Statistical M-Estimation and Consistency in Large Deformable Models for Image Warping

The problem of defining appropriate distances between shapes or images and modeling the variability of natural images by group transformations is at the heart of modern image analysis. A current trend is the study of probabilistic and statistical aspects of deformation models, and the development of consistent statistical procedure for the estimation of template images. In this paper, we consider a set of images randomly warped from a mean template which has to be recovered. For this, we define an appropriate statistical parametric model to generate random diffeomorphic deformations in two-dimensions. Then, we focus on the problem of estimating the mean pattern when the images are observed with noise. This problem is challenging both from a theoretical and a practical point of view. M-estimation theory enables us to build an estimator defined as a minimizer of a well-tailored empirical criterion. We prove the convergence of this estimator and propose a gradient descent algorithm to compute this M-estimator in practice. Simulations of template extraction and an application to image clustering and classification are also provided

Kernel methods in medical imaging

We introduce machine learning techniques, more specifically kernel methods, and show how they can be used for medical imaging. After a tutorial presentation of machine learning concepts and tools, including Support Vector Machine (SVM), kernel ridge regression and kernel PCA, we present an application of these tools to the prediction of Computed Tomography (CT) images based on Magnetic Resonance (MR) images

Thésaurus d’interventions pharmaceutiques associées aux prescriptions injustifiées d’inhibiteurs de la pompe à protons

International audienceObjectives: Proton pump inhibitors (PPI) are the most effective drugs in the treatment of acid-related gastrointestinal disorders. Yet, many studies reported potential adverse drug reactions associated with long-term use. In order to reduce the rates of inappropriate PPI prescriptions and to improve patient safety, a tool aimed at guiding pharmacists to analyze PPI prescriptions was designed. It results in a thesaurus of clinical situations designed to argue about the inappropriateness of some PPI prescriptions and to highlight the risk associated with them.Methods: Clinical situations in which PPIs are inappropriate were identified by four pharmacists in one gastroenterological, one surgery/liver transplantation, one internal medicine and one oncology units. A scientific literature search was performed for each clinical situation in order to corroborate the pharmacist interventions.Results: The thesaurus comprises two parts, the first one is dedicated to 12 clinical situations in which a PPI is not required (acute pancreatitis, cholecystectomy etc.), while the second one focus on 22 situations in which PPIs are associated with specific adverse drug reactions (Clostridium difficile infection, vitamin deficiency etc.). Eighty-one articles were used to support the pharmacist interventions.Conclusion: This thesaurus is an analysis tool aimed at guiding pharmacists identify and argue about the inappropriateness of some PPI prescriptions in order to convince doctors to discontinue or not to initiate PPI prescriptions

Promoting oral potassium administration in a tertiary care hospital: An eleven-year study

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Quantitative prediction of cytochrome P450(CYP) 2D6-Mediated drug interactions

International audienceBackground and Objectives: An approach was recently proposed for quantitative predictions of cytochrome P450 (CYP) 3A4-mediated drug-drug interactions. This approach relies solely on in vivo data. It is based on two characteristic parameters: the contribution ratio (CR; i.e. the fraction of victim drug clearance due to metabolism by a specific CYP) and the inhibition ratio (IR) of the inhibitor. Knowledge of these parameters allows forecasting of the ratio between the area under the plasma concentration-time curve (AUC) of the victim drug when the inhibitor is co-administered and the AUC of the victim drug administered alone. The goals of our study were to extend this method to CYP2D6-mediated interactions, to validate it, and to forecast the magnitude of a large number of interactions that have not been studied so far.Methods: A three-step approach was pursued. First, initial estimates of CRs and IRs were obtained by several methods, using data from the literature. Second, an external validation of these initial estimates was carried out, by comparing the predicted AUC ratios with the observed values. Third, refined estimates of CRs and IRs were obtained by orthogonal regression in a Bayesian framework.Results: Thirty-nine AUC ratios were available for external validation. The mean prediction error of the ratios was 0.31, while the mean prediction absolute error was 1.14. Seventy AUC ratios were available for the global analysis. Final estimates of CRs and IRs were obtained for 39 substrates and 11 inhibitors, respectively. The mean prediction error of the AUC ratios was 0.04, while the mean prediction absolute error was 0.51.Conclusions: Predictive distributions for 615 possible interactions were obtained, giving detailed information on some drugs or inhibitors that have been poorly studied so far, such as metoclopramide, bupropion and terbinafine.</b

Changes in the American Attitude Towards Jewish Immigration During the 19th and 20th Centuries

The thesis is focusing on the Jewish immigration to the United States from the New Immigration to the events of the 1956 Hungarian revolution. The main topic is that how the attitude of the American public changed towards Jewish immigrants and refugees during this time, and how the economic hardships of the 1930s and the major conflicts of the 20th century affected the image of the Nation of Immigrants of the United States.BSc/BAAnglisztikaB

Pharmacists’ interventions on intravenous to oral conversion for potassium

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