[Isolated uncertain tympanic membrane findings. Central site of tympanic membrane cholesteatomas]

[Principles of cholesteatoma surgery]

As a potentially life-threatening disease, cholesteatoma of the petrous bone generally requires a surgical approach. Surgery aims to produce an ear that is easy to care for and is free of recurrent or residual cholesteatoma. Hearing improvement is of secondary importance. Nevertheless the sound conduction system is generally reconstructed as a single-stage procedure. There are various possible methods of dealing with a cholesteatoma: (i) preserving or reconstructing the posterior meatal wall with an aerated mastoid (closed technique) or obliteration of the mastoid completely or partially after removal of the posterior wall (closed technique); and (ii) leaving the cavity open for inspection (open technique). In our opinion any technique where the mastoid is not open for inspection should be called a closed technique. Both techniques have their specific advantages and disadvantages.

Dark energy: recent observations and future prospects

Dark energy presents us with a challenging puzzle: understanding the new physics seen in the acceleration of the expansion of the Universe. Measurements using type-Ia supernovae (SNe) first detected this acceleration, and this approach remains the most direct route to studying the details of the Universe's expansion history that can teach us more about the nature of the dark energy. Such measurements are, however, extremely demanding in both precision and accuracy, since the different dark-energy models predict very small differences in the expansion history. While several cosmological probes may reach the required statistical uncertainties, the key measurement limit will be the systematic uncertainty. The supernova-measurement approach has the advantage of well-studied systematic uncertainties, allowing a next-generation experiment to be pursued. We briefly review the progress to date and examine the promise of future surveys with large numbers of SNe and well-bounded systematics.