Antenatal and postnatal radiologic diagnosis of holocarboxylase synthetase deficiency: a systematic review

International Nuclear Information System (INIS)

Bandaralage, Sahan P.S.; Farnaghi, Soheil; Dulhunty, Joel M.; Kothari, Alka

2016-01-01

Holocarboxylase synthetase deficiency results in impaired activation of enzymes implicated in glucose, fatty acid and amino acid metabolism. Antenatal imaging and postnatal imaging are useful in making the diagnosis. Untreated holocarboxylase synthetase deficiency is fatal, while antenatal and postnatal biotin supplementation is associated with good clinical outcomes. Although biochemical assays are required for definitive diagnosis, certain radiologic features assist in the diagnosis of holocarboxylase synthetase deficiency. To review evidence regarding radiologic diagnostic features of holocarboxylase synthetase deficiency in the antenatal and postnatal period. A systematic review of all published cases of holocarboxylase synthetase deficiency identified by a search of Pubmed, Scopus and Web of Science. A total of 75 patients with holocarboxylase synthetase deficiency were identified from the systematic review, which screened 687 manuscripts. Most patients with imaging (19/22, 86%) had abnormal findings, the most common being subependymal cysts, ventriculomegaly and intraventricular hemorrhage. Although the radiologic features of subependymal cysts, ventriculomegaly, intraventricular hemorrhage and intrauterine growth restriction may be found in the setting of other pathologies, these findings should prompt consideration of holocarboxylase synthetase deficiency in at-risk children. (orig.)

Antenatal and postnatal radiologic diagnosis of holocarboxylase synthetase deficiency: a systematic review

Energy Technology Data Exchange (ETDEWEB)

Bandaralage, Sahan P.S. [Gold Coast Hospital and Health Service, Southport, Queensland (Australia); Griffith University, School of Medicine, Southport, Queensland (Australia); Farnaghi, Soheil [Caboolture Hospital, Caboolture, Queensland (Australia); Dulhunty, Joel M.; Kothari, Alka [Redcliffe Hospital, Redcliffe, Queensland (Australia); The University of Queensland, School of Medicine, Herston, Queensland (Australia)

2016-03-15

Holocarboxylase synthetase deficiency results in impaired activation of enzymes implicated in glucose, fatty acid and amino acid metabolism. Antenatal imaging and postnatal imaging are useful in making the diagnosis. Untreated holocarboxylase synthetase deficiency is fatal, while antenatal and postnatal biotin supplementation is associated with good clinical outcomes. Although biochemical assays are required for definitive diagnosis, certain radiologic features assist in the diagnosis of holocarboxylase synthetase deficiency. To review evidence regarding radiologic diagnostic features of holocarboxylase synthetase deficiency in the antenatal and postnatal period. A systematic review of all published cases of holocarboxylase synthetase deficiency identified by a search of Pubmed, Scopus and Web of Science. A total of 75 patients with holocarboxylase synthetase deficiency were identified from the systematic review, which screened 687 manuscripts. Most patients with imaging (19/22, 86%) had abnormal findings, the most common being subependymal cysts, ventriculomegaly and intraventricular hemorrhage. Although the radiologic features of subependymal cysts, ventriculomegaly, intraventricular hemorrhage and intrauterine growth restriction may be found in the setting of other pathologies, these findings should prompt consideration of holocarboxylase synthetase deficiency in at-risk children. (orig.)

Fine tuning of reactive oxygen species homeostasis regulates primed immune responses in Arabidopsis.

Science.gov (United States)

Pastor, Victoria; Luna, Estrella; Ton, Jurriaan; Cerezo, Miguel; García-Agustín, Pilar; Flors, Victor

2013-11-01

Selected stimuli can prime the plant immune system for a faster and stronger defense reaction to pathogen attack. Pretreatment of Arabidopsis with the chemical agent β-aminobutyric acid (BABA) augmented H2O2 and callose production after induction with the pathogen-associated molecular pattern (PAMP) chitosan, or inoculation with the necrotrophic fungus Plectosphaerella cucumerina. However, BABA failed to prime H2O2 and callose production after challenge with the bacterial PAMP Flg22. Analysis of Arabidopsis mutants in reactive oxygen species (ROS) production (rbohD) or ROS scavenging (pad2, vtc1, and cat2) suggested a regulatory role for ROS homeostasis in priming of chitosan- and P. cucumerina-inducible callose and ROS. Moreover, rbohD and pad2 were both impaired in BABA-induced resistance against P. cucumerina. Gene expression analysis revealed direct induction of NADPH/respiratory burst oxidase protein D (RBOHD), γ-glutamylcysteine synthetase 1 (GSH1), and vitamin C defective 1 (VTC1) genes after BABA treatment. Conversely, ascorbate peroxidase 1 (APX1) transcription was repressed by BABA after challenge with chitosan or P. cucumerina, probably to provide a more oxidized environment in the cell and facilitate augmented ROS accumulation. Measuring ratios between reduced and oxidized glutathione confirmed that augmented defense expression in primed plants is associated with a more oxidized cellular status. Together, our data indicate that an altered ROS equilibrium is required for augmented defense expression in primed plants.

Expression of Human CTP Synthetase in Saccharomyces cerevisiae Reveals Phosphorylation by Protein Kinase A*

Science.gov (United States)

Han, Gil-Soo; Sreenivas, Avula; Choi, Mal-Gi; Chang, Yu-Fang; Martin, Shelley S.; Baldwin, Enoch P.; Carman, George M.

2005-01-01

CTP synthetase (EC 6.3.4.2, UTP: ammonia ligase (ADP-forming)) is an essential enzyme in all organisms; it generates the CTP required for the synthesis of nucleic acids and membrane phospholipids. In this work we showed that the human CTP synthetase genes, CTPS1 and CTPS2, were functional in Saccharomyces cerevisiae and complemented the lethal phenotype of the ura7Δ ura8Δ mutant lacking CTP synthetase activity. The expression of the CTPS1-and CTPS2-encoded human CTP synthetase enzymes in the ura7Δ ura8Δ mutant was shown by immunoblot analysis of CTP synthetase proteins, the measurement of CTP synthetase activity, and the synthesis of CTP in vivo. Phosphoamino acid and phosphopeptide mapping analyses of human CTP synthetase 1 isolated from 32Pi-labeled cells revealed that the enzyme was phosphorylated on multiple serine residues in vivo. Activation of protein kinase A activity in yeast resulted in transient increases (2-fold) in the phosphorylation of human CTP synthetase 1 and the cellular level of CTP. Human CTP synthetase 1 was also phosphorylated by mammalian protein kinase A in vitro. Using human CTP synthetase 1 purified from Escherichia coli as a substrate, protein kinase A activity was dose- and time-dependent, and dependent on the concentrations of CTP synthetase1 and ATP. These studies showed that S. cerevisiae was useful for the analysis of human CTP synthetase phosphorylation. PMID:16179339

ATP-dependent and NAD-dependent modification of glutamine synthetase from Rhodospirillum rubrum in vitro

International Nuclear Information System (INIS)

Woehle, D.L.; Lueddecke, B.A.; Ludden, P.W.

1990-01-01

Glutamine synthetase from the photosynthetic bacterium Rhodospirillum rubrum is the target of both ATP- and NAD-dependent modification. Incubation of R. rubrum cell supernatant with [α- 32 P]NAD results in the labeling of glutamine synthetase and two other unidentified proteins. Dinitrogenase reductase ADP-ribosyltransferase does not appear to be responsible for the modification of glutamine synthetase or the unidentified proteins. The [α- 32 P]ATP- and [α- 32 P] NAD-dependent modifications of R. rubrum glutamine synthetase appear to be exclusive and the two forms of modified glutamine synthetase are separable on two-dimensional gels. Loss of enzymatic activity by glutamine synthetase did not correlate with [α- 32 P]NAD labeling. This is in contrast to inactivation by nonphysiological ADP-ribosylation of other glutamine synthetases by an NAD:arginine ADP-ribosyltransferase from turkey erythrocytes. A 32 P-labeled protein spot comigrates with the NAD-treated glutamine synthetase spot when glutamine synthetase purified from H 3 32 PO 4 -grown cells is analyzed on two-dimensional gels. The adenylylation site of R. rubrum glutamine synthetase has been determined to be Leu-(Asp)-Tyr-Leu-Pro-Pro-Glu-Glu-Leu-Met; the tyrosine residue is the site of modification

Polyspecific pyrrolysyl-tRNA synthetases from directed evolution

Science.gov (United States)

Guo, Li-Tao; Wang, Yane-Shih; Nakamura, Akiyoshi; Eiler, Daniel; Kavran, Jennifer M.; Wong, Margaret; Kiessling, Laura L.; Steitz, Thomas A.; O’Donoghue, Patrick; Söll, Dieter

2014-01-01

Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNAPyl have emerged as ideal translation components for genetic code innovation. Variants of the enzyme facilitate the incorporation >100 noncanonical amino acids (ncAAs) into proteins. PylRS variants were previously selected to acylate Nε-acetyl-Lys (AcK) onto tRNAPyl. Here, we examine an Nε-acetyl-lysyl-tRNA synthetase (AcKRS), which is polyspecific (i.e., active with a broad range of ncAAs) and 30-fold more efficient with Phe derivatives than it is with AcK. Structural and biochemical data reveal the molecular basis of polyspecificity in AcKRS and in a PylRS variant [iodo-phenylalanyl-tRNA synthetase (IFRS)] that displays both enhanced activity and substrate promiscuity over a chemical library of 313 ncAAs. IFRS, a product of directed evolution, has distinct binding modes for different ncAAs. These data indicate that in vivo selections do not produce optimally specific tRNA synthetases and suggest that translation fidelity will become an increasingly dominant factor in expanding the genetic code far beyond 20 amino acids. PMID:25385624

Polyspecific pyrrolysyl-tRNA synthetases from directed evolution.

Science.gov (United States)

Guo, Li-Tao; Wang, Yane-Shih; Nakamura, Akiyoshi; Eiler, Daniel; Kavran, Jennifer M; Wong, Margaret; Kiessling, Laura L; Steitz, Thomas A; O'Donoghue, Patrick; Söll, Dieter

2014-11-25

Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA(Pyl) have emerged as ideal translation components for genetic code innovation. Variants of the enzyme facilitate the incorporation >100 noncanonical amino acids (ncAAs) into proteins. PylRS variants were previously selected to acylate N(ε)-acetyl-Lys (AcK) onto tRNA(Pyl). Here, we examine an N(ε)-acetyl-lysyl-tRNA synthetase (AcKRS), which is polyspecific (i.e., active with a broad range of ncAAs) and 30-fold more efficient with Phe derivatives than it is with AcK. Structural and biochemical data reveal the molecular basis of polyspecificity in AcKRS and in a PylRS variant [iodo-phenylalanyl-tRNA synthetase (IFRS)] that displays both enhanced activity and substrate promiscuity over a chemical library of 313 ncAAs. IFRS, a product of directed evolution, has distinct binding modes for different ncAAs. These data indicate that in vivo selections do not produce optimally specific tRNA synthetases and suggest that translation fidelity will become an increasingly dominant factor in expanding the genetic code far beyond 20 amino acids.

The reported human NADsyn2 is ammonia-dependent NAD synthetase from a pseudomonad.

Science.gov (United States)

Bieganowski, Pawel; Brenner, Charles

2003-08-29

Nicotinamide-adenine dinucleotide (NAD+) synthetases catalyze the last step in NAD+ metabolism in the de novo, import, and salvage pathways that originate from tryptophan (or aspartic acid), nicotinic acid, and nicotinamide, respectively, and converge on nicotinic acid mononucleotide. NAD+ synthetase converts nicotinic acid adenine dinucleotide to NAD+ via an adenylylated intermediate. All of the known eukaryotic NAD+ synthetases are glutamine-dependent, hydrolyzing glutamine to glutamic acid to provide the attacking ammonia. In the prokaryotic world, some NAD+ synthetases are glutamine-dependent, whereas others can only use ammonia. Earlier, we noted a perfect correlation between presence of a domain related to nitrilase and glutamine dependence and then proved in the accompanying paper (Bieganowski, P., Pace, H. C., and Brenner, C. (2003) J. Biol. Chem. 278, 33049-33055) that the nitrilase-related domain is an essential, obligate intramolecular, thiol-dependent glutamine amidotransferase in the yeast NAD+ synthetase, Qns1. Independently, human NAD+ synthetase was cloned and shown to depend on Cys-175 for glutamine-dependent but not ammonia-dependent NAD+ synthetase activity. Additionally, it was claimed that a 275 amino acid open reading frame putatively amplified from human glioma cell line LN229 encodes a human ammonia-dependent NAD+ synthetase and this was speculated largely to mediate NAD+ synthesis in human muscle tissues. Here we establish that the so-called NADsyn2 is simply ammonia-dependent NAD+ synthetase from Pseudomonas, which is encoded on an operon with nicotinic acid phosphoribosyltransferase and, in some Pseudomonads, with nicotinamidase.

Enzymatic Production of Glutathione by Bifunctional γ-Glutamylcysteine Synthetase/Glutathione Synthetase Coupled with In Vitro Acetate Kinase-Based ATP Generation.

Science.gov (United States)

Jiang, Yu; Tao, Rongsheng; Shen, Zhengquan; Sun, Liangdong; Zhu, Fuyun; Yang, Sheng

2016-12-01

Glutathione (γ-glutamyl-L-cysteinylglycine, GSH) is a pharmaceutical compound often used in food additives and the cosmetics industry. GSH can be produced biologically from L-glutamic acid, L-cysteine, and glycine through an enzymatic process traditionally involving two sequential adenosine triphosphate (ATP)-dependent reactions catalyzed by γ-glutamylcysteine synthetase (γ-GCS or GSHI, EC 6.3.2.2) and GSH synthetase (GS or GSHII, EC 6.3.2.3). Here, we report the enzymatic production of GSH by recombinant cell-free bifunctional γ-glutamylcysteine synthetase/glutathione synthetase (γ-GCS-GS or GshF) coupled with in vitro acetate kinase-based ATP generation. GSH production by an acetate kinase-integrated Escherichia coli Rosetta(DE3) mutant expressing Streptococcus thermophilus GshF reached 18.3 ± 0.1 g l -1 (59.5 ± 0.3 mM) within 3 h, with a molar yield of 0.75 ± 0.00 mol mol -1 added cysteine and a productivity of 6.1 ± 0.0 g l -1  h -1 . This is the highest GSH titer reported to date. This newly developed biocatalytic process offers a promising approach for meeting the industrial requirements for GSH production.

Selective inhibition of type 2 fatty acid synthetase by the antibiotic thiolactomycin

International Nuclear Information System (INIS)

Nishida, Ikuo; Kawaguchi, Akihiko; Yamada, Mitsuhiro

1984-01-01

The antibiotic thiolactomycin inhibits the fatty acid synthesis from both [1- 14 C]-acetate and [2 14 C] malonyl-CoA of spinach leaves, developing castor bean endosperms and avocado mesocarp. On the other hand, fatty acid synthetases of Brevibacterium ammoniagenes and Corynebacterium glutamicum are much less sensitive to this antibiotic. As Hayashi et al. have indicated in their paper that thiolactomycin inhibits fatty acid synthetase of Escherichia coli but has little effect on the synthetases of yeast and rat liver, thiolactomycin is suggested to be a selective inhibitor of type 2 fatty acid synthetases. (author)

Selective inhibition of type 2 fatty acid synthetase by the antibiotic thiolactomycin

Energy Technology Data Exchange (ETDEWEB)

Nishida, Ikuo; Kawaguchi, Akihiko; Yamada, Mitsuhiro (Tokyo Univ. (Japan). Faculty of Science)

1984-03-01

The antibiotic thiolactomycin inhibits the fatty acid synthesis from both (1-/sup 14/C)-acetate and (2/sup 14/C) malonyl-CoA of spinach leaves, developing castor bean endosperms and avocado mesocarp. On the other hand, fatty acid synthetases of Brevibacterium ammoniagenes and Corynebacterium glutamicum are much less sensitive to this antibiotic. As Hayashi et al. have indicated in their paper that thiolactomycin inhibits fatty acid synthetase of Escherichia coli but has little effect on the synthetases of yeast and rat liver, thiolactomycin is suggested to be a selective inhibitor of type 2 fatty acid synthetases.

Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.

LENUS (Irish Health Repository)

Kell, M R

2012-02-03

BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.

Valyl-tRNA synthetase gene of Escherichia coli K12: Molecular genetic characterization and homology within a family of aminoacyl-tRNA synthetases

International Nuclear Information System (INIS)

Heck, J.D. III.

1988-01-01

This work reports the subcloning and characterization of the molecular elements necessary for the expression of the Escherichia coli valS gene encoding valyl-tRNA synthetase. The valS gene was subcloned from plasmid pLC26-22 by genetic complementation of a valS ts strain. The DNA region encoding the valS structural gene was determined by in vitro coupled transcription-translation assays. Cells transformed with a plasmid containing a full length copy of the valS gene enhanced in vivo valyl-tRNA synthetase specific activity twelve-fold. DNA sequences flanking the valS structural gene are presented. The transcription initiation sites of the valS gene were determined, in vivo and in vitro, by S1 nuclease protection studies, primer-extension analysis and both [α- 32 P]labeled and [γ- 32 P]end-labeled in vitro transcription assays. The DNA sequence of the valS gene of Escherichia coli has been determined. Significant similarity at the primary sequence level was detected between valyl-tRNA synthetase of E. coli and other known branched-chain aminoacyl-tRNA synthetases. An extended open reading frame (ORF) encoded on the DNA strand opposite the valS structural gene is described

Evolution of the 2'-5'-Oligoadenylate Synthetase family in eukaryotes and bacteria

DEFF Research Database (Denmark)

Kjær, Karina Hansen; Poulsen, Jesper Buchhave; Reitamm, Tonu

2009-01-01

in bacteria that contains the five OAS-specific motifs. This indicates a specific relationship to OAS. The wide distribution of the OAS genes has made it possible to suggest how the OAS1 gene could have evolved from a common ancestor to choanoflagellates and metazoans. Furthermore, we suggest that the OASL...

Orthogonal use of a human tRNA synthetase active site to achieve multifunctionality.

Science.gov (United States)

Zhou, Quansheng; Kapoor, Mili; Guo, Min; Belani, Rajesh; Xu, Xiaoling; Kiosses, William B; Hanan, Melanie; Park, Chulho; Armour, Eva; Do, Minh-Ha; Nangle, Leslie A; Schimmel, Paul; Yang, Xiang-Lei

2010-01-01

Protein multifunctionality is an emerging explanation for the complexity of higher organisms. In this regard, aminoacyl tRNA synthetases catalyze amino acid activation for protein synthesis, but some also act in pathways for inflammation, angiogenesis and apoptosis. It is unclear how these multiple functions evolved and how they relate to the active site. Here structural modeling analysis, mutagenesis and cell-based functional studies show that the potent angiostatic, natural fragment of human tryptophanyl-tRNA synthetase (TrpRS) associates via tryptophan side chains that protrude from its cognate cellular receptor vascular endothelial cadherin (VE-cadherin). VE-cadherin's tryptophan side chains fit into the tryptophan-specific active site of the synthetase. Thus, specific side chains of the receptor mimic amino acid substrates and expand the functionality of the active site of the synthetase. We propose that orthogonal use of the same active site may be a general way to develop multifunctionality of human tRNA synthetases and other proteins.

Reexamining unconscious response priming: A liminal-prime paradigm.

Science.gov (United States)

Avneon, Maayan; Lamy, Dominique

2018-03-01

Research on the limits of unconscious processing typically relies on the subliminal-prime paradigm. However, this paradigm is limited in the issues it can address. Here, we examined the implications of using the liminal-prime paradigm, which allows comparing unconscious and conscious priming with constant stimulation. We adapted an iconic demonstration of unconscious response priming to the liminal-prime paradigm. On the one hand, temporal attention allocated to the prime and its relevance to the task increased the magnitude of response priming. On the other hand, the longer RTs associated with the dual task inherent to the paradigm resulted in response priming being underestimated, because unconscious priming effects were shorter-lived than conscious-priming effects. Nevertheless, when the impact of long RTs was alleviated by considering the fastest trials or by imposing a response deadline, conscious response priming remained considerably larger than unconscious response priming. These findings suggest that conscious perception strongly modulates response priming. Copyright © 2017 Elsevier Inc. All rights reserved.

Computational Insights into the High-Fidelity Catalysis of Aminoacyl-tRNA Synthetases

Science.gov (United States)

Aboelnga, Mohamed M.

Obtaining insights into the catalytic function of enzymes is an important area of research due to their widespread applications in the biotechnology and pharmaceutical industries. Among these enzymes, the aminoacyl-tRNA synthetases (aaRSs) are known for their remarkable fidelity in catalyzing the aminoacylation reactions of tRNA in protein biosynthesis. Despite the exceptional execution of this critical function, mechanistic details of the reactions catalyzed by aminoacyl-tRNA synthetases remain elusive demonstrating the obvious need to explore their remarkable chemistry. During the PhD studies reported in this thesis the mechanism of aminoacylation, pre?transfer editing and post?transfer editing catalyzed by different aaRS have been established using multi-scale computational enzymology. In the first two chapters a detailed information about aaRS and the addressed questions was given in addition to an overview of the used computational methodology currently used to investigate the enzymatic mechanisms. The aminoacylation mechanism of threonine by Threonyl-tRNA synthetases, glutamine by Glutaminyl-tRNA synthetases and glutamate by Glutamyl-tRNA synthetases have been clearly unveiled in chapter 3 and 4. Also, valuable information regarding the role of cofactors and active site residues has been obtained. While investigating the post-transfer editing mechanisms, which proceed in a remote and distinct active site, two different scenarios were experimentally suggested for two types of threonyl-tRNA synthetase species to correct the misacylation of the structurally related serine. We explored these two mechanisms as in chapters 5 and 6. Moreover, the synthetic site in which the aminoacylation reaction is catalyzed, is also responsible for a second type of proofreading reaction called pre-transfer editing mechanism. In chapter 7, this latter mechanism has been elucidated for both Seryl-tRNA synthetases and Isoleucyl-tRNA synthetases against their non-cognate substrates

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform.

Directory of Open Access Journals (Sweden)

A Theron

Full Text Available Glutamine synthetase is a ubiquitous central enzyme in nitrogen metabolism that is controlled by up to four regulatory mechanisms, including adenylylation of some or all of the twelve subunits by adenylyl transferase. It is considered a potential therapeutic target for the treatment of tuberculosis, being essential for the growth of Mycobacterium tuberculosis, and is found extracellularly only in the pathogenic Mycobacterium strains. Human glutamine synthetase is not regulated by the adenylylation mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does not optimally adenylylate the M. tuberculosis glutamine synthetase. Here, we demonstrate the production of soluble adenylylated M. tuberulosis glutamine synthetase in E. coli by the co-expression of M. tuberculosis glutamine synthetase and M. tuberculosis adenylyl transferase. The differential inhibition of adenylylated M. tuberulosis glutamine synthetase and deadenylylated M. tuberulosis glutamine synthetase by ATP based scaffold inhibitors are reported. Compounds selected on the basis of their enzyme inhibition were also shown to inhibit M. tuberculosis in the BACTEC 460TB™ assay as well as the intracellular inhibition of M. tuberculosis in a mouse bone-marrow derived macrophage assay.

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform.

Science.gov (United States)

Theron, A; Roth, R L; Hoppe, H; Parkinson, C; van der Westhuyzen, C W; Stoychev, S; Wiid, I; Pietersen, R D; Baker, B; Kenyon, C P

2017-01-01

Glutamine synthetase is a ubiquitous central enzyme in nitrogen metabolism that is controlled by up to four regulatory mechanisms, including adenylylation of some or all of the twelve subunits by adenylyl transferase. It is considered a potential therapeutic target for the treatment of tuberculosis, being essential for the growth of Mycobacterium tuberculosis, and is found extracellularly only in the pathogenic Mycobacterium strains. Human glutamine synthetase is not regulated by the adenylylation mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does not optimally adenylylate the M. tuberculosis glutamine synthetase. Here, we demonstrate the production of soluble adenylylated M. tuberulosis glutamine synthetase in E. coli by the co-expression of M. tuberculosis glutamine synthetase and M. tuberculosis adenylyl transferase. The differential inhibition of adenylylated M. tuberulosis glutamine synthetase and deadenylylated M. tuberulosis glutamine synthetase by ATP based scaffold inhibitors are reported. Compounds selected on the basis of their enzyme inhibition were also shown to inhibit M. tuberculosis in the BACTEC 460TB™ assay as well as the intracellular inhibition of M. tuberculosis in a mouse bone-marrow derived macrophage assay.

A 4'-phosphopantetheinyl transferase mediates non-ribosomal peptide synthetase activation in Aspergillus fumigatus.

Science.gov (United States)

Neville, Claire; Murphy, Alan; Kavanagh, Kevin; Doyle, Sean

2005-04-01

Aspergillus fumigatus is a significant human pathogen. Non-ribosomal peptide (NRP) synthesis is thought to be responsible for a significant proportion of toxin and siderophore production in the organism. Furthermore, it has been shown that 4'-phosphopantetheinylation is required for the activation of key enzymes involved in non-ribosomal peptide synthesis in other species. Here we report the cloning, recombinant expression and functional characterisation of a 4'-phosphopantetheinyl transferase from A. fumigatus and the identification of an atypical NRP synthetase (Afpes1), spanning 14.3 kb. Phylogenetic analysis has shown that the NRP synthetase exhibits greatest identity to NRP synthetases from Metarhizium anisolpiae (PesA) and Alternaria brassicae (AbrePsy1). Northern hybridisation and RT-PCR analysis have confirmed that both genes are expressed in A. fumigatus. A 120 kDa fragment of the A. fumigatus NRP synthetase, containing a putative thiolation domain, was cloned and expressed in the baculovirus expression system. Detection of a 4'-phosphopantetheinylated peptide (SFSAMK) from this protein, by MALDI-TOF mass spectrometric analysis after coincubation of the 4'-phosphopantetheinyl transferase with the recombinant NRP synthetase fragment and acetyl CoA, confirms that it is competent to play a role in NRP synthetase activation in A. fumigatus. The 4'-phosphopantetheinyl transferase also activates, by 4'-phosphopantetheinylation, recombinant alpha-aminoadipate reductase (Lys2p) from Candida albicans, a key enzyme involved in lysine biosynthesis.

Equilibria and partitioning of complexes in the S-adenosylmethionine synthetase reaction

International Nuclear Information System (INIS)

Markham, G.D.

1987-01-01

S-adenosylmethionine synthetase (ATP: L-methionine S-adenosyltransferase) catalyzes a reaction in which the [enzyme-ATP-methionine] complex reacts to form an intermediate [enzyme-AdoMet-PPPi] complex: hydrolysis of PPPi yields an [enzyme-AdoMet-PPi-Pi] complex from which AdoMet is the last product to dissociate. Analysis of reaction mixtures which were quenched with acid during turnover of E. coli AdoMet synthetase with saturating substrates containing [α - 32 P]ATP showed that PPPi is present in an amount corresponding to 45% of the total enzyme active sites, reflecting the portion of enzyme present in an [enzyme-AdoMet-PPPi] complex. Similar experiments in which excess pyrophosphatase was included (to hydrolyze PPi as it was released from AdoMet synthetase), showed that enzyme-bound PPi is present in an amount corresponding to 22% of the total AdoMet synthetase. The enzyme not present in complexes with PPPi or PPi is probably distributed between the [enzyme-ATP-methionine] and the [enzyme-AdoMet] complexes. AdoMet synthetase forms enzyme-bound 32 PPPi from added 32 PPi and Pi; the equilibrium constant [enzyme-AdoMet-PPi-Pi]/[enzyme-AdoMet-PPPi] is 2.0, greatly displaced from the equilibrium for hydrolysis of free PPPi. Since the ratio of enzyme-bound PPi to PPPi is 0.5 during the steady state, the PPPi hydrolysis step is not at equilibrium during turnover. Formation of [ 32 P]ATP from the [enzyme-AdoMet- 32 PPPi] complex was not detected

Isolation of the thymidylate synthetase gene (TMP1) by complementation in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Taylor, G.R.; Barclay, B.J.; Storms, R.K.; Friesen, J.D.; Haynes, R.H.

1982-01-01

The structural gene (TMP1) for yeast thymidylate synthetase (thymidylate synthase; EC 2.1.1.45) was isolated from a chimeric plasmid bank by genetic complementation in Saccharomyces cerevisiae. Retransformation of the dTMP auxotroph GY712 and a temperature-sensitive mutant (cdc21) with purified plasmid (pTL1) yielded Tmp/sup +/ transformants at high frequency. In addition, the plasmid was tested for the ability to complement a bacterial thyA mutant that lacks functional thymidylate synthetase. Although it was not possible to select Thy/sup +/ transformants directly, it was found that all pTL1 transformants were phenotypically Thy/sup +/ after several generations of growth in nonselective conditions. Thus, yeast thymidylate synthetase is biologically active in Escherichia coli. Thymidylate synthetase was assayed in yeast cell lysates by high-pressure liquid chromatography to monitor the conversion of [6-/sup 3/H]dUMP to [6-/sup 3/H]dTMP. In protein extracts from the thymidylate auxotroph (tmpl-6) enzymatic conversion of dUMP to dTMP was barely detectable. Lysates of pTL1 transformants of this strain, however, had thymidylate synthetase activity that was comparable to that of the wild-type strain

Masked priming effect reflects evidence accumulated by the prime.

Science.gov (United States)

Kinoshita, Sachiko; Norris, Dennis

2010-01-01

In the same-different match task, masked priming is observed with the same responses but not different responses. Norris and Kinoshita's (2008) Bayesian reader account of masked priming explains this pattern based on the same principle as that explaining the absence of priming for nonwords in the lexical decision task. The pattern of priming follows from the way the model makes optimal decisions in the two tasks; priming does not depend on first activating the prime and then the target. An alternative explanation is in terms of a bias towards responding "same" that exactly counters the facilitatory effect of lexical access. The present study tested these two views by varying both the degree to which the prime predicts the response and the visibility of the prime. Unmasked primes produced effects expected from the view that priming is influenced by the degree to which the prime predicts the response. In contrast, with masked primes, the size of priming for the same response was completely unaffected by predictability. These results rule out response bias as an explanation of the absence of masked priming for different responses and, in turn, indicate that masked priming is not a consequence of automatic lexical access of the prime.

Retinoic acid induces signal transducer and activator of transcription (STAT) 1, STAT2, and p48 expression in myeloid leukemia cells and enhances their responsiveness to interferons.

Science.gov (United States)

Matikainen, S; Ronni, T; Lehtonen, A; Sareneva, T; Melén, K; Nordling, S; Levy, D E; Julkunen, I

1997-06-01

IFNs are antiproliferative cytokines that have growth-inhibitory effects on various normal and malignant cells. Therefore, they have been used in the treatment of certain forms of cancer, such as chronic myelogenous leukemia and hairy cell leukemia. However, there is little evidence that IFNs would be effective in the treatment of acute myelogenous leukemia, and molecular mechanisms underlying IFN unresponsiveness have not been clarified. Here we have studied the activation and induction of IFN-specific transcription factors signal transducer and activator of transcription (STAT) 1, STAT2, and p48 in all-trans-retinoic acid (ATRA)-differentiated myeloid leukemia cells using promyelocytic NB4, myeloblastic HL-60, and monoblastic U937 cells as model systems. These cells respond to ATRA by growth inhibition and differentiation. We show that in undifferentiated NB4 cells, 2',5'-oligoadenylate synthetase and MxB gene expression is not activated by IFN-alpha, possibly due to a relative lack of signaling molecules, especially p48 protein. However, during ATRA-induced differentiation, steady-state STAT1, STAT2, and especially p48 mRNA and corresponding protein levels were elevated both in NB4 and U937 cells, apparently correlating to an enhanced responsiveness of these cells to IFNs. ATRA treatment of NB4 cells sensitized them to IFN action as seen by increased IFN-gamma activation site DNA-binding activity or by efficient formation of IFN-alpha-specific ISGF3 complex and subsequent oligoadenylate synthetase and MxB gene expression. Lack of p48 expression could be one of the mechanisms of promyelocytic leukemia cell escape from growth-inhibitory effects of IFN-alpha.

The early history of tRNA recognition by aminoacyl-tRNA synthetases

Indian Academy of Sciences (India)

Madhu

2006-10-04

Oct 4, 2006 ... Discovery of aminoacyl-tRNA synthetases and importance ... The pioneering work of Fritz Lipmann on the high-energy ... the peculiar structural and functional relationships tRNAs ... a bulk of only 20 families of tRNA molecules in contrast ...... balance of tRNA and aminoacyl-tRNA synthetase; Science 242.

A highly conserved basidiomycete peptide synthetase produces a trimeric hydroxamate siderophore.

Science.gov (United States)

Brandenburger, Eileen; Gressler, Markus; Leonhardt, Robin; Lackner, Gerald; Habel, Andreas; Hertweck, Christian; Brock, Matthias; Hoffmeister, Dirk

2017-08-25

The model white-rot basidiomycete Ceriporiopsis ( Gelatoporia ) subvermispora B encodes putative natural product biosynthesis genes. Among them is the gene for the seven-domain nonribosomal peptide synthetase CsNPS2. It is a member of the as-yet uncharacterized fungal type VI siderophore synthetase family which is highly conserved and widely distributed among the basidiomycetes. These enzymes include only one adenylation (A) domain, i.e., one complete peptide synthetase module and two thiolation/condensation (T-C) di-domain partial modules which, together, constitute an AT 1 C 1 T 2 C 2 T 3 C 3 domain setup. The full-length CsNPS2 enzyme (274.5 kDa) was heterologously produced as polyhistidine fusion in Aspergillus niger as soluble and active protein. N 5 -acetyl- N 5 -hydroxy-l-ornithine (l-AHO) and N 5 - cis -anhydromevalonyl- N 5 -hydroxy-l-ornithine (l-AMHO) were accepted as substrates, as assessed in vitro using the substrate-dependent [ 32 P]ATP-pyrophosphate radioisotope exchange assay. Full-length holo -CsNPS2 catalyzed amide bond formation between three l-AHO molecules to release the linear l-AHO trimer, called basidioferrin, as product in vitro , which was verified by LC-HRESIMS. Phylogenetic analyses suggest that type VI family siderophore synthetases are widespread in mushrooms and have evolved in a common ancestor of basidiomycetes. Importance : The basidiomycete nonribosomal peptide synthetase CsNPS2 represents a member of a widely distributed but previously uninvestigated class (type VI) of fungal siderophore synthetases. Genes orthologous to CsNPS2 are highly conserved across various phylogenetic clades of the basidiomycetes. Hence, our work serves as a broadly applicable model for siderophore biosynthesis and iron metabolism in higher fungi. Also, our results on the amino acid substrate preference of CsNPS2 supports further understanding of the substrate selectivity of fungal adenylation domains. Methodologically, this report highlights the

Growth factors regulate glutamine synthetase activity in ...

African Journals Online (AJOL)

Khaled

2012-07-10

Jul 10, 2012 ... glutamate and ammonia, which in turn, cells are supplied with ammonia ... out to determine the maximum growth time at which cells will be .... Western blot technique for detection the glutamine synthetase enzyme. Lane 1;.

Comparison of the effect of interferon on two human hepatoma cell lines

Energy Technology Data Exchange (ETDEWEB)

Crespi, M; Schoub, B D; Lyons, S F; Chiu, M N [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Virology

1985-06-01

Two human hepatoma cell lines, the PLC/PRF/5 and the Mahlavu cells, which differ in their production of the hepatitis B surface antigen (HBsAg), responded differently to interferon (IFN). After IFN treatment both cell lines were able to inhibit Sindbis virus replication. Oligo A synthetase (E enzyme) could be activated in the PLC/PRF/5 cells although they were not sensitive to exogenous 2 - 5 oligoadenylic acid (2 - 5 A). In contrast, the Mahlavu cells were sensitive to exogenous 2 - 5 A, but unable to activate the E enzyme. Both cell lines were unable to stimulate phosphorylation of the exogenous initiator factor eIF-2.

SCREENING OF ANTIMICROBIAL ACTIVITY AND GENES CODING POLYKETIDE SYNTHETASE AND NONRIBOSOMAL PEPTIDE SYNTHETASE OF ACTINOMYCETE ISOLATES

Directory of Open Access Journals (Sweden)

Silvia Kovácsová

2013-12-01

Full Text Available The aim of this study was to observe antimicrobial activity using agar plate diffusion method and screening genes coding polyketide synthetase (PKS-I and nonribosomal peptide synthetase (NRPS from actinomycetes. A total of 105 actinomycete strains were isolated from arable soil. Antimicrobial activity was demonstrated at 54 strains against at least 1 of total 12 indicator organisms. Antifungal properties were recorded more often than antibacterial properties. The presence of PKS-I and NRPS genes were founded at 61 of total 105 strains. The number of strains with mentioned biosynthetic enzyme gene fragments matching the anticipated length were 19 (18% and 50 (47% respectively. Overall, five actinomycete strains carried all the biosynthetical genes, yet no antimicrobial activity was found against any of tested pathogens. On the other hand, twenty-one strains showed antimicrobial activity even though we were not able to amplify any of the PKS or NRPS genes from them. Combination of the two methods showed broad-spectrum antimicrobial activity of actinomycetes isolated from arable soil, which indicate that actinomycetes are valuable reservoirs of novel bioactive compounds.

Radiation-induced G/sub 2/-arrest is reduced by inhibitors of poly(adenosine diphosphoribose) synthetase

International Nuclear Information System (INIS)

Rowley, R.

1985-01-01

Experiments are in progress to test whether poly(adenosine diphosphoribose) synthesis is required for the induction of G/sub 2/-arrest in growing mammalian cells following X-irradiation. A variety of poly(ADPR) synthetase inhibitors have been tested to determine: 1) whether addition of an inhibitor to X-irradiated CHO cells reduces G/sub 2/-arrest; 2) whether compounds structurally similar to poly-(ADPR) synthetase inhibitors but inactive against this enzyme affect radiation-induced G/sub 2/-arrest and 3) whether the concentration dependence for poly(ADPR) synthetase inhibition matches that for G/sub 2/-arrest reduction. G/sub 2/-arrest was measured in X-irradiated (1.5 Gy) CHO cells using the mitotic cell selection technique. Poly(ADPR) synthetase activity was measured in permeabilized cells by /sup 3/H-NAD incorporation. The synthetase inhibitors used were 3-aminobenzamide, benzamide, nicotinamide, 4-acetyl pyridine, caffeine and theophylline. The inactive compounds used were 3-aminobenzoic acid, benzoic acid, nicotinic acid, adenine, adenosine and 3'-deoxyadenosine. Inhibitors of poly(ADPR) synthetase reduced G/sub 2/-arrest while related compounds which produced no enzyme inhibition did not. The concentration dependencies for G/sub 2/-arrest reduction and enzyme inhibition were similar only for methyl xanthines. Further analysis awaits the determination of intracellular drug concentrations

Construction of hybrid peptide synthetases by module and domain fusions.

Science.gov (United States)

Mootz, H D; Schwarzer, D; Marahiel, M A

2000-05-23

Nonribosomal peptide synthetases are modular enzymes that assemble peptides of diverse structures and important biological activities. Their modular organization provides a great potential for the rational design of novel compounds by recombination of the biosynthetic genes. Here we describe the extension of a dimodular system to trimodular ones based on whole-module fusion. The recombinant hybrid enzymes were purified to monitor product assembly in vitro. We started from the first two modules of tyrocidine synthetase, which catalyze the formation of the dipeptide dPhe-Pro, to construct such hybrid systems. Fusion of the second, proline-specific module with the ninth and tenth modules of the tyrocidine synthetases, specific for ornithine and leucine, respectively, resulted in dimodular hybrid enzymes exhibiting the combined substrate specificities. The thioesterase domain was fused to the terminal module. Upon incubation of these dimodular enzymes with the first tyrocidine module, TycA, incorporating dPhe, the predicted tripeptides dPhe-Pro-Orn and dPhe-Pro-Leu were obtained at rates of 0.15 min(-1) and 2.1 min(-1). The internal thioesterase domain was necessary and sufficient to release the products from the hybrid enzymes and thereby facilitate a catalytic turnover. Our approach of whole-module fusion is based on an improved definition of the fusion sites and overcomes the recently discovered editing function of the intrinsic condensation domains. The stepwise construction of hybrid peptide synthetases from catalytic subunits reinforces the inherent potential for the synthesis of novel, designed peptides.

Effect of heat shock on poly(ADP-ribose) synthetase and DNA repair in Drosophila cells

Energy Technology Data Exchange (ETDEWEB)

Nolan, N.L.; Kidwell, W.R.

1982-04-01

Poly(ADP-ribose) synthetase, a chromatin-bound enzyme which attaches polyanionic chains of ADP-ribose to nuclear proteins, was found to be temperature sensitive in intact Drosophila melanogaster cells. The synthetase was completely inactivated by heat-shocking the cells at 37/sup 0/C for 5 min, a condition which had no appreciable effect on the subsequent growth of Drosophila cells at their physiological temperature. The heat-shock effect on synthetase was reversible; enzyme activity began to reappear about 2 hr post heat shock. During the 2-hr interval when poly(ADP-ribose) synthetase was absent, the cells were competent in repair of ..gamma..-ray-induced DNA strand breaks as shown by DNA sedimentation studies on alkaline sucrose gradients. It is thus concluded that poly(ADP-ribose) synthesis is unnecessary for repair of DNA strand breaks introduced by irradiation. The same conclusion was reached from the fact that two inhibitors of poly(ADP-ribose) synthetase 3-aminobenzamide and 5-methylnicotinamide, failed to block repair of ..gamma..-ray-induced DNA chain breaks even though both inhibitors reduced the amount of poly(ADP-ribose) synthesized in cells by 50-75%. Although it was found that the repair of DNA strand breaks is independent of poly(ADP-ribose) synthesis, irradiation does activate the synthetase in control cells, as shown by radioimmunoassay of poly(ADP-ribose) levels.

Effect of heat shock on poly(ADP-ribose) synthetase and DNA repair in Drosophila cells

International Nuclear Information System (INIS)

Nolan, N.L.; Kidwell, W.R.

1982-01-01

Poly(ADP-ribose) synthetase, a chromatin-bound enzyme which attaches polyanionic chains of ADP-ribose to nuclear proteins, was found to be temperature sensitive in intact Drosophila melanogaster cells. The synthetase was completely inactivated by heat-shocking the cells at 37 0 C for 5 min, a condition which had no appreciable effect on the subsequent growth of Drosophila cells at their physiological temperature. The heat-shock effect on synthetase was reversible; enzyme activity began to reappear about 2 hr post heat shock. During the 2-hr interval when poly(ADP-ribose) synthetase was absent, the cells were competent in repair of γ-ray-induced DNA strand breaks as shown by DNA sedimentation studies on alkaline sucrose gradients. It is thus concluded that poly(ADP-ribose) synthesis is unnecessary for repair of DNA strand breaks introduced by irradiation. The same conclusion was reached from the fact that two inhibitors of poly(ADP-ribose) synthetase 3-aminobenzamide and 5-methylnicotinamide, failed to block repair of γ-ray-induced DNA chain breaks even though both inhibitors reduced the amount of poly(ADP-ribose) synthesized in cells by 50-75%. Although it was found that the repair of DNA strand breaks is independent of poly(ADP-ribose) synthesis, irradiation does activate the synthetase in control cells, as shown by radioimmunoassay of poly(ADP-ribose) levels

Characterization of arachidonate 5-lipoxygenase and leukotriene A4 synthetase from RBL-1 cells

International Nuclear Information System (INIS)

Cook, M.; Hogaboom, G.K.; Sarau, H.M.; Foley, J.J.; Crooke, S.T.

1986-01-01

5-lipoxygenase (LO) and leukotriene (LT) A4 synthetase from RBL-1 high speed (105,000 x g for 60 min) supernatants were partially purified by protein-high performance liquid chromatography (HPLC) and characterized in detail. The partially purified preparation contained only 5-LO and LTA4 synthetase and was isolated from 12-LO, peroxidase and LTA4 hydrolase activities. Reaction products were separated by reversed phase HPLC and quantitated by absorption spectrophotometry and radiochemical detection. The enzyme preparation rapidly converted [ 14 C]arachidonate to [ 14 C]5-hydroperoxyeicosatetraenoic acid (HPETE) and [ 14 C]5,12-dihydroperoxyeicosatetraenoic acids (diHETEs). The 5,12-diHETEs were primarily non-enzymatic breakdown products of LTA4 (e.g., 6-trans-LTB4 and 6-trans-12-epi-LTB4). Both the 5-LO and LTA4 synthetase activities were Ca 2+- and ATP-dependent. For both enzyme activities, the CA 2+ stimulation required the presence of ATP. The fatty acid hydroperoxides, 5-,12-, and 15-HPETE, both stimulated ([ 3 μM]) 5-LO and LTA4 synthetase activities. The rapid isolation and subsequent characterization of 5-LO and LTA4 synthetase provide the bases for the further understanding of the role of the LO pathway in biological processes

Glutamine synthetase gene evolution: A good molecular clock

International Nuclear Information System (INIS)

Pesole, G.; Lanvave, C.; Saccone, C.; Bozzetti, M.P.; Preparata, G.

1991-01-01

Glutamine synthetase gene evolution in various animals, plants, and bacteria was evaluated by a general stationary Markov model. The evolutionary process proved to be unexpectedly regular even for a time span as long as that between the divergence of prokaryotes from eukaryotes. This enabled us to draw phylogenetic trees for species whose phylogeny cannot be easily reconstructed from the fossil record. The calculation of the times of divergence of the various organelle-specific enzymes led us to hypothesize that the pea and bean chloroplast genes for these enzymes originated from the duplication of nuclear genes as a result of the different metabolic needs of the various species. The data indicate that the duplication of plastid glutamine synthetase genes occurred long after the endosymbiotic events that produced the organelles themselves

Transposed-Letter Priming Effects with Masked Subset Primes: A Re-Examination of the "Relative Position Priming Constraint"

Science.gov (United States)

Stinchcombe, Eric J.; Lupker, Stephen J.; Davis, Colin J.

2012-01-01

Three experiments are reported investigating the role of letter order in orthographic subset priming (e.g., "grdn"-GARDEN) using both the conventional masked priming technique as well as the sandwich priming technique in a lexical decision task. In all three experiments, subset primes produced priming with the effect being considerably…

Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

Energy Technology Data Exchange (ETDEWEB)

Larson, Eric T.; Kim, Jessica E.; Napuli, Alberto J.; Verlinde, Christophe L. M. J.; Fan, Erkang; Zucker, Frank H.; Van Voorhis, Wesley C.; Buckner, Frederick S.; Hol, Wim G. J.; Merritt, Ethan A., E-mail: merritt@u.washington.edu [Medical Structural Genomics of Pathogenic Protozoa, (United States); University of Washington, Seattle, WA 98195 (United States)

2012-09-01

The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolution crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine.

Increased PRPP synthetase activity in cultured rat hepatoma cells containing mutations in the hypoxanthine-guanine phosphoribosyltransferase gene.

Science.gov (United States)

Graf, L H; McRoberts, J A; Harrison, T M; Martin, D W

1976-07-01

Nine independently derived clones of mutagenized rat hepatoma cells selected for resistance to 6-mercaptopurine (6-MP) or 6-thioguanine (6-ThioG) have been isolated. Each has severely reduced catalytic activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT) and seven of them possess significantly increased activities of phosphoribosylpyrophosphate (PRPP) synthetase. The degrees of elevations of PRPP synthetase activities do not correlate with the degrees of deficiencies of HPRT activities. The cells from one of these clones, 1020/12, posses 40% of the normal HPRT catalytic activity and overproduce purines. We have extensively examined the cells from this clone. Immunotration studies of 1020/12 cells indicate that there is a mutation in the structural gene for HPRT. Although they possess increased specific catalytic activities of the enzyme. PRPP synthetase, the catalytic parameters, heat stability, and isoelectric pH of PRPP synthetase from 1020/12 cells are indistinguishable from those of the enzyme from wild-type cells. The cause of purine overproduction by 1020/12 cells appears to be the elevated PRPP synthetase activity, rather than a PRPP "sparing" effect stemming from reduced HPRT activity. Support for this idea is provided by the observation that the complete loss of HPRT activity in a clone derived from 1020/12 cells does not further enhance the levels of PRPP synthetase or purine overproduction. We propose that the elevated levels of PRPP synthetase activity in these HPRT deficient cells result from a mutational event in the structural gene for HPRT, and that this causes the disruption of a previously undescribed regulatory function of this gene on the expression of the PRPP synthetase gene.

Genetics Home Reference: carbamoyl phosphate synthetase I deficiency

Science.gov (United States)

... belongs to a class of genetic diseases called urea cycle disorders. In this condition, the carbamoyl phosphate synthetase I ... Management Resources (4 links) Baby's First Test GeneReview: Urea Cycle Disorders Overview MedlinePlus Encyclopedia: Hereditary Urea Cycle Abnormality National ...

Mitochondrial and cytoplasmic isoleucyl-, glutamyl- and arginyl-tRNA synthetases of yeast are encoded by separate genes.

Science.gov (United States)

Tzagoloff, A; Shtanko, A

1995-06-01

Three complementation groups of a pet mutant collection have been found to be composed of respiratory-deficient deficient mutants with lesions in mitochondrial protein synthesis. Recombinant plasmids capable of restoring respiration were cloned by transformation of representatives of each complementation group with a yeast genomic library. The plasmids were used to characterize the complementing genes and to institute disruption of the chromosomal copies of each gene in respiratory-proficient yeast. The sequences of the cloned genes indicate that they code for isoleucyl-, arginyl- and glutamyl-tRNA synthetases. The properties of the mutants used to obtain the genes and of strains with the disrupted genes indicate that all three aminoacyl-tRNA synthetases function exclusively in mitochondrial proteins synthesis. The ISM1 gene for mitochondrial isoleucyl-tRNA synthetase has been localized to chromosome XVI next to UME5. The MSR1 gene for the arginyl-tRNA synthetase was previously located on yeast chromosome VIII. The third gene MSE1 for the mitochondrial glutamyl-tRNA synthetase has not been localized. The identification of three new genes coding for mitochondrial-specific aminoacyl-tRNA synthetases indicates that in Saccharomyces cerevisiae at least 11 members of this protein family are encoded by genes distinct from those coding for the homologous cytoplasmic enzymes.

Orthogonal use of a human tRNA synthetase active site to achieve multi-functionality

Science.gov (United States)

Zhou, Quansheng; Kapoor, Mili; Guo, Min; Belani, Rajesh; Xu, Xiaoling; Kiosses, William B.; Hanan, Melanie; Park, Chulho; Armour, Eva; Do, Minh-Ha; Nangle, Leslie A.; Schimmel, Paul; Yang, Xiang-Lei

2011-01-01

Protein multi-functionality is an emerging explanation for the complexity of higher organisms. In this regard, while aminoacyl tRNA synthetases catalyze amino acid activation for protein synthesis, some also act in pathways for inflammation, angiogenesis, and apoptosis. How multiple functions evolved and their relationship to the active site is not clear. Here structural modeling analysis, mutagenesis, and cell-based functional studies show that the potent angiostatic, natural fragment of human TrpRS associates via Trp side chains that protrude from the cognate cellular receptor VE-cadherin. Modeling indicates that (I prefer the way it was because the conclusion was reached not only by modeling, but more so by experimental studies.)VE-cadherin Trp side chains fit into the Trp-specific active site of the synthetase. Thus, specific side chains of the receptor mimic (?) amino acid substrates and expand the functionality of the active site of the synthetase. We propose that orthogonal use of the same active site may be a general way to develop multi-functionality of human tRNA synthetases and other proteins. PMID:20010843

The influence of prenatal X-irradiation on the activity of SRNA-aminoacyl synthetases in the developing rabbit brain

International Nuclear Information System (INIS)

Wender, M.; Zgorzalewicz, B.

1976-01-01

The activities of sRNA-aminoacyl synthetases were investigated in the cerebral white and grey matter of rabbits subjected during their prenatal life to a single x-ray dose of 150 rad. The results of investigations have shown that ionizing radiation acting during intrauterine development of the experimental animal brings about a distinct depression of all sRNA-aminoacyl synthetase activities in the newborn irradiated litter. During the postnatal development of these animals the activities of some of the synthetases further decreased and even at adulthood, where they are normally very low, their activities were below the control values. The activities of some other synthetases, after the initial depression, showed no further decrease and at adulthood had values comparable to controls. The results indicate clearly that prenatal exposure to ionizing radiation also affects the steps of protein biosynthesis which depend on the activity of sRNA-aminoacyl synthetases. (author)

An archaeal tRNA-synthetase complex that enhances aminoacylation under extreme conditions

DEFF Research Database (Denmark)

Godinic-Mikulcic, Vlatka; Jaric, Jelena; Hausmann, Corinne D

2011-01-01

Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translatio...... of a complex between MtSerRS and MtArgRS provides a means by which methanogenic archaea can optimize an early step in translation under a wide range of extreme environmental conditions....

Recurrent adenylation domain replacement in the microcystin synthetase gene cluster

Directory of Open Access Journals (Sweden)

Laakso Kati

2007-10-01

Full Text Available Abstract Background Microcystins are small cyclic heptapeptide toxins produced by a range of distantly related cyanobacteria. Microcystins are synthesized on large NRPS-PKS enzyme complexes. Many structural variants of microcystins are produced simulatenously. A recombination event between the first module of mcyB (mcyB1 and mcyC in the microcystin synthetase gene cluster is linked to the simultaneous production of microcystin variants in strains of the genus Microcystis. Results Here we undertook a phylogenetic study to investigate the order and timing of recombination between the mcyB1 and mcyC genes in a diverse selection of microcystin producing cyanobacteria. Our results provide support for complex evolutionary processes taking place at the mcyB1 and mcyC adenylation domains which recognize and activate the amino acids found at X and Z positions. We find evidence for recent recombination between mcyB1 and mcyC in strains of the genera Anabaena, Microcystis, and Hapalosiphon. We also find clear evidence for independent adenylation domain conversion of mcyB1 by unrelated peptide synthetase modules in strains of the genera Nostoc and Microcystis. The recombination events replace only the adenylation domain in each case and the condensation domains of mcyB1 and mcyC are not transferred together with the adenylation domain. Our findings demonstrate that the mcyB1 and mcyC adenylation domains are recombination hotspots in the microcystin synthetase gene cluster. Conclusion Recombination is thought to be one of the main mechanisms driving the diversification of NRPSs. However, there is very little information on how recombination takes place in nature. This study demonstrates that functional peptide synthetases are created in nature through transfer of adenylation domains without the concomitant transfer of condensation domains.

Evolutionary anomalies among the aminoacyl-tRNA synthetases

Science.gov (United States)

Doolittle, R. F.; Handy, J.; Bada, J. L. (Principal Investigator)

1998-01-01

Unexpected relationships among the various aminoacyl-tRNA synthetases continue to be uncovered. The question arises - is this mainly the result of promiscuous exchange, or is the confusion really a reflection of the differential loss of past duplications? Phylogenetic analysis may yet provide the answer.

The Prime Numbers Hidden Symmetric Structure and its Relation to the Twin Prime Infinitude and an Improved Prime Number Theorem

CERN Document Server

Mikoss, I

2006-01-01

Due to the sieving process represented by a Secondary Sieving Map; during the generation of the prime numbers, geometric structures with definite symmetries are formed which become evident through their geometrical representations. The study of these structures allows the development of a constructive prime generating formula. This defines a mean prime density yielding a second order recursive and discrete prime producing formula and a second order differential equation whose solutions produce an improved Prime Number Theorem. Applying these results to twin prime pairs is possible to generate a Twin Prime Number Theorem and important conclusions about the infinitude of the twin primes.

Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

DEFF Research Database (Denmark)

Demant, Erland J.F.; Nystrøm, Birthe T.

2001-01-01

acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

Physical studies of adenylosuccinate synthetase

International Nuclear Information System (INIS)

Bass, M.B.

1987-01-01

To determine the chemical mechanism of the reaction catalyzed by adenylosuccinate synthetase, positional isotope exchange studies were performed. Positional isotope exchange from the β-γ bridge to the β nonbridge position of [γ- 18 O]GTP was followed using 31 P NMR. The positional isotope exchange was found to occur in the presence of either IMP or IMP and succinate. The exchange did not occur in the presence of asparate. These results support a reaction mechanism which involves formation of a 6-phosphoryl-IMP intermediate with subsequent attack by aspartate to form adenylosuccinate as originally proposed by Lieberman in 1956. In order to resolve the NMR resonances for positional isotope exchange, it was necessary to find a chelator which would limit exchange broadening. trans-1,2-Diaminocyclohexane-N,N,N',N'-tetraacetic acid was found to be a suitable chelator at neutral and acidic pH. Studies of adenylosuccinate synthetase from Escherichia coli have been limited by the low concentrations of enzyme present in the cell and the difficulty in purifying the enzyme to homogeneity. Overproduction of the enzyme by cloning the purA gene into a runaway replication plasmid allowed the cells to produce a much higher concentration of enzyme. A new purification scheme is reported that takes advantage of the overproduced enzyme. Yields of 75 mg of homogeneous enzyme have been obtained from 76 g of E. coli cell paste

Purification, gene cloning, and characterization of γ-butyrobetainyl CoA synthetase from Agrobacterium sp. 525a.

Science.gov (United States)

Fujimitsu, Hiroshi; Matsumoto, Akira; Takubo, Sayaka; Fukui, Akiko; Okada, Kazuma; Mohamed Ahmed, Isam A; Arima, Jiro; Mori, Nobuhiro

2016-08-01

The report is the first of purification, overproduction, and characterization of a unique γ-butyrobetainyl CoA synthetase from soil-isolated Agrobacterium sp. 525a. The primary structure of the enzyme shares 70-95% identity with those of ATP-dependent microbial acyl-CoA synthetases of the Rhizobiaceae family. As distinctive characteristics of the enzyme of this study, ADP was released in the catalytic reaction process, whereas many acyl CoA synthetases are annotated as an AMP-forming enzyme. The apparent Km values for γ-butyrobetaine, CoA, and ATP were, respectively, 0.69, 0.02, and 0.24 mM.

Henoch-Schönlein purpura nephritis occurring postpartum in a patient with anti-PL-7 anti-synthetase syndrome.

Science.gov (United States)

Nagai, Kojiro; Kishi, Jun; Morizumi, Shun; Minakuchi, Jun; Bando, Yoshimi; Nishioka, Yasuhiko; Doi, Toshio

2017-09-01

A 37-year-old pregnant woman developed purpura which was subsequently diagnosed as Henoch-Schönlein purpura (HSP). After childbirth, the patient developed proteinuria and hematuria. Further examination revealed that the HSP nephritis (HSPN) was associated with anti-threonyl-tRNA synthetase anti-synthetase syndrome. The onset of HSPN during pregnancy or after childbirth is rare. Moreover, to our knowledge, this is the first case to describe renal involvement in anti-synthetase syndrome.

A soluble fatty acyl-acyl carrier protein synthetase from the bioluminescent bacterium Vibrio harveyi.

Science.gov (United States)

Byers, D M; Holmes, C G

1990-01-01

An enzyme catalyzing the ligation of long chain fatty acids to bacterial acyl carrier protein (ACP) has been detected and partially characterized in cell extracts of the bioluminescent bacterium Vibrio harveyi. Acyl-ACP synthetase activity (optimal pH 7.5-8.0) required millimolar concentrations of ATP and Mg2+ and was slightly activated by Ca2+, but was inhibited at high ionic strength and by Triton X-100. ACP from either Escherichia coli (apparent Km = 20 microM) or V. harveyi was used as a substrate. Of the [14C]fatty acids tested as substrates (8-18 carbons), a preference for fatty acids less than or equal to 14 carbons in length was observed. Vibrio harveyi acyl-ACP synthetase appears to be a soluble hydrophilic enzyme on the basis of subcellular fractionation and Triton X-114 phase partition assay. The enzyme was not coinduced with luciferase activity or light emission in vivo during the late exponential growth phase in liquid culture. Acyl-ACP synthetase activity was also detected in extracts from the luminescent bacterium Vibrio fischeri, but not Photobacterium phosphoreum. The cytosolic nature and enzymatic properties of V. harveyi acyl-ACP synthetase indicate that it may have a different physiological role than the membrane-bound activity of E. coli, which has been implicated in phosphatidylethanolamine turnover. Acyl-ACP synthetase activity in V. harveyi could be involved in the intracellular activation and elongation of exogenous fatty acids that occurs in this species or in the reactivation of free myristic acid generated by luciferase.

Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform

CSIR Research Space (South Africa)

Theron, Anjo

2017-10-01

Full Text Available mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does...

Crystallization and preliminary X-ray diffraction studies of FAD synthetase from Corynebacterium ammoniagenes

International Nuclear Information System (INIS)

Herguedas, Beatriz; Martínez-Júlvez, Marta; Frago, Susana; Medina, Milagros; Hermoso, Juan A.

2009-01-01

Native and selenomethionine-labelled FAD synthetase from C. ammoniagenes have been crystallized by the hanging-drop vapour-diffusion method. A MAD data set for SeMet-labelled FAD synthetase was collected to 2.42 Å resolution, while data sets were collected to 1.95 Å resolution for the native crystals. FAD synthetase from Corynebacterium ammoniagenes (CaFADS), a prokaryotic bifunctional enzyme that catalyses the phosphorylation of riboflavin as well as the adenylylation of FMN, has been crystallized using the hanging-drop vapour-diffusion method at 277 K. Diffraction-quality cubic crystals of native and selenomethionine-labelled (SeMet-CaFADS) protein belonged to the cubic space group P2 1 3, with unit-cell parameters a = b = c = 133.47 Å and a = b = c = 133.40 Å, respectively. Data sets for native and SeMet-containing crystals were collected to 1.95 and 2.42 Å resolution, respectively

Priming semantico e museografia / Semantic priming and museography

Directory of Open Access Journals (Sweden)

Annalisa Banzi

2012-05-01

Full Text Available Il priming è una tipologia di memoria implicita che facilita l’apprendimento di stimoli di diversa natura (stimoli visivi, semantici, etc.. Un allestimento museale che adotti strumenti basati sul priming potrebbe aiutare il pubblico a selezionare i contenuti relativi agli oggetti esposti. In questo articolo viene descritta l’applicazione del priming semantico allo spazio museale. Questa operazione in prima battutta potrebbe essere letta come una mancanza di fiducia nelle capacità cognitive del visitatore nel discriminare il significato delle informazioni. In realtà è una forma di sostegno per aiutare il visitatore a sviluppare gradualmente una propria metodologia di approccio ai contenuti proposti nel museo. Grazie al priming, il pubblico riceve una serie di stimoli che possono aiutare a costituire la base delle proprie conoscenze in ambito storico-artistico ed essere il punto di partenza sul quale costruire un metodo critico.   Many psychological aspects such as motivation, emotion, and attention, affect human learning. Among these, priming triggers and tunes implicit memory processes. Hence the goal of this paper is to check whether semantic priming can be used as an effective tool to design a supportive museum environment where people can easily learn. Moreover, the resulting stronger and more persistent memories could encourage museum visitors to learn more and better, and to develop a method to “read” the artworks. After a brief overview of current models of semantic priming, practical and theoretical issues are considered and discussed.

Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.

1986-01-01

of ADP. The nucleotide sequence of the E. coli prs gene has been determined and the coding segment established. The deduced amino acid sequence of P-Rib-PP synthetase contained 314 amino acid residues and the molecular weight was calculated as 34,060. The initiation site of transcription was determined......Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...

Diet- and hormone-induced reversal of the carbamoylphosphate synthetase mRNA gradient in the rat liver lobulus

NARCIS (Netherlands)

Moorman, A. F.; de Boer, P. A.; Charles, R.; Lamers, W. H.

1990-01-01

A hybridocytochemical analysis of adult liver from normal control and from hormonally and dietary-treated rats was carried out, using radioactively-labelled probes for the mRNAs of glutamine synthetase (GS), carbamoylphosphate synthetase (CPS) and phosphoenolpyruvate carboxykinase (PEPCK). In line

Properties of 5-aminolaevulinate synthetase and its relationship to microsomal mixed-function oxidation in the southern armyworm (Spodoptera eridania).

Science.gov (United States)

Brattsten, L B; Wilkinson, C F

1975-07-01

1. Activity of 5-aminolaevulinate synthetase was measured in the midgut and other tissues of the last larval instar of the southern armyworm (Spodoptera eridania Cramer, formerly Prodenia eridania Cramer). 2. Optimum conditions for measuring the activity were established with respect to all variables involved and considerable differences from those reported for mammalian enzyme preparations were found. 3. Maximum activity (20 nmol/h per mg of protein) occurs 18-24 h after the fifth moult and thereafter decreases to trace amounts as the larvae age and approach pupation. 4. Synthetase activity was rapidly induced by oral administration (in the diet) of pentamethylbenzene, phenobarbital, diethyl 1,4-dihydro-2,4,6-trimethylpyridine-3, 5-dicarboxylate, and 2-allyl-2-isopropylacetamide. 5. Puromycin inhibited the induction of synthetase by pentamethylbenzene. 6. Induction of 5-aminolaevulinate synthetase correlated well with the induction of microsomal N-demethylation of p-chloro-N-methylaniline, except for phenobarbital, which induced the microsomal oxidase relatively more than the synthetase.

Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of DHNA synthetase from Geobacillus kaustophilus

International Nuclear Information System (INIS)

Kanaujia, Shankar Prasad; Ranjani, Chellamuthu Vasuki; Jeyakanthan, Jeyaraman; Baba, Seiki; Kuroishi, Chizu; Ebihara, Akio; Shinkai, Akeo; Kuramitsu, Seiki; Shiro, Yoshitsugu; Sekar, Kanagaraj; Yokoyama, Shigeyuki

2007-01-01

DHNA synthetase from G. kaustophilus has been cloned, expressed, purified and crystallized. The aerobic Gram-positive bacterium Geobacillus kaustophilus is a bacillus species that was isolated from deep-sea sediment from the Mariana Trench. 1,4-Dihydroxy-2-naphthoate (DHNA) synthetase plays a vital role in the biosynthesis of menaquinone (vitamin K 2 ) in this bacterium. DHNA synthetase from Geobacillus kaustophilus was crystallized in the orthorhombic space group C222 1 , with unit-cell parameters a = 77.01, b = 130.66, c = 131.69 Å. The crystal diffracted to a resolution of 2.2 Å. Preliminary studies and molecular-replacement calculations reveal the presence of three monomers in the asymmetric unit

Phosphoribosylpyrophosphate synthetase of Bacillus subtilis. Cloning, characterization and chromosomal mapping of the prs gene

DEFF Research Database (Denmark)

Nilsson, Dan; Hove-Jensen, Bjarne

1987-01-01

The gene (prs) encoding phosphoribosylpyrophosphate (PRPP) synthetase has been cloned from a library of Bacillus subtilis DNA by complementation of an Escherichia coli prs mutation. Flanking DNA sequences were pruned away by restriction endonuclease and exonuclease BAL 31 digestions, resulting...... in a DNA fragment of approx. 1.8 kb complementing the E. coli prs mutation. Minicell experiments revealed that this DNA fragment coded for a polypeptide, shown to be the PRPP synthetase subunit, with an Mr of approx. 40,000. B. subtilis strains harbouring the prs gene in a multicopy plasmid contained up...... to nine-fold increased PRPP synthetase activity. The prs gene was cloned in an integration vector and the resulting hybrid plasmid inserted into the B. subtilis chromosome by homologous recombination. The integration site was mapped by transduction and the gene order established as purA-guaA-prs-cysA....

Smelly primes – when olfactory primes do or do not work

Directory of Open Access Journals (Sweden)

Monique A Smeets

2014-02-01

Full Text Available In applied olfactory cognition the effects that olfactory stimulation can have on (human behavior are investigated. To enable an efficient application of olfactory stimuli a model of how they may lead to a change in behavior is proposed. To this end we use the concept of olfactory priming. Olfactory priming may prompt a special view on priming as the olfactory sense has some unique properties which make odors special types of primes. Examples of such properties are the ability of odors to influence our behavior outside of awareness, to lead to strong affective evaluations, to evoke specific memories, and to associate easily and quickly to other environmental stimuli. Opportunities and limitations for using odors as primes are related to these properties, and alternative explanations for reported findings are offered. Implications for olfactory semantic, construal, behavior and goal priming are given based on a brief overview of the priming literature from social psychology and from olfactory perception science. We end by formulating recommendations and ideas for a future research agenda and applications for olfactory priming.

Co-operation between Polymerases and Nucleotide Synthetases in the RNA World.

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Ye Eun Kim

2016-11-01

Full Text Available It is believed that life passed through an RNA World stage in which replication was sustained by catalytic RNAs (ribozymes. The two most obvious types of ribozymes are a polymerase, which uses a neighbouring strand as a template to make a complementary sequence to the template, and a nucleotide synthetase, which synthesizes monomers for use by the polymerase. When a chemical source of monomers is available, the polymerase can survive on its own. When the chemical supply of monomers is too low, nucleotide production by the synthetase is essential and the two ribozymes can only survive when they are together. Here we consider a computational model to investigate conditions under which coexistence and cooperation of these two types of ribozymes is possible. The model considers six types of strands: the two functional sequences, the complementary strands to these sequences (which are required as templates, and non-functional mutants of the two sequences (which act as parasites. Strands are distributed on a two-dimensional lattice. Polymerases replicate strands on neighbouring sites and synthetases produce monomers that diffuse in the local neighbourhood. We show that coexistence of unlinked polymerases and synthetases is possible in this spatial model under conditions in which neither sequence could survive alone; hence, there is a selective force for increasing complexity. Coexistence is dependent on the relative lengths of the two functional strands, the strand diffusion rate, the monomer diffusion rate, and the rate of deleterious mutations. The sensitivity of this two-ribozyme system suggests that evolution of a system of many types of ribozymes would be difficult in a purely spatial model with unlinked genes. We therefore speculate that linkage of genes onto mini-chromosomes and encapsulation of strands in protocells would have been important fairly early in the history of life as a means of enabling more complex systems to evolve.

Stacking faults of {gamma}{prime}{prime} phase precipitated in a Ni-15Cr-8Fe-6Nb alloy; Ni-15Cr-8Fe-6Nb gokin ni sekishutsusuru {gamma}{prime}{prime} sonai no sekiso kekkan

Energy Technology Data Exchange (ETDEWEB)

Kusabiraki, K; Ikeuchi, S [Toyama University, Toyama (Japan). Faculty of Engineering

1995-09-01

The stacking faults of a metastable {gamma}{prime}{prime} phase precipitated in a nickel-base superalloy, a modified NCF 3 type alloy (X-750M) were investigated by transmission electron microscopy and X-ray diffraction method. The {gamma}{prime}{prime} precipitates are circular shaped plates at the early stage of aging and they become elliptic or irregular shaped plates at the latter stage of aging up to 1033K. Contrast which suggests the existence of stacking faults on {l_brace}112{r_brace}{sub {gamma}{prime}{prime}} planes can be seen in many of large {gamma}{prime}{prime} precipitates extracted from the specimens aged at 1033K. It is clear that the values of {gamma}{prime}{prime}/{gamma} lattice mismatch increase with increasing the aging time from the measurement of lattice constants of the {gamma} and the {gamma}{prime}{prime} phase. The formation of stacking faults on {l_brace}112{r_brace}{sub {gamma}{prime}{prime}} in the large {gamma}{prime}{prime} precipitates is due to the movement of an a/6 [111] partial dislocation introduced by {gamma}{prime}{prime} /{gamma} coherency strain. Since a part of stacking sequence has a similar crystal structure to that of a stable {delta} phase precipitates in {gamma} phase, the formation of stacking faults in the {gamma}{prime}{prime} precipitates is considered to be favorable for the stabilization of them. 14 refs., 10 figs., 1 tab.

Nonribosomal Peptide Synthetase Genes pesL and pes1 Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

DEFF Research Database (Denmark)

O'Hanlon, Karen A.; Gallagher, Lorna; Schrettl, Markus

2012-01-01

The identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen, Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end produc...

Changes in Activities of Glutamine Synthetase during Grain Filling and Their Relation to Rice Quality

Directory of Open Access Journals (Sweden)

Zheng-xun JIN

2007-09-01

Full Text Available Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.

Structure of Escherichia coli Arginyl-tRNA Synthetase in Complex with tRNAArg: Pivotal Role of the D-loop.

Science.gov (United States)

Stephen, Preyesh; Ye, Sheng; Zhou, Ming; Song, Jian; Zhang, Rongguang; Wang, En-Duo; Giegé, Richard; Lin, Sheng-Xiang

2018-05-25

Aminoacyl-tRNA synthetases are essential components in protein biosynthesis. Arginyl-tRNA synthetase (ArgRS) belongs to the small group of aminoacyl-tRNA synthetases requiring cognate tRNA for amino acid activation. The crystal structure of Escherichia coli (Eco) ArgRS has been solved in complex with tRNA Arg at 3.0-Å resolution. With this first bacterial tRNA complex, we are attempting to bridge the gap existing in structure-function understanding in prokaryotic tRNA Arg recognition. The structure shows a tight binding of tRNA on the synthetase through the identity determinant A20 from the D-loop, a tRNA recognition snapshot never elucidated structurally. This interaction of A20 involves 5 amino acids from the synthetase. Additional contacts via U20a and U16 from the D-loop reinforce the interaction. The importance of D-loop recognition in EcoArgRS functioning is supported by a mutagenesis analysis of critical amino acids that anchor tRNA Arg on the synthetase; in particular, mutations at amino acids interacting with A20 affect binding affinity to the tRNA and specificity of arginylation. Altogether the structural and functional data indicate that the unprecedented ArgRS crystal structure represents a snapshot during functioning and suggest that the recognition of the D-loop by ArgRS is an important trigger that anchors tRNA Arg on the synthetase. In this process, A20 plays a major role, together with prominent conformational changes in several ArgRS domains that may eventually lead to the mature ArgRS:tRNA complex and the arginine activation. Functional implications that could be idiosyncratic to the arginine identity of bacterial ArgRSs are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Glutamine-dependent carbamoyl-phosphate synthetase and other enzyme activities related to the pyrimidine pathway in spleen of Squalus acanthias (spiny dogfish).

Science.gov (United States)

Anderson, P M

1989-01-01

The first two steps of urea synthesis in liver of marine elasmobranchs involve formation of glutamine from ammonia and of carbamoyl phosphate from glutamine, catalysed by glutamine synthetase and carbamoyl-phosphate synthetase, respectively [Anderson & Casey (1984) J. Biol. Chem. 259, 456-462]; both of these enzymes are localized exclusively in the mitochondrial matrix. The objective of this study was to establish the enzymology of carbamoyl phosphate formation and utilization for pyrimidine nucleotide biosynthesis in Squalus acanthias (spiny dogfish), a representative elasmobranch. Aspartate carbamoyltransferase could not be detected in liver of dogfish. Spleen extracts, however, had glutamine-dependent carbamoyl-phosphate synthetase, aspartate carbamoyltransferase, dihydro-orotase, and glutamine synthetase activities, all localized in the cytosol; dihydro-orotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine-5'-decarboxylase activities were also present. Except for glutamine synthetase, the levels of all activities were very low. The carbamoyl-phosphate synthetase activity is inhibited by UTP and is activated by 5-phosphoribosyl 1-pyrophosphate. The first three enzyme activities of the pyrimidine pathway were eluted in distinctly different positions during gel filtration chromatography under a number of different conditions; although complete proteolysis of inter-domain regions of a multifunctional complex during extraction cannot be excluded, the evidence suggests that in dogfish, in contrast to mammalian species, these three enzymes of the pyrimidine pathway exist as individual polypeptide chains. These results: (1) establish that dogfish express two different glutamine-dependent carbamoyl-phosphate synthetase activities, (2) confirm the report [Smith, Ritter & Campbell (1987) J. Biol. Chem. 262, 198-202] that dogfish express two different glutamine synthetases, and (3) provide indirect evidence that glutamine may not be available in liver for

Prime tight frames

DEFF Research Database (Denmark)

Lemvig, Jakob; Miller, Christopher; Okoudjou, Kasso A.

2014-01-01

to suggest effective analysis and synthesis computation strategies for such frames. Finally, we describe all prime frames constructed from the spectral tetris method, and, as a byproduct, we obtain a characterization of when the spectral tetris construction works for redundancies below two.......We introduce a class of finite tight frames called prime tight frames and prove some of their elementary properties. In particular, we show that any finite tight frame can be written as a union of prime tight frames. We then characterize all prime harmonic tight frames and use thischaracterization...

Non-cognate translation priming in masked priming lexical decision experiments: A meta-analysis.

Science.gov (United States)

Wen, Yun; van Heuven, Walter J B

2017-06-01

The masked translation priming paradigm has been widely used in the last 25 years to investigate word processing in bilinguals. Motivated by studies reporting mixed findings, in particular for second language (L2) to first language (L1) translation priming, we conducted, for the first time in the literature, a meta-analysis of 64 masked priming lexical decision experiments across 24 studies to assess the effect sizes of L1-L2 and L2-L1 non-cognate translation priming effects in bilinguals. Our meta-analysis also investigated the influence of potential moderators of translation priming effects. The results provided clear evidence of significant translation priming effects for both directions, with L1-L2 translation priming significantly larger than L2-L1 translation priming (i.e., effect size of 0.86 vs. 0.31). The analyses also revealed that L1-L2 translation effect sizes were moderated by the interval between prime and target (ISI), whereas L2-L1 translation effect sizes were modulated by the number of items per cell. Theoretical and methodological implications of this meta-analysis are discussed and recommendations for future studies are provided.

Effects of polyamine biosynthesis inhibitors on S-adenosylmethionine synthetase and S-adenosylmethionine decarboxylase activities in carrot cell cultures

Science.gov (United States)

S.C. Minocha; R. Minocha; A. Komamine

1991-01-01

Changes in the activites of S-adcnosylmethionine (SAM) synthetase (methionine adenosyltransferase, EC 2.5.1.6.) and SAM decarboxylase (EC 4.1.1.50) were studied in carrot (Daucus carota) cell cultures in response to 2,4-dichlorophenoxyacetic acid (2,4-D) and several inhibitors of polyamine biosynthesis. Activity of SAM synthetase increased...

Comparative Evaluation of Permissiveness to Dengue Virus Serotype 2 Infection in Primary Rodent Macrophages

Directory of Open Access Journals (Sweden)

Jeanette Prada-Arismendy

2012-01-01

Full Text Available Infection with dengue virus presents a broad clinical spectrum, which can range from asymptomatic cases to severe cases that are characterised by haemorrhagic syndrome and/or shock. The reason for such variability remains unknown. This work evaluated the in vitro permissiveness of mouse, rat, hamster and guinea pig macrophages to infection by dengue virus 2 (DENV2. The results established that macrophages derived from the BALB/c mouse strain showed higher permissiveness to DENV2 infection than macrophages from other rodent species, although all rodent species studied had the C820T mutation in the oligoadenylate synthetase 1b gene, indicating no relationship to the different in vitro susceptibilities of mouse cells at this locus. Other molecular mechanisms related to flavivirus susceptibility remain to be explored.

Structural Analysis of the Active Site Geometry of N5-Carboxyaminoimidazole Ribonucleotide Synthetase from Escherichia coli

International Nuclear Information System (INIS)

Thoden, James B.; Holden, Hazel M.; Firestine, Steven M.

2008-01-01

N 5 -Carboxyaminoimidazole ribonucleotide synthetase (N 5 -CAIR synthetase) converts 5-aminoimidazole ribonucleotide (AIR), MgATP, and bicarbonate into N 5 -CAIR, MgADP, and P i . The enzyme is required for de novo purine biosynthesis in microbes yet is not found in humans suggesting that it represents an ideal and unexplored target for antimicrobial drug design. Here we report the X-ray structures of N 5 -CAIR synthetase from Escherichia coli with either MgATP or MgADP/P i bound in the active site cleft. These structures, determined to 1.6-(angstrom) resolution, provide detailed information regarding the active site geometry before and after ATP hydrolysis. In both structures, two magnesium ions are observed. Each of these is octahedrally coordinated, and the carboxylate side chain of Glu238 bridges them. For the structure of the MgADP/P i complex, crystals were grown in the presence of AIR and MgATP. No electron density was observed for AIR, and the electron density corresponding to the nucleotide clearly revealed the presence of ADP and P i rather than ATP. The bound P i shifts by approximately 3 (angstrom) relative to the γ-phosphoryl group of ATP and forms electrostatic interactions with the side chains of Arg242 and His244. Since the reaction mechanism of N 5 -CAIR synthetase is believed to proceed via a carboxyphosphate intermediate, we propose that the location of the inorganic phosphate represents the binding site for stabilization of this reactive species. Using the information derived from the two structures reported here, coupled with molecular modeling, we propose a catalytic mechanism for N 5 -CAIR synthetase.

Priming in concert: Assimilation and contrast with multiple affective and gender primes.

NARCIS (Netherlands)

Fockenberg, D.A.; Koole, S.L.; Semin, G.R.

2008-01-01

The present research investigated the influence of multiple sequential primes on social categorization processes. Study 1 examined an evaluative decision task in which targets were preceded and succeeded by two primes. As expected, the temporally closest forward primes had assimilative effects on

Structural Basis for Specific Inhibition of tRNA Synthetase by an ATP Competitive Inhibitor.

Science.gov (United States)

Fang, Pengfei; Han, Hongyan; Wang, Jing; Chen, Kaige; Chen, Xin; Guo, Min

2015-06-18

Pharmaceutical inhibitors of aminoacyl-tRNA synthetases demand high species and family specificity. The antimalarial ATP-mimetic cladosporin selectively inhibits Plasmodium falciparum LysRS (PfLysRS). How the binding to a universal ATP site achieves the specificity is unknown. Here we report three crystal structures of cladosporin with human LysRS, PfLysRS, and a Pf-like human LysRS mutant. In all three structures, cladosporin occupies the class defining ATP-binding pocket, replacing the adenosine portion of ATP. Three residues holding the methyltetrahydropyran moiety of cladosporin are critical for the specificity of cladosporin against LysRS over other class II tRNA synthetase families. The species-exclusive inhibition of PfLysRS is linked to a structural divergence beyond the active site that mounts a lysine-specific stabilizing response to binding cladosporin. These analyses reveal that inherent divergence of tRNA synthetase structural assembly may allow for highly specific inhibition even through the otherwise universal substrate binding pocket and highlight the potential for structure-driven drug development. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Tyrosine-Dependent Riboswitch Controls the Expression of a Tyrosyl-tRNA Synthetase from Acidithiobacillus ferrooxidans

Directory of Open Access Journals (Sweden)

Paula Bustamante

2016-06-01

Full Text Available Expression of aminoacyl-tRNA synthetases is regulated by a variety of mechanisms at the level of transcription or translation. A T-box dependent transcription termination / antitermination riboswitch system that responds to charged / uncharged tRNA regulates expression of aminoacyl tRNA synthetase genes in Gram-positive bacteria. TyrZ, the gene encoding tyrosyl-tRNA synthetase from Acidithiobacillus ferrooxidans, a Gram-negative acidophilic bacterium that participates in bioleaching of minerals, resembles the gene from Bacillus subtilis including the 5´-untranslated region encoding the riboswitch. Transcription of A. ferrooxidans tyrZ is induced by the presence of tyrosine by a mechanism involving antitermination of transcription. This mechanism is probably adapted to the low supply of amino acids of acidic environments of autotrophic bioleaching microorganisms. This work is licensed under a Creative Commons Attribution 4.0 International License.

The pimeloyl-CoA synthetase BioW defines a new fold for adenylate-forming enzymes

Energy Technology Data Exchange (ETDEWEB)

Estrada, Paola; Manandhar, Miglena; Dong, Shi-Hui; Deveryshetty, Jaigeeth; Agarwal, Vinayak; Cronan, John E.; Nair, Satish K.

2017-04-17

Reactions that activate carboxylates through acyl-adenylate intermediates are found throughout biology and include acyl- and aryl-CoA synthetases and tRNA synthetases. Here we describe the characterization of Aquifex aeolicus BioW, which represents a new protein fold within the superfamily of adenylating enzymes. Substrate-bound structures identified the enzyme active site and elucidated the mechanistic strategy for conjugating CoA to the seven-carbon α,ω-dicarboxylate pimelate, a biotin precursor. Proper position of reactive groups for the two half-reactions is achieved solely through movements of active site residues, as confirmed by site-directed mutational analysis. The ability of BioW to hydrolyze adenylates of noncognate substrates is reminiscent of pre-transfer proofreading observed in some tRNA synthetases, and we show that this activity can be abolished by mutation of a single residue. These studies illustrate how BioW can carry out three different biologically prevalent chemical reactions (adenylation, thioesterification, and proofreading) in the context of a new protein fold.

Photoaffinity labeling of undecaprenyl pyrophosphate synthetase with a farnesyl pyrophosphate analogue

International Nuclear Information System (INIS)

Baba, T.; Muth, J.; Allen, C.M.

1985-01-01

The prenyl transferase undecaprenyl pyrophosphate synthetase was partially purified from the cytosolic fraction of Escherichia coli. Its enzymic products were characterized as a family of cis-polyprenyl phosphates, which ranged in carbon number from C55 to C25. The enzyme is constituted of two subunits of approximately 30,000 molecular weight. A radiolabeled photolabile analogue of t,t-farnesyl pyrophosphate, [ 3 H]2-diazo-3-trifluoropropionyloxy geranyl pyrophosphate, was shown to label Lactobacillus plantarum and E. coli undecaprenyl pyrophosphate synthetase on UV irradiation in the presence of isopentenyl pyrophosphate and divalent cations. The only labeled polypeptide migrated on electrophoresis in a sodium dodecyl sulfate-polyacrylamide gel at a molecular weight of approximately 30,000. No protein was radiolabeled when the natural substrate, t,t-farnesyl pyrophosphate was included in the irradiation mixture. Irradiation in the presence of MgCl 2 without isopentenyl pyrophosphate gave less labeling of the polypeptide. Irradiation with only isopentenyl pyrophosphate gave little labeling of the polypeptide. When the enzyme was irradiated with 3H-photoprobe, [ 14 C]isopentenyl pyrophosphate, and MgCl 2 , the labeled polypeptide gave a ratio of 14 C/ 3 H that indicated the product must also bind to the enzyme on irradiation. These results demonstrate the ability to radiolabel the allylic pyrophosphate binding site and possibly product binding site of undecaprenyl pyrophosphate synthetase by a process which is favored when both cosubstrate and divalent cations are present

Introduction of a leucine half-zipper engenders multiple high-quality crystals of a recalcitrant tRNA synthetase

International Nuclear Information System (INIS)

Guo, Min; Shapiro, Ryan; Schimmel, Paul; Yang, Xiang-Lei

2010-01-01

E. coli alanyl-tRNA synthetase is recalcitrant to crystallization. A group of leucine substitutions has transformed the protein. Although Escherichia coli alanyl-tRNA synthetase was among the first tRNA synthetases to be sequenced and extensively studied by functional analysis, it has proved to be recalcitrant to crystallization. This challenge remained even for crystallization of the catalytic fragment. By mutationally introducing three stacked leucines onto the solvent-exposed side of an α-helix, an engineered catalytic fragment of the synthetase was obtained that yielded multiple high-quality crystals and cocrystals with different ligands. The engineered α-helix did not form a leucine zipper that interlocked with the same α-helix from another molecule. Instead, using the created hydrophobic spine, it interacted with other surfaces of the protein as a leucine half-zipper (LHZ) to enhance the crystal lattice interactions. The LHZ made crystal lattice contacts in all crystals of different space groups. These results illustrate the power of introducing an LHZ into helices to facilitate crystallization. The authors propose that the method can be unified with surface-entropy reduction and can be broadly used for protein-surface optimization in crystallization

Lack of protective effect of thromboxane synthetase inhibitor (CGS-13080) on single dose radiated canine intestine

International Nuclear Information System (INIS)

Barter, J.F.; Marlow, D.; Kamath, R.K.; Harbert, J.; Torrisi, J.R.; Barnes, W.A.; Potkul, R.K.; Newsome, J.T.; Delgado, G.

1991-01-01

The effect of a thromboxane A2 synthetase inhibitor (CGS-13080) on canine intestine was studied using a single dose of radiation, and radioactive microspheres were used to determine resultant blood flow. Thromboxane A2 causes vasospasm and platelet aggregation and may play a dominant role in radiation injury. However, there was no effect on the intestinal blood flow diminution occurring after radiation in this laboratory model using this thromboxane A2 synthetase inhibitor

The elimination of positive priming with increasing prime duration reflects a transition from perceptual fluency to disfluency rather than bias against primed words.

Science.gov (United States)

Potter, Kevin W; Donkin, Chris; Huber, David E

2018-03-01

With immediate repetition priming of forced choice perceptual identification, short prime durations produce positive priming (i.e., priming the target leads to higher accuracy, while priming the foil leads to lower accuracy). Many theories explain positive priming following short duration primes as reflecting increased perceptual fluency for the primed target (i.e., decreased identification latency). However, most studies only examine either accuracy or response times, rather than considering the joint constraints of response times and accuracy to properly address the role of decision biases and response caution. This is a critical oversight because several theories propose that the transition to negative priming following a long duration prime reflects a decision strategy to compensate for the effect of increased perceptual fluency. In contrast, the nROUSE model of Huber and O'Reilly (2003) explains this transition as reflecting perceptual habituation, and thus a change to perceptual disfluency. We confirmed this prediction by applying a sequential sampling model (the diffusion race model) to accuracy and response time distributions from a new single item same-different version of the priming task. In this way, we measured strategic biases and perceptual fluency in each condition for each subject. The nROUSE model was only applied to accuracy from the original forced-choice version of the priming task. This application of nROUSE produced separate predictions for each subject regarding the degree of fluency and disfluency in each condition, and these predictions were confirmed by the drift rate parameters (i.e., fluency) from the response time model in contrast to the threshold parameters (i.e., bias). Copyright © 2017 Elsevier Inc. All rights reserved.

Bacillus anthracis o-succinylbenzoyl-CoA synthetase: reaction kinetics and a novel inhibitor mimicking its reaction intermediate.

Science.gov (United States)

Tian, Yang; Suk, Dae-Hwan; Cai, Feng; Crich, David; Mesecar, Andrew D

2008-11-25

o-Succinylbenzoyl-CoA (OSB-CoA) synthetase (EC 6.2.1.26) catalyzes the ATP-dependent condensation of o-succinylbenzoate (OSB) and CoA to form OSB-CoA, the fourth step of the menaquinone biosynthetic pathway in Bacillus anthracis. Gene knockout studies have highlighted this enzyme as a potential target for the discovery of new antibiotics. Here we report the first studies on the kinetic mechanism of B. anthracis OSB-CoA synthetase, classifying it as an ordered bi uni uni bi ping-pong mechanism. Through a series of pre-steady-state and steady-state kinetic studies in conjunction with direct binding studies, it is demonstrated that CoA, the last substrate to bind, strongly activates the first half-reaction after the first round of turnover. The activation of the first half-reaction is most likely achieved by CoA stabilizing conformations of the enzyme in the "F" form, which slowly isomerize back to the E form. Thus, the kinetic mechanism of OSB-CoA synthetase may be more accurately described as an ordered bi uni uni bi iso ping-pong mechanism. The substrate specificity of OSB-CoA synthetase was probed using a series of OSB analogues with alterations in the carboxylate groups. OSB-CoA shows a strong preference for OSB over all of the analogues tested as none were active except 4-[2-(trifluoromethyl)phenyl]-4-oxobutyric acid which exhibited a 100-fold decrease in k(cat)/K(m). On the basis of an understanding of OSB-CoA synthetase's kinetic mechanism and substrate specificity, a reaction intermediate analogue of OSB-AMP, 5'-O-{N-[2-(trifluoromethyl)phenyl]-4-oxobutyl}adenosine sulfonamide (TFMP-butyl-AMS), was designed and synthesized. This inhibitor was found to be an uncompetitive inhibitor to CoA and a mixed-type inhibitor to ATP and OSB with low micromolar inhibition constants. Collectively, these results should serve as an important forerunner to more detailed and extensive inhibitor design studies aimed at developing lead compounds against the OSB-CoA synthetase

On the Control of Single-Prime Negative Priming: The Effects of Practice and Time Course

Science.gov (United States)

Chao, Hsuan-Fu

2009-01-01

Single-prime negative priming refers to the phenomenon wherein repetition of a prime as the probe target results in delayed response. Sometimes this effect has been found to be contingent on participants' unawareness of the primes, and sometimes it has not. Further, sometimes this effect has been found to be eliminated when the prime could predict…

Subliminal semantic priming in speech.

Directory of Open Access Journals (Sweden)

Jérôme Daltrozzo

Full Text Available Numerous studies have reported subliminal repetition and semantic priming in the visual modality. We transferred this paradigm to the auditory modality. Prime awareness was manipulated by a reduction of sound intensity level. Uncategorized prime words (according to a post-test were followed by semantically related, unrelated, or repeated target words (presented without intensity reduction and participants performed a lexical decision task (LDT. Participants with slower reaction times in the LDT showed semantic priming (faster reaction times for semantically related compared to unrelated targets and negative repetition priming (slower reaction times for repeated compared to semantically related targets. This is the first report of semantic priming in the auditory modality without conscious categorization of the prime.

Primes, Geometry and Condensed Matter

Directory of Open Access Journals (Sweden)

Al Rabeh R. H.

2009-07-01

Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some "the elementary particles of arithmetic" as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called "the elementary particles of physics" too. This study considers the problem of closely packing similar circles/spheres in 2D/3D space. This is in effect a discretization process of space and the allowable number in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This "number/physical" stability idea applies to bigger collections made from smaller (prime units leading to larger stable prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show convincingly that the growth of prime numbers and that of the masses of

The tRNA synthetase paralog PoxA modifies elongation factor-P with (R)-ß-lysine

DEFF Research Database (Denmark)

Roy, Hervé; Zou, S Betty; Bullwinkle, Tammy J

2011-01-01

The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with a-lysine at low efficiency. Cell-free extracts containing non-a-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of ß-lysine, a substrate also predicted by genomic analyses. EF......-P was efficiently functionally modified with (R)-ß-lysine but not (S)-ß-lysine or genetically encoded a-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases....

Glutamine Synthetase Deficiency in Murine Astrocytes Results in Neonatal Death

NARCIS (Netherlands)

He, Youji; Hakvoort, Theodorus B. M.; Vermeulen, Jacqueline L. M.; Labruyère, Wilhelmina T.; de Waart, D. Rudi; van der Hel, W. Saskia; Ruijter, Jan M.; Uylings, Harry B. M.; Lamers, Wouter H.

2010-01-01

Glutamine synthetase (GS) is a key enzyme in the "glutamine-glutamate cycle" between astrocytes and neurons, but its function in vivo was thus far tested only pharmacologically. Crossing GS(fl/lacZ) or GS(fl/f)l mice with hGFAP-Cre mice resulted in prenatal excision of the GS(fl) allele in

Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats

DEFF Research Database (Denmark)

Galbo, H; Saugmann, P; Richter, Erik

1979-01-01

Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other...

Radioprotective effect of cysteamine in glutathione synthetase-deficient cells

International Nuclear Information System (INIS)

Deschavanne, P.J.; Debieu, D.; Malaise, E.P.; Midander, J.; Revesz, L.

1986-01-01

The radioprotective role of endogenous and exogenous thiols was investigated, with survival as the end-point, after radiation exposure of cells under oxic and hypoxic conditions. Human cell strains originating from a 5-oxoprolinuria patient and from a related control were used. Due to a genetic deficiency in glutathione synthetase, the level of free SH groups, and in particular that of glutathione, is decreased in 5-oxoprolinuria cells. The glutathione synthetase deficient cells have a reduced oxygen enhancement ratio (1.5) compared to control cells (2.7). The radiosensitivity was assessed for both cell strains in the presence of different concentrations of an exogenous radioprotector:cysteamine. At concentrations varying between 0.1 and 20 mM, cysteamine protected the two cell strains to the same extent when irradiated under oxic and hypoxic conditions. The protective effect of cysteamine was lower under hypoxia than under oxic conditions for both cell strains. Consequently, the oxygen enhancement ratio decreased for both cell strains when cysteamine concentration increased. These results suggest that cysteamine cannot replace endogenous thiols as far as they are implicated in the radiobiological oxygen effect. (author)

Cognate status and cross-script translation priming.

Science.gov (United States)

Voga, Madeleine; Grainger, Jonathan

2007-07-01

Greek-French bilinguals were tested in three masked priming experiments with Greek primes and French targets. Related primes were the translation equivalents of target words, morphologically related to targets, or phonologically related to targets. In Experiment 1, cognate translation equivalents (phonologically similar translations) showed facilitatory priming, relative to matched phonologically related primes, in conditions in which morphologically related primes showed no effect (50-msec prime exposure). Cross-language morphological priming emerged at longer prime exposure durations (66 msec), but cognate primes continued to generate more priming than did those in the morphological condition. In Experiments 2 and 3, the level of phonological overlap across translation equivalents was varied, and priming effects were measured against those for matched phonologically related primes and those in an unrelated prime condition. When measured against the unrelated baseline, cognate primes showed the typical advantage over noncognate primes. However, this cognate advantage disappeared when priming was measured against the phonologically related prime condition. The results are discussed in terms of how translation equivalents are represented in bilingual memory.

False memories and lexical decision: even twelve primes do not cause long-term semantic priming.

Science.gov (United States)

Zeelenberg, René; Pecher, Diane

2002-03-01

Semantic priming effects are usually obtained only if the prime is presented shortly before the target stimulus. Recent evidence obtained with the so-called false memory paradigm suggests, however, that in both explicit and implicit memory tasks semantic relations between words can result in long-lasting effects when multiple 'primes' are presented. The aim of the present study was to investigate whether these effects would generalize to lexical decision. In four experiments we showed that even as many as 12 primes do not cause long-term semantic priming. In all experiments, however, a repetition priming effect was obtained. The present results are consistent with a number of other results showing that semantic information plays a minimal role in long-term priming in visual word recognition.

Plasmodium falciparum mitochondria import tRNAs along with an active phenylalanyl-tRNA synthetase.

Science.gov (United States)

Sharma, Arvind; Sharma, Amit

2015-02-01

The Plasmodium falciparum protein translation enzymes aminoacyl-tRNA synthetases (aaRSs) are an emergent family of drug targets. The aaRS ensemble catalyses transfer of amino acids to cognate tRNAs, thus providing charged tRNAs for ribosomal consumption. P. falciparum proteome expression relies on a total of 36 aaRSs for the three translationally independent compartments of cytoplasm, apicoplast and mitochondria. In the present study, we show that, of this set of 36, a single genomic copy of mitochondrial phenylalanyl-tRNA synthetase (mFRS) is targeted to the parasite mitochondria, and that the mFRS gene is exclusive to malaria parasites within the apicomplexan phyla. Our protein cellular localization studies based on immunofluorescence data show that, along with mFRS, P. falciparum harbours two more phenylalanyl-tRNA synthetase (FRS) assemblies that are localized to its apicoplast and cytoplasm. The 'extra' mFRS is found in mitochondria of all asexual blood stage parasites and is competent in aminoacylation. We show further that the parasite mitochondria import tRNAs from the cytoplasmic tRNA pool. Hence drug targeting of FRSs presents a unique opportunity to potentially stall protein production in all three parasite translational compartments.

Primes, Geometry and Condensed Matter

Directory of Open Access Journals (Sweden)

Al Rabeh R. H.

2009-07-01

Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some “the elementary particles of arithmetic” as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called “the elementary particles of physics” too. This study considers the problem of closely packing similar circles / spheres in 2D / 3D space. This is in effect a discretization process of space and the allowable num- ber in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This “number / physical” stability idea applies to bigger collections made from smaller (prime units leading to larger sta- ble prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show con- vincingly that the growth of prime numbers and that

Seryl-tRNA Synthetases in Translation and Beyond

Directory of Open Access Journals (Sweden)

Marko Močibob

2016-06-01

Full Text Available For a long time seryl-tRNA synthetases (SerRSs stood as an archetypal, canonical aminoacyl-tRNA synthetases (aaRS, exhibiting only basic tRNA aminoacylation activity and with no moonlighting functions beyond protein biosynthesis. The picture has changed substantially in recent years after the discovery that SerRSs play an important role in antibiotic production and resistance and act as a regulatory factor in vascular development, as well as after the discovery of mitochondrial morphogenesis factor homologous to SerRS in insects. In this review we summarize the recent research results from our laboratory, which advance the understanding of seryl-tRNA synthetases and further paint the dynamic picture of unexpected SerRS activities. SerRS from archaeon Methanothermobacter thermautotrophicus was shown to interact with the large ribosomal subunit and it was postulated to contribute to a more efficient translation by the"tRNA channeling" hypothesis. Discovery of the atypical SerRS in a small number of methanogenic archaea led to the discovery of a new family of enzymes in numerous bacteria - amino acid:[carrier protein] ligases (aa:CP ligases. These SerRS homologues resigned tRNA aminoacylation activity, and instead adopted carrier proteins as the acceptors of activated amino acids. The crystal structure of the aa:CP ligase complex with the carrier protein revealed that the interactions between two macromolecules are incomparable to tRNA binding by the aaRS and consequently represent a true evolutionary invention. Kinetic investigations of SerRSs and the accuracy of amino acid selection revealed that SerRSs possess pre-transfer proofreading activity, challenging the widely accepted presumption that hydrolytic proofreading activity must reside in an additional, separate editing domain, not present in SerRSs. Finally, the plant tRNA serylation system is discussed, which is particularly interesting due to the fact that protein biosynthesis takes place

Computational discovery of specificity-conferring sites in non-ribosomal peptide synthetases

DEFF Research Database (Denmark)

Knudsen, Michael; Søndergaard, Dan Ariel; Tofting-Olesen, Claus

2016-01-01

Motivation: By using a class of large modular enzymes known as Non-Ribosomal Peptide Synthetases (NRPS), bacteria and fungi are capable of synthesizing a large variety of secondary metabolites, many of which are bioactive and have potential, pharmaceutical applications as e.g.~antibiotics. There ...

Sequential Stereotype Priming: A Meta-Analysis.

Science.gov (United States)

Kidder, Ciara K; White, Katherine R; Hinojos, Michelle R; Sandoval, Mayra; Crites, Stephen L

2017-08-01

Psychological interest in stereotype measurement has spanned nearly a century, with researchers adopting implicit measures in the 1980s to complement explicit measures. One of the most frequently used implicit measures of stereotypes is the sequential priming paradigm. The current meta-analysis examines stereotype priming, focusing specifically on this paradigm. To contribute to ongoing discussions regarding methodological rigor in social psychology, one primary goal was to identify methodological moderators of the stereotype priming effect-whether priming is due to a relation between the prime and target stimuli, the prime and target response, participant task, stereotype dimension, stimulus onset asynchrony (SOA), and stimuli type. Data from 39 studies yielded 87 individual effect sizes from 5,497 participants. Analyses revealed that stereotype priming is significantly moderated by the presence of prime-response relations, participant task, stereotype dimension, target stimulus type, SOA, and prime repetition. These results carry both practical and theoretical implications for future research on stereotype priming.

Binding of Divalent Magnesium by Escherichia coli Phosphoribosyl Diphosphate Synthetase

DEFF Research Database (Denmark)

Willemoës, Martin; Hove-Jensen, Bjarne

1997-01-01

The mechanism of binding of the substrates MgATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-d-ribosyl a-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, a,ß-methylene ATP and (+)-1-a,2-a...

Unconscious Congruency Priming from Unpracticed Words Is Modulated by Prime-Target Semantic Relatedness

Science.gov (United States)

Ortells, Juan J.; Mari-Beffa, Paloma; Plaza-Ayllon, Vanesa

2013-01-01

Participants performed a 2-choice categorization task on visible word targets that were preceded by novel (unpracticed) prime words. The prime words were presented for 33 ms and followed either immediately (Experiments 1-3) or after a variable delay (Experiments 1 and 4) by a pattern mask. Both subjective and objective measures of prime visibility…

Leading, but not trailing, primes influence temporal order perception: further evidence for an attentional account of perceptual latency priming.

Science.gov (United States)

Scharlau, Ingrid

2002-11-01

Presenting a masked prime leading a target influences the perceived onset of the masking target (perceptual latency priming; Scharlau & Neumann, in press). This priming effect is explained by the asynchronous updating model (Neumann, 1982; Scharlau & Neumann, in press): The prime initiates attentional allocation toward its location, which renders a trailing target at the same place consciously available earlier. In three experiments, this perceptual latency priming by leading primes was examined jointly with the effects of trailing primes in order to compare the explanation of the asynchronous updating model with the onset-averaging and the P-center hypotheses. Experiment 1 showed that an attended, as well as an unattended, prime leads to perceptual latency priming. In addition, a large effect of trailing primes on the onset of a target was found. As Experiment 2 demonstrated, this effect is quite robust, although smaller than that of a leading prime. In Experiment 3, masked primes were used. Under these conditions, no influence of trailing primes could be found, whereas perceptual latency priming persisted. Thus, a nonattentional explanation for the effect of trailing primes seems likely.

Mechanisms of subliminal response priming.

Science.gov (United States)

Kiesel, Andrea; Kunde, Wilfried; Hoffmann, Joachim

2008-07-15

Subliminal response priming has been considered to operate on several stages, e.g. perceptual, central or motor stages might be affected. While primes' impact on target perception has been clearly demonstrated, semantic response priming recently has been thrown into doubt (e.g. Klinger, Burton, & Pitts, 2000). Finally, LRP studies have revealed that subliminal primes evoke motor processes. Yet, the premises for such prime-evoked motor activation are not settled. A transfer of priming to stimuli that have never been presented as targets appears particularly interesting because it suggests a level of processing that goes beyond a reactivation of previously acquired S-R links. Yet, such transfer has not always withstood empirical testing. To account for these contradictory results, we proposed a two-process model (Kunde, Kiesel, & Hoffmann, 2003): First, participants build up expectations regarding imperative stimuli for the required responses according to experience and/or instructions. Second, stimuli that match these "action triggers" directly activate the corresponding motor responses irrespective of their conscious identification. In line with these assumptions, recent studies revealed that non-target primes induce priming when they fit the current task intentions and when they are expected in the experimental setting.

Screening of Modified RNA duplexes

DEFF Research Database (Denmark)

Schyth, Brian Dall; Bramsen, Jesper Bertram; Kjems, Jørgen

protection against a fish pathogenic virus. This protection corresponded with an interferon response in the fish. Here we use this fish model to screen siRNAs containing various chemical modifications of the RNA backbone for their antiviral activity, the overall aim being identification of an siRNA form......Because of sequence specific gene targeting activity siRNAs are regarded as promising active compounds in gene medicine. But one serious problem with delivering siRNAs as treatment is the now well-established non-specific activities of some RNA duplexes. Cellular reactions towards double stranded...... RNAs include the 2´-5´ oligoadenylate synthetase system, the protein kinase R, RIG-I and Toll-like receptor activated pathways all resulting in antiviral defence mechanism. We have previously shown that antiviral innate immune reactions against double stranded RNAs could be detected in vivo as partial...

γ-Glutamylcysteine synthetase (γ-GCS) as a target for overcoming chemo- and radio-resistance of human hepatocellular carcinoma cells.

Science.gov (United States)

Lin, Li-Ching; Chen, Chi-Fen; Ho, Chun-Te; Liu, Jun-Jen; Liu, Tsan-Zon; Chern, Chi-Liang

2018-04-01

This study uncovered that the genetically endowed intracellular glutathione contents (iGSH) regulated by the catalytic subunit of γ‑glutamylcysteine synthetase heavy chain (γ‑GCSh) as a prime target for overcoming both the inherited and stimuli-activated chemo- and radio-resistance of hepatocellular carcinoma (HCC) cells. Reactive oxygen species (ROS) production and mitochondrial membrane potential (Δψm) were determined by the probe-based flow cytometry. The TUNEL assay was used as an index of radio-sensitivity and the MTT assay was used as an index of chemo-sensitivity against various anti-cancer agents. iGSH and γ‑GCSh activity were measured by HPLC methods. γ‑GCSh-overexpressing GCS30 cell line was established by tetracycline-controlled Tet-OFF gene expression system in SK-Hep-1 cells. The relative radio-sensitivities of a panel of five HCC cells were found to be correlated negatively with both the contents of iGSH and their corresponding γ‑GCSh activities with an order of abundance being Hep G2 > Hep 3B > J5 > Mahlavu > SK-Hep-1, respectively. Similarly, the cytotoxicity response patterns of these HCC cells against arsenic trioxide (ATO), a ROS-producing anti-cancer drug, were exactly identical to the order of ranking instigated by the radiotherapy (RT) treatment. Next, γ‑GCSh-overexpressing GCS30 cells were found to possess excellent ability to profoundly mitigate both the drop of Δψm and apoptotic TUNEL-positive cell population engendered by ATO, cisplatin, doxorubicin, and RT treatments. Our data unequivocally demonstrate that γ‑GCSh may represent a prime target for overcoming anti-cancer drugs and RT resistance for HCC cells. Copyright © 2018 Elsevier Inc. All rights reserved.

A nonribosomal peptide synthetase (Pes1) confers protection against oxidative stress in Aspergillus fumigatus.

Science.gov (United States)

Reeves, Emer P; Reiber, Kathrin; Neville, Claire; Scheibner, Olaf; Kavanagh, Kevin; Doyle, Sean

2006-07-01

Aspergillus fumigatus is an important human fungal pathogen. The Aspergillus fumigatus genome contains 14 nonribosomal peptide synthetase genes, potentially responsible for generating metabolites that contribute to organismal virulence. Differential expression of the nonribosomal peptide synthetase gene, pes1, in four strains of Aspergillus fumigatus was observed. The pattern of pes1 expression differed from that of a putative siderophore synthetase gene, sidD, and so is unlikely to be involved in iron acquisition. The Pes1 protein (expected molecular mass 698 kDa) was partially purified and identified by immunoreactivity, peptide mass fingerprinting (36% sequence coverage) and MALDI LIFT-TOF/TOF MS (four internal peptides sequenced). A pes1 disruption mutant (delta pes1) of Aspergillus fumigatus strain 293.1 was generated and confirmed by Southern and western analysis, in addition to RT-PCR. The delta pes1 mutant also showed significantly reduced virulence in the Galleria mellonella model system (P < 0.001) and increased sensitivity to oxidative stress (P = 0.002) in culture and during neutrophil-mediated phagocytosis. In addition, the mutant exhibited altered conidial surface morphology and hydrophilicity, compared to Aspergillus fumigatus 293.1. It is concluded that pes1 contributes to improved fungal tolerance against oxidative stress, mediated by the conidial phenotype, during the infection process.

Natural aminoacyl tRNA synthetase fragment enhances cardiac function after myocardial infarction.

Directory of Open Access Journals (Sweden)

Margaret E McCormick

Full Text Available A naturally-occurring fragment of tyrosyl-tRNA synthetase (TyrRS has been shown in higher eukaryotes to 'moonlight' as a pro-angiogenic cytokine in addition to its primary role in protein translation. Pro-angiogenic cytokines have previously been proposed to be promising therapeutic mechanisms for the treatment of myocardial infarction. Here, we show that systemic delivery of the natural fragment of TyRS, mini-TyrRS, improves heart function in mice after myocardial infarction. This improvement is associated with reduced formation of scar tissue, increased angiogenesis of cardiac capillaries, recruitment of c-kitpos cells and proliferation of myocardial fibroblasts. This work demonstrates that mini-TyrRS has beneficial effects on cardiac repair and regeneration and offers support for the notion that elucidation of the ever expanding repertoire of noncanonical functions of aminoacyl tRNA synthetases offers unique opportunities for development of novel therapeutics.

Rhizosphere priming: a nutrient perspective

Directory of Open Access Journals (Sweden)

Feike Auke Dijkstra

2013-07-01

Full Text Available Rhizosphere priming is the change in decomposition of soil organic matter (SOM caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P limited. Under P limitation, rhizodeposition may be used for mobilisation of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils.

Expression of acyl-CoA synthetase 5 reflects the state of villus architecture in human small intestine

DEFF Research Database (Denmark)

Gassler, Nikolaus; Kopitz, Jürgen; Tehrani, Arman

2004-01-01

Several disorders of the small intestine are associated with disturbances in villus architecture. Thus, an understanding of the molecular mechanisms associated with the differentiation of villi represents an important step in the improvement of the understanding of small intestinal pathology......-CoA synthetase 5 pattern correlate with conversion of intestinal epithelial cells to a gastric phenotype. These results suggest that deranged acyl-CoA synthetase 5 expression, synthesis, and activity are closely related to the state of villus architecture and epithelial homeostasis in human small intestine....

Degree of handedness and priming: Further evidence for a distinction between production and identification priming mechanisms.

Directory of Open Access Journals (Sweden)

Donna J. LaVoie

2015-02-01

Full Text Available The distinction between implicit and explicit forms of memory retrieval is long-standing, and important to the extent it reveals how different neural architecture supports different aspects of memory function. Similarly, distinctions have been made between kinds of repetition priming, a form of implicit memory retrieval. This study focuses on the production-identification priming distinction, which delineates priming tasks involving verification of stimulus features as compared to priming tasks that require use of a cue to guide response retrieval. Studies investigating this dissociation in dementia or similar patient populations indicate that these forms of priming may differ in their neural bases. The current study looks at degree of handedness as a way of investigating inferred neural architecture supporting these two forms of priming. A growing body of research indicates that degree of handedness (consistent, or CH, versus inconsistent, or ICH is associated with greater interhemispheric interaction and functional access to right hemisphere processing in ICH, with superior performance seen in ICH on memory tasks reliant on this processing. Arguments about the theoretical mechanisms underlying identification and production forms of perceptual priming tasks suggest that performance on these tasks will differ as a function of degree of handedness. We tested this question in a group of CH and ICH young adults, who were asked to study lists of words prior to performing a production priming task (word stem completion, a perceptual word identification task, and a word stem cued recall task. While both handedness groups exhibited reliable priming across tasks, word stem completion priming was greater in ICH than CH participants, with identification priming not differing between groups. This dissociation supports the argument that production and identification forms of priming have different underlying neural bases.

Rapid response learning of brand logo priming: Evidence that brand priming is not dominated by rapid response learning.

Science.gov (United States)

Boehm, Stephan G; Smith, Ciaran; Muench, Niklas; Noble, Kirsty; Atherton, Catherine

2017-08-31

Repetition priming increases the accuracy and speed of responses to repeatedly processed stimuli. Repetition priming can result from two complementary sources: rapid response learning and facilitation within perceptual and conceptual networks. In conceptual classification tasks, rapid response learning dominates priming of object recognition, but it does not dominate priming of person recognition. This suggests that the relative engagement of network facilitation and rapid response learning depends on the stimulus domain. Here, we addressed the importance of the stimulus domain for rapid response learning by investigating priming in another domain, brands. In three experiments, participants performed conceptual decisions for brand logos. Strong priming was present, but it was not dominated by rapid response learning. These findings add further support to the importance of the stimulus domain for the relative importance of network facilitation and rapid response learning, and they indicate that brand priming is more similar to person recognition priming than object recognition priming, perhaps because priming of both brands and persons requires individuation.

Mechanisms of masked evaluative priming: task sets modulate behavioral and electrophysiological priming for picture and words differentially.

Science.gov (United States)

Kiefer, Markus; Liegel, Nathalie; Zovko, Monika; Wentura, Dirk

2017-04-01

Research with the evaluative priming paradigm has shown that affective evaluation processes reliably influence cognition and behavior, even when triggered outside awareness. However, the precise mechanisms underlying such subliminal evaluative priming effects, response activation vs semantic processing, are matter of a debate. In this study, we determined the relative contribution of semantic processing and response activation to masked evaluative priming with pictures and words. To this end, we investigated the modulation of masked pictorial vs verbal priming by previously activated perceptual vs semantic task sets and assessed the electrophysiological correlates of priming using event-related potential (ERP) recordings. Behavioral and electrophysiological effects showed a differential modulation of pictorial and verbal subliminal priming by previously activated task sets: Pictorial priming was only observed during the perceptual but not during the semantic task set. Verbal priming, in contrast, was found when either task set was activated. Furthermore, only verbal priming was associated with a modulation of the N400 ERP component, an index of semantic processing, whereas a priming-related modulation of earlier ERPs, indexing visuo-motor S-R activation, was found for both picture and words. The results thus demonstrate that different neuro-cognitive processes contribute to unconscious evaluative priming depending on the stimulus format. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Fatty acid biosynthesis VII. Substrate control of chain-length of products synthesised by rat liver fatty acid synthetase

DEFF Research Database (Denmark)

Hansen, Heinz Johs. Max; Carey, E.M.; Dils, R.

1970-01-01

- 1. Gas-liquid and paper chromatography have been used to determine the chain-lengths of fatty acids synthesised by purified rat liver fatty acid synthetase from [1-14C]acetyl-CoA, [1,3-14C2]malonyl-CoA and from [1-14C]acetyl-CoA plus partially purified rat liver acetyl-CoA carboxylase. - 2....... A wide range (C4:0–C18:0) of fatty acids was synthesised and the proportions were modified by substrate concentrations in the same manner as for purified rabbit mammary gland fatty acid synthetase. - 3. The relative amount of radioactivity incorporated from added acetyl-CoA and malonyl-CoA depended...... of long-chain fatty acids was synthesised from carboxylated acetyl-CoA than from added malonyl-CoA. - 5. It is suggested that acetyl-CoA carboxylase may carboxylate acetate bound to fatty acid synthetase....

Holocarboxylase synthetase deficiency pre and post newborn screening

Directory of Open Access Journals (Sweden)

Taraka R. Donti

2016-06-01

Full Text Available Holocarboxylase synthetase deficiency is an autosomal recessive disorder of biotin metabolism resulting in multiple carboxylase deficiency. The typical presentation described in the medical literature is of neonatal onset within hours to weeks of birth with emesis, hypotonia, lethargy, seizures, metabolic ketolactic acidosis, hyperammonemia, developmental delay, skin rash and alopecia. The condition is screened for by newborn screening (NBS tandem mass spectroscopy by elevated hydroxypentanoylcarnitine on dried blood spots. Urine organic acid profile may demonstrate elevated lactic, 3-OH isovaleric, 3-OH propionic, 3-MCC, methylcitric acids, and tiglylglycine consistent with loss of function of the above carboxylases. Here we describe a cohort of patients, 2 diagnosed pre-NBS and 3 post-NBS with broad differences in initial presentation and phenotype. In addition, prior to the advent of NBS, there are isolated reports of late-onset holocarboxylase synthetase deficiency in the medical literature, which describe patients diagnosed between 1 and 8 years of life, however to our knowledge there are no reports of late-onset HCLS being missed by NBS. Also we report two cases, each with novel pathogenic variants HCLS, diagnosed at age 3 years and 21 months respectively. The first patient had a normal newborn screen whilst the second had an abnormal newborn screen but was misdiagnosed as 3-methylcrotonylcarboxylase (3-MCC deficiency and subsequently lost to follow-up until they presented again with severe metabolic acidosis.

Structural modeling of tissue-specific mitochondrial alanyl-tRNA synthetase (AARS2 defects predicts differential effects on aminoacylation

Directory of Open Access Journals (Sweden)

Liliya eEuro

2015-02-01

Full Text Available The accuracy of mitochondrial protein synthesis is dependent on the coordinated action of nuclear-encoded mitochondrial aminoacyl-tRNA synthetases (mtARSs and the mitochondrial DNA-encoded tRNAs. The recent advances in whole-exome sequencing have revealed the importance of the mtARS proteins for mitochondrial pathophysiology since nearly every nuclear gene for mtARS (out of 19 is now recognized as a disease gene for mitochondrial disease. Typically, defects in each mtARS have been identified in one tissue-specific disease, most commonly affecting the brain, or in one syndrome. However, mutations in the AARS2 gene for mitochondrial alanyl-tRNA synthetase (mtAlaRS have been reported both in patients with infantile-onset cardiomyopathy and in patients with childhood to adulthood-onset leukoencephalopathy. We present here an investigation of the effects of the described mutations on the structure of the synthetase, in an effort to understand the tissue-specific outcomes of the different mutations.The mtAlaRS differs from the other mtARSs because in addition to the aminoacylation domain, it has a conserved editing domain for deacylating tRNAs that have been mischarged with incorrect amino acids. We show that the cardiomyopathy phenotype results from a single allele, causing an amino acid change p.R592W in the editing domain of AARS2, whereas the leukodystrophy mutations are located in other domains of the synthetase. Nevertheless, our structural analysis predicts that all mutations reduce the aminoacylation activity of the synthetase, because all mtAlaRS domains contribute to tRNA binding for aminoacylation. According to our model, the cardiomyopathy mutations severely compromise aminoacylation whereas partial activity is retained by the mutation combinations found in the leukodystrophy patients. These predictions provide a hypothesis for the molecular basis of the distinct tissue-specific phenotypic outcomes.

A Prime Example of the Maluma/Takete Effect? Testing for Sound Symbolic Priming.

Science.gov (United States)

Sidhu, David M; Pexman, Penny M

2017-09-01

Certain nonwords, like maluma and takete, are associated with roundness and sharpness, respectively. However, this has typically been demonstrated using explicit tasks. We investigated whether this association would be detectable using a more implicit measure-a sequential priming task. We began with a replication of the standard Maluma/Takete effect (Experiments 1a and 1b) before examining whether round and sharp nonword primes facilitated the categorization of congruent shapes (Experiment 2). We found modest evidence of a priming effect in response accuracy. We next examined whether nonword primes affected categorization of ambiguous shapes, using visual (Experiment 3) and auditory primes (Experiment 4). We found that ambiguous shapes were categorized as round (sharp) more often following the presentation of a round (sharp) nonword. This suggests that phonemes may activate related shape information which then affects the processing of shapes, and that this association emerges even when participants are not explicitly searching for it. Copyright © 2016 Cognitive Science Society, Inc.

Recoding aminoacyl-tRNA synthetases for synthetic biology by rational protein-RNA engineering.

Science.gov (United States)

Hadd, Andrew; Perona, John J

2014-12-19

We have taken a rational approach to redesigning the amino acid binding and aminoacyl-tRNA pairing specificities of bacterial glutaminyl-tRNA synthetase. The four-stage engineering incorporates generalizable design principles and improves the pairing efficiency of noncognate glutamate with tRNA(Gln) by over 10(5)-fold compared to the wild-type enzyme. Better optimized designs of the protein-RNA complex include substantial reengineering of the globular core region of the tRNA, demonstrating a role for specific tRNA nucleotides in specifying the identity of the genetically encoded amino acid. Principles emerging from this engineering effort open new prospects for combining rational and genetic selection approaches to design novel aminoacyl-tRNA synthetases that ligate noncanonical amino acids onto tRNAs. This will facilitate reconstruction of the cellular translation apparatus for applications in synthetic biology.

Reaction Intermediate Analogues as Bisubstrate Inhibitors of Pantothenate Synthetase

OpenAIRE

Xu, Zhixiang; Yin, Wei; Martinelli, Leonardo K.; Evans, Joanna; Chen, Jinglei; Yu, Yang; Wilson, Daniel J.; Mizrahi, Valerie; Qiao, Chunhua; Aldrich, Courtney C.

2014-01-01

The biosynthesis of pantothenate, the core of coenzyme A (CoA), has been considered an attractive target for the development of antimicrobial agents since this pathway is essential in prokaryotes, but absent in mammals. Pantothenate synthetase, encoded by the gene panC, catalyzes the final condensation of pantoic acid with β–alanine to afford pantothenate via an intermediate pantoyl adenylate. We describe the synthesis and biochemical characterization of five PanC inhibitors that mimic the in...

Prime Slaughter

DEFF Research Database (Denmark)

Valente, Andrea; Marchetti, Emanuela

2011-01-01

of primality and factorization into playful interactions, addressed to primary and early secondary school children. Taking into account individual needs expressed by children regarding play, during a participatory design processes aimed at enhancing learning in museums, Prime Slaughter allows for multiple......Starting from the difficulty of creating playful representation of domain-specific abstract concepts, this study discusses the design of Prime Slaughter, a computer game aimed at facilitating individual sense-making of abstract mathematical concepts. Specifically the game proposes a transposition...

Three-dimensional structure of phosphoribosyl pyrophosphate synthetase from E. coli at 2.71 Å resolution

Energy Technology Data Exchange (ETDEWEB)

Timofeev, V. I., E-mail: inna@ns.crys.ras.ru, E-mail: tostars@mail.ru, E-mail: ugama@yandex.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Abramchik, Yu. A. [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Zhukhlistova, N. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Muravieva, T. I.; Esipov, R. S. [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Kuranova, I. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2016-01-15

Phosphoribosyl pyrophosphate synthetase from Escherichia coli was cloned, purified, and crystallized. Single crystals of the enzyme were grown under microgravity. The X-ray diffraction data set was collected at the Spring-8 synchrotron facility and used to determine the three-dimensional structure of the enzyme by the molecular-replacement method at 2.71 Å resolution. The active and regulatory sites in the molecule of E. coli phosphoribosyl pyrophosphate synthetase were revealed by comparison with the homologous protein from Bacillus subtilis, the structure of which was determined in a complex with functional ligands. The conformations of polypeptide-chain fragments surrounding and composing the active and regulatory sites were shown to be identical in both proteins.

Selective and specific inhibition of the plasmodium falciparum lysyl-tRNA synthetase by the fungal secondary metabolite cladosporin.

Science.gov (United States)

Hoepfner, Dominic; McNamara, Case W; Lim, Chek Shik; Studer, Christian; Riedl, Ralph; Aust, Thomas; McCormack, Susan L; Plouffe, David M; Meister, Stephan; Schuierer, Sven; Plikat, Uwe; Hartmann, Nicole; Staedtler, Frank; Cotesta, Simona; Schmitt, Esther K; Petersen, Frank; Supek, Frantisek; Glynne, Richard J; Tallarico, John A; Porter, Jeffrey A; Fishman, Mark C; Bodenreider, Christophe; Diagana, Thierry T; Movva, N Rao; Winzeler, Elizabeth A

2012-06-14

With renewed calls for malaria eradication, next-generation antimalarials need be active against drug-resistant parasites and efficacious against both liver- and blood-stage infections. We screened a natural product library to identify inhibitors of Plasmodium falciparum blood- and liver-stage proliferation. Cladosporin, a fungal secondary metabolite whose target and mechanism of action are not known for any species, was identified as having potent, nanomolar, antiparasitic activity against both blood and liver stages. Using postgenomic methods, including a yeast deletion strains collection, we show that cladosporin specifically inhibits protein synthesis by directly targeting P. falciparum cytosolic lysyl-tRNA synthetase. Further, cladosporin is >100-fold more potent against parasite lysyl-tRNA synthetase relative to the human enzyme, which is conferred by the identity of two amino acids within the enzyme active site. Our data indicate that lysyl-tRNA synthetase is an attractive, druggable, antimalarial target that can be selectively inhibited. Copyright © 2012 Elsevier Inc. All rights reserved.

Discovery: Prime Numbers

Science.gov (United States)

de Mestre, Neville

2008-01-01

Prime numbers are important as the building blocks for the set of all natural numbers, because prime factorisation is an important and useful property of all natural numbers. Students can discover them by using the method known as the Sieve of Eratosthenes, named after the Greek geographer and astronomer who lived from c. 276-194 BC. Eratosthenes…

Novel insights into regulation of asparagine synthetase in conifers

Directory of Open Access Journals (Sweden)

Javier eCanales

2012-05-01

Full Text Available Asparagine, a key amino acid for nitrogen storage and transport in plants, is synthesized via the ATP-dependent reaction catalyzed by the enzyme asparagine synthetase (AS; EC 6.3.5.4. In this work, we present the molecular analysis of two full-length cDNAs that encode asparagine synthetase in maritime pine (Pinus pinaster Ait., PpAS1 and PpAS2. Phylogenetic analyses of the deduced amino acid sequences revealed that both genes are class II AS, suggesting an ancient origin of these genes in plants. A comparative study of PpAS1 and PpAS2 gene expression profiles showed that PpAS1 gene is highly regulated by developmental and environmental factors, while PpAS2 is expressed constitutively. To determine the molecular mechanisms underpinning the differential expression of PpAS1, the promoter region of the gene was isolated and putative binding sites for MYB transcription factors were identified. Gel mobility shift assays showed that a MYB protein from Pinus taeda (PtMYB1 was able to interact with the promoter region of PpAS1. Furthermore, transient expression analyses in pine cells revealed a negative effect of PtMYB1 on PpAS1 expression. The potential role of MYB factors in the transcriptional regulation of PpAS1 in vascular cells is discussed.

The Bacillus subtilis and Bacillus halodurans Aspartyl-tRNA Synthetases Retain Recognition of tRNA(Asn).

Science.gov (United States)

Nair, Nilendra; Raff, Hannah; Islam, Mohammed Tarek; Feen, Melanie; Garofalo, Denise M; Sheppard, Kelly

2016-02-13

Synthesis of asparaginyl-tRNA (Asn-tRNA(Asn)) in bacteria can be formed either by directly ligating Asn to tRNA(Asn) using an asparaginyl-tRNA synthetase (AsnRS) or by synthesizing Asn on the tRNA. In the latter two-step indirect pathway, a non-discriminating aspartyl-tRNA synthetase (ND-AspRS) attaches Asp to tRNA(Asn) and the amidotransferase GatCAB transamidates the Asp to Asn on the tRNA. GatCAB can be similarly used for Gln-tRNA(Gln) formation. Most bacteria are predicted to use only one route for Asn-tRNA(Asn) formation. Given that Bacillus halodurans and Bacillus subtilis encode AsnRS for Asn-tRNA(Asn) formation and Asn synthetases to synthesize Asn and GatCAB for Gln-tRNA(Gln) synthesis, their AspRS enzymes were thought to be specific for tRNA(Asp). However, we demonstrate that the AspRSs are non-discriminating and can be used with GatCAB to synthesize Asn. The results explain why B. subtilis with its Asn synthetase genes knocked out is still an Asn prototroph. Our phylogenetic analysis suggests that this may be common among Firmicutes and 30% of all bacteria. In addition, the phylogeny revealed that discrimination toward tRNA(Asp) by AspRS has evolved independently multiple times. The retention of the indirect pathway in B. subtilis and B. halodurans likely reflects the ancient link between Asn biosynthesis and its use in translation that enabled Asn to be added to the genetic code. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cylindrospermopsin and Saxitoxin Synthetase Genes in Cylindrospermopsis raciborskii Strains from Brazilian Freshwater

Science.gov (United States)

Hoff-Risseti, Caroline; Dörr, Felipe Augusto; Schaker, Patricia Dayane Carvalho; Pinto, Ernani; Werner, Vera Regina; Fiore, Marli Fatima

2013-01-01

The Cylindrospermopsis raciborskii population from Brazilian freshwater is known to produce saxitoxin derivatives (STX), while cylindrospermopsin (CYN), which is commonly detected in isolates from Australia and Asia continents, has thus far not been detected in South American strains. However, during the investigation for the presence of cyrA, cyrB, cyrC and cyrJ CYN synthetase genes in the genomes of four laboratory-cultured C. raciborskii Brazilian strains, the almost complete cyrA gene sequences were obtained for all strains, while cyrB and cyrC gene fragments were observed in two strains. These nucleotide sequences were translated into amino acids, and the predicted protein functions and domains confirmed their identity as CYN synthetase genes. Attempts to PCR amplify cyrJ gene fragments from the four strains were unsuccessful. Phylogenetic analysis grouped the nucleotide sequences together with their homologues found in known CYN synthetase clusters of C. raciborskii strains with high bootstrap support. In addition, fragments of sxtA, sxtB and sxtI genes involved in STX production were also obtained. Extensive LC-MS analyses were unable to detect CYN in the cultured strains, whereas the production of STX and its analogues was confirmed in CENA302, CENA305 and T3. To our knowledge, this is the first study reporting the presence of cyr genes in South American strains of C. raciborskii and the presence of sxt and cyr genes in a single C. raciborskii strain. This discovery suggests a shift in the type of cyanotoxin production over time of South American strains of C. raciborskii and contributes to the reconstruction of the evolutionary history and diversification of cyanobacterial toxins. PMID:24015317

Cylindrospermopsin and saxitoxin synthetase genes in Cylindrospermopsis raciborskii strains from Brazilian freshwater.

Directory of Open Access Journals (Sweden)

Caroline Hoff-Risseti

Full Text Available The Cylindrospermopsis raciborskii population from Brazilian freshwater is known to produce saxitoxin derivatives (STX, while cylindrospermopsin (CYN, which is commonly detected in isolates from Australia and Asia continents, has thus far not been detected in South American strains. However, during the investigation for the presence of cyrA, cyrB, cyrC and cyrJ CYN synthetase genes in the genomes of four laboratory-cultured C. raciborskii Brazilian strains, the almost complete cyrA gene sequences were obtained for all strains, while cyrB and cyrC gene fragments were observed in two strains. These nucleotide sequences were translated into amino acids, and the predicted protein functions and domains confirmed their identity as CYN synthetase genes. Attempts to PCR amplify cyrJ gene fragments from the four strains were unsuccessful. Phylogenetic analysis grouped the nucleotide sequences together with their homologues found in known CYN synthetase clusters of C. raciborskii strains with high bootstrap support. In addition, fragments of sxtA, sxtB and sxtI genes involved in STX production were also obtained. Extensive LC-MS analyses were unable to detect CYN in the cultured strains, whereas the production of STX and its analogues was confirmed in CENA302, CENA305 and T3. To our knowledge, this is the first study reporting the presence of cyr genes in South American strains of C. raciborskii and the presence of sxt and cyr genes in a single C. raciborskii strain. This discovery suggests a shift in the type of cyanotoxin production over time of South American strains of C. raciborskii and contributes to the reconstruction of the evolutionary history and diversification of cyanobacterial toxins.

Influence of endogenous pyrogen on the cerebral prostaglandin-synthetase system.

Science.gov (United States)

Ziel, R; Krupp, P

1976-11-15

The biotransformation of arachidonic acid to prostaglandins in vitro is specifically augmented by endogenous pyrogen to a degree depending on the concentration applied, providing that the microsomal fraction of the cerebral cortex is used as prostaglandin-synthetase system. This effect is inhibited by non-steroidal anti-inflammatory agents. These findings are compatible with the hypothesis that prostaglandins might act as mediators of the febrile reaction induced by endogenous pyrogen.

Superficial Priming in Episodic Recognition

Science.gov (United States)

Dopkins, Stephen; Sargent, Jesse; Ngo, Catherine T.

2010-01-01

We explored the effect of superficial priming in episodic recognition and found it to be different from the effect of semantic priming in episodic recognition. Participants made recognition judgments to pairs of items, with each pair consisting of a prime item and a test item. Correct positive responses to the test item were impeded if the prime…

Structure of the gene encoding phosphoribosylpyrophosphate synthetase (prsA) in Salmonella typhimurium

DEFF Research Database (Denmark)

Bower, Stanley G.; Hove-Jensen, Bjarne; Switzer, Robert L.

1988-01-01

in a 416-base-pair 5' untranslated leader in the prsA transcript, which was shown by deletion to be necessary for maximal synthesis of phosphoribosylpyrophosphate synthetase. The S. typhimurium leader contains a 115-base-pair insert relative to the E. coli leader. The insert appears to have no functional...

Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Nygaard, Per

1982-01-01

, stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib...

Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity

OpenAIRE

Sanya Chadha; N. Arjunreddy Mallampudi; Debendra K. Mohapatra; Rentala Madhubala; Ira J. Blader; Greg Matlashewski; Frederick Buckner

2017-01-01

ABSTRACT Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L.?donovani lysyl-tRNA synthetase (LdLysRS). Two different codin...

Syntactic priming in American Sign Language.

Science.gov (United States)

Hall, Matthew L; Ferreira, Victor S; Mayberry, Rachel I

2015-01-01

Psycholinguistic studies of sign language processing provide valuable opportunities to assess whether language phenomena, which are primarily studied in spoken language, are fundamentally shaped by peripheral biology. For example, we know that when given a choice between two syntactically permissible ways to express the same proposition, speakers tend to choose structures that were recently used, a phenomenon known as syntactic priming. Here, we report two experiments testing syntactic priming of a noun phrase construction in American Sign Language (ASL). Experiment 1 shows that second language (L2) signers with normal hearing exhibit syntactic priming in ASL and that priming is stronger when the head noun is repeated between prime and target (the lexical boost effect). Experiment 2 shows that syntactic priming is equally strong among deaf native L1 signers, deaf late L1 learners, and hearing L2 signers. Experiment 2 also tested for, but did not find evidence of, phonological or semantic boosts to syntactic priming in ASL. These results show that despite the profound differences between spoken and signed languages in terms of how they are produced and perceived, the psychological representation of sentence structure (as assessed by syntactic priming) operates similarly in sign and speech.

Rheb Protein Binds CAD (Carbamoyl-phosphate Synthetase 2, Aspartate Transcarbamoylase, and Dihydroorotase) Protein in a GTP- and Effector Domain-dependent Manner and Influences Its Cellular Localization and Carbamoyl-phosphate Synthetase (CPSase) Activity*

Science.gov (United States)

Sato, Tatsuhiro; Akasu, Hitomi; Shimono, Wataru; Matsu, Chisa; Fujiwara, Yuki; Shibagaki, Yoshio; Heard, Jeffrey J.; Tamanoi, Fuyuhiko; Hattori, Seisuke

2015-01-01

Rheb small GTPases, which consist of Rheb1 and Rheb2 (also known as RhebL1) in mammalian cells, are unique members of the Ras superfamily and play central roles in regulating protein synthesis and cell growth by activating mTOR. To gain further insight into the function of Rheb, we carried out a search for Rheb-binding proteins and found that Rheb binds to CAD protein (carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase), a multifunctional enzyme required for the de novo synthesis of pyrimidine nucleotides. CAD binding is more pronounced with Rheb2 than with Rheb1. Rheb binds CAD in a GTP- and effector domain-dependent manner. The region of CAD where Rheb binds is located at the C-terminal region of the carbamoyl-phosphate synthetase domain and not in the dihydroorotase and aspartate transcarbamoylase domains. Rheb stimulated carbamoyl-phosphate synthetase activity of CAD in vitro. In addition, an elevated level of intracellular UTP pyrimidine nucleotide was observed in Tsc2-deficient cells, which was attenuated by knocking down of Rheb. Immunostaining analysis showed that expression of Rheb leads to increased accumulation of CAD on lysosomes. Both a farnesyltransferase inhibitor that blocks membrane association of Rheb and knockdown of Rheb mislocalized CAD. These results establish CAD as a downstream effector of Rheb and suggest a possible role of Rheb in regulating de novo pyrimidine nucleotide synthesis. PMID:25422319

Rheb protein binds CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase) protein in a GTP- and effector domain-dependent manner and influences its cellular localization and carbamoyl-phosphate synthetase (CPSase) activity.

Science.gov (United States)

Sato, Tatsuhiro; Akasu, Hitomi; Shimono, Wataru; Matsu, Chisa; Fujiwara, Yuki; Shibagaki, Yoshio; Heard, Jeffrey J; Tamanoi, Fuyuhiko; Hattori, Seisuke

2015-01-09

Rheb small GTPases, which consist of Rheb1 and Rheb2 (also known as RhebL1) in mammalian cells, are unique members of the Ras superfamily and play central roles in regulating protein synthesis and cell growth by activating mTOR. To gain further insight into the function of Rheb, we carried out a search for Rheb-binding proteins and found that Rheb binds to CAD protein (carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase), a multifunctional enzyme required for the de novo synthesis of pyrimidine nucleotides. CAD binding is more pronounced with Rheb2 than with Rheb1. Rheb binds CAD in a GTP- and effector domain-dependent manner. The region of CAD where Rheb binds is located at the C-terminal region of the carbamoyl-phosphate synthetase domain and not in the dihydroorotase and aspartate transcarbamoylase domains. Rheb stimulated carbamoyl-phosphate synthetase activity of CAD in vitro. In addition, an elevated level of intracellular UTP pyrimidine nucleotide was observed in Tsc2-deficient cells, which was attenuated by knocking down of Rheb. Immunostaining analysis showed that expression of Rheb leads to increased accumulation of CAD on lysosomes. Both a farnesyltransferase inhibitor that blocks membrane association of Rheb and knockdown of Rheb mislocalized CAD. These results establish CAD as a downstream effector of Rheb and suggest a possible role of Rheb in regulating de novo pyrimidine nucleotide synthesis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Repetition Priming Magnitude Depends on Affirmative Prime Responses: A Test of Two Congruity Explanations.

Science.gov (United States)

Fiet, Paula; Sorensen, Linda; Mayne, Zachary; Corgiat, Damon; Woltz, Dan

2016-01-01

We conducted 2 experiments to evaluate the impact of positive prime responses on repetition priming effects while decoupling this impact from content congruity and specific evaluation operations. Our first experiment consisted of word-meaning comparison trials that required participants to evaluate synonyms or antonyms. A crossing of evaluation operation with semantic content allowed us to test the goal-content congruity hypothesis against the semantic congruity explanation for greater facilitation from positive response primes. Results suggested that operation-based priming is affected by goal-content congruity. A second experiment tested the observed effect of positive responses on repetition priming using mental rotation of irregular shapes, affording a test of the impact of congruity in evaluation goals and content in a nonverbal stimulus domain. Both experiments produced a pattern of results inconsistent with Schulman's (1974) semantic congruity account and instead implicated a different form of congruity that affects memory for prior operations rather than memory for semantic and episodic content.

Complex architecture of primes and natural numbers.

Science.gov (United States)

García-Pérez, Guillermo; Serrano, M Ángeles; Boguñá, Marián

2014-08-01

Natural numbers can be divided in two nonoverlapping infinite sets, primes and composites, with composites factorizing into primes. Despite their apparent simplicity, the elucidation of the architecture of natural numbers with primes as building blocks remains elusive. Here, we propose a new approach to decoding the architecture of natural numbers based on complex networks and stochastic processes theory. We introduce a parameter-free non-Markovian dynamical model that naturally generates random primes and their relation with composite numbers with remarkable accuracy. Our model satisfies the prime number theorem as an emerging property and a refined version of Cramér's conjecture about the statistics of gaps between consecutive primes that seems closer to reality than the original Cramér's version. Regarding composites, the model helps us to derive the prime factors counting function, giving the probability of distinct prime factors for any integer. Probabilistic models like ours can help to get deeper insights about primes and the complex architecture of natural numbers.

Z(prime) Phenomenology and the LHC

International Nuclear Information System (INIS)

Rizzo, Thomas G.

2006-01-01

A brief pedagogical overview of the phenomenology of Z(prime) gauge bosons is ILC in determining Z(prime) properties is also discussed. and explore in detail how the LHC may discover and help elucidate the models, review the current constraints on the possible properties of a Z(prime) nature of these new particles. We provide an overview of the Z(prime) studies presented. Such particles can arise in various electroweak extensions of that have been performed by both ATLAS and CMS. The role of the the Standard Model (SM). We provide a quick survey of a number of Z(prime)

Steric and thermodynamic limits of design for the incorporation of large unnatural amino acids in aminoacyl-tRNA synthetase enzymes.

Science.gov (United States)

Armen, Roger S; Schiller, Stefan M; Brooks, Charles L

2010-06-01

Orthogonal aminoacyl-tRNA synthetase/tRNA pairs from archaea have been evolved to facilitate site specific in vivo incorporation of unnatural amino acids into proteins in Escherichia coli. Using this approach, unnatural amino acids have been successfully incorporated with high translational efficiency and fidelity. In this study, CHARMM-based molecular docking and free energy calculations were used to evaluate rational design of specific protein-ligand interactions for aminoacyl-tRNA synthetases. A series of novel unnatural amino acid ligands were docked into the p-benzoyl-L-phenylalanine tRNA synthetase, which revealed that the binding pocket of the enzyme does not provide sufficient space for significantly larger ligands. Specific binding site residues were mutated to alanine to create additional space to accommodate larger target ligands, and then mutations were introduced to improve binding free energy. This approach was used to redesign binding sites for several different target ligands, which were then tested against the standard 20 amino acids to verify target specificity. Only the synthetase designed to bind Man-alpha-O-Tyr was predicted to be sufficiently selective for the target ligand and also thermodynamically stable. Our study suggests that extensive redesign of the tRNA synthatase binding pocket for large bulky ligands may be quite thermodynamically unfavorable.

Transposed-letter priming of prelexical orthographic representations.

Science.gov (United States)

Kinoshita, Sachiko; Norris, Dennis

2009-01-01

A prime generated by transposing two internal letters (e.g., jugde) produces strong priming of the original word (judge). In lexical decision, this transposed-letter (TL) priming effect is generally weak or absent for nonword targets; thus, it is unclear whether the origin of this effect is lexical or prelexical. The authors describe the Bayesian Reader theory of masked priming (D. Norris & S. Kinoshita, 2008), which explains why nonwords do not show priming in lexical decision but why they do in the cross-case same-different task. This analysis is followed by 3 experiments that show that priming in this task is not based on low-level perceptual similarity between the prime and target, or on phonology, to make the case that priming is based on prelexical orthographic representation. The authors then use this task to demonstrate equivalent TL priming effects for nonwords and words. The results are interpreted as the first reliable evidence based on the masked priming procedure that letter position is not coded absolutely within the prelexical, orthographic representation. The implications of the results for current letter position coding schemes are discussed.

Wrath of God: religious primes and punishment.

Science.gov (United States)

McKay, Ryan; Efferson, Charles; Whitehouse, Harvey; Fehr, Ernst

2011-06-22

Recent evidence indicates that priming participants with religious concepts promotes prosocial sharing behaviour. In the present study, we investigated whether religious priming also promotes the costly punishment of unfair behaviour. A total of 304 participants played a punishment game. Before the punishment stage began, participants were subliminally primed with religion primes, secular punishment primes or control primes. We found that religious primes strongly increased the costly punishment of unfair behaviours for a subset of our participants--those who had previously donated to a religious organization. We discuss two proximate mechanisms potentially underpinning this effect. The first is a 'supernatural watcher' mechanism, whereby religious participants punish unfair behaviours when primed because they sense that not doing so will enrage or disappoint an observing supernatural agent. The second is a 'behavioural priming' mechanism, whereby religious primes activate cultural norms pertaining to fairness and its enforcement and occasion behaviour consistent with those norms. We conclude that our results are consistent with dual inheritance proposals about religion and cooperation, whereby religions harness the byproducts of genetically inherited cognitive mechanisms in ways that enhance the survival prospects of their adherents.

Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism

NARCIS (Netherlands)

Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Lamers, Wouter H.; Chaudhry, Farrukh A.; Verlander, Jill W.; Weiner, I. David

2016-01-01

Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of

Cytosolic glutamine synthetase in barley

DEFF Research Database (Denmark)

Thomsen, Hanne Cecilie

remobilisation from ageing plant parts. Thus, GS is highly involved in determining crop yield and NUE. The major objective of this PhD project was to investigate the NUE properties of transgenic barley designed to constitutively overexpress a GS1 isogene (HvGS1.1). These transgenic lines exhibited an increased...... for N demand. Of the GS isogenes, only the transcript levels of root HvGS1.1 increased when plants were transferred from high to low N. This change coincided with an increase in total GS activity. Pronounced diurnal variation was observed for root nitrate transporter genes and GS isogenes in both root...... fertilizer requirement. The enzyme glutamine synthetase (GS) has been a major topic in plant nitrogen research for decades due to its central role in plant N metabolism. The cytosolic version of this enzyme (GS1) plays an important role in relation to primary N assimilation as well as in relation to N...

Phosphorolytic activity of Escherichia coli glycyl-tRNA synthetase towards its cognate aminoacyl adenylate detected by 31P-NMR spectroscopy and thin-layer chromatography

DEFF Research Database (Denmark)

Led, Jens Jørgen; Switon, Werner K.; Jensen, Kaj Frank

1983-01-01

The catalytic activity of highly purified Escherichia coli glycyl-tRNA synthetase has been studied by 31P-NMR spectroscopy and thin-layer chromatography on poly(ethyleneimine)-cellulose. It was found that this synthetase, besides the activation of its cognate amino acid and the syntheses...

Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.

1986-01-01

Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...... the UAA translation stop codon, within a Thy-rich region following an inverted repeat sequence, indicative of an rho-independent transcription terminator....

Recognizing Plant Defense Priming

NARCIS (Netherlands)

Martinez-Medina, Ainhoa; Flors, Victor; Heil, Martin; Mauch-Mani, Brigitte; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; Pozo, Maria J; Ton, Jurriaan; van Dam, Nicole M; Conrath, Uwe

2016-01-01

Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in

Recognizing plant defense priming

NARCIS (Netherlands)

Martinez-Medina, A.; Flors, V.; Heil, M.; Mauch-Mani, B.; Pieterse, C.M.J.; Pozo, M.J.; Ton, J.; Van Dam, N.M.; Conrath, U.

2016-01-01

Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in

Bacillus anthracis o-succinylbenzoyl-CoA synthetase: reaction kinetics and a novel inhibitor mimicking its reaction intermediate †

Science.gov (United States)

Tian, Yang; Suk, Dae-Hwan; Cai, Feng; Crich, David; Mesecar, Andrew D.

2009-01-01

O-succinylbenzoyl-CoA (OSB-CoA) synthetase (EC 6.2.1.26) catalyzes the ATP-dependent condensation of o-succinylbenzoate (OSB) and CoA to form OSB-CoA, the fourth step of the menaquinone biosynthetic pathway in Bacillus anthracis. Gene knockout studies have highlighted this enzyme as a potential target for the discovery of new antibiotics. Here we report the first studies on the kinetic mechanism of B. anthracis OSB-CoA synthetase, classifying it as an ordered Bi Uni Uni Bi ping-pong mechanism. Through a series of pre-steady-state and steady-state kinetic studies in conjunction with direct-binding studies, it is demonstrated that CoA, the last substrate to bind, strongly activates the first half-reaction after the first round of turnover. The activation of the first-half reaction is most likely achieved by CoA stabilizing conformations of the enzyme in the ‘F’ form, which slowly isomerize back to the E form. Thus, the kinetic mechanism of OSB-CoA synthetase may be more accurately described as an ordered Bi Uni Uni Bi Iso ping-pong mechanism. The substrate specificity of OSB-CoA synthetase was probed using a series of OSB analogs with alterations in the carboxylate groups. OSB-CoA shows a strong preference for OSB over all of the analogs tested as none were active except 4-(2-trifluoromethylphenyl)-4-oxobutyric acid which exhibited a 100-fold decrease in kcat/Km. Based on an understanding of OSB-CoA synthetase’s kinetic mechanism and substrate specificity, a reaction intermediate analog of OSB-AMP, 5’-O-(N-(2-trifluoromethylphenyl)-4-oxobutyl) adenosine sulfonamide (TFMP-butyl-AMS), was designed and synthesized. This inhibitor was found to be an uncompetitive inhibitor to CoA and a mixed-type inhibitor to ATP and OSB with low micromolar inhibition constants. Collectively, these results should serve as an important forerunner to more detailed and extensive inhibitor design studies aimed at developing lead compounds against the OSB-CoA synthetase class of

Syntactic priming in American Sign Language.

Directory of Open Access Journals (Sweden)

Matthew L Hall

Full Text Available Psycholinguistic studies of sign language processing provide valuable opportunities to assess whether language phenomena, which are primarily studied in spoken language, are fundamentally shaped by peripheral biology. For example, we know that when given a choice between two syntactically permissible ways to express the same proposition, speakers tend to choose structures that were recently used, a phenomenon known as syntactic priming. Here, we report two experiments testing syntactic priming of a noun phrase construction in American Sign Language (ASL. Experiment 1 shows that second language (L2 signers with normal hearing exhibit syntactic priming in ASL and that priming is stronger when the head noun is repeated between prime and target (the lexical boost effect. Experiment 2 shows that syntactic priming is equally strong among deaf native L1 signers, deaf late L1 learners, and hearing L2 signers. Experiment 2 also tested for, but did not find evidence of, phonological or semantic boosts to syntactic priming in ASL. These results show that despite the profound differences between spoken and signed languages in terms of how they are produced and perceived, the psychological representation of sentence structure (as assessed by syntactic priming operates similarly in sign and speech.

Multisensory Flavor Priming

DEFF Research Database (Denmark)

Dijksterhuis, Garmt Bernard

2016-01-01

with a taxonomy of different priming situations. In food-related applications of flavor, both bottom-up (sensory) as well as top-down (expectations) processes are at play. Most of the complex interactions that this leads to take place outside the awareness of the perceiving subject. A model is presented where...... many, past and current, aspects (sensory, surroundings, social, somatic, sentimental) of a (flavor) perception, together result in the perception of a flavor, its liking. or its choice. This model borrows on ideas from priming, situated/embodied cognition, and (food-related) perception.......Flavor is multisensory; several interacting sensory systems-taste, smell, and mouthfeel-together comprise "flavor," making it a cognitively constructed percept rather than a bottom-up sensory one. In this chapter, some of the complications this entails for flavor priming are introduced, along...

Proofreading in vivo: Editing of homocysteine by methionyl-tRNA synthetase in Escherichia coli

International Nuclear Information System (INIS)

Jakubowski, H.

1990-01-01

Previous in vitro studies have established a pre-transfer proofreading mechanism for editing of homocysteine by bacterial methionyl-, isoleucyl-, and valyl-tRNA synthetases. The unusual feature of the editing is the formation of a distinct compound, homocysteine thiolactone. Now, two-dimensional TLC analysis of 35S-labeled amino acids extracted from cultures of the bacterium Escherichia coli reveals that the thiolactone is also synthesized in vivo. In E. coli, the thiolactone is made from homocysteine in a reaction catalyzed by methionyl-tRNA synthetase. One molecule of homocysteine is edited as thiolactone per 109 molecules of methionine incorporated into protein in vivo. These results not only directly demonstrate that the adenylate proofreading pathway for rejection of misactivated homocysteine operates in vivo in E. coli but, in general, establish the importance of error-editing mechanisms in living cells

Semantic priming, not repetition priming, is to blame for false hearing.

Science.gov (United States)

Rogers, Chad S

2017-08-01

Contextual and sensory information are combined in speech perception. Conflict between the two can lead to false hearing, defined as a high-confidence misidentification of a spoken word. Rogers, Jacoby, and Sommers (Psychology and Aging, 27(1), 33-45, 2012) found that older adults are more susceptible to false hearing than are young adults, using a combination of semantic priming and repetition priming to create context. In this study, the type of context (repetition vs. sematic priming) responsible for false hearing was examined. Older and young adult participants read and listened to a list of paired associates (e.g., ROW-BOAT) and were told to remember the pairs for a later memory test. Following the memory test, participants identified words masked in noise that were preceded by a cue word in the clear. Targets were semantically associated to the cue (e.g., ROW-BOAT), unrelated to the cue (e.g., JAW-PASS), or phonologically related to a semantic associate of the cue (e.g., ROW-GOAT). How often each cue word and its paired associate were presented prior to the memory test was manipulated (0, 3, or 5 times) to test effects of repetition priming. Results showed repetitions had no effect on rates of context-based listening or false hearing. However, repetition did significantly increase sensory information as a basis for metacognitive judgments in young and older adults. This pattern suggests that semantic priming dominates as the basis for false hearing and highlights context and sensory information operating as qualitatively different bases for listening and metacognition.

Fusion of the subunits α and β of succinyl-CoA synthetase as a phylogenetic marker for Pezizomycotina fungi

Directory of Open Access Journals (Sweden)

Amanda M. Koire

2011-01-01

Full Text Available Gene fusions, yielding the formation of multidomain proteins, are evolutionary events that can be utilized as phylogenetic markers. Here we describe a fusion gene comprising the α and β subunits of succinyl-coA synthetase, an enzyme of the TCA cycle, in Pezizomycotina fungi. This fusion is present in all Pezizomycotina with complete genome sequences and absent from all other organisms. Phylogenetic analysis of the α and β subunits of succinyl-CoA synthetase suggests that both subunits were duplicated and retained in Pezizomycotina while one copy was lost from other fungi. One of the duplicated copies was then fused in Pezizomycotina. Our results suggest that the fusion of the α and β subunits of succinyl-CoA synthetase can be used as a molecular marker for membership in the Pezizomycotina subphylum. If a species has the fusion it can be reliably classified as Pezizomycotina, while the absence of the fusion is suggestive that the species is not a member of this subphylum.

Modified Multi Prime RSA Cryptosystem

Science.gov (United States)

Ghazali Kamardan, M.; Aminudin, N.; Che-Him, Norziha; Sufahani, Suliadi; Khalid, Kamil; Roslan, Rozaini

2018-04-01

RSA [1] is one of the mostly used cryptosystem in securing data and information. Though, it has been recently discovered that RSA has some weaknesses and in advance technology, RSA is believed to be inefficient especially when it comes to decryption. Thus, a new algorithm called Multi prime RSA, an extended version of the standard RSA is studied. Then, a modification is made to the Multi prime RSA where another keys is shared secretly between the receiver and the sender to increase the securerity. As in RSA, the methodology used for modified Multi-prime RSA also consists of three phases; 1. Key Generation in which the secret and public keys are generated and published. In this phase, the secrecy is improved by adding more prime numbers and addition of secret keys. 2. Encryption of the message using the public and secret keys given. 3. Decryption of the secret message using the secret key generated. For the decryption phase, a method called Chinese Remainder Theorem is used which helps to fasten the computation. Since Multi prime RSA use more than two prime numbers, the algorithm is more efficient and secure when compared to the standard RSA. Furthermore, in modified Multi prime RSA another secret key is introduced to increase the obstacle to the attacker. Therefore, it is strongly believed that this new algorithm is better and can be an alternative to the RSA.

The pros and cons of masked priming.

Science.gov (United States)

Forster, K I

1998-03-01

Masked priming paradigms offer the promise of tapping automatic, strategy-free lexical processing, as evidenced by the lack of expectancy disconfirmation effects, and proportionality effects in semantic priming experiments. But several recent findings suggest the effects may be prelexical. These findings concern nonword priming effects in lexical decision and naming, the effects of mixed-case presentation on nonword priming, and the dependence of priming on the nature of the distractors in lexical decision, suggesting possible strategy effects. The theory underlying each of these effects is discussed, and alternative explanations are developed that do not preclude a lexical basis for masked priming effects.

Structural basis of malaria parasite lysyl-tRNA synthetase inhibition by cladosporin.

Science.gov (United States)

Khan, Sameena; Sharma, Arvind; Belrhali, Hassan; Yogavel, Manickam; Sharma, Amit

2014-06-01

Malaria parasites inevitably develop drug resistance to anti-malarials over time. Hence the immediacy for discovering new chemical scaffolds to include in combination malaria drug therapy. The desirable attributes of new chemotherapeutic agents currently include activity against both liver and blood stage malaria parasites. One such recently discovered compound called cladosporin abrogates parasite growth via inhibition of Plasmodium falciparum lysyl-tRNA synthetase (PfKRS), an enzyme central to protein translation. Here, we present crystal structure of ternary PfKRS-lysine-cladosporin (PfKRS-K-C) complex that reveals cladosporin's remarkable ability to mimic the natural substrate adenosine and thereby colonize PfKRS active site. The isocoumarin fragment of cladosporin sandwiches between critical adenine-recognizing residues while its pyran ring fits snugly in the ribose-recognizing cavity. PfKRS-K-C structure highlights ample space within PfKRS active site for further chemical derivatization of cladosporin. Such derivatives may be useful against additional human pathogens that retain high conservation in cladosporin chelating residues within their lysyl-tRNA synthetase.

Priming Ability Emotional Intelligence

Science.gov (United States)

Schutte, Nicola S.; Malouff, John M.

2012-01-01

Two studies examined whether priming self-schemas relating to successful emotional competency results in better emotional intelligence performance. In the first study participants were randomly assigned to a successful emotional competency self-schema prime condition or a control condition and then completed an ability measure of emotional…

Purification, crystallization and preliminary X-ray diffraction analysis of the seryl-tRNA synthetase from Candida albicans

International Nuclear Information System (INIS)

Rocha, Rita; Barbosa Pereira, Pedro José; Santos, Manuel A. S.; Macedo-Ribeiro, Sandra

2010-01-01

The seryl-tRNA synthetase from C. albicans was crystallized by the sitting-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belonged to the hexagonal space group P6 1 22 and diffraction data were collected to 2.0 Å resolution at a synchrotron source. The seryl-tRNA synthetase (SerRS) from Candida albicans exists naturally as two isoforms resulting from ambiguity in the natural genetic code. Both enzymes were crystallized by the sitting-drop vapour-diffusion method using 3.2–3.4 M ammonium sulfate as precipitant. The crystals belonged to the hexagonal space group P6 1 22 and contained one monomer per asymmetric unit, despite the synthetase existing as a homodimer (with a molecular weight of ∼116 kDa) in solution. Diffraction data were collected to 2.0 Å resolution at a synchrotron source and the crystal structures of unliganded SerRS and of its complexes with ATP and with a seryl-adenylate analogue were solved by molecular replacement. The structure of C. albicans SerRS represents the first reported structure of a eukaryotic cytoplasmic SerRS

Assembly of the novel five-component apicomplexan multi-aminoacyl-tRNA synthetase complex is driven by the hybrid scaffold protein Tg-p43.

Directory of Open Access Journals (Sweden)

Jason M van Rooyen

Full Text Available In Toxoplasma gondii, as in other eukaryotes, a subset of the amino-acyl-tRNA synthetases are arranged into an abundant cytoplasmic multi-aminoacyl-tRNA synthetase (MARS complex. Through a series of genetic pull-down assays, we have identified the enzymes of this complex as: methionyl-, glutaminyl-, glutamyl-, and tyrosyl-tRNA synthetases, and we show that the N-terminal GST-like domain of a partially disordered hybrid scaffold protein, Tg-p43, is sufficient for assembly of the intact complex. Our gel filtration studies revealed significant heterogeneity in the size and composition of isolated MARS complexes. By targeting the tyrosyl-tRNA synthetases subunit, which was found exclusively in the complete 1 MDa complex, we were able to directly visualize MARS particles in the electron microscope. Image analyses of the negative stain data revealed the observed heterogeneity and instability of these complexes to be driven by the intrinsic flexibility of the domain arrangements within the MARS complex. These studies provide unique insights into the assembly of these ubiquitous but poorly understood eukaryotic complexes.

Psychotherapy augmentation through preconscious priming

Directory of Open Access Journals (Sweden)

Francois eBorgeat

2013-03-01

Full Text Available Objective: To test the hypothesis that repeated preconscious (masked priming of personalized positive cognitions could augment cognitive change and facilitate achievement of patients’ goals following a therapy.Methods: Twenty social phobic patients (13 women completed a 36 weeks study beginning by 12 weeks of group behavioural therapy. After the therapy, they received 6 weeks of preconscious priming and 6 weeks of a control procedure in a randomized cross-over design. The Priming condition involved listening twice daily with a passive attitude to a recording of individualized formulations of appropriate cognitions and attitudes masked by music. The Control condition involved listening to an indistinguishable recording where the formulations had been replaced by random numbers. Changes in social cognitions were measured by the Social Interaction Self Statements Test (SISST.Results: Patients improved following therapy. The Priming procedure was associated with increased positive cognitions and decreased negative cognitions on the SISST while the Control procedure was not. The Priming procedure induced more cognitive change when applied immediately after the group therapy. Conclusion: An effect of priming was observed on social phobia related cognitions in the expected direction. This self administered addition to a therapy could be seen as an augmentation strategy.

Prime time news: the influence of primed positive and negative emotion on susceptibility to false memories.

Science.gov (United States)

Porter, Stephen; ten Brinke, Leanne; Riley, Sean N; Baker, Alysha

2014-01-01

We examined the relation between emotion and susceptibility to misinformation using a novel paradigm, the ambiguous stimuli affective priming (ASAP) paradigm. Participants (N = 88) viewed ambiguous neutral images primed either at encoding or retrieval to be interpreted as either highly positive or negative (or neutral/not primed). After viewing the images, they either were asked misleading or non-leading questions. Following a delay, memory accuracy for the original images was assessed. Results indicated that any emotional priming at encoding led to a higher susceptibility to misinformation relative to priming at recall. In particular, inducing a negative interpretation of the image at encoding led to an increased susceptibility of false memories for major misinformation (an entire object not actually present in the scene). In contrast, this pattern was reversed when priming was used at recall; a negative reinterpretation of the image decreased memory distortion relative to unprimed images. These findings suggest that, with precise experimental control, the experience of emotion at event encoding, in particular, is implicated in false memory susceptibility.

Space-Valence Priming with Subliminal and Supraliminal Words

Directory of Open Access Journals (Sweden)

Ulrich eAnsorge

2013-02-01

Full Text Available To date it is unclear whether (1 awareness-independent non-evaluative semantic processes influence affective semantics and whether (2 awareness-independent affective semantics influence non-evaluative semantic processing. In the current study, we investigated these questions with the help of subliminal (masked primes and visible targets in a space-valence across-category congruence effect. In line with (1, we found that subliminal space prime words influenced valence classification of supraliminal target words (Experiment 1: Classifications were faster with a congruent prime (e.g., the prime ‘up’ before the target ‘happy’ than with an incongruent prime (e.g., the prime ‘up’ before the target ‘sad’. In contrast to (2, no influence of subliminal valence primes on the classification of supraliminal space targets into up- and down-words was found (Experiment 2. Control conditions showed that standard masked response-priming effects were found with both subliminal prime types, and that an across-category congruence effect was also found with supraliminal valence primes and spatial target words. The final Experiment 3 confirmed that the across-category congruence effect indeed reflected priming of target categorization of a relevant meaning category. Together, the data jointly confirmed prediction (1 that awareness-independent non-evaluative semantic priming influences valence judgments.

Association of mitochondrial lysyl-tRNA synthetase with HIV-1 GagPol involves catalytic domain of the synthetase and transframe and integrase domains of Pol

Directory of Open Access Journals (Sweden)

Shalak V. F.

2011-10-01

Full Text Available Aim. Analyze the interaction between Lysyl-tRNA synthetase (LysRS and HIV-1 GagPol to know whether a particular N-terminal sequence of mitochondrial LysRS triggers a specific recognition with GagPol. Methods. Yeast two-hybrid analysis, immunoprecipitation. Results. We have shown that LysRS associates with the Pol domain of GagPol. Conclusions. A model of the assembly of the LysRS:tRNA3Lys:GagPol packaging complex is proposed.

Purification and properties of the dihydrofolate synthetase from Serratia indica

International Nuclear Information System (INIS)

Ikeda, Masamichi; Iwai, Kazuo

1976-01-01

The dihydrofolate synthetase (EC6.3.2.12) responsible for catalyzing the synthesis of dihydrofolic acid from dihydropteroic acid and L-glutamic acid was purified about 130-fold from extracts of Serratia indica IFO 3759 by ammonium sulfate fractionation, DEAE-Sephadex column chromatography, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The enzyme preparation obtained was shown to be homogeneous by DEAE-cellulose column chromatography and ultracentrifugal analysis. The sedimentation coefficient of this enzyme was 3.9 S, and the molecular weight was determined to be about 47,000 by Sephadex G-100. The optimum pH for the reaction was 9.0. The enzymatic reaction required dihydropteroate, L-glutamate and ATP as substrates, and Mg 2+ and K + as cofactors. γ-L-Glutamyl-L-glutamic acid cannot replace L-glutamic acid as the substrate. Neither pteroic acid nor tetrahydropteroic acid can be used as the substrate. ATP was partially replaced by ITP or GTP. The enzyme reaction was inhibited by the addition of ADP, but not by AMP. One mole of dihydrofolate, 1 mole of ADP and 1 mole of orthophosphate were produced from each 1 mole of dihydropteroic acid, L-glutamic acid, and ATP. These results suggest that the systematic name for the dihydrofolate synthetase is 7,8-dihydropteroate: L-glutamate ligase (ADP). (auth.)

Building Numbers from Primes

Science.gov (United States)

Burkhart, Jerry

2009-01-01

Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and…

Recognizing Plant Defense Priming.

Science.gov (United States)

Martinez-Medina, Ainhoa; Flors, Victor; Heil, Martin; Mauch-Mani, Brigitte; Pieterse, Corné M J; Pozo, Maria J; Ton, Jurriaan; van Dam, Nicole M; Conrath, Uwe

2016-10-01

Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

The structure factor of primes

Science.gov (United States)

Zhang, G.; Martelli, F.; Torquato, S.

2018-03-01

Although the prime numbers are deterministic, they can be viewed, by some measures, as pseudo-random numbers. In this article, we numerically study the pair statistics of the primes using statistical-mechanical methods, particularly the structure factor S(k) in an interval M ≤slant p ≤slant M + L with M large, and L/M smaller than unity. We show that the structure factor of the prime-number configurations in such intervals exhibits well-defined Bragg-like peaks along with a small ‘diffuse’ contribution. This indicates that primes are appreciably more correlated and ordered than previously thought. Our numerical results definitively suggest an explicit formula for the locations and heights of the peaks. This formula predicts infinitely many peaks in any non-zero interval, similar to the behavior of quasicrystals. However, primes differ from quasicrystals in that the ratio between the location of any two predicted peaks is rational. We also show numerically that the diffuse part decays slowly as M and L increases. This suggests that the diffuse part vanishes in an appropriate infinite-system-size limit.

AMP-forming acetyl-CoA synthetases in Archaea show unexpected diversity in substrate utilization

Science.gov (United States)

Ingram-Smith, Cheryl; Smith, Kerry S.

2007-01-01

Adenosine monophosphate (AMP)-forming acetyl-CoA synthetase (ACS; acetate:CoA ligase (AMP-forming), EC 6.2.1.1) is a key enzyme for conversion of acetate to acetyl-CoA, an essential intermediate at the junction of anabolic and catabolic pathways. Phylogenetic analysis of putative short and medium chain acyl-CoA synthetase sequences indicates that the ACSs form a distinct clade from other acyl-CoA synthetases. Within this clade, the archaeal ACSs are not monophyletic and fall into three groups composed of both bacterial and archaeal sequences. Kinetic analysis of two archaeal enzymes, an ACS from Methanothermobacter thermautotrophicus (designated as MT-ACS1) and an ACS from Archaeoglobus fulgidus (designated as AF-ACS2), revealed that these enzymes have very different properties. MT-ACS1 has nearly 11-fold higher affinity and 14-fold higher catalytic efficiency with acetate than with propionate, a property shared by most ACSs. However, AF-ACS2 has only 2.3-fold higher affinity and catalytic efficiency with acetate than with propionate. This enzyme has an affinity for propionate that is almost identical to that of MT-ACS1 for acetate and nearly tenfold higher than the affinity of MT-ACS1 for propionate. Furthermore, MT-ACS1 is limited to acetate and propionate as acyl substrates, whereas AF-ACS2 can also utilize longer straight and branched chain acyl substrates. Phylogenetic analysis, sequence alignment and structural modeling suggest a molecular basis for the altered substrate preference and expanded substrate range of AF-ACS2 versus MT-ACS1. PMID:17350930

AMP-forming acetyl-CoA synthetases in Archaea show unexpected diversity in substrate utilization

Directory of Open Access Journals (Sweden)

Cheryl Ingram-Smith

2006-01-01

Full Text Available Adenosine monophosphate (AMP-forming acetyl-CoA synthetase (ACS; acetate:CoA ligase (AMP-forming, EC 6.2.1.1 is a key enzyme for conversion of acetate to acetyl-CoA, an essential intermediate at the junction of anabolic and catabolic pathways. Phylogenetic analysis of putative short and medium chain acyl-CoA synthetase sequences indicates that the ACSs form a distinct clade from other acyl-CoA synthetases. Within this clade, the archaeal ACSs are not monophyletic and fall into three groups composed of both bacterial and archaeal sequences. Kinetic analysis of two archaeal enzymes, an ACS from Methanothermobacter thermautotrophicus (designated as MT-ACS1 and an ACS from Archaeoglobus fulgidus (designated as AF-ACS2, revealed that these enzymes have very different properties. MT-ACS1 has nearly 11-fold higher affinity and 14-fold higher catalytic efficiency with acetate than with propionate, a property shared by most ACSs. However, AF-ACS2 has only 2.3-fold higher affinity and catalytic efficiency with acetate than with propionate. This enzyme has an affinity for propionate that is almost identical to that of MT-ACS1 for acetate and nearly tenfold higher than the affinity of MT-ACS1 for propionate. Furthermore, MT-ACS1 is limited to acetate and propionate as acyl substrates, whereas AF-ACS2 can also utilize longer straight and branched chain acyl substrates. Phylogenetic analysis, sequence alignment and structural modeling suggest a molecular basis for the altered substrate preference and expanded substrate range of AF-ACS2 versus MT-ACS1.

PrimeFaces beginner's guide

CERN Document Server

Reddy, K Siva Prasad

2013-01-01

A guide for beginner's with step-by-step instructions and an easy-to-follow approach.PrimeFaces Beginners Guide is a simple and effective guide for beginners, wanting to learn and implement PrimeFaces in their JSF-based applications. Some basic JSF and jQuery skills are required before you start working through the book.

Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase

DEFF Research Database (Denmark)

Jochimsen, Bjarne; Hove-Jensen, Bjarne; Garber, Bruce B.

1985-01-01

This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity. This strain was isolated in a purE deoD gpt purine auxotroph by a procedure designed to select guanosin...

Semantic priming without association: a meta-analytic review.

Science.gov (United States)

Lucas, M

2000-12-01

A meta-analysis of 26 studies indicated that automatic semantic priming can occur without association. Priming did not vary substantially with differences in variables that affect automatic versus strategic processing, such as time spent processing the prime and target, relationship proportion, and task (except that average effects were smaller in the naming task). Although category coordinates were investigated in the majority of studies, synonyms, antonyms, and script relations also demonstrated priming; functional relations showed greater priming, and essential and perceptual relations showed less. The average effect size for semantic priming was smaller than that for associative priming, suggesting that there is an "associative boost" from adding an associative relationship to a semantic one. The implications of these findings for the modularity thesis and for models of semantic priming are discussed.

Priming methods in semantics and pragmatics.

Science.gov (United States)

Maldonado, Mora; Spector, Benjamin; Chemla, Emmanuel

2017-01-01

Structural priming is a powerful method to inform linguistic theories. We argue that this method extends nicely beyond syntax to theories of meaning. Priming, however, should still be seen as only one of the tools available for linguistic data collection. Specifically, because priming can occur at different, potentially conflicting levels, it cannot detect every aspect of linguistic representations.

Distinctive properties and expression profiles of glutamine synthetase from a plant symbiotic fungus.

Science.gov (United States)

Montanini, Barbara; Betti, Marco; Márquez, Antonio J; Balestrini, Raffaella; Bonfante, Paola; Ottonello, Simone

2003-01-01

The nucleotide sequences reported in this paper have been submitted to the GenBank(R)/EBI Nucleotide Sequence Databases with accession numbers AF462037 (glutamine synthetase) and AF462032 (glutamate synthase). Nitrogen retrieval and assimilation by symbiotic ectomycorrhizal fungi is thought to play a central role in the mutualistic interaction between these organisms and their plant hosts. Here we report on the molecular characterization of the key N-assimilation enzyme glutamine synthetase from the mycorrhizal ascomycete Tuber borchii (TbGS). TbGS displayed a strong positive co-operativity ( n =1.7+/-0.29) and an unusually high S(0.5) value (54+/-16 mM; S(0.5) is the substrate concentration value at which v =(1/2) V (max)) for glutamate, and a correspondingly low sensitivity towards inhibition by the glutamate analogue herbicide phosphinothricin. The TbGS mRNA, which is encoded by a single-copy gene in the Tuber genome, was up-regulated in N-starved mycelia and returned to basal levels upon resupplementation of various forms of N, the most effective of which was nitrate. Both responses were accompanied by parallel variations of TbGS protein amount and glutamine synthetase activity, thus indicating that TbGS levels are primarily controlled at the pre-translational level. As revealed by a comparative analysis of the TbGS mRNA and of the mRNAs for the metabolically related enzymes glutamate dehydrogenase and glutamate synthase, TbGS is not only the sole messenger that positively responds to N starvation, but also the most abundant under N-limiting conditions. A similar, but even more discriminating expression pattern, with practically undetectable glutamate dehydrogenase mRNA levels, was observed in fruitbodies. The TbGS mRNA was also found to be expressed in symbiosis-engaged hyphae, with distinctively higher hybridization signals in hyphae that were penetrating among and within root cells. PMID:12683951

Structural priming, action planning, and grammar.

Science.gov (United States)

MacDonald, Maryellen C; Weiss, Daniel J

2017-01-01

Structural priming is poorly understood and cannot inform accounts of grammar for two reasons. First, those who view performance as grammar + processing will always be able to attribute psycholinguistic data to processing rather than grammar. Second, structural priming may be simply an example of hysteresis effects in general action planning. If so, then priming offers no special insight into grammar.

The priming of basic combinatory responses in MEG.

Science.gov (United States)

Blanco-Elorrieta, Esti; Ferreira, Victor S; Del Prato, Paul; Pylkkänen, Liina

2018-01-01

Priming has been a powerful tool for the study of human memory and especially the memory representations relevant for language. However, although it is well established that lexical access can be primed, we do not know exactly what types of computations can be primed above the word level. This work took a neurobiological approach and assessed the ways in which the complex representation of a minimal combinatory phrase, such as red boat, can be primed, as evidenced by the spatiotemporal profiles of magnetoencephalography (MEG) signals. Specifically, we built upon recent progress on the neural signatures of phrasal composition and tested whether the brain activities implicated for the basic combination of two words could be primed. In two experiments, MEG was recorded during a picture naming task where the prime trials were designed to replicate previously reported combinatory effects and the target trials to test whether those combinatory effects could be primed. The manipulation of the primes was successful in eliciting larger activity for adjective-noun combinations than single nouns in left anterior temporal and ventromedial prefrontal cortices, replicating prior MEG studies on parallel contrasts. Priming of similarly timed activity was observed during target trials in anterior temporal cortex, but only when the prime and target shared an adjective. No priming in temporal cortex was observed for single word repetition and two control tasks showed that the priming effect was not elicited if the prime pictures were simply viewed but not named. In sum, this work provides evidence that very basic combinatory operations can be primed, with the necessity for some lexical overlap between prime and target suggesting combinatory conceptual, as opposed to syntactic processing. Both our combinatory and priming effects were early, onsetting between 100 and 150ms after picture onset and thus are likely to reflect the very earliest planning stages of a combinatory message

Social priming increases nonverbal expressive behaviors in schizophrenia.

Directory of Open Access Journals (Sweden)

Jonathan Del-Monte

Full Text Available Semantic priming tasks are classically used to influence and implicitly promote target behaviors. Recently, several studies have demonstrated that prosocial semantic priming modulated feelings of social affiliation. The main aim of this study was to determine whether inducing feelings of social affiliation using priming tasks could modulate nonverbal social behaviors in schizophrenia. We used the Scrambled Sentence Task to prime schizophrenia patients according to three priming group conditions: pro-social, non-social or anti-social. Forty-five schizophrenia patients, diagnosed according to DSM-IV-TR, were randomly assigned to one of the three priming groups of 15 participants. We evaluated nonverbal social behaviors using the Motor-Affective subscale of the Motor-Affective-Social-Scale. Results showed that schizophrenia patients with pro-social priming had significantly more nonverbal behaviors than schizophrenia patients with anti-social and non-social priming conditions. Schizophrenia patient behaviors are affected by social priming. Our results have several clinical implications for the rehabilitation of social skills impairments frequently encountered among individuals with schizophrenia.

Phosphorylation and Acetylation of Acyl-CoA Synthetase- I

DEFF Research Database (Denmark)

Frahm, Jennifer L; Li, Lei O; Grevengoed, Trisha J

2011-01-01

Long chain acyl-CoA synthetase 1 (ACSL1) contributes 50 to 90% of total ACSL activity in liver, adipose tissue, and heart and appears to direct the use of long chain fatty acids for energy. Although the functional importance of ACSL1 is becoming clear, little is understood about its post...... and acetylated amino acids by mass spectrometry. We then compared these results to the post-translational modifications observed in vivo in liver and brown adipose tissue after mice were fasted or exposed to a cold environment. We identified universal N-terminal acetylation, 15 acetylated lysines, and 25...

Amino acid environment determines expression of carbamoylphosphate synthetase and phosphoenolpyruvate carboxykinase in embryonic rat hepatocytes

NARCIS (Netherlands)

Lamers, W. H.; van Roon, M.; Mooren, P. G.; de Graaf, A.; Charles, R.

1985-01-01

A completely defined medium (EHM-1), which reflects the amino acid composition of fetal rat serum and contains albumin as the sole proteinaceous compound, allows the accumulation of carbamoylphosphate synthetase and phosphoenolpyruvate carboxykinase in the presence of dexamethasone, dibutyryl cyclic

Optical coding theory with Prime

CERN Document Server

Kwong, Wing C

2013-01-01

Although several books cover the coding theory of wireless communications and the hardware technologies and coding techniques of optical CDMA, no book has been specifically dedicated to optical coding theory-until now. Written by renowned authorities in the field, Optical Coding Theory with Prime gathers together in one volume the fundamentals and developments of optical coding theory, with a focus on families of prime codes, supplemented with several families of non-prime codes. The book also explores potential applications to coding-based optical systems and networks. Learn How to Construct

Priming of antiherbivore defensive responses in plants

Institute of Scientific and Technical Information of China (English)

Jinwon Kim; Gary W.Felton

2013-01-01

Defense priming is defined as increased readiness of defense induction.A growing body of literature indicates that plants (or intact parts of a plant) are primed in anticipation of impending environmental stresses,both biotic and abiotic,and upon the following stimulus,induce defenses more quickly and strongly.For instance,some plants previously exposed to herbivore-inducible plant volatiles (HIPVs) from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding.Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently,but significant advances were made in the past three years,including non-HIPV-mediated defense priming,epigenetic modifications as the molecular mechanism of priming,and others.It is timely to consider the advances in research on defense priming in the plantinsect interactions.

Aminoacyl-tRNA synthetases database Y2K.

Science.gov (United States)

Szymanski, M; Barciszewski, J

2000-01-01

The aminoacyl-tRNA synthetases (AARS) are a diverse group of enzymes that ensure the fidelity of transfer of genetic information from DNA into protein. They catalyse the attachment of amino acids to transfer RNAs and thereby establish the rules of the genetic code by virtue of matching the nucleotide triplet of the anticodon with its cognate amino acid. Currently, 818 AARS primary structures have been reported from archaebacteria, eubacteria, mitochondria, chloro-plasts and eukaryotic cells. The database is a compilation of the amino acid sequences of all AARSs, known to date, which are available as separate entries or alignments of related proteins via the WWW at http://rose.man.poznan.pl/aars/index.html

Random reward priming is task-contingent: The robustness of the 1-trial reward priming effect

Directory of Open Access Journals (Sweden)

Árni Gunnar Ásgeirsson

2014-04-01

Full Text Available Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings are thought to reflect that rewarded features become more salient than unrewarded ones on the subsequent trial. Here we attempt to conceptually replicate this effect, testing its generalizability. In three versions of an analogous paradigm to the additional singleton paradigm involving singleton search for a Gabor patch of odd spatial frequency we found no evidence of reward priming, while we only partially replicate the reward priming in the exact original paradigm tested by Hickey and colleagues. The results cast doubt on the proposal that random reward enhances salience, suggested in the original papers, and highlight the need for a more nuanced account. In many other paradigms reward effects have been found to progress gradually, becoming stronger as they build up, and we argue that for robust reward priming, reward schedules need to be more consistent than in the original 1-trial reward priming paradigm.

Kinetic isotope effect studies of the S-adenosylmethionine synthetase reaction

International Nuclear Information System (INIS)

Markham, G.D.; Parkin, D.W.; Schramm, V.L.

1986-01-01

S-adenosylmethionine (AdoMet) synthetase catalyzes a unique substitution reaction at the 5' carbon of MgATP. Kinetic isotope effect (V/K) measurements have been used to investigate the mechanism of AdoMet synthetase from E. coli. Changes in 3 H/ 14 C ratios when AdoMet is formed from a mixture of either ([5'- 14 C]ATP and [5'- 12 C,1'- 3 H]ATP) or ([5'- 3 H]ATP and [5'- 1 H,1'- 14 C]ATP) were examined. The effects of varying the concentrations of the co-substrate methionine and the monovalent cation activator K + were investigated. Substitution of 14 C for 12 C at the 5' position of ATP yields a primary V/K kinetic isotope effect ( 12 C/ 14 C) of 1.128 +/- 0.004 at low K + and methionine concentrations. The observed isotope effect diminishes slightly to 1.107 +/- 0.003 when both K + and methionine are present at saturating concentrations, suggesting that MgATP has only a low commitment to catalysis from at conditions near Vmax. No secondary V/K 3 H isotope effect from [5'- 3 H]ATP was detected ( 1 H/ 3 H) = 0.997 +/- 0.003. The magnitude of the primary 14 C isotope effect and the small secondary 3 H effect demonstrate that AdoMet synthesis occurs with a S/sub N/ 2 transition state which is symmetric with respect to the sulfur nucleophile and the departing tripolyphosphate group

Noncoding RNA of Glutamine Synthetase I Modulates Antibiotic Production in Streptomyces coelicolor A3(2)

NARCIS (Netherlands)

D'Alia, Davide; Nieselt, Kay; Steigele, Stephan; Mueller, Jonas; Verburg, Ilse; Takano, Eriko; Alia, Davide D’; Müller, Jonas

Overexpression of antisense chromosomal cis-encoded noncoding RNAss (ncRNAs) in glutamine synthetase I resulted in a decrease in growth, protein synthesis, and antibiotic production in Streptomyces coelicolor. In addition, we predicted 3,597 cis-encoded ncRNAs and validated 13 of them

Mechanisms of masked evaluative priming: task sets modulate behavioral and electrophysiological priming for picture and words differentially

OpenAIRE

Kiefer, Markus; Liegel, Nathalie; Zovko, Monika; Wentura, Dirk

2016-01-01

Research with the evaluative priming paradigm has shown that affective evaluation processes reliably influence cognition and behavior, even when triggered outside awareness. However, the precise mechanisms underlying such subliminal evaluative priming effects, response activation vs semantic processing, are matter of a debate. In this study, we determined the relative contribution of semantic processing and response activation to masked evaluative priming with pictures and words. To this end,...

Priming analogical reasoning with false memories.

Science.gov (United States)

Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

2015-08-01

Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

Priming intelligent behavior: an elusive phenomenon.

Directory of Open Access Journals (Sweden)

David R Shanks

Full Text Available Can behavior be unconsciously primed via the activation of attitudes, stereotypes, or other concepts? A number of studies have suggested that such priming effects can occur, and a prominent illustration is the claim that individuals' accuracy in answering general knowledge questions can be influenced by activating intelligence-related concepts such as professor or soccer hooligan. In 9 experiments with 475 participants we employed the procedures used in these studies, as well as a number of variants of those procedures, in an attempt to obtain this intelligence priming effect. None of the experiments obtained the effect, although financial incentives did boost performance. A Bayesian analysis reveals considerable evidential support for the null hypothesis. The results conform to the pattern typically obtained in word priming experiments in which priming is very narrow in its generalization and unconscious (subliminal influences, if they occur at all, are extremely short-lived. We encourage others to explore the circumstances in which this phenomenon might be obtained.

Priming Intelligent Behavior: An Elusive Phenomenon

Science.gov (United States)

Shanks, David R.; Newell, Ben R.; Lee, Eun Hee; Balakrishnan, Divya; Ekelund, Lisa; Cenac, Zarus; Kavvadia, Fragkiski; Moore, Christopher

2013-01-01

Can behavior be unconsciously primed via the activation of attitudes, stereotypes, or other concepts? A number of studies have suggested that such priming effects can occur, and a prominent illustration is the claim that individuals' accuracy in answering general knowledge questions can be influenced by activating intelligence-related concepts such as professor or soccer hooligan. In 9 experiments with 475 participants we employed the procedures used in these studies, as well as a number of variants of those procedures, in an attempt to obtain this intelligence priming effect. None of the experiments obtained the effect, although financial incentives did boost performance. A Bayesian analysis reveals considerable evidential support for the null hypothesis. The results conform to the pattern typically obtained in word priming experiments in which priming is very narrow in its generalization and unconscious (subliminal) influences, if they occur at all, are extremely short-lived. We encourage others to explore the circumstances in which this phenomenon might be obtained. PMID:23637732

The Disappearance of a Hepatic Mass in Anti-Synthetase Syndrome

Directory of Open Access Journals (Sweden)

Christopher J Mesa

2017-06-01

Full Text Available Anti-Synthetase Syndrome (ASyS is a rare chronic autoimmune disorder characterized by myositis, interstitial lung disease (ILD, polyarthralgia, “mechanic’s hands” and Raynaud’s phenomenon. Liver lesions are quite rare in ASyS. In our ASyS case, we will discuss a 58-year-old man presenting with muscle weakness, arthralgia, and interstitial lung disease (ILD. He was positive for anti-Jo-1 antibodies, substantiating the diagnosis, and was started on treatment. This was followed by the appearance of a liver mass that disappeared when the patient achieved remission.

MPQS with three large primes

NARCIS (Netherlands)

Leyland, P.; Lenstra, A.K.; Dodson, B.; Muffett, A.; Wagstaff, S.; Fieker, C.; Kohel, D.R.

2002-01-01

We report the factorization of a 135-digit integer by the triple-large-prime variation of the multiple polynomial quadratic sieve. Previous workers [6][10] had suggested that using more than two large primes would be counterproductive, because of the greatly increased number of false reports from

Mapping hisS, the structural gene for histidyl-transfer ribonucleic acid synthetase, in Escherichia coli.

Science.gov (United States)

Parker, J; Fishman, S E

1979-04-01

The structural gene for histidyl-tRNA synthetase was localized to 53.8 min on the Escherichia coli genome. The gene order in this region was determined to be dapE-purC-upp-purG-(guaA, guaB)-hisS-glyA.

Shifting evaluation windows : predictable forward primes with long SOAs eliminate the impact of backward primes.

NARCIS (Netherlands)

Fockenberg, D. A. F.; Koole, S.L.; Lakens, D.; Semin, G.R.

2013-01-01

Recent work suggests that people evaluate target stimuli within short and flexible time periods called evaluation windows. Stimuli that briefly precede a target (forward primes) or briefly succeed a target (backward primes) are often included in the target's evaluation. In this article, the authors

Wheat seed enhancement by vitamin and hormonal priming

International Nuclear Information System (INIS)

Khan, M.B.; Gurchani, M.A.; Hussain, M.

2011-01-01

Seed priming has proven beneficial in many important agricultural crops. The present study was conducted to explore the role (if any) of hormonal and vitamin seed priming to improve the germination, seedling emergence, early seedling establishment, electrolyte leakage and nutrients uptake in wheat seedlings. The wheat seeds were soaked for 48 hours in aerated solution of salicylic acid, ascorbic acid, kinetin and GA3 with 20 ppm concentration of each solution, whereas untreated seeds were taken as control. Seed priming with ascorbic acid resulted in maximum final germination and emergence percentage (FGP and FEP), radical and plumule length, root and shoot length, number of secondary roots, root shoot ratio, root dry weight, shoot dry weight and seedling dry weight compared to control (untreated seeds). Minimum mean germination and emergence time (MGT and MET) was recorded in seeds primed with kinetin and GA3. While in case of biochemical attributes, seedling potassium contents were decreased by hormonal seed priming while total soluble sugars were increased by salicylic acid and ascorbic acid seed priming. Hormonal seed priming had non-significant effect on phosphorus seedling contents. Untreated (Control) seeds showed maximum electrical conductivity at 0.5, 1, 2, 6, 12 and 24 h after inbibition than primed seeds against the minimum electrical conductivity that was recorded in seeds primed with salicylic acid and ascorbic acid. In conclusion, the wheat seeds primed with 20 ppm solution of ascorbic acid may be used for wheat seed invigoration. (author)

Mapping hisS, the structural gene for histidyl-transfer ribonucleic acid synthetase, in Escherichia coli.

Science.gov (United States)

Parker, J; Fishman, S E

1979-01-01

The structural gene for histidyl-tRNA synthetase was localized to 53.8 min on the Escherichia coli genome. The gene order in this region was determined to be dapE-purC-upp-purG-(guaA, guaB)-hisS-glyA. PMID:374370

Purification, crystallization and preliminary X-ray characterization of a human mitochondrial phenylalanyl-tRNA synthetase

International Nuclear Information System (INIS)

Levin, Inna; Kessler, Naama; Moor, Nina; Klipcan, Liron; Koc, Emine; Templeton, Paul; Spremulli, Linda; Safro, Mark

2007-01-01

The expression, purification and crystallization of recombinant human mitochondrial phenylalanyl-tRNA synthetase (mitPheRS) are reported. Diffraction data were collected to 2.2 Å resolution and the mitPheRS structure was solved using the molecular-replacement method. Human monomeric mitochondrial phenylalanyl-tRNA synthetase (mitPheRS) is an enzyme that catalyzes the charging of tRNA with the cognate amino acid phenylalanine. Human mitPheRS is a chimera of the bacterial α-subunit of PheRS and the B8 domain of its β-subunit. Together, the α-subunit and the ‘RNP-domain’ (B8 domain) at the C-terminus form the minimal structural set to construct an enzyme with phenylalanylation activity. The recombinant human mitPheRS was purified to homogeneity and crystallized in complex with phenylalanine and ATP. The crystals diffracted to 2.2 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 55, b = 90, c = 96 Å

Lexical priming in Alzheimer's disease and aphasia.

Science.gov (United States)

Arroyo-Anlló, Eva Maria; Beauchamps, Mireille; Ingrand, Pierre; Neau, Jean Philippe; Gil, Roger

2013-01-01

Lexical priming was examined in patients with Alzheimer's disease and in aphasic patients. Control participants were divided into young and elderly [cf. Arroyo-Anlló et al.: Eur J Cogn Psychol 2004;16:535-553]. For lexical priming, a word-stem completion task was used. Normal elderly participants had lexical priming scores that were significantly lower than those of young individuals. Analysis of covariance with age and educational level as covariates showed that the control participants, aphasic and Alzheimer patients did not differ significantly on the lexical priming task. Our results suggest that performance in the lexical priming task diminishes with physiological aging, but is not significantly affected by mild or moderate Alzheimer's disease or by fluent or non-fluent aphasia. Copyright © 2013 S. Karger AG, Basel.

Reaction Mechanism of Mycobacterium Tuberculosis Glutamine Synthetase Using Quantum Mechanics/Molecular Mechanics Calculations.

Science.gov (United States)

Moreira, Cátia; Ramos, Maria J; Fernandes, Pedro Alexandrino

2016-06-27

This paper is devoted to the understanding of the reaction mechanism of mycobacterium tuberculosis glutamine synthetase (mtGS) with atomic detail, using computational quantum mechanics/molecular mechanics (QM/MM) methods at the ONIOM M06-D3/6-311++G(2d,2p):ff99SB//B3LYP/6-31G(d):ff99SB level of theory. The complete reaction undergoes a three-step mechanism: the spontaneous transfer of phosphate from ATP to glutamate upon ammonium binding (ammonium quickly loses a proton to Asp54), the attack of ammonia on phosphorylated glutamate (yielding protonated glutamine), and the deprotonation of glutamine by the leaving phosphate. This exothermic reaction has an activation free energy of 21.5 kcal mol(-1) , which is consistent with that described for Escherichia coli glutamine synthetase (15-17 kcal mol(-1) ). The participating active site residues have been identified and their role and energy contributions clarified. This study provides an insightful atomic description of the biosynthetic reaction that takes place in this enzyme, opening doors for more accurate studies for developing new anti-tuberculosis therapies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Glutamine synthetase in Medicago truncatula, unveiling new secrets of a very old enzyme

Directory of Open Access Journals (Sweden)

Ana Rita Seabra

2015-07-01

Full Text Available Glutamine Synthetase (GS catalyses the first step at which nitrogen is brought into cellular metabolism and is also involved in the reassimilation of ammonium released by a number of metabolic pathways. Due to its unique position in plant nitrogen metabolism, GS plays essential roles in all aspects of plant development, from germination to senescence, and is a key component of nitrogen use efficiency (NUE and plant yield. Understanding the mechanisms regulating GS activity is therefore of utmost importance and a great effort has been dedicated to understand how GS is regulated in different plant species. The present review summarizes exciting recent developments concerning the structure and regulation of glutamine synthetase isoenzymes, using the model legume Medicago truncatula. These include the understanding of the structural determinants of both the cytosolic and plastid located isoenzymes, the existence of a seed-specific GS gene unique to M. truncatula and closely related species and the discovery that GS isoenzymes are regulated by nitric oxide at the post-translational level. The data is discussed and integrated with the potential roles of the distinct GS isoenzymes within the whole plant context.

The prime numbers and their distribution

CERN Document Server

Tenenbaum, Gerald

2000-01-01

One notable new direction this century in the study of primes has been the influx of ideas from probability. The goal of this book is to provide insights into the prime numbers and to describe how a sequence so tautly determined can incorporate such a striking amount of randomness. The book opens with some classic topics of number theory. It ends with a discussion of some of the outstanding conjectures in number theory. In between are an excellent chapter on the stochastic properties of primes and a walk through an elementary proof of the Prime Number Theorem. This book is suitable for anyone who has had a little number theory and some advanced calculus involving estimates. Its engaging style and invigorating point of view will make refreshing reading for advanced undergraduates through research mathematicians.

Semantic transparency affects morphological priming . . . eventually.

Science.gov (United States)

Heyer, Vera; Kornishova, Dana

2018-05-01

Semantic transparency has been in the focus of psycholinguistic research for decades, with the controversy about the time course of the application of morpho-semantic information during the processing of morphologically complex words not yet resolved. This study reports two masked priming studies with English - ness and Russian - ost' nominalisations, investigating how semantic transparency modulates native speakers' morphological priming effects at short and long stimulus onset asynchronies (SOAs). In both languages, we found increased morphological priming for nominalisations at the transparent end of the scale (e.g. paleness - pale) in comparison to items at the opaque end of the scale (e.g. business - busy) but only at longer prime durations. The present findings are in line with models that posit an initial phase of morpho-orthographic (semantically blind) decomposition.

Continued Funding for Prime Development

Science.gov (United States)

2012-04-18

PHP language with the help of CMF Drupal-6. The standard modules of the Drupal core set are developed by third parties and obtained from the...repository drupal.org. Part of the modules was modified specifically for the PrIMe portal. The PrIMe portal uses MySQL for the database technology. It is

Inducibility of carbamoylphosphate synthetase (ammonia) in cultures of embryonic hepatocytes: ontogenesis of the responsiveness to hormones

NARCIS (Netherlands)

Lamers, W. H.; Zonneveld, D.; Charles, R.

1984-01-01

Glucocorticosteroids and cyclic AMP induce carbamoylphosphate synthetase (ammonia) (CPS) in rat hepatocytes. Using an enzyme immunoassay applied to hepatocyte cultures fixed in situ, it has been demonstrated that the capacity of hepatocytes to synthesize CPS in the presence of both hormones is

Rapid modulation of spoken word recognition by visual primes.

Science.gov (United States)

Okano, Kana; Grainger, Jonathan; Holcomb, Phillip J

2016-02-01

In a masked cross-modal priming experiment with ERP recordings, spoken Japanese words were primed with words written in one of the two syllabary scripts of Japanese. An early priming effect, peaking at around 200ms after onset of the spoken word target, was seen in left lateral electrode sites for Katakana primes, and later effects were seen for both Hiragana and Katakana primes on the N400 ERP component. The early effect is thought to reflect the efficiency with which words in Katakana script make contact with sublexical phonological representations involved in spoken language comprehension, due to the particular way this script is used by Japanese readers. This demonstrates fast-acting influences of visual primes on the processing of auditory target words, and suggests that briefly presented visual primes can influence sublexical processing of auditory target words. The later N400 priming effects, on the other hand, most likely reflect cross-modal influences on activity at the level of whole-word phonology and semantics.

The Inhibition of Folylpolyglutamate Synthetase (folC in the Prevention of Drug Resistance in Mycobacterium tuberculosis by Traditional Chinese Medicine

Directory of Open Access Journals (Sweden)

Tzu-Chieh Hung

2014-01-01

Full Text Available Tuberculosis (TB is an infectious disease caused by many strains of mycobacteria, but commonly Mycobacterium tuberculosis. As a possible method of reducing the drug resistance of M. tuberculosis, this research investigates the inhibition of Folylpolyglutamate synthetase, a protein transcript from the resistance association gene folC. After molecular docking to screen the traditional Chinese medicine (TCM database, the candidate TCM compounds, with Folylpolyglutamate synthetase, were selected by molecular dynamics. The 10,000 ps simulation in association with RMSD analysis and total energy and structural variation defined the protein-ligand interaction. The selected TCM compounds Saussureamine C, methyl 3-O-feruloylquinate, and Labiatic acid have been found to inhibit the activity of bacteria and viruses and to regulate immunity. We also suggest the possible pathway in protein for each ligand. Compared with the control, similar interactions and structural variations indicate that these compounds might have an effect on Folylpolyglutamate synthetase. Finally, we suggest Saussureamine C is the best candidate compound as the complex has a high score, maintains its structural composition, and has a larger variation value than the control, thus inhibiting the drug resistance ability of Mycobacterium tuberculosis.

Prime implicants in dynamic reliability analysis

International Nuclear Information System (INIS)

Tyrväinen, Tero

2016-01-01

This paper develops an improved definition of a prime implicant for the needs of dynamic reliability analysis. Reliability analyses often aim to identify minimal cut sets or prime implicants, which are minimal conditions that cause an undesired top event, such as a system's failure. Dynamic reliability analysis methods take the time-dependent behaviour of a system into account. This means that the state of a component can change in the analysed time frame and prime implicants can include the failure of a component at different time points. There can also be dynamic constraints on a component's behaviour. For example, a component can be non-repairable in the given time frame. If a non-repairable component needs to be failed at a certain time point to cause the top event, we consider that the condition that it is failed at the latest possible time point is minimal, and the condition in which it fails earlier non-minimal. The traditional definition of a prime implicant does not account for this type of time-related minimality. In this paper, a new definition is introduced and illustrated using a dynamic flowgraph methodology model. - Highlights: • A new definition of a prime implicant is developed for dynamic reliability analysis. • The new definition takes time-related minimality into account. • The new definition is needed in dynamic flowgraph methodology. • Results can be represented by a smaller number of prime implicants.

48 CFR 45.501 - Prime contractor alternate locations.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Prime contractor alternate... CONTRACT MANAGEMENT GOVERNMENT PROPERTY Support Government Property Administration 45.501 Prime contractor... administration from another contract administration office, for purposes of evaluating prime contractor...

Event generators for {{\\eta }}/{{{\\eta }}}^{^{\\prime} } decays at BESIII

Science.gov (United States)

Qin, Nian; Zhang, Zhen-Yu; Fang, Shuang-Shi; Zhou, Xiang; Du, Lin-Lin; Qiao, Hao-Xue

2018-01-01

The light unflavoured meson {{η }}/{{{η }}}^{\\prime } decays are valuable for testing non-perturbative quantum chromodynamics and exploring new physics beyond the Standard Model. This paper describes a series of event generators, including {{η }}/{{{η }}}^{\\prime }\\to {{γ }}{{{l}}}+{{{l}}}-, {{η }}/{{{η }}}^{\\prime }\\to {{γ }}{{{π }}}+{{{π }}}-, {{{η }}}^{\\prime }\\to {{ω }}{{{e}}}+{{{e}}}-, {{η }}\\to {{{π }}}+{{{π }}}-{{{π }}}0, {{η }}/{{{η }}}^{\\prime }\\to {{{π }}}0{{{π }}}0{{{π }}}0, {{{η }}}^{\\prime }\\to {{η }}{{π }}{{π }} and {{{η }}}^{\\prime }\\to {{{π }}}+{{{π }}}-{{{π }}}+{{{π }}}-/{{{π }}}+{{{π }}}-{{{π }}}0{{{π }}}0, which have been developed for investigating {{η }}/{{{η }}}^{\\prime } decay dynamics. For most of these generators, their usability has been validated in BESIII analyses for determining the detection efficiency, and background studies. The consistency between data and Monte Carlo shows that these generators work well in the BESIII simulation, and will also be useful for ongoing BESIII analyses and other experiments for studying {{η }}/{{{η }}}^{\\prime } physics. Supported by National Natural Science Foundation of China (NSFC) (11205117, 11575133, 11675184), the China Scholarship Council (201506275156), the Wuhan University PhD Short-time Mobility Program 2016, the Joint Funds of the NSFC and Henan Province (U1504112)

Regulation of Angiogenesis by Aminoacyl-tRNA Synthetases

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Adam C. Mirando

2014-12-01

Full Text Available In addition to their canonical roles in translation the aminoacyl-tRNA synthetases (ARSs have developed secondary functions over the course of evolution. Many of these activities are associated with cellular survival and nutritional stress responses essential for homeostatic processes in higher eukaryotes. In particular, six ARSs and one associated factor have documented functions in angiogenesis. However, despite their connection to this process, the ARSs are mechanistically distinct and exhibit a range of positive or negative effects on aspects of endothelial cell migration, proliferation, and survival. This variability is achieved through the appearance of appended domains and interplay with inflammatory pathways not found in prokaryotic systems. Complete knowledge of the non-canonical functions of ARSs is necessary to understand the mechanisms underlying the physiological regulation of angiogenesis.

The frequency attenuation effect in identity and associative priming.

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Nievas, Francisco

2010-05-01

Three lexical decision experiments were carried out, where the masked priming paradigm is used to study the role of the frequency attenuation effect (more priming in low-frequency target words than in high-frequency target words) in repetition and associative priming, manipulating Prime Duration (PD) and Stimulus Onset Asynchrony (SOA). A new concept was introduced, Minimum Time Threshold (MTT), this is, the minimum time interval of exposure to the masked word in order to become aware of it. Results support the notion that MTT is a key to the appearance of the frequency attenuation effect when enough word processing time is allowed. Results do not support the unified explanation of masked priming and long-term priming as proposed by Bodner and Masson (2001). Moreover, information feedback from the semantic level was not the reason for the frequency attenuation effect in repetition priming.

The effects of divided attention on auditory priming.

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Mulligan, Neil W; Duke, Marquinn; Cooper, Angela W

2007-09-01

Traditional theorizing stresses the importance of attentional state during encoding for later memory, based primarily on research with explicit memory. Recent research has begun to investigate the role of attention in implicit memory but has focused almost exclusively on priming in the visual modality. The present experiments examined the effect of divided attention on auditory implicit memory, using auditory perceptual identification, word-stem completion and word-fragment completion. Participants heard study words under full attention conditions or while simultaneously carrying out a distractor task (the divided attention condition). In Experiment 1, a distractor task with low response frequency failed to disrupt later auditory priming (but diminished explicit memory as assessed with auditory recognition). In Experiment 2, a distractor task with greater response frequency disrupted priming on all three of the auditory priming tasks as well as the explicit test. These results imply that although auditory priming is less reliant on attention than explicit memory, it is still greatly affected by at least some divided-attention manipulations. These results are consistent with research using visual priming tasks and have relevance for hypotheses regarding attention and auditory priming.

Redox status affects the catalytic activity of glutamyl-tRNA synthetase

DEFF Research Database (Denmark)

Katz, Assaf; Banerjee, Rajat; de Armas, Merly

2010-01-01

Glutamyl-tRNA synthetases (GluRS) provide Glu-tRNA for different processes including protein synthesis, glutamine transamidation and tetrapyrrole biosynthesis. Many organisms contain multiple GluRSs, but whether these duplications solely broaden tRNA specificity or also play additional roles in t...... inactivation by hemin plus hydrogen peroxide. The sensitivity to oxidation of A. ferrooxidans GluRS1 might provide a means to regulate tetrapyrrole and protein biosynthesis in response to extreme changes in both the redox and heme status of the cell via a single enzyme....

Affective priming using facial expressions modulates liking for abstract art.

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Flexas, Albert; Rosselló, Jaume; Christensen, Julia F; Nadal, Marcos; Olivera La Rosa, Antonio; Munar, Enric

2013-01-01

We examined the influence of affective priming on the appreciation of abstract artworks using an evaluative priming task. Facial primes (showing happiness, disgust or no emotion) were presented under brief (Stimulus Onset Asynchrony, SOA = 20 ms) and extended (SOA = 300 ms) conditions. Differences in aesthetic liking for abstract paintings depending on the emotion expressed in the preceding primes provided a measure of the priming effect. The results showed that, for the extended SOA, artworks were liked more when preceded by happiness primes and less when preceded by disgust primes. Facial expressions of happiness, though not of disgust, exerted similar effects in the brief SOA condition. Subjective measures and a forced-choice task revealed no evidence of prime awareness in the suboptimal condition. Our results are congruent with findings showing that the affective transfer elicited by priming biases evaluative judgments, extending previous research to the domain of aesthetic appreciation.

Affective priming using facial expressions modulates liking for abstract art.

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Albert Flexas

Full Text Available We examined the influence of affective priming on the appreciation of abstract artworks using an evaluative priming task. Facial primes (showing happiness, disgust or no emotion were presented under brief (Stimulus Onset Asynchrony, SOA = 20 ms and extended (SOA = 300 ms conditions. Differences in aesthetic liking for abstract paintings depending on the emotion expressed in the preceding primes provided a measure of the priming effect. The results showed that, for the extended SOA, artworks were liked more when preceded by happiness primes and less when preceded by disgust primes. Facial expressions of happiness, though not of disgust, exerted similar effects in the brief SOA condition. Subjective measures and a forced-choice task revealed no evidence of prime awareness in the suboptimal condition. Our results are congruent with findings showing that the affective transfer elicited by priming biases evaluative judgments, extending previous research to the domain of aesthetic appreciation.

Object color affects identification and repetition priming.

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Uttl, Bob; Graf, Peter; Santacruz, Pilar

2006-10-01

We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.

Preserved semantic priming effect in alexia.

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Mimura, M; Goodglass, H; Milberg, W

1996-09-01

BH, a left-handed patient with alexia and nonfluent aphasia, was presented with a lexical-decision task in which words and pronounceable pseudowords were preceded by semantically related or unrelated picture primes (Experiment 1). In Experiment 2, BH was given an explicit reading task using the word lists from Experiment 1. Performance on Experiment 2 disclosed severe reading deficits in both oral reading and semantic matching of the words to pictures. However, in Experiment 1, BH demonstrated a significant semantic priming effect, responding more accurately and more quickly to words preceded by related primes than by unrelated primes. The present results suggest that even in a patient with severe alexia, implicit access to semantic information can be preserved in the absence of explicit identification. The possibility of categorical gradient in implicit activation (living vs. nonliving) in BH was also discussed, which, however, needs to be clarified in the further investigation.

Australia's First Prime Ministerial Library: Past and Future

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Carman-Brown, Lesley; Henderson, Kandy-Jane; Wallace, Lesley

2005-01-01

In creating Australia's first prime ministerial library, a new cultural institution was developed which blends professional practice from the fields of librarianship, education, archives, journalism and museums. The John Curtin Prime Ministerial Library honours the contribution of wartime prime minister John Curtin, works towards the advancement…

The carB gene encoding the large subunit of carbamoylphosphate synthetase from Lactococcus lactis is transcribed monocistronically

DEFF Research Database (Denmark)

Martinussen, Jan; Hammer, Karin

1998-01-01

The biosynthesis of carbamoylphosphate is catalysed by the heterodimeric enzyme carbamoylphosphate synthetase (CPSase). The genes encoding the two subunits in procaryotes are normally transcribed as an operon, whereas in Lactococcus lactis, the gene encoding the large subunit (carB) is shown...

Severe respiratory failure as a presenting feature of an interstitial lung disease associated with anti-synthetase syndrome (ASS).

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Piroddi, Ines Maria Grazia; Ferraioli, Gianluca; Barlascini, Cornelius; Castagneto, Corrado; Nicolini, Antonello

2016-07-01

Anti-synthetase syndrome (ASS) is defined as a heterogeneous connective tissue disorder characterized by the association of an interstitial lung disease (ILD) with or without inflammatory myositis with the presence of anti-aminoacyl-tRNA-synthetase antibodies. ILD is one of the major extra-muscular manifestations of polymyositis and dermatomyositis. We report a case of a patient with dyspnea, cough, and intermittent fever as well as ILD associated ASS in the absence of muscular involvement. This patient was admitted to the emergency department with severe respiratory failure requiring non-invasive ventilation. Our patient's case demonstrates that the diagnosis of ASS may not be obvious. However, its diagnosis leads to appropriate and potentially life-saving treatment. Copyright © 2016 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity.

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Chadha, Sanya; Mallampudi, N Arjunreddy; Mohapatra, Debendra K; Madhubala, Rentala

2017-01-01

Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L. donovani lysyl-tRNA synthetase ( Ld LysRS). Two different coding sequences for lysyl-tRNA synthetases are annotated in the Leishmania genome database. Ld LysRS-1 (LdBPK_150270.1), located on chromosome 15, is closer to apicomplexans and eukaryotes, whereas Ld LysRS-2 (LdBPK_300130.1), present on chromosome 30, is closer to bacteria. In the present study, we have characterized Ld LysRS-1. Recombinant Ld LysRS-1 displayed aminoacylation activity, and the protein localized to the cytosol. The Ld LysRS-1 heterozygous mutants had a restrictive growth phenotype and attenuated infectivity. Ld LysRS-1 appears to be an essential gene, as a chromosomal knockout of Ld LysRS-1 could be generated when the gene was provided on a rescuing plasmid. Cladosporin, a fungal secondary metabolite and a known inhibitor of LysRS, was more potent against promastigotes (50% inhibitory concentration [IC 50 ], 4.19 µM) and intracellular amastigotes (IC 50 , 1.09 µM) than were isomers of cladosporin (3-epi-isocladosporin and isocladosporin). These compounds exhibited low toxicity to mammalian cells. The specificity of inhibition of parasite growth caused by these inhibitors was further assessed using Ld LysRS-1 heterozygous mutant strains and rescue mutant promastigotes. These inhibitors inhibited the aminoacylation activity of recombinant Ld LysRS. Our data provide a framework for the development of a new class of drugs against this parasite. IMPORTANCE Aminoacyl-tRNA synthetases are housekeeping enzymes essential for protein translation, providing charged tRNAs for

Cloning, expression, purification, crystallization and preliminary X-ray analysis of Thermus aquaticus succinyl-CoA synthetase

International Nuclear Information System (INIS)

Joyce, Michael A.; Brownie, Edward R.; Hayakawa, Koto; Fraser, Marie E.

2007-01-01

Attempts to crystallize succinyl-CoA synthetase from the thermophile T. aquaticus were thwarted by proteolysis of the β-subunit and preferential crystallization of a truncated form. Crystals of the full-length enzyme were grown after the purification protocol was modified to include frequent additions of protease inhibitors. Succinyl-CoA synthetase (SCS) is an enzyme of the citric acid cycle and is thus found in most species. To date, there are no structures available of SCS from a thermophilic organism. To investigate how the enzyme adapts to higher temperatures, SCS from Thermus aquaticus was cloned, overexpressed, purified and crystallized. Attempts to crystallize the enzyme were thwarted by proteolysis of the β-subunit and preferential crystallization of the truncated form. Crystals of full-length SCS were grown after the purification protocol was modified to include frequent additions of protease inhibitors. The resulting crystals, which diffract to 2.35 Å resolution, are of the protein in complex with Mn 2+ -GDP

Effects of aeration on formation and localization of the acetyl coenzyme A synthetases of Saccharomyces cerevisiae

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Klein, H. P.; Jahnke, L.

1979-01-01

Previous studies on the yeast Saccharomyces cerevisiae have shown that two different forms of the enzyme acetyl coenzyme A synthetase (ACS) are present, depending on the conditions under which the cells are grown. The paper evaluates the usefulness of a method designed to assay both synthetases simultaneously in yeast homogenates. The data presented confirm the possibility of simultaneous detection and estimation of the amount of both ACSs of S. cerevisiae in crude homogenates of this strain, making possible the study of physiological factors involved in the formation of these isoenzymes. One important factor for specifying which of the two enzymes is found in these yeast cells is the presence or absence of oxygen in their environment. Aeration not only affects the ratio of the two ACSs but also appears to affect the cellular distribution of these enzymes. Most of the data presented suggest the possibility that the nonaerobic ACS may serve as a precursor to the aerobic form.

A computational approach to negative priming

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Schrobsdorff, H.; Ihrke, M.; Kabisch, B.; Behrendt, J.; Hasselhorn, M.; Herrmann, J. Michael

2007-09-01

Priming is characterized by a sensitivity of reaction times to the sequence of stimuli in psychophysical experiments. The reduction of the reaction time observed in positive priming is well-known and experimentally understood (Scarborough et al., J. Exp. Psycholol: Hum. Percept. Perform., 3, pp. 1-17, 1977). Negative priming—the opposite effect—is experimentally less tangible (Fox, Psychonom. Bull. Rev., 2, pp. 145-173, 1995). The dependence on subtle parameter changes (such as response-stimulus interval) usually varies. The sensitivity of the negative priming effect bears great potential for applications in research in fields such as memory, selective attention, and ageing effects. We develop and analyse a computational realization, CISAM, of a recent psychological model for action decision making, the ISAM (Kabisch, PhD thesis, Friedrich-Schiller-Universitat, 2003), which is sensitive to priming conditions. With the dynamical systems approach of the CISAM, we show that a single adaptive threshold mechanism is sufficient to explain both positive and negative priming effects. This is achieved by comparing results obtained by the computational modelling with experimental data from our laboratory. The implementation provides a rich base from which testable predictions can be derived, e.g. with respect to hitherto untested stimulus combinations (e.g. single-object trials).

The effect of unimodal affective priming on dichotic emotion recognition.

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Voyer, Daniel; Myles, Daniel

2017-11-15

The present report concerns two experiments extending to unimodal priming the cross-modal priming effects observed with auditory emotions by Harding and Voyer [(2016). Laterality effects in cross-modal affective priming. Laterality: Asymmetries of Body, Brain and Cognition, 21, 585-605]. Experiment 1 used binaural targets to establish the presence of the priming effect and Experiment 2 used dichotically presented targets to examine auditory asymmetries. In Experiment 1, 82 university students completed a task in which binaural targets consisting of one of 4 English words inflected in one of 4 emotional tones were preceded by binaural primes consisting of one of 4 Mandarin words pronounced in the same (congruent) or different (incongruent) emotional tones. Trials where the prime emotion was congruent with the target emotion showed faster responses and higher accuracy in identifying the target emotion. In Experiment 2, 60 undergraduate students participated and the target was presented dichotically instead of binaurally. Primes congruent with the left ear produced a large left ear advantage, whereas right congruent primes produced a right ear advantage. These results indicate that unimodal priming produces stronger effects than those observed under cross-modal priming. The findings suggest that priming should likely be considered a strong top-down influence on laterality effects.

Essential nontranslational functions of tRNA synthetases.

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Guo, Min; Schimmel, Paul

2013-03-01

Nontranslational functions of vertebrate aminoacyl tRNA synthetases (aaRSs), which catalyze the production of aminoacyl-tRNAs for protein synthesis, have recently been discovered. Although these new functions were thought to be 'moonlighting activities', many are as critical for cellular homeostasis as their activity in translation. New roles have been associated with their cytoplasmic forms as well as with nuclear and secreted extracellular forms that affect pathways for cardiovascular development and the immune response and mTOR, IFN-γ and p53 signaling. The associations of aaRSs with autoimmune disorders, cancers and neurological disorders further highlight nontranslational functions of these proteins. New architecture elaborations of the aaRSs accompany their functional expansion in higher organisms and have been associated with the nontranslational functions for several aaRSs. Although a general understanding of how these functions developed is limited, the expropriation of aaRSs for essential nontranslational functions may have been initiated by co-opting the amino acid-binding site for another purpose.

The expression of selected non-ribosomal peptide synthetases in Aspergillus fumigatus is controlled by the availability of free iron.

Science.gov (United States)

Reiber, Kathrin; Reeves, Emer P; Neville, Claire M; Winkler, Robert; Gebhardt, Peter; Kavanagh, Kevin; Doyle, Sean

2005-07-01

Three non-ribosomal peptide synthetase genes, termed sidD, sidC and sidE, have been identified in Aspergillus fumigatus. Gene expression analysis by RT-PCR confirms that expression of both sidD and C was reduced by up to 90% under iron-replete conditions indicative of a likely role in siderophore biosynthesis. SidE expression was less sensitive to iron levels. In addition, two proteins purified from mycelia grown under iron-limiting conditions corresponded to SidD ( approximately 200 kDa) and SidC (496 kDa) as determined by MALDI ToF peptide mass fingerprinting and MALDI LIFT-ToF/ToF. Siderophore synthetases are unique in bacteria and fungi and represent an attractive target for antimicrobial chemotherapy.

Impact of the Disruption of ASN3-Encoding Asparagine Synthetase on Arabidopsis Development

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Laure Gaufichon

2016-02-01

Full Text Available The aim of this study was to investigate the role of ASN3-encoded asparagine synthetase (AS, EC 6.3.5.4 during vegetative growth, seed development and germination of Arabidopsis thaliana. Phenotypic analysis of knockout (asn3-1 and knockdown (asn3-2 T-DNA insertion mutants for the ASN3 gene (At5g10240 demonstrated wild-type contents of asparagine synthetase protein, chlorophyll and ammonium in green leaves at 35 days after sowing. In situ hybridization localized ASN3 mRNA to phloem companion cells of vasculature. Young siliques of the asn3-1 knockout line showed a decrease in asparagine but an increase in glutamate. The seeds of asn3-1 and asn3-2 displayed a wild-type nitrogen status expressed as total nitrogen content, indicating that the repression of ASN3 expression had only a limited effect on mature seeds. An analysis of amino acid labeling of seeds imbibed with (15N ammonium for 24 h revealed that asn3-1 seeds contained 20% less total asparagine while 15N-labeled asparagine ((2-15Nasparagine, (4-15Nasparagine and (2,4-15Nasparagine increased by 12% compared to wild-type seeds. The data indicate a fine regulation of asparagine synthesis and hydrolysis in Arabidopsis seeds.

Stress priming in picture naming: an SOA study.

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Schiller, Niels O; Fikkert, Paula; Levelt, Clara C

2004-01-01

This study investigates whether or not the representation of lexical stress information can be primed during speech production. In four experiments, we attempted to prime the stress position of bisyllabic target nouns (picture names) having initial and final stress with auditory prime words having either the same or different stress as the target (e.g., WORtel-MOtor vs. koSTUUM-MOtor; capital letters indicate stressed syllables in prime-target pairs). Furthermore, half of the prime words were semantically related, the other half unrelated. Overall, picture names were not produced faster when the prime word had the same stress as the target than when the prime had different stress, i.e., there was no stress-priming effect in any experiment. This result would not be expected if stress were stored in the lexicon. However, targets with initial stress were responded to faster than final-stress targets. The reason for this effect was neither the quality of the pictures nor frequency of occurrence or voice-key characteristics. We hypothesize here that this stress effect is a genuine encoding effect, i.e., words with stress on the second syllable take longer to be encoded because their stress pattern is irregular with respect to the lexical distribution of bisyllabic stress patterns, even though it can be regular with respect to metrical stress rules in Dutch. The results of the experiments are discussed in the framework of models of phonological encoding.

Purification, crystallization and preliminary X-ray characterization of a human mitochondrial phenylalanyl-tRNA synthetase

Energy Technology Data Exchange (ETDEWEB)

Levin, Inna; Kessler, Naama [Department of Structural Biology, Weizmann Institute of Science, 76100 Rehovot (Israel); Moor, Nina [Institute of Chemical Biology and Fundamental Medicine, 630090 Novosibirsk (Russian Federation); Klipcan, Liron [Department of Structural Biology, Weizmann Institute of Science, 76100 Rehovot (Israel); Koc, Emine [Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802 (United States); Templeton, Paul [Department Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215 (United States); Spremulli, Linda [Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290 (United States); Safro, Mark, E-mail: mark.safro@weizmann.ac.il [Department of Structural Biology, Weizmann Institute of Science, 76100 Rehovot (Israel)

2007-09-01

The expression, purification and crystallization of recombinant human mitochondrial phenylalanyl-tRNA synthetase (mitPheRS) are reported. Diffraction data were collected to 2.2 Å resolution and the mitPheRS structure was solved using the molecular-replacement method. Human monomeric mitochondrial phenylalanyl-tRNA synthetase (mitPheRS) is an enzyme that catalyzes the charging of tRNA with the cognate amino acid phenylalanine. Human mitPheRS is a chimera of the bacterial α-subunit of PheRS and the B8 domain of its β-subunit. Together, the α-subunit and the ‘RNP-domain’ (B8 domain) at the C-terminus form the minimal structural set to construct an enzyme with phenylalanylation activity. The recombinant human mitPheRS was purified to homogeneity and crystallized in complex with phenylalanine and ATP. The crystals diffracted to 2.2 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 55, b = 90, c = 96 Å.

Structural analysis of malaria-parasite lysyl-tRNA synthetase provides a platform for drug development.

Science.gov (United States)

Khan, Sameena; Garg, Ankur; Camacho, Noelia; Van Rooyen, Jason; Kumar Pole, Anil; Belrhali, Hassan; Ribas de Pouplana, Lluis; Sharma, Vinay; Sharma, Amit

2013-05-01

Aminoacyl-tRNA synthetases are essential enzymes that transmit information from the genetic code to proteins in cells and are targets for antipathogen drug development. Elucidation of the crystal structure of cytoplasmic lysyl-tRNA synthetase from the malaria parasite Plasmodium falciparum (PfLysRS) has allowed direct comparison with human LysRS. The authors' data suggest that PfLysRS is dimeric in solution, whereas the human counterpart can also adopt tetrameric forms. It is shown for the first time that PfLysRS is capable of synthesizing the signalling molecule Ap4a (diadenosine tetraphosphate) using ATP as a substrate. The PfLysRS crystal structure is in the apo form, such that binding to ATP will require rotameric changes in four conserved residues. Differences in the active-site regions of parasite and human LysRSs suggest the possibility of exploiting PfLysRS for selective inhibition. These investigations on PfLysRS further validate malarial LysRSs as attractive antimalarial targets and provide new structural space for the development of inhibitors that target pathogen LysRSs selectively.

Specific and non-specific match effects in negative priming.

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Labossière, Danielle I; Leboe-McGowan, Jason P

2018-01-01

The negative priming effect occurs when withholding a response to a stimulus impairs generation of subsequent responding to a same or a related stimulus. Our goal was to use the negative priming procedure to obtain insights about the memory representations generated by ignoring vs. attending/responding to a prime stimulus. Across three experiments we observed that ignoring a prime stimulus tends to generate higher identity-independent, non-specific repetition effects, owing to an overlap in the coarse perceptual form of a prime distractor and a probe target. By contrast, attended repetition effects generate predominantly identity-specific sources of facilitation. We use these findings to advocate for using laboratory phenomena to illustrate general principles that can be of practical use to non-specialists. In the case of the negative priming procedure, we propose that the procedure provides a useful means for investigating attention/memory interactions, even if the specific cause (or causes) of negative priming effects remain unresolved. Copyright © 2017 Elsevier B.V. All rights reserved.

The impact of auditory white noise on semantic priming.

Science.gov (United States)

Angwin, Anthony J; Wilson, Wayne J; Copland, David A; Barry, Robert J; Myatt, Grace; Arnott, Wendy L

2018-04-10

It has been proposed that white noise can improve cognitive performance for some individuals, particularly those with lower attention, and that this effect may be mediated by dopaminergic circuitry. Given existing evidence that semantic priming is modulated by dopamine, this study investigated whether white noise can facilitate semantic priming. Seventy-eight adults completed an auditory semantic priming task with and without white noise, at either a short or long inter-stimulus interval (ISI). Measures of both direct and indirect semantic priming were examined. Analysis of the results revealed significant direct and indirect priming effects at each ISI in noise and silence, however noise significantly reduced the magnitude of indirect priming. Analyses of subgroups with higher versus lower attention revealed a reduction to indirect priming in noise relative to silence for participants with lower executive and orienting attention. These findings suggest that white noise focuses automatic spreading activation, which may be driven by modulation of dopaminergic circuitry. Copyright © 2018 Elsevier Inc. All rights reserved.

Anti-synthetase syndrome associated with anti PL-12 and anti-Signal recognition particle antibodies and a necrotizing auto-immune myositis.

Science.gov (United States)

Malkan, Ashish; Cappelen-Smith, Cecilia; Beran, Roy; Griffith, Neil; Toong, Catherine; Wang, Min-Xia; Cordato, Dennis

2015-02-01

We report a 37-year-old woman with a 2 month history of proximal muscle weakness and extremely high creatine kinase (21,808 U/L) due to necrotizing auto-immune myositis (NAM) in association with anti-synthetase syndrome. Myositis-specific auto-immune antibody panel was positive for anti-Signal recognition particle and anti-PL-12. CT scan of the chest confirmed interstitial lung disease. Prednisolone, intravenous immunoglobulin and cyclophosphamide therapy was given with gradual improvement. This patient is notable for the unusual combination of NAM and anti-synthetase syndrome with the rare finding of two myositis-specific autoantibodies, which directed testing for associated extramuscular features and management with more aggressive immunotherapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bounded Gaps between Products of Special Primes

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Ping Ngai Chung

2014-03-01

Full Text Available In their breakthrough paper in 2006, Goldston, Graham, Pintz and Yıldırım proved several results about bounded gaps between products of two distinct primes. Frank Thorne expanded on this result, proving bounded gaps in the set of square-free numbers with r prime factors for any r ≥ 2, all of which are in a given set of primes. His results yield applications to the divisibility of class numbers and the triviality of ranks of elliptic curves. In this paper, we relax the condition on the number of prime factors and prove an analogous result using a modified approach. We then revisit Thorne’s applications and give a better bound in each case.

Negative Priming in Free Recall Reconsidered

Science.gov (United States)

Hanczakowski, Maciej; Beaman, C. Philip; Jones, Dylan M.

2016-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and…

The growing pipeline of natural aminoacyl-tRNA synthetase inhibitors for malaria treatment

OpenAIRE

Saint-L?ger, Ad?la?de; Sinadinos, Christopher; Ribas de Pouplana, Llu?s

2016-01-01

Malaria remains a major global health problem. Parasite resistance to existing drugs makes development of new antimalarials an urgency. The protein synthesis machinery is an excellent target for the development of new anti-infectives, and aminoacyl-tRNA synthetases (aaRS) have been validated as antimalarial drug targets. However, avoiding the emergence of drug resistance and improving selectivity to target aaRS in apicomplexan parasites, such as Plasmodium falciparum, remain crucial challenge...

Novel Word Lexicalization and the Prime Lexicality Effect

Science.gov (United States)

Qiao, Xiaomei; Forster, Kenneth I.

2013-01-01

This study investigates how newly learned words are integrated into the first-language lexicon using masked priming. Two lexical decision experiments are reported, with the aim of establishing whether newly learned words behave like real words in a masked form priming experiment. If they do, they should show a prime lexicality effect (PLE), in…

Identity negative priming: a phenomenon of perception, recognition or selection?

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Hecke Schrobsdorff

Full Text Available The present study addresses the problem whether negative priming (NP is due to information processing in perception, recognition or selection. We argue that most NP studies confound priming and perceptual similarity of prime-probe episodes and implement a color-switch paradigm in order to resolve the issue. In a series of three identity negative priming experiments with verbal naming response, we determined when NP and positive priming (PP occur during a trial. The first experiment assessed the impact of target color on priming effects. It consisted of two blocks, each with a different fixed target color. With respect to target color no differential priming effects were found. In Experiment 2 the target color was indicated by a cue for each trial. Here we resolved the confounding of perceptual similarity and priming condition. In trials with coinciding colors for prime and probe, we found priming effects similar to Experiment 1. However, trials with a target color switch showed such effects only in trials with role-reversal (distractor-to-target or target-to-distractor, whereas the positive priming (PP effect in the target-repetition trials disappeared. Finally, Experiment 3 split trial processing into two phases by presenting the trial-wise color cue only after the stimulus objects had been recognized. We found recognition in every priming condition to be faster than in control trials. We were hence led to the conclusion that PP is strongly affected by perception, in contrast to NP which emerges during selection, i.e., the two effects cannot be explained by a single mechanism.

Can False Memories Prime Problem Solutions?

Science.gov (United States)

Howe, Mark L.; Garner, Sarah R.; Dewhurst, Stephen A.; Ball, Linden J.

2010-01-01

Previous research has suggested that false memories can prime performance on related implicit and explicit memory tasks. The present research examined whether false memories can also be used to prime higher order cognitive processes, namely, insight-based problem solving. Participants were asked to solve a number of compound remote associate task…

Affective Priming in Major Depressive Disorder

Directory of Open Access Journals (Sweden)

Joelle eLeMoult

2012-10-01

Full Text Available Research on cognitive biases in depression has provided considerable evidence for the impact of emotion on cognition. Individuals with depression tend to preferentially process mood-congruent material and to show deficits in the processing of positive material leading to biases in attention, memory, and judgments. More research is needed, however, to fully understand which cognitive processes are affected. The current study further examines the impact of emotion on cognition using a priming design with facial expressions of emotion. Specifically, this study tested whether the presentation of facial expressions of emotion affects subsequent processing of affective material in participants with major depressive disorder (MDD and healthy controls (CTL. Facial expressions displaying happy, sad, angry, disgusted, or neutral expressions were presented as primes for 500ms, and participants’ speed to identify a subsequent target’s emotional expression was assessed. All participants displayed greater interference from emotional versus neutral primes, marked by slower response times to judge the emotion of the target face when it was preceded by an emotional prime. Importantly, the CTL group showed the strongest interference when happy emotional expressions served as primes whereas the MDD group failed to show this bias. These results add to a growing literature that shows that depression is associated with difficulties in the processing of positive material.

Instant PrimeFaces starter

CERN Document Server

Hlavats, Ian

2013-01-01

Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. Instant Primefaces Starter is a fast-paced, introductory guide designed to give you all the information you need to start using Primfaces, instantly.Instant PrimeFaces Starter is great for developers looking to get started quickly with PrimeFaces. It's assumed that you have some JSF experience already, as well as familiarity with other Java technologies such as CDI and JPA and an understanding of MVC principles, object-relational mapping (ORM),

Facial expression primes and implicit regulation of negative emotion.

Science.gov (United States)

Yoon, HeungSik; Kim, Shin Ah; Kim, Sang Hee

2015-06-17

An individual's responses to emotional information are influenced not only by the emotional quality of the information, but also by the context in which the information is presented. We hypothesized that facial expressions of happiness and anger would serve as primes to modulate subjective and neural responses to subsequently presented negative information. To test this hypothesis, we conducted a functional MRI study in which the brains of healthy adults were scanned while they performed an emotion-rating task. During the task, participants viewed a series of negative and neutral photos, one at a time; each photo was presented after a picture showing a face expressing a happy, angry, or neutral emotion. Brain imaging results showed that compared with neutral primes, happy facial primes increased activation during negative emotion in the dorsal anterior cingulated cortex and the right ventrolateral prefrontal cortex, which are typically implicated in conflict detection and implicit emotion control, respectively. Conversely, relative to neutral primes, angry primes activated the right middle temporal gyrus and the left supramarginal gyrus during the experience of negative emotion. Activity in the amygdala in response to negative emotion was marginally reduced after exposure to happy primes compared with angry primes. Relative to neutral primes, angry facial primes increased the subjectively experienced intensity of negative emotion. The current study results suggest that prior exposure to facial expressions of emotions modulates the subsequent experience of negative emotion by implicitly activating the emotion-regulation system.

Masked priming for the comparative evaluation of camouflage conspicuity.

Science.gov (United States)

Brunyé, Tad T; Eddy, Marianna D; Cain, Matthew S; Hepfinger, Lisa B; Rock, Kathryn

2017-07-01

Human observer test and evaluation of camouflage patterns is critical for understanding relative pattern conspicuity against a range of background scenes. However, very few validated methodologies exist for this purpose, and those that do carry several limitations. Five experiments examined whether masked priming with a dot probe could be used to reliably differentiate camouflage patterns. In each experiment, participants were primed with a camouflaged target appearing on the left or right of the screen, and then made a speeded response to a dot probe appearing on the same (congruent) or different (incongruent) side. Across experiments we parametrically varied prime duration between 35, 42, 49, 56, and 63 ms. Results demonstrated that as prime duration increased, a response time disadvantage for incongruent trials emerged with certain camouflage patterns. Interestingly, the most conspicuous patterns showed behavioral differences at a relatively brief (49 ms) prime duration, whereas behavioral differences were only found at longer prime durations for less conspicuous patterns; this overall results pattern matched that predicted by a visual salience model. Together, we demonstrate the viability of masked priming for the test and evaluation of camouflage patterns, and correlated outcomes for saliency models and primed object processing. Published by Elsevier Ltd.

Long-term repetition priming with symmetrical polygons and words.

Science.gov (United States)

Kersteen-Tucker, Z

1991-01-01

In two different tasks, subjects were asked to make lexical decisions (word or nonword) and symmetry judgments (symmetrical or nonsymmetrical) about two-dimensional polygons. In both tasks, every stimulus was repeated at one of four lags (0, 1, 4, or 8 items interposed between the first and second stimulus presentations). This paradigm, known as repetition priming, revealed comparable short-term priming (Lag 0) and long-term priming (Lags 1, 4, and 8) both for symmetrical polygons and for words. A shorter term component (Lags 0 and 1) of priming was observed for nonwords, and only very short-term priming (Lag 0) was observed for nonsymmetrical polygons. These results indicate that response facilitation accruing from repeated exposure can be observed for stimuli that have no preexisting memory representations and suggest that perceptual factors contribute to repetition-priming effects.

Efficient procedure for transferring specific human genes into Chinese hamster cell mutants: interspecific transfer of the human genes encoding leucyl- and asparaginyl-tRNA synthetases

International Nuclear Information System (INIS)

Cirullo, R.E.; Dana, S.; Wasmuth, J.J.

1983-01-01

A simple and efficient procedure for transferring specific human genes into mutant Chinese hamster ovary cell recipients has been developed that does not rely on using calcium phosphate-precipitated high-molecular-weight DNA. Interspecific cell hybrids between human leukocytes and temperature-sensitive Chinese hamster cell mutants with either a thermolabile leucyl-tRNA synthetase or a thermolabile asparaginyl-tRNA synthetase were used as the starting material in these experiments. These hybrids contain only one or a few human chromosomes and require expression of the appropriate human aminoacyl-tRNA synthetase gene to grow at 39 degrees C. Hybrids were exposed to very high doses of gamma-irradiation to extensively fragment the chromosomes and re-fused immediately to the original temperature-sensitive Chinese hamster mutant, and secondary hybrids were isolated at 39 degrees C. Secondary hybrids, which had retained small fragments of the human genome containing the selected gene, were subjected to another round of irradiation, refusion, and selection at 39 degrees C to reduce the amount of human DNA even further. Using this procedure, Chinese hamster cell lines have been constructed that express the human genes encoding either asparaginyl- or leucyl-tRNA synthetase, yet less than 0.1% of their DNA is derived from the human genome, as quantitated by a sensitive dot-blot nucleic acid hybridization procedure

Semantic Priming for Coordinate Distant Concepts in Alzheimer's Disease Patients

Science.gov (United States)

Perri, R.; Zannino, G. D.; Caltagirone, C.; Carlesimo, G. A.

2011-01-01

Semantic priming paradigms have been used to investigate semantic knowledge in patients with Alzheimer's disease (AD). While priming effects produced by prime-target pairs with associative relatedness reflect processes at both lexical and semantic levels, priming effects produced by words that are semantically related but not associated should…

Syntactic Priming.

Science.gov (United States)

Nicol, Janet L.

1996-01-01

Reviews the syntactic priming task, a paradigm involving the presentation of a phrasal or clausal context, followed by the presentation of a target item for lexical decision or naming. Notes that response times are faster for targets syntactically congruent with the preceding context than for incongruent targets. Outlines how to administer this…

A prime a day keeps calories away: The effects of supraliminal priming on food consumption and the moderating role of gender and eating restraint.

Science.gov (United States)

Minas, Randall K; Poor, Morgan; Dennis, Alan R; Bartelt, Valerie L

2016-10-01

The link between intentions and action in weight control is weaker than previously thought, so recent research has called for further investigation of ways to improve weight control that bypass conscious intentions. Priming has been shown to have effects on individual behavior in a variety of contexts by influencing subconscious cognition. This paper investigates the effects of semantic priming using healthy body image, goal-oriented words on food consumption. The moderating role of both restrained eating and gender is investigated. 161 participants were involved in an experiment using a novel version of a scrambled sentence priming game. The outcome measure was the number of kilocalories consumed, examined using a between subjects ANCOVA with priming, gender, restrained eating index, self-reported BMI, and two interaction terms (primingxgender, and primingxrestrained eating index). There was no main effect of priming but there was an interaction of priming with gender. Females consumed significantly fewer kilocalories after being exposed to priming words related to a healthy body image (i.e. "slim", "fit,") compared to females receiving the neutral prime, with a medium effect size (d = 0.58). The body image prime did not significantly affect food intake for males, nor did it have a differential effect on restrained eaters. This study shows that priming can be an effective method for influencing females to reduce food intake, regardless of whether they are restrained or unrestrained eaters. Future studies could investigate whether different priming words related to a male's healthy body image goal (i.e. "buff," "muscles," etc.) would similarly reduce food intake for males. Copyright © 2016. Published by Elsevier Ltd.

Euclidean Primes Have the Minimum Number of Primitive Roots

Czech Academy of Sciences Publication Activity Database

Křížek, Michal; Somer, L.

2008-01-01

Roč. 12, č. 1 (2008), s. 121-127 ISSN 0972-5555 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : Euclidean primes * Fermat primes * Sophie Germain primes Subject RIV: BA - General Mathematics

Italy's Prime Minister visits CERN

CERN Multimedia

Stefania Pandolfi

2015-01-01

On Tuesday, 7 July 2015, the Prime Minister of the Italian Republic, Matteo Renzi, visited CERN. He was accompanied by a delegation that included Italy's Minister for Education, University and Research, Stefania Giannini.   From left to right: Fernando Ferroni, President of the Istituto Nazionale di Fisica Nucleare (INFN); Sergio Bertolucci, CERN Director for Research and Scientific Computing; Stefania Giannini, Italy's Minister of Education, University and Research; Matteo Renzi, Prime Minister of the Italian Republic; Fabiola Gianotti, CERN Director-General Designate; Rolf Heuer, CERN Director-General.   The Prime Minister was welcomed by members of the CERN Management together with former CERN Director-General and Senator for Life of the Italian Republic, Carlo Rubbia. After a brief general introduction to CERN’s activities by Rolf Heuer, the Italian delegation visited LHC Point 1. After a tour of the ATLAS control room, they donned helmets to visit th...

Overexpression, purification and crystallization of tyrosyl-tRNA synthetase from the hyperthermophilic archaeon Aeropyrum pernix K1

International Nuclear Information System (INIS)

Iwaki, Jun; Suzuki, Ryuichiro; Fujimoto, Zui; Momma, Mitsuru; Kuno, Atsushi; Hasegawa, Tsunemi

2005-01-01

Tyrosyl-tRNA synthetase from the hyperthermophilic archaeon A. pernix K1 was cloned, purified and crystallized. The crystals belonged to the tetragonal space group P4 3 2 1 2, with unit-cell parameters a = b = 66.1, c = 196.2 Å, and diffracted to beyond 2.15 Å resolution at 100 K. Hyperthermophilic archaeal tyrosyl-tRNA synthetase from Aeropyrum pernix K1 was cloned and overexpressed in Escherichia coli. The expressed protein was purified by Cibacron Blue affinity chromatography following heat treatment at 363 K. Crystals suitable for X-ray diffraction studies were obtained under optimized crystallization conditions in the presence of 1.5 M ammonium sulfate using the hanging-drop vapour-diffusion method. The crystals belonged to the tetragonal space group P4 3 2 1 2, with unit-cell parameters a = b = 66.1, c = 196.2 Å, and diffracted to beyond 2.15 Å resolution at 100 K

Prime alternative algebras that are nearly commutative

International Nuclear Information System (INIS)

Pchelintsev, S V

2004-01-01

We prove that by deforming the multiplication in a prime commutative alternative algebra using a C-operation we obtain a prime non-commutative alternative algebra. Under certain restrictions on non-commutative algebras this relation between algebras is reversible. Isotopes are special cases of deformations. We introduce and study a linear space generated by the Bruck C-operations. We prove that the Bruck space is generated by operations of rank 1 and 2 and that 'general' Bruck operations of rank 2 are independent in the following sense: a sum of n operations of rank 2 cannot be written as a linear combination of (n-1) operations of rank 2 and an arbitrary operation of rank 1. We describe infinite series of non-isomorphic prime non-commutative algebras of bounded degree that are deformations of a concrete prime commutative algebra

Syntactic Variance and Priming Effects in Translation

DEFF Research Database (Denmark)

Bangalore, Srinivas; Behrens, Bergljot; Carl, Michael

2016-01-01

The present work investigates the relationship between syntactic variation and priming in translation. It is based on the claim that languages share a common cognitive network of neural activity. When the source and target languages are solicited in a translation context, this shared network can...... lead to facilitation effects, so-called priming effects. We suggest that priming is a default setting in translation, a special case of language use where source and target languages are constantly co-activated. Such priming effects are not restricted to lexical elements, but do also occur...... on the syntactic level. We tested these hypotheses with translation data from the TPR database, more specifically for three language pairs (English-German, English-Danish, and English-Spanish). Our results show that response times are shorter when syntactic structures are shared. The model explains this through...

Glutamine Synthetase: Localization Dictates Outcome

Directory of Open Access Journals (Sweden)

Alessandra Castegna

2018-02-01

Full Text Available Glutamine synthetase (GS is the adenosine triphosphate (ATP-dependent enzyme that catalyses the synthesis of glutamine by condensing ammonium to glutamate. In the circulatory system, glutamine carries ammonia from muscle and brain to the kidney and liver. In brain reduction of GS activity has been suggested as a mechanism mediating neurotoxicity in neurodegenerative disorders. In cancer, the delicate balance between glutamine synthesis and catabolism is a critical event. In vitro evidence, confirmed in vivo in some cases, suggests that reduced GS activity in cancer cells associates with a more invasive and aggressive phenotype. However, GS is known to be highly expressed in cells of the tumor microenvironment, such as fibroblasts, adipocytes and immune cells, and their ability to synthesize glutamine is responsible for the acquisition of protumoral phenotypes. This has opened a new window into the complex scenario of the tumor microenvironment, in which the balance of glutamine consumption versus glutamine synthesis influences cellular function. Since GS expression responds to glutamine starvation, a lower glutamine synthesizing power due to the absence of GS in cancer cells might apply a metabolic pressure on stromal cells. This event might push stroma towards a GS-high/protumoral phenotype. When referred to stromal cells, GS expression might acquire a ‘bad’ significance to the point that GS inhibition might be considered a conceivable strategy against cancer metastasis.

The Nature of Affective Priming in Music and Speech

NARCIS (Netherlands)

Goerlich, K.S.; Witteman, J.; Schiller, N.O.; Van Heuven, V.J.; Aleman, A.; Martens, S.

The phenomenon of affective priming has caught scientific interest for over 30 years, yet the nature of the affective priming effect remains elusive. This study investigated the underlying mechanism of cross-modal affective priming and the influence of affective incongruence in music and speech on

Recognition of Escherichia coli valine transfer RNA by its cognate synthetase: A fluorine-19 NMR study

International Nuclear Information System (INIS)

Chu, Wenchy; Horowitz, J.

1991-01-01

Interactions of 5-fluorouracil-substituted Escherichia coli tRNA Val with its cognate synthetase have been investigated by fluorine-19 nuclear magnetic resonance. Valyl-tRNA synthetase (VRS) (EC 6.1.1.9), purified to homogeneity from an overproducing strain of E. coli, differs somewhat from VRS previously isolated from E. coli K12. Its amino acid composition and N-terminal sequence agree well with results derived from the sequence of the VRS gene. Apparent K M and V max values of the purified VRS are the same for both normal and 5-fluorouracil (FUra)-substituted tRNA Val . Binding of VRS to (FUra)tRNA Val induces structural perturbations that are reflected in selective changes in the 19 F NMR spectrum of the tRNA. Addition of increasing amounts of VRS results in a gradual loss of intensity at resonances corresponding to FU34, FU7, and FU67, with FU34, at the wobble position of the anticodon, being affected most. At higher VRS/tRNA ratios, a broadening and shifting of FU12 and of FU4 and/or FU8 occur. These results indicate that VRS interacts with tRNA Val along the entire inside of the L-shape molecule, from the acceptor stem to the anticodon. Valyl-tRNA synthetase also causes a splitting of resonances FU55 and FU64 in the T-loop and stem of tRNA Val , suggesting conformational changes in this part of the molecule. No 19 F NMR evidence was found for formation of the Michael adduct between VRS and FU8 of 5-fluorouracil-substituted tRNA Val that has been proposed as a common intermediate in the aminoacylation reaction

The priming of priming: Evidence that the N400 reflects context-dependent post-retrieval word integration in working memory.

Science.gov (United States)

Steinhauer, Karsten; Royle, Phaedra; Drury, John E; Fromont, Lauren A

2017-06-09

Which cognitive processes are reflected by the N400 in ERPs is still controversial. Various recent articles (Lau et al., 2008; Brouwer et al., 2012) have revived the idea that only lexical pre-activation processes (such as automatic spreading activation, ASA) are strongly supported, while post-lexical integrative processes are not. Challenging this view, the present ERP study replicates a behavioral study by McKoon and Ratcliff (1995) who demonstrated that a prime-target pair such as finger - hand shows stronger priming when a majority of other pairs in the list share the analogous semantic relationship (here: part-whole), even at short stimulus onset asynchronies (250ms). We created lists with four different types of semantic relationship (synonyms, part-whole, category-member, and opposites) and compared priming for pairs in a consistent list with those in an inconsistent list as well as unrelated items. Highly significant N400 reductions were found for both relatedness priming (unrelated vs. inconsistent) and relational priming (inconsistent vs. consistent). These data are taken as strong evidence that N400 priming effects are not exclusively carried by ASA-like mechanisms during lexical retrieval but also include post-lexical integration in working memory. We link the present findings to a neurocomputational model for relational reasoning (Knowlton et al., 2012) and to recent discussions of context-dependent conceptual activations (Yee and Thompson-Schill, 2016). Copyright © 2017 Elsevier B.V. All rights reserved.

Improving Consumer Decisions: The Conscious Use of Primes as Performance Enhancers

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Leonardo Nicolao

2016-01-01

Full Text Available Through this article we examine ways through which consumers can take advantage of marketers’ priming attempts and make better decisions. Specifically, we investigate what happens when individuals are made aware of primes that may potentially improve their performance. Using an Embedded Figures Test, we demonstrate that individuals can be consciously primed into an analytic thinking mindset and perform better when they believe that the prime will enhance performance. Individuals are able to successfully ignore the prime when they believe that the prime hinders performance. Utilizing both holistic and analytic primes and by alternating the valence of the prime’s potential outcome, we are able to disentangle the conscious effects of primes from demand effects. We discuss how these findings may lead to and suggest avenues for future research.

Activation of the 2-5OAS/RNase L pathway in CVB1 or HAV/18f infected FRhK-4 cells does not require induction of OAS1 or OAS2 expression

International Nuclear Information System (INIS)

Kulka, Michael; Calvo, Mona S.; Ngo, Diana T.; Wales, Samantha Q.; Goswami, Biswendu B.

2009-01-01

The latent, constitutively expressed protein RNase L is activated in coxsackievirus and HAV strain 18f infected FRhK-4 cells. Endogenous oligoadenylate synthetase (OAS) from uninfected and virus infected cell extracts synthesizes active forms of the triphosphorylated 2-5A oligomer (the only known activator of RNase L) in vitro and endogenous 2-5A is detected in infected cell extracts. However, only the largest OAS isoform, OAS3, is readily detected throughout the time course of infection. While IFNβ treatment results in an increase in the level of all three OAS isoforms in FRhK-4 cells, IFNβ pretreatment does not affect the temporal onset or enhancement of RNase L activity nor inhibit virus replication. Our results indicate that CVB1 and HAV/18f activate the 2-5OAS/RNase L pathway in FRhK-4 cells during permissive infection through endogenous levels of OAS, but contrary to that reported for some picornaviruses, CVB1 and HAV/18f replication is insensitive to this activated antiviral pathway.

Persistent Structural Priming from Language Comprehension to Language Production

Science.gov (United States)

Bock, Kathryn; Dell, Gary S.; Chang, Franklin; Onishi, Kristine H.

2007-01-01

To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit…

Effects of Religious Priming Concepts on Prosocial Behavior Towards Ingroup and Outgroup.

Science.gov (United States)

Batara, Jame Bryan L; Franco, Pamela S; Quiachon, Mequia Angelo M; Sembrero, Dianelle Rose M

2016-11-01

Several studies show that there is a connection between religion and prosociality (e.g., Saroglou, 2013). To investigate whether there is a causal relationship between these two variables, a growing number of scholars employed priming religious concepts and measure its influence on prosocial behavior (e.g., Pichon, Boccato, & Saroglou, 2007). In the recent development of religious priming, Ritter and Preston (2013) argued that different primes (agent prime, spiritual/abstract prime, and institutional prime) may also have varying influence on prosocial behavior specifically helping an ingroup or an outgroup target. With this in mind, a 2 (social categorization of the target of help) by 3 (agent prime, institutional prime, spiritual prime) experiment was conducted to directly investigate this hypothesis. Results suggest that priming religious concepts especially the spiritual prime can increase prosocial behaviors. However, no significant effect was found on the social categorization which implies that Filipino participants elicit prosocial behavior regardless of the social categorization (be it ingroup or outgroup) of the target of help. The present study's findings contribute to further the literature on religious priming and its influence on prosocial behavior.

Arithmetically Related Ideal Topologies and the Infinitude of Primes ...

African Journals Online (AJOL)

algebra. Mathematics Subject Classification (1991): 11N80, 11N25, 11A41, 11T99, 13A15, 20M25 Keywords: x-ideal, topological semigroup, ideal topology, infinitude of primes, generalized primes and integers, distribution, integers, specified multiplicative constraints, primes, ideals, multiplicative ideal theory, semigroup

Crystallization and preliminary X-ray diffraction analysis of recombinant phosphoribosylpyrophosphate synthetase from the Thermophilic thermus thermophilus strain HB27

Energy Technology Data Exchange (ETDEWEB)

Abramchik, Yu. A. [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Timofeev, V. I., E-mail: tostars@mail.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Muravieva, T. I.; Sinitsyna, E. V.; Esipov, R. S., E-mail: esipov@mx.ibch.ru [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Kuranova, I. P., E-mail: inna@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation)

2017-01-15

Phosphoribosylpyrophosphate synthetases (PRPP synthetases) are among the key enzymes essential for vital functions of organisms and are involved in the biosynthesis of purine and pyrimidine nucleotides, coenzymes, and the amino acids histidine and tryptophan. These enzymes are used in biotechnology for the combined chemoenzymatic synthesis of natural nucleotide analogs. Recombinant phosphoribosylpyrophosphate synthetase I from the thermophilic strain HB27 of the bacterium Thermus thermophilus (T. th HB27) has high thermal stability and shows maximum activity at 75°Ð¡, due to which this enzyme holds promise for biotechnological applications. In order to grow crystals and study them by X-ray crystallography, an enzyme sample, which was produced using a highly efficient producer strain, was purified by affinity and gel-filtration chromatography. The screening of crystallization conditions was performed by the vapor-diffusion technique. The crystals of the enzyme suitable for X-ray diffraction were grown by the counter-diffusion method through a gel layer. These crystals were used to collect the X-ray diffraction data set at the SPring-8 synchrotron radiation facility (Japan) to 3-Å resolution. The crystals belong to sp. gr. P2{sub 1} and have the following unitcell parameters: a = 107.7 Å, b = 112.6 Å, c = 110.2 Å, α = γ = 90°, β = 116.6°. The X-ray diffraction data set is suitable for determining the three-dimensional structure of the enzyme at 3.0-Å resolution.

Religious Priming: A Meta-Analysis With a Focus on Prosociality.

Science.gov (United States)

Shariff, Azim F; Willard, Aiyana K; Andersen, Teresa; Norenzayan, Ara

2016-02-01

Priming has emerged as a valuable tool within the psychological study of religion, allowing for tests of religion's causal effect on a number of psychological outcomes, such as prosocial behavior. As the literature has grown, questions about the reliability and boundary conditions of religious priming have arisen. We use a combination of traditional effect-size analyses, p-curve analyses, and adjustments for publication bias to evaluate the robustness of four types of religious priming (Analyses 1-3), review the empirical evidence for religion's effect specifically on prosocial behavior (Analyses 4-5), and test whether religious-priming effects generalize to individuals who report little or no religiosity (Analyses 6-7). Results across 93 studies and 11,653 participants show that religious priming has robust effects across a variety of outcome measures-prosocial measures included. Religious priming does not, however, reliably affect non-religious participants-suggesting that priming depends on the cognitive activation of culturally transmitted religious beliefs. © 2015 by the Society for Personality and Social Psychology, Inc.

Promoting Physical Activity through Priming the Content of Motivation

Directory of Open Access Journals (Sweden)

Tom St Quinton

2017-09-01

Full Text Available Non-conscious processes are important in influencing the performance of a number of behaviors, such as physical activity. One way that such processes can be influenced is through priming. Despite this, approaches within health psychology have predominantly focused on reflective processes with a number of psychological theories dedicated to identifying the predictors of intention. In doing so, critical beliefs and thoughts are first identified and then altered within interventions. Such work has shown limited effectiveness, however, with a gap apparent between what one intends to do and what subsequently ensues. Although there have been attempts to bridge this gap, such as theoretical integration, recent efforts include priming implicit processes. The aim of this commentary is to demonstrate the potential effectiveness of priming non-conscious processes and to suggest that the content of motivation should also succumb to priming influences. This brief review suggests that priming one of the most influential conscious processes, that of self-efficacy, could demonstrate particular effectiveness in promoting physical activity. Thus, the main purpose of the article is to suggest that the content of implicit processes as well their more traditional conscious counterparts may provide useful intervention targets. To achieve this, the article will first introduce the role of non-conscious processes and behavioral priming. Following this, the more common reflective processes will be outlined as well as attempts at theoretical integration. Finally, the article will identify studies priming non-conscious processes and will then suggest priming self-efficacy.

Method for priming and DNA sequencing

Energy Technology Data Exchange (ETDEWEB)

Mugasimangalam, R.C.; Ulanovsky, L.E.

1997-12-01

A method is presented for improving the priming specificity of an oligonucleotide primer that is non-unique in a nucleic acid template which includes selecting a continuous stretch of several nucleotides in the template DNA where one of the four bases does not occur in the stretch. This also includes bringing the template DNA in contract with a non-unique primer partially or fully complimentary to the sequence immediately upstream of the selected sequence stretch. This results in polymerase-mediated differential extension of the primer in the presence of a subset of deoxyribonucleotide triphosphates that does not contain the base complementary to the base absent in the selected sequence stretch. These reactions occur at a temperature sufficiently low for allowing the extension of the non-unique primer. The method causes polymerase-mediated extension reactions in the presence of all four natural deoxyribonucleotide triphosphates or modifications. At this high temperature discrimination occurs against priming sites of the non-unique primer where the differential extension has not made the primer sufficiently stable to prime. However, the primer extended at the selected stretch is sufficiently stable to prime.

Auditory phonological priming in children and adults during word repetition

Science.gov (United States)

Cleary, Miranda; Schwartz, Richard G.

2004-05-01

Short-term auditory phonological priming effects involve changes in the speed with which words are processed by a listener as a function of recent exposure to other similar-sounding words. Activation of phonological/lexical representations appears to persist beyond the immediate offset of a word, influencing subsequent processing. Priming effects are commonly cited as demonstrating concurrent activation of word/phonological candidates during word identification. Phonological priming is controversial, the direction of effects (facilitating versus slowing) varying with the prime-target relationship. In adults, it has repeatedly been demonstrated, however, that hearing a prime word that rhymes with the following target word (ISI=50 ms) decreases the time necessary to initiate repetition of the target, relative to when the prime and target have no phonemic overlap. Activation of phonological representations in children has not typically been studied using this paradigm, auditory-word + picture-naming tasks being used instead. The present study employed an auditory phonological priming paradigm being developed for use with normal-hearing and hearing-impaired children. Initial results from normal-hearing adults replicate previous reports of faster naming times for targets following a rhyming prime word than for targets following a prime having no phonemes in common. Results from normal-hearing children will also be reported. [Work supported by NIH-NIDCD T32DC000039.

Effects of Religious Priming Concepts on Prosocial Behavior Towards Ingroup and Outgroup

Directory of Open Access Journals (Sweden)

Jame Bryan L. Batara

2016-11-01

Full Text Available Several studies show that there is a connection between religion and prosociality (e.g., Saroglou, 2013. To investigate whether there is a causal relationship between these two variables, a growing number of scholars employed priming religious concepts and measure its influence on prosocial behavior (e.g., Pichon, Boccato, & Saroglou, 2007. In the recent development of religious priming, Ritter and Preston (2013 argued that different primes (agent prime, spiritual/abstract prime, and institutional prime may also have varying influence on prosocial behavior specifically helping an ingroup or an outgroup target. With this in mind, a 2 (social categorization of the target of help by 3 (agent prime, institutional prime, spiritual prime experiment was conducted to directly investigate this hypothesis. Results suggest that priming religious concepts especially the spiritual prime can increase prosocial behaviors. However, no significant effect was found on the social categorization which implies that Filipino participants elicit prosocial behavior regardless of the social categorization (be it ingroup or outgroup of the target of help. The present study’s findings contribute to further the literature on religious priming and its influence on prosocial behavior.

Stochastic resolution analysis of co-prime arrays in radar

NARCIS (Netherlands)

Pribic, R; Coutiño Minguez, M.A.; Leus, G.J.T.

2016-01-01

Resolution from co-prime arrays and from a full ULA of the size equal to the virtual size of co-prime arrays is investigated. We take into account not only the resulting beam width but also the fact that fewer measurements are acquired by co-prime arrays. This fact is relevant in compressive

ASN1-encoded asparagine synthetase in floral organs contributes to nitrogen filling in Arabidopsis seeds.

Science.gov (United States)

Gaufichon, Laure; Marmagne, Anne; Belcram, Katia; Yoneyama, Tadakatsu; Sakakibara, Yukiko; Hase, Toshiharu; Grandjean, Olivier; Clément, Gilles; Citerne, Sylvie; Boutet-Mercey, Stéphanie; Masclaux-Daubresse, Céline; Chardon, Fabien; Soulay, Fabienne; Xu, Xiaole; Trassaert, Marion; Shakiebaei, Maryam; Najihi, Amina; Suzuki, Akira

2017-08-01

Despite a general view that asparagine synthetase generates asparagine as an amino acid for long-distance transport of nitrogen to sink organs, its role in nitrogen metabolic pathways in floral organs during seed nitrogen filling has remained undefined. We demonstrate that the onset of pollination in Arabidopsis induces selected genes for asparagine metabolism, namely ASN1 (At3g47340), GLN2 (At5g35630), GLU1 (At5g04140), AapAT2 (At5g19950), ASPGA1 (At5g08100) and ASPGB1 (At3g16150), particularly at the ovule stage (stage 0), accompanied by enhanced asparagine synthetase protein, asparagine and total amino acids. Immunolocalization confined asparagine synthetase to the vascular cells of the silique cell wall and septum, but also to the outer and inner seed integuments, demonstrating the post-phloem transport of asparagine in these cells to developing embryos. In the asn1 mutant, aberrant embryo cell divisions in upper suspensor cell layers from globular to heart stages assign a role for nitrogen in differentiating embryos within the ovary. Induction of asparagine metabolic genes by light/dark and nitrate supports fine shifts of nitrogen metabolic pathways. In transgenic Arabidopsis expressing promoter Ca MV 35S ::ASN1 fusion, marked metabolomics changes at stage 0, including a several-fold increase in free asparagine, are correlated to enhanced seed nitrogen. However, specific promoter Napin2S ::ASN1 expression during seed formation and a six-fold increase in asparagine toward the desiccation stage result in wild-type seed nitrogen, underlining that delayed accumulation of asparagine impairs the timing of its use by releasing amide and amino nitrogen. Transcript and metabolite profiles in floral organs match the carbon and nitrogen partitioning to generate energy via the tricarboxylic acid cycle, GABA shunt and phosphorylated serine synthetic pathway. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Associative priming in a masked perceptual identification task: evidence for automatic processes.

Science.gov (United States)

Pecher, Diane; Zeelenberg, René; Raaijmakers, Jeroen G W

2002-10-01

Two experiments investigated the influence of automatic and strategic processes on associative priming effects in a perceptual identification task in which prime-target pairs are briefly presented and masked. In this paradigm, priming is defined as a higher percentage of correctly identified targets for related pairs than for unrelated pairs. In Experiment 1, priming was obtained for mediated word pairs. This mediated priming effect was affected neither by the presence of direct associations nor by the presentation time of the primes, indicating that automatic priming effects play a role in perceptual identification. Experiment 2 showed that the priming effect was not affected by the proportion (.90 vs. .10) of related pairs if primes were presented briefly to prevent their identification. However, a large proportion effect was found when primes were presented for 1000 ms so that they were clearly visible. These results indicate that priming in a masked perceptual identification task is the result of automatic processes and is not affected by strategies. The present paradigm provides a valuable alternative to more commonly used tasks such as lexical decision.

A novel tool for studying auxin-metabolism: the inhibition of grapevine indole-3-acetic acid-amido synthetases by a reaction intermediate analogue.

Directory of Open Access Journals (Sweden)

Christine Böttcher

Full Text Available An important process for the regulation of auxin levels in plants is the inactivation of indole-3-acetic acid (IAA by conjugation to amino acids. The conjugation reaction is catalysed by IAA-amido synthetases belonging to the family of GH3 proteins. Genetic approaches to study the biological significance of these enzymes have been hampered by large gene numbers and a high degree of functional redundancy. To overcome these difficulties a chemical approach based on the reaction mechanism of GH3 proteins was employed to design a small molecule inhibitor of IAA-amido synthetase activity. Adenosine-5'-[2-(1H-indol-3-ylethyl]phosphate (AIEP mimics the adenylated intermediate of the IAA-conjugation reaction and was therefore proposed to compete with the binding of MgATP and IAA in the initial stages of catalysis. Two grapevine IAA-amido synthetases with different catalytic properties were chosen to test the inhibitory effects of AIEP in vitro. GH3-1 has previously been implicated in the grape berry ripening process and is restricted to two amino acid substrates, whereas GH3-6 conjugated IAA to 13 amino acids. AIEP is the most potent inhibitor of GH3 enzymes so far described and was shown to be competitive against MgATP and IAA binding to both enzymes with K(i-values 17-68-fold lower than the respective K(m-values. AIEP also exhibited in vivo activity in an ex planta test system using young grape berries. Exposure to 5-20 µM of the inhibitor led to decreased levels of the common conjugate IAA-Asp and reduced the accumulation of the corresponding Asp-conjugate upon treatment with a synthetic auxin. AIEP therefore represents a novel chemical probe with which to study IAA-amido synthetase function.

Suggestibility and negative priming: two replication studies.

Science.gov (United States)

David, Daniel; Brown, Richard J

2002-07-01

Research suggests that inhibiting the effect of irrelevant stimuli on subsequent thought and action (cognitive inhibition) may be an important component of suggestibility. Two small correlation studies were conducted to address the relationship between different aspects of suggestibility and individual differences in cognitive inhibition, operationalized as the degree of negative priming generated by to-be-ignored stimuli in a semantic categorization task. The first study found significant positive correlations between negative priming, hypnotic suggestibility, and creative imagination; a significant negative correlation was obtained between negative priming and interrogative suggestibility, demonstrating the discriminant validity of the study results. The second study replicated the correlation between negative priming and hypnotic suggestibility, using a different suggestibility measurement procedure that assessed subjective experience and hypnotic involuntariness as well as objective responses to suggestions. These studies support the notion that the ability to engage in cognitive inhibition may be an important component of hypnotic responsivity and maybe of other forms of suggestibility.

DNA polymerase preference determines PCR priming efficiency.

Science.gov (United States)

Pan, Wenjing; Byrne-Steele, Miranda; Wang, Chunlin; Lu, Stanley; Clemmons, Scott; Zahorchak, Robert J; Han, Jian

2014-01-30

Polymerase chain reaction (PCR) is one of the most important developments in modern biotechnology. However, PCR is known to introduce biases, especially during multiplex reactions. Recent studies have implicated the DNA polymerase as the primary source of bias, particularly initiation of polymerization on the template strand. In our study, amplification from a synthetic library containing a 12 nucleotide random portion was used to provide an in-depth characterization of DNA polymerase priming bias. The synthetic library was amplified with three commercially available DNA polymerases using an anchored primer with a random 3' hexamer end. After normalization, the next generation sequencing (NGS) results of the amplified libraries were directly compared to the unamplified synthetic library. Here, high throughput sequencing was used to systematically demonstrate and characterize DNA polymerase priming bias. We demonstrate that certain sequence motifs are preferred over others as primers where the six nucleotide sequences at the 3' end of the primer, as well as the sequences four base pairs downstream of the priming site, may influence priming efficiencies. DNA polymerases in the same family from two different commercial vendors prefer similar motifs, while another commercially available enzyme from a different DNA polymerase family prefers different motifs. Furthermore, the preferred priming motifs are GC-rich. The DNA polymerase preference for certain sequence motifs was verified by amplification from single-primer templates. We incorporated the observed DNA polymerase preference into a primer-design program that guides the placement of the primer to an optimal location on the template. DNA polymerase priming bias was characterized using a synthetic library amplification system and NGS. The characterization of DNA polymerase priming bias was then utilized to guide the primer-design process and demonstrate varying amplification efficiencies among three commercially

Partial response to biotin therapy in a patient with holocarboxylase synthetase deficiency: clinical, biochemical, and molecular genetic aspects

NARCIS (Netherlands)

Santer, R.; Muhle, H.; Suormala, T.; Baumgartner, E. R.; Duran, M.; Yang, X.; Aoki, Y.; Suzuki, Y.; Stephani, U.

2003-01-01

We report the clinical course and biochemical findings of a 10-year-old, mentally retarded girl with late-onset holocarboxylase synthetase (HCS, gene symbol HLCS) deficiency and only partial response to biotin. On treatment, even with an unusually high dose of 200mg/day, activities of the

Alcohol Primes, Expectancies, and the Working Self-Concept

Science.gov (United States)

Hicks, Joshua A.; Schlegel, Rebecca J.; Friedman, Ronald S.; McCarthy, Denis M.

2016-01-01

Previous research has shown that alcohol consumption can lead to momentary changes in the self-concept (e.g., Steele & Josephs, 1990). In two studies (n = 150), we examined whether the implicit activation of alcohol expectancies (i.e., sociability-related expectancies) would also lead to changes in self-perception. To test this idea, participants first completed a measure of sociability-related alcohol expectancies. In a subsequent laboratory session, participants were exposed to either alcohol-related primes (i.e., pictures or words associated with alcohol) or neutral primes. After the priming task, participants completed an ostensibly unrelated self-concept survey that contained words related to sociability (e.g., “outgoing”) and non-sociability related words (e.g., “clever”). For both studies, results revealed that sociability-related alcohol expectancies were positively associated with sociability-related self-concept ratings for participants exposed to alcohol primes, but not for participants exposed to the neutral primes. Implications for the role implicit self-concept activation may have on drinking behaviors are discussed. PMID:19769437

11th IUBMB Focused Meeting on the Aminoacyl-tRNA Synthetases: Sailing a New Sea of Complex Functions in Human Biology and Disease.

Science.gov (United States)

Francklyn, Christopher; Roy, Herve; Alexander, Rebecca

2018-05-01

The 11th IUBMB Focused Meeting on Aminoacyl-tRNA Synthetases was held in Clearwater Beach, Florida from 29 October⁻2 November 2017, with the aim of presenting the latest research on these enzymes and promoting interchange among aminoacyl-tRNA synthetase (ARS) researchers. Topics covered in the meeting included many areas of investigation, including ARS evolution, mechanism, editing functions, biology in prokaryotic and eukaryotic cells and their organelles, their roles in human diseases, and their application to problems in emerging areas of synthetic biology. In this report, we provide a summary of the major themes of the meeting, citing contributions from the oral presentations in the meeting.

Visual Priming of Inverted and Rotated Objects

Science.gov (United States)

Knowlton, Barbara J.; McAuliffe, Sean P.; Coelho, Chase J.; Hummel, John E.

2009-01-01

Object images are identified more efficiently after prior exposure. Here, the authors investigated shape representations supporting object priming. The dependent measure in all experiments was the minimum exposure duration required to correctly identify an object image in a rapid serial visual presentation stream. Priming was defined as the change…

Essential Non-Translational Functions of tRNA Synthetases

Science.gov (United States)

Guo, Min; Schimmel, Paul

2013-01-01

Nontranslational functions of vertebrate aminoacyl tRNA synthetases (aaRSs), which catalyze the production of aminoacyl-tRNAs for protein synthesis, have recently been discovered. While these new functions were thought to be ‘moonlighting activities’, many are as critical for cellular homeostasis as the activity in translation. New roles have been associated with cytoplasmic forms as well as with nuclear and secreted extracellular forms that impact pathways for cardiovascular development, the immune response, and mTOR, IFN-γ and p53 signaling. The associations of aaRSs with autoimmune disorders, cancers and neurological disorders further highlight nontranslational functions of these proteins. Novel architecture elaborations of the aaRSs accompany their functional expansion in higher organisms and have been associated with the nontranslational functions for several aaRSs. While a general understanding of how these functions developed is limited, the expropriation of aaRSs for essential nontranslational functions may have been initiated by co-opting the amino acid binding site for another purpose. PMID:23416400

Priming in the Type I-F CRISPR-Cas system triggers strand-independent spacer acquisition, bi-directionally from the primed protospacer.

Science.gov (United States)

Richter, Corinna; Dy, Ron L; McKenzie, Rebecca E; Watson, Bridget N J; Taylor, Corinda; Chang, James T; McNeil, Matthew B; Staals, Raymond H J; Fineran, Peter C

2014-07-01

Clustered regularly interspaced short palindromic repeats (CRISPR), in combination with CRISPR associated (cas) genes, constitute CRISPR-Cas bacterial adaptive immune systems. To generate immunity, these systems acquire short sequences of nucleic acids from foreign invaders and incorporate these into their CRISPR arrays as spacers. This adaptation process is the least characterized step in CRISPR-Cas immunity. Here, we used Pectobacterium atrosepticum to investigate adaptation in Type I-F CRISPR-Cas systems. Pre-existing spacers that matched plasmids stimulated hyperactive primed acquisition and resulted in the incorporation of up to nine new spacers across all three native CRISPR arrays. Endogenous expression of the cas genes was sufficient, yet required, for priming. The new spacers inhibited conjugation and transformation, and interference was enhanced with increasing numbers of new spacers. We analyzed ∼ 350 new spacers acquired in priming events and identified a 5'-protospacer-GG-3' protospacer adjacent motif. In contrast to priming in Type I-E systems, new spacers matched either plasmid strand and a biased distribution, including clustering near the primed protospacer, suggested a bi-directional translocation model for the Cas1:Cas2-3 adaptation machinery. Taken together these results indicate priming adaptation occurs in different CRISPR-Cas systems, that it can be highly active in wild-type strains and that the underlying mechanisms vary. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Identification of the nuclear export signals that regulate the intracellular localization of the mouse CMP-sialic acid synthetase

International Nuclear Information System (INIS)

Fujita, Akiko; Sato, Chihiro; Kitajima, Ken.

2007-01-01

The CMP-sialic acid synthetase (CSS) catalyzes the activation of sialic acid (Sia) to CMP-Sia which is a donor substrate of sialyltransferases. The vertebrate CSSs are usually localized in nucleus due to the nuclear localization signal (NLS) on the molecule. In this study, we first point out that a small, but significant population of the mouse CMP-sialic acid synthetase (mCSS) is also present in cytoplasm, though mostly in nucleus. As a mechanism for the localization in cytoplasm, we first identified two nuclear export signals (NESs) in mCSS, based on the localization studies of the potential NES-deleted mCSS mutants as well as the potential NES-tagged eGFP proteins. These two NESs are conserved among mammalian and fish CSSs, but not present in the bacterial or insect CSS. These results suggest that the intracellular localization of vertebrate CSSs is regulated by not only the NLS, but also the NES sequences

[Neural correlates of priming in vision: evidence from neuropsychology and neuroimaging].

Science.gov (United States)

Kristjánsson, Arni

2005-04-01

When we look around us, we are overall more likely to notice objects that we have recently looked at; an effect known as priming. For example, when the color or shape of a visual search target is repeated, observers find the target faster than otherwise. Here I summarize recent research undertaken to uncover the temporary changes in brain activity that accompany these priming effects. In light of the fact that priming seems to have a large effect on how attention is allocated, we investigated priming effects in a visual search task on patients suffering from the neurological disorder "hemispatial neglect" in which patients typically fail to notice display items in one of their visual hemifields. Priming of target color was relatively normal for these patients, while priming of target location seemed to require awareness of the briefly presented visual search target. An experiment with functional magnetic resonance imaging of normal observers revealed that both color and location priming had a strong modulatory influence on attentional mechanisms of the frontal and parietal cortex. Color priming was also correlated with changes in activity in visual cortex as well as color processing areas in the temporal lobe. Location priming was correlated with changes in activity near the temporo- parietal junction and lateral inferior frontal cortex, areas that have been connected with attentional capture; which ties well with our finding of deficits of location priming for the neglect patients who indeed have lesions in the temporo-parietal junction. Overall, the results confirm the tight coupling of visual attention and priming in vision, and also that the visual areas of the brain show some modulation of activity as priming develops.

Natural gas prime movers: A prime income opportunity?

International Nuclear Information System (INIS)

Katz, M.G.

1997-01-01

Although almost every factory, for example, uses compressed air to operate and control equipment--from power tools to packaging machinery--most air compressors are driven by electric motors. Similarly, although industry uses refrigeration for everything from freezing food to chilling warehouses to making chemicals and ice to operating skating rinks, natural gas powers only about 100 industrial refrigeration units in North America. But several factors are beginning to make natural gas more attractive as a prime mover. For one thing, the rising cost of electricity, with its demand or time-of-day and summer on-peak charges, has everyone looking for ways to cut their electric bills. At the same time, in the wake of deregulation of the nation's electric industry, customers can build on-site power plants that use natural gas to generate their own electricity, or have outside power suppliers or energy service companies (ESCOs) do it for them. Waste and exhaust heat, which can represent up to 60% of the total energy supplied from both engines and turbines, can be captured and used. Finally, growing concern over electric power outages has made natural gas more attractive for mission-critical operations, while new financing options let people buy and install natural gas prime movers more easily

Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

Science.gov (United States)

Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

2017-08-01

Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

The role of the C8 proton of ATP in the regulation of phosphoryl transfer within kinases and synthetases

Directory of Open Access Journals (Sweden)

Nkosi Thokozani C

2011-07-01

Full Text Available Abstract Background The kinome comprises functionally diverse enzymes, with the current classification indicating very little about the extent of conserved regulatory mechanisms associated with phosphoryl transfer. The apparent Km of the kinases ranges from less than 0.4 μM to in excess of 1000 μM for ATP. It is not known how this diverse range of enzymes mechanistically achieves the regulation of catalysis via an affinity range for ATP varying by three-orders of magnitude. Results We have demonstrated a previously undiscovered mechanism in kinase and synthetase enzymes where the overall rate of reaction is regulated via the C8-H of ATP. Using ATP deuterated at the C8 position (C8D-ATP as a molecular probe it was shown that the C8-H plays a direct role in the regulation of the overall rate of reaction in a range of kinase and synthetase enzymes. Using comparative studies on the effect of the concentration of ATP and C8D-ATP on the activity of the enzymes we demonstrated that not only did C8D-ATP give a kinetic isotope effect (KIE but the KIE's obtained are clearly not secondary KIE effects as the magnitude of the KIE in all cases was at least 2 fold and in most cases in excess of 7 fold. Conclusions Kinase and synthetase enzymes utilise C8D-ATP in preference to non-deuterated ATP. The KIE obtained at low ATP concentrations is clearly a primary KIE demonstrating strong evidence that the bond to the isotopically substituted hydrogen is being broken. The effect of the ATP concentration profile on the KIE was used to develop a model whereby the C8H of ATP plays a role in the overall regulation of phosphoryl transfer. This role of the C8H of ATP in the regulation of substrate binding appears to have been conserved in all kinase and synthetase enzymes as one of the mechanisms associated with binding of ATP. The induction of the C8H to be labile by active site residues coordinated to the ATP purine ring may play a significant role in explaining the

The effects of the concreteness of differently valenced words on affective priming.

Science.gov (United States)

Yao, Zhao; Wang, Zhenhong

2013-07-01

This study aimed to determine whether affective priming is influenced by the concreteness of emotional words. To address this question, we conducted three experiments using lexical decision-priming task. In Experiment 1, positive-abstract (PA) and positive-concrete (PC) words were used as primes to examine the effect of the concreteness of positive words on affective priming, and in Experiment 2, negative-abstract (NA) and negative-concrete (NC) words were used as primes to examine the effect of the concreteness of negative words on affective priming. Results showed that participants responded faster to affectively congruent-abstract trails than incongruent-abstract trails in PA prime conditions, but for PC or negative word (NC and NA) prime conditions, there were no differences between the response times of congruent trails and incongruent trails. To examine the reliability of the priming effects observed in Experiments 1 and 2, we set up a neutral condition as a baseline in Experiment 3, through which we confirmed the difference in the affective priming effect between positive and negative primes in a concrete-abstract dimension. PA words were found to have the tendency to possess more emotional load and facilitate affective association between the prime and the target. The study finding suggests that aside from arousal and valence, the concreteness of positive words also has an impact on affective priming effect. Copyright © 2013 Elsevier B.V. All rights reserved.

Oxygen transfer rate identifies priming compounds in parsley cells.

Science.gov (United States)

Schilling, Jana Viola; Schillheim, Britta; Mahr, Stefan; Reufer, Yannik; Sanjoyo, Sandi; Conrath, Uwe; Büchs, Jochen

2015-11-25

In modern agriculture, the call for an alternative crop protection strategy increases because of the desired reduction of fungicide and pesticide use and the continuously evolving resistance of pathogens and pests to agrochemicals. The direct activation of the plant immune system does not provide a promising plant protection measure because of high fitness costs. However, upon treatment with certain natural or synthetic compounds, plant cells can promote to a fitness cost-saving, primed state of enhanced defense. In the primed state, plants respond to biotic and abiotic stress with faster and stronger activation of defense, and this is often associated with immunity and abiotic stress tolerance. Until now, the identification of chemical compounds with priming-inducing activity (so-called plant activators) relied on tedious and invasive approaches, or required the late detection of secreted furanocoumarin phytoalexins in parsley cell cultures. Thus, simple, fast, straightforward, and noninvasive techniques for identifying priming-inducing compounds for plant protection are very welcome. This report demonstrates that a respiration activity-monitoring system (RAMOS) can identify compounds with defense priming-inducing activity in parsley cell suspension in culture. RAMOS relies on the quasi-continuous, noninvasive online determination of the oxygen transfer rate (OTR). Treatment of parsley culture cells with the known plant activator salicylic acid (SA), a natural plant defense signal, resulted in an OTR increase. Addition of the defense elicitor Pep13, a cell wall peptide of Phythophthora sojae, induced two distinctive OTR peaks that were higher in SA-primed cells than in unprimed cells upon Pep13 challenge. Both, the OTR increase after priming with SA and the Pep13 challenge were dose-dependent. Furthermore, there was a close correlation of a compound's activity to enhance the oxygen consumption in parsley cells and its capacity to prime Pep13-induced furanocoumarin

The role of the C8 proton of ATP in the regulation of phosphoryl transfer within kinases and synthetases

CSIR Research Space (South Africa)

Kenyon, CP

2011-07-01

Full Text Available Kinase and synthetase enzymes utilise C8D-ATP in preference to non-deuterated ATP. The KIE obtained at low ATP concentrations is clearly a primary KIE demonstrating strong evidence that the bond to the isotopically substituted hydrogen is being...

Measurement of Branching Fractions and Charge Asymmetries in B Meson Decays to eta(prime)K*, eta(prime)rho, and eta pi

CERN Document Server

Ford, W

2003-01-01

The present preliminary measurements of branching fractions and charge asymmetries for the B meson decays B -> eta(prime) K*, B -> eta(prime)rho, and B sup + -> eta(prime)pi sup +. The data were recorded with the BABAR detector at PEP-II and correspond to 89 x 10 sup 6 B(bar B) pairs produced in e sup + e sup - annihilation through the UPSILON(4S) resonance. They find the branching fractions BETA(B sup 0 -> eta K* sup 0) = (19.0 sub - sub 2 sub . sub 1 sup + sup 2 sup . sup 2 +- 1.3) x 10 sup - sup 6 , BETA(B sup + -> eta K* sup +) = (25.7 sub - sub 3 sub . sub 6 sup + sup 3 sup . sup 8 +- 1.8) x 10 sup - sup 6 with 90% confidence, and BETA(B sup + -> eta(prime)pi sup +) = (2.8 sub - sub 1 sub . sub 0 sup + sup 1 sup . sup 3 +- 0.3) x 10 sup - sup 6 ( eta(prime)K* sup 0) eta(prime)K* sup +) < 12 x 10 sup - sup 6. The time-integrated charge asymmetries are A sub c sub h (eta K* sup 0) = +0.03 +- 0.11 +- 0.02, A sub c sub h (eta K* sup +) = +0.15 +- 0.14 +- 0.02, and A sub c sub h (eta rho sup +) = +0.06 +-...

Purification and properties of phosphoribosyl-diphosphate synthetase from Bacillus subtilis

DEFF Research Database (Denmark)

Arnvig, Kirsten; Hove-Jensen, Bjarne; Switzer, Robert L.

1990-01-01

enzyme required Mg2+ and inorganic phosphate for activity; Mn2+ supported only 30% the activity seen with Mg2+. Michaelis constants for ATP and ribose 5-phosphate (Rib5P) were 0.66 mM and 0.48 mM, respectively. Of several end products tested, only ADP was strongly inhibitory; GDP was a weak inhibitor....... ADP inhibition displayed homotropic cooperativity and was enhanced by increasing saturation of the enzyme with ATP. These observations strongly suggest a specific allosteric site for ADP binding. A comparison of physical and kinetic properties of bacterial and mammalian PPRibP synthetases is presented....

7 CFR 29.1166 - Primings (P Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Primings (P Group). 29.1166 Section 29.1166... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1166 Primings (P Group). This group consists of round-tipped leaves from the lowest portion of the stalk. Leaves of the P group ripen prematurely as a result...

Priming healthy eating. You can't prime all the people all of the time.

Science.gov (United States)

Forwood, Suzanna E; Ahern, Amy L; Hollands, Gareth J; Ng, Yin-Lam; Marteau, Theresa M

2015-06-01

In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population. In two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height. In Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26-0.56), p choice was unaffected by hunger or the prime. This study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Priming healthy eating. You can't prime all the people all of the time☆

Science.gov (United States)

Forwood, Suzanna E.; Ahern, Amy L.; Hollands, Gareth J.; Ng, Yin-Lam; Marteau, Theresa M.

2015-01-01

Objective In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population. MethodsIn two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height. ResultsIn Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26–0.56), p choice was unaffected by hunger or the prime. ConclusionThis study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice. PMID:25636234

Suggestion-Induced Modulation of Semantic Priming during Functional Magnetic Resonance Imaging

Science.gov (United States)

Ulrich, Martin; Kiefer, Markus; Bongartz, Walter; Grön, Georg; Hoenig, Klaus

2015-01-01

Using functional magnetic resonance imaging during a primed visual lexical decision task, we investigated the neural and functional mechanisms underlying modulations of semantic word processing through hypnotic suggestions aimed at altering lexical processing of primes. The priming task was to discriminate between target words and pseudowords presented 200 ms after the prime word which was semantically related or unrelated to the target. In a counterbalanced study design, each participant performed the task once at normal wakefulness and once after the administration of hypnotic suggestions to perceive the prime as a meaningless symbol of a foreign language. Neural correlates of priming were defined as significantly lower activations upon semantically related compared to unrelated trials. We found significant suggestive treatment-induced reductions in neural priming, albeit irrespective of the degree of suggestibility. Neural priming was attenuated upon suggestive treatment compared with normal wakefulness in brain regions supporting automatic (fusiform gyrus) and controlled semantic processing (superior and middle temporal gyri, pre- and postcentral gyri, and supplementary motor area). Hence, suggestions reduced semantic word processing by conjointly dampening both automatic and strategic semantic processes. PMID:25923740

Suggestion-Induced Modulation of Semantic Priming during Functional Magnetic Resonance Imaging.

Directory of Open Access Journals (Sweden)

Martin Ulrich

Full Text Available Using functional magnetic resonance imaging during a primed visual lexical decision task, we investigated the neural and functional mechanisms underlying modulations of semantic word processing through hypnotic suggestions aimed at altering lexical processing of primes. The priming task was to discriminate between target words and pseudowords presented 200 ms after the prime word which was semantically related or unrelated to the target. In a counterbalanced study design, each participant performed the task once at normal wakefulness and once after the administration of hypnotic suggestions to perceive the prime as a meaningless symbol of a foreign language. Neural correlates of priming were defined as significantly lower activations upon semantically related compared to unrelated trials. We found significant suggestive treatment-induced reductions in neural priming, albeit irrespective of the degree of suggestibility. Neural priming was attenuated upon suggestive treatment compared with normal wakefulness in brain regions supporting automatic (fusiform gyrus and controlled semantic processing (superior and middle temporal gyri, pre- and postcentral gyri, and supplementary motor area. Hence, suggestions reduced semantic word processing by conjointly dampening both automatic and strategic semantic processes.

Filling in the Gaps: Priming and the Ethics of Pharmaceutical Advertising.

Science.gov (United States)

Biegler, Paul

2015-06-01

A prime is a cue that makes associated concepts, behaviors, and goals more psychologically accessible to people, influencing their responses in subsequent related environments. I build a case that Direct to Consumer Advertising of Prescription Pharmaceuticals (DTCA) operates as a prime that causes some viewers to prefer and pursue the advertised drug. Drawing on literature from social psychology I show that people subject to priming are mostly unaware of its influence and liable to misattribute the reasons for their primed actions. Misattribution typically includes heightened appraisals of the value of a primed goal. Consistent with this account, I argue that viewers primed by DTCA hold favorable, yet false beliefs about the safety and efficacy of the advertised drug. I further argue that, because those drug properties are material to viewers with the relevant illness, priming in DTCA can undermine the autonomy of their medicine choices. The threat to autonomy posed by priming in DTCA suggests it warrants attention from both regulators and the wider research community. It also adds further reason to be sceptical about the permissibility of this form of advertising.

Anterior medial prefrontal cortex implements social priming of mimicry.

Science.gov (United States)

Wang, Yin; Hamilton, Antonia F de C

2015-04-01

The neural and cognitive mechanisms by which primed constructs can impact on social behavior are poorly understood. In the present study, we used functional magnetic resonance imaging (fMRI) to explore how scrambled sentence priming can impact on mimicry behavior. Sentences involving pro/antisocial events from a first/third-person point of view were presented in short blocks, followed by a reaction-time assessment of mimicry. Behavioral results showed that both prosociality and viewpoint impact on mimicry, and fMRI analysis showed this effect is implemented by anterior medial prefrontal cortex (amPFC). We suggest that social primes may subtly modulate processing in amPFC in a manner linked to the later behavior, and that this same region also implements the top-down control of mimicry responses. This priming may be linked to processing of self-schemas in amPFC. Our findings demonstrate how social priming can be studied with fMRI, and have important implications for our understanding of the underlying mechanisms of prime-to-behavior effects as well as for current theories in social psychology. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Positional priming of pop-out is nested in visuospatial context.

Science.gov (United States)

Gokce, Ahu; Müller, Hermann J; Geyer, Thomas

2013-11-26

The present study investigated facilitatory and inhibitory positional priming using a variant of Maljkovic and Nakayama's (1996) priming of pop-out task. Here, the singleton target and the distractors could be presented in different visuospatial contexts-but identical screen locations-across trials, permitting positional priming based on individual locations to be disentangled from priming based on interitem configural relations. The results revealed both significant facilitatory priming, i.e., faster reaction times (RTs) to target presented at previous target relative to previously empty locations, and inhibitory priming, i.e., slower RTs to target at previous distractor relative to previously empty locations. However, both effects were contingent on repetitions versus changes of stimulus arrangement: While facilitation of target locations was dependent on the repetition of the exact item configuration (e.g., T-type followed by T-type stimulus arrangement), the inhibitory effect was more "tolerant," being influenced by repetitions versus changes of the item's visuospatial category (T-type followed by Z-type pattern; cf. Garner & Clement, 1963). The results suggest that facilitatory and inhibitory priming are distinct phenomena (Finke et al., 2009) and that both effects are sensitive to subtle information about the arrangement of the display items (Geyer, Zehetleitner, & Müller, 2010). The results are discussed with respect to the stage(s) of visual pop-out search that are influenced by positional priming.

Almost Fixed-Point-Free Automorphisms of Prime Power Order

Directory of Open Access Journals (Sweden)

B.A.F. Wehrfritz

2016-06-01

Full Text Available We study the effect under various rank restrictions of a group having an automorphism of prime power order whose fixed-point set is also finite of prime power order for the same prime. Generally our conclusions are that the group has a soluble normal subgroup of bounded derived length. Not surprisingly the bound gets larger as the rank restrictions get weaker.

Seed priming improves salinity tolerance of wheat varieties

International Nuclear Information System (INIS)

Jamal, Y.; Shafi, M.; Arif, M.

2011-01-01

To evaluate the response of wheat varieties to seed priming and salinity, an experiment was conducted in completely randomized design (CRD) with three replications at Institute of Biotechnology and Genetic Engineering (IBGE), KPK Agricultural University, Peshawar, Pakistan. The performance of 6 wheat varieties (Tatara-96, Ghaznavi-98, Fakhri Sarhad, Bakhtawar-92, Pirsabaq-2004 and Auqab-2000) at two seed conditions (primed with 30 mM NaCl and un primed) under four salinity levels (0, 40, 80 and 120 mM) was studied. Statistical analysis of the data revealed that salinity, seed priming and varieties had significantly (P= 0.05) affected shoot fresh weight plant/sup -1/ shoot dry weight plant/sup -1/, shoot Na/sup +/ contents (mg g/sup -1/ dry weight), shoot K/sup +/ contents (mg g/sup -1/ dry weight) and shoot K/sup +/Na/sup +/ ratio. Maximum shoot fresh weight plant/sup -1/ (7.71 g), shoot dry weight plant/sup -1/ (1.68 g), shoot K/sup +/ contents (1.39 mg g/sup -1/ dry weight) and shoot K/sup +/ Na/sup +/ratio (1.45) were recorded from Bakhtawar-92 as compared with other varieties. Highest shoot Na/sup +/ contents (1.43 mg g/sup -1/ dry weight) were recorded from Auqab-2000 when compared with other varieties. All parameters were enhanced with seed priming except shoot Na/sup +/ contents, which reduced significantly (p= 0.05) with seed priming. (author)

Mammalian folylpoly-γ-glutamate synthetase. 1. Purification and general properties of the hog liver enzyme

International Nuclear Information System (INIS)

Cichowicz, D.J.; Shane, B.

1987-01-01

Folylpolyglutamate synthetase was purified 30,000-150,000-fold from hog liver. Purification required the use of protease inhibitors, and the protein was purified to homogeneity in two forms. Both forms of the enzyme were monomers of M/sub r/ 62,000 and had similar specific activities. The specific activity of the homogeneous protein was over 2000-fold higher than reported for partially purified folylpolyglutamate synthetases from other mammalian sources. Enzyme activity was absolutely dependent on the presence of a reducing agent and a monovalent cation, of which K + was most effective. The purified enzyme catalyzed a MgATP-dependent addition of glutamate to tetrahydrofolate with the concomitant stoichiometric formation of MgADP and phosphate. Under conditions that resembled the expected substrate and enzyme concentrations in hog liver, tetrahydrofolate was metabolized to long glutamate chain length derivatives with the hexaglutamate, the major in vivo folate derivative, predominating. Enzyme activity was maximal at about pH 9.5. The high-pH optimum was primarily due to an increase in the K/sub m/ value for the L-glutamate substrate at lower pH values, and the reaction proceeded effectively at physiological pH provided high levels of glutamate were supplied

Behavioral Priming 2.0: Enter a Dynamical Systems Perspective

Science.gov (United States)

Krpan, Dario

2017-01-01

On a daily basis, people are exposed to numerous stimuli, ranging from colors and smells to sounds and words, that could potentially activate different cognitive constructs and influence their actions. This type of influence on human behavior is referred to as priming. Roughly two decades ago, behavioral priming was hailed as one of the core forces that shape automatic behavior. However, failures to replicate some of the representative findings in this domain soon followed, which posed the following question: “How robust are behavioral priming effects, and to what extent are they actually important in shaping people's actions?” To shed a new light on this question, I revisit behavioral priming through the prism of a dynamical systems perspective (DSP). The DSP is a scientific paradigm that has been developed through a combined effort of many different academic disciplines, ranging from mathematics and physics to biology, economics, psychology, etc., and it deals with behavior of simple and complex systems over time. In the present paper, I use conceptual and methodological tools stemming from the DSP to propose circumstances under which behavioral priming effects are likely to occur. More precisely, I outline three possible types of the influence of priming on human behavior, to which I refer as emergence, readjustment, and attractor switch, and propose experimental designs to examine them. Finally, I discuss relevant implications for behavioral priming effects and their replications. PMID:28769846

Behavioral Priming 2.0: Enter a Dynamical Systems Perspective

Directory of Open Access Journals (Sweden)

Dario Krpan

2017-07-01

Full Text Available On a daily basis, people are exposed to numerous stimuli, ranging from colors and smells to sounds and words, that could potentially activate different cognitive constructs and influence their actions. This type of influence on human behavior is referred to as priming. Roughly two decades ago, behavioral priming was hailed as one of the core forces that shape automatic behavior. However, failures to replicate some of the representative findings in this domain soon followed, which posed the following question: “How robust are behavioral priming effects, and to what extent are they actually important in shaping people's actions?” To shed a new light on this question, I revisit behavioral priming through the prism of a dynamical systems perspective (DSP. The DSP is a scientific paradigm that has been developed through a combined effort of many different academic disciplines, ranging from mathematics and physics to biology, economics, psychology, etc., and it deals with behavior of simple and complex systems over time. In the present paper, I use conceptual and methodological tools stemming from the DSP to propose circumstances under which behavioral priming effects are likely to occur. More precisely, I outline three possible types of the influence of priming on human behavior, to which I refer as emergence, readjustment, and attractor switch, and propose experimental designs to examine them. Finally, I discuss relevant implications for behavioral priming effects and their replications.

An extracellular subtilase switch for immune priming in Arabidopsis.

Directory of Open Access Journals (Sweden)

Vicente Ramírez

Full Text Available In higher eukaryotes, induced resistance associates with acquisition of a priming state of the cells for a more effective activation of innate immunity; however, the nature of the components for mounting this type of immunological memory is not well known. We identified an extracellular subtilase from Arabidopsis, SBT3.3, the overexpression of which enhances innate immune responses while the loss of function compromises them. SBT3.3 expression initiates a durable autoinduction mechanism that promotes chromatin remodeling and activates a salicylic acid(SA-dependent mechanism of priming of defense genes for amplified response. Moreover, SBT3.3 expression-sensitized plants for enhanced expression of the OXI1 kinase gene and activation of MAP kinases following pathogen attack, providing additional clues for the regulation of immune priming by SBT3.3. Conversely, in sbt3.3 mutant plants pathogen-mediated induction of SA-related defense gene expression is drastically reduced and activation of MAP kinases inhibited. Moreover, chromatin remodeling of defense-related genes normally associated with activation of an immune priming response appear inhibited in sbt3.3 plants, further indicating the importance of the extracellular SBT3.3 subtilase in the establishment of immune priming. Our results also point to an epigenetic control in the regulation of plant immunity, since SBT3.3 is up-regulated and priming activated when epigenetic control is impeded. SBT3.3 represents a new regulator of primed immunity.

Semantic priming effects of synonyms, antonyms, frame, implication and verb-object categories

Directory of Open Access Journals (Sweden)

Elsa Skënderi-Rakipllari

2017-12-01

Full Text Available Semantic priming has been a major subject of interest for psycholinguists, whose aim is to discover how lexical memory is structured and organized. The facilitation process of word retrieval through semantic priming has long been studied. The present research is aimed to reveal which semantic category has the best priming effect. Through a lexical decision task experiment we compared the reaction times of masked primed pairs and unprimed pairs. In addition, we analyzed the reaction times and priming effect of connected semantic relations: antonymy, frame, synonymy, implication and verb-object. The data collected and interpreted unveiled that the mean reaction times of primed pairs were shorter than those of unprimed pairs. As to semantic priming, the most significantly primed pairs were those of implications and verb- objects, and not those of synonymy or antonymy as it might be expected.

Structural Basis for Specific Inhibition of tRNA Synthetase by an ATP Competitive Inhibitor

OpenAIRE

Fang, Pengfei; Han, Hongyan; Wang, Jing; Chen, Kaige; Chen, Xin; Guo, Min

2015-01-01

Pharmaceutical inhibitors of aminoacyl-tRNA synthetases demand high species and family specificity. The antimalarial ATP-mimetic cladosporin selectively inhibits P. falciparum LysRS (PfLysRS). How the binding to a universal ATP site achieves the specificity is unknown. Here we report 3 crystal structures of cladosporin with human LysRS, PfLysRS, and a Pf-like human LysRS mutant. In all 3 structures, cladosporin occupies the class defining ATP-binding pocket, replacing the adenosine portion of...

Number theory an introduction via the density of primes

CERN Document Server

Fine, Benjamin

2016-01-01

Now in its second edition, this textbook provides an introduction and overview of number theory based on the density and properties of the prime numbers. This unique approach offers both a firm background in the standard material of number theory, as well as an overview of the entire discipline. All of the essential topics are covered, such as the fundamental theorem of arithmetic, theory of congruences, quadratic reciprocity, arithmetic functions, and the distribution of primes. New in this edition are coverage of p-adic numbers, Hensel's lemma, multiple zeta-values, and elliptic curve methods in primality testing. Key topics and features include: A solid introduction to analytic number theory, including full proofs of Dirichlet's Theorem and the Prime Number Theorem Concise treatment of algebraic number theory, including a complete presentation of primes, prime factorizations in algebraic number fields, and unique factorization of ideals Discussion of the AKS algorithm, which shows that primality testing is...

Spectral statistics and scattering resonances of complex primes arrays

Science.gov (United States)

Wang, Ren; Pinheiro, Felipe A.; Dal Negro, Luca

2018-01-01

We introduce a class of aperiodic arrays of electric dipoles generated from the distribution of prime numbers in complex quadratic fields (Eisenstein and Gaussian primes) as well as quaternion primes (Hurwitz and Lifschitz primes), and study the nature of their scattering resonances using the vectorial Green's matrix method. In these systems we demonstrate several distinctive spectral properties, such as the absence of level repulsion in the strongly scattering regime, critical statistics of level spacings, and the existence of critical modes, which are extended fractal modes with long lifetimes not supported by either random or periodic systems. Moreover, we show that one can predict important physical properties, such as the existence spectral gaps, by analyzing the eigenvalue distribution of the Green's matrix of the arrays in the complex plane. Our results unveil the importance of aperiodic correlations in prime number arrays for the engineering of gapped photonic media that support far richer mode localization and spectral properties compared to usual periodic and random media.

Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase

NARCIS (Netherlands)

Luna, E.; Van Hulten, M.; Zhang, Y.; Berkowitz, O.; López, A.; Pétriacq, P.; Sellwood, M.A.; Chen, B.; Burrell, M.; Van de Meene, A.; Pieterse, C.M.J.; Flors, V.; Ton, J.

2014-01-01

Specific chemicals can prime the plant immune system for augmented defense. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defense

Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase

NARCIS (Netherlands)

Luna, Estrella; van Hulten, Marieke; Zhang, Yuhua; Berkowitz, Oliver; López, Ana; Pétriacq, Pierre; Sellwood, Matthew A; Chen, Beining; Burrell, Mike; van de Meene, Allison; Pieterse, Corné M J; Flors, Victor; Ton, Jurriaan

Specific chemicals can prime the plant immune system for augmented defense. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defense

New perspectives on glutamine synthetase in grasses.

Science.gov (United States)

Swarbreck, Stéphanie M; Defoin-Platel, M; Hindle, M; Saqi, M; Habash, Dimah Z

2011-02-01

Members of the glutamine synthetase (GS) gene family have now been characterized in many crop species such as wheat, rice, and maize. Studies have shown that cytosolic GS isoforms are involved in nitrogen remobilization during leaf senescence and emphasized a role in seed production particularly in small grain crop species. Data from the sequencing of genomes for model crops and expressed sequence tag (EST) libraries from non-model species have strengthened the idea that the cytosolic GS genes are organized in three functionally and phylogenetically conserved subfamilies. Using a bioinformatic approach, the considerable publicly available information on high throughput gene expression was mined to search for genes having patterns of expression similar to GS. Interesting new hypotheses have emerged from searching for co-expressed genes across multiple unfiltered experimental data sets in rice. This approach should inform new experimental designs and studies to explore the regulation of the GS gene family further. It is expected that understanding the regulation of GS under varied climatic conditions will emerge as an important new area considering the results from recent studies that have shown nitrogen assimilation to be critical to plant acclimation to high CO(2) concentrations.

Attentional Control and the Relatedness Proportion Effect in Semantic Priming

Science.gov (United States)

Hutchison, Keith A.

2007-01-01

In 2 experiments, participants completed both an attentional control battery (OSPAN, antisaccade, and Stroop tasks) and a modified semantic priming task. The priming task measured relatedness proportion (RP) effects within subjects, with the color of the prime indicating the probability that the to-be-named target would be related. In Experiment…

Does pizza prime coin? Perceptual priming in lexical decision and pronunciation.

NARCIS (Netherlands)

Pecher, D.; Zeelenberg, R.; Raaijmakers, J.G.W.

1998-01-01

In 6 experiments the authors investigated priming for perceptually related word pairs (i.e., words that refer to objects with the same shape such as pizza-coin), trying to replicate earlier findings by R. Schreuder et al (see record 1985-06198-001) while avoiding some of the methodological problems

Allograph priming is based on abstract letter identities: Evidence from Japanese kana.

Science.gov (United States)

Kinoshita, Sachiko; Schubert, Teresa; Verdonschot, Rinus G

2018-04-23

It is well-established that allographs like the uppercase and lowercase forms of the Roman alphabet (e.g., a and A) map onto the same "abstract letter identity," orthographic representations that are independent of the visual form. Consistent with this, in the allograph match task ("Are 'a' and 'A' the same letter?"), priming by a masked letter prime is equally robust for visually dissimilar prime-target pairs (e.g., d and D) and similar pairs (e.g., c and C). However, in principle this pattern of priming is also consistent with the possibility that allograph priming is purely phonological, based on the letter name. Because different allographic forms of the same letter, by definition, share a letter name, it is impossible to rule out this possibility a priori. In the present study, we investigated the influence of shared letter names by taking advantage of the fact that Japanese is written in two distinct writing systems, syllabic kana-that has two parallel forms, hiragana and katakana-and logographic kanji. Using the allograph match task, we tested whether a kanji prime with the same pronunciation as the target kana (e.g., - い, both pronounced /i/) produces the same amount of priming as a kana prime in the opposite kana form (e.g., イ- い). We found that the kana primes produced substantially greater priming than the phonologically identical kanji prime, which we take as evidence that allograph priming is based on abstract kana identity, not purely phonology. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Acyl-CoA hydrolysis by the high molecular weight protein 1 subunit of yersiniabactin synthetase: Mutational evidence for a cascade of four acyl-enzyme intermediates during hydrolytic editing

OpenAIRE

Suo, Zucai; Chen, Huawei; Walsh, Christopher T.

2000-01-01

Yersiniabactin (Ybt) synthetase is a three-subunit, 17-domain [7 domains in high molecular weight protein (HMWP)2, 9 in HMWP1, and 1 in YbtE] enzyme producing the virulence-conferring siderophore yersiniabactin in Yersinia pestis. The 350-kDa HMWP1 subunit contains a polyketide synthase module (KS-AT-MT2-KR-ACP) and a nonribosomal peptide synthetase module (Cy3-MT3-PCP3-TE). The full-length HMWP1 was heterologously overexpressed in Escherichia coli and purified...

Effect of intramolecular photochemical cross-linking and of alkylation of 4-thiouridine in E. coli tRNAsub(l)sup(Val). On the heterologous misccharging by yeast phenylalanyl-tRNA synthetase

Energy Technology Data Exchange (ETDEWEB)

Kumar, S A; Krauskopf, M; Ofengand, J [Roche Inst. of Molecular Biology, Nutley, N.J. (USA)

1973-08-01

The ability of yeast phenylalanyl-tRNA synthetase to carry out the heterologous mischarging of nine E. coli tRNAs with phenylalanine, and the presence of a common sequence in these tRNAs in the double stranded region adjacent to the dihydrouridine loop, have led to the proposal (by Dudock) that this region of the tRNA is involved in recognition by the yeast enzyme. The validity of this hypothesis has now been examined by chemical modification of the region in question using as a test tRNA, E. coli tRNA/sub 1/sup( val). Photochemical cross-linking of /sup 4/S(8) and C(13) by irradiation at 335 nm led to a complete loss of the ability of yeast phenylalanyl-tRNA synthetase to functionally recognize tRNA/sub 1/sup( val) and the rate of cross-linking was correlated with the rate of loss of activity when appropriate assay conditions were used. Cross-linking had no effect on the recognition by the homologous E. coli valyl-tRNA synthetase (EC 6.1.1.9). Similarly, S-alkylation of the /sup 4/S(8) residue with iodoacetamide at pH 9 yielded the uridine-4-thio(2-acetamide) derivative of tRNA with no loss of homologous recognition but with complete loss of heterologous charging activity. These results provide evidence that at least part of the yeast phenylalanyl-tRNA synthetase recognition site is located in the region of the tRNA proposed by Dudock, and, as a corollary, show that the E. coli valyl-tRNA synthetase recognition site(s) must be elsewhere in the molecule.

Influence of Individual and Group Priming on Medical Students

OpenAIRE

McGeown, Helen Rosemary

2009-01-01

This study investigated the impact of information on level of prototypicality of the ingroup ‘medical students’, comparing self-esteem effects for those primed as individuals with self-esteem effects for those primed as group members. Indication of prototypicality was given by false feedback on purported individual levels of empathy, an important group norm for medical students. As well as priming type having interactive effects with prototypicality information, it was hypothesized that initi...

Positions priming in briefly presented search arrays

DEFF Research Database (Denmark)

Asgeirsson, Arni Gunnar; Kristjánsson, Árni; Kyllingsbæk, Søren

2011-01-01

Repetition priming in visual search has been a topic of extensive research since Maljkovic & Nakayama [1994, Memory & Cognition, 22, 657-672] presented the first detailed studies of such effects. Their results showed large reductions in reaction times when target color was repeated on consecutive...... the targets are oddly colored alphanumeric characters. The effects arise at very low exposure durations and benefit accuracy at all exposure durations towards the subjects’ ceiling. We conclude that temporally constricted experimental conditions can add to our understanding priming in visual search...... pop-out search trials. Such repetition effects have since been generalized to a multitude of target attributes. Priming has primarily been investigated using self-terminating visual search paradigms, comparing differences in response times. Response accuracy has predominantly served as a control...

Emotion potentiates response activation and inhibition in masked priming.

Science.gov (United States)

Bocanegra, Bruno R; Zeelenberg, René

2012-01-01

Previous studies have shown that emotion can have 2-fold effects on perception. At the object-level, emotional stimuli benefit from a stimulus-specific boost in visual attention at the relative expense of competing stimuli. At the visual feature-level, recent findings indicate that emotion may inhibit the processing of small visual details and facilitate the processing of coarse visual features. In the present study, we investigated whether emotion can boost the activation and inhibition of automatic motor responses that are generated prior to overt perception. To investigate this, we tested whether an emotional cue affects covert motor responses in a masked priming task. We used a masked priming paradigm in which participants responded to target arrows that were preceded by invisible congruent or incongruent prime arrows. In the standard paradigm, participants react faster, and commit fewer errors responding to the directionality of target arrows, when they are preceded by congruent vs. incongruent masked prime arrows (positive congruency effect, PCE). However, as prime-target SOAs increase, this effect reverses (negative congruency effect, NCE). These findings have been explained as evidence for an initial activation and a subsequent inhibition of a partial response elicited by the masked prime arrow. Our results show that the presentation of fearful face cues, compared to neutral face cues, increased the size of both the PCE and NCE, despite the fact that the primes were invisible. This is the first demonstration that emotion prepares an individual's visuomotor system for automatic activation and inhibition of motor responses in the absence of visual awareness.

Prime Slaughter

DEFF Research Database (Denmark)

Valente, Andrea; Marchetti, Emanuela

2011-01-01

of primality and factorization into playful interactions, addressed to primary and early secondary school children. Taking into account individual needs expressed by children regarding play, during a participatory design processes aimed at enhancing learning in museums, Prime Slaughter allows for multiple...... forms of play and their integration. A simple working prototype has already been developed; it will be tested and re-designed through participatory workshops, involving a group of children in our target group....

Color coherent effects in (e,e{prime}N) and (e,e{prime}N,N(h)) processes at CEBAF

Energy Technology Data Exchange (ETDEWEB)

Frankfurt, L.L.; Sargsyan, M.M. [Tel Aviv Univ. (Israel); Strikman, M.I. [Pennsylvania State Univ., University Park, PA (United States)]|[St. Petersburg Nuclear Physics Inst. (Russian Federation)

1994-04-01

The options for investigating color coherent effects and competing nuclear effects of nucleon-nucleon correlations in nuclei, nuclear shell effects in (e, e{prime}N) and (e, e{prime}NN(h)) reactions are considered. They argue that extension of CEBAF energies to reach Q{sup 2} = 10 GeV{sup 2} will allow systematical investigations of color coherent effects in nonperturbative regime of QCD and their interplay with nuclear effects.

STEP--a System for Teaching Experimental Psychology using E-Prime.

Science.gov (United States)

MacWhinney, B; St James, J; Schunn, C; Li, P; Schneider, W

2001-05-01

Students in psychology need to learn to design and analyze their own experiments. However, software that allows students to build experiments on their own has been limited in a variety of ways. The shipping of the first full release of the E-Prime system later this year will open up a new opportunity for addressing this problem. Because E-Prime promises to become the standard for building experiments in psychology, it is now possible to construct a Web-based resource that uses E-Prime as the delivery engine for a wide variety of instructional materials. This new system, funded by the National Science Foundation, is called STEP (System for the Teaching of Experimental Psychology). The goal of the STEP Project is to provide instructional materials that will facilitate the use of E-Prime in various learning contexts. We are now compiling a large set of classic experiments implemented in E-Prime and available over the Internet from http://step.psy.cmu.edu. The Web site also distributes instructional materials for building courses in experimental psychology based on E-Prime.

Prime Minister of Pakistan visits CERN

CERN Multimedia

Anaïs Schaeffer

2016-01-01

On Saturday, 23 January 2016, CERN welcomed Mr Muhammad Nawaz Sharif, Prime Minister of Pakistan.   From left to right: Minister of Finance Mr Mohammad Ishaq Dar, Prime Minister of the Islamic Republic of Pakistan, Muhammad Nawaz Sharif, CERN Director-General Fabiola Gianotti and CMS national contact physicist Hafeez Hoorani. Mr Muhammad Nawaz Sharif arrived at Point 5 in Cessy, where he was welcomed onto French soil by the sous-préfet of Cessy, Stéphane Donnot, and, representing CERN, Director-General Fabiola Gianotti, Directors Eckhard Elsen and Charlotte Warakaulle, and Rüdiger Voss, the adviser for relations with Pakistan. It was the first visit by a head of government of Pakistan since the country became CERN's latest Associate Member State in July 2015. The Prime Minister then had the opportunity to visit the CMS underground experimental area accompanied by the CMS Spokesperson, Tiziano Camporesi, and the CMS collaboration’...

Mutations of the aminoacyl-tRNA-synthetases SARS and WARS2 are implicated in the etiology of autosomal recessive intellectual disability.

Science.gov (United States)

Musante, Luciana; Püttmann, Lucia; Kahrizi, Kimia; Garshasbi, Masoud; Hu, Hao; Stehr, Henning; Lipkowitz, Bettina; Otto, Sabine; Jensen, Lars R; Tzschach, Andreas; Jamali, Payman; Wienker, Thomas; Najmabadi, Hossein; Ropers, Hans Hilger; Kuss, Andreas W

2017-06-01

Intellectual disability (ID) is the hallmark of an extremely heterogeneous group of disorders that comprises a wide variety of syndromic and non-syndromic phenotypes. Here, we report on mutations in two aminoacyl-tRNA synthetases that are associated with ID in two unrelated Iranian families. In the first family, we identified a homozygous missense mutation (c.514G>A, p.Asp172Asn) in the cytoplasmic seryl-tRNA synthetase (SARS) gene. The mutation affects the enzymatic core domain of the protein and impairs its enzymatic activity, probably leading to reduced cytoplasmic tRNA Ser concentrations. The mutant protein was predicted to be unstable, which could be substantiated by investigating ectopic mutant SARS in transfected HEK293T cells. In the second family, we found a compound heterozygous genotype of the mitochondrial tryptophanyl-tRNA synthetase (WARS2) gene, comprising a nonsense mutation (c.325delA, p.Ser109Alafs*15), which very likely entails nonsense-mediated mRNA decay and a missense mutation (c.37T>G, p.Trp13Gly). The latter affects the mitochondrial localization signal of WARS2, causing protein mislocalization. Including AIMP1, which we have recently implicated in the etiology of ID, three genes with a role in tRNA-aminoacylation are now associated with this condition. We therefore suggest that the functional integrity of tRNAs in general is an important factor in the development and maintenance of human cognitive functions. © 2017 Wiley Periodicals, Inc.

Targeted Disruption of Nonribosomal Peptide Synthetase pes3 Augments the Virulence of Aspergillus fumigatus

DEFF Research Database (Denmark)

O'Hanlon, Karen A.; Cairns, Timothy; Stack, Deirdre

2011-01-01

metabolite profiling revealed that Pes3 does not produce a secreted or intracellularly stored NRP in A. fumigatus. Macrophage infections and histological analysis of infected murine tissue indicate that Δpes3 heightened virulence appears to be mediated by aberrant innate immune recognition of the fungus....... Proteome alterations in A. fumigatus Δpes3 strongly suggest impaired germination capacity. Uniquely, our data strongly indicate a structural role for the Pes3-encoded NRP, a finding that appears to be novel for an NRP synthetase....

Structure of Prolyl-tRNA Synthetase-Halofuginone Complex Provides Basis for Development of Drugs against Malaria and Toxoplasmosis.

Science.gov (United States)

Jain, Vitul; Yogavel, Manickam; Oshima, Yoshiteru; Kikuchi, Haruhisa; Touquet, Bastien; Hakimi, Mohamed-Ali; Sharma, Amit

2015-05-05

The Chinese herb Dichroa febrifuga has traditionally treated malaria-associated fever. Its active component febrifugine (FF) and derivatives such as halofuginone (HF) are potent anti-malarials. Here, we show that FF-based derivatives arrest parasite growth by direct interaction with and inhibition of the protein translation enzyme prolyl-tRNA synthetase (PRS). Dual administration of inhibitors that target different tRNA synthetases suggests high utility of these drug targets. We reveal the ternary complex structure of PRS-HF and adenosine 5'-(β,γ-imido)triphosphate where the latter facilitates HF integration into the PRS active site. Structural analyses also highlight spaces within the PRS architecture for HF derivatization of its quinazolinone, but not piperidine, moiety. We also show a remarkable ability of HF to kill the related human parasite Toxoplasma gondii, suggesting wider HF efficacy against parasitic PRSs. Hence, our cell-, enzyme-, and structure-based data on FF-based inhibitors strengthen the case for their inclusion in anti-malarial and anti-toxoplasmosis drug development efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

PrimeFaces blueprints

CERN Document Server

Jonna, Sudheer

2014-01-01

If you are a Java developer with experience of frontend UI development, and want to take the plunge to develop stunning UI applications with the most popular JSF framework, PrimeFaces, then this book is for you. For those with entrepreneurial aspirations, this book will provide valuable insights into how to utilize successful business models.

Neural correlates of cross-domain affective priming.

Science.gov (United States)

Zhang, Qin; Li, Xiaohua; Gold, Brian T; Jiang, Yang

2010-05-06

The affective priming effect has mostly been studied using reaction time (RT) measures; however, the neural bases of affective priming are not well established. To understand the neural correlates of cross-domain emotional stimuli presented rapidly, we obtained event-related potential (ERP) measures during an affective priming task using short SOA (stimulus onset asynchrony) conditions. Two sets of 480 picture-word pairs were presented at SOAs of either 150ms or 250ms between prime and target stimuli. Participants decided whether the valence of each target word was pleasant or unpleasant. Behavioral results from both SOA conditions were consistent with previous reports of affective priming, with longer RTs for incongruent than congruent pairs at SOAs of 150ms (771 vs. 738ms) and 250ms (765 vs. 720ms). ERP results revealed that the N400 effect (associated with incongruent pairs in affective processing) occurred at anterior scalp regions at an SOA of 150ms, and this effect was only observed for negative target words across the scalp at an SOA of 250ms. In contrast, late positive potentials (LPPs) (associated with attentional resource allocation) occurred across the scalp at an SOA of 250ms. LPPs were only observed for positive target words at posterior parts of the brain at an SOA of 150ms. Our finding of ERP signatures at very short SOAs provides the first neural evidence that affective pictures can exert an automatic influence on the evaluation of affective target words. Copyright 2010 Elsevier B.V. All rights reserved.

The action of Saraca asoca Roxb. de Wilde bark on the PGH2 synthetase enzyme complex of the sheep vesicular gland.

Science.gov (United States)

Middelkoop, T B; Labadie, R P

1985-01-01

Extracts of S. asoca bark and pure compounds isolated from the bark were tested for properties that might inhibit the conversion of arachidonic acid by the PGH2 synthetase. They were assayed spectrophotometrically with adrenaline as cofactor. Methanol- and ethyl acetate extracts inhibited the conversion. The observed inhibition was confirmed in an oxygraphic assay. Two procyanidin dimers from the ethyl acetate extract showed enzyme catalyzed oxidation in our assay. The ether extract of the bark was also found to contain yet unknown substances which were capable of being oxidised by the PGH2 synthetase. The combined action of the components of the bark may explain the mode of action of the drug Asoka Aristha, the main ingredient of which is the bark of S. asoca. The drug is traditionally used in Sri Lanka to treat menorrhagia.

The set of prime numbers: Multiscale analysis and numeric accelerators

International Nuclear Information System (INIS)

Iovane, Gerardo

2009-01-01

In this work, we show that the prime numbers follow a multiscale distribution. Indeed they can be classified thanks to tree structures, which are expressed in terms of two maximal subsets of N and using multilayer selection rules, acting on these sets of prime candidates. Consequently, the prime numbers follow a specific deterministic rules. Indeed, a numeric accelerator for generating primes can be realized in terms of the above mentioned specific rules. From the comparison with the Fibonacci numbers a beautiful harmony comes in terms of the Golden Mean which is relevant to high energy physics and E-Infinity theory too.

In situ autoradiographic detection of folylpolyglutamate synthetase activity

International Nuclear Information System (INIS)

Sussman, D.J.; Milman, G.; Osborne, C.; Shane, B.

1986-01-01

The enzyme folylpolyglutamate synthetase (FPGS) catalyzes the conversion of folate (pteroylmonoglutamate) to the polyglutamate forms (pteroylpolyglutamates) that are required for folate retention by mammalian cells. A rapid in situ autoradiographic assay for FPGS was developed which is based on the folate cofactor requirement of thymidylate synthase. Chinese hamster AUX B1 mutant cells lack FPGS activity and are unable to accumulate folate. As a result, the conversion of [6- 3 H]deoxyuridine to thymidine via the thymidylate synthase reaction is impaired in AUX B1 cells and no detectable label is incorporated into DNA. In contrast, FPGS in wild-type Chinese hamster CHO cells causes folate retention and enables the incorporation of [6- 3 H]deoxyuridine into DNA. Incorporation may be detected by autoradiography of monolayer cultures or of colonies replica plated onto polyester discs. Introduction of Escherichia coli FPGS into AUX B1 cells restores the activity of the thymidylate synthase pathway and demonstrates that the E. coli FPGS enzyme can provide pteroylpolyglutamates which functions in mammalian cells

Ovation Prime Real-Time

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Ovation Prime Real-Time (OPRT) product is a real-time forecast and nowcast model of auroral power and is an operational implementation of the work by Newell et...

Priming of disability and elderly stereotype in motor performance: similar or specific effects?

Science.gov (United States)

Ginsberg, Frederik; Rohmer, Odile; Louvet, Eva

2012-04-01

In three experimental studies, the effects of priming participants with the disability stereotype were investigated with respect to their subsequent motor performance. Also explored were effects of activating two similar stereotypes, persons with a disability and elderly people. In Study 1, participants were primed with the disability stereotype versus with a neutral prime, and then asked to perform on a motor coordination task. In Studies 2 and 3, a third condition was introduced: priming participants with the elderly stereotype. Results indicated that priming participants with the disability stereotype altered their motor performance: they showed decreased manual dexterity and performed slower than the non-primed participants. Priming with the elderly stereotype decreased only performance speed. These findings underline that prime-to-behavior effects may depend on activation of specific stereotype content.

Recognition of tRNAs with a long variable arm by aminoacyl-tRNA synthetases

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Tukalo M. A.

2013-07-01

Full Text Available In prokaryotic cells three tRNA species, tRNASer, tRNALeu and tRNATyr, possess a long variable arm of 11–20 nucleotides (type 2 tRNA rather than usual 4 or 5 nucleotides (type 1 tRNA. In this review we have summarized the results of our research on the structural basis for recognition and discrimination of type 2 tRNAs by Thermus thermophilus seryl-, tyrosyl- and leucyl-tRNA synthetases (SerRS, TyrRS and LeuRS obtained by X-ray crystallography and chemical probing tRNA in solution. Crystal structures are now known of all three aminoacyl-tRNA synthetases complexed with type 2 tRNAs and the different modes of tRNA recognition represented by these structures will be discussed. In particular, emphasis will be given to the results on recognition of characteristic shape of type 2 tRNAs by cognate synthetases. In tRNASer, tRNATyr and tRNALeu the orientation of the long variable arm with respect to the body of the tRNA is different and is controlled by different packing of the core. In the case of SerRS the N-terminal domain and in the case of TyrRS, the C-terminal domain, bind to the characteristic long variable arm of the cognate RNA, thus recognizing the unique shape of the tRNA. The core of T. thermophilus tRNALeu has several layers of unusual base-pairs, which are revealed by the crystal structure of tRNALeu complexed with T. thermophilus LeuRS and by probing a ligand-free tRNA by specific chemical reagents in solution. In the crystal structure of the LeuRS-tRNALeu complex the unique D-stem structure is recognized by the C-terminal domain of LeuRS and these data are in good agreement with those obtained in solution. LeuRS has canonical class I mode of tRNA recognition, approaching the tRNA acceptor stem from the D-stem and minor groove of the acceptor stem side. SerRS also has canonical class II mode of tRNA recognition and approaches tRNASer from opposite, variable stem and major groove of acceptor stem site. And finally, TyrRS in strong

Target Categorization with Primes that Vary in Both Congruency and Sense Modality

Directory of Open Access Journals (Sweden)

Kathryn eWeatherford

2015-01-01

Full Text Available In two experiments we examined conceptual priming within and across sense modalities by varying the modality (picture and environmental sounds and the category congruency of prime-target pairs. Both experiments used a repetition priming paradigm, but Experiment 1 studied priming effects with a task that required a superordinate categorization response (man-made or natural, while Experiment 2 used a lower-level category response (musical instruments or animal: one that was more closely associated with the basic level of the semantic network. Results from Experiment 1 showed a strong effect of target modality and two distinct patterns of conceptual priming effects with picture and environmental sound targets. However, no priming advantage was found when congruent and incongruent primes were compared. Results from Experiment 2, found congruency effects that were specific to environmental sound targets when preceded by picture primes. The findings provide support for the intermodal event file and multisensory framework, and suggest that auditory and visual features about a single item in a conceptual category may be more tightly connected than two different items from the same category.

Colorimetry and prime colours--a theorem.

Science.gov (United States)

Hornaes, Hans Petter; Wold, Jan Henrik; Farup, Ivar

2005-08-01

Human colour vision is the result of a complex process involving topics ranging from physics of light to perception. Whereas the diversity of light entering the eye in principle span an infinite-dimensional vector space in terms of the spectral power distributions, the space of human colour perceptions is three dimensional. One important consequence of this is that a variety of colours can be visually matched by a mixture of only three adequately chosen reference lights. It has been observed that there exists one particular set of monochromatic reference lights that, according to a certain definition, is optimal for producing colour matches. These reference lights are commonly denoted prime colours. In the present paper, we intend to rigorously show that the existence of prime colours is not particular to the human visual system as sometimes stated, but rather an algebraic consequence of the manner in which a kind of colorimetric functions called colour-matching functions are defined and transformed. The solution is based on maximisation of a determinant determining the gamut size of the colour space spanned by the prime colours. Cramer's rule for solving a set of linear equations is an essential part of the proof. By means of examples, it is shown that mathematically the optimal set of reference lights is not unique in general, and that the existence of a maximum determinant is not a necessary condition for the existence of prime colours.

Making sense of the Sense Model: translation priming with Japanese-English bilinguals

OpenAIRE

Allen, David; Conklin, Kathy; Van Heuven, Walter J.B.

2015-01-01

Many studies have reported that first language (L1) translation primes speed responses to second language (L2) targets, whereas L2 translation primes generally do not speed up responses to L1 targets in lexical decision. According to the Sense Model (Finkbeiner, Forster, Nicol & Nakamura, 2004) this asymmetry is due to the proportion of senses activated by the prime. Because L2 primes activate only a subset of the L1 translations senses, priming is not observed. In this study we test the pred...

Withania somnifera Root Extract Enhances Chemotherapy through 'Priming'.

Directory of Open Access Journals (Sweden)

Aine Brigette Henley

Full Text Available Withania somnifera extracts are known for their anti-cancerous, anti-inflammatory and antioxidative properties. One of their mechanisms of actions is to modulate mitochondrial function through increasing oxidative stress. Recently 'priming' has been suggested as a potential mechanism for enhancing cancer cell death. In this study we demonstrate that 'priming', in HT-29 colon cells, with W. somnifera root extract increased the potency of the chemotherapeutic agent cisplatin. We have also showed the W. somnifera root extract enhanced mitochondrial dysfunction and that the underlying mechanism of 'priming' was selectively through increased ROS. Moreover, we showed that this effect was not seen in non-cancerous cells.

CROSS-TOLERANCE MECHANISM INDUCTION IN MELON SEEDS BY PRIMING PRIOR DRYING

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Jean Marcel Sousa Lira

2015-04-01

Full Text Available The loss of benefits after re-drying is one of the drawbacks of the seed priming technique. Different types of stresses have been used before re-drying to preserve the priming benefits. This process may be seen as promoting cross tolerance to increase the defense mechanisms that prevent loss of viability in seeds primed after drying. We tested the effect of some stresses to induce cross-tolerance and different drying conditions with the aim of maintaining priming benefits in melon seeds. The seeds were primed in an aerated KNO3 solution (0.35M, -1.7MPa, 25 °C, in the dark for six days. The primed seeds were then submitted to slow drying, fast drying, cold shock + slow drying, cold shock + fast drying, heat shock + slow drying, heat shock + fast drying, PEG + slow drying, PEG + fast drying, ABA + slow drying, ABA + fast drying and no drying (planted directly after priming. We evaluated antioxidant enzyme activities (SOD, CAT and APX, germinability, mean time of germination (MTG and mean rate of germination (MRG. A completely randomized design was used with three repetitions of 50 seeds in each treatment. Data were analyzed by ANOVA and means were compared by the Scott-Knott test (p ≤ 0.05. ABA increased SOD activity after drying and CAT activity was reduced by priming. APX activity was not observed. The stress submission prior to re-drying improved the MRG and reduced MTG. Therefore, the induction of the cross-tolerance mechanism could be effective to maintain priming benefits in melon seeds.

Conscious, but not unconscious, logo priming of brands and related words.

Science.gov (United States)

Brintazzoli, Gigliola; Soetens, Eric; Deroost, Natacha; Van den Bussche, Eva

2012-06-01

This study assessed whether real-life stimulus material can elicit conscious and unconscious priming. A typical masked priming paradigm was used, with brand logo primes. We used a rigorous method to assess participants' awareness of the subliminal information. Our results show that shortly presented and masked brand logos (e.g., logo of McDonald's) have the power to prime their brand names (e.g., "McDonald's") and, remarkably, words associated to the brand (e.g., "hamburger"). However, this only occurred when the logos could be categorized clearly above the consciousness threshold. Once the primes were presented close to the consciousness threshold, no subliminal influences on behavior were observed. Copyright © 2012 Elsevier Inc. All rights reserved.

On prime ideals and associated spectrum of BCK-algebras

International Nuclear Information System (INIS)

Ahsan, J.; Thaheem, A.B.; Deeba, E.Y.

1989-07-01

In this paper we study prime ideals and define the spectrum of a bounded commutative BCK-algebra. We also obtain a characterization of minimal prime (lattice) ideals of these algebras. (author). 8 refs, 4 tabs

C3-dependent mechanism of microglial priming relevant to multiple sclerosis

NARCIS (Netherlands)

Ramaglia, Valeria; Hughes, Timothy R.; Donev, Rossen M.; Ruseva, Marieta M.; Wu, Xiaobo; Huitinga, Inge; Baas, Frank; Neal, James W.; Morgan, B. Paul

2012-01-01

Microglial priming predisposes the brain to neurodegeneration and affects disease progression. The signal to switch from the quiescent to the primed state is unknown. We show that deleting the C3 convertase regulator complement receptor 1-related protein y (Crry) induces microglial priming. Mice

Overexpression of S-adenosyl-L-methionine synthetase increased tomato tolerance to alkali stress through polyamine metabolism.

Science.gov (United States)

Gong, Biao; Li, Xiu; VandenLangenberg, Kyle M; Wen, Dan; Sun, Shasha; Wei, Min; Li, Yan; Yang, Fengjuan; Shi, Qinghua; Wang, Xiufeng

2014-08-01

S-adenosyl-L-methionine (SAM) synthetase is the key enzyme involved in the biosynthesis of SAM, which serves as a common precursor for polyamines (PAs) and ethylene. A SAM synthetase cDNA (SlSAMS1) was introduced into the tomato genome using the Agrobacterium tumefaciens transformation method. Transgenic plants overexpressing SlSAMS1 exhibited a significant increase in tolerance to alkali stress and maintained nutrient balance, higher photosynthetic capacity and lower oxidative stress compared with WT lines. Both in vivo and in vitro experiments indicated that the function of SlSAMS1 mainly depended on the accumulation of Spd and Spm in the transgenic lines. A grafting experiment showed that rootstocks from SlSAMS1-overexpressing plants provided a stronger root system, increased PAs accumulation, essential elements absorption, and decreased Na(+) absorption in the scions under alkali stress. As a result, fruit set and yield were significantly enhanced. To our knowledge, this is the first report to provide evidence that SlSAMS1 positively regulates tomato tolerance to alkali stress and plays a major role in modulating polyamine metabolism, resulting in maintainability of nutrient and ROS balance. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Inflammasome priming is similar for francisella species that differentially induce inflammasome activation.

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Mohammed G Ghonime

Full Text Available Inflammasome activation is a two-step process where step one, priming, prepares the inflammasome for its subsequent activation, by step two. Classically step one can be induced by LPS priming followed by step two, high dose ATP. Furthermore, when IL-18 processing is used as the inflammasome readout, priming occurs before new protein synthesis. In this context, how intracellular pathogens such as Francisella activate the inflammasome is incompletely understood, particularly regarding the relative importance of priming versus activation steps. To better understand these events we compared Francisella strains that differ in virulence and ability to induce inflammasome activation for their relative effects on step one vs. step two. When using the rapid priming model, i.e., 30 min priming by live or heat killed Francisella strains (step 1, followed by ATP (step 2, we found no difference in IL-18 release, p20 caspase-1 release and ASC oligomerization between Francisella strains (F. novicida, F. holarctica -LVS and F. tularensis Schu S4. This priming is fast, independent of bacteria viability, internalization and phagosome escape, but requires TLR2-mediated ERK phosphorylation. In contrast to their efficient priming capacity, Francisella strains LVS and Schu S4 were impaired in inflammasome triggering compared to F. novicida. Thus, observed differences in inflammasome activation by F. novicida, LVS and Schu S4 depend not on differences in priming but rather on their propensity to trigger the primed inflammasome.

Priming involuntary autobiographical memories in the lab

OpenAIRE

Barzykowski, Krystian; Niedźwieńska, Agnieszka

2018-01-01

Involuntary autobiographical memories (IAMs) are recollections of personal past that frequently and spontaneously occur in daily life. Initial studies by Mace. Priming involuntary autobiographical memories. Showed that deliberately reminiscing about a certain lifetime period (e.g., high school) significantly increased the number of different IAMs from the same period in subsequent days, suggesting that priming may play a significant role in the retrieval of IAMs in everyday life. In the prese...

How visual working memory contents influence priming of visual attention.

Science.gov (United States)

Carlisle, Nancy B; Kristjánsson, Árni

2017-04-12

Recent evidence shows that when the contents of visual working memory overlap with targets and distractors in a pop-out search task, intertrial priming is inhibited (Kristjánsson, Sævarsson & Driver, Psychon Bull Rev 20(3):514-521, 2013, Experiment 2, Psychonomic Bulletin and Review). This may reflect an interesting interaction between implicit short-term memory-thought to underlie intertrial priming-and explicit visual working memory. Evidence from a non-pop-out search task suggests that it may specifically be holding distractors in visual working memory that disrupts intertrial priming (Cunningham & Egeth, Psychol Sci 27(4):476-485, 2016, Experiment 2, Psychological Science). We examined whether the inhibition of priming depends on whether feature values in visual working memory overlap with targets or distractors in the pop-out search, and we found that the inhibition of priming resulted from holding distractors in visual working memory. These results are consistent with separate mechanisms of target and distractor effects in intertrial priming, and support the notion that the impact of implicit short-term memory and explicit visual working memory can interact when each provides conflicting attentional signals.

A proof of the conjecture on the twin primes

Energy Technology Data Exchange (ETDEWEB)

Zuo-ling, Zhou [Department of Lingnan college, Sun Yat-sen University GuangZhou, GuangDong, 510275 (China)

2016-06-08

In this short note, we have proved the conjecture on twin primes using some thoughts of the set theory. Firstly, using the original sieve method and a new notation(concept)introduced by myself, the conjecture on twin primes is summed up as an elementary successive limit, afterwards we form a subsequence of positive integers,and using it,we prove that the successive limits are commutative and complete the proof of the conjecture on twin primes We also give a more straightforward proof of the conjecture.

Comparative analysis of oligonucleotide primers for high-throughput screening of genes encoding adenylation domains of nonribosomal peptide synthetases in actinomycetes

Czech Academy of Sciences Publication Activity Database

Bakal, Tomáš; Goo, K.-S.; Najmanová, Lucie; Plháčková, Kamila; Kadlčík, Stanislav; Ulanová, Dana

2015-01-01

Roč. 108, č. 5 (2015), s. 1267-1274 ISSN 0003-6072 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Nonribosomal peptide synthetase * Adenylation domain * Actinomycetes Subject RIV: EE - Microbiology, Virology Impact factor: 1.944, year: 2015

Aggressive priming online: Facebook adverts can prime aggressive cognitions

OpenAIRE

Buchanan, Tom

2015-01-01

Through the process of priming, incidental stimuli in our environments can influence our thoughts, feelings and behavior. This may be true of incidental stimuli in online environments, such as adverts on websites. Two experiments (N=325, N=331) showed that the mere presence of advertisements with violent content on a simulated Facebook page induced higher levels of aggression-related cognition in comparison to non-violent adverts (d=0.56 , d=0.71). In a subsequent word recognition task, parti...

Seed Priming to Overcome Salinity Stress in Persian Cultivars of Alfalfa (Medicago sativa L.

Directory of Open Access Journals (Sweden)

Ali SEPEHRI

2015-03-01

Full Text Available In order to investigate the effect of hydro-priming on seed germination with distilled water on germination of five Alfalfa cultivars under salinity stress, an experiment was conducted as a factorial experiment based on a completely randomized design with three replications. Seven levels of hydro-priming and salinity of NaCl including prime and non-salinity, prime and 50 mM salinity, prime and 100 mM salinity, prime and 150 mM salinity, prime and 200 mM salinity, prime and 250 mM salinity and without prime and salinity and five alfalfa varieties, including ‘Hamedani’, ‘Isfahani’, ‘Bami’, ‘Yazdi’ and ‘Ghareh Yonjeh’ were used. The results showed that the main effect of prime, salinity and cultivars and their interaction in all studied traits were significantly affected at the 5% probability level. Priming treatments in non-salinity of all cultivars were the highest. In all cultivars, final germination percentage, length and weight of radicle, plumule and seedling, germination rate and time, relative radicle elongation, vigor index and stress index, were significantly improved in response to priming in salinity levels of 50-200 mM, compared to control. Radicle produced higher length and weight than the plumule in hydro- priming and salinity treatments. ‘Hamedani’ cultivar in most of studied characteristics had a better response than others. The lowest response to salinity stress and priming was observed in ‘Yazdi’ cultivar.

Ribosomal incorporation of backbone modified amino acids via an editing-deficient aminoacyl-tRNA synthetase.

Science.gov (United States)

Iqbal, Emil S; Dods, Kara K; Hartman, Matthew C T

2018-02-14

The ability to incorporate non-canonical amino acids (ncAA) using translation offers researchers the ability to extend the functionality of proteins and peptides for many applications including synthetic biology, biophysical and structural studies, and discovery of novel ligands. Here we describe the high promiscuity of an editing-deficient valine-tRNA synthetase (ValRS T222P). Using this enzyme, we demonstrate ribosomal translation of 11 ncAAs including those with novel side chains, α,α-disubstitutions, and cyclic β-amino acids.

Multi-targeted priming for genome-wide gene expression assays

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Adomas Aleksandra B

2010-08-01

Full Text Available Abstract Background Complementary approaches to assaying global gene expression are needed to assess gene expression in regions that are poorly assayed by current methodologies. A key component of nearly all gene expression assays is the reverse transcription of transcribed sequences that has traditionally been performed by priming the poly-A tails on many of the transcribed genes in eukaryotes with oligo-dT, or by priming RNA indiscriminately with random hexamers. We designed an algorithm to find common sequence motifs that were present within most protein-coding genes of Saccharomyces cerevisiae and of Neurospora crassa, but that were not present within their ribosomal RNA or transfer RNA genes. We then experimentally tested whether degenerately priming these motifs with multi-targeted primers improved the accuracy and completeness of transcriptomic assays. Results We discovered two multi-targeted primers that would prime a preponderance of genes in the genomes of Saccharomyces cerevisiae and Neurospora crassa while avoiding priming ribosomal RNA or transfer RNA. Examining the response of Saccharomyces cerevisiae to nitrogen deficiency and profiling Neurospora crassa early sexual development, we demonstrated that using multi-targeted primers in reverse transcription led to superior performance of microarray profiling and next-generation RNA tag sequencing. Priming with multi-targeted primers in addition to oligo-dT resulted in higher sensitivity, a larger number of well-measured genes and greater power to detect differences in gene expression. Conclusions Our results provide the most complete and detailed expression profiles of the yeast nitrogen starvation response and N. crassa early sexual development to date. Furthermore, our multi-targeting priming methodology for genome-wide gene expression assays provides selective targeting of multiple sequences and counter-selection against undesirable sequences, facilitating a more complete and

Conceptual and non-conceptual repetition priming in category exemplar generation: Evidence from bilinguals.

Science.gov (United States)

Francis, Wendy S; Fernandez, Norma P; Bjork, Robert A

2010-10-01

One measure of conceptual implicit memory is repetition priming in the generation of exemplars from a semantic category, but does such priming transfer across languages? That is, do the overlapping conceptual representations for translation equivalents provide a sufficient basis for such priming? In Experiment 1 (N=96) participants carried out a deep encoding task, and priming between languages was statistically reliable, but attenuated, relative to within-language priming. Experiment 2 (N=96) replicated the findings of Experiment 1 and assessed the contributions of conceptual and non-conceptual processes using a levels-of-processing manipulation. Words that underwent shallow encoding exhibited within-language, but not between-language, priming. Priming in shallow conditions cannot therefore be explained by incidental activation of the concept. Instead, part of the within-language priming effect, even under deep-encoding conditions, is due to increased availability of language-specific lemmas or phonological word forms.

Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

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Saddam eHussain

2016-02-01

Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

On the last digits of consecutive primes

OpenAIRE

Holt, Fred B.

2016-01-01

Recently Oliver and Soundararajan made conjectures based on computational enumerations about the frequency of occurrence of pairs of last digits for consecutive primes. By studying Eratosthenes sieve, we have identified discrete dynamic systems that exactly model the populations of gaps across stages of Eratosthenes sieve. Our models provide some insight into the observed biases in the occurrences of last digits in consecutive primes, and the models suggest that the biases will ultimately be ...

A note on the countable union of prime submodules

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M. R. Pournaki

2001-01-01

Full Text Available Let M be a finitely-generated module over a Noetherian ring R. Suppose is an ideal of R and let N=M and =Ann(M/N. If ⫅J(R, M is complete with respect to the -adic topology, {Pi}i≥1 is a countable family of prime submodules of M, and x∈M, then x+N⫅∪i≥1Pi implies that x+N⫅Pj for some i≥1. This extends a theorem of Sharp and Vámos concerning prime ideals to prime submodules.

Physiological quality and seed respiration of primed Jatropha curcas seeds

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Micheli Angelica Horbach

2017-11-01

Full Text Available ABSTRACT Seed deterioration is a natural and irreversible process. Nevertheless, seed priming with water and antioxidants can minimize oxidative damage in oilseeds, resulting in attenuation of seed deterioration. The objective of this assay was to evaluate seed priming on respiratory activity of Jatropha curcas submitted to accelerated aging. Seeds from two provenances (Janauba and Pedro J. Caballero were submitted to three priming treatments (control, immersion in deionized water, and with 750 µmol L-1 of ascorbic acid and treated for accelerated aging at 41 °C for 72 h. The results showed that the priming of J. curcas seeds promoted tolerance to accelerated aging. Primed seeds, with ascorbic acid from Janauba and deionized water from Pedro J. Caballero, resulted in a higher percentage of normal seedlings, and increased germination speed index and seed respiration. The decline of physiological quality of J. curcas seeds after accelerated aging is directly associated with a reduction in respiratory activity that is related to seed moisture content.

Priming patient safety: A middle-range theory of safety goal priming via safety culture communication.

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Groves, Patricia S; Bunch, Jacinda L

2018-05-18

The aim of this paper is discussion of a new middle-range theory of patient safety goal priming via safety culture communication. Bedside nurses are key to safe care, but there is little theory about how organizations can influence nursing behavior through safety culture to improve patient safety outcomes. We theorize patient safety goal priming via safety culture communication may support organizations in this endeavor. According to this theory, hospital safety culture communication activates a previously held patient safety goal and increases the perceived value of actions nurses can take to achieve that goal. Nurses subsequently prioritize and are motivated to perform tasks and risk assessment related to achieving patient safety. These efforts continue until nurses mitigate or ameliorate identified risks and hazards during the patient care encounter. Critically, this process requires nurses to have a previously held safety goal associated with a repertoire of appropriate actions. This theory suggests undergraduate educators should foster an outcomes focus emphasizing the connections between nursing interventions and safety outcomes, hospitals should strategically structure patient safety primes into communicative activities, and organizations should support professional development including new skills and the latest evidence supporting nursing practice for patient safety. © 2018 John Wiley & Sons Ltd.

The structure of semantic person memory: evidence from semantic priming in person recognition.

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Wiese, Holger

2011-11-01

This paper reviews research on the structure of semantic person memory as examined with semantic priming. In this experimental paradigm, a familiarity decision on a target face or written name is usually faster when it is preceded by a related as compared to an unrelated prime. This effect has been shown to be relatively short lived and susceptible to interfering items. Moreover, semantic priming can cross stimulus domains, such that a written name can prime a target face and vice versa. However, it remains controversial whether representations of people are stored in associative networks based on co-occurrence, or in more abstract semantic categories. In line with prominent cognitive models of face recognition, which explain semantic priming by shared semantic information between prime and target, recent research demonstrated that priming could be obtained from purely categorically related, non-associated prime/target pairs. Although strategic processes, such as expectancy and retrospective matching likely contribute, there is also evidence for a non-strategic contribution to priming, presumably related to spreading activation. Finally, a semantic priming effect has been demonstrated in the N400 event-related potential (ERP) component, which may reflect facilitated access to semantic information. It is concluded that categorical relatedness is one organizing principle of semantic person memory. ©2011 The British Psychological Society.

Small-angle X-ray Solution Scattering Study of the Multi-aminoacyl-tRNA Synthetase Complex Reveals an Elongated and Multi-armed particle*

Science.gov (United States)

Dias, José; Renault, Louis; Pérez, Javier; Mirande, Marc

2013-01-01

In animal cells, nine aminoacyl-tRNA synthetases are associated with the three auxiliary proteins p18, p38, and p43 to form a stable and conserved large multi-aminoacyl-tRNA synthetase complex (MARS), whose molecular mass has been proposed to be between 1.0 and 1.5 MDa. The complex acts as a molecular hub for coordinating protein synthesis and diverse regulatory signal pathways. Electron microscopy studies defined its low resolution molecular envelope as an overall rather compact, asymmetric triangular shape. Here, we have analyzed the composition and homogeneity of the native mammalian MARS isolated from rabbit liver and characterized its overall internal structure, size, and shape at low resolution by hydrodynamic methods and small-angle x-ray scattering in solution. Our data reveal that the MARS exhibits a much more elongated and multi-armed shape than expected from previous reports. The hydrodynamic and structural features of the MARS are large compared with other supramolecular assemblies involved in translation, including ribosome. The large dimensions and non-compact structural organization of MARS favor a large protein surface accessibility for all its components. This may be essential to allow structural rearrangements between the catalytic and cis-acting tRNA binding domains of the synthetases required for binding the bulky tRNA substrates. This non-compact architecture may also contribute to the spatiotemporal controlled release of some of its components, which participate in non-canonical functions after dissociation from the complex. PMID:23836901

Thioredoxin priming prolongs lung allograft survival by promoting immune tolerance.

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Hanbo Hu

Full Text Available Tolerance to allograft antigen is the major challenge and final goal of transplant medicine. Our previous study demonstrated that thioredoxin-1 (Trx priming of donor lung significantly protected allogeneic lung graft. To determine whether Trx priming of donor lung inhibits allograft rejection, extends allograft survival and induces immune tolerance, orthotopic left lung transplantation was performed from Lewis to Sprague-Dawley rats without immunosuppression. Donor lungs were primed with Trx at 4°C for 4 hr prior to transplantation. After up to 37 days post-transplantation, allograft lung morphology, recipient T cell and humoral alloantigen-specific immune responses were examined. We found that Trx-primed lungs exhibited much reduced acute rejection and associated lung injuries resulting in loss of graft functional area at 5-37 days post-transplant in contrast to the control groups. CD4+ T cells from the recipients with Trx-primed grafts responded to the stimulation of dendritic cells (DCs of donor origin, in contrast to DCs from the third party, with significantly reduced proliferation. Consistent with above findings, we observed that CD4+Foxp3+ regulatory T cells in spleen cells from the recipients with Trx-primed grafts were significantly increased compared to controls, and CD4+ T cells from the recipients with Trx-primed grafts produced much higher levels of immunosuppressive cytokine, IL-10 when stimulated with allogeneic donor DCs. In addition, humoral immune tolerance was also induced as there was no significant increase levels of serum antibodies against donor antigens in Trx-lung recipients when re-challenged with allogeneic donor antigens. Our results demonstrate that one-time Trx-priming of donor lung grafts prior to transplantation significantly prolongs the survival of the grafts through inducing or promoting cellular and humoral alloantigen-specific immune tolerance, which might be associated with the induction of

Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates.

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Bolton, Diane L; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina

2012-09-07

Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Priming with Rocuronium to Accelerate the Onset Time of Cisatracurium During Intubation

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Shih-Pin Lin

2009-01-01

Conclusion: Priming with rocuronium or cisatracurium for 3 minutes significantly accelerated the onset of cisatracurium. Priming with rocuronium for 3 minutes improved the onset time of cisatracurium even more than priming with cisatracurium itself.

Non-standard amino acid recognition by Escherichia coli leucyl-tRNA synthetase

Science.gov (United States)

Martinis, S. A.; Fox, G. E.

1997-01-01

Recombinant E. coli leucyl-tRNA synthetase was screened for amino acid-dependent pyrophosphate exchange activity using noncognate aliphatic amino acids including norvaline, homocysteine, norleucine, methionine, and homoserine. [32P]-labeled reaction products were separated by thin layer chromatography using a novel solvent system and then quantified by phosphorimaging. Norvaline which differs from leucine by only one methyl group stimulated pyrophosphate exchange activity as did both homocysteine and norleucine to a lesser extent. The KM parameters for leucine and norvaline were measured to be 10 micromoles and 1.5 mM, respectively. Experiments are in progress to determine if norvaline is transferred to tRNA(Leu) and/or edited by a pre- or post-transfer mechanism.

The role of selective attention in perceptual and affective priming

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Stone, M.; Ladd, S. L.; Gabrieli, J. D.

2000-01-01

Two kinds of perceptual priming (word identification and word fragment completion), as well as preference priming (that may rely on special affective mechanisms) were examined after participants either read or named the colors of words and nonwords at study. Participants named the colors of words more slowly than the colors of nonwords, indicating that lexical processing of the words occurred at study. Nonetheless, priming on all three tests was lower after color naming than after reading, despite evidence of lexical processing during color naming shown by slower responses to words than to nonwords. These results indicate that selective attention to (rather than the mere processing of) letter string identity at study is important for subsequent repetition priming.

Fall Colors, 2001-02: Prime Time Diversity Report.

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Parker, McCrae A.; Miller, Patti; Espejo, Eileen; Grossman-Swenson, Sarah

Television is an integral part of American culture, and has the ability to play a major role in shaping belief systems, particularly for the youngest and most impressionable viewers. This study is the third annual study of diversity of characters in prime time television programming. The study examined the first two episodes of each prime time…

Use of genomics to identify bacterial undecaprenyl pyrophosphate synthetase: cloning, expression, and characterization of the essential uppS gene.

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Apfel, C M; Takács, B; Fountoulakis, M; Stieger, M; Keck, W

1999-01-01

The prenyltransferase undecaprenyl pyrophosphate synthetase (di-trans,poly-cis-decaprenylcistransferase; EC 2.5.1.31) was purified from the soluble fraction of Escherichia coli by TSK-DEAE, ceramic hydroxyapatite, TSK-ether, Superdex 200, and heparin-Actigel chromatography. The protein was labeled with the photolabile analogue of the farnesyl pyrophosphate analogue (E, E)-[1-3H]-(2-diazo-3-trifluoropropionyloxy)geranyl diphosphate and was detected on a sodium dodecyl sulfate-polyacrylamide gel as a protein with an apparent molecular mass of 29 kDa. This protein band was cut out from the gel, trypsin digested, and subjected to matrix-assisted laser desorption ionization mass spectrometric analysis. Comparison of the experimental data with computer-simulated trypsin digest data for all E. coli proteins yielded a single match with a protein of unassigned function (SWISS-PROT Q47675; YAES_ECOLI). Sequences with strong similarity indicative of homology to this protein were identified in 25 bacterial species, in Saccharomyces cerevisiae, and in Caenorhabditis elegans. The homologous genes (uppS) were cloned from E. coli, Haemophilus influenzae, and Streptococcus pneumoniae, expressed in E. coli as amino-terminal His-tagged fusion proteins, and purified over a Ni2+ affinity column. An untagged version of the E. coli uppS gene was also cloned and expressed, and the protein purified in two chromatographic steps. We were able to detect Upp synthetase activity for all purified enzymes. Further, biochemical characterization revealed no differences between the recombinant untagged E. coli Upp synthetase and the three His-tagged fusion proteins. All enzymes were absolutely Triton X-100 and MgCl2 dependent. With the use of a regulatable gene disruption system, we demonstrated that uppS is essential for growth in S. pneumoniae R6.

Sulforaphane Modifies Histone H3, Unpacks Chromatin, and Primes Defense.

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Schillheim, Britta; Jansen, Irina; Baum, Stephani; Beesley, Alexander; Bolm, Carsten; Conrath, Uwe

2018-03-01

Modern crop production calls for agrochemicals that prime plants for enhanced defense. Reliable test systems for spotting priming-inducing chemistry, however, are rare. We developed an assay for the high-throughput search for compounds that prime microbial pattern-induced secretion of antimicrobial furanocoumarins (phytoalexins) in cultured parsley cells. The screen produced 1-isothiocyanato-4-methylsulfinylbutane (sulforaphane; SFN), a secondary metabolite in many crucifers, as a novel defense priming compound. While elucidating SFN's mode of action in defense priming, we found that in Arabidopsis ( Arabidopsis thaliana ) the isothiocyanate provokes covalent modification (K4me3, K9ac) of histone H3 in the promoter and promoter-proximal region of defense genes WRKY6 and PDF1 2 , but not PR1 SFN-triggered H3K4me3 and H3K9ac coincide with chromatin unpacking in the WRKY6 and PDF1 2 regulatory regions, primed WRKY6 expression, unprimed PDF1 2 activation, and reduced susceptibility to downy mildew disease ( Hyaloperonospora arabidopsidis ). Because SFN also directly inhibits H arabidopsidis and other plant pathogens, the isothiocyanate is promising for the development of a plant protectant with a dual mode of action. © 2018 American Society of Plant Biologists. All Rights Reserved.

An Intersensory Interaction Account of Priming Effects-and Their Absence.

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Klatzky, Roberta L; Creswell, J David

2014-01-01

Psychological researchers have found that exposures to stimuli (primes) can subsequently influence people's behavior by pathways that would seem to be quite remote. For example, people exposed to words associated with older adults may walk more slowly. Recently priming studies, particularly those showing dramatic effects on social behavior, have been under scrutiny because of the unreliability of empirical results. In this article, we shed light on the issue by describing a general model of intersensory interaction, in which two or more sources of information provide an estimate or "bid" on a property of the world, with the perceptual outcome being a weighted combination of the bids. When it is extended by adding bids that stem from memory or inference, the model identifies systematic factors that might undermine priming, including random variation in estimates, contextual influences on memory retrieval and inference, competition among information sources, and cognitive control. These factors are not only explanatory but are predictive of when priming effects can be expected. Our hope is that by promoting the understanding of underlying processes that may explain how primes can influence behavior, the bidding model and the general approach that it represents offer novel insights into the hotly debated area of priming research. © The Author(s) 2013.

Brand priming effect on consumers’ financial risk taking behavior

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Danielle Mantovani

Full Text Available Abstract Taking the perspective of brand priming theory, this study proposes that brands associated with an audacious personality trait may influence consumers to be take more risks in making subsequent decisions. Two experiments, run in sport brands contexts, showed that individuals exposed to brands with high (vs. low audacity traits demonstrated a higher rate of risk taking in financial decisions. The studies also showed that this effect is moderated by individuals’ experience with the financial market. This moderation suggests that there was an activation of a goal not just semantic activation, but through the brand priming. This research provides insights into how today's consumers deal with brand priming effects in risky choice settings. From a managerial perspective, it can help managers to understand the likely effects of brand priming on behavior and better predict the probability of risk aversion or risk seeking outcomes.

Is Semantic Priming (Ir)rational? Insights from the Speeded Word Fragment Completion Task

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Heyman, Tom; Hutchison, Keith A.; Storms, Gert

2016-01-01

Semantic priming, the phenomenon that a target is recognized faster if it is preceded by a semantically related prime, is a well-established effect. However, the mechanisms producing semantic priming are subject of debate. Several theories assume that the underlying processes are controllable and tuned to prime utility. In contrast, purely…

Affective priming of emotional pictures in parafoveal vision: left visual field advantage.

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Calvo, Manuel G; Avero, Pedro

2008-03-01

This study investigated whether stimulus affective content can be extracted from visual scenes when these appear in parafoveal locations of the visual field and are foveally masked, and whether there is lateralization involved. Parafoveal prime pleasant or unpleasant scenes were presented for 150 msec 2.5 degrees away from fixation and were followed by a foveal probe scene that was either congruent or incongruent in emotional valence with the prime. Participants responded whether the probe was emotionally positive or negative. Affective priming was demonstrated by shorter response latencies for congruent than for incongruent prime-probe pairs. This effect occurred when the prime was presented in the left visual field at a 300-msec prime-probe stimulus onset asynchrony, even when the prime and the probe were different in physical appearance and semantic category. This result reveals that the affective significance of emotional stimuli can be assessed early through covert attention mechanisms, in the absence of overt eye fixations on the stimuli, and suggests that right-hemisphere dominance is involved.

Verbal priming and taste sensitivity make moral transgressions gross.

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Herz, Rachel S

2014-02-01

The aims of the present study were to assess whether: (a) visceral and moral disgust share a common oral origin (taste); (b) moral transgressions that are also viscerally involving are evaluated accordingly as a function of individual differences in taste sensitivity; (c) verbal priming interacts with taste sensitivity to alter how disgust is experienced in moral transgressions; and (d) whether gender moderates these effects. Standard tests of disgust sensitivity, a questionnaire developed for this research assessing different types of moral transgressions (nonvisceral, implied-visceral, visceral) with the terms "angry" and "grossed-out," and a taste sensitivity test of 6-n-propylthiouracil (PROP) were administered to 102 participants. Results confirmed past findings that the more sensitive to PROP a participant was the more disgusted they were by visceral, but not moral, disgust elicitors. Importantly, the findings newly revealed that taste sensitivity had no bearing on evaluations of moral transgressions, regardless of their visceral nature, when "angry" was the emotion primed. However, when "grossed-out" was primed for evaluating moral violations, the more intense PROP tasted to a participant the more "grossed-out" they were by all transgressions. Women were generally more disgust sensitive and morally condemning than men, but disgust test, transgression type, and priming scale modulated these effects. The present findings support the proposition that moral and visceral disgust do not share a common oral origin, but show that linguistic priming can transform a moral transgression into a viscerally repulsive event and that susceptibility to this priming varies as a function of an individual's sensitivity to the origins of visceral disgust-bitter taste.

Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis

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Sherry L. Mowbray

2014-08-01

Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6–9 months and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

Altered thymidylate synthetase in 5-fluorodeoxyuridine-resistant Ehrlich ascites carcinoma cells.

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Jastreboff, M M; Kedzierska, B; Rode, W

1983-07-15

Thymidylate synthetase from 5-fluorodeoxyuridine-resistant Ehrlich ascites carcinoma cells was purified to a state close to electrophoretical homogeneity (sp. act. = 1.3 mumoles/min/mg protein) and studied in parallel with the homogeneous preparation of the enzyme from the parental Ehrlich ascites carcinoma cells. The enzyme from the resistant cells compared to that from the parental cells showed: (i) a higher turnover number (at least 91 against 31 min-1), (ii) a higher inhibition constant (19 against 1.9 nM) for FdUMP (a tight-binding inhibitor of both enzymes), (iii) a lower activation energy at temps above 36 degrees (1.37 against 2.59 kcal/mole), and (iv) a lower inhibition constant (26 against 108 microM) for dTMP, inhibiting both enzymes competitively vs dUMP.

A radiochemical method for carbamoyl-phosphate synthetase I: application to rats fed a hyperproteic diet

OpenAIRE

Arriarán, Sofía; Agnelli, Silvia; Fernández López, José Antonio; Remesar Betlloch, Xavier; Alemany, Marià, 1946-

2012-01-01

A method for the measurement of carbamoyl-phosphate synthetase I activity in animal tissues has been developed using the livers of rats under normal and hyperproteic diets. The method is based on the incorporation of 14C-ammonium bicarbonate to carbamoyl-phosphate in the presence of ATP-Mg and N-acetyl-glutamate. The reaction is stopped by chilling, lowering the pH and adding ethanol. Excess bicarbonate is flushed out under a gentle stream of cold CO2. The only label remaining in the medium w...

MicroRNA-Mediated Myostatin Silencing in Caprine Fetal Fibroblasts

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Zhong, Bushuai; Zhang, Yanli; Yan, Yibo; Wang, Ziyu; Ying, Shijia; Huang, Mingrui; Wang, Feng

2014-01-01

Myostatin functions as a negative regulator of skeletal muscle growth by suppressing proliferation and differentiation of myoblasts. Dysfunction of the myostatin gene, either due to natural mutation or genetic manipulations such as knockout or knockdown, has been reported to increase muscle mass in mammalian species. RNA interference (RNAi) mediated by microRNAs (miRNAs) is a promising method for gene knockdown studies. In the present study, transient and stable silencing of the myostatin gene in caprine fetal fibroblasts (CFF) was evaluated using the two most effective constructs selected from four different miRNA expression constructs screened in 293FT cells. Using these two miRNA constructs, we achieved up to 84% silencing of myostatin mRNA in transiently transfected CFF cells and up to 31% silencing in stably transfected CFF cells. Moreover, off-target effects due to induction of interferon (IFN) response genes, such as interferon beta (IFN-β) and 2′-5′-oligoadenylate synthetase 2 (OAS2), were markedly fewer in stably transfected CFF cells than in transiently transfected cells. Stable expression of anti-myostatin miRNA with minimal induction of interferon shows great promise for increasing muscle mass in transgenic goats. PMID:25244645

MicroRNA-mediated myostatin silencing in caprine fetal fibroblasts.

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Bushuai Zhong

Full Text Available Myostatin functions as a negative regulator of skeletal muscle growth by suppressing proliferation and differentiation of myoblasts. Dysfunction of the myostatin gene, either due to natural mutation or genetic manipulations such as knockout or knockdown, has been reported to increase muscle mass in mammalian species. RNA interference (RNAi mediated by microRNAs (miRNAs is a promising method for gene knockdown studies. In the present study, transient and stable silencing of the myostatin gene in caprine fetal fibroblasts (CFF was evaluated using the two most effective constructs selected from four different miRNA expression constructs screened in 293FT cells. Using these two miRNA constructs, we achieved up to 84% silencing of myostatin mRNA in transiently transfected CFF cells and up to 31% silencing in stably transfected CFF cells. Moreover, off-target effects due to induction of interferon (IFN response genes, such as interferon beta (IFN-β and 2'-5'-oligoadenylate synthetase 2 (OAS2, were markedly fewer in stably transfected CFF cells than in transiently transfected cells. Stable expression of anti-myostatin miRNA with minimal induction of interferon shows great promise for increasing muscle mass in transgenic goats.

[A case-control study on association between OAS1 polymorphism and susceptibility to spontaneous preterm birth and preterm premature rupture of membranes].

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Yang, Xiao; Zhang, Xiao-Ai; Wu, Zhi-Hao; Peng, Wei; Zhu, Li-Na; Wang, Yan

2015-09-01

To investigate the association between the genetic polymorphism of 2',5'-oligoadenylate synthetase 1 (OAS1) and susceptibility to spontaneous preterm birth (SPTB) and preterm premature rupture of membranes (PPROM). The case-control study consisted of 599 preterm infants including 171 cases of PPROM, and 673 full-term infants without maternal histories of SPTB and PPROM as controls. The single nucleotide polymorphism (SNP) at OAS1 intron 5, rs10774671, was analyzed by polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed between the case and control groups in the frequencies of genotypes (AA, GA, and GG) and alleles (A and G) of OAS1 rs10774671. When the case group was divided into two subgroups with or without PPROM, no significant differences in the genotype and allele frequencies were found between each subgroup and the control group. When the case group was divided into three subgroups with different gestational ages at SPTB, no significant differences in the genotype and allele frequencies were detected between each subgroup and the control group. No association is identified between OAS1 SNP and susceptibility to SPTB and PPROM.

Is semantic priming due to association strength or feature overlap? A microanalytic review.

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Hutchison, Keith A

2003-12-01

In a recent meta-analysis, Lucas (2000) concluded that there is strong evidence of an overall pure semantic priming effect but no evidence of priming based purely on association. In the present review, I critically examine the individual studies claiming evidence of featural and associative relations in semantic memory. The most important conclusion is that automatic priming appears to be due to both association strength and feature overlap. Mediated associates provide the strongest evidence of automatic associative priming, whereas functional associates, synonyms, and antonyms instead support priming based on feature overlap. In contrast, automatic priming does not occur for category coordinates or perceptually similar items, at least when presented in the visual modality. The status of other relations, such as collocates, episodic relatives, and script relations, is unclear and requires further experimentation. Implications for current models of semantic representation and priming are discussed.

On the Prime Ideals of C [0, 1

Indian Academy of Sciences (India)

It is well known that the set C[0, 1] of real-valuedcontinuous functions on the closed interval [0, 1]has a natural ring structure. Its maximal idealsare known to be points. Here we show thatalthough there exist prime ideals which are notmaximal, the zero set is again a singleton. In particular,each prime ideal is contained in a ...

De novo design and engineering of non-ribosomal peptide synthetases

Science.gov (United States)

Bozhüyük, Kenan A. J.; Fleischhacker, Florian; Linck, Annabell; Wesche, Frank; Tietze, Andreas; Niesert, Claus-Peter; Bode, Helge B.

2018-03-01

Peptides derived from non-ribosomal peptide synthetases (NRPSs) represent an important class of pharmaceutically relevant drugs. Methods to generate novel non-ribosomal peptides or to modify peptide natural products in an easy and predictable way are therefore of great interest. However, although the overall modular structure of NRPSs suggests the possibility of adjusting domain specificity and selectivity, only a few examples have been reported and these usually show a severe drop in production titre. Here we report a new strategy for the modification of NRPSs that uses defined exchange units (XUs) and not modules as functional units. XUs are fused at specific positions that connect the condensation and adenylation domains and respect the original specificity of the downstream module to enable the production of the desired peptides. We also present the use of internal condensation domains as an alternative to other peptide-chain-releasing domains for the production of cyclic peptides.

The effects of alcohol expectancy priming on group bonding.

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Moltisanti, Allison J; Below, Maureen C; Brandon, Karen O; Goldman, Mark S

2013-12-01

According to alcohol expectancy theory, drinking-related information is stored in memory and, when cue activated, influences alcohol-related behavior. Priming of alcohol cues and expectancies has been shown to elicit both drinking and nonconsumptive behavior associated with alcohol consumption, such as willingness to meet with a stranger and aggression. These social influence effects have been shown to be moderated by individual differences in alcohol expectancies. In the present study, we tested whether an alcohol prime would facilitate social group bonding even in the absence of consumption, and whether such group bonding would be moderated by individually held social expectancies. One hundred twenty undergraduates (75% female) completed an alcohol expectancy measure prior to participation. Participants were primed with either alcohol or neutral beverage words and completed a collaborative group activity followed by questionnaires measuring perceived group cohesion. Several interactions were found between condition and expectancy reflecting that those in the alcohol prime condition with higher social alcohol expectancies reported greater cohesion on task-related, but not emotion-related, group measures. These findings underscore the complexity of the impact of expectancy and social behavior on drinking: the priming of alcohol expectancies may activate aspects of pro-social behavior, which may influence drinking, which in turn may feedback to positively reinforce social expectancies.

Self-Construal Priming Modulates Self-Evaluation under Social Threat

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Tianyang Zhang

2017-10-01

Full Text Available Previous studies have shown that Westerners evaluate themselves in an especially flattering way when faced with a social-evaluative threat. The current study first investigated whether East Asians also have a similar pattern by recruiting Chinese participants and using social-evaluative threat manipulations in which participants perform self-evaluation tasks while adopting different social-evaluative feedbacks (Experiment 1. Then further examined whether the different response patterns can be modulated by different types of self-construal by using social-evaluative threat manipulations in conjunction with a self-construal priming task (Experiment 2. The results showed that, as opposed to Westerners' pattern, Chinese participants rated themselves as having significantly greater above-average effect only when faced with the nonthreatening feedback but not the social-evaluative threat. More importantly, we found that self-construal modulated the self-evaluation under social-evaluative threat: following independent self-construal priming, participants tended to show a greater above-average effect when faced with a social-evaluative threat. However, this pattern in conjunction with a social threat disappeared after participants received interdependent self-construal priming or neutral priming. These findings suggest that the effects of social-evaluative threat on self-evaluation are not culturally universal and is strongly modulated by self-construal priming.

The Kallikrein-Kinin System in Bartter's Syndrome and Its Response to Prostaglandin Synthetase Inhibition

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Vinci, Joseph M.; Gill, John R.; Bowden, Robert E.; Pisano, John J.; Izzo, Joseph L.; Radfar, Nazam; Taylor, Addison A.; Zusman, Randall M.; Bartter, Frederic C.; Keiser, Harry R.

1978-01-01

The kallikrein-kinin system was characterized in seven patients with Bartter's syndrome on constant metabolic regimens before, during, and after treatment with prostaglandin synthetase inhibitors. Patients with Bartter's syndrome had high values for plasma bradykinin, plasma renin activity (PRA), urinary kallikrein, urinary immunoreactive prostaglandin E excretion, and urinary aldosterone; urinary kinins were subnormal and plasma prekallikrein was normal. Treatment with indomethacin or ibuprofen which decreased urinary immunoreactive prostaglandin E excretion by 67%, decreased mean PRA (patients recumbent) from 17.3±5.3 (S.E.M.) ng/ml per h to 3.3±1.1 ng/ml per h, mean plasma bradykinin (patients recumbent) from 15.4±4.4 ng/ml to 3.9±0.9 ng/ml, mean urinary kallikrein excretion from 24.8±3.2 tosyl-arginine-methyl ester units (TU)/day to 12.4±2.0 TU/day, but increased mean urinary kinin excretion from 3.8±1.3 μg/day to 8.5±2.5 μg/day. Plasma prekallikrein remained unchanged at 1.4 TU/ml. Thus, with prostaglandin synthetase inhibition, values for urinary kallikrein and kinin and plasma bradykinin returned to normal pari passu with changes in PRA, in aldosterone, and in prostaglandin E. The results suggest that, in Bartter's syndrome, prostaglandins mediate the low urinary kinins and the high plasma bradykinin, and that urinary kallikrein, which is aldosterone dependent, does not control kinin excretion. The high plasma bradykinin may be a cause of the pressor hyporesponsiveness to angiotensin II which characterizes the syndrome. PMID:96139

Repetition-priming effect: a cognitive task for the definition of a clinical assessment

Directory of Open Access Journals (Sweden)

Silvia Pagani

2014-04-01

Full Text Available This research aims to study how semantic priming words can influence behavioral measures (RTs, accuracy, to develop an experimental paradigm to differentiate visual neglect and hemianopia. 69 experimental subjects were involved in four experiments. In each experiment target words were preceded by word primes semantically related, neutral or unrelated to the target. The four experiments differed in terms of: number of prime, prime duration and distance between PC monitor and subject. In general, related primes should improve facilitatory effect in target recognition more than unrelated primes, reducing RTs and increasing response accuracy. After repeated ANOVA analysis applied to each experiment and paired comparisons, it is possible to point out that single related primes, shown for 150 ms, greatly improve response behavior in terms of RTs reduction. For future applications to the clinical field, we assume that neglect patients should be facilitated in these specific experimental conditions, due to implicit contralesional prime processing. On the contrary, hemianopics should nowise be facilitated, due to visual field deficit.

Secretory Vesicle Priming by CAPS Is Independent of Its SNARE-Binding MUN Domain

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Cuc Quynh Nguyen Truong

2014-11-01

Full Text Available Priming of secretory vesicles is a prerequisite for their Ca2+-dependent fusion with the plasma membrane. The key vesicle priming proteins, Munc13s and CAPSs, are thought to mediate vesicle priming by regulating the conformation of the t-SNARE syntaxin, thereby facilitating SNARE complex assembly. Munc13s execute their priming function through their MUN domain. Given that the MUN domain of Ca2+-dependent activator protein for secretion (CAPS also binds syntaxin, it was assumed that CAPSs prime vesicles through the same mechanism as Munc13s. We studied naturally occurring splice variants of CAPS2 in CAPS1/CAPS2-deficient cells and found that CAPS2 primes vesicles independently of its MUN domain. Instead, the pleckstrin homology domain of CAPS2 seemingly is essential for its priming function. Our findings indicate a priming mode for secretory vesicles. This process apparently requires membrane phospholipids, does not involve the binding or direct conformational regulation of syntaxin by MUN domains of CAPSs, and is therefore not redundant with Munc13 action.

Up-regulation of asparagine synthetase expression is not linked to the clinical response to L-asparaginase in pediatric acute lymphoblastic leukemia

NARCIS (Netherlands)

I.M. Appel (Inge); M.L. den Boer (Monique); J.P.P. Meijerink (Jules); A.J.P. Veerman (Anjo); N.C.M. Reniers (N. C M); R. Pieters (Rob)

2006-01-01

textabstractL-asparaginase (L-Asp) is an effective drug for treatment of children with acute lymphoblastic leukemia (ALL). The effectiveness is generally thought to result from a rapid depletion of asparagine in serum and cells. Asparagine synthetase (AS) opposes the action of L-Asp by resynthesis

Behavioral priming: it's all in the mind, but whose mind?

Directory of Open Access Journals (Sweden)

Stéphane Doyen

Full Text Available The perspective that behavior is often driven by unconscious determinants has become widespread in social psychology. Bargh, Chen, and Burrows' (1996 famous study, in which participants unwittingly exposed to the stereotype of age walked slower when exiting the laboratory, was instrumental in defining this perspective. Here, we present two experiments aimed at replicating the original study. Despite the use of automated timing methods and a larger sample, our first experiment failed to show priming. Our second experiment was aimed at manipulating the beliefs of the experimenters: Half were led to think that participants would walk slower when primed congruently, and the other half was led to expect the opposite. Strikingly, we obtained a walking speed effect, but only when experimenters believed participants would indeed walk slower. This suggests that both priming and experimenters' expectations are instrumental in explaining the walking speed effect. Further, debriefing was suggestive of awareness of the primes. We conclude that unconscious behavioral priming is real, while real, involves mechanisms different from those typically assumed to cause the effect.

The Influence of Working Memory Load on Semantic Priming

Science.gov (United States)

Heyman, Tom; Van Rensbergen, Bram; Storms, Gert; Hutchison, Keith A.; De Deyne, Simon

2015-01-01

The present research examines the nature of the different processes that have been proposed to underlie semantic priming. Specifically, it has been argued that priming arises as a result of "automatic target activation" and/or the use of strategies like prospective "expectancy generation" and "retrospective semantic…

76 FR 80907 - TRICARE Prime Urgent Care Demonstration Project

Science.gov (United States)

2011-12-27

... care including minor illness or injury for Active Duty Family Members enrolled in TRICARE Prime or.... Current data indicates that the ADFMs frequently need urgent care while traveling to new duty stations for... DEPARTMENT OF DEFENSE Office of the Secretary TRICARE Prime Urgent Care Demonstration Project...

Homophonic and semantic priming of Japanese Kanji words: a time course study.

Science.gov (United States)

Chen, Hsi-Chin; Yamauchi, Takashi; Tamaoka, Katsuo; Vaid, Jyotsna

2007-02-01

In an examination of the time course of activation of phonological and semantic information in processing kanji script, two lexical decision experiments were conducted with native readers of Japanese. Kanji targets were preceded at short (85-msec) and long (150-msec) intervals by homophonic, semantically related, or unrelated primes presented in kanji (Experiment 1) or by hiragana transcriptions of the kanji primes (Experiment 2). When primes were in kanji, semantic relatedness facilitated kanji target recognition at both intervals but homophonic relatedness did not. When primes were in hiragana, kanji target recognition was facilitated by homophonic relatedness at both intervals and by semantic relatedness only at the longer interval. The absence of homophonic priming of kanji targets by kanji primes challenges the universal phonology principle's claim that phonology is central to accessing meaning from print. The stimuli used in the present study may be downloaded from www.psychonomic.org/archive.

Abstract spatial concept priming dynamically influences real-world actions

Directory of Open Access Journals (Sweden)

Sarah M Tower-Richardi

2012-09-01

Full Text Available Experienced regularities in our perceptions and actions play important roles in grounding abstract concepts such as social status, time, and emotion. Might we similarly ground abstract spatial concepts in more experienced-based domains? The present experiment explores this possibility by implicitly priming abstract spatial terms (north, south, east, west and then measuring participants’ hand movement trajectories while they respond to a body-referenced spatial target (up, down, left, right in a verbal (Exp. 1 or spatial (Exp. 2 format. Results from two experiments demonstrate temporally-dynamic and prime-biased movement trajectories when the primes are incongruent with the targets (e.g., north – left, west – up. That is, priming abstract coordinate directions influences subsequent actions in response to concrete target directions. These findings provide the first evidence that abstract concepts of world-centered coordinate axes are implicitly understood in the context of concrete body-referenced axes; critically, this abstract-concrete relationship manifests in motor movements, and may have implications for spatial memory organization.

Priming performance-related concerns induces task-related mind-wandering.

Science.gov (United States)

Jordano, Megan L; Touron, Dayna R

2017-10-01

Two experiments tested the hypothesis that priming of performance-related concerns would (1) increase the frequency of task-related mind-wandering (i.e., task-related interference; TRI) and (2) decrease task performance. In each experiment, sixty female participants completed an operation span task (OSPAN) containing thought content probes. The task was framed as a math task for those in a condition primed for math-related stereotype threat and as a memory task for those in a control condition. In both studies, women whose performance-related concerns were primed via stereotype threat reported more TRI than women in the control. The second experiment used a more challenging OSPAN task and stereotype primed women also had lower math accuracy than controls. These results support the "control failures×current concerns" framework of mind-wandering, which posits that the degree to which the environmental context triggers personal concerns influences both mind-wandering frequency and content. Copyright © 2017 Elsevier Inc. All rights reserved.

Word Meaning Frequencies Affect Negative Compatibility Effects In Masked Priming.

Science.gov (United States)

Brocher, Andreas; Koenig, Jean-Pierre

2016-01-01

Negative compatibility effects (NCEs)-that is, slower responses to targets in related than unrelated prime-target pairs, have been observed in studies using stimulus-response (S-R) priming with stimuli like arrows and plus signs. Although there is no consensus on the underlying mechanism, explanations tend to locate NCEs within the motor-response system. A characteristic property of perceptuo-motor NCEs is a biphasic pattern of activation: A brief period in which very briefly presented (typically) masked primes facilitate processing of related targets is followed by a phase of target processing impairment. In this paper, we present data that suggest that NCEs are not restricted to S-R priming with low-level visual stimuli: The brief (50 ms), backward masked (250 ms) presentation of ambiguous words (bank) leads to slower responses than baseline to words related to the more frequent (rob) but not less frequent meaning (swim). Importantly, we found that slowed responses are preceded by a short phase of response facilitation, replicating the biphasic pattern reported for arrows and plus signs. The biphasic pattern of priming and the fact that the NCEs were found only for target words that are related to their prime word's more frequent meaning has strong implications for any theory of NCEs that locate these effects exclusively within the motor-response system.

Reading "glasses" will prime "vision," but reading a pair of "glasses" will not.

Science.gov (United States)

Neely, J H; VerWys, C A; Kahan, T A

1998-01-01

In a lexical decision task with two primes and a target, the target was preceded 300 msec by the second prime (P2) which in turn was preceded by a brief forward and backward masked first prime (P1). When P1 and P2 were unrelated, reaction times were faster when the target was related to P2 (e.g., wave SALT ... pepper) than when the target was unrelated to P2 (and P1--e.g., wave LOAN ... pepper). However, this semantic priming effect was reduced to statistically nonsignificant levels when P1 and P2 were repetitions of the same word. That is, priming did not occur for salt SALT ... pepper relative to loan LOAN ... pepper. This reduction in priming was observed whether P2 and the target were strongly or weakly related. These findings raise problems for current accounts of semantic priming.

Crystallization of leucyl-tRNA synthetase complexed with tRNALeu from the archaeon Pyrococcus horikoshii

International Nuclear Information System (INIS)

Fukunaga, Ryuya; Ishitani, Ryuichiro; Nureki, Osamu; Yokoyama, Shigeyuki

2004-01-01

The leucyl-tRNA synthetase (LeuRS) from P. horikoshii has been overexpressed in Escherichia coli and purified, and cocrystallizations with each of the tRNA Leu isoacceptors have been attempted. Cocrystals were obtained by the hanging-drop vapour-diffusion method, but only when the tRNA Leu isoacceptor with the anticodon CAA was used. All five tRNA Leu isoacceptors from the archaeon Pyrococcus horikoshii have been transcribed in vitro and purified. The leucyl-tRNA synthetase (LeuRS) from P. horikoshii was overexpressed in Escherichia coli and purified, and cocrystallizations with each of the tRNA Leu isoacceptors were attempted. Cocrystals were obtained by the hanging-drop vapour-diffusion method, but only when the tRNA Leu isoacceptor with the anticodon CAA was used. Electrophoretic analyses revealed that the crystals contain both LeuRS and tRNA Leu , suggesting that they are LeuRS–tRNA Leu complex crystals. A data set diffracting to 3.3 Å resolution was collected from a single crystal at 100 K. The crystal belongs to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 118.18, b = 120.55, c = 231.13 Å. The asymmetric unit is expected to contain two complexes of LeuRS–tRNA Leu , with a corresponding crystal volume per protein weight of 2.9 Å 3 Da −1 and a solvent content of 57.3%

Where perception meets memory: a review of repetition priming in visual search tasks.

Science.gov (United States)

Kristjánsson, Arni; Campana, Gianluca

2010-01-01

What we have recently seen and attended to strongly influences how we subsequently allocate visual attention. A clear example is how repeated presentation of an object's features or location in visual search tasks facilitates subsequent detection or identification of that item, a phenomenon known as priming. Here, we review a large body of results from priming studies that suggest that a short-term implicit memory system guides our attention to recently viewed items. The nature of this memory system and the processing level at which visual priming occurs are still debated. Priming might be due to activity modulations of low-level areas coding simple stimulus characteristics or to higher level episodic memory representations of whole objects or visual scenes. Indeed, recent evidence indicates that only minor changes to the stimuli used in priming studies may alter the processing level at which priming occurs. We also review recent behavioral, neuropsychological, and neurophysiological evidence that indicates that the priming patterns are reflected in activity modulations at multiple sites along the visual pathways. We furthermore suggest that studies of priming in visual search may potentially shed important light on the nature of cortical visual representations. Our conclusion is that priming occurs at many different levels of the perceptual hierarchy, reflecting activity modulations ranging from lower to higher levels, depending on the stimulus, task, and context-in fact, the neural loci that are involved in the analysis of the stimuli for which priming effects are seen.

French Prime Minister tours CERN

CERN Multimedia

Anaïs Schaeffer

2012-01-01

On 30 July, Jean-Marc Ayrault, the Prime Minister of the French Republic, and Geneviève Fioraso, the Minister of Higher Education and Research, visited the Laboratory.   After being met by the Director-General at LHC Point 5, they visited the CMS control centre and experiment cavern, and got a glimpse of the LHC tunnel at Point 5. The visit ended with a round-table discussion with French and other international members of CERN’s scientific community. During the discussion, the Prime Minister reaffirmed that “support for fundamental research has to be maintained, and France must continue to invest in education, research and innovation.” He also paid tribute to CERN's role in international cooperation, which he qualified as “a fine example of science without borders.”

Priming motivation through unattended speech.

Science.gov (United States)

Radel, Rémi; Sarrazin, Philippe; Jehu, Marie; Pelletier, Luc

2013-12-01

This study examines whether motivation can be primed through unattended speech. Study 1 used a dichotic-listening paradigm and repeated strength measures. In comparison to the baseline condition, in which the unattended channel was only composed by neutral words, the presence of words related to high (low) intensity of motivation led participants to exert more (less) strength when squeezing a hand dynamometer. In a second study, a barely audible conversation was played while participants' attention was mobilized on a demanding task. Participants who were exposed to a conversation depicting intrinsic motivation performed better and persevered longer in a subsequent word-fragment completion task than those exposed to the same conversation made unintelligible. These findings suggest that motivation can be primed without attention. © 2013 The British Psychological Society.

Goal-Directed Visual Attention Drives Health Goal Priming: An Eye-Tracking Experiment

NARCIS (Netherlands)

Laan, van der Laura N.; Hooge, I.T.C.; Smeets, P.A.M.

2017-01-01

Objective: Several lab and field experiments have shown that goal priming interventions can be highly effective in promoting healthy food choices. Less is known, however, about the mechanisms by which goal priming affects food choice. This experiment tested the hypothesis that goal priming affects

A genome-wide analysis of nonribosomal peptide synthetase gene clusters and their peptides in a Planktothrix rubescens strain

Directory of Open Access Journals (Sweden)

Nederbragt Alexander J

2009-08-01

Full Text Available Abstract Background Cyanobacteria often produce several different oligopeptides, with unknown biological functions, by nonribosomal peptide synthetases (NRPS. Although some cyanobacterial NRPS gene cluster types are well described, the entire NRPS genomic content within a single cyanobacterial strain has never been investigated. Here we have combined a genome-wide analysis using massive parallel pyrosequencing ("454" and mass spectrometry screening of oligopeptides produced in the strain Planktothrix rubescens NIVA CYA 98 in order to identify all putative gene clusters for oligopeptides. Results Thirteen types of oligopeptides were uncovered by mass spectrometry (MS analyses. Microcystin, cyanopeptolin and aeruginosin synthetases, highly similar to already characterized NRPS, were present in the genome. Two novel NRPS gene clusters were associated with production of anabaenopeptins and microginins, respectively. Sequence-depth of the genome and real-time PCR data revealed three copies of the microginin gene cluster. Since NRPS gene cluster candidates for microviridin and oscillatorin synthesis could not be found, putative (gene encoded precursor peptide sequences to microviridin and oscillatorin were found in the genes mdnA and oscA, respectively. The genes flanking the microviridin and oscillatorin precursor genes encode putative modifying enzymes of the precursor oligopeptides. We therefore propose ribosomal pathways involving modifications and cyclisation for microviridin and oscillatorin. The microviridin, anabaenopeptin and cyanopeptolin gene clusters are situated in close proximity to each other, constituting an oligopeptide island. Conclusion Altogether seven nonribosomal peptide synthetase (NRPS gene clusters and two gene clusters putatively encoding ribosomal oligopeptide biosynthetic pathways were revealed. Our results demonstrate that whole genome shotgun sequencing combined with MS-directed determination of oligopeptides successfully

The effects of associative and semantic priming in the lexical decision task.

Science.gov (United States)

Perea, Manuel; Rosa, Eva

2002-08-01

Four lexical decision experiments were conducted to examine under which conditions automatic semantic priming effects can be obtained. Experiments 1 and 2 analyzed associative/semantic effects at several very short stimulus-onset asynchronies (SOAs), whereas Experiments 3 and 4 used a single-presentation paradigm at two response-stimulus intervals (RSIs). Experiment 1 tested associatively related pairs from three semantic categories (synonyms, antonyms, and category coordinates). The results showed reliable associative priming effects at all SOAs. In addition, the correlation between associative strength and magnitude of priming was significant only at the shortest SOA (66 ms). When prime-target pairs were semantically but not associatively related (Experiment 2), reliable priming effects were obtained at SOAs of 83 ms and longer. Using the single-presentation paradigm with a short RSI (200 ms, Experiment 3), the priming effect was equal in size for associative + semantic and for semantic-only pairs (a 21-ms effect). When the RSI was set much longer (1,750 ms, Experiment 4), only the associative + semantic pairs showed a reliable priming effect (23 ms). The results are interpreted in the context of models of semantic memory.

Repetition priming with Japanese Kana scripts in word-fragment completion.

Science.gov (United States)

Komatsu, S; Naito, M

1992-03-01

Manipulating two types of Japanese Kana script, Katakana and Hiragana, we examined the effects of a script change between study and test on later word-fragment completion. Throughout three experiments, materials were composed of foreign loan nouns normally written in Katakana, but not in Hiragana, according to approved usage in Japanese. Experiment 1 demonstrated the reliable size of cross-script priming between Katakana and Hiragana. In Experiment 2, cross-modal priming was substantial when modality of presentation was changed from auditory to visual. In Experiment 3, generating a target word from its definition induced priming comparable in size to that in the prior reading condition. These results have been confirmed in the Hiragana test, as well as in the Katakana test, thereby suggesting that some conceptual and modality-independent processes may also mediate repetition priming.

scsB, a cDNA encoding the hydrogenosomal beta subunit of succinyl-CoA synthetase from the anaerobic fungus Neocallimastix frontalis

NARCIS (Netherlands)

Brondijk, THC; Durand, R; vanderGiezen, M; Gottschal, JC; Prins, RA; Fevre, M

1996-01-01

A clone containing a Neocallimastix frontalis cDNA assumed to encode the beta subunit of succinyl-CoA synthetase (SCSB) was identified by sequence homology with prokaryotic and eukaryotic counterparts. An open reading frame of 1311 bp was found. The deduced 437 amino acid sequence showed a high

Comparing Repetition Priming Effects in Words and Arithmetic Equations: Robust Priming Regardless of Color or Response Hand Change

Directory of Open Access Journals (Sweden)

Ailsa Humphries

2018-01-01

Full Text Available Previous studies have shown that stimulus repetition can lead to reliable behavioral improvements. Although this repetition priming (RP effect has been reported in a number of paradigms using a variety of stimuli including words, objects, and faces, only a few studies have investigated mathematical cognition involving arithmetic computation, and no prior research has directly compared RP effects in a linguistic task with an arithmetic task. In two experiments, we used a within-subjects design to investigate and compare the magnitude of RP, and the effects of changing the color or the response hand for repeated, otherwise identical, stimuli in a word and an arithmetic categorization task. The results show that the magnitude of RP was comparable between the two tasks and that changing the color or the response hand had a negligible effect on priming in either task. These results extended previous findings in mathematical cognition. They also indicate that priming does not vary with stimulus domain. The implications of the results were discussed with reference to both facilitation of component processes and episodic memory retrieval of stimulus–response binding.

Comparing Repetition Priming Effects in Words and Arithmetic Equations: Robust Priming Regardless of Color or Response Hand Change.

Science.gov (United States)

Humphries, Ailsa; Chen, Zhe; Neumann, Ewald

2017-01-01

Previous studies have shown that stimulus repetition can lead to reliable behavioral improvements. Although this repetition priming (RP) effect has been reported in a number of paradigms using a variety of stimuli including words, objects, and faces, only a few studies have investigated mathematical cognition involving arithmetic computation, and no prior research has directly compared RP effects in a linguistic task with an arithmetic task. In two experiments, we used a within-subjects design to investigate and compare the magnitude of RP, and the effects of changing the color or the response hand for repeated, otherwise identical, stimuli in a word and an arithmetic categorization task. The results show that the magnitude of RP was comparable between the two tasks and that changing the color or the response hand had a negligible effect on priming in either task. These results extended previous findings in mathematical cognition. They also indicate that priming does not vary with stimulus domain. The implications of the results were discussed with reference to both facilitation of component processes and episodic memory retrieval of stimulus-response binding.

Vault Safety and Inventory System users manual, PRIME 2350. Revision 1

International Nuclear Information System (INIS)

Downey, N.J.

1994-01-01

This revision is issued to request review of the attached document: VSIS User Manual, PRIME 2350, which provides user information for the operation of the VSIS (Vault Safety and Inventory System). It describes operational aspects of Prime 2350 minicomputer and vault data acquisition equipment. It also describes the User's Main Menu and menu functions, including REPORTS. Also, system procedures for the Prime 2350 minicomputer are covered

Vault Safety and Inventory System users manual, PRIME 2350. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Downey, N.J.

1994-12-14

This revision is issued to request review of the attached document: VSIS User Manual, PRIME 2350, which provides user information for the operation of the VSIS (Vault Safety and Inventory System). It describes operational aspects of Prime 2350 minicomputer and vault data acquisition equipment. It also describes the User`s Main Menu and menu functions, including REPORTS. Also, system procedures for the Prime 2350 minicomputer are covered.

Exploring Visuomotor Priming Following Biological and Non-Biological Stimuli

Science.gov (United States)

Gowen, E.; Bradshaw, C.; Galpin, A.; Lawrence, A.; Poliakoff, E.

2010-01-01

Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to…

Discovery of antimicrobial compounds targeting bacterial type FAD synthetases.

Science.gov (United States)

Sebastián, María; Anoz-Carbonell, Ernesto; Gracia, Begoña; Cossio, Pilar; Aínsa, José Antonio; Lans, Isaías; Medina, Milagros

2018-12-01

The increase of bacterial strains resistant to most of the available antibiotics shows a need to explore novel antibacterial targets to discover antimicrobial drugs. Bifunctional bacterial FAD synthetases (FADSs) synthesise the flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). These cofactors act in vital processes as part of flavoproteins, making FADS an essential enzyme. Bacterial FADSs are potential antibacterial targets because of differences to mammalian enzymes, particularly at the FAD producing site. We have optimised an activity-based high throughput screening assay targeting Corynebacterium ammoniagenes FADS (CaFADS) that identifies inhibitors of its different activities. We selected the three best high-performing inhibitors of the FMN:adenylyltransferase activity (FMNAT) and studied their inhibition mechanisms and binding properties. The specificity of the CaFADS hits was evaluated by studying also their effect on the Streptococcus pneumoniae FADS activities, envisaging differences that can be used to discover species-specific antibacterial drugs. The antimicrobial effect of these compounds was also evaluated on C. ammoniagenes, S. pneumoniae, and Mycobacterium tuberculosis cultures, finding hits with favourable antimicrobial properties.

Emotion-Specific Priming: Congruence Effects on Affect and Recognition across Negative Emotions.

Science.gov (United States)

Hansen, Christine H.; Shantz, Cynthia A.

1995-01-01

Demonstrated the emotion-specific priming effects of negatively valenced emotions (anger, sadness, and fear) in a divided attention task. Results indicated that a negative emotion displayed by a target that matched the emotion induced by a priming manipulation was significantly stronger than an incongruous priming manipulation and displayed…

Action of. gamma. -radiation on the pH- and heat-stability of phenylalanine-tRNA-synthetases of cotton seeds

Energy Technology Data Exchange (ETDEWEB)

Karakuziev, T U [AN Uzbekskoj SSR, Tashkent. Inst. Biokhimii

1977-01-01

Action of temperature and pH on the activity of phenyl-alanine-tRNA-synthetases has been studied in two-day-old cotton seedlings grown from irradiated (25 and 50 kR) seeds. High thermolability and increased pH sensitivity were exhibited by enzymes E/sub 1/ and, particularly, E/sub 2/ of irradiated organisms as compared to those of the controls.

Comparison of Prime Movers Suitable for USMC Expeditionary Power Sources

Energy Technology Data Exchange (ETDEWEB)

Theiss, T J; Conklin, J. C.; Thomas, John F.; Armstrong, T. R.

2000-04-18

This report documents the results of the ORNL investigation into prime movers that would be desirable for the construction of a power system suitable for the United States Marine Corps (USMC) expeditionary forces under Operational Maneuvers From The Sea (OMFTS) doctrine. Discrete power levels of {approx}1, 5, 15, and 30 kW are considered. The only requirement is that the prime mover consumes diesel fuel. A brief description is given for the prime movers to describe their basic scientific foundations and relative advantages and disadvantages. A list of key attributes developed by ORNL has been weighted by the USMC to indicate the level of importance. A total of 14 different prime movers were scored by ORNL personnel in four size ranges (1,5, 15, & 30 kW) for their relative strength in each attribute area. The resulting weighted analysis was used to indicate which prime movers are likely to be suitable for USMC needs. No single engine or prime mover emerged as the clear-cut favorite but several engines scored as well or better than the diesel engine. At the higher load levels (15 & 30 kW), the results indicate that the open Brayton (gas turbine) is a relatively mature technology and likely a suitable choice to meet USMC needs. At the lower power levels, the situation is more difficult and the market alone is not likely to provide an optimum solution in the time frame desired (2010). Several prime movers should be considered for future developments and may be satisfactory; specifically, the Atkinson cycle, the open Brayton cycle (gas turbine), the 2-stroke diesel. The rotary diesel and the solid oxide fuel cell should be backup candidates. Of all these prime movers, the Atkinson cycle may well be the most suitable for this application but is an immature technology. Additional demonstrations of this engine will be conducted at ORNL. If this analysis is positive, then the performance of a generator set using this engine, the open Brayton and the 2-stroke diesel should

Towers of Function Fields over Non-prime Finite Fields

DEFF Research Database (Denmark)

Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

2015-01-01

Over all non-prime finite fields, we construct some recursive towers of function fields with many rational places. Thus we obtain a substantial improvement on all known lower bounds for Ihara’s quantity A(ℓ), for ℓ = pn with p prime and n > 3 odd. We relate the explicit equations to Drinfeld modu...

Independent priming of location and color in identification of briefly presented letters.

Science.gov (United States)

Ásgeirsson, Árni Gunnar; Kristjánsson, Árni; Bundesen, Claus

2014-01-01

Attention shifts are facilitated if the items to be attended remain the same across trials. Some researchers argue that this priming effect is perceptual, whereas others propose that priming is postperceptual, involving facilitated response selection. The experimental findings have not been consistent regarding the roles of variables such as task difficulty, response repetition, expectancies, and decision-making. Position priming, when repetition of a target position facilitates responses on a subsequent trial, is another source of disagreement among researchers. Experimental results have likewise been inconsistent as to whether position priming is dependent on the repetition of target features or has an independent effect on attention shifts. We attempted to isolate the perceptual components of priming by presenting brief (10-180 ms) search arrays to eight healthy observers. The task was to identify a color-singleton letter among distractors. All stimulus presentation contingencies were randomized, and responses were unspeeded, to avoid effects of observer expectation and postperceptual effects. Repeating target color and/or position strongly improved performance. The effects of color and position repetition were independent of one another and were stable across participants. The results argue for a strong perceptual component in priming, which biases selection toward recent target features and positions, showing that perceptual mechanisms are sufficient to produce priming in visual search and that such effects can be elicited with limited sensory evidence. The results are the first to demonstrate independent priming of color and position in the identification of briefly presented, postmasked stimuli.

Morphological changes of gamma prime precipitates in nickel-base superalloy single crystals

International Nuclear Information System (INIS)

Mackay, R.A.

1984-07-01

Changes in the morphology of the gamma prime precipitate were examined during tensile creep at temperatures between 927 and 1038 C in 001-oriented single crystals of a Ni-Al-Mo-Ta superalloy. In this alloy, which has a large negative misfit of -0.80%, the gamma prime particles link together during creep to form platelets, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The dimensions of the gamma and gamma prime phases were measured as directional coarsening developed in an attempt to trace the changing morphology under various stress levels. In addition, the effects of initial microstructure, as well as slight compositional variations, were related to raft development and creep properties. The results showed that directional coarsening of gamma prime began during primary creep, and under certain conditions, continued to develop after the onset of steady-state creep. The length of the rafts increased linearly with time up to a plateau region. The thickness of the rafts, however, remained equal to the initial gamma prime size at least up through the onset of tertiary creep this is a clear indication of the stability of the finely-spaced gamma-gamma prime lamellar structure. It was found that the single crystals with the finest gamma prime size exhibited the longest creep lives, because the resultant rafted structure had a larger number of gamma-gamma prime interfaces per unit volume of material

Changing the threshold-Signals and mechanisms of mast cell priming.

Science.gov (United States)

Halova, Ivana; Rönnberg, Elin; Draberova, Lubica; Vliagoftis, Harissios; Nilsson, Gunnar P; Draber, Petr

2018-03-01

Mast cells play a key role in allergy and other inflammatory diseases involving engagement of multivalent antigen with IgE bound to high-affinity IgE receptors (FcεRIs). Aggregation of FcεRIs on mast cells initiates a cascade of signaling events that eventually lead to degranulation, secretion of leukotrienes and prostaglandins, and cytokine and chemokine production contributing to the inflammatory response. Exposure to pro-inflammatory cytokines, chemokines, bacterial and viral products, as well as some other biological products and drugs, induces mast cell transition from the basal state into a primed one, which leads to enhanced response to IgE-antigen complexes. Mast cell priming changes the threshold for antigen-mediated activation by various mechanisms, depending on the priming agent used, which alone usually do not induce mast cell degranulation. In this review, we describe the priming processes induced in mast cells by various cytokines (stem cell factor, interleukins-4, -6 and -33), chemokines, other agents acting through G protein-coupled receptors (adenosine, prostaglandin E 2 , sphingosine-1-phosphate, and β-2-adrenergic receptor agonists), toll-like receptors, and various drugs affecting the cytoskeleton. We will review the current knowledge about the molecular mechanisms behind priming of mast cells leading to degranulation and cytokine production and discuss the biological effects of mast cell priming induced by several cytokines. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Attachment Security Balances Perspectives: Effects of Security Priming on Highly Optimistic and Pessimistic Explanatory Styles.

Science.gov (United States)

Deng, Yanhe; Yan, Mengge; Chen, Henry; Sun, Xin; Zhang, Peng; Zeng, Xianglong; Liu, Xiangping; Lye, Yue

2016-01-01

Highly optimistic explanatory style (HOES) and highly pessimistic explanatory style (HPES) are two maladaptive ways to explain the world and may have roots in attachment insecurity. The current study aims to explore the effects of security priming - activating supportive representations of attachment security - on ameliorating these maladaptive explanatory styles. 57 participants with HOES and 57 participants with HPES were randomized into security priming and control conditions. Their scores of overall optimistic attribution were measured before and after priming. Security priming had a moderating effect: the security primed HOES group exhibited lower optimistic attribution, while the security primed HPES group evinced higher scores of optimistic attribution. Furthermore, the security primed HOES group attributed positive outcomes more externally, while the security primed HPES group attributed successful results more internally. The results support the application of security priming interventions on maladaptive explanatory styles. Its potential mechanism and directions for future study are also discussed.

Does the presence of priming hinder subsequent recognition or recall performance?

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Stark, Shauna M; Gordon, Barry; Stark, Craig E L

2008-02-01

Declarative and non-declarative memories are thought be supported by two distinct memory systems that are often posited not to interact. However, Wagner, Maril, and Schacter (2000a) reported that at the time priming was assessed, greater behavioural and neural priming was associated with lower levels of subsequent recognition memory, demonstrating an interaction between declarative and non-declarative memory. We examined this finding using a similar paradigm, in which participants made the same or different semantic word judgements following a short or long lag and subsequent memory test. We found a similar overall pattern of results, with greater behavioural priming associated with a decrease in recognition and recall performance. However, neither various within-participant nor various between-participant analyses revealed significant correlations between priming and subsequent memory performance. These data suggest that both lag and task have effects on priming and declarative memory performance, but that they are largely independent and occur in parallel.

Self-construal priming affects speed of retrieval from short-term memory.

Directory of Open Access Journals (Sweden)

Justin A Macdonald

Full Text Available We investigated the effects of collective or individual self-construal priming on recall in a short-term memory (STM task. We primed participants to either their individual or their collective self-construals or a neutral control condition. Participants then completed a STM retrieval task using either random or patterned digit strings. Findings revealed that priming an individual self-construal resulted in faster retrieval of information from STM for both stimulus types. These results indicate that individual self-accessibility improves retrieval speed of digits from STM, regardless of set configuration. More broadly, the present findings extend prior research by adding further evidence of the effects of self-construal priming on cognitive information processing.

The influence of object relative size on priming and explicit memory.

Science.gov (United States)

Uttl, Bob; Graf, Peter; Siegenthaler, Amy L

2008-09-01

We investigated the effects of object relative size on priming and explicit memory for color photos of common objects. Participants were presented with color photos of pairs of objects displayed in either appropriate or inappropriate relative sizes. Implicit memory was assessed by speed of object size ratings whereas explicit memory was assessed by an old/new recognition test. Study-to-test changes in relative size reduced both priming and explicit memory and had large effects for objects displayed in large vs. small size at test. Our findings of substantial size-specific influences on priming with common objects under some but not other conditions are consistent with instance views of object perception and priming but inconsistent with structural description views.

Developmental differences in masked form priming are not driven by vocabulary growth.

Science.gov (United States)

Bhide, Adeetee; Schlaggar, Bradley L; Barnes, Kelly Anne

2014-01-01

As children develop into skilled readers, they are able to more quickly and accurately distinguish between words with similar visual forms (i.e., they develop precise lexical representations). The masked form priming lexical decision task is used to test the precision of lexical representations. In this paradigm, a prime (which differs by one letter from the target) is briefly flashed before the target is presented. Participants make a lexical decision to the target. Primes can facilitate reaction time by partially activating the lexical entry for the target. If a prime is unable to facilitate reaction time, it is assumed that participants have a precise orthographic representation of the target and thus the prime is not a close enough match to activate its lexical entry. Previous developmental work has shown that children and adults' lexical decision times are facilitated by form primes preceding words from small neighborhoods (i.e., very few words can be formed by changing one letter in the original word; low N words), but only children are facilitated by form primes preceding words from large neighborhoods (high N words). It has been hypothesized that written vocabulary growth drives the increase in the precision of the orthographic representations; children may not know all of the neighbors of the high N words, making the words effectively low N for them. We tested this hypothesis by (1) equating the effective orthographic neighborhood size of the targets for children and adults and (2) testing whether age or vocabulary size was a better predictor of the extent of form priming. We found priming differences even when controlling for effective neighborhood size. Furthermore, age was a better predictor of form priming effects than was vocabulary size. Our findings provide no support for the hypothesis that growth in written vocabulary size gives rise to more precise lexical representations. We propose that the development of spelling ability may be a more

Developmental differences in masked form priming are not driven by vocabulary growth.

Directory of Open Access Journals (Sweden)

Adeetee eBhide

2014-07-01

Full Text Available As children develop into skilled readers, they are able to more quickly and accurately distinguish between words with similar visual forms (i.e. they develop precise lexical representations. The masked form priming lexical decision task is used to test the precision of lexical representations. In this paradigm, a prime (which differs by one letter from the target is briefly flashed before the target is presented. Participants make a lexical decision to the target. Primes can facilitate reaction time by partially activating the lexical entry for the target. If a prime is unable to facilitate reaction time, it is assumed that participants have a precise orthographic representation of the target and thus the prime is not a close enough match to activate its lexical entry. Previous developmental work has shown that children and adults' lexical decision times are facilitated by form primes preceding words from small neighborhoods (i.e. very few words can be formed by changing one letter in the original word; low N words, but only children are facilitated by form primes preceding words from large neighborhoods (high N words. It has been hypothesized that written vocabulary growth drives the increase in the precision of the orthographic representations; children may not know all of the neighbors of the high N words, making the words effectively low N for them. We tested this hypothesis by 1 equating the effective orthographic neighborhood size of the targets for children and adults and 2 testing whether age or vocabulary size was a better predictor of the extent of form priming. We found priming differences even when controlling for effective neighborhood size. Furthermore, age was a better predictor of form priming effects than vocabulary size. Our findings provide no support for the hypothesis that growth in written vocabulary size gives rise to more precise lexical representations. We propose that the development of spelling ability may be a more

75 FR 43166 - Information Collection; Central Contractor Registration Requirements for Prime Grant Recipients

Science.gov (United States)

2010-07-23

...] Information Collection; Central Contractor Registration Requirements for Prime Grant Recipients AGENCY: Office... information collection requirement regarding Central Contractor Registration Requirements for Prime Grant... for the proper performance of functions of the Central Contractor Registration Requirements for Prime...

Prime time sexual harassment.

Science.gov (United States)

Grauerholz, E; King, A

1997-04-01

This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves.

Priming semantic concepts affects the dynamics of aesthetic appreciation.

Science.gov (United States)

Faerber, Stella J; Leder, Helmut; Gerger, Gernot; Carbon, Claus-Christian

2010-10-01

Aesthetic appreciation (AA) plays an important role for purchase decisions, for the appreciation of art and even for the selection of potential mates. It is known that AA is highly reliable in single assessments, but over longer periods of time dynamic changes of AA may occur. We measured AA as a construct derived from the literature through attractiveness, arousal, interestingness, valence, boredom and innovativeness. By means of the semantic network theory we investigated how the priming of AA-relevant semantic concepts impacts the dynamics of AA of unfamiliar product designs (car interiors) that are known to be susceptible to triggering such effects. When participants were primed for innovativeness, strong dynamics were observed, especially when the priming involved additional AA-relevant dimensions. This underlines the relevance of priming of specific semantic networks not only for the cognitive processing of visual material in terms of selective perception or specific representation, but also for the affective-cognitive processing in terms of the dynamics of aesthetic processing. Copyright © 2010 Elsevier B.V. All rights reserved.

Semantic context effects and priming in word association.

Science.gov (United States)

Zeelenberg, René; Pecher, Diane; Shiffrin, Richard M; Raaijmakers, Jeroen G W

2003-09-01

Two experiments investigated priming in word association, an implicit memory task. In the study phase of Experiment 1, semantically ambiguous target words were presented in sentences that biased their interpretation. The appropriate interpretation of the target was either congruent or incongruent with the cue presented in a subsequent word association task. Priming (i.e., a higher proportion of target responses relative to a nonstudied baseline) was obtained for the congruent condition, but not for the incongruent condition. In Experiment 2, study sentences emphasized particular meaning aspects of nonambiguous targets. The word association task showed a higher proportion of target responses for targets studied in the more congruent sentence context than for targets studied in the less congruent sentence context. These results indicate that priming in word association depends largely on the storage of information relating the cue and target.

Priming dose of phenylhydrazine protects against hemolytic and lethal effects of 2-butoxyethanol

International Nuclear Information System (INIS)

Palkar, Prajakta S.; Philip, Binu K.; Reddy, Ramesh N.; Mehendale, Harihara M.

2007-01-01

Protection against a high dose of a toxicant by prior exposure to another toxicant is called heteroprotection. Our objective was to establish a heteroprotection model in RBCs. Female Sprague Dawley rats treated with an LD90 dose of 2-butoxyethanol (BE, 1500 mg/kg in water, 5 ml/kg po) 14 days after priming with 0.9% NaCl suffered 90% mortality by 15 days, whereas all rats receiving the LD90 dose of BE 14 days after priming with phenylhydrazine (PHZ, 125 mg/kg in 0.9% NaCl, 3 ml/kg po) survived. Hematocrit decreased from normal 45% to 24% by day 3 after PHZ priming and improved thereafter. Increasing the time interval between the priming and LD90 dose to 21 days abolished the heteroprotection. RBCs obtained on days 7 and 14 after PHZ priming unlike those on day 21 were resilient to the hemotoxic metabolite of BE, butoxyacetic acid (BAA). Unaltered hepatic alcohol and aldehyde dehydrogenase activities upon PHZ priming suggested that bioactivation of BE to BAA was unaffected. Lower renal (6 and 12 h) and hepatic (12 h) BAA levels and 3 fold higher excretion of BAA in PHZ-primed rat urine suggested a protective role of toxicokinetics. Higher erythropoietin, reticulocytes, and resiliency of PHZ-primed rat RBCs indicated that newly formed RBCs are resilient to hemolytic BAA. The antioxidant levels in the PHZ-primed rat RBCs did not indicate a protective role in heteroprotection. In conclusion, the resistance of PHZ-primed rats against BE-induced hemotoxicity and lethality is mediated by a combination of altered toxicokinetics, robust erythropoiesis, and resiliency of new RBCs

Precision probes of a leptophobic Z{sup Prime} boson

Energy Technology Data Exchange (ETDEWEB)

Buckley, Matthew R., E-mail: mbuckley@fnal.gov [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Ramsey-Musolf, Michael J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-06-06

Extensions of the Standard Model that contain leptophobic Z{sup Prime} gauge bosons are theoretically interesting but difficult to probe directly in high-energy hadron colliders. However, precision measurements of Standard Model neutral current processes can provide powerful indirect tests. We demonstrate that parity-violating deep inelastic scattering of polarized electrons off of deuterium offer a unique probe leptophobic Z{sup Prime} bosons with axial quark couplings and masses above 100 GeV. In addition to covering a wide range of previously uncharted parameter space, planned measurements of the deep inelastic parity-violating eD asymmetry would be capable of testing leptophobic Z{sup Prime} scenarios proposed to explain the CDF W plus dijet anomaly.

The impact of locus of control and priming on the endowment effect.

Science.gov (United States)

Sun, Ya-Chung

2011-10-01

This paper demonstrates the effects of different priming conditions on the endowment effect with respect to seller and buyer roles for individuals with different loci of control. Individuals with an external locus of control process information less rationally, and they are more susceptible to external influences. In addition, the literature reports that when individuals are making a purchasing decision, they tend to perceive the value of the product as being higher because of its utility aspect because decision makers search for reasons and arguments to justify their choices (Shafir 1993; Tversky & Griffin, 1991). Therefore, this study investigates the effects of different priming conditions (utilitarian priming vs. hedonic priming) on the endowment effect according to each type of locus of control (internal vs. external). The results showed that the endowment effect was larger when externals were exposed to utilitarian priming as opposed to hedonic priming. Finally, the implications of these findings and suggestions for future research are discussed. © 2011 The Author. Scandinavian Journal of Psychology © 2011 The Scandinavian Psychological Associations.

Accessing world knowledge: evidence from N400 and reaction time priming.

Science.gov (United States)

Chwilla, Dorothee J; Kolk, Herman H J

2005-12-01

How fast are we in accessing world knowledge? In two experiments, we tested for priming for word triplets that described a conceptual script (e.g., DIRECTOR-BRIBE-DISMISSAL) but were not associatively related and did not share a category relationship. Event-related brain potentials were used to track the time course at which script information becomes available. In Experiment 1, in which participants made lexical decisions, we found a facilitation for script-related relative to unrelated triplets, as indicated by (i) a decrease in both reaction time and errors, and (ii) an N400-like priming effect. In Experiment 2, we further explored the locus of script priming by increasing the contribution of meaning integration processes. The participants' task was to indicate whether the three words presented a plausible scenario. Again, an N400 script priming effect was obtained. Directing attention to script relations was effective in enhancing the N400 effect. The time course of the N400 effect was similar to that of the standard N400 effect to semantic relations. The present results show that script priming can be obtained in the visual modality, and that script information is immediately accessed and integrated with context. This supports the view that script information forms a central aspect of word meaning. The RT and N400 script priming effects reported in this article are problematic for most current semantic priming models, like spreading activation models, expectancy models, and task-specific semantic matching/integration models. They support a view in which there is no clear cutoff point between semantic knowledge and world knowledge.

Inactivation of Escherichia coli phosphoribosylpyrophosphate synthetase by the 2',3'-dialdehyde derivative of ATP. Identification of active site lysines

DEFF Research Database (Denmark)

Hilden, Ida; Hove-Jensen, Bjarne; Harlow, Kenneth W.

1995-01-01

M. Reaction with radioactive oATP demonstrated that complete inactivation of the enzyme corresponded to reaction at two or more sites with limiting stoichiometries of approximately 0.7 and 1.3 mol of oATP incorporated/mol of PRPP synthetase subunit. oATP served as a substrate in the presence of ribose-5...

Small-angle X-ray-scattering investigation and structural-model study of the fatty-acid synthetase from pig liver

International Nuclear Information System (INIS)

Folkhard, W.; Felser, B.; Pilz, I.; Kratky, O.; Dutler, H.; Vogel, H.

1977-01-01

The structure of the fatty acid synthetase from pig liver was studied on models based upon structural and functional properties selected from pertinent results available from numerous investigations carried out with fatty acid synthetase from this and other sources. When comparing small-angle X-ray-scattering curves calculated with these models and curves obtained from small-angle X-ray-scattering experiments carried out with the pig-liver enzyme, we tried to select a model which would lead to an acceptable correlation between the calculated and the experimental curves and at the same time fulfil the known structural and the functional requirements. The comparison of the curves was started with a model of low complexity. The observed discrepancy, together with arguments from the structural and the functional properties, helped decide which is the next most reasonable model to be considered. This procedure was repeated for five models of increasing complexity. In the model which led to the best fit the multienzyme complex is composed of two halves in an asymmetric conformation including hollow spaces. This highly anisotropic model would imply that the two halves change their conformation each time a synthetic cycle is completed and that the growing fatty acid is handed over from one half to the other. (orig.) [de

Mutation of the human mitochondrial phenylalanine-tRNA synthetase causes infantile-onset epilepsy and cytochrome c oxidase deficiency.

Science.gov (United States)

Almalki, Abdulraheem; Alston, Charlotte L; Parker, Alasdair; Simonic, Ingrid; Mehta, Sarju G; He, Langping; Reza, Mojgan; Oliveira, Jorge M A; Lightowlers, Robert N; McFarland, Robert; Taylor, Robert W; Chrzanowska-Lightowlers, Zofia M A

2014-01-01

Mitochondrial aminoacyl-tRNA synthetases (aaRSs) are essential enzymes in protein synthesis since they charge tRNAs with their cognate amino acids. Mutations in the genes encoding mitochondrial aaRSs have been associated with a wide spectrum of human mitochondrial diseases. Here we report the identification of pathogenic mutations (a partial genomic deletion and a highly conserved p. Asp325Tyr missense variant) in FARS2, the gene encoding mitochondrial phenylalanyl-tRNA synthetase, in a patient with early-onset epilepsy and isolated complex IV deficiency in muscle. The biochemical defect was expressed in myoblasts but not in fibroblasts and associated with decreased steady state levels of COXI and COXII protein and reduced steady state levels of the mt-tRNA(Phe) transcript. Functional analysis of the recombinant mutant p. Asp325Tyr FARS2 protein showed an inability to bind ATP and consequently undetectable aminoacylation activity using either bacterial tRNA or human mt-tRNA(Phe) as substrates. Lentiviral transduction of cells with wildtype FARS2 restored complex IV protein levels, confirming that the p.Asp325Tyr mutation is pathogenic, causing respiratory chain deficiency and neurological deficits on account of defective aminoacylation of mt-tRNA(Phe). © 2013. Published by Elsevier B.V. All rights reserved.

Exploring the evolutionary diversity and assembly modes of multi-aminoacyl-tRNA synthetase complexes: lessons from unicellular organisms.

Science.gov (United States)

Laporte, Daphné; Huot, Jonathan L; Bader, Gaétan; Enkler, Ludovic; Senger, Bruno; Becker, Hubert Dominique

2014-11-28

Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and ancient enzymes, mostly known for their essential role in generating aminoacylated tRNAs. During the last two decades, many aaRSs have been found to perform additional and equally crucial tasks outside translation. In metazoans, aaRSs have been shown to assemble, together with non-enzymatic assembly proteins called aaRSs-interacting multifunctional proteins (AIMPs), into so-called multi-synthetase complexes (MSCs). Metazoan MSCs are dynamic particles able to specifically release some of their constituents in response to a given stimulus. Upon their release from MSCs, aaRSs can reach other subcellular compartments, where they often participate to cellular processes that do not exploit their primary function of synthesizing aminoacyl-tRNAs. The dynamics of MSCs and the expansion of the aaRSs functional repertoire are features that are so far thought to be restricted to higher and multicellular eukaryotes. However, much can be learnt about how MSCs are assembled and function from apparently 'simple' organisms. Here we provide an overview on the diversity of these MSCs, their composition, mode of assembly and the functions that their constituents, namely aaRSs and AIMPs, exert in unicellular organisms. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Preparing to fight back: Generation and storage of priming compounds.

Directory of Open Access Journals (Sweden)

Victoria ePastor

2014-06-01

Full Text Available Immune-stimulated plants are able to respond more rapidly and adequately to various biotic stresses allowing them to efficiently combat an infection. During the priming phase, plant are stimulated in absence of a challenge, and can accumulate and store conjugates or precursors of molecules as well as other compounds that play a role in defense. These molecules can be released during the defensive phase following stress. These metabolites can also participate in the first stages of the stress perception. Here, we report the metabolic changes occuring in primed plants during the priming phase. β-aminobutyric acid (BABA causes a boost of the primary metabolism through the tricarboxylic acids (TCA such as citrate, fumarate, (S-malate and 2-oxoglutarate, and the potentiation of phenylpropanoid biosynthesis and the octodecanoic pathway. On the contrary, Pseudomonas syringae pv tomato (PstAvrRpt2 represses the same pathways. Both systems used to prime plants share some common signals like the changes in the synthesis of amino acids and the production of SA and its glycosides, as well as IAA. Interestingly, a product of the purine catabolism, xanthosine, was found to accumulate following both BABA- and PstAvrRpt2-treatement. The compounds that are strongly affected in this stage are called priming compounds, since their effect on the metabolism of the plant is to induce the production of primed compounds that will help to combat the stress. At the same time, additional identified metabolites suggest the possible defense pathways that plants are using to get ready for the battle.

The influence of object relative size on priming and explicit memory.

Directory of Open Access Journals (Sweden)

Bob Uttl

Full Text Available We investigated the effects of object relative size on priming and explicit memory for color photos of common objects. Participants were presented with color photos of pairs of objects displayed in either appropriate or inappropriate relative sizes. Implicit memory was assessed by speed of object size ratings whereas explicit memory was assessed by an old/new recognition test. Study-to-test changes in relative size reduced both priming and explicit memory and had large effects for objects displayed in large vs. small size at test. Our findings of substantial size-specific influences on priming with common objects under some but not other conditions are consistent with instance views of object perception and priming but inconsistent with structural description views.

A single Danio rerio hars gene encodes both cytoplasmic and mitochondrial histidyl-tRNA synthetases.

Directory of Open Access Journals (Sweden)

Ashley L Waldron

Full Text Available Histidyl tRNA Synthetase (HARS is a member of the aminoacyl tRNA synthetase (ARS family of enzymes. This family of 20 enzymes is responsible for attaching specific amino acids to their cognate tRNA molecules, a critical step in protein synthesis. However, recent work highlighting a growing number of associations between ARS genes and diverse human diseases raises the possibility of new and unexpected functions in this ancient enzyme family. For example, mutations in HARS have been linked to two different neurological disorders, Usher Syndrome Type IIIB and Charcot Marie Tooth peripheral neuropathy. These connections raise the possibility of previously undiscovered roles for HARS in metazoan development, with alterations in these functions leading to complex diseases. In an attempt to establish Danio rerio as a model for studying HARS functions in human disease, we characterized the Danio rerio hars gene and compared it to that of human HARS. Using a combination of bioinformatics, molecular biology, and cellular approaches, we found that while the human genome encodes separate genes for cytoplasmic and mitochondrial HARS protein, the Danio rerio genome encodes a single hars gene which undergoes alternative splicing to produce the respective cytoplasmic and mitochondrial versions of Hars. Nevertheless, while the HARS genes of humans and Danio differ significantly at the genomic level, we found that they are still highly conserved at the amino acid level, underscoring the potential utility of Danio rerio as a model organism for investigating HARS function and its link to human diseases in vivo.

Priming involuntary autobiographical memories in the lab.

Science.gov (United States)

Barzykowski, Krystian; Niedźwieńska, Agnieszka

2018-02-01

Involuntary autobiographical memories (IAMs) are recollections of personal past that frequently and spontaneously occur in daily life. Initial studies by Mace (2005) showed that deliberately reminiscing about a certain lifetime period (e.g., high school) significantly increased the number of different IAMs from the same period in subsequent days, suggesting that priming may play a significant role in the retrieval of IAMs in everyday life. In the present study, we used a modified experimental paradigm, originally used by Schlagman and Kvavilashvili (2008), to study IAMs under well-controlled laboratory conditions. Participants completed a monotonous vigilance task twice and reported the occurrence of any spontaneous thoughts that were later classed as IAMs or other thoughts. Priming was manipulated by having experimental participants reminiscing about high school period between the two vigilance tasks and control participants playing simple games. Results showed that participants in the experimental group reported IAMs relating to high school period more frequently during the second vigilance task than those in the control group. In the experimental group, the number of high school memories was marginally higher in the second vigilance task compared to the first vigilance task with the medium effect size, but this within subjects effect was not significant in the control group. Finally, priming also enhanced the retrieval of more remote IAMs in the experimental group compared to the control group. These results suggest that priming may play a significant role in the activation and recall of IAMs and open up interesting avenues for future research.

Lack of semantic priming effects in famous person recognition in Mild Cognitive Impairment.

Science.gov (United States)

Brambati, Simona M; Peters, Frédéric; Belleville, Sylvie; Joubert, Sven

2012-04-01

Growing evidence indicates that individuals with Mild Cognitive Impairment (MCI) manifest semantic deficits that are often more severe for items that are characterized by a unique semantic and lexical association, such as famous people and famous buildings, than common concepts, such as objects. However, it is still controversial whether the semantic deficits observed in MCI are determined by a degradation of semantic information or by a deficit in intentional access to semantic knowledge. Here we used a semantic priming task in order to assess the integrity of the semantic system without requiring explicit access to this system. This paradigm may provide new insights in clarifying the nature of the semantic deficits in MCI. We assessed the semantic and repetition priming effect in 13 individuals with MCI and 13 age-matched controls who engaged in a familiarity judgment task of famous names. In the semantic priming condition, the prime was the name of a member of the same occupation category as the target (Tom Cruise-Brad Pitt), while in the repetition priming condition the prime was the same name as the target (Charlie Chaplin-Charlie Chaplin). The results showed a defective priming effect in MCI in the semantic but not in the repetition priming condition. Specifically, when compared to controls, MCI patients did not show a facilitation effect in responding to the same occupation prime-target pairs, but they showed an equivalent facilitation effect when the target was the same name as the prime. The present results provide support to the hypothesis that the semantic impairments observed in MCI cannot be uniquely ascribed to a deficit in intentional access to semantic information. Instead, these findings point to the semantic nature of these deficits and, in particular, to a degraded representation of semantic information concerning famous people. Copyright © 2011 Elsevier Srl. All rights reserved.

Priming effects in boreal black spruce forest soils: quantitative evaluation and sensitivity analysis.

Directory of Open Access Journals (Sweden)

Zhaosheng Fan

Full Text Available Laboratory studies show that introduction of fresh and easily decomposable organic carbon (OC into soil-water systems can stimulate the decomposition of soil OC (SOC via priming effects in temperate forests, shrublands, grasslands, and agro-ecosystems. However, priming effects are still not well understood in the field setting for temperate ecosystems and virtually nothing is known about priming effects (e.g., existence, frequency, and magnitude in boreal ecosystems. In this study, a coupled dissolved OC (DOC transport and microbial biomass dynamics model was developed to simultaneously simulate co-occurring hydrological, physical, and biological processes and their interactions in soil pore-water systems. The developed model was then used to examine the importance of priming effects in two black spruce forest soils, with and without underlying permafrost. Our simulations showed that priming effects were strongly controlled by the frequency and intensity of DOC input, with greater priming effects associated with greater DOC inputs. Sensitivity analyses indicated that priming effects were most sensitive to variations in the quality of SOC, followed by variations in microbial biomass dynamics (i.e., microbial death and maintenance respiration, highlighting the urgent need to better discern these key parameters in future experiments and to consider these dynamics in existing ecosystem models. Water movement carries DOC to deep soil layers that have high SOC stocks in boreal soils. Thus, greater priming effects were predicted for the site with favorable water movement than for the site with limited water flow, suggesting that priming effects might be accelerated for sites where permafrost degradation leads to the formation of dry thermokarst.

Priming effects in boreal black spruce forest soils: quantitative evaluation and sensitivity analysis.

Science.gov (United States)

Fan, Zhaosheng; Jastrow, Julie D; Liang, Chao; Matamala, Roser; Miller, Raymond Michael

2013-01-01

Laboratory studies show that introduction of fresh and easily decomposable organic carbon (OC) into soil-water systems can stimulate the decomposition of soil OC (SOC) via priming effects in temperate forests, shrublands, grasslands, and agro-ecosystems. However, priming effects are still not well understood in the field setting for temperate ecosystems and virtually nothing is known about priming effects (e.g., existence, frequency, and magnitude) in boreal ecosystems. In this study, a coupled dissolved OC (DOC) transport and microbial biomass dynamics model was developed to simultaneously simulate co-occurring hydrological, physical, and biological processes and their interactions in soil pore-water systems. The developed model was then used to examine the importance of priming effects in two black spruce forest soils, with and without underlying permafrost. Our simulations showed that priming effects were strongly controlled by the frequency and intensity of DOC input, with greater priming effects associated with greater DOC inputs. Sensitivity analyses indicated that priming effects were most sensitive to variations in the quality of SOC, followed by variations in microbial biomass dynamics (i.e., microbial death and maintenance respiration), highlighting the urgent need to better discern these key parameters in future experiments and to consider these dynamics in existing ecosystem models. Water movement carries DOC to deep soil layers that have high SOC stocks in boreal soils. Thus, greater priming effects were predicted for the site with favorable water movement than for the site with limited water flow, suggesting that priming effects might be accelerated for sites where permafrost degradation leads to the formation of dry thermokarst.

Density of primes in l-th power residues

Indian Academy of Sciences (India)

Given a prime number , a finite set of integers S={a1,…,am} and many -th roots of unity ril,i=1,…,m we study the distribution of primes in Q(l) such that the -th residue symbol of ai with respect to is ril, for all . We find out that this is related to the degree of the extension Q(a1l1,…,a1lm)/Q. We give an algorithm ...

Facial Features Can Induce Emotion: Evidence from Affective Priming Tasks

Directory of Open Access Journals (Sweden)

Chia-Chen Wu

2011-05-01

Full Text Available Our previous study found that schematic faces with direct gazes, with mouths, with horizontal oval eyes, or without noses, tend to be perceived as in negative emotion. In this study we further explore these factors by the affective priming task. Faces were taking as prime, and positive or negative words were probe. The task was to judge the valence of the probe. If the faces could induce emotions, a target word with the same emotional valence should be judged faster than with opposite valence (the congruency effect. Experiment 1 used the most positive and negative rated faces in previous study as the primes. The positive faces were with vertical oval eyes and without mouth, while the negative faces were with horizontal eyes and with mouth. Results of 34 participants showed that those faces indeed elicited congruency effects. Experiment 2 manipulated gaze directions (N = 16. After the task the participants were asked to rate the prime faces. According to their rating, faces with direct gaze was perceive as positive, and elicited congruency effect with positive words in affective priming task. Our data thus support the conjecture that shape of eyes, the existence of mouths, and gaze directions could induces emotion.

Inhibition of protein synthesis and malaria parasite development by drug targeting of methionyl-tRNA synthetases.

Science.gov (United States)

Hussain, Tahir; Yogavel, Manickam; Sharma, Amit

2015-04-01

Aminoacyl-tRNA synthetases (aaRSs) are housekeeping enzymes that couple cognate tRNAs with amino acids to transmit genomic information for protein translation. The Plasmodium falciparum nuclear genome encodes two P. falciparum methionyl-tRNA synthetases (PfMRS), termed PfMRS(cyt) and PfMRS(api). Phylogenetic analyses revealed that the two proteins are of primitive origin and are related to heterokonts (PfMRS(cyt)) or proteobacteria/primitive bacteria (PfMRS(api)). We show that PfMRS(cyt) localizes in parasite cytoplasm, while PfMRS(api) localizes to apicoplasts in asexual stages of malaria parasites. Two known bacterial MRS inhibitors, REP3123 and REP8839, hampered Plasmodium growth very effectively in the early and late stages of parasite development. Small-molecule drug-like libraries were screened against modeled PfMRS structures, and several "hit" compounds showed significant effects on parasite growth. We then tested the effects of the hit compounds on protein translation by labeling nascent proteins with (35)S-labeled cysteine and methionine. Three of the tested compounds reduced protein synthesis and also blocked parasite growth progression from the ring stage to the trophozoite stage. Drug docking studies suggested distinct modes of binding for the three compounds, compared with the enzyme product methionyl adenylate. Therefore, this study provides new targets (PfMRSs) and hit compounds that can be explored for development as antimalarial drugs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Kinetic and metabolic studies on the priming effect of interferon in L cells

International Nuclear Information System (INIS)

Rosztoczy, I.

1977-01-01

In cultures primed by interferon pretreatment before stimulation by polyriboinosinic-polyribocytidylic acid interferon was detected one hour earlier, its production followed an enhanced pattern and became resistant to actinomycin D 30 min sooner than in unprimed cultures. The kinetics of development of the primed state was found to be a time- and dose-dependent phenomenon. The continuous presence of interferon during the pretreatment period was not required for the development of the primed state. Actinomycin D at a concentration inhibitory for nuclear RNA synthesis did not influence the development of priming. Higher concentrations of the drug and long term α-amanitin or cycloheximide pretreatments, inhibitory for heterogeneous nuclear RNA synthesis, prevented the establishment of the primed state. (author)

Reassessment of primed constant-infusion tracer method to measure urea kinetics

International Nuclear Information System (INIS)

Jahoor, F.; Wolfe, R.R.

1987-01-01

The validity of the primed constant-infusion tracer technique to make short-term measurements of urea production rates (R/sub a/) in humans in a physiological steady state and during disruption of steady state was evaluated. Four subjects received a primed constant infusion (P/I = 560 min) of [ 13 C]urea for 8 h. A plateau in urea enrichment was reached after 2 h and maintained throughout. When [ 13 C]- and [ 18 O]urea were simultaneously infused into four subjects at P/I ratios of 560:1 and 360:1, respectively, both tracers reached plateau enrichment at the same time (2-4 h). The enrichment at plateau was a function of the infusion rate rather than the priming dose, and calculated urea R/sub a/ was the same with either prime. In five additional experiments the technique responded acutely to a physiological perturbation (alanine infusion) in a dose-dependent manner. The results confirm that this technique is appropriate for short-term measurements of urea R/sub a/, and the requirement for accuracy in estimating the priming dose is not impractically stringent

UniPrime2: a web service providing easier Universal Primer design.

Science.gov (United States)

Boutros, Robin; Stokes, Nicola; Bekaert, Michaël; Teeling, Emma C

2009-07-01

The UniPrime2 web server is a publicly available online resource which automatically designs large sets of universal primers when given a gene reference ID or Fasta sequence input by a user. UniPrime2 works by automatically retrieving and aligning homologous sequences from GenBank, identifying regions of conservation within the alignment, and generating suitable primers that can be used to amplify variable genomic regions. In essence, UniPrime2 is a suite of publicly available software packages (Blastn, T-Coffee, GramAlign, Primer3), which reduces the laborious process of primer design, by integrating these programs into a single software pipeline. Hence, UniPrime2 differs from previous primer design web services in that all steps are automated, linked, saved and phylogenetically delimited, only requiring a single user-defined gene reference ID or input sequence. We provide an overview of the web service and wet-laboratory validation of the primers generated. The system is freely accessible at: http://uniprime.batlab.eu. UniPrime2 is licenced under a Creative Commons Attribution Noncommercial-Share Alike 3.0 Licence.

Modified Three-Dimensional Multicarrier Optical Prime Codes

Directory of Open Access Journals (Sweden)

Rajesh Yadav

2016-01-01

Full Text Available We propose a mathematical model for novel three-dimensional multicarrier optical codes in terms of wavelength/time/space based on the prime sequence algorithm. The proposed model has been extensively simulated on MATLAB for prime numbers (P to analyze the performance of code in terms of autocorrelation and cross-correlation. The simulated outcome resembles the mathematical model and gives better results over other methods available in the literature as far as autocorrelation and cross-correlation are concerned. The proposed 3D optical codes are more efficient in terms of cardinality, improved security, and providing quality of services.

Integers without large prime factors in short intervals: Conditional ...

Indian Academy of Sciences (India)

α > 0 the interval (X, X +. √. X(log X)1/2+o(1)] contains an integer having no prime factor exceeding Xα for all X sufficiently large. Keywords. Smooth numbers; Riemann zeta function. 1. Introduction. Suppose P (n) denotes the largest prime factor of an integer n > 1 and let us declare. P(1) = 1. Given a positive real number y, ...

Thymidine kinase 2 and alanyl-tRNA synthetase 2 deficiencies cause lethal mitochondrial cardiomyopathy: case reports and review of the literature.

Science.gov (United States)

Mazurova, Stella; Magner, Martin; Kucerova-Vidrova, Vendula; Vondrackova, Alzbeta; Stranecky, Viktor; Pristoupilova, Anna; Zamecnik, Josef; Hansikova, Hana; Zeman, Jiri; Tesarova, Marketa; Honzik, Tomas

2017-07-01

Cardiomyopathy is a common manifestation in neonates and infants with mitochondrial disorders. In this study, we report two cases manifesting with fatal mitochondrial hypertrophic cardiomyopathy, which include the third known patient with thymidine kinase 2 deficiency and the ninth patient with alanyl-tRNA synthetase 2 deficiency. The girl with thymidine kinase 2 deficiency had hypertrophic cardiomyopathy together with regression of gross motor development at the age of 13 months. Neurological symptoms and cardiac involvement progressed into severe myopathy, psychomotor arrest, and cardiorespiratory failure at the age of 22 months. The imaging methods and autoptic studies proved that she suffered from unique findings of leucoencephalopathy, severe, mainly cerebellar neuronal degeneration, and hepatic steatosis. The girl with alanyl-tRNA synthetase 2 deficiency presented with cardiac failure and underlying hypertrophic cardiomyopathy within 12 hours of life and subsequently died at 9 weeks of age. Muscle biopsy analyses demonstrated respiratory chain complex I and IV deficiencies, and histological evaluation revealed massive mitochondrial accumulation and cytochrome c oxidase-negative fibres in both cases. Exome sequencing in the first case revealed compound heterozygozity for one novel c.209T>C and one previously published c.416C>T mutation in the TK2 gene, whereas in the second case homozygozity for the previously described mutation c.1774C>T in the AARS2 gene was determined. The thymidine kinase 2 mutations resulted in severe mitochondrial DNA depletion (to 12% of controls) in the muscle. We present, for the first time, severe leucoencephalopathy and hepatic steatosis in a patient with thymidine kinase 2 deficiency and the finding of a ragged red fibre-like image in the muscle biopsy in a patient with alanyl-tRNA synthetase 2 deficiency.

The functional unit of Japanese word naming: evidence from masked priming.

Science.gov (United States)

Verdonschot, Rinus G; Kiyama, Sachiko; Tamaoka, Katsuo; Kinoshita, Sachiko; Heij, Wido La; Schiller, Niels O

2011-11-01

Theories of language production generally describe the segment as the basic unit in phonological encoding (e.g., Dell, 1988; Levelt, Roelofs, & Meyer, 1999). However, there is also evidence that such a unit might be language specific. Chen, Chen, and Dell (2002), for instance, found no effect of single segments when using a preparation paradigm. To shed more light on the functional unit of phonological encoding in Japanese, a language often described as being mora based, we report the results of 4 experiments using word reading tasks and masked priming. Experiment 1 demonstrated using Japanese kana script that primes, which overlapped in the whole mora with target words, sped up word reading latencies but not when just the onset overlapped. Experiments 2 and 3 investigated a possible role of script by using combinations of romaji (Romanized Japanese) and hiragana; again, facilitation effects were found only when the whole mora and not the onset segment overlapped. Experiment 4 distinguished mora priming from syllable priming and revealed that the mora priming effects obtained in the first 3 experiments are also obtained when a mora is part of a syllable. Again, no priming effect was found for single segments. Our findings suggest that the mora and not the segment (phoneme) is the basic functional phonological unit in Japanese language production planning.

Effects of dividing attention during encoding on perceptual priming of unfamiliar visual objects

Science.gov (United States)

Soldan, Anja; Mangels, Jennifer A.; Cooper, Lynn A.

2008-01-01

According to the distractor-selection hypothesis (Mulligan, 2003), dividing attention during encoding reduces perceptual priming when responses to non-critical (i.e., distractor) stimuli are selected frequently and simultaneously with critical stimulus encoding. Because direct support for this hypothesis comes exclusively from studies using familiar word stimuli, the present study tested whether the predictions of the distractor-selection hypothesis extend to perceptual priming of unfamiliar visual objects using the possible/impossible object-decision test. Consistent with the distractor-selection hypothesis, Experiments 1 and 2 found no reduction in priming when the non-critical stimuli were presented infrequently and non-synchronously with the critical target stimuli, even though explicit recognition memory was reduced. In Experiment 3, non-critical stimuli were presented frequently and simultaneously during encoding of critical stimuli; however, no decrement in priming was detected, even when encoding time was reduced. These results suggest that priming in the possible/impossible object-decision test is relatively immune to reductions in central attention and that not all aspects of the distractor-selection hypothesis generalize to priming of unfamiliar visual objects. Implications for theoretical models of object-decision priming are discussed. PMID:18821167

Attention and Implicit Memory: Priming-Induced Benefits and Costs Have Distinct Attentional Requirements

OpenAIRE

Keane, Margaret M.; Cruz, Matt E.; Verfaellie, Mieke

2015-01-01

Attention at encoding plays a critical and ubiquitous role in explicit memory performance, but its role in implicit memory performance (i.e., priming) is more variable: Some, but not all, priming effects are reduced by division of attention at encoding. A wealth of empirical and theoretical work has aimed to define the critical features of priming effects that do or do not require attention at encoding. This work, however, has focused exclusively on priming effects that are beneficial in natu...

Masked and unmasked priming effects as a function of semantic relatedness and associative strength.

Science.gov (United States)

Sánchez-Casas, Rosa; Ferré, Pilar; Demestre, Josep; García-Chico, Teófilo; García-Albea, José E

2012-11-01

The study presented in this paper aimed to investigate the pattern of semantic priming effects, under masked and unmasked conditions, in the lexical decision task, manipulating type of semantic relation and associative strength. Three different kinds of word relations were examined in two experiments: only-semantically related words [e.g., codo (elbow)-rodilla (knee)] and semantic/associative related words with strong [e.g., mesa (table)-silla (chair) and weak association strength [e.g., sapo (toad)-rana (frog)]. In Experiment 1 a masked priming procedure was used with a prime duration of 56 ms, and in Experiment 2, the prime was presented unmasked for 150 ms. The results showed that there were masked priming effects with strong associates, but no evidence of these effects was found with weak associates or only-semantic related word pairs. When the prime was presented unmasked, the three types of relations produced significant priming effects and they were not influenced by association strength.

Conflict processing in the anterior cingulate cortex constrains response priming.

Science.gov (United States)

Pastötter, Bernhard; Hanslmayr, Simon; Bäuml, Karl-Heinz T

2010-05-01

A prominent function of the anterior cingulate cortex (ACC) is to process conflict between competing response options. In this study, we investigated the role of conflict processing in a response-priming task in which manual responses were either validly or invalidly cued. Examining electrophysiological measurements of oscillatory brain activity on the source level, we found response priming to be related to a beta power decrease in the premotor cortex and conflict processing to be linked to a theta power increase in the ACC. In particular, correlation of oscillatory brain activities in the ACC and the premotor cortex showed that conflict processing reduces response priming by slowing response time in valid trials and lowering response errors in invalid trials. This relationship emerged on a between subjects level as well as within subjects, on a single trial level. These findings suggest that conflict processing in the ACC constrains the automatic priming process. 2010 Elsevier Inc. All rights reserved.

On primes in Lucas sequences

Czech Academy of Sciences Publication Activity Database

Křížek, Michal; Somer, L.

2015-01-01

Roč. 53, č. 1 (2015), s. 2-23 ISSN 0015-0517 R&D Projects: GA ČR GA14-02067S Institutional support: RVO:67985840 Keywords : Lucas sequence * primes Subject RIV: BA - General Mathematics http://www.fq.math.ca/Abstracts/53-1/somer.pdf

A yeast model for target-primed (non-LTR retrotransposition

Directory of Open Access Journals (Sweden)

Busby Jason N

2007-08-01

Full Text Available Abstract Background Target-primed (non-LTR retrotransposons, such as the human L1 element, are mobile genetic elements found in many eukaryotic genomes. They are often present in large numbers and their retrotransposition can cause mutations and genomic rearrangements. Despite their importance, many aspects of their replication are not well understood. Results We have developed a yeast model system for studying target-primed retrotransposons. This system uses the Zorro3 element from Candida albicans. A cloned copy of Zorro3, tagged with a retrotransposition indicator gene, retrotransposes at a high frequency when introduced into an appropriate C. albicans host strain. Retrotransposed copies of the tagged element exhibit similar features to the native copies, indicating that the natural retrotransposition pathway is being used. Retrotransposition is dependent on the products of the tagged element's own genes and is highly temperature-regulated. The new assay permits the analysis of the effects of specific mutations introduced into the cloned element. Conclusion This Zorro3 retrotransposition assay system complements previously available target-primed retrotransposition assays. Due to the relative simplicity of the growth, manipulation and analysis of yeast cells, the system should advance our understanding of target-primed retrotransposition.

Understanding the relationship between repetition priming and mere exposure.

Science.gov (United States)

Butler, Laurie T; Berry, Dianne C

2004-11-01

Over the last two decades interest in implicit memory, most notably repetition priming, has grown considerably. During the same period, research has also focused on the mere exposure effect. Although the two areas have developed relatively independently, a number of studies has described the mere exposure effect as an example of implicit memory. Tacit in their comparisons is the assumption that the effect is more specifically a demonstration of repetition priming. Having noted that this assumption has attracted relatively little attention, this paper reviews current evidence and shows that it is by no means conclusive. Although some evidence is suggestive of a common underlying mechanism, even a modified repetition priming (perceptual fluency/attribution) framework cannot accommodate all of the differences between the two phenomena. Notwithstanding this, it seems likely that a version of this theoretical framework still offers the best hope of a comprehensive explanation for the mere exposure effect and its relationship to repetition priming. As such, the paper finishes by offering some initial guidance as to ways in which the perceptual fluency/attribution framework might be extended, as well as outlining important areas for future research.

Prime Numbers Comparison using Sieve of Eratosthenes and Sieve of Sundaram Algorithm

Science.gov (United States)

Abdullah, D.; Rahim, R.; Apdilah, D.; Efendi, S.; Tulus, T.; Suwilo, S.

2018-03-01

Prime numbers are numbers that have their appeal to researchers due to the complexity of these numbers, many algorithms that can be used to generate prime numbers ranging from simple to complex computations, Sieve of Eratosthenes and Sieve of Sundaram are two algorithm that can be used to generate Prime numbers of randomly generated or sequential numbered random numbers, testing in this study to find out which algorithm is better used for large primes in terms of time complexity, the test also assisted with applications designed using Java language with code optimization and Maximum memory usage so that the testing process can be simultaneously and the results obtained can be objective

Search for W(prime) → tb resonances with left- and right-handed couplings to fermions

International Nuclear Information System (INIS)

2011-01-01

We present a search for the production of a heavy gauge boson, W(prime), that decays to third-generation quarks, by the D0 Collaboration in p(bar p) collisions at √s = 1.96 TeV. We set 95% confidence level upper limits on the production cross section times branching fraction. For the first time, we set limits for arbitrary combinations of left- and right-handed couplings of the W(prime) boson to fermions. For couplings with the same strength as the standard model W boson, we set the following limits for M(W(prime)) > m(ν R ): M(W(prime)) > 863 GeV for purely left-handed couplings, M(W(prime)) > 885 GeV for purely right-handed couplings, and M(W(prime)) > 916 GeV if both left- and right-handed couplings are present. The limit for right-handed couplings improves for M(W(prime)) R ) to M(W(prime)) > 890 GeV.

Flavor changing neutral currents and a Z Prime

Energy Technology Data Exchange (ETDEWEB)

Valencia, German, E-mail: valencia@iastate.edu [Iowa State University (United States)

2013-03-15

We consider a non-universal Z Prime that affects primarily the third generation fermions as an example of new physics associated with the top-quark. We first discuss constraints on the mass and coupling strength of such a Z Prime . We then turn our attention to the flavor changing neutral currents (FCNC) present in the model. We discuss the experimental constraints and their implications. We propose an ansatz to understand the smallness of the FCNC in terms of the CKM matrix.

The distribution of prime numbers and associated problems in number theory

International Nuclear Information System (INIS)

Nair, M.

1991-01-01

Some problems in number theory, namely the gaps between consecutive primes, the distribution of primes in arithmetic progressions, Brun-Titchmarsh theorem, Fermat's last theorem, The Thue equation, the gaps between square-free numbers are discussed

Priming in Episodic and Semantic Memory.

Science.gov (United States)

McKoon, Gail; Ratcliff, Roger

1979-01-01

Four experiments examined priming between newly learned paired associates through two procedures, lexical decision and item recognition. Results argue against a functional separation of the semantic and episodic memory systems. (Author/AM)

Structures of nitrato-(2-hydroxybenzaldehydo) (2,2 Prime -bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper

Energy Technology Data Exchange (ETDEWEB)

Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paladi, L. G. [Moldova State University (Moldova, Republic of); Antosyak, B. Ya.; Simonov, Yu. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [Moldova State University (Moldova, Republic of); Bocelli, G. [Institute of Materials for Electronics and Magnetism (Italy); Gulea, A. P. [Moldova State University (Moldova, Republic of); Ginju, D. [Alexandru Ioan Cuza University of Iasi (Romania); Palomares-Sanchez, S. A. [Autonomous University of San Luis Potosi (Mexico)

2011-03-15

Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2 Prime -bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2 Prime -bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO{sub 2} groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2 Prime -bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.

Seeing emotions in the eyes – Inverse priming effects induced by eyes expressing mental states

Directory of Open Access Journals (Sweden)

Caroline eWagenbreth

2014-09-01

Full Text Available ObjectiveAutomatic emotional processing of faces and facial expressions gain more and more of relevance in terms of social communication. Among a variety of different primes, targets and tasks, whole face images and facial expressions have been used to affectively prime emotional responses. This study investigates whether emotional information provided solely in eye regions that display mental states can also trigger affective priming.MethodsSixteen subjects answered a lexical decision task (LDT coupled with an affective priming paradigm. Emotion-associated eye regions were extracted from photographs of faces and acted as primes, whereas targets were either words or pseudo-words. Participants had to decide whether the targets were real German words or generated pseudo-words. Primes and targets belonged to the emotional categories fear, disgust, happiness and neutral.ResultsA general valence effect for positive words was observed: Responses in the LDT were faster for target words of the emotional category happiness when compared to other categories. Importantly, pictures of emotional eye regions preceding the target words affected their subsequent classification. While we show a classical priming effect for neutral target words - with shorter RT for congruent compared to incongruent prime-target pairs- , we observed an inverse priming effect for fearful and happy target words - with shorter RT for incongruent compared to congruent prime-target pairs. These inverse priming effects were driven exclusively by specific prime-target pairs.ConclusionReduced facial emotional information is sufficient to induce automatic implicit emotional processing. The emotional-associated eye regions were processed with respect to their emotional valence and affected the performance on the LDT.

Can gender priming eliminate the effects of stereotype threat? The case of simple dynamic systems.

Science.gov (United States)

Lungwitz, Vivien; Sedlmeier, Peter; Schwarz, Marcus

2018-05-31

Mathematics and mental rotation are classic fields where it has been shown that priming women with their gender identity impedes performance. Whereas past research focused mainly on stereotype threat effects in women in a narrowly defined context, this study broadened the research focus: We primed 264 women and men equally with a male, a neutral, or a female prime before they had to solve a simple dynamic system task. As expected, female-primed women subsequently performed worst of all six groups. Solution rates were almost 14% higher for the women in the male-primed condition. Men performed better than women in all three priming conditions. However, this difference was reduced in the male-primed condition as women's performance had increased as anticipated. Unexpected was a decline in the male performance in the same condition. The study showed that gender priming had a significant effect on women in tasks involving simple dynamic systems. However, mathematical knowledge and area of occupation clearly were stronger predictors for both men and women. Priming alone cannot eliminate the effects of stereotype threat. Copyright © 2018. Published by Elsevier B.V.

Comparing different kinds of words and word-word relations to test an habituation model of priming.

Science.gov (United States)

Rieth, Cory A; Huber, David E

2017-06-01

Huber and O'Reilly (2003) proposed that neural habituation exists to solve a temporal parsing problem, minimizing blending between one word and the next when words are visually presented in rapid succession. They developed a neural dynamics habituation model, explaining the finding that short duration primes produce positive priming whereas long duration primes produce negative repetition priming. The model contains three layers of processing, including a visual input layer, an orthographic layer, and a lexical-semantic layer. The predicted effect of prime duration depends both on this assumed representational hierarchy and the assumption that synaptic depression underlies habituation. The current study tested these assumptions by comparing different kinds of words (e.g., words versus non-words) and different kinds of word-word relations (e.g., associative versus repetition). For each experiment, the predictions of the original model were compared to an alternative model with different representational assumptions. Experiment 1 confirmed the prediction that non-words and inverted words require longer prime durations to eliminate positive repetition priming (i.e., a slower transition from positive to negative priming). Experiment 2 confirmed the prediction that associative priming increases and then decreases with increasing prime duration, but remains positive even with long duration primes. Experiment 3 replicated the effects of repetition and associative priming using a within-subjects design and combined these effects by examining target words that were expected to repeat (e.g., viewing the target word 'BACK' after the prime phrase 'back to'). These results support the originally assumed representational hierarchy and more generally the role of habituation in temporal parsing and priming. Copyright © 2017 Elsevier Inc. All rights reserved.