TY - JOUR A1 - Thiel, M. A1 - Romano, Maria Carmen A1 - Schwarz, Udo A1 - Kurths, Jürgen A1 - Timmer, Jens T1 - Surrogate-based hypothesis test without surrogates N2 - Fourier surrogate data are artificially generated time series, that - based on a resampling scheme - share the linear properties with an observed time series. In this paper we study a statistical surrogate hypothesis test to detect deviations from a linear Gaussian process with respect to asymmetry in time (Q-statistic). We apply this test to a Fourier representable function and obtain a representation of the asymmetry in time of the sample data, a characteristic for nonlinear processes, and the significance in terms of the Fourier coefficients. The main outcome is that we calculate the expected value of the mean and the standard deviation of the asymmetries of the surrogate data analytically and hence, no surrogates have to be generated. To illustrate the results we apply our method to the saw tooth function, the Lorenz system and to measured X-ray data of Cygnus X-1 Y1 - 2004 SN - 0218-1274 ER - TY - GEN A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes F. A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1081 KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472873 SN - 1866-8372 IS - 1081 ER - TY - JOUR A1 - Jobst, Anne A1 - Ette, Ottmar A1 - Martí Marco, María Rosario A1 - Müller, Tom A1 - Präßler, Ulrich A1 - Thiemer-Sachse, Ursula A1 - Biermann, Kurt-Reinhard A1 - Schwarz, Ingo ED - Ette, Ottmar ED - Knobloch, Eberhard T1 - HiN : Alexander von Humboldt im Netz N2 - Inhalt: - Hinweis auf die elektronischen Ressourcen, bereitgestellt von der Alexander von-Humboldt-Forschungsstelle der Berlin-Brandenburgischen Akademie der Wissenschaften - Anne Jobst: „wie man die Gabe aplicirt“ : der Briefwechsel zwischen Humboldt und Ehrenberg, ein Beispiel - Ottmar Ette: Hallar e inventar un público. Nuevos proyectos editoriales acerca de la obra de Alexander von Humboldt - María Rosario Martí Marco: La figura del botánico Valenciano Antonio José Cavanilles en su relación científica con Humboldt y los botánicos alemanes - Tom Müller: Roger Bacon in der Sicht Alexander von Humboldts Ulrich Päßler: Alexander von Humboldt und die transnationale Wissenschaftskommunikation im 19. Jahrhundert - Ursula Thiemer-Sachse: La visión de Alejandro de Humboldt de la situación social y cultural de los indígenas mexicanos contemporáneos, tal como fue reflejada en su diario de iaje y en el “Ensayo Político del Reino de la Nueva España” - Kurt-R. Biermann/Ingo Schwarz: Warum bezeichnete sich Alexander von Humboldt als DER ALTE VOM BERGE (Vecchio della Montagna)? T3 - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies - IX.2008, 17 KW - Briefedition und -korrespondenz KW - Christian Gottfried Ehrenberg KW - Johann Seifert KW - Asie Centrale KW - Daniel Kehlmann KW - Examen critique KW - Humboldt-Projekt KW - Kosmos KW - Relation historique KW - Vues des Cordilleres KW - 1799-1804 KW - Antonio José Cavanilles KW - Botanik KW - Valencia KW - Bacon KW - Columbus KW - Wissenschaftsgeschichte Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42446 SN - 1617-5239 SN - 2568-3543 VL - IX IS - 17 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes Florian A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper JF - Nutrients N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2019 U6 - https://doi.org/10.3390/nu11092112 SN - 2072-6643 VL - 11 IS - 9 PB - MDPI CY - Basel ER - TY - JOUR A1 - Finke, Hannah A1 - Winkelbeiner, Nicola Lisa A1 - Lossow, Kristina A1 - Hertel, Barbara A1 - Wandt, Viktoria Klara Veronika A1 - Schwarz, Maria A1 - Pohl, Gabriele A1 - Kopp, Johannes Florian A1 - Ebert, Franziska A1 - Kipp, Anna Patricia A1 - Schwerdtle, Tanja T1 - Effects of a Cumulative, Suboptimal Supply of Multiple Trace Elements in Mice BT - trace element status, genomic stability, inflammation, and epigenetics JF - Molecular nutrition & food research N2 - Scope: Trace element (TE) deficiencies often occur accumulated, as nutritional intake is inadequate for several TEs, concurrently. Therefore, the impact of a suboptimal supply of iron, zinc, copper, iodine, and selenium on the TE status, health parameters, epigenetics, and genomic stability in mice are studied. Methods and results: Male mice receive reduced or adequate amounts of TEs for 9 weeks. The TE status is analyzed mass‐spectrometrically in serum and different tissues. Furthermore, gene and protein expression of TE biomarkers are assessed with focus on liver. Iron concentrations are most sensitive toward a reduced supply indicated by increased serum transferrin levels and altered hepatic expression of iron‐related genes. Reduced TE supply results in smaller weight gain but higher spleen and heart weights. Additionally, inflammatory mediators in serum and liver are increased together with hepatic genomic instability. However, global DNA (hydroxy)methylation is unaffected by the TE modulation. Conclusion: Despite homeostatic regulation of most TEs in response to a low intake, this condition still has substantial effects on health parameters. It appears that the liver and immune system react particularly sensitive toward changes in TE intake. The reduced Fe status might be the primary driver for the observed effects. Y1 - 2020 U6 - https://doi.org/10.1002/mnfr.202000325 SN - 1613-4125 VL - 64 IS - 16 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Knobloch, Eberhard A1 - Schwarz, Ingo A1 - Lubrich, Oliver A1 - Siegel, Eva-Maria A1 - Weigl, Engelhard ED - Ette, Ottmar ED - Knobloch, Eberhard T1 - HiN : Alexander von Humboldt im Netz N2 - Inhalt: - Eberhard Knobloch und Ingo Schwarz: Alexander von Humboldt und Hector Berlioz - Oliver Lubrich: „[M]on extrême répugnance à écrire la relation de mon voyage“ – Alejandro de Humboldt deconstruye la relación de viaje - Eva-Maria Siegel: Repräsentation und Augenschein. Organisation des Wissens und Wahrnehmung des Fremden um 1800 am Beispiel der Reiseberichte und -tagebücher Alexander von Humboldts - Engelhard Weigl: Acclimatization: The Schomburgk brothers in South Australia T3 - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies - IV.2003, 7 KW - Briefe KW - Hector Berlioz KW - 1814-1831 KW - Dekonstruktion KW - José Aníbal Campos KW - relation historique KW - 1800 KW - Georg Foster KW - Moderne KW - Naturgemälde KW - Naturphilosophie KW - Reisetagebuch KW - 1849 KW - Australien KW - Schomburgk Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424398 SN - 2568-3543 SN - 1617-5239 VL - IV IS - 7 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Komalapriya, Chandrasekaran A1 - Romano Blasco, Maria Carmen A1 - Thiel, Marco A1 - Schwarz, Udo A1 - Kurths, Jürgen A1 - Simonotto, Jennifer A1 - Furman, Michael A1 - Ditto, William L. A1 - Carney, Paul R. T1 - Analysis of high-resulution microelectrode EEG recordings in an animal model of spontaneous limbic seizures Y1 - 2009 UR - http://www.worldscinet.com/ijbc/ijbc.shtml U6 - https://doi.org/10.1142/S0218127409023226 SN - 0218-1274 ER - TY - JOUR A1 - Romano, Maria Carmen A1 - Thiel, Marco A1 - Schwarz, Udo A1 - Kurths, Jürgen A1 - Lange, Holger A1 - Hauhs, M. T1 - Conceptual model of runoff from a forested catchment N2 - We investigate the relationship between precipitation and runoff data from a small forested catchment in the Harz mountains (Germany). For this purpose, we develop a conceptual model including memory effects to predict the runoff signal using the precipitation data as input. An enhanced variant of the model also includes air temperature as input variable. We show in terms of correlation functions that this model describes main dynamical properties of the runoff, especially the delay between rain event and runoff response as the annual persistence in the runoff data. Y1 - 2001 UR - http://journals.worldscientific.com.sg/ijbc/11/1110/S0218127401003619.html ER - TY - JOUR A1 - Thiel, Marco A1 - Romano, Maria Carmen A1 - Schwarz, Udo A1 - Kurths, Jürgen A1 - Hasinger, Günther A1 - Belloni, Tomaso T1 - Nonlinear Time series analysis of the X-ray flux of compact objects N2 - We analyse the X-ray light curves of compact objects using linear and nonlinear time series analysis methods. A Power Density Spectrum (PDS) describes the overall second order properties of the observed data well. To look beyond we propose the nonlinear Q-statistic to detect an asymmetry of the time series. This allows us to find relevant time scales. This method even grants a subclassification of the known states of X-ray sources. Y1 - 2001 SN - 0004-640x ER - TY - JOUR A1 - Whiteley, Liam A1 - Haug, Maria A1 - Klein, Kristina A1 - Willmann, Matthias A1 - Bohn, Erwin A1 - Chiantia, Salvatore A1 - Schwarz, Sandra T1 - Cholesterol and host cell surface proteins contribute to cell-cell fusion induced by the Burkholderia type VI secretion system 5 JF - PLoS one N2 - Following escape into the cytoplasm of host cells, Burkholderia pseudomallei and the related species Burkholderia thailandensis employ the type VI secretion system 5 ( T6SS-5) to induce plasma membrane fusion with an adjacent host cell. This process leads to the formation of multinucleated giant cells and facilitates bacterial access to an uninfected host cell in a direct manner. Despite its importance in virulence, the mechanism of the T6SS-5 and the role of host cell factors in cell-cell fusion remain elusive. To date, the T6SS-5 is the only system of bacterial origin known to induce host-cell fusion. To gain insight into the nature of T6SS-5-stimulated membrane fusion, we investigated the contribution of cholesterol and proteins exposed on the host cell surface, which were shown to be critically involved in virus-mediated giant cell formation. In particular, we analyzed the effect of host cell surface protein and cholesterol depletion on the formation of multinucleated giant cells induced by B. thailandensis. Acute protease treatment of RAW264.7 macrophages during infection with B. thailandensis followed by agarose overlay assays revealed a strong reduction in the number of cell-cell fusions compared with EDTA treated cells. Similarly, proteolytic treatment of specifically infected donor cells or uninfected recipient cells significantly decreased multinucleated giant cell formation. Furthermore, modulating host cell cholesterol content by acute cholesterol depletion from cellular membranes by methyl-beta-cyclodextrin treatment or exogenous addition of cholesterol impaired the ability of B. thailandensis to induce cell-cell fusions. The requirement of physiological cholesterol levels suggests that the membrane organization or mechanical properties of the lipid bilayer influence the fusion process. Altogether, our data suggest that membrane fusion induced by B. pseudomallei and B. thailandensis involves a complex interplay between the T6SS-5 and the host cell. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0185715 SN - 1932-6203 VL - 12 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Kraft, Tobias A1 - Drozdowska-Broering, Izabela A1 - Leitner, Ulrike A1 - Mikolajczyk, Aniela Maria A1 - Päßler, Ulrich A1 - Schwarz, Ingo A1 - Walravens, Hartmut A1 - Werner, Petra ED - Ette, Ottmar ED - Knobloch, Eberhard T1 - HiN : Alexander von Humboldt im Netz T2 - HIN : Alexander von Humboldt im Netz ; international review for Humboldtian studies N2 - Inhalt: - Tobias Kraft: Die Berliner Edition Humboldt digital - Izabela Drozdowska-Broering: Alexander von Humboldt und die polnische Wissenschafts- und Kulturwelt - Ulrike Leitner: Sobre ríos y canales – Aspectos geográficos y cartográficos en el legado de Humboldt - Aniela Maria Mikolajczyk: Alexander von Humboldts Manuskript Isle de Cube. Antilles en général in der Biblioteka Jagiellońska als Vorstufe des Essai politique sur l‘île de Cuba - Ulrich Päßler: A Political Economy of Nature: Alexander von Humboldt‘s Essay on the Fluctuations in the Supplies of Gold - Ingo Schwarz: “Any American will always be welcome to the study of Alexander von Humboldt”. Ein Besucher aus den Vereinigten Staaten von Amerika bei Alexander von Humboldt 1836 - Hartmut Walravens: Zu den von A. v. Humboldt aus Rußland mitgebrachten Büchern - Petra Werner: Franz Julius Ferdinand Meyen: gefördert und frühvollendet. Zwischen Poesie und totem Zoo - Ingo Schwarz: Nachtrag zu HiN XVII, 33 (2016) - Ingo Schwarz: Bernd Kölbel: Geologe und Alexander-von-Humboldt-Forscher T3 - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies - XVIII.2017, 34 KW - Editionsphilologie KW - Akademienvorhaben "Alexander von Humboldt auf Reisen - Wissenschaft aus der Bewegung KW - Nachlass Alexander von Humboldt KW - Polen KW - Novemberaufstand KW - polnische Wissenschaftler KW - polnische Romantik KW - Humboldt KW - Kartographie KW - Bergbau KW - Flüsse KW - Bifurkation KW - Sklaverei KW - Cuba-Manuskript KW - Essai politique sur l'île de Cuba KW - Abolitionismus KW - Amerikanische Reisetagebücher KW - Reiseliteraur KW - USA KW - Berlin KW - Russlandreise KW - Buchgeschenke KW - Bucherwerbungen KW - Bücherkatalog KW - Königliche Bibliothek Berlin KW - Karl Friedrich Neumann KW - Wirtschaftgeschichte KW - Wissenschaftsgeschichte KW - Kameralismus KW - Edelmetalle KW - Gold KW - Silber KW - Platin KW - Brillenpinguin KW - Humboldt-Pinguin KW - Förderung KW - Guanaco KW - Kulturpflanzen KW - Leopoldina KW - Mumien von Ureinwohnern Perus KW - Namensgebung für Humboldt-Pinguin KW - Naturkundemuseum zu Berlin KW - Pflanzengeographie KW - Stiftung Preußische Seehandlung KW - Reisetagebücher Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395914 SN - 1617-5239 SN - 2568-3543 VL - XVIII IS - 34 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - CHAP A1 - Loßow, Kristina A1 - Schwarz, Maria A1 - Kopp, Johannes A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Age- and sex-dependent changes of trace elements and redox parameters in mice T2 - Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research Y1 - 2021 U6 - https://doi.org/10.1016/j.freeradbiomed.2020.12.346 SN - 0891-5849 SN - 1873-4596 VL - 165 IS - Suppl. 1 SP - 34 PB - Elsevier CY - New York ER - TY - GEN A1 - Hauffe, Robert A1 - Rath, Michaela A1 - Agyapong, Wilson A1 - Jonas, Wenke A1 - Vogel, Heike A1 - Schulz, Tim Julius A1 - Schwarz, Maria A1 - Kipp, Anna Patricia A1 - Blüher, Matthias A1 - Kleinridders, André T1 - Obesity Hinders the Protective Effect of Selenite Supplementation on Insulin Signaling T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The intake of high-fat diets (HFDs) containing large amounts of saturated long-chain fatty acids leads to obesity, oxidative stress, inflammation, and insulin resistance. The trace element selenium, as a crucial part of antioxidative selenoproteins, can protect against the development of diet-induced insulin resistance in white adipose tissue (WAT) by increasing glutathione peroxidase 3 (GPx3) and insulin receptor (IR) expression. Whether selenite (Se) can attenuate insulin resistance in established lipotoxic and obese conditions is unclear. We confirm that GPX3 mRNA expression in adipose tissue correlates with BMI in humans. Cultivating 3T3-L1 pre-adipocytes in palmitate-containing medium followed by Se treatment attenuates insulin resistance with enhanced GPx3 and IR expression and adipocyte differentiation. However, feeding obese mice a selenium-enriched high-fat diet (SRHFD) only resulted in a modest increase in overall selenoprotein gene expression in WAT in mice with unaltered body weight development, glucose tolerance, and insulin resistance. While Se supplementation improved adipocyte morphology, it did not alter WAT insulin sensitivity. However, mice fed a SRHFD exhibited increased insulin content in the pancreas. Overall, while selenite protects against palmitate-induced insulin resistance in vitro, obesity impedes the effect of selenite on insulin action and adipose tissue metabolism in vivo. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1267 KW - selenite KW - insulin KW - adipose tissue KW - obesity KW - insulin resistance Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-561709 SN - 1866-8372 SP - 1 EP - 16 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Hauffe, Robert A1 - Rath, Michaela A1 - Agyapong, Wilson A1 - Jonas, Wenke A1 - Vogel, Heike A1 - Schulz, Tim Julius A1 - Schwarz, Maria A1 - Kipp, Anna Patricia A1 - Blüher, Matthias A1 - Kleinridders, André T1 - Obesity Hinders the Protective Effect of Selenite Supplementation on Insulin Signaling JF - Antioxidants N2 - The intake of high-fat diets (HFDs) containing large amounts of saturated long-chain fatty acids leads to obesity, oxidative stress, inflammation, and insulin resistance. The trace element selenium, as a crucial part of antioxidative selenoproteins, can protect against the development of diet-induced insulin resistance in white adipose tissue (WAT) by increasing glutathione peroxidase 3 (GPx3) and insulin receptor (IR) expression. Whether selenite (Se) can attenuate insulin resistance in established lipotoxic and obese conditions is unclear. We confirm that GPX3 mRNA expression in adipose tissue correlates with BMI in humans. Cultivating 3T3-L1 pre-adipocytes in palmitate-containing medium followed by Se treatment attenuates insulin resistance with enhanced GPx3 and IR expression and adipocyte differentiation. However, feeding obese mice a selenium-enriched high-fat diet (SRHFD) only resulted in a modest increase in overall selenoprotein gene expression in WAT in mice with unaltered body weight development, glucose tolerance, and insulin resistance. While Se supplementation improved adipocyte morphology, it did not alter WAT insulin sensitivity. However, mice fed a SRHFD exhibited increased insulin content in the pancreas. Overall, while selenite protects against palmitate-induced insulin resistance in vitro, obesity impedes the effect of selenite on insulin action and adipose tissue metabolism in vivo. KW - selenite KW - insulin KW - adipose tissue KW - obesity KW - insulin resistance Y1 - 2022 U6 - https://doi.org/10.3390/antiox11050862 SN - 2076-3921 VL - 11 SP - 1 EP - 16 PB - MDPI CY - Basel, Schweiz ET - 5 ER - TY - JOUR A1 - Agthe, Maria A1 - Kayser, Daniela Niesta A1 - Schwarz, Sascha A1 - Maner, Jon K. T1 - Antecedents of the red-romance effect BT - men's attractiveness and women's fertility JF - PLOS ONE / Public Library of Science N2 - The color red has been implicated in a variety of social processes, including those involving mating. While previous research suggests that women sometimes wear red strategically to increase their attractiveness, the replicability of this literature has been questioned. The current research is a reasonably powered conceptual replication designed to strengthen this literature by testing whether women are more inclined to display the color red 1) during fertile (as compared with less fertile) days of the menstrual cycle, and 2) when expecting to interact with an attractive man (as compared with a less attractive man and with a control condition). Analyses controlled for a number of theoretically relevant covariates (relationship status, age, the current weather). Only the latter hypothesis received mixed support (mainly among women on hormonal birth control), whereas results concerning the former hypothesis did not reach significance. Women (N = 281) displayed more red when expecting to interact with an attractive man; findings did not support the prediction that women would increase their display of red on fertile days of the cycle. Findings thus suggested only mixed replicability for the link between the color red and psychological processes involving romantic attraction. They also illustrate the importance of further investigating the boundary conditions of color effects on everyday social processes. Y1 - 2023 U6 - https://doi.org/10.1371/journal.pone.0284035 SN - 1932-6203 VL - 18 IS - 4 PB - PLOS CY - San Fransisco ER -