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See detailDynamiques d’occupation et de valorisation des espaces pastoraux : État de lieu, enjeux et perspectives (cas du département de Madaoua au Niger)
Sambo, Bodé; kabou, Moussa; Andres, Ludovic ULg et al

Scientific conference (2015, May)

Les espaces pastoraux subissent des empiétements partout dans le monde. Au Niger, ils sont menacés dans la partie nord par l’avancée du désert et les installations minières, au sud par la mise en culture ... [more ▼]

Les espaces pastoraux subissent des empiétements partout dans le monde. Au Niger, ils sont menacés dans la partie nord par l’avancée du désert et les installations minières, au sud par la mise en culture et les habitations. Le département de Madaoua est localisé en zone agricole avec un système de production à dominante agropastorale. Le présent travail a été réalisé selon une démarche méthodologique qui combine à la fois la capitalisation des données existantes et les enquêtes de terrain. Les résultats montrent que les acteurs développent des stratégies d’adaptation souvent divergentes dans un environnement de rareté des ressources de terres exploitables. Les organes de régulation du foncier quoique peu dynamiques travaillent dans un contexte de dénuement total. Ainsi, la pratique de mise en valeur pastorale devient un problème crucial. Plusieurs variables concourent à expliquer ces phénomènes. Ainsi, on note entre autres, la combinaison des facteurs dont la pression démographique dans un contexte de saturation foncière. Les systèmes de production qui restent dominés par des pratiques encore extensives lourdement affectés par la variabilité et changement climatique. La gouvernance des ressources naturelles aujourd’hui qui est mal appropriée avec la décentralisation. L’enjeu à long terme reste de trouver une solution durable pour nourrir une population en perpétuelle croissance dans un espace invariant. [less ▲]

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See detailOptical polarization from AGN
Hutsemekers, Damien ULg

Conference (2015, May)

I review the optical polarization properties of both low- and high-luminosity AGN, focusing on the origin of the polarization and its relation to AGN properties, in particular the geometry of the ... [more ▼]

I review the optical polarization properties of both low- and high-luminosity AGN, focusing on the origin of the polarization and its relation to AGN properties, in particular the geometry of the scattering regions. The use of polarization to follow AGN orientations along the large-scale structures will also be discussed. [less ▲]

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See detailAdapting Nitrogen management to the increasing climatic uncertainty
Dumont, Benjamin ULg; Basso, Bruno; Bodson, Bernard ULg et al

in Shirmohammadi, Adel; Bosch, David; Muñoz-Carpena, Rafa (Eds.) Proceedings of the 1st ASABE Climate Change Symposium - Adaptation and Mitigation (2015, May)

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See detailLinear and propeller-like fluoro-isoindigo based donor–acceptor small molecules for organic solar cells
Ouhib, Farid ULg; Tomassetti, Mirco ULg; Dierckx, Wauter et al

in Organic Electronics (2015), 20

Two donor–acceptor type fluoro-isoindigo based small molecule semiconductors are syn- thesized and their optical, electrochemical, thermal, and charge transport properties are investigated. The two ... [more ▼]

Two donor–acceptor type fluoro-isoindigo based small molecule semiconductors are syn- thesized and their optical, electrochemical, thermal, and charge transport properties are investigated. The two molecular chromophores differ by their architecture, linear (M1) vs propeller-like (M2). Both molecules present a broad absorption in the visible range and a low optical HOMO–LUMO gap (?1.6 eV). AFM images of solution-processed thin films show that the trigonal molecule M2 forms highly oriented fibrils after a few seconds of solvent vapor annealing. The materials are evaluated as electron donor components in bulk heterojunction organic solar cells using PC61BM as the electron acceptor. The devices based on the propeller-like molecule M2 exhibit a high open-circuit voltage (around 1.0 V) and a power conversion efficiency of 2.23%. [less ▲]

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See detailEffects of a walk phase at the warm up onset on physiological and behavioural parameters of ridden horses (Equus caballus)
Jacquot, Marion; Grosjean, Adeline; Emrot, Cassandre et al

Poster (2015, May)

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See detailFractured bedrock investigation by using high-resolution borehole images and the Distributed Temperature Sensing technique
Radioti, Georgia ULg; Delvoie, Simon ULg; Radu, Jean-Pol ULg et al

in ISRM Congress 2015 Proceedings - Int’l Symposium on Rock Mechanics (2015, May)

In order to investigate the fracturing of the bedrock and its possible heterogeneous distribution in situ, four boreholes equipped with double-U geothermal pipes of 100 m long were installed on the campus ... [more ▼]

In order to investigate the fracturing of the bedrock and its possible heterogeneous distribution in situ, four boreholes equipped with double-U geothermal pipes of 100 m long were installed on the campus of the University of Liege (Liege, Belgium) over a surface area of 32 m². The bedrock, which starts at a depth approximately of 8 m, is quite fractured and consists mainly of siltstone and shale interbedded with sandstone. Different geophysical methods are applied at two different phases, after drilling the boreholes and after injecting the grouting material. The first approach consists in lowering an ultrasonic borehole imager (borehole televiewer; Zemanek, Glenn, Norton, & Caldwell, 1970), an instrument that acts as an ultrasonic transducer and receiver, into the boreholes to obtain high-resolution, continuous images with 360° coverage of the local geology and fracturing. Moreover gamma-ray logs of the four boreholes are obtained and inclinometry is conducted. After drilling the boreholes fiber optic cables are attached along the pipe loops and the double-U pipes are installed inside the boreholes. Then the grouting material is injected. The second approach consists in measuring the temperature along the fibers by applying the Distributed Temperature Sensing technique (Soto, Sahu, Faralli, Bolognini, Di Pasquale, Nebendahl, & Rueck, 2007). A laser pulse is injected into the optical fiber and the temperature along the fiber is determined by the intensity of Raman stokes and anti-stokes reemitted signals. Temperature evolution is measured during hardening of the grouting material. Local maxima of the temperature curve are probably due to a local lower thermal conductivity and/or a local larger quantity of grouting material due to gathering of fractures. A detailed fracture characterisation (position, opening, orientation, dip angle) is obtained based on the acoustic signal travel time and amplitude. The fractures are characterised by the same dipping and orientation but significantly vary in number and location in the four boreholes, despite the close distance between them. Gamma-ray data and observation of the cuttings during drilling result in rock identification through depth as well as in determination of the layer dipping. The inclination of the four boreholes tends to be perpendicular to the dipping. The combination of the two geophysical methods as presented provides information useful for the hydro-thermo-mechanical behaviour of the bedrock. The contribution of the thermal behaviour of borehole heat exchangers to bedrock investigation will be further studied by conducting Distributed Thermal Response tests (Fujii, Okubo, & Itoi, 2006). During the tests we will measure the temperature variation thanks to the installed fiber optics. These data will allow us to correlate any anisotropic thermal behaviour to the geological characteristics. The available information could be used for a detailed numerical model. [less ▲]

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See detailA comparison of within-season yield prediction algorithms based on crop model behaviour analysis
Dumont, Benjamin ULg; Basso, Bruno; Leemans, Vincent ULg et al

in Agricultural and Forest Meteorology (2015), 204

The development of methodologies for predicting crop yield, in real-time and in response to different agro-climatic conditions, could help to improve the farm management decision process by providing an ... [more ▼]

The development of methodologies for predicting crop yield, in real-time and in response to different agro-climatic conditions, could help to improve the farm management decision process by providing an analysis of expected yields in relation to the costs of investment in particular practices. Based on the use of crop models, this paper compares the ability of two methodologies to predict wheat yield (Triticum aestivum L.), one based on stochastically generated climatic data and the other on mean climate data. It was shown that the numerical experimental yield distribution could be considered as a log-normal distribution. This function is representative of the overall model behaviour. The lack of statistical differences between the numerical realisations and the logistic curve showed in turn that the Generalised Central Limit Theorem (GCLT) was applicable to our case study. In addition, the predictions obtained using both climatic inputs were found to be similar at the inter and intra-annual time-steps, with the root mean square and normalised deviation values below an acceptable level of 10% in 90% of the climatic situations. The predictive observed lead-times were also similar for both approaches. Given (i) the mathematical formulation of crop models, (ii) the applicability of the CLT and GLTC to the climatic inputs and model outputs, respectively, and (iii) the equivalence of the predictive abilities, it could be concluded that the two methodologies were equally valid in terms of yield prediction. These observations indicated that the Convergence in Law Theorem was applicable in this case study. For purely predictive purposes, the findings favoured an algorithm based on a mean climate approach, which needed far less time (by 300-fold) to run and converge on same predictive lead time than the stochastic approach. [less ▲]

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See detailLarge-scale polarization alignments of quasars in the JVAS/CLASS 8.4-GHz surveys
Pelgrims, Vincent ULg; Hutsemekers, Damien ULg

Poster (2015, May)

We analyse the large sample of polarization measurements of the flat-spectrum radio sources of the JVAS/CLASS 8.4-GHz surveys compiled by Jackson et al. (2007). We tested the uniformity of the ... [more ▼]

We analyse the large sample of polarization measurements of the flat-spectrum radio sources of the JVAS/CLASS 8.4-GHz surveys compiled by Jackson et al. (2007). We tested the uniformity of the polarization position angles for a wide range of angular (2D) and comoving (3D) separations and studied the several subsamples, dividing the main sample of 4155 sources regarding their object type (QSO, galaxies, radio sources,...). We found regions of the sky of about 20 degree radius in which quasars (only) have correlated polarization position angles. Those regions coincide with the regions of alignment at optical wavelength pinpointed in 1998 by Hutsemékers. [less ▲]

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See detailBiscuits et thé à la menthe aux fêtes interculturelles. Entre essentialisation et participation des femmes marocaines en Italie.
Mescoli, Elsa ULg

Conference (2015, May)

Cette communication est issue d’une recherche ethnographique autour des pratiques culinaires d’un groupe de femmes marocaines résidentes dans une ville de la province de Milan, en Italie. Le matériel ... [more ▼]

Cette communication est issue d’une recherche ethnographique autour des pratiques culinaires d’un groupe de femmes marocaines résidentes dans une ville de la province de Milan, en Italie. Le matériel collecté au sein des entretiens et des observations a permis d’étudier d’un côté la définition des sujets au travers des pratiques alimentaires, d’un autre côté leur modalité de prendre part à la vie sociale locale. Grâce aux activités de la vie quotidienne, une appartenance culturelle et religieuse peut être affirmée, en permettant ainsi la revendication du « droit à la diversité ». La performance publique des pratiques culinaires permet aux femmes considérées d’exercer une agency à l’intérieur des espaces institutionnellement concédés à l’expression des migrants. Lors des fêtes interculturelles, les rituels d’une sorte de « cannibalisme exogène » se mettent en place : la population majoritaire, en goûtant les plats des Autres, incorpore la diversité afin de la contrôler. Néanmoins, les femmes migrantes en charge des préparations choisissent activement quels ingrédients (du soi et des plats) faire consommer, en présentant ainsi certains aspects qui vont au-delà de la culture alimentaire. Le partage de nourriture leur permet d’assumer un rôle actif dans la communauté locale, tout en affirmant leurs propres spécificités. Les femmes considérées acquièrent une position politiquement importante au sein de la société et sont ainsi légitimées à participer aux débats et décisions autour de certains questions clefs de la pratique de la diversité. [less ▲]

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See detailSuétone et le bilinguisme des Julio-Claudiens
Rochette, Bruno ULg

in Devillers, Olivier (Ed.) Autour de Pline le Jeune. En hommage à Nicole Méthy (2015)

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See detailRocking behaviour of simple unreinforced load-bearing masonry walls including soundproofing rubber layers
Mordant, Christophe ULg; Denoël, Vincent ULg; Degée, Hervé

in Proceedings of 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (2015, May)

This paper compares experimental measurements with predictions of different rocking models. These comparisons are carried out on the base of recent experimental results obtained by shake-table tests of ... [more ▼]

This paper compares experimental measurements with predictions of different rocking models. These comparisons are carried out on the base of recent experimental results obtained by shake-table tests of four simple unreinforced load-bearing clay masonry walls that have exhibited a significant rocking behaviour for the highest acceleration inputs. In a first stage, the simple model proposed by Housner is used after slight modifications needed to properly consider the actual mass distribution. Two parameters are identified as governing the model response, namely the criterion defining the initiation of motion and the restitution coefficient. Then, a two stacked blocks model is developed and solved by an event-driven strategy. This two-block model is intended to allow a better description of the behaviour of tested specimens through a more precise modelling of the additional mass. Finally, the pres-ence of rubber layers positioned at the top and bottom of two of the tested walls with the pur-pose of improving their acoustic behaviour required the development of an updated rocking model with viscous and flexible interfaces at the base of the wall and between the two stacked blocks. The properties of these interfaces are deduced from experimental data and their sig-nificant influence on the response is evidenced. [less ▲]

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See detailL'alcool rapporte-t-il à la société plus qu'il ne lui coûte ?
Demaret, Isabelle ULg

in Seutin, Vincent; Scuvée-Moreau, Jacqueline; Quertemont, Etienne (Eds.) L'alcool en questions (2015)

L’alcool remonte le moral. Une petite cuite n’a jamais tué personne. Boire un café atténue l’effet de l’alcool. Le binge drinking est un fléau nouveau… De nombreuses idées reçues, certaines fondées ... [more ▼]

L’alcool remonte le moral. Une petite cuite n’a jamais tué personne. Boire un café atténue l’effet de l’alcool. Le binge drinking est un fléau nouveau… De nombreuses idées reçues, certaines fondées, d’autres pas, sont véhiculées à propos de l’alcool et de ses conséquences. L’alcool soulève aussi de multiples questions : L’alcool est-il une drogue ? L’alcool est-il aphrodisiaque ? L’alcoolisme est-il héréditaire ? Combien l’alcool coûte/rapporte-t-il à la société ? Peut-on guérir de l’alcoolisme ?… Ce livre a pour but de démont(r)er certaines idées reçues sur l’alcool et d’apporter des réponses aux questions que chacun se pose. Les auteurs ne se bornent pas à répondre par vrai ou faux, ils fournissent les explications, appuyées sur l’état des connaissances scientifiques actuelles, qui permettent d’infirmer ou de confirmer ces idées reçues ou de répondre à ces questions. Ils nuancent le propos lorsque la réponse n’est pas de l’ordre du tout ou rien. Il est indéniable que l’excès d’alcool est nuisible à la santé. Il existe cependant une littérature scientifique démontrant des effets positifs sur la santé de la consommation en quantités modérées de certaines boissons alcoolisées. Ce mélange d’effets positifs et négatifs explique que le public a développé une relation d’amour-haine avec l’alcool. Ainsi, les abstinents complets sont parfois qualifiés de rabat-joie. Les alcooliques chroniques (5 à 10 % des occidentaux, selon les études épidémiologiques !) sont, quant à eux, souvent trop vite jugés. Ce qui est certain c’est que l’alcoolo-dépendance est source de beaucoup de souffrances pour la personne et son entourage. Ces 41 réponses à des questions sur l’alcool visent à donner des balises au lecteur, littérature scientifique à l’appui. [less ▲]

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See detailImproving adjuvant systems for polyclonal egg yolk antibody (IgY) production in laying hens in terms of productivity and animal welfare
Marcq, Christopher ULg; Marlier, Didier ULg; Beckers, Yves ULg

in Veterinary Immunology and Immunopathology (2015), 165(1-2), 54-63

The antibody production in the egg yolks of immunized laying hens is seen as a way of improving animal welfare compared with conventional production by mammals. Immunoglobulin Y (IgY) technology, however ... [more ▼]

The antibody production in the egg yolks of immunized laying hens is seen as a way of improving animal welfare compared with conventional production by mammals. Immunoglobulin Y (IgY) technology, however, has still to address welfare issues linked to the widespread use of an adjuvant in vaccines. Currently, Freund's adjuvants, complete (FCA) or incomplete (FIA), remain the standard. This study sought to evaluate various approaches used to enhance egg yolk antibody production in terms of both productivity and avian welfare. The outer membrane protein (OMP) of Salmonella Typhimurium was used as the prototype antigen. At 20 weeks of age, 56 ISA Brown hens, with specific-Salmonella-free status, were divided into seven groups (n = 8) and received an initial intramuscular immunization. Hens in the two negative control groups received phosphate buffered saline (PBS) or FIA alone. Hens in the other groups received 80 μg of Salmonella OMP emulsified with one of the following adjuvants: 200 μl of FIA alone (T1); 200 μl of FIA supplemented with 8 μg of C-phosphate-guanosine oligodeoxynucleotides (CpG-ODN) (T2); and 280 μl of Montanide ISA 70 VG (T4). Birds in the T3 group received the antigen in emulsion with FIA and were given the tested immunostimulatory component (l-carnitine) via their feed (100 mg/kg). A positive control group (PC) received FCA for the first and final immunizations and FIA for the other boosters. Immunization was repeated after 20, 46, 82 and 221 days. Eggs were collected regularly until 242 days after the first immunization and the anti-Salmonella Typhimurium activities in the yolk were determined by ELISA. After 242 days, the birds were euthanized and the injection sites were evaluated for gross and microscopic lesions. Among the tested immunostimulatory approaches, supplementation of FIA with CpG-ODN led to a significant and long-lasting enhancement of the specific antibody response. This treatment was even higher than the positive benchmark using FCA in the first immunization. The study results showed that a clinical examination of injection sites is insufficient for drawing conclusions about the local tolerance of vaccines. Tissue damage was noticeable in all treatment groups. The birds receiving the Montanide adjuvant, however, had fewer and less severe lesions. Given these limited side-effects, Montanide ISA 70 VG could provide the depot effect needed to ensure the immunomodulatory efficiency of CpG-ODN. The association of these two adjuvants could prove a promising alternative to Freund's adjuvants (FA). [less ▲]

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See detailLe binge drinking (biture expresse) est-il un phénomène récent ?
Demaret, Isabelle ULg; Quertemont, Etienne ULg

in Seutin, Vincent; Scuvée-Moreau, Jacqueline; Quertemont, Etienne (Eds.) L'alcool en questions (2015)

L’alcool remonte le moral. Une petite cuite n’a jamais tué personne. Boire un café atténue l’effet de l’alcool. Le binge drinking est un fléau nouveau… De nombreuses idées reçues, certaines fondées ... [more ▼]

L’alcool remonte le moral. Une petite cuite n’a jamais tué personne. Boire un café atténue l’effet de l’alcool. Le binge drinking est un fléau nouveau… De nombreuses idées reçues, certaines fondées, d’autres pas, sont véhiculées à propos de l’alcool et de ses conséquences. L’alcool soulève aussi de multiples questions : L’alcool est-il une drogue ? L’alcool est-il aphrodisiaque ? L’alcoolisme est-il héréditaire ? Combien l’alcool coûte/rapporte-t-il à la société ? Peut-on guérir de l’alcoolisme ?… Ce livre a pour but de démont(r)er certaines idées reçues sur l’alcool et d’apporter des réponses aux questions que chacun se pose. Les auteurs ne se bornent pas à répondre par vrai ou faux, ils fournissent les explications, appuyées sur l’état des connaissances scientifiques actuelles, qui permettent d’infirmer ou de confirmer ces idées reçues ou de répondre à ces questions. Ils nuancent le propos lorsque la réponse n’est pas de l’ordre du tout ou rien. Il est indéniable que l’excès d’alcool est nuisible à la santé. Il existe cependant une littérature scientifique démontrant des effets positifs sur la santé de la consommation en quantités modérées de certaines boissons alcoolisées. Ce mélange d’effets positifs et négatifs explique que le public a développé une relation d’amour-haine avec l’alcool. Ainsi, les abstinents complets sont parfois qualifiés de rabat-joie. Les alcooliques chroniques (5 à 10 % des occidentaux, selon les études épidémiologiques !) sont, quant à eux, souvent trop vite jugés. Ce qui est certain c’est que l’alcoolo-dépendance est source de beaucoup de souffrances pour la personne et son entourage. Ces 41 réponses à des questions sur l’alcool visent à donner des balises au lecteur, littérature scientifique à l’appui. [less ▲]

Detailed reference viewed: 43 (18 ULg)