Quantum Solution of Coordination Problems

We present a quantum solution to coordination problems that can be implemented with present technologies. It provides an alternative to existing approaches, which rely on explicit communication, prior commitment or trusted third parties. This quantum mechanism applies to a variety of scenarios for which existing approaches are not feasible

Measurements of positive ions and air-earth current density at Maitri, Antarctica

Simultaneous measurements of the small-, intermediate- and large- positive ions and air earth current density made at a coastal station, Maitri at Antarctica during January to February 2005, are reported. Although, small and large positive ion concentrations do not show any systematic diurnal variations, variations in them are almost similar to each other. On the other hand, variations in intermediate positive ion concentrations are independent of variations in the small/large positive ions and exhibit a diurnal variation which is similar to that in atmospheric temperature on fair weather days with a maximum during the day and minimum during the night hours. No such diurnal variation in intermediate positive ion concentration is observed on cloudy days when variations in them are also similar to those insmall/large positive ion concentrations. Magnitude of diurnal variation in intermediate positive ion concentration on fair weather days increases with the lowering of atmospheric temperature in this season. Scavenging of ions by snowfall and trapping of Alha - rays from the ground radioactivity by a thin layer of snow on ground, is demonstrated from observations. Variations in intermediate positive ion concentration are explained on the basis of the formation of new particles by the photolytic nucleation process.Comment: 38 pages, 11 figure and 2 tabl

Efficiencies of Quantum Optical Detectors

We propose a definition for the efficiency that can be universally applied to all classes of quantum optical detectors. This definition is based on the maximum amount of optical loss that a physically plausible device can experience while still replicating the properties of a given detector. We prove that detector efficiency cannot be increased using linear optical processing. That is, given a set of detectors, as well as arbitrary linear optical elements and ancillary light sources, it is impossible to construct detection devices that would exhibit higher efficiencies than the initial set.Comment: 5 pages, 3 figure

What mattered ten years on? Young people’s reflections on their involvement with a charitable youth participation project

Youth work in England is experiencing ongoing rapid and significant change, fuelling debate about its very function. This paper contributes to this debate by presenting original research on what young people themselves prioritised as significant in-service provision and highlights the longer-term impact that engagement with a voluntary sector organisation can have on the lives of vulnerable young people. Drawing on qualitative interviews with ten former youth participants involved in youth participation projects, the findings presented in this paper suggest that participants felt the support they received was, in many cases, ‘transformative’. However, they primarily defined their experiences and the impact through their relationships with individuals supporting them, through the sense of achievement and ability to effect change they developed and through finding a voice to affect community decisions