Non-local signatures of the chiral magnetic effect in Dirac semimetal Bi0.97_{0.97}Sb0.03_{0.03}

The field of topological materials science has recently been focussing on three-dimensional Dirac semimetals, which exhibit robust Dirac phases in the bulk. However, the absence of characteristic surface states in accidental Dirac semimetals (DSM) makes it difficult to experimentally verify claims about the topological nature using commonly used surface-sensitive techniques. The chiral magnetic effect (CME), which originates from the Weyl nodes, causes an $\textbf{E}\cdot\textbf{B}$-dependent chiral charge polarization, which manifests itself as negative magnetoresistance. We exploit the extended lifetime of the chirally polarized charge and study the CME through both local and non-local measurements in Hall bar structures fabricated from single crystalline flakes of the DSM Bi$_{0.97}$Sb$_{0.03}$. From the non-local measurement results we find a chiral charge relaxation time which is over one order of magnitude larger than the Drude transport lifetime, underlining the topological nature of Bi$_{0.97}$Sb$_{0.03}$.Comment: 6 pages, 6 figures + 7 pages of supplemental materia

Vitality club: a proof-of-principle of peer coaching for daily physical activity by older adults

Many age-related diseases can be prevented or delayed by daily physical activity. Unfortunately, many older adults do not per- form physical activity at the recommended level. Professional interventions do not reach large numbers of older adults for a long period of time. We studied a peer-coach intervention, in which older adults coach each other, that increased daily physi- cal activity of community dwelling older adults for over 6 years. We studied the format and e ects of this peer coach interven- tion for possible future implementation elsewhere. Through interviews and participatory observation we studied the format of the intervention. We also used a questionnaire (n = 55) and collected 6-min walk test data (n = 261) from 2014 to 2016 to determine the motivations of participants and effects of the intervention on health, well-being and physical capacity. Vitality Club is a self-sustainable group of older adults that gather every weekday to exercise coached by an older adult. Members attend on average 2.5 days per week and retention rate is 77.5% after 6 years. The members perceived improve- ments in several health measures. In line with this, the 6-min walk test results of members of this Vitality Club improved with 21.7 meters per year, compared with the decline of 2–7 meters per year in the general population. This Vitality Club is successful in durably engaging its members in physical activity. The members perceive improvements in health that are in line with improvements in a physical function test. Because of the self-sustainable character of the intervention, peer coaching has the potential to be scaled up at low cost and increase physical activity in the increasing number of older adults.  Prevention, Population and Disease management (PrePoD

Thickness-Dependent Sign Change of the Magnetoresistance in VTe₂ Thin Films

Transition metal dichalcogenides of type VX2 (X = S, Se, Te) have recently attracted great interest as it has been predicted that they host ferromagnetism at room temperature. Whether ferromagnetism is indeed present is an open experimental question. An in-depth study of the structural and magnetoelectric properties of VTe2 thin films is presented in this work. The VTe2 thin films were grown through molecular beam epitaxy, which allows for precise control of thicknesses, ranging from several nanometers down to monolayers. The low-temperature magnetoelectric transport studies reveal no sign of intrinsic ferromagnetism. However, a transition from positive to negative magnetoresistance is present upon decreasing film thickness

Revisiting the van der Waals Epitaxy in the Case of (Bi0.4Sb0.6)2Te3 Thin Films on Dissimilar Substrates

Ultrathin films of the ternary topological insulator (Bi0.4Sb0.6)2Te3 are fabricated by molecular beam epitaxy. Although it is generally assumed that the ternary topological insulator tellurides grow by van der Waals epitaxy, our results show that the influence of the substrate is substantial and governs the formation of defects, mosaicity, and twin domains. For this comparative study, InP (111)A, Al2O3 (001), and SrTiO3 (111) substrates were selected. While the films deposited on lattice-matched InP (111)A show van der Waals epitaxial relations, our results point to a quasi-van der Waals epitaxy for the films grown on substrates with a larger lattice mismatch

Foerderungsstrategien in der Wohnungswirtschaft

TIB: RN 2846 (27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The binding of syndapin SH3 domain to dynamin proline-rich domain involves short and long distance elements

Dynamin is a GTPase that mediates vesicle fission during synaptic vesicle endocytosis. Its long C-terminal proline-rich domain contains 13 PxxP motifs, which orchestrate its interactions with multiple proteins. The SH3 domains of syndapin and endophilin bind the PxxP motifs called Site 2 and 3 (P786−P793) at the N-terminal end of the proline-rich domain, whereas the amphiphysin SH3 binds Site 9 (P833−P836) towards the C-terminal end. In some proteins, SH3/peptide interactions also involve short distance elements, which are 5−15 amino acid extensions flanking the central PxxP motif for high affinity binding. Here we found two previously unrecognised elements in the central and the C-terminal end of the dynamin proline-rich domain that account for a significant increase in syndapin binding affinity compared to a previously reported Site 2 and Site 3 PxxP peptide alone. The first new element (G807−G811) is short distance element on the C-terminal side of Site 2 PxxP, which might contact a groove identified under the RT loop of the SH3 domain. The second element (R838−P844) is located about 50 amino acids downstream of the Site 2. These two elements provide additional specificity to the syndapin SH3 domain outside of the well-described polyproline-binding groove. Thus, the dynamin:syndapin interaction is mediated via a network of multiple contacts outside the core PxxP motif over a previously unrecognised extended region of the proline-rich domain. To our knowledge this is the first example among known SH3 interactions to involve spatially separated and extended long-range elements that combine to provide a higher affinity interaction