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See detailColonisation credit in recent wet heathland butterfly communities
Cristofoli, Sara ULg; Mahy, Grégory ULg

in Insect Conservation and Diversity (2010), 3

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See detailLa colonisation entomologique en présence de drogues: une approche expérimentale
Caparros Megido, Rudy ULg; Dekeirsschieter, Jessica; Haubruge, Eric ULg

in Insectes, cadavres et scènes de crime : Principe et applications de l'entomologie médico-légale (2014)

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See detailColonisation épiphyte de Posidonia oceanica (L.) Delile: Comparaison entre des feuilles artificielles et des feuilles naturelles.
Pete, Dorothée ULg

Master's dissertation (2005)

Face aux importantes perturbations, principalement d’origines anthropiques, qui affectent l’écosystème côtier méditerranéen, il est nécessaire de mettre en place des outils de diagnostic rapides de ces ... [more ▼]

Face aux importantes perturbations, principalement d’origines anthropiques, qui affectent l’écosystème côtier méditerranéen, il est nécessaire de mettre en place des outils de diagnostic rapides de ces perturbations. Posidonia oceanica (L.) Delile, qui est un des piliers de cet écosystème, a souvent été utilisée pour évaluer l’état de santé du milieu côtier méditerranéen. Cependant, comme son turnover est relativement lent et que cette plante peut accumuler des réserves qui lui permettent, durant des périodes relativement longues, du garder une phénologie stationnaire, malgré des changement environnementaux, il est parfois trop tard lorsqu’elle montre les effets d’une perturbation. Dans ce contexte, il devient nécessaire de trouver des outils de diagnostic précoces de ces perturbations. Dans ce cadre, les modifications des populations épiphytes, qui ont un turnover plus rapide que la plante, apparaissent comme des marqueurs plus précoces de la pollution. Dans ce cadre, nous avons tenté de déterminer si les communautés épiphytes se développant sur des feuilles artificielles imitant les feuilles de posidonies étaient semblables à celles s’installant sur les feuilles naturelles, et ce afin de voir si les feuilles artificielles pouvaient être utilisées comme modèle de feuilles de posidonies dans le cadre d’études d’impact. Les résultats obtenus ont montrés que la colonisation des deux types de feuilles n’était pas similaire. En effet, la densité des épiphytes était beaucoup plus importante à la base des feuilles artificielles qu’à la base des feuilles de posidonies mais la diversité et l’équitabilité calculées pour les grands taxa était plus élevée sur les feuilles naturelles. Cependant, l’étude de la colonisation par les épiphytes réalisée sur toute la longueur de la feuille artificielle a montré une zonation proche de celle normalement rencontrée sur les feuilles matures de posidonies. Ainsi, au début de la colonisation et pour la base des feuilles, les feuilles artificielles ne sont pas de bons modèles des feuilles de posidonies et ne peuvent pas être utilisées dans le cadre d’études d’impact. Cependant, au vu des résultats obtenus pour toute la longueur des feuilles artificielles et des données de la littérature, on ne peut pas exclure que, pour des stades plus avancés de la colonisation, la feuille artificielle soit un bon modèle de la feuille naturelle. [less ▲]

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See detailColonisation of the Mucosae - Adherence Factors and their Interaction with Host Cells
Mainil, Jacques ULg

in Annales de Médecine Vétérinaire (2005), 149C(Special issue), 5-14

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See detailColonization Credit in Restored Wet Heathlands
Cristofoli, Sara ULg; Piqueray, Julien ULg; Dufrêne, Marc ULg et al

in Restoration Ecology (2010), 18(5), 645-655

Although human-driven landscape modification is generally characterized by habitat destruction and fragmentation, it may also result in the creation of new habitat patches, providing conditions conducive ... [more ▼]

Although human-driven landscape modification is generally characterized by habitat destruction and fragmentation, it may also result in the creation of new habitat patches, providing conditions conducive to spontaneous colonization. In this article, we propose the concept of ‘‘colonization credit’’ (i.e., the number of species yet to colonize a patch, following landscape changes) as a framework to evaluate the success of colonization, in terms of species richness, in new/restored habitats, taking into account the spatial structure of landscapes. The method mirrors similar approaches used to estimate extinction debt in the context of habitat fragmentation, that is, comparisons, between old and new habitat patches, of the relationships among spatial patch metrics and patch species richness. We applied our method to the case of spontaneous colonization of newly created habitat patches suitable for wet heathland plant communities in South Belgium. Colonization credit was estimated for the total species richness, the specialist species richness, and the species richness of three emergent groups (EGs) of specialist species, delineated on the basis of dispersal traits. No significant colonization credit was identified either in patches created 25–55 years ago or in those created within the past 25 years, with the exception of species from our first EG (mostly anemochorous species with long-term persistent seed bank). However, the differential response of species in that first EG could not be explained through their characteristic life history traits. The results of this study are encouraging and suggest that deliberate, directed restoration activities could yield positive developments in a relatively short period of time. [less ▲]

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See detailColonization of a new habitat by copepods: An in situ experiment
Mascart, Thibaud ULg; Lepoint, Gilles ULg; Biondo, Renzo ULg et al

Conference (2014, December 12)

Colonization of new habitats by a biological community is conspicuous and this dynamic process is one of the architectural forces of the biogeographical distribution we know today. Within the meiofauna ... [more ▼]

Colonization of new habitats by a biological community is conspicuous and this dynamic process is one of the architectural forces of the biogeographical distribution we know today. Within the meiofauna (<1mm), copepods (Crustacea) have successfully adapted to nearly every ecosystem and heir colonization power of permanent habitats is therefore well-established. However, few studies tackled the colonization of new naturally occurring provisional habitats, which are of ecological interest since they are rich in organic material, structurally complex and devoted of native fauna. Hence, the present study investigated the copepod colonization of provisional macrophytodetritus (mainly composed of senescent leaves and drift macroalgae) accumulated on bare sand patches inside a Mediterranean Posidonia oceanica seagrass meadow. General motive of colonization such as food and shelter are well-defined. However, little is known regarding the mode of the colonization and source pool of the associated colonists. Here, an in situ experiment was deployed in order to understand the mode of copepod’s colonization to fauna deprived macrophytodetritus. The objectives were: (1) assessing the adjacent colonist’s source pool (i.e. sediment, water column or P. oceanica canopy), (2) investigating the speed of settlement and (3) quantifying the species composition of the colonizing copepods. In summary: (1) species from every source pool actively colonized the macrophytodetritus through the water column and through the sediment-macrophytodetritus interface. (2) The initial settlement occurred within the first 24 hours. (3) The species composition showed to be different than the source’s composition. After 24h, the composition was similar to 45% of the P. oceanica, 28% of the water column and 25% of the sediments. After 96h, the composition was similar to 24% of the P. oceanica, 13% of the water column and 10% of the sediments. Indicating an evolution towards a macrophytodetritus copepod specific community composed of a mixture of the adjacent habitats first colonizers. [less ▲]

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See detailColonne lithologique du sondage de Latour (494 m): une coupe de référence pour le Secondaire de la Gaume
Boulvain, Frédéric ULg; Monteyne, R.

in Professional paper Belgian geological survey (1993), 267

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See detailColony collapse disorder: a descriptive study.
Vanengelsdorp, Dennis; Evans, Jay D; Saegerman, Claude ULg et al

in PLoS ONE (2009), 4(8), 6481

BACKGROUND: Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this ... [more ▼]

BACKGROUND: Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. METHODS AND PRINCIPAL FINDINGS: Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. CONCLUSIONS/SIGNIFICANCE: This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted. [less ▲]

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See detailColor terms in medieval artists’ recipe books : diversity and variability. The puzzling case of ‘Paris Red’
Neven, Sylvie ULg

Conference (2013)

Occurrences of historical color terms can be found in several old written sources and, notably, in medieval artists’ recipe books. In parallel to the physical descriptions of pigments and colorants, these ... [more ▼]

Occurrences of historical color terms can be found in several old written sources and, notably, in medieval artists’ recipe books. In parallel to the physical descriptions of pigments and colorants, these writings deliver information about their optical characteristics, conservation, (in)compatibility with other sorts of materials, and ageing properties. Examination conducted within a corpus of more than 400 recipe books, dating from 1300 to 1650 and produced in Northern Europe, has shed light on the diversity of color denominations and the several ways of designating a coloring material, such as pigments and colorants. Color terms used in artists’ recipe books may have had various meanings and correspond to different hues, subtances or qualities. Moreover, the concept or the material designated by a color term may change, not just in time and space, but from one recipe to another even if they derive from the same source. Looking through a large number of instructions dedicated to colors, it is possible to propose some categories for describing the different sorts of nomenclature and their nature, and it is also possible to suggest the range of pigments and colorants that one word could refer to. Variety and importance given to color names can also be put in relation with the importance and the symbolic value accorded to a coloring agent or a color. This paper will focuss on the various appellations of red color. In particular, it will examine in depth the puzzling name “Paris Red”. [less ▲]

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See detailI colori di Place de la République (Wölfflin, Floch e la fotografia)
Beyaert-Geslin, Anne; Dondero, Maria Giulia ULg

in Dondero, Maria Giulia; Basso Fossali, Pierluigi (Eds.) Semiotica della fotografia. Investigazioni teoriche e pratiche di analisi (2006)

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See detailA Colorimetric Assay for the Simultaneous Measurement of Plasminogen Activators and Plasminogen Activator Inhibitors in Serum-Free Conditioned Media from Cultured Cells
Leprince, Pierre ULg; Rogister, Bernard ULg; Moonen, Gustave ULg

in Analytical Biochemistry (1989), 177(2), 341-6

The coupled photometric assay for plasminogen activator reported by Coleman and Green (1981) Methods in Enzymology (Lorand, L., Ed.), Vol. 80, pp. 408-414, Academic Press, San Diego, CA) has been adapted ... [more ▼]

The coupled photometric assay for plasminogen activator reported by Coleman and Green (1981) Methods in Enzymology (Lorand, L., Ed.), Vol. 80, pp. 408-414, Academic Press, San Diego, CA) has been adapted for use with 96-well plates and an automatic microplates spectrophotometer. The assay allows the discrimination between tissue-type and urokinase-type plasminogen activators in cell culture-conditioned media. It provides a level of detection of these enzymes in the range 10(-17) to 10(-13) mol (determined using purified human plasminogen activators), uses no radioisotopes, and is faster and more economical than similar assays using specific peptide substrates for plasminogen activators. Levels of free plasminogen activator inhibitor activity can be simultaneously measured on the same samples by a simple adaptation of the assay. This method allows an easy treatment of the data by interfacing with a computer and should thus be useful when large numbers of samples are assayed. [less ▲]

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See detailA colorimetric method for the determination of lipase activity in soil
Margesin, R.; Feller, Georges ULg; Hammerle, M. et al

in Biotechnology Letters (2002), 24(1), 27-33

A colorimetric method for the determination of lipase activity in soil has been developed. Using p-nitrophenyl butyrate as substrate, soil samples are incubated at 30 degreesC and pH 7.25 for 10 min ... [more ▼]

A colorimetric method for the determination of lipase activity in soil has been developed. Using p-nitrophenyl butyrate as substrate, soil samples are incubated at 30 degreesC and pH 7.25 for 10 min. After cooling on ice and centrifugation, the released p-nitrophenol is determined at 400 nm. To allow for the adsorption of p-nitrophenol onto soil, a calibration curve is prepared in the presence of soil. [less ▲]

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See detailColoring Graphs Using Two Colors while Avoiding Monochromatic Cycles
Talla Nobibon, Fabrice ULg; Hurkens, Cor A. J.; Leus, Roel et al

in INFORMS Journal on Computing (2011)

We consider the problem of deciding whether a given directed graph can be vertex partitioned into two acyclic subgraphs. Applications of this problem include testing rationality of collective consumption ... [more ▼]

We consider the problem of deciding whether a given directed graph can be vertex partitioned into two acyclic subgraphs. Applications of this problem include testing rationality of collective consumption behavior, a subject in microeconomics. We prove that the problem is NP-complete even for oriented graphs and argue that the existence of a constant-factor approximation algorithm is unlikely for an optimization version that maximizes the number of vertices that can be colored using two colors while avoiding monochromatic cycles. We present three exact algorithms—namely, an integer-programming algorithm based on cycle identification, a backtracking algorithm, and a branch-and-check algorithm. We compare these three algorithms both on real-life instances and on randomly generated graphs. We find that for the latter set of graphs, every algorithm solves instances of considerable size within a few seconds; however, the CPU time of the integer-programming algorithm increases with the number of vertices in the graph more clearly than the CPU time of the two other procedures. For real-life instances, the integer-programming algorithm solves the largest instance in about a half hour, whereas the branch-and-check algorithm takes approximately 10 minutes and the backtracking algorithm less than 5 minutes. Finally, for every algorithm, we also study empirically the transition from a high to a low probability of a YES answer as a function of the number of arcs divided by the number of vertices. [less ▲]

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See detailColoring of the infinite grid
Vandomme, Elise ULg; Gravier, Sylvain

Poster (2012, May 23)

We present a method that links (r,a,b)-codes in the infinite grid and particular colorings of weighted cycles, called constant 2-labellings.

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See detailColoss Working Group 1: monitoring and diagnosis.
Nguyen, Bach Kim ULg; Van der zee, Romée; Vejsnaes, Flemming et al

in Journal of Apicultural Research (2010), 49(1), 97-99

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See detailColossal positive magnetoresistance in a doped nearly magnetic semiconductor
Hu, Rongwei; Thomas, K. J.; Lee, Y. et al

in Physical Review B (2008), 77(8),

We report on a positive colossal magnetoresistance (MR) induced by metallization of FeSb2, a nearly magnetic or "Kondo" semiconductor with 3d ions. We discuss the contribution of orbital MR and quantum ... [more ▼]

We report on a positive colossal magnetoresistance (MR) induced by metallization of FeSb2, a nearly magnetic or "Kondo" semiconductor with 3d ions. We discuss the contribution of orbital MR and quantum interference to the enhanced magnetic field response of electrical resistivity. [less ▲]

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See detailColosses et perspective: de la prise en considération de la parallaxe dans la statuaire pharaonique de grandes dimensions au Nouvel Empire
Laboury, Dimitri ULg

in Revue d'Egyptologie (2008), 59

The deformation which affects the physiognomy of colossal sculptures of the New Kingdom suggests that Ancient Egyptian Art could have taken into account the parallax effects or distortions due to ... [more ▼]

The deformation which affects the physiognomy of colossal sculptures of the New Kingdom suggests that Ancient Egyptian Art could have taken into account the parallax effects or distortions due to perspective. This question and its methodological and theoretical implications are investigated, with a special focus on the colossi of Amenhotep IV from Karnak. [less ▲]

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See detailLe colostrum bovin : "une solution pour réduire les effets négatifs du sevrage"
Boudry, Christelle ULg

Article for general public (2008)

Detailed reference viewed: 28 (12 ULg)