TY  - JOUR
A1  - Kaboth-Bahr, Stefanie
A1  - Bahr, André
A1  - Zeeden, Christian
A1  - Yamoah, Kweku A.
A1  - Lone, Mahjoor Ahmad
A1  - Chuang, Chih-Kai
A1  - Löwemark, Ludvig
A1  - Wei, Kuo-Yen
T1  - A tale of shifting relations
BT  - East Asian summer and winter monsoon variability during the Holocene
JF  - Scientific Reports
N2  - Understanding the dynamics between the East Asian summer (EASM) and winter monsoon (EAWM) is needed to predict their variability under future global warming scenarios. Here, we investigate the relationship between EASM and EAWM as well as the mechanisms driving their variability during the last 10,000 years by stacking marine and terrestrial (non-speleothem) proxy records from the East Asian realm. This provides a regional and proxy independent signal for both monsoonal systems. The respective signal was subsequently analysed using a linear regression model. We find that the phase relationship between EASM and EAWM is not time-constant and significantly depends on orbital configuration changes. In addition, changes in the Atlantic Meridional Overturning circulation, Arctic sea-ice coverage, El Niño-Southern Oscillation and Sun Spot numbers contributed to millennial scale changes in the EASM and EAWM during the Holocene. We also argue that the bulk signal of monsoonal activity captured by the stacked non-speleothem proxy records supports the previously argued bias of speleothem climatic archives to moisture source changes and/or seasonality.
KW  - Environmental sciences
KW  - Ocean sciences
KW  - Solid Earth sciences
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-021-85444-7
SN  - 2045-2322
VL  - 11
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Söchting, Maximilian
A1  - Trapp, Matthias
T1  - Controlling image-stylization techniques using eye tracking
JF  - Science and Technology Publications
N2  - With the spread of smart phones capable of taking high-resolution photos and the development of high-speed mobile data infrastructure, digital visual media is becoming one of the most important forms of modern communication. With this development, however, also comes a devaluation of images as a media form with the focus becoming the frequency at which visual content is generated instead of the quality of the content. In this work, an interactive system using image-abstraction techniques and an eye tracking sensor is presented, which allows users to experience diverting and dynamic artworks that react to their eye movement. The underlying modular architecture enables a variety of different interaction techniques that share common design principles, making the interface as intuitive as possible. The resulting experience allows users to experience a game-like interaction in which they aim for a reward, the artwork, while being held under constraints, e.g., not blinking. The co nscious eye movements that are required by some interaction techniques hint an interesting, possible future extension for this work into the field of relaxation exercises and concentration training.
KW  - Eye-tracking
KW  - Image Abstraction
KW  - Image Processing
KW  - Artistic Image Stylization
KW  - Interactive Media
Y1  - 2020
SN  - 2184-4321
PB  - Springer
CY  - Berlin
ER  - 
TY  - GEN
A1  - Ceulemans, Ruben
A1  - Gaedke, Ursula
A1  - Klauschies, Toni
A1  - Guill, Christian
T1  - The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 744 
KW  - early-warning signals
KW  - top-down control
KW  - community ecology
KW  - regime shifts
KW  - food webs
KW  - compensatory dynamics
KW  - consumer diversity
KW  - metabolic theory
KW  - rapid evolution
KW  - stable states
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435439
SN  - 1866-8372
IS  - 744
ER  - 
TY  - GEN
A1  - Heuer, Leonie
A1  - Orland, Andreas
T1  - Cooperation in the Prisoner’s Dilemma
BT  - an experimental comparison between pure and mixed strategies
T2  - Postprints der Universität Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner’s Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts’ level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects’ level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 107 
KW  - cooperation
KW  - experiment
KW  - human behaviour
KW  - Prisoner's Dilemma
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435929
SN  - 1867-5808
IS  - 107
ER  - 
TY  - JOUR
A1  - Paraskevopoulou, Sofia
A1  - Dennis, Alice B.
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers
JF  - Scientific Reports
N2  - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming.
KW  - Ecology
KW  - Evolution
KW  - Oyster Crassostrea-gigas
KW  - cryptic species complex
KW  - pacific oyster
KW  - thermal-stress
KW  - genetic differentiation
KW  - expression patterns
KW  - molecular phylogeny
KW  - shock proteins
KW  - evolutionary
KW  - hsp70
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-70173-0
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Schnitzler, Joseph G.
A1  - Pinzone, Marianna
A1  - Autenrieth, Marijke
A1  - van Neer, Abbo
A1  - IJsseldijk, Lonneke L.
A1  - Barber, Jonathan  L.
A1  - Deaville, Rob
A1  - Jepson, Paul
A1  - Brownlow, Andrew
A1  - Schaffeld, Tobias
A1  - Thomé, Jean-Pierre
A1  - Tiedemann, Ralph
A1  - Das, Krishna
A1  - Siebert, Ursula
T1  - Inter-individual differences in contamination profiles as tracer of social group association in stranded sperm whales
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Ecological and physiological factors lead to different contamination patterns in individual marine mammals. The objective of the present study was to assess whether variations in contamination profiles are indicative of social structures of young male sperm whales as they might reflect a variation in feeding preferences and/or in utilized feeding grounds. We used a total of 61 variables associated with organic compounds and trace element concentrations measured in muscle, liver, kidney and blubber gained from 24 sperm whales that stranded in the North Sea in January and February 2016. Combining contaminant and genetic data, there is evidence for at least two cohorts with different origin among these stranded sperm whales; one from the Canary Island region and one from the northern part of the Atlantic. While genetic data unravel relatedness and kinship, contamination data integrate over areas, where animals occured during their lifetime. Especially in long-lived animals with a large migratory potential, as sperm whales, contamination data may carry highly relevant information about aggregation through time and space.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 692 
KW  - porpoises phococena-phococena
KW  - North-sea
KW  - physeter-macrocephalus
KW  - Galapagos-Islands
KW  - harbor porpoises
KW  - cetacean strandings
KW  - aggregations
KW  - pollutants
KW  - behavior
KW  - mammals
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426525
SN  - 1866-8372
IS  - 692
ER  - 
TY  - JOUR
A1  - Scheibel, Willy
A1  - Trapp, Matthias
A1  - Limberger, Daniel
A1  - Döllner, Jürgen Roland Friedrich
T1  - A taxonomy of treemap visualization techniques
JF  - Science and Technology Publications
N2  - A treemap is a visualization that has been specifically designed to facilitate the exploration of tree-structured data and, more general, hierarchically structured data. The family of visualization techniques that use a visual metaphor for parent-child relationships based “on the property of containment” (Johnson, 1993) is commonly referred to as treemaps. However, as the number of variations of treemaps grows, it becomes increasingly important to distinguish clearly between techniques and their specific characteristics. This paper proposes to discern between Space-filling Treemap TS, Containment Treemap TC, Implicit Edge Representation Tree TIE, and Mapped Tree TMT for classification of hierarchy visualization techniques and highlights their respective properties. This taxonomy is created as a hyponymy, i.e., its classes have an is-a relationship to one another: TS TC TIE TMT. With this proposal, we intend to stimulate a discussion on a more unambiguous classification of treemaps and, furthermore, broaden what is understood by the concept of treemap itself.
KW  - Treemaps
KW  - Taxonomy
Y1  - 2020
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schnitzler, Joseph G.
A1  - Pinzone, Marianna
A1  - Autenrieth, Marijke
A1  - van Neer, Abbo
A1  - IJsseldijk, Lonneke L.
A1  - Barber, Jonathan L.
A1  - Deaville, Rob
A1  - Jepson, Paul
A1  - Brownlow, Andrew
A1  - Schaffeld, Tobias
A1  - Thome, Jean-Pierre
A1  - Tiedemann, Ralph
A1  - Das, Krishna
A1  - Siebert, Ursula
T1  - Inter-individual differences in contamination profiles as tracer of social group association in stranded sperm whales
JF  - Scientific reports
N2  - Ecological and physiological factors lead to different contamination patterns in individual marine mammals. The objective of the present study was to assess whether variations in contamination profiles are indicative of social structures of young male sperm whales as they might reflect a variation in feeding preferences and/or in utilized feeding grounds. We used a total of 61 variables associated with organic compounds and trace element concentrations measured in muscle, liver, kidney and blubber gained from 24 sperm whales that stranded in the North Sea in January and February 2016. Combining contaminant and genetic data, there is evidence for at least two cohorts with different origin among these stranded sperm whales; one from the Canary Island region and one from the northern part of the Atlantic. While genetic data unravel relatedness and kinship, contamination data integrate over areas, where animals occured during their lifetime. Especially in long-lived animals with a large migratory potential, as sperm whales, contamination data may carry highly relevant information about aggregation through time and space.
Y1  - 2018
U6  - https://doi.org/10.1038/s41598-018-29186-z
SN  - 2045-2322
VL  - 8
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - GEN
A1  - Nagel, Rebecca
A1  - Kirschbaum, Frank
A1  - Engelmann, Jacob
A1  - Hofmann, Volker
A1  - Pawelzik, Felix
A1  - Tiedemann, Ralph
T1  - Male-mediated species recognition among African weakly electric fishes
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Effective communication among sympatric species is often instrumental for behavioural isolation, where the failure to successfully discriminate between potential mates could lead to less fit hybrid offspring. Discrimination between con- and heterospecifics tends to occur more often in the sex that invests more in offspring production, i.e. females, but males may also mediate reproductive isolation. In this study, we show that among two Campylomormyrus Africanweakly electric fish species, males preferentially associate with conspecific females during choice tests using live fish as stimuli, i.e. when all sensory modalities potentially used for communication were present. We then conducted playback experiments to determine whether the species-specific electric organ discharge (EOD) used for electrocommunication serves as the cue for this conspecific association preference. Interestingly, only C. compressirostris males associated significantly more with the conspecific EOD waveform when playback stimuli were provided, while no such association preference was observed in C. tamandua males. Given our results, the EOD appears to serve, in part, as a male-mediated pre-zygotic isolation mechanism among sympatric species. However, the failure of C. tamandua males to discriminate between con- and heterospecific playback discharges suggests that multiple modalities may be necessary for species recognition in some African weakly electric fish species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 645 
KW  - Campylomormyrus
KW  - communication
KW  - electric fishes
KW  - pre-zygotic isolation
KW  - species recognition
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425016
SN  - 1866-8372
IS  - 645
ER  - 
TY  - JOUR
A1  - Nagel, Rebecca
A1  - Kirschbaum, Frank
A1  - Engelmann, Jacob
A1  - Hofmann, Volker
A1  - Pawelzik, Felix
A1  - Tiedemann, Ralph
T1  - Male-mediated species recognition among African weakly electric fishes
JF  - Royal Society Open Science
N2  - Effective communication among sympatric species is often instrumental for behavioural isolation, where the failure to successfully discriminate between potential mates could lead to less fit hybrid offspring. Discrimination between con- and heterospecifics tends to occur more often in the sex that invests more in offspring production, i.e. females, but males may also mediate reproductive isolation. In this study, we show that among two Campylomormyrus Africanweakly electric fish species, males preferentially associate with conspecific females during choice tests using live fish as stimuli, i.e. when all sensory modalities potentially used for communication were present. We then conducted playback experiments to determine whether the species-specific electric organ discharge (EOD) used for electrocommunication serves as the cue for this conspecific association preference. Interestingly, only C. compressirostris males associated significantly more with the conspecific EOD waveform when playback stimuli were provided, while no such association preference was observed in C. tamandua males. Given our results, the EOD appears to serve, in part, as a male-mediated pre-zygotic isolation mechanism among sympatric species. However, the failure of C. tamandua males to discriminate between con- and heterospecific playback discharges suggests that multiple modalities may be necessary for species recognition in some African weakly electric fish species.
KW  - Campylomormyrus
KW  - communication
KW  - electric fishes
KW  - pre-zygotic isolation
KW  - species recognition
Y1  - 2018
U6  - https://doi.org/10.1098/rsos.170443
SN  - 2054-5703
VL  - 5
IS  - 2
PB  - Royal Society
CY  - London
ER  - 
TY  - GEN
A1  - Biterova, Ekaterina
A1  - Esmaeeli Moghaddam Tabalvandani, Mariam
A1  - Alanen, Heli I.
A1  - Saaranen, Mirva
A1  - Ruddock, Lloyd W.
T1  - Structures of Angptl3 and Angptl4
BT  - modulators of triglyceride levels and coronary artery disease
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Coronary artery disease is the most common cause of death globally and is linked to a number of risk factors including serum low density lipoprotein, high density lipoprotein, triglycerides and lipoprotein(a). Recently two proteins, angiopoietin-like protein 3 and 4, have emerged from genetic studies as being factors that significantly modulate plasma triglyceride levels and coronary artery disease. The exact function and mechanism of action of both proteins remains to be elucidated, however, mutations in these proteins results in up to 34% reduction in coronary artery disease and inhibition of function results in reduced plasma triglyceride levels. Here we report the crystal structures of the fibrinogen-like domains of both proteins. These structures offer new insights into the reported loss of function mutations, the mechanisms of action of the proteins and open up the possibility for the rational design of low molecular weight inhibitors for intervention in coronary artery disease.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1048 
KW  - angiopoitin-like 4
KW  - of-function mutations
KW  - cardiovascular-disease
KW  - lipoprotein-lipase
KW  - heart-disease
KW  - risk
KW  - recognition
KW  - protein
KW  - metaanalysis
KW  - association
KW  - cardiovascular biology
KW  - x-ray crystallography
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-467943
SN  - 1866-8372
IS  - 1048
ER  - 
TY  - GEN
A1  - Lemaire, Olivier N.
A1  - Infossi, Pascale
A1  - Chaouche, Amine Ali
A1  - Espinosa, Leon
A1  - Leimkühler, Silke
A1  - Giudici-Orticoni, Marie-Thérèse
A1  - Méjean, Vincent
A1  - Iobbi-Nivol, Chantal
T1  - Small membranous proteins of the TorE/NapE family, crutches for cognate respiratory systems in Proteobacteria
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - In this report, we investigate small proteins involved in bacterial alternative respiratory systems that improve the enzymatic efficiency through better anchorage and multimerization of membrane components. Using the small protein TorE of the respiratory TMAO reductase system as a model, we discovered that TorE is part of a subfamily of small proteins that are present in proteobacteria in which they play a similar role for bacterial respiratory systems. We reveal by microscopy that, in Shewanella oneidensis MR1, alternative respiratory systems are evenly distributed in the membrane contrary to what has been described for Escherichia coli. Thus, the better efficiency of the respiratory systems observed in the presence of the small proteins is not due to a specific localization in the membrane, but rather to the formation of membranous complexes formed by TorE homologs with their c-type cytochrome partner protein. By an in vivo approach combining Clear Native electrophoresis and fluorescent translational fusions, we determined the 4: 4 stoichiometry of the complexes. In addition, mild solubilization of the cytochrome indicates that the presence of the small protein reinforces its anchoring to the membrane. Therefore, assembly of the complex induced by this small protein improves the efficiency of the respiratory system.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 933 
KW  - trimethylamine n-oxide
KW  - molybdenum cofactor biosynthesis
KW  - cytochrome bd oxidase
KW  - c-type cytochromes
KW  - escherichia-coli
KW  - swiss-model
KW  - native electrophoresis
KW  - mutational analysis
KW  - reductase
KW  - nitrate
KW  - microbiology
KW  - microbiology techniques
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459208
SN  - 1866-8372
IS  - 933
ER  - 
TY  - GEN
A1  - Senczuk, Gabriele
A1  - Havenstein, Katja
A1  - Milana, Valentina
A1  - Ripa, Chiara
A1  - De Simone, Emanuela
A1  - Tiedemann, Ralph
A1  - Castiglia, Riccardo
T1  - Spotlight on islands
BT  - on the origin and diversification of an ancient lineage of the Italian wall lizard Podarcis siculus in the western Pontine Islands
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Groups of proximate continental islands may conceal more tangled phylogeographic patterns than oceanic archipelagos as a consequence of repeated sea level changes, which allow populations to experience gene flow during periods of low sea level stands and isolation by vicariant mechanisms during periods of high sea level stands. Here, we describe for the first time an ancient and diverging lineage of the Italian wall lizard Podarcis siculus from the western Pontine Islands. We used nuclear and mitochondrial DNA sequences of 156 individuals with the aim of unraveling their phylogenetic position, while microsatellite loci were used to test several a priori insular biogeographic models of migration with empirical data. Our results suggest that the western Pontine populations colonized the islands early during their Pliocene volcanic formation, while populations from the eastern Pontine Islands seem to have been introduced recently. The inter-island genetic makeup indicates an important role of historical migration, probably due to glacial land bridges connecting islands followed by a recent vicariant mechanism of isolation. Moreover, the most supported migration model predicted higher gene flow among islands which are geographically arranged in parallel. Considering the threatened status of small insular endemic populations, we suggest this new evolutionarily independent unit be given priority in conservation efforts.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 991 
KW  - mitochondrial dna sequences
KW  - genetic diversity
KW  - haplotype reconstruction
KW  - evolutionary history
KW  - geological evolution
KW  - population structure
KW  - Tyrrhenian Sea
KW  - endemic lizard
KW  - genotype data
KW  - biogeography
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446360
SN  - 1866-8372
IS  - 991
ER  - 
TY  - GEN
A1  - Pauly, Maren
A1  - Helle, Gerhard
A1  - Miramont, Cécile
A1  - Büntgen, Ulf
A1  - Treydte, Kerstin
A1  - Reinig, Frederick
A1  - Guibal, Frédéric
A1  - Sivan, Olivier
A1  - Heinrich, Ingo
A1  - Riedel, Frank
A1  - Kromer, Bernd
A1  - Balanzategui, Daniel
A1  - Wacker, Lukas
A1  - Sookdeo, Adam Sookdeo
A1  - Brauer, Achim
T1  - Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (delta O-18, delta C-13) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (delta O-18(sw)) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (delta O-18(sw)), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low delta O-18(sw)) versus Mediterranean (high delta O-18(sw)) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1135 
KW  - annually laminated sediments
KW  - lake Meerfelder Maar
KW  - isotopic composition
KW  - oxygen isotope
KW  - climate
KW  - cellulose
KW  - radiocarbon
KW  - temperature
KW  - record
KW  - model
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459169
SN  - 1866-8372
IS  - 1135
ER  - 
TY  - GEN
A1  - Omori, Toshihiro
A1  - Winter, Katja
A1  - Shinohara, Kyosuke
A1  - Hamada, Hiroshi
A1  - Ishikawa, Takuji
T1  - Simulation of the nodal flow of mutant embryos with a small number of cilia
BT  - comparison of mechanosensing and vesicle transport hypotheses
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Left-right (L-R) asymmetry in the body plan is determined by nodal flow in vertebrate embryos. Shinohara et al. (Shinohara K et al. 2012 Nat. Commun. 3, 622 (doi:10.1038/ncomms1624)) used Dpcd and Rfx3 mutant mouse embryos and showed that only a few cilia were sufficient to achieve L-R asymmetry. However, the mechanism underlying the breaking of symmetry by such weak ciliary flow is unclear. Flow-mediated signals associated with the L-R asymmetric organogenesis have not been clarified, and two different hypotheses-vesicle transport and mechanosensing-are now debated in the research field of developmental biology. In this study, we developed a computational model of the node system reported by Shinohara et al. and examined the feasibilities of the two hypotheses with a small number of cilia. With the small number of rotating cilia, flow was induced locally and global strong flow was not observed in the node. Particles were then effectively transported only when they were close to the cilia, and particle transport was strongly dependent on the ciliary positions. Although the maximum wall shear rate was also influenced by ciliary position, the mean wall shear rate at the perinodal wall increased monotonically with the number of cilia. We also investigated the membrane tension of immotile cilia, which is relevant to the regulation of mechanotransduction. The results indicated that tension of about 0.1 mu Nm(-1) was exerted at the base even when the fluid shear rate was applied at about 0.1 s(-1). The area of high tension was also localized at the upstream side, and negative tension appeared at the downstream side. Such localization may be useful to sense the flow direction at the periphery, as time-averaged anticlockwise circulation was induced in the node by rotation of a few cilia. Our numerical results support the mechanosensing hypothesis, and we expect that our study will stimulate further experimental investigations of mechanotransduction in the near future.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1056 
KW  - nodal flow
KW  - left-right asymmetry
KW  - boundary element method
KW  - fluid-structure interaction
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468734
SN  - 1866-8372
IS  - 1056
ER  - 
TY  - GEN
A1  - Beermann, Jan
A1  - Westbury, Michael V.
A1  - Hofreiter, Michael
A1  - Hilgers, Leon
A1  - Deister, Fabian
A1  - Neumann, Hermann
A1  - Raupach, Michael J.
T1  - Cryptic species in a well-known habitat
BT  - applying taxonomics to the amphipod genus Epimeria (Crustacea, Peracarida)
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Taxonomy plays a central role in biological sciences. It provides a communication system for scientists as it aims to enable correct identification of the studied organisms. As a consequence, species descriptions should seek to include as much available information as possible at species level to follow an integrative concept of 'taxonomics'. Here, we describe the cryptic species Epimeria frankei sp. nov. from the North Sea, and also redescribe its sister species, Epimeria cornigera. The morphological information obtained is substantiated by DNA barcodes and complete nuclear 18S rRNA gene sequences. In addition, we provide, for the first time, full mitochondrial genome data as part of a metazoan species description for a holotype, as well as the neotype. This study represents the first successful implementation of the recently proposed concept of taxonomics, using data from high-throughput technologies for integrative taxonomic studies, allowing the highest level of confidence for both biodiversity and ecological research.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1059 
KW  - multiple sequence alignment
KW  - Oxidase Subunit-I
KW  - mitochondrial genome
KW  - control region
KW  - Ribosomal-RNA
KW  - asellota crustacea
KW  - gammarus crustacea
KW  - deep-sea
KW  - DNA
KW  - evolution
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460792
SN  - 1866-8372
IS  - 1059
ER  - 
TY  - GEN
A1  - Küken, Anika
A1  - Sommer, Frederik
A1  - Yaneva-Roder, Liliya
A1  - Mackinder, Luke C.M.
A1  - Höhne, Melanie
A1  - Geimer, Stefan
A1  - Jonikas, Martin C.
A1  - Schroda, Michael
A1  - Stitt, Mark
A1  - Nikoloski, Zoran
A1  - Mettler-Altmann, Tabea
T1  - Effects of microcompartmentation on flux distribution and metabolic pools in Chlamydomonas reinhardtii chloroplasts
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Cells and organelles are not homogeneous but include microcompartments that alter the spatiotemporal characteristics of cellular processes. The effects of microcompartmentation on metabolic pathways are however difficult to study experimentally. The pyrenoid is a microcompartment that is essential for a carbon concentrating mechanism (CCM) that improves the photosynthetic performance of eukaryotic algae. Using Chlamydomonas reinhardtii, we obtained experimental data on photosynthesis, metabolites, and proteins in CCM-induced and CCM-suppressed cells. We then employed a computational strategy to estimate how fluxes through the Calvin-Benson cycle are compartmented between the pyrenoid and the stroma. Our model predicts that ribulose-1,5-bisphosphate (RuBP), the substrate of Rubisco, and 3-phosphoglycerate (3PGA), its product, diffuse in and out of the pyrenoid, respectively, with higher fluxes in CCM-induced cells. It also indicates that there is no major diffusional barrier to metabolic flux between the pyrenoid and stroma. Our computational approach represents a stepping stone to understanding microcompartmentalized CCM in other organisms.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1122 
KW  - carbon concentrating mechanism
KW  - B12-dependent 1,2-propanediol degradation
KW  - green algae
KW  - co2 concentrating mechanism
KW  - salmonella typhimurium
KW  - co2 concentration
KW  - enzyme activities
KW  - anhydrase CAH3
KW  - protein
KW  - expression
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446358
SN  - 1866-8372
IS  - 1122
ER  - 
TY  - JOUR
A1  - Fritsch, Daniel
T1  - Revisiting the Cu-Zn disorder in kesterite type Cu2ZnSnSe4 employing a novel approach to hybrid functional calculations
JF  - Applied Sciences : open access journal
N2  - In recent years, the search for more efficient and environmentally friendly materials to be employed in the next generation of thin film solar cell devices has seen a shift towards hybrid halide perovskites and chalcogenide materials crystallising in the kesterite crystal structure. Prime examples for the latter are Cu2ZnSnS4, Cu2ZnSnSe4, and their solid solution Cu2ZnSn(SxSe1-x)(4), where actual devices already demonstrated power conversion efficiencies of about 13 %. However, in their naturally occurring kesterite crystal structure, the so-called Cu-Zn disorder plays an important role and impacts the structural, electronic, and optical properties. To understand the influence of Cu-Zn disorder, we perform first-principles calculations based on density functional theory combined with special quasirandom structures to accurately model the cation disorder. Since the electronic band gaps and derived optical properties are severely underestimated by (semi)local exchange and correlation functionals, supplementary hybrid functional calculations have been performed. Concerning the latter, we additionally employ a recently devised technique to speed up structural relaxations for hybrid functional calculations. Our calculations show that the Cu-Zn disorder leads to a slight increase in the unit cell volume compared to the conventional kesterite structure showing full cation order, and that the band gap gets reduced by about 0.2 eV, which is in very good agreement with earlier experimental and theoretical findings. Our detailed results on structural, electronic, and optical properties will be discussed with respect to available experimental data, and will provide further insights into the atomistic origin of the disorder-induced band gap lowering in these promising kesterite type materials.
KW  - Cu2ZnSnSe4
KW  - CZTSe
KW  - chalcogenide
KW  - kesterite
KW  - Cu-Zn disorder
KW  - density
KW  - functional theory
KW  - hybrid functional
KW  - special quasirandom structure
Y1  - 2022
U6  - https://doi.org/10.3390/app12052576
SN  - 2076-3417
VL  - 12
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Glugla, Markus
A1  - Schulz, Ralf Kiran
T1  - Generated-X LMS (GXLMS)
BT  - A modified LMS Algorithm without external reference signal
JF  - Proceedings of the 27th International Congress on Sound and Vibration
N2  - The quality of the reference signal is essential for the adaptation process of an LMS or one of its derivatives. The reference signal affects the stability, the convergence rate and the maximum achievable attenuation. Since the error signal and the control signal are available as numerical values in the algorithm for the LMS, the reference signal can be calculated from both signals. The error signal is the interference between the control signal and the reference signal. This interference of the control signal and the reference signal can be noted mathematically as a simple addition. It is therefore possible to deduce the reference signal from a known error signal and control signal. This approach is the basis of the generated-x LMS (GxLMS) developed by us. It calculates the reference signal itself without having to rely on an externally supplied reference signal. The advantages of the GxLMS are primarily in fields where the reference signal is difficult or impossible to detect. For example, the detection of the reference signal can be problematic due to design reasons or measurement technology. For example, flow noise could have a negative effect on an acoustic detection of the reference signal. However, the calculation of the reference signal in the GxLMS represents a further feedback signal path, which affects the stability of the algorithm as a whole. Based on the theoretical principles mathematically sufficient convergence conditions can be formulated taking into account the delays existing in the signal paths. The experimental testing took place on an acoustic duct with monofrequency disturb signals. Since the use of an efficient design of experiments (DoE) could be excluded, the measurement was designed as parameter variation (one factor at time) and therefore very time-consuming. The theoretical background of the GxLMS as well as the results from the experiments are presented.
KW  - LMS without reference signal
KW  - GxLMS algorithm
KW  - Active noise control
KW  - Convergence
Y1  - 2021
UR  - https://iiav.org/content/archives_icsv_last/2021_icsv27/content/papers/papers/full_paper_524_20210503203519677.pdf
SN  - 978-83-7880-799-5
SP  - 1
EP  - 8
PB  - Silesian University Press
CY  - Prague
ER  - 
TY  - JOUR
A1  - Omori, Toshihiro
A1  - Winter, Katja
A1  - Shinohara, Kyosuke
A1  - Hamada, Hiroshi
A1  - Ishikawa, Takuji
T1  - Simulation of the nodal flow of mutant embryos with a small number of cilia
BT  - comparison of mechanosensing and vesicle transport hypotheses
JF  - Royal Society Open Science
N2  - Left-right (L-R) asymmetry in the body plan is determined by nodal flow in vertebrate embryos. Shinohara et al. (Shinohara K et al. 2012 Nat. Commun. 3, 622 (doi:10.1038/ncomms1624)) used Dpcd and Rfx3 mutant mouse embryos and showed that only a few cilia were sufficient to achieve L-R asymmetry. However, the mechanism underlying the breaking of symmetry by such weak ciliary flow is unclear. Flow-mediated signals associated with the L-R asymmetric organogenesis have not been clarified, and two different hypotheses-vesicle transport and mechanosensing-are now debated in the research field of developmental biology. In this study, we developed a computational model of the node system reported by Shinohara et al. and examined the feasibilities of the two hypotheses with a small number of cilia. With the small number of rotating cilia, flow was induced locally and global strong flow was not observed in the node. Particles were then effectively transported only when they were close to the cilia, and particle transport was strongly dependent on the ciliary positions. Although the maximum wall shear rate was also influenced by ciliary position, the mean wall shear rate at the perinodal wall increased monotonically with the number of cilia. We also investigated the membrane tension of immotile cilia, which is relevant to the regulation of mechanotransduction. The results indicated that tension of about 0.1 mu Nm(-1) was exerted at the base even when the fluid shear rate was applied at about 0.1 s(-1). The area of high tension was also localized at the upstream side, and negative tension appeared at the downstream side. Such localization may be useful to sense the flow direction at the periphery, as time-averaged anticlockwise circulation was induced in the node by rotation of a few cilia. Our numerical results support the mechanosensing hypothesis, and we expect that our study will stimulate further experimental investigations of mechanotransduction in the near future.
KW  - nodal flow
KW  - left-right asymmetry
KW  - boundary element method
KW  - fluid-structure interaction
Y1  - 2018
U6  - https://doi.org/10.1098/rsos.180601
SN  - 2054-5703
VL  - 5
IS  - 8
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Jakupec, Viktor
T1  - Development Aid
BT  - an historic-political overview
JF  - Development Aid—Populism and the End of the Neoliberal Agenda
N2  - Development aid has been an important catalyst for economic development and international politics since the end of WWII. A critical analysis of the main political, social and economic advances in development aid, traces the development agenda from the advent of the Bretton Woods agreement, the Truman Doctrine and the Marshall Plan, to the Washington Consensus and its neoliberal manifesto. The failure of the Washington Consensus and the rise of the post-Washington Consensus is analysed providing a backdrop for the critique of economic globalisation as a development aid cornerstone. Trump’s rejection of the neoliberal globalisation agenda and departure from post-WWII ideologies is discussed.
KW  - Bretton woods
KW  - Truman doctrine
KW  - Washington consensus Development aid
KW  - Neoliberalism
KW  - Populism
KW  - Globalisation
Y1  - 2017
SN  - 978-3-319-72748-6
SN  - 978-3-319-72747-9
U6  - https://doi.org/10.1007/978-3-319-72748-6_2
SN  - 2211-4548
SN  - 2211-4556
SP  - 19
EP  - 36
PB  - Springer
CY  - Cham
ER  - 
TY  - GEN
A1  - Heinicker, Paul
A1  - Likavcan, Lukas
A1  - Lin, Qiao
T1  - alt'ai: designing machine-to-machine interfaces for automated landscapes
N2  - alt'ai is an agent-based simulation inspired by aesthetics, culture and environmental conditions of the Altai mountain region on the borders between Russia, Kazakhstan, China and Mongolia. It is set into a scenario of a remote automated landscape populated by sentient machines, where biological species, machines and environments autonomously interact to produce unforeseeable visual outputs. It poses a question of designing future machine-to-machine authentication protocols that are based on the use of images encoding agent behavior. Also, the simulation provides rich visual perspective on this challenge. The project pleads for a heavily aestheticized approach to design practice and highlights the importance of productively inefficient and information redundant systems.
Y1  - 2019
SN  - 978-1-4503-6311-2
U6  - https://doi.org/10.1145/3306211.3320146
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Bose, Käthe von
T1  - Umweltfürsorge im Krankenhaus
BT  - Hygienische Sauberkeit und die feminisierte Arbeit an der Atmosphäre
JF  - NTM : Zeitschrift für Geschichte der Wissenschaften, Technik und Medizin
N2  - Den Boden putzen, das Bett abziehen, einen Blumenstrauß arrangieren – Bemühungen um Sauberkeit sowie eine angenehme Raumatmosphäre obliegen im Krankenhaus meist weiblichen* Pflegerinnen, Reinigungskräften und Hauswirtschafterinnen. Im Klinikalltag vermischen sich Anforderungen an hygienische Sauberkeit unter Prozessen der Ökonomisierung mit Logiken des Marketings sowie mit affektiv-emotionalen Bedürfnissen der Akteur_innen dieser Räume. Obwohl die Maßstäbe klinischer Hygiene auf medizinischem Wissen basieren, sind die Arbeitsteilung sowie Ansprüche an Sauberkeit auf verschiedenen Hierarchieebenen zugleich von vergeschlechtlichten und teils rassifizierten Vorstellungen durchdrungen, die über den klinischen Kontext hinausweisen. Dies legt schon eine Beschäftigung mit der Geschichte der Bakteriologie nahe: Die Logik und Sprache der Infektionsabwehr ist in Wissenschaft und Alltag auch verwoben mit sozialen Differenzmarkierungen.
Unter Rückgriff auf die Ergebnisse einer Ethnografie zu Sauberkeit und Reinigungsarbeiten im Krankenhaus, die wissensgeschichtlich fundiert werden, wird in dem Beitrag die Frage nach der (feminisierten) Sorge für die Umwelt mit der Frage nach der Atmosphäre klinischer Räume verknüpft. Auf welche Weise und mit welchen Effekten verschränken sich wissenschaftlich-medizinisches Hygienewissen mit einem alltäglichen, jedoch historisierbaren Wissen über schöne und angenehme Sauberkeit, das immer noch weiblich konnotiert ist?
N2  - Cleaning the floor, stripping the bed, arranging a bouquet of flowers-such tasks are essential to keeping a hospital room clean and creating a pleasant atmosphere. They usually fall under the purview of female* nurses, cleaning staff and housekeepers. In everyday hospital life, the demands for hygienic cleanliness commingle with the imperatives of economization, marketing logic, and attention to the affective and emotional needs of the actors in these rooms. Although the standards of clinical hygiene are based on medical knowledge, the division of labor and the demands for cleanliness at various hierarchical levels also reveal gendered and partly racialized ideas that point beyond the clinical context. This blending of imperatives in the hospital environment invites deeper consideration of the history of bacteriology: The logic and language of defense against infection in science and everyday life is also interwoven with social markers of difference. Drawing on the findings of an ethnography on cleanliness and cleaning work in hospitals, as well as a history of knowledge approach, the article links the question of (feminized) care for the environment with the question of the atmosphere of clinical rooms. In what ways, and to what effect, does scientific knowledge about medical hygiene also carry with it cultural and aesthetic perceptions of beautiful and pleasant cleanliness that reveal feminine connotations rooted in the nineteenth century?
T2  - Environmental care in hospitals
KW  - Krankenhaus
KW  - Hygiene
KW  - Geschlecht
KW  - Atmosphäre
KW  - Umwelt
KW  - Hospital
KW  - Hygiene
KW  - Gender
KW  - Atmosphere
KW  - Environment
Y1  - 2021
U6  - https://doi.org/10.1007/s00048-020-00289-x
SN  - 0036-6978
SN  - 1420-9144
VL  - 29
IS  - 1
SP  - 113
EP  - 141
PB  - Birkhäuser
CY  - Basel ; Berlin
ER  - 
TY  - JOUR
A1  - Lemaire, Olivier N.
A1  - Infossi, Pascale
A1  - Chaouche, Amine Ali
A1  - Espinosa, Leon
A1  - Leimkühler, Silke
A1  - Giudici-Orticoni, Marie-Therese
A1  - Mejean, Vincent
A1  - Iobbi-Nivol, Chantal
T1  - Small membranous proteins of the TorE/NapE family, crutches for cognate respiratory systems in Proteobacteria
JF  - Scientific reports
N2  - In this report, we investigate small proteins involved in bacterial alternative respiratory systems that improve the enzymatic efficiency through better anchorage and multimerization of membrane components. Using the small protein TorE of the respiratory TMAO reductase system as a model, we discovered that TorE is part of a subfamily of small proteins that are present in proteobacteria in which they play a similar role for bacterial respiratory systems. We reveal by microscopy that, in Shewanella oneidensis MR1, alternative respiratory systems are evenly distributed in the membrane contrary to what has been described for Escherichia coli. Thus, the better efficiency of the respiratory systems observed in the presence of the small proteins is not due to a specific localization in the membrane, but rather to the formation of membranous complexes formed by TorE homologs with their c-type cytochrome partner protein. By an in vivo approach combining Clear Native electrophoresis and fluorescent translational fusions, we determined the 4: 4 stoichiometry of the complexes. In addition, mild solubilization of the cytochrome indicates that the presence of the small protein reinforces its anchoring to the membrane. Therefore, assembly of the complex induced by this small protein improves the efficiency of the respiratory system.
Y1  - 2018
U6  - https://doi.org/10.1038/s41598-018-31851-2
SN  - 2045-2322
VL  - 8
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - GEN
A1  - Paerels, Frits
A1  - Kaastra, Jelle
A1  - Ohashi, Takaya
A1  - Richter, Philipp
A1  - Bykov, Andrei
A1  - Nevalainen, Jukka
T1  - Future instrumentation for the study of the warm-hot intergalactic medium
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - We briefly review capabilities and requirements for future instrumentation in UV- and X-ray astronomy that can contribute to advancing our understanding of the diffuse, highly ionised intergalactic medium.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 859 
KW  - instrumentation: spectrographs
KW  - instrumentation: photometers
KW  - ultraviolet: general
KW  - x-rays: general
KW  - γ -rays: general
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434057
SN  - 1866-8372
IS  - 859
SP  - 405
EP  - 418
ER  - 
TY  - GEN
A1  - Richter, Philipp
A1  - Paerels, Frits  B. S.
A1  - Kaastra, Jelle S.
T1  - FUV and X-Ray absorption in the warm-hot intergalactic medium
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of Hi and high ions such as Ovi, Ovii, and Oviii in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 864 
KW  - galaxies : intergalactic medium
KW  - quasars : absorption lines
KW  - cosmology : large-scale structure of the Universe
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434226
SN  - 1866-8372
IS  - 864
SP  - 25
EP  - 49
ER  - 
TY  - GEN
A1  - Kindler, Oliver
A1  - Pulkkinen, Otto
A1  - Cherstvy, Andrey G.
A1  - Metzler, Ralf
T1  - Burst Statistics in an Early Biofilm Quorum Sensing Mode
BT  - The Role of Spatial Colony-Growth Heterogeneity
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Quorum-sensing bacteria in a growing colony of cells send out signalling molecules (so-called “autoinducers”) and themselves sense the autoinducer concentration in their vicinity. Once—due to increased local cell density inside a “cluster” of the growing colony—the concentration of autoinducers exceeds a threshold value, cells in this clusters get “induced” into a communal, multi-cell biofilm-forming mode in a cluster-wide burst event. We analyse quantitatively the influence of spatial disorder, the local heterogeneity of the spatial distribution of cells in the colony, and additional physical parameters such as the autoinducer signal range on the induction dynamics of the cell colony. Spatial inhomogeneity with higher local cell concentrations in clusters leads to earlier but more localised induction events, while homogeneous distributions lead to comparatively delayed but more concerted induction of the cell colony, and, thus, a behaviour close to the mean-field dynamics. We quantify the induction dynamics with quantifiers such as the time series of induction events and burst sizes, the grouping into induction families, and the mean autoinducer concentration levels. Consequences for different scenarios of biofilm growth are discussed, providing possible cues for biofilm control in both health care and biotechnology.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 777 
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439099
SN  - 1866-8372
IS  - 777
ER  - 
TY  - GEN
A1  - Gallego-Llorente, Marcos
A1  - Sarah, Connell
A1  - Jones, Eppie R.
A1  - Merrett, Deborah C.
A1  - Jeon, Y.
A1  - Eriksson, Anders
A1  - Siska, Veronika
A1  - Gamba, Cristina
A1  - Meiklejohn, Christopher
A1  - Beyer, Robert
A1  - Jeon, Sungwon
A1  - Cho, Yun Sung
A1  - Hofreiter, Michael
A1  - Bhak, Jong
A1  - Manica, Andrea
A1  - Pinhasi, Ron
T1  - The genetics of an early Neolithic pastoralist from the Zagros, Iran
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The agricultural transition profoundly changed human societies. We sequenced and analysed the first genome (1.39x) of an early Neolithic woman from Ganj Dareh, in the Zagros Mountains of Iran, a site with early evidence for an economy based on goat herding, ca. 10,000 BP. We show that Western Iran was inhabited by a population genetically most similar to hunter-gatherers from the Caucasus, but distinct from the Neolithic Anatolian people who later brought food production into Europe. The inhabitants of Ganj Dareh made little direct genetic contribution to modern European populations, suggesting those of the Central Zagros were somewhat isolated from other populations of the Fertile Crescent. Runs of homozygosity are of a similar length to those from Neolithic farmers, and shorter than those of Caucasus and Western Hunter-Gatherers, suggesting that the inhabitants of Ganj Dareh did not undergo the large population bottleneck suffered by their northern neighbours. While some degree of cultural diffusion between Anatolia, Western Iran and other neighbouring regions is possible, the genetic dissimilarity between early Anatolian farmers and the inhabitants of Ganj Dareh supports a model in which Neolithic societies in these areas were distinct.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 952 
KW  - whole-genome association
KW  - ancient
KW  - domestication
KW  - agriculture
KW  - mountains
KW  - diffusion
KW  - migration
KW  - admixture
KW  - patterns
KW  - sequence
KW  - archaeology
KW  - biological anthropology
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439355
SN  - 1866-8372
IS  - 952
ER  - 
TY  - GEN
A1  - Henkel, Janin
A1  - Coleman Mac Gregor of Inneregny, Charles Dominic
A1  - Schraplau, Anne
A1  - Jöhrens, Korinna
A1  - Weiss, Thomas Siegfried
A1  - Jonas, Wenke
A1  - Schürmann, Annette
A1  - Püschel, Gerhard Paul
T1  - Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 483 
KW  - suppress VLDL secretion
KW  - mice lacking
KW  - nonalcoholic steatohepatthis
KW  - insulin-resistance
KW  - rat hepatocytes
KW  - kupffer cells
KW  - E-2
KW  - disease
KW  - expression
KW  - accumulation
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-420879
SN  - 1866-8372
IS  - 483
ER  - 
TY  - JOUR
A1  - Henkel, Janin
A1  - Coleman Mac Gregor of Inneregny, Charles Dominic
A1  - Schraplau, Anne
A1  - Jöhrens, Korinna
A1  - Weiss, Thomas Siegfried
A1  - Jonas, Wenke
A1  - Schürmann, Annette
A1  - Püschel, Gerhard Paul
T1  - Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model
JF  - Scientific Reports
N2  - In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
KW  - suppress VLDL secretion
KW  - mice lacking
KW  - nonalcoholic steatohepatthis
KW  - insulin-resistance
KW  - rat hepatocytes
KW  - kupffer cells
KW  - E-2
KW  - disease
KW  - expression
KW  - accumulation
Y1  - 2018
U6  - https://doi.org/10.1038/s41598-018-34633-y
SN  - 2045-2322
IS  - 8
SP  - 1
EP  - 11
PB  - Nature Research
CY  - London
ER  - 
TY  - GEN
A1  - Meyer, Matthias
A1  - Palkopoulou, Eleftheria
A1  - Baleka, Sina Isabelle
A1  - Stiller, Mathias
A1  - Penkman, Kirsty E. H.
A1  - Alt, Kurt W.
A1  - Ishida, Yasuko
A1  - Mania, Dietrich
A1  - Mallick, Swapan
A1  - Meijer, Tom
A1  - Meller, Harald
A1  - Nagel, Sarah
A1  - Nickel, Birgit
A1  - Ostritz, Sven
A1  - Rohland, Nadin
A1  - Schauer, Karol
A1  - Schüler, Tim
A1  - Roca, Alfred L.
A1  - Reich, David
A1  - Shapiro, Beth
A1  - Hofreiter, Michael
T1  - Palaeogenomes of Eurasian straight-tusked elephants challenge the current view of elephant evolution
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - The straight-tusked elephants Palaeoloxodon spp. were widespread across Eurasia during the Pleistocene. Phylogenetic reconstructions using morphological traits have grouped them with Asian elephants (Elephas maximus), and many paleontologists place Palaeoloxodon within Elephas. Here, we report the recovery of full mitochondrial genomes from four and partial nuclear genomes from two P. antiquus fossils. These fossils were collected at two sites in Germany, Neumark-Nord and Weimar-Ehringsdorf, and likely date to interglacial periods similar to 120 and similar to 244 thousand years ago, respectively. Unexpectedly, nuclear and mitochondrial DNA analyses suggest that P. antiquus was a close relative of extant African forest elephants (Loxodonta cyclotis). Species previously referred to Palaeoloxodon are thus most parsimoniously explained as having diverged from the lineage of Loxodonta, indicating that Loxodonta has not been constrained to Africa. Our results demonstrate that the current picture of elephant evolution is in need of substantial revision.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 790 
KW  - genome sequence
KW  - woolly mammoth
KW  - Palaeoloxodon-antiquus
KW  - phylogenetic analysis
KW  - African elephants
KW  - DNA
KW  - Pleistocene
KW  - alignment
KW  - ancient
KW  - reveal
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-440139
SN  - 1866-8372
IS  - 790
ER  - 
TY  - GEN
A1  - Jiang, Yi
A1  - Mansfeld, Ulrich
A1  - Fang, Liang
A1  - Kratz, Karl
A1  - Lendlein, Andreas
T1  - Temperature-induced evolution of microstructures on poly[ethylene-co-(vinyl acetate)] substrates switches their underwater wettability
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Material surfaces with tailored aerophobicity are crucial for applications where gas bubble wettability has to be controlled, e.g., gas storage and transport, electrodes, bioreactors or medical devices.

Here, we present switchable underwater aerophobicity of hydrophobic polymeric substrates, which respond to heat with multilevel micro- and nanotopographical changes. The cross-linked poly[ethylene-co-(vinyl acetate)] substrates possess arrays of microcylinders with a nanorough top surface. It is hypothesized that the specific micro-/nanotopography of the surface allows trapping of a water film at the micro interspace and in this way generates the aerophobic behavior. The structured substrates were programmed to a temporarily stable, nanoscale flat substrate showing aerophilic behavior. Upon heating, the topographical changes caused a switch in contact angle from aerophilic to aerophobic for approaching air bubbles. In this way, the initial adhesion of air bubbles to the programmed flat substrate could be turned into repellence for the recovered substrate surface. The temperature at which the repellence of air bubbles starts can be adjusted from 58 ± 3 °C to 73 ± 3 °C by varying the deformation temperature applied during the temperature-memory programming procedure. The presented actively switching polymeric substrates are attractive candidates for applications, where an on-demand gas bubble repellence is advantageous.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 639 
KW  - aerophobicity
KW  - temperature-memory effect
KW  - switchable wettability
KW  - air bubble repellence
KW  - thermo-responsive polymer
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424601
SN  - 1866-8372
IS  - 639
ER  - 
TY  - GEN
A1  - Sperber, Hannah Sabeth
A1  - Welke, Robert-William
A1  - Petazzi, Roberto Arturo
A1  - Bergmann, Ronny
A1  - Schade, Matthias
A1  - Shai, Yechiel
A1  - Chiantia, Salvatore
A1  - Herrmann, Andreas
A1  - Schwarzer, Roland
T1  - Self-association and subcellular localization of Puumala hantavirus envelope proteins
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Hantavirus assembly and budding are governed by the surface glycoproteins Gn and Gc. In this study, we investigated the glycoproteins of Puumala, the most abundant Hantavirus species in Europe, using fluorescently labeled wild-type constructs and cytoplasmic tail (CT) mutants. We analyzed their intracellular distribution, co-localization and oligomerization, applying comprehensive live, single-cell fluorescence techniques, including confocal microscopy, imaging flow cytometry, anisotropy imaging and Number&Brightness analysis. We demonstrate that Gc is significantly enriched in the Golgi apparatus in absence of other viral components, while Gn is mainly restricted to the endoplasmic reticulum (ER). Importantly, upon co-expression both glycoproteins were found in the Golgi apparatus. Furthermore, we show that an intact CT of Gc is necessary for efficient Golgi localization, while the CT of Gn influences protein stability. Finally, we found that Gn assembles into higher-order homo-oligomers, mainly dimers and tetramers, in the ER while Gc was present as mixture of monomers and dimers within the Golgi apparatus. Our findings suggest that PUUV Gc is the driving factor of the targeting of Gc and Gn to the Golgi region, while Gn possesses a significantly stronger self-association potential.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 648 
KW  - Sin-Nombre-Virus
KW  - nucleocapsid protein
KW  - cytoplasmic tails
KW  - electron cryotomography
KW  - autophagic clearance
KW  - glycoprotein
KW  - Gn
KW  - G1
KW  - brightness
KW  - fever
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425040
SN  - 1866-8372
IS  - 648
ER  - 
TY  - GEN
A1  - Radbruch, Moritz
A1  - Pischon, Hannah
A1  - Ostrowski, Anja
A1  - Volz, Pierre
A1  - Brodwolf, Robert
A1  - Neumann, Falko
A1  - Unbehauen, Michael
A1  - Kleuser, Burkhard
A1  - Haag, Rainer
A1  - Ma, Nan
A1  - Alexiev, Ulrike
A1  - Mundhenk, Lars
A1  - Gruber, Achim D.
T1  - Dendritic core-multishell nanocarriers in murine models of healthy and atopic skin
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Dendritic hPG-amid-C18-mPEG core-multishell nanocarriers (CMS) represent a novel class of unimolecular micelles that hold great potential as drug transporters, e. g., to facilitate topical therapy in skin diseases. Atopic dermatitis is among the most common inflammatory skin disorders with complex barrier alterations which may affect the efficacy of topical treatment.

Here, we tested the penetration behavior and identified target structures of unloaded CMS after topical administration in healthy mice and in mice with oxazolone-induced atopic dermatitis. We further examined whole body distribution and possible systemic side effects after simulating high dosage dermal penetration by subcutaneous injection.

Following topical administration, CMS accumulated in the stratum corneum without penetration into deeper viable epidermal layers. The same was observed in atopic dermatitis mice, indicating that barrier alterations in atopic dermatitis had no influence on the penetration of CMS. Following subcutaneous injection, CMS were deposited in the regional lymph nodes as well as in liver, spleen, lung, and kidney. However, in vitro toxicity tests, clinical data, and morphometry-assisted histopathological analyses yielded no evidence of any toxic or otherwise adverse local or systemic effects of CMS, nor did they affect the severity or course of atopic dermatitis.

Taken together, CMS accumulate in the stratum corneum in both healthy and inflammatory skin and appear to be highly biocompatible in the mouse even under conditions of atopic dermatitis and thus could potentially serve to create a depot for anti-inflammatory drugs in the skin.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 724 
KW  - CMS
KW  - skin
KW  - topical treatment
KW  - dermal delivery
KW  - atopic dermatitis
KW  - oxazolone
KW  - fluorescence lifetime imaging microscopy
KW  - nanomaterials
KW  - multi-domain nanoparticles
KW  - penetration enhancement
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-430136
SN  - 1866-8372
IS  - 724
ER  - 
TY  - JOUR
A1  - Sarhan, Radwan Mohamed
A1  - Koopman, Wouter-Willem Adriaan
A1  - Schuetz, Roman
A1  - Schmid, Thomas
A1  - Liebig, Ferenc
A1  - Koetz, Joachim
A1  - Bargheer, Matias
T1  - The importance of plasmonic heating for the plasmondriven photodimerization of 4-nitrothiophenol
JF  - Scientific Reports
N2  - Metal nanoparticles form potent nanoreactors, driven by the optical generation of energetic electrons and nanoscale heat. The relative influence of these two factors on nanoscale chemistry is strongly debated. This article discusses the temperature dependence of the dimerization of 4-nitrothiophenol (4-NTP) into 4,4′-dimercaptoazobenzene (DMAB) adsorbed on gold nanoflowers by Surface-Enhanced Raman Scattering (SERS). Raman thermometry shows a significant optical heating of the particles. The ratio of the Stokes and the anti-Stokes Raman signal moreover demonstrates that the molecular temperature during the reaction rises beyond the average crystal lattice temperature of the plasmonic particles. The product bands have an even higher temperature than reactant bands, which suggests that the reaction proceeds preferentially at thermal hot spots. In addition, kinetic measurements of the reaction during external heating of the reaction environment yield a considerable rise of the reaction rate with temperature. Despite this significant heating effects, a comparison of SERS spectra recorded after heating the sample by an external heater to spectra recorded after prolonged illumination shows that the reaction is strictly photo-driven. While in both cases the temperature increase is comparable, the dimerization occurs only in the presence of light. Intensity dependent measurements at fixed temperatures confirm this finding.
KW  - enhanced raman-scattering
KW  - charge-transfer
KW  - metal
KW  - nanoparticles
KW  - catalysis
KW  - AU
KW  - 4-nitrobenzenethiol
KW  - aminothiophenol
KW  - photocatalysis
KW  - wavelength
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-38627-2
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - GEN
A1  - Sarhan, Radwan Mohamed
A1  - Koopman, Wouter-Willem Adriaan
A1  - Schuetz, Roman
A1  - Schmid, Thomas
A1  - Liebig, Ferenc
A1  - Koetz, Joachim
A1  - Bargheer, Matias
T1  - The importance of plasmonic heating for the plasmondriven photodimerization of 4-nitrothiophenol
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Metal nanoparticles form potent nanoreactors, driven by the optical generation of energetic electrons and nanoscale heat. The relative influence of these two factors on nanoscale chemistry is strongly debated. This article discusses the temperature dependence of the dimerization of 4-nitrothiophenol (4-NTP) into 4,4′-dimercaptoazobenzene (DMAB) adsorbed on gold nanoflowers by Surface-Enhanced Raman Scattering (SERS). Raman thermometry shows a significant optical heating of the particles. The ratio of the Stokes and the anti-Stokes Raman signal moreover demonstrates that the molecular temperature during the reaction rises beyond the average crystal lattice temperature of the plasmonic particles. The product bands have an even higher temperature than reactant bands, which suggests that the reaction proceeds preferentially at thermal hot spots. In addition, kinetic measurements of the reaction during external heating of the reaction environment yield a considerable rise of the reaction rate with temperature. Despite this significant heating effects, a comparison of SERS spectra recorded after heating the sample by an external heater to spectra recorded after prolonged illumination shows that the reaction is strictly photo-driven. While in both cases the temperature increase is comparable, the dimerization occurs only in the presence of light. Intensity dependent measurements at fixed temperatures confirm this finding.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 698 
KW  - enhanced raman-scattering
KW  - charge-transfer
KW  - metal
KW  - nanoparticles
KW  - catalysis
KW  - AU
KW  - 4-nitrobenzenethiol
KW  - aminothiophenol
KW  - photocatalysis
KW  - wavelength
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427197
SN  - 1866-8372
IS  - 698
ER  - 
TY  - GEN
A1  - Lara, Mark J.
A1  - Nitze, Ingmar
A1  - Grosse, Guido
A1  - Martin, Philip
A1  - McGuire, A. David
T1  - Reduced arctic tundra productivity linked with landform and climate change interactions
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Arctic tundra ecosystems have experienced unprecedented change associated with climate warming over recent decades. Across the Pan-Arctic, vegetation productivity and surface greenness have trended positively over the period of satellite observation. However, since 2011 these trends have slowed considerably, showing signs of browning in many regions. It is unclear what factors are driving this change and which regions/landforms will be most sensitive to future browning. Here we provide evidence linking decadal patterns in arctic greening and browning with regional climate change and local permafrost-driven landscape heterogeneity. We analyzed the spatial variability of decadal-scale trends in surface greenness across the Arctic Coastal Plain of northern Alaska (similar to 60,000 km(2)) using the Landsat archive (1999-2014), in combination with novel 30 m classifications of polygonal tundra and regional watersheds, finding landscape heterogeneity and regional climate change to be the most important factors controlling historical greenness trends. Browning was linked to increased temperature and precipitation, with the exception of young landforms (developed following lake drainage), which will likely continue to green. Spatiotemporal model forecasting suggests carbon uptake potential to be reduced in response to warmer and/or wetter climatic conditions, potentially increasing the net loss of carbon to the atmosphere, at a greater degree than previously expected.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 550 
KW  - winter warming events
KW  - permafrost
KW  - Alaska
KW  - trends
KW  - ice
KW  - CO2
KW  - degradation
KW  - landscapes
KW  - ecosystem
KW  - exchange
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423132
SN  - 1866-8372
IS  - 550
ER  - 
TY  - JOUR
A1  - Ceulemans, Ruben
A1  - Gaedke, Ursula
A1  - Klauschies, Toni
A1  - Guill, Christian
T1  - The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system
JF  - Scientific Reports
N2  - Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.
KW  - early-warning signals
KW  - top-down control
KW  - community ecology
KW  - regime shifts
KW  - food webs
KW  - compensatory dynamics
KW  - consumer diversity
KW  - metabolic theory
KW  - rapid evolution
KW  - stable states
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-43974-1
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - JOUR
A1  - Heuer, Leonie
A1  - Orland, Andreas
T1  - Cooperation in the Prisoner’s Dilemma
BT  - an experimental comparison between pure and mixed strategies
JF  - Royal Society Open Science
N2  - Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner’s Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts’ level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects’ level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.
KW  - cooperation
KW  - experiment
KW  - human behaviour
KW  - Prisoner's Dilemma
Y1  - 2019
U6  - https://doi.org/10.1098/rsos.182142
SN  - 2054-5703
VL  - 6
PB  - Royal Soc. Publ.
CY  - London
ER  - 
TY  - JOUR
A1  - Kindler, Oliver
A1  - Pulkkinen, Otto
A1  - Cherstvy, Andrey G.
A1  - Metzler, Ralf
T1  - Burst Statistics in an Early Biofilm Quorum Sensing Mode
BT  - The Role of Spatial Colony-Growth Heterogeneity
JF  - Scientific Reports
N2  - Quorum-sensing bacteria in a growing colony of cells send out signalling molecules (so-called “autoinducers”) and themselves sense the autoinducer concentration in their vicinity. Once—due to increased local cell density inside a “cluster” of the growing colony—the concentration of autoinducers exceeds a threshold value, cells in this clusters get “induced” into a communal, multi-cell biofilm-forming mode in a cluster-wide burst event. We analyse quantitatively the influence of spatial disorder, the local heterogeneity of the spatial distribution of cells in the colony, and additional physical parameters such as the autoinducer signal range on the induction dynamics of the cell colony. Spatial inhomogeneity with higher local cell concentrations in clusters leads to earlier but more localised induction events, while homogeneous distributions lead to comparatively delayed but more concerted induction of the cell colony, and, thus, a behaviour close to the mean-field dynamics. We quantify the induction dynamics with quantifiers such as the time series of induction events and burst sizes, the grouping into induction families, and the mean autoinducer concentration levels. Consequences for different scenarios of biofilm growth are discussed, providing possible cues for biofilm control in both health care and biotechnology.
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-48525-2
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited part of Springer Nature
CY  - London
ER  - 
TY  - THES
A1  - Schulz-Behrendt, Claudia
T1  - Entwicklung und Evaluation eines berufsorientierten Gruppenprogramms Sozialer Arbeit in der medizinischen Rehabilitation am Beispiel kardiovaskulärer Erkrankungen
N2  - Die vorliegende Untersuchung analysierte den direkten Zusammenhang eines berufsbezogenen Angebots Sozialer Gruppenarbeit mit dem Ergebnis beruflicher Wiedereingliederung bei Rehabilitandinnen und Rehabilitanden in besonderen beruflichen Problemlagen. Sie wurde von der Deutschen Rentenversicherung Bund als Forschungsprojekt vom 01.01.2013 bis 31.12. 2015 gefördert und an der Professur für Rehabilitationswissenschaften der Universität Potsdam realisiert. 
Die Forschungsfrage lautete: Kann eine intensive sozialarbeiterische Gruppenintervention im Rahmen der stationären medizinischen Rehabilitation soweit auf die Stärkung sozialer Kompetenzen und die Soziale Unterstützung von Rehabilitandinnen und Rehabilitanden einwirken, dass sich dadurch langfristige Verbesserungen hinsichtlich der beruflichen Wiedereingliederung im Vergleich zur konventionellen Behandlung ergeben?
Die Studie gliederte sich in eine qualitative und eine quantitative Erhebung mit einer zwischenliegenden Intervention. Eingeschlossen waren 352 Patientinnen und Patienten im Alter zwischen 18 und 65 Jahren mit kardiovaskulären Diagnosen, deren Krankheitsbilder häufig von komplexen Problemlagen begleitet sind, verbunden mit einer schlechten sozialmedizinischen Prognose. 
Die Evaluation der Gruppenintervention erfolgte in einem clusterrandomisierten kontrollierten Studiendesign, um einen empirischen Nachweis darüber zu erbringen, inwieweit die Intervention gegenüber der regulären sozialarbeiterischen Behandlung höhere Effekte erzielen kann. Die Interventionsgruppen nahmen am Gruppenprogramm teil, die Kontrollgruppen erhielten die reguläre sozialarbeiterische Behandlung.
Im Ergebnis konnte mit dieser Stichprobe kein Nachweis zur Verbesserung der beruflichen Wiedereingliederung, der gesundheitsbezogenen Arbeitsfähigkeit, der Lebensqualität sowie der Sozialen Unterstützung durch die Teilnahme am sozialarbeiterischen Gruppenprogramm erbracht werden. Die Return-To-Work-Rate betrug 43,7 %, ein Viertel der Untersuchungsgruppe befand sich nach einem Jahr in Arbeitslosigkeit. Die durchgeführte Gruppenintervention ist dem konventionellen Setting Sozialer Arbeit als gleichwertig anzusehen.
Schlussfolgernd wurde auf eine sozialarbeiterische Unterstützung der beruflichen Wiedereingliederung über einen längeren Zeitraum nach einer kardiovaskulären Erkrankung verwiesen, insbesondere durch wohnortnahe Angebote zu einem späteren Zeitpunkt bei stabilerer Gesundheit. Aus den Erhebungen ließen sich mögliche Erfolge bei engerer Kooperation zwischen dem Fachbereich der Sozialen Arbeit und der Psychologie ableiten. Ebenfalls gab es Hinweise auf die einflussreiche Rolle der Angehörigen, die durch Einbindung in die Soziale Beratung unterstützend auf den Wiedereingliederungsprozess wirken könnten. Die Passgenauigkeit der untersuchten sozialarbeiterischen Gruppeninterventionen ist durch eine gezielte Soziale Diagnostik zu verbessern.
N2  - The present investigation analyzed the direct correlation of a work-related group training by Social Work with the result of occupational reintegration of rehabilitation patients with specific work-related problems. It was supported as a research project by the Deutsche Rentenversicherung Bund from 01.01.2012 to 31.12.2015 and implemented at the professorship for rehabilitation sciences at the university of Potsdam.
The research question was: Is it possible for an intensive group intervention program of Social Work within stationary medical rehabilitation to impact so significantly on the strengthening of social skills and social support of rehabilitation patients as to result in long-term improvements of occupational reintegration in comparison to the conventional treatment?
The study is divided into a qualitative and a quantitative investigation including an intermediate intervention. Comprised were 352 patients at an age between 18 and 65 years with cardiovascular diseases which are frequently connected with complex problems and a poor socio-medical prognosis.
The evaluation of the group intervention was based on a cluster-randomized controlled study design in order to provide empirical evidence about the extent to which the group intervention achieves higher effects than the regular treatment of Social Work.
The intervention groups took part at the group intervention, the control groups received the regular treatment of Social Work.
Ultimately, no evidence of an improvement of occupational reintegration, health-related work ability, quality of life and social support could be provided with that sample. The return-to-work rate was 43,7 %, a quarter of the investigation group was in unemployment after one year. The implemented group intervention may thus be considered equivalent to the conventional setting of Social Work.
In conclusion, it was indicated to support the occupational reintegration by Social Work over a longer period after cardiovascular disease, especially by close-to-home offers at a later moment in time with more stable health.
From this investigation we may derive possible successes for closer cooperation between the disciplines of Social Work and Psychology. Furthermore there were indications of the influential role of the relatives, who could support the process of reintegration by their involvement with the social counselling. The accuracy of fit concerning the investigated group intervention is to be improved through targeted social diagnosis.
KW  - Soziale Arbeit
KW  - social work
KW  - Kardiologische Rehabilitation
KW  - cardiac rehabilitation
KW  - Berufliche Wiedereingliederung
KW  - Return to work
KW  - Medizinisch-beruflich orientierte Rehabilitation (MBOR)
KW  - work-related medical rehabilitation
KW  - randomisierte kontrollierte Studie (RCT)
KW  - randomized controlled trial
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491397
ER  - 
TY  - GEN
A1  - Kaboth-Bahr, Stefanie
A1  - Bahr, André
A1  - Zeeden, Christian
A1  - Yamoah, Kweku A.
A1  - Lone, Mahjoor Ahmad
A1  - Chuang, Chih-Kai
A1  - Löwemark, Ludvig
A1  - Wei, Kuo-Yen
T1  - A tale of shifting relations
BT  - East Asian summer and winter monsoon variability during the Holocene
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Understanding the dynamics between the East Asian summer (EASM) and winter monsoon (EAWM) is needed to predict their variability under future global warming scenarios. Here, we investigate the relationship between EASM and EAWM as well as the mechanisms driving their variability during the last 10,000 years by stacking marine and terrestrial (non-speleothem) proxy records from the East Asian realm. This provides a regional and proxy independent signal for both monsoonal systems. The respective signal was subsequently analysed using a linear regression model. We find that the phase relationship between EASM and EAWM is not time-constant and significantly depends on orbital configuration changes. In addition, changes in the Atlantic Meridional Overturning circulation, Arctic sea-ice coverage, El Niño-Southern Oscillation and Sun Spot numbers contributed to millennial scale changes in the EASM and EAWM during the Holocene. We also argue that the bulk signal of monsoonal activity captured by the stacked non-speleothem proxy records supports the previously argued bias of speleothem climatic archives to moisture source changes and/or seasonality.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1145 
KW  - Environmental sciences
KW  - Ocean sciences
KW  - Solid Earth sciences
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515735
SN  - 1866-8372
ER  - 
TY  - THES
A1  - Hecher, Markus
T1  - Advanced tools and methods for treewidth-based problem solving
N2  - In the last decades, there was a notable progress in solving the well-known Boolean satisfiability (Sat) problem, which can be witnessed by powerful Sat solvers. One of the reasons why these solvers are so fast are structural properties of instances that are utilized by the solver’s interna. This thesis deals with the well-studied structural property treewidth, which measures the closeness of an instance to being a tree. In fact, there are many problems parameterized by treewidth that are solvable in polynomial time in the instance size when parameterized by treewidth.
In this work, we study advanced treewidth-based methods and tools for problems in knowledge representation and reasoning (KR). Thereby, we provide means to establish precise runtime results (upper bounds) for canonical problems relevant to KR. Then, we present a new type of problem reduction, which we call decomposition-guided (DG) that
allows us to precisely monitor the treewidth when reducing from one problem to another problem. This new reduction type will be the basis for a long-open lower bound result for quantified Boolean formulas and allows us to design a new methodology for establishing runtime lower bounds for problems parameterized by treewidth.
Finally, despite these lower bounds, we provide an efficient implementation of algorithms that adhere to treewidth. Our approach finds suitable abstractions of instances, which are subsequently refined in a recursive fashion, and it uses Sat solvers for solving subproblems. It turns out that our resulting solver is quite competitive for two canonical counting problems related to Sat.
N2  - In den letzten Jahrzehnten konnte ein beachtlicher Fortschritt im Bereich der Aussagenlogik verzeichnet werden. Dieser äußerte sich dadurch, dass für das wichtigste Problem in diesem Bereich, genannt „Sat“, welches sich mit der Fragestellung befasst, ob eine gegebene aussagenlogische Formel erfüllbar ist oder nicht, überwältigend schnelle Computerprogramme („Solver“) entwickelt werden konnten. Interessanterweise liefern diese Solver eine beeindruckende Leistung, weil sie oft selbst Probleminstanzen mit mehreren Millionen von Variablen spielend leicht lösen können. Auf der anderen Seite jedoch glaubt man in der Wissenschaft weitgehend an die Exponentialzeithypothese (ETH), welche besagt, dass man im schlimmsten Fall für das Lösen einer Instanz in diesem Bereich exponentielle Laufzeit in der Anzahl der Variablen benötigt. Dieser vermeintliche Widerspruch ist noch immer nicht vollständig geklärt, denn wahrscheinlich gibt es viele ineinandergreifende Gründe für die Schnelligkeit aktueller Sat Solver. Einer dieser Gründe befasst sich weitgehend mit strukturellen Eigenschaften von Probleminstanzen, die wohl indirekt und intern von diesen Solvern ausgenützt werden.

Diese Dissertation beschäftigt sich mit solchen strukturellen Eigenschaften, nämlich mit der sogenannten Baumweite. Die Baumweite ist sehr gut erforscht und versucht zu messen, wie groß der Abstand von Probleminstanzen zu Bäumen ist (Baumnähe). Allerdings ist dieser Parameter sehr generisch und bei Weitem nicht auf Problemstellungen der Aussagenlogik beschränkt. Tatsächlich gibt es viele weitere Probleme, die parametrisiert mit Baumweite in polynomieller Zeit gelöst werden können. Interessanterweise gibt es auch viele Probleme in der Wissensrepräsentation (KR), von denen man davon ausgeht, dass sie härter sind als das Problem Sat, die bei beschränkter Baumweite in polynomieller Zeit gelöst werden können. Ein prominentes Beispiel solcher Probleme ist das Problem QSat, welches sich für die Gültigkeit einer gegebenen quantifizierten, aussagenlogischen Formel (QBF), das sind aussagenlogische Formeln, wo gewisse Variablen existenziell bzw. universell quantifiziert werden können, befasst. Bemerkenswerterweise wird allerdings auch im Zusammenhang mit Baumweite, ähnlich zu Methoden der klassischen Komplexitätstheorie, die tatsächliche Komplexität (Härte) solcher Problemen quantifiziert, wo man die exakte Laufzeitabhängigkeit beim Problemlösen in der Baumweite (Stufe der Exponentialität) beschreibt.

Diese Arbeit befasst sich mit fortgeschrittenen, Baumweite-basierenden Methoden und Werkzeugen für Probleme der Wissensrepräsentation und künstlichen Intelligenz (AI). Dabei präsentieren wir Methoden, um präzise Laufzeitresultate (obere Schranken) für prominente Fragmente der Antwortmengenprogrammierung (ASP), welche ein kanonisches Paradigma zum Lösen von Problemen der Wissensrepräsentation darstellt, zu erhalten. Unsere Resultate basieren auf dem Konzept der dynamischen Programmierung, die angeleitet durch eine sogenannte Baumzerlegung und ähnlich dem Prinzip „Teile-und-herrsche“ funktioniert. Solch eine Baumzerlegung ist eine konkrete, strukturelle Zerlegung einer Probleminstanz, die sich stark an der Baumweite orientiert.

Des Weiteren präsentieren wir einen neuen Typ von Problemreduktion, den wir als „decomposition-guided (DG)“, also „zerlegungsangeleitet“, bezeichnen. Dieser Reduktionstyp erlaubt es, Baumweiteerhöhungen und -verringerungen während einer Problemreduktion von einem bestimmten Problem zu einem anderen Problem präzise zu untersuchen und zu kontrollieren. Zusätzlich ist dieser neue Reduktionstyp die Basis, um ein lange offen gebliebenes Resultat betreffend quantifizierter, aussagenlogischer Formeln zu zeigen. Tatsächlich sind wir damit in der Lage, präzise untere Schranken, unter der Annahme der Exponentialzeithypothese, für das Problem QSat bei beschränkter Baumweite zu zeigen. Genauer gesagt können wir mit diesem Konzept der DG Reduktionen zeigen, dass das Problem QSat, beschränkt auf Quantifizierungsrang ` und parametrisiert mit Baumweite k, im Allgemeinen nicht besser als in einer Laufzeit, die `-fach exponentiell in der Baumweite und polynomiell in der Instanzgröße ist1, lösen. Dieses Resultat hebt auf nicht-inkrementelle Weise ein bekanntes Ergebnis für Quantifizierungsrang 2 auf beliebige Quantifizierungsränge, allerdings impliziert es auch sehr viele weitere Konsequenzen.

Das Resultat über die untere Schranke des Problems QSat erlaubt es, eine neue Methodologie zum Zeigen unterer Schranken einer Vielzahl von Problemen der Wissensrepräsentation und künstlichen Intelligenz, zu etablieren. In weiterer Konsequenz können wir damit auch zeigen, dass die oberen Schranken sowie die DG Reduktionen dieser Arbeit unter der Hypothese ETH „eng“ sind, d.h., sie können wahrscheinlich nicht mehr signifikant verbessert werden. Die Ergebnisse betreffend der unteren Schranken für QSat und die dazugehörige Methodologie konstituieren in gewisser Weise eine Hierarchie von über Baumweite parametrisierte Laufzeitklassen. Diese Laufzeitklassen können verwendet werden, um die Härte von Problemen für das Ausnützen von Baumweite zu quantifizieren und diese entsprechend ihrer Laufzeitabhängigkeit bezüglich Baumweite zu kategorisieren.

Schlussendlich und trotz der genannten Resultate betreffend unterer Schranken sind wir im Stande, eine effiziente Implementierung von Algorithmen basierend auf dynamischer Programmierung, die entlang einer Baumzerlegung angeleitet wird, zur Verfügung zu stellen. Dabei funktioniert unser Ansatz dahingehend, indem er probiert, passende Abstraktionen von Instanzen zu finden, die dann im Endeffekt sukzessive und auf rekursive Art und Weise verfeinert und verbessert werden. Inspiriert durch die enorme Effizienz und Effektivität der Sat Solver, ist unsere Implementierung ein hybrider Ansatz, weil sie den starken Gebrauch von Sat Solvern zum Lösen diverser Subprobleme, die während der dynamischen Programmierung auftreten, pflegt. Dabei stellt sich heraus, dass der resultierende Solver unserer Implementierung im Bezug auf Effizienz beim Lösen von zwei kanonischen, Sat-verwandten Zählproblemen mit bestehenden Solvern locker mithalten kann. Tatsächlich sind wir im Stande, Instanzen, wo die oberen Schranken von Baumweite 260 übersteigen, zu lösen. Diese überraschende Beobachtung zeigt daher, dass Baumweite ein wichtiger Parameter sein könnte, der wohl in modernen Designs von Solvern berücksichtigt werden sollte.
KW  - Treewidth
KW  - Dynamic Programming
KW  - Knowledge Representation and Reasoning
KW  - Artificial Intelligence
KW  - Computational Complexity
KW  - Parameterized Complexity
KW  - Answer Set Programming
KW  - Exponential Time Hypothesis
KW  - Lower Bounds
KW  - Algorithms
KW  - Algorithmen
KW  - Antwortmengenprogrammierung
KW  - Künstliche Intelligenz
KW  - Komplexitätstheorie
KW  - Dynamische Programmierung
KW  - Exponentialzeit Hypothese
KW  - Wissensrepräsentation und Schlussfolgerung
KW  - Untere Schranken
KW  - Parametrisierte Komplexität
KW  - Baumweite
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-512519
ER  - 
TY  - GEN
A1  - Kaastra, Jelle S.
A1  - Paerels, Frits B.S.
A1  - Durret, Florence
A1  - Schindler, Sabine
A1  - Richter, Philipp
T1  - Thermal radiation processes
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - We discuss the different physical processes that are important to understand the thermal X-ray emission and absorption spectra of the diffuse gas in clusters of galaxies and the warm-hot intergalactic medium. The ionisation balance, line and continuum emission and absorption properties are reviewed and several practical examples are given that illustrate the most important diagnostic features in the X-ray spectra.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 891 
KW  - atomic processes
KW  - radiation mechanisms: thermal
KW  - intergalactic medium
KW  - X-rays: general
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436220
SN  - 1866-8372
IS  - 891
SP  - 155
EP  - 190
ER  - 
TY  - JOUR
A1  - Wetzel, Maria
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - Quantifying rock weakening due to decreasing calcite mineral content by numerical simulations
JF  - Materials
N2  - The quantification of changes in geomechanical properties due to chemical reactions is of paramount importance for geological subsurface utilisation, since mineral dissolution generally reduces rock stiffness. In the present study, the effective elastic moduli of two digital rock samples, the Fontainebleau and Bentheim sandstones, are numerically determined based on micro-CT images. Reduction in rock stiffness due to the dissolution of 10% calcite cement by volume out of the pore network is quantified for three synthetic spatial calcite distributions (coating, partial filling and random) using representative sub-cubes derived from the digital rock samples. Due to the reduced calcite content, bulk and shear moduli decrease by 34% and 38% in maximum, respectively. Total porosity is clearly the dominant parameter, while spatial calcite distribution has a minor impact, except for a randomly chosen cement distribution within the pore network. Moreover, applying an initial stiffness reduced by 47% for the calcite cement results only in a slightly weaker mechanical behaviour. Using the quantitative approach introduced here substantially improves the accuracy of predictions in elastic rock properties compared to general analytical methods, and further enables quantification of uncertainties related to spatial variations in porosity and mineral distribution.
KW  - digital rock physics
KW  - micro-CT
KW  - elastic properties
KW  - numerical simulation
KW  - chemical-mechanical interaction
KW  - Code_Aster
KW  - composite properties
Y1  - 2018
U6  - https://doi.org/10.3390/ma11040542
SN  - 1996-1944
VL  - 11
IS  - 4
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Wetzel, Maria
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - Quantifying rock weakening due to decreasing calcite mineral content by numerical simulations
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The quantification of changes in geomechanical properties due to chemical reactions is of paramount importance for geological subsurface utilisation, since mineral dissolution generally reduces rock stiffness. In the present study, the effective elastic moduli of two digital rock samples, the Fontainebleau and Bentheim sandstones, are numerically determined based on micro-CT images. Reduction in rock stiffness due to the dissolution of 10% calcite cement by volume out of the pore network is quantified for three synthetic spatial calcite distributions (coating, partial filling and random) using representative sub-cubes derived from the digital rock samples. Due to the reduced calcite content, bulk and shear moduli decrease by 34% and 38% in maximum, respectively. Total porosity is clearly the dominant parameter, while spatial calcite distribution has a minor impact, except for a randomly chosen cement distribution within the pore network. Moreover, applying an initial stiffness reduced by 47% for the calcite cement results only in a slightly weaker mechanical behaviour. Using the quantitative approach introduced here substantially improves the accuracy of predictions in elastic rock properties compared to general analytical methods, and further enables quantification of uncertainties related to spatial variations in porosity and mineral distribution.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1092 
KW  - digital rock physics
KW  - micro-CT
KW  - elastic properties
KW  - numerical simulation
KW  - chemical-mechanical interaction
KW  - Code_Aster
KW  - composite properties
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-473089
SN  - 1866-8372
IS  - 1092
ER  - 
TY  - JOUR
A1  - Hashemi, Seirana
A1  - Razaghi-Moghadam, Zahra
A1  - Nikoloski, Zoran
T1  - Identification of flux trade-offs in metabolic networks
JF  - Scientific reports
N2  - Trade-offs are inherent to biochemical networks governing diverse cellular functions, from gene expression to metabolism. Yet, trade-offs between fluxes of biochemical reactions in a metabolic network have not been formally studied. Here, we introduce the concept of absolute flux trade-offs and devise a constraint-based approach, termed FluTO, to identify and enumerate flux trade-offs in a given genome-scale metabolic network. By employing the metabolic networks of Escherichia coli and Saccharomyces cerevisiae, we demonstrate that the flux trade-offs are specific to carbon sources provided but that reactions involved in the cofactor and prosthetic group biosynthesis are present in trade-offs across all carbon sources supporting growth. We also show that absolute flux trade-offs depend on the biomass reaction used to model the growth of Arabidopsis thaliana under different carbon and nitrogen conditions. The identified flux trade-offs reflect the tight coupling between nitrogen, carbon, and sulphur metabolisms in leaves of C-3 plants. Altogether, FluTO provides the means to explore the space of alternative metabolic routes reflecting the constraints imposed by inherent flux trade-offs in large-scale metabolic networks.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-03224-9
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Zemella, Anne
A1  - Thoring, Lena
A1  - Hoffmeister, Christian
A1  - Samalikova, Maria
A1  - Ehren, Patricia
A1  - Wüstenhagen, Doreen Anja
A1  - Kubick, Stefan
T1  - Cell-free protein synthesis as a novel tool for directed glycoengineering of active erythropoietin
JF  - Scientific reports
N2  - As one of the most complex post-translational modification, glycosylation is widely involved in cell adhesion, cell proliferation and immune response. Nevertheless glycoproteins with an identical polypeptide backbone mostly differ in their glycosylation patterns. Due to this heterogeneity, the mapping of different glycosylation patterns to their associated function is nearly impossible. In the last years, glycoengineering tools including cell line engineering, chemoenzymatic remodeling and site-specific glycosylation have attracted increasing interest. The therapeutic hormone erythropoietin (EPO) has been investigated in particular by various groups to establish a production process resulting in a defined glycosylation pattern. However commercially available recombinant human EPO shows batch-to-batch variations in its glycoforms. Therefore we present an alternative method for the synthesis of active glycosylated EPO with an engineered O-glycosylation site by combining eukaryotic cell-free protein synthesis and site-directed incorporation of non-canonical amino acids with subsequent chemoselective modifications.
Y1  - 2018
U6  - https://doi.org/10.1038/s41598-018-26936-x
SN  - 2045-2322
VL  - 8
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - GEN
A1  - Paraskevopoulou, Sofia
A1  - Dennis, Alice B.
A1  - Weithoff, Guntram
A1  - Tiedemann, Ralph
T1  - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1012 
KW  - Ecology
KW  - Evolution
KW  - Oyster Crassostrea-gigas
KW  - cryptic species complex
KW  - pacific oyster
KW  - thermal-stress
KW  - genetic differentiation
KW  - expression patterns
KW  - molecular phylogeny
KW  - shock proteins
KW  - evolutionary
KW  - hsp70
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-482280
SN  - 1866-8372
IS  - 1012
ER  - 
TY  - GEN
A1  - Söchting, Maximilian
A1  - Trapp, Matthias
T1  - Controlling image-stylization techniques using eye tracking
T2  - Postprints der Universität Potsdam : Reihe der Digital Engineering Fakultät
N2  - With the spread of smart phones capable of taking high-resolution photos and the development of high-speed mobile data infrastructure, digital visual media is becoming one of the most important forms of modern communication. With this development, however, also comes a devaluation of images as a media form with the focus becoming the frequency at which visual content is generated instead of the quality of the content. In this work, an interactive system using image-abstraction techniques and an eye tracking sensor is presented, which allows users to experience diverting and dynamic artworks that react to their eye movement. The underlying modular architecture enables a variety of different interaction techniques that share common design principles, making the interface as intuitive as possible. The resulting experience allows users to experience a game-like interaction in which they aim for a reward, the artwork, while being held under constraints, e.g., not blinking. The co nscious eye movements that are required by some interaction techniques hint an interesting, possible future extension for this work into the field of relaxation exercises and concentration training.
T3  - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 7 
KW  - eye-tracking
KW  - image abstraction
KW  - image processing
KW  - artistic image stylization
KW  - interactive media
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524717
IS  - 7
ER  - 
TY  - GEN
A1  - Scheibel, Willy
A1  - Trapp, Matthias
A1  - Limberger, Daniel
A1  - Döllner, Jürgen Roland Friedrich
T1  - A taxonomy of treemap visualization techniques
T2  - Postprints der Universität Potsdam : Reihe der Digital Engineering Fakultät
N2  - A treemap is a visualization that has been specifically designed to facilitate the exploration of tree-structured data and, more general, hierarchically structured data. The family of visualization techniques that use a visual metaphor for parent-child relationships based “on the property of containment” (Johnson, 1993) is commonly referred to as treemaps. However, as the number of variations of treemaps grows, it becomes increasingly important to distinguish clearly between techniques and their specific characteristics. This paper proposes to discern between Space-filling Treemap TS, Containment Treemap TC, Implicit Edge Representation Tree TIE, and Mapped Tree TMT for classification of hierarchy visualization techniques and highlights their respective properties. This taxonomy is created as a hyponymy, i.e., its classes have an is-a relationship to one another: TS TC TIE TMT. With this proposal, we intend to stimulate a discussion on a more unambiguous classification of treemaps and, furthermore, broaden what is understood by the concept of treemap itself.
T3  - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 8 
KW  - treemaps
KW  - taxonomy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524693
IS  - 8
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Janhunen, Tomi
A1  - Rintanen, Jussi
T1  - Declarative encodings of acyclicity properties
JF  - Journal of logic and computation
N2  - Many knowledge representation tasks involve trees or similar structures as abstract datatypes. However, devising compact and efficient declarative representations of such structural properties is non-obvious and can be challenging indeed. In this article, we take a number of acyclicity properties into consideration and investigate various logic-based approaches to encode them. We use answer set programming as the primary representation language but also consider mappings to related formalisms, such as propositional logic, difference logic and linear programming. We study the compactness of encodings and the resulting computational performance on benchmarks involving acyclic or tree structures.
KW  - acyclicity properties
KW  - logic-based modeling
KW  - answer set programming
KW  - satisfiability
Y1  - 2015
U6  - https://doi.org/10.1093/logcom/exv063
SN  - 0955-792X
SN  - 1465-363X
VL  - 30
IS  - 4
SP  - 923
EP  - 952
PB  - Oxford Univ. Press
CY  - Eynsham, Oxford
ER  - 
TY  - JOUR
A1  - Seep, Lea
A1  - Razaghi-Moghadam, Zahra
A1  - Nikoloski, Zoran
T1  - Reaction lumping in metabolic networks for application with thermodynamic metabolic flux analysis
JF  - Scientific reports
N2  - Thermodynamic metabolic flux analysis (TMFA) can narrow down the space of steady-state flux distributions, but requires knowledge of the standard Gibbs free energy for the modelled reactions. The latter are often not available due to unknown Gibbs free energy change of formation ,Delta fG0, of metabolites. To optimize the usage of data on thermodynamics in constraining a model, reaction lumping has been proposed to eliminate metabolites with unknown Delta fG0. However, the lumping procedure has not been formalized nor implemented for systematic identification of lumped reactions. Here, we propose, implement, and test a combined procedure for reaction lumping, applicable to genome-scale metabolic models. It is based on identification of groups of metabolites with unknown Delta fG0 whose elimination can be conducted independently of the others via: (1) group implementation, aiming to eliminate an entire such group, and, if this is infeasible, (2) a sequential implementation to ensure that a maximal number of metabolites with unknown Delta fG0 are eliminated. Our comparative analysis with genome-scale metabolic models of Escherichia coli, Bacillus subtilis, and Homo sapiens shows that the combined procedure provides an efficient means for systematic identification of lumped reactions. We also demonstrate that TMFA applied to models with reactions lumped according to the proposed procedure lead to more precise predictions in comparison to the original models. The provided implementation thus ensures the reproducibility of the findings and their application with standard TMFA.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-87643-8
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Hardy, John G.
A1  - Torres-Rendon, Jose Guillermo
A1  - Leal-Egaña, Aldo
A1  - Walther, Andreas
A1  - Schlaad, Helmut
A1  - Cölfen, Helmut
A1  - Scheibel, Thomas R.
T1  - Biomineralization of engineered spider silk protein-based composite materials for bone tissue engineering
N2  - Materials based on biodegradable polyesters, such as poly(butylene terephthalate) (PBT) or poly(butylene terephthalate-co-poly(alkylene glycol) terephthalate) (PBTAT), have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16)), that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of alkaline phosphatase activity suggesting that such composites have potential use for bone tissue engineering.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 359 
KW  - spider silk
KW  - recombinant protein
KW  - biodegradable polymers
KW  - biomaterials
KW  - biomineralization
KW  - bone tissue engineering
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400519
ER  - 
TY  - GEN
A1  - Schälicke, Svenja
A1  - Teubner, Johannes
A1  - Martin-Creuzburg, Dominik
A1  - Wacker, Alexander
T1  - Fitness response variation within and among consumer species can be co-mediated by food quantity and biochemical quality
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - In natural heterogeneous environments, the fitness of animals is strongly influenced by the availability and composition of food. Food quantity and biochemical quality constraints may affect individual traits of consumers differently, mediating fitness response variation within and among species. Using a multifactorial experimental approach, we assessed population growth rate, fecundity, and survival of six strains of the two closely related freshwater rotifer species Brachionus calyciflorus sensu stricto and Brachionus fernandoi. Therefore, rotifers fed low and high concentrations of three algal species differing in their biochemical food quality. Additionally, we explored the potential of a single limiting biochemical nutrient to mediate variations in population growth response. Therefore, rotifers fed a sterol-free alga, which we supplemented with cholesterol-containing liposomes. Co-limitation by food quantity and biochemical food quality resulted in differences in population growth rates among strains, but not between species, although effects on fecundity and survival differed between species. The effect of cholesterol supplementation on population growth was strain-specific but not species-specific. We show that fitness response variations within and among species can be mediated by biochemical food quality. Dietary constraints thus may act as evolutionary drivers on physiological traits of consumers, which may have strong implications for various ecological interactions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 806 
KW  - Polyunsaturated Fatty-Acids
KW  - Life-History Consequences
KW  - 2 Different Strains
KW  - Population-Growth
KW  - Resource Competition
KW  - Body-Size
KW  - Egg Size
KW  - Rotifier
KW  - Limitation
KW  - Carbon
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442256
SN  - 1866-8372
IS  - 806
ER  - 
TY  - JOUR
A1  - Schälicke, Svenja
A1  - Teubner, Johannes
A1  - Martin-Creuzburg, Dominik
A1  - Wacker, Alexander
T1  - Fitness response variation within and among consumer species can be co-mediated by food quantity and biochemical quality
JF  - Scientific Reports
N2  - In natural heterogeneous environments, the fitness of animals is strongly influenced by the availability and composition of food. Food quantity and biochemical quality constraints may affect individual traits of consumers differently, mediating fitness response variation within and among species. Using a multifactorial experimental approach, we assessed population growth rate, fecundity, and survival of six strains of the two closely related freshwater rotifer species Brachionus calyciflorus sensu stricto and Brachionus fernandoi. Therefore, rotifers fed low and high concentrations of three algal species differing in their biochemical food quality. Additionally, we explored the potential of a single limiting biochemical nutrient to mediate variations in population growth response. Therefore, rotifers fed a sterol-free alga, which we supplemented with cholesterol-containing liposomes. Co-limitation by food quantity and biochemical food quality resulted in differences in population growth rates among strains, but not between species, although effects on fecundity and survival differed between species. The effect of cholesterol supplementation on population growth was strain-specific but not species-specific. We show that fitness response variations within and among species can be mediated by biochemical food quality. Dietary constraints thus may act as evolutionary drivers on physiological traits of consumers, which may have strong implications for various ecological interactions.
KW  - Polyunsaturated Fatty-Acids
KW  - Life-History Consequences
KW  - 2 Different Strains
KW  - Population-Growth
KW  - Resource Competition
KW  - Body-Size
KW  - Egg Size
KW  - Rotifier
KW  - Limitation
KW  - Carbon
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-52538-2
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - JOUR
A1  - Wendt, Julia
A1  - Hufenbach, Miriam Catrin
A1  - König, Jörg
A1  - Hamm, Alfons O.
T1  - Effects of verbal instructions and physical threat removal prior to extinction training on the return of conditioned fear
JF  - Scientific Reports
N2  - Instructions given prior to extinction training facilitate the extinction of conditioned skin conductance (SCRs) and fear-potentiated startle responses (FPSs) and serve as laboratory models for cognitive interventions implemented in exposure-based treatments of pathological anxiety. Here, we investigated how instructions given prior to extinction training, with or without the additional removal of the electrode used to deliver the unconditioned stimulus (US), affect the return of fear assessed 24 hours later. We replicated previous instruction effects on extinction and added that the additional removal of the US electrode slightly enhanced facilitating effects on the extinction of conditioned FPSs. In contrast, extinction instructions hardly affected the return of conditioned fear responses. These findings suggest that instruction effects observed during extinction training do not extent to tests of return of fear 24 hours later which serve as laboratory models of relapse and improvement stability of exposure-based treatments.
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-020-57934-7
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Wendt, Julia
A1  - Hufenbach, Miriam Catrin
A1  - König, Jörg
A1  - Hamm, Alfons O.
T1  - Effects of verbal instructions and physical threat removal prior to extinction training on the return of conditioned fear
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Instructions given prior to extinction training facilitate the extinction of conditioned skin conductance (SCRs) and fear-potentiated startle responses (FPSs) and serve as laboratory models for cognitive interventions implemented in exposure-based treatments of pathological anxiety. Here, we investigated how instructions given prior to extinction training, with or without the additional removal of the electrode used to deliver the unconditioned stimulus (US), affect the return of fear assessed 24 hours later. We replicated previous instruction effects on extinction and added that the additional removal of the US electrode slightly enhanced facilitating effects on the extinction of conditioned FPSs. In contrast, extinction instructions hardly affected the return of conditioned fear responses. These findings suggest that instruction effects observed during extinction training do not extent to tests of return of fear 24 hours later which serve as laboratory models of relapse and improvement stability of exposure-based treatments.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 599 
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-444796
SN  - 1866-8364
IS  - 599
ER  - 
TY  - GEN
A1  - Kühne, Katharina
A1  - Fischer, Martin H.
A1  - Zhou, Yuefang
T1  - The Human Takes It All
BT  - Humanlike Synthesized Voices Are Perceived as Less Eerie and More Likable. Evidence From a Subjective Ratings Study
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Background: The increasing involvement of social robots in human lives raises the question as to how humans perceive social robots. Little is known about human perception of synthesized voices.

Aim: To investigate which synthesized voice parameters predict the speaker's eeriness and voice likability; to determine if individual listener characteristics (e.g., personality, attitude toward robots, age) influence synthesized voice evaluations; and to explore which paralinguistic features subjectively distinguish humans from robots/artificial agents.

Methods: 95 adults (62 females) listened to randomly presented audio-clips of three categories: synthesized (Watson, IBM), humanoid (robot Sophia, Hanson Robotics), and human voices (five clips/category). Voices were rated on intelligibility, prosody, trustworthiness, confidence, enthusiasm, pleasantness, human-likeness, likability, and naturalness. Speakers were rated on appeal, credibility, human-likeness, and eeriness. Participants' personality traits, attitudes to robots, and demographics were obtained.

Results: The human voice and human speaker characteristics received reliably higher scores on all dimensions except for eeriness. Synthesized voice ratings were positively related to participants' agreeableness and neuroticism. Females rated synthesized voices more positively on most dimensions. Surprisingly, interest in social robots and attitudes toward robots played almost no role in voice evaluation. Contrary to the expectations of an uncanny valley, when the ratings of human-likeness for both the voice and the speaker characteristics were higher, they seemed less eerie to the participants. Moreover, when the speaker's voice was more humanlike, it was more liked by the participants. This latter point was only applicable to one of the synthesized voices. Finally, pleasantness and trustworthiness of the synthesized voice predicted the likability of the speaker's voice. Qualitative content analysis identified intonation, sound, emotion, and imageability/embodiment as diagnostic features.

Discussion: Humans clearly prefer human voices, but manipulating diagnostic speech features might increase acceptance of synthesized voices and thereby support human-robot interaction. There is limited evidence that human-likeness of a voice is negatively linked to the perceived eeriness of the speaker.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 700 
KW  - human-robot interaction
KW  - paralinguistic features
KW  - synthesized voice
KW  - text-to-speech
KW  - uncanny valley
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491625
SN  - 1866-8364
IS  - 700
ER  - 
TY  - GEN
A1  - Ziege, Madlen
A1  - Theodorou, Panagiotis
A1  - Jüngling, Hannah
A1  - Merker, Stefan
A1  - Plath, Martin
A1  - Streit, Bruno
A1  - Lerp, Hannes
T1  - Population genetics of the European rabbit along a rural-to-urban gradient
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - The European rabbit (Oryctolagus cuniculus) is declining in large parts of Europe but populations in some German cities remained so far unaffected by this decline. The question arises of how urbanization affects patterns of population genetic variation and differentiation in German rabbit populations, as urban habitat fragmentation may result in altered meta-population dynamics. To address this question, we used microsatellite markers to genotype rabbit populations occurring along a rural-to-urban gradient in and around the city of Frankfurt, Germany. We found no effect of urbanization on allelic richness. However, the observed heterozygosity was significantly higher in urban than rural populations and also the inbreeding coefficients were lower, most likely reflecting the small population sizes and possibly on-going loss of genetic diversity in structurally impoverished rural areas. Global FST and G'ST-values suggest moderate but significant differentiation between populations. Multiple matrix regression with randomization ascribed this differentiation to isolation-by-environment rather than isolation-by-distance. Analyses of migration rates revealed asymmetrical gene flow, which was higher from rural into urban populations than vice versa and may again reflect intensified agricultural land-use practices in rural areas. We discuss that populations inhabiting urban areas will likely play an important role in the future distribution of European rabbits.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 880 
KW  - Conservation biology
KW  - Genetics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460354
SN  - 1866-8372
IS  - 880
ER  - 
TY  - THES
A1  - Schneider, Jan Niklas
T1  - Computational approaches for emotion research
T1  - Computergestützte Methoden für die Emotionsforschung
N2  - Emotionen sind ein zentrales Element menschlichen Erlebens und spielen eine wichtige Rolle bei der Entscheidungsfindung. Diese Dissertation identifiziert drei methodische Probleme der aktuellen Emotionsforschung und zeigt auf, wie diese mittels computergestützter Methoden gelöst werden können. Dieser Ansatz wird in drei Forschungsprojekten demonstriert, die die Entwicklung solcher Methoden sowie deren Anwendung auf konkrete Forschungsfragen beschreiben. 
Das erste Projekt beschreibt ein Paradigma welches es ermöglicht, die subjektive und objektive Schwierigkeit der Emotionswahrnehmung zu messen. Darüber hinaus ermöglicht es die Verwendung einer beliebigen Anzahl von Emotionskategorien im Vergleich zu den üblichen sechs Kategorien der Basisemotionen. Die Ergebnisse deuten auf eine Zunahme der Schwierigkeiten bei der Wahrnehmung von Emotionen mit zunehmendem Alter der Darsteller hin und liefern Hinweise darauf, dass junge Erwachsene, ältere Menschen und Männer ihre Schwierigkeit bei der Wahrnehmung von Emotionen unterschätzen. Weitere Analysen zeigten eine geringe Relevanz personenbezogener Variablen und deuteten darauf hin, dass die Schwierigkeit der Emotionswahrnehmung vornehmlich durch die Ausprägung der Wertigkeit des Ausdrucks bestimmt wird. 
Das zweite Projekt zeigt am Beispiel von Arousal, einem etablierten, aber vagen Konstrukt der Emotionsforschung, wie Face-Tracking-Daten dazu genutzt werden können solche Konstrukte zu schärfen. Es beschreibt, wie aus Face-Tracking-Daten Maße für die Entfernung, Geschwindigkeit und Beschleunigung von Gesichtsausdrücken berechnet werden können. Das Projekt untersuchte wie diesen Maße mit der Arousal-Wahrnehmung in Menschen mit und ohne Autismus zusammenhängen. Der Abstand zum Neutralgesicht war prädiktiv für die Arousal-Bewertungen in beiden Gruppen. Die Ergebnisse deuten auf eine qualitativ ähnliche Wahrnehmung von Arousal für Menschen mit und ohne Autismus hin. 
Im dritten Projekt stellen wir die Partial-Least-Squares-Analyse als allgemeine Methode vor, um eine optimale Repräsentation zur Verknüpfung zweier hochdimensionale Datensätze zu finden. Das Projekt demonstriert die Anwendbarkeit dieser Methode in der Emotionsforschung anhand der Frage nach Unterschieden in der Emotionswahrnehmung zwischen Männern und Frauen. Wir konnten zeigen, dass die emotionale Wahrnehmung von Frauen systematisch mehr Varianz der Gesichtsausdrücke erfasst und dass signifikante Unterschiede in der Art und Weise bestehen, wie Frauen und Männer einige Gesichtsausdrücke wahrnehmen. Diese konnten wir als dynamische Gesichtsausdrücke visualisieren. Um die Anwendung der entwickelten Methode für die Forschungsgemeinschaft zu erleichtern, wurde ein Software-Paket für die Statistikumgebung R geschrieben. Zudem wurde eine Website entwickelt (thisemotiondoesnotexist.com), die es Besuchern erlaubt, ein Partial-Least-Squares-Modell von Emotionsbewertungen und Face-Tracking-Daten interaktiv zu erkunden, um die entwickelte Methode zu verbreiten und ihren Nutzen für die Emotionsforschung zu illustrieren.
N2  - Emotions are a central element of human experience. They occur with high frequency in everyday life and play an important role in decision making. However, currently there is no consensus among researchers on what constitutes an emotion and on how emotions should be investigated. This dissertation identifies three problems of current emotion research: the problem of ground truth, the problem of incomplete constructs and the problem of optimal representation. I argue for a focus on the detailed measurement of emotion manifestations with computer-aided methods to solve these problems. This approach is demonstrated in three research projects, which describe the development of methods specific to these problems as well as their application to concrete research questions. 
The problem of ground truth describes the practice to presuppose a certain structure of emotions as the a priori ground truth. This determines the range of emotion descriptions and sets a standard for the correct assignment of these descriptions. The first project illustrates how this problem can be circumvented with a multidimensional emotion perception paradigm which stands in contrast to the emotion recognition paradigm typically employed in emotion research. This paradigm allows to calculate an objective difficulty measure and to collect subjective difficulty ratings for the perception of emotional stimuli. Moreover, it enables the use of an arbitrary number of emotion stimuli categories as compared to the commonly used six basic emotion categories. Accordingly, we collected data from 441 participants using dynamic facial expression stimuli from 40 emotion categories. Our findings suggest an increase in emotion perception difficulty with increasing actor age and provide evidence to suggest that young adults, the elderly and men underestimate their emotion perception difficulty. While these effects were predicted from the literature, we also found unexpected and novel results. In particular, the increased difficulty on the objective difficulty measure for female actors and observers stood in contrast to reported findings. Exploratory analyses revealed low relevance of person-specific variables for the prediction of emotion perception difficulty, but highlighted the importance of a general pleasure dimension for the ease of emotion perception. 
The second project targets the problem of incomplete constructs which relates to vaguely defined psychological constructs on emotion with insufficient ties to tangible manifestations. The project exemplifies how a modern data collection method such as face tracking data can be used to sharpen these constructs on the example of arousal, a long-standing but fuzzy construct in emotion research. It describes how measures of distance, speed and magnitude of acceleration can be computed from face tracking data and investigates their intercorrelations. We find moderate to strong correlations among all measures of static information on one hand and all measures of dynamic information on the other. The project then investigates how self-rated arousal is tied to these measures in 401 neurotypical individuals and 19 individuals with autism. Distance to the neutral face was predictive of arousal ratings in both groups. Lower mean arousal ratings were found for the autistic group, but no difference in correlation of the measures and arousal ratings could be found between groups. Results were replicated in a high autistic traits group consisting of 41 participants. The findings suggest a qualitatively similar perception of arousal for individuals with and without autism. No correlations between valence ratings and any of the measures could be found which emphasizes the specificity of our tested measures for the construct of arousal.
The problem of optimal representation refers to the search for the best representation of emotions and the assumption that there is a one-fits-all solution. In the third project we introduce partial least squares analysis as a general method to find an optimal representation to relate two high-dimensional data sets to each other. The project demonstrates its applicability to emotion research on the question of emotion perception differences between men and women. The method was used with emotion rating data from 441 participants and face tracking data computed on 306 videos. We found quantitative as well as qualitative differences in the perception of emotional facial expressions between these groups. We showed that women’s emotional perception systematically captured more of the variance in facial expressions. Additionally, we could show that significant differences exist in the way that women and men perceive some facial expressions which could be visualized as concrete facial expression sequences. These expressions suggest differing perceptions of masked and ambiguous facial expressions between the sexes. In order to facilitate use of the developed method by the research community, a package for the statistical environment R was written. Furthermore, to call attention to the method and its usefulness for emotion research, a website was designed that allows users to explore a model of emotion ratings and facial expression data in an interactive fashion.
KW  - facial expression
KW  - emotion
KW  - perception
KW  - face tracking
KW  - perception differences
KW  - emotion representation
KW  - Gesichtsausdruck
KW  - Emotionen
KW  - Wahrnehmung
KW  - Wahrnehmungsunterschiede
KW  - computational methods
KW  - emotion research
KW  - computergestützte Methoden
KW  - Emotionsforschung
KW  - arousal perception
KW  - objective difficulty
KW  - Wahrnehmung von Arousal
KW  - Objektive Schwierigkeit
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459275
ER  - 
TY  - JOUR
A1  - Küken, Anika
A1  - Wendering, Philipp
A1  - Langary, Damoun
A1  - Nikoloski, Zoran
T1  - A structural property for reduction of biochemical networks
JF  - Scientific reports
N2  - Large-scale biochemical models are of increasing sizes due to the consideration of interacting organisms and tissues. Model reduction approaches that preserve the flux phenotypes can simplify the analysis and predictions of steady-state metabolic phenotypes. However, existing approaches either restrict functionality of reduced models or do not lead to significant decreases in the number of modelled metabolites. Here, we introduce an approach for model reduction based on the structural property of balancing of complexes that preserves the steady-state fluxes supported by the network and can be efficiently determined at genome scale. Using two large-scale mass-action kinetic models of Escherichia coli, we show that our approach results in a substantial reduction of 99% of metabolites. Applications to genome-scale metabolic models across kingdoms of life result in up to 55% and 85% reduction in the number of metabolites when arbitrary and mass-action kinetics is assumed, respectively. We also show that predictions of the specific growth rate from the reduced models match those based on the original models. Since steady-state flux phenotypes from the original model are preserved in the reduced, the approach paves the way for analysing other metabolic phenotypes in large-scale biochemical networks.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-96835-1
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Haverkamp, Robert
A1  - Sorgenfrei, Nomi L. A. N.
A1  - Giangrisostomi, Erika
A1  - Neppl, Stefan
A1  - Kühn, Danilo
A1  - Föhlisch, Alexander
T1  - Directional charge delocalization dynamics in semiconducting 2H-MoS2 and metallic 1T-LixMoS2
JF  - Scientific reports
N2  - The layered dichalcogenide MoS2 is relevant for electrochemical Li adsorption/intercalation, in the course of which the material undergoes a concomitant structural phase transition from semiconducting 2H-MoS2 to metallic 1T-LixMoS2. With the core hole clock approach at the S L1 X-ray absorption edge we quantify the ultrafast directional charge transfer of excited S3p electrons in-plane () and out-of-plane (perpendicular to) for 2H-MoS2 as tau 2H,=0.38 +/- 0.08 fs and tau 2H,perpendicular to =0.33 +/- 0.06 fs and for 1T-LixMoS2 as tau 1T,=0.32 +/- 0.12 fs and tau 1T,perpendicular to =0.09 +/- 0.07 fs. The isotropic charge delocalization of S3p electrons in the semiconducting 2H phase within the S-Mo-S sheets is assigned to the specific symmetry of the Mo-S bonding arrangement. Formation of 1T-LixMoS2 by lithiation accelerates the in-plane charge transfer by a factor of similar to 1.2 due to electron injection to the Mo-S covalent bonds and concomitant structural repositioning of S atoms within the S-Mo-S sheets. For excitation into out-of-plane orbitals, an accelerated charge transfer by a factor of similar to 3.7 upon lithiation occurs due to S-Li coupling.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-86364-2
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Sauter, Tilman
A1  - Kratz, Karl
A1  - Heuchel, Matthias
A1  - Lendlein, Andreas
T1  - Fiber diameter as design parameter for tailoring the macroscopic shape-memory performance of electrospun meshes
JF  - Materials and design
N2  - Fibrous shape-memory polymer (SMP) scaffolds were investigated considering the fiber as basic microstructural feature. By reduction of the fiber diameter in randomly oriented electrospun polyetherurethane (PEU) meshes from the micro-to the nano-scale, we observed changes in the molecular orientation within the fibers and its impact on the structural and shape-memory performance. It was assumed that a spatial restriction by reduction of the fiber diameter increases molecular orientation along the orientation of the fiber. The stress-strain relation of random PEU scaffolds is initially determined by the 3D arrangement of the fibers and thus is independent of the molecular orientation. Increasing the molecular orientation with decreasing single fiber diameter in scaffolds composed of randomly arranged fibers did not alter the initial stiffness and peak stress but strongly influenced the elongation at break and the stress increase above the Yield point. Reduction of the single fiber diameter also distinctly improved the shape-memory performance of the scaffolds. Fibers with nanoscale diameters (< 100 nm) possessed an almost complete shape recovery, high recovery stresses and fast relaxation kinetics, while the shape fixity was found to decrease with decreasing fiber diameter. Hence, the fiber diameter is a relevant design parameter for SMP.
KW  - Nanofiber
KW  - Shape-memory polymer
KW  - Electrospinning
KW  - Function by design
KW  - Molecular orientation
Y1  - 2021
U6  - https://doi.org/10.1016/j.matdes.2021.109546
SN  - 1873-4197
VL  - 202
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Metje, Jan
A1  - Lever, Fabiano
A1  - Mayer, Dennis
A1  - Squibb, Richard James
A1  - Robinson, Matthew Scott
A1  - Niebuhr, Mario
A1  - Feifel, Raimund
A1  - Düsterer, Stefan
A1  - Gühr, Markus
T1  - URSA-PQ
BT  - A Mobile and Flexible Pump-Probe Instrument for Gas Phase Samples at the FLASH Free Electron Laser
JF  - Applied Sciences
N2  - We present a highly flexible and portable instrument to perform pump-probe spectroscopy with an optical and an X-ray pulse in the gas phase. The so-called URSA-PQ (German for ‘Ultraschnelle Röntgenspektroskopie zur Abfrage der Photoenergiekonversion an Quantensystemen’, Engl. ‘ultrafast X-ray spectroscopy for probing photoenergy conversion in quantum systems’) instrument is equipped with a magnetic bottle electron spectrometer (MBES) and tools to characterize the spatial and temporal overlap of optical and X-ray laser pulses. Its adherence to the CAMP instrument dimensions allows for a wide range of sample sources as well as other spectrometers to be included in the setup. We present the main design and technical features of the instrument. The MBES performance was evaluated using Kr M4,5NN Auger lines using backfilled Kr gas, with an energy resolution ΔE/E ≅ 1/40 in the integrating operative mode. The time resolution of the setup at FLASH 2 FL 24 has been characterized with the help of an experiment on 2-thiouracil that is inserted via the instruments’ capillary oven. We find a time resolution of 190 fs using the molecular 2p photoline shift and attribute this to different origins in the UV-pump—the X-ray probe setup.
KW  - X-ray probe
KW  - molecular dynamics
KW  - gas phase electron spectroscopy
Y1  - 2020
U6  - https://doi.org/10.3390/app10217882
SN  - 2076-3417
VL  - 10
IS  - 21
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Warmt, Christian
A1  - Fenzel, Carolin Kornelia
A1  - Henkel, Jörg
A1  - Bier, Frank Fabian
T1  - Using Cy5-dUTP labelling of RPA-amplicons with downstream microarray analysis for the detection of antibiotic resistance genes
JF  - Scientific reports
N2  - In this report we describe Cy5-dUTP labelling of recombinase-polymerase-amplification (RPA) products directly during the amplification process for the first time. Nucleic acid amplification techniques, especially polymerase-chain-reaction as well as various isothermal amplification methods such as RPA, becomes a promising tool in the detection of pathogens and target specific genes. Actually, RPA even provides more advantages. This isothermal method got popular in point of care diagnostics because of its speed and sensitivity but requires pre-labelled primer or probes for a following detection of the amplicons. To overcome this disadvantages, we performed an labelling of RPA-amplicons with Cy5-dUTP without the need of pre-labelled primers. The amplification results of various multiple antibiotic resistance genes indicating great potential as a flexible and promising tool with high specific and sensitive detection capabilities of the target genes. After the determination of an appropriate rate of 1% Cy5-dUTP and 99% unlabelled dTTP we were able to detect the bla(CTX-M15) gene in less than 1.6E-03 ng genomic DNA corresponding to approximately 200 cfu of Escherichia coli cells in only 40 min amplification time.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-99774-z
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - [London]
ER  - 
TY  - GEN
A1  - Metje, Jan
A1  - Lever, Fabiano
A1  - Mayer, Dennis
A1  - Squibb, Richard James
A1  - Robinson, Matthew Scott
A1  - Niebuhr, Mario
A1  - Feifel, Raimund
A1  - Düsterer, Stefan
A1  - Gühr, Markus
T1  - URSA-PQ
BT  - A Mobile and Flexible Pump-Probe Instrument for Gas Phase Samples at the FLASH Free Electron Laser
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - We present a highly flexible and portable instrument to perform pump-probe spectroscopy with an optical and an X-ray pulse in the gas phase. The so-called URSA-PQ (German for ‘Ultraschnelle Röntgenspektroskopie zur Abfrage der Photoenergiekonversion an Quantensystemen’, Engl. ‘ultrafast X-ray spectroscopy for probing photoenergy conversion in quantum systems’) instrument is equipped with a magnetic bottle electron spectrometer (MBES) and tools to characterize the spatial and temporal overlap of optical and X-ray laser pulses. Its adherence to the CAMP instrument dimensions allows for a wide range of sample sources as well as other spectrometers to be included in the setup. We present the main design and technical features of the instrument. The MBES performance was evaluated using Kr M4,5NN Auger lines using backfilled Kr gas, with an energy resolution ΔE/E ≅ 1/40 in the integrating operative mode. The time resolution of the setup at FLASH 2 FL 24 has been characterized with the help of an experiment on 2-thiouracil that is inserted via the instruments’ capillary oven. We find a time resolution of 190 fs using the molecular 2p photoline shift and attribute this to different origins in the UV-pump—the X-ray probe setup.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1016 
KW  - X-ray probe
KW  - molecular dynamics
KW  - gas phase electron spectroscopy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-483073
SN  - 1866-8372
IS  - 1016
ER  - 
TY  - JOUR
A1  - Wicaksono, Wisnu Adi
A1  - Braun, Maria
A1  - Bernhardt, Jörg
A1  - Riedel, Katharina
A1  - Cernava, Tomislav
A1  - Berg, Gabriele
T1  - Trade-off for survival
BT  - microbiome response to chemical exposure combines activation of intrinsic resistances and adapted metabolic activity
JF  - Environment international : a journal of science, technology, health, monitoring and policy
N2  - The environmental micmbiota is increasingly exposed to chemical pollution. While the emergence of multi-resistant pathogens is recognized as a global challenge, our understanding of antimicrobial resistance (AMR) development from native microbiomes and the risks associated with chemical exposure is limited. By implementing a lichen as a bioindicator organism and model for a native microbiome, we systematically examined responses towards antimicrobials (colistin, tetracycline, glyphosate, and alkylpyrazine). Despite an unexpectedly high resilience, we identified potential evolutionary consequences of chemical exposure in terms of composition and functioning of native bacterial communities. Major shifts in bacterial composition were observed due to replacement of naturally abundant taxa; e.g. Chthoniobacterales by Pseudomonadales. A general response, which comprised activation of intrinsic resistance and parallel reduction of metabolic activity at RNA and protein levels was deciphered by a multi-omics approach. Targeted analyses of key taxa based on metagenome-assembled genomes reflected these responses but also revealed diversified strategies of their players. Chemical-specific responses were also observed, e.g., glyphosate enriched bacterial r-strategists and activated distinct ARGs. Our work demonstrates that the high resilience of the native micmbiota toward antimicrobial exposure is not only explained by the presence of antibiotic resistance genes but also adapted metabolic activity as a trade-off for survival. Moreover, our results highlight the importance of native microbiomes as important but so far neglected AMR reservoirs. We expect that this phenomenon is representative for a wide range of environmental microbiota exposed to chemicals that potentially contribute to the emergence of antibiotic-resistant bacteria from natural environments.
Y1  - 2022
U6  - https://doi.org/10.1016/j.envint.2022.107474
SN  - 1873-6750
VL  - 168
PB  - Elsevier Science
CY  - Amsterdam [u.a.]
ER  - 
TY  - THES
A1  - Perscheid, Cindy
T1  - Integrative biomarker detection using prior knowledge on gene expression data sets
T1  - Integrative Biomarker-Erkennung auf Genexpressions-Daten mithilfe von biologischem Vorwissen
N2  - Gene expression data is analyzed to identify biomarkers, e.g. relevant genes, which serve for diagnostic, predictive, or prognostic use. Traditional approaches for biomarker detection select distinctive features from the data based exclusively on the signals therein, facing multiple shortcomings in regards to overfitting, biomarker robustness, and actual biological relevance. Prior knowledge approaches are expected to address these issues by incorporating prior biological knowledge, e.g. on gene-disease associations, into the actual analysis. However, prior knowledge approaches are currently not widely applied in practice because they are often use-case specific and seldom applicable in a different scope. This leads to a lack of comparability of prior knowledge approaches, which in turn makes it currently impossible to assess their effectiveness in a broader context.

Our work addresses the aforementioned issues with three contributions. Our first contribution provides formal definitions for both prior knowledge and the flexible integration thereof into the feature selection process. Central to these concepts is the automatic retrieval of prior knowledge from online knowledge bases, which allows for streamlining the retrieval process and agreeing on a uniform definition for prior knowledge. We subsequently describe novel and generalized prior knowledge approaches that are flexible regarding the used prior knowledge and applicable to varying use case domains. Our second contribution is the benchmarking platform Comprior. Comprior applies the aforementioned concepts in practice and allows for flexibly setting up comprehensive benchmarking studies for examining the performance of existing and novel prior knowledge approaches. It streamlines the retrieval of prior knowledge and allows for combining it with prior knowledge approaches. Comprior demonstrates the practical applicability of our concepts and further fosters the overall development and comparability of prior knowledge approaches. Our third contribution is a comprehensive case study on the effectiveness of prior knowledge approaches. For that, we used Comprior and tested a broad range of both traditional and prior knowledge approaches in combination with multiple knowledge bases on data sets from multiple disease domains. Ultimately, our case study constitutes a thorough assessment of a) the suitability of selected knowledge bases for integration, b) the impact of prior knowledge being applied at different integration levels, and c) the improvements in terms of classification performance, biological relevance, and overall robustness.

In summary, our contributions demonstrate that generalized concepts for prior knowledge and a streamlined retrieval process improve the applicability of prior knowledge approaches. Results from our case study show that the integration of prior knowledge positively affects biomarker results, particularly regarding their robustness. Our findings provide the first in-depth insights on the effectiveness of prior knowledge approaches and build a valuable foundation for future research.
N2  - Biomarker sind charakteristische biologische Merkmale mit diagnostischer oder prognostischer Aussagekraft. Auf der molekularen Ebene sind dies Gene mit einem krankheitsspezifischen Expressionsmuster, welche mittels der Analyse von Genexpressionsdaten identifiziert werden. Traditionelle Ansätze für diese Art von Biomarker Detection wählen Gene als Biomarker ausschließlich anhand der vorhandenen Signale im Datensatz aus. Diese Vorgehensweise zeigt jedoch Schwächen insbesondere in Bezug auf die Robustheit und tatsächliche biologische Relevanz der identifizierten Biomarker. Verschiedene Forschungsarbeiten legen nahe, dass die Berücksichtigung des biologischen Kontexts während des Selektionsprozesses diese Schwächen ausgleichen kann. Sogenannte wissensbasierte Ansätze für Biomarker Detection beziehen vorhandenes biologisches Wissen, beispielsweise über Zusammenhänge zwischen bestimmten Genen und Krankheiten, direkt in die Analyse mit ein. Die Anwendung solcher Verfahren ist in der Praxis jedoch derzeit nicht weit verbreitet, da existierende Methoden oft spezifisch für einen bestimmten Anwendungsfall entwickelt wurden und sich nur mit großem Aufwand auf andere Anwendungsgebiete übertragen lassen. Dadurch sind Vergleiche untereinander kaum möglich, was es wiederum nicht erlaubt die Effektivität von wissensbasierten Methoden in einem breiteren Kontext zu untersuchen.

Die vorliegende Arbeit befasst sich mit den vorgenannten Herausforderungen für wissensbasierte Ansätze. In einem ersten Schritt legen wir formale und einheitliche Definitionen für vorhandenes biologisches Wissen sowie ihre flexible Integration in den Biomarker-Auswahlprozess fest. Der Kerngedanke unseres Ansatzes ist die automatisierte Beschaffung von biologischem Wissen aus im Internet frei verfügbaren Wissens-Datenbanken. Dies erlaubt eine Vereinfachung der Kuratierung sowie die Festlegung einer einheitlichen Definition für biologisches Wissen. Darauf aufbauend beschreiben wir generalisierte wissensbasierte Verfahren, welche flexibel auf verschiedene Anwendungsfalle anwendbar sind. In einem zweiten Schritt haben wir die Benchmarking-Plattform Comprior entwickelt, welche unsere theoretischen Konzepte in einer praktischen Anwendung realisiert. Comprior ermöglicht die schnelle Umsetzung von umfangreichen Experimenten für den Vergleich von wissensbasierten Ansätzen. Comprior übernimmt die Beschaffung von biologischem Wissen und ermöglicht dessen beliebige Kombination mit wissensbasierten Ansätzen. Comprior demonstriert damit die praktische Umsetzbarkeit unserer theoretischen Konzepte und unterstützt zudem die technische Realisierung und Vergleichbarkeit wissensbasierter Ansätze. In einem dritten Schritt untersuchen wir die Effektivität wissensbasierter Ansätze im Rahmen einer umfangreichen Fallstudie. Mithilfe von Comprior vergleichen wir die Ergebnisse traditioneller und wissensbasierter Ansätze im Kontext verschiedener Krankheiten, wobei wir für wissensbasierte Ansätze auch verschiedene Wissens-Datenbanken verwenden. Unsere Fallstudie untersucht damit a) die Eignung von ausgewählten Wissens-Datenbanken für deren Einsatz bei wissensbasierten Ansätzen, b) den Einfluss verschiedener Integrationskonzepte für biologisches Wissen auf den Biomarker-Auswahlprozess, und c) den Grad der Verbesserung in Bezug auf die Klassifikationsleistung, biologische Relevanz und allgemeine Robustheit der selektierten Biomarker.

Zusammenfassend demonstriert unsere Arbeit, dass generalisierte Konzepte für biologisches Wissen und dessen vereinfachte Kuration die praktische Anwendbarkeit von wissensbasierten Ansätzen erleichtern. Die Ergebnisse unserer Fallstudie zeigen, dass die Integration von vorhandenem biologischen Wissen einen positiven Einfluss auf die selektierten Biomarker hat, insbesondere in Bezug auf ihre biologische Relevanz. Diese erstmals umfassenderen Erkenntnisse zur Effektivität von wissensbasierten Ansätzen bilden eine wertvolle Grundlage für zukünftige Forschungsarbeiten.
KW  - gene expression
KW  - biomarker detection
KW  - prior knowledge
KW  - feature selection
KW  - Biomarker-Erkennung
KW  - Merkmalsauswahl
KW  - Gen-Expression
KW  - biologisches Vorwissen
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-582418
ER  - 
TY  - JOUR
A1  - Crawford, Tim
A1  - Karamat, Fazeelat
A1  - Lehotai, Nóra
A1  - Rentoft, Matilda
A1  - Blomberg, Jeanette
A1  - Strand, Åsa
A1  - Björklund, Stefan
T1  - Specific functions for mediator complex subunits from different modules in the transcriptional response of arabidopsis thaliana to abiotic stress
JF  - Scientific reports
N2  - Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization.
KW  - regulate gene expression
KW  - signal transduction
KW  - circadian clock
KW  - plant Mediator
KW  - salicylic-acid
KW  - activation
KW  - jasmonate
KW  - network
KW  - defense
KW  - MED16
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-61758-w
SN  - 2045-2322
VL  - 10
IS  - 1
SP  - 1
EP  - 18
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Tötzke, Christian
A1  - Kardjilov, Nikolay
A1  - Hilger, André
A1  - Rudolph-Mohr, Nicole
A1  - Manke, Ingo
A1  - Oswald, Sascha Eric
T1  - Three-dimensional in vivo analysis of water uptake and translocation in maize roots by fast neutron tomography
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Root water uptake is an essential process for terrestrial plants that strongly affects the spatiotemporal distribution of water in vegetated soil. Fast neutron tomography is a recently established non-invasive imaging technique capable to capture the 3D architecture of root systems in situ and even allows for tracking of three-dimensional water flow in soil and roots. We present an in vivo analysis of local water uptake and transport by roots of soil-grown maize plants—for the first time measured in a three-dimensional time-resolved manner. Using deuterated water as tracer in infiltration experiments, we visualized soil imbibition, local root uptake, and tracked the transport of deuterated water throughout the fibrous root system for a day and night situation. This revealed significant differences in water transport between different root types. The primary root was the preferred water transport path in the 13-days-old plants while seminal roots of comparable size and length contributed little to plant water supply. The results underline the unique potential of fast neutron tomography to provide time-resolved 3D in vivo information on the water uptake and transport dynamics of plant root systems, thus contributing to a better understanding of the complex interactions of plant, soil and water.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1217 
KW  - Environmental sciences
KW  - Optics and photonics
KW  - Plant sciences
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-529915
SN  - 1866-8372
ER  - 
TY  - JOUR
A1  - Tötzke, Christian
A1  - Kardjilov, Nikolay
A1  - Hilger, André
A1  - Rudolph-Mohr, Nicole
A1  - Manke, Ingo
A1  - Oswald, Sascha Eric
T1  - Three-dimensional in vivo analysis of water uptake and translocation in maize roots by fast neutron tomography
JF  - Scientific Reports
N2  - Root water uptake is an essential process for terrestrial plants that strongly affects the spatiotemporal distribution of water in vegetated soil. Fast neutron tomography is a recently established non-invasive imaging technique capable to capture the 3D architecture of root systems in situ and even allows for tracking of three-dimensional water flow in soil and roots. We present an in vivo analysis of local water uptake and transport by roots of soil-grown maize plants—for the first time measured in a three-dimensional time-resolved manner. Using deuterated water as tracer in infiltration experiments, we visualized soil imbibition, local root uptake, and tracked the transport of deuterated water throughout the fibrous root system for a day and night situation. This revealed significant differences in water transport between different root types. The primary root was the preferred water transport path in the 13-days-old plants while seminal roots of comparable size and length contributed little to plant water supply. The results underline the unique potential of fast neutron tomography to provide time-resolved 3D in vivo information on the water uptake and transport dynamics of plant root systems, thus contributing to a better understanding of the complex interactions of plant, soil and water.
KW  - Environmental sciences
KW  - Optics and photonics
KW  - Plant sciences
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-90062-4
SN  - 2045-2322
VL  - 11
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - GEN
A1  - Weymar, Mathias
A1  - Ventura-Bort, Carlos
A1  - Wendt, Julia
A1  - Lischke, Alexander
T1  - Behavioral and neural evidence of enhanced long-term memory for untrustworthy faces
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - In daily life, we automatically form impressions of other individuals on basis of subtle facial features that convey trustworthiness. Because these face-based judgements influence current and future social interactions, we investigated how perceived trustworthiness of faces affects long-term memory using event-related potentials (ERPs). In the current study, participants incidentally viewed 60 neutral faces differing in trustworthiness, and one week later, performed a surprise recognition memory task, in which the same old faces were presented intermixed with novel ones. We found that after one week untrustworthy faces were better recognized than trustworthy faces and that untrustworthy faces prompted early (350–550 ms) enhanced frontal ERP old/new differences (larger positivity for correctly remembered old faces, compared to novel ones) during recognition. Our findings point toward an enhanced long-lasting, likely familiarity-based, memory for untrustworthy faces. Even when trust judgments about a person do not necessarily need to be accurate, a fast access to memories predicting potential harm may be important to guide social behaviour in daily life.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 594 
KW  - Recognition Memory
KW  - Facial Expressions
KW  - Trustworthiness
KW  - Recollection
KW  - Amygdala
KW  - Metaanalysis
KW  - Information
KW  - Appearance
KW  - Perception
KW  - Trust
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442925
SN  - 1866-8364
IS  - 594
ER  - 
TY  - JOUR
A1  - Weymar, Mathias
A1  - Ventura-Bort, Carlos
A1  - Wendt, Julia
A1  - Lischke, Alexander
T1  - Behavioral and neural evidence of enhanced long-term memory for untrustworthy faces
JF  - Scientific Reports
N2  - In daily life, we automatically form impressions of other individuals on basis of subtle facial features that convey trustworthiness. Because these face-based judgements influence current and future social interactions, we investigated how perceived trustworthiness of faces affects long-term memory using event-related potentials (ERPs). In the current study, participants incidentally viewed 60 neutral faces differing in trustworthiness, and one week later, performed a surprise recognition memory task, in which the same old faces were presented intermixed with novel ones. We found that after one week untrustworthy faces were better recognized than trustworthy faces and that untrustworthy faces prompted early (350–550 ms) enhanced frontal ERP old/new differences (larger positivity for correctly remembered old faces, compared to novel ones) during recognition. Our findings point toward an enhanced long-lasting, likely familiarity-based, memory for untrustworthy faces. Even when trust judgments about a person do not necessarily need to be accurate, a fast access to memories predicting potential harm may be important to guide social behaviour in daily life.
KW  - Recognition Memory
KW  - Facial Expressions
KW  - Trustworthiness
KW  - Recollection
KW  - Amygdala
KW  - Metaanalysis
KW  - Information
KW  - Appearance
KW  - Perception
KW  - Trust
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-55705-7
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - JOUR
A1  - Michałowski, Jarosław M.
A1  - Wiwatowska, Ewa
A1  - Weymar, Mathias
T1  - Brain potentials reveal reduced attention and error-processing during a monetary Go/No-Go task in procrastination
JF  - Scientific reports
N2  - Procrastination is a self-regulatory problem of voluntarily and destructively delaying intended and necessary or personally important tasks. Previous studies showed that procrastination is associated with executive dysfunctions that seem to be particularly strong in punishing contexts. In the present event-related potential (ERP) study a monetary version of the parametric Go/No-Go task was performed by high and low academic procrastinators to verify the influence of motivational context (reward vs. punishment expectation) and task difficulty (easy vs. hard) on procrastination-related executive dysfunctions. The results revealed increased post-error slowing along with reduced P300 and error-related negativity (ERN) amplitudes in high (vs. low) procrastination participants-effects that indicate impaired attention and error-related processing in this group. This pattern of results did not differ as a function of task difficulty and motivation condition. However, when the task got more difficult executive attention deficits became even more apparent at the behavioral level in high procrastinators, as indexed by increased reaction time variability. The findings substantiate prior preliminary evidence that procrastinators show difficulties in certain aspects of executive functioning (in attention and error processing) during execution of task-relevant behavior, which may be more apparent in highly demanding situations.
KW  - Attention
KW  - Cognitive control
KW  - Motivation
KW  - Neurophysiology
KW  - Neuroscience
KW  - Psychology
KW  - Reward
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-75311-2
SN  - 2045-2322
VL  - 10
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Chandra, Johan
A1  - Krügel, André
A1  - Engbert, Ralf
T1  - Modulation of oculomotor control during reading of mirrored and inverted texts
JF  - Scientific Reports
N2  - The interplay between cognitive and oculomotor processes during reading can be explored when the spatial layout of text deviates from the typical display. In this study, we investigate various eye-movement measures during reading of text with experimentally manipulated layout (word-wise and letter-wise mirrored-reversed text as well as inverted and scrambled text). While typical findings (e.g., longer mean fixation times, shorter mean saccades lengths) in reading manipulated texts compared to normal texts were reported in earlier work, little is known about changes of oculomotor targeting observed in within-word landing positions under the above text layouts. Here we carry out precise analyses of landing positions and find substantial changes in the so-called launch-site effect in addition to the expected overall slow-down of reading performance. Specifically, during reading of our manipulated text conditions with reversed letter order (against overall reading direction), we find a reduced launch-site effect, while in all other manipulated text conditions, we observe an increased launch-site effect. Our results clearly indicate that the oculomotor system is highly adaptive when confronted with unusual reading conditions.
KW  - human behaviour
KW  - psychology
KW  - eye-movement control
KW  - e-z reader
KW  - ideal-observer model
KW  - fixation locations
KW  - landing positions
KW  - saccade generation
KW  - cognitive-control
KW  - dynamical model
KW  - decision-theory
KW  - attention
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-020-60833-6
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Rebitschek, Felix G.
A1  - Wagner, Gert G.
T1  - Akzeptanz von assistiven Robotern im Pflege- und Gesundheitsbereich
BT  - Repräsentative Daten zeichnen ein klares Bild für Deutschland
BT  - Representative data show a clear picture for Germany
JF  - Zeitschrift für Gerontologie und Geriatrie
N2  - Angesichts der Alterung der Gesellschaft und der hohen Kosten für die Unterstützung und Pflege in privaten Haushalten stellt sich die Frage, welche Rolle assistive Roboter spielen können. Dieser Beitrag richtet sich auf die Frage, inwieweit Roboter in der Pflege heute von der erwachsenen Bevölkerung in Deutschland akzeptiert werden. Und inwieweit beeinflussen Geschlecht, Alter und Erfahrung (beruflich, persönlich) das Ausmaß dieser Akzeptanz? Die durchgeführten Auswertungen beruhen auf drei repräsentativen Erhebungen mit insgesamt über 7000 Befragten. Zwei Erhebungen fanden in der 2. Jahreshälfte 2017 im Auftrag der Deutschen Akademie der Technikwissenschaften (acatech) und des Lebensversicherers ERGO statt, die dritte Erhebung im Auftrag des Sachverständigenrats für Verbraucherfragen (SVRV) im Frühjahr 2018. Eine vertiefte und kumulative Auswertung dieser Erhebungen und Datensätze, die von den Autoren mitkonzipiert wurden, im Hinblick auf assistive Robotik ist bislang noch nicht veröffentlicht. Trotz unterschiedlicher erfragter Einsatzszenarien für Roboter in der Pflege stimmen die Ergebnisse aller 3 Erhebungen erstaunlich überein: In Deutschland gibt es eine signifikante Minderheit von Menschen, die bereits jetzt eine funktionierende Betreuung von Robotern akzeptieren würden – sofern dadurch menschliche Pflege nicht ersetzt, sondern nur unterstützt würde. Ein gutes Drittel, das nach Alter und Geschlecht differenziert ist, lehnt die Assistenz durch Roboter grundsätzlich ab.
N2  - In view of the ageing society and the high costs of support and care in private households, the question arises as to what role assistive robots can play. This article focuses on the extent to which robots in nursing are accepted by the adult population in Germany today, as well as the extent to which gender, age, and experience (professional and private) influence this level of acceptance. The analysis carried out for this purpose was based on three representative surveys conducted among a total of over 7000 respondents. Of these surveys two were conducted in the second half of 2017 on behalf of the German Academy of Science and Engineering (acatech) and the life insurance company ERGO, while the third was commissioned by the German Council of Economic Experts (SVRV) in the spring of 2018. An in-depth and cumulative analysis of these surveys and data sets, which the authors helped to design, with
respect to assistive robotics has not yet been published. Despite the different application scenarios for assistive care robots, the results of all three surveys are surprisingly consistent: in Germany there is already a significant minority of people who are open to, and would accept nursing care robots as long as they do not replace but rather support traditional human nursing. Roughly one third of the sample differentiated according to age and gender, fundamentally rejected assistance by robots.
T2  - Acceptance of assistive robots in the field of nursing and healthcare
KW  - Einstellungen zur Pflegerobotik
KW  - „Ambient assisted living“
KW  - Risiken und Vorteile
KW  - demografische Faktoren
KW  - repräsentative Studien
Y1  - 2020
U6  - https://doi.org/10.1007/s00391-020-01780-9
SN  - 0948-6704
SN  - 1435-1269
VL  - 53
IS  - 7
SP  - 637
EP  - 643
PB  - Springer Medizin
CY  - Heidelberg
ER  - 
TY  - GEN
A1  - Chandra, Johan
A1  - Krügel, André
A1  - Engbert, Ralf
T1  - Modulation of oculomotor control during reading of mirrored and inverted texts
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - The interplay between cognitive and oculomotor processes during reading can be explored when the spatial layout of text deviates from the typical display. In this study, we investigate various eye-movement measures during reading of text with experimentally manipulated layout (word-wise and letter-wise mirrored-reversed text as well as inverted and scrambled text). While typical findings (e.g., longer mean fixation times, shorter mean saccades lengths) in reading manipulated texts compared to normal texts were reported in earlier work, little is known about changes of oculomotor targeting observed in within-word landing positions under the above text layouts. Here we carry out precise analyses of landing positions and find substantial changes in the so-called launch-site effect in addition to the expected overall slow-down of reading performance. Specifically, during reading of our manipulated text conditions with reversed letter order (against overall reading direction), we find a reduced launch-site effect, while in all other manipulated text conditions, we observe an increased launch-site effect. Our results clearly indicate that the oculomotor system is highly adaptive when confronted with unusual reading conditions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 659 
KW  - human behaviour
KW  - psychology
KW  - eye-movement control
KW  - e-z reader
KW  - ideal-observer model
KW  - fixation locations
KW  - landing positions
KW  - saccade generation
KW  - cognitive-control
KW  - dynamical model
KW  - decision-theory
KW  - attention
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-494879
SN  - 1866-8364
IS  - 659
ER  - 
TY  - JOUR
A1  - Oesch, Tyler
A1  - Weise, Frank
A1  - Bruno, Giovanni
T1  - Detection and quantification of cracking in concrete aggregate through virtual data fusion of X-ray computed tomography images
JF  - Materials
N2  - In this work, which is part of a larger research program, a framework called "virtual data fusion" was developed to provide an automated and consistent crack detection method that allows for the cross-comparison of results from large quantities of X-ray computed tomography (CT) data. A partial implementation of this method in a custom program was developed for use in research focused on crack quantification in alkali-silica reaction (ASR)-sensitive concrete aggregates. During the CT image processing, a series of image analyses tailored for detecting specific, individual crack-like characteristics were completed. The results of these analyses were then "fused" in order to identify crack-like objects within the images with much higher accuracy than that yielded by any individual image analysis procedure. The results of this strategy demonstrated the success of the program in effectively identifying crack-like structures and quantifying characteristics, such as surface area and volume. The results demonstrated that the source of aggregate has a very significant impact on the amount of internal cracking, even when the mineralogical characteristics remain very similar. River gravels, for instance, were found to contain significantly higher levels of internal cracking than quarried stone aggregates of the same mineralogical type.
KW  - X-ray computed tomography (CT)
KW  - concrete
KW  - alkali-silica reaction (ASR)
KW  - ASR-sensitive aggregate
KW  - solubility test
KW  - specific surface area
KW  - crack
KW  - detection
KW  - automated image processing
KW  - damage quantification
Y1  - 2020
U6  - https://doi.org/10.3390/ma13183921
SN  - 1996-1944
VL  - 13
IS  - 18
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Léonard, Fabien
A1  - Zhang, Zhen
A1  - Krebs, Holger
A1  - Bruno, Giovanni
T1  - Structural and morphological quantitative 3D characterisation of ammonium nitrate prills by X-ray computed tomography
JF  - Materials
N2  - The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.
KW  - ANFO
KW  - explosives
KW  - specific surface area
KW  - porosity
KW  - XCT
KW  - data processing
Y1  - 2020
U6  - https://doi.org/10.3390/ma13051230
SN  - 1996-1944
VL  - 13
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Epp, Laura Saskia
A1  - Kruse, Stefan
A1  - Kath, Nadja J.
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Tiedemann, Ralph
A1  - Pestryakova, Luidmila Agafyevna
A1  - Herzschuh, Ulrike
T1  - Temporal and spatial patterns of mitochondrial haplotype and species distributions in Siberian larches inferred from ancient environmental DNA and modeling
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Changes in species' distributions are classically projected based on their climate envelopes. For Siberian forests, which have a tremendous significance for vegetation-climate feedbacks, this implies future shifts of each of the forest-forming larch (Larix) species to the north-east. However, in addition to abiotic factors, reliable projections must assess the role of historical biogeography and biotic interactions. Here, we use sedimentary ancient DNA and individual-based modelling to investigate the distribution of larch species and mitochondrial haplotypes through space and time across the treeline ecotone on the southern Taymyr peninsula, which at the same time presents a boundary area of two larch species. We find spatial and temporal patterns, which suggest that forest density is the most influential driver determining the precise distribution of species and mitochondrial haplotypes. This suggests a strong influence of competition on the species' range shifts. These findings imply possible climate change outcomes that are directly opposed to projections based purely on climate envelopes. Investigations of such fine-scale processes of biodiversity change through time are possible using paleoenvironmental DNA, which is available much more readily than visible fossils and can provide information at a level of resolution that is not reached in classical palaeoecology.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1052 
KW  - ecological genetics
KW  - ecological modelling
KW  - palaeoecology
KW  - plant ecology
KW  - climate change
KW  - introgression
KW  - temperature
KW  - treeline
KW  - vegetation
KW  - mitochondrial haplotypes
KW  - Siberian larch
KW  - larch species
KW  - range shifts
KW  - vegetation-climate feedbacks
KW  - ecosystems
KW  - impacts
KW  - dynamics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468352
SN  - 1866-8372
IS  - 1052
ER  - 
TY  - JOUR
A1  - Enssle, Jörg
A1  - Weylandt, Karsten-Henrich
T1  - Secure and optimized detection of PNPLA3 rs738409 genotype by an improved PCR-restriction fragment length polymorphism method
JF  - BioTechniques : the international journal of life science methods
N2  - The PNPLA3 reference single-nucleotide polymorphism rs738409 has been identified as a predisposing factor for nonalcoholic fatty liver disease. A simple method based on PCR and restriction fragment length polymorphism (RFLP) analysis had been published to detect the nonpathogenic allele PNPLA3 rs738409 variant. The presence of the pathogenic variant was deduced by the indigestibility of the corresponding PCR product with BtsCI recognizing the nonpathogenic allele. However, one cannot exclude that an enzymatic reaction does not occur for other, more trivial, reasons. For safe and secure detection of the pathogenic PNPLA3 rs738409, we have further developed the PCR-restriction fragment length polymorphism method by adding a second restriction enzyme digest, clearly identifying the correct PNPLA3 alleles and in particular the pathogenic variant. <br /> METHOD SUMMARY <br /> The method presented here represents an improved genetic diagnosis of the PNPLA3 rs738409 alleles based on conventional and inexpensive molecular biological methods. We used methodology based on PCR and restriction fragment length polymorphisms and clearly identified both described alleles by the use of two restriction enzymes. Digestion of individuals' specific PNPLA3 PCR fragments with both enzymes in independent reactions clearly showed the PNPLA3 rs738409 genotype.
KW  - n-3 polyunsaturated fatty acid therapies
KW  - nonalcoholic fatty liver
KW  - disease
KW  - PCR– RFLP
KW  - PNPLA3
KW  - rs738409
Y1  - 2021
U6  - https://doi.org/10.2144/btn-2020-0163
SN  - 0736-6205
SN  - 1940-9818
VL  - 70
IS  - 6
SP  - 345
EP  - 349
PB  - Future Science Ltd.
CY  - London
ER  - 
TY  - JOUR
A1  - Steding, Svenja
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - How insoluble inclusions and intersecting layers affect the leaching process within potash seams
JF  - Applied Sciences : open access journal
N2  - Potash seams are a valuable resource containing several economically interesting, but also highly soluble minerals. In the presence of water, uncontrolled leaching can occur, endangering subsurface mining operations. In the present study, the influence of insoluble inclusions and intersecting layers on leaching zone evolution was examined by means of a reactive transport model. For that purpose, a scenario analysis was carried out, considering different rock distributions within a carnallite-bearing potash seam. The results show that reaction-dominated systems are not affected by heterogeneities at all, whereas transport-dominated systems exhibit a faster advance in homogeneous rock compositions. In return, the ratio of permeated rock in vertical direction is higher in heterogeneous systems. Literature data indicate that most natural potash systems are transport-dominated. Accordingly, insoluble inclusions and intersecting layers can usually be seen as beneficial with regard to reducing hazard potential as long as the mechanical stability of leaching zones is maintained. Thereby, the distribution of insoluble areas is of minor impact unless an inclined, intersecting layer occurs that accelerates leaching zone growth in one direction. Moreover, it is found that the saturation dependency of dissolution rates increases the growth rate in the long term, and therefore must be considered in risk assessments.
KW  - salt dissolution
KW  - reactive transport
KW  - heterogeneity
KW  - density-driven
KW  - convection
KW  - PHREEQC
KW  - porous media
Y1  - 2021
U6  - https://doi.org/10.3390/app11199314
SN  - 2076-3417
VL  - 11
IS  - 19
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Pries, Christopher
A1  - Razaghi-Moghadam, Zahra
A1  - Kopka, Joachim
A1  - Nikoloski, Zoran
T1  - Integration of relative metabolomics and transcriptomics time-course data in a metabolic model pinpoints effects of ribosome biogenesis defects on Arabidopsis thaliana metabolism
JF  - Scientific reports
N2  - Ribosome biogenesis is tightly associated to plant metabolism due to the usage of ribosomes in the synthesis of proteins necessary to drive metabolic pathways. Given the central role of ribosome biogenesis in cell physiology, it is important to characterize the impact of different components involved in this process on plant metabolism. Double mutants of the Arabidopsis thaliana cytosolic 60S maturation factors REIL1 and REIL2 do not resume growth after shift to moderate 10 degrees C chilling conditions. To gain mechanistic insights into the metabolic effects of this ribosome biogenesis defect on metabolism, we developed TC-iReMet2, a constraint-based modelling approach that integrates relative metabolomics and transcriptomics time-course data to predict differential fluxes on a genome-scale level. We employed TC-iReMet2 with metabolomics and transcriptomics data from the Arabidopsis Columbia 0 wild type and the reil1-1 reil2-1 double mutant before and after cold shift. We identified reactions and pathways that are highly altered in a mutant relative to the wild type. These pathways include the Calvin-Benson cycle, photorespiration, gluconeogenesis, and glycolysis. Our findings also indicated differential NAD(P)/NAD(P)H ratios after cold shift. TC-iReMet2 allows for mechanistic hypothesis generation and interpretation of system biology experiments related to metabolic fluxes on a genome-scale level.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-84114-y
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Kühne, Katharina
A1  - Fischer, Martin H.
A1  - Zhou, Yuefang
T1  - The Human Takes It All
BT  - Humanlike Synthesized Voices Are Perceived as Less Eerie and More Likable. Evidence From a Subjective Ratings Study
JF  - Frontiers in  Neurorobotics
N2  - Background: The increasing involvement of social robots in human lives raises the question as to how humans perceive social robots. Little is known about human perception of synthesized voices.

Aim: To investigate which synthesized voice parameters predict the speaker's eeriness and voice likability; to determine if individual listener characteristics (e.g., personality, attitude toward robots, age) influence synthesized voice evaluations; and to explore which paralinguistic features subjectively distinguish humans from robots/artificial agents.

Methods: 95 adults (62 females) listened to randomly presented audio-clips of three categories: synthesized (Watson, IBM), humanoid (robot Sophia, Hanson Robotics), and human voices (five clips/category). Voices were rated on intelligibility, prosody, trustworthiness, confidence, enthusiasm, pleasantness, human-likeness, likability, and naturalness. Speakers were rated on appeal, credibility, human-likeness, and eeriness. Participants' personality traits, attitudes to robots, and demographics were obtained.

Results: The human voice and human speaker characteristics received reliably higher scores on all dimensions except for eeriness. Synthesized voice ratings were positively related to participants' agreeableness and neuroticism. Females rated synthesized voices more positively on most dimensions. Surprisingly, interest in social robots and attitudes toward robots played almost no role in voice evaluation. Contrary to the expectations of an uncanny valley, when the ratings of human-likeness for both the voice and the speaker characteristics were higher, they seemed less eerie to the participants. Moreover, when the speaker's voice was more humanlike, it was more liked by the participants. This latter point was only applicable to one of the synthesized voices. Finally, pleasantness and trustworthiness of the synthesized voice predicted the likability of the speaker's voice. Qualitative content analysis identified intonation, sound, emotion, and imageability/embodiment as diagnostic features.

Discussion: Humans clearly prefer human voices, but manipulating diagnostic speech features might increase acceptance of synthesized voices and thereby support human-robot interaction. There is limited evidence that human-likeness of a voice is negatively linked to the perceived eeriness of the speaker.
KW  - human-robot interaction
KW  - paralinguistic features
KW  - synthesized voice
KW  - text-to-speech
KW  - uncanny valley
Y1  - 2020
U6  - https://doi.org/10.3389/fnbot.2020.593732
SN  - 1662-5218
VL  - 14
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Ziege, Madlen
A1  - Theodorou, Panagiotis
A1  - Jüngling, Hannah
A1  - Merker, Stefan
A1  - Plath, Martin
A1  - Streit, Bruno
A1  - Lerp, Hannes
T1  - Population genetics of the European rabbit along a rural-to-urban gradient
JF  - Scientific Reports
N2  - The European rabbit (Oryctolagus cuniculus) is declining in large parts of Europe but populations in some German cities remained so far unaffected by this decline. The question arises of how urbanization affects patterns of population genetic variation and differentiation in German rabbit populations, as urban habitat fragmentation may result in altered meta-population dynamics. To address this question, we used microsatellite markers to genotype rabbit populations occurring along a rural-to-urban gradient in and around the city of Frankfurt, Germany. We found no effect of urbanization on allelic richness. However, the observed heterozygosity was significantly higher in urban than rural populations and also the inbreeding coefficients were lower, most likely reflecting the small population sizes and possibly on-going loss of genetic diversity in structurally impoverished rural areas. Global FST and G'ST-values suggest moderate but significant differentiation between populations. Multiple matrix regression with randomization ascribed this differentiation to isolation-by-environment rather than isolation-by-distance. Analyses of migration rates revealed asymmetrical gene flow, which was higher from rural into urban populations than vice versa and may again reflect intensified agricultural land-use practices in rural areas. We discuss that populations inhabiting urban areas will likely play an important role in the future distribution of European rabbits.
KW  - Conservation biology
KW  - Genetics
Y1  - 2018
U6  - https://doi.org/10.1038/s41598-020-57962-3
SN  - 2045-2322
VL  - 10
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - GEN
A1  - Weber, Edzard
A1  - Tiefenbacher, Anselm
A1  - Gronau, Norbert
T1  - Need for standardization and systematization of test data for job-shop scheduling
T2  - Postprints der Universität Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - The development of new and better optimization and approximation methods for Job Shop Scheduling Problems (JSP) uses simulations to compare their performance. The test data required for this has an uncertain influence on the simulation results, because the feasable search space can be changed drastically by small variations of the initial problem model. Methods could benefit from this to varying degrees. This speaks in favor of defining standardized and reusable test data for JSP problem classes, which in turn requires a systematic describability of the test data in order to be able to compile problem adequate data sets. This article looks at the test data used for comparing methods by literature review. It also shows how and why the differences in test data have to be taken into account. From this, corresponding challenges are derived which the management of test data must face in the context of JSP research.
Keywords
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 134 
KW  - job shop scheduling
KW  - JSP
KW  - social network analysis
KW  - method comparision
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472229
SN  - 1867-5808
IS  - 134
ER  - 
TY  - JOUR
A1  - Weber, Edzard
A1  - Tiefenbacher, Anselm
A1  - Gronau, Norbert
T1  - Need for Standardization and Systematization of Test Data for Job-Shop Scheduling
JF  - Data
N2  - The development of new and better optimization and approximation methods for Job Shop Scheduling Problems (JSP) uses simulations to compare their performance. The test data required for this has an uncertain influence on the simulation results, because the feasable search space can be changed drastically by small variations of the initial problem model. Methods could benefit from this to varying degrees. This speaks in favor of defining standardized and reusable test data for JSP problem classes, which in turn requires a systematic describability of the test data in order to be able to compile problem adequate data sets. This article looks at the test data used for comparing methods by literature review. It also shows how and why the differences in test data have to be taken into account. From this, corresponding challenges are derived which the management of test data must face in the context of JSP research.
KW  - job shop scheduling
KW  - JSP
KW  - social network analysis
KW  - method comparision
Y1  - 2019
U6  - https://doi.org/10.3390/data4010032
SN  - 2306-5729
VL  - 4
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Büchele, Dominique
A1  - Chao, Madlen
A1  - Ostermann, Markus
A1  - Leenen, Matthias
A1  - Bald, Ilko
T1  - Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 784 
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439988
SN  - 1866-8372
IS  - 784
ER  - 
TY  - JOUR
A1  - Büchele, Dominique
A1  - Chao, Madlen
A1  - Ostermann, Markus
A1  - Leenen, Matthias
A1  - Bald, Ilko
T1  - Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF
JF  - Scientific Reports
N2  - Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred.
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-53426-5
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - GEN
A1  - Listek, Martin
A1  - Hönow, Anja
A1  - Gossen, Manfred
A1  - Hanack, Katja
T1  - A novel selection strategy for antibody producing hybridoma cells based on a new transgenic fusion cell line
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - The use of monoclonal antibodies is ubiquitous in science and biomedicine but the generation and validation process of antibodies is nevertheless complicated and time-consuming. To address these issues we developed a novel selective technology based on an artificial cell surface construct by which secreted antibodies were connected to the corresponding hybridoma cell when they possess the desired antigen-specificity. Further the system enables the selection of desired isotypes and the screening for potential cross-reactivities in the same context. For the design of the construct we combined the transmembrane domain of the EGF-receptor with a hemagglutinin epitope and a biotin acceptor peptide and performed a transposon-mediated transfection of myeloma cell lines. The stably transfected myeloma cell line was used for the generation of hybridoma cells and an antigen- and isotype-specific screening method was established. The system has been validated for globular protein antigens as well as for haptens and enables a fast and early stage selection and validation of monoclonal antibodies in one step.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 865 
KW  - Antibody generation
KW  - Assay systems
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459893
SN  - 1866-8372
IS  - 865
ER  - 
TY  - JOUR
A1  - Listek, Martin
A1  - Hönow, Anja
A1  - Gossen, Manfred
A1  - Hanack, Katja
T1  - A novel selection strategy for antibody producing hybridoma cells based on a new transgenic fusion cell line
JF  - Scientific Reports
N2  - The use of monoclonal antibodies is ubiquitous in science and biomedicine but the generation and validation process of antibodies is nevertheless complicated and time-consuming. To address these issues we developed a novel selective technology based on an artificial cell surface construct by which secreted antibodies were connected to the corresponding hybridoma cell when they possess the desired antigen-specificity. Further the system enables the selection of desired isotypes and the screening for potential cross-reactivities in the same context. For the design of the construct we combined the transmembrane domain of the EGF-receptor with a hemagglutinin epitope and a biotin acceptor peptide and performed a transposon-mediated transfection of myeloma cell lines. The stably transfected myeloma cell line was used for the generation of hybridoma cells and an antigen- and isotype-specific screening method was established. The system has been validated for globular protein antigens as well as for haptens and enables a fast and early stage selection and validation of monoclonal antibodies in one step.
KW  - Antibody generation
KW  - Assay systems
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-020-58571-w
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Balk, Maria
A1  - Behl, Marc
A1  - Nöchel, Ulrich
A1  - Lendlein, Andreas
T1  - Enzymatically triggered Jack-in-the-box-like hydrogels
JF  - ACS applied materials & interfaces / American Chemical Society
N2  - Enzymes can support the synthesis or degradation of biomacromolecules in natural processes. Here, we demonstrate that enzymes can induce a macroscopic-directed movement of microstructured hydrogels following a mechanism that we call a "Jack-in-the-box" effect. The material's design is based on the formation of internal stresses induced by a deformation load on an architectured microscale, which are kinetically frozen by the generation of polyester locking domains, similar to a Jack-in-thebox toy (i.e., a compressed spring stabilized by a closed box lid). To induce the controlled macroscopic movement, the locking domains are equipped with enzyme-specific cleavable bonds (i.e., a box with a lock and key system). As a result of enzymatic reaction, a transformed shape is achieved by the release of internal stresses. There is an increase in entropy in combination with a swelling-supported stretching of polymer chains within the microarchitectured hydrogel (i.e., the encased clown pops-up with a pre-stressed movement when the box is unlocked). This utilization of an enzyme as a physiological stimulus may offer new approaches to create interactive and enzyme-specific materials for different applications such as an optical indicator of the enzyme's presence or actuators and sensors in biotechnology and in fermentation processes.
KW  - enzyme
KW  - hydrogels
KW  - stimuli-sensitive materials
KW  - shape change
KW  - poly(e-caprolactone)
KW  - switch
KW  - microporous
Y1  - 2021
U6  - https://doi.org/10.1021/acsami.1c00466
SN  - 1944-8244
SN  - 1944-8252
VL  - 13
IS  - 7
SP  - 8095
EP  - 8101
PB  - American Chemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Kühn, Andrea A.
A1  - Busch, Johannes Leon
T1  - Real-time estimation of phase and amplitude with application to neural data
JF  - Scientific reports
N2  - Computation of the instantaneous phase and amplitude via the Hilbert Transform is a powerful tool of data analysis. This approach finds many applications in various science and engineering branches but is not proper for causal estimation because it requires knowledge of the signal’s past and future. However, several problems require real-time estimation of phase and amplitude; an illustrative example is phase-locked or amplitude-dependent stimulation in neuroscience. In this paper, we discuss and compare three causal algorithms that do not rely on the Hilbert Transform but exploit well-known physical phenomena, the synchronization and the resonance. After testing the algorithms on a synthetic data set, we illustrate their performance computing phase and amplitude for the accelerometer tremor measurements and a Parkinsonian patient’s beta-band brain activity.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-97560-5
SN  - 2045-2322
VL  - 11
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Dunsing, Valentin
A1  - Petrich, Annett
A1  - Chiantia, Salvatore
T1  - Multicolor fluorescence fluctuation spectroscopy in living cells via spectral detection
JF  - eLife
N2  - Signaling pathways in biological systems rely on specific interactions between multiple biomolecules. Fluorescence fluctuation spectroscopy provides a powerful toolbox to quantify such interactions directly in living cells. Cross-correlation analysis of spectrally separated fluctuations provides information about intermolecular interactions but is usually limited to two fluorophore species. Here, we present scanning fluorescence spectral correlation spectroscopy (SFSCS), a versatile approach that can be implemented on commercial confocal microscopes, allowing the investigation of interactions between multiple protein species at the plasma membrane. We demonstrate that SFSCS enables cross-talk-free cross-correlation, diffusion, and oligomerization analysis of up to four protein species labeled with strongly overlapping fluorophores. As an example, we investigate the interactions of influenza A virus (IAV) matrix protein 2 with two cellular host factors simultaneously. We furthermore apply raster spectral image correlation spectroscopy for the simultaneous analysis of up to four species and determine the stoichiometry of ternary IAV polymerase complexes in the cell nucleus.
KW  - fluorescence
KW  - optical microscopy
KW  - virus assembly
KW  - protein-protein
KW  - interactions
KW  - diffusion
KW  - Viruses
Y1  - 2021
U6  - https://doi.org/10.7554/eLife.69687
SN  - 2050-084X
VL  - 10
PB  - eLife Sciences Publications
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Caliendo, Marco
A1  - Künn, Steffen
A1  - Weissenberger, Martin
T1  - Catching up or lagging behind?
BT  - the long-term business and innovation potential of subsidized start-ups out of unemployment
JF  - Research policy : policy, management and economic studies of science, technology and innovation
N2  - From an active labor market policy perspective, start-up subsidies for unemployed individuals are very effective in improving long-term labor market outcomes for participants. From a business perspective, however, the assessment of these public programs is less clear since they might attract individuals with low entrepreneurial abilities and produce businesses with low survival rates and little contribution to job creation, economic growth, and innovation. In this paper, we use a rich data set to compare participants of a German start-up subsidy program for unemployed individuals to a group of regular founders who started from non-unemployment and did not receive the subsidy. The data allows us to analyze their business performance up until 40 months after business formation. We find that formerly subsidized founders lag behind not only in survival and job creation, but especially also in innovation activities. The gaps in these business outcomes are relatively constant or even widening over time. Hence, we do not see any indication of catching up in the longer run. While the gap in survival can be entirely explained by initial differences in observable start-up characteristics, the gap in business development remains and seems to be the result of restricted access to capital as well as differential business strategies and dynamics. Considering these conflicting results for the assessment of the subsidy program from an ALMP and business perspective, policy makers need to carefully weigh the costs and benefits of such a strategy to find the right policy mix.
KW  - entrepreneurship
KW  - start-up subsidies
KW  - business growth
KW  - innovation
KW  - job
KW  - creation
Y1  - 2020
U6  - https://doi.org/10.1016/j.respol.2020.104053
SN  - 0048-7333
SN  - 1873-7625
VL  - 49
IS  - 10
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ploner, Tina
A1  - Hess, Steffen
A1  - Grum, Marcus
A1  - Drewe-Boss, Philipp
A1  - Walker, Jochen
T1  - Using gradient boosting with stability selection on health insurance claims data to identify disease trajectories in chronic obstructive pulmonary disease
JF  - Statistical methods in medical research
N2  - Objective We propose a data-driven method to detect temporal patterns of disease progression in high-dimensional claims data based on gradient boosting with stability selection. Materials and methods We identified patients with chronic obstructive pulmonary disease in a German health insurance claims database with 6.5 million individuals and divided them into a group of patients with the highest disease severity and a group of control patients with lower severity. We then used gradient boosting with stability selection to determine variables correlating with a chronic obstructive pulmonary disease diagnosis of highest severity and subsequently model the temporal progression of the disease using the selected variables. Results We identified a network of 20 diagnoses (e.g. respiratory failure), medications (e.g. anticholinergic drugs) and procedures associated with a subsequent chronic obstructive pulmonary disease diagnosis of highest severity. Furthermore, the network successfully captured temporal patterns, such as disease progressions from lower to higher severity grades. Discussion The temporal trajectories identified by our data-driven approach are compatible with existing knowledge about chronic obstructive pulmonary disease showing that the method can reliably select relevant variables in a high-dimensional context. Conclusion We provide a generalizable approach for the automatic detection of disease trajectories in claims data. This could help to diagnose diseases early, identify unknown risk factors and optimize treatment plans.
KW  - Gradient boosting
KW  - stability selection
KW  - claims data
KW  - disease trajectory
KW  - chronic obstructive pulmonary disease
Y1  - 2020
U6  - https://doi.org/10.1177/0962280220938088
SN  - 0962-2802
SN  - 1477-0334
VL  - 29
IS  - 12
SP  - 3684
EP  - 3694
PB  - Sage Publ.
CY  - London [u.a.]
ER  - 
TY  - JOUR
A1  - Loges, Klara
A1  - Tiberius, Victor
T1  - Implementation Challenges of 3D Printing in Prosthodontics
BT  - A Ranking-Type Delphi
JF  - Materials
N2  - The reduction in cost and increasing benefits of 3D printing technologies suggest the potential for printing dental prosthetics. However, although 3D printing technologies seem to be promising, their implementation in practice is complicated. To identify and rank the greatest implementation challenges of 3D printing in dental practices, the present study surveys dentists, dental technicians, and 3D printing companies using a ranking-type Delphi study. Our findings imply that a lack of knowledge is the most crucial obstacle to the implementation of 3D printing technologies. The high training effort of staff and the favoring of conventional methods, such as milling, are ranked as the second and third most relevant factors. Investment costs ranked in seventh place, whereas the lack of manufacturing facilities and the obstacle of print duration ranked below average. An inclusive implementation of additive manufacturing could be achieved primarily through the education of dentists and other staff in dental practices. In this manner, production may be managed internally, and the implementation speed may be increased.
KW  - 3D printing
KW  - prosthodontics
KW  - ranking type Delphi study
KW  - additive manufacturing
KW  - dentistry
Y1  - 2021
U6  - https://doi.org/10.3390/ma15020431
SN  - 1996-1944
VL  - 15
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Loges, Klara
A1  - Tiberius, Victor
T1  - Implementation Challenges of 3D Printing in Prosthodontics
BT  - A Ranking-Type Delphi
T2  - Postprints der Universität Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - The reduction in cost and increasing benefits of 3D printing technologies suggest the potential for printing dental prosthetics. However, although 3D printing technologies seem to be promising, their implementation in practice is complicated. To identify and rank the greatest implementation challenges of 3D printing in dental practices, the present study surveys dentists, dental technicians, and 3D printing companies using a ranking-type Delphi study. Our findings imply that a lack of knowledge is the most crucial obstacle to the implementation of 3D printing technologies. The high training effort of staff and the favoring of conventional methods, such as milling, are ranked as the second and third most relevant factors. Investment costs ranked in seventh place, whereas the lack of manufacturing facilities and the obstacle of print duration ranked below average. An inclusive implementation of additive manufacturing could be achieved primarily through the education of dentists and other staff in dental practices. In this manner, production may be managed internally, and the implementation speed may be increased.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 147 
KW  - 3D printing
KW  - prosthodontics
KW  - ranking type Delphi study
KW  - additive manufacturing
KW  - dentistry
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544024
ER  - 
TY  - JOUR
A1  - Serrano-Munoz, Itziar
A1  - Mishurova, Tatiana
A1  - Thiede, Tobias
A1  - Sprengel, Maximilian
A1  - Kromm, Arne
A1  - Nadammal, Naresh
A1  - Nolze, Gert
A1  - Saliwan-Neumann, Romeo
A1  - Evans, Alexander
A1  - Bruno, Giovanni
T1  - The residual stress in as-built laser powder bed fusion IN718 alloy as a consequence of the scanning strategy induced microstructure
JF  - Scientific reports
N2  - The effect of two types of scanning strategies on the grain structure and build-up of Residual Stress (RS) has been investigated in an as-built IN718 alloy produced by Laser Powder Bed Fusion (LPBF). The RS state has been investigated by X-ray diffraction techniques. The microstructural characterization was performed principally by Electron Backscatter Diffraction (EBSD), where the application of a post-measurement refinement technique enables small misorientations (< 2 degrees) to be resolved. Kernel average misorientation (KAM) distributions indicate that preferably oriented columnar grains contain higher levels of misorientation, when compared to elongated grains with lower texture. The KAM distributions combined with X-ray diffraction stress maps infer that the increased misorientation is induced via plastic deformation driven by the thermal stresses, acting to self-relieve stress. The possibility of obtaining lower RS states in the build direction as a consequence of the influence of the microstructure should be considered when envisaging scanning strategies aimed at the mitigation of RS.
KW  - EBSD
KW  - components
KW  - deposition
KW  - diffraction
KW  - distortion
KW  - heat-treatment
KW  - mechanical properties
KW  - melting slm
KW  - superalloys
KW  - texture
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-71112-9
SN  - 2045-2322
VL  - 10
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  -