106 research outputs found
Vom Zwang zur Pockenschutzimpfung zum Nationalen Impfplan
Im Deutschen Reich wurden Pockenschutzimpfungen staatlich organisiert. Eine reichsweite Impfpflicht wurde 1874 eingeführt, die in der Bundesrepublik Deutschland (BRD) und Deutschen Demokratischen Republik (DDR) bis 1982/1983 fortgeführt wurde. Zuständig für Impfungen waren die 1935 gegründeten Gesundheitsämter. In der DDR wurde das Impfwesen straff organisiert: Man unternahm große Anstrengungen zur Erzielung hoher Impfquoten. Die diesbezüglichen Zuständigkeiten waren auf allen Ebenen und für jedes Lebensalter klar definiert. Während es zunächst nur regionale Impfpflichten gab, enthielt der spätere Impfkalender in Form einer Rechtsvorschrift nationale Pflichtimpfungen beispielsweise gegen Masern. Auch in der BRD bestanden zunächst auf Länderebene vereinzelte Impfpflichten. Mit Einführung des Bundes-Seuchengesetzes 1961 setzte man auf freiwillige Impfungen basierend auf Impfempfehlungen. Seit den 1980er-Jahren verlagerte sich die Durchführung von Impfungen zunehmend vom öffentlichen Gesundheitsdienst (ÖGD) hin zu den niedergelassenen Ärzten. Inzwischen impft der ÖGD überwiegend nur noch subsidiär und 2007 wurden Impfungen Pflichtleistungen der gesetzlichen Krankenkassen. Die Länder entwickelten unlängst zur Förderung von Impfstrategien einen Nationalen Impfplan.In the German Reich, smallpox vaccinations were organized by the state. A mandatory vaccination throughout the empire was introduced in 1874, which was continued in the Federal Republic of Germany (FRG) and the German Democratic Republic (GDR) until 1982/1983. From 1935, health departments were responsible for vaccinations. In the GDR, immunization was tightly organized: The state made great efforts to achieve high vaccination rates. Responsibilities were clearly defined at all levels and for all ages. While vaccination was initially mandatory only at the regional level, the legally mandated immunization schedule later contained compulsory vaccinations, e.g., against measles. In the beginning there were mandatory vaccinations in the FRG at the Länder level. Since 1961, the Federal Epidemics Act has impeded obligatory vaccinations. Instead, voluntary vaccinations based on recommendations were stressed. Since the 1980s, vaccinations have been shifted from the public health service sector to office-based physicians. Today, public health authorities offer mainly supplementary vaccinations. In 2007, protective immunizations were introduced as compulsory benefits of the statutory health insurance (SHI). Recently, the German federal states developed a National Vaccination Plan to support immunization strategies
In-medium mass from the reaction
Data on the photoproduction of mesons on nuclei have been
re-analyzed in a search for in-medium modifications. The data were taken with
the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in
Bonn. First results from the analysis of the data set were published by D.
Trnka et al. in Phys. Rev. Lett 94 (2005) 192303 \cite{david}, claiming a
lowering of the mass in the nuclear medium by 14 at normal nuclear
matter density. The extracted line shape was found to be sensitive to
the background subtraction. For this reason a re-analysis of the same data set
has been initiated and a new method has been developed to reduce the background
and to determine the shape and absolute magnitude of the background directly
from the data. Details of the re-analysis and of the background determination
are described. The signal on the target, extracted in the
re-analysis, does not show a deviation from the corresponding line shape on a
target, measured as reference. The earlier claim of an in-medium mass
shift is thus not confirmed. The sensitivity of the line shape to
different in-medium modification scenarios is discussed.Comment: 13 pages and 11 figures, submitted for publicatio
Quasi-free photoproduction of eta-mesons of the neutron
Quasi-free photoproduction of eta-mesons off nucleons bound in the deuteron
has been measured with the CBELSA/TAPS detector for incident photon energies up
to 2.5 GeV at the Bonn ELSA accelerator. The eta-mesons have been detected in
coincidence with recoil protons and recoil neutrons, which allows a detailed
comparison of the quasi-free n(gamma,eta)n and p(gamma,eta)p reactions. The
excitation function for eta-production off the neutron shows a pronounced
bump-like structure at W=1.68 GeV (E_g ~ 1 GeV), which is absent for the
proton.Comment: accepted for publication in Phys. Rev. Let
Modification of the -Meson Lifetime in Nuclear Matter
The photo production of mesons on the nuclei C, Ca, Nb and Pb has
been measured using the Crystal Barrel/TAPS detector at the ELSA tagged photon
facility in Bonn. The dependence of the meson cross section on the
nuclear mass number has been compared with three different types of models, a
Glauber analysis, a BUU analysis of the Giessen theory group and a calculation
by the Valencia theory group. In all three cases, the inelastic width
is found to be at normal nuclear matter density for an
average 3-momentum of 1.1 GeV/c. In the restframe of the meson, this
inelastic width corresponds to a reduction of the lifetime by
a factor . For the first time, the momentum dependent N
cross section has been extracted from the experiment and is in the range of 70
mb.Comment: 5 pages, 4 figure
Photoproduction of pi0 omega off protons for E(gamma) < 3 GeV
Differential and total cross-sections for photoproduction of gamma proton to
proton pi0 omega and gamma proton to Delta+ omega were determined from
measurements of the CB-ELSA experiment, performed at the electron accelerator
ELSA in Bonn. The measurements covered the photon energy range from the
production threshold up to 3GeV.Comment: 8 pages, 13 figure
Photoproduction of -mesons off the deuteron
Abstract.: Quasi-free photoproduction of -mesons off nucleons bound in the deuteron has been measured with the combined Crystal Barrel - TAPS detector. The experiment was done at a tagged photon beam of the ELSA electron accelerator in Bonn for incident photon energies from the production threshold up to 2.5GeV. The -mesons have been detected in coincidence with recoil protons and recoil neutrons. The quasi-free proton data are in good agreement with the results for free protons, indicating that nuclear effects have no significant impact. The coincidence with recoil neutrons provides the first data for the n n reaction. In addition, also first estimates for coherent -production off the deuteron have been obtained. In agreement with model predictions, the total cross-section for this channel is found to be very small, at most at the level of a few nb. The data are compared to model calculations taking into account contributions from nucleon resonances and t -channel exchange
Quasi-free photoproduction of η -mesons off the deuteron
Abstract.: Precise data for quasi-free photoproduction of η-mesons off the deuteron have been measured at the Bonn ELSA accelerator with the combined Crystal Barrel/TAPS detector for incident photon energies up to 2.5GeV. The η-mesons have been detected in coincidence with recoil protons and neutrons. Possible nuclear effects like Fermi motion and re-scattering can be studied via a comparison of the quasi-free reaction off the bound proton to η-production off the free proton. No significant effects beyond the folding of the free cross-section with the momentum distribution of the bound protons have been found. These Fermi motion effects can be removed by an analysis using the invariant mass of the η-nucleon pairs reconstructed from the final-state four-momenta of the particles. The total cross-section for quasi-free η-photoproduction off the neutron reveals even without correction for Fermi motion a pronounced bump-like structure around 1GeV of incident photon energy, which is not observed for the proton. This structure is even narrower in the invariant-mass spectrum of the η-neutron pairs. Position and width of the peak in the invariant-mass spectrum are W ≈ 1665 MeV and FWHM Γ ≈ 25 MeV. The data are compared to the results of different model
Photoproduction of η -mesons off nuclei for Eγ ⩽ 2.2 GeV
The photoproduction of η -mesons off 12C , 40Ca , 93Nb , and nat Pb nuclei has been measured with a tagged photon beam with energies between 0.6 and 2.2GeV. The experiment was performed at the Bonn ELSA accelerator with the combined setup of the Crystal Barrel and TAPS calorimeters. It aimed at the in-medium properties of the S 11(1535) nucleon resonance and the study of the absorption properties of nuclear matter for η -mesons. Careful consideration was given to contributions from ηπ final states and secondary production mechanisms of η -mesons, e.g. from inelastic πN reactions of intermediate pions. The analysis of the mass number scaling shows that the nuclear absorption cross-section for η -mesons is constant over a wide range of the η momentum. The comparison of the excitation functions to data off the deuteron and to calculations in the framework of a BUU model show no unexplained in-medium modifications of the S 11(1535
First observation of in-medium modifications of the omega meson
The photoproduction of omega mesons on nuclei has been investigated using the
Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The
aim is to study possible in-medium modifications of the omega meson via the
reaction A(gamma, omega)X. Results obtained for Nb are compared to a reference
measurement on a liquid hydrogen target. While for recoiling, long-lived mesons
(pi, eta and etaprime), which decay outside of the nucleus, a difference in the
lineshape for the two data samples is not observed, we find a significant
enhancement towards lower masses for omega mesons with low momenta produced on
the Nb target.Comment: Latex, 4 pages, 4 figures, accepted by Phys. Rev. Lett; references
re-arranged, now references in chronological order in first paragrap
Photoproduction of mesons on nuclei near the production threshold
The photoproduction of mesons on LH_2, C and Nb has been studied for
incident photon energies from 900 to 1300 MeV using the CB/TAPS detector at
ELSA. The line shape does not show any significant difference between
the LH_2 and the Nb targets. The data are compared with results of transport
calculations that predict a sensitivity of the line shape to in-medium
modifications near the production threshold on a free nucleon of
= 1109 MeV.}Comment: 5 pages, 3 figure
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