@article{SponslerKallnikRequieretal.2022, author = {Sponsler, Douglas and Kallnik, Katharina and Requier, Fabrice and Classen, Alice and Maihoff, A. Fabienne and Sieger, Johanna and Steffan-Dewenter, Ingolf}, title = {Floral preferences of mountain bumble bees are constrained by functional traits but flexible through elevation and season}, series = {Oikos}, volume = {2022}, journal = {Oikos}, number = {3}, doi = {10.1111/oik.08902}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259653}, year = {2022}, abstract = {Patterns of resource use by animals can clarify how ecological communities have assembled in the past, how they currently function and how they are likely to respond to future perturbations. Bumble bees (Hymentoptera: Bombus spp.) and their floral hosts provide a diverse yet tractable system in which to explore resource selection in the context of plant-pollinator networks. Under conditions of resource limitation, the ability of bumble bees species to coexist should depend on dietary niche overlap. In this study, we report patterns and dynamics of floral morphotype preferences in a mountain bumble bee community based on ~13 000 observations of bumble bee floral visits recorded along a 1400 m elevation gradient. We found that bumble bees are highly selective generalists, rarely visiting floral morphotypes at the rates predicted by their relative abundances. Preferences also differed markedly across bumble bee species, and these differences were well-explained by variation in bumble bee tongue length, generating patterns of preference similarity that should be expected to predict competition under conditions of resource limitation. Within species, though, morphotype preferences varied by elevation and season, possibly representing adaptive flexibility in response to the high elevational and seasonal turnover of mountain floral communities. Patterns of resource partitioning among bumble bee communities may determine which species can coexist under the altered distributions of bumble bees and their floral hosts caused by climate and land use change.}, language = {en} } @article{HornMitesserHovestadtetal.2019, author = {Horn, Melanie and Mitesser, Oliver and Hovestadt, Thomas and Yoshii, Taishi and Rieger, Dirk and Helfrich-F{\"o}rster, Charlotte}, title = {The circadian clock improves fitness in the fruit fly, Drosophila melanogaster}, series = {Frontiers in Physiology}, volume = {10}, journal = {Frontiers in Physiology}, number = {1374}, issn = {1664-042X}, doi = {10.3389/fphys.2019.01374}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195738}, year = {2019}, abstract = {It is assumed that a properly timed circadian clock enhances fitness, but only few studies have truly demonstrated this in animals. We raised each of the three classical Drosophila period mutants for >50 generations in the laboratory in competition with wildtype flies. The populations were either kept under a conventional 24-h day or under cycles that matched the mutant's natural cycle, i.e., a 19-h day in the case of pers mutants and a 29-h day for perl mutants. The arrhythmic per0 mutants were grown together with wildtype flies under constant light that renders wildtype flies similar arrhythmic as the mutants. In addition, the mutants had to compete with wildtype flies for two summers in two consecutive years under outdoor conditions. We found that wildtype flies quickly outcompeted the mutant flies under the 24-h laboratory day and under outdoor conditions, but perl mutants persisted and even outnumbered the wildtype flies under the 29-h day in the laboratory. In contrast, pers and per0 mutants did not win against wildtype flies under the 19-h day and constant light, respectively. Our results demonstrate that wildtype flies have a clear fitness advantage in terms of fertility and offspring survival over the period mutants and - as revealed for perl mutants - this advantage appears maximal when the endogenous period resonates with the period of the environment. However, the experiments indicate that perl and pers persist at low frequencies in the population even under the 24-h day. This may be a consequence of a certain mating preference of wildtype and heterozygous females for mutant males and time differences in activity patterns between wildtype and mutants.}, language = {en} } @article{SeibtMuehlbergerLikowskietal.2015, author = {Seibt, Beate and M{\"u}hlberger, Andreas and Likowski, Katja U. and Weyers, Peter}, title = {Facial mimicry in its social setting}, series = {Frontiers in Psychology}, volume = {6}, journal = {Frontiers in Psychology}, number = {1122}, doi = {10.3389/fpsyg.2015.01122}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151415}, year = {2015}, abstract = {In interpersonal encounters, individuals often exhibit changes in their own facial expressions in response to emotional expressions of another person. Such changes are often called facial mimicry. While this tendency first appeared to be an automatic tendency of the perceiver to show the same emotional expression as the sender, evidence is now accumulating that situation, person, and relationship jointly determine whether and for which emotions such congruent facial behavior is shown. We review the evidence regarding the moderating influence of such factors on facial mimicry with a focus on understanding the meaning of facial responses to emotional expressions in a particular constellation. From this, we derive recommendations for a research agenda with a stronger focus on the most common forms of encounters, actual interactions with known others, and on assessing potential mediators of facial mimicry. We conclude that facial mimicry is modulated by many factors: attention deployment and sensitivity, detection of valence, emotional feelings, and social motivations. We posit that these are the more proximal causes of changes in facial mimicry due to changes in its social setting.}, language = {en} } @article{ZinnerSperlichWahletal.2015, author = {Zinner, Christoph and Sperlich, Billy and Wahl, Patrick and Mester, Joachim}, title = {Classification of selected cardiopulmonary variables of elite athletes of different age, gender, and disciplines during incremental exercise testing}, series = {SpringerPlus}, volume = {4}, journal = {SpringerPlus}, number = {544}, doi = {10.1186/s40064-015-1341-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126275}, year = {2015}, abstract = {Incremental exercise testing is frequently used as a tool for evaluating determinants of endurance performance. The available reference values for the peak oxygen uptake \((VO_{2peak})\), \% of \(VO_{2peak}\) , running speed at the lactate threshold \((v_{LT})\), running economy (RE), and maximal running speed \((v_{peak})\) for different age, gender, and disciplines are not sufficient for the elite athletic population. The key variables of 491 young athletes (age range 12-21 years; 250 males, 241 females) assessed during a running step test protocol \((2.4 m s^{-1} ; increase 0.4 m s^{-1} 5 min^{-1})\) were analysed in five subgroups, which were related to combat-, team-, endurance-, sprint- and power-, and racquet-related disciplines. Compared with female athletes, male athletes achieved a higher \(v_{peak}\) (P = 0.004). The body mass, lean body mass, height, abs. \(VO_{2peak} (ml min^{-1})\), rel. \(VO_{2peak} (ml kg^{-1} min^{-1})\), rel. \(VO_{2peak} (ml min^{-1} kg^{-0.75})\), and RE were higher in the male participants compared with the females (P < 0.01). The \% of \(VO_2\) at \(v_{LT}\) was lower in the males compared with the females (P < 0.01). No differences between gender were detected for the \(v_{LT}\) (P = 0.17) and \% of \(VO_2\) at \(v_{LT}\) (P = 0.42). This study is one of the first to provide a broad spectrum of data to classify nearly 500 elite athletes aged 12-21 years of both gender and different disciplines.}, language = {en} } @article{HovestadtPoethkeMessner2000, author = {Hovestadt, Thomas and Poethke, Hans J. and Messner, Stefan}, title = {Variability in dispersal distances generates typical successional patterns: a simple simulation model}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48178}, year = {2000}, abstract = {More recently, it became clear that conclusions drawn from traditional ecological theory may be altered substantially if the spatial dimension of species interactions is considered explicitly. Regardless of the details of these models, spatially explicit simulations of ecological processes have nearly universally shown that spatial or spatio-temporal patterns in species distributions can emerge even from homogeneous starting conditions; limited dispersal is one of the key factors responsible for the development of such aggregated and patchy distributions (cf., Pacala 1986, Holmes et al. 1994, Molofsky 1994, Tilman 1994, Bascompte and Sole 1995, 1997, 1998, Jeltsch et al. 1999). In line with these ideas, we wish to draw attention to the fact that in heterogeneous landscapes differences in characteristic dispersal distances between species are a sufficient precondition for the emergence of a successional pattern. We will use a simple, spatially explicit simulation program to demonstrate the validity of this statement. We will also show that the speed of the successional progress depends on scale and heterogeneity in the distribution of suitable habitat.}, language = {en} }