Anomalous dynamics of cell migration

Cell movement, for example during embryogenesis or tumor metastasis, is a complex dynamical process resulting from an intricate interplay of multiple components of the cellular migration machinery. At first sight, the paths of migrating cells resemble those of thermally driven Brownian particles. However, cell migration is an active biological process putting a characterization in terms of normal Brownian motion into question. By analyzing the trajectories of wildtype and mutated epithelial (MDCK-F) cells we show experimentally that anomalous dynamics characterizes cell migration. A superdiffusive increase of the mean squared displacement, non-Gaussian spatial probability distributions, and power-law decays of the velocity autocorrelations are the basis for this interpretation. Almost all results can be explained with a fractional Klein- Kramers equation allowing the quantitative classification of cell migration by a few parameters. Thereby it discloses the influence and relative importance of individual components of the cellular migration apparatus to the behavior of the cell as a whole.Comment: 20 pages, 3 figures, 1 tabl

Organizational Culture Change as an Effective Tool for Customer Gaining.

Předmětem bakalářské práce „Změna organizační kultury jako účinný prostředek získání zákazníka“ je analyzovat a navrhnout změny firemní kultury konkrétní společnosti, která působí v automobilovém průmyslu. Hlavním cílem je analyzovat spokojenost zaměstnanců v souvislosti s firemní kulturou a vyzkoumat nejlepší způsob přísunu nových zákazníků.The main task of this bachelor´s thesis called „Organizational Culture Change as an Effective Tool for Customer Gaining“ is to analyse and suggest changes of corporate culture of a specific company working in car industry. The main aim is to analyse the content of the employees in a connection with the corporate culture and find out how to gain new customers.

Identifying causal gateways and mediators in complex spatio-temporal systems

J.R. received support by the German National Academic Foundation (Studienstiftung), a Humboldt University Postdoctoral Fellowship, and the German Federal Ministry of Science and Education (Young Investigators Group CoSy-CC2, grant no. 01LN1306A). J.F.D. thanks the Stordalen Foundation and BMBF (project GLUES) for financial support. D.H. has been funded by grant ERC-CZ CORES LL-1201 of the Czech Ministry of Education. M.P. and N.J. received funding from the Czech Science Foundation project No. P303-14-02634S and from the Czech Ministry of Education, Youth and Sports, project No. DAAD-15-30. J.H. was supported by the Czech Science Foundation project GA13-23940S and Czech Health Research Council project NV15-29835A. We thank Mary Lindsey from the National Oceanic and Atmospheric Administration for her kind help with Fig. 4e. NCEP Reanalysis data provided by NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their web site at http://www.esrl.noaa.gov/psd/.Peer reviewedPublisher PD

BaRe-ESA: A Riemannian Framework for Unregistered Human Body Shapes

We present Basis Restricted Elastic Shape Analysis (BaRe-ESA), a novel Riemannian framework for human body scan representation, interpolation and extrapolation. BaRe-ESA operates directly on unregistered meshes, i.e., without the need to establish prior point to point correspondences or to assume a consistent mesh structure. Our method relies on a latent space representation, which is equipped with a Riemannian (non-Euclidean) metric associated to an invariant higher-order metric on the space of surfaces. Experimental results on the FAUST and DFAUST datasets show that BaRe-ESA brings significant improvements with respect to previous solutions in terms of shape registration, interpolation and extrapolation. The efficiency and strength of our model is further demonstrated in applications such as motion transfer and random generation of body shape and pose.Comment: 13 pages, 7 figures, 3 table

Elastic shape analysis of surfaces with second-order Sobolev metrics: a comprehensive numerical framework

This paper introduces a set of numerical methods for Riemannian shape analysis of 3D surfaces within the setting of invariant (elastic) second-order Sobolev metrics. More specifically, we address the computation of geodesics and geodesic distances between parametrized or unparametrized immersed surfaces represented as 3D meshes. Building on this, we develop tools for the statistical shape analysis of sets of surfaces, including methods for estimating Karcher means and performing tangent PCA on shape populations, and for computing parallel transport along paths of surfaces. Our proposed approach fundamentally relies on a relaxed variational formulation for the geodesic matching problem via the use of varifold fidelity terms, which enable us to enforce reparametrization independence when computing geodesics between unparametrized surfaces, while also yielding versatile algorithms that allow us to compare surfaces with varying sampling or mesh structures. Importantly, we demonstrate how our relaxed variational framework can be extended to tackle partially observed data. The different benefits of our numerical pipeline are illustrated over various examples, synthetic and real.Comment: 25 pages, 16 figures, 1 tabl

Young Adults Performance of Unipedal Dynamic Balance with Various Footwear Conditions

International Journal of Exercise Science 13(4): 206-215, 2020. Wearing barefoot-style (minimalist) shoes is suggested as a transition between wearing shoes and barefoot running. Some sources equate wearing Vibram FiveFingers™(VFFs), a brand of barefoot shoes, with running/walking barefoot. Static and dynamic balance exercises are recommended. Little information is available on the effects barefoot shoes may have on dynamic balance. This study’s purpose was to examine dynamic balance when participants wore VFFs, athletic shoes, or went barefoot (BF). To test dynamic balance, participants used a modified version of the Star Excursion Balance Test (SEBT), in which the reaching leg followed only three spokes of the test: the anterior, posteromedial and posterolateral. For the timed test, participants touched down as quickly as possible in both directions using all 8 spokes. Thirty participants (ages 24.1+/-3.71 years) without lower extremity injury or experience wearing minimalist shoes were tested using the modified SEBT and a timed test wearing VFFs™, athletic shoes, or BF. Three trials for each footwear were completed for three reaching positions: anterior, posterolateral, posteromedial. The timed test measured (seconds) one counterclockwise and one clockwise direction of the 8-spoke figure. A repeated measures analysis of variance determined if any differences existed between footwear type and studied variables. Anterior reach was significantly greater when wearing shoes than with VFF or BF. Posteromedial reach was greater with shoes than BF. Time trials were not significantly different. Because no difference was found in any measured variables between VFF and BF, the results suggest wearing VFFS™ provided similar dynamic balance as going barefoot