19,620 research outputs found

    Wind models for the NSTS ascent trajectory biasing for wind load alleviation

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    New concepts are presented for aerospace vehicle ascent wind profile biasing. The purpose for wind biasing the ascent trajectory is to provide ascent wind loads relief and thus decrease the probability for launch delays due to wind loads exceeding critical limits. Wind biasing trajectories to the profile of monthly mean winds have been widely used for this purpose. The wind profile models presented give additional alternatives for wind biased trajectories. They are derived from the properties of the bivariate normal probability function using the available wind statistical parameters for the launch site. The analytical expressions are presented to permit generalizations. Specific examples are given to illustrate the procedures. The wind profile models can be used to establish the ascent trajectory steering commands to guide the vehicle through the first stage. For the National Space Transportation System (NSTS) program these steering commands are called I-loads

    Involving patients in decisions about preventive medication : A focus group study

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    Original article can be found at: http://www.pccj.eu/ Copyright Sherborne Gibbs Ltd. [reproduced here with permission of publishers]Background: Patients may have unrealistic expectations of preventive treatment and frequently do not take long-term medication. Involvement of the patient in the decision to start such medication may improve this, but enabling an informed decision is notoriously difficult. Aims: To explore patients' perceptions of preventive medication, the desire for informed choice and how this could best be achieved. Method: Purposive sampling was used to select patients registered with one of two general practices in South England. Audio recording, transcription and computer-assisted textual analysis were conducted for focus group discussions. Results: This was a small study, but the majority of focus group participants who had been prescribed a preventive medication said they received very little or no information about benefits and disadvantages when it was started. Some felt that doctors did not want to share information. Older participants thought that choice was over-rated, trusted their doctor to recommend appropriate medication and did not necessarily wish to be involved in the decision. Younger participants wanted to be more involved. However, even those who expressed little interest in involvement felt that personalised information compared with population norms comparing individuals to the 'average person' would be helpful. Written information specific to the individual and on how the medication or lifestyle changes might affect them was considered welcome. Conclusions: Doctors need to be sensitive to patients' preferences for involvement in the decision-making process and for the way information on risk is shared. Providing written information specific to the individual patient is likely to facilitate shared decisions about preventive medication.Peer reviewedFinal Published versio

    Magmatic Cu-Ni-PGE-Au sulfide mineralisation in alkaline igneous systems: An example from the Sron Garbh intrusion, Tyndrum, Scotland

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    Magmatic sulfide deposits typically occur in ultramafic-mafic systems, however, mineralisation can occur in more intermediate and alkaline magmas. Sron Garbh is an appinite-diorite intrusion emplaced into Dalradian metasediments in the Tyndrum area of Scotland that hosts magmatic Cu-Ni-PGE-Au sulfide mineralisation in the appinitic portion. It is thus an example of magmatic sulfide mineralisation hosted by alkaline rocks, and is the most significantly mineralised appinitic intrusion known in the British Isles. The intrusion is irregularly shaped, with an appinite rim, comprising amphibole cumulates classed as vogesites. The central portion of the intrusion is comprised of unmineralised, but pyrite-bearing, diorites. Both appinites and diorites have similar trace element geochemistry that suggests the diorite is a more fractionated differentiate of the appinite from a common source that can be classed with the high Ba-Sr intrusions of the Scottish Caledonides. Mineralisation is present as a disseminated, primary chalcopyrite-pyrite-PGM assemblage and a blebby, pyrite-chalcopyrite assemblage with significant Co-As-rich pyrite. Both assemblages contain minor millerite and Ni-Co-As-sulfides. The mineralisation is Cu-, PPGE-, and Au-rich and IPGE-poor and the platinum group mineral assemblage is overwhelmingly dominated by Pd minerals; however, the bulk rock Pt/Pd ratio is around 0.8. Laser ablation analysis of the sulfides reveals that pyrite and the Ni-Co-sulfides are the primary host for Pt, which is present in solid solution in concentrations of up to 22 ppm in pyrite. Good correlations between all base and precious metals indicate very little hydrothermal remobilisation of metals despite some evidence of secondary pyrite and PGM. Sulfur isotope data indicate some crustal S in the magmatic sulfide assemblages. The source of this is unlikely to have been the local quartzites, but S-rich Dalradian sediments present at depth. The generation of magmatic Cu-Ni-PGE-Au mineralisation at Sron Garbh can be attributed to post-collisional slab drop off that allowed hydrous, low-degree partial melting to take place that produced a Cu-PPGE-Au-enriched melt, which ascended through the crust, assimilating crustal S from the Dalradian sediments. The presence of a number of PGE-enriched sulfide occurrences in appinitic intrusions across the Scottish Caledonides indicates that the region contains certain features that make it more prospective than other alkaline provinces worldwide, which may be linked the post-Caledonian slab drop off event. We propose that the incongruent melting of pre-existing magmatic sulfides or ‘refertilised’ mantle in low-degree partial melts can produce characteristically fractionated, Cu-PPGE-Au-semi metal bearing, hydrous, alkali melts, which, if they undergo sulfide saturation, have the potential to produce alkaline-hosted magmatic sulfide deposits

    Development and Evaluation of a Primary Care Drug Formulary

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    Aim This study asks if practices can collaborate to create a shared formulary, which influences prescribing. Secondary questions If so, how long does the effect last? To what degree can such a formulary influence volume of prescribing, choice of treatment and cost? Is there a limit to the number of practices involved before the effect is lost? Are doctors more influenced by the formulary if they are closely involved with its creation? Method Controlled trial in two stages. 100 general practitioners from 20 urban and semi-rural practices and 50 community nurses worked with a small team of facilitators to create a formulary. Between 1991 and 1999, prescribing by the participating doctors was compared with the prescribing by all other general practitioners in the county. Results Collaborative work resulted in a countywide formulary for primary care. The use of information to support prescribing changed from a few practices using their own formularies, to an evidence-based formulary supported by all five Primary Care Groups in the county. Choice of treatment changed in seven out of thirteen therapeutic groups. Volume of prescribing reduced in three groups. Cost reduced by F-3000 per doctor per annum. Conclusions Sharing resources between practices to create a primary care formulary can lead to modest changes in prescribing, sustained over three years, and lower overall costs. The largest observed changes were a 14% change in the choice of drugs for musculoskeletal conditions, and a saving of ÂŁ5000 per practice per year on antibiotics. Such changes, attributed to the development of a formulary, also occur in practices that have no direct involvement, but later by several years. The greatest change in prescribing is seen immediately after a formulary is created and in those involved with its development. The funding for the work is estimated to amount to 17% of the saving on prescribing. Doctors and nurses from 32 practices can work together on such an intervention

    Time course of morphological alterations of fungiform papillae and taste buds following chorda tympani transection in neonatal rats

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    The time course of structural changes in fungiform papillae was analyzed in rats that received unilateral chorda tympani nerve transection at 10 days of age. Morphological differences between intact and denervated sides of the tongue were first observed at 8 days postsection, with an increase in the number of fungiform papillae that did not have a pore. In addition, the first papilla with a filiform‐like appearance was noted on the denervated side at 8 days postsectioning. By 11 days after surgery, the total number of papillae and the number of papillae with a pore were significantly lower on the transected side of the tongue as compared to the intact side. At 50 days postsection, there was an average of 70.5 fungiform papillae on the intact side and a mean of only 20.8 fungiform papillae the denervated side. Of those few remaining papillae on the cut side, an average of 13.5 papillae were categorized as filiform‐like, while no filiform‐like papillae occurred on the intact side. Significant reduction in taste bud volume was noted at 4 days posttransection and further decrements in taste bud volume were noted at 8 and 30 days postsection. Electron microscopy of the lingual branch of the trigeminal nerve from adult rats that received neonatal chorda tympani transection showed normal numbers of both myelinated and unmyelinated fibers. Thus, in addition to the well‐characterized dependence of taste bud maintenance on the chorda tympani nerve, the present study shows an additional role of the chorda tympani nerve in papilla maintenance during early postnatal development. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 223–236, 2002

    Smart Focal Plane Technologies for VLT Instruments

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    As we move towards the era of ELTs, it is timely to think about the future role of the 8-m class telescopes. Under the OPTICON programme, novel technologies have been developed that are intended for use in multi-object and integral-field spectrographs. To date, these have been targeted at instrument concepts for the European ELT, but there are also significant possibilities for their inclusion in new VLT instruments, ensuring the continued success and productivity of these unique telescopes.Comment: 5 pages, to appear in the proceedings of the ESO Workshop "Science with the VLT in the ELT era

    The EU and Asia within an evolving global order: what is Europe? Where is Asia?

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    The papers in this special edition are a very small selection from those presented at the EU-NESCA (Network of European Studies Centres in Asia) conference on "the EU and East Asia within an Evolving Global Order: Ideas, Actors and Processes" in November 2008 in Brussels. The conference was the culmination of three years of research activity involving workshops and conferences bringing together scholars from both regions primarily to discuss relations between Europe and Asia, perceptions of Europe in Asia, and the relationship between the European regional project and emerging regional forms in Asia. But although this was the last of the three major conferences organised by the consortium, it in many ways represented a starting point rather than the end; an opportunity to reflect on the conclusions of the first phase of collaboration and point towards new and continuing research agendas for the future

    Synthetic High-Resolution Line Spectra of Star-Forming Galaxies Below 1200A

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    We have generated a set of far-ultraviolet stellar libraries using spectra of OB and Wolf-Rayet stars in the Galaxy and the Large and Small Magellanic Cloud. The spectra were collected with the Far Ultraviolet Spectroscopic Explorer and cover a wavelength range from 1003.1 to 1182.7A at a resolution of 0.127A. The libraries extend from the earliest O- to late-O and early-B stars for the Magellanic Cloud and Galactic libraries, respectively. Attention is paid to the complex blending of stellar and interstellar lines, which can be significant, especially in models using Galactic stars. The most severe contamination is due to molecular hydrogen. Using a simple model for the H2_2 line strength, we were able to remove the molecular hydrogen lines in a subset of Magellanic Cloud stars. Variations of the photospheric and wind features of CIII 1176, OVI 1032, 1038, PV 1118, 1128, and SIV 1063, 1073, 1074 are discussed as a function of temperature and luminosity class. The spectral libraries were implemented into the LavalSB and Starburst99 packages and used to compute a standard set of synthetic spectra of star-forming galaxies. Representative spectra are presented for various initial mass functions and star formation histories. The valid parameter space is confined to the youngest ages of less than 10 Myr for an instantaneous burst, prior to the age when incompleteness of spectral types in the libraries sets in. For a continuous burst at solar metallicity, the parameter space is not limited. The suite of models is useful for interpreting the restframe far-ultraviolet in local and high-redshift galaxies.Comment: 33 pages including 13 figures, accepted for publication in Ap

    The Ultraviolet Imaging Telescope: Instrument and Data Characteristics

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    The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images of a variety of astronomical objects, with a 40 arcmin field of view and a resolution of about 3 arcsec, were recorded on photographic film. The data recorded during the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. This paper discusses in detail the design, operation, data reduction, and calibration of UIT, providing the user of the data with information for understanding and using the data. It also provides guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS
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