TY - JOUR A1 - Nishikawa, Ken-Ichi A1 - Mizuno, Yosuke A1 - Niemiec, Jacek A1 - Kobzar, Oleh A1 - Pohl, Martin A1 - Gomez, Jose L. A1 - Dutan, Ioana A1 - Frederiksen, Jacob Trier A1 - Nordlund, Ake A1 - Meli, Athina A1 - Sol, Helene A1 - Hardee, Philip E. A1 - Hartmann, Dieter H. T1 - Microscopic Processes in Global Relativistic Jets Containing Helical Magnetic Fields JF - Galaxies : open access journal N2 - In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields. KW - relativistic jets KW - particle-in-cell simulations KW - global jets KW - helical magnetic fields KW - kinetic instabilities KW - kink instability Y1 - 2016 U6 - https://doi.org/10.3390/galaxies4040038 SN - 2075-4434 VL - 4 PB - MDPI CY - Basel ER - TY - GEN A1 - Nishikawa, Ken-Ichi A1 - Mizuno, Yosuke A1 - Niemiec, Jacek A1 - Kobzar, Oleh A1 - Pohl, Martin A1 - Gómez, Jose L. A1 - Duţan, Ioana A1 - Pe’er, Asaf A1 - Frederiksen, Jacob Trier A1 - Nordlund, Åke A1 - Meli, Athina A1 - Sol, Helene A1 - Hardee, Philip E. A1 - Hartmann, Dieter H. T1 - Microscopic processes in global relativistic jets containing helical magnetic fields T2 - Galaxies N2 - In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 446 KW - relativistic jets KW - particle-in-cell simulations KW - global jets KW - helical magnetic fields KW - kinetic instabilities KW - kink instability Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407604 ER - TY - JOUR A1 - Ohl, Sven A1 - Wohltat, Christian A1 - Kliegl, Reinhold A1 - Pollatos, Olga A1 - Engbert, Ralf T1 - Microsaccades Are Coupled to Heartbeat JF - The journal of neuroscience N2 - During visual fixation, the eye generates microsaccades and slower components of fixational eye movements that are part of the visual processing strategy in humans. Here, we show that ongoing heartbeat is coupled to temporal rate variations in the generation of microsaccades. Using coregistration of eye recording and ECG in humans, we tested the hypothesis that microsaccade onsets are coupled to the relative phase of the R-R intervals in heartbeats. We observed significantly more microsaccades during the early phase after the R peak in the ECG. This form of coupling between heartbeat and eye movements was substantiated by the additional finding of a coupling between heart phase and motion activity in slow fixational eye movements; i.e., retinal image slip caused by physiological drift. Our findings therefore demonstrate a coupling of the oculomotor system and ongoing heartbeat, which provides further evidence for bodily influences on visuomotor functioning. KW - eye movements KW - heartbeat KW - microsaccades Y1 - 2016 U6 - https://doi.org/10.1523/JNEUROSCI.2211-15.2016 SN - 0270-6474 VL - 36 SP - 1237 EP - 1241 PB - Society for Neuroscience CY - Washington ER - TY - THES A1 - Samaras, Stefanos T1 - Microphysical retrieval of non-spherical aerosol particles using regularized inversion of multi-wavelength lidar data T1 - Retrieval der Mikrophysik von nichtkugelförmigen Aerosolpartikeln durch regularisierte Inversion von Mehrwellenlängen-Lidardaten N2 - Numerous reports of relatively rapid climate changes over the past century make a clear case of the impact of aerosols and clouds, identified as sources of largest uncertainty in climate projections. Earth’s radiation balance is altered by aerosols depending on their size, morphology and chemical composition. Competing effects in the atmosphere can be further studied by investigating the evolution of aerosol microphysical properties, which are the focus of the present work. The aerosol size distribution, the refractive index, and the single scattering albedo are commonly used such properties linked to aerosol type, and radiative forcing. Highly advanced lidars (light detection and ranging) have reduced aerosol monitoring and optical profiling into a routine process. Lidar data have been widely used to retrieve the size distribution through the inversion of the so-called Lorenz-Mie model (LMM). This model offers a reasonable treatment for spherically approximated particles, it no longer provides, though, a viable description for other naturally occurring arbitrarily shaped particles, such as dust particles. On the other hand, non-spherical geometries as simple as spheroids reproduce certain optical properties with enhanced accuracy. Motivated by this, we adapt the LMM to accommodate the spheroid-particle approximation introducing the notion of a two-dimensional (2D) shape-size distribution. Inverting only a few optical data points to retrieve the shape-size distribution is classified as a non-linear ill-posed problem. A brief mathematical analysis is presented which reveals the inherent tendency towards highly oscillatory solutions, explores the available options for a generalized solution through regularization methods and quantifies the ill-posedness. The latter will improve our understanding on the main cause fomenting instability in the produced solution spaces. The new approach facilitates the exploitation of additional lidar data points from depolarization measurements, associated with particle non-sphericity. However, the generalization of LMM vastly increases the complexity of the problem. The underlying theory for the calculation of the involved optical cross sections (T-matrix theory) is computationally so costly, that would limit a retrieval analysis to an unpractical point. Moreover the discretization of the model equation by a 2D collocation method, proposed in this work, involves double integrations which are further time consuming. We overcome these difficulties by using precalculated databases and a sophisticated retrieval software (SphInX: Spheroidal Inversion eXperiments) especially developed for our purposes, capable of performing multiple-dataset inversions and producing a wide range of microphysical retrieval outputs. Hybrid regularization in conjunction with minimization processes is used as a basis for our algorithms. Synthetic data retrievals are performed simulating various atmospheric scenarios in order to test the efficiency of different regularization methods. The gap in contemporary literature in providing full sets of uncertainties in a wide variety of numerical instances is of major concern here. For this, the most appropriate methods are identified through a thorough analysis on an overall-behavior basis regarding accuracy and stability. The general trend of the initial size distributions is captured in our numerical experiments and the reconstruction quality depends on data error level. Moreover, the need for more or less depolarization points is explored for the first time from the point of view of the microphysical retrieval. Finally, our approach is tested in various measurement cases giving further insight for future algorithm improvements. N2 - Zahlreiche Berichte von relativ schnellen Klimaveränderungen im vergangenen Jahrhundert liefern überzeugende Argumente über die Auswirkungen von Aerosolen und Wolken auf Wetter und Klima. Aerosole und Wolken wurden als Quellen größter Unsicherheit in Klimaprognosen identifiziert. Die Strahlungsbilanz der Erde wird verändert durch die Partikelgröße, ihre Morphologie und ihre chemische Zusammensetzung. Konkurrierende Effekte in der Atmosphäre können durch die Bestimmung von mikrophysikalischen Partikeleigenschaften weiter untersucht werden, was der Fokus der vorliegenden Arbeit ist. Die Aerosolgrößenverteilung, der Brechungsindex der Partikeln und die Einzel-Streu-Albedo sind solche häufig verwendeten Parameter, die mit dem Aerosoltyp und dem Strahlungsantrieb verbunden sind. Hoch entwickelte Lidare (Light Detection and Ranging) haben die Aerosolüberwachung und die optische Profilierung zu einem Routineprozess gemacht. Lidar-Daten wurden verwendet um die Größenverteilung zu bestimmen, was durch die Inversion des sogenannten Lorenz-Mie-Modells (LMM) gelingt. Dieses Modell bietet eine angemessene Behandlung für sphärisch angenäherte Partikeln, es stellt aber keine brauchbare Beschreibung für andere natürlich auftretende beliebig geformte Partikeln -wie z.B. Staubpartikeln- bereit. Andererseits stellt die Einbeziehung einer nicht kugelförmigen Geometrie –wie z.B. einfache Sphäroide- bestimmte optische Eigenschaften mit verbesserter Genauigkeit dar. Angesichts dieser Tatsache erweitern wir das LMM durch die Approximation von Sphäroid-Partikeln. Dazu ist es notwendig den Begriff einer zweidimensionalen Größenverteilung einzuführen. Die Inversion einer sehr geringen Anzahl optischer Datenpunkte zur Bestimmung der Form der Größenverteilung ist als ein nichtlineares schlecht gestelltes Problem bekannt. Eine kurze mathematische Analyse wird vorgestellt, die die inhärente Tendenz zu stark oszillierenden Lösungen zeigt. Weiterhin werden Optionen für eine verallgemeinerte Lösung durch Regularisierungsmethoden untersucht und der Grad der Schlechtgestelltheit quantifiziert. Letzteres wird unser Verständnis für die Hauptursache der Instabilität bei den berechneten Lösungsräumen verbessern. Der neue Ansatz ermöglicht es uns, zusätzliche Lidar-Datenpunkte aus Depolarisationsmessungen zu nutzen, die sich aus der Nicht-sphärizität der Partikeln assoziieren. Die Verallgemeinerung des LMMs erhöht erheblich die Komplexität des Problems. Die zugrundeliegende Theorie für die Berechnung der beteiligten optischen Querschnitte (T-Matrix-Ansatz) ist rechnerisch so aufwendig, dass eine Neuberechnung dieser nicht sinnvoll erscheint. Darüber hinaus wird ein zweidimensionales Kollokationsverfahren für die Diskretisierung der Modellgleichung vorgeschlagen. Dieses Verfahren beinhaltet Doppelintegrationen, die wiederum zeitaufwendig sind. Wir überwinden diese Schwierigkeiten durch Verwendung vorgerechneter Datenbanken sowie einer hochentwickelten Retrieval-Software (SphInX: Spheroidal Inversion eXperiments). Diese Software wurde speziell für unseren Zweck entwickelt und ist in der Lage mehrere Datensatzinversionen gleichzeitig durchzuführen und eine große Auswahl von mikrophysikalischen Retrieval-Ausgaben bereitzustellen. Eine hybride Regularisierung in Verbindung mit einem Minimierungsverfahren wird als Grundlage für unsere Algorithmen verwendet. Synthetische Daten-Inversionen werden mit verschiedenen atmosphärischen Szenarien durchgeführt, um die Effizienz verschiedener Regularisierungsmethoden zu untersuchen. Die Lücke in der gegenwärtigen wissenschaftlichen Literatur gewisse Unsicherheiten durch breitgefächerte numerische Fälle bereitzustellen, ist ein Hauptanliegen dieser Arbeit. Motiviert davon werden die am besten geeigneten Verfahren einer gründlichen Analyse in Bezug auf ihr Gesamtverhalten, d.h. Genauigkeit und Stabilität, unterzogen. Der allgemeine Trend der Anfangsgrößenverteilung wird in unseren numerischen Experimenten erfasst. Zusätzlich hängt die Rekonstruktionsqualität vom Datenfehler ab. Darüber hinaus wird die Anzahl der notwendigen Depolarisationspunkte zum ersten Mal aus der Sicht des mikrophysikalischen Parameter-Retrievals erforscht. Abschließend verwenden wir unsere Software für verschiedene Messfälle, was weitere Einblicke für künftige Verbesserungen des Algorithmus gibt. KW - microphysics KW - retrieval KW - lidar KW - aerosols KW - regularization KW - ill-posed KW - inversion KW - Mikrophysik KW - Retrieval KW - Lidar KW - Aerosole KW - Regularisierung KW - schlecht gestellt KW - Inversion Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-396528 ER - TY - GEN A1 - Müller, Detlef A1 - Böckmann, Christine A1 - Kolgotin, Alexei A1 - Schneidenbach, Lars A1 - Chemyakin, Eduard A1 - Rosemann, Julia A1 - Znak, Pavel A1 - Romanov, Anton T1 - Microphysical particle properties derived from inversion algorithms developed in the framework of EARLINET T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - We present a summary on the current status of two inversion algorithms that are used in EARLINET (European Aerosol Research Lidar Network) for the inversion of data collected with EARLINET multiwavelength Raman lidars. These instruments measure backscatter coefficients at 355, 532, and 1064 nm, and extinction coefficients at 355 and 532 nm. Development of these two algorithms started in 2000 when EARLINET was founded. The algorithms are based on a manually controlled inversion of optical data which allows for detailed sensitivity studies. The algorithms allow us to derive particle effective radius as well as volume and surface area concentration with comparably high confidence. The retrieval of the real and imaginary parts of the complex refractive index still is a challenge in view of the accuracy required for these parameters in climate change studies in which light absorption needs to be known with high accuracy. It is an extreme challenge to retrieve the real part with an accuracy better than 0.05 and the imaginary part with accuracy better than 0.005-0.1 or +/- 50 %. Single-scattering albedo can be computed from the retrieved microphysical parameters and allows us to categorize aerosols into high-and low-absorbing aerosols. On the basis of a few exemplary simulations with synthetic optical data we discuss the current status of these manually operated algorithms, the potentially achievable accuracy of data products, and the goals for future work. One algorithm was used with the purpose of testing how well microphysical parameters can be derived if the real part of the complex refractive index is known to at least 0.05 or 0.1. The other algorithm was used to find out how well microphysical parameters can be derived if this constraint for the real part is not applied. The optical data used in our study cover a range of Angstrom exponents and extinction-to-backscatter (lidar) ratios that are found from lidar measurements of various aerosol types. We also tested aerosol scenarios that are considered highly unlikely, e.g. the lidar ratios fall outside the commonly accepted range of values measured with Raman lidar, even though the underlying microphysical particle properties are not uncommon. The goal of this part of the study is to test the robustness of the algorithms towards their ability to identify aerosol types that have not been measured so far, but cannot be ruled out based on our current knowledge of aerosol physics. We computed the optical data from monomodal logarithmic particle size distributions, i.e. we explicitly excluded the more complicated case of bimodal particle size distributions which is a topic of ongoing research work. Another constraint is that we only considered particles of spherical shape in our simulations. We considered particle radii as large as 7-10 mu m in our simulations where the Potsdam algorithm is limited to the lower value. We considered optical-data errors of 15% in the simulation studies. We target 50% uncertainty as a reasonable threshold for our data products, though we attempt to obtain data products with less uncertainty in future work. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 565 KW - aerosol-size distribution KW - backscatter lidar data KW - multiwavelength lidar KW - raman-lidar KW - tropospheric aerosol KW - regularization method KW - integral equations KW - optical-data KW - parameters KW - retrieval Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-411934 SN - 1866-8372 IS - 565 ER - TY - JOUR A1 - Müller, Detlef A1 - Böckmann, Christine A1 - Kolgotin, Alexei A1 - Schneidenbach, Lars A1 - Chemyakin, Eduard A1 - Rosemann, Julia A1 - Znak, Pavel A1 - Romanov, Anton T1 - Microphysical particle properties derived from inversion algorithms developed in the framework of EARLINET JF - Atmospheric measurement techniques : an interactive open access journal of the European Geosciences Union N2 - We present a summary on the current status of two inversion algorithms that are used in EARLINET (European Aerosol Research Lidar Network) for the inversion of data collected with EARLINET multiwavelength Raman lidars. These instruments measure backscatter coefficients at 355, 532, and 1064 nm, and extinction coefficients at 355 and 532 nm. Development of these two algorithms started in 2000 when EARLINET was founded. The algorithms are based on a manually controlled inversion of optical data which allows for detailed sensitivity studies. The algorithms allow us to derive particle effective radius as well as volume and surface area concentration with comparably high confidence. The retrieval of the real and imaginary parts of the complex refractive index still is a challenge in view of the accuracy required for these parameters in climate change studies in which light absorption needs to be known with high accuracy. It is an extreme challenge to retrieve the real part with an accuracy better than 0.05 and the imaginary part with accuracy better than 0.005-0.1 or +/- 50 %. Single-scattering albedo can be computed from the retrieved microphysical parameters and allows us to categorize aerosols into high-and low-absorbing aerosols. On the basis of a few exemplary simulations with synthetic optical data we discuss the current status of these manually operated algorithms, the potentially achievable accuracy of data products, and the goals for future work. One algorithm was used with the purpose of testing how well microphysical parameters can be derived if the real part of the complex refractive index is known to at least 0.05 or 0.1. The other algorithm was used to find out how well microphysical parameters can be derived if this constraint for the real part is not applied. The optical data used in our study cover a range of Angstrom exponents and extinction-to-backscatter (lidar) ratios that are found from lidar measurements of various aerosol types. We also tested aerosol scenarios that are considered highly unlikely, e.g. the lidar ratios fall outside the commonly accepted range of values measured with Raman lidar, even though the underlying microphysical particle properties are not uncommon. The goal of this part of the study is to test the robustness of the algorithms towards their ability to identify aerosol types that have not been measured so far, but cannot be ruled out based on our current knowledge of aerosol physics. We computed the optical data from monomodal logarithmic particle size distributions, i.e. we explicitly excluded the more complicated case of bimodal particle size distributions which is a topic of ongoing research work. Another constraint is that we only considered particles of spherical shape in our simulations. We considered particle radii as large as 7-10 mu m in our simulations where the Potsdam algorithm is limited to the lower value. We considered optical-data errors of 15% in the simulation studies. We target 50% uncertainty as a reasonable threshold for our data products, though we attempt to obtain data products with less uncertainty in future work. Y1 - 2016 U6 - https://doi.org/10.5194/amt-9-5007-2016 SN - 1867-1381 SN - 1867-8548 VL - 9 SP - 5007 EP - 5035 PB - Copernicus CY - Göttingen ER - TY - THES A1 - Schroth, Maximilian T1 - Microfinance and the enhancement of economic development in less developed countries T1 - Mikrofinanzierung und die Förderung wirtschaftlicher Entwicklung in weniger entwickelten Ländern N2 - It is the intention of this study to contribute to further rethinking and innovating in the Microcredit business which stands at a turning point – after around 40 years of practice it is endangered to fail as a tool for economic development and to become a doubtful finance product with a random scope instead. So far, a positive impact of Microfinance on the improvement of the lives of the poor could not be confirmed. Over-indebtment of borrowers due to the pre-dominance of consumption Microcredits has become a widespread problem. Furthermore, a rising number of abusive and commercially excessive practices have been reported. In fact, the Microfinance sector appears to suffer from a major underlying deficit: there does not exist a coherent and transparent understanding of its meaning and objectives so that Microfinance providers worldwide follow their own approaches of Microfinance which tend to differ considerably from each other. In this sense the study aims at consolidating the multi-faced and very often confusingly different Microcredit profiles that exist nowadays. Subsequently, in this study, the Microfinance spectrum will be narrowed to one clear-cut objective, in fact away from the mere monetary business transactions to poor people it has gradually been reduced to back towards a tool for economic development as originally envisaged by its pioneers. Hence, the fundamental research question of this study is whether, and under which conditions, Microfinance may attain a positive economic impact leading to an improvement of the living of the poor. The study is structured in five parts: the three main parts (II.-IV.) are surrounded by an introduction (I.) and conclusion (V.). In part II., the Microfinance sector is analysed critically aiming to identify the challenges persisting as well as their root causes. In the third part, a change to the macroeconomic perspective is undertaken in oder to learn about the potential and requirements of small-scale finance to enhance economic development, particularly within the economic context of less developed countries. By consolidating the insights gained in part IV., the elements of a new concept of Microfinance with the objecitve to achieve economic development of its borrowers are elaborated. Microfinance is a rather sensitive business the great fundamental idea of which is easily corruptible and, additionally, the recipients of which are predestined victims of abuse due to their limited knowledge in finance. It therefore needs to be practiced responsibly, but also according to clear cut definitions of its meaning and objectives all institutions active in the sector should be devoted to comply with. This is especially relevant as the demand for Microfinance services is expected to rise further within the years coming. For example, the recent refugee migration movement towards Europe entails a vast potential for Microfinance to enable these people to make a new start into economic life. This goes to show that Microfinance may no longer mainly be associated with a less developed economic context, but that it will gain importance as a financial instrument in the developed economies, too. N2 - Diese Studie soll einen Beitrag zur Grundlagenforschung in der Mikrofinanzierung leisten und zu Reflektion und Innovation im Mikrofinanzsektor anregen. Letzterer befindet sich zurzeit an einem Scheidepunkt: nach knapp 40 Jahren besteht die Gefahr, dass Mikrofinanzierung zu einem zweifelhaften Finanzprodukt ohne klare Richtung verkommt – anstatt sich als ein Mittel zur Förderung wirtschaftlicher Entwicklung zu etablieren. Bislang konnte noch kein Nachweis erbracht werden, dass Mikrofinanzierung einen positiven Einfluss auf die wirtschaftliche Entwicklung der Armen ausübt. Überschuldung der Kreditnehmer ist zu einem weit verbreiteten Problem geworden, die weite Mehrheit der Mikrokredite geht in den Konsum. Außerdem wird vielerorts über eine wachsende Anzahl missbräuchlicher Verleihpraktiken berichtet. Ein Hauptproblem scheint tatsächlich darin zu liegen, dass die Anbieter von Mikrofinanzdienstleistungen allesamt mit eigenen Mikrofinanzkonzepten arbeiten, die sich teilweise sehr stark voneinander unterscheiden. Ein kohärentes und transparentes Verständnis der Bedeutung und Zielsetzungen von Mikrofinanzierung liegt demnach nicht vor. Das Ziel dieser Studie ist daher, die vielschichtigen und oftmals verwirrenden Mikrokreditprofile zu konsolidieren. Das Spektrum von Mikrofinanzierung in dieser Studie soll auf ein klares Ziel eingegrenzt werden: weg von den wenig greifbaren Geldgeschäften für arme Haushalte hin zu einem Mittel zur Förderung der wirtschaftlichen Entwicklung wie ursprünglich von den Erschaffern der Mikrofinanzierung anvisiert. Die zentrale Forschungsfrage dieser Studie lautet daher, ob, und wenn ja, unter welchen Bedingungen, Mikrofinanzierung einen positiven Einfluss auf die wirtschaftliche Entwicklung und die Verbesserung des Lebens der Armen in weniger entwickelten Ländern ausüben kann. Die Studie gliedert sich in fünf Teile: Die drei Hauptteile (II.-IV.) sind eingerahmt von einer Einführung (I.) sowie einem Fazit (V.). In Teil II. wird der Mikrofinanzsektor kritisch analysiert. Es werden die aktuell bestehenden Probleme aufgezeigt und ihre möglichen Ursachen identifiziert. Im dritten Teil werden mithife einer makroökonomischen Betrachtungsweise Erkenntnisse über das Potenzial von Mikrofinanzierung zur Förderung wirtschaftlicher Entwicklung gesammelt. Ebenso über die dazu zu erfüllenden Anforderungen, insbesondere im Kontext weniger entwickelter Länder. In Teil IV. werden die Erkenntnisse konsolidiert und die Elemente eines neuen Mikrofinanzkonzept erarbeitet, das die Förderung der wirtschaftlichen Entwicklung der Kreditnehmer zum Ziel hat. Mikrofinanzierung ist ein sensibles Geschäft, dessen Grundidee leicht korrumpierbar ist und dessen Empfänger prädestinierte Opfer von Betrug und Missbrauch sind, da sie in der Regel über keinerlei Vorerfahrung in Finanzthemen verfügen. Es bedarf daher einer verantwortungsbewussten Praxis, die gleichermaßen nach klaren und transparenten Richtlinien bezüglich Bedeutung und Zielsetzungen ausgerichtet ist, nach denen sich alle aktiven Marktteilnehmer richten. Dies ist insbesondere auch deshalb relevant, da mit einer wachsenden Nachfrage nach Mikrokrediten in den nächsten Jahren zu rechnen ist. Beispielsweise stellt die aktuelle Flüchtlingsbewegung nach Europa ein riesiges Potenzial dar: Mikrokredite könnten den Grundstein für einen Neustart in das Berufsleben dieser Haushalte legen. Dies zeigt auch, dass Mikrofinanzierung nicht mehr ausschließlich mit dem Kontext weniger entwickelter Länder in Verbindung gebracht wird, sondern dass sie auch in den entwickelten Ländern an Bedeutung gewinnen wird. KW - microfinance KW - microcredits KW - money KW - capital market KW - impact KW - indirect help KW - economic development KW - crisis KW - over-indebtment KW - consumption KW - abuse KW - regulation KW - McKinnon KW - less developed countries KW - fragmentation KW - financial repression KW - complementary effect KW - investment KW - savings KW - banking accounts KW - domestic entrepreneurs KW - seed-financing KW - disposable capital KW - ordo-liberal policies KW - mobile banking KW - private wealth KW - foundations KW - impact investing KW - Mikrofinanzierung KW - Mikrokredite KW - Geld KW - Kapitalmarkt KW - Impact KW - indirekte Hilfe KW - wirtschaftliche Entwicklung KW - Krise KW - Überschuldung KW - Konsum KW - Missbrauch KW - Regulierung KW - McKinnon KW - weniger entwickelte Länder KW - Fragmentierung KW - finanzielle Unterdrückung KW - Komplementaritätseffekt KW - Investitionen KW - Sparen KW - Bankkonto KW - lokale Unternehmer KW - Gründungsfinanzierung KW - Kapitaldisposition KW - ordo-liberale Politik KW - mobile banking KW - Privatvermögen KW - Stiftungen KW - Impact Investing Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94735 ER - TY - JOUR A1 - Svanys, Algirdas A1 - Eigemann, Falk A1 - Grossart, Hans-Peter A1 - Hilt, Sabine T1 - Microcystins do not necessarily lower the sensitivity of Microcystis aeruginosa to tannic acid JF - FEMS microbiology letters N2 - Different phytoplankton strains have been shown to possess varying sensitivities towards macrophyte allelochemicals, yet the reasons for this are largely unknown. To test whether microcystin (MC) is responsible for strain-specific sensitivities of Microcystis aeruginosa to macrophyte allelochemicals, we compared the sensitivity of 12 MC- and non-MC-producing M. aeruginosa strains, including an MC-deficient mutant and its wild type, to the polyphenolic allelochemical tannic acid (TA). Non-MC-producing strains showed a significantly higher sensitivity to TA than MC-producing strains, both in Chlorophyll a concentrations and quantum yields of photosystem II. In contrast, an MC-deficient mutant displayed a higher fitness against TA compared to its wild type. These results suggest that the resistance of M. aeruginosa to polyphenolic allelochemicals is not primarily related to MCs per se, but to other yet unknown protective mechanisms related to MCs. KW - allelopathy KW - Delta mcyB mutant KW - microcystin KW - Microcystis aeruginosa KW - tannic acid Y1 - 2016 U6 - https://doi.org/10.1093/femsle/fnv227 SN - 0378-1097 SN - 1574-6968 VL - 363 SP - 53 EP - 77 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Hoehnel, Desirée A1 - Tagle, Roald A1 - Hofmann, Axel A1 - Reimold, W. U. A1 - Mohr-Westheide, Tanja A1 - Fritz, Joerg A1 - Altenberger, Uwe T1 - MICRO-XRF ANALYSIS OF ARCHEAN SPHERULE LAYERS AND HOST ROCKS FROM THE CT3 DRILL CORE, BARBERTON GREENSTONE BELT, SOUTH AFRICA T2 - Monthly notices of the Royal Astronomical Society Y1 - 2016 SN - 1086-9379 SN - 1945-5100 VL - 51 SP - A334 EP - A334 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Park, H. A1 - Walta, S. A1 - Rosencrantz, Ruben R. A1 - Koerner, A. A1 - Schulte, Christoph A1 - Elling, L. A1 - Richtering, Walter A1 - Böker, Alexander T1 - Micelles from self-assembled double-hydrophilic PHEMA-glycopolymer-diblock copolymers as multivalent scaffolds for lectin binding JF - Polymer Chemistry N2 - We introduce a novel double-hydrophilic hydroxyethylmethacrylate (HEMA) based diblock glycopolymer which self-assembles into homogeneous spherical micellar structures in water. The micellar structure renders surface-oriented N-acetylglucocosamine (GlcNAc) sugar moieties for strong multivalent glycan-mediated lectin binding. Structural analysis and lectin binding is performed by microscopy methods, dynamic light scattering (DLS) and two-focus fluorescence correlation spectroscopy (2fFCS), revealing a novel micellar type of multivalent sugar binding scaffold with high potential for biomedical applications. Y1 - 2016 U6 - https://doi.org/10.1039/c5py00797f SN - 1759-9954 SN - 1759-9962 VL - 7 SP - 878 EP - 886 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Bougeois, Laurie A1 - de Rafelis, Marc A1 - Reichart, Gert-Jan A1 - de Nooijer, Lennart J. A1 - Dupont-Nivet, Guillaume T1 - Mg/Ca in fossil oyster shells as palaeotemperature proxy, an example from the Palaeogene of Central Asia JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - Fossil oyster shells are well-suited to provide palaeotemperature proxies from geologic to seasonal timescales due to their ubiquitous occurrence from Triassic to Quaternary sediments, the seasonal nature of their shell growth and their relative strong resistance to post-mortem alteration. However, the common use to translate calcitic oxygen isotopes into palaeotemperatures is challenged by uncertainties in accounting for past seawater delta O-18, especially in shallow coastal environment where oysters calcify. In principle, the Mg/Ca ratio in oyster shells can provide an alternative palaeothermometer. Several studies provided temperature calibrations for this potential proxy based on modem species, nevertheless their application to palaeo-studies remains hitherto unexplored. Here, we show that past temperature variability in seawater can be obtained from Mg/Ca analyses from selected fossil oyster species and specimens. High-resolution Mg/Ca profiles, combined with delta O-18, were obtained along 41 fossil oyster shells of seven different species from the Palaeogene Proto-Paratethys sea (Central Asia) found in similar as well as different depositional age and environments providing comparison. Suitable Mg/Ca profiles, defined by continuous cyclicity and reproducibility within one shell, are found to be consistent for specimens of the same species but differ systematically between species, implying a dominant species-specific effect on the Mg/Ca signal. Two species studied here (Ostrea (Turkostrea) strictiplicata and Sokolowia buhsii) provide an excellent proxy for palaeoclimate reconstruction from China to Europe in Palaeogene marine sediments. More generally, the protocol developed here can be applied to identify other fossil oyster species suitable for palaeoclimate reconstructions. (C) 2015 Elsevier B.V. All rights reserved. KW - Palaeoclimate KW - Oyster KW - Mg/Ca KW - Sclerochronology KW - Palaeogene KW - Central Asia Y1 - 2016 U6 - https://doi.org/10.1016/j.palaeo.2015.09.052 SN - 0031-0182 SN - 1872-616X VL - 441 SP - 611 EP - 626 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Roers, Michael T1 - Methoden zur Dynamisierung von Klimafolgenanalysen im Elbegebiet T1 - Methods for a dynamisation of climate impact studies in the Elbe River basin BT - Aktualisierung von Szenarienstudien zu den Auswirkungen des Klimawandels und fortlaufende Überprüfung ökohydrologischer Modellergebnisse BT - actualisation of scenario studies on impacts of climate change and continuous verification of ecohydrological model results N2 - Die Elbe und ihr Einzugsgebiet sind vom Klimawandel betroffen. Um die Wirkkette von projizierten Klimaveränderungen auf den Wasserhaushalt und die daraus resultierenden Nährstoffeinträge und -frachten für große Einzugsgebiete wie das der Elbe zu analysieren, können integrierte Umweltmodellsysteme eingesetzt werden. Fallstudien, die mit diesen Modellsystemen ad hoc durchgeführt werden, repräsentieren den Istzustand von Modellentwicklungen und -unsicherheiten und sind damit statisch. Diese Arbeit beschreibt den Einstieg in die Dynamisierung von Klimafolgenanalysen im Elbegebiet. Dies umfasst zum einen eine Plausibilitätsprüfung von Auswirkungsrechnungen, die mit Szenarien des statistischen Szenariengenerators STARS durchgeführt wurden, durch den Vergleich mit den Auswirkungen neuerer Klimaszenarien aus dem ISI-MIP Projekt, die dem letzten Stand der Klimamodellierung entsprechen. Hierfür wird ein integriertes Modellsystem mit "eingefrorenem Entwicklungsstand" verwendet. Die Klimawirkungsmodelle bleiben dabei unverändert. Zum anderen wird ein Bestandteil des integrierten Modellsystems – das ökohydrologische Modell SWIM – zu einer "live"-Version weiterentwickelt. Diese wird durch punktuelle Testung an langjährigen Versuchsreihen eines Lysimeterstandorts sowie an aktuellen Abflussreihen validiert und verbessert. Folgende Forschungsfragen werden bearbeitet: (i) Welche Effekte haben unterschiedliche Klimaszenarien auf den Wasserhaushalt im Elbegebiet und ist eine Neubewertung der Auswirkung des Klimawandels auf den Wasserhaushalt notwendig?, (ii) Was sind die Auswirkungen des Klimawandels auf die Nährstoffeinträge und -frachten im Elbegebiet sowie die Wirksamkeit von Maßnahmen zur Reduktion der Nährstoffeinträge?, (iii) Ist unter der Nutzung (selbst einer sehr geringen Anzahl) verfügbarer tagesaktueller Witterungsdaten in einem stark heterogenen Einzugsgebiet eine valide Ansprache der aktuellen ökohydrologischen Situation des Elbeeinzugsgebiets möglich? Die aktuellen Szenarien bestätigen die Richtung, jedoch nicht das Ausmaß der Klimafolgen: Die Rückgänge des mittleren jährlichen Gesamtabflusses und der monatlichen Abflüsse an den Pegeln bis Mitte des Jahrhunderts betragen für das STARS-Szenario ca. 30 %. Die Rückgänge bei den auf dem ISI-MIP-Szenario basierenden Modellstudien liegen hingegen nur bei ca. 10 %. Hauptursachen für diese Divergenz sind die Unterschiede in den Niederschlagsprojektionen sowie die Unterschiede in der jahreszeitlichen Verteilung der Erwärmung. Im STARS-Szenario gehen methodisch bedingt die Niederschläge zurück und der Winter erwärmt sich stärker als der Sommer. In dem ISI-MIP-Szenario bleiben die Niederschläge nahezu stabil und die Erwärmung im Sommer und Winter unterscheidet sich nur geringfügig. Generell nehmen die Nährstoffeinträge und -frachten mit den Abflüssen in beiden Szenarien unterproportional ab, wobei die Frachten jeweils stärker als die Einträge zurückgehen. Die konkreten Effekte der Abflussänderungen sind gering und liegen im einstelligen Prozentbereich. Gleiches gilt für die Unterschiede zwischen den Szenarien. Der Effekt von zwei ausgewählten Maßnahmen zur Reduktion der Nährstoffeinträge und -frachten unterscheidet sich bei verschiedenen Abflussverhältnissen, repräsentiert durch unterschiedliche Klimaszenarien in unterschiedlich feuchter Ausprägung, ebenfalls nur geringfügig. Die Beantwortung der ersten beiden Forschungsfragen zeigt, dass die Aktualisierung von Klimaszenarien in einem ansonsten "eingefrorenen" Verbund von ökohydrologischen Daten und Modellen eine wichtige Prüfoption für die Plausibilisierung von Klimafolgenanalysen darstellt. Sie bildet die methodische Grundlage für die Schlussfolgerung, dass bei der Wassermenge eine Neubewertung der Klimafolgen notwendig ist, während dies bei den Nährstoffeinträgen und -frachten nicht der Fall ist. Die zur Beantwortung der dritten Forschungsfrage mit SWIM-live durchgeführten Validierungsstudien ergeben Diskrepanzen am Lysimeterstandort und bei den Abflüssen aus den Teilgebieten Saale und Spree. Sie lassen sich zum Teil mit der notwendigen Interpolationsweite der Witterungsdaten und dem Einfluss von Wasserbewirtschaftungsmaßnahmen erklären. Insgesamt zeigen die Validierungsergebnisse, dass schon die Pilotversion von SWIM-live für eine ökohydrologische Ansprache des Gebietswasserhaushaltes im Elbeeinzugsgebiet genutzt werden kann. SWIM-live ermöglicht eine unmittelbare Betrachtung und Beurteilung simulierter Daten. Dadurch werden Unsicherheiten bei der Modellierung direkt offengelegt und können infolge dessen reduziert werden. Zum einen führte die Verdichtung der meteorologischen Eingangsdaten durch die Verwendung von nun ca. 700 anstatt 19 Klima- bzw. Niederschlagstationen zu einer Verbesserung der Ergebnisse. Zum anderen wurde SWIM-live beispielhaft für einen Zyklus aus punktueller Modellverbesserung und flächiger Überprüfung der Simulationsergebnisse genutzt. Die einzelnen Teilarbeiten tragen jeweils zur Dynamisierung von Klimafolgenanalysen im Elbegebiet bei. Der Anlass hierfür war durch die fehlerhaften methodischen Grundlagen von STARS gegeben. Die Sinnfälligkeit der Dynamisierung ist jedoch nicht an diesen konkreten Anlass gebunden, sondern beruht auf der grundlegenden Einsicht, dass Ad-hoc-Szenarienanalysen immer auch pragmatische Vereinfachungen zugrunde liegen, die fortlaufend überprüft werden müssen. N2 - The Elbe River basin is affected by climate change. To analyse the chain of effects of projected climate change on the water balance and the resulting nutrient emissions and loads in large river basins such as the Elbe, integrated environmental model systems can be applied. Case studies that are conducted ad hoc with these model systems represent the current state of model developments and uncertainties - therefore, they are static. This thesis describes access to a dynamisation of climate impact studies in the Elbe River basin. On the one hand, this comprises a verification of impact simulations that are conducted with scenarios from the statistical scenario generator STARS, with the impacts of newer climate scenarios from the ISI-MIP project, that represent state-of-the-art climate modelling. For this purpose, an integrated model system with a "frozen" development status is used. At the same time, the climate impact models remain unchanged. On the other hand, one component of the integrated model system - the ecohydrological model SWIM - is enhanced as a "live"-system. This is validated and improved by punctual testing with experimental long time series from a lysimeter site and with recent runoff time series. The following research questions are addressed: (i) What are the effects of different climate scenarios on the water balance in the Elbe River basin, and is a reassessment of the impacts of climate change on the water balance necessary?, (ii) What are the impacts of climate change on the nutrient emissions and loads in the Elbe River basin as well as the effectiveness of measures for reducing nutrient emissions?, (iii) Is a valid assessment of the actual ecohydrological situation in the Elbe River basin possible, using (only a small amount of) available day-to-day weather data in a highly heterogeneous river basin? The recent scenarios confirm the direction, but not the magnitude, of climate impacts: In the STARS scenario, the decrease in mean annual discharge and mean monthly stream ow until the middle of the century is approx. 30 %. However, the model studies based on the ISI-MIP scenarios show only a decrease of approx. 10 %. The main reason for this divergence can be attributed to differences in the precipitation projections and differences in the seasonal distribution of the warming. In the STARS scenario, the precipitation decreases due to the methodological principles applied and the warming in winter is stronger than in summer. In the ISI-MIP scenario, the precipitation is almost stable and the warming differs only slightly between summer and winter. In general, the nutrient emissions and loads decrease underproportionally with the river basin discharge in both scenarios, with loads declining more sharply than the emissions. The concrete effects of the change in river basin discharge are small, reaching only single-digit percentages. The same holds true for the difference between the scenarios. The effect of selected measures for the reduction of nutrient emissions and loads also differs only slightly between varying runoff conditions, represented by different climate scenarios with dry, mean and wet specifications. Answering the first two research questions shows that the actualisation of climate scenarios in an otherwise "frozen" combination of ecohydrological data and models represents an important testing option for the plausibilisation of climate impact studies. It forms the methodological basis for the conclusion that a reassessment of climate impact is necessary in terms of water quantity, whereas this is not the case for the nutrient emissions and loads. The validation studies that were conducted to answer the third research question show discrepancies at the lysimeter site and in the flows from the sub-catchments of the Saale and Spree Rivers. They can be explained in part by the low spatial density of the climate data and the influences from water-management practices. However, the validation results show that the pilot version of SWIM-live can already be used for an eco-hydrological assessment of the water balance in the Elbe River basin. SWIM-live provides an immediate visualisation and assessment of the simulated data. By this means, uncertainties in the simulations are directly revealed and can be reduced. On the one hand, a concentration of the meteorological input data using approx. 700 instead of 19 climate and precipitation stations leads to an improvement of the results. On the other hand, SWIM-live is used exemplarily for a cycle of punctual model improvement and spatial verification of the simulations. The individual parts of this thesis contribute to the dynamisation of climate impact studies in the Elbe River basin. The motivation for the study was the flawed methodological basis of STARS. Dynamisation is relevant not only for this reason, but is also based on the underlying understanding that ad hoc scenario analyses involve pragmatic simplifications that must be verified continuously. KW - Klimawandel KW - Wasserhaushalt KW - Nährstoffeinträge KW - tagesaktuelle Simulation KW - Elbe KW - climate change KW - water balance KW - nutrient emissions KW - simulation on a day-to-day-basis KW - Elbe Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-98844 ER - TY - JOUR A1 - Tang, Kam W. A1 - McGinnis, Daniel F. A1 - Ionescu, Danny A1 - Grossart, Hans-Peter T1 - Methane Production in Oxic Lake Waters Potentially Increases Aquatic Methane Flux to Air JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - Active methane production in oxygenated lake waters challenges the long-standing paradigm that microbial methane production occurs only under anoxic conditions and forces us to rethink the ecology and environmental dynamics of this powerful greenhouse gas. Methane production in the upper oxic water layers places the methane source closer to the air water interface, where convective mixing and microbubble detrainment can lead to a methane efflux higher than that previously assumed. Microorganisms may produce methane in oxic environments by being equipped with enzymes to counteract the effects of molecular oxygen during methanogenesis or using alternative pathways that do not involve oxygen-sensitive enzymes. As this process appears to be influenced by thermal stratification, water transparency, and primary production, changes in lake ecology due to climate change will alter methane formation in oxic water layers, with far-reaching consequences for methane flux and climate feedback. Y1 - 2016 U6 - https://doi.org/10.1021/acs.estlett.6b00150 SN - 2328-8930 VL - 3 SP - 227 EP - 233 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Osudar, Roman T1 - Methane distribution and oxidation across aquatic interfaces T1 - Verteilung und Oxidation von Methan in aquatischen Ökosystemen BT - case studies from Arctic water bodies and the Elbe estuary BT - Fallstudien aus arktischen Wasserkörpern und dem Elbe Ästuar N2 - The increase in atmospheric methane concentration, which is determined by an imbalance between its sources and sinks, has led to investigations of the methane cycle in various environments. Aquatic environments are of an exceptional interest due to their active involvement in methane cycling worldwide and in particular in areas sensitive to climate change. Furthermore, being connected with each other aquatic environments form networks that can be spread on vast areas involving marine, freshwater and terrestrial ecosystems. Thus, aquatic systems have a high potential to translate local or regional environmental and subsequently ecosystem changes to a bigger scale. Many studies neglect this connectivity and focus on individual aquatic or terrestrial ecosystems. The current study focuses on environmental controls of the distribution and aerobic oxidation of methane at the example of two aquatic ecosystems. These ecosystems are Arctic fresh water bodies and the Elbe estuary which represent interfaces between freshwater-terrestrial and freshwater-marine environments, respectively. Arctic water bodies are significant atmospheric sources of methane. At the same time the methane cycle in Arctic water bodies is strongly affected by the surrounding permafrost environment, which is characterized by high amounts of organic carbon. The results of this thesis indicate that the methane concentrations in Arctic lakes and streams substantially vary between each other being regulated by local landscape features (e.g. floodplain area) and the morphology of the water bodies (lakes, streams and river). The highest methane concentrations were detected in the lake outlets and in a floodplain lake complex. In contrast, the methane concentrations measured at different sites of the Lena River did not vary substantially. The lake complexes in comparison to the Lena River, thus, appear as more individual and heterogeneous systems with a pronounced imprint of the surrounding soil environment. Furthermore, connected with each other Arctic aquatic environments have a large potential to transport methane from methane-rich water bodies such as streams and floodplain lakes to aquatic environments relatively poor in methane such as the Lena River. Estuaries represent hot spots of oceanic methane emissions. Also, estuaries are intermediate zones between methane-rich river water and methane depleted marine water. Substantiated through this thesis at the example of the Elbe estuary, the methane distribution in estuaries, however, cannot entirely be described by the conservative mixing model i.e. gradual decrease from the freshwater end-member to the marine water end-member. In addition to the methane-rich water from the Elbe River mouth substantial methane input occurs from tidal flats, areas of significant interaction between aquatic and terrestrial environments. Thus, this study demonstrates the complex interactions and their consequences for the methane distribution within estuaries. Also it reveals how important it is to investigate estuaries at larger spatial scales. Methane oxidation (MOX) rates are commonly correlated with methane concentrations. This was shown in previous research studies and was substantiated by the present thesis. In detail, the highest MOX rates in the Arctic water bodies were detected in methane-rich streams and in the floodplain area while in the Elbe estuary the highest MOX rates were observed at the coastal stations. However, in these bordering environments, MOX rates are affected not only via the regulation through methane concentrations. The MOX rates in the Arctic lakes were shown to be also dependent on the abundance and community composition of methane-oxidising bacteria (MOB), that in turn are controlled by local landscape features (regardless of the methane concentrations) and by the transport of MOB between neighbouring environments. In the Elbe estuary, the MOX rates in addition to the methane concentrations are largely affected by the salinity, which is in turn regulated by the mixing of fresh- and marine waters. The magnitude of the salinity impact on MOX rates thereby depends on the MOB community composition and on the rate of the salinity change. This study extends our knowledge of environmental controls of methane distribution and aerobic methane oxidation in aquatic environments. It also illustrates how important it is to investigate complex ecosystems rather than individual ecosystems to better understand the functioning of whole biomes. N2 - Aufgrund des Anstiegs der Methankonzentration in der Atmosphäre, der durch ein Ungleichgewicht zwischen Quellen und Senken hervorgerufen wird, steht der Methankreislauf im Fokus der Forschung. Aquatische Ökosysteme, und im Speziellen solche, die vom Klimawechsel besonders betroffen sind, spielen eine wichtige Rolle im globalen Methankreislauf. Darüber hinaus können sie über große Areale miteinander verknüpft sein und terrestrische mit marinen Ökosystemen verbinden. In aquatischen Systemen können sich daher lokale und regionale Umweltänderungen auf sehr große räumliche Skalen auswirken. Viele Untersuchungen berücksichtigen diesen Zusammenhang nicht und betrachten aquatische unabhängig von den sich angrenzenden Ökosystemen. Die vorliegende Arbeit untersucht den Einfluss von Umweltfaktoren auf die Methankonzentration und die mikrobielle aerobe Methanoxidation. Der Schwerpunkt liegt dabei auf zwei aquatischen Ökosystemen, arktische Süßwassertransekte und Ästuare, und auf deren mikrobieller Ökologie. Diese beiden Ökosysteme beschreiben typische terrestrisch-limnische und limnisch-marine Übergangsbereiche. Arktische Gewässer stellen eine wichtige Quelle für atmosphärisches Methan dar. Sie werden außerdem stark durch den umgebenden Permafrost, der reich an organischer Substanz ist, beeinflusst. Die Ergebnisse der vorliegenden Arbeit zeigen am Beispiel des Lena-Deltas, dass sich die Methankonzentrationen in arktischen Seen und Fließgewässern wesentlich voneinander unterscheiden. Besonderen Einfluss üben hierbei das örtliche Landschaftsbild (z.B. Überflutungsbereiche) und die Charakteristika der Wasserkörper (Seen, Wasserläufe und Flüsse) aus. Die höchsten Methankonzentrationen wurden in Seeabläufen und in Seen einer Überflutungsebene (Seekomplex) gemessen. Im Gegensatz dazu unterschieden sich die Methankonzentrationen an verschiedenen Messpunkten der Lena nur unwesentlich. Der Seekomplex erscheint daher im Vergleich zur Lena heterogener und stark vom umgebenden Bodenökosystem beeinflusst. Die miteinander vernetzten arktischen aquatischen Ökosysteme haben darüber hinaus ein hohes Potential, Methan von methan-reichen Gewässern, wie Wasserläufen und Überflutungsgebieten, zu relativ methan-armen Gewässern wie der Lena zur transportieren. Ästuare sind „hot spots“ der Methanemission von marin beeinflussten Systemen. Sie stellen Übergangszonen zwischen methan-reichem Flusswasser und methan-armem Meerwasser dar. Wie die Untersuchungen am Elbe Ästuar zeigen, kann die Methanverteilung jedoch nicht immer hinreichend durch das konservative Durchmischungs-Model (graduelle Abnahme vom Süß- zum Meerwasser hin) beschrieben werden. Zusätzlich zum methan-reichen Wasser der Elbemündung konnte der Eintrag von Methan in Wattbereichen, Gegenden starker aquatischer und terrestrischer Interaktion, gezeigt werden. Diese Studie verdeutlicht demnach die Komplexität von Ästuarsystemen hinsichtlich der Methanverteilung und die Notwendigkeit, diese in größeren Maßstäben zu untersuchen. Methanoxidationsraten (MOX-Raten) korrelieren gewöhnlich mit den Methankonzentrationen. Dies zeigen die hier vorliegenden Daten aber auch vorherige Studien. Die höchsten MOX-Raten der arktischen Gewässer wurden im Rahmen dieser Arbeit in methan-reichen Fließgewässern sowie einer Überflutungsebene gemessen. Im Elbeästuar wurden die höchsten Werte an den Küstenstationen aufgezeichnet. In den jeweils untersuchten Übergangszonen werden die MOX-Raten jedoch nicht nur durch die Methankonzentrationen gekennzeichnet. In den arktischen Seen werden sie zusätzlich durch die Zellzahl und Populationsstruktur von Methan oxidierenden Bakterien (MOB) bestimmt, welche wiederum durch lokale Umweltfaktoren (unabhängig von der Methankonzentration) und den Transport von MOB zwischen benachbarten Ökosystemen beeinflusst werden. Im Elbeästuar hingegen werden die MOX-Raten neben den Methankonzentrationen größtenteils von der Salinität, die durch die Vermischung von Süß- und Salzwasser reguliert wird, bedingt. Die Ergebnisse dieser Arbeit zeigen auch, dass im Elbeästuar die Salinität, die durch die Vermischung von Süß- und Salzwasser reguliert wird, einen großen Einfluss auf die MOX-Raten hat. Das Ausmaß dieses Einflusses hängt dabei von der Populationsstruktur der MOB und der Geschwindigkeit des Salinitätswechsels ab. Zusammenfassend trägt die vorliegende Arbeit dazu bei, Zusammenhänge zwischen Methankonzentration, dem Prozess und Mikrobiom der aeroben Methanoxidation und bestimmten Umweltfaktoren wie beispielsweise der Salinität in aquatischen Systemen besser zu verstehen. Sie verdeutlicht außerdem, wie bedeutsam es ist, aquatische Ökosysteme in ihrer räumlichen Komplexität und nicht entkoppelt zu betrachten. KW - microbial methane oxidation KW - mikrobielle aerobe Methanoxidation KW - aquatic ecosystems KW - aquatischen Ökosystemen KW - Elbe estuary KW - Elbe Ästuar KW - Lena Delta KW - arktische Gewässer KW - arctic water bodies Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-96799 ER - TY - JOUR A1 - Siegmund, Jonatan F. A1 - Sanders, Tanja G. M. A1 - Heinrich, Ingo A1 - van der Maaten, Ernst A1 - Simard, Sonia A1 - Helle, Gerhard A1 - Donner, Reik Volker T1 - Meteorological Drivers of Extremes in Daily Stem Radius Variations of Beech, Oak, and Pine in Northeastern Germany: An Event Coincidence Analysis JF - Frontiers in plant science N2 - Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV) of three domestic tree species (beech, oak, and pine) from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA) to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions. KW - dendrometer measurements KW - event coincidence analysis KW - climate extremes KW - growth response Y1 - 2016 U6 - https://doi.org/10.3389/fpls.2016.00733 SN - 1664-462X VL - 7 SP - 4701 EP - 4712 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Siegmund, Jonatan Frederik A1 - Sanders, Tanja G. M. A1 - Heinrich, Ingo A1 - Maaten, Ernst van der A1 - Simard, Sonia A1 - Helle, Gerhard A1 - Donner, Reik Volker T1 - Meteorological drivers of extremes in daily stem radius variations of beech, oak, and pine in Northeastern Germany BT - an event coincidence analysis T2 - Frontiers in plant science N2 - Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV) of three domestic tree species (beech, oak, and pine) from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA) to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 456 KW - dendrometer measurements KW - event coincidence analysis KW - climate extremes KW - growth response Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407943 ER - TY - GEN A1 - Behrendt, Felix Nicolas A1 - Schlaad, Helmut T1 - Metathesis polymerization of cystine-based macrocycles N2 - Macrocycles based on L-cystine were synthesized by ring-closing metathesis (RCM) and subsequently polymerized by entropy-driven ring-opening metathesis polymerization (ED-ROMP). Monomer conversion reached ∼80% in equilibrium and the produced poly(ester-amine-disulfide-alkene)s exhibited apparent molar masses (Mappw) of up to 80 kDa and dispersities (Đ) of ∼2. The polymers can be further functionalized with acid anhydrides and degraded by reductive cleavage of the main-chain disulfide. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 329 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395080 ER - TY - JOUR A1 - Ligorio, G. A1 - Nardi, M. V. A1 - Steyrleuthner, Robert A1 - Ihiawakrim, D. A1 - Crespo-Monteiro, N. A1 - Brinkmann, Martin A1 - Neher, Dieter A1 - Koch, N. T1 - Metal nanoparticle mediated space charge and its optical control in an organic hole-only device JF - Applied physics letters N2 - We reveal the role of localized space charges in hole-only devices based on an organic semiconductor with embedded metal nanoparticles (MNPs). MNPs act as deep traps for holes and reduce the current density compared to a device without MNPs by a factor of 10(4) due to the build-up of localized space charge. Dynamic MNPs charged neutrality can be realized during operation by electron transfer from excitons created in the organic matrix, enabling light sensing independent of device bias. In contrast to the previous speculations, electrical bistability in such devices was not observed. (C) 2016 AIP Publishing LLC. Y1 - 2016 U6 - https://doi.org/10.1063/1.4945710 SN - 0003-6951 SN - 1077-3118 VL - 108 PB - American Institute of Physics CY - Melville ER - TY - GEN A1 - Errard, Audrey A1 - Ulrichs, Christian A1 - Kühne, Stefan A1 - Mewis, Inga A1 - Mishig, Narantuya A1 - Maul, Ronald A1 - Drungowski, Mario A1 - Parolin, Pia A1 - Schreiner, Monika A1 - Baldermann, Susanne T1 - Metabolite profiling reveals a specific response in tomato to predaceous Chrysoperla carnea larvae and herbivore(s)-predator interactions with the generalist pests Tetranychus urticae and Myzus persicae T2 - Frontiers in plant science N2 - The spider mite Tetranychus urticae Koch and the aphid Myzus persicae (Sulzer) both infest a number of economically significant crops, including tomato (Solanurn lycopersicum). Although used for decades to control pests, the impact of green lacewing larvae Chrysoperla carnea (Stephens) on plant biochemistry was not investigated. Here, we used profiling methods and targeted analyses to explore the impact of the predator and herbivore(s)-predator interactions on tomato biochemistry. Each pest and pest -predator combination induced a characteristic metabolite signature in the leaf and the fruit thus, the plant exhibited a systemic response. The treatments had a stronger impact on non-volatile metabolites including abscisic acid and amino acids in the leaves in comparison with the fruits. In contrast, the various biotic factors had a greater impact on the carotenoids in the fruits. We identified volatiles such as myrcene and alpha-terpinene which were induced by pest -predator interactions but not by single species, and we demonstrated the involvement of the phytohormone abscisic acid in tritrophic interactions for the first time. More importantly, C. carnea larvae alone impacted the plant metabolome, but the predator did not appear to elicit particular defense pathways on its own. Since the presence of both C. carnea larvae and pest individuals elicited volatiles which were shown to contribute to plant defense, C. carnea larvae could therefore contribute to the reduction of pest infestation, not only by its preying activity, but also by priming responses to generalist herbivores such as T urticae and M. persicae. On the other hand, the use of C. carnea larvae alone did not impact carotenoids thus, was not prejudicial to the fruit quality. The present piece of research highlights the specific impact of predator and tritrophic interactions with green lacewing larvae, spider mites, and aphids on different components of the tomato primary and secondary metabolism for the first time, and provides cues for further in-depth studies aiming to integrate entomological approaches and plant biochemistry. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 454 KW - carotenoids KW - plant volatiles KW - Chrysopidae KW - Solanaceae KW - multiple-pest infestation KW - tritrophic system KW - Twister TM KW - biological pest control Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407913 ER - TY - JOUR A1 - Errard, Audrey A1 - Ulrichs, Christian A1 - Kühne, Stefan A1 - Mewis, Inga A1 - Mishig, Narantuya A1 - Maul, Ronald A1 - Drungowski, Mario A1 - Parolin, Pia A1 - Schreiner, Monika A1 - Baldermann, Susanne T1 - Metabolite Profiling Reveals a Specific Response in Tomato to Predaceous Chrysoperla carnea Larvae and Herbivore(s)-Predator Interactions with the Generalist Pests Tetranychus urticae and Myzus persicae JF - Frontiers in plant science N2 - The spider mite Tetranychus urticae Koch and the aphid Myzus persicae (Sulzer) both infest a number of economically significant crops, including tomato (Solanurn lycopersicum). Although used for decades to control pests, the impact of green lacewing larvae Chrysoperla carnea (Stephens) on plant biochemistry was not investigated. Here, we used profiling methods and targeted analyses to explore the impact of the predator and herbivore(s)-predator interactions on tomato biochemistry. Each pest and pest -predator combination induced a characteristic metabolite signature in the leaf and the fruit thus, the plant exhibited a systemic response. The treatments had a stronger impact on non-volatile metabolites including abscisic acid and amino acids in the leaves in comparison with the fruits. In contrast, the various biotic factors had a greater impact on the carotenoids in the fruits. We identified volatiles such as myrcene and alpha-terpinene which were induced by pest -predator interactions but not by single species, and we demonstrated the involvement of the phytohormone abscisic acid in tritrophic interactions for the first time. More importantly, C. carnea larvae alone impacted the plant metabolome, but the predator did not appear to elicit particular defense pathways on its own. Since the presence of both C. carnea larvae and pest individuals elicited volatiles which were shown to contribute to plant defense, C. carnea larvae could therefore contribute to the reduction of pest infestation, not only by its preying activity, but also by priming responses to generalist herbivores such as T urticae and M. persicae. On the other hand, the use of C. carnea larvae alone did not impact carotenoids thus, was not prejudicial to the fruit quality. The present piece of research highlights the specific impact of predator and tritrophic interactions with green lacewing larvae, spider mites, and aphids on different components of the tomato primary and secondary metabolism for the first time, and provides cues for further in-depth studies aiming to integrate entomological approaches and plant biochemistry. KW - carotenoids KW - plant volatiles KW - Chrysopidae KW - Solanaceae KW - multiple-pest infestation KW - tritrophic system KW - Twister (TM) KW - biological pest control Y1 - 2016 U6 - https://doi.org/10.3389/fpls.2016.01256 SN - 1664-462X VL - 7 SP - 456 EP - + PB - Frontiers Research Foundation CY - Lausanne ER - TY - THES A1 - Markova, Mariya T1 - Metabolic and molecular effects of two different isocaloric high protein diets in subjects with type 2 diabetes T1 - Metabolische und molekulare Effekte zweier isokalorischer Hochproteindiäten unterschiedlicher Herkunft bei Probanden mit Typ-2-Diabetes N2 - Ernährung stellt ein wichtiger Faktor in der Prävention und Therapie von Typ-2-Diabetes dar. Frühere Studien haben gezeigt, dass Hochproteindiäten sowohl positive als auch negative Effekte auf den Metabolismus hervorrufen. Jedoch ist unklar, ob die Herkunft des Proteins dabei eine Rolle spielt. In der LeguAN-Studie wurden die Effekte von zwei unterschiedlichen Hochproteindiäten, entweder tierischer oder pflanzlicher Herkunft, bei Typ-2-Diabetes Patienten untersucht. Beide Diäten enthielten 30 EN% Proteine, 40 EN% Kohlenhydrate und 30 EN% Fette. Der Anteil an Ballaststoffen, der glykämischer Index und die Fettkomposition waren in beiden Diäten ähnlich. Die Proteinaufnahme war höher, während die Fettaufnahme niedriger im Vergleich zu den früheren Ernährungsgewohnheiten der Probanden war. Insgesamt führten beide Diätinterventionen zu einer Verbesserung der glykämischen Kontrolle, der Insulinsensitivität, des Leberfettgehalts und kardiovaskulärer Risikomarkern ohne wesentliche Unterschiede zwischen den Proteintypen. In beiden Interventionsgruppen wurden die nüchternen Glukosewerte zusammen mit Indizes von Insulinresistenz in einem unterschiedlichen Ausmaß, jedoch ohne signifikante Unterschiede zwischen beiden Diäten verbessert. Die Reduktion von HbA1c war ausgeprägter in der pflanzlichen Gruppe, während sich die Insulinsensitivität mehr in der tierischen Gruppe erhöhte. Die Hochproteindiäten hatten nur einen geringfügigen Einfluss auf den postprandialen Metabolismus. Dies zeigte sich durch eine leichte Verbesserung der Indizes für Insulinsekretion, -sensitivität und –degradation sowie der Werte der freien Fettsäuren. Mit Ausnahme des Einflusses auf die GIP-Sekretion riefen die tierische und die pflanzliche Testmahlzeit ähnliche metabolische und hormonelle Antworten, trotz unterschiedlicher Aminosäurenzusammensetzung. Die tierische Hochproteindiät führte zu einer selektiven Zunahme der fettfreien Masse und Abnahme der Fettmasse, was nicht signifikant unterschiedlich von der pflanzlichen Gruppe war. Darüber hinaus reduzierten die Hochproteindiäten den Leberfettgehalt um durchschnittlich 42%. Die Reduktion des Leberfettgehaltes ging mit einer Verminderung der Lipogenese, der Lipolyse und des freien Fettsäure Flux einher. Beide Interventionen induzierten einen moderaten Abfall von Leberenzymen im Blut. Die Reduktion des Leberfetts war mit einer verbesserten Glukosehomöostase und Insulinsensitivität assoziiert. Blutlipide sanken in allen Probanden, was eventuell auf die niedrigere Fettaufnahme zurückzuführen war. Weiterhin waren die Spiegel an Harnsäure und Inflammationsmarkern erniedrigt unabhängig von der Proteinquelle. Die Werte des systolischen und diastolischen Blutdrucks sanken nur in der pflanzlichen Gruppe, was auf eine potentielle Rolle von Arginin hinweist. Es wurden keine Hinweise auf eine beeinträchtigte Nierenfunktion durch die 6-wöchige Hochproteindiäten beobachtet unabhängig von der Herkunft der Proteine. Serumkreatinin war nur in der pflanzlichen Gruppe signifikant reduziert, was eventuell an dem geringen Kreatingehalt der pflanzlichen Nahrungsmittel liegen könnte. Jedoch sind längere Studien nötig, um die Sicherheit von Hochproteindiäten vollkommen aufklären zu können. Des Weiteren verursachte keine der Diäten eine Induktion des mTOR Signalwegs weder im Fettgewebe noch in Blutzellen. Die Verbesserung der Ganzkörper-Insulinsensitivität deutete auch auf keine Aktivierung von mTOR und keine Verschlechterung der Insulinsensitivität im Skeletmuskel hin. Ein nennenswerter Befund war die erhebliche Reduktion von FGF21, einem wichtigen Regulator metabolischer Prozesse, um ungefähr 50% bei beiden Proteinarten. Ob hepatischer ER-Stress, Ammoniumniveau oder die Makronährstoffpräferenz hinter dem paradoxen Ergebnis stehen, sollte weiter im Detail untersucht werden. Entgegen der anfänglichen Erwartung und der bisherigen Studienlage zeigte die pflanzlich-betonte Hochproteindiät keine klaren Vorteile gegenüber der tierischen Diät. Der ausgeprägte günstige Effekt des tierischen Proteins auf Insulinhomöostase trotz des hohen BCAA-Gehaltes war sicherlich unerwartet und deutet darauf hin, dass bei dem längeren Verzehr andere komplexe metabolische Adaptationen stattfinden. Einen weiteren Aspekt stellt der niedrigere Fettverzehr dar, der eventuell auch zu den Verbesserungen in beiden Gruppen beigetragen hat. Zusammenfassend lässt sich sagen, dass eine 6-wöchige Diät mit 30 EN% Proteinen (entweder pflanzlich oder tierisch), 40 EN% Kohlenhydraten und 30 EN% Fetten mit weniger gesättigten Fetten zu metabolischen Verbesserungen bei Typ-2-Diabetes Patienten unabhängig von Proteinherkunft führt. N2 - Dietary approaches contribute to the prevention and treatment of type 2 diabetes. High protein diets were shown to exert beneficial as well as adverse effects on metabolism. However, it is unclear whether the protein origin plays a role in these effects. The LeguAN study investigated in detail the effects of two high protein diets, either from plant or animal origin, in type 2 diabetic patients. Both diets contained 30 EN% protein, 40 EN% carbohydrates, and 30 EN% fat. Fiber content, glycemic index, and composition of dietary fats were similar in both diets. In comparison to previous dietary habits, the fat content was exchanged for protein, while the carbohydrate intake was not modified. Overall, both high protein diets led to improvements of glycemic control, insulin sensitivity, liver fat, and cardiovascular risk markers without remarkable differences between the protein types. Fasting glucose together with indices of insulin resistance were ameliorated by both interventions to varying extents but without significant differences between protein types. The decline of HbA1c was more pronounced in the plant protein group, whereby the improvement of insulin sensitivity in the animal protein group. The high protein intake had only slight influence on postprandial metabolism seen for free fatty acids and indices of insulin secretion, sensitivity and degradation. Except for GIP release, ingestion of animal and plant meals did not provoke differential metabolic and hormonal responses despite diverse circulating amino acid levels. The animal protein diets led to a selective increase of fat-free mass and decrease of total fat mass, which was not significantly different from the plant protein diet. Moreover, the high protein diets potently decreased liver fat content by 42% on average which was linked to significantly diminished lipogenesis, free fatty acids flux and lipolysis in adipose tissue. Moderate decline of circulating liver enzymes was induced by both interventions. The liver fat reduction was associated with improved glucose homeostasis and insulin sensitivity which underlines the protective effect of the diets. Blood lipid profile improved in all subjects and was probably related to the lower fat intake. Reductions in uric acid and markers of inflammation further argued for metabolic benefits of both high protein diets. Systolic and diastolic blood pressure declined only in the PP group pointing a possible role of arginine. Kidney function was not altered by high protein consumption over 6 weeks. The rapid decrease of serum creatinine in the PP group was noteworthy and should be further investigated. Protein type did not seem to play a role but long-term studies are warranted to fully elucidate safety of high protein regimen. Varying the source of dietary proteins did not affect the mTOR pathway in adipose tissue and blood cells under neither acute nor chronic settings. Enhancement of whole-body insulin sensitivity suggested also no alteration of mTOR and no impairment of insulin sensitivity in skeletal muscle. A remarkable outcome was the extensive reduction of FGF21, critical regulator of metabolic processes, by approximately 50% independently of protein type. Whether hepatic ER-stress, ammonia flux or rather macronutrient preferences is behind this paradoxical finding remains to be investigated in detail. Unlike initial expectations and previous reports plant protein based diet had no clear advantage over animal proteins. The pronounced beneficial effect of animal protein on insulin homeostasis despite high BCAA and methionine intake was certainly unexpected assuming more complex metabolic adaptations occurring upon prolonged consumption. In addition, the reduced fat intake may have also contributed to the overall improvements in both groups. Taking into account the above observed study results, a short-term diet containing 30 EN% protein (either from plant or animal origin), 40 EN% carbohydrates, and 30 EN% fat with lower SFA amount leads to metabolic improvements in diabetic patients, regardless of protein source. KW - type 2 diabetes KW - nutrition KW - protein KW - Typ-2-Diabetes KW - Ernährung KW - high protein diet Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394310 ER - TY - JOUR A1 - Sternagel, Jörg T1 - Merleau-Ponty and the Experience of the Creation JF - Philosophische Rundschau Y1 - 2016 SN - 0031-8159 SN - 1868-7261 VL - 63 SP - 143 EP - 159 PB - J. C. B. Mohr CY - Tübingen ER - TY - JOUR A1 - Scherer, Cedric A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Blaum, Niels T1 - Merging trait-based and individual-based modelling: An animal functional type approach to explore the responses of birds to climatic and land use changes in semi-arid African savannas JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Climate change and land use management practices are major drivers of biodiversity in terrestrial ecosystems. To understand and predict resulting changes in community structures, individual-based and spatially explicit population models are a useful tool but require detailed data sets for each species. More generic approaches are thus needed. Here we present a trait-based functional type approach to model savanna birds. The aim of our model is to explore the response of different bird functional types to modifications in habitat structure. The functional types are characterized by different traits, in particular body mass, which is related to life-history traits (reproduction and mortality) and spatial scales (home range area and dispersal ability), as well as the use of vegetation structures for foraging and nesting, which is related to habitat quality and suitability. We tested the performance of the functional types in artificial landscapes varying in shrub:grass ratio and clumping intensity of shrub patches. We found that an increase in shrub encroachment and a decrease in habitat quality caused by land use mismanagement and climate change endangered all simulated bird functional types. The strength of this effect was related to the preferred habitat. Furthermore, larger-bodied insectivores and omnivores were more prone to extinction due to shrub encroachment compared to small-bodied species. Insectivorous and omnivorous birds were more sensitive to clumping intensity of shrubs whereas herbivorous and carnivorous birds were most affected by a decreasing amount of grass cover. From an applied point of view, our findings emphasize that policies such as woody plant removal and a reduction in livestock stocking rates to prevent shrub encroachment should prioritize the enlargement of existing grassland patches. Overall, our results show that the combination of an individual-based modelling approach with carefully defined functional types can provide a powerful tool for exploring biodiversity responses to environmental changes. Furthermore, the increasing accumulation of worldwide data sets on species’ core and soft traits (surrogates to determine core traits indirectly) on one side and the refinement of conceptual frameworks for animal functional types on the other side will further improve functional type approaches which consider the sensitivities of multiple species to climate change, habitat loss, and fragmentation. KW - IBM KW - Functional types KW - Trait-based approach KW - Shrub encroachment KW - Birds Y1 - 2016 U6 - https://doi.org/10.1016/j.ecolmodel.2015.07.005 SN - 0304-3800 SN - 1872-7026 VL - 326 SP - 75 EP - 89 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hennicke, Robert A1 - Klimke, Romy A1 - Mürbe, Ulrike A1 - Nägeler, Pascal A1 - Nowrot, Karsten A1 - Ringkamp, Daniela A1 - Weiß, Norman A1 - Windoffer, Alexander T1 - MenschenRechtsMagazin : Informationen | Meinungen | Analysen T2 - MenschenRechtsMagazin N2 - Aus dem Inhalt: - Menschenrechte, Staatlichkeit und der symbolische Charakter von Menschenrechtsverletzungen - Schädliche traditionelle und kulturelle Praktiken im Menschenrechtsdiskurs seit CEDAW – Eine Annäherung an ein umstrittenes Konzept - Schutz von Menschenrechtsverteidigern - neuere Entwicklungen T3 - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen - 21.2016/1 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93427 SN - 1434-2820 VL - 21 IS - 1 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Ringkamp, Daniela T1 - Menschenrechte, Staatlichkeit und der symbolische Charakter von Menschenrechtsverletzungen JF - MenschenRechtsMagazin : Informationen | Meinungen | Analysen N2 - I. Einleitung II. Politische Menschenrechtskonzeptionen: Allgemeine Merkmale III. Moralische Menschenrechtsbegründungen: Allgemeine Merkmale IV. Der symbolische Gehalt von Menschenrechtsverletzungen: Eine Neuauslegung des official character V. Fazit Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95040 SN - 1434-2820 VL - 21 IS - 1 SP - 5 EP - 15 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Lyu, Xiaojing A1 - Schulze, Bert-Wolfgang T1 - Mellin Operators in the Edge Calculus JF - Complex analysis and operator theory N2 - A manifold M with smooth edge Y is locally near Y modelled on X-Delta x Omega for a cone X-Delta := ( (R) over bar (+) x X)/({0} x X) where Xis a smooth manifold and Omega subset of R-q an open set corresponding to a chart on Y. Compared with pseudo-differential algebras, based on other quantizations of edge-degenerate symbols, we extend the approach with Mellin representations on the r half-axis up to r = infinity, the conical exit of X-boolean AND = R+ x X (sic) (r, x) at infinity. The alternative description of the edge calculus is useful for pseudo-differential structures on manifolds with higher singularities. KW - Edge degenerate operators KW - Mellin and Green operators edge symbols Y1 - 2016 U6 - https://doi.org/10.1007/s11785-015-0511-6 SN - 1661-8254 SN - 1661-8262 VL - 10 SP - 965 EP - 1000 PB - Springer CY - Basel ER - TY - BOOK ED - Rosenberg, Peter ED - Schroeder, Christoph T1 - Mehrsprachigkeit als Ressource in der Schriftlichkeit T3 - DaZ-Forschung ; 10 N2 - Der Band fragt nach dem Vorteil, den die Kompetenz in einer Sprache (meist der Erstsprache) für den Erwerb einer anderen Sprache (meist der Zweitsprache) darstellt. Die These von der "Mehrsprachigkeit als Ressource" wird im Sinne eines positiven Transfers empirisch und in angewandter Perspektive fassbar gemacht. Der Fokus liegt dabei auf der Frage der Schriftlichkeit, die Textentwicklung und Texthabitualität mit einbezieht. Y1 - 2016 SN - 978-3-11-061066-6 PB - de Gruyter CY - Berlin ER - TY - JOUR A1 - Kleger, Heinz T1 - Mehrfachkrise und Populismus JF - WeltTrends : das außenpolitische Journal Y1 - 2016 VL - 24 IS - 113 SP - 42 EP - 44 PB - WeltTrends CY - Potsdam ER - TY - JOUR A1 - Niederer, Daniel A1 - Vogt, Lutz A1 - Wippert, Pia-Maria A1 - Puschmann, Anne-Katrin A1 - Pfeifer, Ann-Christin A1 - Schiltenwolf, Marcus A1 - Banzer, Winfried A1 - Mayer, Frank T1 - Medicine in spine exercise (MiSpEx) for nonspecific low back pain patients: study protocol for a multicentre, single-blind randomized controlled trial JF - Trials N2 - Background: Arising from the relevance of sensorimotor training in the therapy of nonspecific low back pain patients and from the value of individualized therapy, the present trial aims to test the feasibility and efficacy of individualized sensorimotor training interventions in patients suffering from nonspecific low back pain. Methods and study design: A multicentre, single-blind two-armed randomized controlled trial to evaluate the effects of a 12-week (3 weeks supervised centre-based and 9 weeks home-based) individualized sensorimotor exercise program is performed. The control group stays inactive during this period. Outcomes are pain, and pain-associated function as well as motor function in adults with nonspecific low back pain. Each participant is scheduled to five measurement dates: baseline (M1), following centre-based training (M2), following home-based training (M3) and at two follow-up time points 6 months (M4) and 12 months (M5) after M1. All investigations and the assessment of the primary and secondary outcomes are performed in a standardized order: questionnaires - clinical examination biomechanics (motor function). Subsequent statistical procedures are executed after the examination of underlying assumptions for parametric or rather non-parametric testing. Discussion: The results and practical relevance of the study will be of clinical and practical relevance not only for researchers and policy makers but also for the general population suffering from nonspecific low back pain. KW - Sensorimotor training KW - Motor control KW - Low back pain KW - Exercise KW - Functional capacity KW - Individualized intervention Y1 - 2016 U6 - https://doi.org/10.1186/s13063-016-1645-1 SN - 1745-6215 VL - 17 PB - BioMed Central CY - London ER - TY - GEN A1 - Niederer, Daniel A1 - Vogt, Lutz A1 - Wippert, Pia-Maria A1 - Puschmann, Anne-Katrin A1 - Pfeifer, Ann-Christin A1 - Schiltenwolf, Marcus A1 - Banzer, Winfried A1 - Mayer, Frank T1 - Medicine in spine exercise (MiSpEx) for nonspecific low back pain patients BT - study protocol for a multicentre, single-blind randomized controlled trial T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background: Arising from the relevance of sensorimotor training in the therapy of nonspecific low back pain patients and from the value of individualized therapy, the present trial aims to test the feasibility and efficacy of individualized sensorimotor training interventions in patients suffering from nonspecific low back pain. Methods and study design: A multicentre, single-blind two-armed randomized controlled trial to evaluate the effects of a 12-week (3 weeks supervised centre-based and 9 weeks home-based) individualized sensorimotor exercise program is performed. The control group stays inactive during this period. Outcomes are pain, and pain-associated function as well as motor function in adults with nonspecific low back pain. Each participant is scheduled to five measurement dates: baseline (M1), following centre-based training (M2), following home-based training (M3) and at two follow-up time points 6 months (M4) and 12 months (M5) after M1. All investigations and the assessment of the primary and secondary outcomes are performed in a standardized order: questionnaires – clinical examination – biomechanics (motor function). Subsequent statistical procedures are executed after the examination of underlying assumptions for parametric or rather non-parametric testing. Discussion: The results and practical relevance of the study will be of clinical and practical relevance not only for researchers and policy makers but also for the general population suffering from nonspecific low back pain. Trial registration: Identification number DRKS00010129. German Clinical Trial registered on 3 March 2016. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 444 KW - sensorimotor training KW - motor control KW - exercise KW - low back painExercise KW - functional capacity KW - individualized intervention Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407308 IS - 444 ER - TY - JOUR A1 - Hassan, Rabeay Y. A. A1 - Wollenberger, Ursula T1 - Mediated bioelectrochemical system for biosensing the cell viability of Staphylococcus aureus JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry and Analusis N2 - Staphylococcus aureus is one of the most dangerous human pathogens and is the cause of numerous illnesses ranging from moderate skin infections to life-threatening diseases. Despite advances made in identifying microorganisms, rapid detection methods for the viability of bacteria are still missing. Here, we report a rapid electrochemical assay for cell viability combining the use of double redox mediators and multiwall carbon nanotubes-screen printed electrodes (MWCNTs-SPE), ferricyanide (FCN) and 2,6-dichlorophenolindophenol (DCIP), which served as electron shuttle to enable the bacterial-electrode communications. The current originating from the metabolically active cells was recorded for probing the activity of the intracellular redox centers. Blocking of the respiratory chain pathways with electron transfer inhibitors demonstrated the involvement of the electron transport chain in the reaction. A good correlation between the number of the metabolically active cells and the current was obtained. The proposed assay has been exploited for monitoring cell proliferation of S. aureus during the growth. The sensitivity of the detection method reached 0.1 OD600. Therefore, the technique described is promising for estimating the cell number, measuring the cell viability, and probing intracellular redox center(s). KW - Microbial electrochemistry KW - Pathogenic detection KW - Probing living Staphylococcus aureus KW - CNTs-based screen printed electrodes Y1 - 2016 U6 - https://doi.org/10.1007/s00216-015-9134-z SN - 1618-2642 SN - 1618-2650 VL - 408 SP - 579 EP - 587 PB - Springer CY - Heidelberg ER - TY - GEN A1 - Guardado-Calvo, Pablo A1 - Bignon, Eduardo A. A1 - Stettner, Eva A1 - Jeffers, Scott Allen A1 - Pérez-Vargas, Jimena A1 - Pehau-Arnaudet, Gerard A1 - Tortorici, M. Alejandra A1 - Jestin, Jean- Luc A1 - England, Patrick A1 - Tischler, Nicole D. A1 - Rey, Félix A. T1 - Mechanistic insight into bunyavirus-induced membrane fusion from structure-function analyses of the hantavirus envelope glycoprotein Gc T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic beta-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha-and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 676 KW - Semliki-forest-virus KW - Borne encephalitis-virus KW - N-linked glycosylation KW - human dendritic cells KW - Valley fever virus KW - Hantaan-virus KW - Hemorrhagic-fever KW - crystal-structure KW - electron crytomography KW - pulmonary syndrome Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-411599 SN - 1866-8372 IS - 676 ER - TY - JOUR A1 - Guardado-Calvo, Pablo A1 - Bignon, Eduardo A. A1 - Stettner, Eva A1 - Jeffers, Scott Allen A1 - Perez-Vargas, Jimena A1 - Pehau-Arnaudet, Gerard A1 - Tortoric, M. Alejandra A1 - Jestin, Jean-Luc A1 - England, Patrick A1 - Tischler, Nicole D. A1 - Rey, Felix A. T1 - Mechanistic Insight into Bunyavirus-Induced Membrane Fusion from Structure-Function Analyses of the Hantavirus Envelope Glycoprotein Gc JF - PLoS Pathogens N2 - Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic beta-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha-and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens. Y1 - 2016 U6 - https://doi.org/10.1371/journal.ppat.1005813 SN - 1553-7366 SN - 1553-7374 VL - 12 SP - 153 EP - 166 PB - PLoS CY - San Fransisco ER - TY - GEN A1 - Tomov, Petar A1 - Pena, Rodrigo F. O. A1 - Roque, Antonio C. A1 - Zaks, Michael A. T1 - Mechanisms of self-sustained oscillatory states in hierarchical modular networks with mixtures of electrophysiological cell types T2 - Frontiers in computational neuroscience N2 - In a network with a mixture of different electrophysiological types of neurons linked by excitatory and inhibitory connections, temporal evolution leads through repeated epochs of intensive global activity separated by intervals with low activity level. This behavior mimics "up" and "down" states, experimentally observed in cortical tissues in absence of external stimuli. We interpret global dynamical features in terms of individual dynamics of the neurons. In particular, we observe that the crucial role both in interruption and in resumption of global activity is played by distributions of the membrane recovery variable within the network. We also demonstrate that the behavior of neurons is more influenced by their presynaptic environment in the network than by their formal types, assigned in accordance with their response to constant current. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 452 KW - self-sustained activity KW - cortical oscillations KW - irregular firing activity KW - hierarchical modular networks KW - cortical network models KW - intrinsic neuronal diversity KW - up-down states KW - chaotic neural dynamics Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407724 ER - TY - JOUR A1 - Tomov, Peter A1 - Pena, Rodrigo F. O. A1 - Roque, Antonio C. A1 - Zaks, Michael A. T1 - Mechanisms of Self-Sustained Oscillatory States in Hierarchical Modular Networks with Mixtures of Electrophysiological Cell Types JF - Frontiers in computational neuroscience / Frontiers Research Foundation N2 - In a network with a mixture of different electrophysiological types of neurons linked by excitatory and inhibitory connections, temporal evolution leads through repeated epochs of intensive global activity separated by intervals with low activity level. This behavior mimics "up" and "down" states, experimentally observed in cortical tissues in absence of external stimuli. We interpret global dynamical features in terms of individual dynamics of the neurons. In particular, we observe that the crucial role both in interruption and in resumption of global activity is played by distributions of the membrane recovery variable within the network. We also demonstrate that the behavior of neurons is more influenced by their presynaptic environment in the network than by their formal types, assigned in accordance with their response to constant current. KW - self-sustained activity KW - cortical oscillations KW - irregular firing activity KW - hierarchical modular networks KW - cortical network models KW - intrinsic neuronal diversity KW - up-down states KW - chaotic neural dynamics Y1 - 2016 U6 - https://doi.org/10.3389/fncom.2016.00023 SN - 1662-5188 VL - 10 SP - 476 EP - + PB - Frontiers Research Foundation CY - Lausanne ER - TY - THES A1 - Gomez, David T1 - Mechanisms of biochemical reactions within crowded environments T1 - Mechanismus der Biochemische Reaktionen im vollgestopfte Umgebungen N2 - The cell interior is a highly packed environment in which biological macromolecules evolve and function. This crowded media has effects in many biological processes such as protein-protein binding, gene regulation, and protein folding. Thus, biochemical reactions that take place in such crowded conditions differ from diluted test tube conditions, and a considerable effort has been invested in order to understand such differences. In this work, we combine different computationally tools to disentangle the effects of molecular crowding on biochemical processes. First, we propose a lattice model to study the implications of molecular crowding on enzymatic reactions. We provide a detailed picture of how crowding affects binding and unbinding events and how the separate effects of crowding on binding equilibrium act together. Then, we implement a lattice model to study the effects of molecular crowding on facilitated diffusion. We find that obstacles on the DNA impair facilitated diffusion. However, the extent of this effect depends on how dynamic obstacles are on the DNA. For the scenario in which crowders are only present in the bulk solution, we find that at some conditions presence of crowding agents can enhance specific-DNA binding. Finally, we make use of structure-based techniques to look at the impact of the presence of crowders on the folding a protein. We find that polymeric crowders have stronger effects on protein stability than spherical crowders. The strength of this effect increases as the polymeric crowders become longer. The methods we propose here are general and can also be applied to more complicated systems. N2 - Innerhalb einer Zelle, im Zytosol, entstehen und arbeiten sehr viele biologische Makromoleküle. Die Dichte dieser Moleküle ist sehr hoch und dieses ‘vollgestopfte’ Zytosol hat vielfältige Auswirkungen auf viele biologische Prozessen wie zum Beispiel Protein-Protein Interaktionen, Genregulation oder die Faltung von Proteinen. Der Ablauf von vielen biochemische Reaktionen in dieser Umgebung weicht von denen unter verdünnte Laborbedingungen ab. Um die Effekte dieses ‘makromolekularen Crowdings’ zu verstehen, wurde in den letzten Jahren bereits viel Mühe investiert. In dieser Arbeit kombinieren wir verschiede Computermethoden, um die Wirkungen des ‘makromolekularen Crowdings’ auf biologische Prozesse besser zu verstehen. Zuerst schlagen wir ein Gittermodell vor, um damit die Effekte des ‘makromolekularen Crowdings’ auf enzymatische Reaktionen zu studieren. Damit stellen wir ein detailliertes Bild zusammen, wie Crowding die Assoziations- und Dissozotationsraten beeinflusst und wie verschiedene crowding-Effekte zusammen auf die Gleichgewichtskonstante wirken. Weiterhin implementieren wir ein Gittermodell der ‘erleichterte Diffusion’. Unsere Ergebnisse zeigen, dass Hindernisse an der DNA die vereinfachte Diffusion beeinträchtigen. Das Ausmass dieser Wirkung hängt dabei von der Dynamik der Hindernisse an der DNA ab. Im dem Fall dass Crowder ausschließlich in der Lösung vorhanden sind, erhöhen sich unter bestimmten Bedingungen DNA-spezifische Bindungen. Schließlich nutzten wir strukturbasierte Techniken um damit die Auswirkungen von Crowding auf die Faltung von Proteinen zu untersuchen. Wir fanden dabei, dass Polymer Crowder stärkere Wirkungen auf die Proteinstabilität haben als kugelförmige Crowder. Dieser Effekt verstärkte sich mit der Länge der untersuchten Polymere. Die Methoden die hier vorgeschlagen werden, sind generell anwendbar und können auch an deutlich komplexeren Systemen angewandt werden. KW - molecular crowding KW - gene expression KW - enzymatic activity KW - protein folding KW - Molecular crowding KW - enzymatische Reaktionen KW - Genregulation KW - Faltung von Proteinen Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94593 ER - TY - JOUR A1 - Zhou, Qihui A1 - Wuennemann, Patrick A1 - Kuhn, Philipp Till A1 - de Vries, Joop A1 - Helmin, Marta A1 - Böker, Alexander A1 - van Kooten, Theo G. A1 - van Rijn, Patrick T1 - Mechanical Properties of Aligned Nanotopologies for Directing Cellular Behavior JF - Advanced materials interfaces N2 - Tailoring cell–surface interactions is important for the of design medical implants as well as regenerative medicine and tissue engineering materials. Here the single parameter system is transcended via translating hard nanotopology into soft polymeric hydrogel structures via hydrogel imprinting lithography. The response of these cells to the nanotopology of the same dimensions but with different mechanical properties displays unexpected behavior between “hard” tissue cells and “soft” tissue cells. Y1 - 2016 U6 - https://doi.org/10.1002/admi.201600275 SN - 2196-7350 VL - 3 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Gimenez-Garcia, Ana A1 - Shenar, Tomer A1 - Torrejon, J. M. A1 - Oskinova, Lidia M. A1 - Martinez-Nunez, S. A1 - Hamann, Wolf-Rainer A1 - Rodes-Roca, J. J. A1 - González-Galan, A. A1 - Alonso-Santiago, J. A1 - González-Fernández, C. A1 - Bernabeu, Guillermo A1 - Sander, Andreas Alexander Christoph T1 - Measuring the stellar wind parameters in IGR J17544-2619 and Vela X-1 constrains the accretion physics in supergiant fast X-ray transient and classical supergiant X-ray binaries JF - Siberian Mathematical Journal N2 - Aims. To close this gap, we perform a comparative analysis of the optical companion in two important systems: IGR J175442619 (SFXT) and Vela X-1 (SGXB). We analyze the spectra of each star in detail and derive their stellar and wind properties. As a next step, we compare the wind parameters, giving us an excellent chance of recognizing key differences between donor winds in SFXTs and SGXBs. Methods. We use archival infrared, optical and ultraviolet observations, and analyze them with the non-local thermodynamic equilibrium (NLTE) Potsdam Wolf-Rayet model atmosphere code. We derive the physical properties of the stars and their stellar winds, accounting for the influence of X-rays on the stellar winds. Results. We find that the stellar parameters derived from the analysis generally agree well with the spectral types of the two donors: O9I (IGR J17544-2619) and B0.5Iae (Vela X-1). The distance to the sources have been revised and also agree well with the estimations already available in the literature. In IGR J17544-2619 we are able to narrow the uncertainty to d = 3.0 +/- 0.2 kpc. From the stellar radius of the donor and its X-ray behavior, the eccentricity of IGR J17544-2619 is constrained to e < 0.25. The derived chemical abundances point to certain mixing during the lifetime of the donors. An important difference between the stellar winds of the two stars is their terminal velocities (v(infinity) = 1500 km s(-1) in IGR J17544-2619 and v(infinity) = 700 km s(-1) in Vela X-1), which have important consequences on the X-ray luminosity of these sources. Conclusions. The donors of IGR J17544-2619 and Vela X-1 have similar spectral types as well as similar parameters that physically characterize them and their spectra. In addition, the orbital parameters of the systems are similar too, with a nearly circular orbit and short orbital period. However, they show moderate differences in their stellar wind velocity and the spin period of their neutron star which has a strong impact on the X-ray luminosity of the sources. This specific combination of wind speed and pulsar spin favors an accretion regime with a persistently high luminosity in Vela X-1, while it favors an inhibiting accretion mechanism in IGR J17544-2619. Our study demonstrates that the relative wind velocity is critical in class determination for the HMXBs hosting a supergiant donor, given that it may shift the accretion mechanism from direct accretion to propeller regimes when combined with other parameters. KW - accretion, accretion disks KW - methods: observational KW - techniques: spectroscopic KW - stars: atmospheres KW - X-rays: binaries KW - stars: winds, outflows Y1 - 2016 U6 - https://doi.org/10.1051/0004-6361/201527551 SN - 1432-0746 VL - 591 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Fischer, Martin H. A1 - Shaki, Samuel T1 - Measuring spatial-numerical associations: evidence for a purely conceptual link JF - Psychological research : an international journal of perception, attention, memory, and action N2 - Previous work on spatial-numerical association (SNAs) included either spatially distributed stimuli or responses. This raises the possibility that the inferred spatial nature of number concepts was a methodological artifact. We present results from a novel task that involves two categories (spatially oriented objects and number magnitudes) and dissociates spatial classification from number classification. The results reveal SNAs without inferential limitations of previous work and point to a working memory mechanism that transfers spatial coding across categories. Y1 - 2016 U6 - https://doi.org/10.1007/s00426-015-0646-0 SN - 0340-0727 SN - 1430-2772 VL - 80 SP - 109 EP - 112 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Liu, Bing A1 - Böker, Alexander T1 - Measuring rotational diffusion of colloidal spheres with confocal microscopy JF - Soft matter N2 - We report an experimental method to measure the translational and rotational dynamics of colloidal spheres in three dimensions with confocal microscopy and show that the experimental values reasonably agree with the theoretical values. This method can be extended to study rotational dynamics in concentrated colloidal systems and complex bio-systems. Y1 - 2016 U6 - https://doi.org/10.1039/c6sm01082b SN - 1744-683X SN - 1744-6848 VL - 12 SP - 6033 EP - 6037 PB - Royal Society of Chemistry CY - Cambridge ER - TY - THES A1 - Tamasi, Katalin T1 - Measuring children’s sensitivity to phonological detail using eye tracking and pupillometry T1 - Untersuchung der Sensitivität von Kleinkindern für phonologische Details mit Hilfe von Eye-Tracking und Pupillometrie N2 - Infants' lexical processing is modulated by featural manipulations made to words, suggesting that early lexical representations are sufficiently specified to establish a match with the corresponding label. However, the precise degree of detail in early words requires further investigation due to equivocal findings. We studied this question by assessing children’s sensitivity to the degree of featural manipulation (Chapters 2 and 3), and sensitivity to the featural makeup of homorganic and heterorganic consonant clusters (Chapter 4). Gradient sensitivity on the one hand and sensitivity to homorganicity on the other hand would suggest that lexical processing makes use of sub-phonemic information, which in turn would indicate that early words contain sub-phonemic detail. The studies presented in this thesis assess children’s sensitivity to sub-phonemic detail using minimally demanding online paradigms suitable for infants: single-picture pupillometry and intermodal preferential looking. Such paradigms have the potential to uncover lexical knowledge that may be masked otherwise due to cognitive limitations. The study reported in Chapter 2 obtained a differential response in pupil dilation to the degree of featural manipulation, a result consistent with gradient sensitivity. The study reported in Chapter 3 obtained a differential response in proportion of looking time and pupil dilation to the degree of featural manipulation, a result again consistent with gradient sensitivity. The study reported in Chapter 4 obtained a differential response to the manipulation of homorganic and heterorganic consonant clusters, a result consistent with sensitivity to homorganicity. These results suggest that infants' lexical representations are not only specific, but also detailed to the extent that they contain sub-phonemic information. N2 - Die lexikalische Verarbeitung bei Kleinkindern kann durch die Manipulation von phonologischen Merkmalen moduliert werden. Dies deutet darauf hin, dass frühe lexikalische Repräsentationen hinreichend spezifiziert sind, um einen Abgleich mit einem gehörten Wort herzustellen. Aufgrund von nicht einheitlichen Befunden ist jedoch weitere Forschung notwendig, um zu bestimmen, wie detailliert erste Wörter repräsentiert werden. Dieser Frage wurde nachgegangen, indem die Sensitivität der Kinder gegenüber dem Grad der Merkmalmanipulation (Kapitel 2 und 3) und gegenüber homorganischen und heterorganischen Konsonantenclustern (Kapitel 4) untersucht wurde. Eine gradiente Sensitivität gegenüber der Manipulation phonologischer Merkmale und eine Sensitivität gegenüber der Homorganizität deuten darauf hin, dass Gradientenempfindlichkeit auf der einen Seite und die Empfindlichkeit gegenüber der für die lexikalische Verarbeitung subphonemische Informationen relevant sind, was wiederum darauf schließen lässt, dass lexikalische Repräsentationen subphonemische Details enthalten. Die Studien, die in dieser Arbeit vorgestellt werden, untersuchen die Sensitivität von 30 Monate alten Kindern für subphonemische Details mit Online-Paradigmen, die für Kleinkinder geeignet sind: Einzelbild-Pupillometrie und "intermodal preferential looking". Diese Paradigmen haben das Potenzial, lexikalisches Wissen aufzudecken, das sonst aufgrund kognitiver Beanspruchungen verdeckt bleibt. Die in Kapitel 2 berichtete Studie zeigt eine differenzielle Reaktion in der Pupillendilatation in Verbindung mit dem Grad der Merkmalsmanipulation, ein Ergebnis, das die Sensitivität gegenüber der Gradienz der phonologischen Distanz nahelegt. Die Studie in Kapitel 3 zeigt eine differenzielle Reaktion sowohl in der Pupillendilatation auch in den Blickzeiten in Abhängigkeit vom Grad der phonologischen Merkmalmanipulation, ein Ergebnis das das der Studie 2 unterstützt. Die in Kapitel 4 berichtete Studie zeigt Unterschiede in der Pupillendilation nur in Reaktion auf eine phonologische Manipulation der homorganischen nicht aber der heterorganischen Konsonantencluster. Dieses Ergebnis stützt die Annahme, einer frühen Sensitivität gegenüber Homorganizität. Diese Ergebnisse deuten darauf hin, dass die lexikalischen Repräsentationen von Kleinkindern nicht nur spezifisch, sondern auch detailliert sind, da sie subphonemische Informationen enthalten. KW - phonological development KW - consonant clusters KW - mispronunciation detection KW - pupillometry KW - eye tracking KW - phonologische Entwicklung KW - Konsonantencluster KW - mispronunciation detection KW - Pupillometrie KW - Eye-Tracking Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395954 ER - TY - JOUR A1 - ´Cwiek-Kupczynska, Hanna A1 - Altmann, Thomas A1 - Arend, Daniel A1 - Arnaud, Elizabeth A1 - Chen, Dijun A1 - Cornut, Guillaume A1 - Fiorani, Fabio A1 - Frohmberg, Wojciech A1 - Junker, Astrid A1 - Klukas, Christian A1 - Lange, Matthias A1 - Mazurek, Cezary A1 - Nafissi, Anahita A1 - Neveu, Pascal A1 - van Oeveren, Jan A1 - Pommier, Cyril A1 - Poorter, Hendrik A1 - Rocca-Serra, Philippe A1 - Sansone, Susanna-Assunta A1 - Scholz, Uwe A1 - van Schriek, Marco A1 - Seren, Ümit A1 - Usadel, Bjorn A1 - Weise, Stephan A1 - Kersey, Paul A1 - Krajewski, Pawel T1 - Measures for interoperability of phenotypic data: minimum information requirements and formatting JF - Plant Methods N2 - Background: Plant phenotypic data shrouds a wealth of information which, when accurately analysed and linked to other data types, brings to light the knowledge about the mechanisms of life. As phenotyping is a field of research comprising manifold, diverse and time-consuming experiments, the findings can be fostered by reusing and combining existing datasets. Their correct interpretation, and thus replicability, comparability and interoperability, is possible provided that the collected observations are equipped with an adequate set of metadata. So far there have been no common standards governing phenotypic data description, which hampered data exchange and reuse. Results: In this paper we propose the guidelines for proper handling of the information about plant phenotyping experiments, in terms of both the recommended content of the description and its formatting. We provide a document called "Minimum Information About a Plant Phenotyping Experiment", which specifies what information about each experiment should be given, and a Phenotyping Configuration for the ISA-Tab format, which allows to practically organise this information within a dataset. We provide examples of ISA-Tab-formatted phenotypic data, and a general description of a few systems where the recommendations have been implemented. Conclusions: Acceptance of the rules described in this paper by the plant phenotyping community will help to achieve findable, accessible, interoperable and reusable data. KW - Data standardisation and formatting KW - Experimental metadata KW - Minimum information recommendations KW - Plant phenotyping KW - Experiment description Y1 - 2016 U6 - https://doi.org/10.1186/s13007-016-0144-4 SN - 1746-4811 VL - 12 PB - BioMed Central CY - London ER - TY - GEN A1 - Ćwiek-Kupczyńska, Hanna A1 - Altmann, Thomas A1 - Arend, Daniel A1 - Arnaud, Elizabeth A1 - Chen, Dijun A1 - Cornut, Guillaume A1 - Fiorani, Fabio A1 - Frohmberg, Wojciech A1 - Junker, Astrid A1 - Klukas, Christian A1 - Lange, Matthias A1 - Mazurek, Cezary A1 - Nafissi, Anahita A1 - Neveu, Pascal A1 - van Oeveren, Jan A1 - Pommier, Cyril A1 - Poorter, Hendrik A1 - Rocca-Serra, Philippe A1 - Sansone, Susanna-Assunta A1 - Scholz, Uwe A1 - van Schriek, Marco A1 - Seren, Ümit A1 - Usadel, Björn A1 - Weise, Stephan A1 - Kersey, Paul A1 - Krajewski, Paweł T1 - Measures for interoperability of phenotypic data BT - minimum information requirements and formatting T2 - Plant methods N2 - Background: Plant phenotypic data shrouds a wealth of information which, when accurately analysed and linked to other data types, brings to light the knowledge about the mechanisms of life. As phenotyping is a field of research comprising manifold, diverse and time ‑consuming experiments, the findings can be fostered by reusing and combin‑ ing existing datasets. Their correct interpretation, and thus replicability, comparability and interoperability, is possible provided that the collected observations are equipped with an adequate set of metadata. So far there have been no common standards governing phenotypic data description, which hampered data exchange and reuse. Results: In this paper we propose the guidelines for proper handling of the information about plant phenotyping experiments, in terms of both the recommended content of the description and its formatting. We provide a docu‑ ment called “Minimum Information About a Plant Phenotyping Experiment”, which specifies what information about each experiment should be given, and a Phenotyping Configuration for the ISA ‑Tab format, which allows to practically organise this information within a dataset. We provide examples of ISA ‑Tab ‑formatted phenotypic data, and a general description of a few systems where the recommendations have been implemented. Conclusions: Acceptance of the rules described in this paper by the plant phenotyping community will help to achieve findable, accessible, interoperable and reusable data. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 450 KW - data standardisation and formatting KW - experimental metadata KW - minimum information recommendations KW - plant phenotyping KW - experiment description Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407299 ER - TY - JOUR A1 - Waldrip, S. H. A1 - Niven, R. K. A1 - Abel, Markus A1 - Schlegel, M. T1 - Maximum Entropy Analysis of Hydraulic Pipe Flow Networks JF - Journal of hydraulic engineering KW - Maximum entropy method KW - Water distribution systems KW - Hydraulic networks KW - Pipe networks KW - Hydraulic models KW - Non-linear analysis KW - Probability Y1 - 2016 U6 - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001126 SN - 0733-9429 SN - 1943-7900 VL - 142 SP - 332 EP - 347 PB - American Society of Civil Engineers CY - Reston ER - TY - JOUR A1 - Böhne, Sebastian A1 - Kreitz, Christoph A1 - Knobelsdorf, Maria T1 - Mathematisches Argumentieren und Beweisen mit dem Theorembeweiser Coq JF - Commentarii informaticae didacticae (CID) N2 - Informatik-Studierende haben in der Mehrzahl Schwierigkeiten, einen Einstieg in die Theoretische Informatik zu finden und die Leistungsanforderungen in den Endklausuren der zugehörigen Lehrveranstaltungen zu erfüllen. Wir argumentieren, dass dieser Symptomatik mangelnde Kompetenzen im Umgang mit abstrakten und stark formalisierten Themeninhalten zugrunde liegen und schlagen vor, einen Beweisassistenten als interaktives Lernwerkzeug in der Eingangslehre der Theoretischen Informatik zu nutzen, um entsprechende Kompetenzen zu stärken. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94824 SN - 978-3-86956-376-3 SN - 1868-0844 SN - 2191-1940 IS - 10 SP - 69 EP - 80 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Gopalakrishnan, Sathej T1 - Mathematical modelling of host-disease-drug interactions in HIV disease T1 - Mathematische Modellierung von Pathogen-Wirkstoff-Wirt-Interaktionen im Kontext der HIV Erkrankung N2 - The human immunodeficiency virus (HIV) has resisted nearly three decades of efforts targeting a cure. Sustained suppression of the virus has remained a challenge, mainly due to the remarkable evolutionary adaptation that the virus exhibits by the accumulation of drug-resistant mutations in its genome. Current therapeutic strategies aim at achieving and maintaining a low viral burden and typically involve multiple drugs. The choice of optimal combinations of these drugs is crucial, particularly in the background of treatment failure having occurred previously with certain other drugs. An understanding of the dynamics of viral mutant genotypes aids in the assessment of treatment failure with a certain drug combination, and exploring potential salvage treatment regimens. Mathematical models of viral dynamics have proved invaluable in understanding the viral life cycle and the impact of antiretroviral drugs. However, such models typically use simplified and coarse-grained mutation schemes, that curbs the extent of their application to drug-specific clinical mutation data, in order to assess potential next-line therapies. Statistical models of mutation accumulation have served well in dissecting mechanisms of resistance evolution by reconstructing mutation pathways under different drug-environments. While these models perform well in predicting treatment outcomes by statistical learning, they do not incorporate drug effect mechanistically. Additionally, due to an inherent lack of temporal features in such models, they are less informative on aspects such as predicting mutational abundance at treatment failure. This limits their application in analyzing the pharmacology of antiretroviral drugs, in particular, time-dependent characteristics of HIV therapy such as pharmacokinetics and pharmacodynamics, and also in understanding the impact of drug efficacy on mutation dynamics. In this thesis, we develop an integrated model of in vivo viral dynamics incorporating drug-specific mutation schemes learned from clinical data. Our combined modelling approach enables us to study the dynamics of different mutant genotypes and assess mutational abundance at virological failure. As an application of our model, we estimate in vivo fitness characteristics of viral mutants under different drug environments. Our approach also extends naturally to multiple-drug therapies. Further, we demonstrate the versatility of our model by showing how it can be modified to incorporate recently elucidated mechanisms of drug action including molecules that target host factors. Additionally, we address another important aspect in the clinical management of HIV disease, namely drug pharmacokinetics. It is clear that time-dependent changes in in vivo drug concentration could have an impact on the antiviral effect, and also influence decisions on dosing intervals. We present a framework that provides an integrated understanding of key characteristics of multiple-dosing regimens including drug accumulation ratios and half-lifes, and then explore the impact of drug pharmacokinetics on viral suppression. Finally, parameter identifiability in such nonlinear models of viral dynamics is always a concern, and we investigate techniques that alleviate this issue in our setting. N2 - Das Humane Immundefiecienz-Virus (HIV) widerstanden hat fast drei Jahrzehnten eff Orts targeting eine Heilung. Eine anhaltende Unterdrückung des Virus hat noch eine Herausforderung, vor allem aufgrund der bemerkenswerten evolutionären Anpassung, dass das Virus Exponate durch die Ansammlung von Medikamenten-resistenten Mutationen in seinem Genom. Aktuelle therapeutische Strategien zielen auf das Erreichen und die Erhaltung einer niedrigen virale Belastung und umfassen in der Regel mehrere Medikamente. Die Wahl der optimalen Kombinationen dieser Medikamente ist von entscheidender Bedeutung, besonders im Hintergrund der Behandlung Fehler eingetreten, die zuvor mit bestimmten anderen Medikamenten. Ein Verständnis für die Dynamik der viralen mutierten Genotypen Aids in die Bewertung der Behandlung Fehler mit einer bestimmten Kombination und der Erkundung potenzieller Bergung Behandlungsschemata. Mathematische Modelle für virale Dynamik haben sich als unschätzbar erwiesen hat im Verständnis der viralen Lebenszyklus und die Auswirkungen von antiretroviralen Medikamenten. Allerdings sind solche Modelle verwenden in der Regel simplified und grobkörnigen Mutation Regelungen, dass Aufkantungen den Umfang ihrer Anwendung auf Arzneimittel-ganz speziellec Mutation klinische Daten, um zu beurteilen, mögliche nächste-line Therapien. Statistische Modelle der Mutation Anhäufung gedient haben gut in präparieren Mechanismen der Resistenz Evolution durch Mutation Rekonstruktion Pathways unter verschiedenen Medikamenten-Umgebungen. Während diese Modelle führen gut in der Vorhersage der Ergebnisse der Behandlung durch statistische lernen, sie enthalten keine Droge E ffect mechanistisch. Darüber hinaus aufgrund einer innewohnenden Mangel an zeitlichen Funktionen in solchen Modellen, sie sind weniger informativ auf Aspekte wie die Vorhersage mutational Fülle an Versagen der Behandlung. Dies schränkt die Anwendung in der Analyse der Pharmakologie von antiretroviralen Medikamenten, insbesondere, Zeit-abhängige Merkmale der HIV-Therapie wie Pharmakokinetik und Pharmakodynamik, und auch in dem Verständnis der Auswirkungen von Drogen e fficacy auf Mutation Dynamik. In dieser Arbeit, die wir bei der Entwicklung eines integrierten Modells von In-vivo-virale Dynamik Einbeziehung drug-ganz speziellec Mutation Systeme gelernt aus den klinischen Daten. Unsere kombinierten Modellansatz ermöglicht uns die Untersuchung der Dynamik von diff schiedene mutierten Genotypen und bewerten mutational Fülle an virologischem Versagen. Als Anwendung unseres Modells schätzen wir In-vivo-fitness Merkmale der viralen Mutanten unter di fferent drug Umgebungen. Unser Ansatz erstreckt sich auch natürlich auf mehrere-Therapien. Weitere zeigen wir die Vielseitigkeit unseres Modells zeigen, wie es können Modified zu integrieren kürzlich aufgeklärt Mechanismen der Drug Action einschließlich Molekülen, dass target host Faktoren. Zusätzlich haben wir Adresse ein weiterer wichtiger Aspekt in der klinischen Management der HIV-Erkrankung, das heißt Drogen Pharmakokinetik. Es ist klar, dass die Zeit-abhängige Änderungen in In-vivo-Wirkstoffkonzentration könnten die Auswirkungen auf die antivirale E ffect und haben auch Einfluss auf die Entscheidungen über Dosierungsintervalle. Wir präsentieren ein Framework, bietet ein integriertes Verständnis der wichtigsten Merkmale von mehreren Dosierungsschemata einschließlich Kumulation Übersetzungen und Halbwertszeiten, und untersuchen Sie die Auswirkungen von Drogen auf die Pharmakokinetik Virussuppression. Schließlich, Parameter identifiFähigkeit in solchen nichtlineare Modelle der virale Dynamik ist immer ein Anliegen, und wir untersuchen Methoden, um dieses Problem in unserer Einstellung. KW - HIV KW - mathematical modelling KW - viral fitness KW - pharmacokinetics KW - parameter estimation KW - HIV Erkrankung KW - Pharmakokinetik KW - Fitness KW - mathematische Modellierung KW - Kombinationstherapie Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-100100 ER - TY - JOUR A1 - Li, Jian A1 - Lu, Yong Ping A1 - Reichetzeder, Christoph A1 - Kalk, Philipp A1 - Kleuser, Burkhard A1 - Adamski, Jerzy A1 - Hocher, Berthold T1 - Maternal PCaaC38:6 is Associated With Preterm Birth - a Risk Factor for Early and Late Adverse Outcome of the Offspring JF - Journal of European public policy N2 - Background/Aims: Preterm birth (PTB) and low birth weight (LBW) significantly influence mortality and morbidity of the offspring in early life and also have long-term consequences in later life. A better understanding of the molecular mechanisms of preterm birth could provide new insights regarding putative preventive strategies. Metabolomics provides a powerful analytic tool to readout complex interactions between genetics, environment and health and may serve to identify relevant biomarkers. In this study, the association between 163 targeted maternal blood metabolites and gestational age was investigated in order to find candidate biomarkers for PTB. Methods: Five hundred twenty-three women were included into this observational study. Maternal blood was obtained before delivery. The concentration of 163 maternal serum metabolites was measured by flow injection tandem mass spectrometry. To find putative biomarkers for preterm birth, a three-step analysis was designed: bivariate correlation analysis followed by multivariable regression analysis and a comparison of mean values among gestational age groups. Results: Bivariate correlation analysis showed that 2 acylcarnitines (C16:2, C2), 1 amino acids (xLeu), 8 diacyl-PCs (PCaaC36:4, PCaaC38:4, PCaaC38:5, PCaaC38:6, PCaaC40:4, PCaaC40:5, PCaaC40:6, PCaaC42:4), and 1 Acylalkyl-PCs (PCaeC40:5) were inversely correlated with gestational age. Multivariable regression analysis confounded for PTB history, maternal body mass index (BMI) before pregnancy, systolic blood pressure at the third trimester, and maternal body weight at the third trimester, showed that the diacyl-PC PCaaC38:6 was the only metabolite inversely correlated with gestational age. Conclusions: Maternal blood concentrations of PCaaC38:6 are independently associated with gestational age. (C) 2016 The Author(s) Published by S. Karger AG, Basel KW - Metabolomics KW - PCaaC38:6 KW - Biomarker KW - Preterm birth Y1 - 2016 U6 - https://doi.org/10.1159/000443428 SN - 1420-4096 SN - 1423-0143 VL - 41 SP - 250 EP - 257 PB - Karger CY - Basel ER - TY - JOUR A1 - Hocher, Berthold A1 - Haumann, Hannah A1 - Rahnenführer, Jan A1 - Reichetzeder, Christoph A1 - Kalk, Philipp A1 - Pfab, Thiemo A1 - Tsuprykov, Oleg A1 - Winter, Stefan A1 - Hofmann, Ute A1 - Li, Jian A1 - Püschel, Gerhard Paul A1 - Lang, Florian A1 - Schuppan, Detlef A1 - Schwab, Matthias A1 - Schaeffeler, Elke T1 - Maternal eNOS deficiency determines a fatty liver phenotype of the offspring in a sex dependent manner JF - Epigenetics : the official journal of the DNA Methylation Society N2 - Maternal environmental factors can impact on the phenotype of the offspring via the induction of epigenetic adaptive mechanisms. The advanced fetal programming hypothesis proposes that maternal genetic variants may influence the offspring's phenotype indirectly via epigenetic modification, despite the absence of a primary genetic defect. To test this hypothesis, heterozygous female eNOS knockout mice and wild type mice were bred with male wild type mice. We then assessed the impact of maternal eNOS deficiency on the liver phenotype of wild type offspring. Birth weight of male wild type offspring born to female heterozygous eNOS knockout mice was reduced compared to offspring of wild type mice. Moreover, the offspring displayed a sex specific liver phenotype, with an increased liver weight, due to steatosis. This was accompanied by sex specific differences in expression and DNA methylation of distinct genes. Liver global DNA methylation was significantly enhanced in both male and female offspring. Also, hepatic parameters of carbohydrate metabolism were reduced in male and female offspring. In addition, male mice displayed reductions in various amino acids in the liver. Maternal genetic alterations, such as partial deletion of the eNOS gene, can affect liver metabolism of wild type offspring without transmission of the intrinsic defect. This occurs in a sex specific way, with more detrimental effects in females. This finding demonstrates that a maternal genetic defect can epigenetically alter the phenotype of the offspring, without inheritance of the defect itself. Importantly, these acquired epigenetic phenotypic changes can persist into adulthood. KW - Epigenetics KW - eNOS KW - Fetal programming KW - fatty liver KW - metabolism Y1 - 2016 U6 - https://doi.org/10.1080/15592294.2016.1184800 SN - 1559-2294 SN - 1559-2308 VL - 11 SP - 539 EP - 552 PB - Routledge, Taylor & Francis Group CY - Philadelphia ER - TY - THES A1 - Schöppler, Vanessa T1 - Material properties of Banksia follicles Y1 - 2016 ER - TY - JOUR A1 - Bolotov, M. I. A1 - Osipov, Grigory V. A1 - Pikovskij, Arkadij T1 - Marginal chimera state at cross-frequency locking of pulse-coupled neural networks JF - Physical review : E, Statistical, nonlinear and soft matter physics N2 - We consider two coupled populations of leaky integrate-and-fire neurons. Depending on the coupling strength, mean fields generated by these populations can have incommensurate frequencies or become frequency locked. In the observed 2:1 locking state of the mean fields, individual neurons in one population are asynchronous with the mean fields, while in another population they have the same frequency as the mean field. These synchronous neurons form a chimera state, where part of them build a fully synchronized cluster, while other remain scattered. We explain this chimera as a marginal one, caused by a self-organized neutral dynamics of the effective circle map. Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevE.93.032202 SN - 2470-0045 SN - 2470-0053 VL - 93 PB - American Physical Society CY - College Park ER -