21 research outputs found

    The Pierre Auger Observatory offline software

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    The Pierre Auger Observatory aims to discover the nature and origins of the highest energy cosmic rays. The large number of physicists involved in the project and the diversity of simulation and reconstruction tasks pose a challenge for the offline analysis software, not unlike the challenges confronting software for very large high energy physics experiments. Previously we have reported on the design and implementation of a general purpose but relatively lightweight framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. In this report, we update the status of this work and describe some of the successes and difficulties encountered over the last few years of use. We explain the machinery used to manage user contributions, to organize the abundance of configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information residing in various data sources. We also describe the testing procedures used to help maintain stability of the code in the face of a large number of contributions. Foundation classes will also be discussed, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice

    Measurement of Aerosols at the Pierre Auger Observatory

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    The air fluorescence detectors (FDs) of the Pierre Auger Observatory are vital for the determination of the air shower energy scale. To compensate for variations in atmospheric conditions that affect the energy measurement, the Observatory operates an array of monitoring instruments to record hourly atmospheric conditions across the detector site, an area exceeding 3,000 square km. This paper presents results from four instruments used to characterize the aerosol component of the atmosphere: the Central Laser Facility (CLF), which provides the FDs with calibrated laser shots; the scanning backscatter lidars, which operate at three FD sites; the Aerosol Phase Function monitors (APFs), which measure the aerosol scattering cross section at two FD locations; and the Horizontal Attenuation Monitor (HAM), which measures the wavelength dependence of aerosol attenuation.Comment: Contribution to the 30th International Cosmic Ray Conference, Merida Mexico, July 2007; 4 pages, 4 figure

    The Pierre Auger Observatory Offline Software

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    The Pierre Auger Observatory aims to discover the nature and origins of the highest energy cosmic rays. The large number of physicists involved in the project and the diversity of simulation and reconstruction tasks pose a challenge for the offline analysis software, not unlike the challenges confronting software for very large high energy physics experiments. Previously we have reported on the design and implementation of a general purpose but relatively lightweight framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. In this report, we update the status of this work and describe some of the successes and difficulties encountered over the last few years of use. We explain the machinery used to manage user contributions, to organize the abundance of configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information residing in various data sources. We also describe the testing procedures used to help maintain stability of the code in the face of a large number of contributions. Foundation classes will also be discussed, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. © 2008 IOP Publishing Ltd.1193Abraham J et al. [Pierre Auger Collaboration] 2004 Nucl. Instrum. Meth. A 523, 50Ghia, P., Pierre Auger Collaboration (2007) Proc. 30th Intl. Cosmic Ray Conference (ICRC 2007), Merida, Mexico, 3-10 July 2007 Preprint, , arXiv:0706.1212 [astro-phKlages, H., HEAT : Enhancement Telescopes for the Pierre Auger Southern Observatory in Argentina Pierre Auger CollaborationMedina, M., Berisso, M., Allekotte, I., Etchegoyen, A., Tanco, G., Supanitsky, A., (2006) Nucl. Instrum. Meth. A, 566, p. 302AMIGA: A muon detector and infilled array for the Auger Observatory (2007) Proc. 30th Intl. Cosmic Ray Conference (ICRC 2007), Merida, , Etchegoyen A [Pierre Auger Collaboration, Mexico, 3-10 JulyArgirò, S., The offline software framework of the Pierre Auger Observatory (2005), Pierre Auger CollaborationArgiro S et al. 2007 Nucl. Instr. and Meth. A, doi:10.1016/j.nima.2007.07.010 Preprint arXiv:0707.1652 [astro-ph]http://www.w3.org/XMLhttp://tools.ietf.org/html/rfc3986http://www.w3.org/TR/xpathhttp:subversion.tigris.orghttp://www.gnu.org/software/autoconfhttp://www.gnu.org/software/ automakehttp://www.gnu.org/software/libtoolhttp://www.w3.org/XML/SchemaRivest, R., http://www.faqs.org/rfcsPatton, S., Concrete uses of XML in software development and data analysis (2003) Proc. Intl. Conf. on Computing in High-Energy Physics and Nuclear Physics (CHEP 2003), , See for example, La Jolla, California, USA 24-28 MarchSciutto, S., Preprint arXiv:astro-ph/9911331Heck, D., Knapp, J., Capdevielle, J., Schatz, G., Thuow, T., (1998) Report FZKA, , 6019Bergmann, T., (2007) Astropart. Phys, 26, p. 420Drescher, H., Farrar, G., Bleicher, M., Reiter, M., Soff, S., Stoecker, H., (2003) Phys.Rev, D67, p. 116001http://root.cern.chhttp://dev.mysql.comhttp://xml.apache.orgJosuttis, N., (1999) The C++ Standard Library, , see for example, Addison-Wesley, ISBN 0-201-37926-0http://www.w3.org/TR/REC-xmlhttp://cppunit.sourceforge.net/doc/1.8.0http://buildbot.sourceforge.nethttp://www.boost.orghttp://proj-clhep.web.cern.ch/proj-clhephttp://geant4.cern.ch/Agostinelli S et al. 2003 Nucl. Instrum. Meth. A 506, 250http://www.python.orgChudoba, J., Simulations and Offline Data Processing for the Auger Experiment Presented at EGEE User Forum, , http://indico.cern.ch/conferenceDisplay.py?confId=7247, Manchester, UK, 9-11 May 200

    Sensitization of cervix cancer cells to Adriamycin by Pentoxifylline induces an increase in apoptosis and decrease senescence

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    <p>Abstract</p> <p>Background</p> <p>Chemotherapeutic drugs like Adriamycin (ADR) induces apoptosis or senescence in cancer cells but these cells often develop resistance and generate responses of short duration or complete failure. The methylxantine drug Pentoxifylline (PTX) used routinely in the clinics setting for circulatory diseases has been recently described to have antitumor properties. We evaluated whether pretreatment with PTX modifies apoptosis and senescence induced by ADR in cervix cancer cells.</p> <p>Methods</p> <p>HeLa (HPV 18+), SiHa (HPV 16+) cervix cancer cells and non-tumorigenic immortalized HaCaT cells (control) were treated with PTX, ADR or PTX + ADR. The cellular toxicity of PTX and survival fraction were determinated by WST-1 and clonogenic assay respectively. Apoptosis, caspase activation and ADR efflux rate were measured by flow cytometry, senescence by microscopy. IκBα and DNA fragmentation were determinated by ELISA. Proapoptotic, antiapoptotic and senescence genes, as well as HPV-E6/E7 mRNA expression, were detected by time real RT-PCR. p53 protein levels were assayed by Western blot.</p> <p>Results</p> <p>PTX is toxic (WST-1), affects survival (clonogenic assay) and induces apoptosis in cervix cancer cells. Additionally, the combination of this drug with ADR diminished the survival fraction and significantly increased apoptosis of HeLa and SiHa cervix cancer cells. Treatments were less effective in HaCaT cells. We found caspase participation in the induction of apoptosis by PTX, ADR or its combination. Surprisingly, in spite of the antitumor activity displayed by PTX, our results indicate that methylxantine, <it>per se </it>does not induce senescence; however it inhibits senescence induced by ADR and at the same time increases apoptosis. PTX elevates IκBα levels. Such sensitization is achieved through the up-regulation of proapoptotic factors such as <it>caspase </it>and <it>bcl </it>family gene expression. PTX and PTX + ADR also decrease E6 and E7 expression in SiHa cells, but not in HeLa cells. p53 was detected only in SiHa cells treated with ADR.</p> <p>Conclusion</p> <p>PTX is a good inducer of apoptosis but does not induce senescence. Furthermore, PTX reduced the ADR-induced senescence and increased apoptosis in cervix cancer cells.</p

    Milagro limits and HAWC sensitivity for the rate-density of evaporating Primordial Black Holes

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    On the sensitivity of the HAWC observatory to gamma-ray bursts

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    We present the sensitivity of HAWC to Gamma Ray Bursts (GRBs). HAWC is a very high-energy gamma-ray observatory currently under construction in Mexico at an altitude of 4100 m. It will observe atmospheric air showers via the water Cherenkov method. HAWC will consist of 300 large water tanks instrumented with 4 photomultipliers each. HAWC has two data acquisition (DAQ) systems. The main DAQ system reads out coincident signals in the tanks and reconstructs the direction and energy of individual atmospheric showers. The scaler DAQ counts the hits in each photomultiplier tube (PMT) in the detector and searches for a statistical excess over the noise of all PMTs. We show that HAWC has a realistic opportunity to observe the high-energy power law components of GRBs that extend at least up to 30 GeV, as it has been observed by Fermi LAT. The two DAQ systems have an energy threshold that is low enough to observe events similar to GRB 090510 and GRB 090902b with the characteristics observed by Fermi LAT. HAWC will provide information about the high-energy spectra of GRBs which in turn could help to understanding about e-pair attenuation in GRB jets, extragalactic background light absorption, as well as establishing the highest energy to which GRBs accelerate particles

    All-sky measurement of the anisotropy of cosmic rays at 10 TeV and mapping of the local interstellar magnetic field

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    We present the first full-sky analysis of the cosmic ray arrival direction distribution with data collected by the High-Altitude Water Cherenkov and IceCube observatories in the northern and southern hemispheres at the same median primary particle energy of 10 TeV. The combined sky map and angular power spectrum largely eliminate biases that result from partial sky coverage and present a key to probe into the propagation properties of TeV cosmic rays through our local interstellar medium and the interaction between the interstellar and heliospheric magnetic fields. From the map, we determine the horizontal dipole components of the anisotropy δ0h= 9.16×10¯⁴ and δ6h=7.25×10¯⁴(±0.04 × 10¯⁴). In addition, we infer the direction (229°.2 ± 3°.5 R.A., 11°.4 ± 3°.0 decl.) of the interstellar magnetic field from the boundary between large-scale excess and deficit regions from which we estimate the missing corresponding vertical dipole component of the large-scale anisotropy to be δN ~ 3.97 −₂⋅₀¯¹·⁰ ×10¯⁴A. U. Abeysekara, R. Alfaro, C. Alvarez, R. Arceo, J. C. Arteaga-Velázquez ... Gary C. Hill ... et al. (HAWC Collaboration and IceCube Collaboration

    Milagro limits and HAWC sensitivity for the rate-density of evaporating Primordial Black Holes

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    Primordial Black Holes (PBHs) are gravitationally collapsed objects that may have been created by density fluctuations in the early universe and could have arbitrarily small masses down to the Planck scale. Hawking showed that due to quantum effects, a black hole has a temperature inversely proportional to its mass and will emit all species of fundamental particles thermally. PBHs with initial masses of ∼5.0 × 1014 g should be expiring in the present epoch with bursts of high-energy particles, including gamma radiation in the GeV-TeV energy range. The Milagro high energy observatory, which operated from 2000 to 2008, is sensitive to the high end of the PBH evaporation gamma-ray spectrum. Due to its large field-of-view, more than 90% duty cycle and sensitivity up to 100 TeV gamma rays, the Milagro observatory is well suited to perform a search for PBH bursts. Based on a search on the Milagro data, we report new PBH burst rate density upper limits over a range of PBH observation times. In addition, we report the sensitivity of the Milagro successor, the High Altitude Water Cherenkov (HAWC) observatory, to PBH evaporation events. © Published by Elsevier B.V

    Sensitivity of HAWC to high-mass dark matter annihilations

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    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19° North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi-TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from nonluminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross sections below thermal. HAWC should also be sensitive to nonthermal cross sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained. © 2014 American Physical Society
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