Peter Naur, Donald E. Osterbrock,
... Export Citation NASA/ADS Convective Cores in Stars. Naur, Peter ; Osterbrock, Donald E. Abstract A necessary condition for ...
Tópico(s): Astro and Planetary Science
1953 - IOP Publishing | The Astrophysical Journal
... Two Models for the Interior of the Sun. Naur, Peter Abstract Two models for the sun, based on ...
Tópico(s): Astro and Planetary Science
1954 - IOP Publishing | The Astrophysical Journal
Edda Sveinsdottir, Erik Frøkjær,
... computer science has been practised in Denmark under Peter Naur's termdatalogy, the science of data processes. Starting ... of realistic solutions known primarily through actual experience. Peter Naur early recognized the particular educational challenges presented by ... the view of computer science which has characterized Peter Naur's research. We illustrate how the study of ...
Tópico(s): Data Visualization and Analytics
1988 - Springer Science+Business Media | BIT Numerical Mathematics
... Access Share on Computing versus human thinking Author: Peter Naur University of Copenhagen, Denmark University of Copenhagen, DenmarkView ...
Tópico(s): Ethics and Social Impacts of AI
2007 - Association for Computing Machinery | Communications of the ACM
... programs within an ALGOL compiler (GIER ALGOL) Author: Peter Naur Regnecentralen, Copenhagen, Denmark Regnecentralen, Copenhagen, DenmarkView Profile Authors ...
Tópico(s): Advanced Software Engineering Methodologies
1965 - Association for Computing Machinery | Communications of the ACM
Haseem Ashraf, Shella Krag-Andersen, Matiullah Naqibullah, Valentina Minddal, Annette Nørgaard, Therese Maria Henriette Naur, Peter Sand Myschetzky, Paul Frost Clementsen,
Background: Interactive breath-hold control (IBC) may improve the accuracy and decrease the complication rate of computed tomography (CT)-guided lung biopsy, but this presumption has not been proven in a randomized study. Methods: Patients admitted for CT-guided lung biopsy were randomized to biopsy either with (N=201) or without (N=206) IBC. Biopsy accuracy, procedure time, radiation, and complications were compared in the two groups. Predictors for pneumothorax were analyzed. Results: Procedures performed ...
Tópico(s): Advanced Radiotherapy Techniques
2017 - AME Publishing Company | Annals of Translational Medicine
Cecilia K. Blomstedt, Roslyn M. Gleadow, Natalie O’Donnell, Peter Naur, Kenneth Jensen, Tomas Laursen, Carl Erik Olsen, Peter Stuart, John D. Hamill, Birger Lindberg Møller, Alan Neale,
Summary Cyanogenic glucosides are present in several crop plants and can pose a significant problem for human and animal consumption, because of their ability to release toxic hydrogen cyanide. Sorghum bicolor L. contains the cyanogenic glucoside dhurrin. A qualitative biochemical screen of the M2 population derived from EMS treatment of sorghum seeds, followed by the reverse genetic technique of Targeted Induced Local Lesions in Genomes (TILLING), was employed to identify mutants with altered hydrogen ...
Tópico(s): Plant Micronutrient Interactions and Effects
2011 - Wiley | Plant Biotechnology Journal
Anders S. Kristensen, Kasper B. Hansen, Peter Naur, Lars Olsen, Natalie L. Kurtkaya, Shashank M. Dravid, Trine Kvist, Feng Yi, Jacob Pøhlsgaard, Rasmus P. Clausen, Michael Gajhede, J.S. Kastrup, Stephen F. Traynelis,
The GluD2 receptor is a fundamental component of postsynaptic sites in Purkinje neurons, and is required for normal cerebellar function. GluD2 and the closely related GluD1 are classified as members of the ionotropic glutamate receptor (iGluR) superfamily on the basis of sequence similarity, but do not bind l-glutamate. The amino acid neurotransmitter D-Ser is a GluD2 receptor ligand, and endogenous D-Ser signaling through GluD2 has recently been shown to regulate endocytosis of α -amino-3-hydroxy- ...
Tópico(s): Receptor Mechanisms and Signaling
2015 - American Society for Pharmacology and Experimental Therapeutics | Molecular Pharmacology
Maria Wadsäter, Jens B. Simonsen, Torsten Lauridsen, Erlend Grytli Tveten, Peter Naur, Thomas Bjørnholm, Hanna Wacklin, Kell Mortensen, Lise Arleth, R. Feidenhans’l, Marité Cárdenas,
Nanodiscs are self-assembled nanostructures composed of a belt protein and a small patch of lipid bilayer, which can solubilize membrane proteins in a lipid bilayer environment. We present a method for the alignment of a well-defined two-dimensional layer of nanodiscs at the air-water interface by careful design of an insoluble surfactant monolayer at the surface. We used neutron reflectivity to demonstrate the feasibility of this approach and to elucidate the structure of the nanodisc layer. The ...
Tópico(s): Surfactants and Colloidal Systems
2011 - American Chemical Society | Langmuir
Christian Krintel, Karla Frydenvang, Lars Olsen, Maria T. Kristensen, Oriol de Barrios, Peter Naur, Pierre Francotte, Bernard Pirotte, Michael Gajhede, J.S. Kastrup,
Positive allosteric modulators of the ionotropic glutamate receptor-2 (GluA2) are promising compounds for the treatment of cognitive disorders, e.g. Alzheimer's disease. These modulators bind within the dimer interface of the LBD (ligand-binding domain) and stabilize the agonist-bound conformation slowing receptor desensitization and/or deactivation. In the present study, we employ isothermal titration calorimetry to determine binding affinities and thermodynamic details of binding of modulators of ...
Tópico(s): Computational Drug Discovery Methods
2011 - Portland Press | Biochemical Journal
Kenneth Jensen, Sarah A. Osmani, Thomas Hamann, Peter Naur, Birger Lindberg Møller,
Formation of metabolons (macromolecular enzyme complexes) facilitates the channelling of substrates in biosynthetic pathways. Metabolon formation is a dynamic process in which transient structures mediated by weak protein–protein interactions are formed. In Sorghum, the cyanogenic glucoside dhurrin is derived from l-tyrosine in a pathway involving the two cytochromes P450 (CYPs) CYP79A1 and CYP71E1, a glucosyltransferase (UGT85B1), and the redox partner NADPH-dependent cytochrome P450 reductase (CPR). ...
Tópico(s): Polyamine Metabolism and Applications
2011 - Elsevier BV | Phytochemistry
Kasper B. Hansen, Peter Naur, Natalie L. Kurtkaya, Anders S. Kristensen, Michael Gajhede, J.S. Kastrup, Stephen F. Traynelis,
GluRδ2 is a member of the iGluR family, but despite a prominent role in cerebellar synaptic plasticity, this receptor does not appear to function as an ion channel. Endogenous ligands that modulate the activity of native GluRδ2 in the cerebellum have not been identified, but two candidate modulators are d -serine and extracellular calcium. Taking advantage of known crystal structures and spontaneously active GluRδ2 receptors containing the lurcher mutation (GluRδ2 Lc ), we investigated the mechanism ...
Tópico(s): Amino Acid Enzymes and Metabolism
2009 - Society for Neuroscience | Journal of Neuroscience
Karla Frydenvang, L. Leanne Lash, Peter Naur, Pekka A. Postila, Darryl S. Pickering, Caleb M. Smith, Michael Gajhede, Makoto Sasaki, Ryuichi Sakai, Olli T. Pentikäinen, Geoffrey T. Swanson, J.S. Kastrup,
The prevailing structural model for ligand activation of ionotropic glutamate receptors posits that agonist efficacy arises from the stability and magnitude of induced domain closure in the ligand-binding core structure. Here we describe an exception to the correlation between ligand efficacy and domain closure. A weakly efficacious partial agonist of very low potency for homomeric iGluR5 kainate receptors, 8,9-dideoxyneodysiherbaine (MSVIII-19), induced a fully closed iGluR5 ligand-binding core. ...
Tópico(s): Molecular Sensors and Ion Detection
2009 - Elsevier BV | Journal of Biological Chemistry
Rasmus P. Clausen, Peter Naur, Anders S. Kristensen, Jeremy R. Greenwood, Mette Strange, Hans Bräuner‐Osborne, Anders A. Jensen, Anne Sophie T. Nielsen, Ulla Geneser, Lone M. Ringgaard, Birgitte Nielsen, Darryl S. Pickering, Lotte Brehm, Michael Gajhede, Povl Krogsgaard‐Larsen, J.S. Kastrup,
The design, synthesis, and pharmacological characterization of a highly potent and selective glutamate GluR5 agonist is reported. (S)-2-Amino-3-((RS)-3-hydroxy-8-methyl-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid (5) is the 8-methyl analogue of (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid ((S)-4-AHCP, 4). Compound 5 displays an improved selectivity profile compared to 4. A versatile stereoselective synthetic route for this class of compounds is presented ...
Tópico(s): Bioactive Compounds and Antitumor Agents
2009 - American Chemical Society | Journal of Medicinal Chemistry
... article by Morten Hertzum, Niels Jacobsen, Effie Law, Peter Naur, and Mikael Skov. We also wish to thank ...
Tópico(s): Team Dynamics and Performance
2008 - Taylor & Francis | Human-Computer Interaction
... been expressed by William James, Otto Jespersen, and Peter Naur.
Tópico(s): Language, Metaphor, and Cognition
2007 - Elsevier BV | Language & Communication
Helle Hald, Peter Naur, Darryl S. Pickering, D. Sprogøe, Ulf Madsen, Daniel B. Timmermann, Philip K. Ahring, Tommy Liljefors, Arne Schousboe, Jan Egebjerg, Michael Gajhede, J.S. Kastrup,
More than 50 structures have been reported on the ligand-binding core of the ionotropic glutamate receptor iGluR2 that belongs to the 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid-type of receptors. In contrast, the ligand-binding core of the kainic acid-type receptor iGluR5 has only been crystallized with three different ligands. Hence, additional structures of iGluR5 are needed to broaden the understanding of the ligand-binding properties of iGluR5, and the conformational changes leading ...
Tópico(s): Amino Acid Enzymes and Metabolism
2007 - Elsevier BV | Journal of Biological Chemistry
Peter Naur, Kasper B. Hansen, Anders S. Kristensen, Shashank M. Dravid, Darryl S. Pickering, Lars Olsen, Bente Vestergaard, Jan Egebjerg, Michael Gajhede, Stephen F. Traynelis, J.S. Kastrup,
The orphan glutamate-like receptor GluRδ2 is predominantly expressed in Purkinje cells of the central nervous system. The classification of GluRδ2 to the ionotropic glutamate receptor family is based on sequence similarities, because GluRδ2 does not form functional homomeric glutamate-gated ion channels in transfected cells. Studies in GluRδ2 −/− knockout mice as well as in mice with naturally occurring mutations in the GluRδ2 gene have demonstrated an essential role of GluRδ2 in cerebellar long-term ...
Tópico(s): Chemical Synthesis and Analysis
2007 - National Academy of Sciences | Proceedings of the National Academy of Sciences
Peter Naur, Bente Vestergaard, Lars K. Skov, Jan Egebjerg, Michael Gajhede, J.S. Kastrup,
The X‐ray structure of the ligand‐binding core of the kainate receptor GluR5 (GluR5‐S1S2) in complex with ( S )‐glutamate was determined to 1.95 Å resolution. The overall GluR5‐S1S2 structure comprises two domains and is similar to the related AMPA receptor GluR2‐S1S2J. ( S )‐glutamate binds as in GluR2‐S1S2J. Distinct features are observed for Ser741, which stabilizes a highly coordinated network of water molecules and forms an interdomain bridge. The GluR5 complex exhibits a high degree of domain closure ( ...
Tópico(s): Neuropeptides and Animal Physiology
2005 - Wiley | FEBS Letters
Mai Marie Holm, Peter Naur, Bente Vestergaard, Matthew T. Geballe, Michael Gajhede, J.S. Kastrup, Stephen F. Traynelis, Jan Egebjerg,
Binding of an agonist to the 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)-propionic acid (AMPA) receptor family of the glutamate receptors (GluRs) results in rapid activation of an ion channel. Continuous application results in a non-desensitizing response for agonists like kainate, whereas most other agonists, such as the endogenous agonist (S)-glutamate, induce desensitization. We demonstrate that a highly conserved tyrosine, forming a wedge between the agonist and the N-terminal part of the bi-lobed ...
Tópico(s): Enzyme Structure and Function
2005 - Elsevier BV | Journal of Biological Chemistry
Michael Dalgaard Mikkelsen, Peter Naur, Barbara Ann Halkier,
We report characterization of SUPERROOT1 (SUR1) as the C-S lyase in glucosinolate biosynthesis. This is evidenced by selective metabolite profiling of sur1, which is completely devoid of aliphatic and indole glucosinolates. Furthermore, following in vivo feeding with radiolabeled p-hydroxyphenylacetaldoxime to the sur1 mutant, the corresponding C-S lyase substrate accumulated. C-S lyase activity of recombinant SUR1 heterologously expressed in Escherichia coli was demonstrated using the C-S lyase ...
Tópico(s): Plant Stress Responses and Tolerance
2004 - Wiley | The Plant Journal
Sixue Chen, Erich Glawischnig, Kirsten Jörgensen, Peter Naur, Bodil Jørgensen, Carl Erik Olsen, Carsten Hørslev Hansen, Hasse B. Rasmussen, John A. Pickett, Barbara Ann Halkier,
Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer-preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant ...
Tópico(s): Allelopathy and phytotoxic interactions
2003 - Wiley | The Plant Journal
Peter Naur, Bent Larsen Petersen, Michael Dalgaard Mikkelsen, Søren Bak, Hasse B. Rasmussen, Carl Erik Olsen, Barbara Ann Halkier,
In the glucosinolate pathway, the postoxime enzymes have been proposed to have low specificity for the side chain and high specificity for the functional group. Here, we provide biochemical evidence for the functional role of the two cytochromes P450, CYP83A1 and CYP83B1, from Arabidopsis in oxime metabolism in the biosynthesis of glucosinolates. In a detailed analysis of the substrate specificities of the recombinant enzymes heterologously expressed in yeast (Saccharomyces cerevisiae), we show that ...
Tópico(s): Moringa oleifera research and applications
2003 - Oxford University Press | PLANT PHYSIOLOGY
Peter Naur, Carsten Hørslev Hansen, Søren Bak, Bjarne Gram Hansen, Niels Bjerg Jensen, Hanne Linde Nielsen, Barbara Ann Halkier,
The cytochrome P450 CYP79B1 from Sinapis alba has been heterologously expressed in Escherichia coli and shown to catalyze the conversion of tryptophan to indole-3-acetaldoxime. Three expression constructs were made, one expressing the native protein and two expressing proteins with different N-terminal modifications. The native construct gave the highest yield as estimated by enzymatic activity per liter of culture. Spheroplasts of E. coli expressing CYP79B1 were reconstituted with the Arabidopsis ...
Tópico(s): Biochemical Acid Research Studies
2002 - Elsevier BV | Archives of Biochemistry and Biophysics
Carsten Hørslev Hansen, Liangcheng Du, Peter Naur, Carl Erik Olsen, Kristian B. Axelsen, A. J. Hick, John A. Pickett, Barbara Ann Halkier,
CYP83B1 from Arabidopsis thaliana has been identified as the oxime-metabolizing enzyme in the biosynthetic pathway of glucosinolates. Biosynthetically active microsomes isolated from Sinapis alba converted p-hydroxyphenylacetaldoxime and cysteine into S-alkylated p-hydroxyphenylacetothiohydroximate, S-(p-hydroxyphenylacetohydroximoyl)-l-cysteine, the next proposed intermediate in the glucosinolate pathway. The production was shown to be dependent on a cytochrome P450 monooxygenase. We searched the ...
Tópico(s): Free Radicals and Antioxidants
2001 - Elsevier BV | Journal of Biological Chemistry
Tópico(s): Classical Philosophy and Thought
1995 - Springer Nature (Netherlands) | Studies in cognitive systems
It is a deplorable consequence of the lack of influence of mathematical thinking on the way in which computer programming is currently being pursued, that the regular use of systematic proof procedures, or even the realization that such proof procedures exist, is unknown to the large majority of programmers. Undoubtedly, this fact accounts for at least a large share of the unreliability and the attendant lack of over-all effectiveness of programs as they are used to-day.
Tópico(s): semigroups and automata theory
1993 - Springer Nature (Netherlands) | Studies in cognitive systems
In recent years several authors concerned with the methodology of program development have claimed that the use of formalized modes of expression in certain particular manners offers considerable benefits to the program development activity. The claims are related to a few key notions, most conspicuously formal specifications of programs and abstract data types. The present study is an analysis of some of the arguments given in support of these claims. It will be found that several of these arguments ...
Tópico(s): Teaching and Learning Programming
1993 - Springer Nature (Netherlands) | Studies in cognitive systems
Abstract The study presents the results of an experiment on programmers' descriptions and understanding. The 12 participants, students of computing, have produced notes on Turing's description of his universal machine and, in a second experiment phase, have made mutual evaluations of their notes. The analysis of the resulting notes shows large individual differences of styles and evaluations with respect to all significant issues of the descriptions and understanding, including the evaluations of ...
Tópico(s): Evolutionary Algorithms and Applications
1993 - Oxford University Press | The Computer Journal
Tópico(s): Teaching and Learning Programming
1985 - Elsevier BV | Microprocessing and Microprogramming