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See detailEfficient refolding of a recombinant abzyme : Structural and catalytic characterizations.
Ben Naya, Raouia; Matti, Kalyankumar; Guellier, Adeline et al

in Applied Microbiology & Biotechnology (2013), 97(17), 7721-31

Catalytic antibodies are currently being investigated in order to understand their role under physio-pathological situations. To this end, the knowledge of structure-function relationships is of great ... [more ▼]

Catalytic antibodies are currently being investigated in order to understand their role under physio-pathological situations. To this end, the knowledge of structure-function relationships is of great interest. Recombinant scFv fragments are smaller and easier to genetically manipulate than whole antibodies, making them well suited for this kind of study. Nevertheless they are often described as proteins being laborious to produce. This paper describes a highly efficient method to produce large quantities of refolded soluble catalytic scFv. For the first time, the functionality of a refolded catalytic scFv displaying a beta-lactamase activity has been validated by three approaches: (1) use of circular dichroism to ensure that the refolded had secondary structure consistent with a native scFv fold, (2) development of enzyme-linked immunosorbant assay and surface plasmon resonance (SPR) approaches for testing that the binding characteristics of an inhibitory peptide have been retained, and (3) proof of the subtle catalytic properties conservation through the development of a new sensitive catalytic assay using a fluorogenic substrate. [less ▲]

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See detailAn Efficient Sampling Technique Used to Detect Four Foodborne Pathogens on Pork and Beef Carcasses in Nine Belgian Abattoirs
Korsak Koulagenko, Nicolas ULg; Daube, Georges ULg; Ghafir, Yasmine et al

in Journal of Food Protection (1998), 61(5), 535-541

The method presented in this paper should prove useful in assessing the effectiveness of HACCP plans developed in slaughterhouses. Samples were collected by swabbing well-defined areas of pork and beef ... [more ▼]

The method presented in this paper should prove useful in assessing the effectiveness of HACCP plans developed in slaughterhouses. Samples were collected by swabbing well-defined areas of pork and beef carcasses with sterile gauze. Between 160 and 420 half-carcasses were swabbed in each of nine pork or beef slaughterhouses. Swabs from five carcasses were placed in the same sterile Stomacher bag, constituting a single composite sample. Standard or validated analytical methods were used to isolate and characterize four foodborne pathogens. Salmonella spp., Listeria monocytogenes, Campylobacter spp., and verocytotoxin-producing E. coli were detected, respectively, in 27, 2, 2, and 14% of the pork samples and 0, 22, 10, and 5% of the beef samples. Of the 10 samples positive for E. coli O157, only one yielded an isolate confirmed to be enterohemorrhagic. Since Salmonella spp. appear as the main contaminant port (27%) and L. monocytogenes as the main containment of beef (22%), any slaughterhouse sampling plan should include testing for the former in the case of pork carcasses and for the latter in the case of beef carcasses. One should also test regularly for the presence of E. coli O157 and Campylobacter spp. in pork and beef abattoirs. The method presented here is an easy way to assess the contamination rate of carcasses at the end of the slaughtering process. [less ▲]

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See detailAn efficient simulation tool for predicting chatter during cutting operations
Le Lan, Jean-Vincent; Masset, Luc ULg; Marty, Audrey et al

Conference (2006, April)

The trends in chatter prediction are to compute stability lobes showing the maximal depth of cut versus spindle speed, following the work of Tlusty, Tobias and, more recently, Altintas. For mass ... [more ▼]

The trends in chatter prediction are to compute stability lobes showing the maximal depth of cut versus spindle speed, following the work of Tlusty, Tobias and, more recently, Altintas. For mass production such as the production of automotive parts, this kind of approach is not suitable because the goal is to find cutting conditions stable and independent of perturbations inherent to machining (clamping, rough part dimensions...). Still, in this method, the greatest allowable depth of cut to avoid chatter at any spindle speed is considered. The model is based on Tlusty's theory and the local stiffness of the machined surface is computed through a static finite element analysis. The result is a chatter map of the machined surface showing the maximal depth of cut at each node. [less ▲]

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See detailEfficient sludge thermal processing: from drying to thermal valorisation
Arlabosse, Patricia; Ferrasse, J. H.; Lecomte, D. et al

in Tsotsas, E.; Mujumdar, A. S. (Eds.) Modern Drying Technology, Vol 4. Energy savings (2012)

Detailed reference viewed: 93 (15 ULg)
See detailEfficient springback prediction based on Enhanced Assumed Strain Elements
BUI, Q. V.; Papeleux, Luc ULg; Ponthot, Jean-Philippe ULg

in Proceedings of COMPLAS 2003, VII International Conference on Computational Plasticity. Fundamentals and Applications (2003, April)

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See detailAn efficient standard error formula for the weighted likelihood estimator of ability
Magis, David ULg

Scientific conference (2014, March 04)

The weighted likelihood estimator (WLE; Warm, 1989) has become a very popular ability estimator in item response theory. It was developed to basically cancel the estimation bias of the maximum likelihood ... [more ▼]

The weighted likelihood estimator (WLE; Warm, 1989) has become a very popular ability estimator in item response theory. It was developed to basically cancel the estimation bias of the maximum likelihood estimator (MLE) with short tests. However, some uncertainty remains about its standard error formula. Warm (1989) established the asymptotic equivalence of the standard errors of both MLE and WLE, but there exists actually various practical formulas for the latter (Magis & Raîche, 2012; Nydick, 2013; Partchev, 2012; Warm, 2007), leading obviously to confusion. The purpose of this talk is to briefly sketch a general approach to derive a first-order approximation of the standard error of the WLE. Based on asymptotic adjustments of the law of large numbers and central limit theorem, a simple formula is derived. The efficiency of the latter is compared to aforementioned formulas by means of a simulation study under Rasch modeling. Preliminary results indicate that the derived formula has lower bias and RMSE than any other competing formula, especially with short tests. All formulas behave similarly with longer tests, as expected. [less ▲]

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See detailEfficient standard error formulas of ability estimators with dichotomous item response models
Magis, David ULg

in Psychometrika (in press)

This paper focuses on the computation of asymptotic standard errors (ASE) of ability estimators with dichotomous item response models. A general framework is considered and ability estimators are defined ... [more ▼]

This paper focuses on the computation of asymptotic standard errors (ASE) of ability estimators with dichotomous item response models. A general framework is considered and ability estimators are defined from a very restricted set of assumptions and formulas. This approach encompasses most standard methods such as maximum likelihood, weighted likelihood, maximum a posteriori and robust estimators. A general formula for the ASE is derived from the theory of M-estimation. Well-known results are found back as particular cases for the maximum and robust estimators, while new ASE proposals for the weighted likelihood and maximum a posteriori estimators are presented. These new formulas are compared to traditional ones by means of a simulation study under Rasch modeling. [less ▲]

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See detailEfficient synthesis of 2,5-diketopiperazines by Staudinger-mediated cyclization
Beagle, Lucas; Hansen, Finn; Monbaliu, Jean-Christophe ULg et al

in Synlett (2012), 23(16), 2337-2340

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See detailEfficient targeted energy transfers in coupled nonlinear oscillators through 1:1 transcient resonance captures:
Sapsis, Themistoklis; Quinn, D. Dane; Gendelman, Oleg et al

in Sixth EUROMECH Nonlinear Dynamics Conference, Saint Petersbourg, 2008 (2008)

We study targeted energy transfer (TET) in a two degree-of-freedom damped system caused by 1:1 transient resonance capture (TRC). The system consists of a linear oscillator strongly coupled to an ... [more ▼]

We study targeted energy transfer (TET) in a two degree-of-freedom damped system caused by 1:1 transient resonance capture (TRC). The system consists of a linear oscillator strongly coupled to an essentially nonlinear attachment. First, we study the underlying structure of the Hamiltonian dynamics of the system, and then show that, for sufficiently small values of viscous damping, the nonlinear damped transitions are strongly influenced by the underlying topological structure of periodic and quasiperiodic orbits of the hamiltonian system. Then, a detailed computational study of the different types of nonlinear transitions that occur in the weakly damped system is presented. As a result of these studies, conditions that lead to effective or even optimal TET from the linear system to the nonlinear attachment are determined. Finally, direct analytical treatment of the governing strongly nonlinear damped equations of motion is performed through slow/fast partition of the transient responses, in order to analytically model the dynamics the region of optimal TET, and to determine the characteristic time scales of the dynamics that influence the capacity of the nonlinear attachment to passively absorb and locally dissipate broadband energy from the linear oscillator. [less ▲]

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See detailEfficient transformation and regeneration of transgenic cassava using the neomycin phosphotransferase gene as aminoglycoside resistance marker gene.
Niklaus, Michael; Gruissem, Wilhelm; Vanderschuren, Hervé ULg

in GM Crops (2011), 2(3), 193-200

Cassava is one of the most important crops in the tropics. Its industrial use for starch and biofuel production is also increasing its importance for agricultural production in tropical countries. In the ... [more ▼]

Cassava is one of the most important crops in the tropics. Its industrial use for starch and biofuel production is also increasing its importance for agricultural production in tropical countries. In the last decade cassava biotechnology has emerged as a valuable alternative to the breeding constraints of this highly heterozygous crop for improved trait development of cassava germplasm. Cassava transformation remains difficult and time-consuming because of limitations in selecting transgenic tissues and regeneration of transgenic plantlets. We have recently reported an efficient and robust cassava transformation protocol using the hygromycin phosphotransferase II (hptII) gene as selection marker and the aminoglycoside hygromycin at optimal concentrations to maximize the regeneration of transgenic plantlets. In the present work, we expanded the transformation protocol to the use of the neomycin phosphotransferase II (nptII) gene as selection marker. Several aminoglycosides compatible with the use of nptII were tested and optimal concentrations for cassava transformation were determined. Given its efficiency equivalent to hptII as selection marker with the described protocol, the use of nptII opens new possibilities to engineer transgenic cassava lines with multiple T-DNA insertions and to produce transgenic cassava with a resistance marker gene that is already deregulated in several commercial transgenic crops. [less ▲]

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See detailEfficient uncoupled stochastic analysis with non-proportional damping
Canor, Thomas ULg; Blaise, Nicolas ULg; Denoël, Vincent ULg

in Journal of Sound & Vibration (2012), 331(2012), 52835291

The use of normal modes of vibration in the analysis of structures with nonproportional damping reduces the size of the resulting set of governing equations, but does not decouple them. A common practice ... [more ▼]

The use of normal modes of vibration in the analysis of structures with nonproportional damping reduces the size of the resulting set of governing equations, but does not decouple them. A common practice consists in decoupling the equations by disregarding the o -diagonal elements in the modal damping matrix. Recently, an approximation based on an asymptotic expansion of the modal transfer matrix has been proposed in a deterministic framework to partially account for o -diagonal terms, but still with a set of uncoupled equations. This paper aims at extending this method in a stochastic context. First the mathematical background is introduced and the method is illustrated with a simple example. Then its relevance is demonstrated within the context of the structural analysis of a large and realistic structure. [less ▲]

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See detailEfficient Visualization of High-Order Finite Elements
Remacle, J.-F.; Chevaugeon, N.; Marchandise, E. et al

in International Journal for Numerical Methods in Engineering (2007), 69(4), 750--771

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See detailEfficiently approximating Markov tree bagging for high-dimensional density estimation
Schnitzler, François ULg; ammar, sourour; leray, philippe et al

in Gunopulos, Dimitrios; Hofmann, Thomas; Malerba, Donato (Eds.) et al Machine Learning and Knowledge Discovery in Databases, Part III (2011, September)

We consider algorithms for generating Mixtures of Bagged Markov Trees, for density estimation. In problems defined over many variables and when few observations are available, those mixtures generally ... [more ▼]

We consider algorithms for generating Mixtures of Bagged Markov Trees, for density estimation. In problems defined over many variables and when few observations are available, those mixtures generally outperform a single Markov tree maximizing the data likelihood, but are far more expensive to compute. In this paper, we describe new algorithms for approximating such models, with the aim of speeding up learning without sacrificing accuracy. More specifically, we propose to use a filtering step obtained as a by-product from computing a first Markov tree, so as to avoid considering poor candidate edges in the subsequently generated trees. We compare these algorithms (on synthetic data sets) to Mixtures of Bagged Markov Trees, as well as to a single Markov tree derived by the classical Chow-Liu algorithm and to a recently proposed randomized scheme used for building tree mixtures. [less ▲]

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See detailEfficiently Approximating Markov Tree Bagging for High-Dimensional Density Estimation
Schnitzler, François ULg

Scientific conference (2011, December 07)

Detailed reference viewed: 14 (2 ULg)
See detailEffondrement culturel à l'île de Pâques ? Ce qu'en dit l'archéologie.
Flas, Damien ULg; Cauwe, Nicolas ULg

Conference given outside the academic context (2015)

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See detailEffondrement d’un mur de berge sur la Vesdre
Dewals, Benjamin ULg

in Interview on the Belgian radio RTBF (2010)

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See detailL'effondrement de la Générale des Carrières et des Mines.Chronique d'un processus de privatisation informelle
Rubbers, Benjamin ULg

in Cahiers d'Etudes Africaines (2006), 181

How this mining giant abruptly collapsed is the focus of this article. Instead of adopting what has become a classic interpretation-Mobutu's patrimonial politics and a poor economic environment, this work ... [more ▼]

How this mining giant abruptly collapsed is the focus of this article. Instead of adopting what has become a classic interpretation-Mobutu's patrimonial politics and a poor economic environment, this work underscores the internal dynamics of the company, in its particular social setting. [less ▲]

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See detailL'effort cognitif
Adam, Stéphane ULg

Conference (2007, April 11)

Detailed reference viewed: 4 (0 ULg)
See detailL'effort excentrique sur dynamomètre isocinétique
Croisier, Jean-Louis ULg; Crielaard, Jean-Michel ULg

in Actes de la 1ère Journée Belge d'Isocinétisme (1997, February)

Detailed reference viewed: 42 (3 ULg)