@article{WaldvogelFreylerHelmetal.2023, author = {Waldvogel, Janice and Freyler, Kathrin and Helm, Michael and Monti, Elena and St{\"a}udle, Benjamin and Gollhofer, Albert and Narici, Marco V. and Ritzmann, Ramona and Albracht, Kirsten}, title = {Changes in gravity affect neuromuscular control, biomechanics, and muscle-tendon mechanics in energy storage and dissipation tasks}, series = {Journal of Applied Physiology}, volume = {134}, journal = {Journal of Applied Physiology}, number = {1}, publisher = {American Physiological Society}, address = {Bethesda, Md.}, issn = {1522-1601 (Onlineausgabe)}, doi = {10.1152/japplphysiol.00279.2022}, pages = {190 -- 202}, year = {2023}, abstract = {This study evaluates neuromechanical control and muscle-tendon interaction during energy storage and dissipation tasks in hypergravity. During parabolic flights, while 17 subjects performed drop jumps (DJs) and drop landings (DLs), electromyography (EMG) of the lower limb muscles was combined with in vivo fascicle dynamics of the gastrocnemius medialis, two-dimensional (2D) kinematics, and kinetics to measure and analyze changes in energy management. Comparisons were made between movement modalities executed in hypergravity (1.8 G) and gravity on ground (1 G). In 1.8 G, ankle dorsiflexion, knee joint flexion, and vertical center of mass (COM) displacement are lower in DJs than in DLs; within each movement modality, joint flexion amplitudes and COM displacement demonstrate higher values in 1.8 G than in 1 G. Concomitantly, negative peak ankle joint power, vertical ground reaction forces, and leg stiffness are similar between both movement modalities (1.8 G). In DJs, EMG activity in 1.8 G is lower during the COM deceleration phase than in 1 G, thus impairing quasi-isometric fascicle behavior. In DLs, EMG activity before and during the COM deceleration phase is higher, and fascicles are stretched less in 1.8 G than in 1 G. Compared with the situation in 1 G, highly task-specific neuromuscular activity is diminished in 1.8 G, resulting in fascicle lengthening in both movement modalities. Specifically, in DJs, a high magnitude of neuromuscular activity is impaired, resulting in altered energy storage. In contrast, in DLs, linear stiffening of the system due to higher neuromuscular activity combined with lower fascicle stretch enhances the buffering function of the tendon, and thus the capacity to safely dissipate energy.}, language = {en} } @article{WaldvogelRitzmannFreyleretal.2021, author = {Waldvogel, Janice and Ritzmann, Ramona and Freyler, Kathrin and Helm, Michael and Monti, Elena and Albracht, Kirsten and St{\"a}udle, Benjamin and Gollhofer, Albert and Narici, Marco}, title = {The Anticipation of Gravity in Human Ballistic Movement}, series = {Frontiers in Physiology}, journal = {Frontiers in Physiology}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2021.614060}, year = {2021}, abstract = {Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.}, language = {en} } @inproceedings{WalentaSchellekensFerreinetal.2017, author = {Walenta, Robert and Schellekens, Twan and Ferrein, Alexander and Schiffer, Stefan}, title = {A decentralised system approach for controlling AGVs with ROS}, series = {AFRICON, Proceedings}, booktitle = {AFRICON, Proceedings}, publisher = {IEEE}, isbn = {978-1-5386-2775-4}, issn = {2153-0033}, doi = {10.1109/AFRCON.2017.8095693}, pages = {1436 -- 1441}, year = {2017}, language = {en} } @inproceedings{WalkLaufferRaupachDilgeretal.2004, author = {Walk-Lauffer, Bernd and Raupach, Michael and Dilger, Klaus and B{\"o}hm, Stefan and Mundt, F. and Dilthey, Ulrich and Schleser, Markus}, title = {The interconnection between inner filaments of textile reinforcement by means of polymer modified concrete}, series = {Proceedings of the First International Conference on Innovative Materials and Technologies for Construction and Restoration : : Lecce, June 6 - 9, 2004 / Universit{\`a} degli Studi di Lecce / ed. Antonio La Tegola. Vol. 1: Key-notes, materials, construction}, booktitle = {Proceedings of the First International Conference on Innovative Materials and Technologies for Construction and Restoration : : Lecce, June 6 - 9, 2004 / Universit{\`a} degli Studi di Lecce / ed. Antonio La Tegola. Vol. 1: Key-notes, materials, construction}, publisher = {Liguori}, address = {Napoli}, pages = {150 -- 159}, year = {2004}, language = {en} } @article{WallerBraunHojdisetal.2007, author = {Waller, Mark P. and Braun, Heiko and Hojdis, Nils and B{\"u}hl, Michael}, title = {Geometries of Second-Row Transition-Metal Complexes from Density-Functional Theory}, series = {Journal of Chemical Theory and Computation}, volume = {3}, journal = {Journal of Chemical Theory and Computation}, number = {6}, issn = {1549-9626}, doi = {10.1021/ct700178y}, pages = {2234 -- 2242}, year = {2007}, language = {en} } @inproceedings{WalterGligorevicDetertetal.2010, author = {Walter, Michael and Gligorevic, Snjezana and Detert, Thorben and Schnell, Michael}, title = {UHF/VHF air-to-air propagation measurements}, series = {Proceedings of the Fourth European Conference on Antennas and Propagation (EuCAP) : 12 - 16 April 2010, Barcelona, Spain}, booktitle = {Proceedings of the Fourth European Conference on Antennas and Propagation (EuCAP) : 12 - 16 April 2010, Barcelona, Spain}, organization = {European Association on Antennas and Propagation}, isbn = {978-1-4244-6431-9 ; 978-84-7653-472-4}, pages = {1 -- 5}, year = {2010}, language = {en} } @inproceedings{WalterElsenMuelleretal.1999, author = {Walter, Peter and Elsen, Ingo and M{\"u}ller, Holger and Kraiss, Karl-Friedrich}, title = {3D object recognition with a specialized mixtures of experts architecture}, series = {IJCNN'99. International Joint Conference on Neural Networks. Proceedings}, booktitle = {IJCNN'99. International Joint Conference on Neural Networks. Proceedings}, publisher = {IEEE}, address = {New York}, isbn = {0-7803-5529-6}, issn = {1098-7576}, doi = {10.1109/IJCNN.1999.836243}, pages = {3563 -- 3568}, year = {1999}, abstract = {Aim of the AXON2 project (Adaptive Expert System for Object Recogniton using Neuml Networks) is the development of an object recognition system (ORS) capable of recognizing isolated 3d objects from arbitrary views. Commonly, classification is based on a single feature extracted from the original image. Here we present an architecture adapted from the Mixtures of Eaqerts algorithm which uses multiple neuml networks to integmte different features. During tmining each neural network specializes in a subset of objects or object views appropriate to the properties of the corresponding feature space. In recognition mode the system dynamically chooses the most relevant features and combines them with maximum eficiency. The remaining less relevant features arz not computed and do therefore not decelerate the-recognition process. Thus, the algorithm is well suited for ml-time applications.}, language = {en} } @article{WaltherGerthsenCariusetal.1993, author = {Walther, T. and Gerthsen, D. and Carius, Reinhard and F{\"o}rster, Arnold}, title = {AlAs/GaAs Quantum well structures: Interface properties investigated by high-resolution transmission electron microscopy and photoluminescence spectroscopy / T. Walther ; D. Gerthsen ; R. Carius ; A. F{\"o}rster ...}, series = {Microscopy of semiconducting materials 1993 : proceedings of the Royal Microscopical Society Conference held at Oxford University, 5 - 8 April 1993 / ed. by A. G. Cullis ... - (Conference series / Institute of Physics ; 134)}, journal = {Microscopy of semiconducting materials 1993 : proceedings of the Royal Microscopical Society Conference held at Oxford University, 5 - 8 April 1993 / ed. by A. G. Cullis ... - (Conference series / Institute of Physics ; 134)}, publisher = {Institute of Physics}, address = {Bristol [u.a.]}, isbn = {0-7503-0290-9}, pages = {449 -- ff.}, year = {1993}, language = {en} } @misc{WandreyBiselliSchroederetal.1999, author = {Wandrey, Christian and Biselli, Manfred and Schr{\"o}der, Bernd and Schmoll, Hans-Joachim}, title = {Culturing cells on macroporous glass carriers coated with gelatin, extracellular matrix protein and stromal cells}, pages = {1 -- 12}, year = {1999}, language = {en} } @article{WangKrauseBlocketal.2003, author = {Wang, J. and Krause, R. and Block, K. and Musameh, M. and Mulchandani, A. and Sch{\"o}ning, Michael Josef}, title = {Flow injection amperometric detection of OP nerve agents based on organophosphorus-hydrolase biosensor detector}, series = {Biosensors \& Bioelectronics. 18 (2003), H. 2-3}, journal = {Biosensors \& Bioelectronics. 18 (2003), H. 2-3}, isbn = {0956-5663}, pages = {255 -- 260}, year = {2003}, language = {en} }