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This article in the journal Gruppe. Interaktion. Organization (GIO) deals with the application of the theory of functional psycho-dynamic positions by Raoul Schindler on problem-solving groups. Until now, there has been no empirical research substantiating this model and the emergence of the group positions. To do so, the relationship between the functional group positions and members’ contact behavior was examined with a sociometrical approach. A study with 138 participants from 22 groups was conducted. The results clearly confirm the model and show typical contact behavior patterns for each group position. Finally, types of informal group structures were compared in regards to group performance and practical applications for agile teams and shared leadership., Peer Reviewed

Mother–calf interactions and the behaviors of mothers during separation from their calves were examined in four Commerson’s dolphin (Cephalorhynchus commersonii) mother–calf pairs. Four infants were observed: 56.8 h over 30 days from birth to 263 days of age, 36.9 h over 20 days from birth to 149 days of age, 10.4 h over 3 days from birth to 2 days of age, and 15.0 h over 3 days from birth to 2 days of age. All four pairs shared common characteristics in the rate and frequencies of mother–calf interactions and the behaviors of mothers during the first week of life. After the first week, individual differences in changes in the frequency of each behavior were observed. The three behaviors considered representative of maternal care (parallel swimming, synchronous breathing, and body-to-body contact) were frequently performed in the first week; thereafter, the frequencies declined. Separate behaviors of mothers were infrequent during the first week and increased with an increase in infants’ age. Bumping by infants increased with time, suggesting an increase in soliciting by calves and conflict between mothers and calves. The frequency of flipper-to-body rubbing also changed but in a complex manner, probably because the calves needed to learn how to perform this behavior from their mothers and because initiator and recipient of this behavior can be changed quickly.

Dowel-type steel-to-timber connections are commonly used to transfer a large range of loads. Although they are simple to produce and assemble, the load-carrying behavior and the local stress and strain distribution within the connection area are highly complex. In addition to that, wood is a challenging material from an engineering point of view due to its highly anisotropic structure and behavior and due to its natural origin, which results often in inhomogeneities. The failure characteristics of wood are very different in tension and shear and in compression, where brittle failure and plastic-ductile failure modes occur, respectively. The aim of this thesis is to study the load-carrying behavior of dowel-type steel-to-timber connections in detail. This is achieved by performing experimental tests on single-dowel connections. A large variety of influencing parameters is assessed, which include wood density, connection width, the dowel roughness, and the application of reinforcements in order to prevent brittle behavior. Separate stages in the loading history are identified, starting from an initial consolidation phase, the region of maximum stiffness during load increase, and the point of maximum connection strength. Ductility is of great interest as well as the final failure modes. During the experiments, unloading and reloading cycles are performed, where distinctively higher stiffnesses are observed than during the first loading. The results of the experiments are compared to the design practice in Eurocode 5 for strength and stiffness estimation. Strength prediction is conservative except for slender connections, while stiffness prediction complied with experimental results only for connections of intermediate width. The initial consolidation phase of the experiments is then investigated further. It is concluded, that the properties of the bore-hole surface, where not a smooth but a rough surface with valleys and rifts is encountered, is responsible for the ini