TY - JOUR A1 - Kagel, Heike A1 - Bier, Frank Fabian A1 - Frohme, Marcus A1 - Glökler, Jörn F. T1 - A Novel Optical Method To Reversibly Control Enzymatic Activity Based On Photoacids JF - Scientific reports N2 - Most biochemical reactions depend on the pH value of the aqueous environment and some are strongly favoured to occur in an acidic environment. A non-invasive control of pH to tightly regulate such reactions with defined start and end points is a highly desirable feature in certain applications, but has proven difficult to achieve so far. We report a novel optical approach to reversibly control a typical biochemical reaction by changing the pH and using acid phosphatase as a model enzyme. The reversible photoacid G-acid functions as a proton donor, changing the pH rapidly and reversibly by using high power UV LEDs as an illumination source in our experimental setup. The reaction can be tightly controlled by simply switching the light on and off and should be applicable to a wide range of other enzymatic reactions, thus enabling miniaturization and parallelization through non-invasive optical means. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-50867-w SN - 2045-2322 VL - 9 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Wehrhan, Marc A1 - Sommer, Michael T1 - A parsimonious approach to estimate soil organic carbon applying Unmanned Aerial System (UAS) multispectral imagery and the topographic position index in a heterogeneous soil landscape JF - Remote sensing / Molecular Diversity Preservation International (MDPI) N2 - Remote sensing plays an increasingly key role in the determination of soil organic carbon (SOC) stored in agriculturally managed topsoils at the regional and field scales. Contemporary Unmanned Aerial Systems (UAS) carrying low-cost and lightweight multispectral sensors provide high spatial resolution imagery (<10 cm). These capabilities allow integrate of UAS-derived soil data and maps into digitalized workflows for sustainable agriculture. However, the common situation of scarce soil data at field scale might be an obstacle for accurate digital soil mapping. In our case study we tested a fixed-wing UAS equipped with visible and near infrared (VIS-NIR) sensors to estimate topsoil SOC distribution at two fields under the constraint of limited sampling points, which were selected by pedological knowledge. They represent all releva nt soil types along an erosion-deposition gradient; hence, the full feature space in terms of topsoils' SOC status. We included the Topographic Position Index (TPI) as a co-variate for SOC prediction. Our study was performed in a soil landscape of hummocky ground moraines, which represent a significant of global arable land. Herein, small scale soil variability is mainly driven by tillage erosion which, in turn, is strongly dependent on topography. Relationships between SOC, TPI and spectral information were tested by Multiple Linear Regression (MLR) using: (i) single field data (local approach) and (ii) data from both fields (pooled approach). The highest prediction performance determined by a leave-one-out-cross-validation (LOOCV) was obtained for the models using the reflectance at 570 nm in conjunction with the TPI as explanatory variables for the local approach (coefficient of determination (R-2) = 0.91; root mean square error (RMSE) = 0.11% and R-2 = 0.48; RMSE = 0.33, respectively). The local MLR models developed with both reflectance and TPI using values from all points showed high correlations and low prediction errors for SOC content (R-2 = 0.88, RMSE = 0.07%; R-2 = 0.79, RMSE = 0.06%, respectively). The comparison with an enlarged dataset consisting of all points from both fields (pooled approach) showed no improvement of the prediction accuracy but yielded decreased prediction errors. Lastly, the local MLR models were applied to the data of the respective other field to evaluate the cross-field prediction ability. The spatial SOC pattern generally remains unaffected on both fields; differences, however, occur concerning the predicted SOC level. Our results indicate a high potential of the combination of UAS-based remote sensing and environmental covariates, such as terrain attributes, for the prediction of topsoil SOC content at the field scale. The temporal flexibility of UAS offer the opportunity to optimize flight conditions including weather and soil surface status (plant cover or residuals, moisture and roughness) which, otherwise, might obscure the relationship between spectral data and SOC content. Pedologically targeted selection of soil samples for model development appears to be the key for an efficient and effective prediction even with a small dataset. KW - Unmanned Aerial System (UAS) KW - multispectral KW - Topographic Position Index KW - (TPI) KW - Multiple Linear Regression (MLR) KW - soil organic carbon (SOC) KW - agriculture KW - erosion KW - soil landscape KW - hummocky ground moraine Y1 - 2021 U6 - https://doi.org/10.3390/rs13183557 SN - 2072-4292 VL - 13 IS - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Großmann, Robert A1 - Aranson, Igor S. A1 - Peruani, Fernando T1 - A particle-field approach bridges phase separation and collective motion in active matter JF - Nature Communications N2 - Whereas self-propelled hard discs undergo motility-induced phase separation, self-propelled rods exhibit a variety of nonequilibrium phenomena, including clustering, collective motion, and spatio-temporal chaos. In this work, we present a theoretical framework representing active particles by continuum fields. This concept combines the simplicity of alignment-based models, enabling analytical studies, and realistic models that incorporate the shape of self-propelled objects explicitly. By varying particle shape from circular to ellipsoidal, we show how nonequilibrium stresses acting among self-propelled rods destabilize motility-induced phase separation and facilitate orientational ordering, thereby connecting the realms of scalar and vectorial active matter. Though the interaction potential is strictly apolar, both, polar and nematic order may emerge and even coexist. Accordingly, the symmetry of ordered states is a dynamical property in active matter. The presented framework may represent various systems including bacterial colonies, cytoskeletal extracts, or shaken granular media. Interacting self-propelled particles exhibit phase separation or collective motion depending on particle shape. A unified theory connecting these paradigms represents a major challenge in active matter, which the authors address here by modeling active particles as continuum fields. Y1 - 2020 U6 - https://doi.org/10.1038/s41467-020-18978-5 SN - 2041-1723 VL - 11 IS - 1 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Malass, Ihsane A1 - Tarkhanov, Nikolaj Nikolaevič T1 - A perturbation of the de Rham complex T1 - Возмущение комплекса де Рама JF - Journal of Siberian Federal University : Mathematics & Physics JF - Žurnal Sibirskogo Federalʹnogo Universiteta : Matematika i fizika N2 - We consider a perturbation of the de Rham complex on a compact manifold with boundary. This perturbation goes beyond the framework of complexes, and so cohomology does not apply to it. On the other hand, its curvature is "small", hence there is a natural way to introduce an Euler characteristic and develop a Lefschetz theory for the perturbation. This work is intended as an attempt to develop a cohomology theory for arbitrary sequences of linear mappings. N2 - Рассмотрим возмущение комплекса де Рама на компактном многообразии с краем. Это возмущение выходит за рамки комплексов, и поэтому когомологии к нему не относятся. С другой стороны, его кривизна "мала", поэтому существует естественный способ ввести характеристику Эйлера и разработать теорию Лефшеца для возмущения. Данная работа предназначена для попытки разработать теорию когомологий для произвольных последовательностей линейных отображений. KW - de Rham complex KW - cohomology KW - Hodge theory KW - Neumann problem KW - комплекс де Рама KW - когомологии KW - теория Ходжа KW - проблема Неймана Y1 - 2020 U6 - https://doi.org/10.17516/1997-1397-2020-13-5-519-532 SN - 1997-1397 SN - 2313-6022 VL - 13 IS - 5 SP - 519 EP - 532 PB - Siberian Federal University CY - Krasnojarsk ER - TY - JOUR A1 - Spikes, Montrai A1 - Rodríguez-Silva, Rodet A1 - Bennett, Kerri-Ann A1 - Bräger, Stefan A1 - Josaphat, James A1 - Torres-Pineda, Patricia A1 - Ernst, Anja A1 - Havenstein, Katja A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - A phylogeny of the genus Limia (Teleostei: Poeciliidae) suggests a single-lake radiation nested in a Caribbean-wide allopatric speciation scenario JF - BMC Research Notes N2 - Objective The Caribbean is an important global biodiversity hotspot. Adaptive radiations there lead to many speciation events within a limited period and hence are particularly prominent biodiversity generators. A prime example are freshwater fish of the genus Limia, endemic to the Greater Antilles. Within Hispaniola, nine species have been described from a single isolated site, Lake Miragoâne, pointing towards extraordinary sympatric speciation. This study examines the evolutionary history of the Limia species in Lake Miragoâne, relative to their congeners throughout the Caribbean. Results For 12 Limia species, we obtained almost complete sequences of the mitochondrial cytochrome b gene, a well-established marker for lower-level taxonomic relationships. We included sequences of six further Limia species from GenBank (total N  = 18 species). Our phylogenies are in concordance with other published phylogenies of Limia. There is strong support that the species found in Lake Miragoâne in Haiti are monophyletic, confirming a recent local radiation. Within Lake Miragoâne, speciation is likely extremely recent, leading to incomplete lineage sorting in the mtDNA. Future studies using multiple unlinked genetic markers are needed to disentangle the relationships within the Lake Miragoâne clade. KW - Cytochrome b KW - Island biogeography KW - Fresh water fish KW - Phylogeny Y1 - 2021 U6 - https://doi.org/10.1186/s13104-021-05843-x SN - 1756-0500 VL - 14 SP - 1 EP - 8 PB - BMC Research Notes / Biomed Central CY - London ER - TY - JOUR A1 - Hintsche, Marius A1 - Waljor, Veronika A1 - Grossmann, Robert A1 - Kühn, Marco J. A1 - Thormann, Kai M. A1 - Peruani, Fernando A1 - Beta, Carsten T1 - A polar bundle of flagella can drive bacterial swimming by pushing, pulling, or coiling around the cell body JF - Scientific reports N2 - Bacteria swim in sequences of straight runs that are interrupted by turning events. They drive their swimming locomotion with the help of rotating helical flagella. Depending on the number of flagella and their arrangement across the cell body, different run-and-turn patterns can be observed. Here, we present fluorescence microscopy recordings showing that cells of the soil bacterium Pseudomonas putida that are decorated with a polar tuft of helical flagella, can alternate between two distinct swimming patterns. On the one hand, they can undergo a classical push-pull-push cycle that is well known from monopolarly flagellated bacteria but has not been reported for species with a polar bundle of multiple flagella. Alternatively, upon leaving the pulling mode, they can enter a third slow swimming phase, where they propel themselves with their helical bundle wrapped around the cell body. A theoretical estimate based on a random-walk model shows that the spreading of a population of swimmers is strongly enhanced when cycling through a sequence of pushing, pulling, and wrapped flagellar configurations as compared to the simple push-pull-push pattern. Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-16428-9 SN - 2045-2322 VL - 7 PB - Macmillan Publishers Limited, part of Springer Nature CY - London ER - TY - JOUR A1 - Päßler, Ulrich T1 - A Political Economy of Nature BT - Alexander von Humboldt's Essay on the Fluctuations in the Supplies of Gold JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - In seinem Aufsatz „Ueber die Schwankungen der Goldproduktion mit Rücksicht auf staatswirthschaftliche Probleme“ (1838) entfaltet Alexander von Humboldt auf wenigen Seiten eine Weltgeschichte des Edelmetallverkehrs von der Antike bis ins 19. Jahrhundert. Der vorliegende Artikel geht Humboldts ökonomischem Denken als Teil seiner Forschungen zur Natur- und Menschheitsgeschichte nach. Er beginnt mit einem kurzen Abriss der von spätmerkantilistischen und frühliberalen Einflüssen geprägten Ausbildung Humboldts. Der Artikel diskutiert anschließend eine von Humboldt angefertigte Weltkarte sowie vier darauf bezogene Schaubilder, die historische und zeitgenössische statistische Daten zur graphischen Vision eines globalen Wirtschaftskreislaufs kombinieren. In einem weiteren Schritt geht der Artikel Humboldts Anwendung historischer und naturgeschichtlicher Forschungsmethoden auf dem Gebiet der politischen Ökonomie am Beispiel des Aufsatzes von 1838 nach. Den Schluss der Untersuchung bildet Humboldts Auseinandersetzung mit dem Edelmetall Platin, dessen begrenzte Verbreitung im Widerspruch zur Idee eines freien weltweiten Austauschs stand. N2 - Dans son mémoire « Sur la production de l’or considérée dans ses fluctuations » (1838), Alexandre de Humboldt développa une histoire universelle de la circulation des métaux précieux de l’antiquité jusqu’au XIXe siècle. Le présent article poursuit la pensée économique de Humboldt en la mettant dans le contexte de ses études physiques, naturelles et historiques. L’article commence par un abrégé de l’éducation professionnelle de Humboldt, qui était marquée par des influences caméralistes et libérales à la fois. Puis l’article commente une mappemonde et quatre diagrammes, dessinés par Humboldt; la combinaison des données statistiques historiques et contemporaines constitue la vision cartographique d’un circuit économique global. Dans un second temps, l’article aborde le mémoire de 1838 et analyse l’emploi des méthodes de recherche des sciences naturelles et historiques dans le domaine de l’économie politique. L’article se conclut par un examen des remarques de Humboldt sur le platine, un métal précieux qui en raison de sa répartition naturelle limitée était en contradiction avec l’idée d’un libre échange mondial. N2 - In his “Essay on the Fluctuations in the Supplies of Gold” (1838) Humboldt presents a global history of the flow of precious metals from antiquity to the 19th century. This paper traces Humboldt’s economic thinking within his natural and historical research, starting with an outline of his educational background which incorporated late mercantilist and early liberal influences. It then discusses a world map and four charts drawn by Humboldt, which combine historical and contemporary statistical data into a cartographical vision of a global economic circuit. In a next step, the article explores Humboldt’s application of natural and historical research methods in the field of political economy, using the example of his 1838 essay. Finally, the article addresses Humboldt’s discussion of platinum, a precious metal whose limited natural distribution contradicted the idea of free global exchange. KW - Wirtschaftgeschichte KW - Wissenschaftsgeschichte KW - Kameralismus KW - Bergbau KW - Edelmetalle KW - Gold KW - Silber KW - Platin Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395781 SN - 1617-5239 SN - 2568-3543 VL - XVIII IS - 34 SP - 80 EP - 91 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Warschburger, Petra A1 - Kamrath, Clemens A1 - Lanzinger, Stefanie A1 - Sengler, Claudia A1 - Wiegand, Susanna A1 - Göldel, Julia Marlen A1 - Weihrauch-Blüher, Susann A1 - Holl, Reinhard A1 - Minden, Kirsten T1 - A prospective analysis of the long-term impact of the COVID-19 pandemic on well-being and health care among children with a chronic condition and their families BT - a study protocol of the KICK-COVID study JF - BMC pediatrics N2 - Background There is consistent evidence that the COVID-19 pandemic is associated with an increased psychosocial burden on children and adolescents and their parents. Relatively little is known about its particular impact on high-risk groups with chronic physical health conditions (CCs). Therefore, the primary aim of the study is to analyze the multiple impacts on health care and psychosocial well-being on these children and adolescents and their parents. Methods We will implement a two-stage approach. In the first step, parents and their underage children from three German patient registries for diabetes, obesity, and rheumatic diseases, are invited to fill out short questionnaires including questions about corona-specific stressors, the health care situation, and psychosocial well-being. In the next step, a more comprehensive, in-depth online survey is carried out in a smaller subsample. Discussion The study will provide insights into the multiple longer-term stressors during the COVID-19 pandemic in families with a child with a CC. The simultaneous consideration of medical and psycho-social endpoints will help to gain a deeper understanding of the complex interactions affecting family functioning, psychological well-being, and health care delivery. KW - Chronic conditions KW - COVID-19 KW - Children and adolescents KW - Parents KW - Risk perception KW - Psychosocial strain KW - Diabetes KW - Rheumatic diseases KW - Obesity Y1 - 2023 U6 - https://doi.org/10.1186/s12887-023-03912-7 SN - 1471-2431 VL - 23 IS - 1 PB - BioMed Central CY - London 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 - JOUR A1 - Heimann, Sebastian A1 - Vasyura-Bathke, Hannes A1 - Sudhaus, Henriette A1 - Isken, Marius Paul A1 - Kriegerowski, Marius A1 - Steinberg, Andreas A1 - Dahm, Torsten T1 - A Python framework for efficient use of pre-computed Green's functions in seismological and other physical forward and inverse source problems JF - Solid earth N2 - The computation of such synthetic GFs is computationally and operationally demanding. As a consequence, the onthe-fly recalculation of synthetic GFs in each iteration of an optimisation is time-consuming and impractical. Therefore, the pre-calculation and efficient storage of synthetic GFs on a dense grid of source to receiver combinations enables the efficient lookup and utilisation of GFs in time-critical scenarios. We present a Python-based framework and toolkit - Pyrocko-GF - that enables the pre-calculation of synthetic GF stores, which are independent of their numerical calculation method and GF transfer function. The framework aids in the creation of such GF stores by interfacing a suite of established numerical forward modelling codes in seismology (computational back ends). So far, interfaces to back ends for layered Earth model cases have been provided; however, the architecture of Pyrocko-GF is designed to cover back ends for other geometries (e.g. full 3-D heterogeneous media) and other physical quantities (e.g. gravity, pressure, tilt). Therefore, Pyrocko-GF defines an extensible GF storage format suitable for a wide range of GF types, especially handling elasticity and wave propagation problems. The framework assists with visualisations, quality control, and the exchange of GF stores, which is supported through an online platform that provides many pre-calculated GF stores for local, regional, and global studies. The Pyrocko-GF toolkit comes with a well-documented application programming interface (API) for the Python programming language to efficiently facilitate forward modelling of geophysical processes, e.g. synthetic waveforms or static displacements for a wide range of source models. Y1 - 2019 U6 - https://doi.org/10.5194/se-10-1921-2019 SN - 1869-9510 SN - 1869-9529 VL - 10 IS - 6 SP - 1921 EP - 1935 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Shlaka, Souhad A1 - Ouahib, Sara A1 - Berrada, Khalid ED - Meinel, Christoph ED - Schweiger, Stefanie ED - Staubitz, Thomas ED - Conrad, Robert ED - Alario Hoyos, Carlos ED - Ebner, Martin ED - Sancassani, Susanna ED - Żur, Agnieszka ED - Friedl, Christian ED - Halawa, Sherif ED - Gamage, Dilrukshi ED - Scott, Jeffrey ED - Kristine Jonson Carlon, May ED - Deville, Yves ED - Gaebel, Michael ED - Delgado Kloos, Carlos ED - von Schmieden, Karen T1 - A retrospective feedback of MOOCS in Morocco BT - what is the best scenario for the Moroccan higher education? JF - EMOOCs 2023 : Post-Covid Prospects for Massive Open Online Courses - Boost or Backlash? N2 - The integration of MOOCs into the Moroccan Higher Education (MHE) took place in 2013 by developing different partnerships and projects at national and international levels. As elsewhere, the Covid-19 crisis has played an important role in accelerating distance education in MHE. However, based on our experience as both university professors and specialists in educational engineering, the effective execution of the digital transition has not yet been implemented. Thus, in this article, we present a retrospective feedback of MOOCs in Morocco, focusing on the policies taken by the government to better support the digital transition in general and MOOCs in particular. We are therefore seeking to establish an optimal scenario for the promotion of MOOCs, which emphasizes the policies to be considered, and which recalls the importance of conducting a delicate articulation taking into account four levels, namely environmental, institutional, organizational and individual. We conclude with recommendations that are inspired by the Moroccan academic contex that focus on the major role that MOOCs plays for university students and on maintaining lifelong learning. KW - Digitale Bildung KW - Kursdesign KW - MOOC KW - Micro Degree KW - Online-Lehre KW - Onlinekurs KW - Onlinekurs-Produktion KW - digital education KW - e-learning KW - micro degree KW - micro-credential KW - online course creation KW - online course design KW - online teaching Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-624826 SP - 317 EP - 327 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Kühn, Daniela A1 - Hainzl, Sebastian A1 - Dahm, Torsten A1 - Richter, Gudrun A1 - Vera Rodriguez, Ismael T1 - A review of source models to further the understanding of the seismicity of the Groningen field JF - Netherlands journal of geosciences : NJG N2 - The occurrence of felt earthquakes due to gas production in Groningen has initiated numerous studies and model attempts to understand and quantify induced seismicity in this region. The whole bandwidth of available models spans the range from fully deterministic models to purely empirical and stochastic models. In this article, we summarise the most important model approaches, describing their main achievements and limitations. In addition, we discuss remaining open questions and potential future directions of development. KW - deterministic KW - empirical KW - hybrid KW - machine learning KW - seismicity model Y1 - 2022 U6 - https://doi.org/10.1017/njg.2022.7 SN - 0016-7746 SN - 1573-9708 VL - 101 PB - Cambridge Univ. Press CY - Cambridge ER - TY - JOUR A1 - Solger, Franziska A1 - Kunz, Tobias C. A1 - Fink, Julian A1 - Paprotka, Kerstin A1 - Pfister, Pauline A1 - Hagen, Franziska A1 - Schumacher, Fabian A1 - Kleuser, Burkhard A1 - Seibel, Jürgen A1 - Rudel, Thomas T1 - A role of sphingosine in the intracellular survival of Neisseria gonorrhoeae JF - Frontiers in Cellular and Infection Microbiology N2 - Obligate human pathogenic Neisseria gonorrhoeae are the second most frequent bacterial cause of sexually transmitted diseases. These bacteria invade different mucosal tissues and occasionally disseminate into the bloodstream. Invasion into epithelial cells requires the activation of host cell receptors by the formation of ceramide-rich platforms. Here, we investigated the role of sphingosine in the invasion and intracellular survival of gonococci. Sphingosine exhibited an anti-gonococcal activity in vitro. We used specific sphingosine analogs and click chemistry to visualize sphingosine in infected cells. Sphingosine localized to the membrane of intracellular gonococci. Inhibitor studies and the application of a sphingosine derivative indicated that increased sphingosine levels reduced the intracellular survival of gonococci. We demonstrate here, that sphingosine can target intracellular bacteria and may therefore exert a direct bactericidal effect inside cells. KW - Neisseria gonorrhoeae KW - sphingosine KW - sphingolipids KW - sphingosine kinases KW - invasion KW - survival KW - click chemistry Y1 - 2020 U6 - https://doi.org/10.3389/fcimb.2020.00215 SN - 2235-2988 VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Grewing, Farouk F. ED - Ambühl, Annemarie T1 - A Saturnalian poet as a literary critic BT - the carnivalesque poetics of Martial’s Apophoreta 183-196 JF - thersites = tessellae – Birthday Issue for Christine Walde N2 - This paper analyzes a specific section of Martial’s Apophoreta (Book 14), the ‘list’ of fourteen literary works that the poet-persona suggests to the reader as potentially suitable presents to give to friends on the occasion of the Saturnalia. It focuses strictly on the literary aspects of the poems and their underlying carnivalesque poetics. This includes an assessment of the logic of the poems’ arrangement and alleged inconsistencies. It is suggested that the section be read as a complex statement of Martial’s on various works and genres of Greek and Roman literature. The last couplet of the section (14.196), a certain Calvus’ work ‘On the use of cold water’ (De aquae frigidae usu), which is unidentifiable, receives particular attention, for previous scholarship has wasted a lot of ink on guessing what kind of work this may have been, thereby losing touch with the rich (meta-)poetics the couplet actually conveys. KW - Martial KW - epigram KW - Saturnalia KW - poetics KW - Apophoreta Y1 - 2020 U6 - https://doi.org/10.34679/thersites.vol11.170 SN - 2364-7612 VL - 2020 IS - 11 SP - 176 EP - 204 ER - TY - JOUR A1 - Bürger, Gerd T1 - A seamless filter for daily to seasonal forecasts, with applications to Iran and Brazil JF - Quarterly Journal of the Royal Meteorological Society N2 - A digital filter is introduced which treats the problem of predictability versus time averaging in a continuous, seamless manner. This seamless filter (SF) is characterized by a unique smoothing rule that determines the strength of smoothing in dependence on lead time. The rule needs to be specified beforehand, either by expert knowledge or by user demand. As a result, skill curves are obtained that allow a predictability assessment across a whole range of time-scales, from daily to seasonal, in a uniform manner. The SF is applied to downscaled SEAS5 ensemble forecasts for two focus regions in or near the tropical belt, the river basins of the Karun in Iran and the Sao Francisco in Brazil. Both are characterized by strong seasonality and semi-aridity, so that predictability across various time-scales is in high demand. Among other things, it is found that from the start of the water year (autumn), areal precipitation is predictable with good skill for the Karun basin two and a half months ahead; for the Sao Francisco it is only one month, longer-term prediction skill is just above the critical level. KW - climate drift KW - ensemble prediction KW - seamless prediction KW - seasonal forecast skill Y1 - 2019 VL - 146 IS - 726 PB - WILEY-VCH CY - Weinheim ER - TY - JOUR A1 - Schmidt, Imanuel Clemens T1 - A Secular Tradition BT - Horace Kallen on American Democracy in the United States and Israel JF - PaRDeS : Journal of the Association for Jewish Studies in Germany JF - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien N2 - This article focuses on the social philosopher Horace Kallen and the revisions he made to the concept of cultural pluralism that he first developed in the early 20th century, applying it to postwar America and the young State of Israel. It shows how he opposed the assumption that the United States’ social order was based on a “Judeo-Christian tradition.” By constructing pluralism as a civil religion and carving out space for secular self-understandings in midcentury America, Kallen attempted to preserve the integrity of his earlier political visions, developed during World War I, of pluralist societies in the United States and Palestine within an internationalist global order. While his perspective on the State of Israel was largely shaped by his American experiences, he revised his approach to politically functionalizing religious traditions as he tested his American understanding of a secular, pluralist society against the political theology effective in the State of Israel. The trajectory of Kallen’s thought points to fundamental questions about the compatibility of American and Israeli understandings of religion’s function in society and its relation to political belonging, especially in light of their transnational connection through American Jewish support for the recently established state. KW - modern Jewish history KW - United States KW - Israel KW - 20th century KW - Horace Kallen KW - cultural pluralism KW - intellectual history KW - moderne jüdische Geschichte KW - USA KW - Israel KW - 20. Jahrhundert KW - Horace Kallen KW - kultureller Pluralismus KW - Geistesgeschichte Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-532868 SN - 978-3-86956-520-0 SN - 1614-6492 SN - 1862-7684 IS - 27 SP - 85 EP - 100 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Gailleton, Boris A1 - Mudd, Simon M. A1 - Clubb, Fiona J. A1 - Peifer, Daniel A1 - Hurst, Martin D. T1 - A segmentation approach for the reproducible extraction and quantification of knickpoints from river long profiles JF - Earth surface dynamics N2 - Changes in the steepness of river profiles or abrupt vertical steps (i.e. waterfalls) are thought to be indicative of changes in erosion rates, lithology or other factors that affect landscape evolution. These changes are referred to as knickpoints or knickzones and are pervasive in bedrock river systems. Such features are thought to reveal information about landscape evolution and patterns of erosion, and therefore their locations are often reported in the geomorphic literature. It is imperative that studies reporting knickpoints and knickzones use a reproducible method of quantifying their locations, as their number and spatial distribution play an important role in interpreting tectonically active landscapes. In this contribution we introduce a reproducible knickpoint and knickzone extraction algorithm that uses river profiles transformed by integrating drainage area along channel length (the so-called integral or chi method). The profile is then statistically segmented and the differing slopes and step changes in the elevations of these segments are used to identify knickpoints, knickzones and their relative magnitudes. The output locations of identified knickpoints and knickzones compare favourably with human mapping: we test the method on Santa Cruz Island, CA, using previously reported knickzones and also test the method against a new dataset from the Quadrilatero Ferrifero in Brazil. The algorithm allows for the extraction of varying knickpoint morphologies, including stepped, positive slope-break (concave upward) and negative slope-break knickpoints. We identify parameters that most affect the resulting knickpoint and knickzone locations and provide guidance for both usage and outputs of the method to produce reproducible knickpoint datasets. Y1 - 2019 U6 - https://doi.org/10.5194/esurf-7-211-2019 SN - 2196-6311 SN - 2196-632X VL - 7 IS - 1 SP - 211 EP - 230 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Mumm, Rebekka A1 - Hermanussen, Michael T1 - A short note on the BMI and on secular changes in BMI JF - Human biology and public health N2 - Human size changes over time with worldwide secular trends in height, weight, and body mass index (BMI). There is general agreement to relate the state of nutrition to height and weight, and to ratios of weight-to-height. The BMI is a ratio. It is commonly used to classify underweight, overweight and obesity in adults. Yet, the BMI is inappropriate to provide any immediate information on body composition. It is accepted that the BMI is “a simple index to classify underweight, overweight and obesity in adults”. It is stated that “policies, programmes and investments need to be “nutrition-sensitive”, which means they must have positive impacts on nutrition”. It is also stated that “a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions“. But these statements are neither warranted by arithmetic considerations, nor by historic evidence. Measuring the BMI is an appropriate screening tool for detecting an unusual weight-to-height ratio, but the BMI is an inappropriate tool for estimating body composition, or suggesting medical and health policy decisions. KW - body mass index KW - secular trend KW - weight-to-height ratio KW - malnutrition KW - obesity Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.17 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schlemm, Tanja A1 - Levermann, Anders T1 - A simple parametrization of mélange buttressing for calving glaciers JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union N2 - Both ice sheets in Greenland and Antarctica are discharging ice into the ocean. In many regions along the coast of the ice sheets, the icebergs calve into a bay. If the addition of icebergs through calving is faster than their transport out of the embayment, the icebergs will be frozen into a melange with surrounding sea ice in winter. In this case, the buttressing effect of the ice melange can be considerably stronger than any buttressing by mere sea ice would be. This in turn stabilizes the glacier terminus and leads to a reduction in calving rates. Here we propose a simple parametrization of ice melange buttressing which leads to an upper bound on calving rates and can be used in numerical and analytical modelling. Y1 - 2021 U6 - https://doi.org/10.5194/tc-15-531-2021 SN - 1994-0416 SN - 1994-0424 VL - 15 IS - 2 SP - 531 EP - 545 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Schlemm, Tanja A1 - Levermann, Anders T1 - A simple stress-based cliff-calving law JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union N2 - Over large coastal regions in Greenland and Antarctica the ice sheet calves directly into the ocean. In contrast to ice-shelf calving, an increase in calving from grounded glaciers contributes directly to sea-level rise. Ice cliffs with a glacier freeboard larger than approximate to 100 m are currently not observed, but it has been shown that such ice cliffs are increasingly unstable with increasing ice thickness. This cliff calving can constitute a self-amplifying ice loss mechanism that may significantly alter sea-level projections both of Greenland and Antarctica. Here we seek to derive a minimalist stress-based parametrization for cliff calving from grounded glaciers whose freeboards exceed the 100m stability limit derived in previous studies. This will be an extension of existing calving laws for tidewater glaciers to higher ice cliffs. To this end we compute the stress field for a glacier with a simplified two-dimensional geometry from the two-dimensional Stokes equation. First we assume a constant yield stress to derive the failure region at the glacier front from the stress field within the glacier. Secondly, we assume a constant response time of ice failure due to exceedance of the yield stress. With this strongly constraining but very simple set of assumptions we propose a cliff-calving law where the calving rate follows a power-law dependence on the freeboard of the ice with exponents between 2 and 3, depending on the relative water depth at the calving front. The critical freeboard below which the ice front is stable decreases with increasing relative water depth of the calving front. For a dry water front it is, for example, 75 m. The purpose of this study is not to provide a comprehensive calving law but to derive a particularly simple equation with a transparent and minimalist set of assumptions. Y1 - 2019 U6 - https://doi.org/10.5194/tc-13-2475-2019 SN - 1994-0416 SN - 1994-0424 VL - 13 IS - 9 SP - 2475 EP - 2488 PB - Copernicus CY - Göttingen ER -