Long distance entanglement swapping with photons from separated sources

We report the first experimental realization of entanglement swapping over large distances in optical fibers. Two photons separated by more than two km of optical fibers are entangled, although they never directly interacted. We use two pairs of time-bin entangled qubits created in spatially separated sources and carried by photons at telecommunication wavelengths. A partial Bell state measurement is performed with one photon from each pair which projects the two remaining photons, formerly independent onto an entangled state. A visibility high enough to violate a Bell inequality is reported, after both photons have each travelled through 1.1 km of optical fiber.Comment: 4 pages, 3 figures, submitte

Experimental Quantum Teleportation with a 3-Bell-state Analyzer

We present a Bell-state analyzer for time-bin qubits allowing the detection of three out of four Bell-states with linear optics, two detectors and no auxiliary photons. The theoretical success rate of this scheme is 50%. A teleportation experiment was performed to demonstrate its functionality. We also present a teleportation experiment with a Fidelity larger than the cloning limit of F=5/6.Comment: 11 pages, 14 figure

Quantum Teleportation with a 3-Bell-state Analyzer

We present a novel Bell-state analyzer for time-bin qubits allowing the detection of three out of four Bell-states with linear optics, only two detectors and no auxiliary photons. The theoretical success rate of this scheme is 50%. A teleportation experiment was performed to demonstrate its functionality. We also present a teleportation experiment with a fidelity larger than the cloning limit.Comment: 4 pages, 6 figure

Understanding Landmarking and Its Relation with Time-Dependent Cox Regression

Development and application of statistical models for medical scientific researc

Het behandelen van met AVB besmette kasten

Bestrijden van Amarikaans vuilbroed (AVB), een gewone bijenziekte. Rubrieken in dit artikel: 1) Uitbraak in een volk; 2) Resistentie tegen AVB en bestrijding; 3) Ontsmetten of schoonmaken van de kasten

An undergraduate course on pain: Its impact on students' empathy

INTRODUCTION: Empathy towards patients in pain involves an internal process in which both affective and cognitive processes in the observer are responsible for a final behavioral reaction. This study investigated the impact of an undergraduate elective course on pain on students' empathy in a mixed-method design. METHODS: Undergraduate students of the elective course on pain (intervention group) as well as undergraduate students of a compulsory course on neuropharmacology (control group) completed the Dutch version of the Interpersonal Reactivity Index (IRI) questionnaire at the beginning and the end of the course. In addition, students' empathy in the intervention group was explored by content analysis of students' reflective writing assignments related to documentary films that were part of the course activities. RESULTS: Twenty students (intervention group) and seven students (control group) completed both IRI questionnaires. IRI scores for subscales perspective taking, fantasy, and personal distress significantly increased over time more in the intervention group than in the control group (intervention x time interaction). Effect sizes (generalized eta squared) for these effects were 0.084, 0.041, and 0.139 for perspective taking, fantasy, and personal distress, respectively. The qualitative data revealed information on cognitive and affective responses, and to some extent behavioral responses. CONCLUSIONS: Both IRI outcomes and analysis of the reflective assignments demonstrate that students' empathy increased during the course on pain. Further research should explore in-depth the effects of different documentaries in the course on students' empathy development and the long-term effect of the course on students' empathy

Ook onder drijvende mestafdekking ontstaat drijflaag

Ondanks het regelmatig mengen is het niet gelukt drijflaagvorming onder de afdekking te voorkomen

Teelt van mais op klei-op-veengrond. Bemesting en grondbewerking

rapport bevat de resultaten van veldproeven op het gebied van bemesting en grondbewerking, die in de periode 1997-1999 door proefbedrijf Zegveld van het Praktijkonderzoek Rundvee, Schapen en Paarden (PR) zijn uitgevoerd

Statistical models for quantifying diagnostic accuracy with multiple lesions per patient

We propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive lesions was assumed to be distributed as a binomial mixture. We considered univariate and bivariate, both parametric and nonparametric mixture models. We applied our tools to simulated data and data of a study assessing diagnostic accuracy of virtual colonography with computed tomography in 200 patients suspected of having one or more polyps