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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 detailColonoscopie virtuelle par scanner
HOCK, DANIELLE; MATERNE, R.; OUHADI, ROXANNE et al

in Colonoscopie virtuelle par scanner. EMC Radiologie et imagerie médicale : Abdominale - Digestive (2011)

Detailed reference viewed: 11 (0 ULg)
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See detailColonoscopie virtuelle par scanner. Encyclopédie Médico-Chirurgicale, Gastro-entérologie
HOCK, D.; MATERNE, R.; OUHADI, Roxanne et al

in Colonoscopie virtuelle par scanner. Encyclopédie Médico-Chirurgicale, Gastro-entérologie (2013)

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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)

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See detailColostrum. De nouvelles voies de valorisation
Boudry, Christelle ULg

Article for general public (2006)

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See detailColour ConText
Neven, Sylvie ULg

Textual, factual or bibliographical database (2014)

For several centuries, the literature of artists’ recipe books has been considered one of the most original and comprehensive primary sources for the historical study of artistic practices and materials ... [more ▼]

For several centuries, the literature of artists’ recipe books has been considered one of the most original and comprehensive primary sources for the historical study of artistic practices and materials. In addition to the famous Libro dell’arte of Cennino Cennini, nearly five hundred European manuscripts containing artistic recipes survive from before circa 1550. A great number of these are still unpublished and virtually unknown. Our work on a large corpus of recipe collections has generated the material for a database that facilitates consultation and exploitation of the source material.Current structure of the database The core data consists of mediaeval and pre-modern manuscripts and printed books from Northern and Southern Europe. The various layouts of the ‘Colour ConText’ database allow access to the metadata of the sources with details such as title, current location, place and date of origin, scribes or authors, previous owners, and description of any other (non-recipe) content. The database also allows access to digital images of these sources via European Cultural Heritage Online (ECHO) or via digital collections made available by external institutes, and to the transcription and translation of the recipe texts. Reference to primary and secondary sources, together with the related bibliographical data, is integrated throughout the database. To date, over 400 manuscripts have been considered and 4,500 recipes - some constituting only a few lines, others covering several folios - have been transcribed and recorded within the database. The database also includes a complete index of the ‘simples’ (substances mentioned as ingredients). Thus materials are indexed both by their current scientific name and by the terms exactly as they appear in the source texts. Each ingredient’s appellation is linked by relational tables to its contemporary and modern synonyms. This allows the retrieval of all the different appellations used for one ingredient – detailing the historical written context – but also the various ingredients that may be related to one ‘appellation’. A survey of artistic materials and techniques The database helps not only to observe the global frequency and recurrence of each ingredient and technical instruction, but also to deduce the availability of artistic material within a chronologically and geographically defined area. Many of these recipes can be used to identify specific, datable practices and materials, as compilers often specify the name and/or place of origin of the artists from whom they obtained their information. Information related to the historical provenance of the source material (obtained through codicological or philological analysis) has also been recorded within the database and may be used for that purpose. Moreover, it is possible to observe, through factors such as frequency within the corpus, basic structure, and evolution, how recipes were modified over time or by other external phenomena. It is also possible to link the development of specific artistic procedures and technical traditions, and to correlate these with more widely diffused techniques. Thus, recipe books allow us to study the geography, chronology, circulation and dissemination of artists’ knowledge. Colour material and terminology This project notably aims at considering and evaluating the importance and interest accorded to knowledge of the materials and substances used by artists and shared with other professionals (such as apothecaries), focusing on pigments and colouring material. For that purpose, other written sources related to colour will be included (notably texts on colour theory, on colour symbolism, on colour systems, on the pharmaceutical qualities of colours, etc.). In parallel to the physical descriptions of pigments and colourants, these written sources deliver information concerning their optical characteristics, conservation, (in)compatibility with other sorts of materials and their ageing properties. The diversity of colour denominations and the complexity of the varied technical terminology will be made transparent through a glossary of all the substances, ingredients, and their synonyms mentioned in the recipe books. Transmission of artists’ knowledge Such collections of recipes were often gathered in the same book with other subjects (such as theology, alchemy, botany or medicine) and these are also described within the database. The database also includes information concerning the provenance and circulation of these books outside the workshop. This allows other questions to be addressed - notably those related to the ownership and readership of collections of recipes. [less ▲]

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See detail"Colour ConText". A Database on Colour Practice and Colour Knowledge in Pre-Modern Europe
Neven, Sylvie ULg; Leonhard, Karin; Dupré, Sven

in Dubois, Hélène; Eyb-Green, Sigrid; Kroustallis, Stephanos (Eds.) et al Making and transforming art : changes in artists’ materials and practice (2014)

Detailed reference viewed: 61 (6 ULg)