@article{RocesPielstroem2014, author = {Roces, Flavio and Pielstr{\"o}m, Steffen}, title = {Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest}, doi = {10.1371/journal.pone.0095658}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111298}, year = {2014}, abstract = {The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.}, language = {en} } @article{BatschingWolfHeisenberg2016, author = {Batsching, Sophie and Wolf, Reinhard and Heisenberg, Martin}, title = {Inescapable Stress Changes Walking Behavior in Flies - Learned Helplessness Revisited}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0167066}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178640}, year = {2016}, abstract = {Like other animals flies develop a state of learned helplessness in response to unescapable aversive events. To show this, two flies, one 'master', one 'yoked', are each confined to a dark, small chamber and exposed to the same sequence of mild electric shocks. Both receive these shocks when the master fly stops walking for more than a second. Behavior in the two animals is differently affected by the shocks. Yoked flies are transiently impaired in place learning and take longer than master flies to exit from the chamber towards light. After the treatment they walk more slowly and take fewer and shorter walking bouts. The low activity is attributed to the fly's experience that its escape response, an innate behavior to terminate the electric shocks, does not help anymore. Earlier studies using heat pulses instead of electric shocks had shown similar effects. This parallel supports the interpretation that it is the uncontrollability that induces the state.}, language = {en} } @phdthesis{Hellmuth2008, author = {Hellmuth, Hans-J{\"o}rg}, title = {Diagnostik und Pr{\"a}vention von R{\"u}ckenleiden bei Hubschrauberbesatzungen der Bundeswehr auf Bell UH1D : Differenzierung und Pr{\"a}vention von R{\"u}ckenleiden und m{\"o}glichen Berufskrankheiten}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32745}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Ziel dieser Arbeit war es zu erforschen, ob mittels einer strukturierten Anamnese und einer intensiven manueller Untersuchung ein Weg zur Pr{\"a}vention von R{\"u}ckenschmerzen und einer m{\"o}glicherweise daraus resultierenden Berufskrankheit zu finden ist. Je 20 m{\"a}nnliche Hubschrauberpiloten und Bordmechaniker des Transporthubschrauberregimentes 30 im Alter von 25-50 Jahren bildeten die Untersuchungsgruppen. Sie alle sind Teil der Besatzungen auf der Bell UH-1D, einem seit 1965 in der Bundeswehr ein-gef{\"u}hrtem Hubschrauber mit einem Triebwerk und 2 Rotorbl{\"a}ttern, wodurch sehr starke und niederfrequente Vibrationen erzeugt werden. Grundlagen der Untersuchungen waren ein validierter und standardisierter Erhebungsbogen, eine umfassende manuelle Untersuchungstechnik sowie eine genaue Kenntnis der Arbeitspl{\"a}tze von und Anforderungen an Hubschrauberbesatzungen des Heeres auf Bell UH-1D. Die Untersuchungen erfolgten jeweils ohne Kenntnis der Anamnese nach den vorgegebenen Schritten des Untersuchungsbogens}, subject = {Kreuzschmerz}, language = {de} }