Geloof in kloppend bewijs

Rede, In verkorte vorm uitgesproken ter gelegenheid van het aanvaarden van het ambt van bijzonder hoogleraar Klinische epidemiologie van hart- en vaatziekten aan het Erasmus MC, faculteit van de Erasmus Universiteit Rotterdam op 20 maart 2009. De leidende gedachte binnen het vakgebied Klinische epidemiologie is dat medisch handelen gebaseerd dient te zijn op het best beschikbare bewijs van zijn werkzaamheid en doeltreffendheid. Dat bewijs is niet gegrond op de persoonlijke ervaring van patiënten, noch op de klinische expertise van individuele artsen, hoe waardevol deze elementen ook zijn. Maar het bewijs voor de effectiviteit van het klinisch handelen is bij voorkeur afkomstig van wetenschappelijk onderzoek onder groepen patiënten, waarin theoretische concepten worden getoetst, en waarbij gezocht wordt naar relaties tussen het optreden en het beloop van ziekten enerzijds, en verklarende factoren of determinanten daarvan anderzijds.|1 Deze determinanten kunnen zowel oorzakelijke als niet-oorzakelijke factoren zijn. Vanzelfsprekend dient onderzoek naar determinant-uitkomst relaties te worden opgezet en uitgevoerd in overeenstemming met kwalitatief hoogstaande standaarden

Relativistic Structure of the Nucleon Self-Energy in Asymmetric Nuclei

The Dirac structure of the nucleon self-energy in asymmetric nuclear matter cannot reliably be deduced from the momentum dependence of the single-particle energies. It is demonstrated that such attempts yield an isospin dependence with even a wrong sign. Relativistic studies of finite nuclei have been based on such studies of asymmetric nuclear matter. The effects of these isospin components on the results for finite nuclei are investigated.Comment: 9 pages, Latex 4 figures include

Correlations and the relativistic structure of the nucleon self-energy

A key point of Dirac Brueckner Hartree Fock calculations for nuclear matter is to decompose the self energy of the nucleons into Lorentz scalar and vector components. A new method is introduced for this decomposition. It is based on the dependence of the single-particle energy on the small component in the Dirac spinors used to calculate the matrix elements of the underlying NN interaction. The resulting Dirac components of the self-energy depend on the momentum of the nucleons. At densities around and below the nuclear matter saturation density this momentum dependence is dominated by the non-locality of the Brueckner G matrix. At higher densities these correlation effects are suppressed and the momentum dependence due to the Fock exchange terms is getting more important. Differences between symmetric nuclear matter and neutron matter are discussed. Various versions of the Bonn potential are considered.Comment: 18 pages LaTeX, including 6 figure

Case study: Ticagrelor in plato and prasugrel in triton-timi 38 and trilogy-acs trials in patients with acute coronary syndromes

Copyrigh

Averaging kernels for DOAS total-column satellite retrievals

International audienceThe Differential Optical Absorption Spectroscopy (DOAS) method is used extensively to retrieve total column amounts of trace gases based on UV-visible measurements of satellite spectrometers, such as ERS-2 GOME. In practice the sensitivity of the instrument to the tracer density is strongly height dependent, especially in the troposphere. The resulting tracer profile dependence may introduce large systematic errors in the retrieved columns that are difficult to quantify without proper additional information, as provided by the averaging kernel (AK). In this paper we discuss the DOAS retrieval method in the context of the general retrieval theory as developed by Rodgers. An expression is derived for the DOAS AK for optically thin absorbers. It is shown that the comparison with 3D chemistry-transport models and independent profile measurements, based on averaging kernels, is no longer influenced by errors resulting from a priori profile assumptions. The availability of averaging kernel information as part of the total column retrieval product is important for the interpretation of the observations, and for applications like chemical data assimilation and detailed satellite validation studies

Tailored reperfusion therapy of patients with evolving myocardial infarction: Models to guide clinical decision making

Myocardial infarction is one of the leading causes of death among adults in the Western World. In The Netherlands, yearly approximately 20,000 men and 10,000 women are admitted with this diseas