In school teachers, burnout syndrome, a construct that derived from occupational psychology and occupational medicine, is significantly correlated with psychological and psychosomatic symptoms. Teachers rate destructive and aggressive behaviour of pupils as the primary stress factor.

At present, the working situation of teachers appears to be characterized by a perceived imbalance of effort and reward and is associated with a high risk of developing burnout symptoms.

To be a teacher is a hard work and requires coping of considerable amount of adverse events. Based on the GHQ, nearly 30% of teachers suffer from significant mental health problems.

In the strong Coulomb field of a nucleus or quasimolecule with Z > 172 a change of the QED vacuum has been predicted, signalled by the spontaneous emission of positrons if holes in the K-shell are available. The dynamical semiclassical theory of positron excitation in heavy ion scattering is presented and extended to collisions with nuclear contact. Interference patterns in the energy spectrum of the emitted positrons and, for sufficiently long reaction time T, the emerging of a characteristic line at the position of the lsa-resonance is predicted. The position and width of the lsa-resonance is calculated in dependence on the nuclear configuration, the effect of electron screening is taken into account. Recent experimental indications [1,2] for structures in the spectra of positrons emitted in U-U collisions at energies close to the Coulomb barrier are discussed in terms of spontaneous positron creation. The observed spectra could be explained under the assumption of long lasting nuclear reactions (T >4-10 .2o s) with a cross section in the millibarn region. Various consequences of this interpretation are discussed.

Positron creation in crossed-beam collisions of high-energy, fully stripped heavy ions is investigated within the coupled-channel formalism. In comparison with fixed-target collisions of highly stripped heavy-ion projectiles positron production probabilities are enhanced by more than one order of magnitude. The increase results from the possibility to excite electrons from the negative energy continuum into all bound states. The positron spectrum is shifted towards higher energies because of the absence of electron screening. Rutherford scattering as well as nuclear collisions with time delay are investigated. We also discuss the filling of empty bound states by electrons from pair-production processes.