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OBJECTIVES The authors aimed at investigating the occurrence of depression and the level of quality of life in patients with amyotrophic lateral sclerosis (ALS), an incurable neurodegenerative disease leading to progressive motor paralysis. They further wished to elucidate correlates of depression and quality of life, such as physical impairment, time since(More)
Successional phases describe changes in ecological communities that proceed in steps rather than continuously. Despite their importance for the understanding of ecosystem development, there still exists no reliable definition of phases and no quantitative measure of phase transitions. In order to obtain these data, we investigated primary succession in an(More)
During early plant succession, the phylogenetic structure of a community changes in response to important environmental filters and emerging species interactions. We traced the development of temperate-zone plant communities during the first 7 years of primary succession on catchment soils to explore patterns of initial species assembly. We found pronounced(More)
We developed a fast and robust algorithm to register intraoperative three dimensional ultrasound data of the spine with preoperative CT data. We compared different gradient based and evolutionary optimization strategies for solving the registration problem. The iRprop, a fast gradient based optimization algorithm, quickly and reliably led to higher(More)
We studied the effects of transcranial magnetic stimulation (TMS) on slow cortical potentials (SCPs) of the brain elicited during performance of a feedback and reward task. Ten healthy participants were trained to self-regulate their SCP amplitude using visual feedback and reward for increased or decreased amplitudes. Subjects participated in 27 runs (each(More)
Computer based navigated surgery assists the spatial orientation of the surgeon. Our system registers preoperative data like CT or MR with intraoperative ultrasound data to get the coordinate transformation between the preoperative and the intraoperative data. With a surface volume registration we avoid a difficult surface segmentation in the ultrasound(More)
For many navigated surgical procedures, the precise registration of preoperative data sets with bones of the patient is an important requisite. Conventional navigation systems use paired point registration based on anatomical landmarks or fiducial markers. This approach increases the invasiveness, since landmarks must be exposed and fiducial markers must be(More)
Zusammenfassung. Ein zentrales Problem in der bildgestützten, na-vigierten Chirurgie ist die exakte Registrierung präoperativer CT/MR-Daten im Koordinatensystem des Operationssaales. Um die Nachteile einer landmarkenbasierten Registrierung zu umgehen, dient bei unse-rem Ansatz 3-dimensionaler, intraoperativer Ultraschall zur Registrie-rung. Ein(More)