Does the 1/f frequency-scaling of brain signals reflect self-organized critical states?

Many complex systems display self-organized critical states characterized by 1/f frequency scaling of power spectra. Global variables such as the electroencephalogram, scale as 1/f, which could be the sign of self-organized critical states in neuronal activity. By analyzing simultaneous recordings of global and neuronal activities, we confirm the 1/f scaling of global variables for selected frequency bands, but show that neuronal activity is not consistent with critical states. We propose a model of 1/f scaling which does not rely on critical states, and which is testable experimentally.Comment: 3 figures, 6 page

Real-time phase-shift detection of the surface plasmon resonance

We investigate a method to directly measure the phase of a laser beam reflected from a metallic film after excitation of surface plasmon polaritons. This method permits real time access to the phase information, it increases the possible speed of data acquisition, and it may thus prove useful for increasing the sensitivity of surface plasmon based sensors

Development of intuitive rules: Evaluating the application of the dual-system framework to understanding children's intuitive reasoning

This is an author-created version of this article. The original source of publication is Psychon Bull Rev. 2006 Dec;13(6):935-53 The final publication is available at www.springerlink.com Published version: http://dx.doi.org/10.3758/BF0321390

Perceptions of the Impact of Positive Action in EU and non-EU Countries

yesAbstract: Around the world, inequalities exist around boundaries of race, social class, gender, disability, religious beliefs and sexual orientation, often resulting from past and current discriminatory practices. Governments have taken certain measures, including enacting policies such as positive action, to remedy such discrimination. This paper provides a comparative analysis of perceptions of the impact of positive action in seven EU and three non-EU countries. The study adopted participatory methods including consensus workshops, interviews and policy analysis to obtain data from designers of positive action. Findings are discussed, conclusions drawn and wide-ranging recommendations are made at the EC, individual countries and organisational levels

Interleukin-1 regulates multiple atherogenic mechanisms in response to fat feeding

Background: Atherosclerosis is an inflammatory process that develops in individuals with known risk factors that include hypertension and hyperlipidaemia, influenced by diet. However, the interplay between diet, inflammatory mechanisms and vascular risk factors requires further research. We hypothesised that interleukin-1 (IL-1) signaling in the vessel wall would raise arterial blood pressure and promote atheroma. Methodology/Principal Findings: Apoe(-/-) and Apoe(-/-)/IL-1R1(-/-) mice were fed high fat diets for 8 weeks, and their blood pressure and atherosclerosis development measured. Apoe(-/-)/IL-R1(-/-) mice had a reduced blood pressure and significantly less atheroma than Apoe(-/-) mice. Selective loss of IL-1 signaling in the vessel wall by bone marrow transplantation also reduced plaque burden (p<0.05). This was associated with an IL-1 mediated loss of endothelium-dependent relaxation and an increase in vessel wall Nox 4. Inhibition of IL-1 restored endothelium-dependent vasodilatation and reduced levels of arterial oxidative stress. Conclusions/Significance: The IL-1 cytokine system links atherogenic environmental stimuli with arterial inflammation, oxidative stress, increased blood pressure and atherosclerosis. This is the first demonstration that inhibition of a single cytokine can block the rise in blood pressure in response to an environmental stimulus. IL-1 inhibition may have profound beneficial effects on atherogenesis in man

Methodological Challenges of Researching Positive Action Measures

This paper highlights some ofthe methodological challenges which have arisen in collecting data for an international study on positive action measures. It will describe strategies employed to encourage participation in the study from as wide a range of organisations and individuals using a mixed method approach. The paper will also discuss the methodological and sensitive issues related to this type of research in organisations and strategies adopted by the research team to ameliorate any problems that have arisen whilst maintaining trustworthiness and rigour in the study