TRAVELLING CHEMOTACTIC AGGREGATES AT MESOSCOPIC SCALE AND BISTABILITY

A model consisting of a kinetic equation for \run-and-tumble" biased bacteria motion, coupled with two reaction-diusion equations for chemical signals, is studied. It displays time- asymptotic propagation at constant velocity, i.e., aggregated travelling (exponential) layers. To capture them for various parameters, a well-balanced setup is based on both \Case's elementary solutions" and L-spline reconstruction. Far from the diusive regime, waves travelling at dierent velocities (bistability) are proved to coexist.

Mathematical Modelling of Variable Porosity Coatings for Dual Drug Delivery

In this paper we describe a theoretical mathematical model of dual drug delivery from a durable polymer coated medical device. We demonstrate how the release rate of each drug may in principle be controlled by altering the initial loading configuration of the two drugs. By varying the underlying microstructure of polymer coating, further control may be obtained, providing the opportunity to tailor the release profile of each drug for the given application.

Combining Mathematical Modelling with In- Vitro Experiments to Predict In-Vivo Drug-Eluting Stent Kinetics,

In this paper we describe a combined in-vitro experimental and mathematical modelling approach to predict in-vivo drug-eluting stent kinetics. We coated stents with a mixture of sirolimus and a novel acrylic-based polymer in two different ratios. Our results indicate differential release kinetics between low and high drug dose formulations. Furthermore, mathematical model simulations of target receptor saturation suggest potential differences in efficacy.

Time-reversal symmetry for systems in a constant external magnetic field

The time-reversal properties of charged systems in a constant external magnetic field are reconsidered in this paper. We show that the evolution equations of the system are invariant under a new symmetry operation that implies a new signature property for time-correlation functions under time reversal. We then show how these findings can be combined with a previously identified symmetry to determine, for example, null components of the correlation functions of velocities and currents and of the associated transport coefficients.

Microscopic and macroscopic models for the onset and progression of Alzheimer's disease

In the first part of this paper we review a mathematical model for the onset and progression of Alzheimer's disease (AD) that was developed in subsequent steps over several years. The model is meant to describe the evolution of AD in vivo. In Achdou et al (2013 J. Math. Biol. 67 1369-92) we treated the problem at a microscopic scale, where the typical length scale is a multiple of the size of the soma of a single neuron. Subsequently, in Bertsch et al (2017 Math. Med. Biol.

GPU based detection of topological changes in Voronoi diagrams

The Voronoi diagrams are an important tool having theoretical and practical applications in a large number of fields. We present a new procedure, implemented as a set of CUDA kernels, which detects, in a general and efficient way, topological changes in case of dynamic Voronoi diagrams whose generating points move in time. The solution that we provide has been originally developed to identify plastic events during simulations of soft-glassy materials based on a lattice Boltzmann model with frustrated-short range attractive and mid/long-range repulsive-interactions.

Fluidization and wall slip of soft glassy materials by controlled surface roughness

We present a comprehensive study of concentrated emulsions flowing in microfluidic channels, one wall of which is patterned with micron-size equally spaced grooves oriented perpendicularly to the flow direction. We find a scaling law describing the roughness-induced fluidization as a function of the density of the grooves, thus fluidization can be predicted and quantitatively regulated. This suggests common scenarios for droplet trapping and release, potentially applicable for other jammed systems as well.

The action of Volterra integral operators with highly singular kernels on Holder continuous, Lebesgue and Sobolev functions

For kernels zi which are positive and integrable we show that the operator g bar right arrow J(v)g = integral(x)(0) v(x-s)g(s)ds on a finite time interval enjoys a regularizing effect when applied to Holder continuous and Lebesgue functions and a "contractive" effect when applied to Sobolev functions. For Holder continuous functions, we establish that the improvement of the regularity of the modulus of continuity is given by the integral of the kernel, namely by the factor N(x) = integral(x)(0) v(s)ds.

Vortex interaction with free-surface by a coupled FV-SPH solver

Recently, an algorithm for coupling a Finite Volume (FV) method, that discretize the Navier-Stokes equations on block structured Eulerian grids, with the weakly-compressible SPH was presented. The algorithm takes advantage of the SPH method to discretize flow regions close to free-surfaces and of Finite Volume method to resolve the bulk flow and the wall regions. The continuity between the two solution is guaranteed by overlapping zones.