3,473 research outputs found

    Issues of alcohol misuse among older people : attitudes and experiences of social work practitioners

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    This small-scale qualitative research focused on the experiences of social workers vis--vis older people who misuse alcohol. Based in an Older People's Team in the west of Scotland, the study explored service provision for alcohol misuse and examined whether practitioners felt the existing services provided by the Substance Misuse Team were effective in meeting the needs of older people with an alcohol problem. Using semi-structured interviews, data were collected from 18 participants, the majority (14) of whom were female and whose ages ranged from 31 to 54 years. Several key themes emerged including the extent of alcohol problems among older people and the complex reasons that cause older people to misuse alcohol. These reasons commonly related to the increasing challenges of old age. The data also demonstrated that current services are not meeting the needs of older people. Practitioners identified a need for an 'age-specific' approach to target more effectively the complex needs of older people. Recommendations from practitioners included ways to develop new and more effective services, including a more age-specific service, such as providing longer term support in older people's own homes, using a specialised support worker, and increasing staff training on alcohol use among older people

    Evidence from Meteorites for Multiple Possible Amino Acid Alphabets for the Origins of Life

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    A key question for the origins of life is understanding which amino acids made up the first proteins synthesized during the origins of life. The canonical set of 20 - 22 amino acids used in proteins are all alpha-amino, alpha-hydrogen isomers that, nevertheless, show considerable variability in properties including size, hydrophobicity, and ionizability. Abiotic amino acid synthesis experiments such as Miller-Urey spark discharge reactions produce a set of up to 23 amino acids, depending on starting materials and reaction conditions, with significant abundances of both alpha- and non-alpha-amino acid isomers. These two sets of amino acids do not completely overlap; of the 23 spark discharge amino acids, only 11 are used in modern proteins. Furthermore, because our understanding of conditions on the early Earth are limited, it is unclear which set(s) of conditions employed in spark discharge or hydrothermal reactions are correct, leaving us with significant uncertainty about the amino acid alphabet available for the origins of life on Earth. Meteorites, the surviving remnants of asteroids and comets that fall to the Earth, offer the potential to study authentic samples of naturally-occurring abiotic chemistry, and thus can provide an alternative approach to constraining the amino acid library during the origins of life

    Distribution of Amino Acids in Lunar Regolith

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    One of the most eagerly studied questions upon initial return of lunar samples was whether significant amounts of organic compounds, including amino acids, were present. Analyses during the 1970s produced only tentative and inconclusive identifications of indigenous amino acids. Those analyses were hampered by analytical difficulties including relative insensitivity to certain compounds, the inability to separate chiral enantiomers, and the lack of compound-specific isotopic measurements, which made it impossible to determine whether the detected amino acids were indigenous to the lunar samples or the results of contamination. Numerous advances have been made in instrumentation and methodology for amino acid characterization in extraterrestrial samples in the intervening years, yet the origin of amino acids in lunar regolith samples has been revisited only once for a single lunar sample, (3) and remains unclear. Here, we present initial data from the analyses of amino acid abundances in 12 lunar regolith samples. We discuss these abundances in the context of four potential amino acid sources: (1) terrestrial biological contamination; (2) contamination from lunar module (LM) exhaust; (3) derivation from solar windimplanted precursors; and (4) exogenous delivery from meteorites

    A well-separated pairs decomposition algorithm for k-d trees implemented on multi-core architectures

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    Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Variations of k-d trees represent a fundamental data structure used in Computational Geometry with numerous applications in science. For example particle track tting in the software of the LHC experiments, and in simulations of N-body systems in the study of dynamics of interacting galaxies, particle beam physics, and molecular dynamics in biochemistry. The many-body tree methods devised by Barnes and Hutt in the 1980s and the Fast Multipole Method introduced in 1987 by Greengard and Rokhlin use variants of k-d trees to reduce the computation time upper bounds to O(n log n) and even O(n) from O(n2). We present an algorithm that uses the principle of well-separated pairs decomposition to always produce compressed trees in O(n log n) work. We present and evaluate parallel implementations for the algorithm that can take advantage of multi-core architectures.The Science and Technology Facilities Council, UK

    Distribution and Origin of Amino Acids in Lunar Regolith Samples

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    The existence of organic compounds on the lunar surface has been a question of interest from the Apollo era to the present. Investigations of amino acids immediately after collection of lunar samples yielded inconclusive identifications, in part due to analytical limitations including insensitivity to certain compounds, an inability to separate enantiomers, and lack of compound-specific isotopic measurements. It was not possible to determine if the detected amino acids were indigenous to the lunar samples or the result of terrestrial contamination. Recently, we presented initial data from the analysis of amino acid abundances in 12 lunar regolith samples and discussed those results in the context of four potential amino acid sources [5]. Here, we expand on our previous work, focusing on amino acid abundances and distributions in seven regolith samples and presenting the first compound-specific carbon isotopic ratios measured for amino acids in a lunar sample

    Measurement of the neutron lifetime using an asymmetric magneto- gravitational trap and in situ detection

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    The precise value of the mean neutron lifetime, τn\tau_n, plays an important role in nuclear and particle physics and cosmology. It is a key input for predicting the ratio of protons to helium atoms in the primordial universe and is used to search for new physics beyond the Standard Model of particle physics. There is a 3.9 standard deviation discrepancy between τn\tau_n measured by counting the decay rate of free neutrons in a beam (887.7 ±\pm 2.2 s) and by counting surviving ultracold neutrons stored for different storage times in a material trap (878.5±\pm0.8 s). The experiment described here eliminates loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls and neutrons in quasi-stable orbits rapidly exit the trap. As a result of this approach and the use of a new in situ neutron detector, the lifetime reported here (877.7 ±\pm 0.7 (stat) +0.4/-0.2 (sys) s) is the first modern measurement of τn\tau_n that does not require corrections larger than the quoted uncertainties.Comment: 9 pages, 3 figures, 2 table
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