TY - JOUR A1 - Heyde, Jürgen T1 - Daniel B. Schwartz, Ghetto: The History of a Word (Cambridge, MA: Harvard University Press, 2019), 288 p. JF - PaRDeS : Journal of the Association for Jewish Studies in Germany JF - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-537530 SN - 978-3-86956-520-0 SN - 1614-6492 SN - 1862-7684 IS - 27 SP - 151 EP - 154 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Clegg, Mark R. A1 - Wacker, Alexander A1 - Spijkerman, Elly T1 - Phenotypic Diversity and Plasticity of Photoresponse Across an Environmentally Contrasting Family of Phytoflagellates JF - Frontiers in plant science : FPLS N2 - Organisms often employ ecophysiological strategies to exploit environmental conditions and ensure bio-energetic success. However, the many complexities involved in the differential expression and flexibility of these strategies are rarely fully understood. Therefore, for the first time, using a three-part cross-disciplinary laboratory experimental analysis, we investigated the diversity and plasticity of photoresponsive traits employed by one family of environmentally contrasting, ecologically important phytoflagellates. The results demonstrated an extensive inter-species phenotypic diversity of behavioural, physiological, and compositional photoresponse across the Chlamydomonadaceae, and a multifaceted intra-species phenotypic plasticity, involving a broad range of beneficial photoacclimation strategies, often attributable to environmental predisposition and phylogenetic differentiation. Deceptively diverse and sophisticated strong (population and individual cell) behavioural photoresponses were observed, with divergence from a general preference for low light (and flexibility) dictated by intra-familial differences in typical habitat (salinity and trophy) and phylogeny. Notably, contrasting lower, narrow, and flexible compared with higher, broad, and stable preferences were observed in freshwater vs. brackish and marine species. Complex diversity and plasticity in physiological and compositional photoresponses were also discovered. Metabolic characteristics (such as growth rates, respiratory costs and photosynthetic capacity, efficiency, compensation and saturation points) varied elaborately with species, typical habitat (often varying more in eutrophic species, such as Chlamydomonas reinhardtii), and culture irradiance (adjusting to optimise energy acquisition and suggesting some propensity for low light). Considerable variations in intracellular pigment and biochemical composition were also recorded. Photosynthetic and accessory pigments (such as chlorophyll a, xanthophyll-cycle components, chlorophyll a:b and chlorophyll a:carotenoid ratios, fatty acid content and saturation ratios) varied with phylogeny and typical habitat (to attune photosystem ratios in different trophic conditions and to optimise shade adaptation, photoprotection, and thylakoid architecture, particularly in freshwater environments), and changed with irradiance (as reaction and harvesting centres adjusted to modulate absorption and quantum yield). The complex, concomitant nature of the results also advocated an integrative approach in future investigations. Overall, these nuanced, diverse, and flexible photoresponsive traits will greatly contribute to the functional ecology of these organisms, addressing environmental heterogeneity and potentially shaping individual fitness, spatial and temporal distribution, prevalence, and ecosystem dynamics. KW - photoresponse KW - behaviour KW - physiology KW - composition KW - photosynthesis KW - acclimation KW - Chlamydomonas KW - ecophysiology Y1 - 2021 U6 - https://doi.org/10.3389/fpls.2021.707541 SN - 1664-462X IS - 12 PB - Frontiers Media CY - Lausanne ER - TY - RPRT A1 - Borck, Rainald A1 - Oshiro, Jun A1 - Satō, Yasuhiro T1 - Property tax competition BT - A quantitative assessment T2 - CEPA Discussion Papers N2 - We develop a model of property taxation and characterize equilibria under three alternative taxa-tion regimes often used in the public finance literature: decentralized taxation, centralized taxation, and “rent seeking” regimes. We show that decentralized taxation results in inefficiently high tax rates, whereas centralized taxation yields a common optimal tax rate, and tax rates in the rent-seeking regime can be either inefficiently high or low. We quantify the effects of switching from the observed tax system to the three regimes for Japan and Germany. The decentralized or rent-seeking regime best describes the Japanese tax system, whereas the centralized regime does so for Germany. We also quantify the welfare effects of regime changes. T3 - CEPA Discussion Papers - 52 KW - property taxes KW - tax competition KW - efficiency Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-562228 SN - 2628-653X ER - TY - RPRT A1 - Andres, Maximilian A1 - Bruttel, Lisa Verena A1 - Friedrichsen, Jana T1 - How communication makes the difference between a cartel and tacit collusion BT - a machine learning approach T2 - CEPA Discussion Papers N2 - This paper sheds new light on the role of communication for cartel formation. Using machine learning to evaluate free-form chat communication among firms in a laboratory experiment, we identify typical communication patterns for both explicit cartel formation and indirect attempts to collude tacitly. We document that firms are less likely to communicate explicitly about price fixing and more likely to use indirect messages when sanctioning institutions are present. This effect of sanctions on communication reinforces the direct cartel-deterring effect of sanctions as collusion is more difficult to reach and sustain without an explicit agreement. Indirect messages have no, or even a negative, effect on prices. T3 - CEPA Discussion Papers - 53 KW - cartel KW - collusion KW - communication KW - machine learning KW - experiment Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-562234 SN - 2628-653X ER - TY - RPRT A1 - Dehnen, Elias T1 - Juridifying Bolsonaro’s mass deforestation policies in Brazil through the International Criminal Court BT - Chances and Challenges T2 - Staat, Recht und Politik – Forschungs- und Diskussionspapiere T2 - State, Law, and Politics — Research and Discussion Papers N2 - Under Brazil's ex-president Bolsonaro, deforestation of the Amazon increased dramatically. An Austrian NGO filed a complaint to the Prosecutor of the International Criminal Court (ICC) against Bolsonaro in October 2021, accusing him of crimes against humanity against the backdrop of his involvement in environmental destruction. This paper deals with the question of whether this initi-ative constitutes a promising means of juridification to mitigate conflicts revolving around mass deforestation in Brazil. It thematizes attempts to juridify environmental destruction in international criminal law and examines the Climate Fund Case at the Brazilian Supreme Court. Finally, emerging problems and arguments in favour of starting preliminary examinations at the ICC against Bolsonaro are illuminated. This paper provides arguments as to why the initiative might be a promising undertaking, even though it is unlikely that Bolsonaro will be arrested. N2 - In der Amtszeit des brasilianischen Ex-Präsidenten Bolsonaro nahm die Abholzung des Amazonasgebiets drastisch zu. Eine österreichi-sche NGO reichte im Oktober 2021 beim Anklä-ger des Internationalen Strafgerichtshofs (IStGH) eine Beschwerde gegen Bolsonaro ein, die seine Abholzungspolitik als Verbrechen gegen die Menschlichkeit einstuft. Der Beitrag behandelt die Frage, ob die Initiative ein vielversprechen-des Mittel der Verrechtlichung darstellt, um Kon-flikte rund um die Massenabholzung des Amazo-nas zu entschärfen. Dafür werden Versuche be-leuchtet, Umweltzerstörung im internationalen Strafrecht zu verrechtlichen. Zudem wird der Klimafonds-Fall vor dem Obersten Gerichtshof Brasiliens vorgestellt. Abschließend werden Probleme und Argumente für die Einleitung von Voruntersuchungen gegen Bolsonaro vor dem IStGH diskutiert. Der Beitrag liefert Argumente, weshalb die Initiative erfolgreich sein könnte, obgleich es unwahrscheinlich ist, dass Bolsonaro verhaftet wird. T3 - Staat, Recht und Politik – Forschungs- und Diskussionspapiere = State, Law, and Politics - Research and Discussion Papers - 14 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-581742 SN - 2509-6974 IS - 14 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - RPRT A1 - Franks, Max A1 - Kalkuhl, Matthias A1 - Lessmann, Kai T1 - Optimal Pricing for Carbon Dioxide Removal Under Inter-Regional Leakage T2 - CEPA Discussion Papers N2 - Carbon dioxide removal (CDR) moves atmospheric carbon to geological or land-based sinks. In a first-best setting, the optimal use of CDR is achieved by a removal subsidy that equals the optimal carbon tax and marginal damages. We derive second-best subsidies for CDR when no global carbon price exists but a national government implements a unilateral climate policy. We find that the optimal carbon tax differs from an optimal CDR subsidy because of carbon leakage, terms-of-trade and fossil resource rent dynamics. First, the optimal removal subsidy tends to be larger than the carbon tax because of lower supply-side leakage on fossil resource markets. Second, terms-of-trade effects exacerbate this wedge for net resource exporters, implying even larger removal subsidies. Third, the optimal removal subsidy may fall below the carbon tax for resource-poor countries when marginal environmental damages are small. T3 - CEPA Discussion Papers - 43 KW - carbon pricing KW - trade KW - unilateral climate policy KW - terms-of-trade effects KW - removal subsidies Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-538080 SN - 2628-653X IS - 43 ER - TY - JOUR A1 - Gallas, Elisabeth A1 - Rürup, Miriam T1 - “Advocate of the Jewish People” BT - Nehemia Robinson’s Legal Activism after 1945 : An Introduction JF - PaRDeS : Journal of the Association for Jewish Studies in Germany JF - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien KW - Modern Jewish history KW - United States KW - legal history KW - 20th century KW - Nehemia Robinson KW - German history KW - moderne jüdische Geschichte KW - USA KW - Rechtsgeschichte KW - 20. Jahrhundert KW - Nehemia Robinson KW - deutsche Geschichte Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-537501 SN - 978-3-86956-520-0 SN - 1614-6492 SN - 1862-7684 IS - 27 SP - 135 EP - 142 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Scheffler, Christiane A1 - Nguyen, Thi Hong A1 - Hermanussen, Michael T1 - Vietnamese migrants are as tall as they want to be JF - Human biology and public health N2 - Background: Members of the same social group tent to have the same body height. Migrants tend to adjust in height to their host communities. Objectives: Social-Economic-Political-Emotional (SEPE) factors influence growth. We hypothesized that Vietnamese young adult migrants in Germany (1) are taller than their parents, (2) are as tall as their German peers, and (3) are as tall as predicted by height expectation at age 13 years. Sample: The study was conducted in 30 male and 54 female Vietnamese migrants (mean age 26.23 years. SD=4.96) in Germany in 2020. Methods: Information on age, sex, body height, school and education, job, height and ethnicity of best friend, migration history and cultural identification, parental height and education, and recalled information on their personal height expectations at age 13 years were obtained by questionnaire. The data were analyzed by St. Nicolas House Analysis (SNHA) and multiple regression. Results: Vietnamese young adults are taller than their parents (females 3.85cm, males 7.44cm), but do not fully attain height of their German peers. The body height is positively associated with the height of best friend (p < 0.001), the height expectation at age 13 year (p < 0.001), and father’s height (p=0.001). Conclusion: Body height of Vietnamese migrants in Germany reflects competitive growth and strategic growth adjustments. The magnitude of this intergenerational trend supports the concept that human growth depends on SEPE factors. KW - body height KW - regulation of growth KW - migrants KW - Social-Economic-Political-Emotional (SEPE) factors Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.12 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Scheffler, Christiane A1 - Hermanussen, Michael T1 - Stunting does not impair physical fitness in Indonesian school children JF - Human biology and public health N2 - Background: Physical fitness is decreased in malnourished children and adults. Poor appearance and muscular flaccidity are among the first signs of malnutrition. Malnutrition is often associated with stunting. Objectives: We test the hypotheses that stunted children of low social strata are physically less fit than children of high social strata. Sample: We investigated 354 school girls and 369 school boys aged 5.83 to 13.83 (mean 9.54) years from three different social strata in Kupang (West-Timor, Indonesia) in 2020. Methods: We measured height, weight, and elbow breadth, calculated standard deviation (SDS) of height and weight according to CDC references, and the Frame index as an indicator of long-term physical fitness, and we tested physical fitness in standing long jump and hand grip strength. Results: Children of low social strata are physically fittest. They jump longer distances, and they have higher values in the Frame index. No association exists between height SDS and physical fitness, neither in respect to standing long jump, nor to hand grip strength. Conclusion: Stunting does not impair physical fitness in Indonesian school children. Our results support the concept that SEPE (social-economic-political-emotional) factors are involved in the regulation of human growth. KW - stunting KW - standing long jump KW - handgrip strength KW - SEPE KW - frame index Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.19 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Maaser, Lucas T1 - Transitional Justice and Nonviolent Resistance BT - Mutually Reinforcing Frameworks for the Consolidation of Democracies? JF - Transitional Justice : Theoretical and Practical Approaches (Potsdamer Studien zu Staat, Recht und Politik ; 7) N2 - At different times and places, civic engagement in nonviolent resistance (NVR) has repeatedly shown to be an effective tool in times of conflict to initiate societal change from below. History teaches us that there have been successes (Mahatma Gandhi in India) and failures (the Tiananmen Square protests in China). Along with the recognition of the duality between transformative potential and stark consequences, the historical development of NVR was accompanied by the emergence of scholarly debate, fractured along disputes around purpose, character and effectivity of nonviolent actions taken by civil society stakeholders engaged in making their voices heard. One of the field’s current points of interest is the examination of the long-term effects of NVR movements resulting in societal transformation on the stability and adequacy of a subsequently altered or emerging democracy, suggesting that NVR contributes positively to the sustainable and representative design of an egalitarian governing system. The conclusion of the Nepalese civil war in 2006 should pose as an unambiguous example for the illustration of this phenomenon, but simultaneously raises the question why there was no successful implementation of a transitional process focusing on the needs of the victims. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-570470 SN - 978-3-86956-473-9 SN - 1869-2443 SN - 1867-2663 IS - 7 SP - 139 EP - 165 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Conner, Sean T1 - Structural and Socioeconomic Approaches to Justice BT - Transformative Justice in Nicaragua’s ‘Dual Transition’ JF - Transitional Justice : Theoretical and Practical Approaches (Potsdamer Studien zu Staat, Recht und Politik ; 7) N2 - Transitional justice is conventionally theorized as how a society deals with past injustices after regime change and alongside democratization. Nonetheless, scholars have not reached a consensus on what is to be included or excluded. Recent ideas of transformative justice seek to expand the understanding of transitional justice to include systemic restructuring and socioeconomic considerations. In the context of Nicaragua — where two transitions occurred within an 11-year span — very little transitional justice took place, in terms of the conventional concept of top-down legalistic mechanisms; however, distinct structural changes and socioeconomic policies can be found with each regime change. By analyzing the transformative justice elements of Nicaragua’s dual transition, this chapter seeks to expand the understanding of transitional justice to include how these factors influence goals of transitions such as sustainable peace and reconciliation for past injustices. The results argue for increased attention to transformative justice theories and a more nuanced conception of justice. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-570170 SN - 978-3-86956-473-9 SN - 1869-2443 SN - 1867-2663 IS - 7 SP - 111 EP - 138 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - RPRT A1 - Borck, Rainald A1 - Schrauth, Philipp T1 - Urban pollution BT - A global perspective T2 - CEPA Discussion Papers N2 - We use worldwide satellite data to analyse how population size and density affect urban pollution. We find that density significantly increases pollution exposure. Looking only at urban areas, we find that population size affects exposure more than density. Moreover, the effect is driven mostly by population commuting to core cities rather than the core city population itself. We analyse heterogeneity by geography and income levels. By and large, the influence of population on pollution is greatest in Asia and middle-income countries. A counterfactual simulation shows that PM2.5 exposure would fall by up to 36% and NO2 exposure up to 53% if within countries population size were equalized across all cities. T3 - CEPA Discussion Papers - 60 KW - population density KW - air pollution KW - gridded data Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-572049 SN - 2628-653X IS - 60 ER - TY - GEN A1 - Busch, Jan Philip A1 - Meißner, Tobias A1 - Potthoff, Annegret A1 - Oswald, Sascha T1 - Plating of nano zero-valent iron (nZVI) on activated carbon : a fast delivery method of iron for source remediation? N2 - The use of nano zerovalent iron (nZVI) for environmental remediation is a promising new technique for in situ remediation. Due to its high surface area and high reactivity, nZVI is able to dechlorinate organic contaminants and render them harmless. Limited mobility, due to fast aggregation and sedimentation of nZVI, limits the capability for source and plume remediation. Carbo-Iron is a newly developed material consisting of activated carbon particles (d50 = 0,8 µm) that are plated with nZVI particles. These particles combine the mobility of activated carbon and the reactivity of nZVI. This paper presents the first results of the transport experiments. N2 - Der Einsatz von elementarem Nanoeisen ist eine vielversprechende Technik zur Sanierung von Altlastenschadensfällen. Aufgrund der hohen Oberfläche und der hohen Reaktivität kannn ZVI chlororganische Schadstoffe dechlorieren und zu harmlosen Substanzen umwandeln. Der Einsatz von Nanoeisen zur Quellen- und Fahnensanierung wird jedoch durch mangelnde Mobilität im Boden im eingeschränkt. Carbo-Iron ist ein neu entwickeltes Material, das aus Aktivkohlepartikeln (d50 = 0,8 µm) und nZVI besteht. Diese Partikel kombinieren die Mobilit ät von Aktivkohle mit der Reaktivität von nZVI. Dieser Artikel beschreibt erste Ergebnisse von Transportuntersuchungen. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 165 KW - Carbo-Iron KW - Nanoeisen KW - nZVI KW - Grundwassersanierung KW - Carbo-Iron KW - nano zero-valent iron KW - nZVI KW - remediation Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-53792 ER - TY - THES A1 - Brill, Fabio Alexander T1 - Applications of machine learning and open geospatial data in flood risk modelling N2 - Der technologische Fortschritt erlaubt es, zunehmend komplexe Vorhersagemodelle auf Basis immer größerer Datensätze zu produzieren. Für das Risikomanagement von Naturgefahren sind eine Vielzahl von Modellen als Entscheidungsgrundlage notwendig, z.B. in der Auswertung von Beobachtungsdaten, für die Vorhersage von Gefahrenszenarien, oder zur statistischen Abschätzung der zu erwartenden Schäden. Es stellt sich also die Frage, inwiefern moderne Modellierungsansätze wie das maschinelle Lernen oder Data-Mining in diesem Themenbereich sinnvoll eingesetzt werden können. Zusätzlich ist im Hinblick auf die Datenverfügbarkeit und -zugänglichkeit ein Trend zur Öffnung (open data) zu beobachten. Thema dieser Arbeit ist daher, die Möglichkeiten und Grenzen des maschinellen Lernens und frei verfügbarer Geodaten auf dem Gebiet der Hochwasserrisikomodellierung im weiteren Sinne zu untersuchen. Da dieses übergeordnete Thema sehr breit ist, werden einzelne relevante Aspekte herausgearbeitet und detailliert betrachtet. Eine prominente Datenquelle im Bereich Hochwasser ist die satellitenbasierte Kartierung von Überflutungsflächen, die z.B. über den Copernicus Service der Europäischen Union frei zur Verfügung gestellt werden. Große Hoffnungen werden in der wissenschaftlichen Literatur in diese Produkte gesetzt, sowohl für die akute Unterstützung der Einsatzkräfte im Katastrophenfall, als auch in der Modellierung mittels hydrodynamischer Modelle oder zur Schadensabschätzung. Daher wurde ein Fokus in dieser Arbeit auf die Untersuchung dieser Flutmasken gelegt. Aus der Beobachtung, dass die Qualität dieser Produkte in bewaldeten und urbanen Gebieten unzureichend ist, wurde ein Verfahren zur nachträglichenVerbesserung mittels maschinellem Lernen entwickelt. Das Verfahren basiert auf einem Klassifikationsalgorithmus der nur Trainingsdaten von einer vorherzusagenden Klasse benötigt, im konkreten Fall also Daten von Überflutungsflächen, nicht jedoch von der negativen Klasse (trockene Gebiete). Die Anwendung für Hurricane Harvey in Houston zeigt großes Potenzial der Methode, abhängig von der Qualität der ursprünglichen Flutmaske. Anschließend wird anhand einer prozessbasierten Modellkette untersucht, welchen Einfluss implementierte physikalische Prozessdetails auf das vorhergesagte statistische Risiko haben. Es wird anschaulich gezeigt, was eine Risikostudie basierend auf etablierten Modellen leisten kann. Solche Modellketten sind allerdings bereits für Flusshochwasser sehr komplex, und für zusammengesetzte oder kaskadierende Ereignisse mit Starkregen, Sturzfluten, und weiteren Prozessen, kaum vorhanden. Im vierten Kapitel dieser Arbeit wird daher getestet, ob maschinelles Lernen auf Basis von vollständigen Schadensdaten einen direkteren Weg zur Schadensmodellierung ermöglicht, der die explizite Konzeption einer solchen Modellkette umgeht. Dazu wird ein staatlich erhobener Datensatz der geschädigten Gebäude während des schweren El Niño Ereignisses 2017 in Peru verwendet. In diesem Kontext werden auch die Möglichkeiten des Data-Mining zur Extraktion von Prozessverständnis ausgelotet. Es kann gezeigt werden, dass diverse frei verfügbare Geodaten nützliche Informationen für die Gefahren- und Schadensmodellierung von komplexen Flutereignissen liefern, z.B. satellitenbasierte Regenmessungen, topographische und hydrographische Information, kartierte Siedlungsflächen, sowie Indikatoren aus Spektraldaten. Zudem zeigen sich Erkenntnisse zu den Schädigungsprozessen, die im Wesentlichen mit den vorherigen Erwartungen in Einklang stehen. Die maximale Regenintensität wirkt beispielsweise in Städten und steilen Schluchten stärker schädigend, während die Niederschlagssumme in tiefliegenden Flussgebieten und bewaldeten Regionen als aussagekräftiger befunden wurde. Ländliche Gebiete in Peru weisen in der präsentierten Studie eine höhere Vulnerabilität als die Stadtgebiete auf. Jedoch werden auch die grundsätzlichen Grenzen der Methodik und die Abhängigkeit von spezifischen Datensätzen and Algorithmen offenkundig. In der übergreifenden Diskussion werden schließlich die verschiedenen Methoden – prozessbasierte Modellierung, prädiktives maschinelles Lernen, und Data-Mining – mit Blick auf die Gesamtfragestellungen evaluiert. Im Bereich der Gefahrenbeobachtung scheint eine Fokussierung auf neue Algorithmen sinnvoll. Im Bereich der Gefahrenmodellierung, insbesondere für Flusshochwasser, wird eher die Verbesserung von physikalischen Modellen, oder die Integration von prozessbasierten und statistischen Verfahren angeraten. In der Schadensmodellierung fehlen nach wie vor die großen repräsentativen Datensätze, die für eine breite Anwendung von maschinellem Lernen Voraussetzung ist. Daher ist die Verbesserung der Datengrundlage im Bereich der Schäden derzeit als wichtiger einzustufen als die Auswahl der Algorithmen. N2 - Technological progress allows for producing ever more complex predictive models on the basis of increasingly big datasets. For risk management of natural hazards, a multitude of models is needed as basis for decision-making, e.g. in the evaluation of observational data, for the prediction of hazard scenarios, or for statistical estimates of expected damage. The question arises, how modern modelling approaches like machine learning or data-mining can be meaningfully deployed in this thematic field. In addition, with respect to data availability and accessibility, the trend is towards open data. Topic of this thesis is therefore to investigate the possibilities and limitations of machine learning and open geospatial data in the field of flood risk modelling in the broad sense. As this overarching topic is broad in scope, individual relevant aspects are identified and inspected in detail. A prominent data source in the flood context is satellite-based mapping of inundated areas, for example made openly available by the Copernicus service of the European Union. Great expectations are directed towards these products in scientific literature, both for acute support of relief forces during emergency response action, and for modelling via hydrodynamic models or for damage estimation. Therefore, a focus of this work was set on evaluating these flood masks. From the observation that the quality of these products is insufficient in forested and built-up areas, a procedure for subsequent improvement via machine learning was developed. This procedure is based on a classification algorithm that only requires training data from a particular class to be predicted, in this specific case data of flooded areas, but not of the negative class (dry areas). The application for hurricane Harvey in Houston shows the high potential of this method, which depends on the quality of the initial flood mask. Next, it is investigated how much the predicted statistical risk from a process-based model chain is dependent on implemented physical process details. Thereby it is demonstrated what a risk study based on established models can deliver. Even for fluvial flooding, such model chains are already quite complex, though, and are hardly available for compound or cascading events comprising torrential rainfall, flash floods, and other processes. In the fourth chapter of this thesis it is therefore tested whether machine learning based on comprehensive damage data can offer a more direct path towards damage modelling, that avoids explicit conception of such a model chain. For that purpose, a state-collected dataset of damaged buildings from the severe El Niño event 2017 in Peru is used. In this context, the possibilities of data-mining for extracting process knowledge are explored as well. It can be shown that various openly available geodata sources contain useful information for flood hazard and damage modelling for complex events, e.g. satellite-based rainfall measurements, topographic and hydrographic information, mapped settlement areas, as well as indicators from spectral data. Further, insights on damaging processes are discovered, which mainly are in line with prior expectations. The maximum intensity of rainfall, for example, acts stronger in cities and steep canyons, while the sum of rain was found more informative in low-lying river catchments and forested areas. Rural areas of Peru exhibited higher vulnerability in the presented study compared to urban areas. However, the general limitations of the methods and the dependence on specific datasets and algorithms also become obvious. In the overarching discussion, the different methods – process-based modelling, predictive machine learning, and data-mining – are evaluated with respect to the overall research questions. In the case of hazard observation it seems that a focus on novel algorithms makes sense for future research. In the subtopic of hazard modelling, especially for river floods, the improvement of physical models and the integration of process-based and statistical procedures is suggested. For damage modelling the large and representative datasets necessary for the broad application of machine learning are still lacking. Therefore, the improvement of the data basis in the field of damage is currently regarded as more important than the selection of algorithms. KW - flood risk KW - machine learning KW - open data KW - damage modelling KW - data-mining KW - Schadensmodellierung KW - Data-Mining KW - Hochwasserrisiko KW - maschinelles Lernen KW - offene Daten Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-555943 ER - TY - JOUR A1 - Fernandez-Fernandez, Jaime A1 - Granacher, Urs A1 - Martinez-Martin, Isidoro A1 - Garcia-Tormo, José Vicente A1 - Herrero-Molleda, Alba A1 - Barbado, David A1 - García López, Juan T1 - Physical fitness and throwing speed in U13 versus U15 male handball players JF - BMC Sports Science, Medicine and Rehabilitation N2 - Background The aim of this study was to analyze the shoulder functional profile (rotation range of motion [ROM] and strength), upper and lower body performance, and throwing speed of U13 versus U15 male handball players, and to establish the relationship between these measures of physical fitness and throwing speed. Methods One-hundred and nineteen young male handball players (under (U)-13 (U13) [n = 85]) and U15 [n = 34]) volunteered to participate in this study. The participating athletes had a mean background of sytematic handball training of 5.5 ± 2.8 years and they exercised on average 540 ± 10.1 min per week including sport-specific team handball training and strength and conditioning programs. Players were tested for passive shoulder range-of-motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, overhead medicine ball throw (OMB), hip isometric abductor (ABD) and adductor (ADD) strength, hip ROM, jumps (countermovement jump [CMJ] and triple leg-hop [3H] for distance), linear sprint test, modified 505 change-of-direction (COD) test and handball throwing speed (7 m [HT7] and 9 m [HT9]). Results U15 players outperformed U13 in upper (i.e., HT7 and HT9 speed, OMB, absolute IR and ER strength of the dominant and non-dominant sides; Cohen’s d: 0.76–2.13) and lower body (i.e., CMJ, 3H, 20-m sprint and COD, hip ABD and ADD; d: 0.70–2.33) performance measures. Regarding shoulder ROM outcomes, a lower IR ROM was found of the dominant side in the U15 group compared to the U13 and a higher ER ROM on both sides in U15 (d: 0.76–1.04). It seems that primarily anthropometric characteristics (i.e., body height, body mass) and upper body strength/power (OMB distance) are the most important factors that explain the throw speed variance in male handball players, particularly in U13. Conclusions Findings from this study imply that regular performance monitoring is important for performance development and for minimizing injury risk of the shoulder in both age categories of young male handball players. Besides measures of physical fitness, anthropometric data should be recorded because handball throwing performance is related to these measures. KW - Overhead athletes KW - Shoulder KW - Injury risk KW - Sport-specific performance Y1 - 2022 U6 - https://doi.org/10.1186/s13102-022-00507-0 SN - 1758-2555 VL - 14 PB - Springer CY - London ER - TY - JOUR A1 - Jararnezhadgero, AmirAli A1 - Mamashli, Elaheh A1 - Granacher, Urs T1 - An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy JF - Frontiers in physiology / Frontiers Research Foundation N2 - Background: The prevalence of diabetes worldwide is predicted to increase from 2.8% in 2000 to 4.4% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility. Objective: We aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO2max), ground reaction forces, and muscle activities during walking in patients with moderate DN. Methods: Sixty male and female individuals aged 45–65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40–55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO2max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s. Results: No statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO2max (p < 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p < 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001–0.037; d = 0.56–1.53). For IG, post-hoc analyses showed decreases in peak lateral (p < 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p < 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001–0.044; d = 0.54–0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p < 0.001; d = 1.28). Conclusions: This study demonstrated that an endurance-dominated exercise program has the potential to improve VO2max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics. KW - oxygen consumption KW - kinetics KW - electromyography KW - diabetic KW - gait Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.654755 SN - 1664-042X VL - 12 SP - 1 EP - 15 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Kasmi, Sofien A1 - Zouhal, Hassane A1 - Hammami, Raouf A1 - Clark, Cain Craig Truman A1 - Hackney, Anthony C. A1 - Hammami, Amri A1 - Chtara, Moktar A1 - Chortane, Sabri Gaied A1 - Ben Salah, Fatma Zohra A1 - Granacher, Urs A1 - Ben Ounis, Omar T1 - The Effects of Eccentric and Plyometric Training Programs and Their Combination on Stability and the Functional Performance in the Post-ACL-Surgical Rehabilitation Period of Elite Female Athletes JF - Frontiers in physiology N2 - Background: The standard method to treat physically active patients with anterior cruciate ligament (ACL) rupture is ligament reconstruction surgery. The rehabilitation training program is very important to improve functional performance in recreational athletes following ACL reconstruction. Objectives: The aims of this study were to compare the effects of three different training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on dynamic balance (Y-BAL), the Lysholm Knee Scale (LKS), the return to sport index (RSI), and the leg symmetry index (LSI) for the single leg hop test for distance in elite female athletes after ACL surgery. Materials and Methods: Fourteen weeks after rehabilitation from surgery, 40 elite female athletes (20.3 ± 3.2 years), who had undergone an ACL reconstruction, participated in a short-term (6 weeks; two times a week) training study. All participants received the same rehabilitation protocol prior to the training study. Athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and to a control group (CON: n = 10). Testing was conducted before and after the 6-week training programs and included the Y-BAL, LKS, and RSI. LSI was assessed after the 6-week training programs only. Results: Adherence rate was 100% across all groups and no training or test-related injuries were reported. No significant between-group baseline differences (pre-6-week training) were observed for any of the parameters. Significant group-by-time interactions were found for Y-BAL (p < 0.001, ES = 1.73), LKS (p < 0.001, ES = 0.76), and RSI (p < 0.001, ES = 1.39). Contrast analysis demonstrated that COMB yielded significantly greater improvements in Y-BAL, LKS, and RSI (all p < 0.001), in addition to significantly better performances in LSI (all p < 0.001), than CON, PLYO, and ECC, respectively. Conclusion: In conclusion, combined (eccentric/plyometric) training seems to represent the most effective training method as it exerts positive effects on both stability and functional performance in the post-ACL-surgical rehabilitation period of elite female athletes. KW - return-to-sport KW - anterior cruciate ligament KW - eccentric-plyometric KW - training KW - stability KW - functional performance Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.688385 SN - 1664-042X VL - 12 SP - 1 EP - 11 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Delfan, Maryam A1 - Vahed, Alieh A1 - Bishop, David A1 - Juybari, Raheleh Amadeh A1 - Laher, Ismail A1 - Saeidi, Ayoub A1 - Granacher, Urs A1 - Zouhal, Hassane T1 - Effects of two workload-matched high-intensity interval training protocols on regulatory factors associated with mitochondrial biogenesis in the soleus muscle of diabetic rats JF - Frontiers in Physiology N2 - Aims: High intensity interval training (HIIT) improves mitochondrial characteristics. This study compared the impact of two workload-matched high intensity interval training (HIIT) protocols with different work:recovery ratios on regulatory factors related to mitochondrial biogenesis in the soleus muscle of diabetic rats. Materials and methods: Twenty-four Wistar rats were randomly divided into four equal-sized groups: non-diabetic control, diabetic control (DC), diabetic with long recovery exercise [4–5 × 2-min running at 80%–90% of the maximum speed reached with 2-min of recovery at 40% of the maximum speed reached (DHIIT1:1)], and diabetic with short recovery exercise (5–6 × 2-min running at 80%–90% of the maximum speed reached with 1-min of recovery at 30% of the maximum speed reached [DHIIT2:1]). Both HIIT protocols were completed five times/week for 4 weeks while maintaining equal running distances in each session. Results: Gene and protein expressions of PGC-1α, p53, and citrate synthase of the muscles increased significantly following DHIIT1:1 and DHIIT2:1 compared to DC (p ˂ 0.05). Most parameters, except for PGC-1α protein (p = 0.597), were significantly higher in DHIIT2:1 than in DHIIT1:1 (p ˂ 0.05). Both DHIIT groups showed significant increases in maximum speed with larger increases in DHIIT2:1 compared with DHIIT1:1. Conclusion: Our findings indicate that both HIIT protocols can potently up-regulate gene and protein expression of PGC-1α, p53, and CS. However, DHIIT2:1 has superior effects compared with DHIIT1:1 in improving mitochondrial adaptive responses in diabetic rats. KW - diabetes mellitus KW - muscle metabolism KW - time-efficient exercise KW - mitochondrial adaptation KW - exercise training Y1 - 2022 U6 - https://doi.org/10.3389/fphys.2022.927969 SN - 1664-042X SP - 1 EP - 12 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Mtilatila, Lucy Mphatso Ng'ombe A1 - Bronstert, Axel A1 - Vormoor, Klaus Josef T1 - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa JF - Frontiers in Water N2 - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021–2050) and far-term period (2071–2100) with reference to 1976–2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021–2050 and between +131 and +388% during 2071–2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture. KW - meteorological drought KW - drought intensity KW - climate change KW - drought events KW - Lake Malawi KW - Shire River KW - drought projections KW - South-Eastern Africa Y1 - 2022 U6 - https://doi.org/10.3389/frwa.2022.1041452 SN - 2624-9375 SP - 1 EP - 16 PB - Frontiers Media S.A. CY - Lausanne, Schweiz ER - TY - JOUR A1 - Nobari, Hadi A1 - Mahmoudzadeh Khalili, Sara A1 - Denche Zamorano, Angel Manuel A1 - Bowman, ‪Thomas G. A1 - Granacher, Urs T1 - Workload is associated with the occurrence of non-contact injuries in professional male soccer players: A pilot study JF - Frontiers in Psychology N2 - Injuries in professional soccer are a significant concern for teams, and they are caused amongst others by high training load. This cohort study describes the relationship between workload parameters and the occurrence of non-contact injuries, during weeks with high and low workload in professional soccer players throughout the season. Twenty-one professional soccer players aged 28.3 ± 3.9 yrs. who competed in the Iranian Persian Gulf Pro League participated in this 48-week study. The external load was monitored using global positioning system (GPS, GPSPORTS Systems Pty Ltd) and the type of injury was documented daily by the team's medical staff. Odds ratio (OR) and relative risk (RR) were calculated for non-contact injuries for high- and low-load weeks according to acute (AW), chronic (CW), acute to chronic workload ratio (ACWR), and AW variation (Δ-Acute) values. By using Poisson distribution, the interval between previous and new injuries were estimated. Overall, 12 non-contact injuries occurred during high load and 9 during low load weeks. Based on the variables ACWR and Δ-AW, there was a significantly increased risk of sustaining non-contact injuries (p < 0.05) during high-load weeks for ACWR (OR: 4.67), and Δ-AW (OR: 4.07). Finally, the expected time between injuries was significantly shorter in high load weeks for ACWR [1.25 vs. 3.33, rate ratio time (RRT)] and Δ-AW (1.33 vs. 3.45, RRT) respectively, compared to low load weeks. The risk of sustaining injuries was significantly larger during high workload weeks for ACWR, and Δ-AW compared with low workload weeks. The observed high OR in high load weeks indicate that there is a significant relationship between workload and occurrence of non-contact injuries. The predicted time to new injuries is shorter in high load weeks compared to low load weeks. Therefore, the frequency of injuries is higher during high load weeks for ACWR and Δ-AW. ACWR and Δ-AW appear to be good indicators for estimating the injury risk, and the time interval between injuries. KW - ACWR KW - external load KW - football KW - prevention KW - performance KW - injury risk Y1 - 2022 U6 - https://doi.org/10.3389/fpsyg.2022.925722 SN - 1664-1078 SP - 1 EP - 9 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - EL-Ashker, Said A1 - Chaabene, Helmi A1 - Prieske, Olaf T1 - Maximal isokinetic elbow and knee flexor–extensor strength measures in combat sports athletes: the role of movement velocity and limb side JF - BMC Sports Science, Medicine and Rehabilitation N2 - Background Maximal isokinetic strength ratios of joint flexors and extensors are important parameters to indicate the level of muscular balance at the joint. Further, in combat sports athletes, upper and lower limb muscle strength is affected by the type of sport. Thus, this study aimed to examine the differences in maximal isokinetic strength of the flexors and extensors and the corresponding flexor–extensor strength ratios of the elbows and knees in combat sports athletes. Method Forty male participants (age = 22.3 ± 2.5 years) from four different combat sports (amateur boxing, taekwondo, karate, and judo; n = 10 per sport) were tested for eccentric peak torque of the elbow/knee flexors (EF/KF) and concentric peak torque of the elbow/knee extensors (EE/KE) at three different angular velocities (60, 120, and 180°/s) on the dominant and non-dominant side using an isokinetic device. Results Analyses revealed significant, large-sized group × velocity × limb interactions for EF, EE, and EF–EE ratio, KF, KE, and KF–KE ratio (p ≤ 0.03; 0.91 ≤ d ≤ 1.75). Post-hoc analyses indicated that amateur boxers displayed the largest EE strength values on the non-dominant side at ≤ 120°/s and the dominant side at ≥ 120°/s (p < 0.03; 1.21 ≤ d ≤ 1.59). The largest EF–EE strength ratios were observed on amateur boxers’ and judokas’ non-dominant side at ≥ 120°/s (p < 0.04; 1.36 ≤ d ≤ 2.44). Further, we found lower KF–KE strength measures in karate (p < 0.04; 1.12 ≤ d ≤ 6.22) and judo athletes (p ≤ 0.03; 1.60 ≤ d ≤ 5.31) particularly on the non-dominant side. Conclusions The present findings indicated combat sport-specific differences in maximal isokinetic strength measures of EF, EE, KF, and KE particularly in favor of amateur boxers on the non-dominant side. KW - Dynamometry KW - Martial arts KW - Hamstring-quadriceps ratio KW - Eccentric muscle action KW - Injury Y1 - 2022 U6 - https://doi.org/10.1186/s13102-022-00432-2 SN - 1758-2555 VL - 13 PB - Springer Nature CY - London ER - TY - THES A1 - Jongejans, Loeka Laura T1 - Organic matter stored in ice-rich permafrost T1 - Ablagerung von organischem Kohlenstoff in eisreichem Permafrost BT - future permafrost thaw and greenhouse gas release BT - zukünftige Permafrosttauen und Treibhausgasemissionen N2 - The Arctic is changing rapidly and permafrost is thawing. Especially ice-rich permafrost, such as the late Pleistocene Yedoma, is vulnerable to rapid and deep thaw processes such as surface subsidence after the melting of ground ice. Due to permafrost thaw, the permafrost carbon pool is becoming increasingly accessible to microbes, leading to increased greenhouse gas emissions, which enhances the climate warming. The assessment of the molecular structure and biodegradability of permafrost organic matter (OM) is highly needed. My research revolves around the question “how does permafrost thaw affect its OM storage?” More specifically, I assessed (1) how molecular biomarkers can be applied to characterize permafrost OM, (2) greenhouse gas production rates from thawing permafrost, and (3) the quality of OM of frozen and (previously) thawed sediments. I studied deep (max. 55 m) Yedoma and thawed Yedoma permafrost sediments from Yakutia (Sakha Republic). I analyzed sediment cores taken below thermokarst lakes on the Bykovsky Peninsula (southeast of the Lena Delta) and in the Yukechi Alas (Central Yakutia), and headwall samples from the permafrost cliff Sobo-Sise (Lena Delta) and the retrogressive thaw slump Batagay (Yana Uplands). I measured biomarker concentrations of all sediment samples. Furthermore, I carried out incubation experiments to quantify greenhouse gas production in thawing permafrost. I showed that the biomarker proxies are useful to assess the source of the OM and to distinguish between OM derived from terrestrial higher plants, aquatic plants and microbial activity. In addition, I showed that some proxies help to assess the degree of degradation of permafrost OM, especially when combined with sedimentological data in a multi-proxy approach. The OM of Yedoma is generally better preserved than that of thawed Yedoma sediments. The greenhouse gas production was highest in the permafrost sediments that thawed for the first time, meaning that the frozen Yedoma sediments contained most labile OM. Furthermore, I showed that the methanogenic communities had established in the recently thawed sediments, but not yet in the still-frozen sediments. My research provided the first molecular biomarker distributions and organic carbon turnover data as well as insights in the state and processes in deep frozen and thawed Yedoma sediments. These findings show the relevance of studying OM in deep permafrost sediments. N2 - Die Arktis ist eine der sich am schnellsten verändernden Regionen der Erde, was zum tauen des dortigen Permafrosts führt. Eisreicher Permafrost, wie der spätpleistozäne Yedoma, ist besonders anfällig für schnelle und tiefe Auftauprozesse infolge von Absenkungen der Oberfläche nach dem Schmelzen des Grundeises. Durch das Auftauen des Permafrosts wird der im Permafrost gespeicherte Kohlenstoff für Mikroben zunehmend zugänglich, was zu erhöhten Treibhausgasemissionen führt und die Klimaerwärmung verstärkt. Die Untersuchung der molekularen Struktur und der biologischen Abbaubarkeit von organischem Material (OM) im Permafrost ist dringend erforderlich. In meiner Forschung geht es um die zentrale Frage inwieweit das Auftauen des Permafrost die Speicherfähigkeit von OM beeinflusst. Insbesondere untersuchte ich (1) wie molekulare Biomarker bei der Charakterisierung von Permafrost-OM verwendet werden können, (2) Treibhausgasproduktionsraten in auftauendem Permafrost und (3) die Qualität von OM in gefrorenen und (vorher) aufgetauten Sedimenten. Dazu habe ich tiefe (bis zu 55 m) Yedoma und aufgetaute Yedoma Permafrostsedimente aus Jakutien (Republik Sacha) untersucht. Es wurden Sedimentkerne unter Thermokarstseen auf der Bykovsky-Halbinsel (südöstlich des Lenadeltas) und im Yukechi-Alas (Zentraljakutien) entnommen, und deren Biomarkerkonzentrationen gemessen. Desweiteren wurden Bodenproben von der Permafrostklippe Sobo-Sise (Lenadelta) und der Taurutschung Batagai (Jana-Hochland) genommen und untersucht. Darüber hinaus habe ich Inkubationsexperimente durchgeführt, um die Treibhausgasproduktion in auftauenden Permafrost zu quantifizieren. Ich habe gezeigt, dass Biomarker-Proxies nützlich sind, um die Quelle des OM zu ermitteln und zwischen OM aus Landpflanzen, Wasserpflanzen und mikrobieller Aktivität zu unterscheiden. Außerdem sind einige Proxies hilfreich, den Abbaugrad von Permafrost-OM zu beurteilen. Dies trifft insbesondere in Kombination mit sedimentologischen Daten in einem Multi-Proxy-Ansatz. Ich zeigte dass der OM von Yedoma im Allgemeinen besser erhalten ist als der von aufgetauten Yedoma-Sedimenten. Die Treibhausgasproduktion in den erstmalig auftauenden Permafrostsedimenten war am höchsten. Dies bedeutet, dass die gefrorenen Yedoma-Sedimente das meiste labile OM enthielten. Außerdem zeigte ich, dass sich die methanproduzierenden Gemeinschaften in den frisch aufgetauten Sedimenten etabliert hatten, jedoch nicht in den noch gefrorenen Sedimenten. Meiner Forschung hat die ersten molekularen Biomarkerverteilungen und Kohlenstoffumsatzdaten geliefert und Einsichten in den Zustand und Prozesse von gefrorenen und aufgetauten Yedoma-Sedimenten geschaffen. Diese Ergebnisse demonstrieren die Relevanz der Untersuchung von OM in tiefen Permafrostsedimenten. N2 - Het Noordpoolgebied verandert snel en permafrost ontdooit. Met name ijsrijke permafrost, zoals Yedoma uit het laat Pleistoceen, is gevoelig voor snelle en diepe dooiprocessen als gevolg van bodemdaling na het smelten van bodemijs. Door het ontdooien van permafrost wordt het permafrostkoolstofreservoir beter toegankelijk voor microben, wat tot verhoogde broeikasgasemissies leidt en de klimaatopwarming versterkt. Het is van groot belang om de moleculaire structuur en de biologische afbreekbaarheid van organisch materiaal (OM) in permafrost vast te leggen. Mijn onderzoek draait om de vraag "hoe beinvloedt permafrostdooi de OM-opslag?" Specifiek heb ik onderzocht (1) hoe moleculaire biomarkers kunnen worden gebruikt om permafrost-OM te karakteriseren, (2) wat broeikasgasproductiesnelheden in ontdooiende permafrost zijn en (3) wat de kwaliteit is van het OM in bevroren en (eerder) ontdooide sedimenten. Ik heb diepe (max. 55 m) Yedoma en ontdooide Yedoma permafrostsedimenten uit Jakoetië (republiek Sacha) onderzocht. Sedimentkernen zijn genomen onder thermokarstmeren op het Bykovsky schiereiland (ten zuidoosten van de Lenadelta) en in de Yukechi Alas (centraal Jakoetië). Ook zijn bodemmonsters genomen van de permafrostklif Sobo-Sise (Lenadelta) en de zogenaamde thaw slump Batagai (Jana-hoogvlakte). In alle monsters heb ik de biomarkerconcentraties gemeten. Ook heb ik incubatie-experimenten uitgevoerd om de broeikasgasproductie in ontdooiende permafrost te kwantificeren. Mijn onderzoek wijst uit dat de biomarkerproxies nuttig zijn bij het vaststellen van de bron van het OM en om onderscheid te kunnen maken tussen OM van landplanten, waterplanten en OM afkomstig van microbiële activiteit. Daarnaast heb ik aangetoond dat sommige proxies nuttig zijn om de mate van degradatie van het OM vast te stellen, vooral in combinatie met sedimentologische data in een multi-proxy-benadering. Het blijkt dat het OM in Yedoma over het algemeen beter bewaard gebleven is dan het OM in ontdooide Yedoma-sedimenten. De broeikasgasproductie bleek het hoogst in de voor het eerst ontdooide permafrostsedimenten, wat betekent dat de bevroren Yedoma-sedimenten het meeste labiele OM bevatten. Bovendien heb ik aangetoond dat de methaan-producerende gemeenschappen zich wel in de recentelijk ontdooide sedimenten hebben gevestigd, maar nog niet in de nog bevroren sedimenten. Mijn onderzoek heeft de eerste moleculaire biomarker- en koolstofomzetdata en inzichten opgeleverd in de toestand en processen van diepe, bevroren en ontdooide Yedoma-sedimenten. Deze resultaten tonen de relevantie van het bestuderen van OM in diepe permafrostsedimenten. KW - permafrost sediments KW - organic matter KW - molecular biomarkers KW - anaerobic incubation experiments KW - Russian Arctic KW - Permafrostsedimente KW - organisches Material KW - molekulare Biomarker KW - anaerobe Inkubationensexperimente KW - russische Arktis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-564911 ER - TY - JOUR A1 - Ramirez-Campillo, Rodrigo A1 - Moran, Jason A1 - Oliver, Jonathan L. A1 - Pedley, Jason S. A1 - Lloyd, Rhodri S. A1 - Granacher, Urs T1 - Programming Plyometric-Jump Training in Soccer: A Review JF - Sports N2 - The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., “ballistic” and “plyometric”). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1–2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24–48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research. KW - human physical conditioning KW - exercise KW - resistance training KW - muscle strength KW - plyometric exercise KW - musculoskeletal and neural physiological phenomena KW - movement KW - sports KW - football KW - youth sport Y1 - 2022 U6 - https://doi.org/10.3390/sports10060094 SN - 2075-4663 VL - 10 SP - 1 EP - 20 PB - MDPI CY - Basel, Schweiz ET - 6 ER - TY - JOUR A1 - Sariati, Dorsaf A1 - Hammami, Raouf A1 - Zouhal, Hassane A1 - Clark, Cain Craig Truman A1 - Nebigh, Ammar A1 - Chtara, Moktar A1 - Chortane, Sabri Gaied A1 - Hackney, Anthony C. A1 - Souissi, Nizar A1 - Granacher, Urs A1 - Ben Ounis, Omar ED - Trecroci, Athos T1 - Improvement of Physical Performance Following a 6 Week Change-of-Direction Training Program in Elite Youth Soccer Players of Different Maturity Levels JF - Frontiers in physiology N2 - Background: Change-of-direction (CoD) is a necessary physical ability of a field sport and may vary in youth players according to their maturation status. Objectives: The aim of this study is: to compare the effectiveness of a 6-week CoD training intervention on dynamic balance (CS-YBT), horizontal jump (5JT), speed (10 and 30-m linear sprint times), CoD with (15 m-CoD + B) and without (15 m-CoD) the ball, in youth male soccer players at different levels of maturity [pre- and post-peak height velocity (PHV)]. Materials and Methods: Thirty elite male youth soccer players aged 10–17 years from the Tunisian first division participated in this study. The players were divided into pre- (G1, n = 15) and post-PHV (G2, n = 15) groups. Both groups completed a similar 6-week training program with two sessions per week of four CoD exercises. All players completed the following tests before and after intervention: CS-YBT; 5 JT; 10, 30, and 15 m-CoD; and 15 m-CoD + B, and data were analyzed using ANCOVA. Results: All 30 players completed the study according to the study design and methodology. Adherence rate was 100% across all groups, and no training or test-related injuries were reported. Pre-PHV and post-PHV groups showed significant amelioration post-intervention for all dependent variables (after test > before test; p < 0.01, d = 0.09–1.51). ANOVA revealed a significant group × time interaction only for CS-YBT (F = 4.45; p < 0.04; η2 = 0.14), 5JT (F = 6.39; p < 0.02; η2 = 0.18), and 15 m-CoD (F = 7.88; p < 0.01; η2 = 0.22). CS-YBT, 5JT, and 15 m-CoD improved significantly in the post-PHV group (+ 4.56%, effect size = 1.51; + 4.51%, effect size = 1.05; and -3.08%, effect size = 0.51, respectively), more than the pre-PHV group (+ 2.77%, effect size = 0.85; + 2.91%, effect size = 0.54; and -1.56%, effect size = 0.20, respectively). Conclusion: The CoD training program improved balance, horizontal jump, and CoD without the ball in male preadolescent and adolescent soccer players, and this improvement was greater in the post-PHV players. The maturity status of the athletes should be considered when programming CoD training for soccer players. KW - youth soccer KW - peak height velocity KW - change of direction speed KW - training adaptation KW - football Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.668437 SN - 1664-042X VL - 12 SP - 1 EP - 8 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - THES A1 - Metz, Malte T1 - Finite fault earthquake source inversions T1 - Ausgedehnte Erdbebenquellinversion BT - implementation and testing of a novel physics-based rupture model BT - Implementierung und Validierung eines neuen selbst-ähnlichen Bruchmodels N2 - Earthquake modeling is the key to a profound understanding of a rupture. Its kinematics or dynamics are derived from advanced rupture models that allow, for example, to reconstruct the direction and velocity of the rupture front or the evolving slip distribution behind the rupture front. Such models are often parameterized by a lattice of interacting sub-faults with many degrees of freedom, where, for example, the time history of the slip and rake on each sub-fault are inverted. To avoid overfitting or other numerical instabilities during a finite-fault estimation, most models are stabilized by geometric rather than physical constraints such as smoothing. As a basis for the inversion approach of this study, we build on a new pseudo-dynamic rupture model (PDR) with only a few free parameters and a simple geometry as a physics-based solution of an earthquake rupture. The PDR derives the instantaneous slip from a given stress drop on the fault plane, with boundary conditions on the developing crack surface guaranteed at all times via a boundary element approach. As a side product, the source time function on each point on the rupture plane is not constraint and develops by itself without additional parametrization. The code was made publicly available as part of the Pyrocko and Grond Python packages. The approach was compared with conventional modeling for different earthquakes. For example, for the Mw 7.1 2016 Kumamoto, Japan, earthquake, the effects of geometric changes in the rupture surface on the slip and slip rate distributions could be reproduced by simply projecting stress vectors. For the Mw 7.5 2018 Palu, Indonesia, strike-slip earthquake, we also modelled rupture propagation using the 2D Eikonal equation and assuming a linear relationship between rupture and shear wave velocity. This allowed us to give a deeper and faster propagating rupture front and the resulting upward refraction as a new possible explanation for the apparent supershear observed at the Earth's surface. The thesis investigates three aspects of earthquake inversion using PDR: (1) to test whether implementing a simplified rupture model with few parameters into a probabilistic Bayesian scheme without constraining geometric parameters is feasible, and whether this leads to fast and robust results that can be used for subsequent fast information systems (e.g., ground motion predictions). (2) To investigate whether combining broadband and strong-motion seismic records together with near-field ground deformation data improves the reliability of estimated rupture models in a Bayesian inversion. (3) To investigate whether a complex rupture can be represented by the inversion of multiple PDR sources and for what type of earthquakes this is recommended. I developed the PDR inversion approach and applied the joint data inversions to two seismic sequences in different tectonic settings. Using multiple frequency bands and a multiple source inversion approach, I captured the multi-modal behaviour of the Mw 8.2 2021 South Sandwich subduction earthquake with a large, curved and slow rupturing shallow earthquake bounded by two faster and deeper smaller events. I could cross-validate the results with other methods, i.e., P-wave energy back-projection, a clustering analysis of aftershocks and a simple tsunami forward model. The joint analysis of ground deformation and seismic data within a multiple source inversion also shed light on an earthquake triplet, which occurred in July 2022 in SE Iran. From the inversion and aftershock relocalization, I found indications for a vertical separation between the shallower mainshocks within the sedimentary cover and deeper aftershocks at the sediment-basement interface. The vertical offset could be caused by the ductile response of the evident salt layer to stress perturbations from the mainshocks. The applications highlight the versatility of the simple PDR in probabilistic seismic source inversion capturing features of rather different, complex earthquakes. Limitations, as the evident focus on the major slip patches of the rupture are discussed as well as differences to other finite fault modeling methods. N2 - Erdbebenmodelle sind der Schlüssel zu einem detaillierten Verständnis der zugrunde liegenden Bruchprozesse. Die kinematischen oder dynamischen Brucheigenschaften werden mit Hilfe von ausgedehnten Bruchmodellen bestimmt. Dadurch können Details, wie z.B. die Bruchrichtung und -geschwindigkeit oder die Verschiebungsverteilung, aufgelöst werden. Häufig sind ausgedehnte Bruchmodelle durch sehr viele freie Parameter definiert, etwa individuelle Verschiebungen und Verschiebungsrichtungen auf den diskretisierten Bruchflächenelementen. Die große Anzahl an Parametern sorgt dafür, dass Inversionsprobleme hochgradig unterbestimmt sind. Um daraus resultierende numerische Instabilitäten zu verhinden, werden diese Modelle häufig mit zusätzlichen eher geometrischen als physikalischen Annahmen stabilisiert, z.B. im Bezug auf die Rauigkeit der Verschiebung auf der Bruchfläche. Die Basis für die Inversionsmethode in dieser Dissertaton bildet das von uns entwickelete pseudo-dynamische Bruchmodel (PDR). Die PDR basiert auf wenigen freien Parametern und einer simplen, planaren Geometrie und ergibt eine physik-gestützte Lösung für Erdbebenbrüche. Die PDR bestimmt die instantane Verschiebung basierend auf gegebenen Spannungsänderungen auf der Bruchfläche. Die Randbedingung der Spannungsänderung wird dabei zu jedem Zeitpunkt der Bruchentwicklung über eine Randelementmethode eingehalten. Als Nebenprodukt dessen kann die Herdzeitfunktion an jedem Punkt der Bruchfläche als Ergebnis des Models bestimmt werden, und muss daher nicht vorher definiert werden. Der PDR-Modellierungsansatz wurde mit anderen Modellen anhand verschiedener Erdbeben verglichen. Am Beispiel des Mw 7,1 2016 Kumamoto, Japan, Bebens konnte der Effekt einer gekrümmten Bruchfläche auf die daraus resultierenden Verschiebungsverteilung und Verschiebungsraten durch eine Projezierung der Spannungsvektoren reproduziert werden. Für das Mw 7,5 2018 Palu, Indonesien, Beben haben wir die Bruchausbreitung auf Grundlage der 2D-Eikonalgleichung und basierend auf einem angenommenen linearen Zusammenhang zwischen Bruch- und Scherwellengeschwindigkeit modelliert. Dadurch konnten wir die beobachtete Supershear-Bruchausbreitung als Ergebnis einer möglichen tiefen und daher schnelleren Bruchfront mit einer Abstrahlung an die Erdoberfläche erklären. Der PDR-Vorwärtsmodellierungs-Code wurde in den Open-Source Python Paketen Pyrocko und Grond veröffentlicht. Meine Dissertation beleuchtet drei Aspekte der Erdbebeninversion unter Zuhilfenahme der PDR: (1) Ist eine Implementation eines simplen Bruchmodels mit wenigen Parametern in ein probabalistisches Bayesisches Inversionsprogramm möglich? Kann dies schnelle und robuste Ergebnisse für weitere Folgeanwendungen, wie Bodenbeschleunigungsvorhersagen, liefern? (2) Wie hilft die Kombination aus seismischen Breitband- und Accelerometerdaten mit Nahfelddeformationsdaten, Inversionsergebnisse mit der PDR zu verbessern? (3) Können komplexe Brüche über einen multiplen PDR-Quellinversionsansatz aufgelöst werden und wenn ja, wann ist dies möglich? Ich habe den PDR-Inversionsansatz entwickelt und auf zwei Erdbeben-Sequenzen in verschiedenen tektonischen Umgebungen angewandt. Mit Hilfe von verschiedenen Datensätzen in mehreren Frequenzbändern innerhalb von einfachen und multiplen Bruchflächeninversionen konnte ich das multi-modale Mw 8,2 2021 South Sandwich Erdbeben characterisieren. Dieses bestand aus einem langen, flachen, langsam brechenden Beben entlang der gekrümmten Subduktionszone, welches durch zwei kleinere, tiefere Brüche mit schnelleren Bruchgeschwindigkeiten begrenzt wurde. Die Validierung mit Ergebnissen aus einer P-Wellen Back-Projection, der Clusteranalyse von Nachbeben und einer Tsunami-Modelierung zeigten eine hohe Konsistenz mit den PDR-Resultaten. Die Kombination von seismischen Daten und Oberflächendeformationen in einer multiplen PDR-Inversion habe ich auch zur Analyse eines Beben-Triplets vom Juni 2022 im Südosten des Irans genutzt. Die Inversionen konnten im Zusammenspiel mit relokalisierten Nachbeben einen neuen Fall von vertikaler Haupt-/Nachbebenseparation auflösen. Während die großen Hauptbeben im flachen Sediment stattfanden, sind die Nachbeben hauptsächlich entlang der tieferen Grenzfläche zwischen Sediment und kristallinem Grundgebirge aufgetreten. Eine Erklärung dafür ist das duktile Fließen einer vorhandenen Salzschicht auf der Grenzfläche, ausgelöst durch Spannungsänderungen im Zuge der Hauptbeben. Die Anwendungen konnten die Vielseitigkeit der PDR als simples Quellmodel innerhalb von seismischen Quellinversionen zeigen. Limitierungen der Inversion, wie der augenscheinliche Fokus auf den Hauptverschiebungsbereich eines Bebens, werden in dieser Arbeit genauso diskutiert wie die Einordnung der PDR im Vergleich zu anderen ausgedehnten Quellmodellen. KW - seismology KW - inversion KW - source model KW - Seismologie KW - Inversion KW - Bruchmodel Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-619745 ER - TY - THES A1 - Donges, Jonathan T1 - Complex networks in the climate system N2 - Complex network theory provides an elegant and powerful framework to statistically investigate the topology of local and long range dynamical interrelationships, i.e., teleconnections, in the climate system. Employing a refined methodology relying on linear and nonlinear measures of time series analysis, the intricate correlation structure within a multivariate climatological data set is cast into network form. Within this graph theoretical framework, vertices are identified with grid points taken from the data set representing a region on the the Earth's surface, and edges correspond to strong statistical interrelationships between the dynamics on pairs of grid points. The resulting climate networks are neither perfectly regular nor completely random, but display the intriguing and nontrivial characteristics of complexity commonly found in real world networks such as the internet, citation and acquaintance networks, food webs and cortical networks in the mammalian brain. Among other interesting properties, climate networks exhibit the "small-world" effect and possess a broad degree distribution with dominating super-nodes as well as a pronounced community structure. We have performed an extensive and detailed graph theoretical analysis of climate networks on the global topological scale focussing on the flow and centrality measure betweenness which is locally defined at each vertex, but includes global topological information by relying on the distribution of shortest paths between all pairs of vertices in the network. The betweenness centrality field reveals a rich internal structure in complex climate networks constructed from reanalysis and atmosphere-ocean coupled general circulation model (AOGCM) surface air temperature data. Our novel approach uncovers an elaborately woven meta-network of highly localized channels of strong dynamical information flow, that we relate to global surface ocean currents and dub the backbone of the climate network in analogy to the homonymous data highways of the internet. This finding points to a major role of the oceanic surface circulation in coupling and stabilizing the global temperature field in the long term mean (140 years for the model run and 60 years for reanalysis data). Carefully comparing the backbone structures detected in climate networks constructed using linear Pearson correlation and nonlinear mutual information, we argue that the high sensitivity of betweenness with respect to small changes in network structure may allow to detect the footprints of strongly nonlinear physical interactions in the climate system. The results presented in this thesis are thoroughly founded and substantiated using a hierarchy of statistical significance tests on the level of time series and networks, i.e., by tests based on time series surrogates as well as network surrogates. This is particularly relevant when working with real world data. Specifically, we developed new types of network surrogates to include the additional constraints imposed by the spatial embedding of vertices in a climate network. Our methodology is of potential interest for a broad audience within the physics community and various applied fields, because it is universal in the sense of being valid for any spatially extended dynamical system. It can help to understand the localized flow of dynamical information in any such system by combining multivariate time series analysis, a complex network approach and the information flow measure betweenness centrality. Possible fields of application include fluid dynamics (turbulence), plasma physics and biological physics (population models, neural networks, cell models). Furthermore, the climate network approach is equally relevant for experimental data as well as model simulations and hence introduces a novel perspective on model evaluation and data driven model building. Our work is timely in the context of the current debate on climate change within the scientific community, since it allows to assess from a new perspective the regional vulnerability and stability of the climate system while relying on global and not only on regional knowledge. The methodology developed in this thesis hence has the potential to substantially contribute to the understanding of the local effect of extreme events and tipping points in the earth system within a holistic global framework. N2 - Die Theorie komplexer Netzwerke bietet einen eleganten Rahmen zur statistischen Untersuchung der Topologie lokaler und langreichweitiger dynamischer Zusammenhänge (Telekonnektionen) im Klimasystem. Unter Verwendung einer verfeinerten, auf linearen und nichtlinearen Korrelationsmaßen der Zeitreihenanalyse beruhenden Netzwerkkonstruktionsmethode, bilden wir die komplexe Korrelationsstruktur eines multivariaten klimatologischen Datensatzes auf ein Netzwerk ab. Dabei identifizieren wir die Knoten des Netzwerkes mit den Gitterpunkten des zugrundeliegenden Datensatzes, während wir Paare von besonders stark korrelierten Knoten als Kanten auffassen. Die resultierenden Klimanetzwerke zeigen weder die perfekte Regularität eines Kristallgitters, noch eine vollkommen zufällige Topologie. Vielmehr weisen sie faszinierende und nichttriviale Eigenschaften auf, die charakteristisch für natürlich gewachsene Netzwerke wie z.B. das Internet, Zitations- und Bekanntschaftsnetzwerke, Nahrungsnetze und kortikale Netzwerke im Säugetiergehirn sind. Besonders erwähnenswert ist, dass in Klimanetzwerken das Kleine-Welt-Phänomen auftritt. Desweiteren besitzen sie eine breite Gradverteilung, werden von Superknoten mit sehr vielen Nachbarn dominiert, und bilden schließlich regional wohldefinierte Untergruppen von intern dicht vernetzten Knoten aus. Im Rahmen dieser Arbeit wurde eine detaillierte, graphentheoretische Analyse von Klimanetzwerken auf der globalen topologischen Skala durchgeführt, wobei wir uns auf das Netzwerkfluss- und Zentralitätsmaß Betweenness konzentrierten. Betweenness ist zwar lokal an jedem Knoten definiert, enthält aber trotzdem Informationen über die globale Netzwerktopologie. Dies beruht darauf, dass die Verteilung kürzester Pfade zwischen allen möglichen Paaren von Knoten in die Berechnung des Maßes eingeht. Das Betweennessfeld zeigt reichhaltige und zuvor verborgene Strukturen in aus Reanalyse- und Modelldaten der erdoberflächennahen Lufttemperatur gewonnenen Klimanetzen. Das durch unseren neuartigen Ansatz enthüllte Metanetzwerk, bestehend aus hochlokalisierten Kanälen stark gebündelten Informationsflusses, bringen wir mit der Oberflächenzirkulation des Weltozeans in Verbindung. In Analogie mit den gleichnamigen Datenautobahnen des Internets nennen wir dieses Metanetzwerk den Backbone des Klimanetzwerks. Unsere Ergebnisse deuten insgesamt darauf hin, dass Meeresoberflächenströmungen einen wichtigen Beitrag zur Kopplung und Stabilisierung des globalen Oberflächenlufttemperaturfeldes leisten. Wir zeigen weiterhin, dass die hohe Sensitivität des Betweennessmaßes hinsichtlich kleiner Änderungen der Netzwerktopologie die Detektion stark nichtlinearer physikalischer Wechselwirkungen im Klimasystem ermöglichen könnte. Die in dieser Arbeit vorgestellten Ergebnisse wurden mithilfe statistischer Signifikanztests auf der Zeitreihen- und Netzwerkebene gründlich auf ihre Robustheit geprüft. In Anbetracht fehlerbehafteter Daten und komplexer statistischer Zusammenhänge zwischen verschiedenen Netzwerkmaßen ist diese Vorgehensweise besonders wichtig. Weiterhin ist die Entwicklung neuer, allgemein anwendbarer Surrogate für räumlich eingebettete Netzwerke hervorzuheben, die die Berücksichtigung spezieller Klimanetzwerkeigenschaften wie z.B. der Wahrscheinlichkeitsverteilung der Kantenlängen erlauben. Unsere Methode ist universell, weil sie zum Verständnis des lokalisierten Informationsflusses in allen räumlich ausgedehnten, dynamischen Systemen beitragen kann. Deshalb ist sie innerhalb der Physik und anderer angewandter Wissenschaften von potentiell breitem Interesse. Mögliche Anwendungen könnten sich z.B. in der Fluiddynamik (Turbulenz), der Plasmaphysik und der Biophysik (Populationsmodelle, neuronale Netzwerke und Zellmodelle) finden. Darüber hinaus ist der Netzwerkansatz für experimentelle Daten sowie Modellsimulationen gültig, und eröffnet folglich neue Perspektiven für Modellevaluation und datengetriebene Modellierung. Im Rahmen der aktuellen Klimawandeldebatte stellen Klimanetzwerke einen neuartigen Satz von Analysemethoden zur Verfügung, der die Evaluation der lokalen Vulnerabilität und Stabilität des Klimasystems unter Berücksichtigung globaler Randbedingungen ermöglicht. Die in dieser Arbeit entwickelten und untersuchten Methoden könnten folglich in der Zukunft, innerhalb eines holistisch-globalen Ansatzes, zum Verständnis der lokalen Auswirkungen von Extremereignissen und Kipppunkten im Erdsystem beitragen. KW - Komplexe Netzwerke KW - Klimanetzwerke KW - Datenanalyse KW - Graphentheorie KW - Klimadaten KW - Complex networks KW - climate networks KW - data analysis KW - graph theory KW - climate data Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-49775 ER - TY - JOUR A1 - Eckert, Silvia A1 - Herden, Jasmin A1 - Stift, Marc A1 - Durka, Walter A1 - Kleunen, Mark van A1 - Joshi, Jasmin T1 - Traces of genetic but not epigenetic adaptation in the invasive goldenrod Solidago canadensis despite the absence of population structure JF - Frontiers in Ecology and Evolution N2 - Biological invasions may result from multiple introductions, which might compensate for reduced gene pools caused by bottleneck events, but could also dilute adaptive processes. A previous common-garden experiment showed heritable latitudinal clines in fitness-related traits in the invasive goldenrod Solidago canadensis in Central Europe. These latitudinal clines remained stable even in plants chemically treated with zebularine to reduce epigenetic variation. However, despite the heritability of traits investigated, genetic isolation-by-distance was non-significant. Utilizing the same specimens, we applied a molecular analysis of (epi)genetic differentiation with standard and methylation-sensitive (MSAP) AFLPs. We tested whether this variation was spatially structured among populations and whether zebularine had altered epigenetic variation. Additionally, we used genome scans to mine for putative outlier loci susceptible to selection processes in the invaded range. Despite the absence of isolation-by-distance, we found spatial genetic neighborhoods among populations and two AFLP clusters differentiating northern and southern Solidago populations. Genetic and epigenetic diversity were significantly correlated, but not linked to phenotypic variation. Hence, no spatial epigenetic patterns were detected along the latitudinal gradient sampled. Applying genome-scan approaches (BAYESCAN, BAYESCENV, RDA, and LFMM), we found 51 genetic and epigenetic loci putatively responding to selection. One of these genetic loci was significantly more frequent in populations at the northern range. Also, one epigenetic locus was more frequent in populations in the southern range, but this pattern was lost under zebularine treatment. Our results point to some genetic, but not epigenetic adaptation processes along a large-scale latitudinal gradient of S. canadensis in its invasive range. KW - AFLP KW - MSAP KW - cytosine methylation KW - spatial autocorrelation KW - genome scan Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2022.856453 SN - 2296-701X VL - 10 SP - 1 EP - 17 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Pornsawad, Pornsarp A1 - Sapsakul, Nantawan A1 - Böckmann, Christine T1 - A modified asymptotical regularization of nonlinear ill-posed problems JF - Mathematics N2 - In this paper, we investigate the continuous version of modified iterative Runge–Kutta-type methods for nonlinear inverse ill-posed problems proposed in a previous work. The convergence analysis is proved under the tangential cone condition, a modified discrepancy principle, i.e., the stopping time T is a solution of ∥𝐹(𝑥𝛿(𝑇))−𝑦𝛿∥=𝜏𝛿+ for some 𝛿+>𝛿, and an appropriate source condition. We yield the optimal rate of convergence. KW - nonlinear operator KW - regularization KW - discrepancy principle KW - asymptotic method KW - optimal rate Y1 - 2019 U6 - https://doi.org/10.3390/math7050419 SN - 2227-7390 VL - 7 PB - MDPI CY - Basel, Schweiz ET - 5 ER - TY - RPRT A1 - Borck, Rainald A1 - Mulder, Peter T1 - Energy policies and pollution in two developing country cities BT - A quantitative model T2 - CEPA Discussion Papers N2 - We study the effect of energy and transport policies on pollution in two developing country cities. We use a quantitative equilibrium model with choice of housing, energy use, residential location, transport mode, and energy technology. Pollution comes from commuting and residential energy use. The model parameters are calibrated to replicate key variables for two developing country cities, Maputo, Mozambique, and Yogyakarta, Indonesia. In the counterfactual simulations, we study how various transport and energy policies affect equilibrium pollution. Policies may be induce rebound effects from increasing residential energy use or switching to high emission modes or locations. In general, these rebound effects tend to be largest for subsidies to public transport or modern residential energy technology. T3 - CEPA Discussion Papers - 78 KW - pollution KW - energy policy KW - discrete choice KW - developing country cities Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-638472 SN - 2628-653X IS - 78 ER - TY - THES A1 - Rinne, Theresa Charlotte T1 - The effects of nutrients on bone stem cell function and regeneration N2 - Aging is associated with bone loss, which can lead to osteoporosis and high fracture risk. This coincides with the enhanced formation of bone marrow adipose tissue (BMAT), suggesting a negative effect of bone marrow adipocytes on skeletal health. Increased BMAT formation is also observed in pathologies such as obesity, type 2 diabetes and osteoporosis. However, a subset of bone marrow adipocytes forming the constitutive BMAT (cBMAT), arise early in life in the distal skeleton, contain high levels of unsaturated fatty acids and are thought to provide a physiological function. Regulated BMAT (rBMAT) forms during aging and obesity in proximal regions of the bone and contain a large proportion of saturated fatty acids. Paradoxically, BMAT accumulation is also enhanced during caloric restriction (CR), a life-span extending dietary intervention. This indicates, that different types of BMAT can form in response to opposing nutritional stimuli with potentially different functions. To this end, two types of nutritional interventions, CR and high fat diet (HFD), that are both described to induce BMAT accumulation were carried out. CR markedly increased BMAT formation in the proximal tibia and led to a higher proportion of unsaturated fatty acids, making it similar to the physiological cBMAT. Additionally, proximal and diaphyseal tibia regions displayed higher adiponectin expression. In aged mice, CR was associated with an improved trabecular bone structure. Taken together, these findings demonstrate, that the type of BMAT that forms during CR might provide beneficial effects for local bone stem/progenitor cells and metabolic health. The HFD intervention performed in this thesis showed no effect on BMAT accumulation and bone microstructure. RNA Seq analysis revealed alterations in the composition of the collagen-containing extracellular matrix (ECM). In order to investigate the effects of glucose homeostasis on osteogenesis, differentiation capacity of immortalized multipotent mesenchymal stromal cells (MSCs) and osteochondrogenic progenitor cells (OPCs) was analyzed. Insulin improved differentiation in both cell types, however, combination of with a high glucose concentration led to an impaired mineralization of the ECM. In the MSCs, this was accompanied by the formation of adipocytes, indicating negative effects of the adipocytes formed during hyperglycemic conditions on mineralization processes. However, the altered mineralization pattern and structure of the ECM was also observed in OPCs, which did not form any adipocytes, suggesting further negative effects of a hyperglycemic environment on osteogenic differentiation. In summary, the work provided in this thesis demonstrated that differentiation commitment of bone-resident stem cells can be altered through nutrient availability, specifically glucose. Surprisingly, both high nutrient supply, e.g. the hyperglycemic cell culture conditions, and low nutrient supply, e.g. CR, can induce adipogenic differentiation. However, while CR-induced adipocyte formation was associated with improved trabecular bone structure, adipocyte formation in a hyperglycemic cell-culture environment hampered mineralization. This thesis provides further evidence for the existence of different types of BMAT with specific functions. Y1 - 2024 ER - TY - THES A1 - Siegmund, Nicole T1 - Wind driven soil particle uptake Quantifying drivers of wind erosion across the particle size spectrum T1 - Partikelaufwirbelung durch Wind - Über die Quantifizierung von Winderosion über das ganze Partikel-Größenspektrum N2 - Among the multitude of geomorphological processes, aeolian shaping processes are of special character, Pedogenic dust is one of the most important sources of atmospheric aerosols and therefore regarded as a key player for atmospheric processes. Soil dust emissions, being complex in composition and properties, influence atmospheric processes and air quality and has impacts on other ecosystems. In this because even though their immediate impact can be considered low (exceptions exist), their constant and large-scale force makes them a powerful player in the earth system. dissertation, we unravel a novel scientific understanding of this complex system based on a holistic dataset acquired during a series of field experiments on arable land in La Pampa, Argentina. The field experiments as well as the generated data provide information about topography, various soil parameters, the atmospheric dynamics in the very lower atmosphere (4m height) as well as measurements regarding aeolian particle movement across a wide range of particle size classes between 0.2μm up to the coarse sand. The investigations focus on three topics: (a) the effects of low-scale landscape structures on aeolian transport processes of the coarse particle fraction, (b) the horizontal and vertical fluxes of the very fine particles and (c) the impact of wind gusts on particle emissions. Among other considerations presented in this thesis, it could in particular be shown, that even though the small-scale topology does have a clear impact on erosion and deposition patterns, also physical soil parameters need to be taken into account for a robust statistical modelling of the latter. Furthermore, specifically the vertical fluxes of particulate matter have different characteristics for the particle size classes. Finally, a novel statistical measure was introduced to quantify the impact of wind gusts on the particle uptake and its application on the provided data set. The aforementioned measure shows significantly increased particle concentrations during points in time defined as gust event. With its holistic approach, this thesis further contributes to the fundamental understanding of how atmosphere and pedosphere are intertwined and affect each other. N2 - Unter der Vielzahl geomorphologischer Prozesse nehmen äolische Formgebungsprozesse eine besondere Stellung ein, denn obwohl ihre unmittelbaren Auswirkungen als gering einzuschätzen sind (Ausnahmen existieren), sind sie aufgrund ihrer konstanten und großen Kraft ein mächtiger Akteur im Erdsystem. Pedogener Staub ist eine der wichtigsten Quellen atmosphärischer Aerosole und kann daher als Schlüsselfaktor für atmosphärische Prozesse angesehen werden. Bodenstaubemissionen, die in Zusammensetzung und Eigenschaften komplex sind, beeinflussen atmosphärische Prozesse und Luftqualität und haben Auswirkungen auf andere Ökosysteme. Um zum wissenschaftlichen Verständnis dieses komplexen Systems beizutragen, dokumentiert diese Arbeit eine Reihe von Veröffentlichungen, die alle auf einem ganzheitlichen Datensatz basieren, die während einer Reihe von Feldexperimenten auf Ackerland in La Pampa, Argentinien, gewonnen wurden. Die Feldexperimente sowie die generierten Daten liefern Informationen über Topographie, verschiedene Bodenparameter, die atmosphärische Dynamik in der unteren Atmosphäre (4 m Höhe) sowie Messungen zur äolischen Partikelbewegung über einen weiten Bereich von Partikelgrößenklassen zwischen 0,2μm und groben Sand. Die Untersuchungen konzentrieren sich auf drei Themen: Die Auswirkungen kleinräumiger Landschaftsstrukturen auf äolische Transportprozesse der groben Partikelfraktion, die horizontalen und vertikalen Strömungen der sehr feinen Partikel und der Einfluss von Windböen auf die Partikelemissionen. Neben anderen in dieser Arbeit vorgestellten Überlegungen konnte insbesondere gezeigt werden, dass, obwohl die kleinräumige Topologie einen deutlichen Einfluss auf Erosions- und Ablagerungsmuster hat, auch physikalische Bodenparameter für eine robuste statistische Modellierung berücksichtigt werden müssen. Darüber hinaus weisen speziell die vertikalen Feinstaubflüsse unterschiedliche Eigenschaften für die Partikelgrößenklassen auf. Schließlich wurde ein neuartiges statistisches Maß eingeführt, um den Einfluss von Windböen auf die Partikelkonzentration der Luft zu quantifizieren, und seine Anwendung auf den bereitgestellten Datensatz zeigt signifikant erhöhte Partikelkonzentrationen zu Zeitpunkten, die als Böen definiert wurden. Mit ihrem ganzheitlichen Ansatz trägt diese Arbeit weiter zum grundlegenden Verständnis bei, wie Atmosphäre und Pedosphäre miteinander verflochten sind und sich gegenseitig beeinflussen. KW - Winderosion KW - winderosion KW - PM10, PM2, PM1 KW - Horizontal flux KW - horizontaler Fluss KW - Vertical flux KW - vertikaler Fluss KW - Argentina KW - Argentinien KW - wind gusts KW - Windböen Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-574897 ER - TY - THES A1 - Bajerski, Felizitas T1 - Bacterial communities in glacier forefields of the Larsemann Hills, East Antarctica : structure, development & adaptation T1 - Bakterielle Gemeinschaften in Gletschervorfeldern der Larsemann Berge der Ostantarktis : Struktur, Entwicklung & Anpassung N2 - Antarctic glacier forfields are extreme environments and pioneer sites for ecological succession. The Antarctic continent shows microbial community development as a natural laboratory because of its special environment, geographic isolation and little anthropogenic influence. Increasing temperatures due to global warming lead to enhanced deglaciation processes in cold-affected habitats and new terrain is becoming exposed to soil formation and accessible for microbial colonisation. This study aims to understand the structure and development of glacier forefield bacterial communities, especially how soil parameters impact the microorganisms and how those are adapted to the extreme conditions of the habitat. To this effect, a combination of cultivation experiments, molecular, geophysical and geochemical analysis was applied to examine two glacier forfields of the Larsemann Hills, East Antarctica. Culture-independent molecular tools such as terminal restriction length polymorphism (T-RFLP), clone libraries and quantitative real-time PCR (qPCR) were used to determine bacterial diversity and distribution. Cultivation of yet unknown species was carried out to get insights in the physiology and adaptation of the microorganisms. Adaptation strategies of the microorganisms were studied by determining changes of the cell membrane phospholipid fatty acid (PLFA) inventory of an isolated bacterium in response to temperature and pH fluctuations and by measuring enzyme activity at low temperature in environmental soil samples. The two studied glacier forefields are extreme habitats characterised by low temperatures, low water availability and small oligotrophic nutrient pools and represent sites of different bacterial succession in relation to soil parameters. The investigated sites showed microbial succession at an early step of soil formation near the ice tongue in comparison to closely located but rather older and more developed soil from the forefield. At the early step the succession is influenced by a deglaciation-dependent areal shift of soil parameters followed by a variable and prevalently depth-related distribution of the soil parameters that is driven by the extreme Antarctic conditions. The dominant taxa in the glacier forefields are Actinobacteria, Acidobacteria, Proteobacteria, Bacteroidetes, Cyanobacteria and Chloroflexi. The connection of soil characteristics with bacterial community structure showed that soil parameter and soil formation along the glacier forefield influence the distribution of certain phyla. In the early step of succession the relative undifferentiated bacterial diversity reflects the undifferentiated soil development and has a high potential to shift according to past and present environmental conditions. With progressing development environmental constraints such as water or carbon limitation have a greater influence. Adapting the culturing conditions to the cold and oligotrophic environment, the number of culturable heterotrophic bacteria reached up to 108 colony forming units per gram soil and 148 isolates were obtained. Two new psychrotolerant bacteria, Herbaspirillum psychrotolerans PB1T and Chryseobacterium frigidisoli PB4T, were characterised in detail and described as novel species in the family of Oxalobacteraceae and Flavobacteriaceae, respectively. The isolates are able to grow at low temperatures tolerating temperature fluctuations and they are not specialised to a certain substrate, therefore they are well-adapted to the cold and oligotrophic environment. The adaptation strategies of the microorganisms were analysed in environmental samples and cultures focussing on extracellular enzyme activity at low temperature and PLFA analyses. Extracellular phosphatases (pH 11 and pH 6.5), β-glucosidase, invertase and urease activity were detected in the glacier forefield soils at low temperature (14°C) catalysing the conversion of various compounds providing necessary substrates and may further play a role in the soil formation and total carbon turnover of the habitat. The PLFA analysis of the newly isolated species C. frigidisoli showed that the cold-adapted strain develops different strategies to maintain the cell membrane function under changing environmental conditions by altering the PLFA inventory at different temperatures and pH values. A newly discovered fatty acid, which was not found in any other microorganism so far, significantly increased at decreasing temperature and low pH and thus plays an important role in the adaption of C. frigidisoli. This work gives insights into the diversity, distribution and adaptation mechanisms of microbial communities in oligotrophic cold-affected soils and shows that Antarctic glacier forefields are suitable model systems to study bacterial colonisation in connection to soil formation. N2 - Gletschervorfelder der Antarktis stellen extreme Habitate dar und sind Pionierstandorte biologischer Sukzession. Insbesondere unter Berücksichtigung zuletzt beobachteter und vorausgesagter Erwärmungstrends in der Antarktis und der Relevanz der Mikroorganismen für das Antarktische Ökosystem, ist es essentiell mehr Informationen über die Entwicklung frisch exponierter Gletschervorfelder zu erlangen. Ziel dieser Studie ist es, die Struktur und Entwicklung bakterieller Gletschervorfeldgemeinschaften zu verstehen, insbesondere wie die Mikroorganismen von den Bodenparametern beeinflusst werden und wie diese sich an die extremen Bedingungen des Habitats anpassen. Für die Untersuchung der Proben von zwei Gletschervorfeldern aus den Larsemann Bergen der Ostantarktis diente eine Kombination aus Kultivierungsexperimenten und molekularen, geophysikalischen und geochemischen Analysen. Die untersuchten Gletschervorfelder sind durch extrem niedrige Temperaturen, einer geringen biologischen Wasserverfügbarkeit und oligotrophe Nährstoffgehalte charakterisiert und zeigen unterschiedliche Entwicklungsstufen in Verbindung zu den Bodenparametern. In einem frühen Schritt der Bodenbildung in der Nähe der Gletscherzunge sind die Gemeinschaften undifferenziert, doch mit fortschreitender Entwicklung nimmt de Einfluss von Wasser- und Nährstofflimitationen zu. Nachdem die Kultivierungsbedingungen den kalten und nährstoffarmen Bedingungen des Habitats angepasst wurden, konnten 108 koloniebildende Einheiten heterotropher Bakterien pro Gramm Boden angereichert und daraus 148 Isolate gewonnen werden. Zwei neue psychrotolerante Bakterien, Herbaspirillum psychrotolerans PB1T und Chryseobacterium frigidisoli PB4T, wurden detailiert charakterisiert und als jeweils neue Spezies beschrieben. Die Anpassungsstrategien der Mikroorganismen an die extremen antarktischen Bedingungen zeigten sich in der Aktivität extrazellulärer Enzyme bei niedriger Temperatur, die mit derer temperierter Habitate vergleichbar ist, und in der Fähigkeit der Mikroorganismen, die Fettsäurezusammensetzung der Zellmembran zu ändern. Eine neue Fettsäure, die bisher in keinen anderen Mikroorganismus gefunden wurde, spielt eine entscheidende Rolle in der Anpassung des neu-beschriebenen Bakteriums C. frigidisoli an niedrige Temperaturen und saure pH-Werte. Diese Arbeit gibt einen Einblick in die Vielfalt, Verteilung und Anpassung mikrobieller Gemeinschaften in nährstoffarmen und Kälte-beeinflussten Habitaten und zeigt, dass Antarktische Gletschervorfelder geeignete Modellsysteme, um bakterielle Besiedelung in Verbindung zu Bodenbildung zu untersuchen. KW - Antarktis KW - Gletschervorfeld KW - mikrobielle Gemeinschaften KW - Anpassung KW - Kultivierung KW - Antarctica KW - glacier forefield KW - microbial communities KW - adaptation KW - cultivation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-67424 ER - TY - THES A1 - Aue, Lars T1 - Cyclone impacts on sea ice in the Atlantic Arctic Ocean T1 - Auswirkungen von Zyklonen auf das Meereis im Atlantischen Arktischen Ozean N2 - The Arctic is the hot spot of the ongoing, global climate change. Over the last decades, near-surface temperatures in the Arctic have been rising almost four times faster than on global average. This amplified warming of the Arctic and the associated rapid changes of its environment are largely influenced by interactions between individual components of the Arctic climate system. On daily to weekly time scales, storms can have major impacts on the Arctic sea-ice cover and are thus an important part of these interactions within the Arctic climate. The sea-ice impacts of storms are related to high wind speeds, which enhance the drift and deformation of sea ice, as well as to changes in the surface energy budget in association with air mass advection, which impact the seasonal sea-ice growth and melt. The occurrence of storms in the Arctic is typically associated with the passage of transient cyclones. Even though the above described mechanisms how storms/cyclones impact the Arctic sea ice are in principal known, there is a lack of statistical quantification of these effects. In accordance with that, the overarching objective of this thesis is to statistically quantify cyclone impacts on sea-ice concentration (SIC) in the Atlantic Arctic Ocean over the last four decades. In order to further advance the understanding of the related mechanisms, an additional objective is to separate dynamic and thermodynamic cyclone impacts on sea ice and assess their relative importance. Finally, this thesis aims to quantify recent changes in cyclone impacts on SIC. These research objectives are tackled utilizing various data sets, including atmospheric and oceanic reanalysis data as well as a coupled model simulation and a cyclone tracking algorithm. Results from this thesis demonstrate that cyclones are significantly impacting SIC in the Atlantic Arctic Ocean from autumn to spring, while there are mostly no significant impacts in summer. The strength and the sign (SIC decreasing or SIC increasing) of the cyclone impacts strongly depends on the considered daily time scale and the region of the Atlantic Arctic Ocean. Specifically, an initial decrease in SIC (day -3 to day 0 relative to the cyclone) is found in the Greenland, Barents and Kara Seas, while SIC increases following cyclones (day 0 to day 5 relative to the cyclone) are mostly limited to the Barents and Kara Seas. For the cold season, this results in a pronounced regional difference between overall (day -3 to day 5 relative to the cyclone) SIC-decreasing cyclone impacts in the Greenland Sea and overall SIC-increasing cyclone impacts in the Barents and Kara Seas. A cyclone case study based on a coupled model simulation indicates that both dynamic and thermodynamic mechanisms contribute to cyclone impacts on sea ice in winter. A typical pattern consisting of an initial dominance of dynamic sea-ice changes followed by enhanced thermodynamic ice growth after the cyclone passage was found. This enhanced ice growth after the cyclone passage most likely also explains the (statistical) overall SIC-increasing effects of cyclones in the Barents and Kara Seas in the cold season. Significant changes in cyclone impacts on SIC over the last four decades have emerged throughout the year. These recent changes are strongly varying from region to region and month to month. The strongest trends in cyclone impacts on SIC are found in autumn in the Barents and Kara Seas. Here, the magnitude of destructive cyclone impacts on SIC has approximately doubled over the last four decades. The SIC-increasing effects following the cyclone passage have particularly weakened in the Barents Sea in autumn. As a consequence, previously existing overall SIC-increasing cyclone impacts in this region in autumn have recently disappeared. Generally, results from this thesis show that changes in the state of the sea-ice cover (decrease in mean sea-ice concentration and thickness) and near-surface air temperature are most important for changed cyclone impacts on SIC, while changes in cyclone properties (i.e. intensity) do not play a significant role. N2 - Die Arktis ist der Hotspot des globalen Klimawandels. In den letzten Jahrzehnten sind die oberflächennahen Temperaturen in der Arktis fast viermal so schnell gestiegen wie im globalen Durchschnitt. Diese verstärkte Erwärmung der Arktis und die damit verbundenen raschen Umweltveränderungen werden u.a. durch Wechselwirkungen zwischen den einzelnen Komponenten des arktischen Klimasystems angetrieben. Auf täglichen bis wöchentlichen Zeitskalen können Stürme große Einflüsse auf das arktische Meereis haben und sind somit ein wichtiger Teil dieser Wechselwirkungen innerhalb des arktischen Klimas. Der Einfluss der Stürme auf das Meereis resultiert aus den hohen Windgeschwindigkeiten, welche die Drift und Verformung des Meereises verstärken, sowie aus Änderungen in der Oberflächenenergiebilanz im Zusammenhang mit der Advektion von Luftmassen, was das Wachstum und Schmelzen des Meereises beeinflusst. Das Auftreten von Stürmen in der Arktis ist oft mit dem Durchzug von Zyklonen verbunden. Obwohl die oben beschriebenen Mechanismen, wie sich Stürme/Zyklone auf das arktische Meereis auswirken, im Prinzip bekannt sind, fehlt es an einer statistischen Quantifizierung dieser Effekte. Dementsprechend ist das übergeordnete Ziel dieser Arbeit eine statistische Quantifizierung der Auswirkungen von Zyklonen auf die Meereiskonzentration (engl. Sea Ice Concentration, SIC) im atlantischen Arktischen Ozeans über die letzten vier Jahrzehnte. Um ein Verständnis für die zugrunde liegenden Mechanismen zu erlangen, besteht ein weiteres Ziel darin, die dynamischen und thermodynamischen Auswirkungen von Zyklonen auf das Meereis zu trennen und ihre relative Bedeutung zu analysieren. Zuletzt zielt diese Arbeit darauf ab, aktuelle Veränderungen der Zykloneneinflüsse auf das Meereis zu quantifizieren. Zum Erreichen dieser Forschungsziele werden verschiedene Datensätze genutzt, darunter atmosphärische und ozeanische Reanalysedaten sowie eine gekoppelte Modellsimulation und ein Algorithmus zur automatischen Identifikation von Zyklonen. Die Ergebnisse dieser Arbeit zeigen, dass Zyklone die SIC im atlantischen Arktischen Ozean von Herbst bis Frühjahr signifikant beeinflussen, während es im Sommer meist keine signifikanten Auswirkungen gibt. Die Stärke und das Vorzeichen (abnehmende oder zunehmende SIC) der Auswirkungen der Zyklone hängt stark von der betrachteten täglichen Zeitskala und der Region des Arktischen Ozeans ab. So ist ein anfänglicher Rückgang der SIC (Tag -3 bis Tag 0 relativ zum Zyklonendurchgang) in der Grönland-, der Barents- und der Karasee festzustellen, während ein SIC-Anstieg nach dem Zyklonendurchgang (Tag 0 bis Tag 5 relativ zum Zyklonendurchgang) hauptsächlich auf die Barents- und die Karasee beschränkt ist. Für die kalte Jahreszeit ergibt sich daraus ein ausgeprägter regionaler Unterschied zwischen insgesamt (Tag -3 bis Tag 5 relativ zum Zyklon) SIC-verringernden Zyklonenauswirkungen in der Grönlandsee und insgesamt SIC-erhöhenden Zyklonenauswirkungen in der Barents- und Karasee. Die Analyse spezifischer Zyklonenfälle basierend auf einer gekoppelten Modellsimulation zeigt, dass sowohl dynamische als auch thermodynamische Mechanismen zu den Auswirkungen von Zyklonen auf das Meereis im Winter beitragen. Hierbei wurde ein typisches Muster bestehend aus einer anfänglichen Dominanz dynamischer Meereisveränderungen gefolgt von verstärktem thermodynamischem Eiswachstum nach der Zyklonenpassage gefunden. Dieses verstärkte Eiswachstum nach der Zyklonenpassage erklärt u.a. auch die (statistischen) insgesamt SIC-erhöhenden Effekte von Zyklonen in der Barents- und Karasee im Winter. Signifikante Änderungen in den Auswirkungen von Zyklonen auf die SIC über die letzten vier Dekaden sind das ganze Jahr über zu finden. Diese Veränderungen variieren stark von Region zu Region und von Monat zu Monat. Die stärksten Trends in den Auswirkungen von Zyklonen auf die SIC sind im Herbst in der Barents- und Karasee zu beobachten. Hier hat sich die Stärke der zerstörerischen Auswirkungen von Zyklonen auf die SIC in den letzten vier Jahrzehnten ungefähr verdoppelt. Die SIC-erhöhenden Effekte nach der Zyklonenpassage haben sich in der Barentssee im Herbst besonders abgeschwächt. Dadurch sind zuvor existierende, insgesamt SIC-erhöhende Zyklonenauswirkungen in dieser Region und Jahreszeit zuletzt verschwunden. Generell zeigen die Ergebnisse dieser Arbeit, dass Änderungen im Zustand des Meereises (Abnahme der mittleren Meereiskonzentration und -dicke) sowie in der Lufttemperatur die veränderten Auswirkungen der Zyklonen auf die SIC antreiben, während Veränderungen in den Eigenschaften der Zyklonen (z.B. ihre Intensität) keine wesentliche Rolle spielen. KW - Arctic KW - atmosphere KW - sea ice KW - cyclones KW - meteorology KW - Arktis KW - Atmosphäre KW - Meereis KW - Zyklone KW - Meteorologie Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-634458 SP - VIII, 131 ER - TY - JOUR A1 - Wright, Michelle F. A1 - Wachs, Sebastian A1 - Huang, Zheng T1 - Adolescents’ Popularity-Motivated Aggression and Prosocial Behaviors: The Roles of Callous-Unemotional Traits and Social Status Insecurity JF - Frontiers in Psychology N2 - As competition over peer status becomes intense during adolescence, some adolescents develop insecure feelings regarding their social standing among their peers (i.e., social status insecurity). These adolescents sometimes use aggression to defend or promote their status. The aim of this study was to examine the relationships among social status insecurity, callous-unemotional (CU) traits, and popularity-motivated aggression and prosocial behaviors among adolescents, while controlling for gender. Another purpose was to examine the potential moderating role of CU traits in these relationships. Participants were 1,047 (49.2% girls; Mage = 12.44 years; age range from 11 to 14 years) in the 7th or 8th grades from a large Midwestern city. They completed questionnaires on social status insecurity, CU traits, and popularity-motivated relational aggression, physical aggression, cyberaggression, and prosocial behaviors. A structural regression model was conducted, with gender as a covariate. The model had adequate fit. Social status insecurity was associated positively with callousness, unemotional, and popularity-motivated aggression and related negatively to popularity-motivated prosocial behaviors. High social status insecurity was related to greater popularity-motivated aggression when adolescents had high callousness traits. The findings have implications for understanding the individual characteristics associated with social status insecurity. KW - social status insecurity KW - callousness KW - unemotional KW - uncaring KW - callous-unemotional traits KW - aggression KW - cyberaggression KW - prosocial Y1 - 2021 U6 - https://doi.org/10.3389/fpsyg.2021.606865 SN - 1664-1078 SP - 1 EP - 8 PB - Frontiers CY - Lausanne, Schweiz ER - TY - THES A1 - Galushchinskiy, Alexey T1 - Carbon nitride: a flexible platform for net-oxidative and net-neutral photocatalysis BT - Kohlenstoffnitrid: Eine flexible Plattform für netzoxidative und netzneutrale Photokatalyse N2 - Solar photocatalysis is the one of leading concepts of research in the current paradigm of sustainable chemical industry. For actual practical implementation of sunlight-driven catalytic processes in organic synthesis, a cheap, efficient, versatile and robust heterogeneous catalyst is necessary. Carbon nitrides are a class of organic semiconductors who are known to fulfill these requirements. First, current state of solar photocatalysis in economy, industry and lab research is overviewed, outlining EU project funding, prospective synthetic and reforming bulk processes, small scale solar organic chemistry, and existing reactor designs and prototypes, concluding feasibility of the approach. Then, the photocatalytic aerobic cleavage of oximes to corresponding aldehydes and ketones by anionic poly(heptazine imide) carbon nitride is discussed. The reaction provides a feasible method of deprotection and formation of carbonyl compounds from nitrosation products and serves as a convenient model to study chromoselectivity and photophysics of energy transfer in heterogeneous photocatalysis. Afterwards, the ability of mesoporous graphitic carbon nitride to conduct proton-coupled electron transfer was utilized for the direct oxygenation of 1,3-oxazolidin-2-ones to corresponding 1,3-oxazlidine-2,4-diones. This reaction provides an easier access to a key scaffold of diverse types of drugs and agrochemicals. Finally, a series of novel carbon nitrides based on poly(triazine imide) and poly(heptazine imide) structure was synthesized from cyanamide and potassium rhodizonate. These catalysts demonstrated a good performance in a set of photocatalytic benchmark reactions, including aerobic oxidation, dual nickel photoredox catalysis, hydrogen peroxide evolution and chromoselective transformation of organosulfur precursors. Concluding, the scope of carbon nitride utilization for net-oxidative and net-neutral photocatalytic processes was expanded, and a new tunable platform for catalyst synthesis was discovered. N2 - Die solare Photokatalyse ist eines der führenden Forschungskonzepte im aktuellen Paradigma der nachhaltigen chemischen Industrie. Für die praktische Umsetzung von sonnenlichtgetriebenen katalytischen Prozessen in der organischen Synthese ist ein billiger, effizienter, vielseitiger und robuster heterogener Katalysator erforderlich. Kohlenstoffnitride sind eine Klasse von organischen Halbleitern, von denen bekannt ist, dass sie diese Anforderungen erfüllen. Zunächst wird ein Überblick über den aktuellen Stand der solaren Photokatalyse in Wirtschaft, Industrie und Laborforschung gegeben, wobei die Finanzierung von EU-Projekten, künftige Synthese- und Reformierungsprozesse in großen Mengen, organische Solarchemie in kleinem Maßstab sowie bestehende Reaktorkonstruktionen und -prototypen beschrieben und die Durchführbarkeit des Ansatzes erläutert werden. Anschließend wird die photokatalytische aerobe Spaltung von Oximen in die entsprechenden Aldehyde und Ketone durch anionisches Poly(heptazinimid)-Kohlenstoffnitrid diskutiert. Die Reaktion stellt eine praktikable Methode zur Entschützung und Bildung von Carbonylverbindungen aus Nitrosierungsprodukten dar und dient als geeignetes Modell zur Untersuchung der Chromoselektivität und der Photophysik der Energieübertragung in der heterogenen Photokatalyse. Anschließend wurde die Fähigkeit von mesoporösem graphitischem Kohlenstoffnitrid, protonengekoppelten Elektronentransfer zu leiten, für die direkte Oxygenierung von 1,3-Oxazolidin-2-onen zu den entsprechenden 1,3-Oxazlidin-2,4-Dionen genutzt. Diese Reaktion ermöglicht einen leichteren Zugang zu einem wichtigen Gerüst für verschiedene Arten von Medikamenten und Agrochemikalien. Schließlich wurde eine Reihe neuartiger Kohlenstoffnitride auf der Basis von Poly(triazinimid)- und Poly(heptazinimid)-Strukturen aus Cyanamid und Kaliumrhodizonat synthetisiert. Diese Katalysatoren zeigten eine gute Leistung in einer Reihe von photokatalytischen Benchmark-Reaktionen, einschließlich aerober Oxidation, dualer Nickel-Photoredox-Katalyse, Wasserstoffperoxid-Evolution und chromoselektiver Umwandlung von Organoschwefel-Vorläufern. Abschließend wurde der Anwendungsbereich von Kohlenstoffnitrid für netzoxidative und netzneutrale photokatalytische Prozesse erweitert und eine neue abstimmbare Plattform für die Katalysatorsynthese entdeckt. KW - carbon nitrides KW - Kohlenstoffnitriden KW - heterogeneous photocatalysis KW - heterogene Photokatalyse KW - organic synthesis KW - organische Synthese Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-610923 ER - TY - THES A1 - Schneider, Helen T1 - Reactive eutectic media based on ammonium formate for the valorization of bio-sourced materials T1 - Reaktive eutektische Medien auf Basis von Ammoniumformiat zur Aufwertung von biobasierten Substanzen N2 - In the last several decades eutectic mixtures of different compositions were successfully used as solvents for vast amount of chemical processes, and only relatively recently they were discovered to be widely spread in nature. As such they are discussed as a third liquid media of the living cell, that is composed of common cell metabolites. Such media may also incorporate water as a eutectic component in order to regulate properties such as enzyme activity or viscosity. Taking inspiration form such sophisticated use of eutectic mixtures, this thesis will explore the use of reactive eutectic media (REM) for organic synthesis. Such unconventional media are characterized by the reactivity of their components, which means that mixture may assume the role of the solvent as well as the reactant itself. The thesis focuses on novel REM based on ammonium formate and investigates their potential for the valorization of bio-sourced materials. The use of REM allows the performance of a number of solvent-free reactions, which entails the benefits of a superior atom and energy economy, higher yields and faster rates compared to reactions in solution. This is evident for the Maillard reaction between ammonium formate and various monosaccharides for the synthesis of substituted pyrazines as well as for a Leuckart type reaction between ammonium formate and levulinic acid for the synthesis of 5-methyl-2-pyrrolidone. Furthermore, reaction of ammonium formate with citric acid for the synthesis of yet undiscovered fluorophores, shows that synthesis in REM can open up unexpected reaction pathways. Another focus of the thesis is the study of water as a third component in the REM. As a result, the concept of two different dilution regimes (tertiary REM and in REM in solvent) appears useful for understanding the influence of water. It is shown that small amounts of water can be of great benefit for the reaction, by reducing viscosity and at the same time increasing reaction yields. REM based on ammonium formate and organic acids are employed for lignocellulosic biomass treatment. The thesis thereby introduces an alternative approach towards lignocellulosic biomass fractionation that promises a considerable process intensification by the simultaneous generation of cellulose and lignin as well as the production of value-added chemicals from REM components. The thesis investigates the generated cellulose and the pathway to nanocellulose generation and also includes the structural analysis of extracted lignin. Finally, the thesis investigates the potential of microwave heating to run chemical reactions in REM and describes the synergy between these two approaches. Microwave heating for chemical reactions and the use of eutectic mixtures as alternative reaction media are two research fields that are often described in the scope of green chemistry. The thesis will therefore also contain a closer inspection of this terminology and its greater goal of sustainability. N2 - Ein eutektisches System beschreibt eine homogene Mischung verschiedener Substanzen, welche bei einer einzigen Temperatur schmilzt und dabei einen Schmelzpunkt aufweist der unterhalb der Schmelzpunkte der einzelnen Komponenten liegt. Solche Gemische können aus simplen organischen Substanzen gebildet werden und haben deshalb in den letzten Jahrzehnten große Aufmerksamkeit als neuartige Lösungsmittel erhalten. Mittlerweile wird ihr Nutzung für eine Vielzahl chemischer Prozesse erforscht. Zudem wurde Entdeckt das solche Gemische auch in der Natur Verbreitung finden. In diesem Zuge werden sie z.B. als drittes flüssiges Medium der lebenden Zelle diskutiert, welches durch eutektische Gemische von gewöhnlichen Zellmetaboliten gebildet wird. Sie können dabei auch Wasser als eutektische Komponente enthalten, um Eigenschaften wie Enzymaktivität oder Viskosität zu regulieren. Inspiriert durch diesen raffinierten Einsatz eutektischer Gemische untersucht diese Arbeit die Verwendung reaktiver eutektischer Medien (REM) für die chemische Anwendung. Solche unkonventionellen Medien zeichnen sich durch die Reaktivität ihrer Komponenten aus, was bedeutet, dass das Gemisch sowohl die Rolle des Lösungsmittels als auch des Reaktanten selbst übernehmen kann. Die Arbeit konzentriert sich auf neuartige REM auf Basis von Ammoniumformiat und untersucht deren Potenzial für die Nutzung von bio-basierten Substanzen. Die Verwendung von REM ermöglicht die Durchführung einer Reihe lösungsmittelfreier Reaktionen, was im Vergleich zu Reaktionen in Lösung die Vorteile einer besseren Atomökonomie, höhere Ausbeuten und schnellere Reaktionsgeschwindigkeiten mit sich bringt. Dies zeigt sich an der Maillard-Reaktion zwischen Ammoniumformiat und verschiedenen Monosacchariden zur Synthese substituierter Pyrazine sowie an der Leuckart-Reaktion zwischen Ammoniumformiat und Lävulinsäure zur Synthese von 5-Methyl-2-pyrrolidon. Darüber hinaus zeigt die Reaktion von Ammoniumformiat mit Zitronensäure zur Synthese noch unentdeckter Fluorophore, dass die Synthese in REM bisher unerschlossene Reaktionswege eröffnen kann. Ein weiterer Schwerpunkt der Arbeit ist die Untersuchung von Wasser als dritte Komponente im REM. Daher erscheint das Konzept zweier unterschiedlicher Verdünnungsregime (tertiäres REM und REM im Lösungsmittel) nützlich für das Verständnis des Einflusses von Wasser. Es zeigt sich, dass kleine Mengen Wasser von großem Nutzen für die Reaktion sein können, indem sie die Viskosität senken und gleichzeitig die Reaktionsausbeuten erhöhen. Für den Aufschluss von Lignocellulose werden REM auf Basis von Ammoniumformiat und organischen Säuren eingesetzt. Die Arbeit stellt damit einen neuen Ansatz für das Konzept der Bioraffinerie vor, der eine erhebliche Prozessintensivierung durch die gleichzeitige Erzeugung von Cellulose, Lignin sowie die Herstellung von Chemikalien aus REM-Komponenten verspricht. Die Arbeit untersucht die erzeugte Cellulose, sowie die Bedingungen zur Erzeugung von Nanocellulose und umfasst die Strukturanalyse von extrahiertem Lignin. Abschließend untersucht die Arbeit das Potenzial der Mikrowellenenergie zum Erhitzen chemischer Reaktionen in REM und beschreibt die Synergie zwischen diesen beiden Ansätzen. Mikrowellentechnologie für chemische Reaktionen und die Verwendung eutektischer Gemische als alternative Reaktionsmedien sind zwei Forschungsfelder, die häufig im Rahmen der Grünen Chemie beschrieben werden. Die Arbeit beinhaltet daher auch eine genauere Betrachtung dieser Terminologie und ihres übergeordneten Ziels der Nachhaltigkeit. KW - solvent-free reactions KW - deep eutectic solvents KW - microwave synthesis KW - green chemistry KW - biorefinery KW - deoxyfructosazine KW - citrazinic acid KW - Bioraffinerie KW - Citrazinsäure KW - stark eutektisches Lösungsmittel KW - Deoxyfructosazin KW - Grüne Chemie KW - Mikrowellensynthese KW - lösungsmittelfreie Synthese Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-613024 ER - TY - JOUR A1 - Wachs, Sebastian A1 - Machimbarrena, Juan Manuel A1 - Wright, Michelle F. A1 - Gámez-Guadix, Manuel A1 - Yang, Soeun A1 - Sittichai, Ruthaychonnee A1 - Singh, Ritu A1 - Biswal, Ramakrishna A1 - Flora, Katerina A1 - Daskalou, Vassiliki A1 - Maziridou, Evdoxia A1 - Sung Hong, Jun A1 - Krause, Norman T1 - Associations between Coping Strategies and Cyberhate Involvement: Evidence from Adolescents across Three World Regions JF - International Journal of Environmental Research and Public Health N2 - Cyberhate represents a risk to adolescents’ development and peaceful coexistence in democratic societies. Yet, not much is known about the relationship between adolescents’ ability to cope with cyberhate and their cyberhate involvement. To fill current gaps in the literature and inform the development of media education programs, the present study investigated various coping strategies in a hypothetical cyberhate scenario as correlates for being cyberhate victims, perpetrators, and both victim–perpetrators. The sample consisted of 6829 adolescents aged 12–18 years old (Mage = 14.93, SD = 1.64; girls: 50.4%, boys: 48.9%, and 0.7% did not indicate their gender) from Asia, Europe, and North America. Results showed that adolescents who endorsed distal advice or endorsed technical coping showed a lower likelihood to be victims, perpetrators, or victim–perpetrators. In contrast, if adolescents felt helpless or endorsed retaliation to cope with cyberhate, they showed higher odds of being involved in cyberhate as victims, perpetrators, or victim–perpetrators. Finally, adolescents who endorsed close support as a coping strategy showed a lower likelihood to be victim–perpetrators, and adolescents who endorsed assertive coping showed higher odds of being victims. In conclusion, the results confirm the importance of addressing adolescents’ ability to deal with cyberhate to develop more tailored prevention approaches. More specifically, such initiatives should focus on adolescents who feel helpless or feel inclined to retaliate. In addition, adolescents should be educated to practice distal advice and technical coping when experiencing cyberhate. Implications for the design and instruction of evidence-based cyberhate prevention (e.g., online educational games, virtual learning environments) will be discussed. KW - cyberhate KW - hate speech KW - coping strategies KW - cross-national KW - counter-speech Y1 - 2022 U6 - https://doi.org/10.3390/ijerph19116749 SN - 1660-4601 VL - 19 SP - 1 EP - 14 PB - MDPI CY - Basel, Schweiz ET - 11 ER - TY - THES A1 - Pellegrino, Antonio T1 - miRNA profiling for diagnosis of chronic pain in polyneuropathy T1 - miRNA profiling zur Diagnose von chronischem Schmerz in Polyneuropathie N2 - This dissertation aimed to determine differential expressed miRNAs in the context of chronic pain in polyneuropathy. For this purpose, patients with chronic painful polyneuropathy were compared with age matched healthy patients. Taken together, all miRNA pre library preparation quality controls were successful and none of the samples was identified as an outlier or excluded for library preparation. Pre sequencing quality control showed that library preparation worked for all samples as well as that all samples were free of adapter dimers after BluePippin size selection and reached the minimum molarity for further processing. Thus, all samples were subjected to sequencing. The sequencing control parameters were in their optimal range and resulted in valid sequencing results with strong sample to sample correlation for all samples. The resulting FASTQ file of each miRNA library was analyzed and used to perform a differential expression analysis. The differentially expressed and filtered miRNAs were subjected to miRDB to perform a target prediction. Three of those four miRNAs were downregulated: hsa-miR-3135b, hsa-miR-584-5p and hsa-miR-12136, while one was upregulated: hsa-miR-550a-3p. miRNA target prediction showed that chronic pain in polyneuropathy might be the result of a combination of miRNA mediated high blood flow/pressure and neural activity dysregulations/disbalances. Thus, leading to the promising conclusion that these four miRNAs could serve as potential biomarkers for the diagnosis of chronic pain in polyneuropathy. Since TRPV1 seems to be one of the major contributors of nociception and is associated with neuropathic pain, the influence of PKA phosphorylated ARMS on the sensitivity of TRPV1 as well as the part of AKAP79 during PKA phosphorylation of ARMS was characterized. Therefore, possible PKA-sites in the sequence of ARMS were identified. This revealed five canonical PKA-sites: S882, T903, S1251/52, S1439/40 and S1526/27. The single PKA-site mutants of ARMS revealed that PKA-mediated ARMS phosphorylation seems not to influence the interaction rate of TRPV1/ARMS. While phosphorylation of ARMST903 does not increase the interaction rate with TRPV1, ARMSS1526/27 is probably not phosphorylated and leads to an increased interaction rate. The calcium flux measurements indicated that the higher the interaction rate of TRPV1/ARMS, the lower the EC50 for capsaicin of TRPV1, independent of the PKA phosphorylation status of ARMS. In addition, the western blot analysis confirmed the previously observed TRPV1/ARMS interaction. More importantly, AKAP79 seems to be involved in the TRPV1/ARMS/PKA signaling complex. To overcome the problem of ARMS-mediated TRPV1 sensitization by interaction, ARMS was silenced by shRNA. ARMS silencing resulted in a restored TRPV1 desensitization without affecting the TRPV1 expression and therefore could be used as new topical therapeutic analgesic alternative to stop ARMS mediated TRPV1 sensitization. N2 - Ziel dieser Dissertation war es, differentiell exprimierte miRNAs im Kontext von chronischen Schmerzen bei Polyneuropathie zu bestimmen. Zu diesem Zweck wurden Patienten mit chronisch schmerzhafter Polyneuropathie und altersgleiche gesunde Patienten verglichen. Insgesamt waren alle Qualitätskontrollen zur Erstellung der miRNA-Bibliothek erfolgreich und keine der Proben wurde als Ausreißer identifiziert oder ausgeschlossen. Die Qualitätskontrolle vor der Sequenzierung zeigte, dass die Bibliothekserstellung für alle Proben funktionierte, sowie dass alle Proben frei von Adapterdimeren waren und die Mindestmolalität erreichten, woraufhin alle Proben sequenziert wurden. Die Kontrollparameter für die Sequenzierung lagen im optimalen Bereich und führten bei allen Proben zu gültigen Sequenzierungsergebnissen mit einer starken Korrelation zwischen den Proben. Die resultierende FASTQ-Datei jeder miRNA-Bibliothek wurde analysiert und für eine differenzielle Expressionsanalyse verwendet. Die differenziell exprimierten und gefilterten miRNAs wurden mittels miRDB analysiert, um eine Zielvorhersage zu erhalten. Drei dieser vier miRNAs wurden herunterreguliert: hsa-miR-3135b, hsa-miR-584-5p und hsa-miR-12136, während eine hochreguliert wurde: hsa-miR-550a-3p. Die miRNA-Zielvorhersage zeigte, dass chronische Schmerzen bei Polyneuropathie das Ergebnis von miRNA induziertem hohen Blutdruck und neuralen Aktivitätsdysregulationen sein könnten. Daraus ergibt sich die Schlussfolgerung, dass diese vier miRNAs als potenzielle Biomarker für die Diagnose von chronischen Schmerzen bei Polyneuropathie dienen könnten. Da TRPV1 mit Nozizeption und neuropathischen Schmerzen in Verbindung gebracht wird, wurde der Einfluss von PKA-phosphoryliertem ARMS auf die Sensitivität von TRPV1 sowie die Rolle von AKAP79 während der PKA-Phosphorylierung von ARMS untersucht. Dazu wurden mögliche PKA-Stellen in der Sequenz von ARMS identifiziert. Dies ergab fünf kanonische PKA-Stellen: S882, T903, S1251/52, S1439/40 und S1526/27. Die einzelnen ARMS-Mutanten zeigten, dass die PKA-vermittelte ARMS-Phosphorylierung die Interaktion von TRPV1/ARMS nicht zu beeinflussen scheint. Während die Phosphorylierung von ARMST903 die Interaktionsrate mit TRPV1 nicht erhöht, wird ARMSS1526/27 vermutlich nicht phosphoryliert und führt zu einer erhöhten Interaktionsrate. Zusätzlich zeigten Kalziumflussmessungen, dass der EC50 für Capsaicin von TRPV1 umso niedriger ist, je höher die Interaktionsrate von TRPV1/ARMS ist, unabhängig vom PKA-Phosphorylierungsstatus von ARMS. Darüber hinaus bestätigte die Western-Blot-Analyse, dass AKAP79 an dem TRPV1/ARMS/PKA-Signalkomplex beteiligt zu sein scheint. Letztlich sorgte die Stilllegung von ARMS mittels shRNA zu einer wiederhergestellten TRPV1-Desensibilisierung, ohne die TRPV1-Expression zu beeinträchtigen, und könnte als neue topische therapeutische Analgetika-Alternative verwendet werden. KW - miRNA KW - miRNA KW - chronic pain KW - chronischer Schmerz KW - polyneuropathy KW - Polyneuropathie KW - TRPV1 KW - TRPV1 KW - ARMS KW - ARMS Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-583858 ER - TY - THES A1 - Wagner, Dirk T1 - Microbial perspectives of the methane cycle in permafrost ecosystems in the Eastern Siberian Arctic : implications for the global methane budget N2 - The Arctic plays a key role in Earth’s climate system as global warming is predicted to be most pronounced at high latitudes and because one third of the global carbon pool is stored in ecosystems of the northern latitudes. In order to improve our understanding of the present and future carbon dynamics in climate sensitive permafrost ecosystems, the present study concentrates on investigations of microbial controls of methane fluxes, on the activity and structure of the involved microbial communities, and on their response to changing environmental conditions. For this purpose an integrated research strategy was applied, which connects trace gas flux measurements to soil ecological characterisation of permafrost habitats and molecular ecological analyses of microbial populations. Furthermore, methanogenic archaea isolated from Siberian permafrost have been used as potential keystone organisms for studying and assessing life under extreme living conditions. Long-term studies on methane fluxes were carried out since 1998. These studies revealed considerable seasonal and spatial variations of methane emissions for the different landscape units ranging from 0 to 362 mg m-2 d-1. For the overall balance of methane emissions from the entire delta, the first land cover classification based on Landsat images was performed and applied for an upscaling of the methane flux data sets. The regionally weighted mean daily methane emissions of the Lena Delta (10 mg m-2 d-1) are only one fifth of the values calculated for other Arctic tundra environments. The calculated annual methane emission of the Lena Delta amounts to about 0.03 Tg. The low methane emission rates obtained in this study are the result of the used remotely sensed high-resolution data basis, which provides a more realistic estimation of the real methane emissions on a regional scale. Soil temperature and near soil surface atmospheric turbulence were identified as the driving parameters of methane emissions. A flux model based on these variables explained variations of the methane budget corresponding to continuous processes of microbial methane production and oxidation, and gas diffusion through soil and plants reasonably well. The results show that the Lena Delta contributes significantly to the global methane balance because of its extensive wetland areas. The microbiological investigations showed that permafrost soils are colonized by high numbers of microorganisms. The total biomass is comparable to temperate soil ecosystems. Activities of methanogens and methanotrophs differed significantly in their rates and distribution patterns along both the vertical profiles and the different investigated soils. The methane production rates varied between 0.3 and 38.9 nmol h-1 g-1, while the methane oxidation ranged from 0.2 to 7.0 nmol h-1 g-1. Phylogenetic analyses of methanogenic communities revealed a distinct diversity of methanogens affiliated to Methanomicrobiaceae, Methanosarcinaceae and Methanosaetaceae, which partly form four specific permafrost clusters. The results demonstrate the close relationship between methane fluxes and the fundamental microbiological processes in permafrost soils. The microorganisms do not only survive in their extreme habitat but also can be metabolic active under in situ conditions. It was shown that a slight increase of the temperature can lead to a substantial increase in methanogenic activity within perennially frozen deposits. In case of degradation, this would lead to an extensive expansion of the methane deposits with their subsequent impacts on total methane budget. Further studies on the stress response of methanogenic archaea, especially Methanosarcina SMA-21, isolated from Siberian permafrost, revealed an unexpected resistance of the microorganisms against unfavourable living conditions. A better adaptation to environmental stress was observed at 4 °C compared to 28 °C. For the first time it could be demonstrated that methanogenic archaea from terrestrial permafrost even survived simulated Martian conditions. The results show that permafrost methanogens are more resistant than methanogens from non-permafrost environments under Mars-like climate conditions. Microorganisms comparable to methanogens from terrestrial permafrost can be seen as one of the most likely candidates for life on Mars due to their physiological potential and metabolic specificity. N2 - Die Arktis spielt eine Schlüsselrolle im Klimasystem unserer Erde aus zweierlei Gründen. Zum einen wird vorausgesagt, dass die globale Erwärmung in den hohen Breiten am ausgeprägtesten sein wird. Zum anderen ist ein Drittel des globalen Kohlenstoffs in Ökosystemen der nördlichen Breiten gespeichert. Um ein besseres Verständnis der gegenwärtigen und zukünftigen Entwicklung der Kohlenstoffdynamik in klimaempfindlichen Permafrostökosystemen zu erlangen, konzentriert sich die vorliegende Arbeit auf Untersuchungen zur Kontrolle der Methanflüsse durch Mikroorganismen, auf die Aktivität und Struktur der beteiligten Mikroorganismen-gemeinschaften und auf ihre Reaktion auf sich ändernde Umweltbedingungen. Zu diesem Zweck wurde eine integrierte Forschungsstrategie entwickelt, die Spurengasmessungen mit boden- und molekularökologischen Untersuchungen der Mikroorganismengemeinschaften verknüpft. Langzeitmessungen zu den Methanflüssen werden seit 1998 durchgeführt. Diese Untersuchungen zeigten beträchtliche saisonale und räumliche Schwankungen der Methanemissionen auf, die zwischen 0 und 362 mg m-2 d-1 für die untersuchten Landschaftseinheiten schwankten. Für die Bilanzierung der Methanemissionen für das gesamte Delta wurde erstmals eine Klassifikation der unterschiedlichen Landschaftseinheiten anhand von Landsat-Aufnahmen durchgeführt und für eine Hochrechnung der Methandaten genutzt. Die Mittelwerte der regional gewichteten täglichen Methanemissionen des Lenadeltas (10 mg m-2 d-1) sind nur ein Fünftel so hoch wie die berechneten Werte für andere arktische Tundren. Die errechnete jährliche Methanemission des Lenadeltas beträgt demnach ungefähr 0,03 Tg. Die geringen Methanemissionsraten dieser Studie können durch den bisher noch nicht realisierten integrativen Ansatz, der Langzeitmessungen und Landschafts-klassifizierungen beinhaltet, erklärt werden. Bodentemperatur und oberflächennahe atmosphärische Turbulenzen wurden als die antreibenden Größen der Methanfreisetzung identifiziert. Ein Modell, das auf diesen Variablen basiert, erklärt die Veränderungen der Methanflüsse gemäß der dynamischen mikrobiellen Prozesse und der Diffusion von Methan durch den Boden und die Pflanzen zutreffend. Die Ergebnisse zeigen, dass das Lenadelta erheblich zur globalen Methanemission aufgrund seiner weitreichenden Feuchtgebiete beiträgt. Die mikrobiologischen Untersuchungen zeigten, dass Permafrostböden durch eine hohe Anzahl von Mikroorganismen besiedelt wird. Die Gesamtbiomasse ist dabei mit Bodenökosystemen gemäßigter Klimate vergleichbar. Die Stoffwechselaktivitäten von methanogenen Archaeen und methanotrophen Bakterien unterschieden sich erheblich in ihrer Rate und Verteilung im Tiefenprofil sowie zwischen den verschiedenen untersuchten Böden. Die Methanbildungsrate schwankte dabei zwischen 0,3 und 38,9 nmol h-1 g-1, während die Methanoxidation eine Rate von 0,2 bis 7,0 nmol h-1 g-1 aufwies. Phylogenetische Analysen der methanogenen Mikro-organismengemeinschaften zeigten eine ausgeprägte Diversität der methanogenen Archaeen auf. Die Umweltsequenzen bildeten vier spezifische Permafrostcluster aus, die den Gruppen Methanomicrobiaceae, Methanosarcinaceae und Methano-saetaceae zugeordnet werden konnten. Die Ergebnisse zeigen, dass die Methanfreisetzung durch die zugrunde liegenden mikrobiologischen Prozesse im Permafrostboden gesteuert wird. Die beteiligten Mikroorganismen überleben nicht nur in ihrem extremen Habitat, sondern zeigten auch Stoffwechselaktivität unter in-situ-Bedingungen. Ferner konnte gezeigt werden, dass eine geringfügige Zunahme der Temperatur zu einer erheblichen Zunahme der Methanbildungsaktivität in den ständig gefrorenen Permafrostablagerungen führen kann. Im Falle der Permafrostdegradation würde dieses zu einer gesteigerten Freisetzung von Methan führen mit bisher unbekannten Auswirkungen auf das Gesamtbudget der Methanfreistzung aus arktischen Gebieten. Weitere Untersuchungen zur Stresstoleranz von methanogenen Archaeen – insbesondere des neuen Permafrostisolates Methanosarcina SMA-21 - weisen eine unerwartete Widerstandsfähigkeit der Mikroorganismen gegenüber ungünstigen Lebensbedingungen auf. Eine bessere Anpassung an Umweltstress wurde bei 4°C im Vergleich zu 28°C beobachtet. Zum ersten Mal konnte gezeigt werden, dass methanogene Archaeen aus terrestrischem Permafrost unter simulierten Marsbedingungen unbeschadet überleben. Die Ergebnisse zeigen, dass methanogene Archaeen aus Permafrostböden resistenter gegenüber Umweltstress und Marsbedingungen sind als entsprechende Mikroorganismen aus Habitaten, die nicht durch Permafrost gekennzeichnet sind. Mikroorganismen, die den Archaeen aus terrestrischen Permafrosthabitaten ähneln, können als die wahrscheinlichsten Kandidaten für mögliches Leben auf dem Mars angesehen werden. KW - Methankreislauf KW - mikrobielle Prozesse KW - Diversität KW - Spurengasflüsse KW - Permafrostökosysteme KW - methane cycle KW - microbial processes KW - diversity KW - trace gas fluxes KW - permafrost ecosystems Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-15434 ER - TY - JOUR A1 - Gebel, Arnd A1 - Busch, Aglaja A1 - Stelzel, Christine A1 - Hortobágyi, Tibor A1 - Granacher, Urs T1 - Effects of Physical and Mental Fatigue on Postural Sway and Cortical Activity in Healthy Young Adults JF - Frontiers in Human Neuroscience N2 - Physical fatigue (PF) negatively affects postural control, resulting in impaired balance performance in young and older adults. Similar effects on postural control can be observed for mental fatigue (MF) mainly in older adults. Controversial results exist for young adults. There is a void in the literature on the effects of fatigue on balance and cortical activity. Therefore, this study aimed to examine the acute effects of PF and MF on postural sway and cortical activity. Fifteen healthy young adults aged 28 ± 3 years participated in this study. MF and PF protocols comprising of an all-out repeated sit-to-stand task and a computer-based attention network test, respectively, were applied in random order. Pre and post fatigue, cortical activity and postural sway (i.e., center of pressure displacements [CoPd], velocity [CoPv], and CoP variability [CV CoPd, CV CoPv]) were tested during a challenging bipedal balance board task. Absolute spectral power was calculated for theta (4–7.5 Hz), alpha-2 (10.5–12.5 Hz), beta-1 (13–18 Hz), and beta-2 (18.5–25 Hz) in frontal, central, and parietal regions of interest (ROI) and baseline-normalized. Inference statistics revealed a significant time-by-fatigue interaction for CoPd (p = 0.009, d = 0.39, Δ 9.2%) and CoPv (p = 0.009, d = 0.36, Δ 9.2%), and a significant main effect of time for CoP variability (CV CoPd: p = 0.001, d = 0.84; CV CoPv: p = 0.05, d = 0.62). Post hoc analyses showed a significant increase in CoPd (p = 0.002, d = 1.03) and CoPv (p = 0.003, d = 1.03) following PF but not MF. For cortical activity, a significant time-by-fatigue interaction was found for relative alpha-2 power in parietal (p < 0.001, d = 0.06) areas. Post hoc tests indicated larger alpha-2 power increases after PF (p < 0.001, d = 1.69, Δ 3.9%) compared to MF (p = 0.001, d = 1.03, Δ 2.5%). In addition, changes in parietal alpha-2 power and measures of postural sway did not correlate significantly, irrespective of the applied fatigue protocol. No significant changes were found for the other frequency bands, irrespective of the fatigue protocol and ROI under investigation. Thus, the applied PF protocol resulted in increased postural sway (CoPd and CoPv) and CoP variability accompanied by enhanced alpha-2 power in the parietal ROI while MF led to increased CoP variability and alpha-2 power in our sample of young adults. Potential underlying cortical mechanisms responsible for the greater increase in parietal alpha-2 power after PF were discussed but could not be clearly identified as cause. Therefore, further future research is needed to decipher alternative interpretations. KW - balance KW - cognitive/muscular fatigue KW - EEG KW - theta KW - alpha-2 Y1 - 2022 U6 - https://doi.org/10.3389/fnhum.2022.871930 SN - 1662-5161 VL - 16 SP - 1 EP - 14 PB - Frontiers Media S.A. CY - Lausanne, Schweiz ER - TY - THES A1 - Cruz Lemus, Saul Daniel T1 - Enhancing Efficiency of Inverted Perovskite Solar Cells BT - Employing Carbon Nitride and Poly (Ionic -Liquid)s as Interlayers N2 - Carbon nitride and poly(ionic liquid)s (PILs) have been successfully applied in various fields of materials science owing to their outstanding properties. This thesis aims at the successful application of these polymers as innovative materials in the interfaces of hybrid organic–inorganic perovskite solar cells. A critical problem in harnessing the full thermodynamic potential of halide perovskites in solar cells is the design and modification of interfaces to reduce carrier recombination. Therefore, the interface must be properly studied and improved. This work investigated the effect of applying carbon nitride and PILs on a perovskite surface on the device performance. The facile synthetic method for modifying carbon nitride with vinyl thiazole and barbituric acid (CMB-vTA) yields 2.3 nm layers when solution processing is performed using isopropanol. The nanosheets were applied as a metal-free electron transport layer in inverted perovskite solar cells. The application of carbon nitride layers (CMB-vTA) resulted in negligible current-voltage hysteresis with a high open circuit voltage (Voc) of 1.1 V and a short-circuit current (Jsc) of 20.28 mA cm-2, which afforded efficiencies of up to 17%. Thus, the successful implementation of a carbon nitride-based structure enabled good charge extraction with minimized interface recombination between the perovskite and PCBM. Similarly, PILs represent a new strategy of interfacial modification using an ionic polymer in an n-i-p perovskite architecture.. The application of PILs as an interfacial modifier resulted in solar cell devices with an extraordinarily high efficiency of 21.8% and a Voc of 1.17 V. The implementation reduced non-radiative recombination at the perovskite surface through defect passivation. Finally, our work proposes a novel method to efficiently suppress non-radiative charge recombination using the unexplored properties of carbon nitride and PILs in the solar cell field. Additionally, the method for interfacial modification has general applicability because of the simplicity of the post-treatment approach, and therefore has potential applicability in other solar cells. Thus, this work opens the door to a new class of materials to be implemented. Y1 - 2020 ER - TY - JOUR A1 - Aloui, Ali A1 - Tayech, Amel A1 - Arbi Mejri, Mohamed A1 - Makhlouf, Issam A1 - Clark, Cain C. T. A1 - Granacher, Urs A1 - Zouhal, Hassane A1 - Ben Abderrahman, Abderraouf T1 - Reliability and Validity of a New Taekwondo-Specific Change-of-Direction Speed Test With Striking Techniques in Elite Taekwondo Athletes: A Pilot Study JF - Frontiers in Physiology N2 - The purpose of this study was to examine the test-retest reliability, and convergent and discriminative validity of a new taekwondo-specific change-of-direction (COD) speed test with striking techniques (TST) in elite taekwondo athletes. Twenty (10 males and 10 females) elite (athletes who compete at national level) and top-elite (athletes who compete at national and international level) taekwondo athletes with an average training background of 8.9 ± 1.3 years of systematic taekwondo training participated in this study. During the two-week test-retest period, various generic performance tests measuring COD speed, balance, speed, and jump performance were carried out during the first week and as a retest during the second week. Three TST trials were conducted with each athlete and the best trial was used for further analyses. The relevant performance measure derived from the TST was the time with striking penalty (TST-TSP). TST-TSP performances amounted to 10.57 ± 1.08 s for males and 11.74 ± 1.34 s for females. The reliability analysis of the TST performance was conducted after logarithmic transformation, in order to address the problem of heteroscedasticity. In both groups, the TST demonstrated a high relative test-retest reliability (intraclass correlation coefficients and 90% compatibility limits were 0.80 and 0.47 to 0.93, respectively). For absolute reliability, the TST’s typical error of measurement (TEM), 90% compatibility limits, and magnitudes were 4.6%, 3.4 to 7.7, for males, and 5.4%, 3.9 to 9.0, for females. The homogeneous sample of taekwondo athletes meant that the TST’s TEM exceeded the usual smallest important change (SIC) with 0.2 effect size in the two groups. The new test showed mostly very large correlations with linear sprint speed (r = 0.71 to 0.85) and dynamic balance (r = −0.71 and −0.74), large correlations with COD speed (r = 0.57 to 0.60) and vertical jump performance (r = −0.50 to −0.65), and moderate correlations with horizontal jump performance (r = −0.34 to −0.45) and static balance (r = −0.39 to −0.44). Top-elite athletes showed better TST performances than elite counterparts. Receiver operating characteristic analysis indicated that the TST effectively discriminated between top-elite and elite taekwondo athletes. In conclusion, the TST is a valid, and sensitive test to evaluate the COD speed with taekwondo specific skills, and reliable when considering ICC and TEM. Although the usefulness of the TST is questioned to detect small performance changes in the present population, the TST can detect moderate changes in taekwondo-specific COD speed. KW - taekwondo-specific testing KW - sport-specific performance KW - striking combat sports KW - sensitivity KW - taekwondo electronic scoring system Y1 - 2022 U6 - https://doi.org/10.3389/fphys.2022.774546 SN - 1664-042X VL - 13 SP - 1 EP - 15 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Jafarnezhadgero, Amir Ali A1 - Noroozi, Raha A1 - Fakhri Mirzanag, Ehsan A1 - Granacher, Urs A1 - de Souza Castelo Oliveira, Anderson T1 - The Impact of COVID-19 and Muscle Fatigue on Cardiorespiratory Fitness and Running Kinetics in Female Recreational Runners JF - Frontiers in Physiology N2 - Background: There is evidence that fully recovered COVID-19 patients usually resume physical exercise, but do not perform at the same intensity level performed prior to infection. The aim of this study was to evaluate the impact of COVID-19 infection and recovery as well as muscle fatigue on cardiorespiratory fitness and running biomechanics in female recreational runners. Methods: Twenty-eight females were divided into a group of hospitalized and recovered COVID-19 patients (COV, n = 14, at least 14 days following recovery) and a group of healthy age-matched controls (CTR, n = 14). Ground reaction forces from stepping on a force plate while barefoot overground running at 3.3 m/s was measured before and after a fatiguing protocol. The fatigue protocol consisted of incrementally increasing running speed until reaching a score of 13 on the 6–20 Borg scale, followed by steady-state running until exhaustion. The effects of group and fatigue were assessed for steady-state running duration, steady-state running speed, ground contact time, vertical instantaneous loading rate and peak propulsion force. Results: COV runners completed only 56% of the running time achieved by the CTR (p < 0.0001), and at a 26% slower steady-state running speed (p < 0.0001). There were fatigue-related reductions in loading rate (p = 0.004) without group differences. Increased ground contact time (p = 0.002) and reduced peak propulsion force (p = 0.005) were found for COV when compared to CTR. Conclusion: Our results suggest that female runners who recovered from COVID-19 showed compromised running endurance and altered running kinetics in the form of longer stance periods and weaker propulsion forces. More research is needed in this area using larger sample sizes to confirm our study findings. KW - hospitalization KW - running mechanics KW - ground reaction forces KW - virus infection KW - COVID-19 Y1 - 2022 U6 - https://doi.org/10.3389/fphys.2022.942589 SN - 1664-042X VL - 13 SP - 1 EP - 10 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Granacher, Urs A1 - Nobari, Hadi A1 - Ruivo Alves, Ana A1 - Clemente, Filipe Manuel A1 - Pérez-Gómez, Jorge A1 - Clark, Cain Craig Truman A1 - Zouhal, Hassane T1 - Associations Between Variations in Accumulated Workload and Physiological Variables in Young Male Soccer Players Over the Course of a Season JF - Frontiers in physiology N2 - This study sought to analyze the relationship between in-season training workload with changes in aerobic power (VO2max), maximum and resting heart rate (HRmax and HRrest), linear sprint medium (LSM), and short test (LSS), in soccer players younger than 16 years (under-16 soccer players). We additionally aimed to explain changes in fitness levels during the in-season through regression models, considering accumulated load, baseline levels, and peak height velocity (PHV) as predictors. Twenty-three male sub-elite soccer players aged 15.5 ± 0.2 years (PHV: 13.6 ± 0.4 years; body height: 172.7 ± 4.2 cm; body mass: 61.3 ± 5.6 kg; body fat: 13.7% ± 3.9%; VO2max: 48.4 ± 2.6 mL⋅kg–1⋅min–1), were tested three times across the season (i.e., early-season (EaS), mid-season (MiS), and end-season (EnS) for VO2max, HRmax, LSM, and LSS. Aerobic and speed variables gradually improved over the season and had a strong association with PHV. Moreover, the HRmax demonstrated improvements from EaS to EnS; however, this was more evident in the intermediate period (from EaS to MiS) and had a strong association with VO2max. Regression analysis showed significant predictions for VO2max [F(2, 20) = 8.18, p ≤ 0.001] with an R2 of 0.45. In conclusion, the meaningful variation of youth players’ fitness levels can be observed across the season, and such changes can be partially explained by the load imposed. KW - internal load KW - heart rate KW - linear sprint KW - aerobic power KW - football Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.638180 SN - 1664-042X VL - 12 SP - 1 EP - 12 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Sariati, Dorsaf A1 - Zouhal, Hassane A1 - Hammami, Raouf A1 - Clark, Cain Craig Truman A1 - Nebigh, Ammar A1 - Chtara, Moktar A1 - Hackney, Anthony C. A1 - Souissi, Nizar A1 - Granacher, Urs A1 - Ben Ounis, Omar T1 - Association Between Mental Imagery and Change of Direction Performance in Young Elite Soccer Players of Different Maturity Status JF - Frontiers in Psychology N2 - Previous studies have not considered the potential influence of maturity status on the relationship between mental imagery and change of direction (CoD) speed in youth soccer. Accordingly, this cross-sectional study examined the association between mental imagery and CoD performance in young elite soccer players of different maturity status. Forty young male soccer players, aged 10-17 years, were assigned into two groups according to their predicted age at peak height velocity (PHV) (Pre-PHV; n = 20 and Post-PHV; n = 20). Participants were evaluated on soccer-specific tests of CoD with (CoDBall-15m) and without (CoD-15m) the ball. Participants completed the movement imagery questionnaire (MIQ) with the three- dimensional structure, internal visual imagery (IVI), external visual imagery (EVI), as well as kinesthetic imagery (KI). The Post-PHV players achieved significantly better results than Pre-PHV in EVI (ES = 1.58, large; p < 0.001), CoD-15m (ES = 2.09, very large; p < 0.001) and CoDBall-15m (ES = 1.60, large; p < 0.001). Correlations were significantly different between maturity groups, where, for the pre-PHV group, a negative very large correlation was observed between CoDBall-15m and KI (r = –0.73, p = 0.001). For the post-PHV group, large negative correlations were observed between CoD-15m and IVI (r = –0.55, p = 0.011), EVI (r = –062, p = 0.003), and KI (r = –0.52, p = 0.020). A large negative correlation of CoDBall-15m with EVI (r = –0.55, p = 0.012) and very large correlation with KI (r = –0.79, p = 0.001) were also observed. This study provides evidence of the theoretical and practical use for the CoD tasks stimulus with imagery. We recommend that sport psychology specialists, coaches, and athletes integrated imagery for CoD tasks in pre-pubertal soccer players to further improve CoD related performance. KW - mental imagery KW - football KW - maturation KW - speed KW - adolescents Y1 - 2021 U6 - https://doi.org/10.3389/fpsyg.2021.665508 SN - 1664-1078 VL - 12 SP - 1 EP - 9 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Delfan, Maryam A1 - Juybari, Raheleh Amadeh A1 - Gorgani-Firuzjaee, Sattar A1 - Nielsen, Jens Høiriis A1 - Delfan, Neda A1 - Laher, Ismail A1 - Saeidi, Ayoub A1 - Granacher, Urs A1 - Zouhal, Hassane T1 - High-Intensity Interval Training Improves Cardiac Function by miR-206 Dependent HSP60 Induction in Diabetic Rats JF - Frontiers in Cardiovascular Medicine N2 - Objective: A role for microRNAs is implicated in several biological and pathological processes. We investigated the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on molecular markers of diabetic cardiomyopathy in rats. Methods: Eighteen male Wistar rats (260 ± 10 g; aged 8 weeks) with streptozotocin (STZ)-induced type 1 diabetes mellitus (55 mg/kg, IP) were randomly allocated to three groups: control, MICT, and HIIT. The two different training protocols were performed 5 days each week for 5 weeks. Cardiac performance (end-systolic and end-diastolic dimensions, ejection fraction), the expression of miR-206, HSP60, and markers of apoptosis (cleaved PARP and cytochrome C) were determined at the end of the exercise interventions. Results: Both exercise interventions (HIIT and MICT) decreased blood glucose levels and improved cardiac performance, with greater changes in the HIIT group (p < 0.001, η2: 0.909). While the expressions of miR-206 and apoptotic markers decreased in both training protocols (p < 0.001, η2: 0.967), HIIT caused greater reductions in apoptotic markers and produced a 20% greater reduction in miR-206 compared with the MICT protocol (p < 0.001). Furthermore, both training protocols enhanced the expression of HSP60 (p < 0.001, η2: 0.976), with a nearly 50% greater increase in the HIIT group compared with MICT. Conclusions: Our results indicate that both exercise protocols, HIIT and MICT, have the potential to reduce diabetic cardiomyopathy by modifying the expression of miR-206 and its downstream targets of apoptosis. It seems however that HIIT is even more effective than MICT to modulate these molecular markers. KW - diabetes KW - apoptosis KW - miRNAs KW - exercise KW - cardiomyopathy Y1 - 2022 U6 - https://doi.org/10.3389/fcvm.2022.927956 SN - 2297-055X VL - 9 SP - 1 EP - 11 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Gäbler, Martijn A1 - Berberyan, Hermine S. A1 - Prieske, Olaf A1 - Elferink-Gemser, Marije Titia A1 - Hortobágyi, Tibor A1 - Warnke, Torsten A1 - Granacher, Urs T1 - Strength Training Intensity and Volume Affect Performance of Young Kayakers/Canoeists JF - Frontiers in physiology N2 - Purpose: The aim of this study was to compare the effects of moderate intensity, low volume (MILV) vs. low intensity, high volume (LIHV) strength training on sport-specific performance, measures of muscular fitness, and skeletal muscle mass in young kayakers and canoeists. Methods: Semi-elite young kayakers and canoeists (N = 40, 13 ± 0.8 years, 11 girls) performed either MILV (70–80% 1-RM, 6–12 repetitions per set) or LIHV (30–40% 1-RM, 60–120 repetitions per set) strength training for one season. Linear mixed-effects models were used to compare effects of training condition on changes over time in 250 and 2,000 m time trials, handgrip strength, underhand shot throw, average bench pull power over 2 min, and skeletal muscle mass. Both between- and within-subject designs were used for analysis. An alpha of 0.05 was used to determine statistical significance. Results: Between- and within-subject analyses showed that monthly changes were greater in LIHV vs. MILV for the 2,000 m time trial (between: 9.16 s, SE = 2.70, p < 0.01; within: 2,000 m: 13.90 s, SE = 5.02, p = 0.01) and bench pull average power (between: 0.021 W⋅kg–1, SE = 0.008, p = 0.02; within: 0.010 W⋅kg–1, SE = 0.009, p > 0.05). Training conditions did not affect other outcomes. Conclusion: Young sprint kayakers and canoeists benefit from LIHV more than MILV strength training in terms of 2,000 m performance and muscular endurance (i.e., 2 min bench pull power). KW - youth sports KW - water sports KW - exercise test KW - athletic performance KW - anthropometry Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.686744 SN - 1664-042X VL - 12 SP - 1 EP - 10 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - THES A1 - Herrero Alonso, Yohana T1 - Properties of high-redshift galaxies in different environments T1 - Eigenschaften von Galaxien mit hoher Rotverschiebung in verschiedenen Umgebungen N2 - The Lyman-𝛼 (Ly𝛼) line commonly assists in the detection of high-redshift galaxies, the so-called Lyman-alpha emitters (LAEs). LAEs are useful tools to study the baryonic matter distribution of the high-redshift universe. Exploring their spatial distribution not only reveals the large-scale structure of the universe at early epochs, but it also provides an insight into the early formation and evolution of the galaxies we observe today. Because dark matter halos (DMHs) serve as sites of galaxy formation, the LAE distribution also traces that of the underlying dark matter. However, the details of this relation and their co-evolution over time remain unclear. Moreover, theoretical studies predict that the spatial distribution of LAEs also impacts their own circumgalactic medium (CGM) by influencing their extended Ly𝛼 gaseous halos (LAHs), whose origin is still under investigation. In this thesis, I make several contributions to improve the knowledge on these fields using samples of LAEs observed with the Multi Unit Spectroscopic Explorer (MUSE) at redshifts of 3 < 𝑧 < 6. N2 - Die Lyman-𝛼 (Ly𝛼)-Linie erleichtert die Detektion von Galaxien bei hoher Rotverschiebung, sogenannten den Lyman-Alpha-Emittern (LAEs). Die Erforschung ihrer Verteilung enthüllt nicht nur die großräumige Struktur des Universums in frühen Epochen, sondern bietet auch einen Einblick in die Entstehung und Entwicklung der Galaxien, die wir heute beobachten. Da Halos aus Dunkler Materie (DMHs) als Orte der Galaxienentstehung dienen, spiegelt die LAE-Verteilung auch die der zugrunde liegenden Dunklen Materie wider. Darüber hinaus sagen theoretische Studien voraus, dass die Verteilung von LAEs auch Auswirkungen auf ihr eigenes zirkumgalaktisches Medium (CGM) hat, indem sie ihre ausgedehnten gasförmigen Ly𝛼-Halos (LAHs) beeinflusst. In dieser Dissertation leiste ich mehrere Beiträge zur Verbesserung des Wissens über diese Felder anhand von Stichproben von LAEs, die mit dem Multi Unit Spectroscopic Explorer (MUSE) bei Rotverschiebungen von 3 < 𝑧 < 6 beobachtet wurden. KW - high-redshift KW - Lyman-alpha emitters KW - clustering KW - large-scale structure KW - Lyman-Alpha-Emitter KW - Clustering KW - hoher Rotverschiebung KW - großräumige Struktur des Universums Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-613288 ER - TY - JOUR A1 - Warschburger, Petra A1 - Wortmann, Hanna Rosalie A1 - Gisch, Ulrike Alexandra A1 - Baer, Nadja-Raphaela A1 - Schenk, Liane A1 - Anton, Verena A1 - Bergmann, Manuela M. T1 - An experimental approach to training interoceptive sensitivity BT - study protocol for a pilot randomized controlled trial JF - Nutrition Journal N2 - Background Eating in absence of hunger is quite common and often associated with an increased energy intake co-existent with a poorer food choice. Intuitive eating (IE), i.e., eating in accordance with internal hunger and satiety cues, may protect from overeating. IE, however, requires accurate perception and processing of one’s own bodily signals, also referred to as interoceptive sensitivity. Training interoceptive sensitivity might therefore be an effective method to promote IE and prevent overeating. As most studies on eating behavior are conducted in younger adults and close social relationships influence health-related behavior, this study focuses on middle-aged and older couples. Methods The present pilot randomized intervention study aims at investigating the feasibility and effectiveness of a 21-day mindfulness-based training program designed to increase interoceptive sensitivity. A total of N = 60 couples participating in the NutriAct Family Study, aged 50–80 years, will be recruited. This randomized-controlled intervention study comprises three measurement points (pre-intervention, post-intervention, 4-week follow-up) and a 21-day training that consists of daily mindfulness-based guided audio exercises (e.g., body scan). A three-arm intervention study design is applied to compare two intervention groups (training together as a couple vs. training alone) with a control group (no training). Each measurement point includes the assessment of self-reported and objective indicators of interoceptive sensitivity (primary outcome), self-reported indicators of intuitive and maladaptive eating (secondary outcomes), and additional variables. A training evaluation applying focus group discussions will be conducted to assess participants’ overall acceptance of the training and its feasibility. Discussion By investigating the feasibility and effectiveness of a mindfulness-based training program to increase interoceptive sensitivity, the present study will contribute to a deeper understanding of how to promote healthy eating in older age. KW - Digital intervention KW - Older adults KW - Interoception KW - Eating behavior KW - Intuitive eating KW - Partnership KW - Mindfulness KW - Randomized-controlled trial KW - NutriAct Family Study KW - Mixed methods Y1 - 2022 U6 - https://doi.org/10.1186/s12937-022-00827-4 SN - 1475-2891 VL - 21 PB - Springer Nature CY - London ER - TY - JOUR A1 - Stone, Kate A1 - Nicenboim, Bruno A1 - Vasishth, Shravan A1 - Rösler, Frank T1 - Understanding the effects of constraint and predictability in ERP JF - Neurobiology of language N2 - Intuitively, strongly constraining contexts should lead to stronger probabilistic representations of sentences in memory. Encountering unexpected words could therefore be expected to trigger costlier shifts in these representations than expected words. However, psycholinguistic measures commonly used to study probabilistic processing, such as the N400 event-related potential (ERP) component, are sensitive to word predictability but not to contextual constraint. Some research suggests that constraint-related processing cost may be measurable via an ERP positivity following the N400, known as the anterior post-N400 positivity (PNP). The PNP is argued to reflect update of a sentence representation and to be distinct from the posterior P600, which reflects conflict detection and reanalysis. However, constraint-related PNP findings are inconsistent. We sought to conceptually replicate Federmeier et al. (2007) and Kuperberg et al. (2020), who observed that the PNP, but not the N400 or the P600, was affected by constraint at unexpected but plausible words. Using a pre-registered design and statistical approach maximising power, we demonstrated a dissociated effect of predictability and constraint: strong evidence for predictability but not constraint in the N400 window, and strong evidence for constraint but not predictability in the later window. However, the constraint effect was consistent with a P600 and not a PNP, suggesting increased conflict between a strong representation and unexpected input rather than greater update of the representation. We conclude that either a simple strong/weak constraint design is not always sufficient to elicit the PNP, or that previous PNP constraint findings could be an artifact of smaller sample size. KW - N400 KW - anterior PNP KW - posterior P600 KW - probabilistic processing KW - constraint KW - predictability KW - entropy Y1 - 2022 U6 - https://doi.org/10.1162/nol_a_00094 SN - 2641-4368 VL - 4 IS - 2 SP - 221 EP - 256 PB - MIT Press CY - Cambridge, MA, USA ER - TY - THES A1 - Breitenbach, Sebastian Franz Martin T1 - Changes in monsoonal precipitation and atmospheric circulation during the Holocene reconstructed from stalagmites from Northeastern India T1 - Veränderungen monsunalen Niederschlages und atmosphärischer Zirkulation während des Holozäns, rekonstruiert aus Stalagmiten aus Nordostindien N2 - Recent years witnessed a vast advent of stalagmites as palaeoclimate archives. The multitude of geochemical and physical proxies and a promise of a precise and accurate age model greatly appeal to palaeoclimatologists. Although substantial progress was made in speleothem-based palaeoclimate research and despite high-resolution records from low-latitudinal regions, proving that palaeo-environmental changes can be archived on sub-annual to millennial time scales our comprehension of climate dynamics is still fragmentary. This is in particular true for the summer monsoon system on the Indian subcontinent. The Indian summer monsoon (ISM) is an integral part of the intertropical convergence zone (ITCZ). As this rainfall belt migrates northward during boreal summer, it brings monsoonal rainfall. ISM strength depends however on a variety of factors, including snow cover in Central Asia and oceanic conditions in the Indic and Pacific. Presently, many of the factors influencing the ISM are known, though their exact forcing mechanism and mutual relations remain ambiguous. Attempts to make an accurate prediction of rainfall intensity and frequency and drought recurrence, which is extremely important for South Asian countries, resemble a puzzle game; all interaction need to fall into the right place to obtain a complete picture. My thesis aims to create a faithful picture of climate change in India, covering the last 11,000 ka. NE India represents a key region for the Bay of Bengal (BoB) branch of the ISM, as it is here where the monsoon splits into a northwestward and a northeastward directed arm. The Meghalaya Plateau is the first barrier for northward moving air masses and receives excessive summer rainfall, while the winter season is very dry. The proximity of Meghalaya to the Tibetan Plateau on the one hand and the BoB on the other hand make the study area a key location for investigating the interaction between different forcings that governs the ISM. A basis for the interpretation of palaeoclimate records, and a first important outcome of my thesis is a conceptual model which explains the observed pattern of seasonal changes in stable isotopes (d18O and d2H) in rainfall. I show that although in tropical and subtropical regions the amount effect is commonly called to explain strongly depleted isotope values during enhanced rainfall, alone it cannot account for observed rainwater isotope variability in Meghalaya. Monitoring of rainwater isotopes shows no expected negative correlation between precipitation amount and d18O of rainfall. In turn I find evidence that the runoff from high elevations carries an inherited isotopic signature into the BoB, where during the ISM season the freshwater builds a strongly depleted plume on top of the marine water. The vapor originating from this plume is likely to memorize' and transmit further very negative d18O values. The lack of data does not allow for quantication of this plume effect' on isotopes in rainfall over Meghalaya but I suggest that it varies on seasonal to millennial timescales, depending on the runoff amount and source characteristics. The focal point of my thesis is the extraction of climatic signals archived in stalagmites from NE India. High uranium concentration in the stalagmites ensured excellent age control required for successful high-resolution climate reconstructions. Stable isotope (d18O and d13C) and grey-scale data allow unprecedented insights into millennial to seasonal dynamics of the summer and winter monsoon in NE India. ISM strength (i. e. rainfall amount) is recorded in changes in d18Ostalagmites. The d13C signal, reflecting drip rate changes, renders a powerful proxy for dry season conditions, and shows similarities to temperature-related changes on the Tibetan Plateau. A sub-annual grey-scale profile supports a concept of lower drip rate and slower stalagmite growth during dry conditions. During the Holocene, ISM followed a millennial-scale decrease of insolation, with decadal to centennial failures resulting from atmospheric changes. The period of maximum rainfall and enhanced seasonality corresponds to the Holocene Thermal Optimum observed in Europe. After a phase of rather stable conditions, 4.5 kyr ago, the strengthening ENSO system dominated the ISM. Strong El Nino events weakened the ISM, especially when in concert with positive Indian Ocean dipole events. The strongest droughts of the last 11 kyr are recorded during the past 2 kyr. Using the advantage of a well-dated stalagmite record at hand I tested the application of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to detect sub-annual to sub-decadal changes in element concentrations in stalagmites. The development of a large ablation cell allows for ablating sample slabs of up to 22 cm total length. Each analyzed element is a potential proxy for different climatic parameters. Combining my previous results with the LAICP- MS-generated data shows that element concentration depends not only on rainfall amount and associated leaching from the soil. Additional factors, like biological activity and hydrogeochemical conditions in the soil and vadose zone can eventually affect the element content in drip water and in stalagmites. I present a theoretical conceptual model for my study site to explain how climatic signals can be transmitted and archived in stalagmite carbonate. Further, I establish a first 1500 year long element record, reconstructing rainfall variability. Additionally, I hypothesize that volcanic eruptions, producing large amounts of sulfuric acid, can influence soil acidity and hence element mobilization. N2 - Stalagmiten erfuhren in den letzten Jahren vermehrt Aufmerksamkeit als bedeutende Paläoklima- Archive. Paläoklimatologen sind beeindruckt von der grossen Zahl geochemischer und physikalischer Indikatoren (Proxies) und der Möglichkeit, präzise absolute Altersmodelle zu erstellen. Doch obwohl substantielle Fortschritte in der speleothem-basierten Klimaforschung gemacht wurden, und trotz hochaufgelöster Archive aus niederen Breiten, welche zeigen, das Umweltveränderungen auf Zeitskalen von Jahren bis Jahrtausenden archiviert und rekonstruiert werden können, bleibt unser Verständnis der Klimadynamik fragmentarisch. Ganz besonders gilt dies für den Indischen Sommermonsun (ISM) auf dem Indischen Subkontinent. Der ISM ist heute als ein integraler Bestandteil der intertropischen Konvergenzzone verstanden. Sobald dieser Regengürtel während des borealen Sommer nordwärts migriert kann der ISM seine feuchten Luftmassen auf dem Asiatischen Festland entladen. Dabei hängt die Stärke des ISM von einer Vielzahl von Faktoren ab. Zu diesen gehören die Schneedicke in Zentralasien im vorhergehenden Winter und ozeanische Bedingungen im Indischen und Pazifschen Ozean. Heute sind viele dieser Faktoren bekannt. Trotzdem bleiben deren Mechanismen und internen Verbindungen weiterhin mysteriös. Versuche, korrekte Vorhersagen zu Niederschlagsintensität und Häufigkeit oder zu Dürreereignissen zu erstellen ähneln einem Puzzle. All die verschiedenen Interaktionen müssen an die richtige Stelle gelegt werden, um ein sinnvolles Bild entstehen zu lassen. Meine Dissertation versucht, ein vertrauenswürdiges Bild des sich wandelnden Holozänen Klimas in Indien zu erstellen. NE Indien ist eine Schlüsselregion für den östlichen Arm des ISM, da sich hier der ISM in zwei Arme aufteilt, einen nordwestwärts und einen nordostwärts gerichteten. Das Meghalaya Plateau ist das erste Hindernis für die sich nordwärts bewegenden Luftmassen und erhält entsprechend exzessive Niederschläge während des Sommers. Die winterliche Jahreszeit dagegen ist sehr trocken. Die Nähe zum Tibetplateau einerseits und der Bucht von Bengalen andererseits determinieren die Schlüsselposition dieser Region für das Studium der Interaktionen der den ISM beeinflussenden Kräfte. Ein Fundament für die Interpretation der Paläoklimarecords und ein erstes wichtiges Ergebnis meiner Arbeit ist ein konzeptuelles Modell, welches die beobachteten saisonalen Veränderungen stabiler Isotope (d18O und d2H) im Niederschlag erklärt. Ich zeige, das obwohl in tropischen und subtropischen Regionen meist der amount effect zur Erklärung stark negativer Isotopenwerte während starker Niederschläge herangezogen wird, dieser allein nicht ausreicht, um die Isotopenvariabilität im Niederschlag Meghalaya's zu erklären. Die Langzeitbeobachtung der Regenwasserisotopie zeigt keine negative Korrelation zwischen Niederschlagsmenge und d18O. Es finden sich Hinweise, das der Abfluss aus den Hochgebirgsregionen Tibets und des Himalaya eine Isotopensignatur an das Oberflächenwasser der Bucht von Bengalen vererbt. Dort bildet sich aus isotopisch stark abgereicherten Wässern während des ISM eine Süsswasserlinse aus. Es ist wahrscheinlich, das Wasserdampf, der aus dieser Linse stammt, ein Isotopensignal aufgeprägt bekommt, welches abgereichertes d18O weitertransportiert. Der Mangel an Daten lässt es bisher leider nicht zu, quantitative Aussagen über den Einfluss dieses plume effect' auf Niederschläge in Meghalaya zu treffen. Es lässt sich allerdings vermuten, das dieser Einfluss auf saisonalen wie auch auf langen Zeitskalen variabel ist, abhängig vom Abfluss und der Quellencharacteristik. Der Fokus meiner Arbeit liegt in der Herauslösung klimatischer Signale aus nordostindischen Stalagmiten. Hohe Urankonzentrationen in diesen Stalagmiten erlaubt eine exzellente Alterskontrolle, die für hochauflösende Klimarekonstruktionen unerlässlich ist. Die stabilen Isotope (d18O und d13C), sowie Grauwertdaten, erlauben einmalige Einblicke in die Dynamik des Sommer und auch des Wintermonsun in NE Indien. Die ISM Stärke (d. h. Niederschlagsmenge) wird in Veränderungen in den d18Ostalagmites reflektiert. Das d13C Signal, welches Tropfratenänderungen speichert, dient als potenter Indikator für winterliche Trockenheitsbedingungen. Es zeigt Ähnlichkeit zu temperaturabhängigen Veränderungen auf dem Tibetplateau. Das sub-annuell aufgelöste Grauwertprofil stärkt das Konzept, das verminderte Tropfraten und langsameres Stalagmitenwachstum eine Folge von Trockenheit sind. Während des Holozäns folgte der ISM der jahrtausendelangen Verringerung der Insolation. Es finden sich aber ebenso rapide Anomalien, die aus atmosphärischen Veränderungen resultieren. Die Phase des höchsten Niederschlages und erhöhter Saisonalität korrespondiert mit dem Holozänen Thermalen Maximum. Nach einer Phase einigermassen stabilen Bedingungen begann vor ca. 4500 Jahren ENSO einen zunehmenden Einfluss auf den ISM auszuüben. Starke El Nino Ereignisse schwächen den ISM, besonders wenn diese zeitgleich mit positiven Indian Ocean Dipole Ereignissen auftreten. Die stärksten Dürren des gesamten Holozäns traten in den letzten 2000 Jahren auf. Um zusätzliche Informationen aus den hervorragenden Proben zu gewinnen nutzte ich die Vorteile der laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Diese erlaubt die Detektion sub-annueller bis sub-dekadischer Elementkonzentrationsveränderungen in Stalagmiten. Mittels einer neu entwickelten Ablationszelle konnten Proben von maximal 22 cm Länge untersucht werden. Jedes analysierte Element ist ein potentieller Träger einer Klimainformation. Die Kombination der früheren Ergebnisse mit denen der LA-IPC-MS zeigt, das die Elementkonzentrationen nicht nur von Niederschlagsveränderungen und assoziiertem Auswaschen aus dem Boden abhängen. Zusätzlich können auch die biologische Aktivität und hydrogeochemische Bedingungen in der vadosen Zone Einfluss auf die Elementzusammensetzung im Tropfwasser und in den Stalagmiten haben. Darum entwickelte ich ein theoretisches Modell für meinen Standort, um zu klären, wie Klimasignale von der Atmosphäre in die Höhle transportiert werden können. Ein anschliessend rekonstruierter 1500 Jahre langer Proxyrecord zeigt Niederschlagsvariabilität an. Zudem besteht die Möglichkeit, das Vulkaneruptionen, welche grosse Mengen an Schwefelsäure produzieren, eine Bodenversauerung verursachen und damit die Elementmobilisierung verstärken können. KW - Indischer Sommermonsun KW - Stabile Isotope KW - Stalagmiten KW - Holozän KW - Bucht von Bengalen KW - Indian Summer Monsoon KW - Bay of Bengal KW - stable isotopes KW - stalagmites KW - Laser ablation Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-37807 ER - TY - THES A1 - Sieg, Tobias T1 - Reliability of flood damage estimations across spatial scales T1 - Verlässlichkeit von Hochwasserschadensschätzungen über räumliche Skalen N2 - Extreme Naturereignisse sind ein integraler Bestandteil der Natur der Erde. Sie werden erst dann zu Gefahren für die Gesellschaft, wenn sie diesen Ereignissen ausgesetzt ist. Dann allerdings können Naturgefahren verheerende Folgen für die Gesellschaft haben. Besonders hydro-meteorologische Gefahren wie zum Beispiel Flusshochwasser, Starkregenereignisse, Winterstürme, Orkane oder Tornados haben ein hohes Schadenspotential und treten rund um den Globus auf. Einhergehend mit einer immer wärmer werdenden Welt, werden auch Extremwetterereignisse, welche potentiell Naturgefahren auslösen können, immer wahrscheinlicher. Allerdings trägt nicht nur eine sich verändernde Umwelt zur Erhöhung des Risikos von Naturgefahren bei, sondern auch eine sich verändernde Gesellschaft. Daher ist ein angemessenes Risikomanagement erforderlich um die Gesellschaft auf jeder räumlichen Ebene an diese Veränderungen anzupassen. Ein essentieller Bestandteil dieses Managements ist die Abschätzung der ökonomischen Auswirkungen der Naturgefahren. Bisher allerdings fehlen verlässliche Methoden um die Auswirkungen von hydro-meteorologischen Gefahren abzuschätzen. Ein Hauptbestandteil dieser Arbeit ist daher die Entwicklung und Anwendung einer neuen Methode, welche die Verlässlichkeit der Schadensschätzung verbessert. Die Methode wurde beispielhaft zur Schätzung der ökonomischen Auswirkungen eines Flusshochwassers auf einzelne Unternehmen bis hin zu den Auswirkungen auf das gesamte Wirtschaftssystem Deutschlands erfolgreich angewendet. Bestehende Methoden geben meist wenig Information über die Verlässlichkeit ihrer Schätzungen. Da diese Informationen Entscheidungen zur Anpassung an das Risiko erleichtern, wird die Verlässlichkeit der Schadensschätzungen mit der neuen Methode dargestellt. Die Verlässlichkeit bezieht sich dabei nicht nur auf die Schadensschätzung selber, sondern auch auf die Annahmen, die über betroffene Gebäude gemacht werden. Nach diesem Prinzip kann auch die Verlässlichkeit von Annahmen über die Zukunft dargestellt werden, dies ist ein wesentlicher Aspekt für Prognosen. Die Darstellung der Verlässlichkeit und die erfolgreiche Anwendung zeigt das Potential der Methode zur Verwendung von Analysen für gegenwärtige und zukünftige hydro-meteorologische Gefahren. N2 - Natural extreme events are an integral part of nature on planet earth. Usually these events are only considered hazardous to humans, in case they are exposed. In this case, however, natural hazards can have devastating impacts on human societies. Especially hydro-meteorological hazards have a high damage potential in form of e.g. riverine and pluvial floods, winter storms, hurricanes and tornadoes, which can occur all over the globe. Along with an increasingly warm climate also an increase in extreme weather which potentially triggers natural hazards can be expected. Yet, not only changing natural systems, but also changing societal systems contribute to an increasing risk associated with these hazards. These can comprise increasing exposure and possibly also increasing vulnerability to the impacts of natural events. Thus, appropriate risk management is required to adapt all parts of society to existing and upcoming risks at various spatial scales. One essential part of risk management is the risk assessment including the estimation of the economic impacts. However, reliable methods for the estimation of economic impacts due to hydro-meteorological hazards are still missing. Therefore, this thesis deals with the question of how the reliability of hazard damage estimates can be improved, represented and propagated across all spatial scales. This question is investigated using the specific example of economic impacts to companies as a result of riverine floods in Germany. Flood damage models aim to describe the damage processes during a given flood event. In other words they describe the vulnerability of a specific object to a flood. The models can be based on empirical data sets collected after flood events. In this thesis tree-based models trained with survey data are used for the estimation of direct economic flood impacts on the objects. It is found that these machine learning models, in conjunction with increasing sizes of data sets used to derive the models, outperform state-of-the-art damage models. However, despite the performance improvements induced by using multiple variables and more data points, large prediction errors remain at the object level. The occurrence of the high errors was explained by a further investigation using distributions derived from tree-based models. The investigation showed that direct economic impacts to individual objects cannot be modeled by a normal distribution. Yet, most state-of-the-art approaches assume a normal distribution and take mean values as point estimators. Subsequently, the predictions are unlikely values within the distributions resulting in high errors. At larger spatial scales more objects are considered for the damage estimation. This leads to a better fit of the damage estimates to a normal distribution. Consequently, also the performance of the point estimators get better, although large errors can still occur due to the variance of the normal distribution. It is recommended to use distributions instead of point estimates in order to represent the reliability of damage estimates. In addition current approaches also mostly ignore the uncertainty associated with the characteristics of the hazard and the exposed objects. For a given flood event e.g. the estimation of the water level at a certain building is prone to uncertainties. Current approaches define exposed objects mostly by the use of land use data sets. These data sets often show inconsistencies, which introduce additional uncertainties. Furthermore, state-of-the-art approaches also imply problems of missing consistency when predicting the damage at different spatial scales. This is due to the use of different types of exposure data sets for model derivation and application. In order to face these issues a novel object-based method was developed in this thesis. The method enables a seamless estimation of hydro-meteorological hazard damage across spatial scales including uncertainty quantification. The application and validation of the method resulted in plausible estimations at all spatial scales without overestimating the uncertainty. Mainly newly available data sets containing individual buildings make the application of the method possible as they allow for the identification of flood affected objects by overlaying the data sets with water masks. However, the identification of affected objects with two different water masks revealed huge differences in the number of identified objects. Thus, more effort is needed for their identification, since the number of objects affected determines the order of magnitude of the economic flood impacts to a large extent. In general the method represents the uncertainties associated with the three components of risk namely hazard, exposure and vulnerability, in form of probability distributions. The object-based approach enables a consistent propagation of these uncertainties in space. Aside from the propagation of damage estimates and their uncertainties across spatial scales, a propagation between models estimating direct and indirect economic impacts was demonstrated. This enables the inclusion of uncertainties associated with the direct economic impacts within the estimation of the indirect economic impacts. Consequently, the modeling procedure facilitates the representation of the reliability of estimated total economic impacts. The representation of the estimates' reliability prevents reasoning based on a false certainty, which might be attributed to point estimates. Therefore, the developed approach facilitates a meaningful flood risk management and adaptation planning. The successful post-event application and the representation of the uncertainties qualifies the method also for the use for future risk assessments. Thus, the developed method enables the representation of the assumptions made for the future risk assessments, which is crucial information for future risk management. This is an important step forward, since the representation of reliability associated with all components of risk is currently lacking in all state-of-the-art methods assessing future risk. In conclusion, the use of object-based methods giving results in the form of distributions instead of point estimations is recommended. The improvement of the model performance by the means of multi-variable models and additional data points is possible, but small. Uncertainties associated with all components of damage estimation should be included and represented within the results. Furthermore, the findings of the thesis suggest that, at larger scales, the influence of the uncertainty associated with the vulnerability is smaller than those associated with the hazard and exposure. This leads to the conclusion that for an increased reliability of flood damage estimations and risk assessments, the improvement and active inclusion of hazard and exposure, including their uncertainties, is needed in addition to the improvements of the models describing the vulnerability of the objects. KW - hydro-meteorological risk KW - damage modeling KW - uncertainty KW - probabilistic approach KW - economic impacts KW - OpenStreetMap KW - hydro-meteorologische Risiken KW - Schadensmodellierung KW - Unsicherheiten KW - probabilistischer Ansatz KW - ökonomische Auswirkungen KW - OpenStreetMap Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426161 ER - TY - JOUR A1 - Perkins, Anita A1 - Rose, Andrew A1 - Grossart, Hans-Peter A1 - Rojas-Jimenez, Keilor Osvaldo A1 - Barroso Prescott, Selva Kiri A1 - Oakes, Joanne M. T1 - Oxic and Anoxic Organic Polymer Degradation Potential of Endophytic Fungi From the Marine Macroalga, Ecklonia radiata JF - Frontiers in Microbiology N2 - Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention. In this study, we investigated the potential of fungi to degrade kelp detritus, which is a major source of cellulose in marine systems. Given that kelp detritus can be transported considerable distances in the marine environment, we were specifically interested in the capability of endophytic fungi, which are transported with detritus, to ultimately contribute to kelp detritus degradation. We isolated 10 species and two strains of endophytic fungi from the kelp Ecklonia radiata. We then used a dye decolorization assay to assess their ability to degrade organic polymers (lignin, cellulose, and hemicellulose) under both oxic and anoxic conditions and compared their degradation ability with common terrestrial fungi. Under oxic conditions, there was evidence that Ascomycota isolates produced cellulose-degrading extracellular enzymes (associated with manganese peroxidase and sulfur-containing lignin peroxidase), while Mucoromycota isolates appeared to produce both lignin and cellulose-degrading extracellular enzymes, and all Basidiomycota isolates produced lignin-degrading enzymes (associated with laccase and lignin peroxidase). Under anoxic conditions, only three kelp endophytes degraded cellulose. We concluded that kelp fungal endophytes can contribute to cellulose degradation in both oxic and anoxic environments. Thus, endophytic kelp fungi may play a significant role in marine carbon cycling via polymeric organic matter degradation. KW - kelp KW - fungi KW - endophytes KW - carbon cycling KW - extracellular enzymes KW - cellulose polymeric organic matter Y1 - 2021 U6 - https://doi.org/10.3389/fmicb.2021.726138 SN - 1664-302X VL - 12 SP - 1 EP - 13 PB - Frontiers in microbiology CY - Lausanne, Schweiz ER - TY - RPRT A1 - Kritikos, Alexander A1 - Maliranta, Mika A1 - Nippala, Veera A1 - Nurmi, Satu T1 - Does gender of firm ownership matter? BT - Female entrepreneurs and the gender pay gap T2 - CEPA Discussion Papers N2 - We examine how the gender of business-owners is related to the wages paid to female relative to male employees working in their firms. Using Finnish register data and employing firm fixed effects, we find that the gender pay gap is – starting from a gender pay gap of 11 to 12 percent - two to three percentage-points lower for hourly wages in female-owned firms than in male-owned firms. Results are robust to how the wage is measured, as well as to various further robustness checks. More importantly, we find substantial differences between industries. While, for instance, in the manufacturing sector, the gender of the owner plays no role for the gender pay gap, in several service sector industries, like ICT or business services, no or a negligible gender pay gap can be found, but only when firms are led by female business owners. Businesses in male ownership maintain a gender pay gap of around 10 percent also in the latter industries. With increasing firm size, the influence of the gender of the owner, however, fades. In large firms, it seems that others – firm managers – determine wages and no differences in the pay gap are observed between male- and female-owned firms. T3 - CEPA Discussion Papers - 76 KW - entrepreneurship KW - gender pay gap KW - discrimination KW - linked employer-employee data Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-636194 SN - 2628-653X IS - 76 SP - 1 EP - 39 ER - TY - THES A1 - Wischnewski, Juliane T1 - Reconstructing climate variability on the Tibetan Plateau : comparing aquatic and terrestrial signals T1 - Klimarekonstruktionen auf dem Tibet Plateau : aquatische und terrestrische Signale im Vergleich N2 - Spatial and temporal temperature and moisture patterns across the Tibetan Plateau are very complex. The onset and magnitude of the Holocene climate optimum in the Asian monsoon realm, in particular, is a subject of considerable debate as this time period is often used as an analogue for recent global warming. In the light of contradictory inferences regarding past climate and environmental change on the Tibetan Plateau, I have attempted to explain mismatches in the timing and magnitude of change. Therefore, I analysed the temporal variation of fossil pollen and diatom spectra and the geochemical record from palaeo-ecological records covering different time scales (late Quaternary and the last 200 years) from two core regions in the NE and SE Tibetan Plateau. For interpretation purposes I combined my data with other available palaeo-ecological data to set up corresponding aquatic and terrestrial proxy data sets of two lake pairs and two sets of sites. I focused on the direct comparison of proxies representing lacustrine response to climate signals (e.g., diatoms, ostracods, geochemical record) and proxies representing changes in the terrestrial environment (i.e., terrestrial pollen), in order to asses whether the lake and its catchments respond at similar times and magnitudes to environmental changes. Therefore, I introduced the established numerical technique procrustes rotation as a new approach in palaeoecology to quantitatively compare raw data of any two sedimentary records of interest in order to assess their degree of concordance. Focusing on the late Quaternary, sediment cores from two lakes (Kuhai Lake 35.3°N; 99.2°E; 4150 m asl; and Koucha Lake 34.0°N; 97.2°E; 4540 m asl) on the semi-arid northeastern Tibetan Plateau were analysed to identify post-glacial vegetation and environmental changes, and to investigate the responses of lake ecosystems to such changes. Based on the pollen record, five major vegetation and climate changes could be identified: (1) A shift from alpine desert to alpine steppe indicates a change from cold, dry conditions to warmer and more moist conditions at 14.8 cal. ka BP, (2) alpine steppe with tundra elements points to conditions of higher effective moisture and a stepwise warming climate at 13.6 cal. ka BP, (3) the appearance of high-alpine meadow vegetation indicates a further change towards increased moisture, but with colder temperatures, at 7.0 cal. ka BP, (4) the reoccurrence of alpine steppe with desert elements suggests a return to a significantly colder and drier phase at 6.3 cal. ka BP, and (5) the establishment of alpine steppe-meadow vegetation indicates a change back to relatively moist conditions at 2.2 cal. ka BP. To place the reconstructed climate inferences from the NE Tibetan Plateau into the context of Holocene moisture evolution across the Tibetan Plateau, I applied a five-scale moisture index and average link clustering to all available continuous pollen and non-pollen palaeoclimate records from the Tibetan Plateau, in an attempt to detect coherent regional and temporal patterns of moisture evolution on the Plateau. However, no common temporal or spatial pattern of moisture evolution during the Holocene could be detected, which can be assigned to the complex responses of different proxies to environmental changes in an already very heterogeneous mountain landscape, where minor differences in elevation can result in marked variations in microenvironments. Focusing on the past 200 years, I analysed the sedimentary records (LC6 Lake 29.5°N, 94.3°E, 4132 m asl; and Wuxu Lake 29.9°N, 101.1°E, 3705 m asl) from the southeastern Tibetan Plateau. I found that despite presumed significant temperature increases over that period, pollen and diatom records from the SE Tibetan Plateau reveal only very subtle changes throughout their profiles. The compositional species turnover investigated over the last 200 years appears relatively low in comparison to the species reorganisations during the Holocene. The results indicate that climatically induced ecological thresholds are not yet crossed, but that human activity has an increasing influence, particularly on the terrestrial ecosystem. Forest clearances and reforestation have not caused forest decline in our study area, but a conversion of natural forests to semi-natural secondary forests. The results from the numerical proxy comparison of the two sets of two pairs of Tibetan lakes indicate that the use of different proxies and the work with palaeo-ecological records from different lake types can cause deviant stories of inferred change. Irrespective of the timescale (Holocene or last 200 years) or region (SE or NE Tibetan Plateau) analysed, the agreement in terms of the direction, timing, and magnitude of change between the corresponding terrestrial data sets is generally better than the match between the corresponding lacustrine data sets, suggesting that lacustrine proxies may partly be influenced by in-lake or local catchment processes whereas the terrestrial proxy reflects a more regional climatic signal. The current disaccord on coherent temporal and spatial climate patterns on the Tibetan Plateau can partly be ascribed to the complexity of proxy response and lake systems on the Tibetan Plateau. Therefore, a multi-proxy, multi-site approach is important in order to gain a reliable climate interpretation for the complex mountain landscape of the Tibetan Plateau. N2 - Die räumlichen und zeitlichen Temperatur- und Feuchtigkeitsmuster auf dem Tibet-Plateau sind sehr komplex. Im Einzugsbereich der asiatischen Monsune sind insbesondere der Beginn und das Ausmaß des Klimaoptimums während des Holozäns von wissenschaftlichem Interesse, da diese Periode oft als Analogie für die derzeitige globale Klimaerwärmung herangezogen wird. In Hinblick auf sich teilweise widersprechende Paläoklima- und Umweltrekonstruktionen für das Tibet-Plateau, ist es mein Ziel, die bestehenden Unstimmigkeiten bezüglich des Zeitpunktes und des Ausmaßes des Umweltwandels zu erklären. Dafür wurden von mir zeitliche Variationen fossiler Pollen- und Diatomeenspektren und geochemische Untersuchungen an Seesedimenten unterschiedlicher Zeitskalen (Spätquartär und die letzten 200 Jahre) aus zwei Kernregionen auf dem NO und SO Tibet-Plateau analysiert. Zur Unterstützung der Interpretation wurden die hier erhobenen Daten mit bereits vorhandenen paläoökologischen Aufzeichnungen der Lokalitäten kombiniert, um Datensätze der entsprechenden aquatischen und terrestrischen Proxy-Daten (Stellvertreterdaten) zweier Seenpaare aus den beiden Regionen gegenüberstellen zu können. Hierbei konzentrierte ich mich auf den direkten Vergleich von Proxies, die die Seenentwicklung reflektieren (z.B. Diatomeen, Ostracoden, geochemische Eigenschaften), mit Proxies, die Veränderungen der terrestrischen Umgebung des Sees beschreiben (terrestrische Pollen). Durch diesen Vergleich lässt sich beurteilen, ob Veränderungen im See selbst mit Umweltveränderungen in dem jeweiligen Einzugsgebiet zeitlich übereinstimmen. Dafür habe ich die bereits etablierte numerische Methode Procrustes-Rotation als neuen Ansatz in der Paläoökologie eingeführt. Damit ist ein quantitativer Vergleich von Rohdaten zweier beliebiger sedimentärer Datensätze möglich, um den Grad der Übereinstimmung zu prüfen. Um die in dieser Arbeit rekonstruierten Umwelt- und Klimaereignisse des nordöstlichen Tibet-Plateaus in einen größeren Zusammenhang hinsichtlich holozäner Klimaentwicklung des gesamten Plateaus setzen zu können, und um schlüssige zeitliche und räumliche Klimatrends auf dem Plateau erkennen zu können, habe ich auf alle vorhandenen Paläoklimadatensätze einen Fünf-Skalen Feuchtigkeitsindex und eine Clusteranalyse angewandt. Es konnten jedoch keine einheitlichen zeitlichen und räumlichen Trends der holozänen Klimaentwicklung nachgewiesen werden, was meiner Analyse entsprechend, auf die komplexen Reaktionen verschiedener Proxies auf Umweltveränderungen in einer ohnehin sehr heterogen Berglandschaft, zurückgeführt werden kann. Die Ergebnisse des numerischen Proxy-Vergleichs beider Seenpaare zeigen, dass die Verwendung von verschiedenen Proxies und die Arbeit mit paläo-ökologischen Datensätzen unterschiedlicher See-Typen zu abweichenden Klimaableitungen führen können. Unabhängig vom untersuchten Zeitraum (Holozän oder die letzten 200 Jahren) oder der Region (SO oder NO Tibet-Plateau), ist die Übereinstimmung zweier Datensätze hinsichtlich der Richtung, des Zeitpunktes und des Ausmaßes der abgeleiteten Paläo-Umweltverhältnisse in der Regel zwischen den entsprechenden terrestrischen Datensätzen besser als zwischen den entsprechenden lakustrinen Datensätzen. Die derzeitige Uneinigkeit über stimmige zeitliche und räumliche Klimatrends auf dem Tibet-Plateau kann daher teilweise der Komplexität der verschieden Proxies und ihrer individuellen Empfindlichkeiten gegenüber Umweltveränderungen sowie der unterschiedlichen Reaktionsweise verschiedenartiger See-Systeme auf dem Plateau zugeschrieben werden. Meine Ergebnisse zeigen, dass ein „Multi-Proxy-Multi-Site-Ansatz“ für zuverlässige Paläoklimaableitungen für das Tibet-Plateau von zentraler Bedeutung ist. KW - Tibet Plateau KW - Holozän KW - Pollen KW - Diatomeen KW - Prokrustes Analyse KW - Tibetan Plateau KW - Holocene KW - Pollen KW - Diatoms KW - Procrustes rotation analysis Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-52453 ER - TY - JOUR A1 - Puschmann, Anne-Katrin A1 - Lin, Chiao-I A1 - Wippert, Pia-Maria T1 - Sustainability of a motor control exercise intervention BT - Analysis of long-term effects in a low back pain study JF - Frontiers in sports and active living N2 - Development of chronic pain after a low back pain episode is associated with increased pain sensitivity, altered pain processing mechanisms and the influence of psychosocial factors. Although there is some evidence that multimodal therapy (such as behavioral or motor control therapy) may be an important therapeutic strategy, its long-term effect on pain reduction and psychosocial load is still unclear. Prospective longitudinal designs providing information about the extent of such possible long-term effects are missing. This study aims to investigate the long-term effects of a homebased uni- and multidisciplinary motor control exercise program on low back pain intensity, disability and psychosocial variables. 14 months after completion of a multicenter study comparing uni- and multidisciplinary exercise interventions, a sample of one study center (n = 154) was assessed once more. Participants filled in questionnaires regarding their low back pain symptoms (characteristic pain intensity and related disability), stress and vital exhaustion (short version of the Maastricht Vital Exhaustion Questionnaire), anxiety and depression experiences (the Hospital and Anxiety Depression Scale), and pain-related cognitions (the Fear Avoidance Beliefs Questionnaire). Repeated measures mixed ANCOVAs were calculated to determine the long-term effects of the interventions on characteristic pain intensity and disability as well as on the psychosocial variables. Fifty four percent of the sub-sample responded to the questionnaires (n = 84). Longitudinal analyses revealed a significant long-term effect of the exercise intervention on pain disability. The multidisciplinary group missed statistical significance yet showed a medium sized long-term effect. The groups did not differ in their changes of the psychosocial variables of interest. There was evidence of long-term effects of the interventions on pain-related disability, but there was no effect on the other variables of interest. This may be partially explained by participant's low comorbidities at baseline. Results are important regarding costless homebased alternatives for back pain patients and prevention tasks. Furthermore, this study closes the gap of missing long-term effect analysis in this field. KW - MiSpEx KW - low back pain KW - long-term effects KW - multidisciplinary intervention KW - sustainability Y1 - 2021 U6 - https://doi.org/10.3389/fspor.2021.659982 SN - 2624-9367 VL - 3 SP - 1 EP - 8 PB - Frontiers Media CY - Lausanne, Schweiz ER - TY - JOUR A1 - Schaefer, Laura A1 - Dech, Silas A1 - Aehle, Markus A1 - Bittmann, Frank T1 - Disgusting odours affect the characteristics of the adaptive force in contrast to neutral and pleasant odours JF - Scientific Reports N2 - The olfactomotor system is especially investigated by examining the sniffing in reaction to olfactory stimuli. The motor output of respiratory-independent muscles was seldomly considered regarding possible influences of smells. The Adaptive Force (AF) characterizes the capability of the neuromuscular system to adapt to external forces in a holding manner and was suggested to be more vulnerable to possible interfering stimuli due to the underlying complex control processes. The aim of this pilot study was to measure the effects of olfactory inputs on the AF of the hip and elbow flexors, respectively. The AF of 10 subjects was examined manually by experienced testers while smelling at sniffing sticks with neutral, pleasant or disgusting odours. The reaction force and the limb position were recorded by a handheld device. The results show, inter alia, a significantly lower maximal isometric AF and a significantly higher AF at the onset of oscillations by perceiving disgusting odours compared to pleasant or neutral odours (p < 0.001). The adaptive holding capacity seems to reflect the functionality of the neuromuscular control, which can be impaired by disgusting olfactory inputs. An undisturbed functioning neuromuscular system appears to be characterized by a proper length tension control and by an earlier onset of mutual oscillations during an external force increase. This highlights the strong connection of olfaction and motor control also regarding respiratory-independent muscles. Y1 - 2021 U6 - https://doi.org/10.1038/s41598-021-95759-0 SN - 2045-2322 VL - 11 SP - 1 EP - 16 PB - Springer Nature CY - London ER - TY - GEN A1 - Reich, Oliver A1 - Löhmannsröben, Hans-Gerd A1 - Schael, Frank T1 - Optical sensing with photon density waves: investigation of model media N2 - Investigations with frequency domain photon density waves allow elucidation of absorption and scattering properties of turbid media. The temporal and spatial propagation of intensity modulated light with frequencies up to more than 1 GHz can be described by the P1 approximation to the Boltzmann transport equation. In this study, we establish requirements for the appropriate choice of turbid model media and characterize mixtures of isosulfan blue as absorber and polystyrene beads as scatterer. For these model media, the independent determination of absorption and reduced scattering coefficients over large absorber and scatterer concentration ranges is demonstrated with a frequency domain photon density wave spectrometer employing intensity and phase measurements at various modulation frequencies. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 026 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13147 ER - TY - CHAP A1 - Popp, Alexander A1 - Blaum, Niels A1 - Domptail, Stephanie A1 - Herpel, Nicole A1 - Gröngröft, Alexander A1 - Hoffman, T. T. A1 - Jürgens, Norbert A1 - Milton, Sue A1 - Nuppenau, Ernst-August A1 - Rossmanith, Eva A1 - Schmidt, Michael A1 - Vogel, Melanie A1 - Vohland, Katrin A1 - Jeltsch, Florian T1 - From satellite imagery to soil-plant interactions BT - integrating disciplines and scales in process based simulation models N2 - Decisions for the conservation of biodiversity and sustainable management of natural resources are typically related to large scales, i.e. the landscape level. However, understanding and predicting the effects of land use and climate change on scales relevant for decision-making requires to include both, large scale vegetation dynamics and small scale processes, such as soil-plant interactions. Integrating the results of multiple BIOTA subprojects enabled us to include necessary data of soil science, botany, socio-economics and remote sensing into a high resolution, process-based and spatially-explicit model. Using an example from a sustainably-used research farm and a communally used and degraded farming area in semiarid southern Namibia we show the power of simulation models as a tool to integrate processes across disciplines and scales. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7302 N1 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006. [Poster] ER - TY - CHAP A1 - Rossmanith, Eva A1 - Blaum, Niels A1 - Keil, Manfred A1 - Langerwisch, F. A1 - Meyer, Jork A1 - Popp, Alexander A1 - Schmidt, Michael A1 - Schultz, Christoph A1 - Schwager, Monika A1 - Vogel, Melanie A1 - Wasiolka, Bernd A1 - Jeltsch, Florian T1 - Scaling up local population dynamics to regional scales BT - an integrated approach N2 - In semi-arid savannas, unsustainable land use can lead to degradation of entire landscapes, e.g. in the form of shrub encroachment. This leads to habitat loss and is assumed to reduce species diversity. In BIOTA phase 1, we investigated the effects of land use on population dynamics on farm scale. In phase 2 we scale up to consider the whole regional landscape consisting of a diverse mosaic of farms with different historic and present land use intensities. This mosaic creates a heterogeneous, dynamic pattern of structural diversity at a large spatial scale. Understanding how the region-wide dynamic land use pattern affects the abundance of animal and plant species requires the integration of processes on large as well as on small spatial scales. In our multidisciplinary approach, we integrate information from remote sensing, genetic and ecological field studies as well as small scale process models in a dynamic region-wide simulation tool.
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7320 N1 - [Poster] ER - TY - JOUR 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 JF - Remote Sensing 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. KW - CDOM KW - lakes KW - lake catchments KW - permafrost KW - Yamal KW - remote sensing data Y1 - 2018 U6 - https://doi.org/10.3390/rs10020167 SN - 2072-4292 VL - 10 IS - 2 PB - MDPI CY - Basel ER - TY - CHAP A1 - Demske, Ulrike ED - Szczepaniak, Renata ED - Flick, Johanna T1 - The grammaticalization of the definite article in German BT - from demonstratives to weak definites T2 - Walking on the Grammaticalization Path of the Definite Article in German: Functional Main and Side Roads N2 - The present paper looks into the grammaticalization of the definite article in the history of German. Starting with the well-known emergence of the definite article from a demonstrative pronoun over the course of Old High German (750–1050), I will consider the rise of so-called weak definites in Early New High German (1350–1650) as a new piece of evidence for the grammaticalization process. Here, the subclass of possessive weak definites is of particular interest for the grammaticalization of the definite article in German, because of a word order change affecting the position of possessor phrases. As soon as the possessor systematically follows the head noun (except for proper names), we observe three alternatives for the prenominal determiner slot: it may remain empty, or it may be filled either by the indefinite or the definite article in Early New High German. In Present-Day German, the definite article is used in the unmarked case, thus pointing to a second stage in the grammaticalization process of the definite article in German, which has so far not been acknowledged in the literature. KW - grammaticalization KW - definite article KW - weak definites KW - Old High German KW - Early New High German KW - Present-Day German Y1 - 2020 SN - 978-9-027204943 SN - 978-9-027261564 SP - 43 EP - 73 PB - John Benjamins Publishing Company CY - Amsterdam ER - TY - JOUR A1 - Ziegler, Joceline A1 - Pfitzner, Bjarne A1 - Schulz, Heinrich A1 - Saalbach, Axel A1 - Arnrich, Bert T1 - Defending against Reconstruction Attacks through Differentially Private Federated Learning for Classification of Heterogeneous Chest X-ray Data JF - Sensors N2 - Privacy regulations and the physical distribution of heterogeneous data are often primary concerns for the development of deep learning models in a medical context. This paper evaluates the feasibility of differentially private federated learning for chest X-ray classification as a defense against data privacy attacks. To the best of our knowledge, we are the first to directly compare the impact of differentially private training on two different neural network architectures, DenseNet121 and ResNet50. Extending the federated learning environments previously analyzed in terms of privacy, we simulated a heterogeneous and imbalanced federated setting by distributing images from the public CheXpert and Mendeley chest X-ray datasets unevenly among 36 clients. Both non-private baseline models achieved an area under the receiver operating characteristic curve (AUC) of 0.940.94 on the binary classification task of detecting the presence of a medical finding. We demonstrate that both model architectures are vulnerable to privacy violation by applying image reconstruction attacks to local model updates from individual clients. The attack was particularly successful during later training stages. To mitigate the risk of a privacy breach, we integrated Rényi differential privacy with a Gaussian noise mechanism into local model training. We evaluate model performance and attack vulnerability for privacy budgets ε∈{1,3,6,10}�∈{1,3,6,10}. The DenseNet121 achieved the best utility-privacy trade-off with an AUC of 0.940.94 for ε=6�=6. Model performance deteriorated slightly for individual clients compared to the non-private baseline. The ResNet50 only reached an AUC of 0.760.76 in the same privacy setting. Its performance was inferior to that of the DenseNet121 for all considered privacy constraints, suggesting that the DenseNet121 architecture is more robust to differentially private training. KW - federated learning KW - privacy and security KW - privacy attack KW - X-ray Y1 - 2022 U6 - https://doi.org/10.3390/s22145195 SN - 1424-8220 VL - 22 PB - MDPI CY - Basel, Schweiz ET - 14 ER - TY - JOUR A1 - Quarmby, Andrew James A1 - Mönnig, Jamal A1 - Mugele, Hendrik A1 - Henschke, Jakob A1 - Kim, MyoungHwee A1 - Cassel, Michael A1 - Engel, Tilman T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review JF - Frontiers in Sports and Active Living N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn. KW - achilles tendinopathy KW - biomechanics KW - neuromuscular KW - kinetics KW - electromyography KW - athletes KW - runners KW - kinematics Y1 - 2023 U6 - https://doi.org/10.3389/fspor.2022.1012471 SN - 2624-9367 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Arntz, Fabian A1 - Mkaouer, Bessem A1 - Markov, Adrian A1 - Schoenfeld, Brad A1 - Moran, Jason A1 - Ramirez-Campillo, Rodrigo A1 - Behrens, Martin A1 - Baumert, Philipp A1 - Erskine, Robert M. A1 - Hauser, Lukas A1 - Chaabene, Helmi T1 - Effect of Plyometric Jump Training on Skeletal Muscle Hypertrophy in Healthy Individuals: A Systematic Review With Multilevel Meta-Analysis JF - Frontiers in Physiology N2 - Objective: To examine the effect of plyometric jump training on skeletal muscle hypertrophy in healthy individuals. Methods: A systematic literature search was conducted in the databases PubMed, SPORTDiscus, Web of Science, and Cochrane Library up to September 2021. Results: Fifteen studies met the inclusion criteria. The main overall finding (44 effect sizes across 15 clusters median = 2, range = 1–15 effects per cluster) indicated that plyometric jump training had small to moderate effects [standardised mean difference (SMD) = 0.47 (95% CIs = 0.23–0.71); p < 0.001] on skeletal muscle hypertrophy. Subgroup analyses for training experience revealed trivial to large effects in non-athletes [SMD = 0.55 (95% CIs = 0.18–0.93); p = 0.007] and trivial to moderate effects in athletes [SMD = 0.33 (95% CIs = 0.16–0.51); p = 0.001]. Regarding muscle groups, results showed moderate effects for the knee extensors [SMD = 0.72 (95% CIs = 0.66–0.78), p < 0.001] and equivocal effects for the plantar flexors [SMD = 0.65 (95% CIs = −0.25–1.55); p = 0.143]. As to the assessment methods of skeletal muscle hypertrophy, findings indicated trivial to small effects for prediction equations [SMD = 0.29 (95% CIs = 0.16–0.42); p < 0.001] and moderate-to-large effects for ultrasound imaging [SMD = 0.74 (95% CIs = 0.59–0.89); p < 0.001]. Meta-regression analysis indicated that the weekly session frequency moderates the effect of plyometric jump training on skeletal muscle hypertrophy, with a higher weekly session frequency inducing larger hypertrophic gains [β = 0.3233 (95% CIs = 0.2041–0.4425); p < 0.001]. We found no clear evidence that age, sex, total training period, single session duration, or the number of jumps per week moderate the effect of plyometric jump training on skeletal muscle hypertrophy [β = −0.0133 to 0.0433 (95% CIs = −0.0387 to 0.1215); p = 0.101–0.751]. Conclusion: Plyometric jump training can induce skeletal muscle hypertrophy, regardless of age and sex. There is evidence for relatively larger effects in non-athletes compared with athletes. Further, the weekly session frequency seems to moderate the effect of plyometric jump training on skeletal muscle hypertrophy, whereby more frequent weekly plyometric jump training sessions elicit larger hypertrophic adaptations. KW - muscle tissue KW - muscle strength KW - stretch shortening cycle exercise KW - muscle growth KW - human physical conditioning KW - youth sports KW - aged Y1 - 2022 U6 - https://doi.org/10.3389/fphys.2022.888464 SN - 1664-042X VL - 13 SP - 1 EP - 17 PB - Frontiers CY - Lausanne, Schweiz ET - 888464 ER - TY - THES A1 - Zeuschner, Steffen Peer T1 - Magnetoacoustics observed with ultrafast x-ray diffraction N2 - In the present thesis I investigate the lattice dynamics of thin film hetero structures of magnetically ordered materials upon femtosecond laser excitation as a probing and manipulation scheme for the spin system. The quantitative assessment of laser induced thermal dynamics as well as generated picosecond acoustic pulses and their respective impact on the magnetization dynamics of thin films is a challenging endeavor. All the more, the development and implementation of effective experimental tools and comprehensive models are paramount to propel future academic and technological progress. In all experiments in the scope of this cumulative dissertation, I examine the crystal lattice of nanoscale thin films upon the excitation with femtosecond laser pulses. The relative change of the lattice constant due to thermal expansion or picosecond strain pulses is directly monitored by an ultrafast X-ray diffraction (UXRD) setup with a femtosecond laser-driven plasma X-ray source (PXS). Phonons and spins alike exert stress on the lattice, which responds according to the elastic properties of the material, rendering the lattice a versatile sensor for all sorts of ultrafast interactions. On the one hand, I investigate materials with strong magneto-elastic properties; The highly magnetostrictive rare-earth compound TbFe2, elemental Dysprosium or the technological relevant Invar material FePt. On the other hand I conduct a comprehensive study on the lattice dynamics of Bi1Y2Fe5O12 (Bi:YIG), which exhibits high-frequency coherent spin dynamics upon femtosecond laser excitation according to the literature. Higher order standing spinwaves (SSWs) are triggered by coherent and incoherent motion of atoms, in other words phonons, which I quantified with UXRD. We are able to unite the experimental observations of the lattice and magnetization dynamics qualitatively and quantitatively. This is done with a combination of multi-temperature, elastic, magneto-elastic, anisotropy and micro-magnetic modeling. The collective data from UXRD, to probe the lattice, and time-resolved magneto-optical Kerr effect (tr-MOKE) measurements, to monitor the magnetization, were previously collected at different experimental setups. To improve the precision of the quantitative assessment of lattice and magnetization dynamics alike, our group implemented a combination of UXRD and tr-MOKE in a singular experimental setup, which is to my knowledge, the first of its kind. I helped with the conception and commissioning of this novel experimental station, which allows the simultaneous observation of lattice and magnetization dynamics on an ultrafast timescale under identical excitation conditions. Furthermore, I developed a new X-ray diffraction measurement routine which significantly reduces the measurement time of UXRD experiments by up to an order of magnitude. It is called reciprocal space slicing (RSS) and utilizes an area detector to monitor the angular motion of X-ray diffraction peaks, which is associated with lattice constant changes, without a time-consuming scan of the diffraction angles with the goniometer. RSS is particularly useful for ultrafast diffraction experiments, since measurement time at large scale facilities like synchrotrons and free electron lasers is a scarce and expensive resource. However, RSS is not limited to ultrafast experiments and can even be extended to other diffraction techniques with neutrons or electrons. N2 - In der vorliegenden Arbeit untersuche ich die Gitterdynamik von magnetisch geordneten und dünnen Filmen, deren Spinsystem mit Femtosekunden-Laserpulsen angeregt und untersucht wird. Die Quantifizierung der laserinduzierten thermischen Dynamik, der erzeugten Pikosekunden-Schallpulse sowie deren jeweiliger Einfluss auf die Magnetisierungsdynamik ist ein schwieriges Unterfangen. Umso mehr ist die Entwicklung und Anwendung von effizienten experimentellen Konzepten und umfangreichen Modellen grundlegend für das Antreiben des zukünftigen wissenschaftlichen und technologischen Fortschritt. In jedem Experiment dieser kummulativen Dissertation untersuche ich das Kristallgitter von Nanometer dünnen Filmen nach der Anregung mit Femtosekunden-Laserpulsen. Die relative Änderung der Gitterkonstante, hervorgerufen durch thermische Ausdehnung oder Pikosekunden-Schallpulse, wird dabei direkt mittels ultraschneller Röntgenbeugung (UXRD) gemessen. Der Aufbau nutzt zur Bereitstellung von ultrakurzen Röntgenpulsen eine lasergetriebene Plasma-Röntgenquelle (PXS). Phononen und Spins üben gleichermaßen einen Druck auf das Gitter aus, welches entsprechend der elastsischen Eigenschaften des Materials reagiert, was das Gitter zu einem vielseitigen Sensor für ultraschenlle Wechselwirkungen macht. Zum einen untersuche ich Materialien mit starken magnetoelastischen Eigentschaften: die stark magnetostriktive Seltenen-Erden-Verbindung TbFe2, elementares Dysprosium oder das technologisch relavante Invar-Material FePt. Zum anderen habe ich eine umfangreiche Studie der Gitterdynamik von Bi1Y2Fe5O12 (Bi:YIG) angestellt, in dem der Literatur zufolge hochfrequente kohärente Spindynamiken durch Femtosekunden-Laseranregung zu beobachten sind. Diese stehenden Spinwellen (SSWs) höherer Ordnung entstehen durch die kohärente und inkohärente Bewegung von Atomen, in anderen Worten Phononen, welche ich durch UXRD vermessen habe. Somit sind wir in der Lage, die experimentellen Beobachtungen der Gitter- und Spindynamik qualitativ und quantitativ zu vereinigen. Dies geschieht durch eine Kombination von Viel-Temperatur- und Anisotropiemodellierung sowie elastische, magnetoelastische, und mikromagnetsiche Modelle. Die gemeinsamen Daten von UXRD und der zeitaufgelösten magnetooptischen Kerr-Effekt Messungen (tr-MOKE), um jeweils die Gitter- und Spindynamik zu messen, wurden in der Vergangenheit noch an unterschiedlichen experimentellen Aufbauten gemessen. Um die Quantifizierung präziser zu gestalten, haben wir in unserer Arbeitsgruppe UXRD und tr-MOKE in einem einzigen Aufbau kombiniert, welcher somit meines Wissens der erste seiner Art ist. Ich half bei dem Entwurf und der Inbetriebnahme des neuen Aufbaus, welcher die gleichzeitige Messung von Gitter- und Spindynamik auf einer ultraschnellen Zeitskala unter identischen Anregungsbedingungen ermöglicht. Außerdem entwickelte ich eine neue Messroutine für Röntgenbeugung, welche die Messzeit von UXRD-Experimenten um bis zu einer Größenordnungen reduziert. Es nennt sich das Schneiden des reziproken Raumes (reciprocal space slicing, RSS) und nutzt den Vorteil von Flächendetektoren die Bewegung von Beugungsreflexen zu detektieren, was von einer Änderung der Gitterkonstante einhergeht, ohne zeitintensive Scans der Beugungswinkel mit dem Goniometer durchzuführen. RSS ist besonders nützlich für ultraschnelle Beugungsexperimente, weil die Messzeit an Großgeräten wie Synchrotrons oder Freie Elektronen Laser eine seltene und teure Ressource ist. Darüber hinaus ist RSS nicht zwangsläufig auf die Anwendung in ultraschnellen Experimenten beschränkt und kann sogar auf andere Beugungsexperimente, wie die mit Neutronen und Elektronen, ausgeweitet werden. KW - ultrafast KW - X-ray diffraction KW - thin films KW - magnetoelasticity KW - ultraschnell KW - Röntgenbeugung KW - dünne Filme KW - Magnetoelastizität Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-561098 ER - TY - JOUR A1 - Khalil, Samir A1 - Kohler, Ulrich A1 - Tjaden, Jasper Dag T1 - Is There a Rural Penalty in Language Acquisition? Evidence From Germany's Refugee Allocation Policy JF - Frontiers in Sociology N2 - Emerging evidence has highlighted the important role of local contexts for integration trajectories of asylum seekers and refugees. Germany's policy of randomly allocating asylum seekers across Germany may advantage some and disadvantage others in terms of opportunities for equal participation in society. This study explores the question whether asylum seekers that have been allocated to rural areas experience disadvantages in terms of language acquisition compared to those allocated to urban areas. We derive testable assumptions using a Directed Acyclic Graph (DAG) which are then tested using large-N survey data (IAB-BAMF-SOEP refugee survey). We find that living in a rural area has no negative total effect on language skills. Further the findings suggest that the “null effect” is the result of two processes which offset each other: while asylum seekers in rural areas have slightly lower access for formal, federally organized language courses, they have more regular exposure to German speakers. KW - refugees KW - allocation policies KW - rural KW - language acquisition KW - intergroup contacts KW - language courses KW - integration Y1 - 2022 U6 - https://doi.org/10.3389/fsoc.2022.841775 SN - 2297-7775 VL - 7 SP - 1 EP - 11 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Wippert, Pia-Maria A1 - Niederer, Daniel A1 - Drießlein, David A1 - Beck, Heidrun A1 - Banzer, Winfried Eberhard A1 - Schneider, Christian A1 - Schiltenwolf, Marcus A1 - Mayer, Frank T1 - Psychosocial Moderators and Mediators of Sensorimotor Exercise in Low Back Pain: A Randomized Multicenter Controlled Trial JF - Frontiers in Psychiatry N2 - The effects of exercise interventions on unspecific chronic low back pain (CLBP) have been investigated in many studies, but the results are inconclusive regarding exercise types, efficiency, and sustainability. This may be because the influence of psychosocial factors on exercise induced adaptation regarding CLBP is neglected. Therefore, this study assessed psychosocial characteristics, which moderate and mediate the effects of sensorimotor exercise on LBP. A single-blind 3-arm multicenter randomized controlled trial was conducted for 12-weeks. Three exercise groups, sensorimotor exercise (SMT), sensorimotor and behavioral training (SMT-BT), and regular routines (CG) were randomly assigned to 662 volunteers. Primary outcomes (pain intensity and disability) and psychosocial characteristics were assessed at baseline (M1) and follow-up (3/6/12/24 weeks, M2-M5). Multiple regression models were used to analyze whether psychosocial characteristics are moderators of the relationship between exercise and pain, meaning that psychosocial factors and exercise interact. Causal mediation analysis were conducted to analyze, whether psychosocial characteristics mediate the exercise effect on pain. A total of 453 participants with intermittent pain (mean age = 39.5 ± 12.2 years, f = 62%) completed the training. It was shown, that depressive symptomatology (at M4, M5), vital exhaustion (at M4), and perceived social support (at M5) are significant moderators of the relationship between exercise and the reduction of pain intensity. Further depressive mood (at M4), social-satisfaction (at M4), and anxiety (at M5 SMT) significantly moderate the exercise effect on pain disability. The amount of moderation was of clinical relevance. In contrast, there were no psychosocial variables which mediated exercise effects on pain. In conclusion it was shown, that psychosocial variables can be moderators in the relationship between sensorimotor exercise induced adaptation on CLBP which may explain conflicting results in the past regarding the merit of exercise interventions in CLBP. Results suggest further an early identification of psychosocial risk factors by diagnostic tools, which may essential support the planning of personalized exercise therapy. Level of Evidence: Level I. Clinical Trial Registration: DRKS00004977, LOE: I, MiSpEx: grant-number: 080102A/11-14. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004977. KW - low-back-pain KW - motor-control-exercise KW - multidisciplinary-therapy KW - MiSpEx-network KW - yellow flags Y1 - 2021 U6 - https://doi.org/10.3389/fpsyt.2021.629474 SN - 1664-0640 VL - 12 SP - 1 EP - 16 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - JOUR A1 - Wochatz, Monique A1 - Schraplau, Anne A1 - Engel, Tilman A1 - Zecher, Mahli Megan A1 - Sharon, Hadar A1 - Alt, Yasmin A1 - Mayer, Frank A1 - Kalron, Alon T1 - Application of eccentric training in various clinical populations BT - Protocol for a multi-centered pilot and feasibility study in people with low back pain and people with multiple sclerosis JF - PLoS ONE N2 - Physical activity and exercise are effective approaches in prevention and therapy of multiple diseases. Although the specific characteristics of lengthening contractions have the potential to be beneficial in many clinical conditions, eccentric training is not commonly used in clinical populations with metabolic, orthopaedic, or neurologic conditions. The purpose of this pilot study is to investigate the feasibility, functional benefits, and systemic responses of an eccentric exercise program focused on the trunk and lower extremities in people with low back pain (LBP) and multiple sclerosis (MS). A six-week eccentric training program with three weekly sessions is performed by people with LBP and MS. The program consists of ten exercises addressing strength of the trunk and lower extremities. The study follows a four-group design (N = 12 per group) in two study centers (Israel and Germany): three groups perform the eccentric training program: A) control group (healthy, asymptomatic); B) people with LBP; C) people with MS; group D (people with MS) receives standard care physiotherapy. Baseline measurements are conducted before first training, post-measurement takes place after the last session both comprise blood sampling, self-reported questionnaires, mobility, balance, and strength testing. The feasibility of the eccentric training program will be evaluated using quantitative and qualitative measures related to the study process, compliance and adherence, safety, and overall program assessment. For preliminary assessment of potential intervention effects, surrogate parameters related to mobility, postural control, muscle strength and systemic effects are assessed. The presented study will add knowledge regarding safety, feasibility, and initial effects of eccentric training in people with orthopaedic and neurological conditions. The simple exercises, that are easily modifiable in complexity and intensity, are likely beneficial to other populations. Thus, multiple applications and implementation pathways for the herein presented training program are conceivable. Y1 - 2022 U6 - https://doi.org/10.1371/journal.pone.0270875 SN - 1932-6203 VL - 17 IS - 12 PB - Public Library of Science CY - San Francisco, California, USA ER - TY - GEN A1 - Dimigen, Olaf A1 - Valsecchi, Matteo A1 - Sommer, Werner A1 - Kliegl, Reinhold T1 - Human Microsaccade-Related Visual Brain Responses N2 - Microsaccades are very small, involuntary flicks in eye position that occur on average once or twice per second during attempted visual fixation. Microsaccades give rise to EMG eye muscle spikes that can distort the spectrum of the scalp EEG and mimic increases in gamma band power. Here we demonstrate that microsaccades are also accompanied by genuine and sizeable cortical activity, manifested in the EEG. In three experiments, high-resolution eye movements were corecorded with the EEG: during sustained fixation of checkerboard and face stimuli and in a standard visual oddball task that required the counting of target stimuli. Results show that microsaccades as small as 0.15° generate a field potential over occipital cortex and midcentral scalp sites 100 –140 ms after movement onset, which resembles the visual lambda response evoked by larger voluntary saccades. This challenges the standard assumption of human brain imaging studies that saccade-related brain activity is precluded by fixation, even when fully complied with. Instead, additional cortical potentials from microsaccades were present in 86% of the oddball task trials and of similar amplitude as the visual response to stimulus onset. Furthermore, microsaccade probability varied systematically according to the proportion of target stimuli in the oddball task, causing modulations of late stimulus-locked event-related potential (ERP) components. Microsaccades present an unrecognized source of visual brain signal that is of interest for vision research and may have influenced the data of many ERP and neuroimaging studies. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 240 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56923 ER - TY - JOUR A1 - Warschburger, Petra A1 - Petersen, Ann-Christin A1 - von Rezori, Roman Enzio A1 - Buchallik, Friederike A1 - Baumeister, Harald A1 - Holl, Reinhard A1 - Minden, Kirsten A1 - Müller-​Stierlin, Annabel Sandra A1 - Reinauer, Christina A1 - Staab, Doris A1 - COACH consortium, T1 - A prospective investigation of developmental trajectories of psychosocial adjustment in adolescents facing a chronic condition - study protocol of an observational, multi-center study JF - BMC Pediatrics N2 - Background Relatively little is known about protective factors and the emergence and maintenance of positive outcomes in the field of adolescents with chronic conditions. Therefore, the primary aim of the study is to acquire a deeper understanding of the dynamic process of resilience factors, coping strategies and psychosocial adjustment of adolescents living with chronic conditions. Methods/design We plan to consecutively recruit N = 450 adolescents (12–21 years) from three German patient registries for chronic conditions (type 1 diabetes, cystic fibrosis, or juvenile idiopathic arthritis). Based on screening for anxiety and depression, adolescents are assigned to two parallel groups – “inconspicuous” (PHQ-9 and GAD-7 < 7) vs. “conspicuous” (PHQ-9 or GAD-7 ≥ 7) – participating in a prospective online survey at baseline and 12-month follow-up. At two time points (T1, T2), we assess (1) intra- and interpersonal resiliency factors, (2) coping strategies, and (3) health-related quality of life, well-being, satisfaction with life, anxiety and depression. Using a cross-lagged panel design, we will examine the bidirectional longitudinal relations between resiliency factors and coping strategies, psychological adaptation, and psychosocial adjustment. To monitor Covid-19 pandemic effects, participants are also invited to take part in an intermediate online survey. Discussion The study will provide a deeper understanding of adaptive, potentially modifiable processes and will therefore help to develop novel, tailored interventions supporting a positive adaptation in youths with a chronic condition. These strategies should not only support those at risk but also promote the maintenance of a successful adaptation. Trial registration German Clinical Trials Register (DRKS), no. DRKS00025125. Registered on May 17, 2021. KW - Chronic conditions KW - Adolescents KW - Prospective KW - Quality of life KW - Resiliency KW - Coping KW - Protective factors KW - Type 1 diabetes KW - Juvenile idiopathic arthritis KW - Cystic fibrosis Y1 - 2021 U6 - https://doi.org/10.1186/s12887-021-02869-9 SN - 1471-2431 VL - 21 SP - 1 EP - 13 PB - BMC pediatrics CY - London ER - TY - GEN A1 - Kliegl, Reinhold A1 - Masson, Michael E. J. A1 - Richter, Eike M. T1 - A linear mixed model analysis of masked repetition priming N2 - We examined individual differences in masked repetition priming by re-analyzing item-level response-time (RT) data from three experiments. Using a linear mixed model (LMM) with subjects and items specified as crossed random factors, the originally reported priming and word-frequency effects were recovered. In the same LMM, we estimated parameters describing the distributions of these effects across subjects. Subjects’ frequency and priming effects correlated positively with each other and negatively with mean RT. These correlation estimates, however, emerged only with a reciprocal transformation of RT (i.e., -1/RT), justified on the basis of distributional analyses. Different correlations, some with opposite sign, were obtained (1) for untransformed or logarithmic RTs or (2) when correlations were computed using within-subject analyses. We discuss the relevance of the new results for accounts of masked priming, implications of applying RT transformations, and the use of LMMs as a tool for the joint analysis of experimental effects and associated individual differences. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 247 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57073 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Bates, Douglas T1 - International Collaboration in Psychology is on the Rise N2 - There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 244 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57045 ER - TY - JOUR A1 - Schmidt, Lena Katharina A1 - Francke, Till A1 - Rottler, Erwin A1 - Blume, Theresa A1 - Schöber, Johannes A1 - Bronstert, Axel T1 - Suspended sediment and discharge dynamics in a glaciated alpine environment BT - identifying crucial areas and time periods on several spatial and temporal scales in the Ötztal, Austria JF - Earth surface dynamics N2 - Glaciated high-alpine areas are fundamentally altered by climate change, with well-known implications for hydrology, e.g., due to glacier retreat, longer snow-free periods, and more frequent and intense summer rainstorms. While knowledge on how these hydrological changes will propagate to suspended sediment dynamics is still scarce, it is needed to inform mitigation and adaptation strategies. To understand the processes and source areas most relevant to sediment dynamics, we analyzed discharge and sediment dynamics in high temporal resolution as well as their patterns on several spatial scales, which to date few studies have done. We used a nested catchment setup in the Upper Ötztal in Tyrol, Austria, where high-resolution (15 min) time series of discharge and suspended sediment concentrations are available for up to 15 years (2006–2020). The catchments of the gauges in Vent, Sölden and Tumpen range from 100 to almost 800 km2 with 10 % to 30 % glacier cover and span an elevation range of 930 to 3772 m a.s.l. We analyzed discharge and suspended sediment yields (SSY), their distribution in space, their seasonality and spatial differences therein, and the relative importance of short-term events. We complemented our analysis by linking the observations to satellite-based snow cover maps, glacier inventories, mass balances and precipitation data. Our results indicate that the areas above 2500 m a.s.l., characterized by glacier tongues and the most recently deglaciated areas, are crucial for sediment generation in all sub-catchments. This notion is supported by the synchronous spring onset of sediment export at the three gauges, which coincides with snowmelt above 2500 m but lags behind spring discharge onsets. This points at a limitation of suspended sediment supply as long as the areas above 2500 m are snow-covered. The positive correlation of annual SSY with glacier cover (among catchments) and glacier mass balances (within a catchment) further supports the importance of the glacier-dominated areas. The analysis of short-term events showed that summer precipitation events were associated with peak sediment concentrations and yields but on average accounted for only 21 % of the annual SSY in the headwaters. These results indicate that under current conditions, thermally induced sediment export (through snow and glacier melt) is dominant in the study area. Our results extend the scientific knowledge on current hydro-sedimentological conditions in glaciated high-alpine areas and provide a baseline for studies on projected future changes in hydro-sedimentological system dynamics. Y1 - 2022 U6 - https://doi.org/10.5194/esurf-10-653-2022 SN - 2196-632X SN - 2196-6311 VL - 10 IS - 3 SP - 653 EP - 669 PB - Copernicus Publications CY - Göttingen ER - TY - JOUR A1 - Hecker, Pascal A1 - Steckhan, Nico A1 - Eyben, Florian A1 - Schuller, Björn Wolfgang A1 - Arnrich, Bert T1 - Voice Analysis for Neurological Disorder Recognition – A Systematic Review and Perspective on Emerging Trends JF - Frontiers in Digital Health N2 - Quantifying neurological disorders from voice is a rapidly growing field of research and holds promise for unobtrusive and large-scale disorder monitoring. The data recording setup and data analysis pipelines are both crucial aspects to effectively obtain relevant information from participants. Therefore, we performed a systematic review to provide a high-level overview of practices across various neurological disorders and highlight emerging trends. PRISMA-based literature searches were conducted through PubMed, Web of Science, and IEEE Xplore to identify publications in which original (i.e., newly recorded) datasets were collected. Disorders of interest were psychiatric as well as neurodegenerative disorders, such as bipolar disorder, depression, and stress, as well as amyotrophic lateral sclerosis amyotrophic lateral sclerosis, Alzheimer's, and Parkinson's disease, and speech impairments (aphasia, dysarthria, and dysphonia). Of the 43 retrieved studies, Parkinson's disease is represented most prominently with 19 discovered datasets. Free speech and read speech tasks are most commonly used across disorders. Besides popular feature extraction toolkits, many studies utilise custom-built feature sets. Correlations of acoustic features with psychiatric and neurodegenerative disorders are presented. In terms of analysis, statistical analysis for significance of individual features is commonly used, as well as predictive modeling approaches, especially with support vector machines and a small number of artificial neural networks. An emerging trend and recommendation for future studies is to collect data in everyday life to facilitate longitudinal data collection and to capture the behavior of participants more naturally. Another emerging trend is to record additional modalities to voice, which can potentially increase analytical performance. KW - neurological disorders KW - voice KW - speech KW - everyday life KW - multiple modalities KW - machine learning KW - disorder recognition Y1 - 2022 U6 - https://doi.org/10.3389/fdgth.2022.842301 SN - 2673-253X PB - Frontiers Media SA CY - Lausanne, Schweiz ER - TY - JOUR A1 - Göldel, Julia Marlen A1 - Kamrath, Clemens A1 - Minden, Kirsten A1 - Wiegand, Susanna A1 - Lanzinger, Stefanie A1 - Sengler, Claudia A1 - Weihrauch-Blüher, Susann A1 - Holl, Reinhard A1 - Tittel, Sascha René A1 - Warschburger, Petra T1 - Access to Healthcare for Children and Adolescents with a Chronic Health Condition during the COVID-19 Pandemic: First Results from the KICK-COVID Study in Germany JF - Children N2 - This study examines the access to healthcare for children and adolescents with three common chronic diseases (type-1 diabetes (T1D), obesity, or juvenile idiopathic arthritis (JIA)) within the 4th (Delta), 5th (Omicron), and beginning of the 6th (Omicron) wave (June 2021 until July 2022) of the COVID-19 pandemic in Germany in a cross-sectional study using three national patient registries. A paper-and-pencil questionnaire was given to parents of pediatric patients (<21 years) during the routine check-ups. The questionnaire contains self-constructed items assessing the frequency of healthcare appointments and cancellations, remote healthcare, and satisfaction with healthcare. In total, 905 parents participated in the T1D-sample, 175 in the obesity-sample, and 786 in the JIA-sample. In general, satisfaction with healthcare (scale: 0–10; 10 reflecting the highest satisfaction) was quite high (median values: T1D 10, JIA 10, obesity 8.5). The proportion of children and adolescents with canceled appointments was relatively small (T1D 14.1%, JIA 11.1%, obesity 20%), with a median of 1 missed appointment, respectively. Only a few parents (T1D 8.6%; obesity 13.1%; JIA 5%) reported obstacles regarding health services during the pandemic. To conclude, it seems that access to healthcare was largely preserved for children and adolescents with chronic health conditions during the COVID-19 pandemic in Germany. KW - chronic health condition KW - children and adolescents KW - health care KW - COVID-19 pandemic KW - diabetes KW - rheumatic diseases KW - obesity Y1 - 2022 U6 - https://doi.org/10.3390/children10010010 SN - 2227-9067 VL - 10 SP - 1 EP - 11 PB - MDPI CY - Basel, Schweiz ET - 1 ER - TY - GEN A1 - Werner, John S. A1 - Donnelly, Seaneen K. A1 - Kliegl, Reinhold T1 - Aging and human macular pigment density : appended with translations from the work of Max Schultze and Ewald Hering N2 - The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1°, monochromatic light (400–550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5° temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10–0.80), but this variation was not systematically related to age. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 037 KW - Macular pigment KW - Color vision Aging Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16836 ER - TY - GEN A1 - Kliegl, Reinhold A1 - Olsen, Richard K. A1 - Davidson, Brian J. T1 - Regression analyses as a tool for studying reading processes : comment on Just and Carpenter's eye fixation theory N2 - Just and Carpenter (1980) presented a theory of reading based on eye fixations wherein their "psycholinguistic" variables accounted for 72% of the variance in word gaze durations. This comment raises some statistical and theoretical problems with their use of simultaneous regression analysis of gaze duration measures and with the resulting theory of reading. A major problem was the confounding of perceptual with psycholinguistic factors. New eye fixation data are presented to support these criticisms. Analysis of fixations within words revealed that most gaze duration variance was contributed by number of fixations rather than by fixation duration. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 042 Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16857 ER - TY - GEN A1 - Olson, Richard K. A1 - Davidson, Brian J. A1 - Kliegl, Reinhold A1 - Davies, Susan E. T1 - Development of phonetic memory in disabled and normal readers N2 - The development of phonetic codes in memory of 141 pairs of normal and disabled readers from 7.8 to 16.8 years of age was tested with a task adapted from L. S. Mark, D. Shankweiler, I. Y. Liberman, and C. A. Fowler (Memory & Cognition, 1977, 5, 623–629) that measured false-positive errors in recognition memory for foil words which rhymed with words in the memory list versus foil words that did not rhyme. Our younger subjects replicated Mark et al., showing a larger difference between rhyming and nonrhyming false-positive errors for the normal readers. The older disabled readers' phonetic effect was comparable to that of the younger normal readers, suggesting a developmental lag in their use of phonetic coding in memory. Surprisingly, the normal readers' phonetic effect declined with age in the recognition task, but they maintained a significant advantage across age in the auditory WISC-R digit span recall test, and a test of phonological nonword decoding. The normals' decline with age in rhyming confusion may be due to an increase in the precision of their phonetic codes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 039 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16888 ER - TY - JOUR A1 - Fischer, Martin H. A1 - Winter, Bodo A1 - Felisatti, Arianna A1 - Myachykov, Andriy A1 - Jeglinski-Mende, Melinda A. A1 - Shaki, Samuel T1 - More Instructions Make Fewer Subtractions JF - Frontiers in Psychology N2 - Research on problem solving offers insights into how humans process task-related information and which strategies they use (Newell and Simon, 1972; Öllinger et al., 2014). Problem solving can be defined as the search for possible changes in one's mind (Kahneman, 2003). In a recent study, Adams et al. (2021) assessed whether the predominant problem solving strategy when making changes involves adding or subtracting elements. In order to do this, they used several examples of simple problems, such as editing text or making visual patterns symmetrical, either in naturalistic settings or on-line. The essence of the authors' findings is a strong preference to add rather than subtract elements across a diverse range of problems, including the stabilizing of artifacts, creating symmetrical patterns, or editing texts. More specifically, they succeeded in demonstrating that “participants were less likely to identify advantageous subtractive changes when the task did not (vs. did) cue them to consider subtraction, when they had only one opportunity (vs. several) to recognize the shortcomings of an additive search strategy or when they were under a higher (vs. lower) cognitive load” (Adams et al., 2021, p. 258). Addition and subtraction are generally defined as de-contextualized mathematical operations using abstract symbols (Russell, 1903/1938). Nevertheless, understanding of both symbols and operations is informed by everyday activities, such as making or breaking objects (Lakoff and Núñez, 2000; Fischer and Shaki, 2018). The universal attribution of “addition bias” or “subtraction neglect” to problem solving activities is perhaps a convenient shorthand but it overlooks influential framing effects beyond those already acknowledged in the report and the accompanying commentary (Meyvis and Yoon, 2021). Most importantly, while Adams et al.'s study addresses an important issue, their very method of verbally instructing participants, together with lack of control over several known biases, might render their findings less than conclusive. Below, we discuss our concerns that emerged from the identified biases, namely those regarding the instructions and the experimental materials. Moreover, we refer to research from mathematical cognition that provides new insights into Adams et al.'s findings. KW - problem solving KW - addition KW - subtraction KW - cognitive bias KW - SNARC Y1 - 2021 U6 - https://doi.org/10.3389/fpsyg.2021.720616 SN - 1664-1078 VL - 12 SP - 1 EP - 3 PB - Frontiers Media SA CY - Lausanne, Schweiz ER - TY - GEN A1 - MacWhinney, Brian A1 - Bates, Elizabeth A1 - Kliegl, Reinhold T1 - Cue validity and sentence interpretation in English, German, and Italian N2 - Linguistic and psycholinguistic accounts based on the study of English may prove unreliable as guides to sentence processing in even closely related languages. The present study illustrates this claim in a test of sentence interpretation by German-, Italian-, and English-speaking adults. Subjects were presented with simple transitive sentences in which contrasts of (1) word order, (2) agreement, (3) animacy, and (4) stress were systematically varied. For each sentence, subjects were asked to state which of the two nouns was the actor. The results indicated that Americans relied overwhelming on word order, using a first-noun strategy in NVN and a second-noun strategy in VNN and NNV sentences. Germans relied on both agreement and animacy. Italians showed extreme reliance on agreement cues. In both German and Italian, stress played a role in terms of complex interactions with word order and agreement. The findings were interpreted in terms of the “competition model” of Bates and MacWhinney (in H. Winitz (Ed.), Annals of the New York Academy of Sciences Conference on Native and Foreign Language Acquisition. New York: New York Academy of Sciences, 1982) in which cue validity is considered to be the primary determinant of cue strength. According to this model, cues are said to be high in validity when they are also high in applicability and reliability. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 038 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16847 ER - TY - JOUR A1 - Fühner, Thea Heidi A1 - Granacher, Urs A1 - Golle, Kathleen A1 - Kliegl, Reinhold T1 - Age and sex effects in physical fitness components of 108,295 third graders including 515 primary schools and 9 cohorts JF - Scientific Reports N2 - Children’s physical fitness development and related moderating effects of age and sex are well documented, especially boys’ and girls’ divergence during puberty. The situation might be different during prepuberty. As girls mature approximately two years earlier than boys, we tested a possible convergence of performance with five tests representing four components of physical fitness in a large sample of 108,295 eight-year old third-graders. Within this single prepubertal year of life and irrespective of the test, performance increased linearly with chronological age, and boys outperformed girls to a larger extent in tests requiring muscle mass for successful performance. Tests differed in the magnitude of age effects (gains), but there was no evidence for an interaction between age and sex. Moreover, “physical fitness” of schools correlated at r = 0.48 with their age effect which might imply that "fit schools” promote larger gains; expected secular trends from 2011 to 2019 were replicated. Y1 - 2021 U6 - https://doi.org/10.1038/s41598-021-97000-4 SN - 2045-2322 VL - 11 SP - 1 EP - 13 PB - Nature Portfolio CY - Berlin ER - TY - JOUR A1 - Stiegler, Jonas A1 - Lins, Alisa A1 - Dammhahn, Melanie A1 - Kramer-Schadt, Stephanie A1 - Ortmann, Sylvia A1 - Blaum, Niels T1 - Personality drives activity and space use in a mammalian herbivore JF - Movement Ecology N2 - Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum. Methods We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals’ degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population. Results We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant). Conclusions Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes. KW - Animal personality KW - Movement ecology KW - Inter-individual differences KW - ODBA KW - Energy expenditure KW - European hare Y1 - 2022 U6 - https://doi.org/10.1186/s40462-022-00333-6 SN - 2051-3933 VL - 10 PB - BioMed Central (BMC), Springer Nature CY - London ER - TY - JOUR A1 - Risch, Lucie A1 - Stoll, Josefine A1 - Schomöller, Anne A1 - Engel, Tilman A1 - Mayer, Frank A1 - Cassel, Michael T1 - Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons JF - Frontiers in physiology N2 - Objective: This study investigated intraindividual differences of intratendinous blood flow (IBF) in response to running exercise in participants with Achilles tendinopathy. Design: This is a cross-sectional study. Setting: The study was conducted at the University Outpatient Clinic. Participants: Sonographic detectable intratendinous blood flow was examined in symptomatic and contralateral asymptomatic Achilles tendons of 19 participants (42 ± 13 years, 178 ± 10 cm, 76 ± 12 kg, VISA-A 75 ± 16) with clinically diagnosed unilateral Achilles tendinopathy and sonographic evident tendinosis. Intervention: IBF was assessed using Doppler ultrasound “Advanced Dynamic Flow” before (Upre) and 5, 30, 60, and 120 min (U5–U120) after a standardized submaximal constant load run. Main Outcome Measure: IBF was quantified by counting the number (n) of vessels in each tendon. Results: At Upre, IBF was higher in symptomatic compared with asymptomatic tendons [mean 6.3 (95% CI: 2.8–9.9) and 1.7 (0.4–2.9), p < 0.01]. Overall, 63% of symptomatic and 47% of asymptomatic Achilles tendons responded to exercise, whereas 16 and 11% showed persisting IBF and 21 and 42% remained avascular throughout the investigation. At U5, IBF increased in both symptomatic and asymptomatic tendons [difference to baseline: 2.4 (0.3–4.5) and 0.9 (0.5–1.4), p = 0.05]. At U30 to U120, IBF was still increased in symptomatic but not in asymptomatic tendons [mean difference to baseline: 1.9 (0.8–2.9) and 0.1 (-0.9 to 1.2), p < 0.01]. Conclusion: Irrespective of pathology, 47–63% of Achilles tendons responded to exercise with an immediate acute physiological IBF increase by an average of one to two vessels (“responders”). A higher amount of baseline IBF (approximately five vessels) and a prolonged exercise-induced IBF response found in symptomatic ATs indicate a pain-associated altered intratendinous “neovascularization.” KW - achilles tendinopathy KW - tendinosis KW - neovascularization KW - ultrasound KW - advanced dynamic flow KW - sonography Y1 - 2021 U6 - https://doi.org/10.3389/fphys.2021.617497 SN - 1664-042X VL - 12 SP - 1 EP - 8 PB - Frontiers Research Foundation CY - Lausanne, Schweiz ER - TY - GEN A1 - Valsecchi, Matteo A1 - Dimigen, Olaf A1 - Kliegl, Reinhold A1 - Sommer, Werner A1 - Turatto, Massimo T1 - Microsaccadic Inhibition and P300 Enhancement in a Visual Oddball Task N2 - It has recently been demonstrated that the presentation of a rare target in a visual oddball paradigm induces a prolonged inhibition of microsaccades. In the field of electrophysiology, the amplitude of the P300 component in event-related potentials (ERP) has been shown to be sensitive to the stimulus category (target vs. non target) of the eliciting stimulus, its overall probability, and the preceding stimulus sequence. In the present study we further specify the functional underpinnings of the prolonged microsaccadic inhibition in the visual oddball task, showing that the stimulus category, the frequency of a stimulus and the preceding stimulus sequence influence microsaccade rate. Furthermore, by co-recording ERPs and eye-movements, we were able to demonstrate that, despite being largely sensitive to the same experimental manipulation, the amplitude of P300 and the microsaccadic inhibition predict each other very weakly, and thus constitute two independent measures of the brain’s response to rare targets in the visual oddball paradigm. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 256 KW - Visual Oddball Paradigm KW - Microsaccades KW - Microsaccadic Inhibition KW - ERPs KW - P300Psychophysiology KW - 46 (3) 2009 KW - S. 635-644 Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57170 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John A1 - Kliegl, Reinhold A1 - Patil, Umesh A1 - Vasishth, Shravan T1 - Parsing costs as predictors of reading difficulty: An evaluation using the Potsdam Sentence Corpus N2 - The surprisal of a word on a probabilistic grammar constitutes a promising complexity metric for human sentence comprehension difficulty. Using two different grammar types, surprisal is shown to have an effect on fixation durations and regression probabilities in a sample of German readers’ eye movements, the Potsdam Sentence Corpus. A linear mixed-effects model was used to quantify the effect of surprisal while taking into account unigram and bigram frequency, word length, and empirically-derived word predictability; the so-called “early” and “late” measures of processing difficulty both showed an effect of surprisal. Surprisal is also shown to have a small but statistically non-significant effect on empirically-derived predictability itself. This work thus demonstrates the importance of including parsing costs as a predictor of comprehension difficulty in models of reading, and suggests that a simple identification of syntactic parsing costs with early measures and late measures with durations of post-syntactic events may be difficult to uphold. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 253 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57139 ER - TY - GEN A1 - Ming, Yan A1 - Kliegl, Reinhold A1 - Shu, Hua A1 - Pan, Jinger A1 - Zhou, Xiaolin T1 - Parafoveal Load of Word N+1 Modulates Preprocessing Effectivenessof Word N+2 in Chinese Reading N2 - Preview benefits (PBs) from two words to the right of the fixated one (i.e., word N+2)and associated parafoveal-on-foveal effects are critical for proposals of distributed lexical processing during reading. This experiment examined parafoveal processing during reading of Chinese sentences, using a boundary manipulation of N+2-word preview with low- and high-frequency words N+1. The main findings were (a) an identity PB for word N+2 that was (b) primarily observed when word N+1 was of high frequency (i.e., an interaction between frequency of word N+1 and PB for word N+2), and (c) a parafoveal-on-foveal frequency effect of word N+1 for fixation durations on word N. We discuss implications for theories of serial attention shifts and parallel distributed processing of words during reading. T2 - Ming Yan; Reinhold Kliegl; Hua Shu; Jinger Pan; Xiaolin Zhou T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 250 Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57103 ER - TY - GEN A1 - Angele, Bernhard A1 - Slattery, Timothy J. A1 - Yang, Jinmian A1 - Kliegl, Reinhold A1 - Rayner, Keith T1 - Parafoveal processing in reading: Manipulating n+1 and n+2 previews simultaneously N2 - The boundary paradigm (Rayner, 1975) with a novel preview manipulation was used to examine the extent of parafoveal processing of words to the right of fixation. Words n+1 and n+2 had either correct or incorrect previews prior to fixation (prior to crossing the boundary location). In addition, the manipulation utilized either a high or low frequency word in word n+1 location on the assumption that it would be more likely that n+2 preview effects could be obtained when word n+1 was high frequency. The primary findings were that there was no evidence for a preview benefit for word n+2 and no evidence for parafoveal-on-foveal effects when word n+1 is at least four letters long. We discuss implications for models of eye-movement control in reading. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 251 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57128 ER - TY - GEN A1 - Boston, Marisa Ferrara A1 - Hale, John T. A1 - Vasishth, Shravan A1 - Kliegl, Reinhold T1 - Parallel processing and sentence comprehension difficulty N2 - Eye fixation durations during normal reading correlate with processing difficulty but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers’ eyefixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated, and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 252 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-57159 ER - TY - JOUR A1 - Hering, Robert A1 - Hauptfleisch, Morgan A1 - Jago, Mark A1 - Smith, Taylor A1 - Kramer-Schadt, Stephanie A1 - Stiegler, Jonas A1 - Blaum, Niels T1 - Don't stop me now: Managed fence gaps could allow migratory ungulates to track dynamic resources and reduce fence related energy loss JF - Frontiers in Ecology and Evolution N2 - In semi-arid environments characterized by erratic rainfall and scattered primary production, migratory movements are a key survival strategy of large herbivores to track resources over vast areas. Veterinary Cordon Fences (VCFs), intended to reduce wildlife-livestock disease transmission, fragment large parts of southern Africa and have limited the movements of large wild mammals for over 60 years. Consequently, wildlife-fence interactions are frequent and often result in perforations of the fence, mainly caused by elephants. Yet, we lack knowledge about at which times fences act as barriers, how fences directly alter the energy expenditure of native herbivores, and what the consequences of impermeability are. We studied 2-year ungulate movements in three common antelopes (springbok, kudu, eland) across a perforated part of Namibia's VCF separating a wildlife reserve and Etosha National Park using GPS telemetry, accelerometer measurements, and satellite imagery. We identified 2905 fence interaction events which we used to evaluate critical times of encounters and direct fence effects on energy expenditure. Using vegetation type-specific greenness dynamics, we quantified what animals gained in terms of high quality food resources from crossing the VCF. Our results show that the perforation of the VCF sustains herbivore-vegetation interactions in the savanna with its scattered resources. Fence permeability led to peaks in crossing numbers during the first flush of woody plants before the rain started. Kudu and eland often showed increased energy expenditure when crossing the fence. Energy expenditure was lowered during the frequent interactions of ungulates standing at the fence. We found no alteration of energy expenditure when springbok immediately found and crossed fence breaches. Our results indicate that constantly open gaps did not affect energy expenditure, while gaps with obstacles increased motion. Closing gaps may have confused ungulates and modified their intended movements. While browsing, sedentary kudu's use of space was less affected by the VCF; migratory, mixed-feeding springbok, and eland benefited from gaps by gaining forage quality and quantity after crossing. This highlights the importance of access to vast areas to allow ungulates to track vital vegetation patches. KW - veterinary cordon fence KW - ungulate KW - fence ecology KW - resource-tracking KW - energy expenditure KW - accelerometer KW - GPS KW - wildlife and habitat management Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2022.907079 SN - 2296-701X SP - 1 EP - 18 PB - Frontiers CY - Lausanne, Schweiz ER - TY - GEN A1 - Werner, John S. A1 - Cicerone, Carola M. A1 - Kliegl, Reinhold A1 - DellaRosa, Denise T1 - Spectral efficiency of blackness induction N2 - The spectral efficiency of blackness induction was measured in three normal trichromatic observers and in one deuteranomalous observer. The psychophysical task was to adjust the radiance of a monochromatic 60–120′ annulus until a 45′ central broadband field just turned black and its contour became indiscriminable from a dark surrounding gap that separated it from the annulus. The reciprocal of the radiance required to induce blackness with annulus wavelengths between 420 and 680 nm was used to define a spectral-efficiency function for the blackness component of the achromatic process. For each observer, the shape of this blackness-sensitivity function agreed with the spectral-efficiency function based on heterochromatic flicker photometry when measured with the same 60–120′ annulus. Both of these functions matched the Commission Internationale de l'Eclairage Vλ function except at short wavelengths. Ancillary measurements showed that the latter difference in sensitivity can be ascribed to nonuniformities of preretinal absorption, since the annular field excluded the central 60′ of the fovea. Thus our evidence indicates that, at least to a good first approximation, induced blackness is inversely related to the spectral-luminosity function. These findings are consistent with a model that separates the achromatic and the chromatic pathways. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - paper 040 Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16897 ER - TY - RPRT A1 - Lessmann, Kai A1 - Gruner, Friedemann A1 - Kalkuhl, Matthias A1 - Edenhofer, Ottmar T1 - Emissions Trading with Clean-up Certificates BT - Deterring Mitigation or Increasing Ambition? T2 - CEPA Discussion Papers N2 - We analyze how conventional emissions trading schemes (ETS) can be modified by introducing “clean-up certificates” to allow for a phase of net-negative emissions. Clean-up certificates bundle the permission to emit CO2 with the obligation for its removal. We show that demand for such certificates is determined by cost-saving technological progress, the discount rate and the length of the compliance period. Introducing extra clean-up certificates into an existing ETS reduces near-term carbon prices and mitigation efforts. In contrast, substituting ETS allowances with clean-up certificates reduces cumulative emissions without depressing carbon prices or mitigation in the near term. We calibrate our model to the EU ETS and identify reforms where simultaneously (i) ambition levels rise, (ii) climate damages fall, (iii) revenues from carbon prices rise and (iv) carbon prices and aggregate mitigation cost fall. For reducing climate damages, roughly half of the issued clean-up certificates should replace conventional ETS allowances. In the context of the EU ETS, a European Carbon Central Bank could manage the implementation of cleanup certificates and could serve as an enforcement mechanism. T3 - CEPA Discussion Papers - 79 KW - carbon removal KW - carbon pricing KW - net-negative emissions KW - carbon debt Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-641368 SN - 2628-653X IS - 79 ER - TY - JOUR A1 - Herold, Fabian A1 - Theobald, Paula A1 - Gronwald, Thomas A1 - Rapp, Michael A. A1 - Müller, Notger Germar T1 - Going digital – a commentary on the terminology used at the intersection of physical activity and digital health JF - European review of aging and physical activity N2 - In recent years digital technologies have become a major means for providing health-related services and this trend was strongly reinforced by the current Coronavirus disease 2019 (COVID-19) pandemic. As it is well-known that regular physical activity has positive effects on individual physical and mental health and thus is an important prerequisite for healthy aging, digital technologies are also increasingly used to promote unstructured and structured forms of physical activity. However, in the course of this development, several terms (e.g., Digital Health, Electronic Health, Mobile Health, Telehealth, Telemedicine, and Telerehabilitation) have been introduced to refer to the application of digital technologies to provide health-related services such as physical interventions. Unfortunately, the above-mentioned terms are often used in several different ways, but also relatively interchangeably. Given that ambiguous terminology is a major source of difficulty in scientific communication which can impede the progress of theoretical and empirical research, this article aims to make the reader aware of the subtle differences between the relevant terms which are applied at the intersection of physical activity and Digital Health and to provide state-of-art definitions for them. KW - Digital Health KW - Electronic Health KW - Mobile Health KW - Telehealth KW - Telemedicine KW - Physical activity KW - Physical training KW - Aging Y1 - 2022 U6 - https://doi.org/10.1186/s11556-022-00296-y SN - 1861-6909 VL - 19 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Pérez Chaparro, Camilo Germán Alberto A1 - Schuch, Felipe Barreto A1 - Zech, Philipp A1 - Kangas, Maria A1 - Rapp, Michael A. A1 - Heißel, Andreas T1 - Recreational exercising and self-reported cardiometabolic diseases in German people living with HIV BT - A cross-sectional study JF - International journal of environmental research and public health : IJERPH / Molecular Diversity Preservation International N2 - Exercise is known for its beneficial effects on preventing cardiometabolic diseases (CMDs) in the general population. People living with the human immunodeficiency virus (PLWH) are prone to sedentarism, thus raising their already elevated risk of developing CMDs in comparison to individuals without HIV. The aim of this cross-sectional study was to determine if exercise is associated with reduced risk of self-reported CMDs in a German HIV-positive sample (n = 446). Participants completed a self-report survey to assess exercise levels, date of HIV diagnosis, CD4 cell count, antiretroviral therapy, and CMDs. Participants were classified into exercising or sedentary conditions. Generalized linear models with Poisson regression were conducted to assess the prevalence ratio (PR) of PLWH reporting a CMD. Exercising PLWH were less likely to report a heart arrhythmia for every increase in exercise duration (PR: 0.20: 95% CI: 0.10–0.62, p < 0.01) and diabetes mellitus for every increase in exercise session per week (PR: 0.40: 95% CI: 0.10–1, p < 0.01). Exercise frequency and duration are associated with a decreased risk of reporting arrhythmia and diabetes mellitus in PLWH. Further studies are needed to elucidate the mechanisms underlying exercise as a protective factor for CMDs in PLWH. KW - HIV KW - exercise KW - cardiovascular diseases KW - metabolic disease KW - sedentary Y1 - 2021 U6 - https://doi.org/10.3390/ijerph182111579 SN - 1660-4601 VL - 18 IS - 21 SP - 1 EP - 10 PB - MDPI CY - Basel, Schweiz ER - TY - GEN A1 - Ye, Fangyuan A1 - Zhang, Shuo A1 - Warby, Jonathan A1 - Wu, Jiawei A1 - Gutierrez-Partida, Emilio A1 - Lang, Felix A1 - Shah, Sahil A1 - Saglamkaya, Elifnaz A1 - Sun, Bowen A1 - Zu, Fengshuo A1 - Shoaee, Safa A1 - Wang, Haifeng A1 - Stiller, Burkhard A1 - Neher, Dieter A1 - Zhu, Wei-Hong A1 - Stolterfoht, Martin A1 - Wu, Yongzhen T1 - Overcoming C₆₀-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23% with a low non-radiative voltage loss of 110 mV, and retain >97% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1317 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587705 SN - 1866-8372 IS - 1317 ER - TY - JOUR A1 - Schraplau, Anne A1 - Block, Andrea A1 - Häusler, Andreas A1 - Wippert, Pia-Maria A1 - Rapp, Michael A. A1 - Völler, Heinz A1 - Bonaventura, Klaus A1 - Mayer, Frank T1 - Mobile diagnostics and consultation for the prevention of the metabolic syndrome and its secondary diseases in Brandenburg—study protocol of a regional prospective cohort study BT - the Mobile Brandenburg Cohort JF - Pilot and Feasibility Studies N2 - Background The metabolic syndrome (MetS) is a risk cluster for a number of secondary diseases. The implementation of prevention programs requires early detection of individuals at risk. However, access to health care providers is limited in structurally weak regions. Brandenburg, a rural federal state in Germany, has an especially high MetS prevalence and disease burden. This study aims to validate and test the feasibility of a setup for mobile diagnostics of MetS and its secondary diseases, to evaluate the MetS prevalence and its association with moderating factors in Brandenburg and to identify new ways of early prevention, while establishing a “Mobile Brandenburg Cohort” to reveal new causes and risk factors for MetS. Methods In a pilot study, setups for mobile diagnostics of MetS and secondary diseases will be developed and validated. A van will be equipped as an examination room using point-of-care blood analyzers and by mobilizing standard methods. In study part A, these mobile diagnostic units will be placed at different locations in Brandenburg to locally recruit 5000 participants aged 40-70 years. They will be examined for MetS and advice on nutrition and physical activity will be provided. Questionnaires will be used to evaluate sociodemographics, stress perception, and physical activity. In study part B, participants with MetS, but without known secondary diseases, will receive a detailed mobile medical examination, including MetS diagnostics, medical history, clinical examinations, and instrumental diagnostics for internal, cardiovascular, musculoskeletal, and cognitive disorders. Participants will receive advice on nutrition and an exercise program will be demonstrated on site. People unable to participate in these mobile examinations will be interviewed by telephone. If necessary, participants will be referred to general practitioners for further diagnosis. Discussion The mobile diagnostics approach enables early detection of individuals at risk, and their targeted referral to local health care providers. Evaluation of the MetS prevalence, its relation to risk-increasing factors, and the “Mobile Brandenburg Cohort” create a unique database for further longitudinal studies on the implementation of home-based prevention programs to reduce mortality, especially in rural regions. Trial registration German Clinical Trials Register, DRKS00022764; registered 07 October 2020—retrospectively registered. KW - Metabolic syndrome KW - Mobile diagnostics KW - Prevention KW - Nutrition KW - Physical activity KW - Rural health Y1 - 2021 U6 - https://doi.org/10.1186/s40814-021-00898-w SN - 2055-5784 VL - 7 SP - 1 EP - 11 PB - BioMed Central (Springer Nature) CY - London ER - TY - JOUR A1 - Heissel, Andreas A1 - Pietrek, Anou F. A1 - Kangas, Maria A1 - Van der Kaap-Deeder, Jolene A1 - Rapp, Michael A. T1 - The Mediating Role of Rumination in the Relation between Basic Psychological Need Frustration and Depressive Symptoms JF - Journal of Clinical Medicine N2 - Research within the framework of Basic Psychological Need Theory (BPNT) finds strong associations between basic need frustration and depressive symptoms. This study examined the role of rumination as an underlying mechanism in the association between basic psychological need frustration and depressive symptoms. A cross-sectional sample of N = 221 adults (55.2% female, mean age = 27.95, range = 18–62, SD = 10.51) completed measures assessing their level of basic psychological need frustration, rumination, and depressive symptoms. Correlational analyses and multiple mediation models were conducted. Brooding partially mediated the relation between need frustration and depressive symptoms. BPNT and Response Styles Theory are compatible and can further advance knowledge about depression vulnerabilities. KW - psychopathology KW - elf-determination theory KW - response styles theory KW - frustration KW - depressive disorder KW - emotional regulation KW - rumination Y1 - 2023 U6 - https://doi.org/10.3390/jcm12020395 SN - 2077-0383 VL - 12 SP - 1 EP - 10 PB - MDPI CY - Basel, Schweiz ET - 2 ER - TY - JOUR A1 - Pietrek, Anou F. A1 - Kangas, Maria A1 - Kliegl, Reinhold A1 - Rapp, Michael A. A1 - Heinzel, Stephan A1 - Van der Kaap-Deeder, Jolene A1 - Heissel, Andreas T1 - Basic psychological need satisfaction and frustration in major depressive disorder JF - Frontiers in Psychiatry - Mood Disorders N2 - Basic psychological needs theory postulates that a social environment that satisfies individuals’ three basic psychological needs of autonomy, competence, and relatedness leads to optimal growth and well-being. On the other hand, the frustration of these needs is associated with ill-being and depressive symptoms foremost investigated in non-clinical samples; yet, there is a paucity of research on need frustration in clinical samples. Survey data were compared between adult individuals with major depressive disorder (MDD; n = 115; 48.69% female; 38.46 years, SD = 10.46) with those of a non-depressed comparison sample (n = 201; 53.23% female; 30.16 years, SD = 12.81). Need profiles were examined with a linear mixed model (LMM). Individuals with depression reported higher levels of frustration and lower levels of satisfaction in relation to the three basic psychological needs when compared to non-depressed adults. The difference between depressed and non-depressed groups was significantly larger for frustration than satisfaction regarding the needs for relatedness and competence. LMM correlation parameters confirmed the expected positive correlation between the three needs. This is the first study showing substantial differences in need-based experiences between depressed and non-depressed adults. The results confirm basic assumptions of the self-determination theory and have preliminary implications in tailoring therapy for depression. KW - basic need satisfaction and frustration KW - depressive symptoms KW - clinical sample KW - need profiles KW - social environment Y1 - 2022 U6 - https://doi.org/10.3389/fpsyt.2022.962501 SN - 1664-0640 SP - 1 EP - 10 PB - Frontiers Media S.A. CY - Lausanne, Schweiz ER - TY - JOUR A1 - Jara Muñoz, Julius A1 - Melnick, Daniel A1 - Li, Shaoyang A1 - Socquet, Anne A1 - Cortés-Aranda, Joaquín A1 - Brill, Dominik A1 - Strecker, Manfred T1 - The cryptic seismic potential of the Pichilemu blind fault in Chile revealed by off-fault geomorphology JF - Nature Communications N2 - The first step towards assessing hazards in seismically active regions involves mapping capable faults and estimating their recurrence times. While the mapping of active faults is commonly based on distinct geologic and geomorphic features evident at the surface, mapping blind seismogenic faults is complicated by the absence of on-fault diagnostic features. Here we investigated the Pichilemu Fault in coastal Chile, unknown until it generated a Mw 7.0 earthquake in 2010. The lack of evident surface faulting suggests activity along a partly-hidden blind fault. We used off-fault deformed marine terraces to estimate a fault-slip rate of 0.52 ± 0.04 m/ka, which, when integrated with satellite geodesy suggests a 2.12 ± 0.2 ka recurrence time for Mw~7.0 normal-faulting earthquakes. We propose that extension in the Pichilemu region is associated with stress changes during megathrust earthquakes and accommodated by sporadic slip during upper-plate earthquakes, which has implications for assessing the seismic potential of cryptic faults along convergent margins and elsewhere. Y1 - 2022 U6 - https://doi.org/10.1038/s41467-022-30754-1 SN - 2041-1723 VL - 13 PB - Springer Nature CY - London ER - TY - THES A1 - Ketzer, Laura T1 - The impact of stellar activity evolution on atmospheric mass loss of young exoplanets T1 - Der Einfluss der stellaren Aktivitätsentwicklung auf den atmosphärischen Massenverlust von jungen Exoplaneten N2 - The increasing number of known exoplanets raises questions about their demographics and the mechanisms that shape planets into how we observe them today. Young planets in close-in orbits are exposed to harsh environments due to the host star being magnetically highly active, which results in high X-ray and extreme UV fluxes impinging on the planet. Prolonged exposure to this intense photoionizing radiation can cause planetary atmospheres to heat up, expand and escape into space via a hydrodynamic escape process known as photoevaporation. For super-Earth and sub-Neptune-type planets, this can even lead to the complete erosion of their primordial gaseous atmospheres. A factor of interest for this particular mass-loss process is the activity evolution of the host star. Stellar rotation, which drives the dynamo and with it the magnetic activity of a star, changes significantly over the stellar lifetime. This strongly affects the amount of high-energy radiation received by a planet as stars age. At a young age, planets still host warm and extended envelopes, making them particularly susceptible to atmospheric evaporation. Especially in the first gigayear, when X-ray and UV levels can be 100 - 10,000 times higher than for the present-day sun, the characteristics of the host star and the detailed evolution of its high-energy emission are of importance. In this thesis, I study the impact of stellar activity evolution on the high-energy-induced atmospheric mass loss of young exoplanets. The PLATYPOS code was developed as part of this thesis to calculate photoevaporative mass-loss rates over time. The code, which couples parameterized planetary mass-radius relations with an analytical hydrodynamic escape model, was used, together with Chandra and eROSITA X-ray observations, to investigate the future mass loss of the two young multiplanet systems V1298 Tau and K2-198. Further, in a numerical ensemble study, the effect of a realistic spread of activity tracks on the small-planet radius gap was investigated for the first time. The works in this thesis show that for individual systems, in particular if planetary masses are unconstrained, the difference between a young host star following a low-activity track vs. a high-activity one can have major implications: the exact shape of the activity evolution can determine whether a planet can hold on to some of its atmosphere, or completely loses its envelope, leaving only the bare rocky core behind. For an ensemble of simulated planets, an observationally-motivated distribution of activity tracks does not substantially change the final radius distribution at ages of several gigayears. My simulations indicate that the overall shape and slope of the resulting small-planet radius gap is not significantly affected by the spread in stellar activity tracks. However, it can account for a certain scattering or fuzziness observed in and around the radius gap of the observed exoplanet population. N2 - Die steigende Anzahl bekannter Exoplaneten wirft Fragen zu ihrer Demografie und den Mechanismen auf, die Planeten in ihre heutige beobachtete Form bringen. Junge Planeten, die sehr nah um ihren Wirtsstern kreisen, sind extremen Umgebungen ausgesetzt, da der Stern eine hohe magnetische Aktivität aufweist. Das führt wiederum dazu, dass der Planet einer enormen Röntgen- und Extrem-UV-Strahlung ausgesetzt ist. Ist der Planet über einen längeren Zeitraum dieser intensiven photoionisierenden Strahlung ausgesetzt, kann dies dazu führen, dass Planetenatmosphären sich aufheizen, ausdehnen und durch einen hydrodynamischen Entweichungsprozess namens Photoevaporation ins All entweichen, sozusagen verdampfen. Bei Planeten, in der Größenordnung von Super-Erden und Sub-Neptunen, kann dies sogar zur vollständigen Erosion ihrer Ur-Atmosphären führen. Ein interessanter Faktor, der für diesen Massenverlustprozess eine Rolle spielt, ist die Aktivitätsentwicklung des Wirtssterns. Die Rotation eines Sterns, die den Dynamo und damit die magnetische Aktivität antreibt, ändert sich im Laufe der Lebensdauer eines Sterns erheblich. Dies hat einen starken Einfluss auf die Menge der hochenergetischen Strahlung, den ein Planet mit zunehmendem Alter des Sterns empfängt. In jungen Jahren besitzen Planeten noch warme und ausgedehnte Hüllen, was sie besonders anfällig für atmosphärische Verdunstung macht. Insbesondere in den ersten Gigajahren, wenn die Röntgen- und UV-Strahlung 100 - 10,000 Mal höher sein kann als bei der heutigen Sonne, sind die Eigenschaften des Wirtssterns und die detaillierte Entwicklung seiner hochenergetischen Emission von Bedeutung. In dieser Arbeit untersuche ich die Auswirkungen der Entwicklung der stellaren Aktivität auf den durch hochenergetische Strahlung verursachten atmosphärischen Massenverlust junger Exoplaneten. Der PLATYPOS-Code wurde im Rahmen dieser Arbeit entwickelt, um die photoevaporativen Massenverlustraten für verschiedene stellare Alter zu berechnen. Der Code verknüpft parametrisierte Planetenmasse-Radius-Beziehungen mit einem analytischen Modell für den hydrodynamischen Massenverlust. Er wurde zusammen mit Chandra- und eROSITA-Röntgenbeobachtungen dazu verwendet, den zukünftigen Massenverlust der beiden jungen Mehrplanetensysteme V1298 Tau und K2-198 zu untersuchen. Darüber hinaus wurde in einer numerischen Ensemblestudie erstmals der Effekt einer realistischen Verteilung von stellaren Aktivitäts-Tracks auf das sogenannte Radius-Tal bei kleinen Planeten untersucht. Die Arbeiten in dieser Dissertation zeigen, dass für einzelne Systeme, insbesondere wenn die Planetenmassen unbestimmt sind, der Unterschied zwischen einem jungen Wirtsstern, der einem Track mit niedriger Aktivität gegenüber einem solchen mit hoher Aktivität folgt, gravierende Auswirkungen haben kann: Die genaue Form der Aktivitätsentwicklung kann darüber entscheiden, ob ein Planet einen Teil seiner Atmosphäre behält oder seine Hülle vollständig verliert und nur den nackten Gesteinskern behält. Für ein Ensemble von simulierten Planeten ändert eine durch Beobachtungen motivierte Verteilung von Aktivitäts-Tracks die endgültige Radiusverteilung der Planeten nach mehreren Gigajahren nicht wesentlich. Meine Simulationen deuten darauf hin, dass die Form und Steigung des sich ergebenden Radius-Tals bei Kleinplaneten nicht wesentlich von der Streuung der stellaren Aktivitäts-Tracks beeinflusst wird. Eine gewisse Streuung oder Unschärfe im Radius-Tal der beobachteten Exoplanetenpopulation kann damit allerdings durchaus erklärt werden. KW - Exoplaneten KW - star-planet interaction KW - stellar physics KW - exoplanets KW - exoplanet atmospheres KW - Sternphysik KW - Stern-Planeten-Wechselwirkung KW - Exoplanetenatmosphären Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-626819 ER -