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See detailDiscovery of pulsed polar flares in the Jovian aurorae
Bonfond, Bertrand ULg; Vogt, M~F; Grodent, Denis ULg et al

Poster (2010, December)

The most active part of the aurora at Jupiter is certainly the polar region, i.e. the emissions located poleward of the main auroral oval. This region is known to occasionally show localized but dramatic ... [more ▼]

The most active part of the aurora at Jupiter is certainly the polar region, i.e. the emissions located poleward of the main auroral oval. This region is known to occasionally show localized but dramatic enhancements of its brightness, referred to as polar flares. These emissions have been associated with the polar cusp, based on their location in the polar cap. In summer 2009, right after the refurbishment of the Space Telescope Imaging Spectrograph camera, the Hubble Space Telescope acquired the longest high-time resolution sequence ever of images of the Jovian aurora. We report the first observations of a quasi-periodicity in the occurrence of these flares, with a timescale of ~2-3 minutes. By using a magnetic flux mapping model, we show that these features originate from a region located at a radial distance ranging from 80 to 100 Jovian radii and local times between 10:00 and 15:00. As a consequence, by analogy with similar behaviors observed in the Earth aurora, we suggest that these emissions could be attributed to pulsed reconnections in the dayside magnetopause. [less ▲]

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See detailDiscovery of soft X-ray emission from Io, Europa, and the Io Plasma Torus
Elsner, Ronald F.; Gladstone, G. Randall; Waite, J. Hunter et al

in Astrophysical Journal (2002), 572(2), 1077-1082

We report the discovery of soft (0.25-2 keV) X-ray emission from the Galilean satellites Io and Europa, probably Ganymede, and from the Io Plasma Torus (IPT). Bombardment by energetic (greater than 10 keV ... [more ▼]

We report the discovery of soft (0.25-2 keV) X-ray emission from the Galilean satellites Io and Europa, probably Ganymede, and from the Io Plasma Torus (IPT). Bombardment by energetic (greater than 10 keV) H, O, and S ions from the region of the IPT seems to be the likely source of the X-ray emission from the Galilean satellites. According to our estimates, fluorescent X-ray emission excited by solar X-rays, even during flares from the active Sun, charge-exchange processes, previously invoked to explain Jupiter's X-ray aurora and cometary X-ray emission, and ion stripping by dust grains fail to account for the observed emission. On the other hand, bremsstrahlung emission of soft X-rays from nonthermal electrons in the few hundred to few thousand eV range may account for a substantial fraction of the observed X-ray flux from the IPT. [less ▲]

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See detailDiscovery of the first eclipsing binary barium star
Jorissen, A.; Manfroid, Jean ULg; Sterken, C.

in The Messenger (1991), 66

Photometric monitoring of barium stars is discussed with particular attention given to the first eclipsing binary barium star, HD 46407. The spectroscopic ephemeris of HD 46407 was used to predict the ... [more ▼]

Photometric monitoring of barium stars is discussed with particular attention given to the first eclipsing binary barium star, HD 46407. The spectroscopic ephemeris of HD 46407 was used to predict the times of a possible eclipse of the companion by the barium star. It is concluded that the light curve of HD 46407 derived from the photometric observations in the D50 system displays a sharp 'primary' eclipse (companion behind the barium star) and a possible shallow 'secondary' eclipse. The primary eclipse occurred in November 1988 and had a depth of about 0.02 mag. [less ▲]

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See detailDiscovery of WASP-65b and WASP-75b: Two Hot Jupiters Without Highly Inflated Radii
Gómez Maqueo Chew, Y.; Faedi, F.; Pollacco, D. et al

in Astronomy and Astrophysics (2013)

We report the discovery of two transiting hot Jupiters, WASP-65b (Mpl = 1.55 ± 0.16 MJ; Rpl = 1.11 ± 0.06 RJ), and WASP-75b (Mpl = 1.07 ± 0.05 MJ; Rpl = 1.27 ± 0.05 RJ). They orbit their host star every ... [more ▼]

We report the discovery of two transiting hot Jupiters, WASP-65b (Mpl = 1.55 ± 0.16 MJ; Rpl = 1.11 ± 0.06 RJ), and WASP-75b (Mpl = 1.07 ± 0.05 MJ; Rpl = 1.27 ± 0.05 RJ). They orbit their host star every ~2.311, and ~2.484 days, respectively. The planet host WASP-65 is a G6 star (Teff = 5600 K, [Fe/H] = -0.07 ± 0.07, age ≳8 Gyr); WASP-75 is an F9 star (Teff = 6100 K, [Fe/H] = 0.07 ± 0.09, age ~ 3 Gyr). WASP-65b is one of the densest known exoplanets in the mass range 0.1 and 2.0 MJ (rhopl = 1.13 ± 0.08 rhoJ), a mass range where a large fraction of planets are found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of ~1.5 MJ, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of WASP-75b is slightly inflated (≲10%) as compared to theoretical planet models with no core, and has a density similar to that of Saturn (rhopl = 0.52 ± 0.06 rhoJ). [less ▲]

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See detailDiscovery of WASP-85Ab: a hot Jupiter in a visual binary system
Brown, D. J. A.; Anderson, D. R.; Armstrong, D. J. et al

E-print/Working paper (2014)

We report the discovery of the transiting hot Jupiter exoplanet WASP-85Ab. Using a combined analysis of spectroscopic and photometric data, we determine that the planet orbits its host star every 2.66 ... [more ▼]

We report the discovery of the transiting hot Jupiter exoplanet WASP-85Ab. Using a combined analysis of spectroscopic and photometric data, we determine that the planet orbits its host star every 2.66 days, and has a mass of 1.09+/-0.03 M_Jup and a radius of 1.44+/-0.02 R_Jup. The host star is of G5 spectral type, with magnitude V=11.2, and lies 125+/-80 pc distant. We find stellar parameters of T_eff=5685+/-65 K, super-solar metallicity ([Fe/H]=0.08+/-0.10), M_star=1.04+/-0.07 M_sun and R_star=0.96+/-0.13 R_sun. The system has a K-dwarf binary companion, WASP-85B, at a separation of approximately 1.5". The close proximity of this companion leads to contamination of our photometry, decreasing the apparent transit depth that we account for during our analysis. Without this correction, we find the depth to be 50 percent smaller, the stellar density to be 32 percent smaller, and the planet radius to be 18 percent smaller than the true value. Many of our radial velocity observations are also contaminated; these are disregarded when analysing the system in favour of the uncontaminated HARPS observations, as they have reduced semi-amplitudes that lead to underestimated planetary masses. We find a long-term trend in the binary position angle, indicating a misalignment between the binary and orbital planes. WASP observations of the system show variability with a period of 14.64 days, indicative of rotational modulation caused by stellar activity. Analysis of the Ca ii H+K lines shows strong emission that implies that both binary components are strongly active. We find that the system is likely to be less than a few Gyr old. WASP-85 lies in the field of view of K2 Campaign 1. Long cadence observations of the planet clearly show the planetary transits, along with the signature of stellar variability. Analysis of the K2 data, both long and short cadence, is ongoing. [less ▲]

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See detailDiscovery of X-Ray Emission from Young Suns in the Small Magellanic Cloud
Oskinova, L. M.; Sun, W.; Evans, C. J. et al

in Astrophysical Journal (2013), 765

We report the discovery of extended X-ray emission within the young star cluster NGC 602a in the Wing of the Small Magellanic Cloud (SMC) based on observations obtained with the Chandra X-Ray Observatory ... [more ▼]

We report the discovery of extended X-ray emission within the young star cluster NGC 602a in the Wing of the Small Magellanic Cloud (SMC) based on observations obtained with the Chandra X-Ray Observatory. X-ray emission is detected from the cluster core area with the highest stellar density and from a dusty ridge surrounding the H II region. We use a census of massive stars in the cluster to demonstrate that a cluster wind or wind-blown bubble is unlikely to provide a significant contribution to the X-ray emission detected from the central area of the cluster. We therefore suggest that X-ray emission at the cluster core originates from an ensemble of low- and solar-mass pre-main-sequence (PMS) stars, each of which would be too weak in X-rays to be detected individually. We attribute the X-ray emission from the dusty ridge to the embedded tight cluster of the newborn stars known in this area from infrared studies. Assuming that the levels of X-ray activity in young stars in the low-metallicity environment of NGC 602a are comparable to their Galactic counterparts, then the detected spatial distribution, spectral properties, and level of X-ray emission are largely consistent with those expected from low- and solar-mass PMS stars and young stellar objects (YSOs). This is the first discovery of X-ray emission attributable to PMS stars and YSOs in the SMC, which suggests that the accretion and dynamo processes in young, low-mass objects in the SMC resemble those in the Galaxy. [less ▲]

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See detailDiscovery of X-ray pulsations from a massive star
Oskinova, Lidia M.; Nazé, Yaël ULg; Todt, Helge et al

in Nature Communications (2014), 5

X-ray emission from stars much more massive than the Sun was discovered only 35 years ago. Such stars drive fast stellar winds where shocks can develop, and it is commonly assumed that the X-rays emerge ... [more ▼]

X-ray emission from stars much more massive than the Sun was discovered only 35 years ago. Such stars drive fast stellar winds where shocks can develop, and it is commonly assumed that the X-rays emerge from the shock-heated plasma. Many massive stars additionally pulsate. However, hitherto it was neither theoretically predicted nor observed that these pulsations would affect their X-ray emission. All X-ray pulsars known so far are associated with degenerate objects, either neutron stars or white dwarfs. Here we report the discovery of pulsating X-rays from a non-degenerate object, the massive B-type star ξ[SUP]1[/SUP] CMa. This star is a variable of β Cep-type and has a strong magnetic field. Our observations with the X-ray Multi-Mirror (XMM-Newton) telescope reveal X-ray pulsations with the same period as the fundamental stellar oscillations. This discovery challenges our understanding of stellar winds from massive stars, their X-ray emission and their magnetism. [less ▲]

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See detailDiscovery Tools, a Bibliography
Renaville, François ULg

Textual, factual or bibliographical database (2014)

Libraries are continually changing to meet the needs of users. This includes implementing discovery tools, also referred to as web-scale discovery tools or services, to make it easier to search through ... [more ▼]

Libraries are continually changing to meet the needs of users. This includes implementing discovery tools, also referred to as web-scale discovery tools or services, to make it easier to search through their physical, digital and electronic collections. Vendors and suppliers are continuously improving their functionali ties offering new services and improved technologies. Hundreds of publications and communications on implementation, comparison, user experience, information literacy, librarian perception, collection usage, etc. related to discovery tools have already been produced. This bibliography aims to give a selected overview of what (mostly) librarians have written or said about discovery tools. [less ▲]

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See detailDiscrépance et domaines de vie de l’ISQV-E(c) : quels liens avec le mal-être de l’enfant ?
Lemétayer, Fabienne; Lanfranchi, Jean-Baptiste; Missotten, Pierre ULg et al

in Revue Francophone de Clinique Comportementale et Cognitive (2012), XVII(1), 34-43

This study examines the processes and the life domains of the Child Quality of Life Systemic Inventory (ISQV-E(c) in French - Missotten, Etienne & Dupuis, 2007), involved in the suffering of depressed ... [more ▼]

This study examines the processes and the life domains of the Child Quality of Life Systemic Inventory (ISQV-E(c) in French - Missotten, Etienne & Dupuis, 2007), involved in the suffering of depressed children, assessed with the CDI. These questionnaires were administered to 453 to school age children (8-12 years old) and they all spoke French (273 French, 180 Belgian). An initial analysis was undertaken to verify the nature of the model, additive vs multiplicative, underlying the ISQV-E(c). Five factors were tested: the Goal, the Discrepancy (distance between State and Goal), Speed, Rank and the Gap. Regression analysis revealed that only the Goal and the Discrepancy are significantly related to suffering depression (additive model). From these two factors, a second analysis was performed to account for domains of life most involved in suffering from depression. The results dealt with a PLS path modeling helped to update the 10 domains of life, of the twenty-evaluated by the ISQV-E(c), likely to predict depressive suffering of children. The specific contribution of the ISQV-E(c) is discussed in relation to depressive affect assessed with the CDI. [less ▲]

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See detailDISCREPANCIES BETWEEN BIO-ANALYTICAL AND CHEMO-ANALYTICAL RESULTS HAVE A NON-NEGLIGIBLE MESSAGE
Goeyens, L.; Hoogenboom, R.; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2010), 72

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See detailDiscrepancies between creatinine-based and cystatin C-based equations in estimating prevalence of stage 3 chronic kidney disease in an elderly population.
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Saint-Remy, Annie ULg et al

in Scandinavian Journal of Clinical & Laboratory Investigation (2009), 69(3), 344-9

Background . The prevalence of stage 3 chronic kidney disease (CKD) is increasing, calculated using the modification of diet in renal disease (MDRD) study equation for estimating glomerular filtration ... [more ▼]

Background . The prevalence of stage 3 chronic kidney disease (CKD) is increasing, calculated using the modification of diet in renal disease (MDRD) study equation for estimating glomerular filtration rate (GFR). Cystatin C-based equations are also being used to estimate GFR. Using creatinine-based and cystatin C-based equations, the aim of our study was to measure the difference in prevalence of stage 3 CKD in a population. Methods . CKD screening is organized in the Province of Liege, Belgium. On a voluntary basis, people aged between 45 and 75 years are invited for screening. GFR is estimated using the MDRD study equation and by the three recent cystatin C-based equations proposed by Levey's group. The Levey 1 equation is based on cystatin C only and the Levey 2 equation on cystatin C corrected for age and sex. The Levey 3 equation combines cystatin C, creatinine, age and sex. Results . The population screened comprised 754 people. Cystatin C is highly correlated with creatinine (r = 0.6196, p<0.0001). Prevalence of stage 3 CKD when GFR is estimated by the MDRD equation study is 17.2 %, which is significantly and much higher than the prevalence obtained when cystatin C-based equations are used. Indeed, prevalence is 2 %, 3.3 % and 5.8 % with the Levey 1, 2 and 3 equations, respectively. Conclusions . The prevalence of stage 3 CKD varies strongly following the method used for estimating GFR, creatinine-based or cystatin C-based equations. Such discrepancies must be confirmed and explained in additional studies using GFR measured with a reference method. [less ▲]

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See detailDiscrepancy between prolactin (PRL) messenger ribonucleic acid and PRL content in rat fetal pituitary cells: possible role of dopamine
Hooghe-Peters, E. L.; Belayew, A.; Herregodts, P. et al

in Molecular Endocrinology (1988), 2(12), 1163-8

Data are controversial concerning the time when PRL-synthesizing cells are detected for the first time in the rat pituitary. Using a very sensitive immunocytochemical technique, we could visualize only a ... [more ▼]

Data are controversial concerning the time when PRL-synthesizing cells are detected for the first time in the rat pituitary. Using a very sensitive immunocytochemical technique, we could visualize only a few PRL cells before day 10 after birth. At that time, pituitary PRL was still 200 times less abundant than in the adult (on a tissue weight basis) whereas PRL mRNA per mg total RNA was only 80 times lower than in the adult. However, by in situ hybridization, we could demonstrate the presence of PRL mRNA in cells from fetal day 18 on. We have also followed the expression of GH gene in rat pituitary cells during development. In contrast to results obtained with PRL cells, quantitative analysis of cDNA probe hybridization to GH mRNA correlated well with measurements of immunostained cells. We found that PRL was released in the blood from fetal day 19 onwards. Thus, at that time PRL is synthesized and secreted but not stored. We therefore measured brain dopamine levels, and the data support the idea that the rise in dopamine levels after birth contributes to PRL storage. We confirmed in vitro that newborn pituitary cells can store PRL when cultured in the presence of dopamine. [less ▲]

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See detailDiscrepancy in hemoglobin A1c results obtained by HPLC and CE: influence of carbamyl HB
Gougnard, Th; Chapelle, Jean-Paul ULg; Charlier, Corinne ULg et al

Poster (1997, October 18)

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See detailA discrete competitive facility location model with variable attractiveness
Kucukaydin, Hande ULg; Aras, Necati; Altinel, I. Kuban

Conference (2009, July 08)

We consider the discrete version of the competitive facility location problem in which new facilities have to be located by a new market entrant to compete against already existing ones that may belong to ... [more ▼]

We consider the discrete version of the competitive facility location problem in which new facilities have to be located by a new market entrant to compete against already existing ones that may belong to one or more competitors. The objective of the firm is to determine the locations of the new facilities and their attractiveness levels to maximize the profit. We formulate a mixed-integer nonlinear programming model for this problem and propose three methods for its solution: a Lagrangean heuristic, two branch-and-bound methods using Lagrangean and nonlinear programming relaxations. [less ▲]

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See detailA discrete competitive facility location model with variable attractiveness
Kucukaydin, Hande ULg; Aras, Necati; Altinel, I. Kuban

in Journal of the Operational Research Society (2011), 62(9), 1726-1741

We consider the discrete version of the competitive facility location problem in which new facilities have to be located by a new market entrant firm to compete against already existing facilities that ... [more ▼]

We consider the discrete version of the competitive facility location problem in which new facilities have to be located by a new market entrant firm to compete against already existing facilities that may belong to one or more competitors. The demand is assumed to be aggregated at certain points in the plane and the new facilities can be located at predetermined candidate sites. We employ Huff’s gravity-based rule in modelling the behaviour of the customers where the probability that customers at a demand point patronize a certain facility is proportional to the facility attractiveness and inversely proportional to the distance between the facility site and demand point. The objective of the firm is to determine the locations of the new facilities and their attractiveness levels so as to maximize the profit, which is calculated as the revenue from the customers less the fixed cost of opening the facilities and variable cost of setting their attractiveness levels. We formulate a mixed-integer nonlinear programming model for this problem and propose three methods for its solution: a Lagrangean heuristic, a branch-and-bound method with Lagrangean relaxation, and another branch-and-bound method with nonlinear programming relaxation. Computational results obtained on a set of randomly generated instances show that the last method outperforms the others in terms of accuracy and efficiency and can provide an optimal solution in a reasonable amount of time. [less ▲]

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See detailDiscrete element modelling approach to assessment of granular properties in concrete
Stroeven, Piet; He, Huan ULg; Stroeven, Martijn

in Journal of Zhejiang University. Science A (2011), 12(5), 335-344

This paper presents the technological relevance of a concurrent algorithm-based discrete element modelling (DEM) system, HADES. This new system is the successor of SPACE that is limited to spherical ... [more ▼]

This paper presents the technological relevance of a concurrent algorithm-based discrete element modelling (DEM) system, HADES. This new system is the successor of SPACE that is limited to spherical grains only. It can realistically simulate the packing of arbitrary-shaped particles up to the fully compacted state. Generation of families of such particles, i.e., generally representing aggregate of fluvial origin and crushed rock, respectively, and the forming way of particulate structure are described. Similarly shaped particles are proposed for simulation of cement paste because of conformity with experimental results obtained by the X-ray tomography method. Technologically relevant territories inside and outside concrete technology are presently explored in this efficient, reliable, and economic way. Some results obtained by this DEM approach are presented. [less ▲]

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