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Many faces of neuronal activity manipulation in Drosophila

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Neural Regeneration Research 2025年第9期20卷 2574-2576页

作者： Amber Krebs steffen Kautzmann Christian Klämbt Institut für Neuro-und Verhaltensbiologie MünsterGermany

Animals exhibit complex responses to external and internal *** information is computed by interconnected neurons that express numerous ion channels,which modulate the neuronal membrane *** can neuronal activity orchestrate complex motor patterns or allow learning from previous experience?To answer such questions,we need the ability not only to record,but also to modulate neuronal activity in both space(e.g.,neuronal subsets)and time.

关键词： manipulation potential. neuronal

Towards engineering a portable platform for laparoscopic pre-training in virtual reality with haptic feedback

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虚拟现实与智能硬件（中英文） 2024年第2期6卷 83-99页

作者： Hans-Georg ENKLER Wolfgang KUNERT Stefan PFEFFER Kai-Jonas BOCK steffen AXT Jonas JOHANNINK Christoph reich Furtwangen University 78120 FurtwangenGermany University Hospital and Faculty of Medicine Tuebingen 72076 TuebingenGermany

Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the *** some time,efforts have been made to improve surgical pre training through practical exercises on abstracted and reduced *** The authors strive for a portable,easy to use and cost-effective Virtual Reality-based(VR)laparoscopic pre-training platform and therefore address the question of how such a system has to be designed to achieve the quality of today's gold standard using real tissue *** VR controllers are limited regarding haptic *** haptic feedback is necessary or at least beneficial for laparoscopic surgery training,the platform to be developed consists of a newly designed prototype laparoscopic VR controller with haptic feedback,a commercially available head-mounted display,a VR environment for simulating a laparoscopic surgery,and a training *** To take full advantage of benefits such as repeatability and cost-effectiveness of VR-based training,the system shall not require a tissue sample for haptic *** is currently calculated and visually displayed to the user in the VR *** the prototype controller,a first axis was provided with perceptible feedback for test *** of the prototype VR controllers can be combined to simulate a typical both-handed use case,e.g.,laparoscopic suturing.A Unity based VR prototype allows the execution of simple standard *** The first prototype enables full operation of a virtual laparoscopic instrument in *** addition,the simulation can compute simple interaction *** challenges lie in a realistic real-time tissue simulation and calculation of forces for the haptic *** weaknesses were identified in the first hardware prototype,which will be improved in subsequent *** degrees of freedom of the controller are to be provided with haptic *** make forces t

关键词： Laparoscopic surgery Training Virtual reality Controller Haptic feedback Kinesthetic skills

Flash X-ray cinematography analysis of dwell and penetration of smallcaliber projectiles with three types of SiC ceramics

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Defence Technology（防务技术） 2016年第3期12卷 277-283页

作者： Elmar STRASSBURGER steffen BAUER steffen WEBER Heiner GEDON Fraunhofer Institute for High-Speed Dynamics Ernst-Mach-Institute(EMI)Am Christianswuhr 279400 KandernGermany DLR–German Aerospace Center Institute of Structures and DesignPfaffenwaldring 38-4070569 StuttgartGermany WIWeB–Bundeswehr Research Institute for Materials Fuels and LubricantsInstitutsweg 185435 ErdingGermany

In order to improve the performance of ceramic composite armor it is essential to know the mechanisms during each phase of the projectile–target interaction and their influence on the penetration *** the view on the crater zone and the tip of a projectile penetrating a ceramic is rapidly getting obscured by damaged material,a flash X-ray technique has to be applied in order to visualize projectile *** this purpose,usually several flash X-ray tubes are arranged around the target and the radiographs are recorded on *** EMI a flash X-ray imaging method has been developed,which provides up to eight flash radiographs in one experiment.A multi-anode 450 k V flash X-ray tube is utilized with this *** radiation transmitted through the target is then detected on a fluorescent *** fluorescent screen converts the radiograph into an image in the visible wavelength range,which is photographed by means of a high-speed *** technique has been applied to visualize and analyze the penetration of 7.62 mm AP projectiles into three different types of Si C *** commercial Si C grades and MICASIC(Metal Infiltrated Carbon derived Si C),a C-Si Si C ceramic developed by DLR,have been *** influences,not only of the ceramic but also the backing material,on dwell time and projectile erosion have been *** curves have been determined and their relevance to the ballistic resistance is discussed.

关键词： Ballistic resistance Dwell Flash X-ray cinematography SiC ceramics

Spatial Industrial Accident Exposure and Social Vulnerability Assessment of Hazardous Material Sites,Chemical Parks,and Nuclear Power Plants in Germany

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International Journal of Disaster Risk Science 2023年第2期14卷 223-236页

作者： Alexander Fekete steffen Neuner Institute of Rescue Engineering and Civil Protection TH Köln-University of Applied Sciences50679CologneGermany

Industrial accidents have shown that many people can be affected,such as in Seveso,Italy,in *** accidents in nuclear power plants have also led to fatalities and *** better guide preparedness against and mitigation of industrial accidents,an assessment is necessary to evaluate hazard exposure and the type of potentially vulnerable social groups that need to be taken into *** study conducted a spatial assessment of three types of industrial facilities in Germany:facilities registered under the Seveso Directive,chemical parks,and nuclear power *** method consisted of a spatial assessment using a Geographic Information System of exposure around hazardous sites registered under the S eveso Directive in Germany and of census data to analyze social *** analyzed included industrial accidents and *** results revealed that most industrial sites are in urban areas and that population density,the numbers of foreigners,and smaller housing unit sizes are higher in close proximity to these *** buffer zones analyzed in circles between 1 and 40 km show a decreasing vulnerability with more *** can guide emergency management planners and other stakeholders to better prepare for major accidents and better devise disaster risk reduction strategies specifically for different social groups.

关键词： Germany Industrial disaster risk Seveso directives Seveso sites Social vulnerability

Analysis of genetic diversity and phylogenetic relationships among red jungle fowls and Chinese domestic fowls

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Science China(Life Sciences) 2008年第6期51卷 560-568页

作者： steffen WEIGEND Institute for Animal Breeding Federal Agricultural Research Centre

Genetic diversity and phylogenetic relationships among 568 individuals of two red jungle fowl subspe- cies (Gallus gallus spadiceus in China and Gallus gallus gallus in Thailand) and 14 Chinese domestic chicken breeds were evaluated with 29 microstaellite loci, the genetic variability within population and genetic differentiation among population were estimated, and then genetic diversity and phylogenetic relationships were analyzed among red jungle fowls and Chinese domestic fowls. A total of 286 alleles were detected in 16 population with 29 microsatellite markers and the average number of the alleles observed in 29 microsatellite loci was 9.86±6.36. The overall expected heterozygosity of all population was 0.6708±0.0251, and the number of population deviated from Hardy-Weinberg equilibrium per locus ranged from 0 to 7. In the whole population, the average of genetic differentiation among population, measured as FST value, was 16.7% (P<0.001), and all loci contributed significantly (P<0.001) to this differentiation. It can also be seen that the deficit of heterozygotes was very high (0.015) (P<0.01). Reynolds' distance values varied between 0.036 (Xiaoshan chicken-Luyuan chicken pair) and 0.330 (G. gallus gallus-Gushi chicken pair). The Nm value ranged from 0.533 (between G. gallus gallus and Gushi chicken) to 5.833 (between Xiaoshan chicken and Luyuan chicken). An unrooted consensus tree was constructed using the neighbour-joining method and the Reynolds' genetic distance. The heavy-body sized chicken breeds, Luyuan chicken, Xiaoshan chicken, Beijing Fatty chicken, Henan Game chicken, Huainan Partridge and Langshan chicken formed one branch, and it had a close genetic relationship between Xiaoshan chicken-Luyuan chicken pair and Chahua chicken-Tibetan chicken pair. Chahua chicken and Tibetan chicken had closer genetic relationship with these two subspecies of red jungle fowl than other domestic chicken breeds. G. gallus spadiceus showed closer phylogenetic relati

关键词： red jungle fowl domestic fowl microsatellite genetic diversity phylogenetic relationship

Comment on “Evidence for Mesoproterozoic collision,deep burial and rapid exhumation of garbenschiefer in the Namaqua Front,South Africa” by Valby Van Schijndel,David ***,Robert Anczkiewicz,Anders Schersten,Geoscience Frontiers,Volume 11,Issue 2,Pag

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Geoscience Frontiers 2020年第5期11卷 1889-1894页

作者： steffen H.Buttner Department of Geology Rhodes University6139Makhanda(Grahamstown)South Africa

In their recent publication Van Schijndel et al.(2020) present new age data and P-T analysis from the eastern margin of the Namaqua Sector of the Namaqua Natal Metamorphic *** authors claim to provide evidence for the... 详细信息

关键词： Province. burial eastern

Nutrient retention and release in coarse woody debris of three important central European tree species and the use of NIRS to determine deadwood chemical properties

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Forest Ecosystems 2018年第3期5卷 296-310页

作者： steffen Herrmann Jurgen Bauhus Faculty of Environment and Natural Resources University of Freiburg Tennenbacherstr.4D-79106Freiburg i.Br.Germany Thunen Institute of Forest Ecosystems Alfred-M611er-Strabe 1Haus41/4216225EberswaldeGermany

Background: Coarse woody debris(CWD) is very important for forest ecosystems, particularly for biodiversity and carbon storage. Its relevance as a possible reservoir and source of nutrients is less clear, especially in central ***: Based on a chronosequence of known ages of logs, we analyzed the nutrients stored in CWD of Fagus sylvatica, Picea abies, and Pinus sylvestris at different sites in Germany. To quantify nutrient concentrations, we assessed the use of Near Infrared Reflectance Spectroscopy(NIRS) to determine the chemical properties of ***: NIRS models were suitable to predict concentrations of C, N, P, lignin and extractives. Concentrations of most nutrients increased with mass loss, with the exception of potassium, which decreased for beech and pine and remained relatively constant for spruce. The highest nutrient concentrations(N, P, S, Ca and Mn, except Mg and K) were generally observed in highly decomposed spruce logs. The net effect of decreasing CWD mass and increasing nutrient concentrations was either a decreasing(N, P and K in beech; P, Mg, K and Mn in pine), constant(S, Ca and Mg in beech; N, S and Ca in pine) or increasing amount of nutrients(N, P, S and Ca in spruce; Mn in beech) in the logsover the course of decomposition. The C/N ratio decreased for all tree species, most markedly for spruce from ca. 1000 at the beginning of the decomposition process to 180 at 36 years. The N/P ratio converged to a value of about 30 forall three species. Lignin concentrations increased for spruce and beech and remained constant for ***: Our results indicate that most nutrients remain in CWD for long periods. Nutrients may be used and cycled by microorganisms within CWD, but with the exception of P(in beech), Mg(in pine) and K(in beech and pine), there appears to be little net nutrient export until two thirds of the mass is lost. Instead, N, P, S and Ca were accumulated in spruce logs, indicating that CWD became a net sink rathe

关键词： CWD NIRS Decay Carbon F.sylvatica P.abies P.sylvestris

Real-time estimation of the structural utilization level of segmental tunnel lining

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Underground Space 2024年第4期17卷 132-145页

作者： Nicola Gottardi steffen Freitag Gunther Meschke Institute for Structural Mechanics Ruhr University BochumBochum 44801Germany Institute for Structural Analysis Karlsruhe Institute of TechnologyKarlsruhe 76131Germany

Over the last decades,an expansion of the underground network has been taking place to cope with the increasing amount of moving people and *** a consequence,it is of vital importance to guarantee the full functionality of the tunnel network by means of preventive maintenance and the monitoring of the tunnel lining state over time.A new method has been developed for the real-time prediction of the utilization level in tunnel segmental linings based on input monitoring *** new concept is founded on a framework,which encompasses an offline and an online *** the former,the generation of feedforward neural networks is accomplished by employing synthetically produced *** element simulations of the lining structure are conducted to analyze the structural response under multiple loading *** scenarios are generated by assuming ranges of variation of the model input parameters to account for the uncertainty due to the not fully determined in situ *** and target quantities are identified to better assess the structural utilization of the *** latter phase consists in the application of the methodological framework on input monitored data,which allows for a real-time prediction of the physical quantities deployed for the estimation of the lining *** approach is validated on a full-scale test of segmental lining,where the predicted quantities are compared with the actual ***,it is investigated the influence of artificial noise added to the training data on the overall prediction performances and the benefits along with the limits of the concept are set out.

关键词： Segmental lining Artificial neural networks Structural utilization level Real-time prediction Structural health monitoring Monitoring data

Separating polydisperse particles using electrostatic precipitators with wire and spiked-wire discharge electrode design

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Particuology 2018年第3期16卷 10-17页

作者： Soren Sander steffen Gawor Udo Fritsching Process Engineering Stiftung Institut ffir Werlcstofftechnik Badgasteiner Strasse 3 28359 Bremen Germany Particles and Process Engineering University of Bremen Bibliothekstrasse 1 28359 Bremen. Germany

Numerical simulations of electrostatic precipitators featuring wire and spiked electrode designs were performed to determine particle behavior and separation efficiency. The applied-voltage mechanism that alters the flow structure of particles through ionic winds and mean electric fields are revealed. Numeri- cal studies throughout the past years have shown these structures for channel and pipe configurations. However, less attention was given to field averaging for the ni,~r-product and electric field. Our study focuses on this averaging and illustrates relevant differences between multidimensional setups concern- ~ng these fields. Turbulence was modeled using the Reynolds-averaged Navier-Stokes equations with a second-order Reynolds-stress-model closure. A high three-dimensionality of the ionic wind-induced turbulence is presented. This leads to an increase in the submicron-particle precipitation rate. The results confirm the dependence of separation efficiency on particle density and permittivity, thereby showing the advantages of spiked wires compared with wire-plate setups used in electrostatic precipitators.

关键词： Electro-hydrodynamic CFD simulation Electrostatic particle precipitation Electrode design Collection efficiency