The chemistry of the binding of 14C-benzylpenicillin to sporulating cultures of Bacillus megaterium and B. subtilis is similar to that in a 4-hr vegetative culture of Staphylococcus aureus. Unlabeled penicillins prevent the binding of 14C-benzylpenicillin, but benzylpenicilloic acid and benzylpenilloic acid do not. Bound antibiotic can be removed from cells with neutral hydroxylamine at 25 C. Sporulating cultures display two intervals of enhanced binding, whereas binding to stationaryphase S. aureus cells remains constant. The first period of increased binding activity occurs during formation of the spore septum or cell wall primordium development, and the second coincides with cortex biosynthesis.

This paper examines the results obtained by simulating an aircraft navigation system with a partial complement of a typical avionics Sensor array using two different techniques of estimation processes: the conventional Kalman and the federated filter architectures. Areas of interest include error state estimation accuracy, residual behavior under induced Sensor failure conditions, and potential for failure detection and isolation. Several simulations were accomplished for each filter design and the results were compared in order to verify the validity of the recently developed federated filter architecture. Comparison of the error state estimation accuracies of the two filter designs revealed excellent overall performances for both. The identification of failures showed a definite advantage in the federated filter design. Having Sensordedicated local filters allowed for easy sensor failure identification for the federated filter, while the centralized filter design suffered from navigation solution conuption. Once established as a valuable estimation technique, the federated filter will add significantly to the viable alternatives when choosing a filter architecture for avionics modifications or implementations.

Benzylpenicillin inhibits the development of the forespore septum in sporulating Bacillus megaterium cells. The inhibitory effect is a function of the duration of exposure to the antibiotic and is completely reversible by penicillinase. Under the incubation conditions employed, less than 20% of the covalently bound antibiotic is released from the cells. The penicillin which remains bound to the cells after treatment with penicillinase may be necessary but is not sufficient for the effect; unbound antibiotic in the sporulation medium is also required.

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The specific penicillin binding capacity of a postexponential culture of Staphylococcus aureus remains constant, but that of a sporulating Bacillus