Cosmic-ray transparency for a medium-latitude observatory

The access of cosmic-ray particles to a medium-latitude observatory is analysed fromresults coming fromthe numerical solution of the charged-particle motion in the geomagnetic field. Evaluations are performed mainly for the Lomnick´yˇSt´ıt neutron monitor location (LS: 2634 m a.s.l., geographic coordinates 49.20◦ N, 20.22◦ E), but some results for the Antarctic Laboratory for Cosmic Rays (LARC: 40 ma.s.l, 62.20◦ S and 301.04◦ E) are also given. Particular attention is paid to the variability of the magnetospheric screening appearing when the external magnetic field is added to the internal one

Antiproton modulation in the Heliosphere and AMS-02 antiproton over proton ratio prediction

We implemented a quasi time-dependent 2D stochastic model of solar modulation describing the transport of cosmic rays (CR) in the heliosphere. Our code can modulate the Local Interstellar Spectrum (LIS) of a generic charged particle (light cosmic ions and electrons), calculating the spectrum at 1AU. Several measurements of CR antiparticles have been performed. Here we focused our attention on the CR antiproton component and the antiproton over proton ratio. We show that our model, using the same heliospheric parameters for both particles, fit the observed anti-p/p ratio. We show a good agreement with BESS-97 and PAMELA data and make a prediction for the AMS-02 experiment

Latitudinal Dependence of Cosmic Rays Modulation at 1 AU and Interplanetary-Magnetic-Field Polar Correction

The cosmic rays differential intensity inside the heliosphere, for energy below 30 GeV/nuc, depends on solar activity and interplanetary magnetic field polarity. This variation, termed solar modulation, is described using a 2-D (radius and colatitude) Monte Carlo approach for solving the Parker transport equation that includes diffusion, convection, magnetic drift and adiabatic energy loss. Since the whole transport is strongly related to the interplanetary magnetic field (IMF) structure, a better understanding of his description is needed in order to reproduce the cosmic rays intensity at the Earth, as well as outside the ecliptic plane. In this work an interplanetary magnetic field model including the standard description on ecliptic region and a polar correction is presented. This treatment of the IMF, implemented in the HelMod Monte Carlo code (version 2.0), was used to determine the effects on the differential intensity of Proton at 1\,AU and allowed one to investigate how latitudinal gradients of proton intensities, observed in the inner heliosphere with the Ulysses spacecraft during 1995, can be affected by the modification of the IMF in the polar regions.Comment: accepted for publication inAdvances in Astronom

Proton Modulation in the Heliosphere for Different Solar Conditions and Prediction for AMS-02

Spectra of Galactic Cosmic Rays (GCRs) measured at the Earth are the combination of several processes: sources production and acceleration, propagation in the interstellar medium and propagation in the heliosphere. Inside the solar cavity the flux of GCRs is reduced due to the solar modulation, the interaction which they have with the interplanetary medium. We realized a 2D stochastic simulation of solar modulation to reproduce CR spectra at the Earth, and evaluated the importance in our results of the Local Interstellar Spectrum (LIS) model and its agreement with data at high energy. We show a good agreement between our model and the data taken by AMS-01 and BESS experiments during periods with different solar activity conditions. Furthermore we made a prediction for the flux which will be measured by AMS-02 experiment.Comment: Accepted for publication in the Proceedings of the ICATPP Conference on Cosmic Rays for Particle and Astroparticle Physics, Villa Olmo (Como, Italy), 7-8 October, 2010, to be published by World Scientific (Singapore

Suprathermal particle addition to solar wind pressure: possible influence on magnetospheric transmissivity of low energy cosmic rays?

Energetic (suprathermal) solar particles, accelerated in the interplanetary medium, contribute to the solar wind pressure, in particular during high solar activity periods. We estimated the effect of the increase of solar wind pressure due to suprathermal particles on magnetospheric transmissivity of galactic cosmic rays in the case of one recent solar event

Turn-Around-Time Improvements for Positive Blood Cultures from Incorporation of Workflow Modifications

Background: Emergence of direct from positive blood culture bottle identification (ID) methods reveal opportunities for improving bacterial ID and select resistance marker detection turn-around-times. Each system has various advantages and disadvantages; each institution must select the method/s that best fit the laboratory and patient needs. Here we elucidate improvements in 24 hour workflow through incorporating multiple rapid technologies for positive blood culture ID into a 24 hour algorithm. Methods: MALDI-TOF (Bruker) analysis with sepsityper extraction (aerobic Gram-positive and anaerobic bacteria); MALDI-TOF analysis with serum separator tube concentration (Gram-negative bacteria); and a FilmArray Blood Culture Panel (Biofire) were utilized. MALDI was utilized on 1st shift for single bacterium positives. FilmArray was performed on 2nd and 3rd shift for aerobic bottles and on 1st shift for gram-positive cocci in clusters and Candida. We examined all events during our pre-modification (September-November 2013) and post-modification (late-December 2014-March 2015) time periods and defined an event as the first positive blood culture for a patient within the examined data period. The Antimicrobial Stewardship Pharmacist (ASP) was notified with identifications and also KPC carbapenemase positives, to implement a carbapenem-resistant Enterobacteriaceae (CRE) empiric treatment algorithm. For KPC positives (CRE) a custom minimum inhibitory concentration (MIC) panel was utilized, replacing a standard susceptibility panel and Etests. Finally, 2nd shift began susceptibility setup on subcultured bloods that had turned positive from 11 p.m.-6 a.m. Results: Pre- and post- workflow modification average turn-around times (TAT) and p-values are shown in the Table. Detection of either the KPC or the mecA marker significantly improved the TAT needed for phenotypic detection of carbapenem or methicillin resistance. KPC was detected in 3 Enterobactericeae. Conclusions: Improvements to patient care are to be determined, but strong collaboration with ASP is anticipated to make a significant impact on patient outcomes. Of note, while having a universal Staphylococcus species target is useful, it can lead to complications with multi-species positive bottles. With the universal Staphylococcus species target, it is not possible to differentiate between a mixed coagulase negative Staphylococcus species (CNSS) versus Staphylococcus aureus when both are present as the CNSS may harbor the mecA target, preventing adequate treatment. Furthermore, a Staphylococcus lugdunensis specific marker would be clinically useful

Magnetospheric transmission function to separate near earth primary and secondary cosmic rays

The main features of charged particles accessing the Earth magnetosphere have been studied by tracing their trajectories. The reconstruction code has allowed us to perform two simulations of Cosmic Rays (CRs) accessing the AMS detector, one for the 1998 data, and the other for the 2005 (at the moment, the IGRF data are available up to that year). The parameters of the external field model for 2005 have been estimated from the solar conditions in 1982 and 1984, two solar cycles before. The CRs have been assumed to be isotropically impinging on the AMS detector, flying at 400 km altitude with energies reproducing the AMS-01 observed spectrum. The computation of allowed and forbidden primary particle trajectories has enabled us the estimate of the Transmission Function in both periods. A comparison with the overall (primary and secondary) AMS-01 data provides by subtraction the determination of the secondary spectrum

Un Cluster ad alte prestazioni per il progetto AMS

Viene presentato lo sviluppo di un cluster ad architettura PC Linux per calcolo ad alte prestazioni nell'ambito del progetto AMS