Eric Heinemeyer

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For a nonlocally perturbed half-space we consider the scattering of time-harmonic acoustic waves. A second kind boundary integral equation formulation is proposed for the sound-soft case, based on a standard ansatz as a combined single-and double-layer potential but replacing the usual fundamental solution of the Helmholtz equation with an appropriate(More)
Guanosine 3'-diphosphate 5'-diphosphate (ppGpp) is rapidly degraded to guanosine 5'-diphosphate (ppG) and probably pyrophosphate by an enzyme present in the ribosomal fraction prepared from spoT+ strains of Escherichia coli. The ppGpp-degrading enzyme was released from the ribosomes during dissociation at low ionic strength. Ribosomes are not essential for(More)
We consider the problem of scattering of time-harmonic acoustic waves by an unbounded sound-soft rough surface. Recently, a Brakhage–Werner type integral equation formulation of this problem has been proposed, based on an ansatz as a combined single-and double-layer potential, but replacing the usual fundamental solution of the Helmholtz equation with an(More)
Degradation of guanosine tetraphosphate (ppGpp) involves an enzyme associated with the ribosomal fraction from spoT+ strains of Escherichia coli. Double-label experiments with pp[3h]gpp, pp[3H]Gpp, or pp[3H]Gpp as substrate strongly suggest that ppG is the degradation product and that the enzyme releases two phosphates coordinately from the 3' position of(More)
Salmonella contamination of North Sea water was detected for the first time in 1988 in Germany during routine examinations of bathing areas. Since then, subsequent isolations along the coast have been reported regularly. To define the source of contamination, strains isolated from seawater and rivers were studied by molecular marker methods. Their(More)
During monitoring of bathing areas on the German North Sea coast, 24 strains of V. parahaemolyticus were obtained from 32 water samples. The similarity of these strains to 80 V. parahaemolyticus strains isolated in Togo (patients and environment) and Peru (environment), respectively, was studied using 53 tests (fermentation of carbohydrates, decarboxylation(More)