF":56.9,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146222986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
How the mass terminations of "probationary" workers upended careers.
大规模解雇“试用”工人如何颠覆了他们的职业生涯。
{"title":"Fired federal scientists reflect on a year of turmoil.","authors":"Jocelyn Kaiser, Katie Langin, Erik Stokstad","doi":"10.1126/science.aeg5595","DOIUrl":"https://doi.org/10.1126/science.aeg5595","url":null,"abstract":"<p><p>How the mass terminations of \"probationary\" workers upended careers.</p>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":"751-752"},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lab animals deserve compassionate care and updated legal consideration, argues a veterinarian.
一位兽医认为，实验室动物应该得到富有同情心的照顾和最新的法律考虑。
{"title":"Creature comforts<b>The Hidden Lives of Lab Animals</b> <i>Larry Carbone</i> University of California Press, 2026. 360 pp.","authors":"David B Morton","doi":"10.1126/science.aee1009","DOIUrl":"https://doi.org/10.1126/science.aee1009","url":null,"abstract":"<p><p>Lab animals deserve compassionate care and updated legal consideration, argues a veterinarian.</p>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":"772"},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andre Schwarz, Mara Mueller, Helene Will, Lea Dietrich, Stefano L. Giandomenico, Georgi Tushev, Ina Bartnik, Iskander Khusainov, Claudia M. Fusco, Erin M. Schuman
Cells down-regulate protein synthesis when stressed to conserve energy and shift resources toward repair. We found that in some mammalian cells, including neurons, stress also resulted in the formation of inactive ribosome-ribosome clusters (disomes). We used cryo–electron tomography (cryo-ET) to visualize ribosomes in situ and observed that this ribosome dimerization was mediated by a homotypic interaction of the ribosomal RNA (rRNA) expansion segment ES31Lb. ES31Lb interactions were both necessary and sufficient for disome formation and conferred a growth advantage and stress resistance to brain cells. ES31Lb is predicted to homodimerize in ~20% of chordates, including variants in both chicken and human. Cryo-ET analysis of chicken tetrasomes revealed an interaction between ES31Lb and ES9La. Thus, in animal cells, translation regulation can use a flexible component of the protein synthesis machinery—rRNA expansion segments.
{"title":"Ribosomal RNA expansion segments mediate the oligomerization of inactive animal ribosomes","authors":"Andre Schwarz, Mara Mueller, Helene Will, Lea Dietrich, Stefano L. Giandomenico, Georgi Tushev, Ina Bartnik, Iskander Khusainov, Claudia M. Fusco, Erin M. Schuman","doi":"","DOIUrl":"","url":null,"abstract":"<div >Cells down-regulate protein synthesis when stressed to conserve energy and shift resources toward repair. We found that in some mammalian cells, including neurons, stress also resulted in the formation of inactive ribosome-ribosome clusters (disomes). We used cryo–electron tomography (cryo-ET) to visualize ribosomes in situ and observed that this ribosome dimerization was mediated by a homotypic interaction of the ribosomal RNA (rRNA) expansion segment ES31Lb. ES31Lb interactions were both necessary and sufficient for disome formation and conferred a growth advantage and stress resistance to brain cells. ES31Lb is predicted to homodimerize in ~20% of chordates, including variants in both chicken and human. Cryo-ET analysis of chicken tetrasomes revealed an interaction between ES31Lb and ES9La. Thus, in animal cells, translation regulation can use a flexible component of the protein synthesis machinery—rRNA expansion segments.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":""},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146217665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qiang Li, Ren Liu, Zuwan Lin, Xinhe Zhang, Wenbo Wang, Israeli M. Galicia-Silva, Mai Liu, Zihan Gao, Samuel D. Pollock, Juan R. Alvarez-Dominguez, Jia Liu
Understanding how human pancreatic α and β cell electrical activities mature is critical for building fully functional stem cell–derived (SC-) pancreatic organoids for research and therapeutics. We implanted tissue-like, stretchable electronics during organogenesis of human pancreatic organoids, enabling months-long, single cell–resolved electrophysiology. Longitudinal single-cell tracking suggested that improved hormone responsiveness reflects increasing activity of SC-α and -β cells with low and high basal firing, linked to induction of energy and hormone metabolism genes. Daily metabolic entrainment showed that circadian hormone secretion rhythms reflect daily oscillation of SC-α and -β electrical characteristics, tied to induction of cell-cell communication and exocytic gene networks, revealing circadian coordination of cell-level, stimulus-coupled responses. Lastly, we showed that electrical stimulation, via implanted actuators, enhances SC-α and -β glucose responsiveness. Our results establish a bioelectronic framework to trace and modulate functional organoid maturation.
{"title":"Implanted flexible electronics reveal principles of human islet cell electrical maturation","authors":"Qiang Li, Ren Liu, Zuwan Lin, Xinhe Zhang, Wenbo Wang, Israeli M. Galicia-Silva, Mai Liu, Zihan Gao, Samuel D. Pollock, Juan R. Alvarez-Dominguez, Jia Liu","doi":"","DOIUrl":"","url":null,"abstract":"<div >Understanding how human pancreatic α and β cell electrical activities mature is critical for building fully functional stem cell–derived (SC-) pancreatic organoids for research and therapeutics. We implanted tissue-like, stretchable electronics during organogenesis of human pancreatic organoids, enabling months-long, single cell–resolved electrophysiology. Longitudinal single-cell tracking suggested that improved hormone responsiveness reflects increasing activity of SC-α and -β cells with low and high basal firing, linked to induction of energy and hormone metabolism genes. Daily metabolic entrainment showed that circadian hormone secretion rhythms reflect daily oscillation of SC-α and -β electrical characteristics, tied to induction of cell-cell communication and exocytic gene networks, revealing circadian coordination of cell-level, stimulus-coupled responses. Lastly, we showed that electrical stimulation, via implanted actuators, enhances SC-α and -β glucose responsiveness. Our results establish a bioelectronic framework to trace and modulate functional organoid maturation.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":""},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146217666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paul C. Sereno, Daniel Vidal, Nathan P. Myhrvold, Evan Johnson-Ransom, María Ciudad Real, Stephanie L. Baumgart, Noelia Sánchez Fontela, Todd L. Green, Evan T. Saitta, Boubé Adamou, Lauren L. Bop, Tyler M. Keillor, Erin C. Fitzgerald, Didier B. Dutheil, Robert A. S. Laroche, Alexandre V. Demers-Potvin, Álvaro Simarro, Francesc Gascó-Lluna, Ana Lázaro, Arturo Gamonal, Charles V. Beightol, Vincent Reneleau, Rachel Vautrin, Filippo Bertozzo, Alejandro Granados, Grace Kinney-Broderick, Jordan C. Mallon, Rafael M. Lindoso, Jahandar Ramezani
We describe a close relative of Spinosaurus aegyptiacus, the sail-backed, fish-eating giant from nearshore deposits of northern Africa. Spinosaurus mirabilis sp. nov., discovered in the central Sahara alongside long-necked dinosaurs in a riparian habitat, is distinguished by a scimitar-shaped bony crest projecting far above its skull roof. We discern three discrete phases in spinosaurid evolution. During the first phase with roots in the Jurassic, an elongate fish-snaring skull emerged that soon was modified along divergent paths. During a second Early Cretaceous phase, spinosaurids became the dominant predators in circum-Tethyan habitats. The final phase began just before the Late Cretaceous during the opening of the Atlantic Ocean, when spinosaurines attained maximum body size as shallow water ambush specialists limited geographically to northern Africa and South America.
{"title":"Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation","authors":"Paul C. Sereno, Daniel Vidal, Nathan P. Myhrvold, Evan Johnson-Ransom, María Ciudad Real, Stephanie L. Baumgart, Noelia Sánchez Fontela, Todd L. Green, Evan T. Saitta, Boubé Adamou, Lauren L. Bop, Tyler M. Keillor, Erin C. Fitzgerald, Didier B. Dutheil, Robert A. S. Laroche, Alexandre V. Demers-Potvin, Álvaro Simarro, Francesc Gascó-Lluna, Ana Lázaro, Arturo Gamonal, Charles V. Beightol, Vincent Reneleau, Rachel Vautrin, Filippo Bertozzo, Alejandro Granados, Grace Kinney-Broderick, Jordan C. Mallon, Rafael M. Lindoso, Jahandar Ramezani","doi":"","DOIUrl":"","url":null,"abstract":"<div >We describe a close relative of <i>Spinosaurus aegyptiacus</i>, the sail-backed, fish-eating giant from nearshore deposits of northern Africa. <i>Spinosaurus mirabilis</i> sp. nov., discovered in the central Sahara alongside long-necked dinosaurs in a riparian habitat, is distinguished by a scimitar-shaped bony crest projecting far above its skull roof. We discern three discrete phases in spinosaurid evolution. During the first phase with roots in the Jurassic, an elongate fish-snaring skull emerged that soon was modified along divergent paths. During a second Early Cretaceous phase, spinosaurids became the dominant predators in circum-Tethyan habitats. The final phase began just before the Late Cretaceous during the opening of the Atlantic Ocean, when spinosaurines attained maximum body size as shallow water ambush specialists limited geographically to northern Africa and South America.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":""},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146217676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Playing the game of science","authors":"Vijaysree Venkatraman","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":21678,"journal":{"name":"Science","volume":"391 6787","pages":""},"PeriodicalIF":45.8,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146217668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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