References of "Lebrun, Philippe"
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See detailLa recherche dans les aires protégées d'Afrique centrale
Delvingt, Willy; Vermeulen, Cédric ULg; Lebrun, Philippe et al

Book published by Ardenne et Gaume asbl (2014)

- Les drones au secours de la grande faune menacée de RDC - Les Gorilles du Parc National de Lobéké, (Cameroun) : Utilisation de l’habitat et Implications pour la conservation - Conservation de l ... [more ▼]

- Les drones au secours de la grande faune menacée de RDC - Les Gorilles du Parc National de Lobéké, (Cameroun) : Utilisation de l’habitat et Implications pour la conservation - Conservation de l'hippopotame commun (Hippopotamus amphibius) au Parc National des Virunga: population actuelle et mesures de protection - Politique(s) des aires protégées au Cameroun : impératifs écologiques, besoins socio-économiques et routines politiciennes - La Réserve de Faune de Lomako Yokokala en République Démocratique du Congo: une réserve méconnue. [less ▲]

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See detailModulation of the 6-position of benzopyran derivatives and inhibitory effects on the insulin releasing process
Florence, Xavier; Dilly, Sébastien ULg; De Tullio, Pascal ULg et al

in Bioorganic & Medicinal Chemistry (2011)

The synthesis of different series of 4- and 6-substituted R/S-3,4-dihydro-2,2-dimethyl-2H-1- benzopyrans is described. All of these new benzopyran derivatives were bearing, at the 4- position, a ... [more ▼]

The synthesis of different series of 4- and 6-substituted R/S-3,4-dihydro-2,2-dimethyl-2H-1- benzopyrans is described. All of these new benzopyran derivatives were bearing, at the 4- position, a phenylthiourea moiety substituted on the phenyl ring by a meta or a para-electronwithdrawing group such as Cl or CN. The study aimed at exploring the influence of the nature of the substituent at the 6-position in order to develop new benzopyran-type KATP channel activators exhibiting an improved selectivity towards the insulin secreting cells. The original compounds were examined in vitro on rat pancreatic islets (inhibition of insulin release) as well as on rat aorta rings (vasorelaxant effect) and their activity was compared to that of the reference KATP channel activators (±)-cromakalim, (±)-pinacidil, diazoxide and to previously synthesized cromakalim analogues. Structure–activity relationships indicated that the inhibitory effect on the insulin secreting cells was related to the lipophilicity of the molecules and to the size of the substituent located at the 6-position. A marked inhibitory activity on the insulin secretory process was obtained with molecules bearing a bulky tertbutyloxycarbonylamino group at the 6-position (20-23). The latter compounds were found to have the same efficacy on the pancreatic endocrine tissue than some previously described molecules. Lastly, radioisotopic experiments further identified R/S-N-4-chlorophenyl-N’-(6- tert-butyloxycarbonylamino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)thiourea (23) as a KATP channel opener. [less ▲]

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See detailDistribution patterns and indicator species of butterfly assemblages of wet meadows in southern Belgium
Sawchik, Javier; Dufrêne, Marc ULg; Lebrun, Philippe

in Belgian Journal of Zoology (2005), 135(1), 43-52

Focal species are a valuable tool for proposing and evaluating management practices for biodiversity conservation. Assemblages of indicator species could be used to cover a wide range of habitats. We ... [more ▼]

Focal species are a valuable tool for proposing and evaluating management practices for biodiversity conservation. Assemblages of indicator species could be used to cover a wide range of habitats. We identified the main patterns of variation in butterfly assemblages on a diverse set of wet meadows in southern Belgium. We used multivariate techniques to identify the butterfly assemblages and the species that characterize these habitats. Three main assemblages were identified, based principally on the dominance of five butterfly species : Brenthis ino, Closiana selene, Lycaena helle, Lycaena hippothoe and Proclossiana eunomia. These are indicator species of different habitats structured along a vegetation gradient. This gradient is partially determined by altitude and edaphic factors (base-richness, pH, fertility). We assume that focusing the conservation practices upon these species will promote the preservation of a wide range of organisms inhabiting the wet meadows. [less ▲]

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See detailHotspots, complementarity or representativeness? Designing optimal small-scale reserves for biodiversity conservation
Kati, V.; Devillers, P.; Dufrêne, Marc ULg et al

in Biological Conservation (2004), 120(4), 471-480

Reserve networks are a major tool of ecological management aiming at biodiversity conservation. Maximizing the number of species conserved with the minimum land sacrifice is a primary requirement in ... [more ▼]

Reserve networks are a major tool of ecological management aiming at biodiversity conservation. Maximizing the number of species conserved with the minimum land sacrifice is a primary requirement in reserve design. In this study, we examine the efficiency of five different scenarios to conserve: (i) the biodiversity of one target group and (ii) the overall biodiversity of an area. The study was conducted in Dadia Reserve, in northern Greece. Six groups of species were selected to represent its biodiversity: woody plants, orchids, Orthoptera, aquatic and terrestrial herpetofauna, and small terrestrial birds. The scenarios examined represent different conservation approaches to select network sites. For each approach, the starting point was one of the above six groups of species, considered as the target group. In scenario A, which reflects the hotspot approach, the sites richest in species are selected. Scenario B selects the sites most complementary in terms of species richness. The next two scenarios use the principle of environmental representativeness, expressed in terms of habitat (scenario C) or vegetation (scenario D). Under scenario E, sites forming the network are selected at random. The rank of scenarios in terms of preserving the species of the target group was always B>A>C>D>E, irrespective of the group considered as target group. Their rank, when preservation of the total biodiversity was the issue, was B, A>C, D>E. © 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailTesting the value of six taxonomic groups as biodiversity indicators at a local scale
Kati, V.; Devillers, P.; Dufrêne, Marc ULg et al

in Conservation Biology (2004), 18(3), 667-675

We examined six groups of taxa - woody plants, aquatic and terrestrial herpetofauna, small terrestrial birds, orchids, and Orthoptera - to determine their efficiency as biodiversity indicators in the ... [more ▼]

We examined six groups of taxa - woody plants, aquatic and terrestrial herpetofauna, small terrestrial birds, orchids, and Orthoptera - to determine their efficiency as biodiversity indicators in the Dadia Reserve in northern Greece. We investigated the indicator value of each group by examining the degree of congruence of its species-richness pattern with that of the other groups and the efficiency of its complementary network in conserving the other groups and biodiversity. The two techniques differed in many respects in their outputs, but they both showed woody plants as the best biodiversity indicator. There was in general low congruence in the species richness patterns across the different groups. Significant relationships were found between woody plants and birds, Orthoptera and terrestrial herpetofauna, and birds and aquatic herpetofauna. None of the optimal complementary networks of the groups we examined protected all species of the other groups. Nevertheless, the complementary network of woody plants adequately conserved all groups except orchids. We conclude that the principle of complementarity must be integrated into the methodology of evaluating an indicator. In an applied context, our results provide a scientific background on which to base a biomonitoring program for the Dadia Reserve. In a wider scope, if the group of woody plants prove an adequate biodiversity indicator for other Mediterranean areas as well, this will be important because it will facilitate conservation-related decisions for the entire Mediterranean region. [less ▲]

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See detailConservation management for Orthoptera in the Dadia reserve, Greece
Kati, V.; Dufrêne, Marc ULg; Legakis, A. et al

in Biological Conservation (2004), 115(1), 33-44

The diversity patterns, the ecological structure and the typical species of the orthopteran assemblage in the Dadia reserve are investigated. The reserve was designed to protect the black vulture ... [more ▼]

The diversity patterns, the ecological structure and the typical species of the orthopteran assemblage in the Dadia reserve are investigated. The reserve was designed to protect the black vulture (Aegypius monachus) and other raptors. A total of 39 orthopteran species were found, including Paranocarodes chopardi, a pamphagid species with very restricted distribution. All species can be represented in a network of six complementary habitats, including open oak woodlands, agricultural fields separated with hedges, humid grasslands, as well as serpentine grasslands. The buffer zone of the reserve is far more important for Orthoptera conservation than the core areas, which host most of the black vulture nests. Management focusing on raptors is in general compatible with conservation of Orthoptera. We suggest the maintenance of forest openings in the buffer zone, the maintenance of forest heterogeneity, the enhancement of periodical livestock grazing, and the use of nine indicator species and Paranocarodes chopardi in the reserve monitoring program. © 2003 Elsevier Ltd. All rights reserved. [less ▲]

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See detailEstimation of habitat quality based on plant community, and effects of isolation in a network of butterfly habitat patches
Sawchik, J.; Dufrêne, Marc ULg; Lebrun, Philippe

in Acta Oecologica (2003), 24(1), 25-33

Minimum viable site networks are crucial for many threatened species but their design is always a difficult procedure. The present study investigated methods to estimate habitat quality of patches, in an ... [more ▼]

Minimum viable site networks are crucial for many threatened species but their design is always a difficult procedure. The present study investigated methods to estimate habitat quality of patches, in an ecological network for five butterfly species (Brenthis ino, Clossiana selene, Lycaena helle, Lycaena hippothoe, Proclossiana eunomia) inhabiting wet meadows. Abundance predictions were performed on the basis of botanical relevés with a multiple-species approach combining canonical correspondence analysis and multiple regression. Models are defined on a reference site set and are evaluated on a test site set. All the fitted models predicted the abundance of the butterfly species considerably well (from 61 to 86% of the variation). We evaluated the potential consequences of isolation on local populations, by comparing predicted and observed abundance. It was expected that greater differences would be observed when sites were more isolated. On the test set, differences between predicted and observed abundance were largely correlated to site isolation for L. helle and P. eunomia. The most isolated sites had greater chances to be empty, even if they had high-quality habitat. Reciprocally, when the sites were less isolated, the abundance observed was always greater than predicted, seeming to confirm the role of rescue effects. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. [less ▲]

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See detailMetapopulation dynamics of the bog fritillary butterfly: Modelling the effect of habitat fragmentation
Sawchik, J.; Dufrêne, Marc ULg; Lebrun, Philippe et al

in Acta Oecologica (2002), 23(5), 287-296

Population viability analysis (PVA) and metapopulation theory are valuable tools to model the dynamics of spatially structured populations. In this article we used a spatially realistic population dynamic ... [more ▼]

Population viability analysis (PVA) and metapopulation theory are valuable tools to model the dynamics of spatially structured populations. In this article we used a spatially realistic population dynamic model to simulate the trajectory of a Proclossiana eunomia metapopulation in a network of habitat patches located in the Belgian Ardenne. Sensitivity analysis was used to evaluate the relative influence of the different parameters on the model output. We simulated habitat loss by removing a percentage of the original habitat, proportionally in each habitat patch. Additionally, we evaluated isolation and fragmentation effects by removing and dividing habitat parches from the network, respectively. The model predicted a slow decline of the metapopulation size and occupancy. Extinction risks predicted by the model were highly sensitive to environmental stochasticity and carrying capacity. For a determined level of habitat destruction, the expected lifetime of the metapopulation was highly dependent on the spatial configuration of the landscape. Moreover, when the proportion of removed habitat is above 40% of the original habitat, the loss of whole patches invariably leads to the strongest reduction in metapopulation viability. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. [less ▲]

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See detailPharmacological evaluation of cromakalim analogues: towards the discovery of new inhibitors of insulin secretion from rat pancreatic -cells
Sebille, S.; Becker, B.; Antoine, M. H. et al

in Fundamental & Clinical Pharmacology (2002)

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See detailBPDZ 154: a novel activator of KATP channels in beta-cells
Lee, A. T.; Cosgrove, K. E.; Barnes, P. D. et al

in Pflügers Archiv : European Journal of Physiology (2002)

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See detailL'apport des banques de données biogéographiques à la conservation de l'entomofaune
Lebrun, Philippe; Dufrêne, Marc ULg

in Parcs & Réserves (1998), 53

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See detailUn autre regard sur les atlas de France et de Belgique.
Vansteenwegen, Christian; Dufrêne, Marc ULg; Lebrun, Philippe

in AVES (1995), 31

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See detailLes Coléoptères Carabidae (Coleoptera) de la Réserve Naturelle du Pré des Forges à Mirwart
Waeyenbergh, M.; Dufrêne, Marc ULg; Lebrun, Philippe

in Bulletin en Annalen van de Koninklijke Belgische Vereniging voor Entomologie (1995), 131

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See detailReseau d'information sur la faune et la flore en Region de Bruxelles-Capitale.
de Caritat; Dufrêne, Marc ULg; Lebrun, Philippe

Report (1994)

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See detailSurveillance de l'état de l'environnement wallon par bioindicateurs.
Marchal, Didier; Dufrêne, Marc ULg; Lebrun, Philippe et al

in Les Cahiers des Réserves Naturelles (1992), 1

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