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See detailA BAYESIAN PROBABILITY CRITERION TO ASSESS ANALYTICAL RESULTS RELIABILITY
Rozet, Eric ULg; Lebrun, Pierre ULg; Boulanger, B et al

Conference (2013, May 21)

In pharmaceutical and biomedical industries, quantitative analytical methods such as HPLC play a key role. Indeed, the analytical results obtained from them are used to make crucial decisions such as the ... [more ▼]

In pharmaceutical and biomedical industries, quantitative analytical methods such as HPLC play a key role. Indeed, the analytical results obtained from them are used to make crucial decisions such as the release of batches of drugs, the evaluation of safety and efficacy of new drug candidates or the monitoring of patients health. Prior to their routine use, analytical methods are submitted to a stringent validation study [1] where they have to demonstrate that they are fit for their final purpose, i.e. providing accurate results: where is the analytical result, is the theoretical unknown true concentration of analyte in the sample analyzed and a regulatory acceptance limit. Typically this demonstration is made by either providing point estimates of systematic error (bias) and random error (variance) or sometimes by providing interval estimates of these statistical parameters at several well defined concentration levels of the target analyte [2]. They are then compared to maximum acceptable levels. More recently, tolerance intervals approaches have been proposed that are evaluated in a similar way at these key concentration levels [3]. However none of these decision approaches allow knowing the probability to obtain accurate results over the whole concentration range of interest: is a vector of parameters and Pmin is a minimum reliability probability. Frequentist approximations have been proposed to estimate this probability but only at the concentration levels experimentally tested [4,5]. In this work, a linear hierarchical Bayesian approach is proposed. It takes into account the potential random characteristic of the slope and intercept observed from one analytical run to the other, but it also integrates the possible covariance between the parameters. Additionally, heteroscedasticity of the residual variance over the concentration range investigated is taken into account. A situation regularly observed in practice. Finally a reliability profile for the whole concentration range studied is obtained using MCMC sampling. This profile provides the probability (Prel) to obtain accurate results over the full concentration range investigated. This profile is then compared to a minimum reliability probability (Pmin) that will define the valid concentration range of the analytical method. The usefulness of this approach is illustrated through the validation of a bioanalytical method and also compared with one concentration level at a time frequentist approaches [4,5]. [1] International Conference on Harmonization (ICH) of Technical Requirements for registration of Pharmaceuticals for Human Use Topic Q2 (R1): Validation of Analytical Procedures: Text and Methodology, Geneva, 2005. [2] A. Bouabidi and al., J. Chromatogr. A, 1217 (2010) 3180. [3] Ph. Hubert and al., J. Pharm. Biomed. Anal., 36 (2004) 579. [4] W. Dewé and al., Chemometr. Intell. Lab. Syst. 85 (2007) 262. [5] B. Govaerts and al., Qual. Reliab. Engng. Int. 24 (2008) 667. [less ▲]

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See detailBayesian proportional hazards model with time varying regression coefficients: a penalized Poisson regression approach
Lambert, Philippe ULg; Eilers, Paul H.C.

in Statistics in Medicine (2005), 24

One can fruitfully approach survival problems without covariates in an actuarial way. In narrow time bins, the number of people at risk is counted together with the number of events. The relationship ... [more ▼]

One can fruitfully approach survival problems without covariates in an actuarial way. In narrow time bins, the number of people at risk is counted together with the number of events. The relationship between time and probability of an event can then be estimated with a parametric or semi-parametric model. The number of events observed in each bin is described using a Poisson distribution with the log mean speci ed using a exible penalized B-splines model with a large number of equidistant knots. Regression on pertinent covariates can easily be performed using the same log-linear model, leading to the classical proportional hazard model. We propose to extend that model by allowing the regression coe cients to vary in a smooth way with time. Penalized B-splines models will be proposed for each of these coe cients. We show how the regression parameters and the penalty weights can be estimated e ciently using Bayesian inference tools based on the Metropolis-adjusted Langevin algorithm. [less ▲]

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See detailBazooka est-il soluble dans l'art contemporain ?
Dejasse, Erwin ULg

in 9e Art : Les Cahiers du Musée de la Bande Dessinée (2006), 12

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See detailBCL-3 degradation involves its polyubiquitination through a FBW7-independent pathway and its binding to the proteasome subunit PSMB1.
Keutgens, Aurore ULg; Zhang-Shao, Xin ULg; Shostak, Kateryna ULg et al

in Journal of Biological Chemistry (2010), 285(33), 2583125840

The oncogenic protein BCL-3 activates or represses gene transcription through binding with the NF-kappaB proteins p50 and p52 and is degraded through a phospho- and GSK3-dependent pathway. However, the ... [more ▼]

The oncogenic protein BCL-3 activates or represses gene transcription through binding with the NF-kappaB proteins p50 and p52 and is degraded through a phospho- and GSK3-dependent pathway. However, the mechanisms underlying its degradation remain poorly understood. Yeast-two-hybrid analysis led to the identification of the proteasome subunit PSMB1 as a BCL-3-associated protein. The binding of BCL-3 to PSMB1 is required for its degradation through the proteasome. Indeed, PSMB1-depleted cells are defective in degrading polyubiquitinated BCL-3. The N-terminal part of BCL-3 includes lysines 13 and 26 required for the K48-linked polyubiquitination of BCL-3. Moreover, the E3 ligase FBW7 known to polyubiquitinate a variety of substrates phosphorylated by GSK3 is dispensable for BCL-3 degradation. Thus, our data defined an unique motif of BCL-3 that is needed for its recruitment to the proteasome and identified PSMB1 as a key protein required for the proteasome-mediated degradation of a nuclear and oncogenic IkappaB protein. [less ▲]

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See detailBCOR analysis in patients with OFCD and Lenz microphthalmia syndromes, mental retardation with ocular anomalies, and cardiac laterality defects.
Hilton, Emma; Johnston, Jennifer; Whalen, Sandra et al

in European Journal of Human Genetics (2009), 17(10), 1325-35

Oculofaciocardiodental (OFCD) and Lenz microphthalmia syndromes form part of a spectrum of X-linked microphthalmia disorders characterized by ocular, dental, cardiac and skeletal anomalies and mental ... [more ▼]

Oculofaciocardiodental (OFCD) and Lenz microphthalmia syndromes form part of a spectrum of X-linked microphthalmia disorders characterized by ocular, dental, cardiac and skeletal anomalies and mental retardation. The two syndromes are allelic, caused by mutations in the BCL-6 corepressor gene (BCOR). To extend the series of phenotypes associated with pathogenic mutations in BCOR, we sequenced the BCOR gene in patients with (1) OFCD syndrome, (2) putative X-linked ('Lenz') microphthalmia syndrome, (3) isolated ocular defects and (4) laterality phenotypes. We present a new cohort of females with OFCD syndrome and null mutations in BCOR, supporting the hypothesis that BCOR is the sole molecular cause of this syndrome. We identify for the first time mosaic BCOR mutations in two females with OFCD syndrome and one apparently asymptomatic female. We present a female diagnosed with isolated ocular defects and identify minor features of OFCD syndrome, suggesting that OFCD syndrome may be mild and underdiagnosed. We have sequenced a cohort of males diagnosed with putative X-linked microphthalmia and found a mutation, p.P85L, in a single case, suggesting that BCOR mutations are not a major cause of X-linked microphthalmia in males. The absence of BCOR mutations in a panel of patients with non-specific laterality defects suggests that mutations in BCOR are not a major cause of isolated heart and laterality defects. Phenotypic analysis of OFCD and Lenz microphthalmia syndromes shows that in addition to the standard diagnostic criteria of congenital cataract, microphthalmia and radiculomegaly, patients should be examined for skeletal defects, particularly radioulnar synostosis, and cardiac/laterality defects. [less ▲]

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See detailLe BCS, une méthode simple à la source de conseils variés : ration, repro et santé
Laloux, Laurent; Bastin, Catherine ULg; Gillon, Alain ULg et al

Poster (2009, February 11)

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See detailLe BCS, une méthode simple à la source de conseils variés : ration, repro et santé
Laloux, Laurent; Bastin, Catherine ULg; Gillon, Alain ULg et al

in 14ième Carrefour des Productions animales: Les filières bovines dans la tourmente, Produire plus et mieux avec moins: Gembloux, le 11 février 2009 (2009)

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See detailLe BCS: un outil de gestion de la fertilité
Bastin, Catherine ULg

Article for general public (2012)

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See detailBcsTx3 is a founder of a novel sea anemone toxin family of potassium channel blocker
Orts, Diego; Moran, Yehu; Cologna, Camila et al

in FEBS Journal (2013), 280

Sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. In this work, BcsTx3, a toxin found in the venom of a ... [more ▼]

Sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. In this work, BcsTx3, a toxin found in the venom of a Bunodosoma caissarum (population captured at the Saint Peter and Saint Paul Archipelago, Brazil) was purified and biochemically and pharmacologically characterized. The pharmacological effects were studied on 12 different subtypes of voltage-gated potassium channels (KV1.1–KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; hERG and Shaker IR) and three cloned voltagegated sodium channel isoforms (NaV1.2, NaV1.4 and BgNaV1.1) expressed in Xenopus laevis oocytes. BcsTx3 shows a high affinity for Drosophila Shaker IR channels over rKv1.2, hKv1.3 and rKv1.6, and is not active on NaV channels. Biochemical characterization reveals that BcsTx3 is a 50 amino acid peptide crosslinked by four disulfide bridges, and sequence comparison allowed BcsTx3 to be classified as a novel type of sea anemone toxin acting on KV channels. Moreover, putative toxins homologous to BcsTx3 from two additional actiniarian species suggest an ancient origin of this newly discovered toxin family. [less ▲]

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See detailBD +03 deg 740 - A new extreme metal-poor dwarf
Magain, Pierre ULg

in The Messenger (1987), 47

The results of a preliminary analysis of BD +03 deg 740 are presented. The analysis was based on the blue spectrum which was obtained with an exposure time of 40 min, giving a good S/N ratio for this 9.8 ... [more ▼]

The results of a preliminary analysis of BD +03 deg 740 are presented. The analysis was based on the blue spectrum which was obtained with an exposure time of 40 min, giving a good S/N ratio for this 9.8-mag star. Graphs are presented which reveal the extreme weakness of the metal lines in the spectrum. The analysis of BD +03 deg 740, which is the most metal-poor dwarf in which s element abundances have been determined, confirms the presence of secondary elements in the atmospheres of the extreme halo dwarfs. [less ▲]

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See detailBe Too Kind to a Woman, She’ll Feel Incompetent: Benevolent Sexism Shifts Self-construal and Autobiographical Memories Toward Incompetence
Dumont, Muriel ULg; Sarlet, Marie ULg; Dardenne, Benoît ULg

in Sex Roles (2010), 62

The present study investigated how benevolent (BS) and hostile sexism (HS) shift women’s self-construal and autobiographical memory. Belgian undergraduates (only women, N=45, mean age=21.8) were ... [more ▼]

The present study investigated how benevolent (BS) and hostile sexism (HS) shift women’s self-construal and autobiographical memory. Belgian undergraduates (only women, N=45, mean age=21.8) were confronted either by BS, HS or neutral comments in the context of a job interview. After performing a cognitive task, participants reported the intrusive thoughts that came to their mind during the task. Later, autobiographical memory for self-incompetence was assessed. Performance response latencies were slower after BS than HS. Also, BS generated more disturbing mental intrusions related to the idea of being incompetent than HS. Autobiographical memory similarly indicated greater access for incompetence after BS. Although HS was more aggressive in tone, it did not shift women’s self-construal and autobiographical memories toward incompetence. [less ▲]

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See detailBeak Trimming
Marlier, Didier ULg

in Veterinary Journal (2005), 170

To trim or not to trim beaks? It is always a good time to raise this difficult question. Indeed, since the release of the Brambell Committee report1 on welfare in the UK in 1965, discussion on the welfare ... [more ▼]

To trim or not to trim beaks? It is always a good time to raise this difficult question. Indeed, since the release of the Brambell Committee report1 on welfare in the UK in 1965, discussion on the welfare of beak-trimmed birds has continued unabated. The aim of this new book (with its 15 contributors) is not, of course, to close the debate but merely to consolidate the huge amount of scientific information available on methods welfare and alternatives to beak-trimming. In the Preface, it is stated that the book will be of interest to welfare groups, policy makers, scientists, industry leaders and students of poultry science who wish to acquaint themselves with the welfare issues associated with beak-trimming and the potential solutions for reducing the need to beak-trim poultry. This goal is achieved to the extent that most of the information (although sometimes rather concisely) is presented in the eight chapters of this 174 page book. The first chapter describes the methods and reasons for beak-trimming. Chapter 2 raises the ethical question of beak-trimming and gives some of the pros and cons of the arguments. Pain and nerve injuries induced by beak-trimming are presented in Chapters 3–5 and the production responses (improved liveability, plumage quality and feed efficiency during egg laying) of beak-trimmed birds are assessed in Chapter 6 with bird health and handling issues associated with beak-trimming in Chapter 7. The last chapter is devoted to alternatives to beak-trimming. It includes environmental enrichment methods; a consideration of the genetics of feather pecking and cannibalism; dietary recommendations to reduce cannibalism in chickens and laying hens; manipulation of light intensities and colour to modify behaviour; management of body weight; application of abrasive strips in the feed trough to blunt the tips of the beaks of laying hens and the use of fitted devices and stock wound spray in injured birds to prevent further pecking. Among all these alternatives, the genetic solution might well prove to be the most sustainable, efficacious and cost effective. Overall, however, throughout the book this reviewer had the feeling, rightly or wrongly, that it was mostly written by opponents of beak-trimming and that arguments of the defence were sometimes omitted. [less ▲]

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See detailBeam-foil spectroscopy of Ne IV
Bastin, Thierry ULg; Blanche, Pierre-Alexandre ULg; Garnir, Henri-Pierre ULg et al

Poster (1994)

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See detailBeam-gas excitation of Ar III 3s3p5 singlet and triplet terms
Garnir, Henri-Pierre ULg; Träbert, E.; Dumont, Paul-Dominique ULg et al

Poster (2001)

Detailed reference viewed: 12 (5 ULg)