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See detailPion-photon transition distribution amplitudes
Courtoy, Aurore ULg; Noguera, S.

in AIP Conference Proceedings (2008), 1038

The newly introduced Transition Distribution Amplitudes (TDAs) are discussed for the π-γ transitions. Relations between π-γ and γ-π TDAs for different cases are given. Numerical values for the π-γ TDAs in ... [more ▼]

The newly introduced Transition Distribution Amplitudes (TDAs) are discussed for the π-γ transitions. Relations between π-γ and γ-π TDAs for different cases are given. Numerical values for the π-γ TDAs in different models are compared. GPD's features are extended to TDAs and the role of PCAC highlighted. We give hints for the evaluation of cross sections for meson pair production in our approach. © 2008 American Institute of Physics. [less ▲]

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See detailPion-photon transition distribution amplitudes in the Nambu-Jona-Lasinio model
Courtoy, Aurore ULg; Noguera, S.

in Physical Review D (2007), 76(9),

We define the pion-photon transition distribution amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism ... [more ▼]

We define the pion-photon transition distribution amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism to the Nambu-Jona-Lasinio model, as a realistic theory of the pion. The obtained vector and axial TDAs satisfy all features required by general considerations. In particular, sum rules and the polynomiality condition are explicitly verified. We have numerically proved that the odd coefficients in the polynomiality expansion of the vector TDA vanish in the chiral limit. The role of PCAC and the presence of a pion pole are explicitly shown. © 2007 The American Physical Society. [less ▲]

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See detailThe pioneering investigations in the field of the interstellar molecules, 1935-1942.
Swings, Polydore ULg

in Astrophysics & Space Science (1978), 55(1), 263-265

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See detail" PIONEERS of the BLUES REVIVAL" by Steve CUSHING
Sacré, Robert ULg

in ABS Magazine (2014), (n° 43),

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See detailPIONIER : A Four Telescope VLTI Instrument
Lazareff, B.; Le Bouquin, J.-L.; Berger, J.-P. et al

in Surdej, Jean; Le Coroller, Hervé; Arnold, Luc (Eds.) Improving the Performances of Current Optical Interferometers & Future Designs (2014, April 01)

Pionier is a guest instrument, the first four-telescope recombiner at ESO's VLTI. We discuss salient design features and illustrate selected scientific results from the fi

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See detailPIONIER: a 4-telescope visitor instrument at VLTI
Le Bouquin, J.-B.; Berger, J.-P.; Lazareff, B. et al

in Astronomy and Astrophysics (2011), 535

Context. PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or four 8m Unit Telescopes of the Very Large Telescope Interferometer ... [more ▼]

Context. PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or four 8m Unit Telescopes of the Very Large Telescope Interferometer (ESO, Chile) using an integrated optics combiner. The instrument was integrated at IPAG in December 2009 and commissioned at the Paranal Observatory in October 2010. It has provided scientific observations since November 2010. <BR /> Aims: In this paper, we explain the instrumental concept and describe the standard operational modes and the data reduction strategy. We present the typical performance and discuss how to improve them. <BR /> Methods: This paper is based on laboratory data obtained during the integrations at IPAG, as well as on-sky data gathered during the commissioning at VLTI. We illustrate the imaging capability of PIONIER on the binaries δ Sco and HIP11231. <BR /> Results: PIONIER provides six visibilities and three independent closure phases in the H band, either in a broadband mode or with a low spectral dispersion (R = 40), using natural light (i.e. unpolarized). The limiting magnitude is Hmag = 7 in dispersed mode under median atmospheric conditions (seeing < 1, τ[SUB]0[/SUB] > 3ms) with the 1.8m Auxiliary Telescopes. We demonstrate a precision of 0.5deg on the closure phases. The precision on the calibrated visibilities ranges from 3% to 15% depending on the atmospheric conditions. <BR /> Conclusions: PIONIER was installed and successfully tested as a visitor instrument for the VLTI. It permits high angular resolution imaging studies at an unprecedented level of sensitivity. The successful combination of the four 8m Unit Telescopes in March 2011 demonstrates that VLTI is ready for four-telescope operation. Based on observations collected at the European Southern Observatory, Paranal, Chile (commissioning data and 087.C-0709). [less ▲]

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See detailPIONIER: a visitor instrument for VLTI
Berger, Jean-Philippe; Zins, G.; Lazareff, B. et al

in Danchi, W. C.; Delplancke, F.; Rajagopal, J. K. (Eds.) Optical and Infrared Interferometry II (2010, July)

PIONIER is a 4-telescope visitor instrument for the VLTI, planned to see its first fringes in 2010. It combines four ATs or four UTs using a pairwise ABCD integrated optics combiner that can also be used ... [more ▼]

PIONIER is a 4-telescope visitor instrument for the VLTI, planned to see its first fringes in 2010. It combines four ATs or four UTs using a pairwise ABCD integrated optics combiner that can also be used in scanning mode. It provides low spectral resolution in H and K band. PIONIER is designed for imaging with a specific emphasis on fast fringe recording to allow closure-phases and visibilities to be precisely measured. In this work we provide the detailed description of the instrument and present its updated status. [less ▲]

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See detailUn pionnier de la physiologie. Léon Frédéricq. Œuvres choisies. Volume publié à l’occasion du centenaire de sa naissance
Fredericq, Léon ULg; Bacq, Zénon; Florkin,-, Marcel

Book published by Sciences et lettres (1953)

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See detailUn pionnier des études littéraires francophones
Provenzano, François ULg

in Intervalles (2008), 81(automne), 37-50

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See detailThe PIP training programme: building of ACP experts capacities in crop protection and food safety to support local companies to comply with EU regulations on pesticides residues.
Schiffers, Bruno ULg; Schubert, Annick; Schiffers, Christophe ULg et al

in Communications in agricultural and applied biological sciences (2006), 71(2A), 39-48

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See detailPip, a novel activator of phenazine biosynthesis in Pseudomonas chlororaphis PCL1391
Girard, Geneviève; Barends, S.; Rigali, Sébastien ULg et al

in Journal of Bacteriology (2006), 188(23), 8283-8293

Secondary metabolites are important factors for interactions between bacteria and other organisms. Pseudomonas chlororaphis PCL1391 produces the antifungal secondary metabolite phenazine-1-carboxamide ... [more ▼]

Secondary metabolites are important factors for interactions between bacteria and other organisms. Pseudomonas chlororaphis PCL1391 produces the antifungal secondary metabolite phenazine-1-carboxamide (PCN) that inhibits growth of Fusarium oxysporum f. sp. radius lycopersici the causative agent of tomato foot and root rot. Our previous work unraveled a cascade of genes regulating the PCN biosynthesis operon, phzABCDEFGH. Via a genetic screen, we identify in this study a novel TetR/AcrR regulator, named Pip (phenazine inducing protein), which is essential for PCN biosynthesis. A combination of a phenotypical characterization of a pip mutant, in trans complementation assays of various mutant strains, and electrophoretic mobility shift assays identified Pip as the fifth DNA-binding protein so far involved in regulation of PCN biosynthesis. In this regulatory pathway, Pip is positioned downstream of PsrA (Pseudomonas sigma factor regulator) and the stationary-phase sigma factor RpoS, while it is upstream of the quorum-sensing system PhzI/PhzR. These findings provide further evidence that the path leading to the expression of secondary metabolism gene clusters in Pseudomonas species is highly complex. [less ▲]

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See detailPiracetam Inhibits The Lipid-Destabilising Effect Of The Amyloid Peptide A Beta C-Terminal Fragment
Mingeot-Leclercq, Mp.; Lins, Laurence ULg; Bensliman, M. et al

in Biochimica et Biophysica Acta-Biomembranes (2003), 1609(1), 28-38

Amyloid peptide (Abeta) is a 40/42-residue proteolytic fragment of a precursor protein (APP), implicated in the pathogenesis of Alzheimer's disease. The hypothesis that interactions between Abeta ... [more ▼]

Amyloid peptide (Abeta) is a 40/42-residue proteolytic fragment of a precursor protein (APP), implicated in the pathogenesis of Alzheimer's disease. The hypothesis that interactions between Abeta aggregates and neuronal membranes play an important role in toxicity has gained some acceptance. Previously, we showed that the C-terminal domain (e.g. amino acids 29-42) of Abeta induces membrane permeabilisation and fusion, an effect which is related to the appearance of non-bilayer structures. Conformational studies showed that this peptide has properties similar to those of the fusion peptide of viral proteins i.e. a tilted penetration into membranes. Since piracetam interacts with lipids and has beneficial effects on several symptoms of Alzheimer's disease, we investigated in model membranes the ability of piracetam to hinder the destabilising effect of the Abeta 29-42 peptide. Using fluorescence studies and 31P and 2H NMR spectroscopy, we have shown that piracetam was able to significantly decrease the fusogenic and destabilising effect of Abeta 29-42, in a concentration-dependent manner. While the peptide induced lipid disorganisation and subsequent negative curvature at the membrane-water interface, the conformational analysis showed that piracetam, when preincubated with lipids, coats the phospholipid headgroups. Calculations suggest that this prevents appearance of the peptide-induced curvature. In addition, insertion of molecules with an inverted cone shape, like piracetam, into the outer membrane leaflet should make the formation of such structures energetically less favourable and therefore decrease the likelihood of membrane fusion. [less ▲]

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See detailPiracetam-Induced Changes To Membrane Physical-Properties - A Combined Approach By P-31 Nuclear-Magnetic-Resonance And Conformational-Analysis
Peuvot, J.; Schanck, A.; Deleers, M. et al

in Biochemical Pharmacology (1995), 50(8), 1129-34

Piracetam, Nootropil (2-oxo-1-pyrrolidine acetamide), is a drug promoting erythrocyte deformability. To establish the mode of action of this compound, we have investigated its influence on the ... [more ▼]

Piracetam, Nootropil (2-oxo-1-pyrrolidine acetamide), is a drug promoting erythrocyte deformability. To establish the mode of action of this compound, we have investigated its influence on the organization of model phospholipid membranes. 31P NMR data show that the drug induces a structural modification in liposomes made of phosphatidylcholine and phosphatidylethanolamine. Our conformational analysis results have allowed the interpretation of the effect of piracetam on these model membranes: the specific interaction between the drug molecules and the phosphate headgroups induces a new organization of the lipids favouring formation of mobile drug-phospholipid complexes that exhibit an isotropic-type signal in the 31P NMR spectra. [less ▲]

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See detailPiracy prevention and the pricing of information goods
Cremer, Helmuth; Pestieau, Pierre ULg

in Information Economics and Policy (2009), (21), 34-42

This paper studies the effects of piracy on prices and welfare and determines the optimal enforcement policy. A monopolist sells an information good at a non-linear price in two versions designed for two ... [more ▼]

This paper studies the effects of piracy on prices and welfare and determines the optimal enforcement policy. A monopolist sells an information good at a non-linear price in two versions designed for two types of consumers with different willingness to pay. Consumers with low willingness to pay consumers can copy the good at some cost and with some quality loss. High valuation customers cannot engage in full-fledged piracy. However, they can consume the version designed for the other customer type. We show that copying or piracy may be welfare enhancing because it enables a good to be provided to individuals with a low willingness to pay without undermining the producing firm’s ability to finance the development cost via the pricing scheme applied to high valuation consumers. There are then three levels of piracy control. The highest is that chosen by the private monopoly. The next level is the one chosen by a welfare-maximizing monopoly. The lowest level, which can be zero, is the level of control chosen by the public authority when the good is sold (and priced) by a profit-maximizing monopoly. ! 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailPirandello far from Nature?: A reading of I vecchi e i giovani Focusing on Landscape
de Seta, Ilaria ULg

in Pirandello Studies (2007), 27

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See detailPiranesi's Haunt: the fascination for paradoxical spaces in the aesthetics of architecture today.
Dawans, Stéphane ULg

Conference (2013, July 24)

Rem Koolhaas, a major provocative figure on the global scene of architecture theory since 1978—when he published Delirious New York—clearly bases his rhetorics on obsessive patterns such as the loop or ... [more ▼]

Rem Koolhaas, a major provocative figure on the global scene of architecture theory since 1978—when he published Delirious New York—clearly bases his rhetorics on obsessive patterns such as the loop or intertwined spaces claimed as Piranesian. This is notably the case in Euralille, this large urban complex meant to revive the old French industrial city, where the reference to the 18th-century engraver is most obvious in a large destructured hall, in an accumulation of stairs, footbridges and escalators which, on the way out of the railway station, are deliberate reminders of the engravings of imaginary jails that emerged from the Venetian artist’s brain. Of course engraving, painting, photography and cinema have been using similar processes for quite some time to create a dizzying sensation with the spectator. Those high and low angle views of entangled planes based on seemingly paradoxical geometry denote a willingness to use the features of the sublime to create mixed feelings of fascination and anguish or to remind mankind of their mortal condition, in other words, of their finite nature. Romanticism is known to have been quite inspired by this dramatic force. Yet what appeals to us in this revival of an aesthetics of the sublime is that it now crosses a new border as it imposes itself into public space, into city life. If films or 3ds digital games attract informed and consenting viewers, Piranesian spaces—Koolhaas also speaks of Junkspace—impose themselves to all and dramatize the modern man’s anguish without the slightest concern for his opinion. What kinds of ethos and of pathos underlie this contemporary theory of architectural and urban spaces inspired by Piranesi’s or Escher’s engravings? What literary strategies are at play? Why can the same obsessive spatial leitmotivs be found in plane puzzles, in films and in the new urban scenery? What does this aesthetics tell us about man in the 21st century? Can we talk of post-humanism? These are some of the basic questions this paper wishes to address in relation to the symposium’s theme Architecture and Urban Space. [less ▲]

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See detailPirates informatiques et mathématique modulaire
Rigo, Michel ULg

Learning material (2007)

De nos jours, l'envoi de messages secrets requiert la manipulation de nombres ayant plus de cent chiffres décimaux. Nous illustrons une technique cryptographique standard (le RSA) dont la sécurité réside ... [more ▼]

De nos jours, l'envoi de messages secrets requiert la manipulation de nombres ayant plus de cent chiffres décimaux. Nous illustrons une technique cryptographique standard (le RSA) dont la sécurité réside dans le fait qu'il est "rapide", sur le plus banal des ordinateurs personnels, de calculer le produit de deux "grands" nombres (cela se compte au pire en secondes), alors que le temps nécessaire pour effectuer l'opération inverse de factorisation prend, dans l'état actuel des connaissances mathématiques, énormément plus de temps (que l'on pourrait estimer en milliards d'années même pour un super-calculateur !). [less ▲]

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See detailLe pire ami de l'homme. Du lapin de garenne aux guerres biologiques
Mougenot, Catherine ULg; Strivay, Lucienne ULg

Book published by La Découverte (2011)

Mais pourquoi donc écrire une histoire des lapins ? Longtemps on a considéré que l'Histoire relevait des seuls humains : on voulait croire que la « nature » restait extérieure et indifférente à nos ... [more ▼]

Mais pourquoi donc écrire une histoire des lapins ? Longtemps on a considéré que l'Histoire relevait des seuls humains : on voulait croire que la « nature » restait extérieure et indifférente à nos affaires. Mais nous découvrons peu à peu, grâce à l'écologie, que nos vies sont depuis longtemps imbriquées à celles des animaux et qu'elles seraient impossibles sans eux. Tant qu'on les considère comme des matériaux indifférents, façonnables à notre gré, on s'expose à de sérieux retours de flamme. Les lapins en sont un exemple fameux : ils ne font jamais ce qu'on attend d'eux. Ils sont récalcitrants, rebelles, résistants... Dans ce livre qui propose une nouvelle manière de faire de l'histoire avec les animaux, les auteures sont engagées dans une folle course-poursuite avec des lapins qui toujours inventent, changent les règles du jeu, colonisent, se retirent... Ils sont toujours actifs, là où on aurait juré qu'ils seraient passivement soumis à nos projets et ambitions. Les auteures elles-mêmes ont été prises au piège ! Et s'il fallait en passer par les lapins pour mieux comprendre les humains ? Et si, mieux qu'une histoire des lapins, il s'agissait de commencer à écrire du point de vue des lapins ? Si on ne peut plus penser les humains sans les animaux, alors l'histoire, la sociologie, la philosophie doivent apprendre à bien les traiter... [less ▲]

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