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See detailThe mysterious Of?p class and the magnetic O-star theta(1) Ori C: Confronting observations
Nazé, Yaël ULg; Walborn, Nolan R.; Martins, Fabrice

in Revista Mexicana de Astronomía y Astrofísica (2008), 44(2), 331-340

In recent years, the stars of the Of?p category have revealed a wealth of peculiar phenomena: varying line profiles, photometric changes, and X-ray over-luminosity are only a few of their characteristics ... [more ▼]

In recent years, the stars of the Of?p category have revealed a wealth of peculiar phenomena: varying line profiles, photometric changes, and X-ray over-luminosity are only a few of their characteristics. Here we review their physical properties to facilitate comparisons among the Galactic members of this class. As one of them his been proposed to resemble the magnetic oblique rotator theta(1) Ori C, though with a longer period, this latter object is also included in our study to illuminate its similarities and differences with the Of?p category. [less ▲]

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See detailChandra monitoring of the very massive binary WR20a and the young massive cluster Westerlund 2
Nazé, Yaël ULg; Rauw, Grégor ULg; Manfroid, Jean ULg

in Astronomy and Astrophysics (2008), 483(1), 171-182

Context. Westerlund 2 is a young and massive, obscured stellar cluster of our Galaxy. It harbors the most massive star with well-determined parameters, WR20a (82 + 83 M-circle dot), a dozen very early O ... [more ▼]

Context. Westerlund 2 is a young and massive, obscured stellar cluster of our Galaxy. It harbors the most massive star with well-determined parameters, WR20a (82 + 83 M-circle dot), a dozen very early O-type stars (O3-7), and a wealth of PMS stars. Although of clear significance, this star cluster has not been well-studied. Aims. The high-energy properties of this cluster, especially those of its early-type stars are examined in detail. The variability of the X-ray sources is investigated. Methods. A monitoring of the field was performed using three Chandra observations. This dataset probes daily as well as monthly to yearly timescales and provides the deepest X-ray view of the cluster to date. Results. The two Wolf-Rayet stars WR20a (WN6ha+WN6ha) and WR20b (WN6ha) were analyzed in detail. They are both luminous and display hard spectra, but WR20b does not appear to vary. In contrast, WR20a, a known eclipsing, colliding-wind binary, brightens in the X-ray domain during eclipses, i.e. when the collision is seen face-on. This can be explained by the properties of the wind-wind collision zone, whose high density leads to a large absorbing column (2 x 10(24) cm(-2)). All twelve O-type stars previously classified spectroscopically, two eclipsing binaries previously identified and nine newly-identified, O-type star candidates are detected in the high-energy domain; ten of those could be analyzed spectroscopically. Four are overluminous, but the others have typical LX/LBOL ratios, suggesting that several O-type objects are actually binaries. Variability at the similar to 2 sigma level is detected for a majority of the sources, of unknown origin for single objects. Faint, soft, diffuse emission pervades the entire field-of-view but no clear structure can be identified, even at the position of a blister proposed to correspond to the TeV source HESS J1023-575. The X-ray properties of PMS objects, in particular the brightest flaring ones, are also investigated. They provided an additional argument in favor of a large distance (similar to 8 kpc) for the cluster. [less ▲]

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See detailHD 148937: A multiwavelength study of the third galactic member of the Of?p class
Nazé, Yaël ULg; Walborn, Nolan R.; Rauw, Grégor ULg et al

in Astronomical Journal (The) (2008), 135(5), 1946-1957

Three Galactic O-type stars belong to the rare class of Of? p objects: HD 108, HD 191612, and HD 148937. The first two stars show a wealth of phenomena, including strong X-ray emission, light variability ... [more ▼]

Three Galactic O-type stars belong to the rare class of Of? p objects: HD 108, HD 191612, and HD 148937. The first two stars show a wealth of phenomena, including strong X-ray emission, light variability, and dramatic periodic spectral variability. We present here the first detailed optical and X-ray study of the third Galactic Of? p star, HD 148937. Spectroscopic monitoring has revealed low-level variability in the Balmer and He II lambda 4686 lines, but constancy at He I and C III lambda 4650. The H alpha line exhibits profile variations at a possible periodicity of similar to 7 days. Model atmosphere fits yield T-eff = 41000 +/- 2000 K, log(g) = 4.0 +/- 0.1, M-sph less than or similar to 10(-7) M-circle dot yr(-1), and an overabundance of nitrogen by a factor of 4. At X-ray wavelengths, HD 148937 resembles HD 108 and HD 191612 in having a thermal spectrum dominated by a relatively cool component (kT = 0.2 keV), broad lines (>= 1700 km s(-1)), and an order-of-magnitude overluminosity compared to normal O stars (log[L-X(unabs) / L-BOL]similar to -6). [less ▲]

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See detailEvaluation de la fonction renale: une actualisation.
Froissart, Marc; Delanaye, Pierre ULg; Seronie-Vivien, Sophie et al

in Annales de Biologie Clinique (2008), 66(3), 269-75

During the last years, GFR estimation has received substantial attention with a focus on comparing results of new formulas with GFR measurements, and standardization of creatinine assays. Calibration of ... [more ▼]

During the last years, GFR estimation has received substantial attention with a focus on comparing results of new formulas with GFR measurements, and standardization of creatinine assays. Calibration of creatinine should improve performances. However, frequently used equations have lower precision in high GFR populations. This is the reason why a continuous effort in improving predicting equations is still needed. The use of calibrated creatinine, the onset of new GFR markers such as cystatin C, and pooling data across many study populations are underway to develop better prediction. [less ▲]

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See detailReproducibility of GFR measured by chromium-51-EDTA and iohexol.
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Froissart, Marc et al

in Nephrology Dialysis Transplantation (2008), 23(12), 4077-84078

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See detailCalcium chez les patients hemodialyses : calcemie totale ou calcium ionise ? Le laboratoire doit-il systematiquement fournir au clinicien une valeur de calcemie totale corrigee obtenue par calcul ?
Monfort, Mélanie ULg; Delanaye, Pierre ULg; Chapelle, Jean-Paul ULg et al

in Annales de Biologie Clinique (2008), 66(5), 573-6

Ionized calcium is the only physiologically active form of calcium. Because of the variation of albumin, pH and haemoconcentration observed during haemodialysis session in patients with chronic renal ... [more ▼]

Ionized calcium is the only physiologically active form of calcium. Because of the variation of albumin, pH and haemoconcentration observed during haemodialysis session in patients with chronic renal failure, measure of total calcium does not reflect the real variation of ionized calcium. However, many formulae to correct total calcium by albumin have been proposed but none of them has been validated in dialysis patients. At present time, computing progress permit laboratory to systematically provide a value of corrected total calcium on protocols but is it really indicated? Our results showed that any of those formulae allows obtaining a value of total calcium that possesses a significant critical difference in relation to total calcium. Thus, correction formulae must be abandoned in aid of ionized calcium in haemodialysis patients. [less ▲]

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See detailActualite sur les effets de la vitamine D et l'evaluation du statut vitaminique D.
Souberbielle, Jean-Claude; Prié, Dominique; Courbebaisse, Marie et al

in Annales d'Endocrinologie (2008), 69(6), 501-10

Knowledge about vitamin D has greatly improved during the last few years. Vitamin D cannot any more be considered as exclusively necessary to prevent ricket/osteomalacia. Its role in the prevention of ... [more ▼]

Knowledge about vitamin D has greatly improved during the last few years. Vitamin D cannot any more be considered as exclusively necessary to prevent ricket/osteomalacia. Its role in the prevention of some osteoporotic fractures in the elderly (in association with calcium nutrition) is now well demonstrated and many epidemiologic and laboratory data argue for a role in the prevention of several diseases or anomalies (cancer, auto-immune diseases, cardiovascular events, sarcopenia...). A few intervention studies confirming some of these effects also exist. Vitamin D status can easily be assessed by measuring serum 25 hydroxy vitamin D (25OHD) level. However, many experts have claimed that the population-based reference values for 25OHD are too low and that the cut-off value below which vitamin D insufficiency can be present is somewhere between 20 and 40ng/mL with a clear tendency to target values above 30ng/mL (75nmol/L). The main consequences are that vitamin D insufficiency is highly frequent whereas the currently recommended supplementation doses are not sufficient. [less ▲]

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See detailVitamine D2 ou vitamine D3?
Mistretta, Virginie ULg; Delanaye, Pierre ULg; Chapelle, Jean-Paul ULg et al

in Revue de Médecine Interne (2008), 29(10), 815-20

PURPOSE: Nearly one billion people around the world are deficient in vitamin D and need to be supplemented. Vitamin D is available in medicines and fortified foods. It is available in two forms: vitamin ... [more ▼]

PURPOSE: Nearly one billion people around the world are deficient in vitamin D and need to be supplemented. Vitamin D is available in medicines and fortified foods. It is available in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). KEY POINTS: The pharmacopeiae consider these steroid hormones as equivalent and interchangeable. However, several studies have showed that serum level of 25(OH)D is increased more effectively with vitamin D3 than vitamin D2. Vitamin D2 has shorter plasma half-life and a lower affinity for the vitamin D binding protein, the hepatic vitamin D hydroxylase and the vitamin D receptor. CONCLUSION: Vitamin D2 should not be regarded anymore as suitable for supplementation or fortification. Currently though, it is still the most used in some countries such as Portugal and Australia. [less ▲]

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See detailLa carence en vitamine d chez les femmes enceintes en region liegeoise: un probleme meconnu.
Cavalier, Etienne ULg; Delanaye, Pierre ULg; Morreale, Alessandro et al

in Revue Médicale de Liège (2008), 63(2), 87-91

We have evaluated the prevalence of the 25-hydroxy vitamin D (25VTD) deficiency in recently pregnant women and new mothers in the area of Liege, Belgium. The study took place in November 2006. Twenty four ... [more ▼]

We have evaluated the prevalence of the 25-hydroxy vitamin D (25VTD) deficiency in recently pregnant women and new mothers in the area of Liege, Belgium. The study took place in November 2006. Twenty four women who underwent a positive pregnancy test and 65 new mothers were enrolled. The level of 25VTD did not differ between the two groups. Only 12% of the pregnant women and 14% of the new mothers (>12 ng/ml) had an optimal level of 25VTD (>30 ng/ ml). We also observed a severe 25VTD deficiency in 21% of pregnant women and 32% of new mothers. Our results showed that more than 80% of pregnant women and new mothers in the area of Liege presented a deficiency in 25VTD. In Belgium, daily vitamin supplementation of pregnant women is common, but the level of vitamin D3 concentration range from 10 microg (400 UI) to zero microg. In our area, vitamin D production in the skin is not always important enough to achieve optimal levels. Our data show that vitamin D supplementation of pregnant women is not enough and that 25VTD deficiency is not diagnosed in this high-risk population. Children born from deficient mothers will present a higher risk of suffering from bone mineral diseases as well as other pathologies, as type 1 diabetes or neurological disorders. Of course, this insufficiency will also have an impact on mother's bone reserve, but these mothers will also be at higher risk for preeclampsia. [less ▲]

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See detailMisdiagnosis of vitamin D insufficiency in subjects who received vitamin D2
Cavalier, Etienne ULg; Wallace, Andrew Michael; Mistretta, Virginie ULg et al

in Clinical Chemistry (2008), 54(6), 110

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See detailVaccinia virus lacking the Bcl-2-like protein N1 induces a stronger natural killer cell response to infection.
Jacobs, Nathalie ULg; Bartlett, Nathan W; Clark, Richard H et al

in Journal of General Virology (The) (2008), 89(Pt 11), 2877-81

The vaccinia virus (VACV) N1 protein is an intracellular virulence factor that has a Bcl-2-like structure and inhibits both apoptosis and signalling from the interleukin 1 receptor, leading to nuclear ... [more ▼]

The vaccinia virus (VACV) N1 protein is an intracellular virulence factor that has a Bcl-2-like structure and inhibits both apoptosis and signalling from the interleukin 1 receptor, leading to nuclear factor kappa B activation. Here, we investigated the immune response to intranasal infection with a virus lacking the N1L gene (vDeltaN1L) compared with control viruses expressing N1L. Data presented show that deletion of N1L did not affect the proportion of CD4+ and CD8+ T cells infiltrating the lungs or the cytotoxic T-cell activity of these cells. However, vDeltaN1L induced an increased local natural killer cell activity between days 4 and 6 post-infection. In addition, in the absence of N1 the host inflammatory infiltrate was characterized by a reduced proportion of lymphocytes bearing the early activation marker CD69. Notably, there was a good correlation between the level of CD69 expression and weight loss. The implications of these findings are discussed. [less ▲]

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See detailExperimental dissociations between memory measures: Influence of retrieval strategies.
Willems, Sylvie ULg; Van der Linden, Martial

in Consciousness & Cognition (2008)

The objective of this study was to explore the participants' processing strategies on the mere exposure effect, object decision priming and explicit recognition. In Experiments 1, we observed that ... [more ▼]

The objective of this study was to explore the participants' processing strategies on the mere exposure effect, object decision priming and explicit recognition. In Experiments 1, we observed that recognition and the mere exposure effect for unfamiliar three-dimensional objects were not dissociated by plane rotations in the same way as recognition and object decision priming. However, we showed that, under identical conditions, prompting analytic (part-based) processing at testing produced a large plane rotation effect on recognition and the mere exposure effect similar to that observed for object decision priming (Experiment 2). Furthermore, inducing a non-analytic (whole-based) processing strategy at testing produced a reduced plane rotation effect on recognition and object decision (Experiments 3 and 4), similar to that observed for the mere exposure effect. These findings suggest that participants' processing strategies influence performance on the three tasks. [less ▲]

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See detailBaulicher Brandschutz
Schneider, Ulrich; Franssen, Jean-Marc ULg; Lebeda, Christian

Book published by Bauwerk Verlag, GmbH - 2nd edition (2008)

This book contains: fire safety concepts as a base for fire safety of building constructions; fire safety requirements ; etc

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See detailLe syndrome métabolique, physiopathologie et traitement
Scheen, André ULg

in Athérosclérose, athérothrombose. Quoi de neuf? (2008)

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See detailUnitarisation and black-disk limit at the LHC in the presence of a hard pomeron
Cudell, Jean-René ULg; Selyugin, Oleg Viktorovich

in Physics Letters B (2008), 662(5), 417-423

Recent models of soft diffraction include a hard pomeron pole besides the usual soft term. Such models violate the black-disk limit around Tevatron energies, so that they need to be supplemented by a ... [more ▼]

Recent models of soft diffraction include a hard pomeron pole besides the usual soft term. Such models violate the black-disk limit around Tevatron energies, so that they need to be supplemented by a unitarisation scheme. Two standard schemes are considered in this Letter, and we show that they lead to an uncertainty at the LHC much larger than previously estimated. We also examine the signature of unitarisation on various small-t observables, the slope in t of the elastic cross section, or the ratio of the real to imaginary parts of the scattering amplitude, and show that the existence of a unitarised hard pomeron in soft scattering may be confirmed by LHC data. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailDineren onder vrienden (en rivalen). Literaire prijzen, netwerken en consecratiestrategieën
Dozo, Björn-Olav ULg; Lacroix, Michel

in Freespace Nieuwzuid (2008), 32

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