Study of the performance and capability of the new ultra-fast 2 GSample/s FADC data acquisition system of the MAGIC telescope

In February 2007 the MAGIC Air Cherenkov Telescope for gamma-ray astronomy was fully upgraded with an ultra fast 2 GSamples/s digitization system. Since the Cherenkov light flashes are very short, a fast readout can minimize the influence of the background from the light of the night sky. Also, the time structure of the event is an additional parameter to reduce the background from unwanted hadronic showers. An overview of the performance of the new system and its impact on the sensitivity of the MAGIC instrument will be presented.Comment: Contribution to the 30th ICRC, Merida Mexico, July 2007 on behalf of the MAGIC Collaboratio

Long term monitoring of bright TeV Blazars with the MAGIC telescope

The MAGIC telescope has performed long term monitoring observations of the bright TeV Blazars Mrk421, Mrk501 and 1ES1959+650. Up to 40 observations, 30 to 60 minutes each have been performed for each source evenly distributed over the observable period of the year. The sensitivity of MAGIC is sufficient to establish a flux level of 25% of the Crab flux for each measurement. These observations are well suited to trigger multiwavelength ToO observations and the overall collected data allow an unbiased study of the flaring statistics of the observed AGNs.Comment: 4 pages, 4 figures, to appear in the proceedings of the 30th International Cosmic Ray Conference, Merida, July 200

Monte Carlo Performance Studies for the Site Selection of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) represents the next generation of ground-based instruments for very-high-energy (VHE) gamma-ray astronomy, aimed at improving on the sensitivity of current-generation experiments by an order of magnitude and providing coverage over four decades of energy. The current CTA design consists of two arrays of tens of imaging atmospheric Cherenkov telescopes, comprising Small, Medium and Large-Sized Telescopes, with one array located in each of the Northern and Southern Hemispheres. To study the effect of the site choice on the overall \gls{cta} performance and support the site evaluation process, detailed Monte Carlo simulations have been performed. These results show the impact of different site-related attributes such as altitude, night-sky background and local geomagnetic field on CTA performance for the observation of VHE gamma rays.Comment: 34 pages, 11 figures, Accepted for publication in AP

Productive evaluations of Aberdeen Angus and Argentina Criollo beef in two feeding systems in the northeast of The Pampa. Argentina

The objective of the study is to evaluate the productivity of two winter pastures under a rotational grazing system with and without energetic concentrates in the diet; in order to evaluate the productive behavior in Aberdeen Angus and Argentine Criollo beef. Sixty steer, castrated males of the breed Aberdeen Angus, of 6-7 months of age and 175 kg, and Argentine Criollo, at 8-9 months of age and 199 kg. The steer study were divided into four groups of 15 steer each. The study was conducted for 13 months in the first five months they grazed on oat farming (Avena sativa); and the following seven months on cebadilla (Bromus uniloides) and Lucerne (Medicago sativa) sown grassland, and the final month on oat. As a supplement they received ground grain sorghum (33 percent of the diet). The weight increment during the 13 months of the study went from 294,23 kg; 239,20 kg; 214,00 kg and 203,19 kg; an average weight gain of 0,754 kg/d; 0,613 kg/d; 0,549 kg/d and 0,520 kg/ d; a production per hectare of 374 kg/ha; 304 kg/ ha; 272 kg/ha and 258 kg/ha; and a stock efficiency of 77 percent, 67 percent, 59 percent, and 61 percent in the groups ACS, ASS, CCS and CSS, respectively.El objetivo del estudio es evaluar la productividad de dos invernadas pastoriles, bajo un sistema de pastoreo rotativo con y sin complemento de concentrados energéticos en la dieta; así como evaluar el comportamiento productivo de terneros Aberdeen Angus (AA) y Criollo Argentino (CA). Se cuenta con 60 terneros, machos castrados, de las razas Aberdeen Angus, con 6-7 meses de edad y 175 kg de peso, y Criollo Argentino, 8-9 meses de edad y 199 kg de peso. Se forman cuatro lotes de 15 terneros (ASS= Aberdeen sin complemento, ACS= Aberdeen con complemento, CSS= Criollo sin complemento y CCS= Criollo con complemento). El ensayo se realiza durante 13 meses: en los 5 primeros pastan en un cultivo de avena (Avena sativa) los siete meses siguientes en una pradera de alfalfa (Medicago sativa) y de cebadilla (Bromus uniloides) y en el último mes en un cultivo de avena. Como suplemento reciben grano de sorgo molido (33 p.100 de la dieta). El incremento medio de peso de los terneros, en los 13 meses de ensayo, fue 294,23 kg; 239,20 kg; 214,00 kg y 203,19 kg; la ganancia media de peso de 0,754 kg/d; 0,613 kg/d; 0,549 kg/d y 0,520 kg/d; la producción por hectárea de 374 kg/ ha, 304 kg/ha, 272kg/ha y 258 kg/ha; y la eficiencia en los lotes ACS, ASS, CCS y CSS, fue del 77, 67, 59 y 61 p.100, respectivamente

The MAGIC Experiment and Its First Results

With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray astrophysics. It is sensitive to photons above an energy of 30 GeV. MAGIC started operations in October 2003 and is currently taking data. This report summarizes its main characteristics, its rst results and its potential for physics.Comment: 6 pages, 3 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200

Interventions to improve hand hygiene compliance in patient care: Reflections on three systematic reviews for the Cochrane Collaboration 2007-2017

This article presents highlights from a recently updated systematic Cochrane review evaluating the effectiveness of interventions to improve hand hygiene compliance in patient care. It is an advance on the two earlier reviews we undertook on the same topic as it has, for the first time, provided very rigorous synthesis of evidence that such interventions can improve practice. In this article, we provide highlights from a recently updated Cochrane systematic review. We identify omissions in the information reported and point out important aspects of hand hygiene intervention studies that were beyond the scope of the review. A full report of the review is available free of charge on the Cochrane website

Observations of the BL Lac Object 3C 66A with STACEE

We present the analysis and results of recent high-energy gamma-ray observations of the BL Lac object 3C 66A conducted with the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). During the 2003-2004 observing season, STACEE extensively observed 3C 66A as part of a multiwavelength campaign on the source. A total of 33.7 hours of data was taken on the source, plus an equivalent-duration background observation. After cleaning the data set a total of 16.3 hours of live time remained, and a net on-source excess of 1134 events was seen against a background of 231742 events. At a significance of 2.2 standard deviations this excess is insufficient to claim a detection of 3C 66A, but is used to establish flux upper limits for the source.Comment: Accepted for publication in the Astrophysical Journa

A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained within the MAGIC experiment using a new technique for the reduction of the background. Particle showers produced by gamma rays show a different temporal distribution with respect to showers produced by hadrons; the background due to accidental counts shows no dependence on time. Such novel strategy can increase the sensitivity of present instruments.Comment: 4 pages, 3 figures, Proc. of the 9th Int. Syposium "Frontiers of Fundamental and Computational Physics" (FFP9), (AIP, Melville, New York, 2008, in press