@article{Omel'chenko2022,
  author    = {Omel'chenko, Oleh},
  title     = {Mathematical framework for breathing chimera states},
  series = {Journal of nonlinear science},
  volume    = {32},
  journal   = {Journal of nonlinear science},
  number    = {2},
  publisher = {Springer},
  address   = {New York},
  issn      = {0938-8974},
  doi       = {10.1007/s00332-021-09779-1},
  pages     = {34},
  year      = {2022},
  abstract  = {About two decades ago it was discovered that systems of nonlocally coupled oscillators can exhibit unusual symmetry-breaking patterns composed of coherent and incoherent regions. Since then such patterns, called chimera states, have been the subject of intensive study but mostly in the stationary case when the coarse-grained system dynamics remains unchanged over time. Nonstationary coherence-incoherence patterns, in particular periodically breathing chimera states, were also reported, however not investigated systematically because of their complexity. In this paper we suggest a semi-analytic solution to the above problem providing a mathematical framework for the analysis of breathing chimera states in a ring of nonlocally coupled phase oscillators. Our approach relies on the consideration of an integro-differential equation describing the long-term coarse-grained dynamics of the oscillator system. For this equation we specify a class of solutions relevant to breathing chimera states. We derive a self-consistency equation for these solutions and carry out their stability analysis. We show that our approach correctly predicts macroscopic features of breathing chimera states. Moreover, we point out its potential application to other models which can be studied using the Ott-Antonsen reduction technique.},
  language  = {en}
}
@article{StarkBachGuill2021,
  author    = {Stark, Markus and Bach, Moritz and Guill, Christian},
  title     = {Patch isolation and periodic environmental disturbances have idiosyncratic effects on local and regional population variabilities in meta-food chains},
  series = {Theoretical ecology},
  volume    = {14},
  journal   = {Theoretical ecology},
  number    = {3},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1874-1738},
  doi       = {10.1007/s12080-021-00510-0},
  pages     = {489 -- 500},
  year      = {2021},
  abstract  = {While habitat loss is a known key driver of biodiversity decline, the impact of other landscape properties, such as patch isolation, is far less clear. When patch isolation is low, species may benefit from a broader range of foraging opportunities, but are at the same time adversely affected by higher predation pressure from mobile predators. Although previous approaches have successfully linked such effects to biodiversity, their impact on local and metapopulation dynamics has largely been ignored. Since population dynamics may also be affected by environmental disturbances that temporally change the degree of patch isolation, such as periodic changes in habitat availability, accurate assessment of its link with isolation is highly challenging. To analyze the effect of patch isolation on the population dynamics on different spatial scales, we simulate a three-species meta-food chain on complex networks of habitat patches and assess the average variability of local populations and metapopulations, as well as the level of synchronization among patches. To evaluate the impact of periodic environmental disturbances, we contrast simulations of static landscapes with simulations of dynamic landscapes in which 30 percent of the patches periodically become unavailable as habitat. We find that increasing mean patch isolation often leads to more asynchronous population dynamics, depending on the parameterization of the food chain. However, local population variability also increases due to indirect effects of increased dispersal mortality at high mean patch isolation, consequently destabilizing metapopulation dynamics and increasing extinction risk. In dynamic landscapes, periodic changes of patch availability on a timescale much slower than ecological interactions often fully synchronize the dynamics. Further, these changes not only increase the variability of local populations and metapopulations, but also mostly overrule the effects of mean patch isolation. This may explain the often small and inconclusive impact of mean patch isolation in natural ecosystems.},
  language  = {en}
}
@article{GaertnerBrunner2018,
  author    = {G{\"a}rtner, Holger and Brunner, Martin},
  title     = {Once good teaching, always good teaching?},
  series = {Educational Assessment, Evaluation and Accountability},
  volume    = {30},
  journal   = {Educational Assessment, Evaluation and Accountability},
  number    = {2},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1874-8597},
  doi       = {10.1007/s11092-018-9277-5},
  pages     = {159 -- 182},
  year      = {2018},
  abstract  = {In many countries, students are asked about their perceptions of teaching in order to make decisions about the further development of teaching practices on the basis of this feedback. The stability of this measurement of teaching quality is a prerequisite for the ability to generalize the results to other teaching situations. The present study aims to expand the extant empirical body of knowledge on the effects of situational factors on the stability of students' perceptions of teaching quality. Therefore, we investigate whether the degree of stability is moderated by three situational factors: time between assessments, subjects taught by teachers, and students' grade levels. To this end, we analyzed data from a web-based student feedback system. The study involved 497 teachers, each of whom conducted two student surveys. We examined the differential stability of student perceptions of 16 teaching constructs that were operationalized as latent correlations between aggregated student perceptions of the same teacher's teaching. Testing metric invariance indicated that student ratings provided measures of teaching constructs that were invariant across time, subjects, and grade levels. Stability was moderated to some extent by grade level but not by subjects taught nor time spacing between surveys. The results provide evidence of the extent to which situational factors may affect the stability of student perceptions of teaching constructs. The generalizability of the students' feedback results to other teaching situations is discussed.},
  language  = {en}
}
@article{AppiahDwomohMuellerMayer2018,
  author    = {Appiah-Dwomoh, Edem Korkor and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Reproducibility of Static and Dynamic Postural Control Measurement in Adolescent Athletes with Back Pain},
  series = {Rehabilitation Research and Practice},
  volume    = {2018},
  journal   = {Rehabilitation Research and Practice},
  publisher = {Hindawi},
  address   = {New York},
  issn      = {2090-2875},
  doi       = {10.1155/2018/8438350},
  pages     = {1 -- 8},
  year      = {2018},
  abstract  = {Static (one-legged stance) and dynamic (star excursion balance) postural control tests were performed by 14 adolescent athletes with and 17 without back pain to determine reproducibility. The total displacement, mediolateral and anterior-posterior displacements of the centre of pressure in mm for the static, and the normalized and composite reach distances for the dynamic tests were analysed. Intraclass correlation coefficients, 95\% confidence intervals, and a Bland-Altman analysis were calculated for reproducibility. Intraclass correlation coefficients for subjects with (0.54 to 0.65), (0.61 to 0.69) and without (0.45 to 0.49), (0.52 to 0.60) back pain were obtained on the static test for right and left legs, respectively. Likewise, (0.79 to 0.88), (0.75 to 0.93) for subjects with and (0.61 to 0.82), (0.60 to 0.85) for those without back pain were obtained on the dynamic test for the right and left legs, respectively. Systematic bias was not observed between test and retest of subjects on both static and dynamic tests. The one-legged stance and star excursion balance tests have fair to excellent reliabilities on measures of postural control in adolescent athletes with and without back pain. They can be used as measures of postural control in adolescent athletes with and without back pain.},
  language  = {en}
}
@misc{AppiahDwomohMuellerMayer2018,
  author    = {Appiah-Dwomoh, Edem Korkor and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Reproducibility of Static and Dynamic Postural Control Measurement in Adolescent Athletes with Back Pain},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {470},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417526},
  pages     = {8},
  year      = {2018},
  abstract  = {Static (one-legged stance) and dynamic (star excursion balance) postural control tests were performed by 14 adolescent athletes with and 17 without back pain to determine reproducibility. The total displacement, mediolateral and anterior-posterior displacements of the centre of pressure in mm for the static, and the normalized and composite reach distances for the dynamic tests were analysed. Intraclass correlation coefficients, 95\% confidence intervals, and a Bland-Altman analysis were calculated for reproducibility. Intraclass correlation coefficients for subjects with (0.54 to 0.65), (0.61 to 0.69) and without (0.45 to 0.49), (0.52 to 0.60) back pain were obtained on the static test for right and left legs, respectively. Likewise, (0.79 to 0.88), (0.75 to 0.93) for subjects with and (0.61 to 0.82), (0.60 to 0.85) for those without back pain were obtained on the dynamic test for the right and left legs, respectively. Systematic bias was not observed between test and retest of subjects on both static and dynamic tests. The one-legged stance and star excursion balance tests have fair to excellent reliabilities on measures of postural control in adolescent athletes with and without back pain. They can be used as measures of postural control in adolescent athletes with and without back pain.},
  language  = {en}
}
@article{FredeHenzeKhaliletal.2014,
  author    = {Frede, Katja and Henze, Andrea and Khalil, Mahmoud and Baldermann, Susanne and Schweigert, Florian J. and Rawel, Harshadrai Manilal},
  title     = {Stability and cellular uptake of lutein-loaded emulsions},
  series = {Journal of functional food},
  volume    = {8},
  journal   = {Journal of functional food},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1756-4646},
  doi       = {10.1016/j.jff.2014.03.011},
  pages     = {118 -- 127},
  year      = {2014},
  abstract  = {The carotenoid lutein can improve human health. Since only a fraction is absorbed from food, lutein supplementation might be recommended. Emulsions could be good carrier systems to improve the bioavailability of lutein. Six different emulsifier compositions were used in this study to prepare lutein-loaded emulsions: beta-lactoglobulin, beta-lactoglobulin/lecithin, Biozate 1, Biozate 1/lecithin, Been 20 and Tween 20/lecithin. The droplet size, resistance to creaming, lutein stability, cytotoxicity and lutein uptake by HT29 cells were investigated. The whey protein beta-lactoglobulin, the whey protein hydrolysate Biozate 1 and the combination with lecithin brought the most promising results. The small droplet sizes and resistance to creaming were an indication of physical stable emulsions. Furthermore, these emulsifiers prevented oxidation of lutein. The choice of emulsifier had a strong impact on the uptake by HT29 cells. The highest lutein absorption was observed with the combination of Biozate 1 and lecithin.},
  language  = {en}
}
@article{CurtsdotterBinzerBroseetal.2011,
  author    = {Curtsdotter, Alva and Binzer, Amrei and Brose, Ulrich and de Castro, Francisco and Ebenman, Bo and Ekloef, Anna and Riede, Jens O. and Thierry, Aaron and Rall, Bjoern C.},
  title     = {Robustness to secondary extinctions comparing trait-based sequential deletions in static and dynamic food webs},
  series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie},
  volume    = {12},
  journal   = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie},
  number    = {7},
  publisher = {Elsevier},
  address   = {Jena},
  issn      = {1439-1791},
  doi       = {10.1016/j.baae.2011.09.008},
  pages     = {571 -- 580},
  year      = {2011},
  abstract  = {The loss of species from ecological communities can unleash a cascade of secondary extinctions, the risk and extent of which are likely to depend on the traits of the species that are lost from the community. To identify species traits that have the greatest impact on food web robustness to species loss we here subject allometrically scaled, dynamical food web models to several deletion sequences based on species' connectivity, generality, vulnerability or body mass. Further, to evaluate the relative importance of dynamical to topological effects we compare robustness between dynamical and purely topological models. This comparison reveals that the topological approach overestimates robustness in general and for certain sequences in particular. Top-down directed sequences have no or very low impact on robustness in topological analyses, while the dynamical analysis reveals that they may be as important as high-impact bottom-up directed sequences. Moreover, there are no deletion sequences that result, on average, in no or very few secondary extinctions in the dynamical approach. Instead, the least detrimental sequence in the dynamical approach yields an average robustness similar to the most detrimental (non-basal) deletion sequence in the topological approach. Hence, a topological analysis may lead to erroneous conclusions concerning both the relative and the absolute importance of different species traits for robustness. The dynamical sequential deletion analysis shows that food webs are least robust to the loss of species that have many trophic links or that occupy low trophic levels. In contrast to previous studies we can infer, albeit indirectly, that secondary extinctions were triggered by both bottom-up and top-down cascades.},
  language  = {en}
}
@inproceedings{KhalilIsalmRailaetal.2011,
  author    = {Khalil, Mahomound and Isalm, K. Shaiful and Raila, Jens and Schenk, R. and Rawel, Harshadrai Manilal and Schweigert, Florian J.},
  title     = {Content of lutein and lutein ester in tagetes and improvement of their stability},
  series = {Annals of nutrition \& metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS)},
  volume    = {58},
  booktitle = {Annals of nutrition \& metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS)},
  number    = {3},
  publisher = {Karger},
  address   = {Basel},
  issn      = {0250-6807},
  pages     = {16 -- 16},
  year      = {2011},
  language  = {en}
}
@article{FuerstLevermann2012,
  author    = {F{\"u}rst, Johannes J. and Levermann, Anders},
  title     = {A minimal model for wind- and mixing-driven overturning threshold behavior for both driving mechanisms},
  series = {Climate dynamics : observational, theoretical and computational research on the climate system},
  volume    = {38},
  journal   = {Climate dynamics : observational, theoretical and computational research on the climate system},
  number    = {1-2},
  publisher = {Springer},
  address   = {New York},
  issn      = {0930-7575},
  doi       = {10.1007/s00382-011-1003-7},
  pages     = {239 -- 260},
  year      = {2012},
  abstract  = {We present a minimal conceptual model for the Atlantic meridional overturning circulation which incorporates the advection of salinity and the basic dynamics of the oceanic pycnocline. Four tracer transport processes following Gnanadesikan in Science 283(5410):2077-2079, (1999) allow for a dynamical adjustment of the oceanic pycnocline which defines the vertical extent of a mid-latitudinal box. At the same time the model captures the salt-advection feedback (Stommel in Tellus 13(2):224-230, (1961)). Due to its simplicity the model can be solved analytically in the purely wind- and purely mixing-driven cases. We find the possibility of abrupt transition in response to surface freshwater forcing in both cases even though the circulations are very different in physics and geometry. This analytical approach also provides expressions for the critical freshwater input marking the change in the dynamics of the system. Our analysis shows that including the pycnocline dynamics in a salt-advection model causes a decrease in the freshwater sensitivity of its northern sinking up to a threshold at which the circulation breaks down. Compared to previous studies the model is restricted to the essential ingredients. Still, it exhibits a rich behavior which reaches beyond the scope of this study and might be used as a paradigm for the qualitative behaviour of the Atlantic overturning in the discussion of driving mechanisms.},
  language  = {en}
}
@article{KhalilRailaAlietal.2012,
  author    = {Khalil, Mahmoud and Raila, Jens and Ali, Mostafa and Islam, Khan M. S. and Schenk, Regina and Krause, Jens-Peter and Schweigert, Florian J. and Rawel, Harshadrai Manilal},
  title     = {Stability and bioavailability of lutein ester supplements from Tagetes flower prepared under food processing conditions},
  series = {Journal of functional food},
  volume    = {4},
  journal   = {Journal of functional food},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1756-4646},
  doi       = {10.1016/j.jff.2012.03.006},
  pages     = {602 -- 610},
  year      = {2012},
  abstract  = {Tagetes spp. belongs to the Asteraceae family. It is recognized as a major source of lutein ester (lutein esterified with fatty acids such as lauric, myristic and palmitic acids), a natural colorant belonging to the xanthophylls or oxygenated carotenoids. Four species of Tagetes flower (Tagetes tenuifolia, Tagetes erecta, Tagetes patula, and Tagetes lucida) were used to extract lutein and lutein esters with three different methods. The results showed that T. erecta, type "orangeprinz", is the richest source of lutein esters (14.4 +/- 0.234 mg/g) in comparison to other Tagetes spp. No significant differences between extractions of lutein esters with medium-chain triacylglycerols (MCT) oil, orange oil or solvent (hexane/isopropanol) could be observed. MCT oil also improved stability of lutein esters at 100 degrees C for 40 min. Emulsification of MCT oil improved the stability of lutein ester extract against UV light at 365 nm for 72 h. Finally, an emulsion was prepared under food processing conditions, spray dried and its bioavailability investigated in a preliminary human intervention study. The results show a lower resorption, but further data suggest improvements in implementation of such supplements. (c) 2012 Elsevier Ltd. All rights reserved.},
  language  = {en}
}