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See detailBaltic seagrass meadows as a sediment carbon sink
Jankowska, Emilia; Włodarska-Kowalczuk, Maria; Michel, Loïc ULg et al

Conference (2015, September 25)

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See detailHabitants des petites villes et des villages face à la nature dans les paysages ordinaires
Vanderheyden, Vincent ULg

Conference (2015, September 25)

La recherche sur les perceptions paysagères dénigre souvent les paysages ordinaires, ces paysages modifiés par l’homme qui n’appellent pas à la protection. Pourtant, dans les régions de forte densité de ... [more ▼]

La recherche sur les perceptions paysagères dénigre souvent les paysages ordinaires, ces paysages modifiés par l’homme qui n’appellent pas à la protection. Pourtant, dans les régions de forte densité de population comme la Belgique, les paysages naturels sont rares ou inexistants, sans pour autant que la nature ait disparu des paysages ordinaires. Il est donc intéressant de se poser la question de la nature dans de tels paysages : à partir de quand un paysage est-il perçu comme naturel par ceux qui l’observent ou y vivent ? Les critères dépendent-ils du mode d’habiter (petite ville, village périurbain ou village rural) ou d’autres facteurs liés à la trajectoire biographique des gens ? Trois terrains d’études ont été retenus pour la recherche : la Wallonie picarde, l’Entre-Sambre et Meuse et l’Ardenne. Ces terrains offrent des paysages ruraux assez typés et suffisamment différenciés et éloignés des grandes agglomérations urbaines, hormis Tournai, ville d’envergure régionale. La Wallonie picarde présente des paysages de vastes plateaux agricoles limoneux au relief plan et peu élevé, occasionnellement surplombé de petites collines. L’Entre-Sambre-et-Meuse offre des paysages mixtes, alternant cultures, prairies et boisement dans un relief plus accidenté d’altitude moyenne. Enfin, l’Ardenne, troisième terrain, montre des paysages de hauts plateaux disséqués, dominés par les massifs forestiers et les pâturages. Ces terrains offrent un bel aperçu du continuum urbain-rural belge : de la petite ville en milieu rural au semis d’habitat très lâche du village ardennais, loin de l’habituelle dichotomie ville - campagne. Dans ces terrains, une approche empirique a été privilégiée. Nous y avons interviewé trois groupes de neuf étudiants (18-25 ans) d’un niveau d’éducation moyen (Bac +1 à Bac +3), non spécialistes en analyse du paysage, habitant dans de petites villes ou villages et un de leurs parents. Durant l’enquête, les personnes devaient classer des photos de paysages ruraux belges plus ou moins impactés par la présence de l’homme (habitat, cultures, éoliennes, pylônes, zones périurbaines) puis devaient motiver leur classement. Les entretiens ont été enregistrés, retranscrits et codés à l’aide d’un logiciel d’analyse qualitative. L’analyse de contenu montre des résultats contrastés. Un certain consensus indépendant du mode d’habiter semble se dégager concernant la présence d’éléments anthropiques récents, tels quel les éoliennes, les zones industrielles ou les pylônes électriques : cela participe à la dénaturation d’un paysage, avec une subtile nuance pour les éoliennes, où la symbolique positive écologique peut pour certains contrebalancer la perte de naturalité induite. Chez des personnes vivant dans un milieu plus urbanisé, le paysage naturel attire, car il change des habitudes de vie. Certains n’hésitent pas à qualifier un paysage de naturel pour peu qu’il contienne suffisamment de végétation, fusse une vaste étendue agricole dédiée à la monoculture. Chez des personnes vivant dans des milieux très ruraux par contre, on ne constate pas toujours la tendance inverse : même la petite ville voisine semble parfois trop urbanisée à leurs yeux pour y vivre. A leurs yeux, les paysages deviennent moins attractifs au fur et à mesure que la densité du bâti devient perceptible. Plus qu’une analyse du visuel, cette recherche montre également que les gens s’imaginent être dans le paysage, entendant les bruits ou ressentant une perte de convivialité à mesure que le paysage s’industrialise ou se remplit de maisons. [less ▲]

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See detailThe historical shaping of lactation physiology : from art to science. Part I.
Burvenich, Christian; Hanzen, Christian ULg

in Knight, Christopher; Burvenich, Christian (Eds.) De fabulis, artibus et scientiis. Historia physiologiae. (2015)

Detailed reference viewed: 17 (0 ULg)
See detailThe historical shaping of lactation physiology : from art to science. Part II
Burvenich, Christian; Hanzen, Christian ULg; Knight, Christopher

in Knight, Christopher; Burvenich, Christian (Eds.) De fabulis, artibus et scientiis. Historiae physiologiae. (2015)

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See detailTools for Measuring a City’s Resilience in a Fire Following Earthquake Scenario
Elhami Khorasani, Negar; Gernay, Thomas ULg; Garlock, Maria

in Proceedings of IABSE Conference - Structural Engineering: Providing Solutions to Global Challenges (2015, September 25)

The paper provides a framework to evaluate the response of buildings in a community subject to fire following earthquake. First, a model is developed to determine the probability of ignition in buildings ... [more ▼]

The paper provides a framework to evaluate the response of buildings in a community subject to fire following earthquake. First, a model is developed to determine the probability of ignition in buildings of a community due to an earthquake. Second, fragility functions are developed for buildings subject to fire, to quantify the structural damage and the expected losses. The ignition model, combined with the fragility functions, can be implemented in a GIS based risk management platform to evaluate economical losses in a region from fire following an earthquake. [less ▲]

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See detailAcetylene (C2H2) and hydrogen cyanide (HCN) from IASI satellite observations: global distributions, validation, and comparison with model
Duflot, V.; Wespes, C.; Clarisse, L. et al

in Atmospheric Chemistry and Physics (2015), 15

We present global distributions of C2H2 and hydrogen cyanide (HCN) total columns derived from the Infrared Atmospheric Sounding Interferometer (IASI) for the years 2008–2010. These distributions are ... [more ▼]

We present global distributions of C2H2 and hydrogen cyanide (HCN) total columns derived from the Infrared Atmospheric Sounding Interferometer (IASI) for the years 2008–2010. These distributions are obtained with a fast method allowing to retrieve C2H2 abundance globally with a 5% precision and HCN abundance in the tropical (subtropical) belt with a 10% (25 %) precision. IASI data are compared for validation purposes with ground-based Fourier transform infrared (FTIR) spectrometer measurements at four selected stations. We show that there is an overall agreement between the ground-based and space measurements with correlation coefficients for daily mean measurements ranging from 0.28 to 0.81, depending on the site. Global C2H2 and subtropical HCN abundances retrieved from IASI spectra show the expected seasonality linked to variations in the anthropogenic emissions and seasonal biomass burning activity, as well as exceptional events, and are in good agreement with previous spaceborne studies. Total columns simulated by the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4) are compared to the ground-based FTIR measurements at the four selected stations. The model is able to capture the seasonality in the two species in most of the cases, with correlation coefficients for daily mean measurements ranging from 0.50 to 0.86, depending on the site. IASI measurements are also compared to the distributions from MOZART-4. Seasonal cycles observed from satellite data are reasonably well reproduced by the model with correlation coefficients ranging from -0.31 to 0.93 for C2H2 daily means, and from 0.09 to 0.86 for HCN daily means, depending on the considered region. However, the anthropogenic (biomass burning) emissions used in the model seem to be overestimated (underestimated), and a negative global mean bias of 1% (16 %) of the model relative to the satellite observations was found for C2H2 (HCN). [less ▲]

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See detailPerformances of a simple exhaust mechanical ventilation coupled to a mini heat pump: modeling and experimental investigations
Ransy, Frédéric ULg; Gendebien, Samuel ULg; Lemort, Vincent ULg

Conference (2015, September 24)

According to the European directive 2012/27/EU of October 2012 on energy efficiency, buildings represented 40 % of the EU’s final energy consumption in 2011. The major part of this energy consumption is ... [more ▼]

According to the European directive 2012/27/EU of October 2012 on energy efficiency, buildings represented 40 % of the EU’s final energy consumption in 2011. The major part of this energy consumption is due to the residential sector for space heating and domestic hot water production. Moreover, buildings are crucial to achieve the EU objective of reducing greenhouse gas emissions by 80-95 % by 2050 compared to 1990. In order to reduce these greenhouse gas emissions, retrofit measures regarding insulation and air-tightness have to be taken. However, such improvements of the building envelope lead to a relative increase in consumption related to ventilation. Indeed, according to Orme (2001), Roulet et al. (2001) and Fouih et al. (2012), the heating demand due to ventilation can reach more than 50 % of the total building heating demand for new and retrofitted buildings. To reduce the energy consumption due to ventilation, exhaust air heat pumps (EAHPs) can be used instead of the traditional heat recovery with an air-to-air heat exchanger. EAHPs recover heat from the exhaust air of the ventilation system to produce domestic hot water and space heating. According to Fehrm et al. (2002), this technology is already widely used in the northern countries such as Germany and Sweden. In fact, according to Fracastoro et al. (2010), efficiencies of EAHPs are higher than those obtained with outside air or geothermal heat pumps in certain conditions, whatever the climate location. Berg et al. (2010) have monitored three houses in Sweden equiped with exhaust air heat pumps. The seasonal performance factor (SPF) values were all within the range 1.4-1.7. This factor takes into account the energy consumption of the heat pumps and the auxiliary heating systems. A 17 kW exhaust air heat pump has also been tested by Mikola et al. (2014). The measured SPF for the heat pump only (without taking into account the auxiliary heating system) was about 2.9-3.4 in winter and 3 in the summer. Exhaust air heat pumps coupled with simple exhaust mechanical ventilation systems have many advantages compared to traditional balanced systems with heat recovery: • Only one fan is necessary and the duct system is simpler. Consequently, EAHPs are suitable for retrofitted buildings. • The heat pump can provide the whole part of the heating demand related to domestic hot water and 50 % of the heating demand related to space heating, according to Fracastoro et al. (2010). • The heat pump can also provide active cooling by inversing the refrigerating cycle. • The heat pump performance is high and remains constant with outdoor temperature changes since the temperature of the heat sink is constant (20°C). As a result, the system is cost-effective. • The system is compact, quiet and requires little maintenance. In the present paper, the energetic performances of an exhaust air heat pump are assessed through numerical and experimental studies. The thermal capacity of the machine is 1.5 kW when the inside air temperature is 20°C and the outside water temperature is 35°C. The heat pump is therefore ideally suited for new or retrofitted buildings. The system including a mechanical exhaust ventilation system and an exhaust air heat pump is first presented. Secondly, the heat pump model used afterwards to determine the heat pump seasonal performance factor is described. Thirdly, the model is calibrated to fit the measurement data. Finally, the heat pump model is coupled to a building model to determine the annual performance of the system. The system is compared to a traditional balanced ventilation system with heat recovery in terms of primary energy consumption, for different heating and DHW production systems (electric heater, heat pump, gas condensing boiler). [less ▲]

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See detailMyoferlin: an indispensable component in VEGFA secretion by pancreas cancer cells.
Fahmy, Karim ULg

Poster (2015, September 24)

In this poster, our laboratory showed the importance of myoferlin, a biomarker of pancreas cancer, in the controle of VEGF-A mediated angiogenesis. Our laboratory showed that silencing myoferlin in ... [more ▼]

In this poster, our laboratory showed the importance of myoferlin, a biomarker of pancreas cancer, in the controle of VEGF-A mediated angiogenesis. Our laboratory showed that silencing myoferlin in pancreas cancer cells, BxPC-3, provoques a decrease in cell prolifération in vitro and a decrease in tumor volumes in animal model. Myoferlin silencing also provokes a decrease in VEGF-A secretion in the conditioned medium and that decrease was abserved in the animal model as a decrease in microvessels dencity. It appeared that this decrease in secretion is due to a a blockage in the exocytosis. Our data also showed a significate correlation between myoferlin expression and microvessels density in patients section. [less ▲]

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See detailMedicinal plants, malaria and biotechnology
Frederich, Michel ULg; Jansen, Olivia ULg; Muganga, Raymond et al

Conference (2015, September 24)

The first part of the talk will be dedicated to the investigation of medicinal plants with the objective to identify new antimalarial treatments. According to the last World Malaria Report [1], there were ... [more ▼]

The first part of the talk will be dedicated to the investigation of medicinal plants with the objective to identify new antimalarial treatments. According to the last World Malaria Report [1], there were 584 000 deaths for 198 millions malaria cases worldwide in 2013. Particularly, the disease caused an estimated 437 000 African children died before their fifth birthday, still in 2013. Malaria is caused by a parasite, Plasmodium sp. and transmitted by Anopheles mosquitoes. The problem of parasite resistance towards common available medicines such as chloroquine, mefloquine, quinine, is increasing. In this context, the vegetal kingdom remains the main source of pharmacologically active compounds against this parasitic infection as attested by the famous quinine, isolated from Cinchona sp., artemisinin extracted from Artemisia annua and also atovaquone derived from lapachol found in several Bignoniaceae. All these substances are related to plants with traditional use against fever and malaria. Beside these well-known examples, various new antiplasmodial compounds are frequently discovered from Nature, particularly following an ethnopharmacological approach, as reviewed by several authors in recent years [2-6]. Then, the pharmacological and phytochemical study of plants from traditional pharmacopoeias can be of first interest not only to discover new antimalarial “lead compounds”, but also to valorize local vegetal species whose efficacy and safety would have been demonstrated in laboratory and by clinical investigations [7,8]. Some results obtained with Dicoma tomentosa from Burkina-Faso [9] and Terminalia mollis from Rwanda [10] will be presented. In the second part of the talk, two applications of biotechnology for the production of artemisinin and paclitaxel and then some works developed at the ‘Université de la Réunion’ will be presented. In the framework of this collaboration, Psiadia arguta, an endemic plant from Reunion Island, which is known to have cytotoxic, anti-plasmodial and anti-inflammatory properties, was subjected to micropropagation. The objective of the work was to compare the biological properties and the phytochemical composition of callus, vitroplants and acclimatized plants of Psiadia arguta [11]. 1. WHO, World Malaria Report 2014, December 2014, Geneva (http://www.who.int/malaria/publications/world_malaria_report_2014/en/). 2. Batista R, Silva Ade J Jr, de Oliveira AB: Plant-derived antimalarial agents: new leads and efficient phytomedicines. Part II. Non-alkaloidal natural products. Molecules 2009, 14:3037-72. 3. Bero J, Frédérich M, Quetin-Leclercq J : Antimalarial compounds isolated from plants used in traditional medicine. Journal of Pharmacy and Pharmacology 2009, 61:1401–1433. 4. Bero J and Quetin-Leclercq J: Natural products published in 2009 from plants traditionally used to treat malaria. Planta Medica 2011, 77:631-40. 5. Kaur K, Jain M, Kaur T, Jain R: Antimalarials from nature. Bioorganic & Medicinal Chemistry 2009, 17:3229–3256. 6. Nogueira CR and Lopes LMX: Antiplasmodial Natural Products. Molecules 2011, 16:2146-2190 7. Ginsburg H and Deharo E: A call for using natural compounds in the development of new antimalarial treatments – an introduction. Malaria Journal 2011, 10 (suppl. 1):S1 8. Willcox M, Graz B, Falquet J, Diakite C, Giani S, Diallo D: A “reverse pharmacology” approach for developing an antimalarial phytomedicine. Malaria journal 2011, 10(suppl1):S8 9. Jansen, O., Tits, M., Angenot, L., Nicolas, J.-P., De Mol, P., Nikiema, J.-B., & Frédérich, M : Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15-O-acetate as the main active compound. Malaria Journal 2012, 11, 289. 10. Muganga, R., Angenot, L., Tits, M., & Frédérich, M : In vitro and in vivo antiplasmodial activity of three Rwandan medicinal plants and identification of their active compounds. Planta Medica 2013, 80(6), 482-489. 11. Mahy Justine, Comparative study of biological activities and analysis of volatile compounds of Psiadia arguta in various cultures: vitroplants and acclimatized plants. Mémoire de M2, 2013, Université de Liège/Université de la Réunion. [less ▲]

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See detailOn generalized Hölder spaces
Kreit, Damien; Nicolay, Samuel ULg

Conference (2015, September 24)

We introduce generalized pointwise Hölder spaces as the point wise version of generalized uniform Hölder spaces. These last ones can be seen as a special case of generalized Besov spaces.

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See detailVALIDATION RELEVANCE OF ANALYTICAL METHODS IN BIOTECHNOLOGY
Marini Djang'Eing'A, Roland ULg; Hubert, Philippe ULg

Conference (2015, September 24)

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See detailComprendre et maîtriser la littérature scientifique
Pochet, Bernard ULg

Book published by Presses agronomiques de Gembloux (2015)

Il est essentiel pour l'étudiant universitaire ou d'école supérieure d'être capable de repérer rapidement, de manière autonome et critique, des informations valides et de qualité. Les précédents manuels ... [more ▼]

Il est essentiel pour l'étudiant universitaire ou d'école supérieure d'être capable de repérer rapidement, de manière autonome et critique, des informations valides et de qualité. Les précédents manuels mettaient l'accent sur l'article scientifique, sur le double rôle, de lecteur et d'auteur, des utilisateurs de la littérature scientifique ainsi que sur la nécessité d'une recherche d'information méthodique. Ce manuel ajoute une dimension supplémentaire. Il se focalise sur une bonne compréhension des différents processus en jeux dans la diffusion de l'information scientifique. Les objectifs de cet ouvrage sont d'amener le lecteur, d'une part, à bien comprendre le fonctionnement de la littérature scientifique et ses processus et, d'autre part, maîtriser les méthodes de recherche d'information, de veille informationnelle, de tri, de sélection et d'organisation de l'information ainsi que les méthodes de production d'information scientifique, de citations et de rédaction. [less ▲]

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See detailDynamical modelling from resting-state brain imaging
Liegeois, Raphaël ULg

Doctoral thesis (2015)

The statistical dependencies among neuroimaging time courses observed in different brain regions are collectively named functional connectivity (FC). This quantity is widely used in order to characterize ... [more ▼]

The statistical dependencies among neuroimaging time courses observed in different brain regions are collectively named functional connectivity (FC). This quantity is widely used in order to characterize normal brain functioning or neurodegenerative diseases. It is classically measured in a static way, by averaging the dependencies over the whole imaging acquisition. However, there is increasing evidence that considering the temporal fluctuations of FC leads to a finer description of FC properties and corresponding brain function. This observation is the starting point of the work developed throughout this thesis. First, we study the role of cerebral anatomy in the FC fluctuations. We observe that it guides transitions of FC between different patterns supporting consciousness-related processes such as mind wandering. Following this new characterisation of the fluctuating nature of FC, we develop statistical tools capturing static and dynamic properties of FC. We first introduce three markers of FC, collectively named spatiotemporal connectivity (STC), and computed from the power spectral density of the neuroimaging time series. STC captures spatial properties of FC, as classically computed, but also dynamical properties. We show on real data that STC provides a finer characterisation of FC, as well as higher robustness against inherent flaws of the imaging modality considered in our study. Then, in order to identify dynamical patterns of FC at the whole-brain level, we recast the concept of component analysis in the context of dynamical models. The corresponding development is based on a particular representation of statistical interactions: dynamical graphical models. We first propose an algorithm providing a decomposition of these models in a sparse contribution, reflecting parsimony of the direct interactions between cerebral regions, and a low-rank contribution, modelling the presence of hidden variables spreading a common behaviour in many of these regions. Then, we propose to interpret the identified hidden variables as dynamical neuronal networks, as for component analysis, but with an additional spectral characterisation of the corresponding components. In conclusion, this thesis presents descriptive contributions from the analyses of several datasets, and methodological contributions inspired from the properties of these datasets. [less ▲]

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See detailUse of the wavelet theory as a tool to investigate the l-abelian complexity of a sequence
Kleyntssens, Thomas ULg; Nicolay, Samuel ULg; Vandomme, Elise ULg et al

Poster (2015, September 23)

The concept of k-automatic sequences is at the intersection of number theory and formal language theory. It has been generalized by the notion of k-regularity that allows to study sequences with values in ... [more ▼]

The concept of k-automatic sequences is at the intersection of number theory and formal language theory. It has been generalized by the notion of k-regularity that allows to study sequences with values in a (possibly infinite) ring. This concept provides us with structural information about how the different terms of the sequence are related to each other. They are many different notions related to the measure of complexity of an infinite sequence w. A classical approach is its factor complexity. In an abelian context, the analogue to the factor complexity is the abelian complexity where the number of distinct factors of length n is counted up to abelian equivalence. The notion of abelian complexity was extended to that of l-abelian complexity. In this talk, I propose to use tools from the wavelet theory to analyze the l-abelian complexity. For the numerical simulations, I apply the wavelet leaders method that allows to study the pointwise regularity of signals. [less ▲]

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See detailPerformances analytiques d’un biomarqueur : dialogue
CAVALIER, Etienne ULg

Conference (2015, September 23)

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See detailStratospheric HCl increasing again, caused by dynamic variability, driven by increased tropopsheric wave activity
Notholt, J; Mahieu, Emmanuel ULg; Pfloeger, F et al

Conference (2015, September 22)

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See detailIntroduction au droit
Grandjean, Geoffrey ULg

Learning material (2015)

Detailed reference viewed: 36 (2 ULg)