Conclusions: CoRoT observations are supplying seismic constraints for the most populated class of He-burning stars in the galactic disk. This opens a new access gate to probing the properties of red-giant stars that, coupled with classical observations, promises to extend our knowledge of these advanced phases of stellar evolution and to add relevant constraints to models of composite stellar populations in the Galaxy. The CoRoT space mission was developed and is operated by the French space agency CNES, with the participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. [less ▲]Detailed reference viewed: 5 (0 ULg) Probing recognition processes, forces and motions within single moleculesWillet, Nicolas ; Duwez, Anne-Sophie Scientific conference (2012, May 09)Detailed reference viewed: 6 (0 ULg) Probing recognition processes, forces and motions within single moleculesWillet, Nicolas Scientific conference (2011, June)Detailed reference viewed: 8 (1 ULg) Probing the cores of Extreme Horizontal Branch stars by gravity-mode seismologyVan Grootel, Valérie ; Charpinet, Stéphane; Fontaine, Gilles et alConference (2011, June)We present a seismic analysis of the pulsating subdwarf B star KPD 0629-0016 on the basis of the long-period, gravity-mode pulsations uncovered by CoRoT. Thanks to space- based facilities, g-mode ... [more ▼]We present a seismic analysis of the pulsating subdwarf B star KPD 0629-0016 on the basis of the long-period, gravity-mode pulsations uncovered by CoRoT. Thanks to space- based facilities, g-mode seismology can now be exploited quantitatively for stars on the ex- treme horizontal branch, an objective undermined so far by the limitations of ground-based observations. The optimal seismic model offers an excellent fit, with a relative dispersion of 0.23%, to the 18 observed periods identified with theoretical modes of degrees l =1 and 2. The inferred structural parameters for KPD 0629–0016 include the total stellar mass, the thickness of the H-rich envelope, and, thanks to the sensitivity of g-modes, the size and the composition of the convective core. Our results suggest that extra mixing processes shape the helium-burning cores, that are representative of all horizontal branch stars in general, an intermediate and underrated stage of stellar evolution. [less ▲]Detailed reference viewed: 8 (0 ULg) Probing the discrete motion of vortices with rf excitationsVan de Vondel, J.; Silhanek, Alejandro ; Moshchalkov, V. V. et alin Physica C: Superconductivity (2010), 470(19), 857-859In this work we present experimental results on the rectification of vortices in a superconductor/ferromagnet system under a high frequency drive. The two-dimensional pinning landscape, induced by the ... [more ▼]In this work we present experimental results on the rectification of vortices in a superconductor/ferromagnet system under a high frequency drive. The two-dimensional pinning landscape, induced by the stray fields of the ferromagnetic template, has no intrinsic asymmetry. Nevertheless, an asymmetric potential is artificially induced by an applied dc bias. The experimental results unambiguously show a biased, discrete motion of the vortices in the periodic potential at frequencies above 10 MHz. This synchronized motion is very sensitive to the external applied field. Increasing temperature leads to a reduction of the pinning potential, which in turn results in a lower ac power needed to drive the vortex lattice. (C) 2010 Elsevier B.V. All rights reserved. [less ▲]Detailed reference viewed: 12 (0 ULg) Probing the existence of axions with the polarization of objects at cosmological distancesHutsemekers, Damien Conference (2006)Photon - axion conversion within a magnetic field over cosmological distances can affect the polarization of distant objects like quasars. We report the observation of large-scale alignments of quasar ... [more ▼]Photon - axion conversion within a magnetic field over cosmological distances can affect the polarization of distant objects like quasars. We report the observation of large-scale alignments of quasar polarization vectors as well as a rotation of their polarization angles with distance. This effect might be due to the presence of axions along the line of sight. [less ▲]Detailed reference viewed: 8 (2 ULg) Probing The Interaction Forces Between Hydrophobic Peptides And Supported Lipid Bilayers Using AfmAndre, G.; Brasseur, Robert ; Dufrene, Yf.in Journal of Molecular Recognition (2007), 20(6), 538-45Despite the vast body of literature that has accumulated on tilted peptides in the past decade, direct information on the forces that drive their interaction with lipid membranes is lacking. Here, we ... [more ▼]Despite the vast body of literature that has accumulated on tilted peptides in the past decade, direct information on the forces that drive their interaction with lipid membranes is lacking. Here, we attempted to use atomic force microscopy (AFM) to explore the interaction forces between the Simian immunodeficiency virus peptide and phase-separated supported bilayers composed of various lipids, i.e. dipalmitoylphosphatidylcholine, dioleoylphosphatidylcholine, dioleoylphosphatidic acid and dipalmitoylphosphatidylethanolamine. Histidine-tagged peptides were attached onto AFM tips terminated with nitrilotriacetate and tri(ethylene glycol) groups, an approach expected to ensure optimal exposure of the C-terminal hydrophobic domain. Force-distance curves recorded between peptide-tips and the different bilayer domains always showed a long-range repulsion upon approach and a lack of adhesion upon retraction, in marked contrast with the hydrophobic nature of the peptide. To explain this unexpected behaviour, we suggest a mechanism in which lipids are pulled out from the bilayer due to strong interactions with the peptide-tip, in agreement with the very low force needed to extract lipids from supported bilayers. [less ▲]Detailed reference viewed: 5 (0 ULg) Probing the interactions of early-type stars with their surroundings through X-ray and optical observationsNazé, Yaël Doctoral thesis (2004)This work is devoted to the study of the interactions of massive stars with their environment, either through their intense radiation fields or through their powerful stellar winds. First, we have studied ... [more ▼]This work is devoted to the study of the interactions of massive stars with their environment, either through their intense radiation fields or through their powerful stellar winds. First, we have studied the close neighbourhood of the peculiar Of?p star HD108, i.e. its stellar wind and associated emissions. We have notably uncovered the important variations of the emission lines seen in the visible domain. At the same time, in contrast, the X-ray emission remained stable. To better understand the X-rays emitted by the star, we have developed a program for modelling the ionisation of the stellar wind, that enabled us to determine the absorption of this ionised wind in the X-ray domain. Our X-ray observations have then permitted us to discard several models proposed to explain the nature of the system, and we have discussed the remaining possibilities in the light of the behaviour of the two other Of?p stars, the possible twins" of HD108. The wind modelling program was also used to study the properties, in the X-ray range, of the Wolf-Rayet star WR40: combined to the observations taken by XMM-Newton, we have shown that the non-detection of X-rays from this star can be explained by the very large opacity of its wind. The study of the ionisation of the surrounding gas by Wolf-Rayet stars was extended through the analysis of HeII nebulae. For the first time, high quality images of the highly excited regions surrounding Wolf-Rayet stars were taken and analysed, enabling to derive the extreme UV flux of these stars, and thus their temperature, from ground-based observations. In addition to the ionisation by massive stars, the impact of their stellar winds was also considered in this work, especially the wind-blown structures called bubbles''. These bubbles arise from the action of the winds of massive stars, in isolation or in clusters, onto the interstellar medium. We first focused on the bubbles blown by isolated stars, and we started by the study of the high energy properties of the bubble blown by WR40. Thanks to XMM-Newton data, we showed that even the most recent theoretical models cannot account for the lack of X-ray emission of this bubble. To better understand the discrepancies between the theory and the observations of wind-blown bubbles, we then turned to the most simple structures, the ones blown by single main sequence massive stars. Several bubbles have been discovered in N11B, N180B, and N44, and their properties agree better with theoretical expectations than in the case of WR bubbles and superbubbles. Before our study, only a few interstellar bubbles were known: we showed that a simple morphological search was insufficient, and that kinematic studies were essential. In fact, the low-velocity expansion of these bubbles implies a weak compression of the gas, that can inhibit the morphological detection. Finally, we investigated the properties of the interaction of massive star clusters with their surroundings in the high-energy range. The clusters of N11 were observed in X-rays and UV thanks to the XMM-Newton satellite: their differences or similarities appear clearly at these energies, and we note that the diffuse X-ray emission always exceeded the expected level. Moreover, a unique dataset composed of Chandra and XMM-Newton observations enabled us to study the largest star formation region of the Small Magellanic Cloud, NGC346. Notably, the X-ray emissions from the NGC346 cluster itself and from the peculiar WR binary system HD5980 were discovered and analysed in details. Our work underlines the complementarity between the visible, UV and X-ray domains, and the necessity to have observatories on the ground as well as in space. It also illustrates the important contribution of multiwavelength datasets to the study of massive stars. These observations indeed play a crucial role in the determination of the properties of early-type stars but they also provide critical tests for theoretical models (present or future). [less ▲]Detailed reference viewed: 11 (7 ULg) Probing the origins, diagnosis and treatment of amyloid diseases using antibodies.Dumoulin, Mireille ; Dobson, Christopherin Biochimie (2004), 86The deposition of proteins in the form of amyloid fibrils is the characteristic feature of more than 20 medical conditions affecting the central nervous system or a variety of peripheral tissues. These ... [more ▼]The deposition of proteins in the form of amyloid fibrils is the characteristic feature of more than 20 medical conditions affecting the central nervous system or a variety of peripheral tissues. These disorders, which include Alzheimer's disease, the prion diseases and type II diabetes, are of enormous importance in the context of present-day human health and welfare. Extensive research is therefore being carried out to define the molecular details of the mechanism of the pathological conversion of amyloidogenic proteins from their soluble forms into fibrillar structures. This review focuses on recent studies that demonstrate the power of using antibodies or antibody fragments to probe the process of fibril formation, and discusses the emerging potential of these species as diagnostic and therapeutic agents. [less ▲]Detailed reference viewed: 13 (1 ULg) Probing the phase of the elastic $pp$ scattering amplitude with vortex proton beamsIvanov, Igor in AIP Conference Proceedings (2013)We show that colliding vortex proton beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the scattering amplitude changes with the scattering angle. In ... [more ▼]We show that colliding vortex proton beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the scattering amplitude changes with the scattering angle. In elastic $pp$ scattering, this will open a novel way to measure the parameter $\rho(t)$ and probe the real part of the Pomeron. [less ▲]Detailed reference viewed: 9 (1 ULg) Probing the properties of convective cores through g modes: high-order g modes in SPB and γ Doradus starsMiglio, Andrea ; Montalban Iglesias, Josefa ; Noels-Grötsch, Arlette et alin Monthly Notices of the Royal Astronomical Society (2008), 386(3), 1487-1502In main-sequence stars, the periods of high-order gravity modes are sensitive probes of stellar cores and, in particular, of the chemical composition gradient that develops near the outer edge of the ... [more ▼]In main-sequence stars, the periods of high-order gravity modes are sensitive probes of stellar cores and, in particular, of the chemical composition gradient that develops near the outer edge of the convective core. We present an analytical approximation of high-order g modes that takes into account the effect of the μ gradient near the core. We show that in main-sequence models, similarly to the case of white dwarfs, the periods of high-order gravity modes are accurately described by a uniform period spacing superposed to an oscillatory component. The periodicity and amplitude of such component are related, respectively, to the location and sharpness of the μ gradient. We investigate the properties of high-order gravity modes for stellar models in a mass domain range between 1 and 10M[SUB]solar[/SUB], and the effects of the stellar mass, evolutionary state and extra-mixing processes on period spacing features. In particular, we show that for models of a typical Slowly Pulsating B (SPB) star, a chemical mixing that could likely be induced by the slow rotation observed in these stars is able to significantly change the g-mode spectra of the equilibrium model. Prospects and challenges for the asteroseismology of γ Doradus and SPB stars are also discussed. [less ▲]Detailed reference viewed: 5 (0 ULg) Probing the stereoselectivity of the ruthenium-catalyzed ring-opening metathesis polymerization of norbornene and norbornadiene diestersDelaude, Lionel ; Demonceau, Albert ; Noels, Alfred in Macromolecules (2003), 36(5), 1446-1456The ring-opening metathesis polymerization (ROMP) of two optically active 2,3-dicarboalkoxynorbornadienes derived from (S)-(-)-2-methyl-1-butanol and (R)-(-)-2-butanol were carried out in the presence of ... [more ▼]The ring-opening metathesis polymerization (ROMP) of two optically active 2,3-dicarboalkoxynorbornadienes derived from (S)-(-)-2-methyl-1-butanol and (R)-(-)-2-butanol were carried out in the presence of the [RuCl2(P-cymene)](2) catalyst precursor activated by trimethylsilyldiazomethane (TMSD). H-1 and C-13 NMR analyses showed that a high degree of stereoregularity was achieved, and homonuclear proton-proton COSY spectroscopy indicated that the major trans fractions of the polymers were most likely isotactic, while the minor cis fractions were syndiotactic. Ring-opened metathesis polymers were also made from 2,3-dicarbomethoxynorbornadiene and exo,exo-2,3-dicarbomethoxy-5-norbornene. They were hydrogenated into the corresponding polynorbornanes using diimide. The NMR spectra of the reduced materials confirmed that the unsaturated parent polymers had an all-trans highly isotactic microstructure. A tentative mechanism involving arene loss, carbene formation, and monomer chelation is proposed to account for the observed stereoselectivities. [less ▲]Detailed reference viewed: 5 (0 ULg) Probing the Surface Molecular Structure in the UPS Spectra of Octadecanethiol and 1-Cyclohexyl-12-dodecanethiol Self-Assembled on GoldDuwez, Anne-Sophie ; Riga, Joseph; Han, Bo-Ying et alin Journal of Electron Spectroscopy & Related Phenomena (1996), 81Detailed reference viewed: 1 (0 ULg) Probing the tacticity of ring-opened metathesis polymers of norbornene and norbornadiene diesters by NMR spectroscopyDelaude, Lionel ; Demonceau, Albert ; Noels, Alfred in Bencze, Laszlo; Imamoglu, Yavuz (Eds.) Novel metathesis chemistry: designing well-defined initiator systems for specialty chemical synthesis, tailored polymers and advanced material application (2003)This chapter summarizes the various NMR experiments that were applied to probe the main stereochemical features of polymers prepared by ring-opening metathesis polymerization (ROMP) of 2,3 ... [more ▼]This chapter summarizes the various NMR experiments that were applied to probe the main stereochemical features of polymers prepared by ring-opening metathesis polymerization (ROMP) of 2,3-dicarboalkoxynorbornadienes and 2,3-dicarboalkoxynorbornenes catalyzed by the dichloro ruthenium arene dimer (RuCl2(p-cymene))2 in the presence of trimethylsilyldiazomethane (TMSD). Direct spectroscopic methods based on the examination of cross-coupling peaks in polymers derived from optically active monomers (1H COSY NMR) and indirect methods based on the analysis of the hydrogenated derivatives of unsaturated parent polyolefins (1H and 13C NMR) led to the same conclusion. They both showed that high trans, highly isotactic polymers were formed using the ruthenium-arene catalyst precursor. [less ▲]Detailed reference viewed: 24 (0 ULg) Probing thermoplastic matrix-carbon fiber interphases. 1. Preferential segregation of low molar mass chains to the interfaceCarlier, V.; Sclavons, M.; Jonas, Alain M et alin Macromolecules (2001), 34(11), 3725-3729The molecular mobility of polystyrene (PS) chains near the surface of carbon fibers was investigated. The glass transition temperature of very thin coatings deposited on carbon fibers was measured by ... [more ▼]The molecular mobility of polystyrene (PS) chains near the surface of carbon fibers was investigated. The glass transition temperature of very thin coatings deposited on carbon fibers was measured by supported DMTA in order to probe the properties of the thermoplastic interphase. Depending on the fiber impregnation method from the melt or from solution, Tg changed in an opposite way for the thinnest coatings, decreasing with coating thickness in the case of impregnation in the melt and increasing when a polymer solution was used. This observation is explained by degradation of PS in the melt and subsequent preferential segregation of low molar mass chains to the interface. This conclusion is supported by the study of the Tg of coatings made from a bimodal molar mass distribution. [less ▲]Detailed reference viewed: 17 (0 ULg) Probing ultrafast purely electronic charge migration in small peptidesRemacle, Françoise ; Levine, R. D.in Zeitschrift Fur Physikalische Chemie-International Journal Of Research In Physical Chemistry & Chemical Physics (2007), 221(5), 647-661A pump-probe experiment that can examine a pure charge migration on a time scale short compared to the onset of nuclear motion is discussed. The mass spectrometric studies of Schlag et al. suggest that ... [more ▼]A pump-probe experiment that can examine a pure charge migration on a time scale short compared to the onset of nuclear motion is discussed. The mass spectrometric studies of Schlag et al. suggest that short peptide terminated by an aromatic amino acid are particularly suitable test compounds. The pump pulse needs to ionize the molecule on a time scale short compared to the period of the electronic motion, typically sub-fs. However, ionization occurs preferentially when the electrical field of the light is maximal so that the duration of the pulse envelope can be somewhat longer. Detection by photoelectron spectrometry of the peptide cation, to produce a dication, is shown to be able to probe the electronic rearrangement. [less ▲]Detailed reference viewed: 17 (6 ULg) Probiotic bacterial molecules and their use in methods to treat/prevent infection by harmful bacteria and to provide nutritional healthGriffiths, Mansel; Medellin-Pena, Maira; Delcenserie, Véronique Patent (2011)Detailed reference viewed: 14 (4 ULg) Problem and challenges of image-guided neurosurgical navigation and interventionVerly, Jacques ; Kavec, Martin; Vigneron, Lara M. et alConference (2006)Detailed reference viewed: 4 (0 ULg) Problem Based Learning in SLT education : Apprentissage de la Démarche Logopédique (Learning of SLT approach)Sadzot, Agnès ; Maillart, Christelle Poster (2009, May)Detailed reference viewed: 55 (18 ULg) A problem checklist and the clinical resumeGraitson, M.; Gaspard, Ulysse ; Moonen, Gustave et alin Revue Médicale de Liège (1983), 38(23), 897-905Detailed reference viewed: 5 (0 ULg)