We present new spectroscopic observations of WC9 stars. As predicted by Williams & van der Hucht (2000), O II lines are weak in the dust-free star WR 88, which also shows a high ionization. Spectral variability is detected in WR 106 and WR 121. These findings are briefly discussed in terms of the conditions for dust formation in Wolf-Rayet winds.

We report on the in-orbit calibration of staring and chopped observations performed with the spectrophotometer ISOPHOT-S. Staring observations are calibrated using a Spectral Response Function which depends both on the signal and the elapsed observing time. Chopped observations are calibrated with a signal dependent Spectral Response Function

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We propose a systematic study of the environments of a representative sample of Radio Loud Quasars (RLQ) and Radio Quiet Quasars (RQQ) in two different redshift ranges: z˜3.1 and z˜4. These redshift ranges are optimal for the study of environment evolution in the early universe. Furthermore, the sample of RLQ and RQQ are designed to disentangle the

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