Clinical photon-counting CT increases CT number precision and reduces patient size dependence compared to single- and dual- energy CT.

Objectives: To study whether photon-counting computed tomography (PCCT) can improve CT number accuracy, precision and reduce patient size dependence compared to dual-energy CT (DECT) virtual monoenergetic imaging (VMI) and single-energy CT (SECT).

Methods: Clinical PCCT, DECT and SECT scanners were used to image a multi-energy quality assurance phantom and tissue-equivalent inserts with/without an outer nested annulus, representing two object sizes (18 and 33 cm). CT numbers were converted to linear attenuation coefficients (LAC) and regions-of-interest applied.

GraTeLPy: graph-theoretic linear stability analysis.

Background: A biochemical mechanism with mass action kinetics can be represented as a directed bipartite graph (bipartite digraph), and modeled by a system of differential equations. If the differential equations (DE) model can give rise to some instability such as multistability or Turing instability, then the bipartite digraph contains a structure referred to as a critical fragment. In some cases the existence of a critical fragment indicates that the DE model can display oscillations for some parameter values.

Deterministic versus stochastic cell polarisation through wave-pinning.

Cell polarization is an important part of the response of eukaryotic cells to stimuli, and forms a primary step in cell motility, differentiation, and many cellular functions. Among the important biochemical players implicated in the onset of intracellular asymmetries that constitute the early phases of polarization are the Rho GTPases, such as Cdc42, Rac, and Rho, which present high active concentration levels in a spatially localized manner. Rho GTPases exhibit positive feedback-driven interconversion between distinct active and inactive forms, the former residing on the cell membrane, and the latter predominantly in the cytosol.