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See detailNavigating the uncertain seas of controversies – A pedagogical wind rose
Verpoorten, Dominique ULg

in Melard, François; Stassart, Pierre M (Eds.) Proceedings of the International Interdisciplinary Working Conference "Teaching complexity and uncertainty on Environmental Issues - Practices, Theories and Products" (2014, December 23)

The Arlon conference brought together lecturers willing to share and discuss aspects of their practice of “controversies”, seen as a teaching/learning method suited to the contextual needs and demands of ... [more ▼]

The Arlon conference brought together lecturers willing to share and discuss aspects of their practice of “controversies”, seen as a teaching/learning method suited to the contextual needs and demands of higher education environmental studies. The paper contributes to this joint reflective effort by providing conceptual tools helping to interpret the practice, to question what it puts at stake and to detect, from a pedagogical viewpoint, key issues and upcoming questions. The contribution falls within the Conference's aim n°2: “share theories or conceptual propositions that make it possible to equip the teaching approaches and to give them theoretical and methodological foundations” (Program Arlon Conference 2014, p. 2). The article takes a traditional stance, looking at the contributions to the conference through “constructive alignment”(Biggs, 1996), a basic principle meant to secure the pedagogical validity of any given learning situation by establishing a triple consistency (Kovertaite & Leclercq, 2006; Leclercq, 1995; Petit, Castaigne, & Verpoorten, 2007; Tyler, 1949) between objectives, methods and assessment. [less ▲]

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See detailRapid dynamic activation of a marine-based Arctic ice cap
McMillan, M; Shepherd, A; Gourmelen, N et al

in Geophysical Research Letters (2014), 41(24), 89028909

We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two ... [more ▼]

We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two decades, the sector ice discharge has increased 45-fold, the velocity regime has switched from predominantly slow (~ 101 m/yr) to fast (~ 103 m/yr) flow, and rates of ice thinning have exceeded 25 m/yr. At the time of widespread dynamic activation, parts of the terminus may have been near floatation. Subsequently, the imbalance has propagated 50 km inland to within 8 km of the ice cap summit. Our observations demonstrate the ability of slow-flowing ice to mobilize and quickly transmit the dynamic imbalance inland; a process that we show has initiated rapid ice loss to the ocean and redistribution of ice mass to locations more susceptible to melt, yet which remains poorly understood. [less ▲]

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See detailEarly history of extended irreversible thermodynamics (1953-1983): an exploration beyond local equilibrium and classical transport theory
Lebon, Georgy ULg; Jou, david

in European Physical Journal H. Historical Perspectives on Contemporary Physics (2014), 5(23),

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See detailToward a Consistent Application of International Financial Reporting Standards (IFRSs) across Companies and Countries
Yammine, Mira ULg

Doctoral thesis (2014)

International Financial Reporting Standards (IFRSs) were developed to be a single set of high-quality globally accepted accounting standards. They are meant to allow uniformity in financial reporting ... [more ▼]

International Financial Reporting Standards (IFRSs) were developed to be a single set of high-quality globally accepted accounting standards. They are meant to allow uniformity in financial reporting, enhance comparability of financial statements in the midst of economical globalization, and allow companies with international subsidiaries to prepare their financial statements using similar global standards. The objective of the dissertation is to study whether the application of IFRSs is consistent across companies and countries; in particular we tackle the following two questions: -Does the application of IFRSs in the preparation of financial statements lead to consistency? -Does the public enforcement of accounting standards impact the consistent application of IFRSs? To answer the first question we have addressed standard IAS 36 that was developed by the International Accounting Standards Board (IASB) and covering impairment of assets. We found that managers’ opportunism still has an impact on the impairment of assets recognition and magnitude when taking impairment decisions. To address the second question, a survey covering enforcement of accounting standards activities was prepared and sent to public enforcement bodies in a number of countries mandating the adoption of IFRSs. The survey allowed us to construct an index that represents the activities of the public enforcement bodies. We studied the impact of public enforcement on specific applications of the standards, the results show a decrease in earnings management in countries with effective public enforcement. [less ▲]

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See detailLa thermoplastie bronchique dans le traitement de l'asthme sévère de l'adulte.
Chanez, P.; Boulet, L.-P.; Brillet, P.-Y. et al

in Revue des maladies respiratoires (2014)

Bronchial thermoplasty is a recent endoscopic technique for the treatment of severe asthma. It is an innovative treatment whose clinical efficacy and safety are beginning to be better understood. Since ... [more ▼]

Bronchial thermoplasty is a recent endoscopic technique for the treatment of severe asthma. It is an innovative treatment whose clinical efficacy and safety are beginning to be better understood. Since this is a device-based treatment, the evaluation procedure of risks and benefits is different that for pharmaceutical products; safety aspects, regulatory requirements, study design and the assessment of the magnitude of effects may all be different. The mechanism of action and optimal patient selection need to be assessed further in rigorous clinical and scientific studies. This technique is in harmony with the development of personalised medicine in the 21st century. It should be developed further in response to the numerous challenges and needs not yet met in the management of severe asthma. [less ▲]

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See detailDrivers of inorganic carbon dynamics in first-year sea ice: A model study.
Moreau, Sebastien; Vancoppenolle, Martin; Delille, Bruno ULg et al

in Journal of Geophysical Research. Oceans (2014)

Sea ice is an active source or a sink for carbon dioxide (CO2), although to what extent is not clear. Here, we analyze CO2 dynamics within sea ice using a one-dimensional halo-thermodynamic sea ice model ... [more ▼]

Sea ice is an active source or a sink for carbon dioxide (CO2), although to what extent is not clear. Here, we analyze CO2 dynamics within sea ice using a one-dimensional halo-thermodynamic sea ice model including gas physics and carbon biogeochemistry. The ice-ocean fluxes and vertical transport of total dissolved inorganic carbon (DIC) and total alkalinity (TA) are represented using fluid transport equations. [less ▲]

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See detailGathering and Handling of Granular Materials under Microgravity Conditions
Opsomer, Eric ULg

Doctoral thesis (2014)

When a granular material is driven in microgravity environment, one can assist to the formation of dense and slow regions in the system. Indeed, given the dissipative character of the collisions in the ... [more ▼]

When a granular material is driven in microgravity environment, one can assist to the formation of dense and slow regions in the system. Indeed, given the dissipative character of the collisions in the media, energy is lost at each particle interaction and the grains begin to clump locally. The phenomenon has been observed for the first time in the late nineties during sounding rocket experimentation by Falcon and his coworkers and has attracted the interest of many scientists since then. However, precise laws describing the formation and the dynamics of such clusters are still lacking. In order to allow an intensive study of the phenomenon, the European Space Agency set up the SpaceGrains project. Small bronze spheres are enclosed in a rectangular cell and vertically driven by to pistons oscillating in phase opposition. Our work consists in the preparation of the SpaceGrains experiment via molecular dynamics simulations and the elaboration of models predicting the behaviour of the system. Before we started our study concerning SpaceGrains, we reproduced and extended Falcon’s sounding rocket experiments. We showed that, in addition to the granular gas and the cluster, another dynamical regime can be observed in the system. Indeed, for higher filling fractions, the entire granular media behaves like one single completely dissipative particle called the bouncing aggregate. Bouncing modes are observed and can be explained considering the bouncing ball paradigm. Moreover, we highlighted the role of the packing fraction φ as well as the size of the particles R on the different observed dynamics. Within the frame of the SpaceGrains device, we studied the impact of all tunable parameters of the experiment on the dynamics of the system. Thanks to an appropriate scaling all transition points that we obtained by varying the driving amplitude A, the packing fraction and the dimen- sions of the cell L fall along a same theoretical curve. The latter is explained regarding the energy transfer from the piston towards the center of the cell. Once the clustering was controlled, we investigated the handling of the agglomerate. By compartmentalizing the container, local trapping can be achieved and a granular pendant of Maxwell’s demon can be observed in microgravity. Based on the measured particle flux between the compartments, we realized a theoretical model predicting the asymptotic steady state of the system depending on the total number N of particles. In a clustered system, we investigated the impact of asymmetrical driving on the system’s dy- namics. We showed that the mean position of the cluster can be fully controlled via the amplitude ratio a. Moreover, the natural fluctuations of the agglomerate around its equilibrium position are dictated by the driving frequency f and the mass of the cluster. Finally, we realized simulations of driven bi-disperse gases and investigated the segregation phenomena in the system. We showed that clustering and segregation are strongly linked and that the size and the mass of the particles impact the segregation dynamics in different ways. [less ▲]

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See detailDécouverte d'un gène du gigantisme
Beckers, Albert ULg

Scientific conference (2014, December 19)

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See detailThe Politics of National Accounting: Assessing Walloon Public Debt
Piron, Damien ULg

Conference (2014, December 19)

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See detailUn guide de la rédaction du mémoire : pourquoi et comment ?
Grandjean, Geoffrey ULg

Scientific conference (2014, December 19)

Detailed reference viewed: 38 (3 ULg)
See detailUn exemple de détournement du jeu vidéo par les joueurs : la pratique du speedrun
Barnabé, Fanny ULg

Scientific conference (2014, December 18)

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See detailMapping Gene Regulatory Networks in Drosophila Eye Development by Large-Scale Transcriptome Perturbations and Motif Inference
Potier, Delphine; Davie, Kristofer; Hulselmans, Gert et al

in Cell Reports (2014), 9(6), 2290-2303

Genome control is operated by transcription factors (TFs) controlling their target genes by binding to promoters and enhancers. Conceptually, the interactions between TFs, their binding sites, and their ... [more ▼]

Genome control is operated by transcription factors (TFs) controlling their target genes by binding to promoters and enhancers. Conceptually, the interactions between TFs, their binding sites, and their functional targets are represented by gene regulatory networks (GRNs). Deciphering in vivo GRNs underlying organ development in an unbiased genome-wide setting involves identifying both functional TF-gene interactions and physical TF-DNA interactions. To reverse engineer the GRNs of eye development in Drosophila, we performed RNA-seq across 72 genetic perturbations and sorted cell types and inferred a coexpression network. Next, we derived direct TF-DNA interactions using computational motif inference, ultimately connecting 241 TFs to 5,632 direct target genes through 24,926 enhancers. Using this network, we found network motifs, cis-regulatory codes, and regulators of eye development. We validate the predicted target regions of Grainyhead by ChIP-seq and identify this factor as a general cofactor in the eye network, being bound to thousands of nucleosome-free regions. [less ▲]

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See detailHors-cadre : quand le documentaire ne peut pas tout montrer
Hamers, Jérémy ULg

Scientific conference (2014, December 18)

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See detailEtude et Modélisation de la contribution des macrophytes flottants (Lemna minor) dans le fonctionnement des lagunes naturellles
Tangou Tabou, Thierry ULg

Doctoral thesis (2014)

Waste stabilization ponds (WSP) are widely used in the treatment of domestic and industrial wastewaters in industrialized countries and in developing countries including the Democratic Republic of Congo ... [more ▼]

Waste stabilization ponds (WSP) are widely used in the treatment of domestic and industrial wastewaters in industrialized countries and in developing countries including the Democratic Republic of Congo. Several organisms (e.g., bacteria, algae, protozoa, and aquatic plants) are involved in the treatment process occurring in the WSP. Therefore, the performance of such systems strongly depends upon the management of the existing macrophytes (or at least the management of the most dominant species). Indeed, large biomass coverage of floating macrophytes can induce several dysfunctions within the ponds (e.g., second pollution due to the death and the settling of the macrophytes, difficulties in harvesting valuable biomass for animal feeding or pharmaceutical purposes, etc.) and can threaten the surrounding ecosystems (i.e., fauna and flora) through the releases of partially or unpurified waters. This study aimed at investigating the contribution of floating macrophytes, namely that of duckweed (Lemna minor), which are the most common species, in the functioning of natural WSP. Specifically, the objectives were: (i) the modeling of the growth kinetics of Lemna minor based on the key environmental influencing factors (nutrients concentrations, light intensity, pH, temperature); (ii) the characterizations of the stoichiometry of the growth of Lemna minor and the gas/liquid transfers in the ponds; and (iii) the set-up of a mathematical model, i.e. the MLLE (Modèle de Lagunage par Lentilles d'eau) through the mass balances approach based on the Petersen’s matrix. The study of the growth kinetics of L. minor was carried out in a growth chamber (phytotron) using a pilot involving initial fresh L. minor biomass and different set of concentrations in nutrient nitrogen (N) and phosphorus (P), light intensity, pH, and temperature. The growth was monitored using the gravimetric methods and digital images processing. The results showed that the growth of L. Minor was optimum for concentrations of N and P of circa 10 mg N-NH4+.L-1 and 1 mg P-PO43-.L-1, respectively, with a maximum growth rate of approximately 0.09 j-1. However, the growth decreased progressively when the respective concentrations of N and P reached approximately 16 mg N-NH4+L-1 and 6 mg P-PO43-.L-1. A possible inhibition due to the excess of substrates might be the cause of such decrease. Moreover, a light intensity greater than 450 μmol.m-².s-1 was potentially harmful for L. minor surviving (growth rate dropped by 60%), though the mortality rate was low (< 0.05 j-1). Characterizing the stoichiometry of L. minor resulted in the formulation of the plant biomol (C88H163O70N10P) and the description of biochemical processes occurring within the ponds, as well as the determination of the conversion rates substrate-biomass in each of these processes. The Lavoisier's principle (conservation of the matter) also was confirmed for the stoichiometric relationship developed for chemical oxygen demands through our experiments. Furthermore, the aeration test assays revealed the influence of the biomass coverage on the gaz/liquid transfers parameters. An exponential decrease of the transfer coefficients, the oxygenation capacity and hourly inputs was associated with increasing coverage rates in both absence and presence of plants. The hypothesis of a main release (about 80%) of oxygen (consumption of carbon dioxide) toward the atmosphere was also confirmed. The third fold of our study was then undertaken based on our findings on the biochemical processes (kinetics and stoichiometry of growth and mortality of plants) and findings on physical processes (gas/liquid transfer) occurring in WSP. A mathematical model, the MLLE, was thus developed and its validity assessed through the equilibrium of the Petersen's matrix. The impact of key nutrients (i.e., nitrogen and phosphorus) on the growth of duckweed, along with the influence of the release of oxygen (consumption carbon dioxide) by the floating macrophytes (L. minor) can be, therefore, thoroughly assessed based on the state variables of the model. Additional simulations using the West® (World Wide Engine for Simulation, Training and Automation) software could help in further calibrating and/or validating the MLLE, and guide in its implementation for industrial purposes. Keywords: Lemna minor, biomass, image processing, nutrient, biomole, gas/liquid transfer, model [less ▲]

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See detailEtude de step-down des corticostéroïdes inhalés chez des patients asthmatiques non-éosinophiliques
Demarche, Sophie ULg

Scientific conference (2014, December 18)

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See detailEtude des facteurs influençant la visite des oiseaux dans les champs de riz
Nasasagare, Régine-Pacis; Ntakimazi, Gaspard; Libois, Roland ULg

in Bulletin scientifique de l'Institut national pour l'environnement et la conservation de la nature (2014), 13

This study was conducted in order to show pest bird species on rice in Burundi. An exhaustive ornithologic inventory was done in 45 fields in the plain of Rusizi and 30 in Ngozi fields were randomly ... [more ▼]

This study was conducted in order to show pest bird species on rice in Burundi. An exhaustive ornithologic inventory was done in 45 fields in the plain of Rusizi and 30 in Ngozi fields were randomly chosen and classified in 3 categories for Rusizi plain (2 for Ngozi): fully guarded plots, partially guarded plots and not guarded plots. There were no fields partially guarded for Ngozi. Resultats revealed a list of bird species that have a real impact on rice production in Burundi. The current study also allowed to put in evidence factors of the motivation of their visit. [less ▲]

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See detailContribution to the epidemiology of bovine brucellosis in Ivory Coast
Sanogo, Moussa ULg

Doctoral thesis (2014)

Bovine brucellosis is an endemic infectious disease which can negatively impact on cattle productivity and welfare as well as on human health. In many developing countries such as Ivory Coast, there is a ... [more ▼]

Bovine brucellosis is an endemic infectious disease which can negatively impact on cattle productivity and welfare as well as on human health. In many developing countries such as Ivory Coast, there is a need for knowledge on the distribution and the frequency of the disease (or evidence of its presence) within the animal population and the possible factors associated with the disease. Information is also needed on species and biovars of Brucella at national and regional scales, on the performance of commonly used diagnostic tests for accurate estimation of the true disease prevalence, and on determination of risk factors associated with the disease. These informations are of key importance to set up and implement appropriate and efficient prevention and control measures against brucellosis. For these reasons, the research presented in this thesis aimed to contribute to a better understanding of the epidemiology of bovine brucellosis in Ivory Coast. The thesis is structured into three main parts. The introduction part includes three chapters. The first chapter presents an overview of the literature on the pathogen causing brucellosis, their characteristics and distribution. The impact and the existing strategies for preventing and controlling brucellosis are discussed with a particular reference to the situation of bovine brucellosis in Ivory Coast. The presence and the importance of the disease were confirmed in the country but the disease is still uncontrolled. In the second chapter (Chapter 2), an insight on statistical, epidemiological principles and concepts applied to achieve the different objectives (Chapter 3) is given, including a discussion on available approaches to estimate diagnostic test characteristics and the true prevalence of a disease. The second part of the thesis includes research on different aspects of the epidemiology of bovine brucellosis in Ivory Coast and West Africa (Chapter 4, 5, 6 and 7). Chapter 4 specifically provides a state-of–the-art knowledge on species and biovars of Brucella reported in cattle from Ivory Coast and all other countries of West Africa, through a review of available literature. From the synthesized literature, Brucella abortus was demonstrated to be the most prevalent species in cattle in West Africa, in line with the known host preference for Brucellae. So far, biovars 3 appeared to be commonly the most isolated in West Africa and was also recently identified in Ivory Coast. However, the presence of B. melitensis and/or B. suis was not reported yet in cattle in this part of Africa. Results on prevailing strains of Brucella in cattle were related with commonly used serological diagnostic tools. Thus, chapter 5 was dedicated to verify their appropriateness and to assess the performance of two serological tests, Rose Bengal Test (RBT) and indirect Enzyme-linked Immunosorbent assay (iELISA). Using a Bayesian approach, the correlation-adjusted sensitivity of iELISA was estimated at 96.1 % (Credibility Interval (CrI): 92.7-99.8) whereas that of RBT was 54.9 % (CrI: 23.5-95.1). High correlation-adjusted specificities were found for both tests, 95.0 % (CrI: 91.1-99.6) for iELISA and 97.7 % (CrI: 95.3-99.4) for RBT, respectively. The true prevalence of brucellosis was also estimated using the 1228 tested serum samples to be 4.6 with a 95% credibility interval ranging from 0.6 to 9.5% (Chapter 5 and 6). These results also revealed a good performance for the iELISA, which might consequently be a valuable screening assay under the epidemiological conditions prevailing in Ivory Coast. In Chapter 7, risk factors associated with bovine brucellosis seropositivity were investigated using serological results obtained from 907 serum samples collected from unvaccinated cattle of at least 6 months of age in the savannah-forest region of Ivory Coast. Serum samples were tested using the Rose Bengal test (RBT) and indirect enzyme linked immunosorbent assay (iELISA). The logistic regression analysis indicated that brucellosis seropositivity was associated with age and herd size. Cattle above 5 years of age were found to be more likely seropositive (Odd Ratio (OR) =2.8; 95% Confidence Interval (CI): 1.3, 6.4) compared to cattle under 3 years of age. Similarly, the odds of brucellosis seropositivity for herds with more than 100 cattle was 3.3 (95% CI: 1.2, 8.9) times higher compared to those with less than 50 cattle. The third part presents a general discussion on the overall contribution of the current research (Chapter 8), by highlighting the main results and pointing out their significance. The need for more investigations on the epidemiology of brucellosis, in Ivory Coast and at West African scale, is highlighted. It is neccessary to provide additional knowledge on prevailing field strains of Brucella, on the distribution of the disease and on associated risk factors to implement preventive and control measures. Finally, for more cost-effectiveness and efficiency, the need to strengthen the capabilities of the veterinary services and national laboratories and to consider the control of brucellosis and other zoonotic diseases through a regional, integrated and collaborative perspective is also highlighted. [less ▲]

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See detailDiagnosis and clinical interest of asthma inflammatory phenotypes
SCHLEICH, FLorence ULg

Doctoral thesis (2014)

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See detailCyclovirus CyCV-VN species distribution is not limited to Vietnam and extends to Africa
Garigliany, Mutien-Marie ULg; Hagen, Ralf Mathias; Frickmann, Hagen et al

in Scientific Reports (2014), 4

Cycloviruses, small ssDNA viruses of the Circoviridae family, have been identified in the cerebrospinal fluid from symptomatic human patients. One of these species, cyclovirus-Vietnam (CyCV-VN), was shown ... [more ▼]

Cycloviruses, small ssDNA viruses of the Circoviridae family, have been identified in the cerebrospinal fluid from symptomatic human patients. One of these species, cyclovirus-Vietnam (CyCV-VN), was shown to be restricted to central and southern Vietnam. Here we report the detection of CyCV-VN species in stool samples from pigs and humans from Africa, far beyond their supposed limited geographic distribution. [less ▲]

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