3,455 research outputs found
Anomalous \phi Meson Suppression in Au+Au Collisions at \sqrt{s_{NN}}=200 GeV Measured by the PHENIX Experiment at RHIC
The PHENIX experiment at RHIC has measured the \phi-meson production at
mid-rapidity in p+p, d+Au, Cu+Cu and Au+Au collisions at \sqrt{s_{NN}}=200 GeV
via the K^+K^- decay mode. The transverse momentum spectra of the \phi-meson
and the nuclear modification factor as a function of centrality are reviewed
here.Comment: 4 pages, 4 figures; To appear in the conference proceedings for Quark
Matter 2009, March 30 - April 4, Knoxville, Tennesse
Female teat size is a reliable indicator of annual breeding success in European badgers: Genetic validation
Assessing which females have bred successfully is a central requirement in many ecological field studies,
providing an estimate of the effective female population size. Researchers have applied teat measurements
previously to assess whether females, in a variety of mammalian species, have bred; however, this
technique has not been validated genetically. Furthermore, several analytical techniques are available to
classify individuals, but their misclassification rates have not been compared. We used 22 microsatellite
loci to assign maternity, with 95% confidence, within a high-density population of European badgers Meles
meles, as plural and subterranean breeding means that maternity cannot be inferred from behavioural
observations. The teat lengths and diameters of 136 females, measured MayâJuly 1994â2005, from social
groups in which all offspring were assigned a mother, were reliable indicators of recent breeding success.
A Generalised Linear Mixed Model (GLMM) classified both breeding and non-breeding females with
lower error rates than discriminant analyses and crude teat-size criteria. The GLMM model logit probability
=
â20 + 1.8 month + 1.6 mean teat length + 1.0 mean teat diameter can be applied quickly in the field
to assess the probability with which a female badger should be assigned maternity. This is a low-cost
measure which, after validation, could be used in other badger or mammalian populations to assess the
breeding success of females. This may be a particularly useful welfare tool for veterinary practitioners,
especially during badger culls
A Cosmic Ray Positron Anisotropy due to Two Middle-Aged, Nearby Pulsars?
Geminga and B0656+14 are the closest pulsars with characteristic ages in the
ran ge of 100 kyr to 1 Myr. They both have spindown powers of the order 3e34
erg/s at present. The winds of these pulsars had most probably powered pulsar
wind nebulae (PWNe) that broke up less than about 100 kyr after the birth of
the pulsars. Assuming that leptonic particles accelerated by the pulsars were
confined in th e PWNe and were released into the interstellar medium (ISM) on
breakup of the PW Ne, we show that, depending on the pulsar parameters, both
pulsars make a non-ne gligible contribution to the local cosmic ray (CR)
positron spectrum, and they m ay be the main contributors above several GeV.
The relatively small angular dist ance between Geminga and B0656+14 thus
implies an anisotropy in the local CR po sitron flux at these energies. We
calculate the contribution of these pulsars to the locally observed CR electr
on and positron spectra depending on the pulsar birth period and the magnitude
o f the local CR diffusion coefficient. We further give an estimate of the
expecte d anisotropy in the local CR positron flux. Our calculations show that
within the framework of our model, the local CR posit ron spectrum imposes
constraints on pulsar parameters for Geminga and B0656+14, notably the pulsar
period at birth, and also the local interstellar diffusion co efficient for CR
leptons.Comment: accepted for publication in ApJ
Berufsbedingte Atemwegsbeschwerden in Ost- und Westdeutschland
Berufsbedingte Atemwegserkrankungen zÀhlen zu den hÀufigsten Berufskrankheiten. Ziel dieser Querschnittsstudie war die Aufdeckung von Risikoberufen, der Ost-West-Vergleich von SymptomprÀvalenzen in einzelnen Berufen, sowie die Untersuchung des Einflusses der beruflichen Passivrauchexposition auf die Entstehung von Atemwegsbeschwerden.
Herangezogen wurden Daten aus Fragebögen, sowie Ergebnisse klinischer Untersuchungen, die in einer bevölkerungsbezogenen Zufallsstichprobe in Erfurt (n=731) und Hamburg (n=1159) bei Personen im Alter von 20-44 Jahren erhoben worden waren. Untersuchte Merkmale waren bronchiale HyperreagibilitÀt, Allergie, Asthmasymptome, Asthma und Bronchitis.
Allergische Erkrankungen traten signifikant hĂ€ufiger bei Teilnehmern aus Hamburg auf. Bereits bekannte Risikoberufe konnten weitgehend bestĂ€tigt werden (Landwirtschaft, Bau). Des weiteren zeigte sich ein erhöhtes Risiko fĂŒr ReinigungskrĂ€fte (PrĂ€valenz Odds Ratio [95% Konfidenzintervall] Asthma: Erfurt: 2,02 [0,24-17,62]; Hamburg: 1,78 [0,58-5,40]) und Elektriker (Asthma: Erfurt: 2,47 [0,64-9,53]; Hamburg: 1,38 [0,17-11,21]). Im Ost-West-Vergleich fanden sich Unterschiede in den PrĂ€valenzraten fĂŒr BeschĂ€ftigte auf dem Bau, in der Metallindustrie und in der Elektroindustrie. In der Untersuchung ergab sich weiterhin ein statistisch signifikanter Zusammenhang zwischen beruflicher Passivrauchexposition und der Entstehung von Asthma (1,80 (1,12-2,94), Asthmasymptomen (1,39 [1,00-1,95]) und Bronchitis (2,82 [1,55-5,12]).
Dem konsistent erhöhten Asthmarisiko fĂŒr Reinigungspersonal und BeschĂ€ftigte in der Elektroindustrie sollte nachgegangen werden. Des weiteren deuten die Ergebnisse bezĂŒglich der Passivrauchexposition daraufhin, dass Personen am Arbeitsplatz noch stĂ€rker vor Passivrauch geschĂŒtzt werden sollten.
Die Unterschiede in den PrÀvalenz Odds Ratios in den einzelnen Berufsgruppen in Ost- und Westdeutschland können auf unterschiedlichen Aufgabenspektren, Unterschieden in der Arbeitsweise und in der Verwendung von Arbeitsstoffen, sowie auf den zum Teil geringen Fallzahlen beruhen
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