Last 7 days
Bookmark and Share    
Full Text
See detailPlanetary missions in the STAR institute
Palmaerts, Benjamin ULg

Scientific conference (2017, September 15)

Quick overview of all the current and future planetary missions in which the STAR institute is involved.

Peer Reviewed
See detailExecutive functions in normal aging: the mediating effect of processing speed and attentional system
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2017, September 14)

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se ... [more ▼]

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se. Therefore, this present study is aimed at determining whether speed of processing and attentional variables would mediate the effect of age on the executive functioning. Participants and Methods Young (n = 104) and old (n = 63) participants were enrolled and carried out a large battery made of 21 executive (inhibition, shifting, working memory updating, and double task coordination), attentional (phasic alertness, selective attention, and sustained attention), and processing speed tasks. Based on Baron & Kenny’s recommendations (1986), mediation models of the age effect on the executive functioning were carried out with processing speed and attentional system taken as mediators. Results Selective attention significantly mediated the effect of age on working memory updating [􀇻R2 = 7%, p < .001]. Moreover, processing speed significantly mediated the effect of age on shifting [􀇻R2 = 7%, p < .001], working memory updating [􀇻R2 = 5%, p < .001], and double task coordination [􀇻R2 = 14%, p < .001]. Conclusions The mediating effect of age on most of the executive functions by measures of processing speed is in agreement with the literature showing a major influence of the slowdown of the processing speed on cognition (Salthouse, 1992; 2000; 2005). The age effect on inhibition did not seem to be mediated neither by the attentional variables nor the speed variables, which is in accordance with Zacks & Hasher’s hypothesis (1988). According to these authors, inhibition would be the first cognitive function to decline with age. [less ▲]

Peer Reviewed
See detailThe artistic patronage of Cardinal Charles II de Bourbon (1433-1488)
Laruelle, Anne-Sophie ULg

Conference (2017, September 14)

As one of the most important political and religious figures of the mid-fifteenth century, Charles II de Bourbon (1433-1488) has not received the attention he deserves. Charles, archbishop of Lyon (1446 ... [more ▼]

As one of the most important political and religious figures of the mid-fifteenth century, Charles II de Bourbon (1433-1488) has not received the attention he deserves. Charles, archbishop of Lyon (1446), was made cardinal by the pope Sixtus IV in 1476. He was also an important courtier, and a confidant of King Louis XI of France, to whom he was related by marriage. Charles was present at the interview of Kings Louis XI and Edward IV of England in 1475 and in the signature of the peace treaty concluded between them, which formally ended the Hundred Years’ War. Among other posts, Charles held the governorship of Paris and was the head of the King’s Council. Grandson of John the Fearless and cousin to Charles the Bold, he also bore numerous connections with the Burgundian Court and the Southern Netherlands. This paper aims at re-appreciating the artistic patronage of the wealthy cardinal, in spite of the difficulties raised by the paucity of surviving artworks he commissioned. Charles was indeed an important patron, who founded a splendid funerary chapel in Lyon Cathedral, and had the archiepiscopal palace of Lyon built. The cardinal owned a lot of exceptional manuscripts, sculptures and tapestries. Due to his position, Charles may have influenced tastes of Louis XI for the arts, but also the future king Charles VIII’s (Charles de Bourbon was, along with Joan of Valois, Duchess of Bourbon and Edward of Westminster, godparent of the dauphin in 1470).Particular attention will be paid to his collection of tapestries, which have never received detailed analysis. Charles II de Bourbon’s arms (motto, initials, and his device of a flaming sword) appear on only three pieces today: “The Adoration of the Magi”, “The Three Coronations” (both preserved in Sens cathedral), and a scene from the “Story of Hercules” (Mobilier National, Paris). Woven with extremely high quality, probably in the Southern Netherlands, the cardinal’s tapestries are undoubtedly among the finest and most expensive pieces of the 15th century. [less ▲]

Full Text
See detailPush-Pull strategy to control aphids in Belgium and China
Xu, Qingxuan ULg

Doctoral thesis (2017)

Wheat (Triticum aestivum L.) is one of the most cultivated crops in temperate climates. As its pests are mainly controlled with insecticides which are harmful to the environment and human health ... [more ▼]

Wheat (Triticum aestivum L.) is one of the most cultivated crops in temperate climates. As its pests are mainly controlled with insecticides which are harmful to the environment and human health, alternative practices such as intercropping have been studied for their potential to promote biological control. Fifty original research papers were obtained from a systematic search of the peer-reviewed literature. Results from a vote-counting analysis indicated that, in the majority of studies, pest abundance was significantly reduced in intercropping systems compared with pure stands. However, the occurrence of their natural enemies as well as predation and parasitism rates were not significantly increased. Nevertheless, other practices could be combined with intercropping to favour natural enemies and enhance pest control. Dispersal of viruses is intimately tied to their vectors. Aphids are known to invest in costly antipredator behavior when perceiving cues of predators. Before presenting the results and the answers to the previous questions, a brief research was conducted in order to have an overview of the intercropping on the spread of aphids, to assess the potential impact of intercropping systems attracting natural enemies on the virus transmission. We studied aphid antipredator behavior in intercropping with wheat-broad bean (Vicia faba L.) as a model. The bird cherry-oat aphid, Rhopalosiphum padi Linnaeus, is an important vector of the barley yellow dwarf virus. The effects of two natural aphid enemies, adult and larvae of the seven-spot ladybeetle, Coccinella septempunctata Linneaus, on R. padi dispersion was studied under laboratory conditions. Results show that the total number of aphids was higher in intercropping than monoculture in treatments without ladybeetles, while the contrary was observed in the presence of ladybeetle larvae. These results might be explained by the non-host plant chemical cues and the physical barrier that was broad-bean plants confusing R. padi when searching for their host plants after being dropped from wheat by predators (i.e. associational resistance). After make sure that the intercropping can reduce the dispersal of aphids in the presence of predators, in fine potentially limiting virus dispersal, especially shortly after aphids colonize plants. Next step will be to solve how to increase the number of natural enemies of intercropping in Belgium and China. Semiochemical substances have been tested to enhance biological control, with inconsistent results. Combining semiochemical and intercropping can be an interesting way to maximize pest control. In Belgium, a two-year setup involving wheat–pea strip intercropping combined with the release of E-β-farnesene (EBF) or methyl salicylate (MeSA) was tested as a push–pull strategy to simultaneously repell aphids and attract beneficials. Two types of slow-release formulation (i.e., oil and alginate beads) containing EBF or MeSA were deployed with intercropping. The abundance of aphids was significantly decreased, hoverfly larvae and mummified aphids increased on both pea plants and wheat tillers by the release of oil-formulated EBF and MeSA. The proportion parasitism of aphids-parasitism rate was also increased by treating both crops in both years. Releasing EBF through oil rather than alginate beads proved significantly better for attracting natural enemies and reducing aphids. Aphids were negatively correlated with the density of hoverflies (both adults and larvae) and numbers of mummies. We also tested the combining in China and the experiments were set-up: wheat-pea strip intercropping solely, intercropping combined with the release of EBF, and intercropping combined with the release of MeSA, each treatment repeated three times. The total number of aphids throughout the growing season was significantly decreased in treatments with releases of semiochemicals compared to intercropping solely. The effect was stronger with MeSA than with EBF on the control of R. padi, and hoverflies and lacewings were twice more numerous in MeSA. All these results showed that combining intercropping with the release of EBF or MeSA formulated in oil can significantly reduce aphid density and attract their natural enemies. Therefore, the combination of both strategies could help farmers reduce the use of insecticides. [less ▲]

Detailed reference viewed: 26 (1 ULg)
Full Text
See detailAtelier de Grounded Theory Method
Lejeune, Christophe ULg

Scientific conference (2017, September 14)

De nombreuses publications se réclament de l'analyse par théorisation ancrée (Grounded Theory Method). Ce succès suggère même que cette technique constitue une formalisation générique de la recherche ... [more ▼]

De nombreuses publications se réclament de l'analyse par théorisation ancrée (Grounded Theory Method). Ce succès suggère même que cette technique constitue une formalisation générique de la recherche qualitative. Un examen approfondi révèle cependant que, de ces nombreux travaux se réclamant de la GTM, peu rencontrent effectivement les critères essentiels que constituent l'étiquetage de l'expérience vécue, la tenue d'un journal de bord et l'élaboration d'une conceptualisation originale. Croisant ses expériences de sociologue de terrain et de formateur en recherche qualitative, Christophe Lejeune met en garde contre les pièges que recèle la recherche qualitative et présente les solutions pratiques qu'y apporte l'analyse par théorisation ancrée. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
See detailFrom Metabolomics Study of Age-Related Macular Degeneration (AMD) to the Development of New Pyruvate Dehydrogenase Kinase Inhibitors (PDK)
Arslan, Deniz ULg; Schoumacher, Matthieu ULg; Pirotte, Bernard ULg et al

Poster (2017, September 14)

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of ... [more ▼]

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of the retina specialized for the high-acuity vision. Exudative AMD, called “wet”, is characterized by the formation of new blood vessels growing under the retina according to a process named choroidal neovascularization (CNV). Currently, the aetiology and pathogenesis of AMD remain unclear. Nevertheless, a recent metabolomics study performed on the serum of “wet” AMD patients and on a CNV murine model, that mimics the effect of “wet” AMD, have demonstrated that lactate level is clearly involved in the severity of the pathology as well as the relationship between lactate, CNV and AMD [1]. According to this result, we suggest a new therapeutic approach of AMD based on the normalization of blood lactate level. The modulation of the lactate plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate Dehydrogenase Kinase (PDK) inhibitors significantly decrease the CNV. PDK and its four isoforms (PDK1-4) regulate the activity of the pyruvate dehydrogenase complex (PDH), a mitochondrial enzyme that plays a major role in the metabolic pathway of glucose, by reversible phosphorylation. Starting from these results, development of new PDK inhibitors could open the way to innovative treatment opportunities in AMD disease. Different analogues of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide (fig.1) have been already synthetized and pharmacological evaluation is currently in progress. According to the results obtained, various pharmacomodulations will be investigated. [less ▲]

Full Text
See detailLes documents d'urbanisme. Vers quel typologies de représentation sous le paradigme du BIM ?
Boutemadja, Abdelkader ULg

Conference (2017, September 14)

Sous le nouveau paradigme du BIM et du SIG 3D, quel typologies de représentation graphique doivent adopter les documents d'urbanisme. Il s'agit d'une reflexion qui donne à entrevoir les possibilités de ... [more ▼]

Sous le nouveau paradigme du BIM et du SIG 3D, quel typologies de représentation graphique doivent adopter les documents d'urbanisme. Il s'agit d'une reflexion qui donne à entrevoir les possibilités de représentation qu'offrent les nouvelles technologies. [less ▲]

See detailDevelopment of SERS nanosensors for the detection of small bioactive molecules by cellular analysis in complex matrices: Application to dopamine
Dumont, Elodie ULg; De Bleye, Charlotte ULg; Cailletaud, Johan ULg et al

Conference (2017, September 13)

This communication reports the different steps undertaken in order to develop a new Surface-Enhanced Raman Scattering (SERS) nanosensor for the quantification of dopamine in the culture medium of PC-12 ... [more ▼]

This communication reports the different steps undertaken in order to develop a new Surface-Enhanced Raman Scattering (SERS) nanosensor for the quantification of dopamine in the culture medium of PC-12 cells. First, the synthesis of the SERS substrate, gold nanoparticles, and its characterization. Then the development of the method with the help of a design of experiments and the demonstration of the specificity of the method over other structurally related catecholamines. And finally, the implementation of the method on the culture medium of PC-12 cells, on an HEPES buffer having served to wash the cells and on the PC-12 cells. [less ▲]

Full Text
See detailAdvanced data processing for high-contrast imaging - Pushing exoplanet direct detection limits with machine learning
Gómez González, Carlos ULg

Doctoral thesis (2017)

Since ancient times, mankind has wondered whether other solar systems exist around other stars somewhere in the Universe. It took many centuries to finally prove the existence of extra-solar planetary ... [more ▼]

Since ancient times, mankind has wondered whether other solar systems exist around other stars somewhere in the Universe. It took many centuries to finally prove the existence of extra-solar planetary systems. Nowadays, more than 3500 exoplanets have been discovered, mostly thanks to indirect detection methods. Indeed, the task of directly detecting exoplanets through high-contrast imaging (HCI) is a formidable challenge, and has only been enabled in the last decade thanks to advances in instrumentation and dedicated image processing algorithms. This last component of the exoplanet direct imaging pipeline is what ultimately pushes the detection limits and sensitivity of HCI instruments and survey campaigns. Unfortunately, the HCI community has been slow in adopting the latest developments in data management and machine learning for analyzing the increasing amount of available data. This dissertation is an attempt to fill in this very gap, and develops at the interface of computer science, machine learning, statistics, and astrophysics. This work contributes to the field of data processing for HCI in two main ways. On one hand, I have developed an open source \texttt{Python} library for taking HCI data from the raw state up to the characterization of companions. It implements state-of-the-art approaches and is positioning itself as one of the de facto software solutions for building HCI pipelines. I have also participated to the critical analysis of data from different first and second generation HCI instruments. On the other hand, I have approached the task of exoplanet detection in angular differential imaging sequences from a computer vision and machine learning perspective. This interdisciplinary work has led to novel algorithmic solutions, extending unsupervised learning techniques widely used in HCI and proposing advanced supervised learning approaches based on cutting-edge deep learning models. My novel algorithms have been presented using a robust performance assessment framework to produce large comparative performance studies. These studies show the improved sensitivity vs specificity trade-off of the proposed supervised detection approach. The proposed algorithms bring the possibility of re-processing existing HCI databases to maximize their scientific return and potentially improve the demographics of directly imaged exoplanets. [less ▲]

Full Text
See detailEconomic Development and Structural Change
Van Neuss, Leif ULg

Doctoral thesis (2017)

This doctoral dissertation contributes to the understanding of structural change, often defined as the process of reallocation of economic activity and resources across the three broad sectors agriculture ... [more ▼]

This doctoral dissertation contributes to the understanding of structural change, often defined as the process of reallocation of economic activity and resources across the three broad sectors agriculture (primary sector), manufacturing (secondary sector) and services (tertiary sector). Increasingly connected to the study of modern growth, the analysis of structural change has known an important revival over recent decades, due in part to the economic concerns associated with the movement of deindustrialization that has particularly affected the world’s most economically successful countries since the last third of the 20th century. These concerns have indeed fed many discussions on the causes and consequences of structural change, as well as on the role of policy instruments in driving and accompanying the inter-sectoral reallocation of activity. The first part of the thesis gets particularly interested in the driving forces behind the process of structural change. It begins by placing structural change in a very long historical perspective, notably shedding light on the factors that contributed to the emergence of the Industrial Revolution, an event characterized by the acceleration of structural change and traditionally considered as a turning point in the history of mankind because it eventually brought about modernity. It then analyzes the main causes of structural change in market economies, putting a particular emphasis on two mechanisms of structural change that have been largely overlooked in the recent multi-sector growth literature: changes in input-output (sectoral) linkages and changes in comparative advantage via globalization and trade. With respect to trade, an empirical analysis reveals that global exchanges have the potential to influence significantly and substantially a country’s sectoral patterns of employment, and that the estimated contribution of trade, especially of trade with developing countries, to recent structural change (deindustrialization) in affluent countries may be revised upwards when resorting to better-suited indicators of trade in manufactures. The second part of this doctoral thesis deals more with the economic effects of structural change. In particular, it proposes a new shift-share method, which is an accounting method aimed at computing the impact of the economic structure - or structural change - on a territory’s economic performance. By way of illustration, it provides an application to manufacturing employment in the Belgian provinces between 1995 and 2007. [less ▲]

See detailLiDAR aérien et autres nuages de points pour la cartographie multi-échelles
Poux, Florent ULg; Neuville, Romain ULg; Kasprzyk, Jean-Paul ULg et al

Conference (2017, September 12)

Utilisation de nuage de points pour la cartographie 3D multi-échelles. Exemples d'utilisation et définition de workflows pour assurer l'interopérabilité lors de la fusion de données issues de différents ... [more ▼]

Utilisation de nuage de points pour la cartographie 3D multi-échelles. Exemples d'utilisation et définition de workflows pour assurer l'interopérabilité lors de la fusion de données issues de différents capteurs. [less ▲]

Full Text
See detailManaging and authenticating non-institutional users in Alma: two experiences
Brownlie, Helen; De Groof, Robert ULg; Renaville, François ULg

Conference (2017, September 12)

The management of patron information within Alma is primarily reliant on two systems – the creation and updating of patron information by an external system such as student management or HR systems or ... [more ▼]

The management of patron information within Alma is primarily reliant on two systems – the creation and updating of patron information by an external system such as student management or HR systems or internally within Alma itself. A recent survey of the Alma community indicated the majority of institutions utilize a mixture of these external and internal processes. In addition to providing access to affiliated staff and students more than 89% of institutions responded that they provided user accounts to non-affiliated users such as the general public, members of other academic institutions, alumni, etc. Providing authenticated access to library services for the latter group relies heavily on Alma for password management. This presentation will outline the processes in place at the University of Otago and at the University of Liège for managing and authenticating non-institutional users and the possible effect of Ex Libris' proposed changes to internal authentication. [less ▲]

Full Text
Peer Reviewed
See detailComparaison de l'impact de deux méthodes d'apprentissage sur la sécurité d'administration des médicaments : stages cliniques versus simulation
Servotte, Jean-Christophe ULg; Galerin, Catherine ULg; Ghuysen, Alexandre ULg et al

Conference (2017, September 12)

Introduction Drug administration is the act nurses most frequently do. However, 50% of errors occur during administration. The damage these errors causes to patients, results in excess mortality rates and ... [more ▼]

Introduction Drug administration is the act nurses most frequently do. However, 50% of errors occur during administration. The damage these errors causes to patients, results in excess mortality rates and health care costs, hence leading to a major public health problem. Therefore, it is advisable to consider the training of future nurses on the practice of this delicate act. The objective of this study is to evaluate the impact of teaching by simulation combined with the internship on the safety administration of intravenous drugs by nursing students, compared to just the internship alone. Material and method A selection of 99 students from the bachelors’ block two of the Namur-Liege-Luxembourg Higher Institute of Nursing met the inclusion criteria under consideration. They were divided into two groups, one experimental group which participated in a simulation session and a control group, the latter did not participate in the simulation session. At the start of the research, all students were assessed by an objective structured clinical examination (OSCE) with the theme of modifying infusion and syringe flow rates. They were also asked to complete a questionnaire concerning their knowledge and self-efficacy feeling related to drug administration. The experimental group then participated in the simulation sessions. The experimental group and the control group also went into four weeks of training in medical or surgical services before participating in the second stage of the study. The latter consisted of the same tests and questionnaires as stage one of the study. The evolution of the results of the two groups was first observed separately before being compared. Results The majority of the results shows that the simulation improves, in a way significantly more important than the clinical course, the acquisition of skills and knowledge, as well as the feeling of self-efficacy in drug administration. On the other hand, the assessment of the level of stress linked to drug administration and the professional attitude evaluated during the OSCE were not significantly more improved by the simulation than by the training alone (stress: p-value = 0.8269, professional attitude = 0.9857). Conclusions For the students in the experimental group, the simulation showed a positive impact on the skills, knowledge and feeling of self-efficacy associated with drug administration. Changes and continuation of the study would make it possible to go further in the generalization of results, in the evaluation of learning outcomes, and to attest to their sustainability. [less ▲]

Full Text
See detailContent Working Group Report 2016-2017
Renaville, François ULg; Varjabedian, Kathy

Conference (2017, September 11)

Report on the activities in 2016-2017 of the Content Working Group (previously Knowledge Base Advisory Board [KBAB]).

Detailed reference viewed: 18 (4 ULg)
Full Text
Peer Reviewed
See detailPreliminary Phytochemical Content and Antidiabetic Potential Investigations of Panda oleosa (Pierre) Used in Kisangani Areas
Katemo Muhoya, Frédéric; Kadima Ntokamunda, Justin; Njakarinala Ranarivelo et al

in American Journal of Analytical Chemistry (2017), 8

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate ... [more ▼]

Panda oleosa Pierre (POP), a tropical plant tree, has been used in traditional medicine in Kisangani city and around to treat various diseases including diabètes and HIV/AIDs. This study aims to evaluate the chemical composition of POP extracts while setting up chromatographic fingerprints for their quality control, and the anti-hyperglycemic potential of trunk bark aqueous extracts of POP. Common chemical reactions were used for identification of main secondary metabolic groups. Thin layer chromatography was used to set up several chromatographic fingerprints of water and alcoholic extracts while evaluating chemical composition. Oral glucose tolerance test served to induce hyperglycemia in a rabbit model. The extracts were given as 25 mg/kg, 50 mg/kg, and 100 mg/kg body weight, 30 minutes before loading animals with glucose 4 g/kg. Blood samples were collected at various times: just before extracts (T-30), before (T0) and after glucose load (T30, T60, T120, and T180). Blood glucose levels were measured with One Touch Glucometer. The identification tests revealed the presence of saponins (3.58%), tannins (5%); alkaloids, quinones, flavonoids, and terpenes sterols could not be formerly detected by the reagents used. Interesting chromatographic spots were observed whose behaviors are of catechic tannin proanthocyanes. The extract significantly reduced glucose levels in dose dependent manner as compared to control and glibenclamide reference groups. The average of mean percentage of reduction in glucose level at T120 with the extract 100 mg/kg was close to that of glibenclamide 0.25 mg/kg (49% and 40.2%). These findings back the traditional use of the plant to treat diabetic patients and constitute a foundation for an extensive study to find a new antidiabetic phythomedicine. [less ▲]