3,385 research outputs found
A population-based case-control study on social factors and risk of testicular germ cell tumours
Objectives Incidence rates for testicular cancer have risen over the last few decades. Findings of an association between the risk of testicular cancer and social factors are controversial. The association of testicular cancer and different indicators of social factors were examined in this study.<p></p>
Design Caseâcontrol study.<p></p>
Setting Population-based multicentre study in four German regions (city states Bremen and Hamburg, the Saarland region and the city of Essen).<p></p>
Participants The study included 797 control participants and 266 participants newly diagnosed with testicular cancer of which 167 cases were classified as seminoma and 99 as non-seminoma. The age of study participants ranged from 15 to 69â
years.<p></p>
Methods Social position was classified by educational attainment level, posteducational training, occupational sectors according to Erikson-Goldthorpe-Portocarrero (EGP) and the socioeconomic status (SES) on the basis of the International SocioEconomic Index of occupational status (ISEI). ORs and corresponding 95% CIs (95% CIs) were calculated for the whole study sample and for seminoma and non-seminoma separately.<p></p>
Results Testicular cancer risk was modestly increased among participants with an apprenticeship (OR=1.7 (95% CI 1.0 to 2.8)) or a university degree (OR=1.6 (95% CI 0.9 to 2.8)) relative to those whose education was limited to school. Analysis of occupational sectors revealed an excess risk for farmers and farm-related occupations. No clear trend was observed for the analyses according to the ISEI-scale.<p></p>
Conclusions Social factors based on occupational measures were not a risk factor for testicular cancer in this study. The elevated risk in farmers and farm-related occupations warrants further research including analysis of occupational exposures.<p></p>
Fly ash-based waste for ex-situ landfill stabilization of per- and polyfluoroalkyl substance (PFAS)-contaminated soil
In response to world-wide soil and groundwater contamination per- and polyfluoroalkyl substances (PFAS), stakeholders require immediate mitigation. Soil deposition in landfill is a common mitigation scheme, but PFAS losses occur via landfill leachate. These leaching losses can be reduced by strategically utilizing other deposited waste materials for ex-situ contaminant stabilization. This screening study tested activated carbon (AC) and eight types of wastes (compost, rubber granulate, bentonite clay, industrial sludge, incineration slag, incineration bottom ash (n=4), incineration fly ash-based air pollution control residue (FA-APC) (n=16)) in amending (adding 4%, 5%, 10% or 25% sorbent) field-contaminated (n=19) and PFAS-fortified (n=11) soils. A subset of FA-based residue types, all originating from grate-fire incineration (G-F-I) plants, achieved extraordinarily high removal of PFAS. The removal was up to 98% (25% addition) of the sum of six dominant PFAS for field-contaminated soil and >99% of the sum of 11 PFAS for fortified soil (10/25% addition) (>99.9% for PFOS). Calculated partitioning coefficient revealed significant trends between sorption strength and perfluorocarbon chain length (0.21-0.47 log units per CF2-moiety), indicating high importance of hydrophobic sorption (R2>0.98). However, with incremental G-F-I FA-APC addition this relationship disappeared, indicating an alternative sorption mechanism. The exceptional PFAS sorption by G-F-I FA-APC was not explained by G-F-I surface area, surface charge, soil mineral- and metal composition, or solution DOC, metal, or ion composition (H+, Ca2+, Mg2+, Al3+ and Ba2+). Although the mechanism remains unknown, this study showed that landfill sites can utilize G-F-I FA-APC for ex-situ stabilization at negative cost, thus preventing PFAS-containing leachate
Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C
The Glasgow photon tagging spectrometer at Mainz has been upgraded so that it
can be used with the 1500 MeV electron beam now available from the Mainz
microtron MAMI-C. The changes made and the resulting properties of the
spectrometer are discussed.Comment: 20 pages, 12 figure
Photofission of heavy nuclei at energies up to 4 GeV
Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and
natPb have been measured simultaneously, using tagged photons in the energy
range Egamma=0.17-3.84 GeV. This was the first experiment performed using the
Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the
photofission cross section for 238U relative to that for 237Np is about 80%,
implying the presence of important processes that compete with fission. We also
observe that the relative photofission cross sections do not depend strongly on
the incident photon energy over this entire energy range. If we assume that for
237Np the photofission probability is equal to unity, we observe a significant
shadowing effect starting below 1.5 GeV.Comment: 4 pages of RevTex, 6 postscript figures, Submitted to Phys. Rev. Let
Neutrino Telescopes as a Direct Probe of Supersymmetry Breaking
We consider supersymmetric models where the scale of supersymmetry breaking
lies between 5 GeV and 5 GeV. In this class of
theories, which includes models of gauge mediated supersymmetry breaking, the
lightest supersymmetric particle is the gravitino. The next to lightest
supersymmetric particle is typically a long lived charged slepton with a
lifetime between a microsecond and a second, depending on its mass. Collisions
of high energy neutrinos with nucleons in the earth can result in the
production of a pair of these sleptons. Their very high boost means they
typically decay outside the earth. We investigate the production of these
particles by the diffuse flux of high energy neutrinos, and the potential for
their observation in large ice or water Cerenkov detectors. The relatively
small cross-section for the production of supersymmetric particles is partially
compensated for by the very long range of heavy particles. The signal in the
detector consists of two parallel charged tracks emerging from the earth about
100 meters apart, with very little background. A detailed calculation using the
Waxman-Bahcall limit on the neutrino flux and realistic spectra shows that
km experiments could see as many as 4 events a year. We conclude that
neutrino telescopes will complement collider searches in the determination of
the supersymmetry breaking scale, and may even give the first evidence for
supersymmetry at the weak scale.Comment: 4 pages, 3 figure
Light response of pure CsI calorimeter crystals painted with wavelength-shifting lacquer
We have measured scintillation properties of pure CsI crystals used in the
shower calorimeter built for a precise determination of the pi+ -> pi0 e+ nu
decay rate at the Paul Scherrer Institute (PSI). All 240 individual crystals
painted with a special wavelength-shifting solution were examined in a
custom-build detection apparatus (RASTA=radioactive source tomography
apparatus) that uses a 137Cs radioactive gamma source, cosmic muons and a light
emitting diode as complementary probes of the scintillator light response. We
have extracted the total light output, axial light collection nonuniformities
and timing responses of the individual CsI crystals. These results predict
improved performance of the 3 pi sr PIBETA calorimeter due to the painted
lateral surfaces of 240 CsI crystals. The wavelength-shifting paint treatment
did not affect appreciably the total light output and timing resolution of our
crystal sample. The predicted energy resolution for positrons and photons in
the energy range of 10-100 MeV was nevertheless improved due to the more
favorable axial light collection probability variation. We have compared
simulated calorimeter ADC spectra due to 70 MeV positrons and photons with a
Monte Carlo calculation of an ideal detector light response.Comment: Elsevier LaTeX, 35 pages in e-print format, 15 Postscript Figures and
4 Tables, also available at
http://pibeta.phys.virginia.edu/~pibeta/subprojects/csipro/tomo/rasta.p
Light baryon magnetic moments and N -> Delta gamma transition in a Lorentz covariant chiral quark approach
We calculate magnetic moments of light baryons and N -> Delta gamma
transition characteristics using a manifestly Lorentz covariant chiral quark
approach for the study of baryons as bound states of constituent quarks dressed
by a cloud of pseudoscalar mesons.Comment: 29 pages, 10 figures, accepted for publication in Phys. Rev.
The reaction and the magnetic dipole moment of the resonance
The reaction has been measured with
the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for
energies between = 1221--1331 MeV. Cross sections differential in
angle and energy have been determined for all particles in the final state in
three bins of the excitation energy. This reaction channel provides access to
the magnetic dipole moment of the resonance and, for the
first time, a value of has been extracted
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