BACKGROUND A goal of systems biology is to analyze large-scale molecular networks including gene expressions and protein-protein interactions, revealing the relationships between network structures and their biological functions. Dividing a protein-protein interaction (PPI) network into naturally grouped parts is an essential way to investigate the relationship between topology of networks and ...

Cellular responses often require the fast activation or repression of specific genes, which depends on transcription factors (TFs) that have to quickly find the promoters of these genes within a large genome. TFs search for their DNA promoter target by alternating between bulk diffusion and sliding along the DNA, a mechanism known as facilitated diffusion. We study a facilitated diffusion frame...

Fusion reactivity is usually obtained using a Maxwellian distribution. However, energy-dependent radial diffusion can modify the energy distribution. Superbanana diffusion is energy-dependent and occurs in nonaxisymmetric magnetic confinement devices, such as stellarators, because of rippletrapped particles which can take large steps between collisions. In this paper, the D-T fusion reactivity ...

Estimating diffusion tensors is an essential step in many applications - such as diffusion tensor image (DTI) registration, segmentation and fiber tractography. Most of the methods proposed in the literature for this task are not simultaneously statistically robust and feature preserving techniques. In this paper, we propose a novel and robust variational framework for simultaneous smoothing an...

Understanding diffusion in alumina is a long-standing challenge in ceramic science. The present article applies a novel combination of metadynamics and kinetic Monte Carlo simulation approaches to the investigation of oxygen vacancy diffusion in alumina. Three classes of diffusive jumps with different activation energies were identified, the resulting diffusion coefficient being best fitted by ...

Li diffusion in spinel-type structured cubic and hexagonal LixTiS2 with x = 0.6 and 0.7, respectively, was investigated by solid state NMR spectroscopy. In layered hexagonal LixTiS2, Li diffusion is known to be confined to the van-der-Waals gap between the TiS2 planes, i. e., it is two-dimensional (2D). In cubic LixTiS2, however, Li diffusion takes place in the three-dimensional (3D) interstiti...

We present inelastic neutron scattering measurements on liquid mercury at room temperature for wave numbers q in the range 0.3 <q<7.0 A(-1). We find that the energy half width of the incoherent part of the dynamic structure factor S(q,E) is determined by a self-diffusion process. The half width of the coherent part of S(q,E) shows the characteristic behavior expected for a cage diffusion proces...

Recent studies have cast doubt on the dominant role of social contagion in new product diffusion. We critically re-assess what is considered the best evidence of social contagion in the diffusion literature: the Medical Innovation study by Coleman, Katz and Menzel(1966) on the diffusion of the antibiotic tetracycline in the mid 1950s. A descriptive analysis of the tetracycline market indicates ...

We present a combined analytical and numerical approach based on the Mori projection operator formalism and Monte Carlo simulations to study surface diffusion within the lattice-gas model. In the present theory, the average jump rate and the susceptibility factor appearing are evaluated through Monte Carlo simulations, while the memory functions are approximated by the known results for a Langm...

National innovation systems are influencing the path of innovation diffusion like e-business. Important enablers of e-business diffusion are IT mature and innovation friendly enterprises. An indicator of IT maturity is the diffusion of former innovations like electronic data interchange (EDI). The innovation adoption behavior can be described as the adopting date after occurrence of an innovati...