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

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• A long- distance inhibitory system regulates haustoria numbers in parasitic plants AI翻译
  作者：Kokla, Anna; Leso, Martina; Simura, Jan; Wardig, Cecilia; Hayashi, Marina; Nishii, Naoshi; Tsuchiya, Yuichiro; Ljung, Karin; Melnyk, Charles W.
  作者单位：Swedish University of Agricultural Sciences; Swedish University of Agricultural Sciences; Umea University; Nagoya University; Nagoya University
  摘要：The ability of parasitic plants to withdraw nutrients from their hosts depends on the formation of an infective structure known as the haustorium. How parasites regulate their haustoria numbers is poorly understood, and here, we uncovered that existing haustoria in the facultative parasitic plants Phtheirospermum japonicum and Parentucellia viscosa suppressed the formation of new haustoria located on distant roots. Using Phtheirospermum, we found that this effect depended on the formation of m...
• Short-term exposure to filter-bubble recommendation systems has limited polarization effects: Naturalistic experiments on YouTube AI翻译
  作者：Liu, Naijia; Hu, Xinlan Emily; Savas, Yasemin; Baum, Matthew A.; Berinsky, Adam J.; Chaney, Allison J. B.; Lucas, Christopher; Mariman, Rei; de Benedictis-Kessner, Justin; Guess, Andrew M.; Knox, Dean; Stewart, Brandon M.
  作者单位：Harvard University; University of Pennsylvania; Princeton University; Harvard University; Massachusetts Institute of Technology (MIT); Duke University; Washington University (WUSTL); Princeton University; Princeton University; Princeton University
  摘要：An enormous body of literature argues that recommendation algorithms drive political polarization by creating filter bubbles and rabbit holes. Using four experiments with nearly 9,000 participants, we show that manipulating algorithmic recommendations to create these conditions has limited effects on opinions. Our experiments employ a custom-built video platform with a naturalistic, YouTube-like interface presenting real YouTube videos and recommendations. We experimentally manipulate YouTube'...
• Resolving the dynamic correlated disorder in KTa1-XNbXO3 AI翻译
  作者：He, Xing; Gupta, Mayanak K.; Abernathy, Douglas L.; Granroth, Garrett E.; Ye, Feng; Winn, Barry L.; Boatner, Lynn; Delaire, Olivier
  作者单位：Duke University; Bhabha Atomic Research Center (BARC); United States Department of Energy (DOE); Oak Ridge National Laboratory; United States Department of Energy (DOE); Oak Ridge National Laboratory; Duke University; Duke University
  摘要：Understanding the complex temporal and spatial correlations of ions in disordered perovskite oxides is critical to rationalize their functional properties. Here, we provide insights into the longstanding controversy regarding the off-centering of transition metal (TM) ions in the archetypal ferroelectric alloy KTa1-xNbxO3 (KTN). By mapping the full energy (E) and wavevector (Q) dependence of the dynamical structure factor S(Q, E) using neutron scattering, and rationalizing our observations wit...
• Stepwise activation of SARM1 for cell death and axon degeneration revealed by a biosynthetic NMN mimic AI翻译
  作者：Huang, Yinpin; Zhang, Jun; Zhang, Wenbin; Chen, Jie; Chen, Sijia; Wu, Qincui; Zheng, Sanduo; Wang, Xiaodong
  作者单位：Tsinghua University; National Institute of Biological Sciences, Beijing
  摘要：Axon degeneration, driven by the NAD+ hydrolyzing enzyme SARM1, is an early pathological hallmark of numerous neurodegenerative diseases. SARM1 exists in an inactive form and is activated following nerve injury. However, the precise molecular mechanism underlying SARM1 activation remains to be fully elucidated. In this study, we report the identification of a potent proactivator of SARM1, G10, which is converted into a direct activator (M1) by the enzyme nicotinamide phosphoribosyltransferase....
• Broad-spectrum tolerance to disinfectant- mediated bacterial killing due to mutation of the PheS aminoacyl tRNA synthetase AI翻译
  作者：Chen, Miaomiao; Cui, Runbo; Hong, Shouqiang; Zhu, Weiwei; Yang, Qiong; Li, Jiahao; Nie, Zihan; Zhang, Xue; Ye, Yanghui; Xue, Yunxin; Wang, Dai; Hong, Yuzhi; Drlica, Karl; Niu, Jianjun; Zhao, Xilin
  作者单位：Xiamen University; Xiamen University; Soochow University - China; Rutgers University System; Rutgers University New Brunswick; Rutgers University Biomedical & Health Sciences; Rutgers University Newark; Rutgers University System; Rutgers University New Brunswick; Rutgers University Biomedical & Health Sciences; Rutgers University Newark
  摘要：Disinfectants are essential tools for controlling infectious diseases and maintaining sterile conditions in many medical and food- industry settings. Recent work revealed that a deficiency in the carbohydrate phosphotransferase system (PTS) confers pan- tolerance to killing by diverse disinfectant types through its interaction with the cAMP- CRP regulatory network. The present work characterized a pan- tolerance mutant obtained by enrichment using phenol as a lethal probe and an Escherichia co...
• The revised elastic field of an edge dislocation AI翻译
  作者：Hirth, J. P.; Anderson, P. M.
  作者单位：University System of Ohio; Ohio State University
  摘要：We modify the traditional linear- elastic field of an edge dislocation. The modifications stem from symmetry and energy requirements imposed in terms of embedded (deformed) coordinates. These requirements are satisfied if a line force is added to the dislocation field. The modification to the stress field is expressed by coefficients that are a function only of Poisson's ratio. Qualitatively, the field of the dislocation is increased in the glide direction and decreased in the climb direction....
• Spatiotemporal distribution of the North American Indigenous population prior to European contact AI翻译
  作者：Kelly, Robert L.; Mackie, Madeline E.; Pelton, Spencer R.; Robinson, Erick
  作者单位：University of Wyoming; Michigan State University; University of Wyoming; Nevada System of Higher Education (NSHE); Desert Research Institute NSHE; Arizona State University; Arizona State University-Tempe
• Intracranial substrates of meditation- induced neuromodulation in the amygdala and hippocampus AI翻译
  作者：Maher, Christina; Tortolero, Lea; Jun, Soyeon; Cummins, Daniel D.; Saad, Adam; Young, James; Martinez, Lizbeth Nunez; Schulman, Zachary; Marcuse, Lara; Waters, Allison; Mayberg, Helen S.; Davidson, Richard J.; Panov, Fedor; Saez, Ignacio
  作者单位：Icahn School of Medicine at Mount Sinai; Icahn School of Medicine at Mount Sinai; Icahn School of Medicine at Mount Sinai; Icahn School of Medicine at Mount Sinai; Icahn School of Medicine at Mount Sinai; Icahn School of Medicine at Mount Sinai; University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison
  摘要：Meditation is an accessible mental practice associated with emotional regulation and well- being. Loving- kindness meditation (LKM), a specific subtype of meditative prac-tice, involves focusing one's attention on thoughts of well- being for oneself and others. Meditation has been proven to be beneficial in a variety of settings, including therapeutic applications, but the neural activity underlying meditative practices and their positive effects are not well understood. It has been difficult ...
• PgpP is a broadly conserved phosphatase required for phosphatidylglycerol lipid synthesis AI翻译
  作者：Grundling, Angelika; Brogan, Anna P.; James, Michael J.; Ramirez-Guadiana, Fernando H.; Roney, Ian J.; Bernhardt, Thomas G.; Rudner, David Z.
  作者单位：Imperial College London; Imperial College London; Harvard University; Harvard Medical School; Howard Hughes Medical Institute
  摘要：The cytoplasmic membrane of bacteria is composed of a phospholipid bilayer made up of a diverse set of lipids. Phosphatidylglycerol (PG) is one of the principal constituents and its production is essential for growth in many bacteria. All the enzymes required for PG biogenesis in Escherichia coli have been identified and characterized decades ago. However, it has remained poorly understood how gram- positive bacteria perform the terminal step in the pathway that produces this essential lipid. ...
• Growth decline in European beech associated with temperature- driven increase in reproductive allocation AI翻译
  作者：Hacket-Pain, Andrew; Szymkowiak, Jakub; Journe, Valentin; Barczyk, Maciej K.; Thomas, Peter A.; Lageard, Jonathan G. A.; Kelly, Dave; Bogdziewicz, Michal
  作者单位：University of Liverpool; Adam Mickiewicz University; Adam Mickiewicz University; Keele University; Manchester Metropolitan University; University of Canterbury
  摘要：Climate change is impacting forests in complex ways, with indirect effects arising from interactions between tree growth and reproduction often overlooked. Our 43- y study of European beech (Fagus sylvatica) showed that rising summer temperatures since 2005 have led to more frequent seed production events. This shift increases reproductive effort but depletes the trees' stored resources due to insufficient recovery periods between seed crops. Consequently, annual tree ring increments have decl...