Population of 13Be in a Nucleon Exchange Reaction

The neutron-unbound nucleus 13Be was populated with a nucleon-exchange reaction from a 71 MeV/u secondary 13B beam. The decay energy spectrum was reconstructed using invariant mass spectroscopy based on 12Be fragments in coincidence with neutrons. The data could be described with an s-wave resonance at E = 0.73(9) MeV with a width of Gamma = 1.98(34) MeV and a d-wave resonance at E = 2.56(13) MeV with a width of Gamma = 2.29(73) MeV. The observed spectral shape is consistent with previous one-proton removal reaction measurements from 14B.Comment: Published in Phys. Rev.

Self-aligned fabrication process for silicon quantum computer devices

We describe a fabrication process for devices with few quantum bits (qubits), which are suitable for proof-of-principle demonstrations of silicon-based quantum computation. The devices follow the Kane proposal to use the nuclear spins of 31P donors in 28Si as qubits, controlled by metal surface gates and measured using single electron transistors (SETs). The accurate registration of 31P donors to control gates and read-out SETs is achieved through the use of a self-aligned process which incorporates electron beam patterning, ion implantation and triple-angle shadow-mask metal evaporation

How primary care can contribute to good mental health in adults.

The need for support for good mental health is enormous. General support for good mental health is needed for 100% of the population, and at all stages of life, from early childhood to end of life. Focused support is needed for the 17.6% of adults who have a mental disorder at any time, including those who also have a mental health problem amongst the 30% who report having a long-term condition of some kind. All sectors of society and all parts of the NHS need to play their part. Primary care cannot do this on its own. This paper describes how primary care practitioners can help stimulate such a grand alliance for health, by operating at four different levels - as individual practitioners, as organisations, as geographic clusters of organisations and as policy-makers

Aluminum-, Calcium- And Titanium-Rich Oxide Stardust In Ordinary Chondrite Meteorites

We report isotopic data for a total of 96 presolar oxide grains found in residues of several unequilibrated ordinary chondrite meteorites. Identified grain types include Al2O3, MgAl2O4, hibonite (CaAl12O19) and Ti oxide. This work greatly increases the presolar hibonite database, and is the first report of presolar Ti oxide. O-isotopic compositions of the grains span previously observed ranges and indicate an origin in red giant and asymptotic giant branch (AGB) stars of low mass (<2.5 MSun) for most grains. Cool bottom processing in the parent AGB stars is required to explain isotopic compositions of many grains. Potassium-41 enrichments in hibonite grains are attributable to in situ decay of now-extinct 41Ca. Inferred initial 41Ca/40Ca ratios are in good agreement with model predictions for low-mass AGB star envelopes, provided that ionization suppresses 41Ca decay. Stable Mg and Ca isotopic ratios of most of the hibonite grains reflect primarily the initial compositions of the parent stars and are generally consistent with expectations for Galactic chemical evolution, but require some local interstellar chemical inhomogeneity. Very high 17O/16O or 25Mg/24Mg ratios suggest an origin for some grains in binary star systems where mass transfer from an evolved companion has altered the parent star compositions. A supernova origin for the hitherto enigmatic 18O-rich Group 4 grains is strongly supported by multi-element isotopic data for two grains. The Group 4 data are consistent with an origin in a single supernova in which variable amounts of material from the deep 16O-rich interior mixed with a unique end-member mixture of the outer layers. The Ti oxide grains primarily formed in low-mass AGB stars. They are smaller and rarer than presolar Al2O3, reflecting the lower abundance of Ti than Al in AGB envelopes.Comment: Accepted for publication in ApJ; 47 pages, 13 figure

Identity as a causal power : contextualising entrepreneurs' concerns

We propose a critical realist-informed conception of entrepreneurial identity – the personal power to create a new venture. Although most people have the power to become an entrepreneur, not everyone can, or is motivated to, realize that potential. Other countervailing powers – personal, material and social – can constrain, or discourage, action. Utilizing a stratified, emergent ontology, we contextualize entrepreneurial identity within three analytical orders – natural, practical and social. We distinguish personal identity, the set of concerns in the three orders that motivate action, from social identity, the roles we commit to in society. While entrepreneurial identity is a type of social identity, the underlying concerns that motivate commitment to an entrepreneurial role cannot be reduced to social interaction alone. The concept of internal conversation is used to theorize the connection of entrepreneurial motivation, context and behaviour. We draw on qualitative data from three UK-based disabled entrepreneurs to demonstrate the value of our framework

Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity

Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38‰. All tests were normal at baseline. VOR gain measured by vHIT decreased 25% by the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.NHMR

The future of sovereignty in multilevel governance Europe: a constructivist reading

Multilevel governance presents a depiction of contemporary structures in EU Europe as consisting of overlapping authorities and competing competencies. By focusing on emerging non-anarchical structures in the international system, hence moving beyond the conventional hierarchy/anarchy dichotomy to distinguish domestic and international arenas, this seems a radical transformation of the familiar Westphalian system and to undermine state sovereignty. Paradoxically, however, the principle of sovereignty proves to be resilient despite its alleged empirical decline. This article argues that social constructivism can explain the paradox, by considering sovereign statehood as a process-dependent institutional fact, and by showing that multilevel governance can feed into this process

Smelting conditions and smelting products: Experimental insights into the development of iron bloomery furnaces

The material record for bloomery furnaces in Iron Age and Roman Britain is fragmentary and, because of this paucity of evidence, the reconstruction of the ceramic structures used in iron production is difficult. Experiments have nevertheless been carried out to explore the working parameters and efficiency of iron smelting in bowl furnaces (small structures with little structure above ground level, interior measuring about 30 cm in height) (Craddock, 1995; Girbal, 2013) and shaft furnaces (height c.1m) (Smith, 2013; Crew, 2013; Doonan and Dungworth, 2013; Tylecote and Merkel, 1985; Tylecote and Wynne, 1958). These experiments aimed to clarify which furnace is more efficient for iron smelting and therefore what method was most likely used in Iron Age and Roman Britain. It is theorised that iron smelting furnaces developed from bowl structures to shaft structures over time, as smelters sought furnaces which could reach higher temperatures and create more reducing atmospheres (Dungworth 2013; Tylecote and Merkel, 1985; Tylecote and Wynne, 1958). These experiments suggest that the shaft furnace was used as it could meet these requirements. This study looks at the working conditions of a shaft furnace at an intermediary height - between that of a bowl furnace and of a shaft furnace - in order to understand its working parameters and to consequently better understand the progression from a bowl to a 1m high shaft structure