@article{22533,
author = {{Meier, F. and Protte, M. and Baron, E. and Feneberg, M. and Goldhahn, R. and Reuter, Dirk and As, D. J.}},
issn = {{2158-3226}},
journal = {{AIP Advances}},
title = {{{Selective area growth of cubic gallium nitride on silicon (001) and 3C-silicon carbide (001)}}},
doi = {{10.1063/5.0053865}},
year = {{2021}},
}
@article{22631,
author = {{Krull, Sebastian and Loschelder, David D. and Boecker, Lea}},
journal = {{Frontiers in Psychology}},
title = {{{The Power and Peril of Precise vs. Round Health Message Interventions to Increase Stair-Use}}},
doi = {{10.3389/fpsyg.2021.624198}},
year = {{2021}},
}
@article{22637,
abstract = {{Abstract
Doxorubicin (DOX) is a common drug in cancer chemotherapy, and its high DNA-binding affinity can be harnessed in preparing DOX-loaded DNA nanostructures for targeted delivery and therapeutics. Although DOX has been widely studied, the existing literature of DOX-loaded DNA-carriers remains limited and incoherent. Here, based on an in-depth spectroscopic analysis, we characterize and optimize the DOX loading into different 2D and 3D scaffolded DNA origami nanostructures (DONs). In our experimental conditions, all DONs show similar DOX binding capacities (one DOX molecule per two to three base pairs), and the binding equilibrium is reached within seconds, remarkably faster than previously acknowledged. To characterize drug release profiles, DON degradation and DOX release from the complexes upon DNase I digestion was studied. For the employed DONs, the relative doses (DOX molecules released per unit time) may vary by two orders of magnitude depending on the DON superstructure. In addition, we identify DOX aggregation mechanisms and spectral changes linked to pH, magnesium, and DOX concentration. These features have been largely ignored in experimenting with DNA nanostructures, but are probably the major sources of the incoherence of the experimental results so far. Therefore, we believe this work can act as a guide to tailoring the release profiles and developing better drug delivery systems based on DNA-carriers.}},
author = {{Ijäs, Heini and Shen, Boxuan and Heuer-Jungemann, Amelie and Keller, Adrian and Kostiainen, Mauri A and Liedl, Tim and Ihalainen, Janne A and Linko, Veikko}},
issn = {{0305-1048}},
journal = {{Nucleic Acids Research}},
pages = {{3048--3062}},
title = {{{Unraveling the interaction between doxorubicin and DNA origami nanostructures for customizable chemotherapeutic drug release}}},
doi = {{10.1093/nar/gkab097}},
volume = {{49}},
year = {{2021}},
}
@article{22723,
author = {{Yoon, Gwanho and Tanaka, Takuo and Zentgraf, Thomas and Rho, Junsuk}},
issn = {{0022-3727}},
journal = {{Journal of Physics D: Applied Physics}},
title = {{{Recent progress on metasurfaces: applications and fabrication}}},
doi = {{10.1088/1361-6463/ac0faa}},
volume = {{54}},
year = {{2021}},
}
@unpublished{22807,
abstract = {{Photonic quantum technologies [1] with applications in quantum
communication, sensing as well as quantum simulation and computing, are on the
verge of becoming commercially available. One crucial building block are
tailored nanoscale integratable quantum light sources, matching the specific
needs of use-cases. Several different approaches to realize solid-state quantum
emitters [2] with high performance [3] have been pursued. However, the
properties of the emitted single photons are always defined by the individual
quantum light source and despite numerous quantum emitter tuning
techniques [4-7], scalability is still a major challenge. Here we show an
emitter-independent method to tailor and control the properties of the single
photon emission. We demonstrate a laser-controlled down-conversion process from
an excited state of a quantum three-level system [8]. Starting from a biexciton
state, a tunable control laser field defines a virtual state in a stimulated
process. From there, spontaneous emission to the ground state leads to
optically controlled single photon emission. Based on this concept, we
demonstrate energy tuning of the single photon emission with a control laser
field. The nature of the involved quantum states furthermore provides a unique
basis for the future control of polarization and bandwidth, as predicted by
theory [9,10]. Our demonstration marks an important step towards tailored
single photon emission from a photonic quantum system based on quantum optical
principles.}},
author = {{Jonas, B. and Heinze, D. and Schöll, E. and Kallert, P. and Langer, T. and Krehs, S. and Widhalm, A. and Jöns, K. D. and Reuter, D. and Schumacher, S. and Zrenner, Artur}},
booktitle = {{arXiv:2105.12393}},
title = {{{Nonlinear down-conversion in a single quantum dot}}},
year = {{2021}},
}
@article{22926,
abstract = {{Implant-associated infections are an increasingly severe burden on healthcare systems worldwide and many research activities currently focus on inhibiting microbial colonization of biomedically relevant surfaces. To obtain molecular-level understanding of the involved processes and interactions, we investigate the adsorption of synthetic adhesin-like peptide sequences derived from the type IV pili of the Pseudomonas aeruginosa strains PAK and PAO at abiotic model surfaces, i.e., Au, SiO2, and oxidized Ti. These peptides correspond to the sequences of the receptor-binding domain 128–144 of the major pilin protein, which is known to facilitate P. aeruginosa adhesion at biotic and abiotic surfaces. Using quartz crystal microbalance with dissipation monitoring (QCM-D), we find that peptide adsorption is material- as well as strain-dependent. At the Au surface, PAO(128–144) shows drastically stronger adsorption than PAK(128–144), whereas adsorption of both peptides is markedly reduced at the oxide surfaces with less drastic differences between the two sequences. These observations suggest that peptide adsorption is influenced by not only the peptide sequence, but also peptide conformation. Our results furthermore highlight the importance of molecular-level investigations to understand and ultimately control microbial colonization of surfaces.}},
author = {{Yang, Yu and Schwiderek, Sabrina and Grundmeier, Guido and Keller, Adrian}},
issn = {{2673-8023}},
journal = {{Micro}},
number = {{1}},
pages = {{129--139}},
title = {{{Strain-Dependent Adsorption of Pseudomonas aeruginosa-Derived Adhesin-like Peptides at Abiotic Surfaces}}},
doi = {{10.3390/micro1010010}},
volume = {{1}},
year = {{2021}},
}
@article{23023,
abstract = {{DNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg2+ ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg2+ concentrations, however, present a serious limitation in such experiments as they may interfere with the reactions and processes under investigation. Therefore, we here evaluate three approaches to efficiently immobilize DONs at mica surfaces under essentially Mg2+-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni2+, poly-l-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni2+ shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg2+-mediated adsorption in terms of surface coverage, depending on the employed solution. For 3D six-helix bundles, less pronounced differences between the individual strategies are observed. Our results provide some general guidance for the immobilization of DONs at mica surfaces under Mg2+-free conditions and may aid future in situ AFM studies.}},
author = {{Xin, Yang and Zargariantabrizi, Amir Ardalan and Grundmeier, Guido and Keller, Adrian}},
issn = {{1420-3049}},
journal = {{Molecules}},
pages = {{4798}},
title = {{{Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy}}},
doi = {{10.3390/molecules26164798}},
volume = {{26}},
year = {{2021}},
}
@article{21815,
abstract = {{Sowohl Berufsethos als auch Berufswahlmotivation tragen zu relevanten lern-, leistungs- und laufbahnbedingenden Prozessen eines Individuums bei und prägen dessen Lebensverlauf wesentlich. Während die Berufswahlmotivation bereits verstärkt im wirtschaftspädagogischen Kontext untersucht wurde, existieren zum Berufsethos von Wirtschaftspädagog*innen nur vereinzelt empirische Studien. So ist beispielsweise wenig darüber bekannt, wie das Berufsethos von Wirtschaftspädagog*innen in der Ausbildungsphase ausgeprägt ist. Auch die Erforschung des Zusammenhangs zwischen den Konstrukten des Berufsethos und der Berufswahlmotivation blieb bisher unbeachtet. In diesem Beitrag wird entsprechend dieses Forschungsdesiderats untersucht, wie das anfänglich ausgebildete Berufsethos von Wirtschaftspädagogikstudierenden in der universitären Ausbildung ausgeprägt ist, ob sich die Ausprägung nach dem angegebenen Berufswunsch der Studierenden unterscheidet und inwiefern das anfänglich ausgeprägte Berufsethos mit der Berufswahlmotivation von Studierenden zusammenhängt. Dafür wurden im Wintersemester 2019/20 an zwölf deutschen Universitäten insgesamt 879 Wirtschaftspädagogikstudierende schriftlich befragt. Die Ergebnisse zeigen, dass das anfängliche Berufsethos der Befragten bereits in der universitären Ausbildungsphase relativ stark ausgeprägt ist. Weiterhin ist zu erkennen, dass das Berufsethos bei angehenden Wirtschaftspädagog*innen, die den Berufswunsch Lehrkraft haben, ausgeprägter ist als bei Wirtschaftspädagogikstudierenden, die eine Tätigkeit außerhalb des Schuldienstes anstreben bzw. noch unentschlossen sind. Letztlich kann aufgezeigt werden, dass grundsätzlich positive Zusammenhänge zwischen dem anfänglich ausgeprägten Berufsethos und der Berufswahlmotivation von angehenden Wirtschaftspädagog*innen bestehen.}},
author = {{Goller, Michael and Ziegler, Simone}},
issn = {{1618-8543}},
journal = {{bwp@ Spezial}},
keywords = {{Berufsethos, Berufswahlmotivation, Wirtschaftspädagogik, Studierende}},
pages = {{1--28}},
title = {{{Zum Zusammenhang von Berufsethos und der Berufswahlmotivation angehender Wirtschaftspädagog*innen}}},
volume = {{18}},
year = {{2021}},
}
@article{21922,
author = {{Diehr, Bärbel and Rumlich, Dominik}},
journal = {{Fremdsprachen Lehren und Lernen}},
number = {{1}},
pages = {{3--14}},
title = {{{Bilingualer Unterricht. Aktuelle Herausforderungen und neue Chancen: Zur Einführung in den Themenschwerpunkt [koordiniert von B. Diehr & D. Rumlich]}}},
doi = {{10.2357/FLuL-2021-0001}},
volume = {{50}},
year = {{2021}},
}
@article{22003,
abstract = {{AbstractThe coherent electron spin dynamics of an ensemble of singly charged (In,Ga)As/GaAs quantum dots in a transverse magnetic field is driven by periodic optical excitation at 1 GHz repetition frequency. Despite the strong inhomogeneity of the electron g factor, the spectral spread of optical transitions, and the broad distribution of nuclear spin fluctuations, we are able to push the whole ensemble of excited spins into a single Larmor precession mode that is commensurate with the laser repetition frequency. Furthermore, we demonstrate that an optical detuning of the pump pulses from the probed optical transitions induces a directed dynamic nuclear polarization and leads to a discretization of the total magnetic field acting on the electron ensemble. Finally, we show that the highly periodic optical excitation can be used as universal tool for strongly reducing the nuclear spin fluctuations and preparation of a robust nuclear environment for subsequent manipulation of the electron spins, also at varying operation frequencies.}},
author = {{Evers, E. and Kopteva, N. E. and Yugova, I. A. and Yakovlev, D. R. and Reuter, Dirk and Wieck, A. D. and Bayer, M. and Greilich, A.}},
issn = {{2056-6387}},
journal = {{npj Quantum Information}},
title = {{{Suppression of nuclear spin fluctuations in an InGaAs quantum dot ensemble by GHz-pulsed optical excitation}}},
doi = {{10.1038/s41534-021-00395-1}},
year = {{2021}},
}
@article{22004,
author = {{Schall, Johannes and Deconinck, Marielle and Bart, Nikolai and Florian, Matthias and Helversen, Martin and Dangel, Christian and Schmidt, Ronny and Bremer, Lucas and Bopp, Frederik and Hüllen, Isabell and Gies, Christopher and Reuter, Dirk and Wieck, Andreas D. and Rodt, Sven and Finley, Jonathan J. and Jahnke, Frank and Ludwig, Arne and Reitzenstein, Stephan}},
issn = {{2511-9044}},
journal = {{Advanced Quantum Technologies}},
title = {{{Bright Electrically Controllable Quantum‐Dot‐Molecule Devices Fabricated by In Situ Electron‐Beam Lithography}}},
doi = {{10.1002/qute.202100002}},
year = {{2021}},
}
@article{30645,
abstract = {{As a new and innovative processing method for fabrication for fiber-reinforced thermoplastic composites (CFRTs), the feasibility of ultrasonic welding technology was proven in several studies. This method offers potential for the direct manufacturing of CFRT–metal structures via embedded pin structures. Despite the previous studies, a deeper understanding of the process of energy input and whether fibers work as energy directors and consequently can, in combination with chosen processing parameters, influence the consolidation quality of the CFRTs, is still unknown. Consequently, the aim of this work is to establish a deeper process understanding of the ultrasonic direct impregnation of fiber-reinforced thermoplastics with an emphasis on the fiber’s function as energy directors. Based on the generated insights, a better assessment of the feasibility of direct, hybrid part manufacturing is possible. The produced samples were primarily evaluated by optical and mechanical test methods. It is demonstrated that with higher welding time and amplitude, a better consolidation quality can be achieved and that independent of the process parameters chosen in this study, no significant fiber breakage occurs. This is interpreted as a sign of a gentle impregnation process. Furthermore, based on the examination of single roving and 5-layer set-ups, it is shown that the glass fibers function as energy directors and can influence the transformation of sonic energy into thermal energy. In comparison to industrially available CFRT material, the mechanical properties are weaker, but materials and processes offer potential for significant improvement. Based on these findings, proposals for a direct impregnation and joining process are made.}},
author = {{Popp, J. and Wolf, M. and Mattner, T. and Drummer, D.}},
journal = {{Journal of Composites Science}},
pages = {{239}},
title = {{{Energy direction in ultrasonic impregnation of continuous fiber-reinforced thermoplastics}}},
doi = {{10.3390/jcs5090239}},
volume = {{5}},
year = {{2021}},
}
@article{30644,
abstract = {{Computational homogenization is a powerful tool allowing to obtain homogenized properties of materials on the macroscale from simulations of the underlying microstructure. The response of the microstructure is, however, strongly affected by variations in the microstructure geometry. In particular, we consider heterogeneous materials with randomly distributed non-overlapping inclusions, which radii are also random. In this work we extend the earlier proposed non-deterministic computational homogenization framework to plastic materials, thereby increasing the model versatility and overall realism. We apply novel soft periodic boundary conditions and estimate their effect in case of non-periodic material microstructures. We study macroscopic plasticity signatures like the macroscopic von-Mises stress and make useful conclusions for further constitutive modeling. Simulations demonstrate the effect of the novel boundary conditions, which significantly differ from the standard periodic boundary conditions, and the large influence of parameter variations and hence the importance of the stochastic modeling.}},
author = {{Pivovarov, D. and Mergheim, J. and Willner, K. and Steinmann, P.}},
journal = {{Computational Mechanics}},
title = {{{Stochastic local FEM for computational homogenization of heterogeneous materials exhibiting large plastic deformations}}},
doi = {{10.1007/s00466-021-02099-x}},
year = {{2021}},
}
@article{30650,
abstract = {{Due to increasingly strict emission targets and regulatory requirements, especially for companies in the transport industry, the demand for multi-material-systems is continuously rising in order to lower energy consumption. In this context, mechanical joining processes offer an environmentally friendly and flexible alternative to established joining methods, especially in the field of lightweight design. For example, cold-formed cylindrical pin structures show high potentials in joining multi-material-systems without auxiliary elements. The pin structures are joined either by pressing them directly into the joining partner or by caulking with a pre-punched part. However, to evaluate the strength of the joint and to ensure the joining reliability for versatile processes, such as changing joining partners or batch variations, engineering designers currently have only limited design principles available compared to thermal joining processes. Consequently, the design of an optimal pin joint requires cost- and time-intensive experimental investigations and adjustments to design or process parameters. As a solution, data-driven methods offer procedures for structuring data and identifying dependencies between varying process parameters and resulting pin structure characteristics. Motivated by this, the paper presents an approach for the data-driven analysis of cold-formed pin structures and offers a deeper understanding of how versatile processes affect the pin characteristics. Therefore, the application of an intelligent design of experiment in combination with several machine learning methods enable the setup of a best-fitting meta-model. Resulting, the determination of a mathematical model provides the opportunity to accurately estimate the pin height considering only relevant geometrical and process parameters with a prediction quality of 95 %.}},
author = {{Römisch, D. and Zirngibl, C. and Schleich, B. and Wartzack, S. and Merklein, M.}},
journal = {{IOP Conference Series: Materials Science and Engineering}},
pages = {{012077}},
title = {{{Data-driven analysis of cold-formed pin structure characteristics in the context of versatile joining processes}}},
doi = {{10.1088/1757-899X/1157/1/012077}},
volume = {{1157}},
year = {{2021}},
}
@article{30653,
abstract = {{Continuous Fiber Reinforced Thermoplastic (CFRT) hybrid parts offer interesting possibilities for lightweight application, which can exceed the capabilities of mono material metal or CFRT parts. In this case, the joining technology oftentimes is the limiting factor. This study investigates a joining operation with metal pin structures which are additively manufactured via powder bed fusion featuring different diameters and tip geometries, which are inserted into the locally infrared heated CFRT part. The resulting fiber rearrangement is assessed using transmitted light microscopy, confocal laser scanning microscopy as well as micro-computer-tomography. It could be shown that for all assessed pin variants a similar distinct fiber displacement can be seen and that the pin diameter has a significant effect on the resulting fiber orientation with smaller pin diameters being advantageous because of gentle fiber displacement and reduced undulation. The tip geometry has only minor effect on the fiber orientation. Especially in the X/Y plane no systematic influence of the tip geometry on the fiber displacement could be observed. Based on the gained insights a three-stage model of the fiber orientation processes is proposed.}},
author = {{Popp, J. and Kleffel, T. and Römisch, D. and Papke, T. and Merklein, M. and Drummer, D.}},
journal = {{Applied Composite Materials}},
pages = {{951–972}},
title = {{{Fiber Orientation Mechanism of Continuous Fiber Reinforced Thermoplastics Hybrid Parts Joined with Metallic Pins}}},
doi = {{10.1007/s10443-021-09892-0}},
volume = {{28}},
year = {{2021}},
}
@article{30659,
abstract = {{In lightweight design, clinching is a cost-efficient solution as the joint is created through localized cold-forming of the joining parts. A clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In-situ methods such as the force-displacement evaluation are used to control a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in-situ computed tomography (in-situ CT). However, a clinching tool made of steel would cause strong artefacts and a high attenuation in the CT measurement, reducing the significance of this method. Additionally, when joining parts of the same material, the sheet-sheet interface is hardly detectable. This work aims at identifying, firstly, tool materials that allow artefact-reduced CT measurements during clinching, and, secondly, radiopaque materials that can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. Therefore, both CT-suitable tool materials and radiopaque materials are selected and experimentally investigated. In the clinching process, two aluminium sheets with radiopaque material in between are clinched in a single-step (rotationally symmetric joint without cut section). It is shown that e.g. silicon nitride is suited as tool material and a tin layer is suitable to enhance the detectability of the sheet-sheet interface. }},
author = {{Köhler, D. and Kupfer, R. and Troschitz, J. and Gude, M.}},
journal = {{ESAFORM 2021}},
title = {{{Clinching in In-situ CT – Experimental Study on Suitable Tool Materials}}},
doi = {{10.25518/esaform21.2781}},
year = {{2021}},
}
@article{30661,
abstract = {{As lightweight design gains more and more attention, time and cost-efficient joining methods such as clinching are becoming more popular. A clinch point’s quality is usually determined by ex situ destructive analyses such as microsectioning. However, these methods do not yield the detection of phenomena occurring during loading such as elastic deformations and cracks that close after unloading. Alternatively, in situ computed tomography (in situ CT) can be used to investigate the loading process of clinch points. In this paper, a method for in situ CT analysis of a single-lap shear test with clinched metal sheets is presented at the example of a clinched joint with two 2 mm thick aluminum sheets. Furthermore, the potential of this method to validate numerical simulations is shown. Since the sheets’ surfaces are locally in contact with each other, the interface between both aluminum sheets and therefore the exact contour of the joining partners is difficult to identify in CT analyses. To compensate for this, the application of copper varnish between the sheets is investigated. The best in situ CT results are achieved with both sheets treated. It showed that with this treatment, in situ CT is suitable to properly observe the three-dimensional deformation behavior and to identify the failure modes.}},
author = {{Köhler, D. and Kupfer, R. and Troschitz, J. and Gude, M.}},
journal = {{Materials}},
pages = {{1859}},
title = {{{In Situ Computed Tomography—Analysis of a Single-Lap Shear Test with Clinch Points}}},
doi = {{10.3390/ma14081859}},
volume = {{14}},
year = {{2021}},
}
@article{30906,
abstract = {{Abstract
Background
Hand amputation can have a truly debilitating impact on the life of the affected person. A multifunctional myoelectric prosthesis controlled using pattern classification can be used to restore some of the lost motor abilities. However, learning to control an advanced prosthesis can be a challenging task, but virtual and augmented reality (AR) provide means to create an engaging and motivating training.
Methods
In this study, we present a novel training framework that integrates virtual elements within a real scene (AR) while allowing the view from the first-person perspective. The framework was evaluated in 13 able-bodied subjects and a limb-deficient person divided into intervention (IG) and control (CG) groups. The IG received training by performing simulated clothespin task and both groups conducted a pre- and posttest with a real prosthesis. When training with the AR, the subjects received visual feedback on the generated grasping force. The main outcome measure was the number of pins that were successfully transferred within 20 min (task duration), while the number of dropped and broken pins were also registered. The participants were asked to score the difficulty of the real task (posttest), fun-factor and motivation, as well as the utility of the feedback.
Results
The performance (median/interquartile range) consistently increased during the training sessions (4/3 to 22/4). While the results were similar for the two groups in the pretest, the performance improved in the posttest only in IG. In addition, the subjects in IG transferred significantly more pins (28/10.5 versus 14.5/11), and dropped (1/2.5 versus 3.5/2) and broke (5/3.8 versus 14.5/9) significantly fewer pins in the posttest compared to CG. The participants in IG assigned (mean ± std) significantly lower scores to the difficulty compared to CG (5.2 ± 1.9 versus 7.1 ± 0.9), and they highly rated the fun factor (8.7 ± 1.3) and usefulness of feedback (8.5 ± 1.7).
Conclusion
The results demonstrated that the proposed AR system allows for the transfer of skills from the simulated to the real task while providing a positive user experience. The present study demonstrates the effectiveness and flexibility of the proposed AR framework. Importantly, the developed system is open source and available for download and further development.
}},
author = {{Boschmann, Alexander and Neuhaus, Dorothee and Vogt, Sarah and Kaltschmidt, Christian and Platzner, Marco and Dosen, Strahinja}},
issn = {{1743-0003}},
journal = {{Journal of NeuroEngineering and Rehabilitation}},
keywords = {{Health Informatics, Rehabilitation}},
number = {{1}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Immersive augmented reality system for the training of pattern classification control with a myoelectric prosthesis}}},
doi = {{10.1186/s12984-021-00822-6}},
volume = {{18}},
year = {{2021}},
}
@unpublished{32244,
abstract = {{We push the boundaries of electronic structure-based \textit{ab-initio}
molecular dynamics (AIMD) beyond 100 million atoms. This scale is otherwise
barely reachable with classical force-field methods or novel neural network and
machine learning potentials. We achieve this breakthrough by combining
innovations in linear-scaling AIMD, efficient and approximate sparse linear
algebra, low and mixed-precision floating-point computation on GPUs, and a
compensation scheme for the errors introduced by numerical approximations. The
core of our work is the non-orthogonalized local submatrix method (NOLSM),
which scales very favorably to massively parallel computing systems and
translates large sparse matrix operations into highly parallel, dense matrix
operations that are ideally suited to hardware accelerators. We demonstrate
that the NOLSM method, which is at the center point of each AIMD step, is able
to achieve a sustained performance of 324 PFLOP/s in mixed FP16/FP32 precision
corresponding to an efficiency of 67.7% when running on 1536 NVIDIA A100 GPUs.}},
author = {{Schade, Robert and Kenter, Tobias and Elgabarty, Hossam and Lass, Michael and Schütt, Ole and Lazzaro, Alfio and Pabst, Hans and Mohr, Stephan and Hutter, Jürg and Kühne, Thomas D. and Plessl, Christian}},
booktitle = {{arXiv:2104.08245}},
title = {{{Towards Electronic Structure-Based Ab-Initio Molecular Dynamics Simulations with Hundreds of Millions of Atoms}}},
year = {{2021}},
}
@article{32438,
abstract = {{Abstract
Objective
External focus (EF) of attention leads to improved balance performance. Consideration of the neuromodulatory effects of EF may inform its clinical utility in addressing neuroplastic impairments after musculoskeletal injuries. We aimed to determine whether electrocortical activity and balance performance changed with attentional foci that prioritized differing sensory feedback and whether changes in electrocortical activity and balance were associated.
Methods
Individuals who were healthy (n = 15) performed a single-limb balance task under 3 conditions: internal focus (IF), somatosensory focus [EF with a baton (EF-baton)], and visual focus [EF with a laser (EF-laser)]. Electrocortical activity and postural sway were recorded concurrently using electroencephalography and a triaxial force plate. Electroencephalographic signals were decomposed, localized, and clustered to generate power spectral density in θ and α-2 frequency bands. Postural sway signals were analyzed with center-of-pressure sway metrics (eg, area, distance, velocity) and knee angle. The relationship between percent change in clustered brain activity and task performance metrics was assessed.
Results
Both EF conditions resulted in increased cortical activity and improved balance performance compared to IF. EF-laser had the largest effect, demonstrating increased frontal θ power (d = 0.64), decreased central θ power (d = −0.30), and decreased bilateral motor, bilateral parietal, and occipital α-2 power (d = −1.38 to −4.27) as well as a shorter path distance (d = −0.94) and a deeper (d = 0.70) and less variable (d = −1.15) knee angle than IF. Weak to moderate associations exist between increases in cortical activity and improved balance performance (ρ = 0.405–0.584).
Conclusions
EF resulted in increased cortical activity associated with cognitive, motor, somatosensory, and visual processing. EF-laser, which prioritized visual feedback, had the largest and broadest effects. Changes in cortical activity resulting from EF were independently associated with improved balance performance.
Impact
This study demonstrates that goal-oriented attention results in functional increases in brain activity compared to internally directed self-focus. These results suggest EF may target neurophysiologic impairments and improve balance in clinical populations.
}},
author = {{Sherman, David A and Lehmann, Tim and Baumeister, Jochen and Gokeler, Alli and Donovan, Luke and Norte, Grant E}},
issn = {{0031-9023}},
journal = {{Physical Therapy}},
keywords = {{Physical Therapy, Sports Therapy and Rehabilitation}},
publisher = {{Oxford University Press (OUP)}},
title = {{{External Focus of Attention Influences Cortical Activity Associated with Single Limb Balance Performance}}},
doi = {{10.1093/ptj/pzab223}},
year = {{2021}},
}