Quantum rainbow scattering at tunable velocities

Elastic scattering cross sections are measured for lithium atoms colliding with rare gas atoms and SF6 molecules at tunable relative velocities down to ~50 m/s. Our scattering apparatus combines a velocity-tunable molecular beam with a magneto-optic trap that provides an ultracold cloud of lithium atoms as a scattering target. Comparison with theory reveals the quantum nature of the collision dynamics in the studied regime, including both rainbows as well as orbiting resonances

Improved setup for producing slow beams of cold molecules using a rotating nozzle

Intense beams of cold and slow molecules are produced by supersonic expansion out of a rapidly rotating nozzle, as first demonstrated by Gupta and Herschbach. An improved setup is presented that allows to accelerate or decelerate cold atomic and molecular beams by up to 500 m/s. Technical improvements are discussed and beam parameters are characterized by detailed analysis of time of flight density distributions. The possibility of combining this beam source with electrostatic fields for guiding polar molecules is demonstrated

Conformal dimension and random groups

We give a lower and an upper bound for the conformal dimension of the boundaries of certain small cancellation groups. We apply these bounds to the few relator and density models for random groups. This gives generic bounds of the following form, where $l$ is the relator length, going to infinity. (a) 1 + 1/C < \Cdim(\bdry G) < C l / \log(l), for the few relator model, and (b) 1 + l / (C\log(l)) < \Cdim(\bdry G) < C l, for the density model, at densities $d < 1/16$. In particular, for the density model at densities $d < 1/16$, as the relator length $l$ goes to infinity, the random groups will pass through infinitely many different quasi-isometry classes.Comment: 32 pages, 4 figures. v2: Final version. Main result improved to density < 1/16. Many minor improvements. To appear in GAF

Guiding slow polar molecules with a charged wire

We demonstrate experimentally the guiding of cold and slow ND3 molecules along a thin charged wire over a distance of ~0.34 m through an entire molecular beam apparatus. Trajectory simulations confirm that both linear and quadratic high-field-seeking Stark states can be efficiently guided from the beam source up to the detector. A density enhancement up to a factor 7 is reached for decelerated beams with velocities ranging down to ~50 m/s generated by the rotating nozzle technique

Exact beta function from the holographic loop equation of large-N QCD_4

We construct and study a previously defined quantum holographic effective action whose critical equation implies the holographic loop equation of large-N QCD_4 for planar self-avoiding loops in a certain regularization scheme. We extract from the effective action the exact beta function in the given scheme. For the Wilsonean coupling constant the beta function is exacly one loop and the first coefficient agrees with its value in perturbation theory. For the canonical coupling constant the exact beta function has a NSVZ form and the first two coefficients agree with their value in perturbation theory.Comment: 42 pages, latex. The exponent of the Vandermonde determinant in the quantum effective action has been changed, because it has been employed a holomorphic rather than a hermitean resolution of identity in the functional integral. Beta function unchanged. New explanations and references added, typos correcte

Estimates of measles case fatality ratios: a comprehensive review of community-based studies.

BACKGROUND: Global deaths from measles have decreased notably in past decades, due to both increases in immunization rates and decreases in measles case fatality ratios (CFRs). While some aspects of the reduction in measles mortality can be monitored through increases in immunization coverage, estimating the level of measles deaths (in absolute terms) is problematic, particularly since incidence-based methods of estimation rely on accurate measures of measles CFRs. These ratios vary widely by geographic and epidemiologic context and even within the same community from year-to-year. METHODS: To understand better the variations in CFRs, we reviewed community-based studies published between 1980 and 2008 reporting age-specific measles CFRs. RESULTS: The results of the search consistently document that measles CFRs are highest in unvaccinated children under age 5 years; in outbreaks; the lowest CFRs occur in vaccinated children regardless of setting. The broad range of case and death definitions, study populations and geography highlight the complexities in extrapolating results for global public health planning. CONCLUSIONS: Values for measles CFRs remain imprecise, resulting in continued uncertainty about the actual toll measles exacts

Triangulated Surfaces in Twistor Space: A Kinematical Set up for Open/Closed String Duality

We exploit the properties of the three-dimensional hyperbolic space to discuss a simplicial setting for open/closed string duality based on (random) Regge triangulations decorated with null twistorial fields. We explicitly show that the twistorial N-points function, describing Dirichlet correlations over the moduli space of open N-bordered genus g surfaces, is naturally mapped into the Witten-Kontsevich intersection theory over the moduli space of N-pointed closed Riemann surfaces of the same genus. We also discuss various aspects of the geometrical setting which connects this model to PSL(2,C) Chern-Simons theory.Comment: 35 pages, references added, slightly revised introductio

Evaluation of a prostate cancer e-health-tutorial

Hintergrund: Angesichts verschiedener Behandlungsoptionen ist die Information und Therapieentscheidung beim lokalisierten Prostatakarzinom eine Herausforderung. Die digitale Informationstechnologie bietet im Vergleich zu gedruckten Informationen mehr Möglichkeiten, die Information und die Patientenkommunikation bedarfsgerecht zu gestalten. Ziele: Zur Unterstützung der Therapieentscheidung und der Kommunikation mit Patienten ist in der deutschsprachigen Schweiz ein Online-Tutorial in einem systematischen Prozess entwickelt und in einer Pilotstudie getestet worden. In der Evaluation interessierten die Nutzerzufriedenheit, die Erfüllung der Informationsbedürfnisse, die Vorbereitung auf die Therapieentscheidung und deren subjektive Qualität. Material und Methoden: Die Plattform wurde in einem iterativen Prozess mittels Fokusgruppen mit Ärzten und Patienten auf der Grundlage von Informationen aus bestehenden Broschüren entwickelt. Für den Test der Plattform wurden in 8 urologischen Kliniken 87 Patienten zur Teilnahme eingeladen. Die 56 Nutzer wurden 4 Wochen nach dem Login und 3 Monate nach dem Therapieentscheid online befragt, 48 Nutzer füllten beide Befragungen aus. Eingesetzte Instrumente waren die Preparation for Decision Making Scale (PDMS), die Decisional Conflict Scale (DCS) und die Decisional Regret Scale (DRS). Ergebnisse und Diskussion: Die Nutzenden sind mit der Plattform sehr zufrieden und finden ihre Informationsbedürfnisse gut erfüllt. Sie zeigen 3 Monate nach dem Entscheid eine gute Vorbereitung auf die Entscheidung (MW PDMS 75, SD 23) und berichten über niedrigen Entscheidungskonflikt (MW DCS 9.6, SD 11) und kaum Bedauern über die Entscheidung (MW DRS 6.4, SD 9.6). Basierend auf diesen Erkenntnissen kann die Plattform zur weiteren Nutzung empfohlen werden.Background: Due to the multitude of therapy options the treatment decision after diagnosis of a localised prostate cancer is challenging. Compared to printed booklets, web based information technology offers more possibilities to tailor information to patients’ individual needs. Objectives: To support the decision making process as well as the communication with patients we developed an online tutorial in a systematic process in the German speaking part of Switzerland and then tested it in a pilot study. The study investigated users’ satisfaction, the coverage of information needs, the preparation for decision making and the subjective quality of the decision. Materials and methods: Based on already existing information material the online tutorial was developed in an iterative process using focus groups with patients and urologists. For the following evaluation in eight clinics a total of 87 patients were invited to access the platform and participate in the study. From these patients 56 used the tutorial and 48 answered both surveys (the first one 4 weeks after the first login and the second one 3 months after treatment decision). The surveys used the Preparation for Decision Making Scale (PDMS), the Decisional Conflict Scale (DCS), and the Decisional Regret Scale (DRS). Results and Conclusion: Satisfaction with the tutorial is very high among patients with newly diagnosed localized prostate cancer. Users find their information needs sufficiently covered. Three months after the decision they felt that they were well prepared for the decision making (Mean PDMS 75, SD 23), they had low decisional conflict (Mean DCS 9.6, SD 11) and almost no decisional regret (Mean DRS 6.4, SD 9.6). Based on these findings the further use of the tutorial can be recommended

Towards agreement on best practice for publishing raw clinical trial data

Many research-funding agencies now require open access to the results of research they have funded, and some also require that researchers make available the raw data generated from that research. Similarly, the journal Trials aims to address inadequate reporting in randomised controlled trials, and in order to fulfil this objective, the journal is working with the scientific and publishing communities to try to establish best practice for publishing raw data from clinical trials in peer-reviewed biomedical journals. Common issues encountered when considering raw data for publication include patient privacy – unless explicit consent for publication is obtained – and ownership, but agreed-upon policies for tackling these concerns do not appear to be addressed in the guidance or mandates currently established. Potential next steps for journal editors and publishers, ethics committees, research-funding agencies, and researchers are proposed, and alternatives to journal publication, such as restricted access repositories, are outlined