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We consider the problem of determining the Robin coefficient of some specimen material, by performing measurements on some part of the boundary. An identifiability result is proved for Robin coefficients which are continuous functions with some negative lower bound. Both local and monotone global Lipschitz stability results are established. Finally, a cost function turning the inverse problem into an optimization one is proposed for numerical purposes. This function, which may be viewed as an energetic least-squares one, has an easy-to-compute Gderivative, which encourages us to consider implementing the gradient algorithm in forthcoming numerical experiments.

We are interested in this paper in recovering lacking data on some part of a domain boundary, from the knowledge of Cauchy data on the other part. It is first proved that the desired solution is the unique fixed point of some appropriate operator, which naturally gives rise to an iterative process that is proved to be convergent. Discretization provides an additional regularization: the algorithm reads as a least square fitting of the given data, with a regularization term the effect of which fades as iterations go on. Displayed numerical results highlight its accuracy, as well as its robustness.

Aims: Detection and identification of new antagonistic activities towards Bacillus cereus and relatives. Methods and Results: Twenty Bacillus thuringiensis strains were screened for their capacity to express bacteriocin‐like agents. Strain BMG1.7, isolated from soil, showed an antagonistic activity called thuricin 7. Thuricin 7 was active against several species of the genus Bacillus, including three of the four known B. thuringiensis/B. cereus bacteriocin producers, as well as against Streptococcus pyogenes and Listeria monocytogenes strains. Antimicrobial activity was lost after treatment with proteinase K. The active protein had an apparent molecular weight of 11·6 kDa, and was secreted at the end of the exponential growth phase. Thuricin 7 retained 55% of the activity after incubation at 98°C for 30 min. The mode of action of thuricin 7 was shown to be bactericidal and bacteriolytic. Conclusions: Thuricin 7 is a novel bacteriocin produced by a newly isolated Bacillus thuringiensis strain BMG1.7. Significance and Impact of the Study: The characteristics of thuricin 7 indicate that it is a new bacteriocin which may have interesting biotechnological applications due to its relatively large activity spectrum.

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