Tuning environmental timescales to evolve and maintain generalists.

abstract：:The aldosterone-induced augmentation of Na+ transport in toad bladder was analyzed by comparing the hormonal actions on the transepithelial short-circuit current and on the amiloride-sensitive 22Na+ uptake in isolated membrane vesicles. Incubating bladders with 0.5 microM aldosterone for 3 hr evoked more than a 2-fold...

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

authors： Asher C,Garty H

更新日期：1988-10-01 00:00:00

abstract：:The production of hybridomas between immunologically activated T cells and malignant T-cell lines offers a potentially unlimited source of soluble T-cell-derived products. Recently, human T-T hybrids have been described; however, their use has been hampered by slow growth and chromosomal instability due at least in pa...

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

authors： Foung SK,Sasaki DT,Grumet FC,Engleman EG

更新日期：1982-12-01 00:00:00

abstract：:There exists a properly embedded minimal surface of genus one with a single end asymptotic to the end of the helicoid. This genus-one helicoid is constructed as the limit of a continuous one-parameter family of screw-motion invariant minimal surfaces, also asymptotic to the helicoid, that have genus equal to one in th...

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

authors： Weber M,Hoffman D,Wolf M

更新日期：2005-11-15 00:00:00

abstract：:Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in...

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

authors： Marlon JR,Bartlein PJ,Gavin DG,Long CJ,Anderson RS,Briles CE,Brown KJ,Colombaroli D,Hallett DJ,Power MJ,Scharf EA,Walsh MK

更新日期：2012-02-28 00:00:00

abstract：:We studied regional cerebral blood flow using the H2(15)O method while normal subjects performed four similar tasks involving three-letter word beginnings (stems). Prior to each task, subjects studied a list of words. Local blood flow was then monitored during a 40-sec period while subjects (i) silently viewed word st...

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

authors： Squire LR,Ojemann JG,Miezin FM,Petersen SE,Videen TO,Raichle ME

更新日期：1992-03-01 00:00:00

abstract：:The rate of Cl- secretion by human airway epithelium is determined, in part, by apical cell membrane Cl- conductance. In cystic fibrosis airway epithelia, defective regulation of Cl- conductance decreases the capability to secrete Cl-. Here we report that extracytosolic ATP in the luminal bath of cultured human airway...

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

authors： Stutts MJ,Chinet TC,Mason SJ,Fullton JM,Clarke LL,Boucher RC

更新日期：1992-03-01 00:00:00

abstract：:Complex three-dimensional biophotonic nanostructures produce the vivid structural colors of many butterfly wing scales, but their exact nanoscale organization is uncertain. We used small angle X-ray scattering (SAXS) on single scales to characterize the 3D photonic nanostructures of five butterfly species from two fam...

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

authors： Saranathan V,Osuji CO,Mochrie SG,Noh H,Narayanan S,Sandy A,Dufresne ER,Prum RO

更新日期：2010-06-29 00:00:00

abstract：:Efficient degradation of plant cell walls by selected anaerobic bacteria is performed by large extracellular multienzyme complexes termed cellulosomes. The spatial arrangement within the cellulosome is organized by a protein called scaffoldin, which recruits the cellulolytic subunits through interactions between cohes...

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

authors： Barth A,Hendrix J,Fried D,Barak Y,Bayer EA,Lamb DC

更新日期：2018-11-27 00:00:00

abstract：:Mutualisms between fungi and fungus-growing animals are model systems for studying coevolution and complex interactions between species. Fungal growing behavior has enabled cultivating animals to rise to major ecological importance, but evolution of farming symbioses is thought to be restricted to three terrestrial in...

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

authors： Silliman BR,Newell SY

更新日期：2003-12-23 00:00:00

abstract：:We discuss the pulling force f required to extrude a lipid tube from a living cell as a function of the extrusion velocity L. The main feature is membrane friction on the cytoskeleton. As recently observed for neutrophils, the tether force exhibits a "shear thinning" response over a large range of pulling velocities, ...

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

authors： Brochard-Wyart F,Borghi N,Cuvelier D,Nassoy P

更新日期：2006-05-16 00:00:00

abstract：:A protein-free nucleic acid preparation method for electron microscopy is described. The basic procedure is very similar to the classical protein monolayer spreading techniques. The carrier protein (usually cytochrome c) is replaced by benzyldimethylalkylammonium chloride. Both the hypophase method and the microdiffus...

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

authors： Vollenweider HJ,Sogo JM,Koller T

更新日期：1975-01-01 00:00:00

abstract：:Glucocorticoids (GCs) are potent anti-inflammatory agents that block cytokine production. We investigated whether GCs also block cytokine signaling via the Janus kinase (Jak)-signal transducer and activator of transcription (STAT) pathway. Dexamethasone inhibited IL-2-induced DNA binding, tyrosine phosphorylation, and...

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

authors： Bianchi M,Meng C,Ivashkiv LB

更新日期：2000-08-15 00:00:00

abstract：:Uropathogenic Escherichia coli invade bladder epithelial cells (BECs) by direct entry into specialized cAMP regulated exocytic compartments. Remarkably, a significant number of these intracellular bacteria are subsequently expelled in a nonlytic and piecemeal fashion by infected BECs. Here, we report that expulsion of...

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

authors： Song J,Bishop BL,Li G,Grady R,Stapleton A,Abraham SN

更新日期：2009-09-01 00:00:00

abstract：:We report a general mass spectrometric approach for the rapid identification and characterization of proteins isolated by preparative two-dimensional polyacrylamide gel electrophoresis. This method possesses the inherent power to detect and structurally characterize covalent modifications. Absolute sensitivities of ma...

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

authors： Clauser KR,Hall SC,Smith DM,Webb JW,Andrews LE,Tran HM,Epstein LB,Burlingame AL

更新日期：1995-05-23 00:00:00

abstract：:In vitro assembly of tobacco mosaic virus (TMV) from its constituent RNA and protein occurs in two steps: formation of the initial complex by interaction of the 5'-end of TMV-RNA with 20S protein aggregate, and growth of the helical rod by sequential addition of protein subunits.Such a process was also observed in the...

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

authors： Ono T,Inoue H,Okada Y

更新日期：1972-12-01 00:00:00

abstract：:Efficient 3'-end processing of cell cycle-regulated mammalian histone premessenger RNAs (pre-mRNAs) requires an upstream stem-loop and a histone downstream element (HDE) that base pairs with the U7 small ribonucleoprotein. Insertions between these elements have two effects: the site of cleavage moves in concert with t...

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

authors： Scharl EC,Steitz JA

更新日期：1996-12-10 00:00:00

abstract：:Gaseous HCl generated from a variety of sources is ubiquitous in both outdoor and indoor air. Oxides of nitrogen (NO(y)) are also globally distributed, because NO formed in combustion processes is oxidized to NO(2), HNO(3), N(2)O(5) and a variety of other nitrogen oxides during transport. Deposition of HCl and NO(y) o...

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

authors： Raff JD,Njegic B,Chang WL,Gordon MS,Dabdub D,Gerber RB,Finlayson-Pitts BJ

更新日期：2009-08-18 00:00:00

abstract：:Many models of morphogenesis are forced to assume specific mechanical properties of cells, because the actual mechanical properties of living tissues are largely unknown. Here, we measure the rheology of epithelial cells in the cellularizing Drosophila embryo by injecting magnetic particles and studying their response...

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

authors： Doubrovinski K,Swan M,Polyakov O,Wieschaus EF

更新日期：2017-01-31 00:00:00

abstract：:Understanding the mechanisms of nanoparticle interaction with cell membranes is essential for designing materials for applications such as bioimaging and drug delivery, as well as for assessing engineered nanomaterial safety. Much attention has focused on nanoparticles that bind strongly to biological membranes or ind...

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

authors： Foreman-Ortiz IU,Liang D,Laudadio ED,Calderin JD,Wu M,Keshri P,Zhang X,Schwartz MP,Hamers RJ,Rotello VM,Murphy CJ,Cui Q,Pedersen JA

更新日期：2020-11-10 00:00:00

abstract：:Intracellular electrophysiological recordings were obtained from a specialized class of "starburst" amacrine cells by using an isolated superperfused retina-eyecup preparation of the rabbit. These cells were injected intracellularly with horseradish peroxidase and identified with light microscopy. A computer-controlle...

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

authors： Miller RF,Bloomfield SA

更新日期：1983-05-01 00:00:00

abstract：:We have previously shown that mammary epithelial specific expression of the activated erbB2 allele under the control of the endogenous promoter in mice resulted in the formation of mammary adenocarcinomas. To assess whether mammary tumorigenesis in this model is influenced by the developmental window of expression, we...

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

authors： Andrechek ER,Hardy WR,Laing MA,Muller WJ

更新日期：2004-04-06 00:00:00

abstract：:DNA and protein determinants of nucleosome positioning have been examined after in vitro reconstitutions of native or modified histone octamers onto tandem repeats of 207- and 172-base-pair DNA sequences containing the Lytechinus variegatus 5S rRNA gene and onto monomeric sequences derived from these by digestion with...

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

authors： Dong F,Hansen JC,van Holde KE

更新日期：1990-08-01 00:00:00

abstract：:A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups. The [14C]lignins were prepared by oxidative polymerization with peroxidase and H2O2 Of spe...

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

authors： Kirk TK,Connors WJ,Bleam RD,Hackett WF,Zeikus JG

更新日期：1975-07-01 00:00:00

abstract：:Acquired immunity to Streptococcus pneumoniae (pneumococcus) has long been assumed to depend on the presence of anticapsular antibodies. We found, however, that colonization with live pneumococci of serotypes 6B, 7F, or 14 protected mice against recolonization by any of the serotypes and that protection from acquisiti...

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

authors： Malley R,Trzcinski K,Srivastava A,Thompson CM,Anderson PW,Lipsitch M

更新日期：2005-03-29 00:00:00

abstract：:ExoU is a type III-secreted cytotoxin expressing A2 phospholipase activity when injected into eukaryotic target cells by the bacterium Pseudomonas aeruginosa The enzymatic activity of ExoU is undetectable in vitro unless ubiquitin, a required cofactor, is added to the reaction. The role of ubiquitin in facilitating Ex...

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

authors： Tessmer MH,Anderson DM,Pickrum AM,Riegert MO,Moretti R,Meiler J,Feix JB,Frank DW

更新日期：2018-01-16 00:00:00

abstract：:The synthesis of graphene materials is typically carried out by oxidizing graphite to graphite oxide followed by a reduction process. Numerous methods exist for both the oxidation and reduction steps, which causes unpredictable contamination from metallic impurities into the final material. These impurities are known ...

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

authors： Wong CH,Sofer Z,Kubešová M,Kučera J,Matějková S,Pumera M

更新日期：2014-09-23 00:00:00

abstract：:The transformation of human cells was examined by transfection of cloned oncogenic DNAs derived from the tumor virus simian virus 40 and from the human bladder carcinoma cell line EJ into diploid fibroblasts derived from foreskin (FS-2 cells). The simian virus 40 DNA was found to induce a morphologically transformed p...

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

authors： Sager R,Tanaka K,Lau CC,Ebina Y,Anisowicz A

更新日期：1983-12-01 00:00:00

abstract：:The nonreceptor tyrosine phosphatase Shp2 (PTPN11) has been implicated in tyrosine kinase, cytokine, and integrin receptor signaling. We show here that conditional mutation of Shp2 in neural crest cells and in myelinating Schwann cells resulted in deficits in glial development that are remarkably similar to those obse...

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

authors： Grossmann KS,Wende H,Paul FE,Cheret C,Garratt AN,Zurborg S,Feinberg K,Besser D,Schulz H,Peles E,Selbach M,Birchmeier W,Birchmeier C

更新日期：2009-09-29 00:00:00

abstract：:The utilization of the isoaccepting species of leucyl-tRNA in protein synthesis has been examined in E. coli. Two minor leucyl-tRNA species, isoacceptors tRNA3Leu and tRNA4Leu, are the predominant species found bound to ribosomes during exponential growth in minimal medium. In rich medium, an increased proportion of t...

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

authors： Holmes WM,Goldman E,Miner TA,Hatfield GW

更新日期：1977-04-01 00:00:00

abstract：:Extensive studies have detailed the molecular regulation of individual components of the hemostatic system, including platelets, coagulation factors, and regulatory proteins. Questions remain, however, about how these elements are integrated at the systems level within a rapidly changing physical environment. To answe...

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

authors： Tomaiuolo M,Matzko CN,Poventud-Fuentes I,Weisel JW,Brass LF,Stalker TJ

更新日期：2019-02-05 00:00:00