88 research outputs found

    Vom Zwang zur Pockenschutzimpfung zum Nationalen Impfplan

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    Im Deutschen Reich wurden Pockenschutzimpfungen staatlich organisiert. Eine reichsweite Impfpflicht wurde 1874 eingefĂŒhrt, die in der Bundesrepublik Deutschland (BRD) und Deutschen Demokratischen Republik (DDR) bis 1982/1983 fortgefĂŒhrt wurde. ZustĂ€ndig fĂŒr Impfungen waren die 1935 gegrĂŒndeten GesundheitsĂ€mter. In der DDR wurde das Impfwesen straff organisiert: Man unternahm große Anstrengungen zur Erzielung hoher Impfquoten. Die diesbezĂŒglichen ZustĂ€ndigkeiten waren auf allen Ebenen und fĂŒr jedes Lebensalter klar definiert. WĂ€hrend es zunĂ€chst nur regionale Impfpflichten gab, enthielt der spĂ€tere Impfkalender in Form einer Rechtsvorschrift nationale Pflichtimpfungen beispielsweise gegen Masern. Auch in der BRD bestanden zunĂ€chst auf LĂ€nderebene vereinzelte Impfpflichten. Mit EinfĂŒhrung des Bundes-Seuchengesetzes 1961 setzte man auf freiwillige Impfungen basierend auf Impfempfehlungen. Seit den 1980er-Jahren verlagerte sich die DurchfĂŒhrung von Impfungen zunehmend vom öffentlichen Gesundheitsdienst (ÖGD) hin zu den niedergelassenen Ärzten. Inzwischen impft der ÖGD ĂŒberwiegend nur noch subsidiĂ€r und 2007 wurden Impfungen Pflichtleistungen der gesetzlichen Krankenkassen. Die LĂ€nder entwickelten unlĂ€ngst 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 LĂ€nder 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 ω\omega mass from the Îł+Nb→π0Îł+X\gamma + Nb \to \pi^{0}\gamma + X reaction

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    Data on the photoproduction of ω\omega 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 ω\omega mass in the nuclear medium by 14% at normal nuclear matter density. The extracted ω\omega 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 ω\omega signal on the NbNb target, extracted in the re-analysis, does not show a deviation from the corresponding line shape on a LH2LH_2 target, measured as reference. The earlier claim of an in-medium mass shift is thus not confirmed. The sensitivity of the ω\omega line shape to different in-medium modification scenarios is discussed.Comment: 13 pages and 11 figures, submitted for publicatio

    Modification of the ω\omega-Meson Lifetime in Nuclear Matter

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    The photo production of ω\omega 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 ω\omega 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 ω\omega width is found to be 130−150MeV/c2130-150 \rm{MeV/c^2} at normal nuclear matter density for an average 3-momentum of 1.1 GeV/c. In the restframe of the ω\omega meson, this inelastic ω\omega width corresponds to a reduction of the ω\omega lifetime by a factor ≈30\approx 30. For the first time, the momentum dependent ω\omegaN 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

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    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 ηâ€Č \eta{^\prime} -mesons off the deuteron

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    Abstract.: Quasi-free photoproduction of ηâ€Č \eta{^\prime} -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 ηâ€Č \eta{^\prime} -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 Îł \gamma n → \rightarrow n ηâ€Č \eta{^\prime} reaction. In addition, also first estimates for coherent ηâ€Č \eta{^\prime} -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

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    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 EÎł â©œ 2.2 GeV

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    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 σNη \sigma_{{N\eta}}^{} 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

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    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 ω\omega mesons on nuclei near the production threshold

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    The photoproduction of ω\omega 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 ω\omega 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 ω\omega line shape to in-medium modifications near the production threshold on a free nucleon of EÎłlabE_{\gamma}^{lab} = 1109 MeV.}Comment: 5 pages, 3 figure

    Neutral pion photoproduction off protons in the energy range 0.3 GeV < E(gamma) < 3 GeV

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    Single pi0 photoproduction has been studied with the CB-ELSA experiment at Bonn using tagged photon energies between 0.3 and 3.0 GeV. The experimental setup covers a very large solid angle of about 98% of 4 pi. Differential cross sections (d sigma)/(d Omega) have been measured. Complicated structures in the angular distributions indicate a variety of different resonances being produced in the s channel intermediate state gamma p --> N* (Delta*) --> p pi0. A combined analysis including the data presented in this letter along with other data sets reveals contributions from known resonances and evidence for a new resonance N(2070)D15.Comment: LaTeX file, 4 pages, 4 encapsulated postscript figures, submitted to Phys. Rev. Lett. The publication of hep-ex/0407022 is accompanied by hep-ex/0311045 on photoproduction of eta mesons. Reference [3]: changed, reference [17]: citation added. Figure 3, 4: SAID added up to 2 GeV for comparison, update
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