Solar Influence on Nuclear Decay Rates: Constraints from the MESSENGER Mission

We have analyzed Cs-137 decay data, obtained from a small sample onboard the MESSENGER spacecraft en route to Mercury, with the aim of setting limits on a possible correlation between nuclear decay rates and solar activity. Such a correlation has been suggested recently on the basis of data from Mn-54 decay during the solar flare of 13 December 2006, and by indications of an annual and other periodic variations in the decay rates of Si-32, Cl-36, and Ra-226. Data from five measurements of the Cs-137 count rate over a period of approximately 5.4 years have been fit to a formula which accounts for the usual exponential decrease in count rate over time, along with the addition of a theoretical solar contribution varying with MESSENGER-Sun separation. The indication of solar influence is then characterized by a non-zero value of the calculated parameter \xi, and we find \xi=(2.8+/-8.1)x10^{-3} for Cs-137. A simulation of the increased data that can hypothetically be expected following Mercury orbit insertion on 18 March 2011 suggests that the anticipated improvement in the determination of \xi could reveal a non-zero value of \xi if present at a level consistent with other data.Comment: Accepted for publication in Astrophysics and Space Science, 2011. 7 pages, 5 figures. Version 2 has corrected Figure 1, since Fig. 1 did not appear correctly in Version

Selection for Dutch postgraduate GP training; time for improvement

Item does not contain fulltextBackground: In the Netherlands we select candidates for the postgraduate GP training by assessing personal qualities in interviews. Because of differences in the ratio of number of candidates and number of vacancies between the eight departments of GP training we questioned whether the risk of being rejected diverged amongst them. Objective: The research question of this study was to which degree department of choice, candidates' characteristics and qualities assessed during interviews explain admission into GP training. Methods: A nationwide observational study was conducted of all candidates who applied for postgraduate GP training in 2009/ 2010. Application ratio per department, candidates' characteristics (gender, age, region of medical school and times of application) and qualities (motivation, orientation on the job, personal attributes and learning needs) were collected. Outcome measures were admission to interview and admission to GP training. Results: The study population addressed 542 candidates. Sixty three candidates were rejected on application letter (11.6%). So 479 candidates were admitted to the interview, of which 340 were admitted to the GP training (71%). Gender and region of medical school outside North West Europe were associated with admission to the interview. Department of choice had a strong association with admission in both stages (RR: 0.30 to 0.74; 0.20 to 0.79 respectively), while candidates' qualities explained admission (RR: 1.09- 1.25) as well. Conclusion:The influence of department of choice yields doubts about fairness of the procedure. So advantages and disadvantages of a national procedure are discussed as well as those of a competency based procedure

The Jovian Auroral Distributions Experiment (JADE) on the Juno Mission to Jupiter

International audienceThe Jovian Auroral Distributions Experiment (JADE) on Juno provides the critical in situ measurements of electrons and ions needed to understand the plasma energy particles and processes that fill the Jovian magnetosphere and ultimately produce its strong aurora. JADE is an instrument suite that includes three essentially identical electron sensors (JADE-Es), a single ion sensor (JADE-I), and a highly capable Electronics Box (EBox) that resides in the Juno Radiation Vault and provides all necessary control, low and high voltages, and computing support for the four sensors. The three JADE-Es are arrayed 120∘ apart around the Juno spacecraft to measure complete electron distributions from ∼0.1 to 100 keV and provide detailed electron pitch-angle distributions at a 1 s cadence, independent of spacecraft spin phase. JADE-I measures ions from ∼5 eV to ∼50 keV over an instantaneous field of view of 270∘×90∘ in 4 s and makes observations over all directions in space each 30 s rotation of the Juno spacecraft. JADE-I also provides ion composition measurements from 1 to 50 amu with m/Δ m∼2.5, which is sufficient to separate the heavy and light ions, as well as O+ vs S+, in the Jovian magnetosphere. All four sensors were extensively tested and calibrated in specialized facilities, ensuring excellent on-orbit observations at Jupiter. This paper documents the JADE design, construction, calibration, and planned science operations, data processing, and data products. Finally, the Appendix describes the Southwest Research Institute [SwRI] electron calibration facility, which was developed and used for all JADE-E calibrations. Collectively, JADE provides remarkably broad and detailed measurements of the Jovian auroral region and magnetospheric plasmas, which will surely revolutionize our understanding of these important and complex regions

Search for a scalar top quark using the OPAL detector

Contains fulltext : 124482.pdf (preprint version ) (Open Access

A search for doubly charged higgs production in z0 decays

Contains fulltext : 124394.pdf (preprint version ) (Open Access