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See detailEffect of clay modification on the mechanism of local deformations in PA6 nanocomposites
Dominkovics, Zita; Naveau, Elodie ULg; Jérôme, Christine ULg et al

in Macromolecular Materials and Engineering (2013), 298(7), 796-805

PA nanocomposites are prepared from clays organophilized with a phosphonium and an ammonium salt, and sodium montmorillonite is used as reference. The analysis of mechanical and micromechanical properties ... [more ▼]

PA nanocomposites are prepared from clays organophilized with a phosphonium and an ammonium salt, and sodium montmorillonite is used as reference. The analysis of mechanical and micromechanical properties of the composites reveal that several micromechanical deformation processes occur in the PA/MMT composites. The matrix cavitates at relatively small stress. Processes related to non-exfoliated clay structural units are initiated at larger stresses. Sound is emitted mainly by the fracture of particles, but debonding may also occur. The plastic deformation of the matrix dominates at larger stresses and deformations. The various local deformations are independent of each other and composite properties are not determined by silicate related processes but by the deformation of the matrix. [less ▲]

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See detailUrban sprawl, commuting and travel energy consumption
Marique, Anne-Françoise ULg; Dujardin, Sébastien; Teller, Jacques ULg et al

in Proceedings of the Institution of Civil Engineers. Energy (2013), 166(1), 29-41

Commuting to and from dense urban centres is often believed to be more energy efficient than commuting from more suburban areas. However, quantitative evidence is lacking. In this context, this paper ... [more ▼]

Commuting to and from dense urban centres is often believed to be more energy efficient than commuting from more suburban areas. However, quantitative evidence is lacking. In this context, this paper investigates the interactions between the spatial structure of the territory and transport energy consumption for commuting. Based on empirical surveys carried out every 10 years in Belgium, a quantitative method was developed and applied to assess energy efficiency of home-to-work and home-to-school travels. Our main findings highlight that urban structure acts upon travel energy consumption for commuting and that major cities present low energy consumption. However, a local-scale approach is useful for refining these observations, and this approach highlights the existence of secondary suburban and rural cores that also are characterized by low transport energy consumption. In this respect, the distance from home to a destination is paramount, whereas the mode of transport used has a lower impact. The method is parameterised and reproducible in other territories. [less ▲]

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See detailModulating absorption and postprandial handling of dietary fatty acids by structuring fat in the meal : a randomized cross-over clinical trial
Vors, C; Pineau, G; Gabert, L et al

in American Journal of Clinical Nutrition (2013), 97(1), 23-36

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See detailComparative study of thermal and structural behaviour of four industrial lauric fats
Anihouvi, Prudent; Blecker, Christophe ULg; Dombrée, A et al

in Food and Bioprocess Technology (2013), 6(12), 3381-3391

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See detailEnclosure-exclosure : management tools of forest-ungulates
Lehaire, François ULg

Scientific conference (2012, October 04)

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See detailFeasibility study for elephant inventory with an Unmanned Aerial Vehicle
Lisein, Jonathan ULg; Vermeulen, Cédric ULg; Bouché, Philippe ULg et al

Scientific conference (2012, October 04)

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See detailCommon Security and Defence Policy Modules 2011 External Evaluation Report
Paile, Sylvain ULg

Book published by Ministry of Defence and Sports of the Federal Republic of Austria (2012)

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See detailQuantification of Acrylamide in Various Belgian Potato Products Using Solid Phase Extraction and Liquid Chromatography Tandem Mass Spectrometry Detection
Douny, Caroline ULg; Widart, Joëlle ULg; Maghuin-Rogister, Guy ULg et al

in Food and Public Health (2012), 2(5), 137-141

Acrylamide (CH2=CHCONH2), a neurotoxic and potentially carcinogenic substance for human health, is in the glare of the spotlights for a few years. This is mostly due to the fact that acrylamide was found ... [more ▼]

Acrylamide (CH2=CHCONH2), a neurotoxic and potentially carcinogenic substance for human health, is in the glare of the spotlights for a few years. This is mostly due to the fact that acrylamide was found worldwide in various heated foodstuffs. Levels reported in the literature vary from 25 to 2000 ìg/kg and potato products are considered as the most contaminated. A possible pathway of synthesis of acrylamide is the Maillard reaction between reducing sugars and the amino acid asparagine. The aim of this study was to develop a liquid chromatography/mass spectrometry method to analyse as quickly as possible acrylamide in a variety of Belgian food samples such as potatoes, French fries, crisp bread, coffee, corn-flakes, etc. The sample preparation consisted in a liquid/liquid extraction, a centrifugation, followed by purification with Solid Phase Extraction (SPE). The instruments used were a Waters 2690 Alliance HPLC system coupled to a Micro-mass Quattro Ultima Platinum triple-quadrupole mass spectrometer. The analysis was performed in MS/MS mode using isotopic dilution technique for quantification. An internal 13C3 labelled standard was added prior to extraction. Quantifica-tion in MS/MS mode was calculated by reconstructing the ion current with the most abundant daughter ions for native and 13C labelled standard (ions of m/z 55 and 58). [less ▲]

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See detailThe use of participatory approaches to evaluate the socio-economic factors impairing the efficacy of animal health surveillance systems
Delabouglise, Alexis; Antoine-Moussiaux, Nicolas ULg; Phan Dang, Thang ULg et al

Poster (2012, August)

The need to set up efficient and sustainable surveillance networks is a major concern which must be continually placed at the heart of the overall issue of development. In developing countries, the ... [more ▼]

The need to set up efficient and sustainable surveillance networks is a major concern which must be continually placed at the heart of the overall issue of development. In developing countries, the political priority to reduce poverty means that it is vital to include social aspects in public decision making on health management in general. This focus on social aspects can be considered all the more important regarding surveillance as it is deeply embedded in agents’ everyday life. The flow of information about animal health involves different non-monetary costs, ensuing from stigmatization or from social pressure to withhold or disclose information. Understanding, measuring and alleviating these social costs of information is required to ensure the effectiveness and viability of surveillance. The present study considers the case of highly pathogenic avian influenza surveillance in Vietnam. It aims at establishing a protocol allowing for understanding and quantifying social costs incurred by surveillance agents at the community level. In this prospect, tools and concepts from anthropology, participative epidemiology and experimental economics were combined. More particularly, social network analysis, participatory observation, companion modeling and stated preference surveys were applied for the thorough examination of constraints and costs of health information flows. The opportunity for the scaling-up of such methodologies and for the inclusion of the so-elicited quantitative values in socio-economic evaluation of surveillance systems are discussed. [less ▲]

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See detailExploring ancient charcoal archives in Central Africa
Hubau, Wannes; Morin-Rivat, Julie ULg; Van den Bulcke, Jan et al

Conference (2012, July)

Fossil pollen and charcoal fragments are preserved in lake sediments, in forest soils and in ancient human settlements, were they can be accompanied by artifacts. As such, vegetation history is remarkably ... [more ▼]

Fossil pollen and charcoal fragments are preserved in lake sediments, in forest soils and in ancient human settlements, were they can be accompanied by artifacts. As such, vegetation history is remarkably well archived and sometimes closely linked to cultural history. Direct evidence for Central African vegetation history has been mainly derived from pollen analysis, while the charcoal archive remains hardly explored. However, analysis of charred wood remains has proven worthwhile for palaeovegetation reconstructions in temperate and arid regions. One of the main challenges for charcoal identification in tropical regions is species diversity. Therefore we developed and present a transparent charcoal identification protocol within an umbrella database of species names and metadata, compiled from the on-line database of wood-anatomical descriptions (InsideWood), the database of the world’s largest reference collection of Central African wood specimens (RMCA, Tervuren, Belgium) and inventory and indicator species lists. We applied the protocol on radiocarbon dated charcoal collections sampled in the Mayumbe forest (Bas-Congo, DRCongo), in human settlements along the Aruwimi and Lomami rivers (Province Orientale, DRCongo), along the Sangha river (Sangha department, Republic of the Congo) and in Pallisco logging concessions (East Province of Cameroon). First charcoal identification results are promising and sometimes seem to be taxonomically more precise than pollen identification. However, next to opportunities, we also present some pitfalls when exploring ancient charcoal archives. [less ▲]

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See detailContribution of new radiocarbon dates to track the impact of past anthropogenic disturbances on current vegetation in Central Africa
Morin-Rivat, Julie ULg; Gillet, Jean-François; Bourland, Nils ULg et al

Poster (2012, July)

Introduction: Understanding current Central Africa vegetation patterns faces the scarcity of data about their past evolution. However, a growing hypothesis suggests that past human activities could have ... [more ▼]

Introduction: Understanding current Central Africa vegetation patterns faces the scarcity of data about their past evolution. However, a growing hypothesis suggests that past human activities could have had a substantial influence on vegetation (Van Gemerden et al. 2003, Brncic et al. 2009). Indeed, by creating large openings (fig. 1), they might have triggered the expansion of light-demanding species currently suffering from a lack of regeneration. This lack of saplings could have been caused by the change in land use since colonization with the sedentarization of shifting cultivators. Aim of the study: To investigate the potential relationship between past anthropogenic disturbances and present vegetation. Material & methods: Fieldworks combining anthracological and ecological approaches have been undertaken in Northern Congo and South-Eastern Cameroon (fig. 2). We excavated thirty 150-200 cm deep pits under different forest covers and vegetation types to identify evidences of past human presence (i.e potsherds, fig. 3, slags from metallurgy, anthropogenic pieces of charcoals and anthropophilous charred seeds). Charcoals and seeds (oil palm Elaeis guineensis, fig. 4, Canarium schweinfurthii) in combination with artifacts have been dated. Results: A set of 38 new radiocarbon dates ranging from 15,200 cal BP to present time have been obtained. They confirm the existence of important past fire events in a region where natural ones seldom occur. Together with artifacts, our findings support the few already available dates documenting evidences of past human activities in Central African rainforests. On the 36 most recent dates (fig. 5), the majority belongs to the 2,300-1,400 cal BP period (61%). The whole semi-deciduous forest zone is concerned by this period of intense disturbances with a high rate of fragmentation. It follows the last great arid phase ca. 2,500 cal BP and might be linked to the iron workers expansion. Another pool of dates between 650 and 250 cal BP (33%) associated with potsherds might be correlated to a dry phase contemporary to the Little Ice Age in Europe. That last group of dates points out the potential positive impact of anthropogenic disturbances connected to a dry climatic event on light-demanding species populations. Indeed, this is consistent with the fact that most of current light-demanding trees have a higher number of stems around 100 cm dbh. Conclusion: Our multidisciplinary approach allowed new insights into the link between human history and vegetation dynamics in Central Africa. Further investigations should be conducted to go deeper into the understanding of the evolution of Central African rainforests and to improve the management of currently logged light-demanding species resulting from the LIA period. Thirty new dates from sixteen soil profiles are forthcoming. References: Brncic T., Willis M., K. J., Harris D. J., Telfer M. W. & Bailey M. W. 2009. Fire and climate change impacts on lowland forest composition in northern Congo during the last 2580 years from palaeoecological analyses of a seasonally flooded swamp. The Holocene, 19, 79-89. Reimer P. J., Baillie M. G. L., Bard E., Bayliss A., Beck J. W., Blackwell P. G., Bronk Ramsey C., Buck C. E., Burr G. S., Edwards R. L., Friedrich M., Grootes P. M., Guilderson T. P., Hajdas I., Heaton T. J., Hogg A. G., Hughen K. A., Kaiser K. F., Kromer B., McCormac F. G., Manning S. W., Reimer R. W., Richards D. A., Southon J.R., Talamo S., Turney C. S. M., van der Plicht J., & Weyhenmeyer, C. E. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000 years cal BP. Radiocarbon, 51(4), 1111-1150. Van Gemerden B. S., Olff H., Parren M. P. E, Bongers F. 2003. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity. Journal of Biogeography, 30, 1381-1390. [less ▲]

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See detailDocumenting the past anthropogenic disturbances in the African tropical forest: back from a fieldwork in Cameroon
Morin-Rivat, Julie ULg

Conference given outside the academic context (2012)

Fieldwork in Cameroon. Excavation of pits to collect charcoals and artifacts. Botanical inventories.

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See detailAncient macro-charcoals analysis as a tool to restitute the past history of African tropical forests
Morin-Rivat, Julie ULg; Doucet, Jean-Louis ULg; Beeckman, Hans

Scientific conference (2012, May 22)

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See detailPerturbations récentes dans le Bassin du Congo : Contribution de l’anthracologie à une restitution paléoenvironnementale
Morin-Rivat, Julie ULg; Hubau, Wannes; Gillet, Jean-François et al

Poster (2012, May 22)

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See detailAnthracologie : perturbations passées et évolution de la végétation
Morin-Rivat, Julie ULg

in CoForChange - La Lettre (2012)

Mettre en évidence la relation entre occupation humaine et distribution de la végétation est l’un des points abordés par CoForChange. Les récentes études montrent que les perturbations anthropiques ont eu ... [more ▼]

Mettre en évidence la relation entre occupation humaine et distribution de la végétation est l’un des points abordés par CoForChange. Les récentes études montrent que les perturbations anthropiques ont eu une influence sur la végétation, permettant notamment l’expansion des espèces héliophiles (cf. Lettre n° 4). Pour contribuer à cette analyse dans un contexte de grande rareté des données anthracologiques en Afrique, nous avons, dans le cadre d’un master, choisi d’étudier les charbons de bois issus de neuf fosses pédologiques du projet CoForChange. L’objectif était d’appréhender les compositions floristiques actuelle et passée des forêts au regard des perturbations passées. Deux protocoles anthracologiques d’identification ont été testés : a) à l’échelle de l’espèce, par une description des caractères anatomiques des charbons de bois, une recherche sur la base de données en ligne InsideWood et une comparaison anatomique au Xylarium de Tervuren ; b) à l’échelle de la communauté, par une recherche des relations statistiques entre traits écologiques des espèces et anatomie du bois. Les résultats montrent que la diversité taxonomique sous les forêts à Marantaceae est plus grande que sous les forêts denses de terre ferme. Trois identifications ont été obtenues sur 48 taxons décrits : Gilbertiodendron dewevrei sous forêt monodominante à G. dewevrei (GIB1 à 40 cm de profondeur, 1 510 ± 30 années cal. BP (calibrated before present), Millettia drastica et Pterocarpus soyauxii sous forêt clairsemée à Marantaceae (F9 à 40 cm, 1 200 ± 30 cal. BP). Notre hypothèse est que les peuplements monodominants à G. dewevrei sont relativement stables. Quant à P. soyauxii, la proportion de cette espèce héliophile semble décroître au cours du temps (niveaux entre 20 et 40 cm) au profit desMarantaceae. Un autre résultat porte sur l’absence de Triplochiton scleroxylon sous T. scleroxylon, ce qui pourrait confirmer l’hypothèse du caractère récent de ces peuplements. Les résultats portant sur la relation entre anatomie du bois et traits fonctionnels restant préliminaires, cette recherche sera poursuivie en thèse de doctorat. Les développements actuels de l’anthracologie pour l’Afrique tropicale permettent désormais d’envisager un plus grand nombre d’identifications par échantillon et ainsi une meilleure connaissance de l’évolution des forêts tropicales. [less ▲]

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See detailAnthracology: past disturbances and vegetation evolution
Morin-Rivat, Julie ULg

in CoForChange - Newsletter (2012)

One of CoForChange aims is to highlight the relationship between human settlement and plant distribution. Recent studies show that anthropogenic disturbances have had an impact on vegetation, including ... [more ▼]

One of CoForChange aims is to highlight the relationship between human settlement and plant distribution. Recent studies show that anthropogenic disturbances have had an impact on vegetation, including enabling the expansion of light-demanding species (see Newsl. No 4). To contribute to this analysis in a context of deep scarcity of anthracological data in Africa, we have been studying the charcoals from nine soil pits of the CoForChange project as part of a Master’s. The objective was to understand past and present species composition of the forests in relation with past disturbances. Two anthracological protocols of identification were tested: 1) at species level, by describing the anatomical characteristics of charcoals, by carrying investigations with InsideWood online database, and by comparing anatomical data at XylariumTervuren; 2) at community level, by searching for statistical relationships between ecological traits of species and wood anatomy. The results show that the taxonomic diversity is greater in Marantaceae forests than in lowland forests. Three identifications were obtained from 48 described taxa: Gilbertiodendron dewevrei under G. dewevrei monodominant forest (GIB1 at 40 cm depth, 1510 ± 30 years cal. BP), Millettia drastica and Pterocarpus soyauxii inMarantaceae open forests (F9 at 40 cm, 1200 ± 30 cal. BP). Our hypothesis is that monodominant stands of G. dewevrei are relatively stable. With regard to P. soyauxii, the proportion of this lightdemanding species seems to be decreasing over time (at levels from 20 to 40 cm) for the benefit of Marantaceae. Another result highlights the absence of Triplochiton scleroxylon under T. scleroxylon, which may confirm the hypothesis of the recent settlement of this species. Results on the relationship between wood anatomy and functional traits are still preliminary, and further research will be conducted through a PhD programme. The on-going developments of anthracology in tropical Africa will help to identify a larger number of collected samples, and thus to understand better the evolution of tropical forests. [less ▲]

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See detailIntroduction
Collette, Bernard; Leclercq, Bruno ULg

in Collette, Bernard; Leclercq, Bruno (Eds.) L'idée de l'"Idée" (2012)

Detailed reference viewed: 12 (1 ULg)