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See detailTemperature dependence of the lower critical field Hc1(T) evidences nodeless superconductivity in FeSe
Abdel-Hafiez, M.; Ge, J.; Vasiliev, A.N. et al

in Physical Review. B : Condensed Matter (2013), 88

We investigate the temperature dependence of the lower critical fi eld Hc1(T) of a high-quality FeSe single crystal under static magnetic fields H parallel to the c axis. The temperature dependence of the ... [more ▼]

We investigate the temperature dependence of the lower critical fi eld Hc1(T) of a high-quality FeSe single crystal under static magnetic fields H parallel to the c axis. The temperature dependence of the first vortex penetration fi eld has been experimentally obtained by two independent methods and the corresponding Hc1(T) was deduced by taking into account demagnetization factors. A pronounced change of the Hc1(T) curvature is observed, which is attributed to multiband superconductivity. The London penetration depth Lambda_ab(T) calculated from the lower critical field does not follow an exponential behavior at low temperatures, as it would be expected for a fully gapped clean s-wave superconductor. Using either a two-band model with s-wave-like gaps of magnitudes Delta_1 = 0.41 +- 0.1meV and Delta_2 = 3.33+- 0.25meV or a single anisotropic s-wave order parameter, the temperature-dependence of the lower critical eld Hc1(T) can be well described. These observations clearly show that the superconducting energy gap in FeSe is nodeless. [less ▲]

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See detailProbabilistic Models of Visual Appearance For Object Identity, Class, and Pose Inference
Teney, Damien ULg

Doctoral thesis (2013)

The topic of object recognition is a central challenge of computer vision. In addition to being studied as a scientific problem in its own right, it also counts many direct practical applications. We ... [more ▼]

The topic of object recognition is a central challenge of computer vision. In addition to being studied as a scientific problem in its own right, it also counts many direct practical applications. We specifically consider robotic applications involving the manipulation, and grasping of everyday objects, in the typical situations that would be encountered by personal service robots. Visual object recognition, in the large sense, is then paramount to provide a robot the sensing capabilities for scene understanding, the localization of objects of interests and the planning of actions such as the grasping of such objects. This thesis presents a number of methods that tackle the related tasks of object detection, localization, recognition, and pose estimation in 2D images, of both specific objects and of object categories. We aim at providing techniques that are the most generally applicable, by considering those different tasks as different sides of a same problem, and by not focusing on a specific type of image information or image features. We first address the use of 3D models of objects for continuous pose estimation. We represent an object by a constellation of points, corresponding to potentially observable features, which serve to define a continuous probability distribution of such features in 3D. This distribution can be projected onto the image plane, and the task of pose estimation is then to maximize its “match” with the test image. Applied to the use of edge segments as observable features, the method is capable of localizing and estimating the pose of non-textured objects, while the probabilistic formulation offers an elegant way of dealing with uncertainty in the definition of the models, which can be learned from observations — as opposed to being available as hand-made CAD models. We also propose a method, framed in a similar probabilistic formulation, in order to obtain, or reconstruct such 3D models, using multiple calibrated views of the object of interest. A larger part of this thesis is then interested in exemplar-based recognition methods, using directly 2D example images for training, without any explicit 3D information. The appearance of objects is also defined as probability distributions of observable features, defined in a nonparametric manner through kernel density estimation, using image features from multiple training examples as supporting particles. The task of object localization is cast as the cross-correlation of distributions of features of the model and of the test image, which we efficiently solve through a voting-based algorithm. We then propose several techniques to perform continuous pose estimation, yielding a precision well beyond a mere classification among the discrete, trained viewpoints. One of the proposed method in this regard consists in a generative model of appearance, capable of interpolating the appearance of learned objects (or object categories), which then allows optimizing explicitly for the pose of the object in the test image. Our model of appearance, initially defined in general terms, is applied to the use of edge segments and of intensity gradients as image features. We are particularly interested in the use of gradients extracted at a coarse scale, and defined densely across images, as they can effectively represent shape as they capture the shading onto smooth non-textured surfaces. This allows handling some cases, common in robotic applications, of objects of primitive shapes with little texture and few discriminative details, which are challenging to recognize with most existing methods. The proposed contributions, which all integrate seamlessly in a same coherent framework, proved successful on a number of tasks and datasets. Most interestingly, we obtain performance on well-studied tasks of localization in clutter and pose estimation, well above baseline methods, often on par with or superior to state-of-the-art method individually designed for each of those specific tasks, whereas the proposed framework is similarly applied to a wide range of problems. [less ▲]

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See detailPrésentation du film "Sur les quais" d'Elia Kazan
Tomasovic, Dick ULg

Conference given outside the academic context (2013)

Présentation du contexte de création et de production du film "Sur les quais".

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See detailWat kunnen wij verwachten van de Europese top van december 2013 ?
Dumoulin, André ULg

E-print/Working paper (2013)

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See detailDer p 1 is the primary activator of Der p 3, Der p 6 and Der p 9 the proteolytic allergens produced by the house dust mite Dermatophagoides pteronyssinus
Herman, Julie ULg; Thelen, Nicolas ULg; Smargiasso, Nicolas ULg et al

in Biochimica et Biophysica Acta - General Subjects (2013), 1840

Background: The enzymatic activity of the four proteases found in the house dust mite Dermatophagoides pteronyssinus is involved in the pathogenesis of allergy. Our aim was to elucidate the activation ... [more ▼]

Background: The enzymatic activity of the four proteases found in the house dust mite Dermatophagoides pteronyssinus is involved in the pathogenesis of allergy. Our aim was to elucidate the activation cascade of their corresponding precursor forms and particularly to highlight the interconnection between proteases during this cascade. Methods: The cleavage of the four peptides corresponding to the mite zymogen activation sites was studied on the basis of the Förster Resonance Energy Transfermethod. The proDer p 6 zymogen was then produced in Pichia pastoris to elucidate its activation mechanismbymite proteases, especially Der p 1. The role of the propeptide in the inhibition of the enzymatic activity of Der p 6 was also examined. Finally, the Der p 1 and Der p 6 proteases were localised via immunolocalisation in D. pteronyssinus. Results: All peptides were specifically cleaved by Der p 1, such as proDer p 6. The propeptide of proDer p 6 inhibited the proteolytic activity of Der p 6, but once cleaved, it was degraded by the protease. The Der p 1 and Der p 6 proteases were both localised to the midgut of the mite. Conclusions: Der p 1 in either its recombinant formor in the natural context of house dustmite extracts specifically cleaves all zymogens, thus establishing its role as a major activator of both mite cysteine and serine proteases. General significance: This finding suggests that Der p 1 may be valuable target against mites. [less ▲]

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See detailWhat can we expect from the December 2013 European Summit ?
Dumoulin, André ULg

E-print/Working paper (2013)

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See detailPRL tumors : diagnosis and treatment
Beckers, Albert ULg

Scientific conference (2013, November 18)

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See detailFactive versus reported speech complements in English
Brems, Lieselotte ULg; Gentens, Caroline; Davidse, Kristin et al

Scientific conference (2013, November 17)

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See detailL’Afrique et la science impériale britannique dans une phase de transition: une étude de cas de l’expédition au Congo en 1816 sous la direction de James Hingston Tuckey
Vandersmissen, Jan ULg

Conference (2013, November 16)

This paper fits in a broader research project funded by the Belgian F.R.S.-Fonds national de la Recherche scientifique. It is entitled: Africa in the “science policies” of France and Great Britain from ... [more ▼]

This paper fits in a broader research project funded by the Belgian F.R.S.-Fonds national de la Recherche scientifique. It is entitled: Africa in the “science policies” of France and Great Britain from the eighteenth to the mid- nineteenth century: the scholarly background of the Scramble. This general project aims at completing in an original way recent studies on the interactions between the “New Science” derived from the Scientific Revolution and the building of colonial empires in the Atlantic area from the Enlightenment to the apogee of the first Industrial Revolution. Its objective is to investigate how in this period Africa has become a scientific object in its own right for the colonial administrations of France and Great Britain. Botanical knowledge (industrial plants, food crops and medicinal herbs) that originated in Africa was first applied in the plantations of slave economies in the Caribbean and North America. It was increased with knowledge about the geography and natural history of the continent’s interior through a revival of exploration in Africa itself. The project aims to relate the increased interest from scholars for Africa to the intensification of economic and military competition between the powers. It also wants to demonstrate how a more precise knowledge of the African terrain influenced the ways in which the governments of both countries have integrated colonial expertise in a complex science policy adapted to the specific needs of the two states. In this paper I will focus on the British side of the spectrum. I will investigate the changing British attitude towards Africa in the early nineteenth century through a case study of an expedition to the River Congo organized in 1816. Although this expedition ended in disaster (a majority of the members died in the course of the undertaking), it offers a series of useful examples that help to illustrate the transformation of British science policies under the pressure of competition with the French. Thus, it is my aim to show how Great Britain in the face of state-oriented French science has abandoned its policy of informal relationships and started to encourage its administration and scientific institutions to intervene more directly in exploration. Crucial in this evolution was the way in which the Admiralty absorbed the scholarly input of a number of learned societies and institutions, such as the Royal Society, the British Museum or the so-called “African Association” – the latter combining both scientific and commercial objectives. Thus the expedition illustrates the transition from Late Enlightenment “Banksian” exploration, inspired by the omnipotent science organizer Sir Joseph Banks (1743-1820), towards a more thorough imperial design of exploration under the command of Sir John Barrow (1764-1848). Already since the French conquest of Egypt, “scientific” expeditions relied on the collaboration between learned networks and the military, an example that would be copied later in Algeria. At the British side, it was the Admiralty that strengthened its grip on exploration. Tuckey’s expedition illustrates very well the amplification of operations, the more direct intervention by the government, and the growing importance of the commercial agendas of science. I will focus here on the interaction between the Admiralty and the learned societies with regard to the composition of the instruction text given to the leader of the expedition on the eve of his departure, on the specific choice of the area he had to explore (related to the “Niger question”), on the practical organization (e.g. the development of special steam engines by the engineer Watt, the scientific equipment offered with the help of the British Museum, etc.), on the choice of the scientists who formed a real team of experts (e.g. Christen Smith, John Cranch, etc.), on the collection of scientific data and their integration in collections in Britain, on the presentation of the expedition’s results in a published report entitled Narrative of an expedition to explore the river Zaire, usually called the Congo, in South Africa, in 1816, under the direction of Captain J. K. Tuckey, R.N., (London, 1818), and finally, on the circulation of these results in the rest of Europe due to the translation of the report in Dutch and French. [less ▲]

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See detailVitamine D et Allergie
GADISSEUR, Romy ULg

Conference (2013, November 16)

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See detailLe plomb atmosphérique enregistré dans les stalagmites de Han-sur-Lesse
Allan, Mouhamd ULg; Verheyden, sophie

Conference (2013, November 16)

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See detailStabilité et clarté du concept de soi : Comment se caractérise l'identité des patients dépressifs ?
Wagener, Aurélie ULg; Weigend, Alicia; Boulanger, Marie ULg et al

Poster (2013, November 16)

BACKGROUND. Depression is a psychopathology that affects many people (33.4 million every year in Europe). Depressed patients may demonstrate large variations in the evaluation of themselves (instability ... [more ▼]

BACKGROUND. Depression is a psychopathology that affects many people (33.4 million every year in Europe). Depressed patients may demonstrate large variations in the evaluation of themselves (instability of self-esteem and of self-efficacy). In addition, it has been demonstrated that, in the general population, negative feelings and emotions are positively correlated with the volatility of self-representations. However, no study has assessed the stability of personal identity in depressed patients. Some researchers have nevertheless shown that changes in personality traits are observable in the development of depressive disorder. HYPTHESES. Depressed patients’ description of their traits of personality varies depending on the mood phases crossings unlike that of control subjects who remained stable. METHOD. Depressed patients (N = 17, M age = 51) were compared to control subjects (N = 18, M age = 47). Severity of depressive symptoms (BDI -II), implicit (name - letter task) and explicit (CSR) self-esteem, stability of identity and self-concept clarity were assessed. RESULTS. Depressed patients have a self-perception less stable than control subjects and a lower clarity of identity. The severity of depressive symptoms was positively correlated with poorer clarity of identity. DISCUSSION. These results support our hypothesis. Experimental and clinical perspectives of these will be discussed. [less ▲]

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See detailQuelles activités pour nos seniors souffrant de maladie de la mémoire ?
Adam, Stéphane ULg

Conference (2013, November 16)

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See detailLes aidants professionnels à domicile face à la démence: intérets d'une formation
Marquet, Manon ULg; Missotten, Pierre ULg; Charlot, Valentine ULg et al

Poster (2013, November 16)

Introduction : Des interventions non pharmacologiques peuvent réduire le risque que des aidants professionnels qui accompagnent des personnes âgées (atteintes ou non de démence) développent des attitudes ... [more ▼]

Introduction : Des interventions non pharmacologiques peuvent réduire le risque que des aidants professionnels qui accompagnent des personnes âgées (atteintes ou non de démence) développent des attitudes âgistes[1], un sentiment d’incompétence[2], une insatisfaction professionnelle[3,4] et un burnout[2]. Ces interventions sont néanmoins essentiellement destinées aux aidants en milieu institutionnel. Objectif : Évaluer, au niveau de différents paramètres (âgisme, connaissances sur la maladie d’Alzheimer, sentiment de compétence, satisfaction professionnelle, burnout, stratégies de coping), l’efficacité d’une formation destinée à des aidants professionnels à domicile. Méthodologie : 18 aides familiales ont bénéficié d’une formation de trois jours visant à améliorer leurs connaissances sur les démences et à les aider à mettre en place des stratégies de résolution de problèmes face aux difficultés rencontrées dans leur pratique, et ceci, afin de favoriser une vision moins stigmatisante de la maladie d’Alzheimer. Différents auto-questionnaires ont été complétés par les participantes avant et après l’intervention. Résultats : Les analyses statistiques indiquent que la formation permet de diminuer l’âgisme des aidantes, d’améliorer leurs connaissances sur la maladie d’Alzheimer et leur satisfaction vis-à-vis de leurs tâches professionnelles. Les stratégies de coping centrée sur la résolution de problème sont également considérées comme plus aidantes. Conclusion : L’intervention est efficace puisqu’elle atteint ses objectifs initiaux. Ces résultats encouragent non seulement la formation des aidants professionnels à domicile mais aussi l’évaluation de l’efficacité des interventions proposées, à la fois auprès des aidants professionnels, informels et des personnes accompagnées. En effet, sur base de la littérature[5,6], nous faisons l’hypothèse que l’amélioration des connaissances et la diminution de l’âgisme réduisent le risque d’induire des comportements de dépendance chez les personnes accompagnées. Ce constat est important compte tenu du rôle des aides familiales, à savoir aider les personnes âgées (atteintes ou non de démence) qui présentent des difficultés dans la réalisation des activités (instrumentales) de la vie quotidienne afin qu’elles restent le plus longtemps possible à leur domicile. Références : 1. Fritsch, T., et al. (2009). Gerontologist, 49, 117-127. 2. Mackenzie, C.S., et al. (2003). J Alzheimers Dis, 18, 291-299. 3. Vernooij-Dassen, M.J., et al. (2009). Aging Ment Health, 13, 383-390. 4. Coogle, C.L., et al. (2006). Educ Gerontol, 32, 611-631. 5. Avorn, J., et al. (1982). J Am Geriatr Soc, 30, 397-400. 6. Coudin, G., et al. (2010). Aging Ment Health, 14, 516-523. [less ▲]

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See detailLa vitamine D, état des lieux et recommandations
CAVALIER, Etienne ULg

Conference (2013, November 16)

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See detailVitamien D et pahtologies cardiovasculaires
LE GOFF, Caroline ULg

Scientific conference (2013, November 16)

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