@article{VermaMatijevičDenkeretal.2021, author = {Verma, Meetu and Matijevič, Gal and Denker, Carsten and Diercke, Andrea and Dineva, Ekaterina Ivanova and Balthasar, Horst and Kamlah, Robert and Kontogiannis, Ioannis and Kuckein, Christoph and Pal, Partha S.}, title = {Classification of high-resolution Solar H alpha spectra using t-distributed stochastic neighbor embedding}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {907}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {1}, publisher = {Institute of Physics Publ.}, address = {London}, issn = {1538-4357}, doi = {10.3847/1538-4357/abcd95}, pages = {14}, year = {2021}, abstract = {The H alpha spectral line is a well-studied absorption line revealing properties of the highly structured and dynamic solar chromosphere. Typical features with distinct spectral signatures in H alpha include filaments and prominences, bright active-region plages, superpenumbrae around sunspots, surges, flares, Ellerman bombs, filigree, and mottles and rosettes, among others. This study is based on high-spectral resolution H alpha spectra obtained with the Echelle spectrograph of the Vacuum Tower Telescope (VTT) located at Observatorio del Teide, Tenerife, Spain. The t-distributed stochastic neighbor embedding (t-SNE) is a machine-learning algorithm, which is used for nonlinear dimensionality reduction. In this application, it projects H alpha spectra onto a two-dimensional map, where it becomes possible to classify the spectra according to results of cloud model (CM) inversions. The CM parameters optical depth, Doppler width, line-of-sight velocity, and source function describe properties of the cloud material. Initial results of t-SNE indicate its strong discriminatory power to separate quiet-Sun and plage profiles from those that are suitable for CM inversions. In addition, a detailed study of various t-SNE parameters is conducted, the impact of seeing conditions on the classification is assessed, results for various types of input data are compared, and the identified clusters are linked to chromospheric features. Although t-SNE proves to be efficient in clustering high-dimensional data, human inference is required at each step to interpret the results. This exploratory study provides a framework and ideas on how to tailor a classification scheme toward specific spectral data and science questions.}, language = {en} } @book{Dosdall2021, author = {Dosdall, Henrik}, title = {Die NSU-Ermittlungen 1998-2011}, publisher = {Springer VS}, address = {Wiesbaden}, isbn = {978-3-658-31526-9}, doi = {10.1007/978-3-658-31527-6}, pages = {IX, 199}, year = {2021}, abstract = {Das Buch analysiert die sicherheitsbeh{\"o}rdlichen Ermittlungen zu der rechten Terrorgruppe „Nationalsozialistischer Untergrund" aus einer Routine- und Lernperspektive. Im Fokus stehen die Ermittlungen der th{\"u}ringischen Sicherheitsbeh{\"o}rden ab 1998 sowie die bundesweiten polizeilichen Ermittlungen ab 2000. Die Analyse zeigt, dass es jeweils organisationale Faktoren waren, die den Misserfolg der Ermittlungen beg{\"u}nstigten: die sicherheitsbeh{\"o}rdlichen Ermittlungsroutinen wurden durch Aufmerksamkeitsverschiebungen unsystematisch, durch mikropolitische Konflikte beeintr{\"a}chtigt und durch vergangene Erfahrungen limitiert, die zu enge Pr{\"a}missen f{\"u}r gegenw{\"a}rtige Ermittlungen setzten. Insgesamt verdeutlicht die Studie, dass eine organisationssoziologische Perspektive auf die Ermittlungen einen entscheidenden Beitrag zum Verst{\"a}ndnis des NSU-Komplexes bietet. - der Ermittlungsfall NSU erstmal organisationssoziologisch analysisiert - Untersuchung von F{\"u}hrungsfragen und Polizeikultur - theoretischer innovativer Ansatz in der Polizeiforschung}, language = {de} } @article{NooshiriBeanDahmetal.2021, author = {Nooshiri, Nima and Bean, Christopher J. and Dahm, Torsten and Grigoli, Francesco and Kristjansdottir, Sigriour and Obermann, Anne and Wiemer, Stefan}, title = {A multibranch, multitarget neural network for rapid point-source inversion in a microseismic environment}, series = {Geophysical journal international}, volume = {229}, journal = {Geophysical journal international}, number = {2}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0956-540X}, doi = {10.1093/gji/ggab511}, pages = {999 -- 1016}, year = {2021}, abstract = {Despite advanced seismological techniques, automatic source characterization for microseismic earthquakes remains difficult and challenging since current inversion and modelling of high-frequency signals are complex and time consuming. For real-time applications such as induced seismicity monitoring, the application of standard methods is often not fast enough for true complete real-time information on seismic sources. In this paper, we present an alternative approach based on recent advances in deep learning for rapid source-parameter estimation of microseismic earthquakes. The seismic inversion is represented in compact form by two convolutional neural networks, with individual feature extraction, and a fully connected neural network, for feature aggregation, to simultaneously obtain full moment tensor and spatial location of microseismic sources. Specifically, a multibranch neural network algorithm is trained to encapsulate the information about the relationship between seismic waveforms and underlying point-source mechanisms and locations. The learning-based model allows rapid inversion (within a fraction of second) once input data are available. A key advantage of the algorithm is that it can be trained using synthetic seismic data only, so it is directly applicable to scenarios where there are insufficient real data for training. Moreover, we find that the method is robust with respect to perturbations such as observational noise and data incompleteness (missing stations). We apply the new approach on synthesized and example recorded small magnitude (M <= 1.6) earthquakes at the Hellisheioi geothermal field in the Hengill area, Iceland. For the examined events, the model achieves excellent performance and shows very good agreement with the inverted solutions determined through standard methodology. In this study, we seek to demonstrate that this approach is viable for microseismicity real-time estimation of source parameters and can be integrated into advanced decision-support tools for controlling induced seismicity.}, language = {en} } @article{HuChengXuetal.2021, author = {Hu, Ting-Li and Cheng, Feng and Xu, Zhen and Chen, Zhong-Zheng and Yu, Lei and Ban, Qian and Li, Chun-Lin and Pan, Tao and Zhang, Bao-Wei}, title = {Molecular and morphological evidence for a new species of the genus Typhlomys (Rodentia: Platacanthomyidae)}, series = {Zoological research : ZR = Dongwuxue-yanjiu : jikan / published by Kunming Institute of Zoology, Chinese Academy of Sciences, Zhongguo Kexueyuan Kunming Dongwu Yanjiusuo zhuban, Dongwuxue-yanjiu Bianji Weiyuanhui bianji}, volume = {42}, journal = {Zoological research : ZR = Dongwuxue-yanjiu : jikan / published by Kunming Institute of Zoology, Chinese Academy of Sciences, Zhongguo Kexueyuan Kunming Dongwu Yanjiusuo zhuban, Dongwuxue-yanjiu Bianji Weiyuanhui bianji}, number = {1}, publisher = {Yunnan Renmin Chubanshe}, address = {Kunming}, issn = {2095-8137}, doi = {10.24272/j.issn.2095-8137.2020.132}, pages = {100 -- 107}, year = {2021}, abstract = {In this study, we reassessed the taxonomic position of Typhlomys (Rodentia: Platacanthomyidae) from Huangshan, Anhui, China, based on morphological and molecular evidence. Results suggested that Typhlomys is comprised of up to six species, including four currently recognized species ( Typhlomys cinereus, T. chapensis, T. daloushanensis, and T. nanus), one unconfirmed candidate species, and one new species ( Typhlomys huangshanensis sp. nov.). Morphological analyses further supported the designation of the Huangshan specimens found at mid-elevations in the southern Huangshan Mountains (600 m to 1 200 m a.s.l.) as a new species.}, language = {en} } @article{FritschSprengelEvansetal.2021, author = {Fritsch, Tobias and Sprengel, Maximilian and Evans, Alexander and Farahbod-Sternahl, Lena and Saliwan-Neumann, Romeo and Hofmann, Michael and Bruno, Giovanni}, title = {On the determination of residual stresses in additively manufactured lattice structures}, series = {Journal of applied crystallography / International Union of Crystallography}, volume = {54}, journal = {Journal of applied crystallography / International Union of Crystallography}, publisher = {Munksgaard}, address = {Copenhagen}, issn = {0021-8898}, doi = {10.1107/S1600576720015344}, pages = {228 -- 236}, year = {2021}, abstract = {The determination of residual stresses becomes more complicated with increasing complexity of the structures investigated. Additive manufacturing techniques generally allow the production of 'lattice structures' without any additional manufacturing step. These lattice structures consist of thin struts and are thus susceptible to internal stress-induced distortion and even cracks. In most cases, internal stresses remain locked in the structures as residual stress. The determination of the residual stress in lattice structures through nondestructive neutron diffraction is described in this work. It is shown how two difficulties can be overcome: (a) the correct alignment of the lattice structures within the neutron beam and (b) the correct determination of the residual stress field in a representative part of the structure. The magnitude and the direction of residual stress are discussed. The residual stress in the strut was found to be uniaxial and to follow the orientation of the strut, while the residual stress in the knots was more hydrostatic. Additionally, it is shown that strain measurements in at least seven independent directions are necessary for the estimation of the principal stress directions. The measurement directions should be chosen according to the sample geometry and an informed choice on the possible strain field. If the most prominent direction is not measured, the error in the calculated stress magnitude increases considerably.}, language = {en} } @article{MendezMasoPuigdellosasSandevetal.2021, author = {Mendez, Vicenc and Maso-Puigdellosas, Axel and Sandev, Trifce and Campos, Daniel}, title = {Continuous time random walks under Markovian resetting}, series = {Physical review : E, Statistical, nonlinear and soft matter physics}, volume = {103}, journal = {Physical review : E, Statistical, nonlinear and soft matter physics}, number = {2}, publisher = {American Physical Society}, address = {College Park}, issn = {2470-0045}, doi = {10.1103/PhysRevE.103.022103}, pages = {8}, year = {2021}, abstract = {We investigate the effects of Markovian resetting events on continuous time random walks where the waiting times and the jump lengths are random variables distributed according to power-law probability density functions. We prove the existence of a nonequilibrium stationary state and finite mean first arrival time. However, the existence of an optimum reset rate is conditioned to a specific relationship between the exponents of both power-law tails. We also investigate the search efficiency by finding the optimal random walk which minimizes the mean first arrival time in terms of the reset rate, the distance of the initial position to the target, and the characteristic transport exponents.}, language = {en} } @article{BrahmsHortobagyiKressigetal.2021, author = {Brahms, Clemens Markus and Hortob{\´a}gyi, Tibor and Kressig, Reto W. and Granacher, Urs}, title = {The Interaction between mobility status and exercise specificity in older adults}, series = {Exercise and sport sciences reviews}, volume = {49}, journal = {Exercise and sport sciences reviews}, number = {1}, publisher = {Lippincott Williams \& Wilkins}, address = {Hagerstown, Md.}, issn = {0091-6331}, doi = {10.1249/JES.0000000000000237}, pages = {15 -- 22}, year = {2021}, abstract = {Many adults older than 60 yr experience mobility limitations. Although physical exercise improves older adults' mobility, differences in baseline mobility produce large variations in individual responses to interventions, and these responses could further vary by the type and dose of exercise. Here, we propose an exercise prescription model for older adults based on their current mobility status.}, language = {en} } @article{TungSunWangetal.2021, author = {Tung, Wing Tai and Sun, Xianlei and Wang, Weiwei and Xu, Xun and Ma, Nan and Lendlein, Andreas}, title = {Structure, mechanical properties and degradation behavior of electrospun PEEU fiber meshes and films}, series = {MRS advances : a journal of the Materials Research Society (MRS)}, volume = {6}, journal = {MRS advances : a journal of the Materials Research Society (MRS)}, number = {10}, publisher = {Springer Nature Switzerland AG}, address = {Cham}, issn = {2059-8521}, doi = {10.1557/s43580-020-00001-0}, pages = {276 -- 282}, year = {2021}, abstract = {The capability of a degradable implant to provide mechanical support depends on its degradation behavior. Hydrolytic degradation was studied for a polyesteretherurethane (PEEU70), which consists of poly(p-dioxanone) (PPDO) and poly(epsilon-caprolactone) (PCL) segments with a weight ratio of 70:30 linked by diurethane junction units. PEEU70 samples prepared in the form of meshes with average fiber diameters of 1.5 mu m (mesh1.5) and 1.2 mu m (mesh1.2), and films were sterilized and incubated in PBS at 37 degrees C with 5 vol\% CO2 supply for 1 to 6 weeks. Degradation features, such as cracks or wrinkles, became apparent from week 4 for all samples. Mass loss was found to be 11 wt\%, 6 wt\%, and 4 wt\% for mesh1.2, mesh1.5, and films at week 6. The elongation at break decreased to under 20\% in two weeks for mesh1.2. In case of the other two samples, this level of degradation was achieved after 4 weeks. The weight average molecular weight of both PEEU70 mesh and film samples decreased to below 30 kg/mol when elongation at break dropped below 20\%. The time period of sustained mechanical stability of PEEU70-based meshes depends on the fiber diameter and molecular weight.}, language = {en} } @article{SchuelerCalabreseAttinger2021, author = {Sch{\"u}ler, Lennart and Calabrese, Justin M. and Attinger, Sabine}, title = {Data driven high resolution modeling and spatial analyses of the COVID-19 pandemic in Germany}, series = {PLoS one}, volume = {16}, journal = {PLoS one}, number = {8}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0254660}, pages = {14}, year = {2021}, abstract = {The SARS-CoV-2 virus has spread around the world with over 100 million infections to date, and currently many countries are fighting the second wave of infections. With neither sufficient vaccination capacity nor effective medication, non-pharmaceutical interventions (NPIs) remain the measure of choice. However, NPIs place a great burden on society, the mental health of individuals, and economics. Therefore the cost/benefit ratio must be carefully balanced and a target-oriented small-scale implementation of these NPIs could help achieve this balance. To this end, we introduce a modified SEIRD-class compartment model and parametrize it locally for all 412 districts of Germany. The NPIs are modeled at district level by time varying contact rates. This high spatial resolution makes it possible to apply geostatistical methods to analyse the spatial patterns of the pandemic in Germany and to compare the results of different spatial resolutions. We find that the modified SEIRD model can successfully be fitted to the COVID-19 cases in German districts, states, and also nationwide. We propose the correlation length as a further measure, besides the weekly incidence rates, to describe the current situation of the epidemic.}, language = {en} } @article{HuangStoofLeichsenringLiuetal.2021, author = {Huang, Sichao and Stoof-Leichsenring, Kathleen R. and Liu, Sisi and Courtin, Jeremy and Andreev, Andrej A. and Pestryakova, Luidmila. A. and Herzschuh, Ulrike}, title = {Plant sedimentary ancient DNA from Far East Russia covering the last 28,000 years reveals different assembly rules in cold and warm climates}, series = {Frontiers in Ecology and Evolution}, volume = {9}, journal = {Frontiers in Ecology and Evolution}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-701X}, doi = {10.3389/fevo.2021.763747}, pages = {15}, year = {2021}, abstract = {Woody plants are expanding into the Arctic in response to the warming climate. The impact on arctic plant communities is not well understood due to the limited knowledge about plant assembly rules. Records of past plant diversity over long time series are rare. Here, we applied sedimentary ancient DNA metabarcoding targeting the P6 loop of the chloroplast trnL gene to a sediment record from Lake Ilirney (central Chukotka, Far Eastern Russia) covering the last 28 thousand years. Our results show that forb-rich steppe-tundra and dwarf-shrub tundra dominated during the cold climate before 14 ka, while deciduous erect-shrub tundra was abundant during the warm period since 14 ka. Larix invasion during the late Holocene substantially lagged behind the likely warmest period between 10 and 6 ka, where the vegetation biomass could be highest. We reveal highest richness during 28-23 ka and a second richness peak during 13-9 ka, with both periods being accompanied by low relative abundance of shrubs. During the cold period before 14 ka, rich plant assemblages were phylogenetically clustered, suggesting low genetic divergence in the assemblages despite the great number of species. This probably originates from environmental filtering along with niche differentiation due to limited resources under harsh environmental conditions. In contrast, during the warmer period after 14 ka, rich plant assemblages were phylogenetically overdispersed. This results from a high number of species which were found to harbor high genetic divergence, likely originating from an erratic recruitment process in the course of warming. Some of our evidence may be of relevance for inferring future arctic plant assembly rules and diversity changes. By analogy to the past, we expect a lagged response of tree invasion. Plant richness might overshoot in the short term; in the long-term, however, the ongoing expansion of deciduous shrubs will eventually result in a phylogenetically more diverse community.}, language = {en} }