Magellanic Clouds PNe line intensities

For the visible spectra with highest S/N, line intensities have been measured to a few tenths of a percent of H_{beta}_. UV spectra are used for the determination of carbon abundances.

This paper discusses the CNO cycle and its implications. We show that the CN or ON cycles are more effective with lower initial metallicities and are always complete for typeI nebulae. The latter cannot easily be distinguished from non-type I PNe on the basis of N or He abundance alone, as continuity exists in all of the standard diagrams.