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Falcke H, Apel WD, Badea AF, Bähren L, Bekk K, Bercuci A, Bertaina M, Biermann PL, Blümer J, Bozdog H, Brancus IM, Buitink S, Brüggemann M, Buchholz P, Butcher H, Chiavassa A, Daumiller K, de Bruyn AG, de Vos CM, Di Pierro F, Doll P, Engel R, Gemmeke H, Ghia PL, Glasstetter R, Grupen C, Haungs A, Heck D, Hörandel JR, Horneffer A, Huege T, Kampert KH, Kant GW, Klein U, Kolotaev Y, Koopman Y, Krömer O, Kuijpers J, Lafebre S, Maier G, Mathes HJ, Mayer HJ, Milke J, Mitrica B, Morello C, Navarra G, Nehls S, Nigl A, Obenland R, Oehlschläger J, Ostapchenko S, Over S, Pepping HJ, Petcu M, Petrovic J, Plewnia S, Rebel H, Risse A, Roth M, Schieler H, Schoonderbeek G, Sima O, Stümpert M, Toma G, Trinchero GC, Ulrich H, Valchierotti S, van Buren J, van Cappellen W, Walkowiak W, Weindl A, Wijnholds S, Wochele J, Zabierowski J, Zensus JA, Zimmermann D. Detection and imaging of atmospheric radio flashes from cosmic ray air showers. Nature 2005; 435:313-6. [PMID: 15902250 DOI: 10.1038/nature03614] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 04/04/2005] [Indexed: 11/09/2022]
Abstract
The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.
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Affiliation(s)
- H Falcke
- Max-Planck-Institut für Radioastronomie, 53121 Bonn, Germany.
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Abstract
In The Netherlands, the government operates a reference price system in which medicines are categorised into groups of interchangeable drugs. The reimbursement within groups is limited. In addition, since drug prices in The Netherlands are currently among the highest in Western Europe, a law was implemented in March 1996 to lower the prices of drugs in The Netherlands to the mean of pharmacy buying prices in 4 surrounding countries (UK, France, Belgium and Germany). Maximum prices for oral formulations will be in force from 1 June 1996, and maximum prices for other formulations will be operational soon thereafter. Reducing the price level will lead to a substantial decrease in discounts for pharmacists. Lower discounts will also mean weaker 'golden chains' between wholesalers, the industry, and pharmacists, and will therefore create business opportunities for companies wishing to compete on the basis of price. Liberalising the distribution of pharmaceuticals and creating a cost-conscious demand side will stimulate price competition in the pharmaceutical market and make it easier for new participants to enter the Dutch market. Price competition will lead to lower prices and, consequently, to lower costs. Further exemptions from the reimbursement list will be recognised. Considerable efforts are also being made to rationalise the prescribing behaviour of physicians and the dispensing behaviour of pharmacists. Through this programme, which has many components, The Netherlands hopes to restrain and effectively control its expenditures on pharmaceuticals.
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Affiliation(s)
- C M de Vos
- Directorate of Pharmaceutical Affairs, Ministry of Health, Welfare and Sports, Rijswijk, The Netherlands
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