Proceedings of the National Academy of Sciences of the United States of America

最新文章

• Maria Iandolo New (1928-2024): Pioneering pediatric endocrinologist AI翻译
  作者：White, Perrin C.; Miller, Walter L.
  作者单位：University of Texas System; University of Texas Southwestern Medical Center; University of California System; University of California San Francisco; University of California System; University of California San Francisco
• Reconciling Archean organic- rich mudrocks with low primary productivity before the Great Oxygenation Event AI翻译
  作者：Lotem, Noam; Rasmussen, Birger; Zi, Jian -Wei; Zeichner, Sarah S.; Present, Theodore M.; On, Yinon M. Bar-; Fischer, Woodward W.
  作者单位：California Institute of Technology; University of Western Australia; Curtin University
  摘要：The organic carbon content of ancient rocks provides a fundamental record of the biosphere on early Earth. For over 50 y, the high organic content of Archean (>2.5 Ga) mudrocks has puzzled geologists and evolutionary biologists, because high biological primary productivity was unexpected for the nascent biosphere before the rise of O-2. Here, we took a different approach to resolve this apparent paradox, by studying the accumulation rates of Archean organic-rich mudrocks. We evaluated the sedi...
• Perspectives on Mars Sample Return: A critical resource for planetary science and exploration AI翻译
  作者：McSween, Harry Y., Jr.; Hamilton, Victoria E.; Farley, Kenneth A.
  作者单位：University of Tennessee System; University of Tennessee Knoxville; Southwest Research Institute; California Institute of Technology
  摘要：mission priority in the last two Planetary Decadal Surveys Medicine (hereafter, the National Academies) and was the highest priority flagship for Mars in the Decadal Survey that preceded them. This inspirational and challenging campaign, like the Apollo program's returned lunar samples, will potentially revolutionize our understanding of Mars and help inform how other planets are explored. MSR's technological advances will keep the NASA and European Space Agency at the forefront of planetary e...
• Reply to Kaestner et al.: Activation of PIEZO1 is not significant for the passage of red blood cells through biomimetic splenic slits AI翻译
  作者：Moreau, Alexis; Yaya, Francois; Lu, Huijie; Surendranath, Anagha; Charrier, Anne; Dehapiot, Benoit; Helfer, Emmanuele; Viallat, Annie; Peng, Zhangli
  作者单位：Aix-Marseille Universite; Centre National de la Recherche Scientifique (CNRS); University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; Aix-Marseille Universite; Centre National de la Recherche Scientifique (CNRS)
• CryoEM structure of an MHC- I/TAPBPR peptide- bound intermediate reveals the mechanism of antigen proofreading AI翻译
  作者：Sun, Yi; Pumroy, Ruth A.; Mallik, Leena; Chaudhuri, Apala; Wang, Chloe; Hwang, Daniel; Danon, Julia N.; Goli, Kimia Dasteh; Moiseenkova-Bell, Vera Y.; Sgourakis, Nikolaos G.
  作者单位：University of Pennsylvania; University of Pennsylvania; Pennsylvania Medicine; Childrens Hospital of Philadelphia; University of Pennsylvania; Pennsylvania Medicine; Childrens Hospital of Philadelphia; University of Pennsylvania; University of Pennsylvania
  摘要：Class I major histocompatibility complex (MHC-I) proteins play a pivotal role in adaptive immunity by displaying epitopic peptides to CD8+ T cells. The chaperones tapasin and TAPBPR promote the selection of immunogenic antigens from a large pool of intracellular peptides. Interactions of chaperoned MHC-I molecules with incoming peptides are transient in nature, and as a result, the precise antigen proofreading mechanism remains elusive. Here, we leverage a high- fidelity TAPBPR variant and con...
• State shifts in the deep Critical Zone drive landscape evolution in volcanic terrains AI翻译
  作者：Karlstrom, Leif; Klema, Nathaniel; Grant, Gordon E.; Finn, Carol; Sullivan, Pamela L.; Cooley, Sarah; Simpson, Alex; Fasth, Becky; Cashman, Katharine; Ferrier, Ken; Ball, Lyndsay; Mckay, Daniele
  作者单位：University of Oregon; Fort Lewis College; United States Department of Agriculture (USDA); United States Forest Service; Oregon State University; United States Department of the Interior; United States Geological Survey; Duke University; University of Oregon; University of Wisconsin System; University of Wisconsin Madison
  摘要：Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that the central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology that are linked to aging volcanic bedrock, suggesting systematic controls on landscape evolution. At the Cascade crest, a locus of Quaternary volcanism, water circulates deeply through the upper similar to 1 km of crust but transitions to shallow and dominantly horizontal flow as rocks ag...
• Stochastic morphological swings in Hydra regeneration: A manifestation of noisy canalized morphogenesis AI翻译
  作者：Agam, Oded; Braun, Erez
  作者单位：Hebrew University of Jerusalem; Technion Israel Institute of Technology
  摘要：Animal morphogenesis, the development of an organism's body form, is commonly perceived as a directed and almost deterministic process. However, noise and stochastic fluctuations are ubiquitous in biological systems. The questions on the role of fluctuations in morphogenesis and what ensures the robustness of this process under noisy conditions remain elusive. Here, we utilize Hydra regeneration, subjected to an external electric field, to provide unique insights into these questions. We found...
• Divergence time and environmental similarity predict the strength of morphological convergence in stick and leaf insects AI翻译
  作者：Boisseau, Romain P.; Bradler, Sven; Emlen, Douglas J.
  作者单位：University of Montana System; University of Montana; University of Lausanne; University of Gottingen
  摘要：Independent evolution of similar traits in lineages inhabiting similar environments (convergent or repeated evolution) is often taken as evidence for adaptation by natural selection, and used to illustrate the predictability of evolution. Yet convergence is rarely perfect for two reasons. First, environments may not be as similar as they appear. Second, responses to selection are contingent upon available genetic variation and independent lineages may differ in the alleles, genetic backgrounds...
• Earliest evidence of sedentism in the Antilles: Multiple isotope data from Canímar Abajo, Cuba AI翻译
  作者：de Armas, Yadira Chinique; Godoy, Silvia Teresita Hernandez; Sanfiel, Luis M. Viera; Buhay, William M.; Laffoon, Jason E.
  作者单位：University of Winnipeg; Leiden University - Excl LUMC; Leiden University; Vrije Universiteit Amsterdam
  摘要：The early populations that inhabited the Antilles were traditionally understood as highly mobile groups of hunters/fishers and gatherers. Although more recent data have demonstrated that some populations engaged in the production of domestic plants and cultivars, questions remain about other aspects of their lifeways, including whether the adoption of domesticates was accompanied by a decrease in residential mobility. The level of sedentism in a population is an instrumental variable to unders...
• A lever hypothesis for Synaptotagmin-1 action in neurotransmitter release AI翻译
  作者：Jaczynska, Klaudia; Esser, Victoria; Xu, Junjie; Sari, Levent; Lin, Milo M.; Rosenmund, Christian; Rizo, Josep
  作者单位：University of Texas System; University of Texas Southwestern Medical Center; University of Texas System; University of Texas Southwestern Medical Center; University of Texas System; University of Texas Southwestern Medical Center; University of Texas System; University of Texas Southwestern Medical Center; Free University of Berlin; Humboldt University of Berlin; Charite Universitatsmedizin Berlin; Free University of Berlin; Humboldt University of Berlin
  摘要：Neurotransmitter release is triggered in microseconds by Ca2+- binding to the dles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca2+- sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker through a primary interface comprising two regions (I and II). The Synaptotagmin- 1 curvature, perturbing lipid bilayers, or helping bridge the membranes, but SNARE from th...