@article{AichnerOttSlowinskietal.2018, author = {Aichner, Bernhard and Ott, Florian and Slowinski, Michal and Norygkiewicz, Agnieszka M. and Brauer, Achim and Sachse, Dirk}, title = {Leaf wax n-alkane distributions record ecological changes during the Younger Dryas at Trzechowskie paleolake (northern Poland) without temporal delay}, series = {Climate of the past : an interactive open access journal of the European Geosciences Union}, volume = {14}, journal = {Climate of the past : an interactive open access journal of the European Geosciences Union}, number = {11}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1814-9324}, doi = {10.5194/cp-14-1607-2018}, pages = {1607 -- 1624}, year = {2018}, abstract = {While of higher plant origin, a specific source assignment of sedimentary leaf wax n-alkanes remains difficult. In addition, it is unknown how fast a changing catchment vegetation would be reflected in sedimentary leaf wax archives. In particular, for a quantitative interpretation of n-alkane C and H isotope ratios in terms of paleohydrological and paleoecological changes, a better understanding of transfer times and dominant sedimentary sources of leaf wax n-alkanes is required. In this study we tested to what extent compositional changes in leaf wax n-alkanes can be linked to known vegetation changes by comparison with high-resolution palynological data from the same archive. We analyzed leaf wax n-alkane concentrations and distributions in decadal resolution from a sedimentary record from Trzechowskie paleolake (TRZ, northern Poland), covering the Late Glacial to early Holocene (13 360-9940 yr BP). As an additional source indicator of targeted n-alkanes, compound-specific carbon isotopic data have been generated in lower time resolution. The results indicated rapid responses of n-alkane distribution patterns coinciding with major climatic and paleoecological transitions. We found a shift towards higher average chain length (ACL) values at the Allerod-Younger Dryas (YD) transition between 12 680 and 12 600 yr BP, co-evaled with a decreasing contribution of arboreal pollen (mainly Pinus and Betula) and a subsequently higher abundance of pollen derived from herbaceous plants (Poaceae, Cyperaceae, Artemisia), shrubs, and dwarf shrubs (Juniperus and Salix). The termination of the YD was characterized by a successive increase in n-alkane concentrations coinciding with a sharp decrease in ACL values between 11 580 and 11 490 yr BP, reflecting the expansion of woodland vegetation at the YD-Holocene transition. A gradual reversal to longer chain lengths after 11 200 yr BP, together with decreasing n-alkane concentrations, most likely reflects the early Holocene vegetation succession with a decline of Betula. These results show that n-alkane distributions reflect vegetation changes and that a fast (i.e., subdecadal) signal transfer occurred. However, our data also indicate that a standard interpretation of directional changes in biomarker ratios remains difficult. Instead, responses such as changes in ACL need to be discussed in the context of other proxy data. In addition, we find that organic geochemical data integrate different ecological information compared to pollen, since some gymnosperm genera, such as Pinus, produce only a very low amount of n-alkanes and for this reason their contribution may be largely absent from biomarker records. Our results demonstrate that a combination of palynological and n-alkane data can be used to infer the major sedimentary leaf wax sources and constrain leaf wax transport times from the plant source to the sedimentary sink and thus pave the way towards quantitative interpretation of compound-specific hydrogen isotope ratios for paleohydrological reconstructions.}, language = {en} } @article{KruseGerdesKathetal.2018, author = {Kruse, Stefan and Gerdes, Alexander and Kath, Nadja J. and Herzschuh, Ulrike}, title = {Implementing spatially explicit wind-driven seed and pollen dispersal in the individual-based larch simulation model}, series = {Geoscientific model development : an interactive open access journal of the European Geosciences Union}, volume = {11}, journal = {Geoscientific model development : an interactive open access journal of the European Geosciences Union}, number = {11}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1991-959X}, doi = {10.5194/gmd-11-4451-2018}, pages = {4451 -- 4467}, year = {2018}, abstract = {It is of major interest to estimate the feedback of arctic ecosystems to the global warming we expect in upcoming decades. The speed of this response is driven by the potential of species to migrate, tracking their climate optimum. For this, sessile plants have to produce and disperse seeds to newly available habitats, and pollination of ovules is needed for the seeds to be viable. These two processes are also the vectors that pass genetic information through a population. A restricted exchange among subpopulations might lead to a maladapted population due to diversity losses. Hence, a realistic implementation of these dispersal processes into a simulation model would allow an assessment of the importance of diversity for the migration of plant species in various environments worldwide. To date, dynamic global vegetation models have been optimized for a global application and overestimate the migration of biome shifts in currently warming temperatures. We hypothesize that this is caused by neglecting important fine-scale processes, which are necessary to estimate realistic vegetation trajectories. Recently, we built and parameterized a simulation model LAVESI for larches that dominate the latitudinal treelines in the northernmost areas of Siberia. In this study, we updated the vegetation model by including seed and pollen dispersal driven by wind speed and direction. The seed dispersal is modelled as a ballistic flight, and for the pollination of ovules of seeds produced, we implemented a wind-determined and distance-dependent probability distribution function using a von Mises distribution to select the pollen donor. A local sensitivity analysis of both processes supported the robustness of the model's results to the parameterization, although it highlighted the importance of recruitment and seed dispersal traits for migration rates. This individual-based and spatially explicit implementation of both dispersal processes makes it easily feasible to inherit plant traits and genetic information to assess the impact of migration processes on the genetics. Finally, we suggest how the final model can be applied to substantially help in unveiling the important drivers of migration dynamics and, with this, guide the improvement of recent global vegetation models.}, language = {en} } @article{Kotowski2018, author = {Kotowski, Elke-Vera}, title = {„Heimat"-Objekte}, series = {Zeitschrift f{\"u}r Religions- und Geistesgeschichte}, volume = {70}, journal = {Zeitschrift f{\"u}r Religions- und Geistesgeschichte}, number = {4}, publisher = {Brill}, address = {Leiden}, issn = {0044-3441}, doi = {10.1163/15700739-07004004}, pages = {324 -- 347}, year = {2018}, abstract = {Bei ihrer zumeist erzwungenen Emigration aus der deutschsprachigen Heimat nach Lateinamerika konnten bei weitem nicht alle ihren gesamten Hausstand mit in das neue Heimatland nehmen. Vielmehr war es der Mehrzahl der Emigranten nicht m{\"o}glich, mehr als ein paar Kofffer aus ihrem alten Leben in das neue zu retten. Verkauft oder beschlagnahmt, vieles musste zur{\"u}ckbleiben, was {\"u}ber Jahre die Wohnungen und H{\"a}user der deutschen Juden gef{\"u}llt hatte. Das Wenige, was doch mitgenommen werden konnte, hatte somit umso mehr pers{\"o}nlichen Wert f{\"u}r den Besitzer. Was also hatten die deutsch-j{\"u}dischen Emigranten und Exilanten in ihren Kofffern und weshalb waren gerade diese Objekte f{\"u}r sie bedeutend genug, um sie auf den beschwerlichen Weg {\"u}ber den Atlantik und auf einen neuen Kontinent in eine unbekannte Zukunft mitzunehmen?Eine Antwort auf diese Frage k{\"o}nnen die Objekte selbst geben, welche bis heute in den Familien der einstigen Emigranten aufbewahrt und benutzt werden. Sie repr{\"a}sentieren die verlorene Heimat, ein St{\"u}ck Geschichte des Ursprungslandes und der eigenen Familie. Diese Gegenst{\"a}nde sind mehr als nur Gebrauchsobjekte, welche ihren monet{\"a}ren Wert hatten und daher nicht zur{\"u}ckgelassen werden sollten. Es sind vielmehr Tr{\"a}ger von gegebenen und zugeschriebenen Bedeutungen und Erinnerungen an Heimat, die ihnen anhaften und {\"u}ber Generationen hinweg weitergegeben und in ihrem Sym-bolgehalt erg{\"a}nzt und erweitert werden.}, language = {de} } @article{Zimmermann2018, author = {Zimmermann, Malte}, title = {Wird Schon Stimmen!}, series = {Journal of semantics}, volume = {35}, journal = {Journal of semantics}, number = {4}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0167-5133}, doi = {10.1093/jos/ffy010}, pages = {687 -- 739}, year = {2018}, abstract = {The article puts forward a novel analysis of the German modal particle schon as a modal degree operator over propositional content. The proposed analysis offers a uniform perspective on the semantics of modal schon and its aspectual counterpart meaning 'already': Both particles are analyzed as denoting a degree operator, expressing a scale-based comparison over relevant alternatives. The alternatives are determined by focus in the case of aspectual schon (Krifka 2000), but are restricted to the polar alternatives p and ¬p in the case of modal schon. Semantically, modal schon introduces a presupposition to the effect that the circumstantial conversational background contains more factual evidence in favor of p than in favor of ¬p⁠, thereby making modal schon the not at-issue counterpart of the overt comparative form eher 'rather' (Herburger \& Rubinstein 2014). The analysis incorporates basic insights from earlier analyses of modal schon in a novel way, and it also offers new insights as to the underlying workings of modality in natural language as involving propositions rather than possible worlds (Kratzer 1977, 2012).}, language = {en} } @article{SoaresYamazakiMatzkaetal.2018, author = {Soares, Gabriel and Yamazaki, Yosuke and Matzka, J{\"u}rgen and Pinheiro, Katia and Morschhauser, Achim and Stolle, Claudia and Alken, Patrick}, title = {Equatorial counter electrojet longitudinal and seasonal variablity in the American sector}, series = {Journal of geophysical research : Space physics}, volume = {123}, journal = {Journal of geophysical research : Space physics}, number = {11}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9380}, doi = {10.1029/2018JA025968}, pages = {9906 -- 9920}, year = {2018}, abstract = {The equatorial electrojet occasionally reverses during morning and afternoon hours, leading to periods of westward current in the ionospheric E region that are known as counter electrojet (CEJ) events. We present the first analysis of CEJ climatology and CEJ dependence on solar flux and lunar phase for the Brazilian sector, based on an extensive ground-based data set for the years 2008 to 2017 from the geomagnetic observatory Tatuoca (1.2 degrees S, 48.5 degrees W), and we compare it to the results found for Huancayo (12.0 degrees S, 75.3 degrees W) observatory in the Peruvian sector. We found a predominance of morning CEJ events for both sectors. The afternoon CEJ occurrence rate in the Brazilian sector is twice as high as in the Peruvian sector. The afternoon CEJ occurrence rate strongly depends on season, with maximum rates occurring during the northern-hemisphere summer for the Brazilian sector and during the northern-hemisphere winter for the Peruvian sector. Significant discrepancies between the two sectors are also found for morning CEJ rates during the northern-hemisphere summer. These longitudinal differences are in agreement with a CEJ climatology derived from contemporary Swarm satellite data and can be attributed in part to the well-known longitudinal wave-4 structure in the background equatorial electrojet strength that results from nonmigrating solar tides and stationary planetary waves. Simulations with the Thermosphere-Ionosphere-Electrodynamics General Circulation Model show that the remaining longitudinal variability in CEJ during northern summer can be explained by the effect of migrating tides in the presence of the varying geomagnetic field in the South Atlantic Anomaly.}, language = {en} } @article{SalamatZoellerZareetal.2018, author = {Salamat, Mona and Z{\"o}ller, Gert and Zare, Mehdi and Amini, Mortaza}, title = {The maximum expected earthquake magnitudes in different future time intervals of six seismotectonic zones of Iran and its surroundings}, series = {Journal of seismology}, volume = {22}, journal = {Journal of seismology}, number = {6}, publisher = {Springer}, address = {Dordrecht}, issn = {1383-4649}, doi = {10.1007/s10950-018-9780-7}, pages = {1485 -- 1498}, year = {2018}, abstract = {One of the crucial components in seismic hazard analysis is the estimation of the maximum earthquake magnitude and associated uncertainty. In the present study, the uncertainty related to the maximum expected magnitude mu is determined in terms of confidence intervals for an imposed level of confidence. Previous work by Salamat et al. (Pure Appl Geophys 174:763-777, 2017) shows the divergence of the confidence interval of the maximum possible magnitude m(max) for high levels of confidence in six seismotectonic zones of Iran. In this work, the maximum expected earthquake magnitude mu is calculated in a predefined finite time interval and imposed level of confidence. For this, we use a conceptual model based on a doubly truncated Gutenberg-Richter law for magnitudes with constant b-value and calculate the posterior distribution of mu for the time interval T-f in future. We assume a stationary Poisson process in time and a Gutenberg-Richter relation for magnitudes. The upper bound of the magnitude confidence interval is calculated for different time intervals of 30, 50, and 100 years and imposed levels of confidence alpha = 0.5, 0.1, 0.05, and 0.01. The posterior distribution of waiting times T-f to the next earthquake with a given magnitude equal to 6.5, 7.0, and7.5 are calculated in each zone. In order to find the influence of declustering, we use the original and declustered version of the catalog. The earthquake catalog of the territory of Iran and surroundings are subdivided into six seismotectonic zones Alborz, Azerbaijan, Central Iran, Zagros, Kopet Dagh, and Makran. We assume the maximum possible magnitude m(max) = 8.5 and calculate the upper bound of the confidence interval of mu in each zone. The results indicate that for short time intervals equal to 30 and 50 years and imposed levels of confidence 1 - alpha = 0.95 and 0.90, the probability distribution of mu is around mu = 7.16-8.23 in all seismic zones.}, language = {en} } @article{AsgarimehrWickertReich2018, author = {Asgarimehr, Milad and Wickert, Jens and Reich, Sebastian}, title = {TDS-1 GNSS Reflectometry}, series = {IEEE journal of selected topics in applied earth observations and remote sensing}, volume = {11}, journal = {IEEE journal of selected topics in applied earth observations and remote sensing}, number = {11}, publisher = {Inst. of Electr. and Electronics Engineers}, address = {Piscataway}, issn = {1939-1404}, doi = {10.1109/JSTARS.2018.2873241}, pages = {4534 -- 4541}, year = {2018}, abstract = {This study presents the development and a systematic evaluation study of GNSS reflectometry wind speeds. After establishing a wind speed retrieval algorithm, UK TechDemoSat-1 (TDS-1) derived winds, from May 2015 to July 2017, are compared to the Advanced Scatterometer (ASCAT). ERA-Interim wind fields of the European Centre for Medium-range Weather Forecasts (ECMWF) and in situ observation from Tropical Atmosphere Ocean buoy array in the Pacific are taken as reference. One-year averaged TDS-1 global winds demonstrate small differences with ECMWF in a majority of areas as well as discuss under- and overestimations. The pioneering TDS-1 winds demonstrate a root-mean-squared error (RMSE) and bias of 2.77 and -0.33 m/s, which are comparable to the RMSE and bias derived by ASCAT winds, as large as 2.31 and 0.25 m/s, respectively. Using buoys measurements as reference, RMSE and bias of 2.23 and -0.03 m/s for TDS-1 as well as 1.40 and -0.68 m/s for ASCAT are obtained. Utilizing rain microwave-infrared estimates of the Tropical Rainfall Measuring Mission, rain-affected observation of both ASCAT and TDS-1 are collected and evaluated. Although ASCAT winds show a significant performance degradation resulting in an RMSE and bias of 3.16 and 1.03 m/s, respectively, during rain condition, TDS-1 shows a more reliable performance with an RMSE and bias of 2.94 and -0.21 m/s, respectively, which indicates the promising capability of GNSS forward scattering for wind retrievals during rain. A decrease in TDS-1-derived bistatic radar cross sections during rain events, at weak winds, is also demonstrated.}, language = {en} } @article{MoeserLorenzSajfutdinowetal.2018, author = {M{\"o}ser, Christin and Lorenz, Jessica S. and Sajfutdinow, Martin and Smith, David M.}, title = {Pinpointed Stimulation of EphA2 Receptors via DNA-Templated Oligovalence}, series = {International journal of molecular sciences}, volume = {19}, journal = {International journal of molecular sciences}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms19113482}, pages = {19}, year = {2018}, abstract = {DNA nanostructures enable the attachment of functional molecules to nearly any unique location on their underlying structure. Due to their single-base-pair structural resolution, several ligands can be spatially arranged and closely controlled according to the geometry of their desired target, resulting in optimized binding and/or signaling interactions. Here, the efficacy of SWL, an ephrin-mimicking peptide that binds specifically to EphrinA2 (EphA2) receptors, increased by presenting up to three of these peptides on small DNA nanostructures in an oligovalent manner. Ephrin signaling pathways play crucial roles in tumor development and progression. Moreover, Eph receptors are potential targets in cancer diagnosis and treatment. Here, the quantitative impact of SWL valency on binding, phosphorylation (key player for activation) and phenotype regulation in EphA2-expressing prostate cancer cells was demonstrated. EphA2 phosphorylation was significantly increased by DNA trimers carrying three SWL peptides compared to monovalent SWL. In comparison to one of EphA2's natural ligands ephrin-A1, which is known to bind promiscuously to multiple receptors, pinpointed targeting of EphA2 by oligovalent DNA-SWL constructs showed enhanced cell retraction. Overall, we show that DNA scaffolds can increase the potency of weak signaling peptides through oligovalent presentation and serve as potential tools for examination of complex signaling pathways.}, language = {en} } @article{AfshariMoeinSomogyvariValleyetal.2018, author = {Afshari Moein, Mohammad J. and Somogyv{\´a}ri, M{\´a}rk and Valley, Beno{\^i}t and Jalali, Mohammadreza and L{\"o}w, Simon and Bayer, Peter}, title = {Fracture network characterization using stress-based tomography}, series = {Journal of geophysical research : JGR}, volume = {123}, journal = {Journal of geophysical research : JGR}, number = {11}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9313}, doi = {10.1029/2018JB016438}, pages = {9324 -- 9340}, year = {2018}, abstract = {Information on structural features of a fracture network at early stages of Enhanced Geothermal System development is mostly restricted to borehole images and, if available, outcrop data. However, using this information to image discontinuities in deep reservoirs is difficult. Wellbore failure data provides only some information on components of the in situ stress state and its heterogeneity. Our working hypothesis is that slip on natural fractures primarily controls these stress heterogeneities. Based on this, we introduce stress-based tomography in a Bayesian framework to characterize the fracture network and its heterogeneity in potential Enhanced Geothermal System reservoirs. In this procedure, first a random initial discrete fracture network (DFN) realization is generated based on prior information about the network. The observations needed to calibrate the DFN are based on local variations of the orientation and magnitude of at least one principal stress component along boreholes. A Markov Chain Monte Carlo sequence is employed to update the DFN iteratively by a fracture translation within the domain. The Markov sequence compares the simulated stress profile with the observed stress profiles in the borehole, evaluates each iteration with Metropolis-Hastings acceptance criteria, and stores acceptable DFN realizations in an ensemble. Finally, this obtained ensemble is used to visualize the potential occurrence of fractures in a probability map, indicating possible fracture locations and lengths. We test this methodology to reconstruct simple synthetic and more complex outcrop-based fracture networks and successfully image the significant fractures in the domain.}, language = {en} } @article{HolzBoeckerSchlierJennenSteinmetzetal.2018, author = {Holz, Nathalie E. and Boecker-Schlier, Regina and Jennen-Steinmetz, Christine and Hohm, Erika and Buchmann, Arlette F. and Blomeyer, Dorothea and Baumeister, Sarah and Plichta, Michael M. and Esser, G{\"u}nter and Schmidt, Martin and Meyer-Lindenberg, Andreas and Banaschewski, Tobias and Brandeis, Daniel and Laucht, Manfred}, title = {Early maternal care may counteract familial liability for psychopathology in the reward circuitry}, series = {Social Cognitive and Affective Neuroscience}, volume = {13}, journal = {Social Cognitive and Affective Neuroscience}, number = {11}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1749-5016}, doi = {10.1093/scan/nsy087}, pages = {1191 -- 1201}, year = {2018}, abstract = {Reward processing is altered in various psychopathologies and has been shown to be susceptible to genetic and environmental influences. Here, we examined whether maternal care may buffer familial risk for psychiatric disorders in terms of reward processing. Functional magnetic resonance imaging during a monetary incentive delay task was acquired in participants of an epidemiological cohort study followed since birth (N = 172, 25 years). Early maternal stimulation was assessed during a standardized nursing/playing setting at the age of 3 months. Parental psychiatric disorders (familial risk) during childhood and the participants' previous psychopathology were assessed by diagnostic interview. With high familial risk, higher maternal stimulation was related to increasing activation in the caudate head, the supplementary motor area, the cingulum and the middle frontal gyrus during reward anticipation, with the opposite pattern found in individuals with no familial risk. In contrast, higher maternal stimulation was associated with decreasing caudate head activity during reward delivery and reduced levels of attention deficit hyperactivity disorder (ADHD) in the high-risk group. Decreased caudate head activity during reward anticipation and increased activity during delivery were linked to ADHD. These findings provide evidence of a long-term association of early maternal stimulation on both adult neurobiological systems of reward underlying externalizing behavior and ADHD during development.}, language = {en} }