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Abstract Oral immunisation of wild boar against classical swine fever (CSF) in the German federal state of Baden-Württemberg has been evaluated on the basis of the seroprevalence rates after application of an improved immunisation procedure consisting of three double vaccinations per year (in spring, summer and autumn). The seroprevalence in the vaccination area increased continuously until the third immunisation campaign (72.4% seropositive animals). Later, a decrease of the seroprevalence rates was detected, especially in young boars. Although in the infected area the seroprevalences were higher, in principle, the same trend could be found in the surveillance zone. The development of the monthly seroprevalence rates of young boars during the first year of their life showed that the new immunisation procedure had a positive effect on their immunisation rate. Fifty percent and more of the wild boar shot at the age of 6–12 months were antibody positive. Neutralising antibody titre levels were the same in young boars (on average 812 ND50) and in sub-adults (on average 997 ND50). Individual antibody positive animals may be detected for more than 2 years after completion of the vaccination programme.

We present local probe tunneling spectroscopy of Bi2Sr2CaCu2O8+d single crystals for different oxygen concentrations, from optimally doped (Tc=92.2 K) to highly overdoped (Tc=56.0 K) phases. With increasing oxygen overdoping, the superconducting gap (?p) is reduced and the dip structure beyond ?p at negative sample bias1 shifts toward the Fermi energy. Apart from the shift in energy of these features, the generic shape of the tunneling spectra remains unchanged. The gap roughly scales with Tc, and 2?p/kBTc stays large even in the highly overdoped phase. We also present preliminary results on the temperature dependence of the tunneling spectra. They are consistent with a gap that is largely independent on temperature up to the vicinity of Tc

Scanning Tunneling Spectroscopy (STS) measurements have been carried out on the high Tc superconductor (HTS) YBa2Cu3O7-d (YBCO). Using very high quality single crystals as well as hard tips, we obtained differential conductance spectra which showed various conductance features in agreement with other spectroscopic techniques. The reproducibility of our spectra allowed us to map for the first time the vortex lattice on a HTS using a STS technique1. The vortices are arranged in a short range order oblique lattice, while the cores of the flux lines show an anisotropic shape. These observations can be related to the in-plane anisotropy of YBCO.