The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems.

abstract：:Prion protein consists of an ensemble of glycosylated variants or glycoforms. The enzymes that direct oligosaccharide processing, and hence control the glycan profile for any given glycoprotein, are often exquisitely sensitive to other events taking place within the cell in which the glycoprotein is expressed. Alterat...

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

authors： Rudd PM,Endo T,Colominas C,Groth D,Wheeler SF,Harvey DJ,Wormald MR,Serban H,Prusiner SB,Kobata A,Dwek RA

更新日期：1999-11-09 00:00:00

abstract：:The rapid worldwide spread of severe acute respiratory syndrome demonstrated the potential threat an infectious disease poses in a closely interconnected and interdependent world. Here we introduce a probabilistic model that describes the worldwide spread of infectious diseases and demonstrate that a forecast of the g...

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

authors： Hufnagel L,Brockmann D,Geisel T

更新日期：2004-10-19 00:00:00

abstract：:The major virulence determinant of the rodent malaria parasite, Plasmodium yoelii, has remained unresolved since the discovery of the lethal line in the 1970s. Because virulence in this parasite correlates with the ability to invade different types of erythrocytes, we evaluated the potential role of the parasite eryth...

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

authors： Otsuki H,Kaneko O,Thongkukiatkul A,Tachibana M,Iriko H,Takeo S,Tsuboi T,Torii M

更新日期：2009-04-28 00:00:00

abstract：:Accurate calculations of force generated and of ATP flux, in steady isotonic contractions, are made on a simple, two-state muscle model of the sliding filament type. The objective is to illustrate the proper formulation and use of a complete and self-consistent molecular model of muscle. Otherwise, the model is not me...

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

authors： Chen YD,Hill TL

更新日期：1974-05-01 00:00:00

abstract：:The effect of fluctuations in rate constants on the kinetic behavior of cyclic reacting systems, caused by a fluctuating external parameter, is studied. It is shown (i) that the stochastic properties of the system can be analyzed analytically by using the usual master equation approach when the external parameter is f...

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

authors： Chen YD

更新日期：1987-02-01 00:00:00

abstract：:High levels of D-serine occur in mammalian brain, where it appears to be an endogenous ligand of the glycine site of N-methyl-D-aspartate receptors. In glial cultures of rat cerebral cortex, D-serine is enriched in type II astrocytes and is released upon stimulation with agonists of non-N-methyl-D-aspartate glutamate ...

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

authors： Wolosker H,Sheth KN,Takahashi M,Mothet JP,Brady RO Jr,Ferris CD,Snyder SH

更新日期：1999-01-19 00:00:00

abstract：:Angiosperms are the largest and most successful clade of land plants with >250,000 species distributed in nearly every terrestrial habitat. Many phylogenetic studies have been based on DNA sequences of one to several genes, but, despite decades of intensive efforts, relationships among early diverging lineages and sev...

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

authors： Jansen RK,Cai Z,Raubeson LA,Daniell H,Depamphilis CW,Leebens-Mack J,Müller KF,Guisinger-Bellian M,Haberle RC,Hansen AK,Chumley TW,Lee SB,Peery R,McNeal JR,Kuehl JV,Boore JL

更新日期：2007-12-04 00:00:00

abstract：:DsrA is an 87-nucleotide regulatory RNA of Escherichia coli that acts in trans by RNA-RNA interactions with two different mRNAs, hns and rpoS. DsrA has opposite effects on these transcriptional regulators. H-NS levels decrease, whereas RpoS (final sigma(s)) levels increase. Here we show that DsrA enhances hns mRNA tur...

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

authors： Lease RA,Belfort M

更新日期：2000-08-29 00:00:00

abstract：:The grand partition function for a long linear system of alternating alpha and beta sequences with the restraint of a fixed number, N(alphabeta), of alphabeta boundaries depends in an extremely simple way on the alpha-sequence and beta-sequence grand partition functions, xi(alpha) and xi(beta). When the restraint is r...

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

authors： Hill TL

更新日期：1972-05-01 00:00:00

abstract：:The BvgAS phosphorelay regulates ∼10% of the annotated genomes of Bordetella pertussis and Bordetella bronchiseptica and controls their infectious cycles. The hierarchical organization of the regulatory network allows the integration of contextual signals to control all or specific subsets of BvgAS-regulated genes. He...

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

authors： Ahuja U,Shokeen B,Cheng N,Cho Y,Blum C,Coppola G,Miller JF

更新日期：2016-03-01 00:00:00

abstract：:Many nearshore fish and invertebrate populations are overexploited even when apparently coherent management structures are in place. One potential cause of mismanagement may be a poor understanding and accounting of stochasticity, particularly for stock recruitment. Many of the fishes and invertebrates that comprise n...

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

authors： Siegel DA,Mitarai S,Costello CJ,Gaines SD,Kendall BE,Warner RR,Winters KB

更新日期：2008-07-01 00:00:00

abstract：:A core operation in speech production is the preparation of words from a semantic base. The theory of lexical access reviewed in this article covers a sequence of processing stages beginning with the speaker's focusing on a target concept and ending with the initiation of articulation. The initial stages of preparatio...

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

authors： Levelt WJ

更新日期：2001-11-06 00:00:00

abstract：:A novel type I transmembrane protein of COPI-coated vesicles, p23, has been demonstrated to be localized mainly to the Golgi complex. This protein and p24, another member of the p24 family, have been shown to bind coatomer via their short cytoplasmic tails. Here we demonstrate that p23 continuously cycles through the ...

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

authors： Nickel W,Sohn K,Bünning C,Wieland FT

更新日期：1997-10-14 00:00:00

abstract：:Previous studies have shown that defective virus vectors (amplicons) derived from herpes simplex viruses could be efficiently propagated in virus stocks in the presence of trans-acting helper virus functions. The present study established that two separate cis-acting functions--a DNA replication origin and a cleavage/...

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

authors： Spaete RR,Frenkel N

更新日期：1985-02-01 00:00:00

abstract：:A solid-phase immunoadsorbent capable of binding mouse interferon has been prepared. Starting from crude tissue-culture material, interferon could be purified 1990 times in a single step of affinity chromatography. Overall recovery ranged from 55 to 103% with tissue culture and mouse-brain interferon; however, only 5%...

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

authors： Sipe JD,de Maeyer-Guignard J,Fauconnier B,de Maeyer E

更新日期：1973-04-01 00:00:00

abstract：:Recent studies have shown that phytoliths are softer than dental enamel but still act as abrasive agents. Thus, phytolith content should be reflected in dental wear. Because native phytoliths show lower indentation hardness than phytoliths extracted by dry ashing, we propose that the hydration state of plant tissue wi...

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

authors： Winkler DE,Schulz-Kornas E,Kaiser TM,De Cuyper A,Clauss M,Tütken T

更新日期：2019-01-22 00:00:00

abstract：:Although x-ray crystallography is the most widely used method for macromolecular structure determination, it does not provide dynamical information, and either experimental tricks or complementary experiments must be used to overcome the inherently static nature of crystallographic structures. Here we used specific x-...

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

authors： Colletier JP,Bourgeois D,Sanson B,Fournier D,Sussman JL,Silman I,Weik M

更新日期：2008-08-19 00:00:00

abstract：:Characterizing the entropy of a system is a crucial, and often computationally costly, step in understanding its thermodynamics. It plays a key role in the study of phase transitions, pattern formation, protein folding, and more. Current methods for entropy estimation suffer from a high computational cost, lack of gen...

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

authors： Nir A,Sela E,Beck R,Bar-Sinai Y

更新日期：2020-12-01 00:00:00

abstract：:Keratins 14 and 5 are the structural hallmarks of the basal keratinocytes of the epidermis and outer root sheath (ORS) of the hair follicle. Their genes are controlled in a tissue-specific manner and thus serve as useful tools to elucidate the regulatory mechanisms involved in keratinocyte-specific transcription. Prev...

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

authors： Sinha S,Fuchs E

更新日期：2001-02-27 00:00:00

abstract：:The influence of oxidation state on the pH dependence of the dissolution of the Fe(4)S(4) clusters of Chromatium vinosum ferredoxin and high-potential iron protein (HIPIP) has been studied. The first-order rate constants (k(obs)) for dissolution of both the Fe(4)S(4)(S-Cys)(4) (2-) and Fe(4)S(4)(S-Cys)(4) (3-) cluster...

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

authors： Maskiewicz R,Bruice TC

更新日期：1977-12-01 00:00:00

abstract：:The evolution of development has been studied through the lens of gene regulation by examining either closely related species or extremely distant animals of different phyla. In nematodes, detailed cell- and stage-specific expression analyses are focused on the model Caenorhabditis elegans, in part leading to the view...

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

authors： Schiffer PH,Polsky AL,Cole AG,Camps JIR,Kroiher M,Silver DH,Grishkevich V,Anavy L,Koutsovoulos G,Hashimshony T,Yanai I

更新日期：2018-04-24 00:00:00

abstract：:Tropical forests hold most of Earth's biodiversity. Their continued loss through deforestation and agriculture is the main threat to species globally, more than disease, invasive species, and climate change. However, not all tropical forests have the same ability to sustain biodiversity. Those that have been disturbed...

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

authors： Hedges SB,Cohen WB,Timyan J,Yang Z

更新日期：2018-11-13 00:00:00

abstract：:The MARCKS protein is a widely distributed cellular substrate for protein kinase C. It is a myristoylprotein that binds calmodulin and actin in a manner reversible by protein kinase C-dependent phosphorylation. It is also highly expressed in nervous tissue, particularly during development. To evaluate a possible devel...

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

authors： Stumpo DJ,Bock CB,Tuttle JS,Blackshear PJ

更新日期：1995-02-14 00:00:00

abstract：:Cytochrome ba3 from Thermus thermophilus reacts slowly with excess HCN at pH 7.4 to create a form of the enzyme in which CuA, cytochrome b, and CuB remain oxidized, while cytochrome a3 is reduced by one electron, presumably with the formation of cyanogen. We have examined this form of the enzyme by UV-visible, resonan...

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

authors： Surerus KK,Oertling WA,Fan C,Gurbiel RJ,Einarsdóttir O,Antholine WE,Dyer RB,Hoffman BM,Woodruff WH,Fee JA

更新日期：1992-04-15 00:00:00

abstract：:Animal movements result from a complex balance of many different forces. Muscles produce force to move the body; the body has inertial, elastic, and damping properties that may aid or oppose the muscle force; and the environment produces reaction forces back on the body. The actual motion is an emergent property of th...

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

authors： Tytell ED,Hsu CY,Williams TL,Cohen AH,Fauci LJ

更新日期：2010-11-16 00:00:00

abstract：:Dravet syndrome is a catastrophic, pharmacoresistant epileptic encephalopathy. Disease onset occurs in the first year of life, followed by developmental delay with cognitive and behavioral dysfunction and substantially elevated risk of premature death. The majority of affected individuals harbor a loss-of-function mut...

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

authors： Richards KL,Milligan CJ,Richardson RJ,Jancovski N,Grunnet M,Jacobson LH,Undheim EAB,Mobli M,Chow CY,Herzig V,Csoti A,Panyi G,Reid CA,King GF,Petrou S

更新日期：2018-08-21 00:00:00

abstract：:Well-differentiated liposarcoma (WDLPS), one of the most common human sarcomas, is poorly responsive to radiation and chemotherapy, and the lack of animal models suitable for experimental analysis has seriously impeded functional investigation of its pathobiology and development of effective targeted therapies. Here, ...

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

authors： Gutierrez A,Snyder EL,Marino-Enriquez A,Zhang YX,Sioletic S,Kozakewich E,Grebliunaite R,Ou WB,Sicinska E,Raut CP,Demetri GD,Perez-Atayde AR,Wagner AJ,Fletcher JA,Fletcher CD,Look AT

更新日期：2011-09-27 00:00:00

abstract：:Myelinated fibers can be demonstrated in thin unstained brain sections of freshly killed uninjected animals. With this method myelinated fibers stand out as clearly as in stained Weigert sections from formalin-fixed brains. Unstained unfixed sections can be viewed under ordinary light within minutes after death of the...

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

authors： Richter CP,Warner CL

更新日期：1974-03-01 00:00:00

abstract：:Proinflammatory signaling pathways are commonly up-regulated in breast cancer. In estrogen receptor-negative (ER-) and triple-negative breast cancer (TNBC), nitric oxide synthase-2 (NOS2) and cyclooxygenase-2 (COX2) have been described as independent predictors of disease outcome. We further explore these findings by ...

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

authors： Basudhar D,Glynn SA,Greer M,Somasundaram V,No JH,Scheiblin DA,Garrido P,Heinz WF,Ryan AE,Weiss JM,Cheng RYS,Ridnour LA,Lockett SJ,McVicar DW,Ambs S,Wink DA

更新日期：2017-12-05 00:00:00

abstract：:Coxiella burnetti, the etiologic agent of Q fever, is an oligate intracellular parasite of eukaryotes. Unlike the majority of successful bacterial parasites, which escape the bactericidal environment of the phagolysosome by various means, C. burnetii multiplies only in the phagolysosome. In view of the relatively hars...

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

authors： Hackstadt T,Williams JC

更新日期：1981-05-01 00:00:00