X-ray Observations of Distant Optically Selected Cluster

We have measured fluxes or flux limits for 31 of the 79 cluster candidates in the Palomar Distant Cluster Survey (PDCS) using archival ROSAT/PSPC pointed observations. Our X-ray survey reaches a flux limit of $\simeq 3 \times 10^{-14}$ erg s$^{-1}$ cm$^{-2}$ (0.4 - 2.0 keV), which corresponds to luminosities of $L_x\simeq 5 \times 10^{43}$ erg s$^{-1}$ ($H_o$ = 50 km s$^{-1}$ Mpc$^{-1}$, $q_o$ = ${1/2}$), if we assume the PDCS estimated redshifts. Of the 31 cluster candidates, we detect six at a signal-to-noise greater than three. We estimate that $2.9^{+3.3}_{-1.4}$ (90% confidence limits) of these six detections are a result of X-ray emission from objects unrelated to the PDCS cluster candidates. The net surface density of X-ray emitting cluster candidates in our survey, $1.71^{+0.91}_{-2.19}$ clusters deg$^{-2}$, agrees with that of other, X-ray selected, surveys. It is possible, given the large error on our contamination rate, that we have not detected X-ray emission from any of our observed PDCS cluster candidates. We find no statistically significant difference between the X-ray luminosities of PDCS cluster candidates and those of Abell clusters of similar optical richness. This suggests that the PDCS contains objects at high redshift similar to the low redshift clusters in the Abell catalogs. We show that the PDCS cluster candidates are not bright X-ray sources, the average luminosity of the six detected candidates is only $\bar{L_x}=0.9\times10^{44}$ erg s$^{-1}$ (0.4-2.0 keV). This finding is in agreement with previous X-ray studies of high redshift, optically selected, rich clusters of galaxies.Comment: 19 pages, LaTeX with AAS Preprint Macros (v. 4), 3 embedded postscript figures, 3 Seperate Tables using aj_pt4.sty, Accepted by the Astronomical Journal for November 199

Use of simulation-based medical training in Swiss pediatric hospitals: a national survey.

Simulation-based medical training (SBMT) is a powerful tool for continuing medical education. In contrast to the Anglo-Saxon medical education community, up until recently, SBMT was scarce in continental Europe's pediatric health care education: In 2009, only 3 Swiss pediatric health care institutions used SBMT. The Swiss catalogue of objectives in Pediatrics does not acknowledge SBMT. The aim of this survey is to describe and analyze the current state of SBMT in Swiss pediatric hospitals and health care departments. A survey was carried out with medical education representatives of every institution. SBMT was defined as any kind of training with a mannequin excluding national and/or international standardized courses. The survey reference day was May 31st 2015. Thirty Swiss pediatric hospitals and health care departments answered our survey (response rate 96.8%) with 66.6% (20 out of 30) offering SBMT. Four of the 20 hospitals offering SMBT had two independently operating training simulation units, resulting in 24 educational units as the basis for our SBMT analysis. More than 90% of the educational units offering SBMT (22 out of 24 units) were conducting in-situ training and 62.5% (15 out of 24) were using high-technology mannequins. Technical skills, communication and leadership ranked among the top training priorities. All institutions catered to inter-professional participants. The vast majority conducted training that was neither embedded within a larger educational curriculum (19 out of 24: 79.2%) nor evaluated (16 out of 24: 66.6%) by its participants. Only 5 institutions (20.8%) extended their training to at least two thirds of their hospital staff. Two thirds of the Swiss pediatric hospitals and health care departments are offering SBMT. Swiss pediatric SBMT is inter-professional, mainly in-situ based, covering technical as well as non-technical skills, and often employing high-technology mannequins. The absence of a systematic approach and reaching only a small number of healthcare employees were identified as shortcomings that need to be addressed

A Turn-over in the Galaxy Luminosity Function of the Coma Cluster Core?

Our previous study of the faint end (R$\leq$21.5) of the galaxy luminosity function (GLF) was based on spectroscopic data in a small region near the Coma cluster center. In this previous study Adami et al. (1998) suggested, with moderate statistical significance, that the number of galaxies actually belonging to the cluster was much smaller than expected. This led us to increase our spectroscopic sample. Here, we have improved the statistical significance of the results of the Coma GLF faint end study (R$\leq$22.5) by using a sample of 85 redshifts. This includes both new spectroscopic data and a literature compilation. The relatively small number of faint galaxies belonging to Coma that was suggested by Adami et al. (1998) and Secker et al. (1998) has been confirmed with these new observations. We also confirm that the color-magnitude relation is not well suited for finding the galaxies inside the Coma cluster core, close to the center at magnitudes fainter than R$\sim$19. We show that there is an enhancement in the Coma line of sight of field galaxies compared to classical field counts. This can be explained by the contribution of groups and of a distant $z\sim 0.5$ cluster along the line of sight. The result is that the Coma GLF appears to turn-over or at least to become flat for the faint galaxies. We suggest that this is due to environmental effects.Comment: 8 pages, 6 postscript figures, accepted in A&A, new table 1, updated figure

De kleine bijenkastkever, Aethina tumida

Uiterlijk, ontwikkeling en gedrag van de kleine bijenkastkever, de invloed op imkerij en natuur, en bestrijding en voorzorgsmaatregelen. De kleine bijenkastkever is inheems in Zuid-Afrika en verspreidt zich nu over de wereld, vooral via de handel in bijen(paketten) en koninginnen. De Europese honingbij herkent de kever niet als parasiet, waardoor kevers en larven hele bijenvolken kunnen vernietigen. Mocht de kever naar Europa komen dan dreigt een ecologische ramp. Om het probleem onder de aandacht te brengen en beschermingsmaatregelen te realiseren (met name een importverbod voor koninginnen en bijenvolken) is de Actie Bijenkastkever gestar

Measurement of the hyperfine structure of antihydrogen in a beam

A measurement of the hyperfine structure of antihydrogen promises one of the best tests of CPT symmetry. We describe an experiment planned at the Antiproton Decelerator of CERN to measure this quantity in a beam of slow antihydrogen atoms.Comment: 5th International Symposium on Symmetries in Subatomic Physics (SSP2012), Groningen (The Netherlands), June 18 to 22, 201