Eine Anwendung des Akteur-Partner-Interdependenz-Modells auf ausgewählte Aspekte der Paarkongruenz

Diese Arbeit bezieht sich auf den Einfluss spezieller Persönlichkeitseigenschaften auf die Beziehungsqualität beider Partner in heterosexuellen Beziehungen. Die erhobene Stichprobe beläuft sich auf 94 Paare. Baron-Cohen (2009) und Fisher (2009) postulieren jeweils Persönlichkeitsdimensionen, die auf pränatale Hormoneinflüsse zurückzuführen sind. Fisher (2009) kam zu dem Schluss, dass sich gewisse Persönlichkeitsdimensions-Paarungen am Idealsten darstellen, was sowohl für Persönlichkeitsähnlichkeit als auch Komplementarität spricht. In Bezug auf hohe Beziehungsqualität konnten diese Ergebnisse in dieser Studie nicht bestätigt werden. Korrelationen zwischen den Dimensionen zeigen aber weitgehend Ergebnisse in Richtung Fishers „Partnerpassung“. Auch die Zusammenhänge hinsichtlich der Paarung von Baron-Cohens (2009) Persönlichkeitsdimensionen zeigen in Richtung Komplementarität. Ingesamt gesehen konnte kein Einfluss der Persönlichkeitsdimension auf die Beziehungsqualität des Partners gefunden werden. Geschlechtliche Unterschiede hinsichtlich gewisser Persönlichkeitsdimensionen von Baron-Cohen (2009) und Fisher (2009) gehen mit den Studien dieser Autoren signifikant dakor. Diese Arbeit konnte weiters einen Zusammenhang zwischen jeweils zwei Dimensionen von Baron-Cohen (2009) und Fisher (2009), welche von gleichen Aspekten ausgehen, gefunden werden

Global radii of curvature, and the biarc approximation of space curves:in pursuit of ideal knot shapes

The distance from self-intersection of a (smooth and either closed or infinite) curve q in three dimensions can be characterised via the global radius of curvature at q(s), which is defined as the smallest possible radius amongst all circles passing through the given point and any two other points on the curve. The minimum value of the global radius of curvature along the curve gives a convenient measure of curve thickness or normal injectivity radius. Given the utility of the construction inherent to global curvature, it is natural to consider variants defined in related ways. The first part of the thesis considers all possible circular and spherical distance functions and the associated, single argument, global radius of curvature functions that are constructed by minimisation over all but one argument. It is shown that among all possible global radius of curvature functions there are only five independent ones. And amongst these five there are two particularly useful ones for characterising thickness of a curve. We investigate the geometry of how these two functions, ρpt and ρtp, can be achieved. Properties and interrelations of the divers global radius of curvature functions are illustrated with the simple examples of ellipses and helices. It is known that any Lipschitz continuous curve with positive thickness actually has C1,1-regularity. Accordingly, C1,1 is the natural space in which to carry out computations involving self-avoiding curves. The second part of the thesis develops the mathematical theory of biarcs, which are a geometrically elegant way of discretizing C1,1 space curves. A biarc is a pair of circular arcs joined in a C1 fashion according to certain matching rules. We establish a self-contained theory of the geometry of biarc interpolation of point-tangent data sampled from an underlying base curve, and demonstrate that such biarc curves have attractive convergence properties in both a pointwise and function-space sense, e.g. the two arcs of the biarc interpolating a coalescent point-tangent data pair on a C2-curve approach the osculating circle of the curve at the limit of the data points, and for a C1,1-base curve and a sequence of (possibly non-uniform) meshes, the interpolating biarc curves approach the base curve in the C1-norm. For smoother base curves, stronger convergence can be obtained, e.g. interpolating biarc curves approach a C2 base curve in the C1,1-norm. The third part of the thesis concerns the practical utility of biarcs in computation. It is shown that both the global radius of curvature function ρpt and thickness can be evaluated efficiently (and to an arbitrarily small, prescribed precision) on biarc curves. Moreover, both the notion of a contact set, i.e. the set of points realising thickness, and an approximate contact set can be defined rigorously. The theory is then illustrated with an application to the computation of ideal shapes of knots. Informally ideal knot shapes can be described as the configuration allowing a given knot to be tied with the shortest possible piece of rope of prescribed thickness. The biarc discretization is combined with a simulated annealing code to obtain approximate ideal shapes. These shapes provide rigorous upper bounds for rope length of ideal knots. The approximate contact set and the function ρpt evaluated on the computed shapes allow us to assess closeness of the computations to ideality. The high accuracy of the computations reveal various, previously unrecognized, features of ideal knot shapes

Neighborly relations: cadherins and mechanotransduction

Cell–cell adhesions are sites where cells experience and resist tugging forces. It has long been postulated, but not directly tested, that cadherin adhesion molecules may serve in mechanotransduction at cell–cell contacts. In this issue, Le Duc et al. (2010. J. Cell Biol. doi: 10.1083/jcb.201001149) provide direct evidence that E-cadherin participates in a mechanosensing pathway that regulates the actomyosin cytoskeleton to modulate cell stiffness in response to pulling force

Perceived Audio Quality Analysis in Digital Audio Broadcasting Plus System Based on PEAQ

Broadcasters need to decide on bitrates of the services in the multiplex transmitted via Digital Audio Broadcasting Plus system. The bitrate should be set as low as possible for maximal number of services, but with high quality, not lower than in conventional analog systems. In this paper, the objective method Perceptual Evaluation of Audio Quality is used to analyze the perceived audio quality for appropriate codecs --- MP2 and AAC offering three profiles. The main aim is to determine dependencies on the type of signal --- music and speech, the number of channels --- stereo and mono, and the bitrate. Results indicate that only MP2 codec and AAC Low Complexity profile reach imperceptible quality loss. The MP2 codec needs higher bitrate than AAC Low Complexity profile for the same quality. For the both versions of AAC High-Efficiency profiles, the limit bitrates are determined above which less complex profiles outperform the more complex ones and higher bitrates above these limits are not worth using. It is shown that stereo music has worse quality than stereo speech generally, whereas for mono, the dependencies vary upon the codec/profile. Furthermore, numbers of services satisfying various quality criteria are presented

Light-activated Frizzled7 reveals a permissive role of non-canonical wnt signaling in mesendoderm cell migration

10.7554/eLife.42093.001Non-canonical Wnt signaling plays a central role for coordinated cell polarization and directed migration in metazoan development. While spatiotemporally restricted activation of non-canonical Wnt-signaling drives cell polarization in epithelial tissues, it remains unclear whether such instructive activity is also critical for directed mesenchymal cell migration. Here, we developed a light-activated version of the non-canonical Wnt receptor Frizzled 7 (Fz7) to analyze how restricted activation of non-canonical Wnt signaling affects directed anterior axial mesendoderm (prechordal plate, ppl) cell migration within the zebrafish gastrula. We found that Fz7 signaling is required for ppl cell protrusion formation and migration and that spatiotemporally restricted ectopic activation is capable of redirecting their migration. Finally, we show that uniform activation of Fz7 signaling in ppl cells fully rescues defective directed cell migration in fz7 mutant embryos. Together, our findings reveal that in contrast to the situation in epithelial cells, non-canonical Wnt signaling functions permissively rather than instructively in directed mesenchymal cell migration during gastrulation