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

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• Logging disrupts the ecology of molecules in headwater streams AI翻译
  作者：[Anonymous]
  摘要：Global demand for wood products is increasing forest harvest. One understudied consequence of logging is that it accelerates mobilization of dissolved organic matter (DOM) from soils to aquatic ecosystems where it is more easily rereleased to the atmosphere. Here, we tested how logging changed DOM in headwaters of hardwood-dominated catchments in northern Ontario, Canada. We applied a before-after-control-impact experiment across four catchments for 3 y and measured DOM monthly during ice-free...
• Diverse thioether macrocyclized peptides through a radical SAM maturase AI翻译
  作者：Eastman, Karsten A. S.; Roberts, Andrew G.; Bandarian, Vahe
  作者单位：Utah System of Higher Education; University of Utah
  摘要：Disulfide bonds stabilize many bioactive peptides, but their susceptibility to reduction under physiological conditions limits broad applicability in biotechnology. PapB is a promiscuous radical S-adenosyl-L-methionine enzyme that is involved in the maturation of PapA, which is a ribosomally produced and posttranslationally modified polypeptide. PapB introduces six thioether linkages between internal Cys residues and carbon atom that is alpha to the side-chain carboxylate of Asp/Glu residues C...
• Underappreciated role of canopy nitrogen deposition for forest productivity AI翻译
  作者：Li, Xiaowei; Zhang, Chenlu; Zhang, Beibei; Jiang, Li; Tang, Shengqi; Sun, Chenhui; Bai, Yulong; Wang, Yubang; Shi, Yifei; Ma, Lei; Zhang, Wei; Ye, Qing; Yan, Junhua; Wang, Keya; Fu, Juemin; Du, Wenzhi; Ha, Denglong; Ju, Yuxi; Wan, Shiqiang; Hong, Liang; Fang, Yunting; Siemann, Evan; Luo, Yiqi; Reich, Peter B.; Ort, Donald
  作者单位：Henan University; Henan University; Henan University; Henan University; Chinese Academy of Agricultural Sciences; Institute of Cotton Research, CAAS; Chinese Academy of Sciences; South China Botanical Garden, CAS; Hebei University; Xinyang Normal University; Chinese Academy of Sciences; Shenyang Institute of Applied Ecology, CAS; Rice University; Cornell University; University of Minnesota System; University of Minnesota Twin Cities; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan
  摘要：Atmospheric nitrogen (N) deposition is generally expected to stimulate plant carbon (C) sequestration and promote tree growth, thereby mitigating atmospheric CO2 accumulation. Yet, the magnitude of N deposition contribution to forest productivity remains contentious. While correlative studies suggest substantial plant growth enhancement, controlled fertilization experiments typically demonstrate a limited impact. This discrepancy may arise from whether or not to consider canopy N uptake proces...
• Locusts employ neuronal sensory prioritization to reconcile two conflicting olfactory signals while aggregating AI翻译
  作者：Yu, Qiaoqiao; Yang, Jing; Yu, Jia; Lei, Hong; Kang, Le; Guo, Xiaojiao
  作者单位：Chinese Academy of Sciences; Institute of Zoology, CAS; Arizona State University; Arizona State University-Tempe; Hebei University; Shenzhen University of Advanced Technology
  摘要：Migratory locusts (Locusta migratoria) emit two key odorants during aggregation: 4-vinylanisole (4VA), which serves as an aggregation pheromone attracting conspecifics to form swarms, and phenylacetonitrile (PAN), which acts as an aposematic signal and a precursor of a defense toxin, deterring conspecifics from cannibalism and protecting against predators. However, how locusts reconcile these two conflicting olfactory signals while aggregating is not yet understood. Our study addresses this by...
• Embolism resistance supports the contribution of dry-season precipitation to transpiration in eastern Amazon forests AI翻译
  作者：Nehemy, Magali F.; Mattos, Caio R. C.; Oliveira, Rafael S.; Hirota, Marina; Fan, Ying; Schlickmann, Monique B.; Penha, Deliane; Giacomin, Leandro L.; Silva, Julliene S. G. M.; Rocha, Mayda; Rodrigues, Gleicy A.; McDonnell, Jeffrey J.
  作者单位：University of British Columbia; University of British Columbia Okanagan; Trent University; Rutgers University System; Rutgers University New Brunswick; Universidade Federal de Santa Catarina (UFSC); Universidade Estadual de Campinas; State University System of Florida; University of Florida; Universidade Federal do Oeste do Para; Universidade Federal da Paraiba; University of Saskatchewan; North China University of Water Resources & Electric Power; University of Birmingham; Universidade Federal do Oeste do Para
  摘要：Transpiration drives most of the local rainfall during the dry season in the Amazon forests by recycling moisture into the atmosphere. However, the source, temporal origin of transpiration, and spatial distribution of transpiration water sources remain unclear. Here, we quantify transpiration sources across a topographic gradient in the eastern Amazon. We show that on hills, dry-season transpiration sources are mostly shallow soil water recharged by dry-season rainfall. This is different in va...
• Refugees from Ukraine value job opportunities over welfare AI翻译
  作者：Adema, Joop; Chargaziia, Lasha; Giesing, Yvonne; Poutvaara, Panu
  作者单位：University of Innsbruck; Leibniz Association; Ifo Institut; University of Munich
  摘要：Understanding refugees' destination choices is key to designing appropriate policies, but little is known about this beyond correlational patterns and the effects of isolated policy changes. To derive causal evidence on how destination country characteristics affect refugees' destination choices, we conducted a forced-choice conjoint experiment among 3,348 Ukrainian refugees across Europe. In the survey experiment, refugees repeatedly chose between two hypothetical countries that varied on eig...
• Lattice materials with topological states optimized on demand AI翻译
  作者：Azizi, Pegah; Kundu, Rahuldev; Li, Weichen; Sun, Kai; Zhang, Xiaojia Shelly; Gonella, Stefano
  作者单位：University of Minnesota System; University of Minnesota Twin Cities; University of Illinois System; University of Illinois Urbana-Champaign; University of Michigan System; University of Michigan
  摘要：Topological states of matter, first discovered in quantum systems, have opened new avenues for wave manipulation beyond the quantum realm. In elastic media, realizing these topological effects requires identifying lattices that support the corresponding topological bands. However, among the vast number of theoretically predicted topological states, only a small fraction has been physically realized. To close this gap, we present a strategy capable of systematically and efficiently discovering ...
• Rapid, interpretable data-driven models of neural dynamics using recurrent mechanistic models AI翻译
  作者：Burghi, Thiago B.; Ivanova, Maria; Morozova, Ekaterina; Wang, Huaxinyu; Marder, Eve; O'Leary, Timothy
  作者单位：University of Cambridge; Brandeis University
  摘要：Obtaining predictive models of a neural system is notoriously challenging. Detailed models suffer from excess model complexity and are difficult to fit efficiently. Simplified models must negotiate a tradeoff between tractability, predictive power, and ease of interpretation. We present a modeling paradigm for estimating predictive, mechanistic models of neurons and small circuits that navigates these issues using methods from systems theory. The key insight is that membrane currents can be mo...
• Progressively greater biological carbon storage in the deep Atlantic during glacial inception AI翻译
  作者：Garity, Monica; Lund, David; Jerris, Hope; McBride, Jacquelyn
  作者单位：University of Connecticut; Middlebury College
  摘要：Changes in oceanic circulation and carbon storage have been implicated as important drivers of atmospheric pCO(2) variability during the last glacial cycle (0 to 150 ka), though consensus on the mechanisms responsible remains elusive due to sparse marine carbonate chemistry reconstructions. Here, we present vertical profiles of carbonate ion concentration ([CO32-]) from the Southwest Atlantic to investigate oceanic carbon sequestration during key intervals of atmospheric CO2 change. During the...
• Foraging ants as liquid brains: Movement heterogeneity shapes collective efficiency AI翻译
  作者：Fernandez-Lopez, Pol; Oro, Daniel; Lloret-Cabot, Roger; Genovart, Meritxell; Garriga, Joan; Bartumeus, Frederic
  作者单位：Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Centre d'Estudis Avancats de Blanes (CEAB); Universite de Toulouse; Universite Toulouse III - Paul Sabatier; Centre National de la Recherche Scientifique (CNRS); ICREA; Centro de Investigacion Ecologica y Aplicaciones Forestales (CREAF-CERCA)
  摘要：Liquid brains conceptualize living systems that operate without central control, where collective outcomes emerge from local and dynamic interactions. This concept extends beyond ants and other social insects to include immune systems, slime molds, and microbiomes. In such systems, connectivity scales with population density, facilitating more efficient information transfer as group size increases. However, in sparse conditions, where fewer individuals interact, movement likely plays a crucial...