The impact of penalties for wrong answers on the gender gap in test scores.

abstract：:Circulating peripheral blood cells and disaggregated yolk sac cells were obtained from normal mouse embryos as early as day 9 of gestation, prior to the formation of the fetal liver. These were cultured in vitro in plasma clots or methylcellulose, in the presence of either embryonic fluid or adult spleen cell-conditio...

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

authors： Wong PM,Clarke BJ,Carr DH,Chui DH

更新日期：1982-05-01 00:00:00

abstract：:beta 2-Glycoprotein I (beta 2-GPI), a phospholipid-binding plasma protein, is an absolute requirement (cofactor) for the binding of autoimmune-type anti-cardiolipin (aCL) antibodies to cardiolipin (CL). The nature of this cofactor activity and the specific regions of the molecule involved have not yet been determined....

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

authors： Hunt JE,Simpson RJ,Krilis SA

更新日期：1993-03-15 00:00:00

abstract：:Myosin generates force by a rotation of its lever arm. Crystal structures of myosin II indicate an unloaded working stroke of 10-12 nm, a range confirmed by recent x-ray interference experiments. However, when an actin filament, held between two weakly, optically trapped beads is made to interact with a single head of...

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

authors： Sleep J,Lewalle A,Smith D

更新日期：2006-01-31 00:00:00

abstract：:Aminoacyl-tRNA synthetases are multidomain proteins responsible for the attachment of specific amino acids to their tRNA substrates. Prolyl-tRNA synthetases (ProRSs) are notable due to their particularly diverse architectures through evolution. For example, Saccharomyces cerevisiae ProRS possesses an N-terminal extens...

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

authors： SternJohn J,Hati S,Siliciano PG,Musier-Forsyth K

更新日期：2007-02-13 00:00:00

abstract：:L-Gulono-gamma-lactone oxidase (L-gulono-gamma-lactone:oxygen 2-oxidoreductase, EC 1.1.3.8) is the enzyme that catalyzes the terminal step of L-ascorbic acid biosynthesis in mammalian liver. The absence of the oxidase activity in primates and guinea pigs is the reason why these animals are subject to scurvy, which mus...

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

authors： Nishikimi M,Udenfriend S

更新日期：1976-06-01 00:00:00

abstract：:Dendritic cells (DCs) play a central role in determining the induction of T cell responses. IL-27 production by DCs favors induction of IL-10-producing regulatory T cells, whereas osteopontin (OPN) promotes pathogenic IL-17 T cell responses. The regulatory mechanisms in DCs that control these two cells types are not u...

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

authors： Murugaiyan G,Mittal A,Weiner HL

更新日期：2010-06-22 00:00:00

abstract：:Recent work has demonstrated that Web search volume can "predict the present," meaning that it can be used to accurately track outcomes such as unemployment levels, auto and home sales, and disease prevalence in near real time. Here we show that what consumers are searching for online can also predict their collective...

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

authors： Goel S,Hofman JM,Lahaie S,Pennock DM,Watts DJ

更新日期：2010-10-12 00:00:00

abstract：:The current epidemic of infections caused by antibiotic-resistant gram-positive bacteria requires the discovery of new drug targets and the development of new therapeutics. Lipoteichoic acid (LTA), a cell wall polymer of gram-positive bacteria, consists of 1,3-polyglycerol-phosphate linked to glycolipid. LTA synthase ...

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

authors： Richter SG,Elli D,Kim HK,Hendrickx AP,Sorg JA,Schneewind O,Missiakas D

更新日期：2013-02-26 00:00:00

abstract：:Thioredoxins are small multifunctional redox active proteins widely if not universally distributed among living organisms. In chloroplasts, two types of thioredoxins (f and m) coexist and play central roles in regulating enzyme activity. Reduction of thioredoxins in chloroplasts is catalyzed by an iron-sulfur disulfid...

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

authors： Balmer Y,Koller A,del Val G,Manieri W,Schürmann P,Buchanan BB

更新日期：2003-01-07 00:00:00

abstract：:The light-harvesting chlorophyll a/b protein (LHCP) is an integral thylakoid membrane protein. It is made in the cytosol as a precursor (pLHCP), imported into chloroplasts, and subsequently integrated into thylakoids. Integration of pLHCP into thylakoids requires a stromal protein factor that functions in part to main...

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

authors： Yuan J,Henry R,Cline K

更新日期：1993-09-15 00:00:00

abstract：:The essential eukaryotic pre-mRNA splicing factor U2AF (U2 small nuclear ribonucleoprotein auxiliary factor) is required to specify the 3' splice at an early step in spliceosome assembly. U2AF binds site-specifically to the intron polypyrimidine tract and recruits U2 small nuclear ribonucleoprotein to the branch site....

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

authors： Rudner DZ,Kanaar R,Breger KS,Rio DC

更新日期：1996-09-17 00:00:00

abstract：:The X-ray crystal structure of the Head module, one-third of the Mediator of transcriptional regulation, has been determined as a complex with the C-terminal domain (CTD) of RNA polymerase II. The structure reveals multiple points of interaction with an extended conformation of the CTD; it suggests a basis for regulat...

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

authors： Robinson PJ,Bushnell DA,Trnka MJ,Burlingame AL,Kornberg RD

更新日期：2012-10-30 00:00:00

abstract：:Loquacious-PD (Loqs-PD) is required for biogenesis of many endogenous siRNAs in Drosophila In vitro, Loqs-PD enhances the rate of dsRNA cleavage by Dicer-2 and also enables processing of substrates normally refractory to cleavage. Using purified components, and Loqs-PD truncations, we provide a mechanistic basis for L...

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

authors： Trettin KD,Sinha NK,Eckert DM,Apple SE,Bass BL

更新日期：2017-09-19 00:00:00

abstract：:Retroviral gene expression is inhibited in embryonal carcinoma (EC) cells. We have constructed a recombinant retroviral vector that is capable of expressing the neomycin-resistance (neo) gene in EC cells. The critical modification that permits expression of the neo gene is the insertion of a composite simian virus 40 ...

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

authors： Rubenstein JL,Nicolas JF,Jacob F

更新日期：1984-11-01 00:00:00

abstract：:We studied the organization of the kappa light chain genes in germ-line (sperm) and somatic (embryo) tissues. We constructed a plasmid containing a DNA insert coding for the kappa chain MOPC 167 and used the Southern blotting technique to determine the organization of kappa variable and constant region genes. In the h...

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

authors： Joho R,Weissman IL,Early P,Cole J,Hood L

更新日期：1980-02-01 00:00:00

abstract：:The circadian clock in eukaryotes controls transcriptional and posttranscriptional events, including regulation of the levels and phosphorylation state of translation factors. However, the mechanisms underlying clock control of translation initiation, and the impact of this potential regulation on rhythmic protein syn...

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

authors： Karki S,Castillo K,Ding Z,Kerr O,Lamb TM,Wu C,Sachs MS,Bell-Pedersen D

更新日期：2020-05-19 00:00:00

abstract：:The prion protein (PrP) is a scrapie-associated fibril protein that accumulates in the brains of hamsters and mice infected with the scrapie agent, and also in the brains of persons affected with kuru or Creutzfeldt-Jakob disease. It has been previously proposed that PrP could be either the primary transmissible agent...

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

authors： Locht C,Chesebro B,Race R,Keith JM

更新日期：1986-09-01 00:00:00

abstract：:S3I-201 (NSC 74859) is a chemical probe inhibitor of Stat3 activity, which was identified from the National Cancer Institute chemical libraries by using structure-based virtual screening with a computer model of the Stat3 SH2 domain bound to its Stat3 phosphotyrosine peptide derived from the x-ray crystal structure of...

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

authors： Siddiquee K,Zhang S,Guida WC,Blaskovich MA,Greedy B,Lawrence HR,Yip ML,Jove R,McLaughlin MM,Lawrence NJ,Sebti SM,Turkson J

更新日期：2007-05-01 00:00:00

abstract：:We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa fol...

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

authors： Eggert JH,Karmon E,Hemley RJ,Mao A,Goncharov AF

更新日期：1999-10-26 00:00:00

abstract：:A 978-base-pair gene that encodes thymidylate synthase (TS; 5,10-methylenetetrahydrofolate:dUMP C-methyltransferase, EC 2.1.1.45) from Lactobacillus casei has been synthesized and inserted into Escherichia coli expression vectors. The DNA sequence contains 35 unique restriction sites that are located an average of 28 ...

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

authors： Climie S,Santi DV

更新日期：1990-01-01 00:00:00

abstract：:The basic helix-loop-helix transcriptional repressor Hairy-related transcription factor 2 (Hrt2) is expressed in ventricular, but not atrial, cardiomyocytes, and in endothelial and vascular smooth muscle cells. Mice homozygous for a null mutation of Hrt2 die perinatally from a spectrum of cardiac abnormalities, raisin...

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

authors： Xin M,Small EM,van Rooij E,Qi X,Richardson JA,Srivastava D,Nakagawa O,Olson EN

更新日期：2007-05-08 00:00:00

abstract：:The Arabidopsis thaliana SOS2 and SOS3 genes are required for intracellular Na(+) and K(+) homeostasis and plant tolerance to high Na(+) and low K(+) environments. SOS3 is an EF hand type calcium-binding protein having sequence similarities with animal neuronal calcium sensors and the yeast calcineurin B. SOS2 is a se...

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

authors： Halfter U,Ishitani M,Zhu JK

更新日期：2000-03-28 00:00:00

abstract：:We explore the question of what are the best ligands for macromolecular targets. A survey of experimental data on a large number of the strongest-binding ligands indicates that the free energy of binding increases with the number of nonhydrogen atoms with an initial slope of approximately -1.5 kcal/mol (1 cal = 4.18 J...

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

authors： Kuntz ID,Chen K,Sharp KA,Kollman PA

更新日期：1999-08-31 00:00:00

abstract：:A discussion of the range of applicability of Forster long-range energy transfer in the determination of macromolecular dimensions and conformational dynamics is given. Emphasis is laid on the effect of restrictions in the orientational freedom of donor and acceptor and on the importance of the orientational averaging...

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

authors： Dale RE,Eisinger J

更新日期：1976-02-01 00:00:00

abstract：:The crystal structure of a recombinant alphaEC domain from human fibrinogen-420 has been determined at a resolution of 2.1 A. The protein, which corresponds to the carboxyl domain of the alphaE chain, was expressed in and purified from Pichia pastoris cells. Felicitously, during crystallization an amino-terminal segme...

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

authors： Spraggon G,Applegate D,Everse SJ,Zhang JZ,Veerapandian L,Redman C,Doolittle RF,Grieninger G

更新日期：1998-08-04 00:00:00

abstract：:We have investigated whether the large (5- to 15-fold) stimulation of synthesis of growth hormone (somatotropin) observed upon exposure of a strain of rat pituitary (GH3) cells to dexamethasone (a synthetic glucocorticoid) arises from a stimulation of pregrowth hormone mRNA. A good agreement was observed between the s...

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

authors： Tushinski RJ,Sussman PM,Yu LY,Bancroft FC

更新日期：1977-06-01 00:00:00

abstract：:The interaction of carboxylate ions (acetate, butyrate) with nucleic aicd bases and nucleosides has been investigated by proton magnetic resonance in dimethyl sulfoxide (d6)/H2O mixtures. Carboxylate ions interacted only with guanine derivatives and led to a large downfield shift of the NH2 resonance. A 1:1 stoichiome...

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

authors： Lancelot G,Hélène C

更新日期：1977-11-01 00:00:00

abstract：:Computational and biochemical studies implicate the blue-light sensor cryptochrome (CRY) as an endogenous light-dependent magnetosensor enabling migratory birds to navigate using the Earth's magnetic field. Validation of such a mechanism has been hampered by the absence of structures of vertebrate CRYs that have funct...

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

authors： Zoltowski BD,Chelliah Y,Wickramaratne A,Jarocha L,Karki N,Xu W,Mouritsen H,Hore PJ,Hibbs RE,Green CB,Takahashi JS

更新日期：2019-09-24 00:00:00

abstract：:The functions of individual basal transcription factors during the formation of an initiation complex by RNA polymerase II remain largely unknown. Transcription factor IIE (TFIIE) has recently been shown to bind to multiple targets in the initiation complex. To assess the role of zinc binding in basal transcription, w...

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

authors： Maxon ME,Tjian R

更新日期：1994-09-27 00:00:00

abstract：:By adapting to sustained stimuli, hair cells in the internal ear retain their sensitivity to minute transient displacements. Because one model for adaptation asserts that this process is mediated by a myosin isozyme, we reasoned that we should be able to arrest adaptation by interfering with myosin's ATPase cycle thou...

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

authors： Gillespie PG,Hudspeth AJ

更新日期：1993-04-01 00:00:00