27期

最新文章

• A molecular timescale for evolution of cobamide biosynthesis AI翻译
  作者：Wang, Jichen; Ai, Chao; Tiedje, James M.; Ge, Yuan
  作者单位：Chinese Academy of Agricultural Sciences; Institute of Agricultural Resources & Regional Planning, CAAS; Michigan State University; Chinese Academy of Sciences; Research Center for Eco-Environmental Sciences (RCEES), CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
  摘要：Cobamides are essential nutrients for most organisms but are only biosynthesized by a limited number of taxa through aerobic and anaerobic pathways. Although the origin of these widespread shared cofactors changed ecosystems and the metabolisms of living organisms, little evolutionary information is available about the biosynthetic genes and the producers. Here, we established a timeframe for the emergence of cobamide biosynthesis genes and producers, using a series of Bayesian molecular clock...
• Histone H1 promotes silencing of unintegrated HIV-1 DNA AI翻译
  作者：Zhu, Jiaqi; Wang, Gary Z.; Pinto, Hugo D.; Healton, Sean E.; Mishra, Laxmi N.; Skoultchi, Arthur I.; Goff, Stephen P.
  作者单位：Columbia University; Columbia University; Columbia University; Yeshiva University; Montefiore Medical Center; Albert Einstein College of Medicine
  摘要：In eukaryotic cells, genomic DNA is packaged into chromatin with nucleosomes formed by core histones H2A, H2B, H3, and H4, and further stabilized by the linker histone H1. During the early stages of retroviral infection, such as with murine leukemia virus (MLV) and human immunodeficiency virus type 1 (HIV-1), host core and H1 histones are rapidly deposited onto unintegrated viral DNAs upon nuclear entry. These unintegrated viral DNAs are transcriptionally silenced through histone posttranslati...
• Nucleotide diversity is a poor predictor of short-term adaptive potential AI翻译
  作者：Abson, Katie L.; Zijmers, Lillith; Mittell, Elizabeth A.; Young, Euan A.; Postma, Erik; Eyre-Walker, Adam; Hadfield, Jarrod D.
  作者单位：University of Edinburgh; University of Sussex; University of Groningen; University of Exeter
  摘要：The capacity to adapt is essential for a population to avoid extinction in a changing world and is recognized as a global conservation priority. Adaptation requires additive (heritable) genetic variation for traits that influence survival and fecundity, but measuring this variation is difficult, particularly in species of conservation concern. Instead, molecular genetic diversity is often used to infer adaptive potential. However, previous research has cast doubt on the suitability of traditio...
• Chemotactic self-organization captures the dynamics of mammalian hair follicle patterning AI翻译
  作者：Ibrahimi, Muhamet; Jahanbakhsh, Ebrahim; Tzika, Athanasia C.; Milinkovitch, Michel C.
  作者单位：University of Geneva; Swiss Institute of Bioinformatics
  摘要：The spatial patterning of mammalian hair follicle precursors in embryonic skin is most commonly studied in the laboratory mouse (Mus musculus), where new follicles form equidistantly from preexisting ones in successive waves. This simple geometric rule has been effectively described as emerging from an expansion-induction process. However, such a description is incompatible with more recent developmental data indicating instead that scale, feather, and hair placodes self-organize through react...
• The emergence of novel versus known three-dimensional structures from random sequences AI翻译
  作者：Yang, Rose; Yang, Hyunjun; Davydenko, Anton; Mawaldi, Zack; Kormos, Rian; Myerscough, Dru; Wu, Yibing; DeGrado, William F.
  作者单位：University of California System; University of California San Francisco; Brandeis University; Tohoku University
  摘要：It has been hypothesized that while random sequences are unlikely to fold into proteins of the length of globular proteins, repeated random sequences are more likely to adopt stably folded structures, with implications for molecular evolution. We used structure prediction methods to determine the foldability of approximately 120-residue sequences composed of 5- to 60-residue random repeats. With repeats of less than 30-residues, sequences were frequently discovered (1 to 12%) that fold with hi...
• Antimicrobial peptoids pass rapidly through bacterial membranes and flocculate ribosomes and DNA: A single-cell fluorescence study AI翻译
  作者：Zhu, Yanyu; Nielsen, Josefine Eilso; Molchanova, Natalia; Mustafi, Mainak; Herlan, Claudine; Fleck, Bettina; Brase, Stefan; Schepers, Ute; Sorensen, Kristian; Zielke, Claudia; Lin, Jennifer S.; Weisshaar, James C.; Jenssen, Havard; Barron, Annelise E.
  作者单位：University of Wisconsin System; University of Wisconsin Madison; Stanford University; Stanford University; Roskilde University; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Helmholtz Association; Karlsruhe Institute of Technology; Helmholtz Association; Karlsruhe Institute of Technology
  摘要：Certain peptoids designed as mimics of host defense peptides such as LL-37 exhibit potent, broad-spectrum antibacterial, antifungal, antiparasitic, and antiviral activity with minimal cytotoxicity. Previous fixed-cell studies have suggested that the peptoids can pass through bacterial membranes and rapidly kill bacteria by aggregating intracellular macroanions, including ribosomes and DNA. However, the dynamic mechanisms of action of these biomimetic peptoids have remained elusive. We employed...
• Local partisan context and mental health AI翻译
  作者：Baxter-King, Ryan; Brown, Jacob R.; Enos, Ryan D.; Naeim, Arash; Vavreck, Lynn
  作者单位：Nevada System of Higher Education (NSHE); University of Nevada Reno; Boston University; Harvard University; Harvard University; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles
  摘要：We find that, relative to Republicans residing in more Republican neighborhoods, Republicans in neighborhoods with a higher concentration of Democratic residents report higher levels of anxiety, depression, and loneliness. While Democrats in general report worse mental health than Republicans, Democrats show no sensitivity to partisan context. Using a large-scale national survey and fine-grained data on residential political context, we establish that these patterns persist even when examining...
• Observation-constrained sensitivities of Arctic methane emissions to warming AI翻译
  作者：Liu, Gang; Peng, Shushi; Shen, Lu; Ciais, Philippe; Nisbet, Euan G.; Lan, Xin; Michel, Sylvia E.
  作者单位：Peking University; Peking University; Peking University; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); CEA; University of London; Royal Holloway University London; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder
  摘要：The sensitivity of pan-Arctic (60 to 90 degrees N) natural methane emissions to climate warming lacks direct observational constraints. Long-term atmospheric measurements of methane, which reflect integrated Arctic fluxes and atmospheric transport, show that in the pan-Arctic the autumn-to-winter CH4 build-up (as indicated by the autumn zero crossing date) is becoming earlier. This advancing trend in autumn zero crossing date is explained by growing natural Arctic CH4 emissions in response to ...
• The cannibalistic trade-off: Why human cannibalism emerges and why taboos suppress it AI翻译
  作者：Misiak, Michal; Turecek, Petr
  作者单位：University of Wroclaw; University of Oxford; Charles University Prague; Charles University Prague; Czech Academy of Sciences; Institute of Philosophy of the Czech Academy of Sciences
  摘要：Cannibalism is among the most widespread taboos in human societies, yet archaeological, ethnographic, and historical evidence indicates that it has repeatedly emerged across human populations. This coexistence of recurrent practice and persistent prohibition raises a fundamental question: when does cannibalism become adaptive, and what mechanisms lead to its suppression? We address this problem using a formal model that treats cannibalism as a potential food source subject to energetic benefit...
• Arm dominance is an emergent effect of practice executing complex trajectory shapes required by tools and objects AI翻译
  作者：Arac, Ahmet; Lee, Nicolas Y. H. Jeong; Krakauer, John W.
  作者单位：University of California System; University of California Los Angeles; David Geffen School of Medicine at UCLA; University of California Los Angeles Medical Center; Johns Hopkins University; Johns Hopkins Medicine; The Santa Fe Institute
  摘要：Limb dominance is a human behavioral characteristic with many cultural, practical, scientific, and clinical implications. Yet why the dominant limb performs better across a range of motor skill-requiring tasks remains unanswered. Is it because of an intrinsic hemispheric advantage or instead is it the result of life-long practice with the dominant side? We tested these alternatives using two tasks either cross sectionally or after training. The first was 3D reaching with either an inertial cha...