Fokker-Planck equation for a test-particle weakly coupled to a magnetized plasma

We consider the derivation of a kinetic equation for a charged test particle weakly interacting with an electrostatic plasma in thermal equilibrium, subject to a uniform external magnetic field. The Liouville equation leads to a generalized master equation to second order in the `weak' interaction; a Fokker-Planck-type equation then follows as a `Markovian' approximation. It is shown that such an equation does not preserve the positivity of the distribution function f(x,v;t). By applying techniques developed in the theory of open systems, a correct Fokker-Planck equation is derived. Explicit expressions for the diffusion and drift coefficients, depending on the magnetic field, are obtained.

Group Design-Build-Test Projects as the Core of an Integrated Curriculum in Product Design and Development

The School of Mechanical and Aerospace Engineering at Queen’s University Belfast introduced a new degree programme in Product Design and Development (PDD) in 2004. As well as setting out to meet all UK-SPEC requirements, the entirely new curriculum was developed in line with the syllabus and standards defined by the CDIO Initiative, an international collaboration of universities aiming to improve the education of engineering students. The CDIO ethos is that students are taught in the context of conceiving, designing, implementing and operating a product or system. Fundamental to this is an integrated curriculum with multiple Design-Build-Test (DBT) experiences at the core. Unlike most traditional engineering courses the PDD degree features group DBT projects in all years of the programme. The projects increase in complexity and challenge in a staged manner, with learning outcomes guided by Bloom’s taxonomy of learning domains. The integrated course structure enables the immediate application of disciplinary knowledge, gained from other modules, as well as development of professional skills and attributes in the context of the DBT activity. This has a positive impact on student engagement and the embedding of these relevant skills, identified from a stakeholder survey, has also been shown to better prepare students for professional practice. This paper will detail the methodology used in the development of the curriculum, refinements that have been made during the first five years of operation and discuss the resource and staffing issues raised in facilitating such a learning environment.

Glucose lowers the threshold for human aortic vascular smooth muscle cell migration: inhibition by protein phosphatase-2A

AIMS/HYPOTHESIS: Atherosclerosis, which occurs prematurely in individuals with diabetes, incorporates vascular smooth muscle cell (VSMC) chemotaxis. Glucose, through protein kinase C-beta(II) signalling, increases chemotaxis to low concentrations of platelet-derived growth factor (PDGF)-BB. In VSMC, a biphasic response in PDGF-beta receptor (PDGF-betaR) level occurs as PDGF-BB concentrations increase. The purpose of this study was to determine whether increased concentrations of PDGF-BB and raised glucose level had a modulatory effect on the mitogen-activated protein kinase/extracellular-regulated protein kinase pathway, control of PDGF-betaR level and chemotaxis.

METHODS: Cultured aortic VSMC, exposed to normal glucose (NG) (5 mmol/l) or high glucose (HG) (25 mmol/l) in the presence of PDGF-BB, were assessed for migration (chemotaxis chamber) or else extracted and immunoblotted.

RESULTS: At concentrations of PDGF-BB <540 pmol/l, HG caused an increase in the level of PDGF-betaR in VSMC (immunoblotting) versus NG, an effect that was abrogated by inhibition of aldose reductase or protein kinase C-beta(II). At higher concentrations of PDGF-BB (>540 pmol/l) in HG, receptor level was reduced but in the presence of aldose reductase or protein kinase C-beta(II) inhibitors the receptor levels increased. It is known that phosphatases may be activated at high concentrations of growth factors. At high concentrations of PDGF-BB, the protein phosphatase (PP)2A inhibitor, endothall, caused an increase in PDGF-betaR levels and a loss of biphasicity in receptor levels in HG. At higher concentrations of PDGF-BB in HG, the chemoattractant effect of PDGF-BB was lost (chemotaxis chamber). Under these conditions inhibition of PP2A was associated with a restoration of chemotaxis to high concentrations of PDGF-BB.

CONCLUSION/INTERPRETATION: The biphasic response in PDGF-betaR level and in chemotaxis to PDGF-BB in HG is due to PP2A activation.

The Victim Test under the Human Rights Act 1998 and its Implications for Domestic Violence Cases

The European Court of Human Rights has now clearly established that domestic violence constitutes a human rights issue. However, there are a number of difficulties involved in using the Human Rights Act 1998 in relation to violence against women in the home. One of these obstacles is the restrictive test of standing found in the Act, which is problematic as regards an ‘unseen crime’ such as domestic violence. This article examines this test of standing and the difficulties it poses in the context of violence against women in the home. It then considers alternative models for the standing requirement and assesses whether a change in the test of standing would produce beneficial results as regards the issue of domestic violence.

Faithful test of nonlocal realism with entangled coherent states

We investigate the violation of Leggett's inequality for nonlocal realism using entangled coherent states and various types of local measurements. We prove mathematically the relation between the violation of the Clauser-Horne-Shimony-Holt form of Bell's inequality and Leggett's one when tested by the same resources. For Leggett inequalities, we generalize the nonlocal realistic bound to systems in Hilbert spaces larger than bidimensional ones and introduce an optimization technique that allows one to achieve larger degrees of violation by adjusting the local measurement settings. Our work describes the steps that should be performed to produce a self-consistent generalization of Leggett's original arguments to continuous-variable states.