Adaptive estimators of proficiency in adaptive testing

Conference (2007, June)

Influence, information and item response theory in discrete data analysis

Doctoral thesis (2007)

Développement de nouvelles méthodes d'estimation des paramètres de sujets dans le cadre des modélisations dichotomiques issues de la théorie de la réponse à l'item

Scientific conference (2006, November)

Sur l'utilisation de la variabilité de sujet pour corriger l'habileté: méthode et premiers résultats

Scientific conference (2006, November)

Un autre regard sur le rapport de vraisemblance pour le test d'homogénéité et les comparaisons multiples

Scientific conference (2006, June)

Evaluation of BM-573, a novel TXA(2) synthase inhibitor and receptor antagonist, in a porcine model of myocardial ischemia-reperfusion

in Prostaglandins & Other Lipid Mediators (2006), 79(1-2), 53-73

Aims: To investigate whether BM-573 (N-tert-butyl-N'-[2-(4'-methylphenylam\ino)-5-nitro-benzenesulfonyl]urea), an original combined thromboxane A(2) synthase inhibitor and receptor antagonist, prevents ... [more ▼]

Aims: To investigate whether BM-573 (N-tert-butyl-N'-[2-(4'-methylphenylam\ino)-5-nitro-benzenesulfonyl]urea), an original combined thromboxane A(2) synthase inhibitor and receptor antagonist, prevents reperfusion injury in acutely ischemic pigs. Methods: Twelve animals were randomly divided in two groups: a control group (n = 6) intravenously infused with vehicle, and a BM-573-treated group (n = 6) infused with BM-573 (10 mg kg(-1) h(-1)). In both groups, the left anterior descending (LAD) coronary artery was Occluded for 60 min and reperfused for 240 min. Either vehicle or BM-573 was infused 30 min before LAD occlusion and throughout the experiment. Platelet aggregation induced by arachidonic acid ex vivo measured was prevented by BM-573. Results: In both groups, LAD occlusion decreased cardiac output, ejection fraction, slope of stroke work-end-diastolic volume relationship, and induced end-systolic pressure-volume relationship (ESPVR) rightward shift, while left ventricular afterload increased. Ventriculo-arterial coupling and mechanical efficiency decreased. In both groups, reperfusion further decreased cardiac output and ejection fraction, while ESPVR displayed a further rightward shift. Ventriculo-arterial coupling and mechanical efficiency remained impaired. Area at risk, evidenced with Evans blue, was 33.2 +/- 3.4% of the LV mass (LVM) in both groups, and mean infarct size, revealed by triphenyltetrazolium chloride (TTC), was 27.3 +/- 2.6% of the LVM in the BM-573-treated group (NS). Histological examination and immunohistochemical identification of desmin revealed necrosis in the anteroseptal region similar in both groups, while myocardial ATP dosages and electron microscopy also showed that BM-573 had no cardioprotective effect. Conclusions: These data suggest that BM-573 failed to prevent reperfusion injury in acutely ischemic pigs. (C) 2005 Elsevier Inc. All rights reserved. [less ▲]

A note on the influence of pairwise misclassification in two-way tables

in Journal of Statistical Computation & Simulation (2006), 76

The influence of subject misclassification on log-linear analysis of two-way contingency tables is investigated. We define pairwise misclassification and focus on both deviance and Pearson statistics as ... [more ▼]

The influence of subject misclassification on log-linear analysis of two-way contingency tables is investigated. We define pairwise misclassification and focus on both deviance and Pearson statistics as goodness-of-fit criteria for testing independence between the variables. Attention is paid to the extremal values of the test statistics that can be reached on the basis of the data set. We derive theoretical properties and use them to detect potentially troubling cells in a simple computing routine. Examples illustrate our purpose. [less ▲]

On the detection of influential subsets of categories in goodness of fit testing

Conference (2005, August)

Effet des erreurs de classification sur le test d’indépendance de deux critères discrets : une approche probabiliste

Scientific conference (2005, January)

Characterization of an original model of myocardial infarction provoked by coronary artery thrombosis induced by ferric chloride in pig

in Thrombosis Research (2005), 116(5), 431-442

Background: Great advances have been made in the prevention of thrombotic disorders by developments of new pharmacological and surgical treatments. Animal models of arterial thrombosis have largely ... [more ▼]

Background: Great advances have been made in the prevention of thrombotic disorders by developments of new pharmacological and surgical treatments. Animal models of arterial thrombosis have largely contributed to the discovery and to the validation of original treatments. The purpose of the present work was to develop and validate an original model of acute myocardial infarction provoked in pig by thrombosis of the left anterior descending (LAD) coronary artery induced by topical application of ferric chloride solution. Methods and results: Myocardial infarction, resulting from an occlusive and adherent mixed thrombus formed in the LAD coronary artery, was examined at macroscopic level using dual staining technique (Evans blue dye; triphenyltetrazolium chloride) and at microscopic level using conventional histological analyses and immunohistochemical detection of desmin. Biochemical markers (troponin T and ATP), platelet reactivity and standard hemodynamic parameters (such as stroke volume, ejection fraction, stroke work and cardiac output) have also been evaluated. From these analyses, it was demonstrated that each pig developed a transmural area of irreversible damage mainly located in the anteroseptal region of the left ventricle. The more progressive development of coronary artery occlusion, as compared to an abrupt Ligation, was accompanied by a correspondingly progressive impairment in hemodynamics. Conclusion: We conclude that this original porcine model of myocardial infarction is quite close to clinical pathophysiological conditions, such as thrombus formation occurring after atherosclerotic plaque rupture. This certainly constitutes a further argument in favour of this model to assess pharmaceutical or mechanical support of an acutely ischemic heart. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]