Measurement of second-order response without perturbation

We study the second order response functions of a colloidal particle being subjected to an anharmonic potential. Contrary to typical response measurements which require an external perturbation, here we experimentally confirm a recently developed approach where the system's susceptibilities up to second order are obtained from the particle's equilibrium trajectory [PCCP $\mathrm{{\bf 17}}$, 6653 (2015)]. The measured susceptibilities are in quantitative agreement with those obtained from the response to an external perturbation.Comment: 4 figure

The Effect of Auditory Stimuli on the Quantitative Electroencephalogram in Patients with Parkinson's Disease

Parkinson’s Disease (PD) is the second most common neurodegenerative disorder worldwide with increasing incidence and prevalence. It mainly affects the motor system due to a loss of dopaminergic neurons in the substantia nigra and leads to cardinal symptoms including brady-/akinesia, tremor, muscle stiffness and postural instability. After clinical diagnosis, treatment is primarily based on L- dopa, dopamine agonists and MAO-B inhibitors. Even with therapy, PD continues to progress and remains uncurable. In recent years, music therapy has been established as a complementary therapy due to a variety of positive effects, mainly on the motor system. However, it is still insufficiently explained what exactly renders music therapy so effective. Possible explanations range from an increased dopamine release to a better functional connectivity of different brain areas. The aim of this methodologically innovative study was to find underlying mechanisms for the effectiveness of music therapy based on EEG analysis. The analysis of the EEG was chosen due to its good temporal resolution, fast availability and relatively low costs. The research questions were first, whether it is generally possible to distinguish patients with PD from Healthy Controls (HC) based on their EEG. Second, whether auditory stimuli show an effect on the EEG. Third, which features precisely a differentiation of both groups in the EEG is based on. And fourth, which characteristics render an auditory stimulus effective. The study was conducted in collaboration between the University of British Columbia (UBC) in Vancouver and the Philipps-Universität Marburg. In 2017 and 2018, 12 patients with PD and 4 age- matched HC were tested at the UBC campus. A total of 5 EEGs (conditions) were recorded from each subject at rest and under auditory stimulation. The three stimuli differed in complexity (Rain vs Spring Walk) and modulation (rhythmic and non-rhythmic). For a more precise interpretation of the results, natural sounds were used as stimuli instead of music. Due to the amount of data, a custom-made pattern recognition algorithm (Support Vector Machine) was used, distinguishing both groups through a hyperplane within a high-dimensional feature space. Redundant data was removed in advance by calculating the mutual information quotient to include only relevant data in the final analysis. It could be shown that, first, the differentiation of both groups on the basis of the EEG is generally possible, in this case even with a convincing classification accuracy of up to 90 %. Second, the auditory stimuli mainly had an effect on the EEG samples of HC and made the classification more complex: the EEG samples of the HC approached those of the PD patients within the feature space, rendering a common hyperplane for all conditions ineffective. Based on shared features but with a separate hyperplane in each condition classification accuracy of 80-90 % and thus very good discrimination of both groups could be achieved again even under the influence of auditory stimuli. 68 Third, the by far most important features to distinguish both groups were related to the delta frequency band (0.5-4 Hz) including band power, indices of the delta band, and harmonic parameters. The increased importance of delta in PD matches existing literature, most likely due to cognitive decline. This study enhances existing literature on delta by the harmonic parameters, mainly the center frequency and the spectral value thereof. In addition, the delta frequency band is often linked to relaxation and sleep. Thus, the convergence of the EEG samples is most likely explained by stimulus- induced relaxation. Another important feature seems to be the phase lag index. It is also mentioned in the literature as an indicator of mild cognitive impairment and decreases under the influence of the stimuli. A link between the PLI and functional connectivity, as mentioned in the literature, cannot be shown in this study. Fourth, the convergence of the HC samples towards the PD samples was particularly evident in the rain conditions with misclassifications of up to 80 %. This was the case in both the rhythmic and non- rhythmic variants. Given the importance of rhythm as often shown in literature on music therapy it appears that the intended modulation was not perceived as rhythmic by the subjects. The convergence of samples was less evident in the spring walk condition, where higher frequency bands were relevant too. Auditory stimuli thus seem to need a basic complexity to show an effect on the EEG. Approaches to further research arise. For example, if the delta band is expected to be important, greater epoch lengths than in this study (3 seconds) could be analyzed to avoid false interpretations due to epochs being too short to capture very slow oscillations. In addition, a general slowing of the EEG is probably not specific for PD. For a more specific analysis, the inclusion of participants with mild cognitive impairment (PD-MCI as well as MCI not caused by PD) would be useful. Testing more complex stimuli such as music, an inclusion of motor functions in the analysis or even a measurement of dopamine levels would also remain of interest. Looking at the study design, a more balanced patient population might be beneficial. In order to show an effect of music therapy in the EEG, a convergence of PD samples towards HC samples would have been desirable. Due to the relaxation, the opposite was the case. The chosen methodology, however, seems very appropriate. The classification of both groups was possible on a convincingly high level and recommends this approach for further research, due to its variability beyond neurology and even medicine

Oscillating Modes of Driven Colloids in Overdamped Systems

Microscopic particles suspended in liquids are the prime example of an overdamped system because viscous forces dominate over inertial effects. Apart from their use as model systems, they receive considerable attention as sensitive probes from which forces on molecular scales can be inferred. The interpretation of such experiments rests on the assumption, that, even if the particles are driven, the liquid remains in equilibrium, and all modes are overdamped. Here, we experimentally demonstrate that this is no longer valid when a particle is forced through a viscoelastic fluid. Even at small driving velocities where Stokes law remains valid, we observe particle oscillations with periods up to several tens of seconds. We attribute these to non-equilibrium fluctuations of the fluid, which are excited by the particle's motion. The observed oscillatory dynamics is in quantitative agreement with an overdamped Langevin equation with negative friction-memory term and which is equivalent to the motion of a stochastically driven underdamped oscillator. This fundamentally new oscillatory mode will largely expand the variety of model systems but has also considerable implications on how molecular forces are determined by colloidal probe particles under natural viscoelastic conditions.Comment: Accepted with Nat. Comm. (originally submitted version, complying with Nature policies). 10 pages, 8 figure

Calculating Gross Hourly Wages : the (Structure of) Earnings Survey and the German Socio-Economic Panel in Comparison

The statutory minimum wage in Germany was set as an hourly wage. Thus, valid information on gross hourly wages must be calculated from monthly wages and weekly working hours. This paper compares the German Socio-Economic Panel (GSOEP) and the (Structure of) Earnings Survey (SES/ES). The sampling and collection of data on employees in the household survey GSOEP, and on jobs in the administrative surveys SES/ES exhibit fundamental conceptual differences. Accordingly, there is variation in the definition of types of employment and in the distribution of the observed units regarding central characteristics. Monthly wages, weekly working hours and gross hourly wages differ especially in the lower range of the respective distribution. Against this backdrop specific implications can be derived for minimum wage research

Von Wissen zur Performanz in der Ausbildung von sportunterrichtenden Lehrpersonen: Eine Delphi-Studie und ein Pretest zur inhaltlichen Validierung der Testinstrumente

The basis for evaluating the effectiveness of interventions in the education and continuing professional development of physical education (PE) teachers involves valid, reliable, and objective instruments, which are largely lacking. Content validity is a necessary basis for the development of such instruments. Accordingly, this study presents the content validation of a test for the assessment of (classroom management-related) professional knowledge and the perception, interpretation, and decision-making (PID) of prospective PE teachers. The result is a content-validated knowledge test (110 test items) as well as a video-based test for the assessment of PID (ten vignettes, 217 items). In a next step, the instruments are empirically validated. (DIPF/Orig.)Die Basis zur Eruierung der Effektivität von Interventionen in der Aus- und Weiterbildung von sportunterrichtenden Lehrpersonen stellen valide, reliable und objektive Instrumente dar, die weitgehend fehlen. Zur Entwicklung derartiger Instrumente ist die Inhaltsvalidität eine notwendige Grundlage. In vorliegender Studie wird dementsprechend die inhaltliche Validierung eines Tests zur Erfassung des (jeweils klassenführungsbezogenen) professionellen Wissens und der Wahrnehmung, Interpretation und Entscheidung (PID) bei (angehenden) sportunterrichtenden Lehrpersonen dargestellt. Es resultiert ein inhaltlich validierter Wissenstest (110 Testitems) sowie ein videobasierter Test zur Erfassung der PID (zehn Vignetten, 217 Items). In einem nächsten Schritt werden die Instrumente empirisch validiert. (DIPF/Orig.

Investigating the sediment transport processes in a river meander

Water Qualit

Zur Berechnung von Bruttostundenlöhnen - Verdienst(struktur)erhebung und Sozio-oekonomisches Panel im Vergleich

Aufgrund der Festlegung des gesetzlichen Mindestlohns als Stundenlohn müssen valide Informationen, zu Bruttostundenlöhnen aus den Angaben zu Monatsentgelten und wöchentlichen Arbeitszeiten, berechnet werden. Dieser Beitrag vergleicht methodisch sowie empirisch das Sozio-oekonomische Panel und die Verdienst(struktur)erhebung. Demnach bestehen grundlegende konzeptionelle Unterschiede, in der Stichprobenziehung und Erhebung von Angaben zu Beschäftigten in der Haushaltsbefragung, des SOEP und zu Beschäftigungsverhältnissen in der amtlichen Erhebung der V(S)E. Dementsprechend, differieren die Abgrenzungsmöglichkeiten der Beschäftigungsformen sowie die Verteilung, der beobachteten Einheiten nach zentralen Merkmalen. Mit Blick auf die monatlichen Arbeitsentgelte, wöchentlichen Arbeitszeiten und Bruttostundenlöhne zeigen sich insbesondere im unteren Bereich, der jeweiligen Verteilung Unterschiede.The statutory minimum wage in Germany was set as hourly wage. Thus, valid information on gross hourly wages must be calculated from monthly wages and weekly working hours. This paper compares the German Socio-Economic Panel and the Structure of Earnings Survey. There exist conceptual differences regarding sampling and collection of data on employees in the household survey (SOEP) and on jobs in the mandatory survey (V(S)E.) Accordingly, weighting and definition of types of employment vary. This also accounts for central characteristics of units observed. Monthly wages, weekly working hours and gross hourly wages differ especially in the lower range of the respective distribution

Revisiting the hierarchical structure of the 24 VIA character strengths: Three global dimensions may suffice to capture their essence

The Values in Action (VIA) framework maps 24 character strengths onto six more abstract virtues through a theoretical classification. However, compared to other individual difference constructs, there is little consensus about the factor-analytic structure of the VIA trait space. Applying Horn's parallel analysis, Goldberg’s Bass-ackwards approach, and cross-country congruency analysis, we scrutinize the factor-analytic solutions-hierarchy of the 24 VIA strengths with the aim to identify one or more useful global levels of abstraction (akin to the Big Five, HEXACO/Big Six, or personality metatraits). We assessed the 24 character strengths with the psychometrically refined IPIP-VIA-R inventory in two large and heterogeneous samples from Germany and the UK (total N ≈ 2,000). Results suggested that three global dimensions suffice to capture the essence of character strengths: Level III recovered more than 50% of the total variation of the 24 character strengths in well-interpretable, global/general, cross-culturally replicable dimensions. We provisionally labeled them positivity, dependability, and mastery. Their superordinate Level-II-dimensions were reminiscent of the "Big Two" personality metatraits Dynamism and Social Self-Regulation. Our results advance the understanding of the VIA character trait space and may serve as a basis for developing scales to assess these global dimensions