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See detailIdentification de la composition en arômes des miels de la région orientale du Maroc (Communication orale)
Abeslami, Azzedine; Fauconnier, Marie-Laure ULg; Sindic, Marianne ULg et al

Scientific conference (2014, May 15)

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See detailHow to build a biological linker dedicated to the engineering of novel drug delivery systems
Crasson, Oscar ULg; Galleni, Moreno ULg; Parente, Raffaella et al

Poster (2014, May 15)

Nowadays, chemical linkages are widely used in industry to coat bioactive molecules on biocompatible supports. However, some issues inherent to the linkage procedure remain. For example, chemical ... [more ▼]

Nowadays, chemical linkages are widely used in industry to coat bioactive molecules on biocompatible supports. However, some issues inherent to the linkage procedure remain. For example, chemical reactions often damage the structure and therefore the activity of the immobilized molecules. In this work, we propose the use of a human chitin binding domain (ChBD) to immobilized bioactive molecules on a polysaccharide-based surface. ChBD belongs to the human chitinase called chitotriosidase and was shown to interact specifically with chitin and chitooligomers. Using molecular biology and protein engineering, we have developped of a new biological tool based on the hybrid protein technology. In this technology, we can create chimeric proteins that have the ability to bind polysaccharidic supports thanks to their binding domain that can be covalently linked with any bioactive molecule that can confer prophylactic or therapeutic activities. In this study, we have successfully shown that we can use the chitin binding domain (ChBD) from the human chitotriosidase as a biological linker dedicated to the engineering of novel drug delivery systems containing chitin or other analogous polysaccharides. [less ▲]

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See detailIdentifying root-secreted proteases in Arabidopsis thaliana: an Activity-Based Protein Profiling approach.
Lallemand, Jérôme ULg; Périlleux, Claire ULg; Tocquin, Pierre ULg

Poster (2014, May 15)

Proteases are involved in many physiological processes during the whole life of the plant, such as embryonic development, defense against pathogens, nutrition or mycorrhiza creation. However, the ... [more ▼]

Proteases are involved in many physiological processes during the whole life of the plant, such as embryonic development, defense against pathogens, nutrition or mycorrhiza creation. However, the functions of many of the 800 proteases of Arabidopsis thaliana still remain unknown. Besides discovering new functions, studying proteases can also result in improving plant biotechnology. Indeed, plants can be used as hosts for recombinant protein production. Some proteins of interest require to be secreted in order to fold properly, but production yields are limited due to their degradation by endogenous extracellular proteases. The aim of our study is to identify active root-secreted proteases of Arabidopsis thaliana. Their activity was first analyzed by in vitro incubation with a target protein (BSA) at different values of pH and in the presence of proteases inhibitors. This analysis identified serine proteases as the major protease class involved in BSA degradation. Then, an Activity-Based Protein Profiling approach led to the labeling of two active serine proteases in the root-secreted sample. Finally, a further step towards the identification by mass spectrometry, based on affinity purification, was developed. [less ▲]

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See detailMaize cold tolerance : in search of relevant parameters for discriminating genotypes
Riva-Roveda, Laetitia ULg; Escale, Brigitte; Giauffret, Catherine et al

Poster (2014, May 15)

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See detailQualitative and quantitative analyses of a pharmaceutical formulation produced by hot melt extrusion using Raman spectroscopy
Netchacovitch, Lauranne ULg; De Bleye, Charlotte ULg; Sacre, Pierre-Yves ULg et al

Poster (2014, May 15)

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ... [more ▼]

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ingredients (API) belong to the Biopharmaceutical Classification System (BCS) II and IV. Their integration in pharmaceutical solid forms is a big deal. HME processes increase the bioavailability and the solubility of those API by encompassing them in a polymeric carrier and by forming solid dispersions [1]. Moreover, in 2004, the FDA’s guidance initiative promoted the usefulness of Process Analytical Technology (PAT) tools when developing a manufacturing process. Vibrational spectroscopy is an appropriate PAT tool to analyze extrudates [2 – 3]. In this case, Raman spectroscopy, which belongs to vibrational spectroscopy, was used to analyze itraconazole extrudates qualitatively and quantitatively. During HME, the main objective is to develop solid dispersions by converting a crystalline API in an amorphous one, in order to improve its solubility and bioavailability [4]. According to Raman spectra, it is possible to identify the polymorphic form of the components in the extrudates by integrating or rationing the Raman bands that are characteristic of the API or by calculating the width at half intensity of some bands [5]. After determining the polymorphic form of the API, a quantitative method was developed in order to measure the ratio between the API and the polymer. Finally, chemical imaging was performed on extrudates to identify the distribution of the homogeneity of the API inside the polymer [6]. In conclusion, Raman spectroscopy is an appropriate tool to follow an extrusion process. By qualitative and quantitative analyses it is possible to determine the composition, the polymorphic form, the homogeneity, and the concentration of pharmaceutical matrices according to Raman fingerprint. References: [1] S. Shah et. al., Int J Pharm 453 (2013) 233 – 252. [2] L. Saerens et. al., Anal Chem 85 (2013) 5420 – 5429. [3] T. De Beer et. al., J Pharm Biomed Anal 48 (2008) 772 – 779. [4] A. Sarode et. al., Eur J Pharm Sci 48 (2013) 371 – 384. [5] E. Widjaja et. al., Eur J Pharm Sci 42 (2011) 45 – 54. [6] J. M. Amigo, Anal Bioanal Chem 398 (2010) 93 – 109. [less ▲]

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See detailInfluence du broyage mécanique sur la taille et les paramètres texturaux de particules de xérogels de carbone
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Traina, Karl et al

Conference (2014, May 15)

Les xérogels de carbone sont des candidats prometteurs pour une utilisation dans de nombreux domaines tels que le stockage de l’énergie électrochimique (anodes pour batteries Li-ion ou supercondensateurs ... [more ▼]

Les xérogels de carbone sont des candidats prometteurs pour une utilisation dans de nombreux domaines tels que le stockage de l’énergie électrochimique (anodes pour batteries Li-ion ou supercondensateurs), l’adsorption ou en tant que supports de catalyseurs (dont les électrocatalyseurs de pile à combustible PEM, par exemple) [1]. En plus de leur grande pureté, un des avantages principaux des xérogels de carbone est de pouvoir contrôler leur texture poreuse notamment via les conditions de synthèse [2, 3]. Ce sont les étapes de séchage et de pyrolyse qui permettent de moduler la texture finale des matériaux obtenus. Après vieillissement, les mélanges aqueux résorcinol-formaldéhyde mènent à des gels polymères susceptibles d’être convertis en polymères secs après séchage sous vide et, in fine, en xérogels de carbone après pyrolyse sous atmosphère inerte. Au cours de ces étapes, les produits obtenus restent cependant sous forme monolithique. Dans le cadre des applications pré-citées (catalyse, stockage électrochimique ou adsorption), il est néanmoins nécessaire de réduire les pièces monolithiques en particules de dimensions appropriées pour l’application cible. Dans ce cas, une étape clé est de pouvoir contrôler leur taille finale. Le comportement à l’attrition de matériaux présentant différentes textures poreuses a été étudié en détail. Les broyages ont été effectués dans un broyeur planétaire en conditions sèche ou humide sur des gels polymères secs ainsi que sur des xérogels de carbone obtenus après pyrolyse à 800°C. La granulométrie laser à diffraction lumineuse ainsi que la microscopie électronique à balayage ont été utilisées afin d’évaluer la distribution des tailles particulaires de la poudre broyée. Les résultats indiquent que la texture poreuse des matériaux, leur nature (polymère ou carbone) et leur dureté sont des facteurs significatifs qui influencent fortement les mécanismes de comminution/fragmentation lors du broyage, en particulier si l’on considère les xérogels de carbone. En effet, il apparait que le broyage par voie sèche de polymères secs (avant pyrolyse) semble être la manière la plus efficace pour obtenir une distribution de taille de particules homogène pour toutes les textures poreuses étudiées. Dans les conditions de broyage employées, il est possible d’obtenir des particules carbonées présentant une distribution de taille de particules centrée sur 10 µm, avec rétention de la texture mésoporeuse. Les résultats de cette recherche montrent également la possibilité d’utiliser la porosimétrie à intrusion de mercure en tant qu’outil pour évaluer simultanément la taille des mésopores ainsi que la taille des particules de matériaux broyés. 1. Yuan, X., Y.-J. Chao, Z.-F. Ma and X. Deng, Electrochemistry Communications, 9(10), 2591-2595 (2007). 2. Job, N., R. Pirard, J. Marien and J.-P. Pirard, Carbon, 42(3): p. 619-628 (2004). 3. Scherdel, C., R. Gayer and G. Reichenauer, J Porous Mater, 19(3): p. 351-360 (2012).  [less ▲]

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See detailÉvolution géomorphologique du littoral occidental de la péninsule tingitane (Maroc)
El Abdellaoui, Jamal ULg

Doctoral thesis (2014)

This work traces the geomorphological evolution of the western coast of the tingitane Peninsula (Morocco) in two time scales: the current scale and the Quaternary scale. Geomorphological characteristics ... [more ▼]

This work traces the geomorphological evolution of the western coast of the tingitane Peninsula (Morocco) in two time scales: the current scale and the Quaternary scale. Geomorphological characteristics have been identified and placed into their morphotectonic and/or morphodynamic contexts. To make our work more interesting, fruitful and realistic, we adopted an empirical approach. Firstly, we based our research on collection of data and analysis of available documents. Secondly, we made measurements, using appropriate techniques to answer specific questions, or to argue the hypotheses. It appears from this study, that the organization of geological units in a NNW-SSE direction has created a rugged shore, mainly in rocky cliff and pocket beaches on the Strait of Gibraltar coast, and a low sandy coast on the Atlantic coast. The geological and geomorphological quaternary history of Gibraltar Strait coast is characterized by a series of marine abrasion stepped and raised surfaces. The history of the Atlantic coast is rather marked by tectonic subsidence. This tectonic subsidence is manifested on the surface by a system of closed depressions (daya) arranged in a NNW-SSE axis, almost parallel to the orientation of geological units. The evolution of the geomorphological depressions is also controlled by the fluvio-marine action and wind activity. The last interglacial period is marked by two transgressive pulsations of eustatic origin. They were recorded at the marine terraces on both coasts. The second pulsation is aged at least 119.6 ± 2.3 ky. After the last interglacial, the central area of the Strait of Gibraltar was raised by an average of 8.1mm/100year from 117ky. The Ouljien was raised to a height of 13 to 16m. The Atlantic coast was stable at 117ky. Marine terraces are 5-6m high. The analysis shows that the current morphodynamics of the Atlantic coast are characterized by a barred beach geomorphology with a high spatio-temporal variability. It appears that a land wind plays a key role in the morphosedimentary evolution of backshore and foreshore. Indeed, the backshore develops, by negative retroaction, a geomorphology with a dune system to slow transport operated by land winds from the east. The foreshore, meanwhile, develops, by a positive retroaction, a system of bar and rip channels to counter a change in slope generated by the wind. On the one hand, risk analysis shows that the succession of anthropic changes at Tangier Bay has brooked the internal sediment balance. Erosion has affected both the sandy and rugged beaches of the eastern sector. The Atlantic coast doesn’t show signs of erosion, but it has a high vulnerability, because it evolves in a closed sedimentary system. On the other hand, the characteristic of a low open ocean coast facilitates the penetration of marine waters within the continent, especially the lower areas. Finally, a barred beach geomorphology creates problems of harbor silting and access disruption. [less ▲]

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See detailThe effects of flowering signals on root architecture in Arabidopsis
Mathieu, Laura ULg; Lobet, Guillaume ULg; Périlleux, Claire ULg

Poster (2014, May 15)

Roots are responsible for water and nutrient uptake and hence are critical to sustain the whole plant life cycle. This study aims at characterizing how root development is affected by flowering. We ... [more ▼]

Roots are responsible for water and nutrient uptake and hence are critical to sustain the whole plant life cycle. This study aims at characterizing how root development is affected by flowering. We therefore focused on the effects of systemic signals produced in the leaves at floral transition, namely the proteins FLOWERING LOCUS T (FT) and TWIN SISTER OF FT (TSF), on root growth and branching. These proteins act in the shoot apical meristem as potent promoters of flowering [1] but their effects in other parts of the plant are still unknown. [less ▲]

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See detailPeripheral Synergism Between Tramadol and Ibuprofen in the Formalin Test
Chavarria Bolanos, Daniel ULg; Perez-Urizar, Jose; Grandfils, Christian ULg et al

in Drug Development Research (2014), 75(4), 224-230

Analgesics with different mechanisms of action can be combined in order to obtain Pharmacological synergism, employing lower doses of each agent, thus diminishing side effects. For instance, an atypical ... [more ▼]

Analgesics with different mechanisms of action can be combined in order to obtain Pharmacological synergism, employing lower doses of each agent, thus diminishing side effects. For instance, an atypical dual analgesic such as tramadol (TMD) and a nonsteroidal anti-inflammatory drug such as ibuprofen (IBU) are good candidates to be evaluated when combined and applied peripherally. The present study was conducted to evaluate possible local synergism between TMD and IBU when combined peripherally using the formalin test in rats. The effects of the individual analgesics and their combinations were evaluated simultaneously using a 5% formalin dilution. Dose–effect curves were determined for TMD (50–400 μg/paw) and IBU (1–100 μg/paw). Experimental effective doses were evaluated and isobolographic analyses were constructed to evaluate TMD-IBU combination synergism. Both drugs produced a dose-dependent analgesic effect when applied separately. Isobolographic analysis showed synergism during phase 1 (0–10 min) and phase 2 (15–60 min) when compared with theoretical doses (P < 0.05), with interaction indexes of 0.06 and 0.09, respectively. The present information supports the peripheral analgesic effect of TMD and IBU, especially when combined at appropriate doses. [less ▲]

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See detailAdaptation to beach erosion in the African coastal cities: from the procrastination by the Government to the forced migration of the most precarious population. The case of Cotonou, Benin
Ozer, Pierre ULg; De Longueville, Florence ULg; Hountondji, Yvon Carmen et al

Poster (2014, May 14)

This analysis shows that the current impacts of geomorphological changes result mainly from the sum of human activities. However, it is necessary to consider the risk of coastal erosion and forced ... [more ▼]

This analysis shows that the current impacts of geomorphological changes result mainly from the sum of human activities. However, it is necessary to consider the risk of coastal erosion and forced migration (of mostly poor people) in the coming decades with the amplification of sea level rise due to global warming. [less ▲]

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See detailBelgian Grasshoppers: A Nutritious Food Source
Paul, Aman ULg; Frederich, Michel ULg; Blecker, Christophe ULg et al

Poster (2014, May 14)

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the ... [more ▼]

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the alternative food that exists are the grasshoppers, about 80 species of which are consumed worldwide. Grasshoppers are not only rich source of proteins and lipids but also some important minor component like vitamins and minerals. Edible species of grasshopper in Belgium were identified and attempts were made for the lab rearing of meadow grasshopper (Chorthippus parallelus). The lipids as well as protein contents of meadow grasshopper (Chorthippus parallelus) & long winged conehead (Conocephalus discolor) were investigated. The fatty acid compositions of these two species were determined by gas chromatography. Some of the physicochemical properties of the lipids extracted were also analyzed. These two grasshopper species could be really nutritious source of food. [less ▲]

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See detailImportant roles of SoHo proteins in vascular development: Sorbs1 and Sorbs2 have related but distinct functions in endothelial cells angiogenic properties
Bleuart, Anouck ULg

Doctoral thesis (2014)

Vascular system in all vertebrate organisms has in charge essential functions such as to bring nutrients, oxygen and signalling molecules to distant organs. Vascular network is established through ... [more ▼]

Vascular system in all vertebrate organisms has in charge essential functions such as to bring nutrients, oxygen and signalling molecules to distant organs. Vascular network is established through sequential and distinct processes. During embryogenesis, angioblasts give rise to differentiated endothelial cells, which form primary vessels through vasculogenesis. Expansion of this primary network is then achieved through a multistep process known as angiogenesis. During angiogenesis, remodelling of endothelial cell shape relies on cytoskeleton dynamics. In this study, our goal was to investigate the potential role of the SoHo family of adaptor proteins in angiogenesis. The SoHo family comprises three members, Sorbs1, Sorbs2 and Sorbs3. Although accumulative evidence links this protein family to the regulation of cell adhesion and actin cytoskeletal organisation, their expression and potential functions in endothelial cells remain unknown. Using zebrafish loss of function experiments combined with confocal imaging, we show that loss of Sorbs1 affects caudal vein-derived vessel formation, whereas Sorbs2 depletion impairs ISV development essentially derived from the dorsal aorta. We then demonstrated that both members impact on EC behaviour via regulation of RhoGTPases activity, leading to the vascular defects observed in vivo. Using a series of in vitro functional assays, we found that Sorbs1 and Sorbs2 have opposite effects on adhesives properties of HUVECs related to their ability to regulate different RhoGTPases. Sorbs1 depleted ECs adhere excessively to the ECM due to decrease in Rac1 activity. In contrast, loss of Sorbs2 impaired RhoA activation during adhesion and decreases cell adhesiveness to the matrix. Interestingly, these opposite effects on cell adhesion lead to similar outcome on EC migratory abilities, a decrease in cell migration. Here, for the first time, we establish a role for Sorbs1 and Sorbs2 in angiogenesis and demonstrate that these SoHo members are essential for EC adhesiveness and subsequent migratory abilities. [less ▲]

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See detailLes PPP comme nouveau mode de régulation du marché de l'emploi
Remy, Céline ULg

Conference (2014, May 14)

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See detailImproving soil conservation through an adapted tillage: experience from the cultivation of potatoes in Bamiléké's hills of Cameroon
Djoukeng, Henri Grisseur ULg; Tankou, Christopher Mubeteneh; Degré, Aurore ULg

Poster (2014, May 14)

The western highlands of Cameroon are an area where the population density and growth rates are the highest in the country. In this region, the main activity is agriculture, and rivers are the main source ... [more ▼]

The western highlands of Cameroon are an area where the population density and growth rates are the highest in the country. In this region, the main activity is agriculture, and rivers are the main source of safe drinking water. Lacks of arable land and especially against very complex land tenure, farmers are increasingly exploiting the hills (9-30 % slope) for the production of vegetable crops, mainly potatoes. The methods of preparation of soil found there are ridging in the direction of the slope and the culture dish. These practices promote erosion by runoff, generally compromises the multiple functions of agriculture, and in particular the environmental function (soil degradation, pollution and silting up of rivers) and the production function (incomes). In order to ensure soil stability and maintain good water quality of rivers, we put it up a new way of preparing the ground: the tied ridging. To quantify the effectiveness of the latter, we conducted tests of erosion by runoff with Wischmeier’s plots on the most exploited slopes, namely 11% and 29%. The run-off water and sediments were collected per plot and per block after every rain. The first analyses show that there is a significant difference between the culture dish or ridging along the slope and tied ridging. The major constraint of this practice lies in the increase of about 17% of the labor. Tied ridging reported losses in average land 16% lower compared with the ridging in the direction of the slope and 22% compared with the culture dish, he also presented higher yields of 65 % compared with the culture dish and the ridging in the direction of the slope. Despite the hardship, the test results have convinced the participants and some curious farmers which have adopted the technology during the next growing season. [less ▲]

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See detailPrévention quaternaire : agir est-il toujours justifié en médecine de famille ?
Widmer, Daniel; Herzig, Lilly; Jamoulle, Marc ULg

in Revue Médicale Suisse (2014), 10(430), 1052-6

La prévention quaternaire vise à protéger le patient ou la po- pulation de la surmédicalisation. Elle imprègne toute l’activité du médecin de famille par une interrogation tant sur l’utilité de la ... [more ▼]

La prévention quaternaire vise à protéger le patient ou la po- pulation de la surmédicalisation. Elle imprègne toute l’activité du médecin de famille par une interrogation tant sur l’utilité de la prévention primaire que du diagnostic précoce, ou sur les risques de la création de nouvelles entités pathologiques et d’une médecine maximaliste. Le médecin de famille favorise la prévention quaternaire en se centrant sur les priorités du patient et sur les ressources locales d’un système de soins efficace. [less ▲]

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See detailCarbon monoxide retrieved from ground based FTIR remote sensing in the mid-­‐ and near infrared spectral region
Petri, Christof; Blumenstock, Thomas; Hase, Frank et al

Conference (2014, May 14)

Detailed reference viewed: 11 (2 ULg)