References of "Visser, Marjolein"
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See detailA review on the use of entropy in landscape ecology: heterogeneity, unpredictability, scale dependence and their links with thermodynamics
Vranken, Isabelle ULg; Baudry, Jacques; Aubinet, Marc ULg et al

in Landscape Ecology (2014)

The identification of a universal law that can predict the spatiotemporal structure of any entity at any scale has long been pursued. Thermodynamics have targeted this goal, and the concept of entropy has ... [more ▼]

The identification of a universal law that can predict the spatiotemporal structure of any entity at any scale has long been pursued. Thermodynamics have targeted this goal, and the concept of entropy has been widely applied for various disciplines and purposes, including landscape ecology. Within this discipline, however, the uses of the entropy concept and its underlying assumptions are various and are seldom described explicitly. In addition, the link between this concept and thermodynamics is unclear. The aim of this paper is to review the various interpretations and applications of entropy in landscape ecology and to sort them into clearly defined categories. First, a retrospective study of the concept genesis from thermodynamics to landscape ecology was conducted. Then, 50 landscape ecology papers that use or discuss entropy were surveyed and classified by keywords, variables and metrics identified as related to entropy. In particular, the thermodynamic component of entropy in landscape ecology and its various interpretations related to landscape structure and dynamics were considered. From the survey results, three major definitions (i.e., spatial heterogeneity, the unpredictability of pattern dynamics and pattern scale dependence) associated with the entropy concept in landscape ecology were identified. The thermodynamic interpretations of these definitions are based on different theories. The thermodynamic interpretation of spatial heterogeneity is not considered relevant. The thermodynamic interpretation related to scale dependence is also questioned by complexity theory. Only unpredictability can be thermodynamically relevant if appropriate measurements are used to test it. [less ▲]

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See detailQuality of life in sarcopenia and frailty
Rizzoli, René; Reginster, Jean-Yves ULg; Arnal, Jean-François et al

in Calcified Tissue International (2013), 93

The reduced muscle mass and impaired muscle performance that define sarcopenia in older individuals are associated with increased risk of physical limitation and a variety of chronic diseases. They may ... [more ▼]

The reduced muscle mass and impaired muscle performance that define sarcopenia in older individuals are associated with increased risk of physical limitation and a variety of chronic diseases. They may also contribute to clinical frailty. A gradual erosion of quality of life (QoL) has been evidenced in these individuals, although much of this research has been done using generic QoL instruments, particularly the SF-36, which may not be ideal in older populations with significant comorbidities. This review and report of an expert meeting presents the current definitions of these geriatric syndromes (sarcopenia and frailty). It then briefly summarizes QoL concepts and specificities in older populations and examines the relevant domains of QoL and what is known concerning QoL decline with these conditions. It calls for a clearer definition of the construct of disability, argues that a disease-specific QoL instrumentfor sarcopenia/frailty would be an asset for future research, and discusses whether there are available and validated components that could be used to this end and whether the psychometric properties of these instruments are sufficiently tested. It calls also for an approach using utility weighting to provide some cost estimates and suggests that a time trade-off study could be appropriate. [less ▲]

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See detailQuality of life in sarcopenia and frailty
Rizzoli, René; Reginster, Jean-Yves ULg; Arnal, Jean-François et al

in Osteoporosis International (2013, April), 24(Suppl.1), 76-77

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See detailThe spatial footprint of the non-ferrous metal industry in Lubumbashi
Vranken, Isabelle ULg; Munyemba Kankumbi, François; Amisi Mwana, Yamba et al

in Tropicultura (2013), 31(1), 20-27

In the south-eastern part of the Katanga Province (Democratic Republic of the Congo), high concentrations of copper and cobalt are found in the soils of the well-known “Copper Belt”. Due to the dominant ... [more ▼]

In the south-eastern part of the Katanga Province (Democratic Republic of the Congo), high concentrations of copper and cobalt are found in the soils of the well-known “Copper Belt”. Due to the dominant south-eastern winds, the metallurgic industry in Lubumbashi has been the source of spatially concentrated atmospheric deposits of non-ferrous metal particles and associated substances in a cone-shaped zone, situated north-west of the metal processing site. The existence of this zone has been evidenced using two different techniques: firstly, by means of landscape metric comparisons of the vegetation and bare soil patterns in two study areas, one inside the pollution cone and one outside; secondly, by means of the theory on city perception developed by Kevin Lynch. Higher fragmentation and lower vegetation presence were observed inside the pollution cone, reflecting the negative impact of atmospheric deposits. Those differences were higher for sites closer to the emission source. Lynch’s approach outlined the negative impact of diverse industrial plants on the perception by the local population. Six pollution districts and several contaminated paths, limits, nodes and polluting landmarks were identified. Citizens even recognize them as part of the collective image of the city. [less ▲]

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See detailEffets de la fragmentation des forêts par l'agriculture itinérante sur la dégradation de quelques propriétés physiques d'un ferralso échantillonné à Yangambi, R.D. Congo
Alongo, Sylvain; Visser, Marjolein; Drouet, Thomas et al

in Tropicultura (2013), 31(1), 36-43

The knowledge of changes occurring in the soil cover at the forest edge is needed to better understand the impact of forest fragmentation on soil parameters. The objective of this study is to evaluate the ... [more ▼]

The knowledge of changes occurring in the soil cover at the forest edge is needed to better understand the impact of forest fragmentation on soil parameters. The objective of this study is to evaluate the effects of forest fragmentation caused by shifting agriculture on texture, bulk density, total porosity and soil hydraulic conductivity in the layers at 0-10, 10-20 and 20-30 cm depth by the transect method in a perspective of sustainable land management in the region of Yangambi. The results obtained show that the edge between the fallow grassland and dense forest has a width of 70 m. Degradation of all the physical properties of soils relative to the dense forest is very significant (p<0.01) for the studied layers. Fragmentation of forests by shifting cultivation increases the phenomenon of selective loss of clays of the surface soil layers and consequently increases its bulk density and decreases the permeability and porosity with depth under the fallow grass and edge. The texture data associated with textural classes in the FAO textural triangle indicate a change in texture of the soil under different land uses for the tree layers studied. [less ▲]

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See detailAnthropisation des paysages: Structure spatiale, impact écologique, entropie
Vranken, Isabelle ULg; Bogaert, Jan ULg; Visser, Marjolein

Poster (2012, February 29)

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting ... [more ▼]

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting different anthropogenic effect intensities have been used. Anthropogenic effects, compositional and configurational entropy have been measured. The scatter plot shows bell curves with maximal entropy at intermediate anthropogenic effects. Distinction of natural and anthropogenic classes shows opposed tendencies according to class and compositional/configurational type. These results have been interpreted as spatial transformation processes, energy production and release, and linked to the habitat heterogeneity and intermediate disturbance hypotheses. [less ▲]

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See detailAnthropogenic effect on landscapes: spatial structure, ecological impact, entropy
Vranken, Isabelle ULg; Bogaert, Jan ULg; Visser, Marjolein

Poster (2012, February 10)

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting ... [more ▼]

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting different anthropogenic effect intensities have been used. Anthropogenic effects, compositional and configurational entropy have been measured. The scatter plot shows bell curves with maximal entropy at intermediate anthropogenic effects. Distinction of natural and anthropogenic classes shows opposed tendencies according to class and compositional/configurational type. These results have been interpreted as spatial transformation processes, energy production and release, and linked to the habitat heterogeneity and intermediate disturbance hypotheses. [less ▲]

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See detailPHYTOSTABILISATION OF COPPER-CONTAMINATED SOIL IN KATANGA: AN EXPERIMENT WITH THREE NATIVE GRASSES AND TWO AMENDMENTS
Ngoy Shutcha, Mylor; Mpundu Mubemba, Michel; Faucon, Michel-Pierre et al

in International Journal of Phytoremediation (2010), 12(6), 616-632

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon and amendments (compost and lime) for the phytostabilisation of soils ... [more ▼]

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon and amendments (compost and lime) for the phytostabilisation of soils contaminated by Cu in the province of Katanga (Democratic Republic of Congo). Species were grown on control and Cu-contaminated plots (artificially contaminated with 2,500 mg kg-1 Cu) unamended (NA), amended with 4.5 kg compost m-2 or 0.2 kg lime m-2. R. altera was also grown on contaminated plots amended with 22.5 kg compost m-2 or 1 kg lime m-2. Plant survival, growth and reproduction were monitored for two years. Cu-concentration in leaves of R. altera and M. ceresiiforme were analysed. pH and extractable Cu (0.01 M CaCl2) in soil were analysed in April 2007 and 2008. Results showed that R. altera seems to be the best candidate because of its highest survival on NA, followed by M. ceresiiforme, while liming was necessary to ensure survival of C. dactylon. Lime increased plant reproduction and reduced Cu accumulation in leaves compared to compost. However, higher survival and number of spikes of R. altera obtained in experiment 2 with 22.5 kg compost m-2 suggest that lime x compost interactions should be investigated in further studies. [less ▲]

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