EphrinB2–EphB4 Signaling in Neurooncological Disease

EphrinB2–EphB4 signaling is critical during embryogenesis for cardiovascular formation and neuronal guidance. Intriguingly, critical expression patterns have been discovered in cancer pathologies over the last two decades. Multiple connections to tumor migration, growth, angiogenesis, apoptosis, and metastasis have been identified in vitro and in vivo. However, the molecular signaling pathways are manifold and signaling of the EphB4 receptor or the ephrinB2 ligand is cancer type specific. Here we explore the impact of these signaling pathways in neurooncological disease, including glioma, brain metastasis, and spinal bone metastasis. We identify potential downstream pathways that mediate cancer suppression or progression and seek to understand it´s role in antiangiogenic therapy resistance in glioma. Despite the Janus-faced functions of ephrinB2–EphB4 signaling in cancer Eph signaling remains a promising clinical target.     

Optimal periodic output feedback control: a continuous-time approach and a case study

This article deals with the problem of optimal static output feedback control of linear periodic systems in continuous time, for which a continuous-time approach, which allows to deal with both stable and unstable open loop systems, is presented. The proposed approach is tested on the problem of designing attitude control laws for a Low-Earth Orbit (LEO) satellite on the basis of feedback from a triaxial magnetometer and a set of high-precision gyros. Simulation results are used to demonstrate the feasibility of the proposed strategy and to evaluate its performance.     

Views on chemical safety information and influences on chemical disposal behaviour in the UK

This study examined how groups representing four tiers in the chemical supply chain (manufacturers, vendors, workers and consumers) understood safety information, and the factors that influenced disposal behaviour. Data from seven, semi-structured, focus groups was analysed both qualitatively (textual analysis) and quantitatively (network analysis). Such combined analytical methods enabled us to achieve both detailed insights into perceptions and behaviour and an objective understanding of the prevailing opinions that occurred within and between the focus group discussions. We found issues around awareness, trust, access and disposal behaviours differed between groups within the supply chain. Participants from the lower tiers perceived chemical safety information to be largely inaccessible. Labels were the main source of information on chemical risks for the middle and bottom tiers of the supply chain. Almost all of the participants were aware of the St Andrew's Cross and skull and crossbones symbols but few were familiar with the Volatile Organic Compound logo or the fish and tree symbol. Both the network and thematic analysis demonstrated that whilst frequent references to health risks associated with chemicals were made environmental risks were usually only articulated after prompting. It is clear that the issues surrounding public understanding of chemical safety labels are highly complex and this is compounded by inconsistencies in the cognitive profiles of chemical users. Substantially different cognitive profiles are likely to contribute towards communication difficulties between different tiers of the supply chain. Further research is needed to examine the most effective ways of communicating chemical hazards information to the public. The findings demonstrate a need to improve and simplify disposal guidance to members of the public, to raise public awareness of the graphic symbols in the CHIP 3.1, 2005 regulations and to improve access to disposal guidance.     

Crack surface interference under cyclic mode I and steady mode II loading: Part II: Modelling analysis

The sliding contact mechanism proposed in Part I of this publication is quantitatively analysed with the assumption of rigid asperity and Coulomb friction. A discrete step-wise iteration program, with a capability to cope with opening, sticking, bottom touching, down and uphill sliding, is developed to solve the crack surface interference under cyclic mode I and steady mode II loads. The effects of plastic/oxidation-induced crack closure combined with sliding contact are considered by introducing a sum total of build-up distributions. Peeling open and close behaviour is simulated and the near-tip build-ups are found to predominate in the determination of effective stress intensity ranges. Case studies based on the situations with or without plastic/oxidation build-ups indicate that the three fundamental factors influencing the effective stress intensity ranges are the friction coefficient, facet angle and the value of steady shear.