Alfred Seiler

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The opc gene is widespread in epidemic and endemic Neisseria meningitidis, but most strains of certain epidemic clones (ET-37 complex, Cluster A4) and a few random endemic isolates lack an opc gene. Four percent of the 1148 bp that contain opc plus the surrounding intergenic region was polymorphic (18 alleles), and many of the alleles contained a 230 bp(More)
Opacity (Opa) proteins are a family of antigenically variable outer-membrane proteins of Neisseria meningitidis. Even among clonally related epidemic meningococcal isolates, there is greater variation of Opa protein expression than can be accounted for by the opa gene repertoire of any individual strain. We characterized the opa genes of eight closely(More)
A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a(More)
One of the key components of a superconducting insertion device is the ultra-high vacuum (UHV) chamber. In order to reach the UHV specifications of the ANKA storage ring, it is very important to control the surface chemical composition and find proper cleaning procedures. To keep the geometric and resistive wall losses caused by the electron beam of the(More)
Serogroup A meningococci of subgroups III, IV-1 and IV-2 are probably descended from a common ancestor that existed in the nineteenth century. The 10.5kb sequences spanning five distinct chromosomal loci, encoding cell-surface antigens, a secreted protease or housekeeping genes and intergenic regions, were almost identical in strains of those subgroups(More)
Multiresistant Salmonella dublin strains isolated between 1971 to 1984 were investigated for their genetic and physical properties. It turned out that the multiresistance of the 1971 to 1973 isolates was plasmid-encoded. In the following years, however, the plasmid profiles of the strains were indistinguishable from sensitive isolates and the genes encoding(More)
Ambystoma tigrinum virus (ATV) is a lethal virus originally isolated from Sonora tiger salamanders Ambystoma tigrinum stebbinsi in the San Rafael Valley in southern Arizona. USA. ATV is implicated in several salamander epizootics. We attempted to transmit ATV experimentally to fish and amphibians by injection, water bath exposure, or feeding to test whether(More)
The principles of molecular biological methods for epidemiological investigation of infectious bacteria are described. They were applied for differentiating S. enteritidis isolates originating from poultry. Among the methods described are the determination of the chromosomal DNA fingerprints (BRENDA), the methods of multilocus enzyme electrophoresis,(More)
The title phase, first detected in the early 1980s but hitherto unpublished, has been resynthesized and structurally characterized. Unambiguous determination of the chemical composition was not possible by structure analysis alone, but required additional analytical methods. The complex structure shows a close similarity to the structures of two related(More)
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