At the end of April 1986 reactor number 4 of the nuclear power plant at Chernobyl explod-ed and large amounts of radioactive particles were then released into the atmosphere due to both the explosion as well as the consecutive fire of the graphite core. A cloud of radioac-tivity was spread over the northern hemisphere, including Sweden, due to the prevailing wind directions. The radioactive particles were washed out from the cloud by rain and snowfall in some areas of Sweden and deposited on the ground. The deposited radionu-clides, primarily cesium and iodine isotopes, were later absorbed into the soil and taken up by the roots of the plants. Some of these radionuclides, like 137Cs, still persist in some of the terrestrial ecosystems at relatively high concentrations which lead to contamination of the meat of moose, roe deer and wild boar even today.The two municipalities Heby and Uppsala, in the eastern part of central Sweden, experi-enced a relatively large deposition of 137Cs which resulted in high levels of 137Cs in moose and other game.

As birch is one of the most common trees in Sweden, and probably one of the easiest for someone who lives here to identify, it is interesting to note that most people do not know how variable the genus is and how widely it is distributed across the northern hemisphere. One can find birch growing at both high and low elevations, demanding different soil conditions and preferring varying amounts of sunlight. Many people may also be surprised to hear that the colour of the bark can vary from bight white to almost black, and different shades of pink, orange and red can also be displayed. This, together with the astonishing beauty of the genus, the important role as a pioneer in many ecological systems and the difficulty in sorting out the taxonomy of the genus, constitutes the background of this thesis. The thesis is written at the Department of Landscape Development in Alnarp, Sweden with Kenneth Lorentzon, researcher at the Swedish University of Agriculture as a supervisor. The aim of this thesis is to highlight which species and cultivars within the genus Betula could be appropriate for horticultural use in Sweden.

Title: Brain Gym®? An approach to increase self-knowledge in situations of learning?- A study at the Malmö Academy of Music from a teacher and student perspective. Brain Gym® is a method developed by Paul Dennison in his studies of physiology and aims to eliminate potential blockages during the process of learning. During the influence of stress, as in learning, we do not possess a total access to our perceptive ability. Instead we are limited to our so called dominance profile.