Microbial phyllosphere populations are more complex than previously realized.

abstract：:Fluoroquinolones are antibacterial agents that attack DNA gyrase and topoisomerase IV on chromosomal DNA. The existence of two fluoroquinolone targets and stepwise accumulation of resistance suggested that new quinolones could be found that would require cells to obtain two topoisomerase mutations to display resistanc...

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

authors： Zhao X,Xu C,Domagala J,Drlica K

更新日期：1997-12-09 00:00:00

abstract：:Targeted drug delivery critically depends on the binding selectivity of cargo-transporting colloidal particles. Extensive theoretical work has shown that two factors are necessary to achieve high selectivity for a threshold receptor density: multivalency and weak interactions. Here, we study a model system of DNA-coat...

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

authors： Scheepers MRW,van IJzendoorn LJ,Prins MWJ

更新日期：2020-09-15 00:00:00

abstract：:The c-Raf-1 protein kinase plays a central role in the mitogenic response of cells to growth factors, cytokines, and many oncogenes. Despite the critical importance of this enzyme, very little is known of its biochemical properties or mechanisms of regulation. In these experiments, we used the only candidate physiolog...

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

authors： Force T,Bonventre JV,Heidecker G,Rapp U,Avruch J,Kyriakis JM

更新日期：1994-02-15 00:00:00

abstract：:Carbachol, an activator of muscarinic acetylcholine receptors of NG108-15 hybrid cells, inhibits adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] rapidly and reversibly and slowly evokes a 200-300% increase in adenylate cyclase activity over a period of 24-30 hr. Both the inhibition of adenylate cyc...

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

authors： Nathanson NM,Klein WL,Nirenberg M

更新日期：1978-04-01 00:00:00

abstract：:We have previously extracted a protein from inflammatory mouse granuloma that fully protects normal mice against lethal Listeria monocytogenes infection. We now report that polyclonal antibodies directed against this protein react with a human urinary fraction that also provides full protection of normal mice against ...

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

authors： Fontan E,Saklani-Jusforgues H,Fauve RM

更新日期：1992-05-15 00:00:00

abstract：:Plants in dense vegetation compete for resources, including light, and optimize their growth based on neighbor detection cues. The best studied of such behaviors is the shade-avoidance syndrome that positions leaves in optimally lit zones of a vegetation. Although proximate vegetation is known to be sensed through a r...

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

authors： de Wit M,Kegge W,Evers JB,Vergeer-van Eijk MH,Gankema P,Voesenek LA,Pierik R

更新日期：2012-09-04 00:00:00

abstract：:The evolutionary stability of cooperation is a problem of fundamental importance for the biological and social sciences. Different claims have been made about this issue: whereas Axelrod and Hamilton's [Axelrod, R. & Hamilton, W. (1981) Science 211, 1390-1398] widely recognized conclusion is that cooperative rules suc...

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

authors： Bendor J,Swistak P

更新日期：1995-04-11 00:00:00

abstract：:We propose a motility mechanism that may result in the displacement of objects within the cell. The mechanism, which we call polymer-guided diffusion, involves a microscopic cycle of polymer association and dissociation from a lateral binding site. Reassociation occurs at the polymer subunit adjacent to that which has...

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

authors： Garel JR,Job D,Margolis RL

更新日期：1987-06-01 00:00:00

abstract：:A species of Rhodopseudomonas that grows under strict anaerobic conditions in the dark and requires CO was isolated from lake and pond sediments. Although anaerobic growth in the dark occurs in a chemically defined mineral medium with CO as the only carbon and energy source, growth is stimulated by adding trypticase. ...

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

authors： Uffen RL

更新日期：1976-09-01 00:00:00

abstract：:Measurements of the effect of DNA on rates of bimolecular energy transfer between ions provide a direct indication of how cations cluster in regions near DNA and how anions are repelled from the same regions. Energy transfer from luminescent lanthanide ions (in the "rapid-diffusion" limit) probes collision frequencies...

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

authors： Wensel TG,Meares CF,Vlachy V,Matthew JB

更新日期：1986-05-01 00:00:00

abstract：:Maximum likelihood analysis for linkage between autosomal dominant aniridia and 12 biochemical and serological markers in a single large family showed a probable linkage between autosomal dominant aniridia and the enzyme acid phosphatase-1. The presence of an autosomal dominant aniridia gene linked to acid phosphatase...

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

authors： Ferrell RE,Chakravarti A,Hittner HM,Riccardi VM

更新日期：1980-03-01 00:00:00

abstract：:Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common extranodal lymphoid cell neoplasia; it frequently follows chronic bacteria-induced inflammation in various tissues. MALT lymphomas are characterized genetically by the t(11;18)(q21;q21) translocation, which yields chimeric transcripts encoding struct...

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

authors： Stoffel A,Chaurushiya M,Singh B,Levine AJ

更新日期：2004-06-15 00:00:00

abstract：:The major auxin-binding protein in maize membranes is thought to function as a physiological receptor. From earlier information, including the use of site-directed irreversible inhibitors, several of the amino acids likely to form part of the active auxin-binding site were provisionally assigned. Inspection of the ami...

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

authors： Venis MA,Napier RM,Barbier-Brygoo H,Maurel C,Perrot-Rechenmann C,Guern J

更新日期：1992-08-01 00:00:00

abstract：:Mitogen-activated protein (MAP) kinases are central components of signal transduction pathways for cell proliferation, stress responses, and differentiation. Signaling efficiency and specificity are modulated in large part by docking interactions between individual MAP kinase and the kinase interaction motif (KIM), (R...

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

authors： Liu S,Sun JP,Zhou B,Zhang ZY

更新日期：2006-04-04 00:00:00

abstract：:The photosynthetic apparatus converts light into chemical energy by a series of reactions that give rise to a coupled flow of electrons and protons that generate reducing power and ATP, respectively. A key intermediate in these reactions is plastoquinone (PQ), the most abundant electron and proton (hydrogen) carrier i...

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

authors： McCauley SW,Melis A,Tang GM,Arnon DI

更新日期：1987-12-01 00:00:00

abstract：:RNA synthesis by the paramyxovirus respiratory syncytial virus, a ubiquitous human pathogen, was found to be more complex than previously appreciated for the nonsegmented negative-strand RNA viruses. Intracellular RNA replication of a plasmid-encoded "minigenome" analog of viral genomic RNA was directed by coexpressio...

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

authors： Collins PL,Hill MG,Cristina J,Grosfeld H

更新日期：1996-01-09 00:00:00

abstract：:Signal transduction by two-component systems involves phosphorylation and thereby activation of the response regulator by the cognate histidine kinase. Bifunctional histidine kinases have two opposing activities: depending on the environmental stimuli they either promote phosphorylation or stimulate the rapid dephosph...

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

authors： Kramer G,Weiss V

更新日期：1999-01-19 00:00:00

abstract：:Radiation leukemia virus, isolated from radiation-induced lymphomas in C57BL/Ka mice and propagated in that strain, is thymotropic and leukemogenic in vivo but replicates poorly, if at all, in mouse and mink fibroblast cultures in vitro. Comparative studies indicate that this naturally occurring virus is distinct from...

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

authors： Declève A,Lieberman M,Ihle JN,Kaplan HS

更新日期：1976-12-01 00:00:00

abstract：:English and Russian color terms divide the color spectrum differently. Unlike English, Russian makes an obligatory distinction between lighter blues ("goluboy") and darker blues ("siniy"). We investigated whether this linguistic difference leads to differences in color discrimination. We tested English and Russian spe...

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

authors： Winawer J,Witthoft N,Frank MC,Wu L,Wade AR,Boroditsky L

更新日期：2007-05-08 00:00:00

abstract：:The mangrove killifish (Kryptolebias marmoratus) is the only vertebrate known to be capable of self-fertilization. Its gonad is typically an ovotestis that simultaneously produces eggs and sperm, and fertilization is internal. Although most populations of this species consist primarily or exclusively of hermaphroditic...

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

authors： Mackiewicz M,Tatarenkov A,Taylor DS,Turner BJ,Avise JC

更新日期：2006-06-27 00:00:00

abstract：:The exceptional sensitivity of Mycobacterium tuberculosis to isonicotinic acid hydrazide (INH) lacks satisfactory definition. M. tuberculosis is a natural mutant in oxyR, a central regulator of peroxide stress response. The ahpC gene, which encodes a critical subunit of alkyl hydroperoxide reductase, is one of the tar...

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

authors： Zhang Y,Dhandayuthapani S,Deretic V

更新日期：1996-11-12 00:00:00

abstract：:How useful can machine learning be in a quantum laboratory? Here we raise the question of the potential of intelligent machines in the context of scientific research. A major motivation for the present work is the unknown reachability of various entanglement classes in quantum experiments. We investigate this question...

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

authors： Melnikov AA,Poulsen Nautrup H,Krenn M,Dunjko V,Tiersch M,Zeilinger A,Briegel HJ

更新日期：2018-02-06 00:00:00

abstract：:Dihydroisohistrionicotoxin inhibits acetylcholine receptor-dependent 22Na+ uptake of cultured chick muscle cells with a KI of 0.2 micrometer. The inhibition is noncompetitive with respect to agonists. The toxin enhances desensitization of the receptor by agonists which is accompanied by a 10-fold increase in receptor ...

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

authors： Burgermeister W,Catterall WA,Witkop B

更新日期：1977-12-01 00:00:00

abstract：:The monoclonal antibodies (mAb) DA6.147, DA6.164, and HIG.48 against human Ia antigens, but not the W6/32 mAb against human class I major histocompatibility complex antigens or the anti-monocyte OKM1 and 63D3 mAb, stimulated monocytes to secrete interleukin 1 (IL-1). IL-1 was measured by its property of promoting the ...

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

authors： Palacios R

更新日期：1985-10-01 00:00:00

abstract：:The Caulobacter crescentus flagellum is formed at a specific time in the cell cycle and its assembly requires the ordered expression of a large number of genes. These genes are controlled in a positive trans-acting hierarchy that reflects the order of assembly of the flagellum. Using plasmids carrying transcriptional ...

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

authors： Xu H,Dingwall A,Shapiro L

更新日期：1989-09-01 00:00:00

abstract：:Renal medullary cells contain high concentrations of myo-inositol, sorbitol, betaine, and glycerophosphocholine, whose levels vary with urinary osmolality. Accumulation of these "compatible" organic osmolytes is believed to help the cells osmoregulate in response to the high extracellular osmolality that occurs as par...

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

authors： Nakanishi T,Turner RJ,Burg MB

更新日期：1989-08-01 00:00:00

abstract：:Turkey erythrocyte membranes showed specific binding of [(3)H]epinephrine. The concentration of hormone required for half-maximal binding (30 muM) was the same as that required for half-maximal activation of the adenylate cyclase located in the same membrane preparation. The binding reaction at 37 degrees C reached co...

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

authors： Schramm M,Feinstein H,Naim E,Lang E,Lasser M

更新日期：1972-02-01 00:00:00

abstract：:Coordinated near-threshold depolarized states in cortical and striatal neurons may contribute to form functionally segregated channels of information processing. Recent anatomical studies have identified pathways that could support spiraling interactions across corticostriatal channels, but a functional outcome of suc...

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

authors： Kasanetz F,Riquelme LA,Della-Maggiore V,O'Donnell P,Murer MG

更新日期：2008-06-10 00:00:00

abstract：:We show that the motion of a slightly compressible fluid is near that of an incompressible fluid. That is, for a given initial velocity field, the motion of a compressible fluid with large sound speed is near to that of an idealized incompressible fluid. We consider the compressible fluid motion in Lagrangian coordina...

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

authors： Ebin DG

更新日期：1975-02-01 00:00:00

abstract：:Calls for the eradication of malaria require the development of global and regional strategies based on a strong and consistent evidence base. Evidence from the previous global malaria eradication program and more recent transborder control campaigns have shown the importance of accounting for human movement in introd...

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

authors： Tatem AJ,Smith DL

更新日期：2010-07-06 00:00:00