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See detailHolocene paleoclimate reconstructions from belgian continental archives
Allan, Mohammed ULg; VERHEYDEN, sophie; CRUCIFIX, Michel et al

Poster (2016, June 28)

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high ... [more ▼]

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high interest due to their dating possibilities and their possibility to preserve multi-proxy records of environmental and climatic dynamics. Combining studies on speleothems and peatbogs from the same area will provide an age-constrained reconstruction of climatic variability at annual resolution for key intervals of the Holocene. The reconstructed precipitation and temperature curves in NW European settings, as proposed in HOPES, are essential to better constrain the Northern Hemisphere climatic record and to test climate models. Our strategy is derived from a comparative study of two continental archives speleothems and peatbogs. Time series of elemental and stable isotope geochemistry will be established for the 2 archives. For peatbog, the reconstructions of temperature (derived from stable C and O isotope), precipitation (derived from humification) and dust flux (from elementary geochemical signature) would track climate changes with subdecadal resolution. As an innovative part, Laser Ablation analyse of elemental geochemistry on impregnated peat section will allow to reach an annual resolution in the dust flux. For speleothems, records of temperature (derived from oxygen and carbon isotopic composition of calcite) and effective rainfall (derived from geochemical ratios) would reach a seasonal resolution. [less ▲]

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See detailA Selective and Highly Sensitive MIR Photoacuostic Sensor for Trace Gas Monitoring
Lassen, M; Lamar, L; Balslev-Harder, D et al

Conference (2016, June 28)

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See detailPhysical education and leisure: What’s the link?
Cloes, Marc ULg

Conference (2016, June 27)

All around the world, practitioners and researchers point out that people are becoming less and less physically active and adopt more and more sedentary behaviours. Such changes in the Human lifestyle ... [more ▼]

All around the world, practitioners and researchers point out that people are becoming less and less physically active and adopt more and more sedentary behaviours. Such changes in the Human lifestyle could have dramatic consequences as pointed out by the ‘Designed to move’ movement (Morris, 2013). To fight against that irresistible evolution, the need of a multisectorial approach is illustrated by the complexity of the socio-ecological model (Sallis et al., 2006). It underlines the large array of variables that play in the physical activity that someone is able to integrate into his/her life. Nevertheless, school has been identified as one major pillar of the promotion of an active lifestyle (van Sluijs et al., 2007). According to the knowledge and specific competences that they acquire during their studies, physical education (PE) teachers are considered as the potential cornerstones of such action (Tappe & Burgeson, 2004). While it was traditionally focused on the development of the youth’s physical, motor, and social competences of the students, since two decades, PE is increasingly more associated to the preparation of physically educated citizens. It means that what the students learn during their PE lessons should be useful outside the school and for a lifelong term. This concept is become a determining pedagogical principle: the physical literacy (Whitehead, 2013). In parallel, PE teachers are now requested to play a role on the health of their students despite if few evidence confirm that they can be successful in influencing the future behaviours of the children/adolescents to who they teach (Green, 2014). New pedagogical approaches are proposed nowadays in order to increase the effectiveness of the PE teachers’ intervention. This is linked to another pedagogical principle: accountability. Leisure activities enter progressively in the PE curriculum. Students benefit of more experiences that they could operate in their community. This requires more partnerships between school and leisure actors in order to implement original projects. Students must learn to become autonomous and smart decision makers able to identify the way to integrate PA in their leisure. [less ▲]

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See detailTweeting is not teaching! But...
Choffray, Jean-Marie ULg

Diverse speeche and writing (2016)

So, that’s it! Hundreds of Tweets on The Art and Science of Investing to “show you the way”, to share my most recent observations on the behavior of the markets, and to illustrate some of the key ... [more ▼]

So, that’s it! Hundreds of Tweets on The Art and Science of Investing to “show you the way”, to share my most recent observations on the behavior of the markets, and to illustrate some of the key heuristics that I learned over the last twenty years. As, without any doubt, I am no Warren Buffett, feel free to disagree and develop you own “theory” of investing. Painful and solitary work... Success is at this price! And, based on what I did - and did not! - achieve, it shouldn’t be hard to do much better... That’s my wish for you! [less ▲]

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See detailHealth Literacy: Eduquer pour mieux soigner
Bragard, Isabelle ULg

Scientific conference (2016, June 24)

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See detailImpact of fire on resilience of tropical dry forests: miombo in Lubumbashi (Democratic Republic of Congo)
Hick, Aurélie ULg

Conference (2016, June 23)

Dry tropical forests are widespread in continental Africa where they account for 70-80% of forested area. Miombo is a dry forest characterized by the dominance of trees in the genera Brachystegia ... [more ▼]

Dry tropical forests are widespread in continental Africa where they account for 70-80% of forested area. Miombo is a dry forest characterized by the dominance of trees in the genera Brachystegia, Julbernardia and Isoberlinia. Dry-season fires are a characteristic feature of these forests. Fire is not a frequent natural disturbance but they originate from anthropic. The impact of fire on forest species depends on the intensity and timing in relation to plant phenology. Due to urban pressure, more than 85% of woodland forests were converted to savannahs given several degree of forest degradation in the landscape. After a disturbance, tropical forest ecosystem can return to a trajectory close to the original ecosystem. The time it takes for this ecosystem recover to its predisturbance ecological condition is termed resilience. Loss of resilience can trigger a shift to another ecological state with ecosystems that are different in species and/or that are different in their functional and structural aspects. The broad goal of our study was to examine impact of fire on resilience of miombo after human disturbances. Mosaic of the MODIS 500m burned area product from 2002 to 2012 were used to calculate return frequency of fires around Lubumbashi. Five degrees of miombo degradation have been established : no degraded forest/little disturbed (level 1), moderately degraded forest (level 2), degraded forest (level 3), severely degraded forest (level 4) et deforested (level 5). For each degree of degradation, 9 circular plots (18 m radius, 0.1ha) were established, excepted for level 4 where 8 plots were laid. Within each circular plot, all woody individuals >= 2 cm diameter at breast height (DBH) were tagged, measured (height and diameter) and identified. Tree seedlings < 2 cm DBH and of height > 20cm were also sampled and identified. Herbaceous biomass was measured. Floristic composition in level 4 corresponded to fire-tolerant species. In other degree of forest degradation, most abundant species in mature trees consisted to tolerant or semi-tolerant species. Floristic composition of regeneration in most degraded degree consisted to a mixte of miombo species and fire-tolerant species. Fire has an impact on resilience of miombo after human degradation. Level 4 corresponded to a typical floristic community of a chipya habitat, where all woody species are fire tolerant. Fire can lead degraded miombo toward an alternative stable degraded states. [less ▲]

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See detail« Comment le réel a déjoué mes plans » : de quelques romans contemporains sur l’emprise par le récit
Claisse, Frédéric ULg; Huppe, Justine ULg

Conference (2016, June 23)

L’un des mérites paradoxaux des pratiques de storytelling, que C. Salmon a contribué à faire connaître au public francophone, réside dans le crédit dont bénéficie aujourd’hui l’idée de pouvoir du récit ... [more ▼]

L’un des mérites paradoxaux des pratiques de storytelling, que C. Salmon a contribué à faire connaître au public francophone, réside dans le crédit dont bénéficie aujourd’hui l’idée de pouvoir du récit. Cette idée place les producteurs littéraires dans une position ambivalente : perçu, d’un côté, comme une menace à leur autonomie et une atteinte au capital fictionnel dont ils sont les dépositaires légitimes, cet « art de raconter des histoires » est aussi une arme à détourner dans une entreprise de guérilla contre-narrative, voire un moyen pour la littérature de reconquérir ses pouvoirs premiers. Dans cette logique d’affrontement, on s’est cependant peu soucié, au fond, de ce que les fictions littéraires elles-mêmes avaient à dire sur le sujet : s’il est vrai que le récit est une prise sur le monde et un moyen d’emprise sur autrui, comment prennent-elles en charge ces situations ? La diffusion tant des pratiques de storytelling que de leur dénonciation ne pouvait rester sans effet sur la production littéraire. Or, le pouvoir du récit est aujourd’hui un thème régulièrement frayé par les romanciers, dans une série de textes qui présentent des convergences remarquables du point de vue des situations qu’ils décrivent. Dans Un Roman russe (2007), Emmanuel Carrère voit sa vie bouleversée pour avoir publié un récit érotique adressé à la femme qu’il aimait, décrivant les réactions de celle-ci à la lecture de son texte lors d’un voyage en train programmé par le narrateur. La même tentation démiurgique de (re)construction de la réalité par le récit habite le héros du triptyque d’Antoine Bello (Les Falsificateurs 2007 ; Les Éclaireurs 2009 ; Les Producteurs 2015), recruté par une organisation secrète, le Consortium de Falsification de la Réalité, pour laquelle il récrit littéralement l’histoire en falsifiant des archives sur la base de scénarios qui finiront par échapper à leurs créateurs, déclenchant une crise de conscience lorsque le héros découvre qu’Al-Qaïda est en réalité le produit d’une saga scénaristique qui a mal tourné. Dans La Revanche de Kevin (2015), Iegor Gran fait preuve de la même cruauté à l’égard de son protagoniste : pour dénoncer les faux-semblants du monde littéraire, Kevin H. fait lui-même œuvre d'imposture, et finit piégé par ses propres mystifications. Karoo de Steve Tesich (1998), devenu depuis sa traduction française en 2012 un véritable phénomène littéraire, participe des mêmes ressorts narratifs : écrivain raté, incapable de s’enivrer comme de montrer son affection à son fils, Saul « Doc » Karoo parachève sa propre destruction en appliquant à son existence les mêmes recettes qu’il inflige aux mauvais scénarios que Hollywood lui demande de récrire. Dans chacun de ces textes, le protagoniste peut faire siens les mots de Carrère au sujet de son récit censé « faire effraction dans le réel »: « le réel a déjoué mes plans ». Avec leurs personnages-scénaristes, mauvais démiurges châtiés par un réel plus résistant que leurs tentatives de le scripter, ces romans (d)énoncent cette modalité narrative du pouvoir que Citton appelle scénarisation, ou capacité d’agencer le comportement d’autrui à travers l’acte de narration. Mais il s’agit d’un savoir immanent à ces romans, une connaissance de la fiction sur elle-même, relevant de sa fonction cognitive. Récits conscients de l’emprise du récit, ils engagent une autre forme de réflexivité que celle des romans que la critique anglo-saxonne qualifie de « postmodernes », qui mettaient en scène leur propre fonctionnement romanesque : assumant pleinement leur statut fictionnel, ils ne jouent de la frontière entre réalité et fiction que pour mieux conforter l’idée que la réalité, bien que médiée et construite par les récits, « déborde » sans cesse. S'ils ne s'opposent pas frontalement au « Nouvel Ordre narratif », ces romans thématisent les effets perlocutoires des récits, mais surtout leur insuffisance face à la force de rappel du réel. Notre communication analysera ces dispositifs fictionnels d’un point de vue formel et socio-pragmatique. [less ▲]

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See detailOn Generalized Hölder-Zygmund Spaces
Kreit, Damien ULg

Doctoral thesis (2016)

To study the regularity of functions, many functional spaces have been introduced during the 20th century. Among them, let us mention the Hölder-Zygmund spaces \Lambda^{\alpha}(\R^{d}) and the Besov ... [more ▼]

To study the regularity of functions, many functional spaces have been introduced during the 20th century. Among them, let us mention the Hölder-Zygmund spaces \Lambda^{\alpha}(\R^{d}) and the Besov spaces B_{p,q}^{\alpha}(\R^{d}) where \alpha>0 somehow indicates the regularity of their elements (p,q\in ]0,+\infty]). The Hölder-Zygmund spaces are particular cases of Besov spaces in the sense that \Lambda^{\alpha}(\R^{d})=B_{\infty,\infty}^{\alpha}(\R^{d}). A generalization of Besov spaces has been introduced in the middle of the seventies and is still studied nowadays. This new type of space allows a deepest study of the regularity of functions. In this thesis, we start from this generalization in order to introduce a generalization of Hölder-Zygmund spaces. The first aim of this thesis is to show that most classical properties of Hölder-Zygmund spaces can be transposed to their generalized version. Among others, a complete characterization of these spaces in terms of wavelet coefficients is proved, which opens their use in the context of the signal analysis. The second aim of this thesis is to introduce a generalized version of the pointwise Hölder spaces similarly to their global version. We then show that most properties of the global spaces can be transposed to their generalized pointwise version. Finally, we study the regularity of some financial stochastic processes. [less ▲]

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See detailReceding-Horizon Control of Distributed Generation to Correct Voltage or Thermal Violations and Track Desired Schedules
Soleimani Bidgoli, Hamid ULg; Glavic, Mevludin ULg; Van Cutsem, Thierry ULg

in Proceedings of the 19th PSCC (2016, June 23)

This paper presents a real-time, centralized control system acting on the active and reactive powers of distributed generators when the network experiences voltage and/or thermal limits violation. The ... [more ▼]

This paper presents a real-time, centralized control system acting on the active and reactive powers of distributed generators when the network experiences voltage and/or thermal limits violation. The control resorts on multi-step receding-horizon optimization. The objective is to minimize the deviations of Dispersed Generation Units (DGU) active and reactive powers from reference values. The reactive power corrections have priority over the active ones. Furthermore, the formulation is such that DGU powers are restored to their desired schedule as soon as operating conditions allow doing so. Three modes of operation of the proposed controller are presented, involving dispatchable units as well as DGUs operated to track maximum power output. The effectiveness of the proposed control is illustrated through detailed simulations of a 75-bus, 11-kV system hosting 22 DGUs. [less ▲]

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See detailDix ans de ``Maths à Modeler à Liège'' ou comment un enseignant/chercheur s'invite dans des classes du secondaire
Rigo, Michel ULg

Conference given outside the academic context (2016)

Les missions d'un professeur d'université sont multiples : recherche, enseignement mais aussi citoyenneté. Depuis une dizaine d'années, je réalise de multiples activités de sensibilisation aux ... [more ▼]

Les missions d'un professeur d'université sont multiples : recherche, enseignement mais aussi citoyenneté. Depuis une dizaine d'années, je réalise de multiples activités de sensibilisation aux mathématiques : exposés, activités ludiques en petits groupes, etc. En répondant modestement à la question : "les maths ça sert à quoi ?", le but recherché est de démontrer l'utilité souvent méconnue des mathématiques, et de la recherche dans ce domaine (Google, réseaux sociaux, jeux vidéos, magie, etc.). Dans cette présentation, je dresserai tout d'abord l'historique du projet et tenterai d'analyser les actions menées. Ensuite, l'auditoire assistera à un tour de mathémagie et participera, de façon interactive, à un jeu démontrant l'importance du concept de preuve en mathématique. Ces jeux sont tirés de "Situations-Recherche pour la classe" développées par des chercheurs grenoblois. Enfin, j'expliquerai comment des étudiants de l'ULg (bacheliers, masters, étudiants à l'agrégation) et des doctorants participent à cette action. [less ▲]

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See detailInsect pathogenic Aspergillus species in mosquito (Diptera: Culicidae) control compared to Metarhizium anisopliae
Bawin, Thomas ULg

Doctoral thesis (2016)

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the ... [more ▼]

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the last decades due to climate changes and increasing global trade. Vector control is essential for public health management. Integrated pest management is now promoted due to harmful side effects of the chemical insecticides classically used for mosquito control and insect resistance development. This PhD thesis takes part in the selection process of insect pathogenic fungi. Three biological models (Aspergillus clavatus Desmazieres, Aspergillus flavus Link, and Metarhizium anisopliae (Metschnikoff) Sorokin) were selected and investigated regarding their spore insecticidal activity, mode of action, and selectivity. Throughout this scheme, the use of agricultural materials and derivatives in fermentation processes was emphasized. Production methods and insecticidal potential of the fungi were first investigated. On the one hand, the two Aspergillus species were compared to M. anisopliae regarding their spore production when cultured on agro-industrial substrates (white rice and wheat bran) and their insecticidal effect on larvae of the southern house mosquito, Culex quinquefasciatus Say. Our results showed that both substrates are suitable to culture the three insect pathogenic fungal species; but wheat bran-based media increased from 3 to 7-fold the spore yields in solid-state compared to white rice-based media. Also, insect pathogenic Aspergillus species were suggested to yield in similar spore levels in such conditions (in a range of 10^9 spores per g of substrate) and be as virulent against mosquito larvae compared to M. anisopliae. On the other hand, a bioreactor design intended to support large-scale production on agricultural materials by combining the technological advantages of submerged and solid-state fermentations was implemented using A. clavatus. This system allowed facility in recuperation and purification of spores (confined on a packed solid substrate) that retained virulence against mosquito larvae; but also metabolites (contained in a circulating liquid medium) that showed insecticidal effect. The mechanisms responsible for the insecticidal effects of the spores, and their selectivity were then investigated. On the one hand, the invasion routes of A. clavatus spores on mosquito larvae were investigated by light and electron microscopy. Histological observations suggest that toxins secreted by active germinating spores of A. clavatus in the digestive tract altered the larval tissues, leading to necrosis and causing larval death. Fungal proliferation and sporulation then occurred during a saprophytic phase. Such action mode also probably occurred in the case of the two other species. On the other hand, the insecticidal activity of the fungi was assessed against the pea aphid, Acyrthosiphon pisum Linnaeus. Adult A. pisum aphids were susceptible (increased mortality and decreased reproductive potential) to the three fungal species. As a consequence, these fungi would probably be able to infect a broad spectrum of insect hosts (whatever terrestrial or aquatic) once released in the environment. The implications of the results for mosquito control and application strategies are finally discussed, and perspectives for future works proposed. [less ▲]

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See detailAnatomie chirurgicale du plancher Pelvien et du rétropéritoine chez la femme
Bonnet, Pierre ULg

Conference (2016, June 22)

Leçon introductive reprenant les notions anatomiques essentielles à maîtriser lors de l'approche chirurgicale du pelvis et du rétropéritoine chez la femme. Approche constructive par la réalisation ... [more ▼]

Leçon introductive reprenant les notions anatomiques essentielles à maîtriser lors de l'approche chirurgicale du pelvis et du rétropéritoine chez la femme. Approche constructive par la réalisation extemporanée de schémas projetés. [less ▲]

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Peer Reviewed
See detailForest Inventory with Terrestrial LiDAR: A Comparison of Static and Hand-Held Mobile Laser Scanning
Bauwens, Sébastien ULg; Bartholomeus, Harm; Calders, Kim et al

in Forests (2016), 7(6), 127

The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract ... [more ▼]

The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract forest attributes. The use of a mobile laser scanner (MLS) would reduce this occlusion. In this study, we assessed and compared a hand-held mobile laser scanner (HMLS) with two TLS approaches (single scan: SS, and multi scan: MS) for the estimation of several forest parameters in a wide range of forest types and structures. We found that SS is competitive to extract the ground surface of forest plots, while MS gives the best result to describe the upper part of the canopy. The whole cross-section at 1.3 m height is scanned for 91% of the trees (DBH > 10 cm) with the HMLS leading to the best results for DBH estimates (bias of 0.08 cm and RMSE of 1.11 cm), compared to no fully-scanned trees for SS and 42% fully-scanned trees for MS. Irregularities, such as bark roughness and non-circular cross-section may explain the negative bias encountered for all of the scanning approaches. The success of using MLS in forests will allow for 3D structure acquisition on a larger scale and in a time-efficient manner. [less ▲]

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See detailDesign criteria and experimental performance - Extended end-plate
Demonceau, Jean-François ULg

Conference (2016, June 21)

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See detailNatural radioactivity and elemental composition of sands in the Douala region, Littoral of Cameroon Using Portable XRF and HPGe detector
Guembou Shouop, Cébastien Joel ULg; Ndontchueng Moyo, Maurice; Chene, Grégoire ULg et al

Scientific conference (2016, June 21)

Twenty four sand samples from seven sand quarries alone the Gulf of Guinea, Douala Littoral region of Cameroon, were analyzed using high purity germanium detector and a portable X-ray fluorescence (PXRF ... [more ▼]

Twenty four sand samples from seven sand quarries alone the Gulf of Guinea, Douala Littoral region of Cameroon, were analyzed using high purity germanium detector and a portable X-ray fluorescence (PXRF) spectrometer. A comprehensive study was conducted to determine the natural radioactivity concentrations and the geological provenience of sand samples from seven different quarries sites of the Douala, a popular city, and its surroundings. The radioactivity investigation was performed by using high resolution gamma-ray spectrometry. From the measured gamma-spectra, the average activity concentrations were determined for 226Ra, 232Th, 40K and 235U for a depth of 5–25 cm. Results of this study were compared to values from other locations around the world. X-ray fluorescence spectrometry (XRF) measurements were performed for the quantitative elemental analysis of the sands, revealing the major, minor and trace elements present in the investigated samples. Reference marine and geological sample are used to check precision and accuracy of the equipment for major and minor components. From XRF experimental results it was possible to estimate the geological provenience of the analyzed sands. These data record the radioactivity background levels in sands and could be used as reference information in Cameroon. The comparison of major (Si, Al), minor (K, Ca,Fe), and trace (Ti, Mn, Zr, Rb, Sr) element ratios was made. The results indicate that the levels of Si and Al can be very helpful in subgroup definition and provide useful clues to the raw materials used for glassmaking in Cameroon. [less ▲]

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