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See detailDispersal ability and speciation mechanisms in bryophytes
Hutsemekers, Virginie ULg

Doctoral thesis (2012)

Detailed reference viewed: 52 (9 ULg)
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See detailDispersal and predation of diaspores of Coula edulis Baill. in an evergreen forest of Gabon
Moupela, Christian ULg; Doucet, Jean-Louis ULg; Daïnou, Kasso ULg et al

in African Journal of Ecology (2013), 52

The African walnut ( Coula edulis) is a tree species of African evergreen forests, the seeds of which are collected and traded by African people. Many animal species consume African walnut diaspores ... [more ▼]

The African walnut ( Coula edulis) is a tree species of African evergreen forests, the seeds of which are collected and traded by African people. Many animal species consume African walnut diaspores; however, their roles as dispersers or predators have yet to be clarified. In this study, we present observations conducted in two different habitats of a Gabonese region over a 3-year period. The originality of this research resides in the combination of three complementary approaches: (i) the use of camera-traps (ii) the exploration of land rodent burrows and (iii) the examination of elephant dung. In total, 408 camera-trap photographs have shown seven animal species involved in the dispersal/predation of C. edulis. Among these seven frugivorous species, the bush pig was found to be the main consumer and predator of seeds. Land rodents (Muridae) are potential predators, as they damaged the seeds and buried them deep in the soil. They may also play a role in the regeneration process as a result of the loss of seeds during transportation. Finally, no seeds appeared to emerge intact from elephant faeces. These results indicate that the natural regeneration rate of this tree species is low, unless other complex mecha-nisms are involved. [less ▲]

Detailed reference viewed: 66 (32 ULg)
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See detailDispersal and regeneration capacity of large-seeded tree species in a forest-savanna mosaic in Western DR Congo
Trolliet, Franck ULg; Huynen, Marie-Claude ULg; Hambuckers, Alain ULg

Poster (2012)

It is widely recognized that the Congo Basin is affected by numerous anthropogenic pressures. A number of studies proved that hunting and forest fragmentation diminish the diversity and abundance of large ... [more ▼]

It is widely recognized that the Congo Basin is affected by numerous anthropogenic pressures. A number of studies proved that hunting and forest fragmentation diminish the diversity and abundance of large vertebrates, more specifically, of large frugivores. The depletion of those animals can directly affect large-seeded tree species as large seeds closely depend on the community of large frugivorous vertebrates for their dispersal. Then, the disruption of animal mediated seed dispersal is thought to deeply impact the plant regeneration capacity. The forest-savanna mosaic situated in Western DR Congo is an ecotone characterized by naturally occurring forest fragments which are also subject to numerous anthropogenic pressures. Those are very likely to disrupt seed dispersal mechanisms and to alter forest regeneration processes. To date, few studies have considered the effect of such an ecosystem on plant-animal interaction dynamics such as seed dispersal, and none have been done in this region. This study will examine if the early stages of regeneration of the large-seeded tree species Anonidium mannii, namely the dispersal capacity and seedling establishment is affected by forest fragment size. We predict that the small fragment size will negatively affect the regeneration capacity of this species. To test this assumption, we will work along a gradient of forest fragment sizes to define the composition of the seed disperser communities. For each disperser assemblage, we will evaluate the quantitative capacity of seed dispersal by combining direct focal observations and camera trapping. A literature review on each disperser species seed retention time and habitat use will allow the computation of the seed dispersal kernels. We will also evaluate the effect of seed ingestion by a presumably important seed disperser, the bonobo, Pan paniscus, on its germination capacity. Seeds will be collected from dung to evaluate the effect of seed ingestion on the rate and velocity of germination. Finally, we will study the predation pressure exerted on dispersed and non-dispersed seeds and seedlings by setting up two sets of seeds below the canopy of parent trees and away from any conspecific trees. One set will be dispersed unprotected to seed predators; another one will be enclosed in a cage and permit seeds to germinate, allowing us to evaluate the herbivores pressure on seedlings. [less ▲]

Detailed reference viewed: 111 (17 ULg)
See detailDispersal, diversity and evolution of the Macaronesian cryptogamic floras
Vanderpoorten, Alain ULg; Laenen, Benjamin ULg; Rumsey, F. J. et al

in Plants and Islands, 2nd ed. (2010)

Detailed reference viewed: 95 (15 ULg)
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See detailDispersed Pd-Ag alloys for selective production of olefins from chlorinated alkanes
Heinrichs, Benoît ULg; Schoebrechts, Jean-Paul; Pirard, Jean-Paul ULg

in Studies in Surface Science and Catalysis (2000), 130

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See detailDispersion Atom Transfer Radical Polymerization of vinyl monomers in supercritical carbon dioxide
Grignard, Bruno ULg; Jérôme, Christine ULg; Calberg, Cédric ULg et al

in Macromolecules (2008), 41(22), 8575-8563

Controlled dispersion atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out in supercritical carbon dioxide in the presence of aminated fluoropolymers ... [more ▼]

Controlled dispersion atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out in supercritical carbon dioxide in the presence of aminated fluoropolymers. These materials played the dual role of macroligand for the copper bromide and also steric stabilizer to support formation of polymer microspheres. The livingness of the PMMA beads was confirmed by the one-pot two-step PMMA chain extension and the synthesis of poly(methyl methacrylate)-b-poly(2,2,2-trifluoroethyl methacrylate) (PMMA-b-PFMA) diblock copolymer in scCO2. Successful activator generated by electron transfer (AGET) for ATRP of MMA, using tin ethylhexanoate as a reducing agent, is also discussed, and the concept of dispersion ATRP of MMA was successfully extended to the controlled dispersion polymerization of styrene by ATRP leading to the formation of PS microparticles. Finally, due to the high solubility of the catalyst in scCO2, the purification of PMMA was investigated by supercritical fluid extraction, leading to the preparation of PMMA beads with low residual catalyst traces. [less ▲]

Detailed reference viewed: 75 (8 ULg)
See detailDispersión de semillas por coleópteros coprófagos
Culot, Laurence ULg

Scientific conference (2010, March 09)

Detailed reference viewed: 30 (1 ULg)
See detailDispersión de semillas por primates
Culot, Laurence ULg

Scientific conference (2010, March 08)

Detailed reference viewed: 22 (0 ULg)
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See detailDispersion nitroxide mediated polymerization of methyl methacrylate in supercritical carbon dioxide using in situ formed stabilizers
Grignard, Bruno ULg; Phan, Tran; Bertin, Denis et al

in Polymer Chemistry (2010), 1(6), 837-840

PMMA microspheres were successfully prepared in supercritical carbon dioxide by controlled dispersion nitroxide mediated polymerization of methyl methacrylate using perfluorinated stabilizers that were ... [more ▼]

PMMA microspheres were successfully prepared in supercritical carbon dioxide by controlled dispersion nitroxide mediated polymerization of methyl methacrylate using perfluorinated stabilizers that were generated “in situ”. [less ▲]

Detailed reference viewed: 32 (12 ULg)
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See detailDispersion nitroxide mediated polymerization of MMA in supercritical carbon dioxide
Grignard, Bruno ULg; Gigmes, Didier; Jérôme, Christine ULg et al

Poster (2009, May 14)

Controlled dispersion Nitroxide Mediated Polymerization (NMP) of methyl methacrylate (MMA) was successfully carried out for the first time in supercritical carbon dioxide (scCO2) in the presence of CO2 ... [more ▼]

Controlled dispersion Nitroxide Mediated Polymerization (NMP) of methyl methacrylate (MMA) was successfully carried out for the first time in supercritical carbon dioxide (scCO2) in the presence of CO2-philic perfluorinated surfactant that was generated “in situ”. The control of the MMA polymerization relies on the strategy developed by Charleux et al. that consists of using a SG1-based alkoxyamine, i.e. the block-builder, in the presence of small amount of styrene. In a first step, CO2 soluble polyheptadecafluorodecylacrylate was prepared in scCO2 using block-builder as an alkoxyamine. In a second step, nitroxide SG1 mediated dispersion polymerization of MMA was conducted at 70°C and 300 bar in the presence of 5 w% of SG1 terminated surfactant compared to the monomer. Different monomer to alkoxyamine molar ratios were investigated in order to target different molecular weights. In each case, the monomer conversion was high (>90 %), the experimental molecular weight was in good agreement with the theoretical value and the polydispersity was narrow (Mw/Mn ~1.2). Moreover, after depressurisation of the cell, PMMA was collected as a free flowing powder consisting of small sized microspheres. [less ▲]

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See detailDispersion of multiwalled carbon nanotubes in water by lignin
Rochez, Olivier; Zorzini, Gwendoline; Amadou, Julien et al

in Journal of Materials Science (2013), 48(14), 4962-4964

Multiwalled carbon nanotubes (MWCNT) can be stably dispersed in water with small amount of lignin. One-step dispersion in the 20.0 g/L concentration range is achieved at room temperature with excellent ... [more ▼]

Multiwalled carbon nanotubes (MWCNT) can be stably dispersed in water with small amount of lignin. One-step dispersion in the 20.0 g/L concentration range is achieved at room temperature with excellent electrical properties of MWCNT. Lignin is depicted to act as an anti-static agent. [less ▲]

Detailed reference viewed: 96 (33 ULg)
See detailDispersion of the liquid trickle flow thhrough packed-beds
Crine, Michel ULg; Asua, José Maria; Marchot, Pierre ULg et al

Conference (1981)

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See detailDispersion relations for meson-proton and proton-proton forward elastic scattering
Alkin, A.; Cudell, Jean-René ULg; Martynov, E.

in Cudell, Jean-René; Lansberg, Jean-Philippe; Mancusi, Davide (Eds.) 30 Years of Strong Interactions: a Three-Day Meeting in Honour of Joseph Cugnon and Hans-Jürgen Pirner (2012)

An analysis of the data on forward $pp, \bar pp, \pi^{\pm}p$ and $K^{\pm}p$ scattering is performed making use of the single- and double-subtraction integral and comparing with derivative dispersion ... [more ▼]

An analysis of the data on forward $pp, \bar pp, \pi^{\pm}p$ and $K^{\pm}p$ scattering is performed making use of the single- and double-subtraction integral and comparing with derivative dispersion relations for amplitudes. Various pomeron and odderon models for the total cross sections are considered and compared. The real part of the amplitude is calculated via dispersion relations. It is shown that the integral dispersion relations lead to a better description of the data for $\sqrt{s}>$5 GeV. Predictions of the considered models for the TOTEM experiment at LHC energies are given [less ▲]

Detailed reference viewed: 13 (1 ULg)