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See detailWASP-86b and WASP-102b: super-dense versus bloated planets
Faedi, F.; Gómez Maqueo Chew, Y.; Pollacco, D. et al

E-print/Working paper (2016)

We report the discovery of two transiting planetary systems: a super dense, sub-Jupiter mass planet WASP-86b (\mpl\ = 0.82 $\pm$ 0.06 \mj, \rpl\ = 0.63 $\pm$ 0.01 \rj), and a bloated, Saturn-like planet ... [more ▼]

We report the discovery of two transiting planetary systems: a super dense, sub-Jupiter mass planet WASP-86b (\mpl\ = 0.82 $\pm$ 0.06 \mj, \rpl\ = 0.63 $\pm$ 0.01 \rj), and a bloated, Saturn-like planet WASP-102b (\mpl\ = 0.62 $\pm$ 0.04 \mj, \rpl\=1.27 $\pm$ 0.03 \rj). They orbit their host star every $\sim$5.03, and $\sim$2.71 days, respectively. The planet hosting WASP-86 is a F7 star (\teff\ = 6330$\pm$110 K, \feh\ = $+$0.23 $\pm$ 0.14 dex, and age $\sim$0.8--1~Gyr), WASP-102 is a G0 star (\teff\ = 5940$\pm$140 K, \feh\ = $-$0.09$\pm$ 0.19 dex, and age $\sim$1~Gyr). These two systems highlight the diversity of planetary radii over similar masses for giant planets with masses between Saturn and Jupiter. WASP-102b shows a larger than model-predicted radius, indicating that the planet is receiving a strong incident flux which contributes to the inflation of its radius. On the other hand, with a density of $\rho_{pl}$ = 3.24$\pm$~0.3~$\rho_{jup}$, WASP-86b is the densest gas giant planet among planets with masses in the range 0.05 $<M$_{pl}$<$ 2.0 \mj. With a stellar mass of 1.34 M$_{\odot}$ and \feh = $+$0.23 dex, WASP-86 could host additional massive and dense planets given that its protoplanetary disc is expected to also have been enriched with heavy elements. In order to match WASP-86b's density, an extrapolation of theoretical models predicts a planet composition of more than 80\% in heavy elements (whether confined in a core or mixed in the envelope). This fraction corresponds to a core mass of approximately 210\me\ for WASP-86b's mass of \mpl$\sim$260\,\me. Only planets with masses larger than about 2\mj\ have larger densities than that of WASP-86b, making it exceptional in its mass range. [less ▲]

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See detailEvidence of magnetic field decay in massive main-sequence stars
Fossati, L.; Schneider, F. R. N.; Castro, N. et al

in Astronomy and Astrophysics (2016), 592

A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of ... [more ▼]

A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well understood. We compile a catalogue of 389 massive main-sequence stars, 61 of which are magnetic, and derive their fundamental parameters and ages. The two samples contain stars brighter than magnitude 9 in the V-band and range in mass between 5 and 100 M[SUB]⊙[/SUB]. We find that the fractional main-sequence age distribution of all considered stars follows what is expected for a magnitude limited sample, while that of magnetic stars shows a clear decrease towards the end of the main sequence. This dearth of old magnetic stars is independent of the choice of adopted stellar evolution tracks, and appears to become more prominent when considering only the most massive stars. We show that the decreasing trend in the distribution is significantly stronger than expected from magnetic flux conservation. We also find that binary rejuvenation and magnetic suppression of core convection are unlikely to be responsible for the observed lack of older magnetic massive stars, and conclude that its most probable cause is the decay of the magnetic field, over a time span longer than the stellar lifetime for the lowest considered masses, and shorter for the highest masses. We then investigate the spin-down ages of the slowly rotating magnetic massive stars and find them to exceed the stellar ages by far in many cases. The high fraction of very slowly rotating magnetic stars thus provides an independent argument for a decay of the magnetic fields. [less ▲]

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See detailThe Gaia-ESO Survey: pre-main-sequence stars in the young open cluster NGC 3293
Delgado, A. J.; Sampedro, L.; Alfaro, E. J. et al

in Monthly Notices of the Royal Astronomical Society (2016), 460

The young open cluster NGC3293 is included in the observing program of the Gaia-ESO survey (GES). The radial velocity values provided have been used to assign cluster membership probabilities by means of ... [more ▼]

The young open cluster NGC3293 is included in the observing program of the Gaia-ESO survey (GES). The radial velocity values provided have been used to assign cluster membership probabilities by means of a single-variable parametric analysis. These membership probabilities are compared to the results of the photometric membership assignment of NGC3293, based on UBVRI photometry. The agreement of the photometric and kinematic member samples amounts to 65 per cent, and could increase to 70 per cent as suggested by the analysis of the differences between both samples. A number of photometric PMS candidate members of spectral type F are found, which are confirmed by the results from VPHAS photometry and SED fitting for the stars in common with VPHAS and GES data sets. Excesses at mid- and near-infrared wavelengths, and signs of Hα emission, are investigated for them. Marginal presence of Hα emission or infilling is detected for the candidate members. Several of them exhibit moderate signs of U excess and weak excesses at mid-IR wavelengths. We suggest that these features originate from accretion discs in their last stages of evolution. [less ▲]

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See detailEnhancing Cover Song Identification with Hierarchical Rank Aggregation
Osmalsky, Julien ULg; Van Droogenbroeck, Marc ULg; Embrechts, Jean-Jacques ULg

in Proceedings of the 17th International for Music Information Retrieval Conference (2016, August)

Abstract Cover song identification involves calculating pairwise similarities between a query audio track and a database of reference tracks. While most authors make exclusively use of chroma features ... [more ▼]

Abstract Cover song identification involves calculating pairwise similarities between a query audio track and a database of reference tracks. While most authors make exclusively use of chroma features, recent work tends to demonstrate that combining similarity estimators based on multiple audio features increases the performance. We improve this approach by using a hierarchical rank aggregation method for combining estimators based on different features. More precisely, we first aggregate estimators based on global features such as the tempo, the duration, the loudness, the beats, and the average chroma vectors. Then, we aggregate the resulting composite estimator with four popular state-of-the-art methods based on chromas as well as timbre sequences. We further introduce a refinement step for the rank aggregation called “local Kemenization” and quantify its benefit for cover song identification. The performance of our method is evaluated on the Second Hand Song dataset. Our experiments show an significant improvement of the performance, up to an increase of more than 200 % of the number of queries identified in the Top-1, compared to previous results. [less ▲]

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See detailCalcium-Iron Oxide as Energy Storage Medium in Rechargeable Oxide Batteries
Berger, Cornelius M.; Mahmoud, Abdelfattah ULg; Hermann, Raphaël ULg et al

in Journal of the American Ceramic Society (2016)

Rechargeable oxide batteries (ROB) comprise a regenerative solid oxide cell (rSOC) and a storage medium for oxygen ions. A sealed ROB avoids pumping loss, heat loss, and gas purity expenses in comparison ... [more ▼]

Rechargeable oxide batteries (ROB) comprise a regenerative solid oxide cell (rSOC) and a storage medium for oxygen ions. A sealed ROB avoids pumping loss, heat loss, and gas purity expenses in comparison with conventional rSOC. However, the iron oxide base storage medium degrades during charging– discharging cycles. In comparison, CaFe3O5 has improved cyclability and a high reversible oxygen storage capacity of 22.3 mol%. In this study, we analyzed the redox mechanism of this compound. After a solid-state synthesis of CaFe3O5, we verified the phase composition and studied the redox reaction by means of X-ray diffraction, Mossbauer spectrometry, and scanning electron microscopy. Results show a great potential to operate the battery with this storage material during multiple charging–discharging cycles. [less ▲]

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See detailHabitat use of an unstudied Lepilemur in the northwest Madagascar: L. mittermeieri
Wilmet, Leslie ULg; Vermeulen, Cédric ULg; Beudels-Jamar et al

Conference (2016, August)

Biodiversity and endemism is very high in Madagascar and Genus Lepilemur is part of the endemic mammalian fauna of the island. Sportive lemurs have small distribution ranges, fairly small total ... [more ▼]

Biodiversity and endemism is very high in Madagascar and Genus Lepilemur is part of the endemic mammalian fauna of the island. Sportive lemurs have small distribution ranges, fairly small total populations and are particularly negatively affected by deforestation and habitat fragmentation, serious threats for the biological diversity of the island. Our research focus on one poorly-known taxon, Lepilemur mittermeieri. The distribution range of this endangered species is restricted to the Ampasindava peninsula in the northwest Madagascar and ecological information is essential for its preservation. The main objective of our study is to analyze habitat use and niche characteristics of the species and the impact of habitat degradation and fragmentation on these parameters in order to design robust conservation guidelines for the Ampasindava peninsula. In this talk, we will present the project as a whole and results of two 4-months field missions conducted in 2015 and in 2016. These field missions were designed to specifically 1)compare home range size between two sites 2)complete forest characterization of the home range of several radio-collared individuals. The methodology includes the monitoring of 16animals equipped with radio-collar (VHS telemetry) during 6hours per night for a number of days, GPS locations being recorded every 10 minutes. The home range is derived from the telemetry observation through MCP method. [less ▲]

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See detailLes fortifications celtique et carolingienne du Rocher du Vieux-Château à Pont-de-Bonne (Modave, Belgique)
Delye, Emmanuel ULg

Book published by Cercle archéologique Hesbaye-Condroz (2016)

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See detailLa parentalité dans un contexte de violence conjugale : support de résilience ?
Glowacz, Fabienne ULg

Conference (2016, August)

L’accès à la parentalité, quels que soient le contexte social ou conjugal et l’histoire de la femme, s’avère une étape-clé de transition dans la trajectoire personnelle. Le fonctionnement parental est ... [more ▼]

L’accès à la parentalité, quels que soient le contexte social ou conjugal et l’histoire de la femme, s’avère une étape-clé de transition dans la trajectoire personnelle. Le fonctionnement parental est influencé par trois types de facteurs interagissant entre eux : la personnalité du parent (elle-même influencée par son histoire développementale), les caractéristiques individuelles de l'enfant et les sources de soutien et de stress de l'environnement (Belsky,1984).Les recherches sur la parentalité et la résilience se sont principalement centrées sur la résilience des enfants ayant vécu des traumatismes tels que les abus sexuels, où la résilience est activée par la disponibilité et le soutien parental ( Glowacz et Buzitu, 2014). Nos récentes études portant sur les trajectoires de femmes ayant vécu des traumatismes majeurs (violences conjugales, violences de guerre) nous conduisent à considérer l’accès à la parentalité comme un turning point, déclencheur d’un processus de résilience de ces femmes. Des analyses cliniques seront mises en perspective avec des données de recherches ayant évalué le sentiment de compétence parentale (incluant le sentiment d’efficacité et le sentiment de satisfaction), le stress parental et le soutien social perçu de femmes ayant vécu ces traumatismes. Nos observations et résultats nous amènent à questionner la résilience de la mère et les résonances de cette résilience sur l’enfant en développement. [less ▲]

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See detailHigh gene flow between alternative morphs and the evolutionary persistence of facultative paedomorphosis
Oromi Farrús, Neus ULg; Michaux, Johan ULg; Denoël, Mathieu ULg

in Scientific Reports (2016), 6

Paedomorphosis and metamorphosis are two major developmental processes that characterize the evolution of complex life cycles in many lineages. Whereas these processes were fixed in some taxa, they ... [more ▼]

Paedomorphosis and metamorphosis are two major developmental processes that characterize the evolution of complex life cycles in many lineages. Whereas these processes were fixed in some taxa, they remained facultative in others, with alternative phenotypes expressed in the same populations. From a genetic perspective, it is still unknown whether such phenotypes form a single population or whether they show some patterns of isolation in syntopy. This has deep implications for understanding the evolution of the phenotypes, i.e. towards their persistence or their fixation and speciation. Newts and salamanders are excellent models to test this hypothesis because they exhibit both developmental processes in their populations: the aquatic paedomorphs retain gills, whereas the metamorphs are able to colonize land. Using microsatellite data of coexisting paedomorphic and metamorphic palmate newts (Lissotriton helveticus), we found that they formed a panmictic population, which evidences sexual compatibility between the two phenotypes. The high gene flow could be understood as an adaptation to unstable habitats in which phenotypic plasticity is favored over the fixation of developmental alternatives. This makes then possible the persistence of a polyphenism: only metamorphosis could be maintained in case of occasional drying whereas paedomorphosis could offer specific advantages in organisms remaining in water. [less ▲]

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See detailNarrowing the science/policy gap for environmental management
Hughes, Kevin A; Liggett, Daniela; Roldan, Gabriela et al

in Antarctic Science (2016), 28(5), 325

Antarctic terrestrial and marine environments are under increasing pressure from national operator activities, tourism and climate change. The Protocol on Environmental Protection to the Antarctic Treaty ... [more ▼]

Antarctic terrestrial and marine environments are under increasing pressure from national operator activities, tourism and climate change. The Protocol on Environmental Protection to the Antarctic Treaty provides overarching legislation concerning the environmental management of the Treaty area, with 2016 marking the Protocol’s 25th anniversary. The Protocol also established the Committee for Environmental Protection (CEP) to provide advice to the Antarctic Treaty Consultative Meeting (ATCM) on environmental matters. Today, the CEP’s Five-Year Work Plan and Climate Change Response Work Programme lists and prioritises issues that need to be addressed to ensure impacts in Antarctica by human activities are both recognized andminimised.Despite all of this, recent evaluations have suggested that a slow pace of environmental policy development presents a significant threat to effective Antarctic conservation. Progress on many environmental issues, including wildlife disturbance, the conservation status of Antarctic species, area protection and pollution management, is glacial or has stalled completely. Whilst in some cases capacity issues concerning those responsible for Antarctic environmental policy work may be a contributing factor, the level of interaction between researchers and those responsible for environmental management and decision-making is also of importance. Without quality science - and effective interpretation of research results - policymakers have little evidence on which to base their decisions. But researchers need to know policymakers’ needs. Two-way communication is essential: policymakers could ask the research community to answer specific environmental questions, and, in turn, researchers could present evidence-based recommendations and highlight emerging threats. But how is this to be funded? Ultimately, effective communication is needed between national government departments responsible for funding Antarctic research and those dealing with Antarctic environmental protection. Hopefully, this will ensure essential research informing environmental policy decisions is adequately resourced. In reality, the cost is likely to be trivial compared with the resources spent by Parties on Antarctic logistics. [less ▲]

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See detailLocal modulation of human brain responses by circadian rhythmicity and sleep debt
Muto, Vincenzo ULg; Jaspar, Mathieu ULg; Meyer, Christelle et al

in Science (2016), 351(6300),

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See detailRelationship between frailty, physical performance and quality of life among nursing home residents: the SENIOR cohort
Buckinx, Fanny ULg; Reginster, Jean-Yves ULg; Petermans, Jean ULg et al

in Aging Clinical and Experimental Research (2016), Epub ahead of print

Background The aim of this study was to assess the relationship between frailty and a large number of indicators related to physical and muscular performance as well as quality of life. Methods This is an ... [more ▼]

Background The aim of this study was to assess the relationship between frailty and a large number of indicators related to physical and muscular performance as well as quality of life. Methods This is an analysis of data collected at baseline in the Sample of Elderly Nursing home Individuals: an Observational Research (SENIOR) cohort including nursing home residents. Subjects are volunteer, oriented and able to walk (walking assistance allowed) nursing home residents in Belgium. A large number of demographic and clinical characteristics, including physical and muscular performance, were collected from each patient. The prevalence of frailty in this population was assessed using Fried’s definition. Results In total, 662 subjects are included in this analysis. The mean age of the sample is 83.2 ± 8.99 years, and 484 (73.1 %) are women. In this population of nursing home residents, the prevalence of frailty is 25.1 %, pre-frailty, 59.8 % and robustness, 15.1 %. Compared to non-frail subjects, frail subjects have lower physical and muscular performances and a lower quality of life. Conclusion Frailty, according to Fried’s definition, seems to be associated with several clinical indicators suggesting a higher level of disability and an increased propensity to develop major clinical consequences. Follow-up data of the SENIOR cohort will be helpful in confirming these findings, establishing cause–effect relationships and identifying the most predictive components of physical frailty for adverse outcomes in nursing homes. [less ▲]

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See detailHorner syndrome in children: a clinical condition with serious underlying disease
Barrea, Christophe ULg; Vigouroux, Tiphaine ULg; Karam, Joe ULg et al

in Neuropediatrics (2016), 47(4), 268-272

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See detailQuel effet cela fait, de mordre dans un citron?
Dewalque, Arnaud ULg; Gauvry, Charlotte ULg

Article for general public (2016)

Le thème de la conscience a connu un regain d’intérêt spectaculaire, ces dernières années, chez les philosophes et les scientifiques. Des théories nouvelles ont vu le jour dans l’espoir de rendre compte ... [more ▼]

Le thème de la conscience a connu un regain d’intérêt spectaculaire, ces dernières années, chez les philosophes et les scientifiques. Des théories nouvelles ont vu le jour dans l’espoir de rendre compte de « l’effet que cela fait », par exemple, de tomber amoureux, de se faire mal ou de… mordre dans un citron. Contrairement à une conception populaire, de nombreux chercheurs ont suggéré que ressentir quelque chose équivalait en réalité à se représenter quelque chose. L’ouvrage "Conscience et représentation. Introduction aux théories représentationnelles de l’esprit" (Paris, Vrin, 2016) dresse un état des lieux des controverses liées à cette question. [less ▲]

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See detailInference in a stochastic SEIR model using Sequential Monte Carlo methods
Bonou, Wilfried ULg; LAMBERT, Philippe

in The 37th Annual Conference of the International Society for Clinical Biostatistics (ISCB): Book of Abstracts. Birmingham, UK, 21-25 August 2016 (2016, August)

Many biological, physical, chemical, economic, and social phenomena are dynamic and are modeled using (systems of) Ordinary Differential Equations (ODEs). But a more realistic way to describe these ... [more ▼]

Many biological, physical, chemical, economic, and social phenomena are dynamic and are modeled using (systems of) Ordinary Differential Equations (ODEs). But a more realistic way to describe these dynamics relies on Discrete Time Markov Chains (DTMC). There is a growing interest in the development of Bayesian statistical methods to infer on the parameters in such dynamic models, particularly those defining epidemic spread, by combining prior information with experimental or observational data. Our proposal aims to explore the merits of the Bayesian Optimal Filtering technique in the estimation of the parameters of a stochastic SEIR (S = Susceptible, E = Exposed, I = Infectious, R = Removed) epidemic model. State Space Models (SSMs) are used to describe the epidemic dynamic. The unknown static parameters are estimated using a combination of Sequential Monte Carlo techniques with a Markov Chain Monte Carlo algorithm, . . . [less ▲]

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See detailHigh selfing rate, limited pollen dispersal and inbreeding depression in the emblematic African rain forest tree Baillonella toxisperma - Management implications
Duminil, Jérôme; Mendene Abessolo, D. T.; Ndiade Bourobou, D. et al

in Forest Ecology & Management (2016), 379

Mating system and gene flow are major influencing factors of species population dynamics and evolution. These factors are often not characterized in tropical tree species, yet they constitute basic ... [more ▼]

Mating system and gene flow are major influencing factors of species population dynamics and evolution. These factors are often not characterized in tropical tree species, yet they constitute basic information that must be considered to implement sustainable management practices. In particular, as logging implies a reduction of the density of congeneric mates, the connectivity through pollination between individuals has to be well characterized (selfing versus outcrossing rates, distances between mates). We conducted a genetic-based analysis (using 10 nuclear microsatellites) to determine the mating system and gene flow characteristics of an emblematic timber tree species from lowland rain forests of the Congo Basin, Baillonella toxisperma (Sapotaceae). The species, which is frequently exploited for its wood and for a number of non-timber forest products, naturally occurs at low densities (ca. 0.01–0.1 individuals/ha). It is supposedly an entomophilous species whose seeds are probably dispersed by mammals. We have shown that the species presents a mixed-mating system (about 20–40% of selfing depending on analysis method). However, the comparison of inbreeding parameters among cohorts suggests that inbred individuals die between seedling and mature tree stages. The mean pollen dispersal distance was relatively low for such a low-density population species (estimated to be 690 or 777 m depending on analysis method) and, together with a low mean number of pollen donors (NEP = 2.76), it suggests a pattern of nearest-neighbour mating where allo-pollen could be a limiting factor. However, B. toxisperma presents a relatively weak genetic structure (Sp statistic = 0.0095) indicative of long gene dispersal distance (rg = 3–5 km according to the assumed effective population density). Overall, this would indicate that gene flow occurs mainly by extensive seed dispersal in this species. These results suggest that mammals and local populations involved in the dispersal of the species play a key role by lowering biparental inbreeding effects. Sustainable population management might require assisted regeneration using unrelated planting material. [less ▲]

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See detailComputational modelling of local calcium ions release from calcium phosphate-based scaffolds
Manhas, Varun ULg; Guyot, Yann; Kerckhofs, Greet et al

in Biomechanics & Modeling in Mechanobiology (2016)

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See detailEvolution of biological innovations in early complex cells
Javaux, Emmanuelle ULg

Conference (2016, August)

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See detailInfluence of cracks on the stiffness of timber structural elements
Mergny, Elke ULg; Mateo, Raquel; Esteban, Miguel et al

Scientific conference (2016, August)

Cracks in timber structural elements lead users to downgrade them, while their influence on the mechanical properties is globally unknown. They are thus disadvantageous and responsible for an ... [more ▼]

Cracks in timber structural elements lead users to downgrade them, while their influence on the mechanical properties is globally unknown. They are thus disadvantageous and responsible for an underutilization of timber in new constructions. The phenomenon also impacts constructions subjected to transformation or renovation that are most of the time fully replaced, simply because of the ignorance of their bearing capacity. The present paper investigates the influence of cracks on stiffness, by analytical and numerical developments. It proposes a classification of cracks in six types (+ composite types) and models real beams, randomly cracked. It shows that the presence of cracks seems to decrease the stiffness of the beam. However, it is not so obvious to give the most damaging type of crack, among the six proposed. Further investigations will be necessary. [less ▲]

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