321 research outputs found
A qualitative assessment of the probability of human exposure to Trichinella spp. in Switzerland
Trichinellosis is a zoonotic disease caused by Trichinella spp. Pork is a potential source of infection for humans. A qualitative assessment was conducted to assess the probability of human exposure to Trichinella spp. in Switzerland via the consumption of pork. For the assessment, both the wildlife cycle and the domestic cycle were taken into account. The probability of occurrence of Trichinella infections in domestic pigs was assessed negligible under controlled housing systems due to biosecurity measures. Free-range pigs were assessed to have a very low probability of being infected. Pork from free-range pigs that were not tested for Trichinella spp. was estimated to carry a very low probability for human exposure to Trichmella spp
Searching for the Annual Modulation of Dark Matter signal with the GENIUS-TF experiment
The annual modulation of the recoil spectrum observed in an underground
detector is well known as the main signature of a possible WIMP signal. The
GENIUS-TF experiment, under construction in the Gran Sasso National Laboratory,
can search for the annual modulation of the Dark Matter signal using 40 kg of
naked-Ge detectors in liquid nitrogen. Starting from a set of data simulated
under the hypothesis of modulation and using different methods, we show the
potential of GENIUS-TF for extracting the modulated signal and the expected
WIMP mass and WIMP cross section.Comment: In press, Nuclear Instruments and Methods in Physics Research Section
A: Accelerators, Spectrometers, Detectors and Associated Equipment (2003) and
in Proc. of IDM2002, York Minster, England, 2-6 September, 2002, World
Scientific 200
Comparing the demonstration of freedom from Trichinella infection of domestic pigs by traditional and risk-based surveillance
Traditionally, the routine artificial digestion test is applied to assess the presence of Trichinella larvae in pigs. However, this diagnostic method has a low sensitivity compared to serological tests. The results from artificial digestion tests in Switzerland were evaluated over a time period of 15 years to determine by when freedom from infection based on these data could be confirmed. Freedom was defined as a 95% probability that the prevalence of infection was below 0·0001%. Freedom was demonstrated after 12 years at the latest. A new risk-based surveillance approach was then developed based on serology. Risk-based surveillance was also assessed over 15 years, starting in 2010. It was shown that by using this design, the sample size could be reduced by at least a factor of 4 when compared with the traditional testing regimen, without lowering the level of confidence in the Trichinella-free status of the pig populatio
A Trigger and Readout Scheme for future Cherenkov Telescope Arrays
The next generation of ground-based gamma-ray observatories, such as e.g.
CTA, will consist of about 50-100 telescopes, and cameras with in total ~100000
to ~200000 channels. The telescopes of the core array will cover and effective
area of ~ 1 km2 and will be possibly accompanied by a large halo of smaller
telescopes spread over about 10 km2 . In order to make maximum use of the
stereoscopic approach, a very flexible inter-telescope trigger scheme is needed
which allows to couple telescopes that located up to ~1 km apart. The
development of a cost effective readout scheme for the camera signals exhibits
a major technological challenge. Here we present ideas on a new asynchronous
inter-telescope trigger scheme, and a very cost-effective, high-bandwidth
frontend to backend data transfer system, both based on standard Ethernet
components and an Ethernet front-end interface based on mass production
standard FPGAs.Comment: 4 pages, 3 figures ; modified version of article to be published in
the proceedings of the "4th Heidelberg International Symposium on High Energy
Gamma-Ray Astronomy 2008
Validation of a Western Blot for the detection of anti- Trichinella spp. antibodies in domestic pigs
Trichinellosis is a zoonotic disease in humans caused by Trichinella spp. According to international regulations and guidelines, serological surveillance can be used to demonstrate the absence of Trichinella spp. in a defined domestic pig population. Most enzyme-linked immunosorbent assay (ELISA) tests presently available do not yield 100% specificity, and therefore, a complementary test is needed to confirm the diagnosis of any initial ELISA seropositivity. The goal of the present study was to evaluate the sensitivity and specificity of a Western Blot assay based on somatic Trichinella spiralis muscle stage (L1) antigen using Bayesian modeling techniques. A total of 295 meat juice and serum samples from pigs negative for Trichinella larvae by artificial digestion, including 74 potentially cross-reactive sera of pigs with other nematode infections, and 93 meat juice samples from pigs infected with Trichinella larvae were included in the study. The diagnostic sensitivity and specificity of the Western Blot were ranged from 95.8% to 96.0% and from 99.5% to 99.6%, respectively. A sensitivity analysis showed that the model outcomes were hardly influenced by changes in the prior distributions, providing a high confidence in the outcomes of the models. This validation study demonstrated that the Western Blot is a suitable method to confirm samples that reacted positively in an initial ELIS
First 10 kg of Naked Germanium Detectors in Liquid Nitrogen installed in the GENIUS-Test-Facility
The first four naked high purity Germanium detectors were installed
successfully in liquid nitrogen in the GENIUS-Test-Facility (GENIUS-TF) in the
GRAN SASSO Underground Laboratory on May 5, 2003. This is the first time ever
that this novel technique aiming at extreme background reduction in search for
rare decays is going to be tested underground. First operational parameters are
presented.Comment: 10 pages, latex2e, 8 figures, Was presented (first presentation) at
4th International Conference on Particle Physics Beyond the Standard Model
BEYOND'2003, Castle Ringberg, Germany, 9-14 June, 2003, Springer, Heidelberg,
Germany, 2003, edited by H.V. Klapdor-Kleingrothau
FlashCam: A fully digital camera for CTA telescopes
The future Cherenkov Telescope Array (CTA) will consist of several tens of
telescopes of different mirror sizes. CTA will provide next generation
sensitivity to very high energy photons from few tens of GeV to >100 TeV.
Several focal plane instrumentation options are currently being evaluated
inside the CTA consortium. In this paper, the current status of the FlashCam
prototyping project is described. FlashCam is based on a fully digital camera
readout concept and features a clean separation between photon detector plane
and signal digitization/triggering electronics.Comment: In Proceedings of the 2012 Heidelberg Symposium on High Energy
Gamma-Ray Astronomy. All CTA contributions at arXiv:1211.184
Air-sea gas transfer velocity for oxygen derived from float data
We estimated the air-sea gas transfer velocity for oxygen using three consecutive years (Sept. 2003 to Aug. 2006) of high-quality oxygen measurements from profiling floats in the central Labrador Sea. Mixed layer oxygen concentrations exhibit strong seasonality characterized by biologically and thermally driven evasion during spring/summer and invasion during fall/winter caused by cooling and ventilation of oxygen-deficient subsurface waters. Mixed layer oxygen budgets entirely excluding the spring bloom
period are employed to estimate the air-sea transfer velocity for oxygen. By using co-located wind speed data acquired by scatterometry from the QuikSCAT satellite, wind speed dependent parameterizations for the air-sea gas transfer velocity k660 (CO2 at 20◦C and salinity 35) are established and compared with prominent parameterizations from the literature. Quadratic, cubic and quartic functions are fitted to the data for short-term and long-term wind
speed averages separately. In both cases the quadratic functions yield the poorest fit to the observations. Overall, the stronger curvature of the cubic functions provides the best fit, while the quartic function also fits the data less well. Our results generally confirm the stronger wind speed dependencies among the suite of published parameterizations. Also the better fits found for cubic function points at the strong importance of very high wind speed for airsea gas exchange of O2
Performance Verification of the FlashCam Prototype Camera for the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is
planned to significantly improve upon the sensitivity and precision of the
current generation of Cherenkov telescopes. The observatory will consist of
several dozens of telescopes with different sizes and equipped with different
types of cameras. Of these, the FlashCam camera system is the first to
implement a fully digital signal processing chain which allows for a traceable,
configurable trigger scheme and flexible signal reconstruction. As of autumn
2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears
completion. First results of the ongoing system tests demonstrate that the
signal chain and the readout system surpass CTA requirements. The stability of
the system is shown using long-term temperature cycling.Comment: 5 pages, 13 figures, Proceedings of the 9th International Workshop on
Ring Imaging Cherenkov Detectors (RICH 2016), Lake Bled, Sloveni
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