3,452 research outputs found
Simulation of a Hybrid Optical/Radio/Acoustic Extension to IceCube for EeV Neutrino Detection
Astrophysical neutrinos at EeV energies promise to be an interesting
source for astrophysics and particle physics. Detecting the predicted
cosmogenic (``GZK'') neutrinos at 10 - 10 eV would test models of
cosmic ray production at these energies and probe particle physics at 100
TeV center-of-mass energy. While IceCube could detect 1 GZK event per
year, it is necessary to detect 10 or more events per year in order to study
temporal, angular, and spectral distributions. The IceCube observatory may be
able to achieve such event rates with an extension including optical, radio,
and acoustic receivers. We present results from simulating such a hybrid
detector.Comment: 4 pages, 2 figures; to appear in the Proceedings of the 29th ICRC,
Pune, Indi
How to assess the external validity of therapeutic trials: a conceptual approach
Background External validity of study results is an important issue from a clinical point of view. From a methodological point of view, however, the concept of external validity is more complex than it seems to be at first glance. Methods Methodological review to address the concept of external validity. Results External validity refers to the question whether results are generalizable to persons other than the population in the original study. The only formal way to establish the external validity would be to repeat the study for that specific target population. We propose a three-way approach for assessing the external validity for specified target populations. (i) The study population might not be representative for the eligibility criteria that were intended. It should be addressed whether the study population differs from the intended source population with respect to characteristics that influence outcome. (ii) The target population will, by definition, differ from the study population with respect to geographical, temporal and ethnical conditions. Pondering external validity means asking the question whether these differences may influence study results. (iii) It should be assessed whether the study's conclusions can be generalized to target populations that do not meet all the eligibility criteria. Conclusion Judging the external validity of study results cannot be done by applying given eligibility criteria to a single target population. Rather, it is a complex reflection in which prior knowledge, statistical considerations, biological plausibility and eligibility criteria all have plac
Can chitinozoan biostratigraphy of the Maquoketa Group (Illinois Basin, USA) help unravel the order of events leading up to the Late Ordovician mass extinction?
The venous thrombotic risk of oral contraceptives, effects of oestrogen dose and progestogen type: results of the MEGA case-control study
Objective To assess the thrombotic risk associated with oral contraceptive use with a focus on dose of oestrogen and type of progestogen of oral contraceptives available in the Netherlands
The PANDA GEM-based TPC Prototype
We report on the development of a GEM-based TPC prototype for the PANDA
experiment. The design and requirements of this device will be illustrated,
with particular emphasis on the properties of the recently tested GEM-detector,
the characterization of the read-out electronics and the development of the
tracking software that allows to evaluate the GEM-TPC data.Comment: submitted to NIMA 4 pages, 6 picture
Development of a SiPM Camera for a Schwarzschild-Couder Cherenkov Telescope for the Cherenkov Telescope Array
We present the development of a novel 11328 pixel silicon photomultiplier
(SiPM) camera for use with a ground-based Cherenkov telescope with
Schwarzschild-Couder optics as a possible medium-sized telescope for the
Cherenkov Telescope Array (CTA). The finely pixelated camera samples air-shower
images with more than twice the optical resolution of cameras that are used in
current Cherenkov telescopes. Advantages of the higher resolution will be a
better event reconstruction yielding improved background suppression and
angular resolution of the reconstructed gamma-ray events, which is crucial in
morphology studies of, for example, Galactic particle accelerators and the
search for gamma-ray halos around extragalactic sources. Packing such a large
number of pixels into an area of only half a square meter and having a fast
readout directly attached to the back of the sensors is a challenging task. For
the prototype camera development, SiPMs from Hamamatsu with through silicon via
(TSV) technology are used. We give a status report of the camera design and
highlight a number of technological advancements that made this development
possible.Comment: 8 pages, 5 figures, In Proceedings of the 34th International Cosmic
Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions
at arXiv:1508.0589
- …