466 research outputs found

    On The Implementation Of Experimental Solenoids In MAD-X And Their Effect On Coupling In The LHC

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    The betatron coupling introduced by the experimental solenoids in the LHC is small at injection and negligible at collision energy. We present a study of these effects and look at possible corrections. Additionally we report about the implementation of solenoids in the MAD-X program. A thin solenoid version is also made available for tracking purposes

    Final-Focus Schemes for CLIC at 3 TeV

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    We discuss benefits and drawbacks of two different final-focus schemes for CLIC at 3 TeV centre-of-mass (c.m.) energy, by examining tolerances, tunability and potential background for a 3.3-km long baseline final-focus system and a shorter advanced design

    Damping rings for CLIC

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    The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant

    A more robust and flexible lattice for LHC

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    To correct more efficiently the arc dispersion, the exact antisymmetry of the LHC optics is now broken, except in the low-b triplets common to the two rings. A new quadrupole is added between the experimental insertions and the dispersion suppressors and several arc quadrupoles are complemented by a small trim quadrupole. The larger number of parameters gives flexibility to the lattice and allows a partial separation of the optical functions, with a decrease of the total number of quadrupole units. It is possible to change rather freely the phase advances of the arc cells. The nominal tunes are split by 4 units to reduce coupling. The bin boot tuning range in the experimental low-b is significantly increased, allowing e.g. a larger beam separation at injection. The super-periodicity of LHC remains 1. We plan to study whether it can be increased within the LHC hardware constraint

    Optics Flexibility and Dispersion Matching at Injection into the LHC

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    The LHC requires very precise matching of transfer line and LHC optics to minimise emittance blow-up and tail repopulation at injection. The recent addition of a comprehensive transfer line collimation system to improve the protection against beam loss has created additional matching constraints and consumed a significant part of the flexibility contained in the initial optics design of the transfer lines. Optical errors, different injection configurations and possible future optics changes require however to preserve a certain tuning range. Here we present methods of tuning optics parameters at the injection point by using orbit correctors in the main ring, with the emphasis on dispersion matching. The benefit of alternative measures to enhance the flexibility is briefly discussed

    Ecology of the Ocean Sunfish, Mola mola, in the southern California Current System

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    The common ocean sunfish, Mola mola, occupies a unique position in the eastern Pacific Ocean and the California Current Large Marine Ecosystem (CCLME) as the world\u27s heaviest, most fecund bony fish, and one of the most abundant gelativores. M. mola frequently occur as bycatch in fisheries worldwide and comprise the greatest portion of the bycatch in California\u27s large-mesh drift gillnet fishery. In this first long-term tagging study of any ocean sunfish species in the eastern Pacific, 15 M. mola (99 cm to 200 cm total length) were tagged in the southern California Bight (SCB) between 2003 and 2010 using 14 satellite pop-off archival tags (PATs) and one Fastloc Mk10 GPS tag. Ten tags provided positional data for a cumulative dataset of 349 tracking days during the months of july through March. Thirteen tags provided temperature and depth data. All M. mola remained within similar to 300 km of the coast, and nearly all exhibited seasonal movement between the SCB and adjacent waters off northern and central Baja California, Mexico. No tagged individuals were tracked north of the SCB. Tag depth data showed diel vertical migration and occasional deep (\u3e500 m) dives. Data from the Fastloc GPS tag allowed close examination of the relationship between the movements of the largest tagged ocean sunfish (2 m TL) and fine-scale oceanographic features. Near-instantaneous satellite sea surface temperature images showed this individual associated with upwelling fronts along its migration path, which exceeded 800 km and ranged from 6 to 128 km from the coast. Tag depth data showed active use of the water column within the frontal zones. Synthetic aperture radar (SAR) images demonstrated that surface slicks, which often indicate convergent circulation, coincided with this type of front. Zooplankton tows in the southern region of tracking off central Baja California, Mexico revealed dense populations of salps toward the warm side of these fronts. Satellite tag and ecosystem data suggest that bio-physical interactions in coastal upwelling fronts create favorable foraging habitat. (C) 2015 The Authors. Published by Elsevier B.V

    Overview of the CLIC Collimation design

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    The collimation system of the Compact Linear Collider (CLIC) should simultaneously fulfill three different functions. It must (1) provide adequate halo collimation to render the detector background acceptable, (2) ensure collimator survival and machine protection against mis-steered beams, and (3) not significantly amplify incoming trajectory fluctuations via the collimator wake fields. We describe the present layout of CLIC post-linac collimation and characterize its potential performance

    Clinical and economic impact of non-adherence in COPD:A systematic review

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    BACKGROUND: Medication for Chronic Obstructive Pulmonary Disease (COPD) has shown to substantially reduce symptoms and slow progression of disease. However, non-adherence to medication is common and associated with worsened clinical and economic outcomes. OBJECTIVE: The objective of this study was to perform a systematic review of published literature to assess the impact of non-adherence to COPD medication on clinical and economic outcomes. METHODS: A search in PubMed and Web of Science databases was conducted of original studies published from database inception to 2012. Studies must report on the association between adherence to COPD medication and outcomes, published in English in peer-reviewed journals and full texts needed to be available. RESULTS: Twelve full articles were included in the review. Most studies were retrospective database studies. Seven studies reported on the association between adherence and clinical outcomes, two on mortality, three on costs, four on quality of life and one on work productivity. Results indicated a clear association between adherence and both clinical and economic outcomes. Evidence from studies revealed increased hospitalizations, mortality, quality of life and loss of productivity among non-adherent patients. CONCLUSION: This review revealed a clear association between non-adherence to COPD medication and worsened clinical and economic outcomes making non-adherent patients a priority for cost-effective interventions.</p

    Primary Care COPD Patients Compared with Large Pharmaceutically-Sponsored COPD Studies:An UNLOCK Validation Study

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    Background: Guideline recommendations for chronic obstructive pulmonary disease (COPD) are based on the results of large pharmaceutically-sponsored COPD studies (LPCS). There is a paucity of data on disease characteristics at the primary care level, while the majority of COPD patients are treated in primary care.Objective: We aimed to evaluate the external validity of six LPCS (ISOLDE, TRISTAN, TORCH, UPLIFT, ECLIPSE, POET-COPD) on which current guidelines are based, in relation to primary care COPD patients, in order to inform future clinical practice guidelines and trials.Methods: Baseline data of seven primary care databases (n = 3508) from Europe were compared to baseline data of the LPCS. In addition, we examined the proportion of primary care patients eligible to participate in the LPCS, based on inclusion criteria.Results: Overall, patients included in the LPCS were younger (mean difference (MD)-2.4; p = 0.03), predominantly male (MD 12.4; p = 0.1) with worse lung function (FEV1% MD -16.4; p &lt;0.01) and worse quality of life scores (SGRQ MD 15.8; p = 0.01). There were large differences in GOLD stage distribution compared to primary care patients. Mean exacerbation rates were higher in LPCS, with an overrepresentation of patients with &gt;= 1 and &gt;= 2 exacerbations, although results were not statistically significant. Our findings add to the literature, as we revealed hitherto unknown GOLD I exacerbation characteristics, showing 34% of mild patients had &gt;= 1 exacerbations per year and 12% had &gt;= 2 exacerbations per year. The proportion of primary care patients eligible for inclusion in LPCS ranged from 17% (TRISTAN) to 42% (ECLIPSE, UPLIFT).Conclusion: Primary care COPD patients stand out from patients enrolled in LPCS in terms of gender, lung function, quality of life and exacerbations. More research is needed to determine the effect of pharmacological treatment in mild to moderate patients. We encourage future guideline makers to involve primary care populations in their recommendations.</p
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