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See detailContribution to the development of an erosivity index adapted to the prediction of erosion in Belgium
Sinzot, Anne; Bolline, Arthur; Laurant, Adrien et al

in Earth Surface Processes & Landforms (1989), 14

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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 detailContribution to the epidemiology of bovine tuberculosis in northern Ecuador
Proaño Perez, Freddy ULg

Doctoral thesis (2011)

See attached document, page vii

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See detailContribution to the evaluation of soil quality around the Naivasha lake (Kenya).
Borgers, nathalie; Colinet, Gilles ULg; Gouder de Beauregard, Anne-Christine et al

Poster (2005, September)

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See detailA contribution to the history of the embryonic development of the Teleosteans
Van Beneden, Édouard ULg

in Quarterly Journal of Microscopical Science (The) (1878), 2(18), 41-57

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See detailContribution to the identification of α-, β- and ε-copper phthalocyanine blue pigments in modern artists' paints by X-ray powder diffraction, attenuated total reflectance micro-fourier transform infrared spectroscopy and micro-Raman spectroscopy
Defeyt, Catherine ULg; Vandenabeele, P.; Gilbert, Bernard ULg et al

in Journal of Raman Spectroscopy (2012), 43

Since the end of the 20th century, the α-, β- and ε-copper phthalocyanine (CuPc) blue pigments are widely used in modern artists' paints. The identification of the CuPc crystalline structure can provide ... [more ▼]

Since the end of the 20th century, the α-, β- and ε-copper phthalocyanine (CuPc) blue pigments are widely used in modern artists' paints. The identification of the CuPc crystalline structure can provide useful technical and chronological information for the study of works of art. Although when a CuPc blue pigment is identified, its crystalline structure often remains unspecified despite the interest for conservation science. In this study, X-ray powder diffraction, attenuated total reflectance micro-Fourier transform infrared spectroscopy and micro-Raman spectroscopy analyses have been carried out on 15 dry pigment samples of CuPc and acrylic, vinylic, alkyd, arabic gum and oil-based artists' paints. By using the polymorphic markers underlined for dry pigments, the CuPc crystalline structure has been successfully identified for most of the analysed artists' paints. However, according to the analytical technique used and the investigated paint sample, the obtained results largely differ. © 2012 John Wiley & Sons, Ltd. [less ▲]

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See detailContribution to the Inverse Dynamics of Flexible Manipulators
Guimaraes Bastos Junior, Guaraci ULg

Doctoral thesis (2013)

This thesis studies innovative, stable but non-causal inverse dynamics algorithms for flexible manipulators. Robust direct optimal control methods are proposed. The nonlinear finite element method is used ... [more ▼]

This thesis studies innovative, stable but non-causal inverse dynamics algorithms for flexible manipulators. Robust direct optimal control methods are proposed. The nonlinear finite element method is used to derive the mechanical model of the multibody system and the time discretization is performed using the generalized-alpha method. The sparse gradients of the optimization constraints are computed using a semi-analytical method. The inverse dynamics of both serial and parallel kinematic manipulators with flexible links and joints is successfully studied using the proposed method. Finally, the possible extension of the method for the integrated control/structure optimization of mechatronic systems is investigated. [less ▲]

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See detailContribution to the knowledge of lichens in northern France
Diederich, Paul; Van Den Broeck, Dries; Ertz, Damien et al

in Bulletin de la Société des Naturalistes Luxembourgeois (2006), 106

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See detailContribution to the Macrophytic Typology of Belgian Reference Watercourses
Galoux, Daniel; Cherot, Frédéric; Rosillon, Francis ULg et al

in Advances in Botany (2015), Volume 2015, Article ID 651369

The objective of the study is to create a typology of macrophytes for the reference watercourses of the Meuse River catchment ... [more ▼]

The objective of the study is to create a typology of macrophytes for the reference watercourses of the Meuse River catchment basininWalloniaasasteptowardstheimplementationoftheEuropeanWaterFrameworkDirective.The50sitesstudiedarethe objectofaphysicochemicalandenvironmentalcharacterizationfollowedbyafloristicsurvey(phanerogams,mosses,liverworts, andmacroalgae).Sixclustersofwatercourseswiththeircharacteristicspeciesarehighlightedbytwo-wayclusteringandindicator species. The abundance of phanerogams in some watercourses of the Arden region is not only linked to light intensity but also dependsonthedegreeofslopeandthenatureofthegeologicalsubstrate [less ▲]

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See detailContribution to the management of inherited disorders in Belgian Blue Cattle Breed
Sartelet, Arnaud ULg

Conference (2013, April 23)

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See detailContribution to the modeling of shellfish zooplankton production in wastewater stabilization ponds (WSP)
Liady, Mouhamadou Nourou Dine ULg; Fiogbé, Emile-Didier; Vasel, Jean-Luc ULg

Conference (2011, May 13)

This bibliographical study falls under the context of researching financial autonomy for durable management of South countries’ wastewater ponds (WSP), and growing interest on shellfish zooplanktons that ... [more ▼]

This bibliographical study falls under the context of researching financial autonomy for durable management of South countries’ wastewater ponds (WSP), and growing interest on shellfish zooplanktons that contribute to water treatment and can be recovered in aquaculture and many industrial applications. Our project w ill start by gathering available data aiming at the development of a mathematical model of the contribution of zooplankton in pond ecosystems. This model would include the effect of most driving factors on the growth of shellfish zooplankton in WSP combined with water treatment effi ciency and biomass productivities. After a description of various types of WSP and their corresponding zooplanktons, emphasis is put on the shellfish cladocerans, especially Daphnia. The range of growth rates in various conditions is provided and expressions of growth kinetic, merging the effect of most important factors identified. These expressions of kinetic and the corresponding stoichiometry will serve as a first approach in our model. We hope that this type of research will help in the development of sustainable sanitation systems in developing countries. [less ▲]

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See detailContribution to the modeling of wastewater sludge drying kinetics: study of the operating conditions effect
Bennamoun, Lyes; Belhamri, A.; Léonard, Angélique ULg

in Tsotsas, E.; Metzger, T.; Peglow, M. (Eds.) Proceedings of IDS 2010 - Drying 2010 (2010, October)

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See detailA contribution to the moss flora of southern South Africa
Vanderpoorten, Alain ULg; Barker, N. P.

in Journal of Bryology (2004), 26(Part 3), 230-232

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See detailContribution to the optimization of closed-loop multibody systems : application to parallel manipulators
Collard, Jean-François; Fisette, Paul; Duysinx, Pierre ULg

in Proceedings of the 5th World Congress of Structural and Multidisciplinary Optimization WCSMO5 (2003, May)

This paper describes an original and robust method to optimize the design of closed-loop mechanisms, especially parallel manipulators. In other words, these mechanisms include assembling constraints we ... [more ▼]

This paper describes an original and robust method to optimize the design of closed-loop mechanisms, especially parallel manipulators. In other words, these mechanisms include assembling constraints we solved using a Newton-Raphson algorithm which may fail when the Jacobian matrix of the constraints is ill-conditioned. Therefore, the technique we propose takes advantage of that conditioning to penalize properly the objective function. Applications are shown: on the one hand, a simple example about the design of a planar ejector and, on the other hand, more realistic examples about the kinematical properties of parallel robots, in particular Delta-type and HexaSlide-type manipulators. [less ▲]

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See detailContribution to the optimization of closed-loop multibody systems: Application to parallel manipulators
Collard, Jean-François; Fisette, Paul; Duysinx, Pierre ULg

in Multibody System Dynamics (2005), 13(1), 69-84

This paper describes an original and robust method to optimize the design of closed-loop mechanisms, especially parallel manipulators. These mechanisms involve non linear assembling constraints. During ... [more ▼]

This paper describes an original and robust method to optimize the design of closed-loop mechanisms, especially parallel manipulators. These mechanisms involve non linear assembling constraints. During optimization, the Newton-Raphson algorithm we use to solve these constraints may fail when the Jacobian matrix of the constraints is ill-conditioned and stops the redesign process. To circumvent the difficulty, the technique we propose takes advantage of numerical conditioning to penalize the objective function. Applications to an academic example and parallel robots demonstrate the capabilities of the methodology. [less ▲]

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See detailContribution to the phylogeography of the garden dormouse (Eliomys quercinus)
Libois, Roland ULg; Michaux, J; Ramalhinho, Maria da Graça et al

in Macholan, Milos; Bryja, Josef; Zima, Jan (Eds.) European Mammalogy 2003 (2003, July)

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See detailContribution to the phytochemical study of indolomonoterpenic alkaloids isolated from Strychnos usambarensis and investigation of their activity on Plasmodium falciparum
Cao, Martine ULg

Doctoral thesis (2012)

Our research focuses on the extended study of antimalarial and anticancer alkaloids isolated from Strychnos usambarensis (leaves and fruits), and is subdivided into two main axes: - The development of a ... [more ▼]

Our research focuses on the extended study of antimalarial and anticancer alkaloids isolated from Strychnos usambarensis (leaves and fruits), and is subdivided into two main axes: - The development of a purification method for natural compounds such as tertiary indolomonoterpenic alkaloids (in particular for isostrychnopentamine or ISP) to improve the isolation process and to get significant quantities of purified compounds. - The investigation of the pharmacological properties of ISP, especially on Plasmodium falciparum. The first part of the thesis is devoted to the phytochemical study of S. usambarensis leaves. It includes the development and the optimization of a simple and rapid HPLC method in order to perform a one-step-transposition in preparative scale (J Pharm Biomed Anal, 2011). In parallel to this work, a brand new alkaloid was isolated from the crude alkaloid extract of S. usambarensis leaves, 17-O-acetyl, 10-hydroxycorynantheol. The compound, assessed for its antiplasmodial activity on the 3D7 and W2 strains of P. falciparum, represents one of the most active monoindolic alkaloid known to date with a remarkable selectivity for the parasite (Planta Medica, 2011). Fruits were also investigated in order to identify the main components and maybe the presence of ISP. Two major alkaloids were characterized by analytical HPLC and were therefore studied in LC-NMR and mass spectrometry (MS) after solid phase extraction (SPE): palicoside and akagerine (Phytochem Letters, 2012). In addition, we also carried out hemisynthesis of isostrychnopentamine during the PhD mandate. The concept was to hemisynthetize ISP from 11-OH usambarine, a tertiary alkaloid more abundant in the leaves. Unfortunately, the first experiments were not as conclusive as expected. The second part of the thesis concerns the investigation of the mode of action of ISP on P. falciparum. A metabolomic approach displaying the metabolomic differences induced in the parasites was combined to a transcriptomic study evaluating genes expression via a microarray analysis, in order to better understand the biological processes involved in P. falciparum in response to ISP. For this purpose we performed a study in 1H NMR metabolomics on culture media of P. falciparum under ISP treatment. In addition, we investigated gene activation using microarrays and analyzed the alterations of the P. falciparum 3D7 transciptome in synchronous cultures after exposure to ISP. Differences in gene expression were highlighted: out of the 4700 genes analyzed, 84 were differentially expressed, 40 over-expressed and 44 under-expressed and some of them were related to specific metabolic pathways. [less ▲]

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