TY  - JOUR
A1  - Folikumah, Makafui Yao
A1  - Neffe, Axel T.
A1  - Behl, Marc
A1  - Lendlein, Andreas
T1  - Thiol Michael-Type reactions of optically active mercapto-acids in aqueous medium
JF  - MRS advances : a journal of the Materials Research Society
N2  - Defined chemical reactions in a physiological environment are a prerequisite for the in situ synthesis of implant materials potentially serving as matrix for drug delivery systems, tissue fillers or surgical glues. ‘Click’ reactions like thiol Michael-type reactions have been successfully employed as bioorthogonal reaction. However, due to the individual stereo-electronic and physical properties of specific substrates, an exact understanding their chemical reactivity is required if they are to be used for in-situ biomaterial synthesis. The chiral (S)-2-mercapto-carboxylic acid analogues of L-phenylalanine (SH-Phe) and L-leucine (SH-Leu) which are subunits of certain collagenase sensitive synthetic peptides, were explored for their potential for in-situ biomaterial formation via the thiol Michael-type reaction.

In model reactions were investigated the kinetics, the specificity and influence of stereochemistry of this reaction. We could show that only reactions involving SH-Leu yielded the expected thiol-Michael product. The inability of SH-Phe to react was attributed to the steric hindrance of the bulky phenyl group. In aqueous media, successful reaction using SH-Leu is thought to proceed via the sodium salt formed in-situ by the addition of NaOH solution, which was intented to aid the solubility of the mercapto-acid in water. Fast reaction rates and complete acrylate/maleimide conversion were only realized at pH 7.2 or higher suggesting the possible use of SH-Leu under physiological conditions for thiol Michael-type reactions. This method of in-situ formed alkali salts could be used as a fast approach to screen mercapto-acids for thio Michael-type reactions without the synthesis of their corresponding esters.
KW  - biomaterial
KW  - biomedical
KW  - biomimetic (chemical reaction)
KW  - chemical synthesis
Y1  - 2019
U6  - https://doi.org/10.1557/adv.2019.308
SN  - 2059-8521
VL  - 4
IS  - 46-47
SP  - 2515
EP  - 2525
PB  - Springer Nature Switzerland AG
CY  - Cham
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  - 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  - 
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  - 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  - 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  - 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  - 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  - 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  - 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  - THES
A1  - Harbart, Vanessa
T1  - The effect of protected cultivation on the nutritional quality of lettuce (Lactuca sativa var capitata L.) with a focus on antifogging additives in polyolefin covers
T1  - Die Bedeutung des geschützten Anbaus für die ernährungsphysiologische Qualität von Kopfsalat (Lactuca sativa var. capitata L.) mit Schwerpunkt auf Antibeschlagmittel in Polyolefinfolien
N2  - Protected cultivation in greenhouses or polytunnels offers the potential for sustainable production of high-yield, high-quality vegetables. This is related to the ability to produce more on less land and to use resources responsibly and efficiently. Crop yield has long been considered the most important factor. However, as plant-based diets have been proposed for a sustainable food system, the targeted enrichment of health-promoting plant secondary metabolites should be addressed. These metabolites include carotenoids and flavonoids, which are associated with several health benefits, such as cardiovascular health and cancer protection. 
Cover materials generally have an influence on the climatic conditions, which in turn can affect the levels of secondary metabolites in vegetables grown underneath. Plastic materials are cost-effective and their properties can be modified by incorporating additives, making them the first choice. However, these additives can migrate and leach from the material, resulting in reduced service life, increased waste and possible environmental release. Antifogging additives are used in agricultural films to prevent the formation of droplets on the film surface, thereby increasing light transmission and preventing microbiological contamination. 
This thesis focuses on LDPE/EVA covers and incorporated antifogging additives for sustainable protected cultivation, following two different approaches. The first addressed the direct effects of leached antifogging additives using simulation studies on lettuce leaves (Lactuca sativa var capitata L). The second determined the effect of antifog polytunnel covers on lettuce quality. Lettuce is usually grown under protective cover and can provide high nutritional value due to its carotenoid and flavonoid content, depending on the cultivar. 
To study the influence of simulated leached antifogging additives on lettuce leaves, a GC-MS method was first developed to analyze these additives based on their fatty acid moieties. Three structurally different antifogging additives (reference material) were characterized outside of a polymer matrix for the first time. All of them contained more than the main fatty acid specified by the manufacturer. Furthermore, they were found to adhere to the leaf surface and could not be removed by water or partially by hexane. 
The incorporation of these additives into polytunnel covers affects carotenoid levels in lettuce, but not flavonoids, caffeic acid derivatives and chlorophylls. Specifically, carotenoids were higher in lettuce grown under polytunnels without antifog than with antifog. This has been linked to their effect on the light regime and was suggested to be related to carotenoid function in photosynthesis. 
In terms of protected cultivation, the use of LDPE/EVA polytunnels affected light and temperature, and both are closely related. The carotenoid and flavonoid contents of lettuce grown under polytunnels was reversed, with higher carotenoid and lower flavonoid levels. At the individual level, the flavonoids detected in lettuce did not differ however, lettuce carotenoids adapted specifically depending on the time of cultivation. Flavonoid reduction was shown to be transcriptionally regulated (CHS) in response to UV light (UVR8). In contrast, carotenoids are thought to be regulated post-transcriptionally, as indicated by the lack of correlation between carotenoid levels and transcripts of the first enzyme in carotenoid biosynthesis (PSY) and a carotenoid degrading enzyme (CCD4), as well as the increased carotenoid metabolic flux. Understanding the regulatory mechanisms and metabolite adaptation strategies could further advance the strategic development and selection of cover materials.
N2  - Der geschützte Anbau in Gewächshäusern oder unter Folientunneln bietet die Möglichkeit einer nachhaltigen Produktion von ertragreichem Gemüse hoher Qualität. Die ressourceneffiziente Produktion von mehr auf weniger Fläche ist dabei ein wichtiger Faktor. Lange galt der Gemüseertrag als wichtigstes Kriterium. Die Anreicherung von gesundheitsfördernden sekundären Pflanzenmetaboliten gewinnt jedoch zunehmend an Bedeutung, nicht zuletzt durch die empfohlene pflanzenbasierte Ernährung für ein nachhaltiges Ernährungssystem. Die Sekundärmetabolite Carotinoide und Flavonoide sind mit verschiedenen gesundheitlichen Vorteilen assoziiert, etwa der kardiovaskulären Gesundheit und der Krebsprävention. 
Das Material eines Gewächshauses beeinflusst die klimatischen Bedingungen im geschützten Anbau. Das resultierende Mikroklima kann sich wiederum auf den Gehalt an Sekundärmetaboliten im Gemüse auswirken. Materialien aus Kunststoff sind kostengünstig und ihre Eigenschaften können durch Zusätze, sogenannte Additive, modifiziert werden. Additive können an die Oberfläche des Materials und aus diesem migrieren, was die Materiallebensdauer einerseits verkürzt und größere Abfallmengen produziert. Andererseits besteht das Risiko einer Umweltemission der Additive. Antifogging-Additive verhindern die Bildung von Kondenswasser Tropfen auf der Oberfläche von Gewächshausfolien, wodurch die Lichtdurchlässigkeit der Folien verbessert, sowie eine mikrobiologische Kontamination vermieden werden kann. 
Die vorliegende Arbeit befasst sich mit LDPE/EVA-Gewächshausfolien mit Antifogging-Additiven für einen nachhaltigen geschützten Anbau und verfolgt dabei zwei unterschiedliche Herangehensweisen. Zum einen befasst sich die Arbeit mit den direkten Auswirkungen von Antifogging-Additiven in Folge eines Übergangs auf Salatblätter (Lactuca sativa var. capitata L.) mittels Simulationsversuchen. Um den simulierten Übergang zu untersuchen, wurde zunächst eine Methode zur Analyse des Fettsäureanteils der Additive mittels GC-MS entwickelt. Drei strukturell unterschiedliche Antifogging-Additive (Referenzmaterial) wurden erstmals außerhalb einer Polymermatrix charakterisiert. Sie enthielten diverse Fettsäuren, und somit mehr, als die vom Hersteller angegebene Hauptfettsäure. Des Weiteren wurde gezeigt, dass sie an der Blattoberfläche haften und weder durch Wasser noch teilweise durch Hexan entfernt werden können.
Zum anderen wurde der Einfluss von Antifogging-Additiven in Gewächshausfolien auf die Salatqualität untersucht. Salat ist ein Gemüse, das üblicherweise auch unter Schutzabdeckungen angebaut wird und sortenspezifisch größere Mengen an Carotinoiden und Flavonoiden enthält. Der Anbau von Salat unter Antifog-Folientunneln beeinflusste den Carotinoidgehalt, nicht aber den Gehalt an Flavonoiden, Kaffeesäurederivaten und Chlorophyll. Salate, die unter Folientunneln ohne Antifog angebaut wurde akkumulierten höhere Gehalte der Carotinoide, als solche unter Antifog-Folientunneln. Es besteht wahrscheinlich ein Zusammenhang mit der Funktion der Carotinoide als Photosynthesepigmente und der Lichtumgebung. Die Verwendung von LDPE/EVA-Folientunneln beeinflusste allgemein Licht und Temperatur im geschützten Anbau, beide Faktoren sind eng verknüpft. Die Carotinoid- und Flavonoidgehalte waren dabei invers, mit höheren gesamt Carotinoid- und niedrigeren gesamt Flavonoidgehalten von Salaten unter Folientunneln. Die individuellen Flavonoid-Glykoside unterschieden sich innerhalb der Versuchszeiträume (Frühjahr und Herbst) nicht. Es konnte gezeigt werden, dass diese hinsichtlich der UV-Lichtumgebung (UVR8) transkriptionell reguliert werden (CHS). Demgegenüber fanden spezifische Anpassungen der individuellen Carotinoidmetabolite in den Versuchszeiträumen statt. Die fehlende Korrelation der Carotinoidmetabolite und der Transkripte des Hauptenzyms der Biosynthese (PSY) und eines Carotinoid-abbauenden Enzyms (CCD4) sowie der erhöhte Carotinoid-Stoffwechselfluss deuten auf eine post-transkriptionelle Regulierung hin. 
Die Regulationsmechanismen und Anpassungsstrategien der sekundären Pflanzenstoffe in Gemüse zu verstehen, könnte zukünftig zur strategischen Entwicklung und Auswahl von Gewächshausmaterialien beitragen.
KW  - protected cultivation
KW  - polytunnel
KW  - lettuce
KW  - antifogging additives
KW  - plant secondary metabolites
KW  - carotenoids
KW  - flavonoids
KW  - mass spectrometry
KW  - plastic additives
KW  - Antibeschlag-Additive
KW  - Carotinoide
KW  - Flavonoide
KW  - Kopfsalat
KW  - Massenspektrometrie
KW  - sekundäre Pflanzenstoffe
KW  - Kunststoff-Additive
KW  - Folientunnel
KW  - geschützter Anbau
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-629375
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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1399 
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  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513666
SN  - 1866-8372
IS  - 1
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  - 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  - 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  - 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  - 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  - Schaller, Jörg
A1  - Scherwietes, Eric
A1  - Gerber, Lukas
A1  - Vaidya, Shrijana
A1  - Kaczorek, Danuta
A1  - Pausch, Johanna
A1  - Barkusky, Dietmar
A1  - Sommer, Michael
A1  - Hoffmann, Mathias
T1  - Silica fertilization improved wheat performance and increased phosphorus concentrations during drought at the field scale
JF  - Scientific reports
N2  - Drought and the availability of mineable phosphorus minerals used for fertilization are two of the important issues agriculture is facing in the future. High phosphorus availability in soils is necessary to maintain high agricultural yields. Drought is one of the major threats for terrestrial ecosystem performance and crop production in future. Among the measures proposed to cope with the upcoming challenges of intensifying drought stress and to decrease the need for phosphorus fertilizer application is the fertilization with silica (Si). Here we tested the importance of soil Si fertilization on wheat phosphorus concentration as well as wheat performance during drought at the field scale. Our data clearly showed a higher soil moisture for the Si fertilized plots. This higher soil moisture contributes to a better plant performance in terms of higher photosynthetic activity and later senescence as well as faster stomata responses ensuring higher productivity during drought periods. The plant phosphorus concentration was also higher in Si fertilized compared to control plots. Overall, Si fertilization or management of the soil Si pools seem to be a promising tool to maintain crop production under predicted longer and more serve droughts in the future and reduces phosphorus fertilizer requirements.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-00464-7
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - [London]
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  - 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  - GEN
A1  - Igual Gil, Carla
A1  - Ost, Mario
A1  - Kasch, Juliane
A1  - Schumann, Sara
A1  - Heider, Sarah
A1  - Klaus, Susanne
T1  - Role of GDF15 in active lifestyle induced metabolic adaptations and acute exercise response in mice
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Physical activity is an important contributor to muscle adaptation and metabolic health. Growth differentiation factor 15 (GDF15) is established as cellular and nutritional stress-induced cytokine but its physiological role in response to active lifestyle or acute exercise is unknown. Here, we investigated the metabolic phenotype and circulating GDF15 levels in lean and obese male C57BI/6J mice with long-term voluntary wheel running (VWR) intervention. Additionally, treadmill running capacity and exercise-induced muscle gene expression was examined in GDF15-ablated mice. Active lifestyle mimic via VWR improved treadmill running performance and, in obese mice, also metabolic phenotype. The post-exercise induction of skeletal muscle transcriptional stress markers was reduced by VWR. Skeletal muscle GDF15 gene expression was very low and only transiently increased post-exercise in sedentary but not in active mice. Plasma GDF15 levels were only marginally affected by chronic or acute exercise. In obese mice, VWR reduced GDF15 gene expression in different tissues but did not reverse elevated plasma GDF15. Genetic ablation of GDF15 had no effect on exercise performance but augmented the post exercise expression of transcriptional exercise stress markers (Atf3, Atf6, and Xbp1s) in skeletal muscle. We conclude that skeletal muscle does not contribute to circulating GDF15 in mice, but muscle GDF15 might play a protective role in the exercise stress response.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1090 
KW  - skeletal-muscle
KW  - growth
KW  - induction
KW  - insulin
KW  - activation
KW  - increases
KW  - glucagon
KW  - health
KW  - gene
KW  - diet
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460541
SN  - 1866-8372
IS  - 1090
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  - Quante, Lennart
A1  - Willner, Sven N.
A1  - Middelanis, Robin
A1  - Levermann, Anders
T1  - Regions of intensification of extreme snowfall under future warming
JF  - Scientific reports
N2  - Due to climate change the frequency and character of precipitation are changing as the hydrological cycle intensifies. With regards to snowfall, global warming has two opposing influences; increasing humidity enables intense snowfall, whereas higher temperatures decrease the likelihood of snowfall. Here we show an intensification of extreme snowfall across large areas of the Northern Hemisphere under future warming. This is robust across an ensemble of global climate models when they are bias-corrected with observational data. While mean daily snowfall decreases, both the 99th and the 99.9th percentiles of daily snowfall increase in many regions in the next decades, especially for Northern America and Asia. Additionally, the average intensity of snowfall events exceeding these percentiles as experienced historically increases in many regions. This is likely to pose a challenge to municipalities in mid to high latitudes. Overall, extreme snowfall events are likely to become an increasingly important impact of climate change in the next decades, even if they will become rarer, but not necessarily less intense, in the second half of the century.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-95979-4
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - Berlin
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  - 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  - 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  - 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  - 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  - 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  - Niebuur, Bart-Jan
A1  - Puchmayr, Jonas
A1  - Herold, Christian
A1  - Kreuzer, Lucas
A1  - Hildebrand, Viet
A1  - Müller-Buschbaum, Peter
A1  - Laschewsky, André
A1  - Papadakis, Christine M.
T1  - Polysulfobetaines in aqueous solution and in thin film geometry
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Polysulfobetaines in aqueous solution show upper critical solution temperature (UCST) behavior. We investigate here the representative of this class of materials, poly (N,N-dimethyl-N-(3-methacrylamidopropyl) ammonio propane sulfonate) (PSPP), with respect to: (i) the dynamics in aqueous solution above the cloud point as function of NaBr concentration; and (ii) the swelling behavior of thin films in water vapor as function of the initial film thickness. For PSPP solutions with a concentration of 5 wt.%, the temperature dependence of the intensity autocorrelation functions is measured with dynamic light scattering as function of molar mass and NaBr concentration (0–8 mM). We found a scaling of behavior for the scattered intensity and dynamic correlation length. The resulting spinodal temperatures showed a maximum at a certain (small) NaBr concentration, which is similar to the behavior of the cloud points measured previously by turbidimetry. The critical exponent of susceptibility depends on NaBr concentration, with a minimum value where the spinodal temperature is maximum and a trend towards the mean-field value of unity with increasing NaBr concentration. In contrast, the critical exponent of the correlation length does not depend on NaBr concentration and is lower than the value of 0.5 predicted by mean-field theory. For PSPP thin films, the swelling behavior was found to depend on film thickness. A film thickness of about 100 nm turns out to be the optimum thickness needed to obtain fast hydration with H 2 O.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 713 
KW  - polyzwitterions
KW  - polysulfobetaines
KW  - dynamic light scattering
KW  - phase behavior
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427363
SN  - 1866-8372
IS  - 713
ER  - 
TY  - JOUR
A1  - Bouncken, Ricarda B.
A1  - Ratzmann, Martin
A1  - Tiberius, Victor
A1  - Brem, Alexander
T1  - Pioneering strategy in supply chain relationships
BT  - how coercive power and contract completeness influence innovation
JF  - IEEE transactions on engineering management
N2  - Today, firms pursuing a pioneering strategy are often engaged in supply chain relationships to benefit from external resources and to improve their innovation. However, this effort can be impeded by power asymmetries in such relationships and especially by the execution of coercive power by their partner firm. Contracts could potentially reduce this risk of opportunistic behavior. Our survey study on 778 small to medium-sized enterprises in the European packaging and medical equipment industries examines how coercive power of the partner and the contractual arrangement between firms moderate the pioneering strategy's innovation outcomes in the short and long run. Our results confirm the negative effect of coercive power on innovation performance in both the short and long term. However, the compensating effect of rather complete contracts differs temporally. Whereas, contract completeness protects against higher dependence at the beginning of the collaboration, their effect diminishes over time. In contrast, rather incomplete contracts enhance the innovation performance in the long term, possibly complemented with trust.
KW  - alliances
KW  - coercive power
KW  - contracts
KW  - pioneering strategy
KW  - R&D
KW  - supply chain
Y1  - 2020
U6  - https://doi.org/10.1109/TEM.2020.3019965
SN  - 0018-9391
VL  - 69
IS  - 6
SP  - 2826
EP  - 2841
PB  - IEEE
CY  - New York
ER  - 
TY  - GEN
A1  - Schaefer, Laura
A1  - Bittmann, Frank
T1  - Parkinson patients without tremor show changed patterns of mechanical muscle oscillations during a specific bilateral motor task compared to controls
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - The pathophysiology of Parkinson’s disease (PD) is still not understood. There are investigations which show a changed oscillatory behaviour of brain circuits or changes in variability of, e.g., gait parameters in PD. The aim of this study was to investigate whether or not the motor output differs between PD patients and healthy controls. Thereby, patients without tremor are investigated in the medication off state performing a special bilateral isometric motor task. The force and accelerations (ACC) were recorded as well as the Mechanomyography (MMG) of the biceps brachii, the brachioradialis and of the pectoralis major muscles using piezoelectric-sensors during the bilateral motor task at 60% of the maximal isometric contraction. The frequency, a specific power ratio, the amplitude variation and the slope of amplitudes were analysed. The results indicate that the oscillatory behaviour of motor output in PD patients without tremor deviates from controls: thereby, the 95%-confidence-intervals of power ratio and of amplitude variation of all signals are disjoint between PD and controls and show significant differences in group comparisons (power ratio: p = 0.000–0.004, r = 0.441–0.579; amplitude variation: p = 0.000–0.001, r = 0.37–0.67). The mean frequency shows a significant difference for ACC (p = 0.009, r = 0.43), but not for MMG. It remains open, whether this muscular output reflects changes of brain circuits and whether the results are reproducible and specific for PD.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 602 
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-445431
SN  - 1866-8364
IS  - 602
ER  - 
TY  - JOUR
A1  - Schaefer, Laura
A1  - Bittmann, Frank
T1  - Parkinson patients without tremor show changed patterns of mechanical muscle oscillations during a specific bilateral motor task compared to controls
JF  - Scientific Reports
N2  - The pathophysiology of Parkinson’s disease (PD) is still not understood. There are investigations which show a changed oscillatory behaviour of brain circuits or changes in variability of, e.g., gait parameters in PD. The aim of this study was to investigate whether or not the motor output differs between PD patients and healthy controls. Thereby, patients without tremor are investigated in the medication off state performing a special bilateral isometric motor task. The force and accelerations (ACC) were recorded as well as the Mechanomyography (MMG) of the biceps brachii, the brachioradialis and of the pectoralis major muscles using piezoelectric-sensors during the bilateral motor task at 60% of the maximal isometric contraction. The frequency, a specific power ratio, the amplitude variation and the slope of amplitudes were analysed. The results indicate that the oscillatory behaviour of motor output in PD patients without tremor deviates from controls: thereby, the 95%-confidence-intervals of power ratio and of amplitude variation of all signals are disjoint between PD and controls and show significant differences in group comparisons (power ratio: p = 0.000–0.004, r = 0.441–0.579; amplitude variation: p = 0.000–0.001, r = 0.37–0.67). The mean frequency shows a significant difference for ACC (p = 0.009, r = 0.43), but not for MMG. It remains open, whether this muscular output reflects changes of brain circuits and whether the results are reproducible and specific for PD.
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-57766-5
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited, part of Springer Nature
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  - Caprioglio, Pietro
A1  - Stolterfoht, Martin
A1  - Wolff, Christian Michael
A1  - Unold, Thomas
A1  - Rech, Bernd
A1  - Albrecht, Steve
A1  - Neher, Dieter
T1  - On the relation between the open‐circuit voltage and quasi‐Fermi level splitting in efficient perovskite solar cells
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Today's perovskite solar cells (PSCs) are limited mainly by their open‐circuit voltage (VOC) due to nonradiative recombination. Therefore, a comprehensive understanding of the relevant recombination pathways is needed. Here, intensity‐dependent measurements of the quasi‐Fermi level splitting (QFLS) and of the VOC on the very same devices, including pin‐type PSCs with efficiencies above 20%, are performed. It is found that the QFLS in the perovskite lies significantly below its radiative limit for all intensities but also that the VOC is generally lower than the QFLS, violating one main assumption of the Shockley‐Queisser theory. This has far‐reaching implications for the applicability of some well‐established techniques, which use the VOC as a measure of the carrier densities in the absorber. By performing drift‐diffusion simulations, the intensity dependence of the QFLS, the QFLS‐VOC offset and the ideality factor are consistently explained by trap‐assisted recombination and energetic misalignment at the interfaces. Additionally, it is found that the saturation of the VOC at high intensities is caused by insufficient contact selectivity while heating effects are of minor importance. It is concluded that the analysis of the VOC does not provide reliable conclusions of the recombination pathways and that the knowledge of the QFLS‐VOC relation is of great importance.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 774 
KW  - electro‐optical materials
KW  - perovskite solar cells
KW  - photovoltaic devices
KW  - thin films
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437595
SN  - 1866-8372
IS  - 774
ER  - 
TY  - JOUR
A1  - Caprioglio, Pietro
A1  - Stolterfoht, Martin
A1  - Wolff, Christian Michael
A1  - Unold, Thomas
A1  - Rech, Bernd
A1  - Albrecht, Steve
A1  - Neher, Dieter
T1  - On the relation between the open-circuit voltage and quasi-fermi level splitting in efficient perovskite solar cells
JF  - advanced energy materials
N2  - Today's perovskite solar cells (PSCs) are limited mainly by their open‐circuit voltage (VOC) due to nonradiative recombination. Therefore, a comprehensive understanding of the relevant recombination pathways is needed. Here, intensity‐dependent measurements of the quasi‐Fermi level splitting (QFLS) and of the VOC on the very same devices, including pin‐type PSCs with efficiencies above 20%, are performed. It is found that the QFLS in the perovskite lies significantly below its radiative limit for all intensities but also that the VOC is generally lower than the QFLS, violating one main assumption of the Shockley‐Queisser theory. This has far‐reaching implications for the applicability of some well‐established techniques, which use the VOC as a measure of the carrier densities in the absorber. By performing drift‐diffusion simulations, the intensity dependence of the QFLS, the QFLS‐VOC offset and the ideality factor are consistently explained by trap‐assisted recombination and energetic misalignment at the interfaces. Additionally, it is found that the saturation of the VOC at high intensities is caused by insufficient contact selectivity while heating effects are of minor importance. It is concluded that the analysis of the VOC does not provide reliable conclusions of the recombination pathways and that the knowledge of the QFLS‐VOC relation is of great importance.
KW  - electro-optical materials
KW  - perovskite solar cells
KW  - photovoltaic devices
KW  - thin films
Y1  - 2019
U6  - https://doi.org/10.1002/aenm.201901631
SN  - 1614-6832
SN  - 1614-6840
VL  - 9
IS  - 33
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - GEN
A1  - Dammhahn, Melanie
A1  - Mazza, Valeria
A1  - Schirmer, Annika
A1  - Göttsche, Claudia
A1  - Eccard, Jana
T1  - Of city and village mice
BT  - behavioural adjustments of striped field mice to urban environments
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1007 
KW  - personality-traits
KW  - apodemus-agrarius
KW  - exploratory-behavior
KW  - fitness consequences
KW  - individual variation
KW  - avian personalities
KW  - animal personality
KW  - rural populations
KW  - natural-selection
KW  - natal dispersal
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-480063
SN  - 1866-8372
IS  - 1007
ER  - 
TY  - JOUR
A1  - Dammhahn, Melanie
A1  - Mazza, Valeria
A1  - Schirmer, Annika
A1  - Göttsche, Claudia
A1  - Eccard, Jana
T1  - Of city and village mice
BT  - behavioural adjustments of striped field mice to urban environments
JF  - Scientific Reports
N2  - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.
KW  - personality-traits
KW  - apodemus-agrarius
KW  - exploratory-behavior
KW  - fitness consequences
KW  - individual variation
KW  - avian personalities
KW  - animal personality
KW  - rural populations
KW  - natural-selection
KW  - natal dispersal
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-020-69998-6
SN  - 2045-2322
VL  - 10
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - JOUR
A1  - Agarwal, Ankit
A1  - Caesar, Levke
A1  - Marwan, Norbert
A1  - Maheswaran, Rathinasamy
A1  - Merz, Bruno
T1  - Network-based identification and characterization of teleconnections on different scales
JF  - Scientific Reports
N2  - Sea surface temperature (SST) patterns can – as surface climate forcing – affect weather and climate at large distances. One example is El Niño-Southern Oscillation (ENSO) that causes climate anomalies around the globe via teleconnections. Although several studies identified and characterized these teleconnections, our understanding of climate processes remains incomplete, since interactions and feedbacks are typically exhibited at unique or multiple temporal and spatial scales. This study characterizes the interactions between the cells of a global SST data set at different temporal and spatial scales using climate networks. These networks are constructed using wavelet multi-scale correlation that investigate the correlation between the SST time series at a range of scales allowing instantaneously deeper insights into the correlation patterns compared to traditional methods like empirical orthogonal functions or classical correlation analysis. This allows us to identify and visualise regions of – at a certain timescale – similarly evolving SSTs and distinguish them from those with long-range teleconnections to other ocean regions. Our findings re-confirm accepted knowledge about known highly linked SST patterns like ENSO and the Pacific Decadal Oscillation, but also suggest new insights into the characteristics and origins of long-range teleconnections like the connection between ENSO and Indian Ocean Dipole.
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-45423-5
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - GEN
A1  - Agarwal, Ankit
A1  - Caesar, Levke
A1  - Marwan, Norbert
A1  - Maheswaran, Rathinasamy
A1  - Merz, Bruno
T1  - Network-based identification and characterization of teleconnections on different scales
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Sea surface temperature (SST) patterns can – as surface climate forcing – affect weather and climate at large distances. One example is El Niño-Southern Oscillation (ENSO) that causes climate anomalies around the globe via teleconnections. Although several studies identified and characterized these teleconnections, our understanding of climate processes remains incomplete, since interactions and feedbacks are typically exhibited at unique or multiple temporal and spatial scales. This study characterizes the interactions between the cells of a global SST data set at different temporal and spatial scales using climate networks. These networks are constructed using wavelet multi-scale correlation that investigate the correlation between the SST time series at a range of scales allowing instantaneously deeper insights into the correlation patterns compared to traditional methods like empirical orthogonal functions or classical correlation analysis. This allows us to identify and visualise regions of – at a certain timescale – similarly evolving SSTs and distinguish them from those with long-range teleconnections to other ocean regions. Our findings re-confirm accepted knowledge about known highly linked SST patterns like ENSO and the Pacific Decadal Oscillation, but also suggest new insights into the characteristics and origins of long-range teleconnections like the connection between ENSO and Indian Ocean Dipole.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 731 
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-430520
SN  - 1866-8372
IS  - 731
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  - 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  - Jentsch, Anna
A1  - Düsing, Walter
A1  - Jolie, Egbert
A1  - Zimmer, Martin
T1  - Monitoring the response of volcanic CO2 emissions to changes in the Los Humeros hydrothermal system
JF  - Scientific reports
N2  - Carbon dioxide is the most abundant, non-condensable gas in volcanic systems, released into the atmosphere through either diffuse or advective fluid flow. The emission of substantial amounts of CO2 at Earth's surface is not only controlled by volcanic plumes during periods of eruptive activity or fumaroles, but also by soil degassing along permeable structures in the subsurface. Monitoring of these processes is of utmost importance for volcanic hazard analyses, and is also relevant for managing geothermal resources. Fluid-bearing faults are key elements of economic value for geothermal power generation. Here, we describe for the first time how sensitively and quickly natural gas emissions react to changes within a deep hydrothermal system due to geothermal fluid reinjection. For this purpose, we deployed an automated, multi-chamber CO2 flux monitoring system within the damage zone of a deep-rooted major normal fault in the Los Humeros Volcanic Complex (LHVC) in Mexico and recorded data over a period of five months. After removing the atmospheric effects on variations in CO2 flux, we calculated correlation coefficients between residual CO2 emissions and reinjection rates, identifying an inverse correlation of rho = - 0.51 to - 0.66. Our results indicate that gas emissions respond to changes in reinjection rates within 24 h, proving an active hydraulic communication between the hydrothermal system and Earth's surface. This finding is a promising indication not only for geothermal reservoir monitoring but also for advanced long-term volcanic risk analysis. Response times allow for estimation of fluid migration velocities, which is a key constraint for conceptual and numerical modelling of fluid flow in fracture-dominated systems.
KW  - Energy and society
KW  - Geochemistry
KW  - Geology
KW  - Geophysics
KW  - Volcanology
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-97023-x
SN  - 2045-2322
VL  - 11
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  - 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  - Li, Yuanqing
A1  - Chen, Li
A1  - Nofal, Issam
A1  - Chen, Mo
A1  - Wang, Haibin
A1  - Liu, Rui
A1  - Chen, Qingyu
A1  - Krstić, Miloš
A1  - Shi, Shuting
A1  - Guo, Gang
A1  - Baeg, Sang H.
A1  - Wen, Shi-Jie
A1  - Wong, Richard
T1  - Modeling and analysis of single-event transient sensitivity of a 65 nm clock tree
JF  - Microelectronics reliability
N2  - The soft error rate (SER) due to heavy-ion irradiation of a clock tree is investigated in this paper. A method for clock tree SER prediction is developed, which employs a dedicated soft error analysis tool to characterize the single-event transient (SET) sensitivities of clock inverters and other commercial tools to calculate the SER through fault-injection simulations. A test circuit including a flip-flop chain and clock tree in a 65 nm CMOS technology is developed through the automatic ASIC design flow. This circuit is analyzed with the developed method to calculate its clock tree SER. In addition, this circuit is implemented in a 65 nm test chip and irradiated by heavy ions to measure its SER resulting from the SETs in the clock tree. The experimental and calculation results of this case study present good correlation, which verifies the effectiveness of the developed method.
KW  - Clock tree
KW  - Modeling
KW  - Single-event transient (SET)
Y1  - 2018
U6  - https://doi.org/10.1016/j.microrel.2018.05.016
SN  - 0026-2714
VL  - 87
SP  - 24
EP  - 32
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Straube, Nicolas
A1  - Preick, Michaela
A1  - Naylor, Gavin J. P.
A1  - Hofreiter, Michael
T1  - Mitochondrial DNA sequencing of a wet-collection syntype demonstrates the importance of type material as genetic resource for lantern shark taxonomy (Chondrichthyes: Etmopteridae)
JF  - Royal Society Open Science
N2  - After initial detection of target archival DNA of a 116-year-old syntype specimen of the smooth lantern shark, Etmopterus pusillus, in a single-stranded DNA library, we shotgun-sequenced additional 9 million reads from this same DNA library. Sequencing reads were used for extracting mitochondrial sequence information for analyses of mitochondrial DNA characteristics and reconstruction of the mitochondrial genome. The archival DNA is highly fragmented. A total of 4599 mitochondrial reads were available for the genome reconstruction using an iterative mapping approach. The resulting genome sequence has 12 times coverage and a length of 16 741 bp. All 37 vertebrate mitochondrial loci plus the control region were identified and annotated. The mitochondrial NADH2 gene was subsequently used to place the syntype haplotype in a network comprising multiple E. pusillus samples from various distant localities as well as sequences from a morphological similar species, the shortfin smooth lantern shark Etmopterus joungi. Results confirm the almost global distribution of E. pusillus and suggest E. joungi to be a junior synonym of E. pusillus. As mitochondrial DNA often represents the only available reference information in non-model organisms, this study illustrates the importance of mitochondrial DNA from an aged, wet collection type specimen for taxonomy.
KW  - museum specimens
KW  - archival DNA
KW  - deep-sea sharks
KW  - Etmopterus pusillus
KW  - Etmopterus joungi
KW  - taxonomy
Y1  - 2021
U6  - https://doi.org/10.1098/rsos.210474
SN  - 2054-5703
VL  - 8
IS  - 9
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Schaefer, Laura
A1  - Löffler, Nils
A1  - Klein, Julia
A1  - Bittmann, Frank
T1  - Mechanomyography and acceleration show interlimb asymmetries in Parkinson patients without tremor compared to controls during a unilateral motor task
JF  - Scientific reports
N2  - The mechanical muscular oscillations are rarely the objective of investigations regarding the identification of a biomarker for Parkinson's disease (PD). Therefore, the aim of this study was to investigate whether or not this specific motor output differs between PD patients and controls. The novelty is that patients without tremor are investigated performing a unilateral isometric motor task. The force of armflexors and the forearm acceleration (ACC) were recorded as well as the mechanomyography of the biceps brachii (MMGbi), brachioradialis (MMGbra) and pectoralis major (MMGpect) muscles using a piezoelectric-sensor-based system during a unilateral motor task at 70% of the MVIC. The frequency, a power-frequency-ratio, the amplitude variation, the slope of amplitudes and their interlimb asymmetries were analysed. The results indicate that the oscillatory behavior of muscular output in PD without tremor deviates from controls in some parameters: Significant differences appeared for the power-frequency-ratio (p=0.001, r=0.43) and for the amplitude variation (p=0.003, r=0.34) of MMGpect. The interlimb asymmetries differed significantly concerning the power-frequency-ratio of MMGbi (p=0.013, r=0.42) and MMGbra (p=0.048, r=0.39) as well as regarding the mean frequency (p=0.004, r=0.48) and amplitude variation of MMGpect (p=0.033, r=0.37). The mean (M) and variation coefficient (CV) of slope of ACC differed significantly (M: p=0.022, r=0.33; CV: p=0.004, r=0.43). All other parameters showed no significant differences between PD and controls. It remains open, if this altered mechanical muscular output is reproducible and specific for PD.
KW  - Diseases
KW  - Neurology
KW  - Neuroscience
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-81672-z
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan
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  - JOUR
A1  - Klippert, Monika
A1  - Stolpmann, Robert
A1  - Grum, Marcus
A1  - Thim, Christof
A1  - Gronau, Norbert
A1  - Albers, Albert
T1  - Knowledge transfer quality improvement
BT  - the quality enhancement of knowledge transfers in product engineering
JF  - Procedia CIRP
N2  - Developing a new product generation requires the transfer of knowledge among various knowledge carriers. Several factors influence knowledge transfer, e.g., the complexity of engineering tasks or the competence of employees, which can decrease the efficiency and effectiveness of knowledge transfers in product engineering. Hence, improving those knowledge transfers obtains great potential, especially against the backdrop of experienced employees leaving the company due to retirement, so far, research results show, that the knowledge transfer velocity can be raised by following the Knowledge Transfer Velocity Model and implementing so-called interventions in a product engineering context. In most cases, the implemented interventions have a positive effect on knowledge transfer speed improvement. In addition to that, initial theoretical findings describe factors influencing the quality of knowledge transfers and outline a setting to empirically investigate how the quality can be improved by introducing a general description of knowledge transfer reference situations and principles to measure the quality of knowledge artifacts. To assess the quality of knowledge transfers in a product engineering context, the Knowledge Transfer Quality Model (KTQM) is created, which serves as a basis to develop and implement quality-dependent interventions for different knowledge transfer situations. As a result, this paper introduces the specifications of eight situation-adequate interventions to improve the quality of knowledge transfers in product engineering following an intervention template. Those interventions are intended to be implemented in an industrial setting to measure the quality of knowledge transfers and validate their effect.
KW  - knowledge transfer
KW  - product generation engineering
KW  - improvement
KW  - quality
KW  - intervention
Y1  - 2023
U6  - https://doi.org/10.1016/j.procir.2023.02.171
SN  - 2212-8271
VL  - 119
SP  - 919
EP  - 925
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wojnarowska, Zaneta
A1  - Lange, Alyna
A1  - Taubert, Andreas
A1  - Paluch, Marian
T1  - Ion and proton transport in aqueous/nonaqueous acidic tonic liquids for fuel-cell applications-insight from high-pressure dielectric studies
JF  - ACS applied materials & interfaces / American Chemical Society
N2  - The use of acidic ionic liquids and solids as electrolytes in fuel cells is an emerging field due to their efficient proton conductivity and good thermal stability. Despite multiple reports describing conducting properties of acidic ILs, little is known on the charge-transport mechanism in the vicinity of liquid-glass transition and the structural factors governing the proton hopping. To address these issues, we studied two acidic imidazolium-based ILs with the same cation, however, different anions-bulk tosylate vs small methanesulfonate. High-pressure dielectric studies of anhydrous and water-saturated materials performed in the close vicinity of T-g have revealed significant differences in the charge-transport mechanism in these two systems being undetectable at ambient conditions. Thereby, we demonstrated the effect of molecular architecture on proton hopping, being crucial in the potential electrochemical applications of acidic ILs.
KW  - proton hopping
KW  - dielectric spectroscopy
KW  - high pressure
KW  - ion transport
KW  - acidic ionic liquids
Y1  - 2021
U6  - https://doi.org/10.1021/acsami.1c06260
SN  - 1944-8244
SN  - 1944-8252
VL  - 13
IS  - 26
SP  - 30614
EP  - 30624
PB  - American Chemical Society
CY  - Washington
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  - 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  - 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  - 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  - GEN
A1  - Mazza, Valeria
A1  - Jacob, Jens
A1  - Dammhahn, Melanie
A1  - Zaccaroni, Marco
A1  - Eccard, Jana
T1  - Individual variation in cognitive style reflects foraging and antipredator strategies in a small mammal
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Balancing foraging gain and predation risk is a fundamental trade-off in the life of animals. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive style and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs. We tested whether cognitive style and personality affect risk-reward trade-off decisions posed by foraging and predation risk. We exposed 21 bank voles (Myodes glareolus) that were bold, fast learning and inflexible and 18 voles that were shy, slow learning and flexible to outdoor enclosures with different risk levels at two food patches. We quantified individual food patch exploitation, foraging and vigilance behaviour. Although both types responded to risk, fast animals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting >50% of visit to vigilance. These patterns indicate that individual differences in cognitive style/personality are reflected in foraging and anti-predator decisions that underlie the individual risk-reward bias.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 761 
KW  - voles clethrionomys-glareolus
KW  - coping styles
KW  - bank voles
KW  - behavioral flexibility
KW  - trade-offs
KW  - exploratory-behavior
KW  - mustelid predation
KW  - social information
KW  - animal personality
KW  - stress
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437118
SN  - 1866-8372
IS  - 761
ER  - 
TY  - JOUR
A1  - Mazza, Valeria
A1  - Jacob, Jens
A1  - Dammhahn, Melanie
A1  - Zaccaroni, Marco
A1  - Eccard, Jana
T1  - Individual variation in cognitive style reflects foraging and antipredator strategies in a small mammal
JF  - Scientific Reports
N2  - Balancing foraging gain and predation risk is a fundamental trade-off in the life of animals. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive style and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs. We tested whether cognitive style and personality affect risk-reward trade-off decisions posed by foraging and predation risk. We exposed 21 bank voles (Myodes glareolus) that were bold, fast learning and inflexible and 18 voles that were shy, slow learning and flexible to outdoor enclosures with different risk levels at two food patches. We quantified individual food patch exploitation, foraging and vigilance behaviour. Although both types responded to risk, fast animals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting >50% of visit to vigilance. These patterns indicate that individual differences in cognitive style/personality are reflected in foraging and anti-predator decisions that underlie the individual risk-reward bias.
KW  - animal personality
KW  - bank voles
KW  - behavioral flexibility
KW  - coping styles
KW  - exploratory-behavior
KW  - mustelid predation
KW  - social information
KW  - stress
KW  - trade-offs
KW  - voles clethrionomys-glareolus
Y1  - 2019
U6  - https://doi.org/10.1038/s41598-019-46582-1
SN  - 2045-2322
VL  - 9
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
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  - 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  - Bekir, Marek
A1  - Sharma, Anjali
A1  - Umlandt, Maren
A1  - Lomadze, Nino
A1  - Santer, Svetlana
T1  - How to make a surface act as a micropump
JF  - Advanced materials interfaces
N2  - In this paper, the phenomenon of light-driven diffusioosmotic (DO) long-range attractive and repulsive interactions between micro-sized objects trapped near a solid wall is investigated. The range of the DO flow extends several times the size of microparticles and can be adjusted to point towards or away from the particle by varying irradiation parameters such as intensity or wavelength of light. The "fuel" of the light-driven DO flow is a photosensitive surfactant which can be photo-isomerized between trans and cis-states. The trans-isomer tends to accumulate at the interface, while the cis-isomer prefers to stay in solution. In combination with a dissimilar photo-isomerization rate at the interface and in bulk, this yields a concentration gradient of the isomers around single particles resulting in local light-driven diffusioosmotic (l-LDDO) flow. Here, the extended analysis of the l-LDDO flow as a function of irradiation parameters by introducing time-dependent development of the concentration excess of isomers near the particle surface is presented. It is also demonstrated that the l-LDDO can be generated at any solid/liquid interface being more pronounced in the case of strongly absorbing material. This phenomenon has plenty of potential applications since it makes any type of surface act as a micropump.
KW  - azobenzene containing surfactant
KW  - light-driven diffusioosmosis
KW  - rate of
KW  - photo-isomerization
Y1  - 2022
U6  - https://doi.org/10.1002/admi.202102395
SN  - 2196-7350
VL  - 9
IS  - 12
PB  - Wiley-VCH
CY  - Weinheim
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  - Lai, Huagui
A1  - Luo, Jincheng
A1  - Zwirner, Yannick
A1  - Olthof, Selina
A1  - Wieczorek, Alexander
A1  - Ye, Fangyuan
A1  - Jeangros, Quentin
A1  - Yin, Xinxing
A1  - Akhundova, Fatima
A1  - Ma, Tianshu
A1  - He, Rui
A1  - Kothandaraman, Radha K.
A1  - Chin, Xinyu
A1  - Gilshtein, Evgeniia
A1  - Muller, Andre
A1  - Wang, Changlei
A1  - Thiesbrummel, Jarla
A1  - Siol, Sebastian
A1  - Prieto, Jose Marquez
A1  - Unold, Thomas
A1  - Stolterfoht, Martin
A1  - Chen, Cong
A1  - Tiwari, Ayodhya N.
A1  - Zhao, Dewei
A1  - Fu, Fan
T1  - High-performance flexible all-Perovskite tandem solar cells with reduced V-OC-deficit in wide-bandgap subcell
JF  - Advanced energy materials
N2  - Among various types of perovskite-based tandem solar cells (TSCs), all-perovskite TSCs are of particular attractiveness for building- and vehicle-integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power-to-weight ratio. However, the efficiency of flexible all-perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide-bandgap (WBG) perovskite solar cells on the flexible substrates as well as their low open-circuit voltage (V-OC). Here, it is reported that the use of self-assembled monolayers as hole-selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, a postdeposition treatment with 2-thiopheneethylammonium chloride is employed to further suppress the bulk and interfacial recombination, boosting the V-OC of the WBG top cell to 1.29 V. Based on this, the first proof-of-concept four-terminal all-perovskite flexible TSC with a power conversion efficiency of 22.6% is presented. When integrating into two-terminal flexible tandems, 23.8% flexible all-perovskite TSCs with a superior V-OC of 2.1 V is achieved, which is on par with the V-OC reported on the 28% all-perovskite tandems grown on the rigid substrate.
KW  - all-perovskite tandems
KW  - flexible tandem solar cells
KW  - perovskite
KW  - V OC-deficit
KW  - wide-bandgap
Y1  - 2022
U6  - https://doi.org/10.1002/aenm.202202438
SN  - 1614-6832
SN  - 1614-6840
VL  - 12
IS  - 45
PB  - Wiley-VCH
CY  - Weinheim
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  - 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  - 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  - JOUR
A1  - Krummenauer, Linda
A1  - Costa, Luís Fílípe Carvalho da
A1  - Prahl, Boris F.
A1  - Kropp, Jürgen
T1  - Future heat adaptation and exposure among urban populations and why a prospering economy alone won’t save us
JF  - Scientific reports
N2  - When inferring on the magnitude of future heat-related mortality due to climate change, human adaptation to heat should be accounted for. We model long-term changes in minimum mortality temperatures (MMT), a well-established metric denoting the lowest risk of heat-related mortality, as a function of climate change and socio-economic progress across 3820 cities. Depending on the combination of climate trajectories and socio-economic pathways evaluated, by 2100 the risk to human health is expected to decline in 60% to 80% of the cities against contemporary conditions. This is caused by an average global increase in MMTs driven by long-term human acclimatisation to future climatic conditions and economic development of countries. While our adaptation model suggests that negative effects on health from global warming can broadly be kept in check, the trade-offs are highly contingent to the scenario path and location-specific. For high-forcing climate scenarios (e.g. RCP8.5) the maintenance of uninterrupted high economic growth by 2100 is a hard requirement to increase MMTs and level-off the negative health effects from additional scenario-driven heat exposure. Choosing a 2 degrees C-compatible climate trajectory alleviates the dependence on fast growth, leaving room for a sustainable economy, and leads to higher reductions of mortality risk.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-99757-0
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - Berlin
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  - 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  - Astudillo-Sotomayor, Luis
A1  - Jara Muñoz, Julius
A1  - Melnick, Daniel
A1  - Cortés‐Aranda, Joaquín
A1  - Tassara, Andrés
A1  - Strecker, Manfred
T1  - Fast Holocene slip and localized strain along the Liquiñe-Ofqui strike-slip fault system, Chile
JF  - Scientific reports
N2  - In active tectonic settings dominated by strike-slip kinematics, slip partitioning across subparallel faults is a common feature; therefore, assessing the degree of partitioning and strain localization is paramount for seismic hazard assessments. Here, we estimate a slip rate of 18.8 +/- 2.0 mm/year over the past 9.0 +/- 0.1 ka for a single strand of the Liquirie-Ofqui Fault System, which straddles the Main Cordillera in Southern Chile. This Holocene rate accounts for similar to 82% of the trench-parallel component of oblique plate convergence and is similar to million-year estimates integrated over the entire fault system. Our results imply that strain localizes on a single fault at millennial time scale but over longer time scales strain localization is not sustained. The fast millennial slip rate in the absence of historical Mw> 6.5 earthquakes along the Liquine-Ofqui Fault System implies either a component of aseismic slip or Mw similar to 7 earthquakes involving multi-trace ruptures and > 150-year repeat times. Our results have implications for the understanding of strike-slip fault system dynamics within volcanic arcs and seismic hazard assessments.
KW  - Geodynamics
KW  - Geomorphology
KW  - Tectonics
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-85036-5
SN  - 2045-2322
VL  - 11
IS  - 1
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Tokmoldin, Nurlan
A1  - Vollbrecht, Joachim
A1  - Hosseini, Seyed Mehrdad
A1  - Sun, Bowen
A1  - Perdigón-Toro, Lorena
A1  - Woo, Han Young
A1  - Zou, Yingping
A1  - Neher, Dieter
A1  - Shoaee, Safa
T1  - Explaining the fill-factor and photocurrent losses of nonfullerene acceptor-based solar cells by probing the long-range charge carrier diffusion and drift lengths
JF  - Advanced energy materials
N2  - Organic solar cells (OSC) nowadays match their inorganic competitors in terms of current production but lag behind with regards to their open-circuit voltage loss and fill-factor, with state-of-the-art OSCs rarely displaying fill-factor of 80% and above. The fill-factor of transport-limited solar cells, including organic photovoltaic devices, is affected by material and device-specific parameters, whose combination is represented in terms of the established figures of merit, such as theta and alpha. Herein, it is demonstrated that these figures of merit are closely related to the long-range carrier drift and diffusion lengths. Further, a simple approach is presented to devise these characteristic lengths using steady-state photoconductance measurements. This yields a straightforward way of determining theta and alpha in complete cells and under operating conditions. This approach is applied to a variety of photovoltaic devices-including the high efficiency nonfullerene acceptor blends-and show that the diffusion length of the free carriers provides a good correlation with the fill-factor. It is, finally, concluded that most state-of-the-art organic solar cells exhibit a sufficiently large drift length to guarantee efficient charge extraction at short circuit, but that they still suffer from too small diffusion lengths of photogenerated carriers limiting their fill factor.
KW  - diffusion length
KW  - drift length
KW  - figure of merit
KW  - lifetime‐ mobility product
KW  - steady‐ state photoconductance
Y1  - 2021
U6  - https://doi.org/10.1002/aenm.202100804
SN  - 1614-6840
VL  - 11
IS  - 22
PB  - Wiley-VCH
CY  - Weinheim
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  - Pranav, Manasi
A1  - Benduhn, Johannes
A1  - Nyman, Mathias
A1  - Hosseini, Seyed Mehrdad
A1  - Kublitski, Jonas
A1  - Shoaee, Safa
A1  - Neher, Dieter
A1  - Leo, Karl
A1  - Spoltore, Donato
T1  - Enhanced charge selectivity via anodic-C60 layer reduces nonradiative losses in organic solar cells
JF  - ACS applied materials & interfaces
N2  - Interfacial layers in conjunction with suitable charge-transport layers can significantly improve the performance of optoelectronic devices by facilitating efficient charge carrier injection and extraction. 
This work uses a neat C-60 interlayer on the anode to experimentally reveal that surface recombination is a significant contributor to nonradiative recombination losses in organic solar cells. 
These losses are shown to proportionally increase with the extent of contact between donor molecules in the photoactive layer and a molybdenum oxide (MoO3) hole extraction layer, proven by calculating voltage losses in low- and high-donor-content bulk heterojunction device architectures. 
Using a novel in-device determination of the built-in voltage, the suppression of surface recombination, due to the insertion of a thin anodic-C-60 interlayer on MoO3, is attributed to an enhanced built-in potential. 
The increased built-in voltage reduces the presence of minority charge carriers at the electrodes-a new perspective on the principle of selective charge extraction layers. 
The benefit to device efficiency is limited by a critical interlayer thickness, which depends on the donor material in bilayer devices. 
Given the high popularity of MoO3 as an efficient hole extraction and injection layer and the increasingly popular discussion on interfacial phenomena in organic optoelectronic devices, these findings are relevant to and address different branches of organic electronics, providing insights for future device design.
KW  - nonradiative losses
KW  - molybdenum oxide
KW  - organic solar cells
KW  - interfacial layers
KW  - charge selectivity
Y1  - 2021
U6  - https://doi.org/10.1021/acsami.1c00049
SN  - 1944-8244
SN  - 1944-8252
VL  - 13
IS  - 10
SP  - 12603
EP  - 12609
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Grischek, Max
A1  - Caprioglio, Pietro
A1  - Zhang, Jiahuan
A1  - Pena-Camargo, Francisco
A1  - Sveinbjornsson, Kari
A1  - Zu, Fengshuo
A1  - Menzel, Dorothee
A1  - Warby, Jonathan H.
A1  - Li, Jinzhao
A1  - Koch, Norbert
A1  - Unger, Eva
A1  - Korte, Lars
A1  - Neher, Dieter
A1  - Stolterfoht, Martin
A1  - Albrecht, Steve
T1  - Efficiency Potential and Voltage Loss of Inorganic CsPbI2Br Perovskite Solar Cells
JF  - Solar RRL
N2  - Inorganic perovskite solar cells show excellent thermal stability, but the reported power conversion efficiencies are still lower than for organic-inorganic perovskites. This is mainly caused by lower open-circuit voltages (V(OC)s). Herein, the reasons for the low V-OC in inorganic CsPbI2Br perovskite solar cells are investigated. Intensity-dependent photoluminescence measurements for different layer stacks reveal that n-i-p and p-i-n CsPbI2Br solar cells exhibit a strong mismatch between quasi-Fermi level splitting (QFLS) and V-OC. Specifically, the CsPbI2Br p-i-n perovskite solar cell has a QFLS-e center dot V-OC mismatch of 179 meV, compared with 11 meV for a reference cell with an organic-inorganic perovskite of similar bandgap. On the other hand, this study shows that the CsPbI2Br films with a bandgap of 1.9 eV have a very low defect density, resulting in an efficiency potential of 20.3% with a MeO-2PACz hole-transporting layer and 20.8% on compact TiO2. Using ultraviolet photoelectron spectroscopy measurements, energy level misalignment is identified as a possible reason for the QFLS-e center dot V-OC mismatch and strategies for overcoming this V-OC limitation are discussed. This work highlights the need to control the interfacial energetics in inorganic perovskite solar cells, but also gives promise for high efficiencies once this issue is resolved.
KW  - CsPbI2Br
KW  - efficiency potentials
KW  - inorganic perovskites
KW  - photoluminescence
KW  - solar cells
KW  - voltage losses
Y1  - 2022
U6  - https://doi.org/10.1002/solr.202200690
SN  - 2367-198X
VL  - 6
IS  - 11
PB  - Wiley-VCH
CY  - Weinheim
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  - 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  - Kühne, Katharina
A1  - Fischer, Martin H.
A1  - Jeglinski-Mende, Melinda A.
T1  - During the COVID-19 pandemic participants prefer settings with a face mask, no interaction and at a closer distance
JF  - Scientific Reports
N2  - Peripersonal space is the space surrounding our body, where multisensory integration of stimuli and action execution take place. The size of peripersonal space is flexible and subject to change by various personal and situational factors. The dynamic representation of our peripersonal space modulates our spatial behaviors towards other individuals. During the COVID-19 pandemic, this spatial behavior was modified by two further factors: social distancing and wearing a face mask. Evidence from offline and online studies on the impact of a face mask on pro-social behavior is mixed. In an attempt to clarify the role of face masks as pro-social or anti-social signals, 235 observers participated in the present online study. They watched pictures of two models standing at three different distances from each other (50, 90 and 150 cm), who were either wearing a face mask or not and were either interacting by initiating a hand shake or just standing still. The observers’ task was to classify the model by gender. Our results show that observers react fastest, and therefore show least avoidance, for the shortest distances (50 and 90 cm) but only when models wear a face mask and do not interact. Thus, our results document both pro- and anti-social consequences of face masks as a result of the complex interplay between social distancing and interactive behavior. Practical implications of these findings are discussed.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-16730-1
SN  - 2045-2322
VL  - 12
SP  - 1
EP  - 12
PB  - Springer Nature
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Arguello de Souza, Felipe Augusto
A1  - Samprogna Mohor, Guilherme
A1  - Guzman Arias, Diego Alejandro
A1  - Sarmento Buarque, Ana Carolina
A1  - Taffarello, Denise
A1  - Mendiondo, Eduardo Mario
T1  - Droughts in São Paulo
BT  - challenges and lessons for a water-adaptive society
JF  - Urban water journal
N2  - Literature has suggested that droughts and societies are mutually shaped and, therefore, both require a better understanding of their coevolution on risk reduction and water adaptation. Although the Sao Paulo Metropolitan Region drew attention because of the 2013-2015 drought, this was not the first event. This paper revisits this event and the 1985-1986 drought to compare the evolution of drought risk management aspects. Documents and hydrological records are analyzed to evaluate the hazard intensity, preparedness, exposure, vulnerability, responses, and mitigation aspects of both events. Although the hazard intensity and exposure of the latter event were larger than the former one, the policy implementation delay and the dependency of service areas in a single reservoir exposed the region to higher vulnerability. In addition to the structural and non-structural tools implemented just after the events, this work raises the possibility of rainwater reuse for reducing the stress in reservoirs.
KW  - droughts
KW  - urban water supply
KW  - water crisis
KW  - drought risk
KW  - paired event
KW  - analysis
KW  - vulnerability
Y1  - 2022
U6  - https://doi.org/10.1080/1573062X.2022.2047735
SN  - 1573-062X
SN  - 1744-9006
VL  - 20
IS  - 10
SP  - 1682
EP  - 1694
PB  - Taylor & Francis
CY  - London [u.a.]
ER  - 
TY  - JOUR
A1  - Schaefer, Laura
A1  - Dech, Silas
A1  - Aehle, Markus
A1  - Bittmann, Frank
T1  - Disgusting odours affect the characteristics of the adaptive force in contrast to neutral and pleasant odours
JF  - Scientific Reports
N2  - The olfactomotor system is especially investigated by examining the sniffing in reaction to olfactory stimuli. The motor output of respiratory-independent muscles was seldomly considered regarding possible influences of smells. The Adaptive Force (AF) characterizes the capability of the neuromuscular system to adapt to external forces in a holding manner and was suggested to be more vulnerable to possible interfering stimuli due to the underlying complex control processes. The aim of this pilot study was to measure the effects of olfactory inputs on the AF of the hip and elbow flexors, respectively. The AF of 10 subjects was examined manually by experienced testers while smelling at sniffing sticks with neutral, pleasant or disgusting odours. The reaction force and the limb position were recorded by a handheld device. The results show, inter alia, a significantly lower maximal isometric AF and a significantly higher AF at the onset of oscillations by perceiving disgusting odours compared to pleasant or neutral odours (p < 0.001). The adaptive holding capacity seems to reflect the functionality of the neuromuscular control, which can be impaired by disgusting olfactory inputs. An undisturbed functioning neuromuscular system appears to be characterized by a proper length tension control and by an earlier onset of mutual oscillations during an external force increase. This highlights the strong connection of olfaction and motor control also regarding respiratory-independent muscles.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-95759-0
SN  - 2045-2322
VL  - 11
SP  - 1
EP  - 16
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Haverkamp, Robert
A1  - Sorgenfrei, Nomi
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  - 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  - 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  - 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  - CHAP
A1  - Panzer, Marcel
A1  - Bender, Benedict
A1  - Gronau, Norbert
T1  - Deep reinforcement learning in production planning and control
BT  - A systematic literature review
T2  - Proceedings of the Conference on Production Systems and Logistics
N2  - Increasingly fast development cycles and individualized products pose major challenges for today's smart production systems in times of industry 4.0. The systems must be flexible and continuously adapt to changing conditions while still guaranteeing high throughputs and robustness against external disruptions. Deep rein- forcement learning (RL) algorithms, which already reached impressive success with Google DeepMind's AlphaGo, are increasingly transferred to production systems to meet related requirements. Unlike supervised and unsupervised machine learning techniques, deep RL algorithms learn based on recently collected sensor- and process-data in direct interaction with the environment and are able to perform decisions in real-time. As such, deep RL algorithms seem promising given their potential to provide decision support in complex environments, as production systems, and simultaneously adapt to changing circumstances. While different use-cases for deep RL emerged, a structured overview and integration of findings on their application are missing. To address this gap, this contribution provides a systematic literature review of existing deep RL applications in the field of production planning and control as well as production logistics. From a performance perspective, it became evident that deep RL can beat heuristics significantly in their overall performance and provides superior solutions to various industrial use-cases. Nevertheless, safety and reliability concerns must be overcome before the widespread use of deep RL is possible which presumes more intensive testing of deep RL in real world applications besides the already ongoing intensive simulations.
KW  - deep reinforcement learning
KW  - machine learning
KW  - production planning
KW  - production control
KW  - systematic literature review
Y1  - 2021
U6  - https://doi.org/10.15488/11238
SN  - 2701-6277
SP  - 535
EP  - 545
PB  - publish-Ing.
CY  - Hannover
ER  - 
TY  - GEN
A1  - Panzer, Marcel
A1  - Bender, Benedict
A1  - Gronau, Norbert
T1  - Deep reinforcement learning in production planning and control
BT  - A systematic literature review
T2  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - Increasingly fast development cycles and individualized products pose major challenges for today's smart production systems in times of industry 4.0. The systems must be flexible and continuously adapt to changing conditions while still guaranteeing high throughputs and robustness against external disruptions. Deep reinforcement learning (RL) algorithms, which already reached impressive success with Google DeepMind's AlphaGo, are increasingly transferred to production systems to meet related requirements. Unlike supervised and unsupervised machine learning techniques, deep RL algorithms learn based on recently collected sensorand process-data in direct interaction with the environment and are able to perform decisions in real-time. As such, deep RL algorithms seem promising given their potential to provide decision support in complex environments, as production systems, and simultaneously adapt to changing circumstances. While different use-cases for deep RL emerged, a structured overview and integration of findings on their application are missing. To address this gap, this contribution provides a systematic literature review of existing deep RL applications in the field of production planning and control as well as production logistics. From a performance perspective, it became evident that deep RL can beat heuristics significantly in their overall performance and provides superior solutions to various industrial use-cases. Nevertheless, safety and reliability concerns must be overcome before the widespread use of deep RL is possible which presumes more intensive testing of deep RL in real world applications besides the already ongoing intensive simulations.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 198 
KW  - deep reinforcement learning
KW  - machine learning
KW  - production planning
KW  - production control
KW  - systematic literature review
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-605722
SN  - 2701-6277
SN  - 1867-5808
ER  -