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See detailH0LiCOW - III. Quantifying the effect of mass along the line of sight to the gravitational lens HE 0435-1223 through weighted galaxy counts★
Rusu, Cristian E.; Fassnacht, Christopher D.; Sluse, Dominique ULg et al

in Monthly Notices of the Royal Astronomical Society (2017), 467

Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence κ[SUB]ext[/SUB ... [more ▼]

Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence κ[SUB]ext[/SUB] for this system. We measure the under/overdensity of the line of sight towards the lens system and compare it to the average line of sight throughout the Universe, determined by using the CFHTLenS (The Canada France Hawaii Lensing Survey) as a control field. Aiming to constrain κ[SUB]ext[/SUB] as tightly as possible, we determine under/overdensities using various combinations of relevant informative weighting schemes for the galaxy counts, such as projected distance to the lens, redshift and stellar mass. We then convert the measured under/overdensities into a κ[SUB]ext[/SUB] distribution, using ray-tracing through the Millennium Simulation. We explore several limiting magnitudes and apertures, and account for systematic and statistical uncertainties relevant to the quality of the observational data, which we further test through simulations. Our most robust estimate of κ[SUB]ext[/SUB] has a median value κ^med_ext = 0.004 and a standard deviation σ[SUB]κ[/SUB] = 0.025. The measured σ[SUB]κ[/SUB] corresponds to 2.5 per cent relative uncertainty on the time delay distance, and hence the Hubble constant H[SUB]0[/SUB] inferred from this system. The median κ^med_ext value varies by ˜0.005 with the adopted aperture radius, limiting magnitude and weighting scheme, as long as the latter incorporates galaxy number counts, the projected distance to the main lens and a prior on the external shear obtained from mass modelling. This corresponds to just ˜0.5 per cent systematic impact on H[SUB]0[/SUB]. The availability of a well-constrained κ[SUB]ext[/SUB] makes HE 0435-1223 a valuable system for measuring cosmological parameters using strong gravitational lens time delays. [less ▲]

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See detailAgression sexuelle lors d’un conflit dans les relations amoureuses : Un statut spécifique
Courtain, Audrey ULg; Glowacz, Fabienne ULg

Poster (2017, June 01)

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension ... [more ▼]

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension sexuelle. Il s’inscrit dans la continuité du CTS-2 (Conflict Tactics Scale ; Strauss et al., 1996) utilisé dans le cadre des violences conjugales, ces deux outils ayant été conçus sur base de la théorie du conflit. Or, celle-ci postule que « conflict is an inevitable part of human association, whereas violence as a tactic to deal with conflict is not. » (Strauss et al., 1996, p.284). Ainsi, agresser sexuellement sa petite amie ou son petit ami, est-ce du ressort d’un contexte conflictuel, ou bien de la violence sexuelle : quelle en est la spécificité ? Méthodologie : Deux versions du CADRI ont été administrées en passation groupale à des étudiants (N>200, 15-23 ans) en Belgique francophone : la première étant une version modifiée où la consigne introductive ne circonscrivait pas les items de violence à du conflit, la seconde étant la version-type délimitant les items de violence à un contexte de conflit. Résultats : Les scores diffèrent selon la version-type et la version modifiée du CADRI, et selon que nous nous situons sur le versant de la perpétration ou de la victimisation sexuelle, ainsi que selon le sexe des répondants. Discussion : Alors que l’importance des consignes introductives est globalement reconnue, l’implication conceptuelle de certaines est loin d'être négligeable pour la description, la compréhension et la prévention de l'agression sexuelle comme VRA. [less ▲]

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See detailThe acquisition of nouns in children with Specific Language Impairment
Krzemien, Magali ULg; Thibaut, Jean-Pierre; Zghonda, Hela ULg et al

Poster (2017, June 01)

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor ... [more ▼]

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor auditory deficit (Leonard, 2014). A difficulty linked to SLI is the poor language productivity and the input dependency that children display compared with their peers: they tend to use a limited variety of verbal forms compared to younger siblings (Conti-Ramsden & Jones, 1997) and use a high proportions of the same verbs as their mothers (Jones & Conti-Ramsden, 1997). Recent studies suggested that these disorders could be linked to a deficit in generalizing constructions (constructions being units of language that vary in complexity and abstractness, Tomasello, 2009) from the input (Leroy et al., 2013). Specifically, some authors proposed that children with SLI would need more exemplars to abstract a given construction from the input and apply it to new instances (Leroy et al., 2013). In this study, we want to broaden this assumption to the acquisition of words: we evaluated the ability of children with SLI to generalize novel words, and in particular relational words. SLI seem indeed to be linked to an impairment in the processing of relations: children with SLI have poorer performance than their age-matched peers in linguistic or non-linguistic analogical tasks, which require to reason about relational structures (Leroy et al., 2014). We draw the hypothesis that children with SLI would need more exemplars in order to generalize words compared to age-matched but also to language-matched peers. We created a novel word extension task to improve this hypothesis: the first part is composed with nine test trials, each associated with a non-word. The child sees one, two, or three exemplars of a novel noun in short animations. The examiner tells him: “This is a /dyfɑ̃/”. Then, the child sees three other animations and the examiner says: “Show me which one of these is a /dyfɑ̃/”. The child has to choose the object that plays the same role as the exemplars among two distractors: an object that looks like one of the exemplar and a non-related distractor. The second part of the task is based on the same protocol but the exemplars are objects that have a specific spatial configuration (like symmetry). Here again, the child sees one, two, or three exemplars of a novel noun associated with the objects. The examiner tells him: “This is a /fegɑ̃/”. Then, the child sees three other objects and the examiner says: “Show me which one of these is a /fegɑ̃/”. The distractors are an object that has the same global form as one of the exemplar but without having the specific configuration required, and the non-related distractor. The participants are 20 children diagnosed with SLI aged from 6 to 12 years-old. Each child is match to a control child in age and non-verbal IQ on the one hand, and to a control child in linguistic age (based on a measure of vocabulary comprehension). Results show that children are better able to extend relational words when presented with several referents of these words, which confirms what has already been found in other experiments (Gentner, 2005). When the feature to be used is a spatial relation between the parts of the objects, children with SLI have more difficulties than age-matched controls extending new words, which confirms that SLI is linked to an impairment in the processing of relations and a greater dependance on perceptual information (Leroy et al., 2014). They also tend to benefit more than age-matched children from the presentation of several referents of a new word in order to extend it, what would mean that they greatly benefit from comparison and variability in order to identify relational similarities. It would be interesting to see if children can learn from several items that relational feature can be pertinent to define categories and extend words, as young children without SLI can do it with shape while children with SLI cannot (Collinson et al., 2015). [less ▲]

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See detailExploration des processus de recollection et de familiarité chez des patients présentant une plainte mnésique : Une étude longitudinale
Simon, Jessica ULg; Collette, Fabienne ULg; Salmon, Eric ULg et al

Poster (2017, June 01)

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la ... [more ▼]

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la familiarité. En effet, certaines études suggèrent une altération précoce de ce processus, alors que d’autres montrent une préservation de celle-ci. Dans ce cadre, nous avons exploré l'impact du type de format de reconnaissance et du matériel sur la recollection et la familiarité chez des patients qui se plaignent de leur mémoire. Nous avons recruté 23 participants âgés contrôles, 9 patients présentant un trouble subjectif de la mémoire (SCI) et 23 patients présentant un trouble cognitif léger (TCL). Les participants ont réalisé une tâche de reconnaissance à choix forcé à deux alternatives et une tâche de reconnaissance Oui-Non incluant des images et des mots. Ces tâches étaient suivies d’une courte évaluation neuropsychologique. Quinze participants âgés contrôles et 23 patients ont participé au suivi, incluant une évaluation neuropsychologique, dans un délai moyen de 21 mois. Nos résultats montrent qu’à l’inclusion, les patients avec TCL avaient des performances moindres en reconnaissance que les deux autres groupes, qui ne différaient pas. De même, ces patients utilisaient moins efficacement la recollection et la familiarité par rapport aux contrôles et aux SCI, qui présentaient des performances similaires. Il n’y avait aucune interaction entre le groupe et le type de format ou le matériel. Lors du suivi, cinq patients avec TCL ont retrouvé un niveau d’efficience cognitive dans la norme et ont été considérés comme des SCI car les plaintes mnésiques étaient toujours présentes. Sur la base de l'adaptation française du test de rappel libre et indicé (RLRI-16), nous avons calculé une pente de déclin mnésique pour chacun de nos patients. Nous avons observé que les indices de recollection et de familiarité étaient expliqués par les pentes de déclin calculées sur le nombre total d’items rappelés librement. Ainsi, nous avons observé un déclin de la recollection et la familiarité dans le groupe de TCL mais pas dans celui des SCI, bien que les deux groupes se plaignent de leur mémoire. En outre, l'efficacité de la familiarité pourrait prédire un déclin cognitif futur. [less ▲]

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See detailState, Church, Censorship and Culture in Brussels in Mid-Sixteenth Century
Adam, Renaud ULg; Delfosse, Annick ULg

Scientific conference (2017, June 01)

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See detailWaste Heat Recovery by Means of Organic Rankine Cycle (ORC) System Coupled with Two-Phase Closed Thermosyphons
Le, Van Long ULg; Declaye, Sébastien ULg; Dumas, Xavier et al

in International Journal of Thermodynamics (2017)

This paper aims at assessing the performance of a waste heat-to-power plant by means of an ORC (Organic Rankine Cycle) system coupled with two-phase closed thermosyphons (or gravity-assisted heat pipes or ... [more ▼]

This paper aims at assessing the performance of a waste heat-to-power plant by means of an ORC (Organic Rankine Cycle) system coupled with two-phase closed thermosyphons (or gravity-assisted heat pipes or wickless heat pipes). The heat exchanger, made up of two-phase closed thermosyphons, is used for conveying heat from exhaust stream to ORC working fluid. In reality, a hot oil loop or a pressurized hot water loop or a saturated ste am loop or even a direct evaporator is often used to transfer heat from the heat source to the ORC system. However, installing a heat exchanger directly in the hot gas paths of ORC system evokes the concerns for the flammability and/or toxicity of organic working fluids especially when the heat source has a relatively high temperature. Also the use of an intermediate heat carrier loop such as thermal oil or saturated steam or pressurized water loop is costly and involves installation of comparatively heavy components. In principle, the use of two-phase closed thermosyphons for capturing and transporting heat from a waste heat source to organic working fluid is less expensive than utilizing an intermediate heat transfer loop and eliminates safety issues as in the case of direct installation of an ORC evaporator in the hot gas paths. [less ▲]

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See detailL'Open Access en Belgique francophone : bientôt une réalité ?
Desseilles, François ULg; Thys, Laurence ULg

E-print/Working paper (2017)

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See detailActivation of the orphan G protein-coupled receptor GPR27 by surrogate ligands promotes β-arrestin 2 recruitment
Dupuis, Nadine ULg; Laschet, Céline ULg; Franssen, Delphine ULg et al

in Molecular Pharmacology (2017), 91(6), 595-608

G protein-coupled receptors are the most important drug targets for human diseases. An important number of them remain devoid of confirmed ligands. GPR27 is one of these orphan receptors, characterized by ... [more ▼]

G protein-coupled receptors are the most important drug targets for human diseases. An important number of them remain devoid of confirmed ligands. GPR27 is one of these orphan receptors, characterized by a high level of conservation among vertebrates and a predominant expression in the central nervous system. In addition, it has recently been linked to insulin secretion. However, the absence of endogenous or surrogate ligands for GPR27 complicates the examination of its biological function. Our aim was to validate GPR27 signaling pathways and therefore we sought to screen a diversity oriented synthesis library to identify GPR27-specific surrogate agonists. In order to select an optimal screening assay, we investigated GPR27 ligand-independent activity. Both in G protein-mediated pathways and in β-arrestin 2 recruitment, no ligand-independent activity could be measured. However, we observed a recruitment of β-arrestin 2 to a GPR27V2 chimera in the presence of membrane-anchored β-adrenergic receptor kinase 1 (GRK2). Therefore, we optimized a firefly luciferase complementation assay to screen against this chimeric receptor. We identified two compounds (N-[4-(anilinocarbonyl)phenyl]-2,4-dichlorobenzamide (ChemBridge ID5128535) and 2,4-dichloro-N-{4-[(1,3-thiazol-2-ylamino)sulfonyl]phenyl}benzamide (ChemBridge ID5217941)) sharing a N-phenyl-2,4-dichlorobenzamide scaffold, which were selective for GPR27 over its closely related family members GPR85 and GPR173. The specificity of the activity was confirmed with a NanoBiT® β-arrestin 2 assay, imaging of GFP-tagged β-arrestin 2 and PathHunter® β-arrestin 2 Assay. Interestingly, no G protein activation was detected upon activation of GPR27 by these compounds. Our study provides the first selective surrogate agonists for the orphan GPR27. [less ▲]

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See detailValidation of MOPITT carbon monoxide using ground-based Fourier transform infrared spectrometer data from NDACC
Buchholz, R. R.; Deeter, M. N.; Worden, H. M. et al

in Atmospheric Measurement Techniques (2017), 10(5), 1927--1956

The Measurements of Pollution in the Troposphere (MOPITT) satellite instrument provides the longest continuous dataset of carbon monoxide (CO) from space. We perform the first validation of MOPITT version ... [more ▼]

The Measurements of Pollution in the Troposphere (MOPITT) satellite instrument provides the longest continuous dataset of carbon monoxide (CO) from space. We perform the first validation of MOPITT version 6 retrievals using total column CO measurements from ground-based remote-sensing Fourier transform infrared spectrometers (FTSs). Validation uses data recorded at 14 stations, that span a wide range of latitudes (80°N to 78°S), in the Network for the Detection of Atmospheric Composition Change (NDACC). MOPITT measurements are spatially co-located with each station, and different vertical sensitivities between instruments are accounted for by using MOPITT averaging kernels (AKs). All three MOPITT retrieval types are analyzed: thermal infrared (TIR-only), joint thermal and near infrared (TIR–NIR), and near infrared (NIR-only). Generally, MOPITT measurements overestimate CO relative to FTS measurements, but the bias is typically less than 10%. Mean bias is 2.4% for TIR-only, 5.1% for TIR–NIR, and 6.5% for NIR-only. The TIR–NIR and NIR-only products consistently produce a larger bias and lower correlation than the TIR-only. Validation performance of MOPITT for TIR-only and TIR–NIR retrievals over land or water scenes is equivalent. The four MOPITT detector element pixels are validated separately to account for their different uncertainty characteristics. Pixel 1 produces the highest standard deviation and lowest correlation for all three MOPITT products. However, for TIR-only and TIR–NIR, the error-weighted average that includes all four pixels often provides the best correlation, indicating compensating pixel biases and well-captured error characteristics. We find that MOPITT bias does not depend on latitude but rather is influenced by the proximity to rapidly changing atmospheric CO. MOPITT bias drift has been bound geographically to within ±0.5%/yr or lower at almost all locations. [less ▲]

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See detailThe state of play in cross-border electricity trade and the challenges towards a global electricity market environment
Chatzivasileiadis, Spyros; Ernst, Damien ULg

in Ilaria, Espa; Cottier, Thomas (Eds.) International trade in sustainable electricity (2017)

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See detailPerformance-based Fire Safety Engineering: Challenges and Opportunities
Gernay, Thomas ULg

Conference given outside the academic context (2017)

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See detailQuand l'enfant révèle un abus sexuel : le vécu du couple, ses fonctions et conséquences
Gallo, Alicia ULg; Wertz, Céline ULg; Blavier, Adelaïde ULg

Conference (2017, June 01)

Cet exposé relate les difficultés du couple à l’annonce d’un abus sexuel d’un enfant. Ce vécu mérite d’être investigué car nous savons combien la souffrance des parents influence celle des enfants et peut ... [more ▼]

Cet exposé relate les difficultés du couple à l’annonce d’un abus sexuel d’un enfant. Ce vécu mérite d’être investigué car nous savons combien la souffrance des parents influence celle des enfants et peut alimenter voire maintenir leurs symptômes. Notre échantillon comprend 6 couples dont l’enfant a été victime. Nous avons réalisé un entretien semi-structuré récoltant les informations sur les circonstances de l’abus. De plus, nous avons administré 5 questionnaires évaluant une dimension spécifique du couple. Les résultats obtenus soulignent une détresse chez chaque couple. Cependant, celle-ci s’exprime différemment, aussi bien entre les couples qu’entre les partenaires conjugaux. Néanmoins, pour chacun d’eux, la dimension de la parentalité semble être une ressource permettant un investissement auprès de leur enfant par une focalisation ayant pour conséquence l’effacement du couple conjugal. Si certains couples manifestent néanmoins un rapprochement, celui-ci se fait autour de l’enfant et du problème. Cette capacité à faire équipe nous laisse penser que ces couples disposent de ressources pour faire face à l’abus. L’intérêt porté à la détresse conjugale et parentale semble primordial car si les parents tentent dans un premier temps de mettre en place des mécanismes assurant l’homéostasie et la sécurité, ceux-ci ne sont pas toujours adaptatifs à long terme (secret de famille, surprotection, étiolement du couple). Ainsi, il nous semble impératif de soutenir et contenir la conjugalité. D’autres études sont nécessaires pour approfondir les difficultés vécues par ces couples. [less ▲]

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See detailSuperconducting weak links created by electromigration
Silhanek, Alejandro ULg

Conference (2017, June 01)

In this presentation, we explore in-situ controlled electromigration to fabricate superconducting weak links. We show evidence that in Al a transition from thermally assisted phase slips (TAPS) to quantum ... [more ▼]

In this presentation, we explore in-situ controlled electromigration to fabricate superconducting weak links. We show evidence that in Al a transition from thermally assisted phase slips (TAPS) to quantum phase slips may takes place when the effective cross section becomes smaller than ~150 nm^2. In the regime dominated by quantum phase slips the nanowire loses completely its capacity to carry current without dissipation, even at the lowest possible temperature. We also discuss the origin of negative magnetoresistance at low magnetic fields in the bow-tie shaped constrictions. Strikingly, the detrimental effect caused by the repeated electromigration can be healed by simply inverting the current direction. These findings reveal perspectives of the proposed fabrication method for exploring various fascinating superconducting phenomena in atomic size constrictions. [less ▲]

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See detailLe réaménagement de la répartition des compétences dans le fédéralisme asymétrique belge
Behrendt, Christian ULg; Vandenbosch, Sofia ULg

in l'IRENEE (Institut de recherches sur l'évolution de la Nation et de l'Etat), Université de Lorraine, Nancy (Ed.) Les nations sans Etat - un droit à l'Etat ? Actes du colloque international tenu à Nancy les 22 et 23 octobre 2015 (2017)

Version publiée de l'exposé donné dans le cadre du colloque international organisé par l'IRENEE (Institut de recherches sur l'évolution de la Nation et de l'Etat), Université de Lorraine, Nancy, 23 ... [more ▼]

Version publiée de l'exposé donné dans le cadre du colloque international organisé par l'IRENEE (Institut de recherches sur l'évolution de la Nation et de l'Etat), Université de Lorraine, Nancy, 23 octobre 2015 [less ▲]

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See detailA seven-planet resonant chain in TRAPPIST-1
Luger, Rodrigo; Sestovic, Marko; Kruse, Ethan et al

in Nature Astronomy (2017), 1

The TRAPPIST-1 system is the first transiting planet system found orbiting an ultracool dwarf star[SUP] 1 [/SUP]. At least seven planets similar in radius to Earth were previously found to transit this ... [more ▼]

The TRAPPIST-1 system is the first transiting planet system found orbiting an ultracool dwarf star[SUP] 1 [/SUP]. At least seven planets similar in radius to Earth were previously found to transit this host star[SUP] 2 [/SUP]. Subsequently, TRAPPIST-1 was observed as part of the K2 mission and, with these new data, we report the measurement of an 18.77 day orbital period for the outermost transiting planet, TRAPPIST-1 h, which was previously unconstrained. This value matches our theoretical expectations based on Laplace relations[SUP] 3 [/SUP] and places TRAPPIST-1 h as the seventh member of a complex chain, with three-body resonances linking every member. We find that TRAPPIST-1 h has a radius of 0.752 R [SUB]⊕[/SUB] and an equilibrium temperature of 173 K. We have also measured the rotational period of the star to be 3.3 days and detected a number of flares consistent with a low-activity, middle-aged, late M dwarf. [less ▲]

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See detailEtude de la gestion des ressources génétiques ovines et caractérisation de leurs marchés en région périurbaine de Ouagadougou, Burkina Faso
Tindano, Kisito ULg

Doctoral thesis (2017)

Sheep production in Burkina Faso supplies internal consumption and exportation markets, in countries of West Africa (Côte d’Ivoire, Ghana, Nigeria, and Benin). In this region, sheep have both economic and ... [more ▼]

Sheep production in Burkina Faso supplies internal consumption and exportation markets, in countries of West Africa (Côte d’Ivoire, Ghana, Nigeria, and Benin). In this region, sheep have both economic and socio-cultural importance. While production is mainly located in the rural area, it is nevertheless noted that suburban livestock is developing, in particular around the capital city of Ouagadougou. Suburban production differs from rural livestock production, in particular by the actors involved, the economic orientation of production as well as by the availability of resources and production factors (services, inputs, land and capital). This context leads to the search for genetic resources favourable to this environment production, allowing for an optimisation of the activity. This implies a specific management of these resources. However, there is no information on how farmers in the suburban area manage their sheep genetic resources and on the sustainability of this management. Aiming to fill this information gap, this work focuses on (i) the characteristics of sheep farms in Ouagadougou suburbs and in neighbouring rural areas, (ii) the sheep traits, that have an impact on the their price, and finally (iii) the relative importance of some traits in the choice of breeding ram by breeders. In order to characterise sheep farming in the suburban area of Ouagadougou in terms of socio-economic motivations, breeding practices, including genetic resources management, and in order to better understand the dynamics of the sector, a survey was conducted among 80 breeders in the area. The results showed that the sector essentially comprises two categories of livestock, with almost half (42.5%) of the breeders who can be described as traditional livestock keepers. The latter breeders are illiterate at 94.1% and have no non-agricultural economic activities (88.2%). They don’t have sheltered enclosures (70.6) and their sheep don’t receive systematic deworming (61.8%). They keep Mossi sheep (88.2%) and their main selection objective is rusticity (64.7%). The other category includes 50% of the livestock keepers. These tend to intensify production through the use of better infrastructures (enclosures, shelters), better feeding and systematic de-worming of animals (87.5%). They report keeping animals for generation of additional income and they practice crossbreeding. Their main selection objective is to improve the young growth and adult weight. Reproduction is generally characterised by a lack of mating control, especially during the dry season when the animals are allowed to graze freely. This phenomenon, in the context of the practice of crossbreeding by some breeders, creates negative externalities for breeders preferring the purity of their herd for rusticity motives. This also undermines the sustainability of the systems by an uncontrolled increase in the share of Fulani genetics in herds and the loss of sources of Mossi pure breed. To investigate the possibility for the rural area to constitute a source for purebred Mossi sheep for the suburban area, another survey was conducted among 63 livestock keepers in the region of the Central Plateau of Burkina Faso. This study showed that sheep in this area are kept in sedentary systems and the Mossi sheep is the most encountered. A selective breeding strategy can be found for all breeders through the choice of males. The most cited selection objectives were the improvement of the adult weight (84.1%), the young growth (79.4%) and the maintenance of the rusticity (73%). In agreement with their goal of improving the weight and growth of animals, Mossi sheep females are often crossed with Fulani ram. These males are eliminated from the herd after the birth of the first crossbred lambs, while the latter are subsequently used for breeding. By removing the Fulani males after a short period of use, management appears to be better mastered and more sustainable compared to the suburban area, but leads to reconsider the notion of "purebred" in the region, as the management of breeders includes the mixed use of available breeds. However, with regard to the use of this area as a source of replacement females, if farmers appear to be willing to sell females to other farmers, the size of their herds doesn’t allow the sale of large numbers because of their own replacement needs. Added to this is the tendency expressed by some farmers to only sell to farmers they know, in hopes of reciprocity, hence for social rather than commercial motives. Consumer market demand for different phenotypic traits was investigated through a monitoring of market transactions (revealed preference surveys) and surveys among sheep exporters and butchers. A total of 338 transactions were monitored over three different periods (the Muslim Eid al-Adha feast period, Christmas and New Year period and a neutral period). The interviews involved 25 exporters and 15 butchers, who were asked about the characteristics of the animals quested for and their purchase localities. Survey results showed that exporters have preferences for large-framed and good body conditions animals while local butchers mark their preferences for small-framed and low-fitness animals. Markets are categorised into collection, assembly and terminal markets through which animals pass before reaching the final consumer. The revealed preferences have shown that phenotypic traits such as coat colour, weight and height at the withers have a highly significant (p<0.001) influence on prices. The weight has shown a non-linear, increasing influence on prices with increasing marginal income per kg of live weight. The purchase period, which is embedded with the purchase motive, also showed a highly significant (p<0.001) influence on prices, showing a superiority of the prices during the Eid al-Adha, but no difference between prices during the Christmas and New Year period and the neutral periods. Finally, the purchase period and coat colour showed highly significant interactions with the weight, the white-coloured animals and the Eid al-Adha period having better valorised the increase in weight. This study sheds light on the links between markets and demands for a certain orientation of sheep genetic resources. It is suggested, for example, that an improvement on the basis of higher weight and white colour criteria, which are more valued on the market, would rather favour a niche market linked to feasts periods and exports, and some breeders benefiting improved livestock resources. On the contrary, an improvement towards rusticity for small-framed animals would supply a more ordinary market, contributing to food security of households and an income generation for a wider range of sheep producers. In this market context, a final study aimed at highlighting the trade-off that breeders are willing to make for the improvement of the different traits, whether "productive" or "adaptive". A stated choice experience, taking into account the traits such as weight, colour, susceptibility to diseases and the feed requirement, was carried out with 137 breeders. These farmers mainly use natural grazing (82.5% of the farmers involved). Crossbreeding is observed in 23.4% of farmers. The highest willingness to pay (WTP) was observed for resistance to diseases with 261€. However, among the farmer practicing crossbreeding, there was an apparent preference for susceptibility to disease with a WTP of 45€. A significant WTP was also revealed for the white coat colour (21€) then preferred to the bicoloured. The preference for large-framed animals compared to medium-framed ones was significant but relatively lower than preferences for white coat colour and resistance to diseases. On the other hand, farmers showed indifference for the transition from the medium body size to the small body size. For all traits, farmers practicing crossbreeding showed a preference for extreme levels compared to intermediate levels. Two trends emerged from this study: on the one hand, farmers willing to take the risk of reducing resistance to diseases in order to increase productivity; on the other hand, those with greater risk aversion, strongly willing to spend to gain resistance to diseases. The case of crossbreeding farmers suggests an interesting double preference, demonstrating a WTP for opposed traits being considered as typical of one breed or the other, then depreciating the intermediate traits indicating the possibility of a crossbred. All the studies indicate that the management of sheep genetic resources in Ouagadougou's suburban area, although it does not really present threats to the different breeds in its present state, nevertheless shows signs, particularly from the market, that could hamper the sustained use of small-framed and environmentally adapted sheep. It is therefore necessary to find a strategy to better organise this management to make it sustainable. The establishment of a terminal crossbreeding scheme involving suburban and rural livestock farmers is a possible strategy. This nevertheless requires truly commercial livestock at the end of the scheme and means to overcome certain constraints raised in this thesis. [less ▲]

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See detailDe l'errance individuelle à la reconnaissance collective: Récits de patients et de proches impliqués dans des associations de maladies rares en Belgique
Duysens, Fanny ULg

Conference (2017, June 01)

Les maladies dites rares affectent moins d’une personne sur 2000 selon les chiffres de l'Union Européenne. Outre ce faible taux de prévalence, elles sont définies comme faisant généralement l'objet d'une ... [more ▼]

Les maladies dites rares affectent moins d’une personne sur 2000 selon les chiffres de l'Union Européenne. Outre ce faible taux de prévalence, elles sont définies comme faisant généralement l'objet d'une insuffisance de connaissance et de reconnaissance, qui conduit souvent à des situations d'errance diagnostique et thérapeutique pour les patients et leurs proches. Ainsi, ceux-ci sont nombreux à se regrouper dans des associations qui visent à guider quelque peu les personnes concernées dans leurs parcours et à améliorer leur qualité de vie. S'inscrivant dans le champ des sciences sociales, et plus particulièrement des Science & Technology Studies et de l'anthropologie de la santé et de la maladie, cette recherche doctorale (en cours) explore les activités d’associations de patients et de proches formées autour de maladies rares en Belgique. Elle se base sur une ethnographie multi-site qui implique notamment des entretiens biographiques avec des personnes engagées. Ce sont des récits de parcours et d'expériences, dans lesquels les personnes ont raconté les manières dont elles se sont trouvées concernées par certaines maladies, les raisons qui les ont conduit à fonder ou à rejoindre une association, ainsi que les enjeux de cet engagement tant sur les plans individuels que collectifs. L'étude des récits des patients et des proches engagés montre qu'ils constituent en eux-mêmes de véritables ressources mobilisées dans les activités des associations de maladies rares. De fait, celles-ci apparaissent comme des espaces de production et de mise en circulation de certains types de récits qui visent entre autres à caractériser la "rareté" d'une maladie et à construire une catégorie univoque de "maladie rare". Les associations travaillent à identifier des problématiques communes, puis élaborer des missions susceptibles de bénéficier à tous au-delà de la multiplicité des personnes, des situations, des conceptions et des expériences vécues. Dans une approche comparative des récits des parcours et des expériences individuelles de représentants de différentes associations, cette communication visait à étudier le fond et la forme de ces récits en vue de comprendre les logiques de leur mobilisation collective pour une catégorisation de la "maladie rare". Plus particulièrement, il s'agissait d'interroger l'articulation entre la singularité des récits et la certaine logique collective qu'ils reflètent. Comment les expériences sont-elles échangées au sein des associations ? Comment sont-elles alignées les unes par rapport aux autres pour en faire des ressources mobilisables collectivement ? Comment est ainsi construite la catégorie de "maladie rare" ? Quels sont les éléments qui font sens et qu’est-ce qui, à l’inverse, se perd dans ce passage de l’individuel au collectif ? Par ailleurs, quels sont les rapports entre les récits des patients et des proches engagés et les contextes sociaux, politiques et médicaux plus larges dans lesquels ils s'inscrivent ? [less ▲]

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See detailThe VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. IV. Gravitational instability rarely forms wide, giant planets
Vigan, A.; Bonavita, M.; Biller, B. et al

in Astronomy and Astrophysics (2017), 603

Understanding the formation and evolution of giant planets (≥1 M[SUB]Jup[/SUB]) at wide orbital separation (≥5 AU) is one of the goals of direct imaging. Over the past 15 yr, many surveys have placed ... [more ▼]

Understanding the formation and evolution of giant planets (≥1 M[SUB]Jup[/SUB]) at wide orbital separation (≥5 AU) is one of the goals of direct imaging. Over the past 15 yr, many surveys have placed strong constraints on the occurrence rate of wide-orbit giants, mostly based on non-detections, but very few have tried to make a direct link with planet formation theories. In the present work, we combine the results of our previously published VLT/NaCo large program with the results of 12 past imaging surveys to constitute a statistical sample of 199 FGK stars within 100 pc, including three stars with sub-stellar companions. Using Monte Carlo simulations and assuming linear flat distributions for the mass and semi-major axis of planets, we estimate the sub-stellar companion frequency to be within 0.75-5.70% at the 68% confidence level (CL) within 20-300 AU and 0.5-75 M[SUB]Jup[/SUB], which is compatible with previously published results. We also compare our results with the predictions of state-of-the-art population synthesis models based on the gravitational instability (GI) formation scenario with and without scattering. We estimate that in both the scattered and non-scattered populations, we would be able to detect more than 30% of companions in the 1-75 M[SUB]Jup[/SUB] range (95% CL). With the threesub-stellar detections in our sample, we estimate the fraction of stars that host a planetary system formed by GI to be within 1.0-8.6% (95% CL). We also conclude that even though GI is not common, it predicts a mass distribution of wide-orbit massive companions that is much closer to what is observed than what the core accretion scenario predicts. Finally, we associate the present paper with the release of the Direct Imaging Virtual Archive (DIVA), a public database that aims at gathering the results of past, present, and future direct imaging surveys. Based on observations collected at the European Southern Observatory, Chile (ESO Large Program 184.C-0157 and Open Time 089.C-0137A and 090.C-0252A). [less ▲]

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