Multiscale model of global inner-core anisotropy induced by hcp-alloy plasticity

$\bullet$ Multiscale model of inner-core anisotropy produced by hcp alloy deformation$\bullet$ 5 to 20% single-crystal elastic anisotropy and plastic deformation by pyramidal slip $\bullet$ Low-degree inner-core formation model with faster crystallization at the equatorThe Earth's solid inner-core exhibits a global seismic anisotropy of several percents. It results from a coherent alignment of anisotropic Fe-alloy crystals through the inner-core history that can be sampled by present-day seismic observations. By combining self-consistent polycrystal plasticity, inner-core formation models, Monte-Carlo search for elastic moduli, and simulations of seismic measurements, we introduce a multiscale model that can reproduce a global seismic anisotropy of several percents aligned with the Earth's rotation axis. Conditions for a successful model are an hexagonal-close-packed structure for the inner-core Fe-alloy, plastic deformation by pyramidal \textless{}c+a\textgreater{} slip, and large-scale flow induced by a low-degree inner-core formation model. For global anisotropies ranging between 1 and 3%, the elastic anisotropy in the single crystal ranges from 5 to 20% with larger velocities along the c-axis

A Strategy for Employing Individual and Communal Spiritual Disciplines for Spiritual Growth at Gurnee Community Church

It was the purpose of this ministry focus paper to present a strategy for helping the collective body of Gurnee Community Church (GCC) to have a growing faith in Jesus Christ through personal and corporate integration of spiritual disciplines. GCC has the mission to lead people to a growing faith in Jesus Christ through love, service, and encouragement as the congregation journeys toward full devotion to God. In recent years, the church has desired to fulfill this purpose through a focus on spiritual disciplines. This ministry focus paper presents plan for pointing spiritually interested people towards discovering spiritual disciplines that will lead them to a deeper understanding and experience of God. Part One is an overview of the church, its history in the community and its present situation describing the church’s people and their diverse spiritual backgrounds. It will also examine the impact of church-wide movements, the desire the church has had to form a “roadmap” for spiritual maturity, and the roadblocks that have stalled spiritual growth despite a grand and inspired mission. Part Two serves as a basic understanding of the nature of individual spiritual growth and maturity. This section will outline a theology of spiritual formation through unintentional and intentional spiritual discipline and show evidence that spiritual growth happens though habits of spiritual activity. The section then identifies the various spiritual disciplines and organizes them into two categories: (1) classical and (2) deeper, more critical spiritual disciplines. Part Three provides a practical strategy for guiding the Christians of GCC to mature spiritually through intentional spiritual disciplines. It will concentrate on the focused atmosphere necessary to raise the importance of spiritual disciplines and on developing pathways for individuals and groups to directly experience God through spiritual disciplines. This section also presents an implementation timeline and a long-range vision for spiritual discipline activity as a way of life and distinguishing character of the church. Theological Mentor: John R. Hull, Jr

Periodically driven stochastic un- and refolding transitions of biopolymers

Mechanical single molecule experiments probe the energy profile of biomolecules. We show that in the case of a profile with two minima (like folded/unfolded) periodic driving leads to a stochastic resonance-like phenomenon. We demonstrate that the analysis of such data can be used to extract four basic parameters of such a transition and discuss the statistical requirements of the data acquisition. As advantages of the proposed scheme, a polymeric linker is explicitly included and thermal fluctuations within each well need not to be resolved.Comment: 7 pages, 5 figures, submitted to EP

Measuring cellular traction forces on non-planar substrates

Animal cells use traction forces to sense the mechanics and geometry of their environment. Measuring these traction forces requires a workflow combining cell experiments, image processing and force reconstruction based on elasticity theory. Such procedures have been established before mainly for planar substrates, in which case one can use the Green's function formalism. Here we introduce a worksflow to measure traction forces of cardiac myofibroblasts on non-planar elastic substrates. Soft elastic substrates with a wave-like topology were micromolded from polydimethylsiloxane (PDMS) and fluorescent marker beads were distributed homogeneously in the substrate. Using feature vector based tracking of these marker beads, we first constructed a hexahedral mesh for the substrate. We then solved the direct elastic boundary volume problem on this mesh using the finite element method (FEM). Using data simulations, we show that the traction forces can be reconstructed from the substrate deformations by solving the corresponding inverse problem with a L1-norm for the residue and a L2-norm for 0th order Tikhonov regularization. Applying this procedure to the experimental data, we find that cardiac myofibroblast cells tend to align both their shapes and their forces with the long axis of the deformable wavy substrate.Comment: 34 pages, 9 figure

Attractive instability of oppositely charged membranes induced by charge density fluctuations

We predict the conditions under which two oppositely charged membranes show a dynamic, attractive instability. Two layers with unequal charges of opposite sign can repel or be stable when in close proximity. However, dynamic charge density fluctuations can induce an attractive instability and thus facilitate fusion. We predict the dominant instability modes and timescales and show how these are controlled by the relative charge and membrane viscosities. These dynamic instabilities may be the precursors of membrane fusion in systems where artificial vesicles are engulfed by biological cells of opposite charge

Coupling JOREK and STARWALL for Non-linear Resistive-wall Simulations

The implementation of a resistive-wall extension to the non-linear MHD-code JOREK via a coupling to the vacuum-field code STARWALL is presented along with first applications and benchmark results. Also, non-linear saturation in the presence of a resistive wall is demonstrated. After completion of the ongoing verification process, this code extension will allow to perform non-linear simulations of MHD instabilities in the presence of three-dimensional resistive walls with holes for limited and X-point plasmas.Comment: Contribution for "Theory Of Fusion Plasmas, Joint Varenna - Lausanne International Workshop, Villa Monastero, Varenna, Italy (27.-31.8.2012)", accepted for publication in Journal of Physics Conference Serie

Tube Width Fluctuations in F-Actin Solutions

We determine the statistics of the local tube width in F-actin solutions, beyond the usually reported mean value. Our experimental observations are explained by a segment fluid theory based on the binary collision approximation (BCA). In this systematic generalization of the standard mean-field approach effective polymer segments interact via a potential representing the topological constraints. The analytically predicted universal tube width distribution with a stretched tail is in good agreement with the data.Comment: Final version, 5 pages, 4 figure