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See detailDirect visualization of magnetic vortex pinning in superconductors
Menghini, Mariela; Kramer, R. B. G.; Silhanek, Alejandro ULg et al

in Physical Review. B : Condensed Matter (2009), 79(14),

We study the vortex structure in a Pb film deposited on top of a periodic array of ferromagnetic square microrings by combining two high-resolution imaging techniques: Bitter decoration and scanning Hall ... [more ▼]

We study the vortex structure in a Pb film deposited on top of a periodic array of ferromagnetic square microrings by combining two high-resolution imaging techniques: Bitter decoration and scanning Hall-probe microscopy (SHPM). The periodicity and strength of the magnetic pinning potential generated by the square microrings are controlled by the magnetic history of the template. When the square rings are in the magnetized dipolar state, known as the onion state, the strong stray field generated at the domain walls prevents the decoration of vortices. SHPM images show that the stray field generated by the dipoles is much stronger than the vortex field, in agreement with the results of simulations. Real-space vortex imaging has revealed that in the onion state, the corners of the square rings act as effective pinning centers for vortices. [less ▲]

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See detailDirect visualization of the Campbell regime in superconducting stripes
Kramer, R. B. G.; Ataklti, G. W.; Moshchalkov, V. V. et al

in Physical Review. B : Condensed Matter (2010), 81(14),

A combination of scanning Hall microscopy and scanning ac-susceptibility measurements in superconducting stripes (ribbons) of width w < 10 mu m was used to observe the dimensional phase transitions of the ... [more ▼]

A combination of scanning Hall microscopy and scanning ac-susceptibility measurements in superconducting stripes (ribbons) of width w < 10 mu m was used to observe the dimensional phase transitions of the vortex lattice and its stability under alternating fields. At low dc magnetic fields applied perpendicularly to the plane of the stripes, vortices form a one-dimensional chain at the center of the stripes. Above a certain field H*(w), the vortex chain splits in two parallel rows displaced laterally in such a way that a zigzag vortex pattern is observed. By shaking the vortices with an external magnetic ac field and detecting their in-phase motion locally, we can identify the degree of mobility of each individual vortex. This technique allows us (i) to directly visualize the transition from intravalley (Campbell regime) to intervalley vortex motion as the amplitude of the ac modulation is increased and (ii) to accurately determine the temperature at which the vortex lattice freezes in a field-cooling experiment. [less ▲]

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See detailDirect visualization of the vortex distributions in a superconducting film with a Penrose array of magnetic pinning centers: Symmetry induced giant vortex state
Kramer, R. B. G.; Silhanek, Alejandro ULg; Van de Vondel, J. et al

in Physica C: Superconductivity (2010), 470(19), 758-761

Using scanning Hall probe microscopy a direct visualization of the flux distribution in a Pb film covering a fivefold Penrose array of Co dots is obtained. We demonstrate that stable vortex configurations ... [more ▼]

Using scanning Hall probe microscopy a direct visualization of the flux distribution in a Pb film covering a fivefold Penrose array of Co dots is obtained. We demonstrate that stable vortex configurations can be found for fields H similar to 0.8H(1), H(1) and 1.6H(1), where H(1) corresponds to one flux quantum per pinning site. The vortex pattern at 0.8H(1) corresponds to one vacancy in one of the vertices of the thin tiles whereas at 1.6H(1) the vortex structure can be associated with one interstitial vortex inside each thick tile. Strikingly, for H = 1.6H(1) interstitial and pinned vortices arrange themselves in ring-like structures ("vortex corrals") which favor the formation of a giant vortex state at their center. (C) 2010 Published by Elsevier B.V. [less ▲]

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See detailDirected evolution on the cold adapted properties of TAB5 alkaline phosphatase
Koutsioulis, D.; Wang, E.; Tzanodaskalaki, M. et al

in Protein Engineering, Design & Selection (2008), 21(5), 319-27

Psychrophilic alkaline phosphatase (AP) from the Antarctic strain TAB5 was subjected to directed evolution in order to identify the key residues steering the enzyme's cold-adapted activity and stability ... [more ▼]

Psychrophilic alkaline phosphatase (AP) from the Antarctic strain TAB5 was subjected to directed evolution in order to identify the key residues steering the enzyme's cold-adapted activity and stability. A round of random mutagenesis and further recombination yielded three thermostable and six thermolabile variants of the TAB5 AP. All of the isolated variants were characterised by their residual activity after heat treatment, Michaelis-Menten kinetics, activation energy and microcalorimetric parameters of unfolding. In addition, they were modelled into the structure of the TAB5 AP. Mutations which affected the cold-adapted properties of the enzyme were all located close to the active site. The destabilised variants H135E and H135E/G149D had 2- and 3-fold higher kcat, respectively, than the wild-type enzyme. Wild-type AP has a complex heat-induced unfolding pattern while the mutated enzymes loose local unfolding transitions and have large shifts of the Tm values. Comparison of the wild-type and mutated TAB5 APs demonstrates that there is a delicate balance between the enzyme activity and stability and that it is possible to improve the activity and thermostability simultaneously as demonstrated in the case of the H135E/G149D variant compared to H135E. [less ▲]

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See detailDirected forgetting and aging: the role of retrieval processes, processing speed, and proactive interference.
Hogge, Michaël; Adam, Stéphane ULg; Collette, Fabienne ULg

in Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition (2008), 15(4), 471-91

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In ... [more ▼]

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items. [less ▲]

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See detailDirected forgetting in normal aging: the role of processing speed
Hogge, Michaël; Adam, Stéphane ULg; Collette, Fabienne ULg

Poster (2004, June 25)

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See detailDIRECTED INFORMATION TRANSFER IN SCALP ELECTROENCEPHALOGRAPHIC RECORDINGS: INSIGHTS ON DISORDERS OF CONSCIOUSNESS
Marinazzo, Daniele; Gosseries, Olivia ULg; Boly, Mélanie ULg et al

in Clinical EEG and Neuroscience : Official Journal of the EEG and Clinical Neuroscience Society (ENCS) (2014)

Introduction: The neural mechanisms underlying electrophysiological changes observed in patients with disorders of consciousness following a coma remain poorly understood. The aim of this article is to ... [more ▼]

Introduction: The neural mechanisms underlying electrophysiological changes observed in patients with disorders of consciousness following a coma remain poorly understood. The aim of this article is to investigate the mechanisms underlying the differences in spontaneous electroencephalography between patients in vegetative/unresponsive wakefulness syndrome, minimally conscious state, emergence of the minimally conscious state and age-matched healthy control subjects. <br />Methods: Forty recording of spontaneous scalp electroencephalography were performed in 27 patients who were comatose on admission, and on healthy controls. Multivariate Granger Causality and Transfer Entropy were applied on the data. <br />Results: Distinctive patterns of putative bottlenecks of information were associated to each conscious state. Healthy controls are characterized by a greater amount of synergetic contributions from duplets of variables. <br />Conclusion: A novel set of measures was tested to get a novel insight on the pattern of information transfer in a network of scalp electrodes in patients with disorders of consciousness. [less ▲]

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See detailLes directeurs de prison : métier de gouvernance et de management
Dubois, Christophe ULg

Scientific conference (2011, November 04)

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See detailDirecting the lipopeptide Mycosubtilin biosynthesis toward C17:0 branched isoform influences the expression of cspB and cspC in Bacillus subtilis
Guez, Jean-Sébastien; Drucbert, A.; Müller, C. et al

Poster (2007)

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See detailDirection of persistent ischemic mitral jet after restrictive valve annuloplasty: Implications for interpretation of perioperative echocardiography
Sénéchal, M.; Magne, Julien ULg; Pibarot, P. et al

in Canadian Journal of Cardiology (2007), 23(SUPPL. B), 48-52

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See detailDirectional and non-directional risk exposures in Hedge Fund returns
Lambert, Marie ULg; Hübner, Georges ULg; Papageorgiou, Nicolas

Conference (2011, April)

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See detailDirectional and Non-Directional Risk Exposures in Hedge Fund Returns
Lambert, Marie ULg; Hübner, Georges ULg; Papageorgiou, Nicolas

Conference (2011, May 13)

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See detailDirectional and Nondirectional Risk Exposures in Hedge Fund Returns
Lambert, Marie ULg; Hübner, Georges ULg; Papageorgiou, Nicolas

Conference (2010, April)

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See detailDirectional and Nondirectional Risk Exposures in Hedge Fund Returns
Lambert, Marie ULg; Hübner, Georges ULg; Papageorgiou, Nicolas

Conference (2010, April)

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See detailDirectional solidification by appropriate chemically active single crystal seed: An alternative way of generating large superconducting 123 single domain
Cloots, Rudi ULg; Auguste, F. X.; Rulmont, André ULg et al

in Journal of Materials Research (1997), 12(12), 3199-3202

A Dy2O3 single crystal has been used as a seed for the growth of isothermally melt-textured DY-123 material. The nucleation-controlled step has been observed to be related to the heterogeneous nucleation ... [more ▼]

A Dy2O3 single crystal has been used as a seed for the growth of isothermally melt-textured DY-123 material. The nucleation-controlled step has been observed to be related to the heterogeneous nucleation of 211 particles at the surface of the dysprosium oxide single crystal. The subsequent growth mode seems to be controlled by a high concentration gradient of dysprosium in the liquid phase. This leads to a directional solidification process of the 123 phase. The size of the 211 particles seems to decrease as the distance from the dysprosium oxide single crystal increases. [less ▲]

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See detailDirections de recherches dans le calcul des notes liant exactitude et réalisme: illustration à travers une démarche en formation à distance
Castaigne, Jean-Loup ULg

in Actes du 22e congrès de l'association internationale de pédagogie universitaire (AIPU) : L'enseignement supérieur du {XXIe} siècle : de nouveaux défis à relever. (2005, September)

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See detailDirections Médicales 112 et projet Phone CPR
Stipulante, Samuel ULg

Conference (2012, February 28)

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