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See detailImportance of intertidal sediment processes and porewater exchange on the water column biogeochemistry in a pristine mangrove creek (Ras Dege, Tanzania)
Bouillon, Steven; Middelburg, Jack J.; Dehairs, Frank et al

in Biogeosciences (2007), 4

We sampled a tidal creek (Ras Dege, Tanzania) during a 24-h cycle to document the variations in a suite of creek water column characteristics and to determine the relative influence of tidal and ... [more ▼]

We sampled a tidal creek (Ras Dege, Tanzania) during a 24-h cycle to document the variations in a suite of creek water column characteristics and to determine the relative influence of tidal and biological driving forces. Since the creek has no upstream freshwater inputs, highest salinity was observed at low tide, due to evaporation effects and porewater seepage. Total suspended matter (TSM) and particulate organic carbon (POC) showed distinct maxima at periods of highest water flow, indicating that erosion of surface sediments and/or resuspension of bottom sediments were an important source of particulate material. Dissolved organic carbon (DOC), in contrast, varied in phase with water height and was highest at low tide. Stable isotope data of POC and DOC displayed large variations in both pools, and similarly followed the variations in water height. Although the variation of 13CDOC (−23.8 to −13.8‰) was higher than that of 13CPOC (−26.2 to −20.5‰), due to the different endmember pool sizes, the 13C signatures of both pools differed only slightly at low tide, but up to 9‰ at high tide. Thus, at low tide both DOC and POC originated from mangrove production. At high tide, however, the DOC pool had signatures consistent with a high contribution of seagrass-derived material, whereas the POC pool was dominated by marine phytoplankton. Daily variations in CH4, and partial pressure of CO2 (pCO2) were similarly governed by tidal influence and were up to 7- and 10-fold higher at low tide, which stresses the importance of exchange of porewater and diffusive fluxes to the water column. When assuming that the high dissolved inorganic carbon (DIC) levels in the upper parts of the creek (i.e. at low tide) are due to inputs from mineralization, 13C data on DIC indicate that the organic matter source for mineralization had a signature of −22.4‰. Hence, imported POC and DOC from the marine environment contributes strongly to overall mineralization within the mangrove system. Our data demonstrate how biogeochemical processes in the intertidal zone appear to be prominent drivers of element concentrations and isotope signatures in the water column, and how pathways of dissolved and particulate matter transport are fundamentally different. [less ▲]

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See detailthe importance of late neuronal migration in the neonatal and following periods
Battisti, Oreste ULg; NYAMUGABO MUNYERE NKANA, Kindja ULg; MAZOIN, Nathalie ULg

in Developmental Medicine and Child Neurology. Supplement (2012), 54

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See detailImportance of left ventricular longitudinal function and functional reserve in patients with degenerative mitral regurgitation: assessment by two-dimensional speckle tracking.
Lancellotti, Patrizio ULg; Cosyns, Bernard; Zacharakis, Dimitris et al

in Journal of the American Society of Echocardiography (2008), 21(12), 1331-6

BACKGROUND: The aim of this study was to determine whether two-dimensional speckle tracking of longitudinal myocardial deformation can detect limited contractile reserve during exercise in patients with ... [more ▼]

BACKGROUND: The aim of this study was to determine whether two-dimensional speckle tracking of longitudinal myocardial deformation can detect limited contractile reserve during exercise in patients with asymptomatic degenerative mitral regurgitation (MR). METHODS: Seventy-one patients with degenerative MR and normal left ventricular (LV) ejection fractions underwent quantitative exercise echocardiography. RESULTS: Compared with 23 normal subjects matched for age and sex, LV volumes were greater in patients with MR. At rest, global longitudinal strain (GLS) was lower in patients, indicating subclinical LV dysfunction. During exercise, the extent and the magnitude of changes in GLS were larger in controls than in patients with MR. On multivariate regression analysis, left atrial volume at rest and changes in GLS at peak exercise were independently associated with changes in LV ejection fraction. CONCLUSION: In asymptomatic patients with degenerative MR, subnormal LV function can be reliably identified by two-dimensional strain imaging. Limited exercise LV longitudinal contractile recruitment during exercise predicts postoperative LV dysfunction. [less ▲]

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See detailImportance of light spectral composition for brain activity
Vandewalle, Gilles ULg

Conference (2011, October)

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See detailThe importance of liposomes as models and tools in the understanding of photosensitization mechanisms
Hoebeke, Maryse ULg

in Journal of Photochemistry and Photobiology B : Biology (1995), 28(3), 189-196

The various applications of liposomes in understanding photosensitization are described in this paper, with particular emphasis on the various kinds of information that these models allow to obtain in ... [more ▼]

The various applications of liposomes in understanding photosensitization are described in this paper, with particular emphasis on the various kinds of information that these models allow to obtain in phototherapy. Liposomes are simple vesicles in which an aqueous phase is enclosed by a phospholipidic membrane. They are suitable models mimicking specific situations occurring <br />m vivo and they allow study of the influence of physieochemieal, photobioiogieal and biochemical factors on the uptake of photosensitizers by tissues, their mechanisms of action and the subsequent photoinduced tumor necrosis. Moreover, solubilization of the sensitizer into the bilayer seems to improve its tumoral selectivity and its photodynamic efficiency. [less ▲]

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See detailImportance of LUC and ILUC on the carbon footprint of bioproduct: case of bio-HDPE
Belboom, Sandra ULg; Léonard, Angélique ULg

in Matériaux et Techniques (2014), 102(2),

Suite à la diminution des ressources fossiles et à l’augmentation des émissions des gaz à effet de serre, des solutions sont nécessaires pour remplacer les produits issus du pétrole. Cela a pour ... [more ▼]

Suite à la diminution des ressources fossiles et à l’augmentation des émissions des gaz à effet de serre, des solutions sont nécessaires pour remplacer les produits issus du pétrole. Cela a pour conséquence une constante augmentation du nombre de produits biobasés développés à partir de ressources agricoles. Cette étude évalue l’empreinte carbone du polyéthylène haute densité (PEHD) produit à partir de canne à sucre brésilienne ou de betterave belge. Le but de cette étude est de comparer l’empreinte carbone du bio-PEHD avec le PEHD fossile en considérant l’effet du changement d’affectation des sols. Les frontières communes des systèmes agricoles regroupent l’étape de culture de la canne à sucre et de la betterave, avec toutes les consommations associées d’énergie et d’engrais, le transport depuis le champ jusqu’à l’unité industrielle, la transformation des plantes sucrières en bioéthanol hydraté, la valorisation des sous-produits, la polymérisation et l’incinération du PEHD. Le scénario fossile comprend la production d’éthylène, sa polymérisation et l’incinération du PEHD. La comparaison du cycle de vie entier des PEHD biobasé et fossile montre des émissions de GES plus faibles avec le produit biobasé, ce qui est l’effet voulu. Ce résultat est uniquement valide s’il n’y pas de changement direct ou indirect d’affectation des sols. Pour évaluer l’impact environnemental de la déforestation ou de la transformation d’un pâturage en champ, les lignes directrices de l’Union Européenne ont été suivies afin de calculer les émissions de CO2 en fonction de divers paramètres. Pour la canne à sucre, le changement direct d’affectation des sols (LUC) est défini par la transformation de pâturages en champs dans la région de Sao Paulo au Brésil. Trois scénarios ont été développés, basés sur différentes pratiques agricoles pour les pâturages et les champs (labour et engrais) : le meilleur, le pire et le moyen. Le meilleur cas engendre un gain environnemental supplémentaire pour le produit biobasé. Le pire et le moyen amènent des émissions complémentaires. Un temps de retour, considérant le temps nécessaire pour récupérer à nouveau un gain environnemental comparativement au produit fossile, a été calculé pour le scenario moyen et s’élève à 12 ans. Le changement indirect d’affectation des sols pour la canne à sucre est modélisé comme étant la transformation d’une forêt en champ induite par les effets du changement direct décrit ci-avant. Le taux de déforestation peut varier entre 16 et 100%, dépendant des statistiques utilisées et entrainant un temps de retour de respectivement 26 et 101 ans. Pour la betterave, aucun changement direct n’est considéré. En effet, aucune expansion des terres agricoles ne peut être envisagée en Belgique au vu des faibles surfaces disponibles. Si une augmentation en termes de production de bioplastiques a lieu, la Belgique devra importer de la betterave provenant des pays voisins, ce qui peut induire un changement indirect d’affectation des sols. Dans cette étude, la betterave est supposée provenir des Pays-Bas. Celle-ci est cultivée sur des pâturages préalablement transformés en champs. Ce scénario moyen induit un temps de retour de 8 ans. Cette étude a mis en évidence l’importance du changement direct et indirect d’affectation des sols, spécialement pour les cultures énergétiques dédiées au remplacement des produits fossiles. Cet effet peut renverser les résultats attendus et engendrer de longs temps de retour. [less ▲]

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See detailImportance of LUC and ILUC on the carbon footprint of bioproduct:case of bio-HDPE
Belboom, Sandra ULg; Léonard, Angélique ULg

in International seminar on society and materials (2013)

Due to the depletion of fossil fuels and the increase of greenhouse gas emissions, solutions are needed to replace petrol based products. As a consequence, the number of biobased products developed using ... [more ▼]

Due to the depletion of fossil fuels and the increase of greenhouse gas emissions, solutions are needed to replace petrol based products. As a consequence, the number of biobased products developed using agricultural feedstock is continuously increasing. This study focuses on the carbon footprint of bio-HDPE produced either from Brazilian sugar cane or Belgian sugar beet. The goal of this study is to compare the carbon footprint of bio-HDPE with the fossil one, taking into account the effect of land use change. Common boundaries of the agricultural systems comprise the cultivation step for both crops, i.e. sugar cane and sugar beet, with all associated energy and fertilizer consumptions, the transportation step from field to the industrial plant, the sugar crops transformation into hydrate bioethanol, the by-products valorisation, the dehydration and polymerization steps and the HDPE incineration as end of life issue. Fossil scenario includes the production of ethylene, its polymerization and its incineration. When comparing the entire life cycle of bio and fossil HDPE, the GHG emissions are lower for the biobased product which is the willing effect. This result is only valid if no Land Use Change (LUC) or Indirect Land Use Change (ILUC) effect appears. To assess the environmental impact of the deforestation or of the transformation of a pasture into a field, the EC-Guidelines from the European Union were used in order to calculate the CO2 emissions depending on several parameters. For sugar cane, LUC consists in the transformation of pastures into fields in the region of Sao Paulo in Brazil. Three scenarios can be developed based on different agricultural practices for pasture and field (tillage and fertilizers inputs): the best, the worst and the average. The best case leads to a supplementary environmental gain. The worst and average achieve additional emissions. A payback time, considering the time needed to find again an environmental gain compared to the fossil counterpart, was calculated for the average scenario which is equal to 12 years. The ILUC effect for sugar cane is assumed to be deforestation due to the transformation of forest into pasture induced by the previous LUC effect. The rate of deforestation can vary between 16% or 100% depending on used statistics and leads to a payback time of respectively 26 and 101 years. For sugar beet, no LUC is considered. Indeed, no land expansion is available in Belgium due to small available areas. In the case of an increase of bioplastics production, Belgium should import sugar beet from neighboring countries which can induce ILUC. In this study, sugar beet is assumed to be provided by the Netherlands on pastures previously transformed into fields. The average scenario implies a payback time of 8 years. This study permits to highlight the importance of LUC and ILUC especially for energetic crops dedicated to replace fossil products. This effect can reverse expected results and induce long payback times. [less ▲]

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See detailImportance of modal cross-correlations on wind loaded structures
Denoël, Vincent ULg; Degée, Hervé ULg; De Ville De Goyet, Vincent ULg

in Proceedings of the 3rd International Conference on Bridge Maintenance, Safety and Management (2006)

In civil engineering applications the dynamic analysis of large structure is often performed in a modal space. This method is known to offer an interesting decrease of the number of degrees of freedom as ... [more ▼]

In civil engineering applications the dynamic analysis of large structure is often performed in a modal space. This method is known to offer an interesting decrease of the number of degrees of freedom as well as a decomposition of the structure’s response in “uncoupled” components. Even if the response in each mode can be computed independently from the responses in the other ones, in the context of stochastic loading, the coherence of these modal responses must be accounted for in the determination of the structural response. These quantities are known as the modal cross-correlations. In this paper we will show that these crosscorrelations can be important (contrarily to what is sometimes thought) even in case of wellseparated natural frequencies. This will be illustrated on the analysis of the famous Viaduct of Millau during an erection stage. [less ▲]

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See detailThe importance of new chemical sources for the hot oxygen geocorona
Gérard, Jean-Claude ULg; Richards, P. G.; Shematovich, V. I. et al

in Geophysical Research Letters (1995), 22

Exothermic reactions involving metastable neutrals and ions were recently proposed as sources of hot oxygen atoms in addition to the classical O2(+) and NO(+) dissociative recombination. The Boltzmann ... [more ▼]

Exothermic reactions involving metastable neutrals and ions were recently proposed as sources of hot oxygen atoms in addition to the classical O2(+) and NO(+) dissociative recombination. The Boltzmann equations for thermal and nonthermal populations of O atoms are solved with Monte Carlo stochastic simulation method. It is shown that the calculated energy distribution functions of O atoms are significantly in nonequilibrium in the transition region between the thermosphere and the exosphere. It is found that the inclusion of additional sources leads to stronger disturbances of the energy distribution function and, as a consequence, increases the nonthermal fraction of hot O atoms. The variation of the vertical distribution of hot O between solar maximum and minimum conditions is also evaluated and shows good agreement with the available experimental evidence. [less ▲]

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See detailImportance of pedogenic factors in the spatial distribution of some soil properties in the Belgian loess belt: some loess-substratum contacts.
Colinet, Gilles ULg; Lacroix, Daniel; Bock, Laurent ULg

in Degryse, Patrick; Sintubin, Manuel (Eds.) Contributions to the Geology of Belgium and Northwest Europe. Proceedings of the first Geologica Belgica International Meeting (2002)

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See detailImportance of pigtailed macaques (Macaca nemestrina leonina) in seed dispersal and impact on the ecological balance of the tropical rainforest at Khao Yai National Park, Thailand
Albert, Aurélie ULg; Huynen, Marie-Claude ULg

Poster (2009, February)

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those ... [more ▼]

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those implying plants and frugivores. Although its diet is largely frugivorous, the pigtailed macaques (Macaca nemestrina leonina) have often been categorized as seed predators. However their morphology, behaviour and ecology suggest they could actually be a key-species in the dispersion of many plant species. A preliminary study by Latinne & al (2007) supported this hypothesis. The study we are planning now in continuity of Latinne’s study will take place in the Khao Yai National Park, Thailand, for three years and will focus on a troop habituated to humans. In order to establish the importance of the pigtailed macaques in the maintenance and the regeneration of the tropical rain forest, we will try to evaluate their capacity of being good seed dispersers. To do so, we will study: 1) the spatiotemporal distribution, the productivity and the characteristics of the plant species present on the home range of the studied troop, 2) the ranging patterns of the macaques within their home range, 3) their feeding behaviour, notably the fruit selection and the various modes of processing seeds, and finally 4) their impact on the viability and the germination potential of seeds. This study will require both direct observations of the macaques and semi-experimental procedures in the field, as well as laboratory control of some seed parameters. We hope the clarification of the macaques’ seed dispersal behaviour would help to re-evaluate their conservation status by recognizing them a paramount role in the maintenance of the tropical rainforest. [less ▲]

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See detailImportance of pigtailed macaques (Macaca nemestrina leonina) in seed dispersal: Impact on the ecological balance of the tropical rainforest at Khao Yai National Park, Thailand
Albert, Aurélie ULg; Huynen, Marie-Claude ULg

Conference (2008, October 22)

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those ... [more ▼]

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those implying plants and frugivores. Today, no study was still undertaken on the pigtailed macaques (Macaca nemestrina leonina) because they are considered seed predator. However, recent studies showed that it could actually be a key-species in the dispersion of many plant species. The study will take place in the Khao Yai National park (2,168 km²), Thailand. We will follow a troop of forty individuals habituated to humans and already well-known. Our goal will be to establish the importance of the pigtailed macaques in the maintenance and the regeneration of the tropical rain forest. Thus we will try to evaluate their capacity of being good seed dispersers. In this purpose we will study: 1) the spatiotemporal distribution, the productivity and the characteristics of the plant species present on the home range of the studied troop, 2) the ranging patterns of the macaques within their home range, 3) their feeding behaviour, notably the fruit selection and the various modes of processing seeds, and finally 4) their impact on the viability and the germination potential of seeds. The study of seed dispersal by these macaques would enable us to step further into the understanding of this environment and, perhaps, to improve the destiny of the pigtailed macaques, species now characterized as “vulnerable”, in recognizing them a paramount role in the conservation of their habitat. [less ▲]

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See detailImportance of pigtailed macaques (Macaca nemestrina leonina) in seed dispersal: impact on the ecological balance of the tropical rainforest at Khao Yai National Park, Thailand
Albert, Aurélie ULg; Huynen, Marie-Claude ULg; Savini, Tommaso ULg

Poster (2010)

Today, many countries of South-East Asia know about the alarming state of the forests existing on their territory and all agree that it is essential to save the remaining primary forest but also to enable ... [more ▼]

Today, many countries of South-East Asia know about the alarming state of the forests existing on their territory and all agree that it is essential to save the remaining primary forest but also to enable the regeneration of degraded areas, through natural or artificial reforestation. The conservation of tropical rainforests thus passes by the necessity to better understand the plant-animal interactions, and in particular, the seed dispersal process. While following a troop of pigtailed macaques (Macaca nemestrina leonina) accustomed to Man in Khao Yai National park (2 168 km ²), Thailand, we will bring important data relating to these seed dispersers potentially necessary but unfortunately vulnerable. Indeed, this vulnerable but little known species, seems to be essential to maintain forest diversity by dispersing many plant species, particularly those inaccessible to smaller frugivores. First results already show that they disperse many seed species, of all kind of size, in all forest types, from primary forest to secondary forest, thanks to various handling techniques. They also seem to show an adaptation in their daily travels according to resources availability. The next fieldworks will enable us to bring more precision in these results and their temporal variations and thus to conclude on the potential role of Macaca nemestrina in the tropical rainforest regeneration. [less ▲]

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See detailImportance of post-transcriptional regulation of chemokine genes by oxidative stress.
JOSSE, Claire ULg; Boelaert, J. R.; Best-Belpomme, M. et al

in Biochemical Journal (2001), 360(Pt 2), 321-33

The transcription factor, nuclear factor kappa B (NF-kappa B), is activated by various stimuli including cytokines, radiation, viruses and oxidative stress. Here we show that, although induction with H(2 ... [more ▼]

The transcription factor, nuclear factor kappa B (NF-kappa B), is activated by various stimuli including cytokines, radiation, viruses and oxidative stress. Here we show that, although induction with H(2)O(2) gives rise to NF-kappa B nuclear translocation in both lymphocyte (CEM) and monocyte (U937) cells, it leads only to the production of mRNA species encoding interleukin-8 (IL-8) and macrophage inflammatory protein 1 alpha in U937 cells. Under similar conditions these mRNA species are not observed in CEM cells. With the use of a transient transfection assay of U937 cells transfected with reporter constructs of the IL-8 promoter and subsequently treated with H(2)O(2), we show that (1) IL-8-promoter-driven transcription is stimulated in both U937 and CEM cells and (2) the NF-kappa B site is crucial for activation because its deletion abolishes activation by H(2)O(2). The production of IL-8 mRNA in U937 cells is inhibited by the NF-kappa B inhibitors clasto-lactacystin-beta-lactone and E-64D (l-3-trans-ethoxycarbonyloxirane-2-carbonyl-L-leucine-3-methyl amide) but requires protein synthesis de novo. Moreover, inhibition of the p38 mitogen-activated protein kinase also decreases the IL-8 mRNA up-regulation mediated by H(2)O(2). Taken together, these results show the importance of post-transcriptional events controlled by a p38-dependent pathway in the production of IL-8 mRNA in U937. The much lower activation of p38 in CEM cells in response to H(2)O(2) could explain the lack of stabilization of IL-8 mRNA in these cells. [less ▲]

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See detailImportance of quantitative return-to-field criteria
Schwartz, Cédric ULg; Cordonnier, Caroline ULg; Lehance, Cédric ULg et al

Conference (2014, July 04)

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See detailImportance of recent extreme weather variation in Djibouti and need for impact quantification
Nour Ayeh, Moustapha; Mahamoud, Ayan; Saad, Osman et al

Poster (2014, February)

This analysis shows that the current rainfall deficit is exceptional and historically unique. The significant population migration induced by the drought to Djibouti city must be supervised, especially ... [more ▼]

This analysis shows that the current rainfall deficit is exceptional and historically unique. The significant population migration induced by the drought to Djibouti city must be supervised, especially during their spontaneous settling. This presented example confirms that current rainfall shortages and increasing temperature extremes are impactinglocal people who urgently need adaptation and DRR strategies. It is necessary to reduce exposure to hydrological risks of these affected populations, in order that victims of the drought are not carried away by a rainfall excess. [less ▲]

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See detailImportance of rheological properties when drying sludge in a fixed bed
Léonard, Angélique ULg; Blandin, Gaëtan; Crine, Michel ULg

in 4th Inter-American Drying Conference: Challenges for efficient drying processes (2009)

Detailed reference viewed: 34 (6 ULg)