1,341 research outputs found
The conjecture concerning time variations in the solar neutrino flux
The results of the Fourier transformation of the unequally-spaced time series of the recorded Ar-37 production rate of the solar neutrino experiment (runs 18 to 80, 1970 to 1983) are reviewed. Significance criteria for every period discovered by the harmonic analysis are determined. A Fourier synthesis of certain discovered harmonics are performed. It seems that the solar neutrino flux increases shock-like with a period of approximately 8.3 years and after that breaks down. Possible connections between the periods found by the harmonic analysis and several observed phenomena on the solar surface are indicated
Start to end simulations of the ERL prototype at Daresbury Laboratory
Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the highbrightness injector, which consists of a DC photocathode Gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code elegant. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV. A brief summary of impedance and wakefield calculations for the whole machine is also given
Electron beam profile imaging in the presence of coherent optical radiation effects
High-brightness electron beams with low energy spread at existing and future
x-ray free-electron lasers are affected by various collective beam
self-interactions and microbunching instabilities. The corresponding coherent
optical radiation effects, e.g., coherent optical transition radiation, render
electron beam profile imaging impossible and become a serious issue for all
kinds of electron beam diagnostics using imaging screens. Furthermore, coherent
optical radiation effects can also be related to intrinsically ultrashort
electron bunches or the existence of ultrashort spikes inside the electron
bunches. In this paper, we discuss methods to suppress coherent optical
radiation effects both by electron beam profile imaging in dispersive beamlines
and by using scintillation imaging screens in combination with separation
techniques. The suppression of coherent optical emission in dispersive
beamlines is shown by analytical calculations, numerical simulations, and
measurements. Transverse and longitudinal electron beam profile measurements in
the presence of coherent optical radiation effects in non-dispersive beamlines
are demonstrated by applying a temporal separation technique.Comment: 12 pages, 11 figures, submitted to Phys. Rev. ST Accel. Beam
Skin tests, T cell responses and self-reported symptoms in children with allergic rhinitis and asthma due to house dust mite allergy
Abstract
BACKGROUND: In allergic responses, a distinction is made between an early-phase response, several minutes after allergen exposure, and a late-phase response after several hours. During the late phase, eosinophils and T cells infiltrate the mucosa and play an important role in inflammation.
OBJECTIVE: The aim of this study was to examine the relationship between allergen-induced late-phase skin responses and in vitro T cel
Die Teilnahme der Arbeiterjugend am sozialistischen Wettbewerb: Parlamentsstudie 1975 ; Teilbericht II.2
Die Studie, basierend auf einer schriftlichen Befragung von ca. 7400 jungen WerktĂ€tigen in der DDR im FrĂŒhjahr 1975, dient der ideologisch-theoretischen Vorbereitung des 10. Parlaments der FDJ. Ihr Ziel besteht in der Analyse der Ergebnisse der sozialistischen Jugendpolitik auf der Grundlage der BeschlĂŒsse des 8. Parteitags des SED, insbesondere bei der Entwicklung des sozialistischen KlassenbewuĂtseins der Jugend, in der Bestimmung der fĂŒr diese Entwicklung wichtigen Prozesse sowie in der Erarbeitung von Empfehlungen fĂŒr die vom 10. Parlament der FDJ zu beschlieĂenden Dokumente zur kommunistischen Erziehung der Jugend. Die Teilnahme der Arbeiterjugend am sozialistischen Wettbewerb wird auf drei Ebenen untersucht: (1) Einsatz der werktĂ€tigen Jugend fĂŒr volle Ausnutzung der Arbeitszeit, hohe QualitĂ€t der Arbeit und sparsamen Umgang mit Material und Energie; (2) Teilnahme der Arbeiterjugend an volkswirtschaftlichen Initiativen und an der Qualifizierung; (3) Informiertheit der Arbeiterjugend ĂŒber grundlegende ökonomische Sachverhalte und Zielstellungen. (ICE
Effect of Fluticasone propionate Aqueous Nasal Spray Treatment on Platelet Activating Factor and Eicosanoid Production By nasal Mucosa in Patients with A house Dust Mite Allergy
The relationship between the release of platelet activating factor
(PAF), leukotriene C4/D4/EE
(LTC4/D4/E4) and prostaglandin D2 (PGD2)
from nasal mucosa in vivo was examined in 24 rhinitis patients
allergic to the house dust mite (HDM). During a double blind placebo
controlled cross-over study 200 ÎŒg fluticasone propionate aqueous
nasal spray (FPANS) was administered twice daily for two weeks. In
response to allergen provocation (100, 1 000, 10 000 Bu/ml) and
during the 9.5 h after this challenge the nasal fluid was obtained
by washing the nose with saline and the levels of PAF, LTC4/D4/E4 and
PGD2, as indicators of mediator release, were measured at the
following time-points: baseline (t = â 1/2), allergen provocation with
10 000 Bu/ml (t = 0), 3.5 and 7.5 h (late phase). After allergen
provocation the levels of the mediators increased in the nasal
fluids of placebo treated patients (x-fold increase to baseline:
PAF, 15; LTC4/D4/E4, 12; PGD2, 1.5). In fluids of patients treated
with FPANS these levels tended to decrease. At the time of
provocation the levels of PAF, LTC4/D4/E4 and PGD2 showed a significant
correlation. The results indicate that these mediators can be used
as markers of allergic reactions against house dust mites and that
fluticasone propionate aqueous nasal spray tended to reduce the
release of mediators of inflammation correlated with beneficial
effects on clinical symptoms in this type of allergic reactions
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