143 research outputs found
Trajectories of Experience Through the Pandemic: A Qualitative Longitudinal Dataset
Here, we present a dataset collected within a longitudinal interview study that has been conducted as part of a larger project (i.e., Viral Communication), exploring (changing) public attitudes and behaviours through the course of the pandemic in Germany. From a nationally representative survey, forty participants were purposively sampled on the basis of gender, age and socioeconomic status for the interviews. Each participant was interviewed three times within a 10 month time frame (between December 2020 and September 2021), with the exception of two dropouts from the study. The semi-structured interviews were developed to further elaborate on some of the responses in the survey instrument and to provide additional insights into topics and controversies surrounding the Covid-19 pandemic in Germany, such as information/misinformation, trust/distrust, compliance, vaccination, and conspiracy beliefs
Evidence of kaon nuclear and Coulomb potential effects on soft K+ production from nuclei
The ratio of forward K+ production on copper, silver and gold targets to that
on carbon has been measured at proton beam energies between 1.5 and 2.3 GeV as
a function of the kaon momentum p_K using the ANKE spectrometer at
COSY-Juelich. The strong suppression in the ratios observed for p_K<200-250
MeV/c can be ascribed to a combination of Coulomb and nuclear repulsion in the
K+A system. This opens a new way to investigate the interaction of K+-mesons in
the nuclear medium. Our data are consistent with a K+A nuclear potential of
V_K~20 MeV at low kaon momenta and normal nuclear density. Given the
sensitivity of the data to the kaon potential, the current experimental
precision might allow one to determine V_K to better than 3 MeV.Comment: 9 pages, 3 figures; changed conten
The Near-Threshold Production of Phi Mesons in pp Collisions
The pp->pp phi reaction has been studied at the Cooler Synchrotron
COSY-Juelich, using the internal beam and ANKE facility. Total cross sections
have been determined at three excess energies epsilon near the production
threshold. The differential cross section closest to threshold at epsilon=18.5
MeV exhibits a clear S-wave dominance as well as a noticeable effect due to the
proton-proton final state interaction. Taken together with data for pp
omega-production, a significant enhancement of the phi/omega ratio of a factor
8 is found compared to predictions based on the Okubo-Zweig-Iizuka rule.Comment: 4 Pages, 3 Figures, 1 Table, submitted to Phys. Rev. Let
An optimised assay for quantitative, high-throughput analysis of polysialyltransferase activity
YesThe polysialyltransferases are biologically important glycosyltransferase enzymes responsible for the biosynthesis of
polysialic acid, a carbohydrate polymer that plays a critical role in the progression of several diseases, notably cancer.
Having improved the chemical synthesis and purification of the fluorescently-labelled DMB-DP3 acceptor, we report
optimisation and validation of a highly sensitive cell-free high-throughput HPLC-based assay for assessment of human
polysialyltransferase activity
Latest Developments from the S-DALINAC*
The S-DALINAC is a 130 MeV superconducting recirculating electron accelerator serving several nuclear and radiation physics experiments as well as driving an infrared free-electron laser. A system of normal conducting rf resonators for noninvasive beam position and current measurement was established. For the measurement of gamma-radiation inside the accelerator cave a system of Compton diodes has been developed and tested. Detailed investigations of the transverse phasespace were carried out with a tomographical reconstruction method of optical transition radiation spots. The method can be applied also to non-Gaussian phasespace distributions. The results are in good accordance with simulations. To improve the quality factor of the superconducting 3 GHz cavities, an external 2K testcryostat was commissioned. The influence of electro-chemical polishing and magnetic shielding is currently under investigation. A digital rf-feedback-system for the accelerator cavities is being developed in order to improve the energy spread of the beam of the S-DALINAC. * Supported by the BMBF under contract no. 06 DA 820, the DFG under contract no. Ri 242/12-1 and -2 and the DFG Graduiertenkolleg 'Physik und Technik von Beschleunigern
a0+(980)-resonance production in pp->dK+Kbar0 reactions close to threshold
The reaction pp->d K+ Kbar0 has been investigated at an excess energy of Q=46
MeV above the (K+ Kbar0) threshold with ANKE at COSY-Juelich. From the detected
coincident dK+ pairs about 1000 events with a missing Kbar0 were identified,
corresponding to a total cross section of sigma(pp->d K+ Kbar0)=(38 +/- 2(stat)
+/- 14(syst)) nb. Invariant-mass and angular distributions have been jointly
analyzed and reveal s-wave dominance between the two kaons, accompanied by a
p-wave between the deuteron and the kaon system. This is interpreted in terms
of a0+(980)-resonance production.Comment: 4 pages, 4 figures; accepted by Phys. Rev. Let
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