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See detailThe Instability Strip of ZZ Ceti White Dwarfs
Van Grootel, Valérie ULg; Fontaine, G.; Brassard, P. et al

in Astronomical Society of the Pacific Conference Series (in press)

The determination of the location of the theoretical ZZ Ceti instability strip in the log g − Teff diagram has remained a challenge over the years, due to the lack of a suitable treatment for convection ... [more ▼]

The determination of the location of the theoretical ZZ Ceti instability strip in the log g − Teff diagram has remained a challenge over the years, due to the lack of a suitable treatment for convection in these stars. We report here a detailed stability survey over the whole ZZ Ceti regime, including the low and extremely low masses. We computed to this aim 29 evolutionary sequences of DA models with various masses, chemical layering, and core compositions. These models are characterized by the so- called ML2/α=1.0 convective efficiency and take into account the important feedback effect of convection on the atmospheric structure. We computed pulsation spectra for these models with the Liège nonadiabatic pulsation code MAD, which is the only one to conveniently incorporate a full time-dependent convection treatment and, thus, provides the best available description of the blue edge of the instability strip. On the other hand, given the failure of all nonadiabatic codes to account properly for the red edge of the strip, including MAD, we tested the idea that the red edge is due to energy leakage through the atmosphere. Using this approach, we found that our theoretical ZZ Ceti instability strip accounts remarkably well for the boundaries of the empirical strip. [less ▲]

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See detailA First Look at the Nonadiabatic Properties of Pulsating Accreting White Dwarfs of the GW Lib Type
Van Grootel, Valérie ULg; Fontaine, G.; Brassard, P. et al

in Astronomical Society of the Pacific Conference Series (in press)

We present results of a detailed stability survey of the pulsation properties of accreting white dwarfs of the GW Lib type. This is based on several state-of-the- art white dwarf evolutionary sequences ... [more ▼]

We present results of a detailed stability survey of the pulsation properties of accreting white dwarfs of the GW Lib type. This is based on several state-of-the- art white dwarf evolutionary sequences with varying envelope compositions, from pure hydrogen to pure helium. Using the same tools as in Van Grootel et al. (2013), where we have presented the first consistent view of the ZZ Ceti instability strip, we have mapped the GW Lib instability strip over the effective temperature-surface gravity plane, and as a function of envelope composition. We find that the location of the GW Lib instability domain is a strong and continuous function of the assumed envelope composition. We can accomodate all of the known GW Lib pulsators in various strips according to their atmospheric compositions. [less ▲]

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See detailA global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b
Lanotte, Audrey ULg; Gillon, Michaël ULg; Demory, B.-O. et al

in Astronomy and Astrophysics (in press)

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further ... [more ▼]

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims. We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods. We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 {\mu}m. Adding the high precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar effects on the flux variation. Results. We present a refined radius estimate of RP=4.10 +/- 0.16 R_Earth, mass MP=25.4 +/- 2.1 M_Earth and eccentricity e= 0.162 +/- 0.004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 {\mu}m that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 {\mu}m that are shallower than in previous works, in particular at 3.6 {\mu}m. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO2, although perhaps less than previously thought. We find no evidence for a potential planetary companion, stellar activity, nor for a stellar spin-orbit misalignment. [ABRIDGED] [less ▲]

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See detailA review of inversion techniques related to the use of relationship matrices in animal breeding
Faux, Pierre ULg; Gengler, Nicolas ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (in press)

In animal breeding, prediction of genetic effects is usually obtained through the use of mixed models. For any of these genetic effects, mixed models require the inversion of the covariance matrix ... [more ▼]

In animal breeding, prediction of genetic effects is usually obtained through the use of mixed models. For any of these genetic effects, mixed models require the inversion of the covariance matrix associated to that effect, which is equal to the associated relationship matrix times the associated component of the genetic variance. Given the size of many genetic evaluation systems, computing the inverses of these relationship matrices is not trivial. In this review, we aim to cover computational techniques that ease inversion of relationship matrices used in animal breeding for prediction of the following different types of genetic effects: additive effect, gametic effect, effect due to presence of marked quantitative trait loci, dominance effect and different epistasis effects. Construction rules and inversion algorithms are detailed for each relationship matrix. In the final discussion, we draw up a common theoretical frame to most of the reviewed techniques. Two computational constraints come out of this theoretical frame: setting up the matrix of dependencies between levels of the effect and setting up some parts (diagonal or block-diagonal elements) of the relationship matrix to be inverted. [less ▲]

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See detailThe construction of workers’ rights consciousness through legal intermediations: the case of employment discrimination in Belgium
Lejeune, Aude ULg; Orianne, Jean-François ULg

in International Journal of Discrimination and the Law (in press)

Through their different encounters with union, court, and government equality agency lawyers, workers report diverse understandings of their personal experience of injustice in the workplace. This paper ... [more ▼]

Through their different encounters with union, court, and government equality agency lawyers, workers report diverse understandings of their personal experience of injustice in the workplace. This paper examines workers’ experiences of discrimination and the role legal professionals play in litigating these issues in Belgium. Bringing together legal and rights consciousness studies and the sociology of intermediation and tracking different stages in the construction of discrimination cases, from the moment when a future litigant describes an event as an injustice to the moment when the judge recognises a discriminatory behaviour (or conversely, dismisses a case), we suggest several possible empirical explanations of the way in which interactions with legal intermediaries affect workers’ rights consciousness. Because we refer to socio-legal studies from common law countries, this paper also calls into question how best to import these studies to assist in analysing legal mobilisations and legal consciousness in continental Europe. [less ▲]

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See detailThe strength of multi-row models
Louveaux, Quentin ULg; Poirrier, Laurent; Salvagnin, Domenico

in Mathematical Programming Computation (in press)

We develop a method for computing facet-defining valid inequalities for any mixed-integer set PJ. Our practical implementation does not return only facet- defining inequalities, but it is able to find a ... [more ▼]

We develop a method for computing facet-defining valid inequalities for any mixed-integer set PJ. Our practical implementation does not return only facet- defining inequalities, but it is able to find a separating cut whenever one exists. The separator is not comparable in speed with the specific cutting-plane generators used in branch-and-cut solvers, but it is general-purpose. We can thus use it to compute cuts derived from any reasonably small relaxation PJ of a general mixed- integer problem, even when there exists no specific implementation for computing cuts with PJ. Exploiting this, we evaluate, from a computational perspective, the usefulness of cuts derived from several types of multi-row relaxations. In particular, we present results with four different strengthenings of the two-row intersection cut model, and multi-row models with up to fifteen rows. We conclude that only fully-strengthened two-row cuts seem to offer a significant advantage over two-row intersection cuts. Our results also indicate that the improvement obtained by going from models with very few rows to models with up to fifteen rows may not be worth the increased computing cost. [less ▲]

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See detailMollino, Carlo
Prina, Daniela ULg

in Atkinson, Harriet; Kettley, Sarah; Edwards, Clive (Eds.) et al Encyclopedia of Design (in press)

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See detailPolymer topology revealed by ion mobility coupled with mass spectrometry
Morsa, Denis ULg; Defize, Thomas ULg; Dehareng, Dominique ULg et al

in Analytical Chemistry (in press)

Hyperbranched and star shaped polymers have raised tremendous interests because of their unusual structural and photochemical properties which provide them potent applications in various domains, namely ... [more ▼]

Hyperbranched and star shaped polymers have raised tremendous interests because of their unusual structural and photochemical properties which provide them potent applications in various domains, namely in the biomedical field. In this context, the development of adequate tools aiming to probe particular three-dimensional features of such polymers is of crucial importance. In this present work, ion mobility coupled with mass spectrometry was used to experimentally derive structural information related to cationized linear and star-shaped poly-ε-caprolactones as a function of their charge state and chain length. Two major conformations were observed and identified using theoretical modeling: (1) near spherical conformations whose size is invariant with the polymer topology for long and lightly charged chains and (2) elongated conformations whose size varies with the polymer topology for short and highly charged chains. These conformations were further confirmed by collisional activation experiments based on the ejection thresholds of the coordinated cations that vary according to the elongation amplitude of the polymer chains. Finally, a comparison between solution and gas-phase conformations highlights a compaction of the structure with a loss of specific chain arrangements during the ionization and desolvation steps of the electrospray process, fueling the long-time debated question related to the preservation of the analyte structure during the transfer into the mass spectrometer. [less ▲]

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See detailIdentifying Semitic loanwords in Late Egyptian
Winand, Jean ULg

in Dils, Peter; Grossman, Eitan; Richter, Sebastian (Eds.) et al Language Contact and Bilingualism in antiquity: What Linguistic Borrowing into Coptic can tell us about it (in press)

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See detailSapper, Richard
Prina, Daniela ULg

in Atkinson, Harriet; Kettley, Sarah; Edwards, Clive (Eds.) et al Encyclopedia of Design (in press)

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See detailEnjeux de la vannerie dans 1 les aires protégées de Madagascar
Guillaud, Sylvie; Vermeulen, Cédric ULg

in Bois et Forêts des Tropiques (in press)

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See detailDevelopment by the sol–gel process of highly dispersed Ni–Cu/SiO2 xerogel catalysts for selective 1,2-dichloroethane hydrodechlorination into ethylene
Pirard, Sophie ULg; Mahy, Julien ULg; Pirard, Jean-Paul ULg et al

in Microporous and Mesoporous Materials (in press)

Ni–Cu/SiO2 xerogel catalysts have been synthesized by cogelation of industrial tetraethoxysilane (Dynasil) and chelates of Ni and Cu with industrial 3-(2-aminoethylamino)propyltrimethoxysilane (Dynasylan ... [more ▼]

Ni–Cu/SiO2 xerogel catalysts have been synthesized by cogelation of industrial tetraethoxysilane (Dynasil) and chelates of Ni and Cu with industrial 3-(2-aminoethylamino)propyltrimethoxysilane (Dynasylan DAMO) in industrial ethanol denatured with diethyl phthalate. Despite the use of industrial grade reagents, highly dispersed bimetallic Ni–Cu/SiO2 xerogel catalysts were obtained. These samples are composed of completely accessible Ni–Cu alloy crystallites with sizes of 1.6–3.4 nm located inside silica particles exhibiting a monodisperse microporous distribution. It appears that the bimetallic complex acts as a nucleation agent in the formation of silica particles. The combination of results obtained from the calculation of the metal ratio in catalysts, H2 chemisorption and transmission electron microscopy allowed calculating the surface composition of the nickel–copper particles in Ni–Cu/SiO2 cogelled xerogel catalysts. Values obtained indicate a very pronounced surface enrichment with copper. While 1,2-dichloroethane hydrodechlorination over pure nickel mainly produces ethane, increasing copper content in bimetallic catalysts results in an increase in ethylene selectivity. The specific consumption rate of 1,2-dichloroethane decreases when copper loading increases. The turnover frequency, that is, the number of catalytic cycle per active site (nickel atom and its surrounding copper atoms) and per second, seems to be independent of surface composition of alloy particles. [less ▲]

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See detailDes ethnonymes aux glottonymes : enjeux de la nomination des pratiques linguistiques en Louisiane francophone
Urbain, Emilie ULg

in Jean-Michel Eloy (Ed.) Nommer des langues romanes (in press)

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See detailLe rôle du Clergé dans la construction d’un discours « d’autorité » sur la langue en milieu francophone minoritaire : l’exemple de l’Acadie du Nouveau-Brunswick à la fin du 19e siècle
Ali-Khodja, Mourad; Urbain, Emilie ULg

in Remysen, Wim (Ed.) Les français d’ici : du discours d’autorité à la description des normes et des usages (in press)

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See detailIntroduction
de Haro Sanchez, Magali ULg; Tissi, Lucia Maddalena

in de Haro Sanchez, Magali (Ed.) "Écrire la magie dans l'Antiquité - Scrivere la magia nell'Antichità". Actes du colloque international (Liège, 13-15 octobre 2011) (in press)

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See detailNatural killer and dendritic cells collaborate in the immune response induced by the vaccine against uterine cervical cancer.
Langers, Inge ULg; Renoux, Virginie; Reschner, Anca et al

in European journal of immunology (in press)

Virus-like particles (VLPs) of human papillomavirus (HPV) are used as a vaccine against HPV-induced cancer, and recently we have shown that these VLPs are able to activate natural killer (NK) cells. Since ... [more ▼]

Virus-like particles (VLPs) of human papillomavirus (HPV) are used as a vaccine against HPV-induced cancer, and recently we have shown that these VLPs are able to activate natural killer (NK) cells. Since NK cells collaborate with dendritic cells (DCs) to induce an immune response against viral infections and tumors, we studied the impact of this crosstalk in the context of HPV vaccination. NK cells in the presence of HPV-VLPs enhanced DC maturation as shown by an upregulation of CD86 and HLA-DR and an increased production of IL-12p70, but not of the immunosuppressive cytokine IL-10. This activation was bi-directional. Indeed, in the presence of HPV-VLPs, DCs further activated NK cells by inducing the upregulation of cell surface activation markers (CD69 and HLA-DR). The function of NK cells was also improved as shown by an increase in IFN-gamma secretion and cytotoxic activity against an HPV+ cell line. This crosstalk between NK cells and DCs needed CD40 interaction and IL-12p70 secretion, whereas NKG2D was not implicated. Our results provide insight into how VLPs interact with innate immune cells and how NK cells and DCs play a role in the immune response induced by this vaccine agent. This article is protected by copyright. All rights reserved. [less ▲]

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