Abstract: A device is dedicated to generating integrity messages relating to at least one satellite navigation system including a set of satellite surveillance stations and to be sent to navigation receivers. The device comprises processor means responsible for determining at chosen times the stations that are active (i.e. nominal or degraded) for each system concerned and, after each such determination, for generating an integrity message including at least primary data representative of the active (i.e. nominal or degraded) stations. The processor means are also responsible, each time they detect that at least one station has become degraded or inactive between two successive chosen times, for generating an integrity alert message including at least primary data representative of each station that has become degraded or inactive.

Abstract: In the preparation of vincadifformine and derivatives thereof, such as 3-oxo-1,2-dehydroaspidospermidine and 1,2-dehydro-aspidospermidine, 2-hydroxy-tryptamine or a derivative thereof substituted in the benzene ring is condensed with dimethyl 4-ethyl-4-formyl-pimelate to form an oxindolic lactam-ester as the first step of the process. By means of this process, vincadifformine and its derivatives can be obtained in a smaller number of steps than in known processes.