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See detailFrom mechanical to chemical impact of anchoring in seagrasses: the premises of anthropogenic patch generation in Posidonia oceanica meadows
Abadie, Arnaud ULg; Lejeune, Pierre; Pergent, Gérard et al

in Marine Pollution Bulletin (in press)

Intensive anchoring of leisure boats in seagrass meadows leads to mechanical damages. This anthropogenic impact creates bare mat patches that are not easily recolonized by the plant. Several tools are ... [more ▼]

Intensive anchoring of leisure boats in seagrass meadows leads to mechanical damages. This anthropogenic impact creates bare mat patches that are not easily recolonized by the plant. Several tools are used to study human impacts on the structure of seagrass meadows but they are not able to assess the indirect and long term implication of mechanical destruction. We chose to investigate the possible changes in the substrate chemistry given contrasted boat impacts. Our observations show that hydrogen sulfide concentrations remain high at 15 and 20 m depth (42.6 µM and 18.8 µM) several months after the highest period of anchoring during the summer. Moreover, our multidisciplinary study reveals that anchoring impacts of large boats at 15 and 20 m depth can potentially change the seascape structure. By taking into account both structural and chemical assessments, different managing strategies must be applied for coastal areas under anthropogenic pressures. [less ▲]

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See detailLes troubles du sommeil chez l'enfant autiste, quel rôle pour le pédopsychiatre?
Abate Ekollo, Joëlle; Malchair, Alain ULg

in Acta Psychiatrica Belgica (in press)

Les troubles du sommeil sont fréquents chez l’enfant et leurs origines sont diverses. Ces troubles ont leur ancrage dans le développement neurophysiologique et psychoaffectif de l’enfant. Les enfants ... [more ▼]

Les troubles du sommeil sont fréquents chez l’enfant et leurs origines sont diverses. Ces troubles ont leur ancrage dans le développement neurophysiologique et psychoaffectif de l’enfant. Les enfants souffrant de troubles du spectre autistique présentent un déficit de sommeil, qui peut durer jusqu’à l’adolescence. Les troubles du spectre autistique comportent des comorbidités multiples, dont des altérations du sommeil. Ils sont importants à caractériser dans cette population, car ils peuvent avoir un impact négatif sur les comportements diurnes. Par ailleurs, ils entrainent souvent des difficultés au sein de la famille. La prise en charge doit avant tout prendre en compte le contexte environnemental afin d’améliorer les habitudes et l’hygiène du sommeil. Des questionnaires ainsi que des agendas de sommeil ont été remplis par des parents afin de démontrer l’importance d’une évaluation et d’une prise en compte des troubles du sommeil chez les enfants souffrant d’autisme en consultation pédopsychiatrique. [less ▲]

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See detailA Theory of Soft Capture
Agrell, Per; Gautier, Axel ULg

in Scandinavian Journal of Economics (in press)

n this paper, wee propose a model for regulatory capture that is based on information transmission and asymmetric information. In a three-tier model, a regulator is charged by a political principal to ... [more ▼]

n this paper, wee propose a model for regulatory capture that is based on information transmission and asymmetric information. In a three-tier model, a regulator is charged by a political principal to provide a signal for the type of a regulated firm. Only the firm can observe his type and the production of a correlated signal with a given accuracy is costly for the regulator. The firm can costlessly provide an alternative signal of lower accuracy that is presented to the regulator. In a self-enforcing equilibrium, the regulator transmits the firm-produced signal, internalizes its own savings in information cost and the firm enjoys higher information rents. The main feature of soft capture is that it is not based on a reciprocity of favors but on a congruence of interests between the firm and the regulator. [less ▲]

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See detailA Quantitative Doignon-Bell-Scarf theorem
Aliev, Iskander; Bassett, Robert; De Loera, Jesus et al

in Combinatorica (in press)

The famous Doignon-Bell-Scarf theorem is a Helly-type result about the existence of integer solutions to systems of linear inequalities. The purpose of this paper is to present the following quantitative ... [more ▼]

The famous Doignon-Bell-Scarf theorem is a Helly-type result about the existence of integer solutions to systems of linear inequalities. The purpose of this paper is to present the following quantitative generalization: Given an integer k, we prove that there exists a constant c(n,k), depending only on the dimension n and on the number k, such that if a bounded polyhedron {x in R^n : Ax <= b} contains exactly k integer points, then there exists a subset of the rows, of cardinality no more than c(n,k), defining a polyhedron that contains exactly the same k integer points. In this case c(n,0)=2^n as in the original case of Doignon-Bell-Scarf for infeasible systems of inequalities. We work on both upper and lower bounds for the constant c(n,k) and discuss some consequences, including a Clarkson-style algorithm to find the l-th best solution of an integer program with respect to the ordering induced by the objective function. [less ▲]

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See detailParametric Polyhedra with at least k Lattice Points: Their Semigroup Structure and the k-Frobenius Problem
Aliev, Iskander; De Loera, Jesus; Louveaux, Quentin ULg

in Beveridge, Andrew; Griggs, Jerold; Hogben, Leslie (Eds.) et al Recent trends in Combinatorics (in press)

The well-studied semigroup Sg(A) = {b : b = Ax; x in Z^n; x >= 0} can be stratified by the sizes of the polyhedral fibers IPA(b) = {x : Ax = b; x >= 0; x in Z^n}. The key theme of this paper is a ... [more ▼]

The well-studied semigroup Sg(A) = {b : b = Ax; x in Z^n; x >= 0} can be stratified by the sizes of the polyhedral fibers IPA(b) = {x : Ax = b; x >= 0; x in Z^n}. The key theme of this paper is a structure theory that characterizes precisely the set Sg_k(A) of all vectors b in Sg(A) such that their fiber IPA(b) has at least k-solutions. We demonstrate that this set is finitely generated, a union of translated copies of a semigroup which can be computed explicitly via Hilbert bases computations. Related results can be derived for those right-hand-side vectors b for which IPA(b) has exactly k solutions or fewer than k solutions. We also show that, when n, k are fixed natural numbers, one can compute in polynomial time an encoding of Sg_k(A) as a generating function, using a short sum of rational functions. As a consequence, one can identify all right-hand-side vectors that have at least k solutions. Using this tool we prove that for fixed n; k the k-Frobenius number can be computed in polynomial time, generalizing a well-known result of R. Kannan. [less ▲]

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See detailLes jugements de Dominique Lampson sur Jan Gossart et Lambert Lombard
Allart, Dominique ULg

in Delfosse, Annick; Glesener, Thomas (Eds.) Ecrire, lire et éduquer à la Renaissance, Hommage en l’honneur de Franz Bierlaire (in press)

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See detailQuantification of anthropogenic effects in the landscape of Lubumbashi
Andre, Marie ULg; Vranken, Isabelle ULg; Boisson, Sylvain ULg et al

in Mahy, Grégory; Colinet, Gilles; Bogaert, Jan (Eds.) Anthropisation au Katanga (in press)

In order to understand the dynamic of the (sub)urbanisation and so, to quantify the anthropogenic effects of the rapid growth of tropical cities, it is crucial to find and apply valuable methods. In this ... [more ▼]

In order to understand the dynamic of the (sub)urbanisation and so, to quantify the anthropogenic effects of the rapid growth of tropical cities, it is crucial to find and apply valuable methods. In this contribution, the transferability of the Rüdisser et al. (2012) «Distance to Nature» hemeroby assessment method to the landscape surrounding the city of Lubumbashi (DRC) is evaluated. That methodology has the advantage of taking structural connectivity into account by computing the distance to natural habitats. As it had never been applied to an African city before, some adjustments (fitting of the local land uses types into the hemeroby levels designed to Austria) and amendments (suppression of the final classification into hemeroby level simplification) are proposed. Moreover, an analysis of the decanal (2002-2013) hemeroby dynamics is presented. Results suggest that the Distance to Nature methodology is transferable but requires good field knowledge to define reference habitats and identify them in the Landsat classified images. There was a dramatic decrease of the «natural» and «near-natural» levels in the study extent during the studied period. In addition, 32% of the land underwent anthropisation increase, mostly around cities and following a ribbon development. [less ▲]

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See detailQuadratic reformulations of nonlinear binary optimization problems
Anthony, Martin; Boros, Endre; Crama, Yves ULg et al

in Mathematical Programming (in press)

Very large nonlinear unconstrained binary optimization problems arise in a broad array of applications. Several exact or heuristic techniques have proved quite successful for solving many of these ... [more ▼]

Very large nonlinear unconstrained binary optimization problems arise in a broad array of applications. Several exact or heuristic techniques have proved quite successful for solving many of these problems when the objective function is a quadratic polynomial. However, no similarly efficient methods are available for the higher degree case. Since high degree objectives are becoming increasingly important in certain application areas, such as computer vision, various techniques have been recently developed to reduce the general case to the quadratic one, at the cost of increasing the number of variables. In this paper we initiate a systematic study of these quadratization approaches. We provide tight lower and upper bounds on the number of auxiliary variables needed in the worst-case for general objective functions, for bounded-degree functions, and for a restricted class of quadratizations. Our upper bounds are constructive, thus yielding new quadratization procedures. Finally, we completely characterize all ``minimal'' quadratizations of negative monomials. [less ▲]

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See detailPower System Dynamic Simulations using a Parallel Two-level Schur-complement Decomposition
Aristidou, Petros; Lebeau, Simon; Van Cutsem, Thierry ULg

in IEEE Transactions on Power Systems (in press)

As the need for faster power system dynamic simulations increases, it is essential to develop new algorithms that exploit parallel computing to accelerate those simulations. This paper proposes a parallel ... [more ▼]

As the need for faster power system dynamic simulations increases, it is essential to develop new algorithms that exploit parallel computing to accelerate those simulations. This paper proposes a parallel algorithm based on a two-level, Schur complement-based, domain decomposition method. The two-level partitioning provides high parallelization potential (coarse and fine-grained). In addition, due to the Schur-complement approach used to update the sub-domain interface variables, the algorithm exhibits high global convergence rate. Finally, it provides significant numerical and computational acceleration. The algorithm is implemented using the shared-memory parallel programming model, targeting inexpensive multi-core machines. Its performance is reported on a real system as well as on a large test system combining transmission and distribution networks. [less ▲]

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See detailContribution of distribution network control to voltage stability: A case study
Aristidou, Petros ULg; Valverde, Gustavo; Van Cutsem, Thierry ULg

in IEEE Transactions on Smart Grid (in press)

A case study dealing with long-term voltage instability in systems hosting active distribution networks is reported in this paper. It anticipates future situations with high penetration of dispersed ... [more ▼]

A case study dealing with long-term voltage instability in systems hosting active distribution networks is reported in this paper. It anticipates future situations with high penetration of dispersed generation, where the latter are used to keep distribution voltages within desired limits, in complement to load tap changers. The interactions between transmission and active distribution networks are investigated on a 3108-bus test system. It involves transmission grid, large generators, and forty distribution networks, each with dispersed generation steered by a controller inspired of model predictive control. The reported simulations show the impact of distribution network voltage restoration as well as the benefit of load voltage reduction actuated by the dispersed generators. [less ▲]

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See detailRadiative Origin of Majorana Neutrino Masses
Aristizabal Sierra, Diego ULg

in PoS - Proceedings of Science (in press)

We discuss raditiative-induced neutrino mass mechanisms. We first briefly discuss systematic one-loop level classifications, and then discuss two-loop classification schemes based on a diagrammatic ... [more ▼]

We discuss raditiative-induced neutrino mass mechanisms. We first briefly discuss systematic one-loop level classifications, and then discuss two-loop classification schemes based on a diagrammatic decomposition of the Weinberg operator. We point out that both, the one and two-loop order systematic sorting provides an exhaustive guide for radiative neutrino mass models. [less ▲]

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See detailTwo-loop-induced neutrino masses: A model-independent perspective
Aristizabal Sierra, Diego ULg

in PoS - Proceedings of Science (in press)

We disucuss Majorana neutrino mass generation mechanisms at the two-loop order. After briefly reviewing the systematic classification of one-loop realizations, we then focus on a general two-loop ... [more ▼]

We disucuss Majorana neutrino mass generation mechanisms at the two-loop order. After briefly reviewing the systematic classification of one-loop realizations, we then focus on a general two-loop classification scheme which provides a model-independent catalog for neutrino mass models at the two-loop order [less ▲]

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See detailInfluence of the secondary endosymbiont Serratia Symbiotica on the resistance to the parasitism in the aphid Acyrthosiphon pisum
Attia, Sabrine; Foray, Vincent; Louâpre, Philippe et al

in Journal of Entomology and Zoology Studies (in press)

Aphids have an obligate association with the primary symbiont Buchnera aphidicola and is known to affect aphid fitness. Aphids commonly harbour other facultative bacterial endosymbionts and may benefit ... [more ▼]

Aphids have an obligate association with the primary symbiont Buchnera aphidicola and is known to affect aphid fitness. Aphids commonly harbour other facultative bacterial endosymbionts and may benefit from their presence through increased resistance to parasitoids [1]. Present results suggest that the ability of hosts to defend against natural enemies depend not only on the presence of symbionts but also on the host genotype. Aphids represent a complex micro-environment for the parasitoid larvae and both the aphid physiology and endosymbiont influence their survival until mummification. [less ▲]

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See detailUn type picard par-delà les frontières : le <nom jeté>
Baiwir, Esther ULg

in Dialectes de Wallonie (in press), 36

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See detailRôle et langue de Tchantchès dans les représentations en castelets des romans de chevalerie : le cas des Quatre fils Aymon
Baiwir, Esther ULg; Impe, Anaëlle

in Enquêtes du Musée de la Vie Wallonne (in press)

Pourquoi et dans quelle mesure les montreurs de marionnettes liégeoises font-ils intervenir Tchantchès aux côtés des grands chevaliers médiévaux, dont les aventures constituent une part importante du ... [more ▼]

Pourquoi et dans quelle mesure les montreurs de marionnettes liégeoises font-ils intervenir Tchantchès aux côtés des grands chevaliers médiévaux, dont les aventures constituent une part importante du répertoire liégeois ? Quels sont ses moyens d'action, mais également ses modes d'expression ? Divers registres de langue apparaissent au fil des spectacles ; quels sont ceux prêtés à notre héros ? Et surtout, ce rôle et cette langue ont-ils évolué au fil du temps ? C’est à ces quelques questions que nous tentons de répondre, en observant les différentes interventions de Tchantchès dans les réécritures des aventures des quatre fils Aymon, l’une des œuvres les plus anciennes et les plus fréquemment jouées dans les théâtres liégeois dévolus aux comédiens de bois. [less ▲]

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See detailCarte géologique de Wallonie (Belgique) 1/10.000, 59/4 Nassogne
Barchy, Laurent; Dejonghe, Léon; Marion, Jean-Marc ULg

Cartographic material (in press)

New geological map of Wallonia published at the scale of 1/25.000 based on a new field work and using previous scientific data, produced since the previous edition published in 1900 (Stainer)

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See detailCarte géologique de Wallonie (Belgique) 1/10.000. 59/3 Rochefort
Barchy, Laurent; Dejonghe, Léon; Marion, Jean-Marc ULg

Cartographic material (in press)

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data, produced since the previous edition published in 1900 (Stainier)

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See detailCarte géologique de Wallonie (Belgique) 1/10.000, 48/7 Modave
Barchy, Laurent; Marion, Jean-Marc ULg

Cartographic material (in press)

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir ... [more ▼]

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir and Mourlon). [less ▲]

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See detailCarte géologique de Wallonie (Belgique) 1/10.000, 48/8 Clavier
Barchy, Laurent; Marion, Jean-Marc ULg

Cartographic material (in press)

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir ... [more ▼]

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir and Mourlon). [less ▲]

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