Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailThe QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG
Jahnke, Knud; Elbaz, David; Pantin, Eric et al

in Astrophysical Journal (2009), 700(2), 1820-1830

(Abridged) The luminous z=0.286 quasar HE0450-2958 is interacting with a companion galaxy at 6.5 kpc distance and the whole system is a ULIRG. A so far undetected host galaxy triggered the hypothesis of a ... [more ▼]

(Abridged) The luminous z=0.286 quasar HE0450-2958 is interacting with a companion galaxy at 6.5 kpc distance and the whole system is a ULIRG. A so far undetected host galaxy triggered the hypothesis of a mostly "naked" black hole (BH) ejected from the companion by three-body interaction. We present new HST/NICMOS 1.6micron imaging data at 0.1" resolution and VLT/VISIR 11.3micron images at 0.35" resolution that for the first time resolve the system in the near- and mid-infrared. We combine these with existing optical HST and CO maps. (i) At 1.6micron we find an extension N-E of the quasar nucleus that is likely a part of the host galaxy, though not its main body. If true, this places HE0450-2958 directly onto the M_BH-M_bulge-relation for nearby galaxies. (ii) HE0450-2958 is consistent with lying at the high-luminosity end of Narrow-Line Seyfert 1 Galaxies, and more exotic explanations like a "naked quasar" are unlikely. (iii) All 11.3micron radiation in the system is emitted by the quasar nucleus, which is radiating at super-Eddington rate, L/L_Edd=6.2+3.8-1.8, or 12 M_sun/yr. (iv) The companion galaxy is covered in optically thick dust and is not a collisional ring galaxy. It emits in the far infrared at ULIRG strength, powered by Arp220-like star formation (strong starburst-like). An M82-like SED is ruled out. (v) With its black hole accretion rate HE0450-2958 produces not enough new stars to maintain its position on the M_BH-M_bulge-relation, and star formation and black hole accretion are spatially disjoint; the bulge has to grow by redistribution of preexisting stars. (vi) Systems similar to HE0450-2958 with spatially disjoint ULIRG-strength star formation and quasar activity are rare. At z<0.43 we only find <4% (3/77) candidates for a similar configuration. [less ▲]

Detailed reference viewed: 32 (7 ULg)
Full Text
Peer Reviewed
See detailAn orbital period of 0.94days for the hot-Jupiter planet WASP-18b
Hellier, Coel; Anderson, D. R.; Cameron, A Collier et al

in Nature (2009), 460

The `hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which ... [more ▼]

The `hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only ~0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94days and a mass of ten Jupiter masses (10M[SUB]Jup[/SUB]), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10[SUP]6[/SUP], as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System. [less ▲]

Detailed reference viewed: 33 (6 ULg)
Full Text
Peer Reviewed
See detailTransiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius
Leger, A.; Rouan, D.; Schneider, J. et al

in Astronomy and Astrophysics (2009), 506

We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as due to the presence of a ... [more ▼]

We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as due to the presence of a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods. We use CoRoT color information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy and preliminary results from Radial Velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star are derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. We examine carefully all conceivable cases of false positives, and all tests performed support the planetary hypothesis. Blends with separation larger than 0.40 arcsec or triple systems are almost excluded with a 8 10-4 risk left. We conclude that, as far as we have been exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which we derive a period of 0.853 59 +/- 3 10-5 day and a radius of Rp = 1.68 +/- 0.09 REarth. Analysis of preliminary radial velocity data yields an upper limit of 21 MEarth for the companion mass, supporting the finding. CoRoT-7b is very likely the first Super-Earth with a measured radius. [less ▲]

Detailed reference viewed: 41 (5 ULg)
Full Text
See detailDes outils pour favoriser une continuité des apprentissages en mathématiques et en sciences lors de la liaison primaire-secondaire : La propagation de la chaleur
Daro, Sabine; Graftiau, Marie-Christine; Stouvenakers, Nadine et al

Report (2009)

outil à usage des enseignants du fondamental qui veulent mettre en place une séquence sur la propagation de la chaleur dans leur classe

Detailed reference viewed: 58 (5 ULg)
Full Text
See detailDes outils pour favoriser une continuité des apprentissages en mathématiques et en sciences lors de la liaison primaire-secondaire : Question d'équilibre
Daro, Sabine; Graftiau, Marie-Christine; Stouvenakers, Nadine et al

Report (2009)

document à l'usage des enseignants du fondamental qui veulent travailler le thème de l'équilibre en classe

Detailed reference viewed: 19 (2 ULg)
Full Text
See detailEstimates of genetic parameters among body condition score and calving traits in first parity Canadian Ayrshire cows
Bastin, Catherine ULg; Loker, Sarah; Gengler, Nicolas ULg et al

in Book of Abstracts of the 60th Annual Meeting of the European Association for Animal Production (2009, August)

Detailed reference viewed: 23 (8 ULg)
Full Text
See detailAdding value to test-day data by using modified best prediction method
Gillon, Alain ULg; Abras, Sven; Mayeres, Patrick et al

in Book of Abstracts of the 60th Annual Meeting of the European Association for Animal Production (2009, August)

Computation of lactation yields from test-day yield has lost much of its importance for genetic evaluations as <br />the use of test-day models is rather widespread. At the same time its importance for ... [more ▼]

Computation of lactation yields from test-day yield has lost much of its importance for genetic evaluations as <br />the use of test-day models is rather widespread. At the same time its importance for intra-farm management <br />increases at farms as a base for advanced management tools. The most common official method to compute <br />lactation yield is the Test Interval Method (TIM). Alternative methods for computing cumulated productions <br />were developed. These methods can be considered as improvements of TIM as the interpolation method, <br />or completely different methods as multiple-trait prediction (MTP) and best prediction (BP). Research <br />in this field has shown the potential to compute lactation parameters (e.g., cumulated production) with <br />test-day models. The aim of this study was to develop a new method which takes into account advantages <br />and disadvantages of existing methods, and to test its potential to provide useful tools to help farmers to <br />make management decisions. The second objective was to compare the accuracy and the robustness of this <br />method with those of BP and TIM. Because of its similarities with BP, the method developed here was <br />called mBP, for modified-BP. The main difference from BP is the definition of the standard lactation curve. <br />To minimize bias, components of standard lactation curves proper to each herd are computed jointly with <br />random individual effects. Recently a new version of mBP was tested that puts expectations of constant <br />animal effects to observed average values using Bayesian prediction, a feature also used by MTP. [less ▲]

Detailed reference viewed: 84 (22 ULg)
Full Text
Peer Reviewed
See detailH4 Histamine Receptors Mediate Cell Cycle Arrest in Growth Factor-Induced Murine and Human Hematopoietic Progenitor Cells
Petit-Bertron, Anne France; Machavoine, François; Defresne, Marie-Paule ULg et al

in PLoS ONE (2009), 4(8), 1-13

Detailed reference viewed: 52 (12 ULg)
Full Text
See detailCe n'est pas tant de l'expérience qu'on apprend, mais de ce qu'on décide d'en garder
Hindryckx, Marie-Noëlle ULg; Laschet, Mélanie ULg

in Puzzle (2009), (26), 44-51

Comment développer chez les étudiants futurs enseignants un recul réflexif qui les aide non seulement à améliorer leurs pratiques, mais également à construire leur identité professionnelle? Récit d'une ... [more ▼]

Comment développer chez les étudiants futurs enseignants un recul réflexif qui les aide non seulement à améliorer leurs pratiques, mais également à construire leur identité professionnelle? Récit d'une expérience de formation initiale en sciences biologiques [less ▲]

Detailed reference viewed: 137 (23 ULg)
Full Text
See detailJ'ai hâte d'y être... Semaine d'immersion en didactique pour les premiers masters en sciences
Hindryckx, Marie-Noëlle ULg

in Puzzle (2009), (26), 75-78

Récit d'une expérience d'initiation à la didactique des sciences pour des étudiants masters en biologie susceptibles de choisir une orientation didactique pour leurs études à l'Université de Liège

Detailed reference viewed: 66 (15 ULg)
Full Text
See detailExpressing female fertility in the Walloon region of Belgium: how to do?
Vanderick, Sylvie ULg; Bastin, Catherine ULg; Gengler, Nicolas ULg

Conference (2009, August)

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility ... [more ▼]

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility. In order to define general way of female fertility expression, a principal component analysis was carried out on six published foreign female fertility indexes. Results of were used to compute a direct female fertility index with the INTERBULL international female fertility proofs available on the Walloon scale. An indirect female fertility index was also developed in order to increase reliability of young bulls. Approximate procedure based on selection index was used to combine both indexes in an overall index called combined female fertility index. This index was highly correlated with the direct female fertility index (.96) and the first principal component (.85), therefore it was considered as good expression of female fertility. Moreover, this allowed recovering 4,019 INTERBULL bulls with a publishable female fertility index. [less ▲]

Detailed reference viewed: 13 (3 ULg)
Full Text
Peer Reviewed
See detailThe HDAC inhibitor panobinostat (LBH589) inhibits mesothelioma and lung cancer cells in vitro and in vivo with particular efficacy for small cell lung cancer
Crisanti, Cecilia; Wallace, Africa; Kapoor, Veena et al

in Molecular Cancer Therapeutics (2009), 8(8), 2221-2231

Lung cancer is the leading cause of cancer deaths in the United States. Current therapies are inadequate. Histone deacetylase inhibitors (HDACi) are a recently developed class of anticancer agents that ... [more ▼]

Lung cancer is the leading cause of cancer deaths in the United States. Current therapies are inadequate. Histone deacetylase inhibitors (HDACi) are a recently developed class of anticancer agents that cause increased acetylation of core histones and nonhistone proteins leading to modulation of gene expression and protein activityin - volved in cancer cell growth and survival pathways. We examined the efficacyof the HDACi panobinostat (LBH589) in a wide range of lung cancers and mesotheliomas. Panobinostat was cytotoxic in almost all 37 cancer cell lines tested. IC50 and LD50 values were in the low nmol/L range (4–470 nmol/L; median, 20 nmol/L). Small cell lung cancer (SCLC) cell lines were among the most sensitive lines, with LD50 values consistently <25 nmol/L. In lung cancer and mesothelioma animal models, panobinostat significantlyde creased tumor growth byan average of 62% when compared with vehicle control. Panobinostat was equallye ffective in immunocompetent and severe combined immunodeficiencymic e, indicating that the inhibition of tumor growth by panobinostat was not due to direct immunologic effects.Panobinostat was, however, particularlyeffective in SCLC xenografts, and the addition of the chemotherapyag ent etoposide augmented antitumor effects. Protein analysis of treated tumor biopsies revealed elevated amounts of cell cycle regulators such as p21 and proapoptosis factors, such as caspase 3 and 7 and cleaved poly[ADP-ribose] polymerase, coupled with decreased levels of antiapoptotic factors such as Bcl-2 and Bcl-XL. These studies together suggest that panobinostat maybe a useful adjunct in the treatment of thoracic malignancies, especiallySCLC. [less ▲]

Detailed reference viewed: 69 (1 ULg)
Full Text
Peer Reviewed
See detailAnchors of morphological operators and algebraic openings
Van Droogenbroeck, Marc ULg

in Hawkes, Peter (Ed.) Advances in Imaging and Electron Physics (2009)

Opening and closing operators play an important role in the field of mathematical morphology, mainly because of their useful property of idempotence, which is similar to the notion of ideal filter in ... [more ▼]

Opening and closing operators play an important role in the field of mathematical morphology, mainly because of their useful property of idempotence, which is similar to the notion of ideal filter in linear filtering. From a theoretical point of view, the study of openings has focused on the algebraic characterization of the operators themselves. Morphological filters have been studied for more than 30 years; the effects of the first filters (erosions, openings, and so on) are known in depth. In discussing the effects of a filter, it is not only the operator that is studied but also its relationship with the processed function or image and, in the particular case of mathematical morphology, the structuring element. In addition, there are several approaches to this analysis. For example, the analysis can consider the whole function or some subparts of the function, as in Van Droogenbroeck and Buckley (2005), who introduced the notion of morphological anchors. Anchors were defined in the context of morphological openings, as defined by the cascade of an erosion followed by a dilation. The extension to other kinds of openings is not straightforward. Despite the fact that all morphological openings induce the appearance of anchors, some opening operators (like the quantization opening defined in this chapter) might have no anchors. This chapter presents the theory of anchors related to morphological erosions and openings, and establishes some properties for the extended scope of algebraic openings. It is shown under which circumstances anchors exist for algebraic openings and how to locate some anchors; for example, it suffices for an opening to be spatial or shift-invariant to guarantee the existence of anchors. As for morphological openings, the existence of anchors may help clarify some algorithms or lead to new algorithms to compute algebraic openings. [less ▲]

Detailed reference viewed: 74 (10 ULg)
Full Text
Peer Reviewed
See detailNetwork Virtualization Architecture: Proposal and Initial Prototype
Schaffrath, Gregor; Werle, Christoph; Papadimitriou, Panagiotis et al

in ACM SIGCOMM Workshops Proceedings (2009, August)

The tussle between reliability and functionality of the Internet is firmly biased on the side of reliability. New enabling technologies fail to achieve traction across the majority of ISPs. We believe ... [more ▼]

The tussle between reliability and functionality of the Internet is firmly biased on the side of reliability. New enabling technologies fail to achieve traction across the majority of ISPs. We believe that the greatest challenge is not in finding solutions and improvements to the Internet's many problems, but in how to actually deploy those solutions and re-balance the tussle between reliability and functionality. Network virtualization provides a promising approach to enable the coexistence of innovation and reliability. We describe a network virtualization architecture as a technology for enabling Internet innovation. This architecture is motivated from both business and technical perspectives and comprises four main players. In order to gain insight about its viability, we also evaluate some of its components based on experimental results from a prototype implementation. [less ▲]

Detailed reference viewed: 82 (1 ULg)
Full Text
Peer Reviewed
See detailWide-area Detection of Voltage Instability from Synchronized Phasor Measurements. Part I: Principle
Glavic, Mevludin; Van Cutsem, Thierry ULg

in IEEE Transactions on Power Systems (2009), 24(3), 1408-1416

This two-part paper deals with the early detection of an impending voltage instability from the system states provided by synchronized phasor measurements. Recognizing that voltage instability detection ... [more ▼]

This two-part paper deals with the early detection of an impending voltage instability from the system states provided by synchronized phasor measurements. Recognizing that voltage instability detection requires assessing a multi-dimensional system, the method fits a set of algebraic equations to the sampled states, and performs an efficient sensitivity computation in order to identify when a combination of load powers has passed through a maximum. The important effects of overexcitation limiters are accounted for. The approach does not require any load model. This first part of the paper is devoted to theoretical foundations of sensitivity calculation along the system trajectory, derivation of the algebraic model, and illustration on a simple 5-bus system involving the long-term dynamics of a load tap changer and a field current limiter. [less ▲]

Detailed reference viewed: 263 (31 ULg)
Full Text
Peer Reviewed
See detailCertified Internet Coordinates
Kaafar, Mohamed Ali; Mathy, Laurent ULg; Barakat, Chadi et al

in ICCCN '09 Proceedings (2009, August)

We address the issue of asserting the accuracy of coordinates advertised by nodes of Internet coordinate systems during distance estimations. Indeed, some nodes may lie deliberately about their ... [more ▼]

We address the issue of asserting the accuracy of coordinates advertised by nodes of Internet coordinate systems during distance estimations. Indeed, some nodes may lie deliberately about their coordinates to mount various attacks against applications and overlays. Our proposed method consists in two steps: 1) establish the correctness of a node’s claimed coordinate (which leverages our previous work on securing the coordinates embedding phase using a Surveyor infrastructure); and 2) issue a time limited validity certificate for each verified coordinate. Validity periods are computed based on an analysis of coordinate inter-shift times observed on PlanetLab, and shown to follow a long-tail distribution (lognormal distribution in most cases, or Weibull distribution otherwise). The effectiveness of the coordinate certification method is validated by measuring the impact of a variety of attacks on distance estimates. [less ▲]

Detailed reference viewed: 24 (0 ULg)
Full Text
Peer Reviewed
See detailWide-area Detection of Voltage Instability from Synchronized Phasor Measurements. Part II: Simulation results
Glavic, Mevludin; Van Cutsem, Thierry ULg

in IEEE Transactions on Power Systems (2009), 24(3), 1417-1425

This two-part paper deals with the early detection of an impending voltage instability from the system states provided by synchronized phasor measurements. Recognizing that voltage instability detection ... [more ▼]

This two-part paper deals with the early detection of an impending voltage instability from the system states provided by synchronized phasor measurements. Recognizing that voltage instability detection requires assessing a multidimensional system, the method fits a set of algebraic equations to the sampled states, and performs an efficient sensitivity in order to identify when a combination of load powers has passed through a maximum. This second part of the paper presents simulation results obtained from detailed time-domain simulation of the Nordic32 test system, without and with measurement noise, respectively. Several practical improvements are described such as anticipation of overexcitation limiter activation, and use of a moving average filter. Robustness to load behaviour, non updated topology and unobservability is also shown. Finally a comparison with Thevenin impedance matching criterion is provided. [less ▲]

Detailed reference viewed: 236 (32 ULg)
Full Text
See detailInnovations in Navigation Lock Design
Rigo, Philippe ULg; INCOM WG29

Book published by PIANC - Report 106 - 2009 (2009)

State of art in navigation locks , focuss on innovations

Detailed reference viewed: 608 (57 ULg)