TY - GEN A1 - Pearce, Warren A1 - Özkula, Suay M. A1 - Greene, Amanda K. A1 - Teeling, Lauren A1 - Bansard, Jennifer S. A1 - Omena, Janna Joceli A1 - Rabello, Elaine Teixeira T1 - Visual cross-platform analysis BT - Digital methods to research social media images T2 - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe N2 - Analysis of social media using digital methods is a flourishing approach. However, the relatively easy availability of data collected via platform application programming interfaces has arguably led to the predominance of single-platform research of social media. Such research has also privileged the role of text in social media analysis, as a form of data that is more readily gathered and searchable than images. In this paper, we challenge both of these prevailing forms of social media research by outlining a methodology for visual cross-platform analysis (VCPA), defined as the study of still and moving images across two or more social media platforms. Our argument contains three steps. First, we argue that cross-platform analysis addresses a gap in research methods in that it acknowledges the interplay between a social phenomenon under investigation and the medium within which it is being researched, thus illuminating the different affordances and cultures of web platforms. Second, we build on the literature on multimodal communication and platform vernacular to provide a rationale for incorporating the visual into cross-platform analysis. Third, we reflect on an experimental cross-platform analysis of images within social media posts (n = 471,033) used to communicate climate change to advance different modes of macro- and meso-levels of analysis that are natively visual: image-text networks, image plots and composite images. We conclude by assessing the research pathways opened up by VCPA, delineating potential contributions to empirical research and theory and the potential impact on practitioners of social media communication. T3 - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 199 KW - research methodology KW - visual analysis KW - social media KW - climate change Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515539 SN - 1867-5808 IS - 2 ER - TY - GEN A1 - Dvornikov, Yury A1 - Leibman, Marina A1 - Heim, Birgit A1 - Bartsch, Annett A1 - Herzschuh, Ulrike A1 - Skorospekhova, Tatiana A1 - Fedorova, Irina A1 - Khomutov, Artem A1 - Widhalm, Barbara A1 - Gubarkov, Anatoly A1 - Rößler, Sebastian T1 - Terrestrial CDOM in lakes of Yamal Peninsula BT - Connection to lake and lake catchment properties T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM) absorption at 440 nm (a(440)(CDOM)) and absorption slope (S300-500) in lakes using field sampling and optical remote sensing data for an area of 350 km(2) in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance) for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a()(CDOM) data from 18 lakes sampled in the field to 356 lakes in the study area (model R-2 = 0.79). Values of a(440)(CDOM) in 356 lakes varied from 0.48 to 8.35 m(-1) with a median of 1.43 m(-1). This a()(CDOM) dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques) in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R-2 = 0.61). Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440)(CDOM) = 5.3 m(-1)). Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440)(CDOM) = 3.8 m(-1)) compared to lakes located on higher terraces. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1333 KW - CDOM KW - lakes KW - lake catchments KW - permafrost KW - Yamal KW - remote sensing data Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459720 SN - 1866-8372 IS - 1333 ER - TY - GEN A1 - Olmer, Ruth A1 - Engels, Lena A1 - Usman, Abdulai A1 - Menke, Sandra A1 - Malik, Muhammad Nasir Hayat A1 - Pessler, Frank A1 - Göhring, Gudrun A1 - Bornhorst, Dorothee A1 - Bolten, Svenja A1 - Abdelilah-Seyfried, Salim A1 - Scheper, Thomas A1 - Kempf, Henning A1 - Zweigerdt, Robert A1 - Martin, Ulrich T1 - Differentiation of Human Pluripotent Stem Cells into Functional Endothelial Cells in Scalable Suspension Culture T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Endothelial cells (ECs) are involved in a variety of cellular responses. As multifunctional components of vascular structures, endothelial (progenitor) cells have been utilized in cellular therapies and are required as an important cellular component of engineered tissue constructs and in vitro disease models. Although primary ECs from different sources are readily isolated and expanded, cell quantity and quality in terms of functionality and karyotype stability is limited. ECs derived from human induced pluripotent stem cells (hiPSCs) represent an alternative and potentially superior cell source, but traditional culture approaches and 2D differentiation protocols hardly allow for production of large cell numbers. Aiming at the production of ECs, we have developed a robust approach for efficient endothelial differentiation of hiPSCs in scalable suspension culture. The established protocol results in relevant numbers of ECs for regenerative approaches and industrial applications that show in vitro proliferation capacity and a high degree of chromosomal stability. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1182 KW - virus infection KW - progenitor cells KW - in vitro KW - telomere dysfunction KW - cord blood KW - cardiomyogenic differentiation KW - angiogenesis KW - efficient KW - aberrations KW - expression Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427095 SN - 1866-8372 IS - 5 ER - TY - THES A1 - Galetzka, Cedric T1 - Reward and prediction errors in Bayesian sensorimotor control N2 - Midbrain dopamine neurons invigorate responses by signaling opportunity costs (tonic dopamine) and promote associative learning by encoding a reward prediction error signal (phasic dopamine). Recent studies on Bayesian sensorimotor control have implicated midbrain dopamine concentration in the integration of prior knowledge and current sensory information. The present behavioral study addressed the contributions of tonic and phasic dopamine in a Bayesian decision-making task by alternating reward magnitude and inferring reward prediction errors. Twenty-four participants were asked to indicate the position of a hidden target stimulus under varying prior and likelihood uncertainty. Trial-by-trial rewards were allocated based on performance and two different reward maxima. Overall, participants’ behavior agreed with Bayesian decision theory, but indicated excessive reliance on likelihood information. These results thus oppose accounts of statistically optimal integration in sensorimotor control, and suggest that the sensorimotor system is subject to additional decision heuristics. Moreover, higher reward magnitude was not observed to induce enhanced response vigor, and was associated with less Bayes-like integration. In addition, the weighting of prior knowledge and current sensory information proceeded independently of reward prediction errors. Taken together, these findings suggest that the process of combining prior and likelihood uncertainties in sensorimotor control is largely robust to variations in reward. N2 - Inwieweit prägen Belohnungen die Integration von vorherigem Wissen und sensorischen Informationen im Kontext der Bayesianischen Entscheidungstheorie? Untersuchungen mit Parkinson-Patienten haben gezeigt, dass die Dopamin-Verfügbarkeit in den Basalganglien Integrationsprozesse in der Sensomotorik beeinflussen. Dopaminerge Neuronen schütten Dopamin tonisch und phasisch aus, wobei diese Modi verschiedenen Funktionen unterliegen, wie dem Signalisieren von Opportunitätskosten oder der Unterstützung assoziativen Lernens. Die Konzentration tonisch freigesetzten Dopamins richtet sich nach Belohnungsgrößen, wogegen phasische Dopamin-Komponenten durch Fehler in der Belohnungserwartung hervorgerufen werden. Die Bedeutung dieser Variablen in sensomotorischem Lernen ist jedoch größtenteils unerforscht. In der vorliegenden Verhaltensstudie wurden vierundzwanzig gesunde Teilnehmer gebeten, eine sensomotorische Schätzaufgabe durchzuführen, in der Belohnungsgrößen manipuliert und Belohnungserwartungsfehler abgeleitet wurden. Es wurde vermutet, dass positive Abweichungen in der Belohnungsvorhersage zu erhöhter Gewichtung von sensorischen Informationen durch den Influx phasischen Dopamins führen. Höhere Belohnungsgrößen sollten dagegen aufgrund vermehrter Opportunitätskosten mit beschleunigten Reaktionen verbunden sein. Das Verhalten der Teilnehmer hat gezeigt, dass aktuelle und a priori Informationen größtenteils unabhängig von Belohnungsgrößen und Belohungserwartungsfehlern integriert werden. Dieses Ergebnis deutet darauf hin, dass “Prior” und “Likelihood” unabhängig von belohnungsrelevanten Prozessen repräsentiert werden, welche in Zusammenhang mit der Dopamin-Konzentration in den Basalganglien stehen. Darüber hinaus entsprachen die Resultate lediglich qualitativ der Bayesianischen Entscheidungstheorie und widersprechen somit früheren Berichten von statistisch-optimaler Integration. Da sensorische Informationen über alle Bedingungen hinweg übermäßig hoch gewichtet wurden, legt diese Studie nahe, dass das sensomotorische System zusätzlichen systematischen Urteilsverzerrungen unterliegt. KW - Bayesian decision theory KW - reward prediction error KW - sensorimotor control KW - prior-likelihood integration KW - dopamine KW - Belohnungserwartungsfehler KW - Belohnungsgrößen KW - Bayesianische Entscheidungstheorie KW - sensomotorische Integration KW - Dopamin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-503507 ER - TY - CHAP A1 - Petsche, Hans-Joachim T1 - In honour of Seymour Papert BT - "Empirical Modelling" of Logo in Forth N2 - Forth is nice and flexible but to a philosopher and teacher educator Logo is the more impressing language. Both are relatives of Lisp, but Forth has a reverse Polish notation where as Logo has an infix notation. Logo allows top down programming, Forth only bottom up. Logo enables recursive programming, Forth does not. Logo includes turtle graphics, Forth has nothing comparable. So what to do if you can't get Logo and have no information about its inner architecture? This should be a case of "empirical modelling": How can you model observable results of the behaviour of Logo in terms of Forth? The main steps to solve this problem are shown in the first part of the paper. The second part of the paper discusses the problem of modelling and shows that the modelling of making and the modelling of recognition have the same mathematical structure. So "empirical modelling" can also serve for modelling desired behaviour of technical systems. The last part of the paper will show that the heuristic potential of a problem which should be modeled is more important than the programming language. The Picasso construal shows, in a very simple way, how children of different ages can model emotional relations in human behaviour with a simple Logo system. KW - Papert KW - LOGO KW - FORTH KW - Empirical Modelling KW - Construal Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-497302 ER - TY - THES A1 - Steiglechner, Peter T1 - Estimating global warming from anthropogenic heat emissions T1 - Abschätzung der globalen Erwärmung durch anthropogene Abwärme BT - conceptual and numerical modelling approaches BT - konzeptionelle und numerische Modellierungsansätze N2 - The forcing from the anthropogenic heat flux (AHF), i.e. the dissipation of primary energy consumed by the human civilisation, produces a direct climate warming. Today, the globally averaged AHF is negligibly small compared to the indirect forcing from greenhouse gas emissions. Locally or regionally, though, it has a significant impact. Historical observations show a constant exponential growth of worldwide energy production. A continuation of this trend might be fueled or even amplified by the exploration of new carbon-free energy sources like fusion power. In such a scenario, the impacts of the AHF become a relevant factor for anthropogenic post-greenhouse gas climate change on the global scale, as well. This master thesis aims at estimating the climate impacts of such a growing AHF forcing. In the first part of this work, the AHF is built into simple and conceptual, zero- and one-dimensional Energy Balance Models (EBMs), providing quick order of magnitude estimations of the temperature impact. In the one-dimensional EBM, the ice-albedo feedback from enhanced ice melting due to the AHF increases the temperature impact significantly compared to the zero-dimensional EBM. Additionally, the forcing is built into a climate model of intermediate complexity, CLIMBER-3α. This allows for the investigation of the effect of localised AHF and gives further insights into the impact of the AHF on processes like the ocean heat uptake, sea ice and snow pattern changes and the ocean circulation. The global mean temperature response from the AHF today is of the order of 0.010 − 0.016 K in all reasonable model configurations tested. A transient tenfold increase of this forcing heats up the Earth System additionally by roughly 0.1 − 0.2 K in the presented models. Further growth can also affect the tipping probability of certain climate elements. Most renewable energy sources do not or only partially contribute to the AHF forcing as the energy from these sources dissipates anyway. Hence, the transition to a (carbon-free) renewable energy mix, which, in particular, does not rely on nuclear power, eliminates the local and global climate impacts from the increasing AHF forcing, independent of the growth of energy production. N2 - Das Forcing durch die Emission von anthropogener Abwärme (AHF), d.h. die Dissipation von konsumierter Primärenergie, stellt einen Beitrag zu einer direkten Klimaerwärmung dar. Der global gemittelte AHF ist heutzutage vernachlässigbar klein im Vergleich zu dem indirekten Forcing durch Treibhausgasemissionen. Auf lokaler oder regionaler Ebene hat das Forcing jedoch einen signifikanten Einfluss. Die Energieproduktion hat in der Vergangenheit ein konstant exponentielles Wachstum aufgezeigt. Dieser Trend kann durch die Erschließung neuer CO2-neutraler Energiequellen, wie zum Beispiel Fusionsenergie, weiter bestärkt und angetrieben werden. In solch einem Szenario führt das AHF Forcing zu einem auch global relevanten Beitrag zum menschengemachten Klimawandel abseits der Treibhausgasemissionen. In dieser Arbeit sollen die Auswirkungen eines wachsenden AHF auf das Klima abgeschätzt werden. Im ersten Teil wird das zusätzliche Forcing in einfache und konzeptionelle, null- und eindimensionale Energiebilanzmodelle (EBM) eingebaut. Diese bieten schnelle Größenordnungsabschätzungen des Temperaturanstiegs. Im eindimensionalen EBM erhöht die Eis-Albedo-Rückkopplung die Temperatur signifikant im Verlgeich zum nulldimensionalen Fall aufgrund von verstärkter Eisschmelze. Zusätzlich, wird das AHF Forcing in das Erdsystemmodell mittlerer Komplexität CLIMBER-3α eingebaut. Dieses erlaubt eine Analyse des Effekts eines heterogenen AHF Forcings und gibt weitere Einblicke in die Einflüsse auf Prozessse wie den Wärmefluss in den Ozean, Veränderungen in Meereis und Schneebedeckung und die Ozeanzirkulation. Der global gemittelte Temperaturanstieg für das heutige AHF Forcing beträgt 0.010 − 0.016 K in allen realistischen, getesteten Modellkonfigurationen. Ein transienter Anstieg des Forcings auf den zehnfachen Wert erwärmt die Erde um weitere 0.1 − 0.2 K in den vorgestellten Modellen. Weiteres Wachstum kann zusätzlich auch das Kippen von bestimmten Klimaelementen beeinflussen. Die meisten erneuerbaren Energiequellen tragen nicht oder nur kaum zu der anthropogenen Abwärme bei, da deren Energie sowieso dissipiert. Daher beseitigt ein Wechsel auf einen CO2-neutralen, erneuerbaren Energiemix, der explizit nicht auf nuklearen Brennstoffen basiert, unabhängig von dem Wachstum der Energieproduktion die lokalen wie auch globalen Auswirkungen des AHF Effekts. KW - climate change KW - waste heat KW - heat island KW - energy balance model KW - climate model of intermediate complexity KW - Klimawandel KW - Abwärme KW - Wärmeinsel KW - Energiebilanzmodell KW - Klimamodell mittlerer Komplexität Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-498866 ER - TY - GEN A1 - Pauly, Maren A1 - Helle, Gerhard A1 - Miramont, Cécile A1 - Büntgen, Ulf A1 - Treydte, Kerstin A1 - Reinig, Frederick A1 - Guibal, Frédéric A1 - Sivan, Olivier A1 - Heinrich, Ingo A1 - Riedel, Frank A1 - Kromer, Bernd A1 - Balanzategui, Daniel A1 - Wacker, Lukas A1 - Sookdeo, Adam Sookdeo A1 - Brauer, Achim T1 - Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (delta O-18, delta C-13) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (delta O-18(sw)) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (delta O-18(sw)), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low delta O-18(sw)) versus Mediterranean (high delta O-18(sw)) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1135 KW - annually laminated sediments KW - lake Meerfelder Maar KW - isotopic composition KW - oxygen isotope KW - climate KW - cellulose KW - radiocarbon KW - temperature KW - record KW - model Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459169 SN - 1866-8372 IS - 1135 ER - TY - GEN A1 - Manzoni, Stefano A1 - Čapek, Petr A1 - Porada, Philipp A1 - Thurner, Martin A1 - Winterdahl, Mattias A1 - Beer, Christian A1 - Brüchert, Volker A1 - Frouz, Jan A1 - Herrmann, Anke M. A1 - Lindahl, Björn D. A1 - Lyon, Steve W. A1 - Šantrůčková, Hana A1 - Vico, Giulia A1 - Way, Danielle T1 - Reviews and syntheses BT - carbon use efficiency from organisms to ecosystems – definitions, theories, and empirical evidence T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The cycling of carbon (C) between the Earth surface and the atmosphere is controlled by biological and abiotic processes that regulate C storage in biogeochemical compartments and release to the atmosphere. This partitioning is quantified using various forms of C-use efficiency (CUE) - the ratio of C remaining in a system to C entering that system. Biological CUE is the fraction of C taken up allocated to biosynthesis. In soils and sediments, C storage depends also on abiotic processes, so the term C-storage efficiency (CSE) can be used. Here we first review and reconcile CUE and CSE definitions proposed for autotrophic and heterotrophic organisms and communities, food webs, whole ecosystems and watersheds, and soils and sediments using a common mathematical framework. Second, we identify general CUE patterns; for example, the actual CUE increases with improving growth conditions, and apparent CUE decreases with increasing turnover. We then synthesize > 5000CUE estimates showing that CUE decreases with increasing biological and ecological organization - from uni-cellular to multicellular organisms and from individuals to ecosystems. We conclude that CUE is an emergent property of coupled biological-abiotic systems, and it should be regarded as a flexible and scale-dependent index of the capacity of a given system to effectively retain C. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1134 KW - gross primary production KW - net primary production KW - plant respiration KW - microbial carbon KW - stoichiometric controls KW - growth efficiency KW - bacterial growth KW - excess carbon KW - soil KW - matter Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446386 SN - 1866-8372 IS - 1134 ER - TY - GEN A1 - Tabben, Montassar A1 - Ihsan, Mohammed A1 - Ghoul, Nihel A1 - Coquart, Jeremy A1 - Chaouachi, Anis A1 - Chaabene, Helmi A1 - Tourny, Claire A1 - Chamari, Karim T1 - Cold Water Immersion Enhanced Athletes’ Wellness and 10-m Short Sprint Performance 24-h After a Simulated Mixed Martial Arts Combat T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Objective: The aim of the present study was to examine the effect of Cold Water Immersion (CWI) on the recovery of physical performance, hematological stress markers and perceived wellness (i.e., Hooper scores) following a simulated Mixed Martial Arts (MMA) competition. Methods: Participants completed two experimental sessions in a counter-balanced order (CWI or passive recovery for control condition: CON), after a simulated MMAs competition (3 x 5-min MMA rounds separated by 1-min of passive rest). During CWI, athletes were required to submerge their bodies, except the trunk, neck and head, in the seated position in a temperature-controlled bath (similar to 10 degrees C) for 15-min. During CON, athletes were required to be in a seated position for 15-min in same room ambient temperature. Venous blood samples (creatine kinase, cortisol, and testosterone concentrations) were collected at rest (PRE-EX, i.e., before MMAs), immediately following MMAs (POST-EX), immediately following recovery (POST-R) and 24 h post MMAs (POST-24), whilst physical fitness (squat jump, countermovement-jump and 5- and 10-m sprints) and perceptual measures (well-being Hooper index: fatigue, stress, delayed onset muscle soreness (DOMS), and sleep) were collected at PRE-EX, POST-R and POST-24, and at PRE-EX and POST-24, respectively. Results: The main results indicate that POST-R sprint (5- and 10-m) performances were 'likely to very likely' (d = 0.64 and 0.65) impaired by prior CWI. However, moderate improvements were in 10-m sprint performance were 'likely' evident at POST-24 after CWI compared with CON (d = 0.53). Additionally, the use of CWI 'almost certainly' resulted in a large overall improvement in Hooper scores (d = 1.93). Specifically, CWI 'almost certainly' resulted in improved sleep quality (d = 1.36), stress (d = 1.56) and perceived fatigue (d = 1.51), and 'likely' resulted in a moderate decrease in DOMS (d = 0.60). Conclusion: The use of CWI resulted in an enhanced recovery of 10-m sprint performance, as well as improved perceived wellness 24-h following simulated MMA competition. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 707 KW - recovery KW - combat sports KW - MMA KW - delayed onset muscle soreness KW - stress KW - fatigue Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446068 SN - 1866-8364 IS - 707 ER - TY - GEN A1 - Odongo, Grace Akinyi A1 - Schlotz, Nina A1 - Baldermann, Susanne A1 - Neugart, Susanne A1 - Huyskens-Keil, Susanne A1 - Ngwene, Benard A1 - Trierweiler, Bernhard A1 - Schreiner, Monika A1 - Lamy, Evelyn T1 - African nightshade (Solanum scabrum Mill.) BT - impact of cultivation and plant processing on its health promoting potential as determined in a human liver cell model T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Plant cultivation and processing may impact nutrient and phytochemical content of vegetables. The present study aimed at determining the influence of cultivation and processing on the health promoting capacity of African nightshade (Solanum scabrum Mill.) leaves, an indigenous vegetable, rich in nutrients and phytochemicals. Anti-genotoxicity against the human liver carcinogen aflatoxin B1 (AFB1) as determined by the comet assay and radical oxygen species (ROS) scavenging capacity of ethanolic and aqueous extracts were investigated in human derived liver (HepG2) cells. ROS scavenging activity was assessed using electron paramagnetic spin resonance and quantification of ARE/Nrf2 mediated gene expression. The cultivation was done under different environmental conditions. The processing included fermentation and cooking; postharvest ultraviolet irradiation (UV-C) treatment was also investigated. Overall, S. scabrum extracts showed strong health promoting potential, the highest potential was observed with the fermented extract, which showed a 60% reduction of AFB1 induced DNA damage and a 38% reduction in FeSO4 induced oxidative stress. The content of total polyphenols, carotenoids and chlorophylls was indeed affected by cultivation and processing. Based on the present in vitro findings consumption of S. scabrum leaves could be further encouraged, preferentially after cooking or fermentation of the plant. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1133 KW - aflatoxin B1 KW - African indigenous vegetables KW - anti-genotoxicity KW - anti-oxidant activity KW - cancer chemoprevention KW - Solanaceae Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459114 SN - 1866-8372 IS - 1133 ER -